WorldWideScience

Sample records for halophilic euryarchaeon haloferax

  1. Biochemical characterisation of LigN, an NAD+-dependent DNA ligase from the halophilic euryarchaeon Haloferax volcanii that displays maximal in vitro activity at high salt concentrations

    DEFF Research Database (Denmark)

    Poidevin, L.; MacNeill, S. A.

    2006-01-01

    Background DNA ligases are required for DNA strand joining in all forms of cellular life. NAD+-dependent DNA ligases are found primarily in eubacteria but also in some eukaryotic viruses, bacteriophage and archaea. Among the archaeal NAD+-dependent DNA ligases is the LigN enzyme of the halophilic...

  2. Overexpression and purification of halophilic proteins in Haloferax volcanii

    OpenAIRE

    Allers, Thorsten

    2010-01-01

    Halophilic enzymes function optimally at high salt concentrations and are active at low water availability. Such conditions are encountered at elevated concentrations of solutes such as salts and sugars, and at high concentrations of organic solvents. However, expression in heterologous hosts such as Escherichia coli can cause problems, since halophilic proteins typically misfold and aggregate in conditions of low ionic strength. We have harnessed the sophisticated genetic tools available for...

  3. RNomics and Modomics in the halophilic archaea Haloferax volcanii: identification of RNA modification genes

    Directory of Open Access Journals (Sweden)

    Decatur Wayne A

    2008-10-01

    Full Text Available Abstract Background Naturally occurring RNAs contain numerous enzymatically altered nucleosides. Differences in RNA populations (RNomics and pattern of RNA modifications (Modomics depends on the organism analyzed and are two of the criteria that distinguish the three kingdoms of life. If the genomic sequences of the RNA molecules can be derived from whole genome sequence information, the modification profile cannot and requires or direct sequencing of the RNAs or predictive methods base on the presence or absence of the modifications genes. Results By employing a comparative genomics approach, we predicted almost all of the genes coding for the t+rRNA modification enzymes in the mesophilic moderate halophile Haloferax volcanii. These encode both guide RNAs and enzymes. Some are orthologous to previously identified genes in Archaea, Bacteria or in Saccharomyces cerevisiae, but several are original predictions. Conclusion The number of modifications in t+rRNAs in the halophilic archaeon is surprisingly low when compared with other Archaea or Bacteria, particularly the hyperthermophilic organisms. This may result from the specific lifestyle of halophiles that require high intracellular salt concentration for survival. This salt content could allow RNA to maintain its functional structural integrity with fewer modifications. We predict that the few modifications present must be particularly important for decoding, accuracy of translation or are modifications that cannot be functionally replaced by the electrostatic interactions provided by the surrounding salt-ions. This analysis also guides future experimental validation work aiming to complete the understanding of the function of RNA modifications in Archaeal translation.

  4. Production of halophilic proteins using Haloferax volcanii H1895 in a stirred-tank bioreactor

    KAUST Repository

    Strillinger, Eva

    2015-10-01

    The success of biotechnological processes is based on the availability of efficient and highly specific biocatalysts, which can satisfy industrial demands. Extreme and remote environments like the deep brine pools of the Red Sea represent highly interesting habitats for the discovery of novel halophilic and thermophilic enzymes. Haloferax volcanii constitutes a suitable expression system for halophilic enzymes obtained from such brine pools. We developed a batch process for the cultivation of H. volcanii H1895 in controlled stirred-tank bioreactors utilising knockouts of components of the flagella assembly system. The standard medium Hv-YPC was supplemented to reach a higher cell density. Without protein expression, cell dry weight reaches 10 g L−1. Two halophilic alcohol dehydrogenases were expressed under the control of the tryptophanase promoter p.tna with 16.8 and 3.2 mg gCDW −1, respectively, at a maximum cell dry weight of 6.5 g L−1. Protein expression was induced by the addition of l-tryptophan. Investigation of various expression strategies leads to an optimised two-step induction protocol introducing 6 mM l-tryptophan at an OD650 of 0.4 followed by incubation for 16 h and a second induction step with 3 mM l-tryptophan followed by a final incubation time of 4 h. Compared with the uncontrolled shaker-flask cultivations used until date, dry cell mass concentrations were improved by a factor of more than 5 and cell-specific enzyme activities showed an up to 28-fold increased yield of the heterologous proteins.

  5. Production of halophilic proteins using Haloferax volcanii H1895 in a stirred-tank bioreactor.

    Science.gov (United States)

    Strillinger, Eva; Grötzinger, Stefan Wolfgang; Allers, Thorsten; Eppinger, Jörg; Weuster-Botz, Dirk

    2016-02-01

    The success of biotechnological processes is based on the availability of efficient and highly specific biocatalysts, which can satisfy industrial demands. Extreme and remote environments like the deep brine pools of the Red Sea represent highly interesting habitats for the discovery of novel halophilic and thermophilic enzymes. Haloferax volcanii constitutes a suitable expression system for halophilic enzymes obtained from such brine pools. We developed a batch process for the cultivation of H. volcanii H1895 in controlled stirred-tank bioreactors utilising knockouts of components of the flagella assembly system. The standard medium Hv-YPC was supplemented to reach a higher cell density. Without protein expression, cell dry weight reaches 10 g L(-1). Two halophilic alcohol dehydrogenases were expressed under the control of the tryptophanase promoter p.tna with 16.8 and 3.2 mg gCDW (-1), respectively, at a maximum cell dry weight of 6.5 g L(-1). Protein expression was induced by the addition of L-tryptophan. Investigation of various expression strategies leads to an optimised two-step induction protocol introducing 6 mM L-tryptophan at an OD650 of 0.4 followed by incubation for 16 h and a second induction step with 3 mM L-tryptophan followed by a final incubation time of 4 h. Compared with the uncontrolled shaker-flask cultivations used until date, dry cell mass concentrations were improved by a factor of more than 5 and cell-specific enzyme activities showed an up to 28-fold increased yield of the heterologous proteins.

  6. Production of halophilic proteins using Haloferax volcanii H1895 in a stirred-tank bioreactor

    KAUST Repository

    Strillinger, Eva; Grö tzinger, Stefan W.; Allers, Thorsten; Eppinger, Jö rg; Weuster-Botz, Dirk

    2015-01-01

    The success of biotechnological processes is based on the availability of efficient and highly specific biocatalysts, which can satisfy industrial demands. Extreme and remote environments like the deep brine pools of the Red Sea represent highly interesting habitats for the discovery of novel halophilic and thermophilic enzymes. Haloferax volcanii constitutes a suitable expression system for halophilic enzymes obtained from such brine pools. We developed a batch process for the cultivation of H. volcanii H1895 in controlled stirred-tank bioreactors utilising knockouts of components of the flagella assembly system. The standard medium Hv-YPC was supplemented to reach a higher cell density. Without protein expression, cell dry weight reaches 10 g L−1. Two halophilic alcohol dehydrogenases were expressed under the control of the tryptophanase promoter p.tna with 16.8 and 3.2 mg gCDW −1, respectively, at a maximum cell dry weight of 6.5 g L−1. Protein expression was induced by the addition of l-tryptophan. Investigation of various expression strategies leads to an optimised two-step induction protocol introducing 6 mM l-tryptophan at an OD650 of 0.4 followed by incubation for 16 h and a second induction step with 3 mM l-tryptophan followed by a final incubation time of 4 h. Compared with the uncontrolled shaker-flask cultivations used until date, dry cell mass concentrations were improved by a factor of more than 5 and cell-specific enzyme activities showed an up to 28-fold increased yield of the heterologous proteins.

  7. The crystal structure of Haloferax volcanii proliferating cell nuclear antigen reveals unique surface charge characteristics due to halophilic adaptation

    Directory of Open Access Journals (Sweden)

    Morroll Shaun

    2009-08-01

    Full Text Available Abstract Background The high intracellular salt concentration required to maintain a halophilic lifestyle poses challenges to haloarchaeal proteins that must stay soluble, stable and functional in this extreme environment. Proliferating cell nuclear antigen (PCNA is a fundamental protein involved in maintaining genome integrity, with roles in both DNA replication and repair. To investigate the halophilic adaptation of such a key protein we have crystallised and solved the structure of Haloferax volcanii PCNA (HvPCNA to a resolution of 2.0 Å. Results The overall architecture of HvPCNA is very similar to other known PCNAs, which are highly structurally conserved. Three commonly observed adaptations in halophilic proteins are higher surface acidity, bound ions and increased numbers of intermolecular ion pairs (in oligomeric proteins. HvPCNA possesses the former two adaptations but not the latter, despite functioning as a homotrimer. Strikingly, the positive surface charge considered key to PCNA's role as a sliding clamp is dramatically reduced in the halophilic protein. Instead, bound cations within the solvation shell of HvPCNA may permit sliding along negatively charged DNA by reducing electrostatic repulsion effects. Conclusion The extent to which individual proteins adapt to halophilic conditions varies, presumably due to their diverse characteristics and roles within the cell. The number of ion pairs observed in the HvPCNA monomer-monomer interface was unexpectedly low. This may reflect the fact that the trimer is intrinsically stable over a wide range of salt concentrations and therefore additional modifications for trimer maintenance in high salt conditions are not required. Halophilic proteins frequently bind anions and cations and in HvPCNA cation binding may compensate for the remarkable reduction in positive charge in the pore region, to facilitate functional interactions with DNA. In this way, HvPCNA may harness its environment as

  8. The crystal structure of Haloferax volcanii proliferating cell nuclear antigen reveals unique surface charge characteristics due to halophilic adaptation

    Science.gov (United States)

    Winter, Jody A; Christofi, Panayiotis; Morroll, Shaun; Bunting, Karen A

    2009-01-01

    Background The high intracellular salt concentration required to maintain a halophilic lifestyle poses challenges to haloarchaeal proteins that must stay soluble, stable and functional in this extreme environment. Proliferating cell nuclear antigen (PCNA) is a fundamental protein involved in maintaining genome integrity, with roles in both DNA replication and repair. To investigate the halophilic adaptation of such a key protein we have crystallised and solved the structure of Haloferax volcanii PCNA (HvPCNA) to a resolution of 2.0 Å. Results The overall architecture of HvPCNA is very similar to other known PCNAs, which are highly structurally conserved. Three commonly observed adaptations in halophilic proteins are higher surface acidity, bound ions and increased numbers of intermolecular ion pairs (in oligomeric proteins). HvPCNA possesses the former two adaptations but not the latter, despite functioning as a homotrimer. Strikingly, the positive surface charge considered key to PCNA's role as a sliding clamp is dramatically reduced in the halophilic protein. Instead, bound cations within the solvation shell of HvPCNA may permit sliding along negatively charged DNA by reducing electrostatic repulsion effects. Conclusion The extent to which individual proteins adapt to halophilic conditions varies, presumably due to their diverse characteristics and roles within the cell. The number of ion pairs observed in the HvPCNA monomer-monomer interface was unexpectedly low. This may reflect the fact that the trimer is intrinsically stable over a wide range of salt concentrations and therefore additional modifications for trimer maintenance in high salt conditions are not required. Halophilic proteins frequently bind anions and cations and in HvPCNA cation binding may compensate for the remarkable reduction in positive charge in the pore region, to facilitate functional interactions with DNA. In this way, HvPCNA may harness its environment as opposed to simply surviving in

  9. DNA Binding in High Salt: Analysing the Salt Dependence of Replication Protein A3 from the Halophile Haloferax volcanii

    Directory of Open Access Journals (Sweden)

    Jody A. Winter

    2012-01-01

    Full Text Available Halophilic archaea maintain intracellular salt concentrations close to saturation to survive in high-salt environments and their cellular processes have adapted to function under these conditions. Little is known regarding halophilic adaptation of the DNA processing machinery, particularly intriguing since protein-DNA interactions are classically salt sensitive. To investigate such adaptation, we characterised the DNA-binding capabilities of recombinant RPA3 from Haloferax volcanii (HvRPA3. Under physiological salt conditions (3 M KCl, HvRPA3 is monomeric, binding 18 nucleotide ssDNA with nanomolar affinity, demonstrating that RPAs containing the single OB-fold/zinc finger architecture bind with broadly comparable affinity to two OB-fold/zinc finger RPAs. Reducing the salt concentration to 1 M KCl induces dimerisation of the protein, which retains its ability to bind DNA. On circular ssDNA, two concentration-dependent binding modes are observed. Conventionally, increased salt concentration adversely affects DNA binding but HvRPA3 does not bind DNA in 0.2 M KCl, although multimerisation may occlude the binding site. The single N-terminal OB-fold is competent to bind DNA in the absence of the C-terminal zinc finger, albeit with reduced affinity. This study represents the first quantitative characterisation of DNA binding in a halophilic protein in extreme salt concentrations.

  10. Study on the resistance of haloferax radiotolerans, an extreme Halophilic archaebacterium from Uromia lake against ultraviolet (UV) light and 60Co gamma-rays

    International Nuclear Information System (INIS)

    Asgarni, E.; Shirzad, M.; Soudi, M. R.; Shahmohammadi, H. R.; Falsafi, T.

    2006-01-01

    In this work, the capacity of an extreme halophilic archaebacterium, isolated from Uromia lake, Haloferax radiotolerans to withstand the lethal effects of ultraviolet light (UV),and 60 Co r-rays has been studied. The resistibility of this organism against the DNA-damaging agents was evaluated by calculating of the survival fractions at different dose rates of W and 60 Co r-rays radiations and compared with those of Escherichia coli B/r (a radioresistant strain of E. coli). D 37 values for Haloferax radiotolerans and E. coli B/r were 23 1, and 9 J/m 2 , respectively, by exposure to the UV light. They were 645, and 99 Gy, respectively, by exposure to 60 Co r-rays. Against these agents, Haloferax radiotolerans shows much more resistance compare to that of E. coli B/r. This is categorized as the first report of resistibility in the member of Archaea

  11. Halocin C8: an antimicrobial peptide distributed among four halophilic archaeal genera: Natrinema, Haloterrigena, Haloferax, and Halobacterium.

    Science.gov (United States)

    Besse, Alison; Vandervennet, Manon; Goulard, Christophe; Peduzzi, Jean; Isaac, Stéphanie; Rebuffat, Sylvie; Carré-Mlouka, Alyssa

    2017-05-01

    Halophilic archaea thrive in hypersaline ecosystems and produce antimicrobial peptides (AMPs) named halocins. AMPs are essential effectors of microbial interactions in natural ecosystems. Halocin C8 is a 7.4 kDa peptide produced by Natrinema sp. AS7092. Surrounded by genes involved in regulation and transport, the halC8 gene encodes a precursor, processed into the mature halocin and an immunity protein, protecting the producing strain against its halocin. This feature constitutes a unique property of halocin C8, as known AMPs and their immunity proteins are generally encoded on distinct ORFs in an operon. By complementary in silico and PCR-based approaches, the presence of halC8 in halophilic archaea collected from various parts of the world was evidenced. The full-length halC8 gene is restricted and consistently found in the genomes of strains belonging to the phylogenetically related genera Natrinema and Haloterrigena, along with transport and regulation genes. Functional expression of halC8 was demonstrated by RT-PCR and antimicrobial assays. Active halocin C8 was shown to contain five disulphide bridges, presumably conferring a compact structure resistant to harsh environmental conditions. In other archaeal genera, Haloferax and Halobacterium, genes encoding halocin C8 with diverging immunity protein moiety were evidenced. A phylogenetic analysis of halocin C8 sequences was conducted.

  12. Crystal structures of a halophilic archaeal malate synthase from Haloferax volcanii and comparisons with isoforms A and G

    Science.gov (United States)

    2011-01-01

    Background Malate synthase, one of the two enzymes unique to the glyoxylate cycle, is found in all three domains of life, and is crucial to the utilization of two-carbon compounds for net biosynthetic pathways such as gluconeogenesis. In addition to the main isoforms A and G, so named because of their differential expression in E. coli grown on either acetate or glycolate respectively, a third distinct isoform has been identified. These three isoforms differ considerably in size and sequence conservation. The A isoform (MSA) comprises ~530 residues, the G isoform (MSG) is ~730 residues, and this third isoform (MSH-halophilic) is ~430 residues in length. Both isoforms A and G have been structurally characterized in detail, but no structures have been reported for the H isoform which has been found thus far only in members of the halophilic Archaea. Results We have solved the structure of a malate synthase H (MSH) isoform member from Haloferax volcanii in complex with glyoxylate at 2.51 Å resolution, and also as a ternary complex with acetyl-coenzyme A and pyruvate at 1.95 Å. Like the A and G isoforms, MSH is based on a β8/α8 (TIM) barrel. Unlike previously solved malate synthase structures which are all monomeric, this enzyme is found in the native state as a trimer/hexamer equilibrium. Compared to isoforms A and G, MSH displays deletion of an N-terminal domain and a smaller deletion at the C-terminus. The MSH active site is closely superimposable with those of MSA and MSG, with the ternary complex indicating a nucleophilic attack on pyruvate by the enolate intermediate of acetyl-coenzyme A. Conclusions The reported structures of MSH from Haloferax volcanii allow a detailed analysis and comparison with previously solved structures of isoforms A and G. These structural comparisons provide insight into evolutionary relationships among these isoforms, and also indicate that despite the size and sequence variation, and the truncated C-terminal domain of the H

  13. Draft genome sequence of a human-associated isolate of Haloferax alexandrinus strain Arc-hr, an extremely halophilic archaea.

    Science.gov (United States)

    Khelaifia, S; Caputo, A; Djossou, F; Raoult, D

    2017-01-01

    We report the draft genome sequence of Haloferax alexandrinus strain Arc-hr (CSUR P798), isolated from the human gut of a 10-year-old Amazonian individual. Its 3 893 626 bp genome exhibits a 66.00% GC content. The genome of the strain Arc-hr contains 37 genes identified as ORFans, seven genes associated to halocin and 11 genes associated with polyketide synthases or nonribosomal peptide synthetases.

  14. ATP- and NAD+-dependent DNA ligases share an essential function in the halophilic archaeon Haloferax volcanii

    DEFF Research Database (Denmark)

    Zhao, A.; Gray, F. C; MacNeill, S. A.

    2006-01-01

    DNA ligases join the ends of DNA molecules during replication, repair and recombination. ATP-dependent ligases are found predominantly in the eukarya and archaea whereas NAD+-dependent DNA ligases are found only in the eubacteria and in entomopoxviruses. Using the genetically tractable halophile....... volcanii also encodes an NAD+-dependent DNA ligase family member, LigN, the first such enzyme to be identified in the archaea, and present phylogenetic analysis indicating that the gene encoding this protein has been acquired by lateral gene transfer (LGT) from eubacteria. As with LigA, we show that Lig...

  15. Transcriptional regulation of dimethyl sulfoxide respiration in a haloarchaeon, Haloferax volcanii.

    Science.gov (United States)

    Qi, Qiuzi; Ito, Yoshiyasu; Yoshimatsu, Katsuhiko; Fujiwara, Taketomo

    2016-01-01

    The halophilic euryarchaeon Haloferax volcanii can grow anaerobically by DMSO respiration. DMSO reductase was induced by DMSO respiration not only under anaerobic growth conditions but also in denitrifying cells of H. volcanii. Deletion of the dmsR gene, encoding a putative regulator for the DMSO reductase, resulted in the loss of anaerobic growth by DMSO respiration. Reporter experiments revealed that only the anaerobic condition was essential for transcription of the dmsEABCD genes encoding DMSO reductase and that transcription was enhanced threefold by supplementation of DMSO. In the ∆dmsR mutant, transcription of the dmsEABCD genes induced by the anaerobic condition was not enhanced by DMSO, suggesting that DmsR is a DMSO-responsive regulator. Transcriptions of the dmsR and mgd genes for Mo-bisMGD biosynthesis were regulated in the same manner as the dmsEABCD genes. These results suggest that the genetic regulation of DMSO respiration in H. volcanii is controlled by at least two systems: one is the DMSO-responsive DmsR, and the other is an unknown anaerobic regulator.

  16. Extracellular DNA metabolism in Haloferax volcanii

    Directory of Open Access Journals (Sweden)

    Scott eChimileski

    2014-02-01

    Full Text Available Extracellular DNA is found in all environments and is a dynamic component of the micro-bial ecosystem. Microbial cells produce and interact with extracellular DNA through many endogenous mechanisms. Extracellular DNA is processed and internalized for use as genetic information and as a major source of macronutrients, and plays several key roles within prokaryotic biofilms. Hypersaline sites contain some of the highest extracellular DNA con-centrations measured in nature–a potential rich source of carbon, nitrogen and phosphorus for halophilic microorganisms. We conducted DNA growth studies for the halophilic archaeon Haloferax volcanii DS2 and show that this model Halobacteriales strain is capable of using exogenous double-stranded DNA as a nutrient. Further experiments with varying medium composition, DNA concentration and DNA types revealed that DNA is utilized primarily as a phosphorus source, that growth on DNA is concentration-dependent and that DNA isolated from different sources is metabolized selectively, with a bias against highly divergent methylated DNA sources. Additionally, fluorescence microscopy experiments showed that labeled DNA colocalized with Haloferax volcanii cells. The gene Hvo_1477 was also identified using a comparative genomic approach as a factor likely to be involved in extracellular DNA processing at the cell surface, and deletion of Hvo_1477 created an H. volcanii strain deficient in its ability to grow on extracellular DNA. Widespread distribution of Hvo_1477 homologs in archaea suggests metabolism of extracellular DNA may be of broad ecological and physiological relevance in this domain of life.

  17. The Adaptive Immune System of Haloferax volcanii

    Directory of Open Access Journals (Sweden)

    Lisa-Katharina Maier

    2015-02-01

    Full Text Available To fight off invading genetic elements, prokaryotes have developed an elaborate defence system that is both adaptable and heritable—the CRISPR-Cas system (CRISPR is short for: clustered regularly interspaced short palindromic repeats and Cas: CRISPR associated. Comprised of proteins and multiple small RNAs, this prokaryotic defence system is present in 90% of archaeal and 40% of bacterial species, and enables foreign intruders to be eliminated in a sequence-specific manner. There are three major types (I–III and at least 14 subtypes of this system, with only some of the subtypes having been analysed in detail, and many aspects of the defence reaction remaining to be elucidated. Few archaeal examples have so far been analysed. Here we summarize the characteristics of the CRISPR-Cas system of Haloferax volcanii, an extremely halophilic archaeon originally isolated from the Dead Sea. It carries a single CRISPR-Cas system of type I-B, with a Cascade like complex composed of Cas proteins Cas5, Cas6b and Cas7. Cas6b is essential for CRISPR RNA (crRNA maturation but is otherwise not required for the defence reaction. A systematic search revealed that six protospacer adjacent motif (PAM sequences are recognised by the Haloferax defence system. For successful invader recognition, a non-contiguous seed sequence of 10 base-pairs between the crRNA and the invader is required.

  18. Perchlorate and halophilic prokaryotes: implications for possible halophilic life on Mars.

    Science.gov (United States)

    Oren, Aharon; Elevi Bardavid, Rahel; Mana, Lily

    2014-01-01

    In view of the finding of perchlorate among the salts detected by the Phoenix Lander on Mars, we investigated the relationships of halophilic heterotrophic microorganisms (archaea of the family Halobacteriaceae and the bacterium Halomonas elongata) toward perchlorate. All strains tested grew well in NaCl-based media containing 0.4 M perchlorate, but at the highest perchlorate concentrations, tested cells were swollen or distorted. Some species (Haloferax mediterranei, Haloferax denitrificans, Haloferax gibbonsii, Haloarcula marismortui, Haloarcula vallismortis) could use perchlorate as an electron acceptor for anaerobic growth. Although perchlorate is highly oxidizing, its presence at a concentration of 0.2 M for up to 2 weeks did not negatively affect the ability of a yeast extract-based medium to support growth of the archaeon Halobacterium salinarum. These findings show that presence of perchlorate among the salts on Mars does not preclude the possibility of halophilic life. If indeed the liquid brines that may exist on Mars are inhabited by salt-requiring or salt-tolerant microorganisms similar to the halophiles on Earth, presence of perchlorate may even be stimulatory when it can serve as an electron acceptor for respiratory activity in the anaerobic Martian environment.

  19. Cell Surface Glycosylation Is Required for Efficient Mating of Haloferax volcanii

    Directory of Open Access Journals (Sweden)

    Yarden Shalev

    2017-07-01

    Full Text Available Halophilic archaea use a fusion-based mating system for lateral gene transfer across cells, yet the molecular mechanisms involved remain unknown. Previous work implied that cell fusion involves cell–cell recognition since fusion occurs more efficiently between cells from the same species. Long believed to be restricted only to Eukarya, it is now known that cells of all three domains of life perform N-glycosylation, the covalent attachment of glycans to select target asparagine residues in proteins, and that this post-translational modification is common for archaeal cell surface proteins. Here, we show that differences in glycosylation of the Haloferax volcanii surface-layer glycoprotein, brought about either by changing medium salinity or by knocking out key glycosylation genes, reduced mating success. Thus, different glycosylation patterns are likely to underlie mating preference in halophilic archaea, contributing to speciation processes.

  20. The complete genome sequence of Haloferax volcanii DS2, a model archaeon.

    Directory of Open Access Journals (Sweden)

    Amber L Hartman

    2010-03-01

    Full Text Available Haloferax volcanii is an easily culturable moderate halophile that grows on simple defined media, is readily transformable, and has a relatively stable genome. This, in combination with its biochemical and genetic tractability, has made Hfx. volcanii a key model organism, not only for the study of halophilicity, but also for archaeal biology in general.We report here the sequencing and analysis of the genome of Hfx. volcanii DS2, the type strain of this species. The genome contains a main 2.848 Mb chromosome, three smaller chromosomes pHV1, 3, 4 (85, 438, 636 kb, respectively and the pHV2 plasmid (6.4 kb.The completed genome sequence, presented here, provides an invaluable tool for further in vivo and in vitro studies of Hfx. volcanii.

  1. Stoichiometric and kinetic analysis of extreme halophilic Archaea on various substrates in a corrosion resistant bioreactor.

    Science.gov (United States)

    Lorantfy, Bettina; Seyer, Bernhard; Herwig, Christoph

    2014-01-25

    Extreme halophilic Archaea are extremophile species which can thrive in hypersaline environments of up to 3-5 M sodium chloride concentration. Although their ecology and physiology are widely identified on the microbiological level, little emphasis has been laid on quantitative bioprocess development with extreme halophiles. The goal of this study was to establish, on the one hand, a methodological basis for quantitative bioprocess analysis of extreme halophilic Archaea with an extreme halophilic strain as an example. Firstly, as a novel usage, a corrosion resistant bioreactor setup for extreme halophiles has been implemented. Then, paying special attention to total bioprocess quantification approaches, an indirect method for biomass quantification using on-line process signals was introduced. Subsequently, robust quantitative data evaluation methods for halophiles could be developed, providing defined and controlled cultivation conditions in the bioreactor and therefore obtaining suitable quality of on-line as well as off-line datasets. On the other hand, new physiological results of extreme halophiles in bioreactor have also been obtained based on the quantitative methodological tools. For the first time, quantitative data on stoichiometry and kinetics were collected and evaluated on different carbon sources. The results on various substrates were interpreted, with proposed metabolic mechanisms, by linking to the reported primary carbon metabolism of extreme halophilic Archaea. Moreover, results of chemostat cultures demonstrated that extreme halophilic organisms show Monod-kinetics on different sole carbon sources. A diauxic growth pattern was described on a mixture of substrates in batch cultivations. In addition, the methodologies presented here enable one to characterize the utilized strain Haloferax mediterranei (HFX) as a potential new host organism. Thus, this study offers a strong methodological basis as well as a fundamental physiological assessment for

  2. Diversity of halophilic archaea from six hypersaline environments in Turkey.

    Science.gov (United States)

    Ozcan, Birgul; Ozcengiz, Gulay; Coleri, Arzu; Cokmus, Cumhur

    2007-06-01

    The diversity of archaeal strains from six hypersaline environments in Turkey was analyzed by comparing their phenotypic characteristics and 16S rDNA sequences. Thirty-three isolates were characterized in terms of their phenotypic properties including morphological and biochemical characteristics, susceptibility to different antibiotics, and total lipid and plasmid contents, and finally compared by 16S rDNA gene sequences. The results showed that all isolates belong to the family Halobacteriaceae. Phylogenetic analyses using approximately 1,388 bp comparisions of 16S rDNA sequences demonstrated that all isolates clustered closely to species belonging to 9 genera, namely Halorubrum (8 isolates), Natrinema (5 isolates), Haloarcula (4 isolates), Natronococcus (4 isolates), Natrialba (4 isolates), Haloferax (3 isolates), Haloterrigena (3 isolates), Halalkalicoccus (1 isolate), and Halomicrobium (1 isolate). The results revealed a high diversity among the isolated halophilic strains and indicated that some of these strains constitute new taxa of extremely halophilic archaea.

  3. DNA replication restart and cellular dynamics of Hef helicase/nuclease protein in Haloferax volcanii.

    Science.gov (United States)

    Lestini, Roxane; Delpech, Floriane; Myllykallio, Hannu

    2015-11-01

    Understanding how frequently spontaneous replication arrests occur and how archaea deal with these arrests are very interesting and challenging research topics. Here we will described how genetic and imaging studies have revealed the central role of the archaeal helicase/nuclease Hef belonging to the XPF/MUS81/FANCM family of endonucleases in repair of arrested replication forks. Special focus will be on description of a recently developed combination of genetic and imaging tools to study the dynamic localization of a functional Hef::GFP (Green Fluorescent Protein) fusion protein in the living cells of halophilic archaea Haloferax volcanii. As Archaea provide an excellent and unique model for understanding how DNA replication is regulated to allow replication of a circular DNA molecule either from single or multiple replication origins, we will also summarize recent studies that have revealed peculiar features regarding DNA replication, particularly in halophilic archaea. We strongly believe that fundamental knowledge of our on-going studies will shed light on the evolutionary history of the DNA replication machinery and will help to establish general rules concerning replication restart and the key role of recombination proteins not only in bacteria, yeast and higher eukaryotes but also in archaea. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  4. Resistance of extremely halophilic archaea to zinc and zinc oxide nanoparticles

    Science.gov (United States)

    Salgaonkar, Bhakti B.; Das, Deepthi; Bragança, Judith Maria

    2016-02-01

    Industrialization as well as other anthropogenic activities have resulted in addition of high loads of metal and/or metal nanoparticles to the environment. In this study, the effect of one of the widely used heavy metal, zinc (Zn) and zinc oxide nanoparticles (ZnO NPs) on extremely halophilic archaea was evaluated. One representative member from four genera namely Halococcus, Haloferax, Halorubrum and Haloarcula of the family Halobacteriaceae was taken as the model organism. All the haloarchaeal genera investigated were resistant to both ZnCl2 and ZnO NPs at varying concentrations. Halococcus strain BK6 and Haloferax strain BBK2 showed the highest resistance in complex/minimal medium of up to 2.0/1.0 mM ZnCl2 and 2.0/1.0-0.5 mM ZnO NP. Accumulation of ZnCl2/ZnO NPs was seen as Haloferax strain BBK2 (287.2/549.6 mg g-1) > Halococcus strain BK6 (165.9/388.5 mg g-1) > Haloarcula strain BS2 (93.2/28.5 mg g-1) > Halorubrum strain BS17 (29.9/16.2 mg g-1). Scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM-EDX) analysis revealed that bulk ZnCl2 was sorbed at a higher concentration (21.77 %) on the cell surface of Haloferax strain BBK2 as compared to the ZnO NPs (14.89 %).

  5. Prospects for robust biocatalysis: engineering of novel specificity in a halophilic amino acid dehydrogenase.

    Science.gov (United States)

    Munawar, Nayla; Engel, Paul C

    2013-01-01

    Heat- and solvent-tolerant enzymes from halophiles, potentially important industrially, offer a robust framework for protein engineering, but few solved halophilic structures exist to guide this. Homology modelling has guided mutations in glutamate dehydrogenase (GDH) from Halobacterium salinarum to emulate conversion of a mesophilic GDH to a methionine dehydrogenase. Replacement of K89, A163 and S367 by leucine, glycine and alanine converted halophilic GDH into a dehydrogenase accepting L-methionine, L-norleucine and L-norvaline as substrates. Over-expression in the halophilic expression host Haloferax volcanii and three-step purification gave ~98 % pure protein exhibiting maximum activity at pH 10. This enzyme also showed enhanced thermostability and organic solvent tolerance even at 70 °C, offering a biocatalyst resistant to harsh industrial environments. To our knowledge, this is the first reported amino acid specificity change engineered in a halophilic enzyme, encouraging use of mesophilic models to guide engineering of novel halophilic biocatalysts for industrial application. Calibrated gel filtration experiments show that both the mutant and the wild-type enzyme are stable hexamers.

  6. Generation of comprehensive transposon insertion mutant library for the model archaeon, Haloferax volcanii, and its use for gene discovery.

    Science.gov (United States)

    Kiljunen, Saija; Pajunen, Maria I; Dilks, Kieran; Storf, Stefanie; Pohlschroder, Mechthild; Savilahti, Harri

    2014-12-09

    Archaea share fundamental properties with bacteria and eukaryotes. Yet, they also possess unique attributes, which largely remain poorly characterized. Haloferax volcanii is an aerobic, moderately halophilic archaeon that can be grown in defined media. It serves as an excellent archaeal model organism to study the molecular mechanisms of biological processes and cellular responses to changes in the environment. Studies on haloarchaea have been impeded by the lack of efficient genetic screens that would facilitate the identification of protein functions and respective metabolic pathways. Here, we devised an insertion mutagenesis strategy that combined Mu in vitro DNA transposition and homologous-recombination-based gene targeting in H. volcanii. We generated an insertion mutant library, in which the clones contained a single genomic insertion. From the library, we isolated pigmentation-defective and auxotrophic mutants, and the respective insertions pinpointed a number of genes previously known to be involved in carotenoid and amino acid biosynthesis pathways, thus validating the performance of the methodologies used. We also identified mutants that had a transposon insertion in a gene encoding a protein of unknown or putative function, demonstrating that novel roles for non-annotated genes could be assigned. We have generated, for the first time, a random genomic insertion mutant library for a halophilic archaeon and used it for efficient gene discovery. The library will facilitate the identification of non-essential genes behind any specific biochemical pathway. It represents a significant step towards achieving a more complete understanding of the unique characteristics of halophilic archaea.

  7. Structural insights into the adaptation of proliferating cell nuclear antigen (PCNA) from Haloferax volcanii to a high-salt environment

    International Nuclear Information System (INIS)

    Morgunova, Ekaterina; Gray, Fiona C.; MacNeill, Stuart A.; Ladenstein, Rudolf

    2009-01-01

    The crystal structure of PCNA from the halophilic archaeon H. volcanii reveals specific features of the charge distribution on the protein surface that reflect adaptation to a high-salt environment and suggests a different type of interaction with DNA in halophilic PCNAs. The sliding clamp proliferating cell nuclear antigen (PCNA) plays vital roles in many aspects of DNA replication and repair in eukaryotic cells and in archaea. Realising the full potential of archaea as a model for PCNA function requires a combination of biochemical and genetic approaches. In order to provide a platform for subsequent reverse genetic analysis, PCNA from the halophilic archaeon Haloferax volcanii was subjected to crystallographic analysis. The gene was cloned and expressed in Escherichia coli and the protein was purified by affinity chromatography and crystallized by the vapour-diffusion technique. The structure was determined by molecular replacement and refined at 3.5 Å resolution to a final R factor of 23.7% (R free = 25%). PCNA from H. volcanii was found to be homotrimeric and to resemble other homotrimeric PCNA clamps but with several differences that appear to be associated with adaptation of the protein to the high intracellular salt concentrations found in H. volcanii cells

  8. The Function of Gas Vesicles in Halophilic Archaeaand Bacteria: Theories and Experimental Evidence

    Science.gov (United States)

    Oren, Aharon

    2012-01-01

    A few extremely halophilic Archaea (Halobacterium salinarum, Haloquadratum walsbyi, Haloferax mediterranei, Halorubrum vacuolatum, Halogeometricum borinquense, Haloplanus spp.) possess gas vesicles that bestow buoyancy on the cells. Gas vesicles are also produced by the anaerobic endospore-forming halophilic Bacteria Sporohalobacter lortetii and Orenia sivashensis. We have extensive information on the properties of gas vesicles in Hbt. salinarum and Hfx. mediterranei and the regulation of their formation. Different functions were suggested for gas vesicle synthesis: buoying cells towards oxygen-rich surface layers in hypersaline water bodies to prevent oxygen limitation, reaching higher light intensities for the light-driven proton pump bacteriorhodopsin, positioning the cells optimally for light absorption, light shielding, reducing the cytoplasmic volume leading to a higher surface-area-to-volume ratio (for the Archaea) and dispersal of endospores (for the anaerobic spore-forming Bacteria). Except for Hqr. walsbyi which abounds in saltern crystallizer brines, gas-vacuolate halophiles are not among the dominant life forms in hypersaline environments. There only has been little research on gas vesicles in natural communities of halophilic microorganisms, and the few existing studies failed to provide clear evidence for their possible function. This paper summarizes the current status of the different theories why gas vesicles may provide a selective advantage to some halophilic microorganisms. PMID:25371329

  9. Characterization of the MCM homohexamer from the thermoacidophilic euryarchaeon Picrophilus torridus

    Science.gov (United States)

    Goswami, Kasturi; Arora, Jasmine; Saha, Swati

    2015-01-01

    The typical archaeal MCM exhibits helicase activity independently in vitro. This study characterizes MCM from the euryarchaeon Picrophilus torridus. While PtMCM hydrolyzes ATP in DNA-independent manner, it displays very poor ability to unwind DNA independently, and then too only under acidic conditions. The protein exists stably in complex with PtGINS in whole cell lysates, interacting directly with PtGINS under neutral and acidic conditions. GINS strongly activates MCM helicase activity, but only at low pH. In consonance with this, PtGINS activates PtMCM-mediated ATP hydrolysis only at low pH, with the amount of ATP hydrolyzed during the helicase reaction increasing more than fifty-fold in the presence of GINS. While the stimulation of MCM-mediated helicase activity by GINS has been reported in MCMs from P.furiosus, T.kodakarensis, and very recently, T.acidophilum, to the best of our knowledge, this is the first report of an MCM helicase demonstrating DNA unwinding activity only at such acidic pH, across all archaea and eukaryotes. PtGINS may induce/stabilize a conducive conformation of PtMCM under acidic conditions, favouring PtMCM-mediated DNA unwinding coupled to ATP hydrolysis. Our findings underscore the existence of divergent modes of replication regulation among archaea and the importance of investigating replication events in more archaeal organisms. PMID:25762096

  10. Unique Features of Halophilic Proteins.

    Science.gov (United States)

    Arakawa, Tsutomu; Yamaguchi, Rui; Tokunaga, Hiroko; Tokunaga, Masao

    2017-01-01

    Proteins from moderate and extreme halophiles have unique characteristics. They are highly acidic and hydrophilic, similar to intrinsically disordered proteins. These characteristics make the halophilic proteins soluble in water and fold reversibly. In addition to reversible folding, the rate of refolding of halophilic proteins from denatured structure is generally slow, often taking several days, for example, for extremely halophilic proteins. This slow folding rate makes the halophilic proteins a novel model system for folding mechanism analysis. High solubility and reversible folding also make the halophilic proteins excellent fusion partners for soluble expression of recombinant proteins.

  11. High salinity facilitates dolomite precipitation mediated by Haloferax volcanii DS52

    Science.gov (United States)

    Qiu, Xuan; Wang, Hongmei; Yao, Yanchen; Duan, Yong

    2017-08-01

    Although most modern dolomites occur in hypersaline environments, the effects of elevated salinity on the microbial mediation of dolomite precipitation have not been fully evaluated. Here we report results of dolomite precipitation in association with a batch culture of Haloferax volcanii DS52, a halophilic archaeon, under various salinities (from 120‰ to 360‰) and the impact of salinity on microbe-mediated dolomite formation. The mineral phases, morphology and atomic arrangement of the precipitates were analyzed by XRD, SEM and TEM, respectively. The amount of amino acids on the archaeal cell surface was quantified by HPLC/MS. The XRD analysis indicated that disordered dolomite formed successfully with the facilitation of cells harvested from cultures with relatively high salinities (200‰ and 280‰) but was not observed in association with cells harvested from cultures with lower salinity (120‰) or the lysates of cells harvested from extremely high salinity (360‰). The TEM analysis demonstrated that the crystals from cultures with a salinity of 200‰ closely matched that of dolomite. Importantly, we found that more carboxyl groups were presented on the cell surface under high salinity conditions to resist the high osmotic pressure, which may result in the subsequent promotion of dolomite formation. Our finding suggests a link between variations in the hydro-chemical conditions and the formation of dolomite via microbial metabolic activity and enhances our understanding about the mechanism of microbially mediated dolomite formation under high salinity conditions.

  12. Recycling of Waste Streams of the Biotechnological Poly(hydroxyalkanoate Production by Haloferax mediterranei on Whey

    Directory of Open Access Journals (Sweden)

    Martin Koller

    2015-01-01

    Full Text Available For manufacturing “bioplastics” such as poly(hydroxyalkanoates (PHA, the combination of utilization of inexpensive carbon sources with the application of robust microbial production strains is considered a decisive step to make this process more cost-efficient and sustainable. PHA production based on surplus whey from dairy industry was accomplished by the extremely halophile archaeon Haloferax mediterranei. After fermentative production of PHA-rich biomass and the subsequent cell harvest and downstream processing for PHA recovery, environmentally hazardous, highly saline residues, namely spent fermentation broth and cell debris, remain as residues. These waste streams were used for recycling experiments to assess their recyclability in subsequent production processes. It was demonstrated that spent fermentation broth can be used to replace a considerable part of fresh saline fermentation medium in subsequent production processes. In addition, 29% of the expensive yeast extract, needed as nitrogen and phosphate source for efficient cultivation of the microorganism, can be replaced by cell debris from prior cultivations. The presented study provides strategies to combine the reduction of costs for biomediated PHA production with minimizing ecological risks by recycling precarious waste streams. Overall, the presented work shall contribute to the quick economic success of these promising biomaterials.

  13. Halophilic & halotolerant prokaryotes in humans.

    Science.gov (United States)

    Seck, El Hadji; Dufour, Jean-Charles; Raoult, Didier; Lagier, Jean-Christophe

    2018-05-04

    Halophilic prokaryotes are described as microorganisms living in hypersaline environments. Here, we list the halotolerant and halophilic bacteria which have been isolated in humans. Of the 52 halophilic prokaryotes, 32 (61.54%) were moderately halophilic, 17 (32.69%) were slightly halophilic and three (5.76%) were extremely halophilic prokaryotes. At the phylum level, 29 (54.72%) belong to Firmicutes, 15 (28.84%) to Proteobacteria, four (7.69%) to Actinobacteria, three (5.78%) to Euryarchaeota and one (1.92%) belongs to Bacteroidetes. Halophilic prokaryotes are rarely pathogenic: of these 52 halophilic prokaryotes only two (3.92%) species were classified in Risk Group 2 (Vibrio cholerae, Vibrio parahaemolyticus) and one (1.96%), species in Risk Group 3 (Bacillus anthracis).

  14. In Vitro Antioxidant, Antihemolytic, and Anticancer Activity of the Carotenoids from Halophilic Archaea.

    Science.gov (United States)

    Hou, Jing; Cui, Heng-Lin

    2018-03-01

    Halophilic archaea represent a promising natural source of carotenoids. However, little information is available about the biological effects of carotenoids from halophilic archaea. In this study, the carotenoids produced by seven halophilic archaeal strains Halogeometricum rufum, Halogeometricum limi, Haladaptatus litoreus, Haloplanus vescus, Halopelagius inordinatus, Halogranum rubrum, and Haloferax volcanii were identified by ultraviolet/visible spectroscopy, thin-layer chromatography, and high-performance liquid chromatography-tandem mass spectrometry. The C 50 carotenoids bacterioruberin and its derivatives monoanhydrobacterioruberin and bisanhydrobacterioruberin were found to be the predominant carotenoids. The antioxidant capacities of the carotenoids from these strains were significantly higher than β-carotene as determined by 1,1-diphenyl-2-picrylhydrazyl radical scavenging assay. The antihemolytic activities of these carotenoid extracts against H 2 O 2 -induced hemolysis in mouse erythrocytes were 3.9-6.3 times higher than β-carotene. A dose-dependent in vitro antiproliferative activity against HepG2 cells was observed for the extract from Hgm. limi, while that from Hpn. vescus exhibited a relatively high activity in a dose-independent manner. These results suggested that halophilic archaea could be considered as an alternative source of natural carotenoids with high antioxidant, antihemolytic, and anticancer activity.

  15. Halophilic Amylase from a Moderately Halophilic Micrococcus

    Science.gov (United States)

    Onishi, Hiroshi

    1972-01-01

    A moderately halophilic Micrococcus sp., isolated from unrefined solar salt, produced a considerable amount of extracellular dextrinogenic amylase when cultivated aerobically in media containing 1 to 3 m NaCl. The Micrococcus amylase had maximal activity at pH 6 to 7 in 1.4 to 2 m NaCl or KCl at 50 C. Calcium ion and a high concentration of NaCl or KCl were essential for activity and stability of the amylase. The salt response of the amylase depended greatly on the pH and temperature of the enzyme assay. PMID:5058445

  16. Taxonomic analysis of extremely halophilic archaea isolated from 56-years-old dead sea brine samples.

    Science.gov (United States)

    Arahal, D R; Gutiérrez, M C; Volcani, B E; Ventosa, A

    2000-10-01

    A taxonomic study comprising both phenotypic and genotypic characterization, has been carried out on a total of 158 extremely halophilic aerobic archaeal strains. These strains were isolated from enrichments prepared from Dead Sea water samples dating from 1936 that were collected by B. E. Volcani for the demonstration of microbial life in the Dead Sea. The isolates were examined for 126 morphological, physiological, biochemical and nutritional tests. Numerical analysis of the data, by using the S(J) coefficient and UPGMA clustering method, showed that the isolates clustered into six phenons. Twenty-two out of the 158 strains used in this study were characterized previously (ARAHAL et al., 1996) and were placed into five phenotypic groups. The genotypic study included both the determination of the guanineplus-cytosine content of the DNA and DNA-DNA hybridization studies. For this purpose, representative strains from the six phenons were chosen. These groups were found to represent some members of three different genera - Haloarcula (phenons A, B, and C), Haloferax (phenons D and E) and Halobacterium (phenon F) - of the family Halobacteriaceae, some of them never reported to occur in the Dead Sea, such as Haloarcula hispanica, while Haloferax volcanii (phenons D and E) was described in the Dead Sea by studies carried out several decades later than Volcani's work.

  17. Deletion of the Sm1 encoding motif in the lsm gene results in distinct changes in the transcriptome and enhanced swarming activity of Haloferax cells.

    Science.gov (United States)

    Maier, Lisa-Katharina; Benz, Juliane; Fischer, Susan; Alstetter, Martina; Jaschinski, Katharina; Hilker, Rolf; Becker, Anke; Allers, Thorsten; Soppa, Jörg; Marchfelder, Anita

    2015-10-01

    Members of the Sm protein family are important for the cellular RNA metabolism in all three domains of life. The family includes archaeal and eukaryotic Lsm proteins, eukaryotic Sm proteins and archaeal and bacterial Hfq proteins. While several studies concerning the bacterial and eukaryotic family members have been published, little is known about the archaeal Lsm proteins. Although structures for several archaeal Lsm proteins have been solved already more than ten years ago, we still do not know much about their biological function, however one can confidently propose that the archaeal Lsm proteins will also be involved in RNA metabolism. Therefore, we investigated this protein in the halophilic archaeon Haloferax volcanii. The Haloferax genome encodes a single Lsm protein, the lsm gene overlaps and is co-transcribed with the gene for the ribosomal L37.eR protein. Here, we show that the reading frame of the lsm gene contains a promoter which regulates expression of the overlapping rpl37R gene. This rpl37R specific promoter ensures high expression of the rpl37R gene in exponential growth phase. To investigate the biological function of the Lsm protein we generated a lsm deletion mutant that had the coding sequence for the Sm1 motif removed but still contained the internal promoter for the downstream rpl37R gene. The transcriptome of this deletion mutant was compared to the wild type transcriptome, revealing that several genes are down-regulated and many genes are up-regulated in the deletion strain. Northern blot analyses confirmed down-regulation of two genes. In addition, the deletion strain showed a gain of function in swarming, in congruence with the up-regulation of transcripts encoding proteins required for motility. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  18. Characterization and antimicrobial potential of extremely halophilic archaea isolated from hypersaline environments of the Algerian Sahara.

    Science.gov (United States)

    Quadri, Inès; Hassani, Imene Ikrame; l'Haridon, Stéphane; Chalopin, Morgane; Hacène, Hocine; Jebbar, Mohamed

    2016-01-01

    Halophilic archaea were isolated from different chotts and sebkha, dry salt lakes and salt flat respectively, of the Algerian Sahara and characterized using phenotypic and phylogenetic approaches. From 102 extremely halophilic strains isolated, forty three were selected and studied. These strains were also screened for their antagonistic potential and the production of hydrolytic enzymes. Sequencing of the 16S rRNA genes and phylogenetic analysis allowed the identification of 10 archaeal genera within the class Halobacteria: Natrinema (13 strains), Natrialba (12 strains), Haloarcula (4 strains), Halopiger (4 strains), Haloterrigena (3 strains), Halorubrum (2 strains), Halostagnicola (2 strains), Natronococcus, Halogeometricum and Haloferax (1 strain each). The most common producers of antimicrobial compounds belong to the genus Natrinema while the most hydrolytic isolates, with combined production of several enzymes, belong to the genus Natrialba. The strain affiliated to Halopiger djelfamassilliensis was found to produce some substances of interest (halocins, anti-Candida, enzymes). After partial purification and characterization of one of the strains Natrinema gari QI1, we found similarities between the antimicrobial compound and the halocin C8. Therefore, the gene encoding halocin C8 was amplified and sequenced. Copyright © 2016 Elsevier GmbH. All rights reserved.

  19. Transcription-coupled repair of UV damage in the halophilic archaea.

    Science.gov (United States)

    Stantial, Nicole; Dumpe, Jarrod; Pietrosimone, Kathryn; Baltazar, Felicia; Crowley, David J

    2016-05-01

    Transcription-coupled repair (TCR) is a subpathway of nucleotide excision repair (NER) in which excision repair proteins are targeted to RNA polymerase-arresting lesions located in the transcribed strand of active genes. TCR has been documented in a variety of bacterial and eukaryotic organisms but has yet to be observed in the Archaea. We used Halobacterium sp. NRC-1 and Haloferax volcanii to determine if TCR occurs in the halophilic archaea. Following UV irradiation of exponentially growing cultures, we quantified the rate of repair of cyclobutane pyrimidine dimers in the two strands of the rpoB2B1A1A2 and the trpDFEG operons of Halobacterium sp. NRC-1 and the pts operon of H. volcanii through the use of a Southern blot assay and strand-specific probes. TCR was observed in all three operons and was dependent on the NER gene uvrA in Halobacterium sp. NRC-1, but not in H. volcanii. The halophilic archaea likely employ a novel mechanism for TCR in which an as yet unknown coupling factor recognizes the arrested archaeal RNA polymerase complex and recruits certain NER proteins to complete the process. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Isolation and characterization of the first xylanolytic hyperthermophilic euryarchaeon Thermococcus sp. strain 2319x1 and its unusual multidomain glycosidase

    Directory of Open Access Journals (Sweden)

    Sergey N Gavrilov

    2016-05-01

    Full Text Available Enzymes from (hyperthermophiles Thermozymes offer a great potential for biotechnological applications. Thermophilic adaptation does not only provide stability towards high temperature but is also often accompanied by a higher resistance to other harsh physicochemical conditions, which are also frequently employed in industrial processes, such as the presence of e.g. denaturing agents as well as low or high pH of the medium. In order to find new thermostable, xylan degrading hydrolases with potential for biotechnological application we used an in situ enrichment strategy incubating Hungate tubes with xylan as the energy substrate in a hot vent located in the tidal zone of Kunashir Island (Kuril archipelago. Using this approach a hyperthermophilic euryarchaeon, designated Thermococcus sp. strain 2319x1, growing on xylan as sole energy and carbon source was isolated. The organism grows optimally at 85°C and pH 7.0 on a variety of natural polysaccharides including xylan, carboxymethyl cellulose (CMC, amorphous cellulose (AMC, xyloglucan, and chitin. The protein fraction extracted from the cells surface with Twin 80 exhibited endoxylanase, endoglucanase and xyloglucanase activities. The genome of Thermococcus sp. strain 2319x1 was sequenced and assembled into one circular chromosome. Within the newly sequenced genome, a gene, encoding a novel type of glycosidase (143 kDa with a unique five-domain structure, was identified. It consists of three glycoside hydrolase (GH domains and two carbohydrate-binding modules (CBM with the domain order GH5-12-12-CBM2-2 (N- to C-terminal direction. The full length protein, as well as truncated versions, were heterologously expressed in Escherichia coli and their activity was analyzed. The full length multidomain glycosidase (MDG was able to hydrolyze various polysaccharides, with the highest activity for barley β-glucan (β-1,3/1,4-glucoside, followed by that for carboxymethyl cellulose (β-1,4-glucoside

  1. Mass production of C50 carotenoids by Haloferax mediterranei in using extruded rice bran and starch under optimal conductivity of brined medium.

    Science.gov (United States)

    Chen, C Will; Hsu, Shu-hui; Lin, Ming-Tse; Hsu, Yi-hui

    2015-12-01

    Microbial carotenoids have potentially healthcare or medical applications. Haloferax mediterranei was difficult to economically grow into a large quantities as well as producing a valuable pigment of carotenoids. This study reports a novel investigation into the optimal conductivity on the mass production of carotenoids from H. mediterranei. The major component at about 52.4% in the extracted red pigment has been confirmed as bacterioruberin, a C50 carotenoids, by liquid chromatography separation and mass spectrometry analysis. By maintaining higher conductivity of 40 S/m in the brined medium, the cell concentration attained to 7.73 × 10(9) cells/L with low pigments concentration of 125 mg/L. When the conductivity was controlled at about 30 S/m, we obtained the highest cell concentration to 1.29 × 10(10) cells/L with pigments of 361.4 mg/L. When the conductivity was maintained at optimal 25 S/m, the pigments can be increased to maximum value of 555.6 mg/L at lower cell concentration of 9.22 × 10(9) cells/L. But conductivity below 20 S/m will cause the significant decrease in cell concentration as well as pigments due to the osmotic stress around the cells. Red pigment of carotenoids from an extremely halophilic archaebacterium could be efficiently produced to a high concentration by applying optimal conductivity control in the brined medium with extruded low-cost rice bran and corn starch.

  2. Antimicrobial Activity and Mechanism of inhibition of Silver Nanoparticles against Extreme Halophilic Archaea

    Directory of Open Access Journals (Sweden)

    Rebecca Thombre

    2016-09-01

    Full Text Available Haloarchaea are salt-loving halophilic microorganism’s that inhabit marine environments, sea water, salterns, and lakes. The resistance of haloarchaea to physical extremities that challenge organismic survival is ubiquitous. Metal and antibiotic resistance of haloarchaea has been on an upsurge due to the exposure of these organisms to metal sinks and drug resistance genes augmented in their natural habitats due to anthropogenic activities and environmental pollution. The efficacy of silver nanoparticles (SNPs as a potent and broad spectrum inhibitory agent is known however, there are no reports on the inhibitory activity of SNPs against haloarchaea. In the present study, we have investigated the antimicrobial potentials of SNPs synthesized using aqueous leaf extract of Cinnamomum tamala against antibiotic resistant haloarchaeal isolates Haloferax prahovense RR8, Haloferax lucentense RR15, Haloarcula argentinensis RR10 and Haloarcula tradensis RR13. The synthesized SNPs were characterized by UV-Vis spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, dynamic light scattering, X-ray diffraction and Fourier transform infrared spectroscopy. The SNPs demonstrated potent antimicrobial activity against the haloarchaea with a minimum inhibitory concentration of 300- 400µg/ml. Growth kinetics of haloarchaea in the presence of SNPs was studied by employing the Baranyi mathematical model for microbial growth using the DMFit curve fitting programme. The C. tamala SNPs also demonstrated cytotoxic activity against human lung adenocarcinoma epithelial cell line (A540 and human breast adenocarcinoma cell line (MCF-7. The mechanism of inhibition of haloarchaea by the SNPs was investigated. The plausible mechanism proposed is the alterations and disruption of haloarchaeal membrane permeability by turbulence, inhibition of respiratory dehydrogenases and lipid peroxidation causing cellular and DNA damage resulting in cell death.

  3. Halophilic microbial communities in deteriorated buildings.

    Science.gov (United States)

    Adamiak, Justyna; Otlewska, Anna; Gutarowska, Beata

    2015-10-01

    Halophilic microorganisms were traditionally isolated from an aquatic environment. There has been little research conducted into halophiles inhabiting the terrestrial environment in which historic monuments deteriorate. Salt efflorescence deposited on the walls is an observed phenomenon on the surface of historic buildings, and would favour the growth of halophiles. However, some conditions have to be fulfilled in order for efflorescence to occur: (1) the presence of salts, (2) porosity, (3) a source of water. Salt crystallization influences the material structure (cracking, detachment, material loss), but active growth of halophilic microorganisms may be a serious threat to historic materials as well, leading to aesthetical changes such as coloured biofilms, orange to pink or even violet stains. This is why it is important to investigate halophilic microorganisms, taking into consideration both the environmental conditions they need to grow in, material characteristics they inhabit, the mechanisms they possess to cope with osmotic stress, and the methods that should be applied for their identification.

  4. Halophilic Nuclease from a Moderately Halophilic Micrococcus varians

    Science.gov (United States)

    Kamekura, Masahiro; Onishi, Hiroshi

    1974-01-01

    The moderately halophilic bacterium Micrococcus varians, isolated from soy sauce mash, produced extracellular nuclease when cultivated aerobically in media containing 1 to 4 M NaCl or KCl. The enzyme, purified to an electrophoretically homogeneous state, had both ribonuclease and deoxyribonuclease activities. The nuclease had maximal activity in the presence of 2.9 M NaCl or 2.1 M KCl at 40 C. The enzymatic activity was lost by dialysis against low-salt buffer, whereas when the inactivated enzyme was dialyzed against 3.4 M NaCl buffer as much as 77% of the initial activity could be restored. Images PMID:4852218

  5. Engineering substrate promiscuity in halophilic alcohol dehydrogenase (HvADH2 by in silico design.

    Directory of Open Access Journals (Sweden)

    Jennifer Cassidy

    Full Text Available An alcohol dehydrogenase from the halophilic archaeon Haloferax volcanii (HvADH2 has been engineered by rational design to broaden its substrate scope towards the conversion of a range of aromatic substrates, including flurbiprofenol, that is an intermediate of the non-steroidal anti-inflammatory drug, flurbiprofen. Wild-type HvADH2 showed minimal activity with flurbiprofenol (11.1 mU/mg. A homology model of HvADH2 was built and docking experiments with this substrate revealed that the biphenyl rings of flurbiprofenol formed strong interactions with residues F85 and F108, preventing its optimal binding in the active site. Mutations at position 85 however did not increase activity. Site directed mutagenesis at position F108 allowed the identification of three variants showing a significant (up to 2.3-fold enhancement of activity towards flurbiprofenol, when compared to wild-type HvADH2. Interestingly, F108G variant did not show the classic inhibition in the presence of (R-enantiomer when tested with rac-1-phenylethanol, underling its potential in racemic resolution of secondary alcohols.

  6. Extreme halophilic alcohol dehydrogenase mediated highly efficient syntheses of enantiopure aromatic alcohols.

    Science.gov (United States)

    Alsafadi, Diya; Alsalman, Safaa; Paradisi, Francesca

    2017-11-07

    Enzymatic synthesis of enantiopure aromatic secondary alcohols (including substituted, hetero-aromatic and bicyclic structures) was carried out using halophilic alcohol dehydrogenase ADH2 from Haloferax volcanii (HvADH2). This enzyme showed an unprecedented substrate scope and absolute enatioselectivity. The cofactor NADPH was used catalytically and regenerated in situ by the biocatalyst, in the presence of 5% ethanol. The efficiency of HvADH2 for the conversion of aromatic ketones was markedly influenced by the steric and electronic factors as well as the solubility of ketones in the reaction medium. Furthermore, carbonyl stretching band frequencies ν (C[double bond, length as m-dash]O) have been measured for different ketones to understand the effect of electron withdrawing or donating properties of the ketone substituents on the reaction rate catalyzed by HvADH2. Good correlation was observed between ν (C[double bond, length as m-dash]O) of methyl aryl-ketones and the reaction rate catalyzed by HvADH2. The enzyme catalyzed the reductions of ketone substrates on the preparative scale, demonstrating that HvADH2 would be a valuable biocatalyst for the preparation of chiral aromatic alcohols of pharmaceutical interest.

  7. Deciphering the Translation Initiation Factor 5A Modification Pathway in Halophilic Archaea

    Directory of Open Access Journals (Sweden)

    Laurence Prunetti

    2016-01-01

    Full Text Available Translation initiation factor 5A (IF5A is essential and highly conserved in Eukarya (eIF5A and Archaea (aIF5A. The activity of IF5A requires hypusine, a posttranslational modification synthesized in Eukarya from the polyamine precursor spermidine. Intracellular polyamine analyses revealed that agmatine and cadaverine were the main polyamines produced in Haloferax volcanii in minimal medium, raising the question of how hypusine is synthesized in this halophilic Archaea. Metabolic reconstruction led to a tentative picture of polyamine metabolism and aIF5A modification in Hfx. volcanii that was experimentally tested. Analysis of aIF5A from Hfx. volcanii by LC-MS/MS revealed it was exclusively deoxyhypusinylated. Genetic studies confirmed the role of the predicted arginine decarboxylase gene (HVO_1958 in agmatine synthesis. The agmatinase-like gene (HVO_2299 was found to be essential, consistent with a role in aIF5A modification predicted by physical clustering evidence. Recombinant deoxyhypusine synthase (DHS from S. cerevisiae was shown to transfer 4-aminobutyl moiety from spermidine to aIF5A from Hfx. volcanii in vitro. However, at least under conditions tested, this transfer was not observed with the Hfx. volcanii DHS. Furthermore, the growth of Hfx. volcanii was not inhibited by the classical DHS inhibitor GC7. We propose a model of deoxyhypusine synthesis in Hfx. volcanii that differs from the canonical eukaryotic pathway, paving the way for further studies.

  8. Structural changes in halophilic and non-halophilic proteases in response to chaotropic reagents.

    Science.gov (United States)

    Sinha, Rajeshwari; Khare, S K

    2014-08-01

    Halophilic enzymes have been established for their stability and catalytic abilities under harsh operational conditions. These have been documented to withstand denaturation at high temperature, pH, organic solvents, and chaotropic agents. However, this stability is modulated by salt. The present study targets an important aspect in understanding protein-urea/GdmCl interactions using proteases from halophilic Bacillus sp. EMB9 and non-halophilic subtilisin (Carlsberg) from Bacillus licheniformis as model systems. While, halophilic protease containing 1 % (w/v) NaCl (0.17 M) retained full activity towards urea (8 M), non-halophilic protease lost about 90 % activity under similar conditions. The secondary and tertiary structure were lost in non-halophilic but preserved for halophilic protein. This effect could be due to the possible charge screening and shielding of the protein surface by Ca(2+) and Na(+) ions rendering it stable against denaturation. The dialyzed halophilic protease almost behaved like the non-halophilic counterpart. Incorporation of NaCl (up to 5 %, w/v or 0.85 M) in dialyzed EMB9 protease containing urea/GdmCl, not only helped regain of proteolytic activity but also evaded denaturing action. Deciphering the basis of this salt modulated stability amidst a denaturing milieu will provide guidelines and templates for engineering stable proteins/enzymes for biotechnological applications.

  9. Halophiles and their enzymes: Negativity put to good use

    Science.gov (United States)

    DasSarma, Shiladitya; DasSarma, Priya

    2015-01-01

    Halophilic microorganisms possess stable enzymes that function in very high salinity, an extreme condition that leads to denaturation, aggregation, and precipitation of most other proteins. Genomic and structural analyses have established that the enzymes of halophilic Archaea and many halophilic Bacteria are negatively charged due to an excess of acidic over basic residues, and altered hydrophobicity, which enhance solubility and promote function in low water activity conditions. Here, we provide an update on recent bioinformatic analysis of predicted halophilic proteomes as well as experimental molecular studies on individual halophilic enzymes. On-going efforts on discovery and utilization of halophiles and their enzymes for biotechnology, including biofuel applications are also considered. PMID:26066288

  10. Halophiles, coming stars for industrial biotechnology.

    Science.gov (United States)

    Yin, Jin; Chen, Jin-Chun; Wu, Qiong; Chen, Guo-Qiang

    2015-11-15

    Industrial biotechnology aims to produce chemicals, materials and biofuels to ease the challenges of shortage on petroleum. However, due to the disadvantages of bioprocesses including energy consuming sterilization, high fresh water consumption, discontinuous fermentation to avoid microbial contamination, highly expensive stainless steel fermentation facilities and competing substrates for human consumption, industrial biotechnology is less competitive compared with chemical processes. Recently, halophiles have shown promises to overcome these shortcomings. Due to their unique halophilic properties, some halophiles are able to grow in high pH and high NaCl containing medium under higher temperature, allowing fermentation processes to run contamination free under unsterile conditions and continuous way. At the same time, genetic manipulation methods have been developed for halophiles. So far, halophiles have been used to produce bioplastics polyhydroxyalkanoates (PHA), ectoines, enzymes, and bio-surfactants. Increasing effects have been made to develop halophiles into a low cost platform for bioprocessing with advantages of low energy, less fresh water consumption, low fixed capital investment, and continuous production. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Magnesium and manganese content of halophilic bacteria

    International Nuclear Information System (INIS)

    de Medicis, E.; Paquette, J.; Gauthier, J.J.; Shapcott, D.

    1986-01-01

    Magnesium and manganese contents were measured by atomic absorption spectrophotometry in bacteria of several halophilic levels, in Vibrio costicola, a moderately halophilic eubacterium growing in 1 M NaCl, Halobacterium volcanii, a halophilic archaebacterium growing in 2.5 NaCl, Halobacterium cutirubrum, an extremely halophilic archaebacterium growing in 4 M NaCl, and Escherichia coli, a nonhalophilic eubacterium growing in 0.17 M NaCl. Magnesium and manganese contents varied with the growth phase, being maximal at the early log phase. Magnesium and manganese molalities in cell water were shown to increase with the halophilic character of the logarithmically growing bacteria, from 30 mmol of Mg per kg of cell water and 0.37 mmol of Mn per kg of cell water for E. coli to 102 mmol of Mg per kg of cell water and 1.6 mmol of Mn per kg of cell water for H cutirubrum. The intracellular concentrations of manganese were determined independently by a radioactive tracer technique in V. costicola and H. volcanii. The values obtained by 54 Mn loading represented about 70% of the values obtained by atomic absorption. The increase of magnesium and manganese contents associated with the halophilic character of the bacteria suggests that manganese and magnesium play a role in haloadaptation

  12. A comparison of liquid-holding recovery and photoreactivation in halophilic and non-halophilic bacteria

    International Nuclear Information System (INIS)

    Fitt, P.S.; Sharma, N.; Castellanos, G.

    1983-01-01

    The ability of the extreme halophile Halobacterium cutirubrum to recover from the effects of ultraviolet radiation during liquid holding in the dark in non-nutrient medium has been compared with that of (i) a moderately halophilic bacterium (NRC 41227) and (ii) Escherichia coli B. The photoreactivabilities of all three bacteria have also been studied. The extreme halophile was incapable of liquid-holding recovery in these conditions, in marked contrast to both E. coli B and the moderate halophile, and also failed to recover when held in nutrient medium in the dark. These results strongly support the hypothesis that H. cutirubrum lacks DNA excision repair. It was also found that ultraviolet-irradiated H. cutirubrum could be almost completely photoreactivated from any level of survival in the range 10 - 4 -80%, provided exposure to visible light was not delayed, whereas the moderate halophile resembled E. coli B and had a comparatively limited capacity for photoreactivation. (Auth.)

  13. Salty sisters: The women of halophiles

    Directory of Open Access Journals (Sweden)

    Bonnie K. Baxter

    2014-06-01

    Full Text Available A history of halophile research reveals the commitment of scientists to uncovering the secrets of the limits of life, in particular life in high salt concentration and under extreme osmotic pressure. During the last 40 years, halophile scientists have indeed made important contributions to extremophile research, and prior international halophiles congresses have documented both the historical and the current work. During this period of salty discoveries, female scientists, in general, have grown in number worldwide. But those who worked in the field when there were small numbers of women sometimes saw their important contributions overshadowed by their male counterparts. Recent studies suggest that modern female scientists experience gender bias in matters such as conference invitations and even representation among full professors. In the field of halophilic microbiology, what is the impact of gender bias? How has the participation of women changed over time? What do women uniquely contribute to this field? What are factors that impact current female scientists to a greater degree? This essay emphasizes the herstory (not history of halophile discovery.

  14. Genetic analysis of RPA single-stranded DNA binding protein in Haloferax volcanii

    OpenAIRE

    Stroud, A. L.

    2012-01-01

    Replication protein A (RPA) is a single-stranded DNA-binding protein that is present in all three domains of life. The roles of RPA include stabilising and protecting single- stranded DNA from nuclease degradation during DNA replication and repair. To achieve this, RPA uses an oligosaccharide-binding fold (OB fold) to bind single- stranded DNA. Haloferax volcanii encodes three RPAs – RPA1, RPA2 and RPA3, of which rpa1 and rpa3 are in operons with genes encoding associated proteins (APs). ...

  15. Isolation, characterization and exploring biotechnological potential of halophilic archaea from salterns of western India.

    Science.gov (United States)

    Singh, Aparna; Singh, Anil Kumar

    2018-01-01

    Thirteen halophilic archaea were isolated from Kandla and Bhayander salt pans. These isolates were grouped into three different genera Halobacterium, Haloferax and Haloarcula based on morphological and biochemical characterization, polar lipid analysis, Amplified 16S rDNA restriction analysis (ARDRA) and 16S rDNA sequence analysis. Biochemical characterization suggested the ability of isolates to produce protease, amylase and poly-hydroxybutyrate (PHB) indicating their biotechnological potential. The isolates were further screened for the amount of extracellular protease produced. Halobacterium sp. SP1(1) showed significant protease production compared to other isolates. Protease producing ability of the isolate was influenced by several factors such as NaCl concentration, type of protein source, metal ions and surfactants, and presence of amino acid supplements in the production medium. Soybean flour, FeCl 3 and dicotylsulfosuccinate were found to increase protease production by 2.36, 1.54 and 1.26 folds, respectively compared to production in basal medium. Effect of organic solvents used in paints (n-decane, n-undecane and n-dodecane) was also investigated on protease production by the isolate. Protease production by Halobacterium sp. SP1(1) was enhanced by 1.2 folds in presence of n-decane compared to control. Furthermore, the ability of isolate to hydrolyse fish protein was investigated using three different edible fishes (Pomfret, Flat fish and Seer fish) as sole protein source. Pomfret was found to be a good protein source for protease production by the isolate. These results revealed that Halobacterium sp. SP1(1) may have potential for paint-based antifouling coating preparations and fish sauce preparation by virtue of its extracellular protease.

  16. Regulated polyploidy in halophilic archaea.

    Directory of Open Access Journals (Sweden)

    Sebastian Breuert

    Full Text Available Polyploidy is common in higher eukaryotes, especially in plants, but it is generally assumed that most prokaryotes contain a single copy of a circular chromosome and are therefore monoploid. We have used two independent methods to determine the genome copy number in halophilic archaea, 1 cell lysis in agarose blocks and Southern blot analysis, and 2 Real-Time quantitative PCR. Fast growing H. salinarum cells contain on average about 25 copies of the chromosome in exponential phase, and their ploidy is downregulated to 15 copies in early stationary phase. The chromosome copy number is identical in cultures with a twofold lower growth rate, in contrast to the results reported for several other prokaryotic species. Of three additional replicons of H. salinarum, two have a low copy number that is not growth-phase regulated, while one replicon even shows a higher degree of growth phase-dependent regulation than the main replicon. The genome copy number of H. volcanii is similarly high during exponential phase (on average 18 copies/cell, and it is also downregulated (to 10 copies as the cells enter stationary phase. The variation of genome copy numbers in the population was addressed by fluorescence microscopy and by FACS analysis. These methods allowed us to verify the growth phase-dependent regulation of ploidy in H. salinarum, and they revealed that there is a wide variation in genome copy numbers in individual cells that is much larger in exponential than in stationary phase. Our results indicate that polyploidy might be more widespread in archaea (or even prokaryotes in general than previously assumed. Moreover, the presence of so many genome copies in a prokaryote raises questions about the evolutionary significance of this strategy.

  17. [Experimental interaction of halophilic prokaryotes and opportunistic bacteria in brine].

    Science.gov (United States)

    Selivanova, E A; Nemtseva, N V

    2013-01-01

    Study the effect of extremely halophilic archaea and moderately halophilic bacteria on preservation of opportunistic bacteria in brine. 17 strains of moderately halophilic bacteria and 2 strains of extremely halophilic archaea were isolated from continental hypersaline lake Razval of Sol-Iletsk area of Orenburg Region. Identification of pure cultures of prokaryotes was carried out taking into account their phenotype properties and based on determination of 16S RNA gene sequence. The effect of halophilic prokaryote on elimination of Escherichia coli from brine was evaluated during co-cultivation. Antagonistic activity of cell extracts of the studied microorganisms was evaluated by photometric method. A more prolonged preservation of an E. coli strain in brine in the presence of live cells of extremely halophilic archaea Halorubrum tebenquichense and moderately halophilic bacteria Marinococcus halophilus was established. Extracts of cells of extremely halophilic archaea and moderately halophilic bacteria on the contrary displayed antagonistic activity. The protective effect of live cells of halophilic prokaryotes and antagonistic activity of their cell extracts change the period of conservation of opportunistic bacteria in brine that regulates inter-microbial interactions and changes the period of self-purification that reflects the sanitary condition of a hypersaline water body.

  18. Isolation and characterization of extreme halophilic archaea

    Energy Technology Data Exchange (ETDEWEB)

    Franze, Madlen; Cherkouk, Andrea [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). HZDR Young Investigator Group

    2017-06-01

    Extreme halophilic archaea from the family Halobactereacea represent a dominant part of the microbial community present in saline soils as well as rock salts. By using a culture-dependent approach different Haloarchaea could be isolated and were phylogenetic analysed. Interestingly, isolates closely related to different Halobacterium spp. were found in both environments.

  19. Isolation and characterization of extreme halophilic archaea

    International Nuclear Information System (INIS)

    Franze, Madlen; Cherkouk, Andrea

    2017-01-01

    Extreme halophilic archaea from the family Halobactereacea represent a dominant part of the microbial community present in saline soils as well as rock salts. By using a culture-dependent approach different Haloarchaea could be isolated and were phylogenetic analysed. Interestingly, isolates closely related to different Halobacterium spp. were found in both environments.

  20. Halophilic and haloalkaliphilic sulfur-oxidizing bacteria

    NARCIS (Netherlands)

    Sorokin, D.Y.; Banciu, H.; Robertson, L.A.; Kuenen, J.G.; Muntyan, M.S.; Muyzer, G.; Rosenberg, E.; DeLong, F.; Delong, E.; Lory, S.; Stackebrandt, E.; Thompson, F.

    2013-01-01

    Chemotrophic sulfur-oxidizing bacteria (SOB) represent an important functional group of microorganisms responsible for the dark oxidation of reduced sulfur compounds generated by sulfidogens. Until recently, only a single genus of halophilic SOB (Halothiobacillus) has been described, and nothing was

  1. Salt-bridge energetics in halophilic proteins.

    Science.gov (United States)

    Nayek, Arnab; Sen Gupta, Parth Sarthi; Banerjee, Shyamashree; Mondal, Buddhadev; Bandyopadhyay, Amal K

    2014-01-01

    Halophilic proteins have greater abundance of acidic over basic and very low bulky hydrophobic residues. Classical electrostatic stabilization was suggested as the key determinant for halophilic adaptation of protein. However, contribution of specific electrostatic interactions (i.e. salt-bridges) to overall stability of halophilic proteins is yet to be understood. To understand this, we use Adaptive-Poison-Boltzmann-Solver Methods along with our home-built automation to workout net as well as associated component energy terms such as desolvation energy, bridge energy and background energy for 275 salt-bridges from 20 extremely halophilic proteins. We then perform extensive statistical analysis on general and energetic attributes on these salt-bridges. On average, 8 salt-bridges per 150 residues protein were observed which is almost twice than earlier report. Overall contributions of salt-bridges are -3.0 kcal mol-1. Majority (78%) of salt-bridges in our dataset are stable and conserved in nature. Although, average contributions of component energy terms are equal, their individual details vary greatly from one another indicating their sensitivity to local micro-environment. Notably, 35% of salt-bridges in our database are buried and stable. Greater desolvation penalty of these buried salt-bridges are counteracted by stable network salt-bridges apart from favorable equal contributions of bridge and background terms. Recruitment of extensive network salt-bridges (46%) with a net contribution of -5.0 kcal mol-1 per salt-bridge, seems to be a halophilic design wherein favorable average contribution of background term (-10 kcal mol-1) exceeds than that of bridge term (-7 kcal mol-1). Interiors of proteins from halophiles are seen to possess relatively higher abundance of charge and polar side chains than that of mesophiles which seems to be satisfied by cooperative network salt-bridges. Overall, our theoretical analyses provide insight into halophilic signature in its

  2. Crystallization and preliminary X-ray analysis of d-2-hydroxyacid dehydrogenase from Haloferax mediterranei

    International Nuclear Information System (INIS)

    Domenech, J.; Baker, P. J.; Sedelnikova, S. E.; Rodgers, H. F.; Rice, D. W.; Ferrer, J.

    2009-01-01

    The d-2-hydroxyacid dehydrogenase from Haloferax mediterranei has been crystallized in two different forms. Diffraction data have been collected to 1.9 Å resolution for the non-productive ternary complex of the enzyme and to 2.7 Å for the selenomethionyl derivative. d-2-Hydroxyacid dehydrogenase (D2-HDH) from Haloferax mediterranei has been overexpressed in Escherichia coli, solubilized in 8 M urea and refolded by rapid dilution. The protein was purified and crystallized by the hanging-drop vapour-diffusion method using ammonium sulfate or PEG 3350 as precipitant. Two crystal forms representing the free enzyme and the nonproductive ternary complex with α-ketohexanoic acid and NAD + grew under these conditions. Crystals of form I diffracted to beyond 3.0 Å resolution and belonged to the monoclinic space group P2 1 , with unit-cell parameters a = 66.0, b = 119.6, c = 86.2 Å, β = 96.3°. Crystals of form II diffracted to beyond 2.0 Å resolution and belonged to the triclinic space group P1, with unit-cell parameters a = 66.5, b = 75.2, c = 77.6 Å, α = 109.1, β = 107.5, γ = 95.9°. The calculated values for V M and analysis of the self-rotation and self-Patterson functions suggest that the asymmetric unit in both crystal forms contains two dimers related by pseudo-translational symmetry

  3. Halophiles and their enzymes: negativity put to good use.

    Science.gov (United States)

    DasSarma, Shiladitya; DasSarma, Priya

    2015-06-01

    Halophilic microorganisms possess stable enzymes that function in very high salinity, an extreme condition that leads to denaturation, aggregation, and precipitation of most other proteins. Genomic and structural analyses have established that the enzymes of halophilic Archaea and many halophilic Bacteria are negatively charged due to an excess of acidic over basic residues, and altered hydrophobicity, which enhance solubility and promote function in low water activity conditions. Here, we provide an update on recent bioinformatic analysis of predicted halophilic proteomes as well as experimental molecular studies on individual halophilic enzymes. Recent efforts on discovery and utilization of halophiles and their enzymes for biotechnology, including biofuel applications are also considered. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Biotechnological applications of halophilic lipases and thioesterases.

    Science.gov (United States)

    Schreck, Steven D; Grunden, Amy M

    2014-02-01

    Lipases and esterases are enzymes which hydrolyze ester bonds between a fatty acid moiety and an esterified conjugate, such as a glycerol or phosphate. These enzymes have a wide spectrum of use in industrial applications where their high activity, broad substrate specificity, and stability under harsh conditions have made them integral in biofuel production, textile processing, waste treatment, and as detergent additives. To date, these industrial applications have mainly leveraged enzymes from mesophilic and thermophilic organisms. However, increasingly, attention has turned to halophilic enzymes as catalysts in environments where high salt stability is desired. This review provides a brief overview of lipases and esterases and examines specific structural motifs and evolutionary adaptations of halophilic lipases. Finally, we examine the state of research involving these enzymes and provide an in-depth look at an exciting algal-based biofuel production system. This system uses a recombinant halophilic lipase to increase oil production efficiency by cleaving algal fatty acids from the acyl carrier protein, which eliminates feedback inhibition of fatty acid synthesis.

  5. Screening and isolation of halophilic bacteria producing industrially important enzymes.

    Science.gov (United States)

    Kumar, Sumit; Karan, Ram; Kapoor, Sanjay; S P, Singh; S K, Khare

    2012-10-01

    Halophiles are excellent sources of enzymes that are not only salt stable but also can withstand and carry out reactions efficiently under extreme conditions. The aim of the study was to isolate and study the diversity among halophilic bacteria producing enzymes of industrial value. Screening of halophiles from various saline habitats of India led to isolation of 108 halophilic bacteria producing industrially important hydrolases (amylases, lipases and proteases). Characterization of 21 potential isolates by morphological, biochemical and 16S rRNA gene analysis found them related to Marinobacter, Virgibacillus, Halobacillus, Geomicrobium, Chromohalobacter, Oceanobacillus, Bacillus, Halomonas and Staphylococcus genera. They belonged to moderately halophilic group of bacteria exhibiting salt requirement in the range of 3-20%. There is significant diversity among halophiles from saline habitats of India. Preliminary characterization of crude hydrolases established them to be active and stable under more than one extreme condition of high salt, pH, temperature and presence of organic solvents. It is concluded that these halophilic isolates are not only diverse in phylogeny but also in their enzyme characteristics. Their enzymes may be potentially useful for catalysis under harsh operational conditions encountered in industrial processes. The solvent stability among halophilic enzymes seems a generic novel feature making them potentially useful in non-aqueous enzymology.

  6. Systematic and biotechnological aspects of halophilic and halotolerant actinomycetes.

    Science.gov (United States)

    Hamedi, Javad; Mohammadipanah, Fatemeh; Ventosa, Antonio

    2013-01-01

    More than 70 species of halotolerant and halophilic actinomycetes belonging to at least 24 genera have been validly described. Halophilic actinomycetes are a less explored source of actinomycetes for discovery of novel bioactive secondary metabolites. Degradation of aliphatic and aromatic organic compounds, detoxification of pollutants, production of new enzymes and other metabolites such as antibiotics, compatible solutes and polymers are other potential industrial applications of halophilic and halotolerant actinomycetes. Especially new bioactive secondary metabolites that are derived from only a small fraction of the investigated halophilic actinomycetes, mainly from marine habitats, have revealed the huge capacity of this physiological group in production of new bioactive chemical entities. Combined high metabolic capacities of actinomycetes and unique features related to extremophilic nature of the halophilic actinomycetes have conferred on them an influential role for future biotechnological applications.

  7. Stability of halophilic proteins: from dipeptide attributes to discrimination classifier.

    Science.gov (United States)

    Zhang, Guangya; Huihua, Ge; Yi, Lin

    2013-02-01

    To investigate the molecular features responsible for protein halophilicity is of great significance for understanding the structure basis of protein halo-stability and would help to develop a practical strategy for designing halophilic proteins. In this work, we have systematically analyzed the dipeptide composition of the halophilic and non-halophilic protein sequences. We observed the halophilic proteins contained more DA, RA, AD, RR, AP, DD, PD, EA, VG and DV at the expense of LK, IL, II, IA, KK, IS, KA, GK, RK and AI. We identified some macromolecular signatures of halo-adaptation, and thought the dipeptide composition might contain more information than amino acid composition. Based on the dipeptide composition, we have developed a machine learning method for classifying halophilic and non-halophilic proteins for the first time. The accuracy of our method for the training dataset was 100.0%, and for the 10-fold cross-validation was 93.1%. We also discussed the influence of some specific dipeptides on prediction accuracy. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Uranium association with halophilic and non-halophilic bacteria and archaea

    International Nuclear Information System (INIS)

    Francis, A.J.; Gillow, J.B.; Dodge, C.J.; Harris, R.; Beveridge, T.J.; Papenguth, H.W.

    2004-01-01

    We determined the association of uranium with bacteria isolated from the Waste Isolation Pilot Plant (WIPP), Carlsbad, New Mexico, and compared this with known strains of halophilic and non-halophilic bacteria and archaea. Examination of the cultures by transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS) showed uranium accumulation extracellularly and/or intracellularly to a varying degree. In Pseudomonas fluorescens and Bacillus subtilis uranium was associated with the cell surface and in the latter it was present as irregularly shaped grains. In Halobacterium halobium, the only archeon studied here, uranium was present as dense deposits and with Haloanaerobium praevalens as spikey deposits. Halomonas sp. isolated from the WIPP site accumulated uranium both extracellularly on the cell surface and intracellularly as electron-dense discrete granules. Extended X-ray absorption fine structure (EXAFS) analysis of uranium with the halophilic and non-halophilic bacteria and archaea showed that the uranium present in whole cells was bonded to an average of 2.4 ± 0.7 phosphoryl groups at a distance of 3.65 ± 0.03 Aa. Comparison of whole cells of Halomonas sp. with the cell wall fragments of lysed cells showed the presence of a uranium bidentate complex at 2.91 ± 0.03 Aa with the carboxylate group on the cell wall, and uranyl hydroxide with U-U interaction at 3.71 ± 0.03 Aa due to adsorption or precipitation reactions; no U-P interaction was observed. Addition of uranium to the cell lysate of Halomonas sp. resulted in the precipitation of uranium due to the inorganic phosphate produced by the cells. These results show that the phosphates released from bacteria bind a significant amount of uranium. However, the bacterially immobilized uranium was readily solubilized by bicarbonate with concurrent release of phosphate into solution. (orig.)

  9. Insights into the sequence parameters for halophilic adaptation.

    Science.gov (United States)

    Nath, Abhigyan

    2016-03-01

    The sequence parameters for halophilic adaptation are still not fully understood. To understand the molecular basis of protein hypersaline adaptation, a detailed analysis is carried out, and investigated the likely association of protein sequence attributes to halophilic adaptation. A two-stage strategy is implemented, where in the first stage a supervised machine learning classifier is build, giving an overall accuracy of 86 % on stratified tenfold cross validation and 90 % on blind testing set, which are better than the previously reported results. The second stage consists of statistical analysis of sequence features and possible extraction of halophilic molecular signatures. The results of this study showed that, halophilic proteins are characterized by lower average charge, lower K content, and lower S content. A statistically significant preference/avoidance list of sequence parameters is also reported giving insights into the molecular basis of halophilic adaptation. D, Q, E, H, P, T, V are significantly preferred while N, C, I, K, M, F, S are significantly avoided. Among amino acid physicochemical groups, small, polar, charged, acidic and hydrophilic groups are preferred over other groups. The halophilic proteins also showed a preference for higher average flexibility, higher average polarity and avoidance for higher average positive charge, average bulkiness and average hydrophobicity. Some interesting trends observed in dipeptide counts are also reported. Further a systematic statistical comparison is undertaken for gaining insights into the sequence feature distribution in different residue structural states. The current analysis may facilitate the understanding of the mechanism of halophilic adaptation clearer, which can be further used for rational design of halophilic proteins.

  10. Halophilic microorganisms in deteriorated historic buildings: insights into their characteristics.

    Science.gov (United States)

    Adamiak, Justyna; Otlewska, Anna; Gutarowska, Beata; Pietrzak, Anna

    2016-01-01

    Historic buildings are constantly being exposed to numerous climatic changes such as damp and rainwater. Water migration into and out of the material's pores can lead to salt precipitation and the so-called efflorescence. The structure of the material may be seriously threatened by salt crystallization. A huge pressure is produced when salt hydrates occupy larger spaces, which leads at the end to cracking, detachment and material loss. Halophilic microorganisms have the ability to adapt to high salinity because of the mechanisms of inorganic salt (KCl or NaCl) accumulation in their cells at concentrations isotonic to the environment, or compatible solutes uptake or synthesis. In this study, we focused our attention on the determination of optimal growth conditions of halophilic microorganisms isolated from historical buildings in terms of salinity, pH and temperature ranges, as well as biochemical properties and antagonistic abilities. Halophilic microorganisms studied in this paper could be categorized as a halotolerant group, as they grow in the absence of NaCl, as well as tolerate higher salt concentrations (Staphylococcus succinus, Virgibacillus halodenitrificans). Halophilic microorganisms have been also observed (Halobacillus styriensis, H. hunanensis, H. naozhouensis, H. litoralis, Marinococcus halophilus and yeast Sterigmatomyces halophilus). With respect to their physiological characteristics, cultivation at a temperature of 25-30°C, pH 6-7, NaCl concentration for halotolerant and halophilic microorganisms, 0-10% and 15-30%, respectively, provides the most convenient conditions. Halophiles described in this study displayed lipolytic, glycolytic and proteolytic activities. Staphylococcus succinus and Marinococcus halophilus showed strong antagonistic potential towards bacteria from the Bacillus genus, while Halobacillus litoralis displayed an inhibiting ability against other halophiles.

  11. Support vector machine with a Pearson VII function kernel for discriminating halophilic and non-halophilic proteins.

    Science.gov (United States)

    Zhang, Guangya; Ge, Huihua

    2013-10-01

    Understanding of proteins adaptive to hypersaline environment and identifying them is a challenging task and would help to design stable proteins. Here, we have systematically analyzed the normalized amino acid compositions of 2121 halophilic and 2400 non-halophilic proteins. The results showed that halophilic protein contained more Asp at the expense of Lys, Ile, Cys and Met, fewer small and hydrophobic residues, and showed a large excess of acidic over basic amino acids. Then, we introduce a support vector machine method to discriminate the halophilic and non-halophilic proteins, by using a novel Pearson VII universal function based kernel. In the three validation check methods, it achieved an overall accuracy of 97.7%, 91.7% and 86.9% and outperformed other machine learning algorithms. We also address the influence of protein size on prediction accuracy and found the worse performance for small size proteins might be some significant residues (Cys and Lys) were missing in the proteins. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. Bioprospecting Archaea: Focus on Extreme Halophiles

    KAUST Repository

    Antunes, André

    2016-12-12

    In 1990, Woese et al. divided the Tree of Life into three separate domains: Eukarya, Bacteria, and Archaea. Archaea were originally perceived as little more than “odd bacteria” restricted to extreme environmental niches, but later discoveries challenged this assumption. Members of this domain populate a variety of unexpected environments (e.g. soils, seawater, and human bodies), and we currently witness ongoing massive expansions of the archaeal branch of the Tree of Life. Archaea are now recognized as major players in the biosphere and constitute a significant fraction of the earth’s biomass, yet they remain underexplored. An ongoing surge in exploration efforts is leading to an increase in the (a) number of isolated strains, (b) associated knowledge, and (c) utilization of Archaea in biotechnology. They are increasingly employed in fields as diverse as biocatalysis, biocomputing, bioplastic production, bioremediation, bioengineering, food, pharmaceuticals, and nutraceuticals. This chapter provides a general overview on bioprospecting Archaea, with a particular focus on extreme halophiles. We explore aspects such as diversity, ecology, screening techniques and biotechnology. Current and future trends in mining for applications are discussed.

  13. Genetic and biochemical identification of a novel single-stranded DNA binding complex in Haloferax volcanii

    Directory of Open Access Journals (Sweden)

    Amy eStroud

    2012-06-01

    Full Text Available Single-stranded DNA binding proteins play an essential role in DNA replication and repair. They use oligosaccharide-binding folds, a five-stranded ß-sheet coiled into a closed barrel, to bind to single-stranded DNA thereby protecting and stabilizing the DNA. In eukaryotes the single-stranded DNA binding protein is known as replication protein A (RPA and consists of three distinct subunits that function as a heterotrimer. The bacterial homolog is termed single-stranded DNA-binding protein (SSB and functions as a homotetramer. In the archaeon Haloferax volcanii there are three genes encoding homologs of RPA. Two of the rpa genes (rpa1 and rpa3 exist in operons with a novel gene specific to Euryarchaeota, this gene encodes a protein that we have termed rpa-associated protein (RPAP. The rpap genes encode proteins belonging to COG3390 group and feature oligosaccharide-binding folds, suggesting that they might cooperate with RPA in binding to single-stranded DNA. Our genetic analysis showed that rpa1 and rpa3 deletion mutants have differing phenotypes; only ∆rpa3 strains are hypersensitive to DNA damaging agents. Deletion of the rpa3-associated gene rpap3 led to similar levels of DNA damage sensitivity, as did deletion of the rpa3 operon, suggesting that RPA3 and RPAP3 function in the same pathway. Protein pull-downs involving recombinant hexahistidine-tagged RPAs showed that RPA3 co-purifies with RPAP3, and RPA1 co-purifies with RPAP1. This indicates that the RPAs interact only with their respective associated proteins; this was corroborated by the inability to construct rpa1 rpap3 and rpa3 rpap1 double mutants. This is the first report investigating the individual function of the archaeal COG3390 RPA-associated proteins. We have shown genetically and biochemically that the RPAPs interact with their respective RPAs, and have uncovered a novel single-stranded DNA binding complex that is unique to Euryarchaeota.

  14. [Diversity and enzyme-producing activity of culturable halophilic bacteria in Daishan Saltern of East China].

    Science.gov (United States)

    Yang, Dan-Dan; Li, Qian; Huang, Jing-Jing; Chen, Min

    2012-11-01

    Soil and saline water samples were collected from the Daishan Saltern of East China, and the halophilic bacteria were isolated and cultured by using selective media, aimed to investigate the diversity and enzyme-producing activity of culturable halophilic bacteria in saltern environment. A total of 181 strains were isolated by culture-dependent method. Specific primers were used to amplify the 16S rRNA gene of bacteria and archaea. The operation taxonomy units (OTUs) were determined by ARDRA method, and the representative strain of each OTU was sequenced. The phylogenetic position of all the isolated strains was determined by 16S rRNA sequencing. The results showed that the isolated 181 strains displayed 21 operational taxonomic units (OTUs), of which, 12 OTUs belonged to halophilic bacteria, and the others belonged to halophilic archaea. Phylogenetic analysis indicated that there were 7 genera presented among the halophilic bacteria group, and 4 genera presented among the halophilic archaea group. The dominant halophilic strains were of Halomonas and Haloarcula, with 46.8% in halophilic bacteria and 49.1% in halophilic archaea group, respectively. Enzyme-producing analysis indicated that most strains displayed enzyme-producing activity, including the activities of producing amylase, proteinase and lipase, and the dominant strains capable of enzyme-producing were of Haloarcula. Our results showed that in the environment of Daishan Saltern, there existed a higher diversity of halophilic bacteria, being a source sink for screening enzyme-producing bacterial strains.

  15. Biomineralization of carbonate and phosphate by moderately halophilic bacteria

    NARCIS (Netherlands)

    Sánchez-Román, Mónica; Rivadeneyra, Maria A.; Vasconcelos, Crisogono; McKenzie, Judith A.

    We investigated the precipitation of carbonate and phosphate minerals by 19 species of moderately halophilic bacteria using media with variable Mg 2+/Ca2+ ratios. The precipitated minerals were calcite, magnesium (Mg) calcite, and struvite (MgNH4PO4· 6H2O) in variable proportions depending on the

  16. Culturable diversity of halophilic bacteria in foreshore soils.

    Science.gov (United States)

    Irshad, Aarzoo; Ahmad, Irshad; Kim, Seung Bum

    2014-01-01

    Halophilic bacteria are commonly found in natural environments containing significant concentration of NaCl such as inland salt lakes and evaporated sea-shore pools, as well as environments such as curing brines, salted food products and saline soils. Dependence on salt is an important phenotypic characteristic of halophilic bacteria, which can be used in the polyphasic characterization of newly discovered microorganisms. In this study the diversity of halophilic bacteria in foreshore soils of Daecheon, Chungnam, and Saemangeum, Jeonbuk, was investigated. Two types of media, namely NA and R2A supplemented with 3%, 5%, 9%, 15%, 20% and 30% NaCl were used. More than 200 halophilic bacteria were isolated and BOX-PCR fingerprinting analysis was done for the typing of the isolates. The BLAST identification results showed that isolated strains were composed of 4 phyla, Firmicutes (60%), Proteobacteria (31%), Bacteriodetes (5%) and Actinobacteria (4%). Isolates were affiliated with 16 genera and 36 species. Bacillus was the dominant genus in the phylum Firmicutes, comprising 24% of the total isolates. Halomonas (12%) and Shewanella (12%) were also found as the main genera. These findings show that the foreshore soil of Daecheon Beach and Saemangeum Sea of Korea represents an untapped source of bacterial biodiversity.

  17. Culturable diversity of halophilic bacteria in foreshore soils

    Directory of Open Access Journals (Sweden)

    Aarzoo Irshad

    2014-06-01

    Full Text Available Halophilic bacteria are commonly found in natural environments containing significant concentration of NaCl such as inland salt lakes and evaporated sea-shore pools, as well as environments such as curing brines, salted food products and saline soils. Dependence on salt is an important phenotypic characteristic of halophilic bacteria, which can be used in the polyphasic characterization of newly discovered microorganisms. In this study the diversity of halophilic bacteria in foreshore soils of Daecheon, Chungnam, and Saemangeum, Jeonbuk, was investigated. Two types of media, namely NA and R2A supplemented with 3%, 5%, 9%, 15%, 20% and 30% NaCl were used. More than 200 halophilic bacteria were isolated and BOX-PCR fingerprinting analysis was done for the typing of the isolates. The BLAST identification results showed that isolated strains were composed of 4 phyla, Firmicutes (60%, Proteobacteria (31%, Bacteriodetes (5% and Actinobacteria (4%. Isolates were affiliated with 16 genera and 36 species. Bacillus was the dominant genus in the phylum Firmicutes, comprising 24% of the total isolates. Halomonas (12% and Shewanella (12% were also found as the main genera. These findings show that the foreshore soil of Daecheon Beach and Saemangeum Sea of Korea represents an untapped source of bacterial biodiversity.

  18. Halophilic Bacteria as a Source of Novel Hydrolytic Enzymes

    Science.gov (United States)

    de Lourdes Moreno, María; Pérez, Dolores; García, María Teresa; Mellado, Encarnación

    2013-01-01

    Hydrolases constitute a class of enzymes widely distributed in nature from bacteria to higher eukaryotes. The halotolerance of many enzymes derived from halophilic bacteria can be exploited wherever enzymatic transformations are required to function under physical and chemical conditions, such as in the presence of organic solvents and extremes in temperature and salt content. In recent years, different screening programs have been performed in saline habitats in order to isolate and characterize novel enzymatic activities with different properties to those of conventional enzymes. Several halophilic hydrolases have been described, including amylases, lipases and proteases, and then used for biotechnological applications. Moreover, the discovery of biopolymer-degrading enzymes offers a new solution for the treatment of oilfield waste, where high temperature and salinity are typically found, while providing valuable information about heterotrophic processes in saline environments. In this work, we describe the results obtained in different screening programs specially focused on the diversity of halophiles showing hydrolytic activities in saline and hypersaline habitats, including the description of enzymes with special biochemical properties. The intracellular lipolytic enzyme LipBL, produced by the moderately halophilic bacterium Marinobacter lipolyticus, showed advantages over other lipases, being an enzyme active over a wide range of pH values and temperatures. The immobilized LipBL derivatives obtained and tested in regio- and enantioselective reactions, showed an excellent behavior in the production of free polyunsaturated fatty acids (PUFAs). On the other hand, the extremely halophilic bacterium, Salicola marasensis sp. IC10 showing lipase and protease activities, was studied for its ability to produce promising enzymes in terms of its resistance to temperature and salinity. PMID:25371331

  19. Halophilic Bacteria as a Source of Novel Hydrolytic Enzymes

    Directory of Open Access Journals (Sweden)

    Encarnación Mellado

    2013-01-01

    Full Text Available Hydrolases constitute a class of enzymes widely distributed in nature from bacteria to higher eukaryotes. The halotolerance of many enzymes derived from halophilic bacteria can be exploited wherever enzymatic transformations are required to function under physical and chemical conditions, such as in the presence of organic solvents and extremes in temperature and salt content. In recent years, different screening programs have been performed in saline habitats in order to isolate and characterize novel enzymatic activities with different properties to those of conventional enzymes. Several halophilic hydrolases have been described, including amylases, lipases and proteases, and then used for biotechnological applications. Moreover, the discovery of biopolymer-degrading enzymes offers a new solution for the treatment of oilfield waste, where high temperature and salinity are typically found, while providing valuable information about heterotrophic processes in saline environments. In this work, we describe the results obtained in different screening programs specially focused on the diversity of halophiles showing hydrolytic activities in saline and hypersaline habitats, including the description of enzymes with special biochemical properties. The intracellular lipolytic enzyme LipBL, produced by the moderately halophilic bacterium Marinobacter lipolyticus, showed advantages over other lipases, being an enzyme active over a wide range of pH values and temperatures. The immobilized LipBL derivatives obtained and tested in regio- and enantioselective reactions, showed an excellent behavior in the production of free polyunsaturated fatty acids (PUFAs. On the other hand, the extremely halophilic bacterium, Salicola marasensis sp. IC10 showing lipase and protease activities, was studied for its ability to produce promising enzymes in terms of its resistance to temperature and salinity.

  20. Generation of PHB from Spent Sulfite Liquor Using Halophilic Microorganisms.

    Science.gov (United States)

    Weissgram, Michaela; Gstöttner, Janina; Lorantfy, Bettina; Tenhaken, Raimund; Herwig, Christoph; Weber, Hedda K

    2015-06-08

    Halophilic microorganisms thrive at elevated concentrations of sodium chloride up to saturation and are capable of growing on a wide variety of carbon sources like various organic acids, hexose and also pentose sugars. Hence, the biotechnological application of these microorganisms can cover many aspects, such as the treatment of hypersaline waste streams of different origin. Due to the fact that the high osmotic pressure of hypersaline environments reduces the risk of contamination, the capacity for cost-effective non-sterile cultivation can make extreme halophilic microorganisms potentially valuable organisms for biotechnological applications. In this contribution, the stepwise use of screening approaches, employing design of experiment (DoE) on model media and subsequently using industrial waste as substrate have been implemented to investigate the applicability of halophiles to generate PHB from the industrial waste stream spent sulfite liquor (SSL). The production of PHB on model media as well as dilutions of industrial substrate in a complex medium has been screened for by fluorescence microscopy using Nile Blue staining. Screening was used to investigate the ability of halophilic microorganisms to withstand the inhibiting substances of the waste stream without negatively affecting PHB production. It could be shown that neither single inhibiting substances nor a mixture thereof inhibited growth in the investigated range, hence, leaving the question on the inhibiting mechanisms open. However, it could be demonstrated that some haloarchaea and halophilic bacteria are able to produce PHB when cultivated on 3.3% w/w dry matter spent sulfite liquor, whereas H. halophila was even able to thrive on 6.6% w/w dry matter spent sulfite liquor and still produce PHB.

  1. Identification of Residues Important for the Activity of Haloferax volcanii AglD, a Component of the Archaeal N-Glycosylation Pathway

    OpenAIRE

    Kaminski, Lina; Eichler, Jerry

    2010-01-01

    In Haloferax volcanii, AglD adds the final hexose to the N-linked pentasaccharide decorating the S-layer glycoprotein. Not knowing the natural substrate of the glycosyltransferase, together with the challenge of designing assays compatible with hypersalinity, has frustrated efforts at biochemical characterization of AglD activity. To circumvent these obstacles, an in vivo assay designed to identify amino acid residues important for AglD activity is described. In the assay, restoration of AglD...

  2. Improvement of halophilic cellulase production from locally isolated fungal strain.

    Science.gov (United States)

    Gunny, Ahmad Anas Nagoor; Arbain, Dachyar; Jamal, Parveen; Gumba, Rizo Edwin

    2015-07-01

    Halophilic cellulases from the newly isolated fungus, Aspergillus terreus UniMAP AA-6 were found to be useful for in situ saccharification of ionic liquids treated lignocelluloses. Efforts have been taken to improve the enzyme production through statistical optimization approach namely Plackett-Burman design and the Face Centered Central Composite Design (FCCCD). Plackett-Burman experimental design was used to screen the medium components and process conditions. It was found that carboxymethylcellulose (CMC), FeSO4·7H2O, NaCl, MgSO4·7H2O, peptone, agitation speed and inoculum size significantly influence the production of halophilic cellulase. On the other hand, KH2PO4, KOH, yeast extract and temperature had a negative effect on enzyme production. Further optimization through FCCCD revealed that the optimization approach improved halophilic cellulase production from 0.029 U/ml to 0.0625 U/ml, which was approximately 2.2-times greater than before optimization.

  3. Transposon-mediated random gene disruption with moderate halophilic bacteria and its application for halophilic bacterial siderophore analysis.

    Science.gov (United States)

    Matsui, Toru; Nishino, Tomohiko

    2016-12-01

    Analytical conditions using chromo azurol S was validated for quantification of siderophore in aqueous samples, followed by the characterization of siderophore derived from newly isolated moderately halophilic bacteria. Conditions with good linearity between the absorbance and the siderophore concentration were obtained at a siderophore concentration less than 20 µM, in the wavelength range between 630 and 660 nm with developing time for at least 2 h. Of the halophilic bacteria isolated from Tunisian soil, Halomonas sp., namely strain 21a was selected as siderophore producing halophiles. The strain produced siderophore significantly in the absence of iron in minimal medium. Siderophore-deficient mutant, namely IIa10, of the strain 21a was obtained from gene disruptant library constructed using transposon complex by electroporation. Genomic sequence analysis of the mutant IIa10 revealed that the transposon-inserted gene was TonB-dependent receptor. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. THE HALOPHILICITY OF FILAMENTOUS FUNGI ISOLATED FROM SALINE SOILS OF SOUTH CAUCASUS

    Directory of Open Access Journals (Sweden)

    Kvesitadze E.

    2015-08-01

    Full Text Available The work is devoted to the isolation, purification, determination of taxonomical characteristics and application in soil improvement and other biotechnological processes halophilic microscopic fungi strains isolated from saline soils of Eastern Georgia (middle part of South Caucasus, where their existence is maximally supposed. In all soilclimatic zones the dominate forms of spread fungi are genera Aspergillus, Penicillium and Fusarium, followed by Trichoderma and Mucor. Other genera are met less intensively. The genera Aspergillus is widely spread in chestnut soils and in chernozem, in green forest soils the genera Penicillium is prevailing. The salinity of soil, lake or any other objects from which the isolation of microscopic fungi is performed greatly determines halophilisity of isolated strains. Finally, the collection of halophilic microscopic fungi has been created accounting 96 isolates of extreme halophiles, halophiles and week halophiles.

  5. Diversity of halophilic archaea in fermented foods and human intestines and their application.

    Science.gov (United States)

    Lee, Han-Seung

    2013-12-01

    Archaea are prokaryotic organisms distinct from bacteria in the structural and molecular biological sense, and these microorganisms are known to thrive mostly at extreme environments. In particular, most studies on halophilic archaea have been focused on environmental and ecological researches. However, new species of halophilic archaea are being isolated and identified from high salt-fermented foods consumed by humans, and it has been found that various types of halophilic archaea exist in food products by culture-independent molecular biological methods. In addition, even if the numbers are not quite high, DNAs of various halophilic archaea are being detected in human intestines and much interest is given to their possible roles. This review aims to summarize the types and characteristics of halophilic archaea reported to be present in foods and human intestines and to discuss their application as well.

  6. Useful halophilic, thermostable and ionic liquids tolerant cellulases

    Science.gov (United States)

    Zhang, Tao; Datta, Supratim; Simmons, Blake A.; Rubin, Edward M.

    2016-06-28

    The present invention provides for an isolated or recombinant polypeptide comprising an amino acid sequence having at least 70% identity with the amino acid sequence of a Halorhabdus utahensis cellulase, such as Hu-CBH1, wherein said amino acid sequence has a halophilic thermostable and/or thermophilic cellobiohydrolase (CBH) activity. In some embodiments, the polypeptide has a CBH activity that is resistant to up to about 20% of ionic liquids. The present invention also provides for compositions comprising and methods using the isolated or recombinant polypeptide.

  7. An experimental point of view on hydration/solvation in halophilic proteins.

    Science.gov (United States)

    Talon, Romain; Coquelle, Nicolas; Madern, Dominique; Girard, Eric

    2014-01-01

    Protein-solvent interactions govern the behaviors of proteins isolated from extreme halophiles. In this work, we compared the solvent envelopes of two orthologous tetrameric malate dehydrogenases (MalDHs) from halophilic and non-halophilic bacteria. The crystal structure of the MalDH from the non-halophilic bacterium Chloroflexus aurantiacus (Ca MalDH) solved, de novo, at 1.7 Å resolution exhibits numerous water molecules in its solvation shell. We observed that a large number of these water molecules are arranged in pentagonal polygons in the first hydration shell of Ca MalDH. Some of them are clustered in large networks, which cover non-polar amino acid surface. The crystal structure of MalDH from the extreme halophilic bacterium Salinibacter ruber (Sr) solved at 1.55 Å resolution shows that its surface is strongly enriched in acidic amino acids. The structural comparison of these two models is the first direct observation of the relative impact of acidic surface enrichment on the water structure organization between a halophilic protein and its non-adapted counterpart. The data show that surface acidic amino acids disrupt pentagonal water networks in the hydration shell. These crystallographic observations are discussed with respect to halophilic protein behaviors in solution.

  8. Transfer of Natrialba asiatica B1T to Natrialba taiwanensis sp. nov. and description of Natrialba aegyptiaca sp. nov., a novel extremely halophilic, aerobic, non-pigmented member of the Archaea from Egypt that produces extracellular poly(glutamic acid).

    Science.gov (United States)

    Hezayen, F F; Rehm, B H; Tindall, B J; Steinbüchel, A

    2001-05-01

    A novel extremely halophilic member of the Archaea, strain 40T, was isolated from Egypt (Aswan). This isolate requires at least 1.6 M sodium chloride for growth and exhibits optimal growth between 37 and 42 degrees C. Determination of the entire 16S rRNA gene sequence revealed the highest similarity to the type strain of Natrialba asiatica (> 99%). Polar lipid analysis indicated that strain 40T and Natrialba asiatica have essentially identical compositions, indicating that the former is a member of genus Natrialba. However, physiological and biochemical data provided evidence that Natrialba asiatica strains B1T and 172P1T, as well as strain 40T, are sufficiently different to be divided in three different species. The G+C content of strain 40T was 61.5+/-0.6 mol%. In addition, DNA-DNA hybridization data supported the placement of the isolate in a new species in the genus Natrialba, Natrialba aegyptiaca sp. nov., and indicated that Natrialba asiatica strain B1T should also be placed in a separate species, Natrialba taiwanensis sp. nov. Morphological studies of strain 40T indicated clearly that this isolate appears in three completely different cell shapes (cocci, rods, tetrads) under different conditions of growth, including different sodium chloride concentrations and different growth temperatures. Another interesting property of strain 40T is the ability to produce an extracellular polymer, which was found to be composed predominantly of glutamic acid (85% w/w), representing poly(glutamic acid), carbohydrates (12.5% w/w) and unidentified compounds (2.5% w/w). Among the Archaea, production of an extracellular polysaccharide has been described for some members of the genera Haloferax and Haloarcula.

  9. Comparative analysis of uranium bioassociation with halophilic bacteria and archaea

    Science.gov (United States)

    Bader, Miriam; Müller, Katharina; Foerstendorf, Harald; Schmidt, Matthias; Simmons, Karen; Swanson, Juliet S.; Reed, Donald T.; Stumpf, Thorsten

    2018-01-01

    Rock salt represents a potential host rock formation for the final disposal of radioactive waste. The interactions between indigenous microorganisms and radionuclides, e.g. uranium, need to be investigated to better predict the influence of microorganisms on the safety assessment of the repository. Hence, the association process of uranium with two microorganisms isolated from rock salt was comparatively studied. Brachybacterium sp. G1, which was isolated from the German salt dome Gorleben, and Halobacterium noricense DSM15987T, were selected as examples of a moderately halophilic bacterium and an extremely halophilic archaeon, respectively. The microorganisms exhibited completely different association behaviors with uranium. While a pure biosorption process took place with Brachybacterium sp. G1 cells, a multistage association process occurred with the archaeon. In addition to batch experiments, in situ attenuated total reflection Fourier-transform infrared spectroscopy was applied to characterize the U(VI) interaction process. Biosorption was identified as the dominating process for Brachybacterium sp. G1 with this method. Carboxylic functionalities are the dominant interacting groups for the bacterium, whereas phosphoryl groups are also involved in U(VI) association by the archaeon H. noricense. PMID:29329319

  10. Insights into Head-Tailed Viruses Infecting Extremely Halophilic Archaea

    Science.gov (United States)

    Pietilä, Maija K.; Laurinmäki, Pasi; Russell, Daniel A.; Ko, Ching-Chung; Jacobs-Sera, Deborah; Butcher, Sarah J.

    2013-01-01

    Extremophilic archaea, both hyperthermophiles and halophiles, dominate in habitats where rather harsh conditions are encountered. Like all other organisms, archaeal cells are susceptible to viral infections, and to date, about 100 archaeal viruses have been described. Among them, there are extraordinary virion morphologies as well as the common head-tailed viruses. Although approximately half of the isolated archaeal viruses belong to the latter group, no three-dimensional virion structures of these head-tailed viruses are available. Thus, rigorous comparisons with bacteriophages are not yet warranted. In the present study, we determined the genome sequences of two of such viruses of halophiles and solved their capsid structures by cryo-electron microscopy and three-dimensional image reconstruction. We show that these viruses are inactivated, yet remain intact, at low salinity and that their infectivity is regained when high salinity is restored. This enabled us to determine their three-dimensional capsid structures at low salinity to a ∼10-Å resolution. The genetic and structural data showed that both viruses belong to the same T-number class, but one of them has enlarged its capsid to accommodate a larger genome than typically associated with a T=7 capsid by inserting an additional protein into the capsid lattice. PMID:23283946

  11. On the Response of Halophilic Archaea to Space Conditions

    Science.gov (United States)

    Leuko, Stefan; Rettberg, Petra; Pontifex, Ashleigh L.; Burns, Brendan P.

    2014-01-01

    Microorganisms are ubiquitous and can be found in almost every habitat and ecological niche on Earth. They thrive and survive in a broad spectrum of environments and adapt to rapidly changing external conditions. It is of great interest to investigate how microbes adapt to different extreme environments and with modern human space travel, we added a new extreme environment: outer space. Within the last 50 years, technology has provided tools for transporting microbial life beyond Earth’s protective shield in order to study in situ responses to selected conditions of space. This review will focus on halophilic archaea, as, due to their ability to survive in extremes, they are often considered a model group of organisms to study responses to the harsh conditions associated with space. We discuss ground-based simulations, as well as space experiments, utilizing archaea, examining responses and/or resistance to the effects of microgravity and UV in particular. Several halophilic archaea (e.g., Halorubrum chaoviator) have been exposed to simulated and actual space conditions and their survival has been determined as well as the protective effects of halite shown. Finally, the intriguing potential of archaea to survive on other planets or embedded in a meteorite is postulated. PMID:25370029

  12. Characterization of Halophilic Bacterial Communities in Turda Salt Mine (Romania)

    Science.gov (United States)

    Carpa, Rahela; Keul, Anca; Muntean, Vasile; Dobrotă, Cristina

    2014-09-01

    Halophilic organisms are having adaptations to extreme salinity, the majority of them being Archaean, which have the ability to grow at extremely high salt concentrations, (from 3 % to 35 %). Level of salinity causes natural fluctuations in the halophilic populations that inhabit this particular habitat, raising problems in maintaining homeostasis of the osmotic pressure. Samples such as salt and water taken from Turda Salt Mine were analyzed in order to identify the eco-physiological bacterial groups. Considering the number of bacteria of each eco-physiological group, the bacterial indicators of salt quality (BISQ) were calculated and studied for each sample. The phosphatase, catalase and dehydrogenases enzymatic activities were quantitatively determined and the enzymatic indicators of salt quality (EISQ) were calculated. Bacterial isolates were analyzed using 16S rRNA gene sequence analysis. Universal bacterial primers, targeting the consensus region of the bacterial 16S rRNA gene were used. Analysis of a large fragment, of 1499 bp was performed to improve discrimination at the species level.

  13. Metabolic flux analysis of the halophilic archaeon Haladaptatus paucihalophilus.

    Science.gov (United States)

    Liu, Guangxiu; Zhang, Manxiao; Mo, Tianlu; He, Lian; Zhang, Wei; Yu, Yi; Zhang, Qi; Ding, Wei

    2015-11-27

    This work reports the (13)C-assisted metabolic flux analysis of Haladaptatus paucihalophilus, a halophilic archaeon possessing an intriguing osmoadaption mechanism. We showed that the carbon flow is through the oxidative tricarboxylic acid (TCA) cycle whereas the reductive TCA cycle is not operative in H. paucihalophilus. In addition, both threonine and the citramalate pathways contribute to isoleucine biosynthesis, whereas lysine is synthesized through the diaminopimelate pathway and not through the α-aminoadipate pathway. Unexpected, the labeling patterns of glycine from the cells grown on [1-(13)C]pyruvate and [2-(13)C]pyruvate suggest that, unlike all the organisms investigated so far, in which glycine is produced exclusively from the serine hydroxymethyltransferase (SHMT) pathway, glycine biosynthesis in H. paucihalophilus involves different pathways including SHMT, threonine aldolase (TA) and the reverse reaction of glycine cleavage system (GCS), demonstrating for the first time that other pathways instead of SHMT can also make a significant contribution to the cellular glycine pool. Transcriptional analysis confirmed that both TA and GCS genes were transcribed in H. paucihalophilus, and the transcriptional level is independent of salt concentrations in the culture media. This study expands our understanding of amino acid biosynthesis and provides valuable insights into the metabolism of halophilic archaea. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. On the Response of Halophilic Archaea to Space Conditions

    Directory of Open Access Journals (Sweden)

    Stefan Leuko

    2014-02-01

    Full Text Available Microorganisms are ubiquitous and can be found in almost every habitat and ecological niche on Earth. They thrive and survive in a broad spectrum of environments and adapt to rapidly changing external conditions. It is of great interest to investigate how microbes adapt to different extreme environments and with modern human space travel, we added a new extreme environment: outer space. Within the last 50 years, technology has provided tools for transporting microbial life beyond Earth’s protective shield in order to study in situ responses to selected conditions of space. This review will focus on halophilic archaea, as, due to their ability to survive in extremes, they are often considered a model group of organisms to study responses to the harsh conditions associated with space. We discuss ground-based simulations, as well as space experiments, utilizing archaea, examining responses and/or resistance to the effects of microgravity and UV in particular. Several halophilic archaea (e.g., Halorubrum chaoviator have been exposed to simulated and actual space conditions and their survival has been determined as well as the protective effects of halite shown. Finally, the intriguing potential of archaea to survive on other planets or embedded in a meteorite is postulated.

  15. Taxonomic study of extreme halophilic archaea isolated from the "Salar de Atacama", Chile.

    Science.gov (United States)

    Lizama, C; Monteoliva-Sánchez, M; Prado, B; Ramos-Cormenzana, A; Weckesser, J; Campos, V

    2001-11-01

    A large number of halophilic bacteria were isolated in 1984-1992 from the Atacama Saltern (North of Chile). For this study 82 strains of extreme halophilic archaea were selected. The characterization was performed by using the phenotypic characters including morphological, physiological, biochemical, nutritional and antimicrobial susceptibility test. The results, together with those from reference strains, were subjected to numerical analysis, using the Simple Matching (S(SM)) coefficient and clustered by the unweighted pair group method of association (UPGMA). Fifteen phena were obtained at an 70% similarity level. The results obtained reveal a high diversity among the halophilic archaea isolated. Representative strains from the phena were chosen to determine their DNA base composition and the percentage of DNA-DNA similarity compared to reference strains. The 16S rRNA studies showed that some of these strains constitutes a new taxa of extreme halophilic archaea.

  16. Ribulose 1,5-bisphosphate dependent CO2 fixation in the halophilic archaebacterium, Halobacterium mediterranei

    International Nuclear Information System (INIS)

    Rawal, N.; Kelkar, S.M.; Altekar, W.

    1988-01-01

    The cell extract of Halobacterium mediterranei catalyses incorporation of 14 CO 2 into 3-phosphoglycerate in the presence of ribulose bisphosphate suggesting the existence of ribulose bisphosphate carboxylase activity in this halophilic archaebacterium

  17. Halophilic polysulfabetaines-synthesis and study of gelation and thermoresponsive behavior

    NARCIS (Netherlands)

    Vasantha, Vivek Arjunan; Jana, Satyasankar; Parthiban, Anbanandam; Vancso, Julius G.

    2014-01-01

    Polysulfabetaines (PSBs) derived from zwitterionic sulfates (contrary to commonly used polysulfobetaines which are derived from zwitterionic sulfonates) were synthesized for the first time. PSBs dissolved in brine (halophilic), swelled in deionized water and also exhibited reversible and

  18. Halophilic-Psychrophilic Bacteria from Tirich Mir Glacier, Pakistan, as Potential Candidate for Astrobiological Studies

    Science.gov (United States)

    Rafiq, M. R.; Anesio, A. M. A.; Hayat, M. H.; Zada, S. Z.; Sajjad, W. S.; Shah, A. A. S.; Hasan, F. H.

    2016-09-01

    Hindu Kush, Karakoram, and Himalaya region is referred to as 'third pole' and could be suitable as a terrestrial analog of Mars and increased possibility of finding polyextremophiles. Study is focused on halophilic psychrophiles.

  19. Arcobacter halophilus sp nov., the first obligate halophile in the genus Arcobacter

    DEFF Research Database (Denmark)

    Donachie, S.P.; Bowman, J.P.; On, Stephen L.W.

    2005-01-01

    . Most notably, LA31B(T) was found to be an obligate halophile, a hitherto undescribed feature among recognized Arcobacter species. These data indicate that LA31B(T) should be considered to represent a novel species in the genus Arcobacter, for which the name Arcobacter halophilus sp. nov. is proposed....... This is the first obligately halophilic member of the genus. The type strain is LA31B(T) (= ATCC BAA- 102 2 T=CIP 108450(T))....

  20. Complete genome of Martelella sp. AD-3, a moderately halophilic polycyclic aromatic hydrocarbons-degrading bacterium.

    Science.gov (United States)

    Cui, Changzheng; Li, Zhijie; Qian, Jiangchao; Shi, Jie; Huang, Ling; Tang, Hongzhi; Chen, Xin; Lin, Kuangfei; Xu, Ping; Liu, Yongdi

    2016-05-10

    Martelella sp. strain AD-3, a moderate halophilic bacterium, was isolated from a petroleum-contaminated soil with high salinity in China. Here, we report the complete genome of strain AD-3, which contains one circular chromosome and two circular plasmids. An array of genes related to metabolism of polycyclic aromatic hydrocarbons and halophilic mechanism in this bacterium was identified by the whole genome analysis. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Osmoadaptative Strategy and Its Molecular Signature in Obligately Halophilic Heterotrophic Protists.

    Science.gov (United States)

    Harding, Tommy; Brown, Matthew W; Simpson, Alastair G B; Roger, Andrew J

    2016-08-03

    Halophilic microbes living in hypersaline environments must counteract the detrimental effects of low water activity and salt interference. Some halophilic prokaryotes equilibrate their intracellular osmotic strength with the extracellular milieu by importing inorganic solutes, mainly potassium. These "salt-in" organisms characteristically have proteins that are highly enriched with acidic and hydrophilic residues. In contrast, "salt-out" halophiles accumulate large amounts of organic solutes like amino acids, sugars and polyols, and lack a strong signature of halophilicity in the amino acid composition of cytoplasmic proteins. Studies to date have examined halophilic prokaryotes, yeasts, or algae, thus virtually nothing is known about the molecular adaptations of the other eukaryotic microbes, that is, heterotrophic protists (protozoa), that also thrive in hypersaline habitats. We conducted transcriptomic investigations to unravel the molecular adaptations of two obligately halophilic protists, Halocafeteria seosinensis and Pharyngomonas kirbyi Their predicted cytoplasmic proteomes showed increased hydrophilicity compared with marine protists. Furthermore, analysis of reconstructed ancestral sequences suggested that, relative to mesophiles, proteins in halophilic protists have undergone fewer substitutions from hydrophilic to hydrophobic residues since divergence from their closest relatives. These results suggest that these halophilic protists have a higher intracellular salt content than marine protists. However, absence of the acidic signature of salt-in microbes suggests that Haloc. seosinensis and P. kirbyi utilize organic osmolytes to maintain osmotic equilibrium. We detected increased expression of enzymes involved in synthesis and transport of organic osmolytes, namely hydroxyectoine and myo-inositol, at maximal salt concentration for growth in Haloc. seosinensis, suggesting possible candidates for these inferred organic osmolytes. © The Author 2016

  2. Response surface method optimization of ectoine fermentation medium with moderate halophilic bacteria Halomonas sp. H02

    Science.gov (United States)

    Li, T. T.; Qu, A.; Yuan, X. N.; Tan, F. X.; Li, X. W.; Wang, T.; Zhang, L. H.

    2017-07-01

    Moderate halophilic bacteria are of halophilic bacteria whose suitable growth of NaCl is 5-10%. When the moderate halophilic bacteria response to high osmotic stress, the intracellular will synthesize small organic molecule compatible solutes. Ectoine, which is the major synthetic osmotic compatible solutes for moderate halophilic bacteria, can help microbial enzymes, nucleic acids and the whole cell resist to hypertonic, high temperature, freezing and other inverse environment. In order to increase the Ectoine production of Moderate halophilic bacteria Halomonas sp. H02, the Ectoine fermentation medium component was optimized by Plackett-Burman (PB) and Response Surface Methodology (RSM) based on the principle of non-complete equilibrium The results of PB experiments showed that the three main influencing factors of Moderate halophilic bacteria Halomonas sp. H02 synthesis Ectoine culture medium were C5H8NNaO4 concentration, NaCl concentration and initial pH. According to the center point of the steepest climbing experiment, the central combination design experiment was used to show that the model is consistent with the actual situation. The optimum combination of three influencing factors were C5H8NNaO4 41 g/L, NaCl 87.2 g/L and initial pH 5.9, and the predicted amount of Ectoine was 1835.8 mg/L, increased by 41.6%.

  3. Structural basis for the aminoacid composition of proteins from halophilic archea.

    Directory of Open Access Journals (Sweden)

    Xavier Tadeo

    2009-12-01

    Full Text Available Proteins from halophilic organisms, which live in extreme saline conditions, have evolved to remain folded at very high ionic strengths. The surfaces of halophilic proteins show a biased amino acid composition with a high prevalence of aspartic and glutamic acids, a low frequency of lysine, and a high occurrence of amino acids with a low hydrophobic character. Using extensive mutational studies on the protein surfaces, we show that it is possible to decrease the salt dependence of a typical halophilic protein to the level of a mesophilic form and engineer a protein from a mesophilic organism into an obligate halophilic form. NMR studies demonstrate complete preservation of the three-dimensional structure of extreme mutants and confirm that salt dependency is conferred exclusively by surface residues. In spite of the statistically established fact that most halophilic proteins are strongly acidic, analysis of a very large number of mutants showed that the effect of salt on protein stability is largely independent of the total protein charge. Conversely, we quantitatively demonstrate that halophilicity is directly related to a decrease in the accessible surface area.

  4. Structural adaptation of extreme halophilic proteins through decrease of conserved hydrophobic contact surface

    Science.gov (United States)

    2011-01-01

    Background Halophiles are extremophilic microorganisms growing optimally at high salt concentrations. There are two strategies used by halophiles to maintain proper osmotic pressure in their cytoplasm: accumulation of molar concentrations of potassium and chloride with extensive adaptation of the intracellular macromolecules ("salt-in" strategy) or biosynthesis and/or accumulation of organic osmotic solutes ("osmolyte" strategy). Our work was aimed at contributing to the understanding of the shared molecular mechanisms of protein haloadaptation through a detailed and systematic comparison of a sample of several three-dimensional structures of halophilic and non-halophilic proteins. Structural differences observed between the "salt-in" and the mesophilic homologous proteins were contrasted to those observed between the "osmolyte" and mesophilic pairs. Results The results suggest that haloadaptation strategy in the presence of molar salt concentration, but not of osmolytes, necessitates a weakening of the hydrophobic interactions, in particular at the level of conserved hydrophobic contacts. Weakening of these interactions counterbalances their strengthening by the presence of salts in solution and may help the structure preventing aggregation and/or loss of function in hypersaline environments. Conclusions Considering the significant increase of biotechnology applications of halophiles, the understanding of halophilicity can provide the theoretical basis for the engineering of proteins of great interest because stable at concentrations of salts that cause the denaturation or aggregation of the majority of macromolecules. PMID:22192175

  5. Structural adaptation of extreme halophilic proteins through decrease of conserved hydrophobic contact surface

    Directory of Open Access Journals (Sweden)

    Siglioccolo Alessandro

    2011-12-01

    Full Text Available Abstract Background Halophiles are extremophilic microorganisms growing optimally at high salt concentrations. There are two strategies used by halophiles to maintain proper osmotic pressure in their cytoplasm: accumulation of molar concentrations of potassium and chloride with extensive adaptation of the intracellular macromolecules ("salt-in" strategy or biosynthesis and/or accumulation of organic osmotic solutes ("osmolyte" strategy. Our work was aimed at contributing to the understanding of the shared molecular mechanisms of protein haloadaptation through a detailed and systematic comparison of a sample of several three-dimensional structures of halophilic and non-halophilic proteins. Structural differences observed between the "salt-in" and the mesophilic homologous proteins were contrasted to those observed between the "osmolyte" and mesophilic pairs. Results The results suggest that haloadaptation strategy in the presence of molar salt concentration, but not of osmolytes, necessitates a weakening of the hydrophobic interactions, in particular at the level of conserved hydrophobic contacts. Weakening of these interactions counterbalances their strengthening by the presence of salts in solution and may help the structure preventing aggregation and/or loss of function in hypersaline environments. Conclusions Considering the significant increase of biotechnology applications of halophiles, the understanding of halophilicity can provide the theoretical basis for the engineering of proteins of great interest because stable at concentrations of salts that cause the denaturation or aggregation of the majority of macromolecules.

  6. Genetic and Biochemical Identification of a Novel Single-Stranded DNA-Binding Complex in Haloferax volcanii.

    Science.gov (United States)

    Stroud, Amy; Liddell, Susan; Allers, Thorsten

    2012-01-01

    Single-stranded DNA (ssDNA)-binding proteins play an essential role in DNA replication and repair. They use oligonucleotide/oligosaccharide-binding (OB)-folds, a five-stranded β-sheet coiled into a closed barrel, to bind to ssDNA thereby protecting and stabilizing the DNA. In eukaryotes the ssDNA-binding protein (SSB) is known as replication protein A (RPA) and consists of three distinct subunits that function as a heterotrimer. The bacterial homolog is termed SSB and functions as a homotetramer. In the archaeon Haloferax volcanii there are three genes encoding homologs of RPA. Two of the rpa genes (rpa1 and rpa3) exist in operons with a novel gene specific to Euryarchaeota; this gene encodes a protein that we have termed RPA-associated protein (rpap). The rpap genes encode proteins belonging to COG3390 group and feature OB-folds, suggesting that they might cooperate with RPA in binding to ssDNA. Our genetic analysis showed that rpa1 and rpa3 deletion mutants have differing phenotypes; only Δrpa3 strains are hypersensitive to DNA damaging agents. Deletion of the rpa3-associated gene rpap3 led to similar levels of DNA damage sensitivity, as did deletion of the rpa3 operon, suggesting that RPA3 and RPAP3 function in the same pathway. Protein pull-downs involving recombinant hexahistidine-tagged RPAs showed that RPA3 co-purifies with RPAP3, and RPA1 co-purifies with RPAP1. This indicates that the RPAs interact only with their respective associated proteins; this was corroborated by the inability to construct rpa1 rpap3 and rpa3 rpap1 double mutants. This is the first report investigating the individual function of the archaeal COG3390 RPA-associated proteins (RPAPs). We have shown genetically and biochemically that the RPAPs interact with their respective RPAs, and have uncovered a novel single-stranded DNA-binding complex that is unique to Euryarchaeota.

  7. Two new sesquiterpenoids produced by halophilic Nocardiopsis chromatogenes YIM 90109.

    Science.gov (United States)

    Sun, Ming-Wei; Zhang, Xiao-Mei; Bi, Hui-Li; Li, Wen-Jun; Lu, Chun-Hua

    2017-01-01

    Two new germacradiene-type sesquiterpenoids, including 1(10)E,5E-germacradiene-9β,11-diol (or 9β-hydroxyl germacradienol) (1) and 11-hydroxy-1(10)E,5E-germacradien-2-one (2-oxygermacradienol) (2), together with a known geosmin-type sesquiterpenoid (1β,4β,4aβ,7α,8aα)-4,8a-dimethyloctahydronaphthalene-1,4a,7(2H)-triol (3), were elucidated by their NMR spectroscopic data, HR-ESI-MS and single-crystal X-ray diffraction from the halophilic strain Nocardiopsis chromatogenes YIM 90109. The antimicrobial activities were evaluated by paper diffusion method.

  8. Metabolic flux analysis of the halophilic archaeon Haladaptatus paucihalophilus

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Guangxiu; Zhang, Manxiao [Key Laboratory of Desert and Desertification, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou, 730000 (China); Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Gansu Province, Lanzhou, 730000 (China); Mo, Tianlu [Department of Chemistry, Fudan University, Shanghai, 200433 (China); He, Lian [Key Laboratory of Combinatory Biosynthesis and Drug Discovery (Ministry of Education), School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071 (China); Zhang, Wei [Key Laboratory of Desert and Desertification, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou, 730000 (China); Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Gansu Province, Lanzhou, 730000 (China); Yu, Yi, E-mail: yu_yi@whu.edu.cn [Key Laboratory of Combinatory Biosynthesis and Drug Discovery (Ministry of Education), School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071 (China); Zhang, Qi, E-mail: qizhang@sioc.ac.cn [Department of Chemistry, Fudan University, Shanghai, 200433 (China); Ding, Wei, E-mail: dingw@lzu.edu.cn [Key Laboratory of Desert and Desertification, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou, 730000 (China); Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Gansu Province, Lanzhou, 730000 (China); Department of Chemistry, Fudan University, Shanghai, 200433 (China)

    2015-11-27

    This work reports the {sup 13}C-assisted metabolic flux analysis of Haladaptatus paucihalophilus, a halophilic archaeon possessing an intriguing osmoadaption mechanism. We showed that the carbon flow is through the oxidative tricarboxylic acid (TCA) cycle whereas the reductive TCA cycle is not operative in H. paucihalophilus. In addition, both threonine and the citramalate pathways contribute to isoleucine biosynthesis, whereas lysine is synthesized through the diaminopimelate pathway and not through the α-aminoadipate pathway. Unexpected, the labeling patterns of glycine from the cells grown on [1-{sup 13}C]pyruvate and [2-{sup 13}C]pyruvate suggest that, unlike all the organisms investigated so far, in which glycine is produced exclusively from the serine hydroxymethyltransferase (SHMT) pathway, glycine biosynthesis in H. paucihalophilus involves different pathways including SHMT, threonine aldolase (TA) and the reverse reaction of glycine cleavage system (GCS), demonstrating for the first time that other pathways instead of SHMT can also make a significant contribution to the cellular glycine pool. Transcriptional analysis confirmed that both TA and GCS genes were transcribed in H. paucihalophilus, and the transcriptional level is independent of salt concentrations in the culture media. This study expands our understanding of amino acid biosynthesis and provides valuable insights into the metabolism of halophilic archaea. - Highlights: • Serine hydroxymethyltransferase, threonine aldolase, and glycine cleavage system all contribute to the glycine pool of H. paucihalophilus. • Threonine and the citramalate pathways contribute equally to the isoleucine biosynthesis in H. paucihalophilus. • Lysine in H. paucihalophilus is synthesized through the diaminopimelate pathway and not through the α-aminoadipate pathway. • Glycine biosynthesis is likely unrelated to the cell osmoadaption mechanism.

  9. Metabolic flux analysis of the halophilic archaeon Haladaptatus paucihalophilus

    International Nuclear Information System (INIS)

    Liu, Guangxiu; Zhang, Manxiao; Mo, Tianlu; He, Lian; Zhang, Wei; Yu, Yi; Zhang, Qi; Ding, Wei

    2015-01-01

    This work reports the "1"3C-assisted metabolic flux analysis of Haladaptatus paucihalophilus, a halophilic archaeon possessing an intriguing osmoadaption mechanism. We showed that the carbon flow is through the oxidative tricarboxylic acid (TCA) cycle whereas the reductive TCA cycle is not operative in H. paucihalophilus. In addition, both threonine and the citramalate pathways contribute to isoleucine biosynthesis, whereas lysine is synthesized through the diaminopimelate pathway and not through the α-aminoadipate pathway. Unexpected, the labeling patterns of glycine from the cells grown on [1-"1"3C]pyruvate and [2-"1"3C]pyruvate suggest that, unlike all the organisms investigated so far, in which glycine is produced exclusively from the serine hydroxymethyltransferase (SHMT) pathway, glycine biosynthesis in H. paucihalophilus involves different pathways including SHMT, threonine aldolase (TA) and the reverse reaction of glycine cleavage system (GCS), demonstrating for the first time that other pathways instead of SHMT can also make a significant contribution to the cellular glycine pool. Transcriptional analysis confirmed that both TA and GCS genes were transcribed in H. paucihalophilus, and the transcriptional level is independent of salt concentrations in the culture media. This study expands our understanding of amino acid biosynthesis and provides valuable insights into the metabolism of halophilic archaea. - Highlights: • Serine hydroxymethyltransferase, threonine aldolase, and glycine cleavage system all contribute to the glycine pool of H. paucihalophilus. • Threonine and the citramalate pathways contribute equally to the isoleucine biosynthesis in H. paucihalophilus. • Lysine in H. paucihalophilus is synthesized through the diaminopimelate pathway and not through the α-aminoadipate pathway. • Glycine biosynthesis is likely unrelated to the cell osmoadaption mechanism.

  10. Halophilic mechanism of the enzymatic function of a moderately halophilic dihydrofolate reductase from Haloarcula japonica strain TR-1.

    Science.gov (United States)

    Miyashita, Yurina; Ohmae, Eiji; Ikura, Teikichi; Nakasone, Kaoru; Katayanagi, Katsuo

    2017-05-01

    Dihydrofolate (DHF) reductase coded by a plasmid of the extremely halophilic archaeon Haloarcula japonica strain TR-1 (HjDHFR P1) shows moderate halophilicity on enzymatic activity at pH 6.0, although there is no significant effect of NaCl on its secondary structure. To elucidate the salt-activation and -inactivation mechanisms of this enzyme, we investigated the effects of pH and salt concentration, deuterium isotope effect, steady-state kinetics, and rapid-phase ligand-binding kinetics. Enzyme activity was increased eightfold by the addition of 500 mM NaCl at pH 6.0, fourfold by 250 mM at pH 8.0, and became independent of salt concentration at pH 10.0. Full isotope effects observed at pH 10.0 under 0-1000 mM NaCl indicated that the rate of hydride transfer, which was the rate-determining step at the basic pH region, was independent of salt concentration. Conversely, rapid-phase ligand-binding experiments showed that the amplitude of the DHF-binding reaction increased and the tetrahydrofolate (THF)-releasing rate decreased with increasing NaCl concentration. These results suggested that the salt-activation mechanism of HjDHFR P1 is via the population change of the anion-unbound and anion-bound conformers, which are binding-incompetent and -competent conformations for DHF, respectively, while that of salt inactivation is via deceleration of the THF-releasing rate, which is the rate-determining step at the neutral pH region.

  11. Hans Georg Trüper (1936–2016 and His Contributions to Halophile Research

    Directory of Open Access Journals (Sweden)

    Aharon Oren

    2016-05-01

    Full Text Available Prof. Hans Georg Trüper, one of the most important scientists in the field of halophile research, passed away on 9 March 2016 at the age of 79. I here present a brief obituary with special emphasis on Prof. Trüper’s contributions to our understanding of the halophilic prokaryotes and their adaptations to life in hypersaline environments. He has pioneered the study of the halophilic anoxygenic phototrophic sulfur bacteria of the Ectothiorhodospira—Halorhodospira group. Some of the species he and his group isolated from hypersaline and haloalkaline environments have become model organisms for the study of the mechanisms of haloadaptation: the functions of three major organic compounds – glycine betaine, ectoine, and trehalose – known to serve as “compatible solutes” in halophilic members of the Bacteria domain, were discovered during studies of these anoxygenic phototrophs. Prof. Trüper’s studies of hypersaline alkaline environments in Egypt also led to the isolation of the first known extremely halophilic archaeon (Natronomonas pharaonis. The guest editors dedicate this special volume of Life to the memory of Prof. Hans Georg Trüper.

  12. Untargeted Metabolomics Approach in Halophiles: Understanding the Biodeterioration Process of Building Materials

    Directory of Open Access Journals (Sweden)

    Justyna Adamiak

    2017-12-01

    Full Text Available The aim of the study was to explore the halophile metabolome in building materials using untargeted metabolomics which allows for broad metabolome coverage. For this reason, we used high-performance liquid chromatography interfaced to high-resolution mass spectrometry (HPLC/HRMS. As an alternative to standard microscopy techniques, we introduced pioneering Coherent Anti-stokes Raman Scattering Microscopy (CARS to non-invasively visualize microbial cells. Brick samples saturated with salt solution (KCl, NaCl (two salinity levels, MgSO4, Mg(NO32, were inoculated with the mixture of preselected halophilic microorganisms, i.e., bacteria: Halobacillus styriensis, Halobacillus naozhouensis, Halobacillus hunanensis, Staphylococcus succinus, Marinococcus halophilus, Virgibacillus halodenitryficans, and yeast: Sterigmatomyces halophilus and stored at 28°C and 80% relative humidity for a year. Metabolites were extracted directly from the brick samples and measured via HPLC/HRMS in both positive and negative ion modes. Overall, untargeted metabolomics allowed for discovering the interactions of halophilic microorganisms with buildings materials which together with CARS microscopy enabled us to elucidate the biodeterioration process caused by halophiles. We observed that halophile metabolome was differently affected by different salt solutions. Furthermore, we found indications for haloadaptive strategies and degradation of brick samples due to microbial pigment production as a salt stress response. Finally, we detected changes in lipid content related to changes in the structure of phospholipid bilayers and membrane fluidity.

  13. Factors Determining the Biodiversity of Halophilic Microorganisms on Historic Masonry Buildings.

    Science.gov (United States)

    Otlewska, Anna; Adamiak, Justyna; Stryszewska, Teresa; Kańka, Stanisław; Gutarowska, Beata

    2017-06-24

    The aim of the present study was to obtain insights into the relationship between the chemical (salt content and pH) and physico-mechanical (humidity and compressive strength) properties of mineral-based materials from historic buildings with salt efflorescence and the growth and biodiversity of halophilic microorganisms. Samples were mainly characterized by pH 6.5-8.5 and a moisture content of between 0.12 and 3.3%. Significant variations were also found in the salt content (sulfates, chlorides, and nitrates) of the materials. An SEM/EDS analysis of material surfaces revealed the presence of halite, calcite, gypsum, sodium sulfate, and potassium-sodium sulfate. Culture-dependent and culture-independent (clone library construction) approaches were both applied to detect halophilic microorganisms. Results derived from culturable methods and the materials analysis revealed a correlation between the total halophile count and pH value as well as sulfate content. A correlation was not observed between the concentration of chlorides or nitrates and the number of halophilic microorganisms. The materials studied were inhabited by the culturable halophilic bacteria Halobacillus sp., Virgibacillus sp., and Marinococcus sp. as well as the yeast Sterigmatomyces sp., which was isolated for the first time from mineral materials. Culture-independent techniques revealed the following bacterial species: Salinibacterium, Salinisphaera, Rubrobacter, Rubricoccus, Halomonas, Halorhodospira, Solirubrobacter, Salinicoccus, and Salinibacter. Biodiversity was the highest in materials with high or moderate salinity.

  14. Factors Determining the Biodiversity of Halophilic Microorganisms on Historic Masonry Buildings

    Science.gov (United States)

    Otlewska, Anna; Adamiak, Justyna; Stryszewska, Teresa; Kańka, Stanisław; Gutarowska, Beata

    2017-01-01

    The aim of the present study was to obtain insights into the relationship between the chemical (salt content and pH) and physico-mechanical (humidity and compressive strength) properties of mineral-based materials from historic buildings with salt efflorescence and the growth and biodiversity of halophilic microorganisms. Samples were mainly characterized by pH 6.5–8.5 and a moisture content of between 0.12 and 3.3%. Significant variations were also found in the salt content (sulfates, chlorides, and nitrates) of the materials. An SEM/EDS analysis of material surfaces revealed the presence of halite, calcite, gypsum, sodium sulfate, and potassium-sodium sulfate. Culture-dependent and culture-independent (clone library construction) approaches were both applied to detect halophilic microorganisms. Results derived from culturable methods and the materials analysis revealed a correlation between the total halophile count and pH value as well as sulfate content. A correlation was not observed between the concentration of chlorides or nitrates and the number of halophilic microorganisms. The materials studied were inhabited by the culturable halophilic bacteria Halobacillus sp., Virgibacillus sp., and Marinococcus sp. as well as the yeast Sterigmatomyces sp., which was isolated for the first time from mineral materials. Culture-independent techniques revealed the following bacterial species: Salinibacterium, Salinisphaera, Rubrobacter, Rubricoccus, Halomonas, Halorhodospira, Solirubrobacter, Salinicoccus, and Salinibacter. Biodiversity was the highest in materials with high or moderate salinity. PMID:28592721

  15. Progress in decontamination by halophilic microorganisms in saline wastewater and soil

    International Nuclear Information System (INIS)

    Zhuang Xuliang; Han Zhen; Bai Zhihui; Zhuang Guoqiang; Shim Hojae

    2010-01-01

    Environments with high-salt concentrations are often populated by dense microbial communities. Halophilic microorganisms can be isolated from different saline environments and different strains even belonging to the same genus have various applications. Wastewater and soil rich in both organic matter and salt are difficult to treat using conventional microorganisms typically found in wastewater treatment and soil bioremediation facilities. Studies on decontaminative capabilities and decontamination pathways of organic contaminants (i.e., aromatic compounds benzoate, cinnamate, 3-phenylpropionate, 4-hydroxybenzoic acid), heavy metals (i.e., tellurium, vanadium), and nutrients in the biological treatment of saline wastewater and soil by halophilic microorganisms are discussed in this review. - Review on the decontaminative capabilities of halophilic microorganisms in saline wastewater and soil.

  16. Protective role of salt in catalysis and maintaining structure of halophilic proteins against denaturation

    Science.gov (United States)

    Sinha, Rajeshwari; Khare, Sunil K.

    2014-01-01

    Search for new industrial enzymes having novel properties continues to be a desirable pursuit in enzyme research. The halophilic organisms inhabiting under saline/ hypersaline conditions are considered as promising source of useful enzymes. Their enzymes are structurally adapted to perform efficient catalysis under saline environment wherein n0n-halophilic enzymes often lose their structure and activity. Haloenzymes have been documented to be polyextremophilic and withstand high temperature, pH, organic solvents, and chaotropic agents. However, this stability is modulated by salt. Although vast amount of information have been generated on salt mediated protection and structure function relationship in halophilic proteins, their clear understanding and correct perspective still remain incoherent. Furthermore, understanding their protein architecture may give better clue for engineering stable enzymes which can withstand harsh industrial conditions. The article encompasses the current level of understanding about haloadaptations and analyzes structural basis of their enzyme stability against classical denaturants. PMID:24782853

  17. Progress in decontamination by halophilic microorganisms in saline wastewater and soil

    Energy Technology Data Exchange (ETDEWEB)

    Zhuang Xuliang, E-mail: xlzhuang@rcees.ac.c [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Haidian District, Beijing 100085 (China); Bureau of Science and Technology for Resources and Environment, Chinese Academy of Sciences, Beijing 100864 (China); Han Zhen [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Haidian District, Beijing 100085 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Bai Zhihui; Zhuang Guoqiang [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Haidian District, Beijing 100085 (China); Shim Hojae [Department of Civil and Environmental Engineering, Faculty of Science and Technology, University of Macau, Macau (China)

    2010-05-15

    Environments with high-salt concentrations are often populated by dense microbial communities. Halophilic microorganisms can be isolated from different saline environments and different strains even belonging to the same genus have various applications. Wastewater and soil rich in both organic matter and salt are difficult to treat using conventional microorganisms typically found in wastewater treatment and soil bioremediation facilities. Studies on decontaminative capabilities and decontamination pathways of organic contaminants (i.e., aromatic compounds benzoate, cinnamate, 3-phenylpropionate, 4-hydroxybenzoic acid), heavy metals (i.e., tellurium, vanadium), and nutrients in the biological treatment of saline wastewater and soil by halophilic microorganisms are discussed in this review. - Review on the decontaminative capabilities of halophilic microorganisms in saline wastewater and soil.

  18. Actinide Biocolloid Formation in Brine by Halophilic Bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Gillow, J.B.; Francis, A.J.; Dodge, C.J.; Harris, R.; Beveridge, T.J.; Brady, P.V.; Papenguth, H.W.

    1999-07-28

    We examined the ability of a halophilic bacterium (WFP 1A) isolated from the Waste Isolation Pilot Plant (WIPP) site to accumulate uranium in order to determine the potential for biocolloid facilitated actinide transport. The bacterial cell Surface functional groups involved in the complexation of the actinide were determined by titration. Uranium, added as uranyl nitrate, was removed from solution at pH 5 by cells but at pH 7 and 9 very little uranium was removed due to its limited volubility. Although present as soluble species, uranyl citrate at pH 5, 7, and 9, and uranyl carbonate at pH 9 were not removed by the bacterium because they were not bioavailable due to their neutral or negative charge. Addition of uranyl EDTA to brine at pH 5, 7, and 9 resulted in the immediate precipitation of U. Transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS) analysis revealed that uranium was not only associated with the cell surface but also accumulated intracellulary as uranium-enriched granules. Extended X-ray absorption fine structure (EXAFS) analysis, of the bacterial cells indicated the bulk sample contained more than one uranium phase. Nevertheless these results show the potential for the formation of actinide bearing bacterial biocolloids that are strictly regulated by the speciation and bioavailability of the actinide.

  19. Actinide biocolloid formation in brine by halophilic bacteria

    International Nuclear Information System (INIS)

    Gillow, J.B.; Francis, A.J.; Dodge, C.J.; Harris, R.; Beveridge, T.J.; Brady, P.V.; Papenguth, H.W.

    1999-01-01

    The authors examined the ability of a halophilic bacterium (WIPP 1A) isolated from the Waste Isolation Pilot Plant (WIPP) site to accumulate uranium in order to determine the potential for biocolloid facilitated actinide transport. The bacterial cell surface functional groups involved in the complexation of the actinide were determined by titration. Uranium, added as uranyl nitrate, was removed from solution at pH 5 by cells but at pH 7 and 9 very little uranium was removed due to its limited solubility. Although present as soluble species, uranyl citrate at pH 5, 7, and 9, and uranyl carbonate at pH 9 were not removed by the bacterium because they were not bioavailable due to their neutral or negative charge. Addition of uranyl EDTA to brine at pH 5, 7, and 9 resulted in the immediate precipitation of U. Transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS) analysis revealed that uranium was not only associated with the cell surface but also accumulated intracellularly as uranium-enriched granules. Extended X-ray absorption fine structure (EXAFS) analysis of the bacterial cells indicated the bulk sample contained more than one uranium phase. Nevertheless these results show the potential for the formation of actinide bearing bacterial biocolloids that are strictly regulated by the speciation and bioavailability of the actinide

  20. Actinide Biocolloid Formation in Brine by Halophilic Bacteria

    International Nuclear Information System (INIS)

    Gillow, J.B.; Francis, A.J.; Dodge, C.J.; Harris, R.; Beveridge, T.J.; Brady, P.V.; Papenguth, H.W.

    1999-01-01

    We examined the ability of a halophilic bacterium (WFP 1A) isolated from the Waste Isolation Pilot Plant (WIPP) site to accumulate uranium in order to determine the potential for biocolloid facilitated actinide transport. The bacterial cell Surface functional groups involved in the complexation of the actinide were determined by titration. Uranium, added as uranyl nitrate, was removed from solution at pH 5 by cells but at pH 7 and 9 very little uranium was removed due to its limited volubility. Although present as soluble species, uranyl citrate at pH 5, 7, and 9, and uranyl carbonate at pH 9 were not removed by the bacterium because they were not bioavailable due to their neutral or negative charge. Addition of uranyl EDTA to brine at pH 5, 7, and 9 resulted in the immediate precipitation of U. Transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS) analysis revealed that uranium was not only associated with the cell surface but also accumulated intracellulary as uranium-enriched granules. Extended X-ray absorption fine structure (EXAFS) analysis, of the bacterial cells indicated the bulk sample contained more than one uranium phase. Nevertheless these results show the potential for the formation of actinide bearing bacterial biocolloids that are strictly regulated by the speciation and bioavailability of the actinide

  1. Actinide biocolloid formation in brine by halophilic bacteria

    International Nuclear Information System (INIS)

    Gillow, J.B.; Francis, A.J.; Dodge, C.J.; Harris, R.; Beveridge, T.J.; Brady, P.B.; Papenguth, H.W.

    1998-01-01

    The authors examined the ability of a halophilic bacterium (WIPP 1A) isolated from the Waste Isolation Pilot Plant (WIPP) site to accumulate uranium in order to determine the potential for biocolloid facilitated actinide transport. The bacterial cell surface functional groups involved in the complexation of the actinide were determined by titration. Uranium, added as uranyl nitrate, was removed from solution at pH 5 by cells but at pH 7 and 9 very little uranium was removed due to its limited solubility. Although present as soluble species, uranyl citrate at pH 5, 7, and 9, and uranyl carbonate at pH 9 were not removed by the bacterium because they were not bioavailable due to their neutral or negative charge. Addition of uranyl EDTA to brine at pH 5, 7, and 9 resulted in the immediate precipitation of U. Transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS) analysis revealed that uranium was not only associated with the cell surface but also accumulated intracellularly as uranium-enriched granules. Extended X-ray absorption fine structure (EXAFS) analysis of the bacterial cells indicated the bulk sample contained more than one uranium phase. Nevertheless these results show the potential for the formation of actinide bearing bacterial biocolloids that are strictly regulated by the speciation and bioavailability of the actinide

  2. Effects of antibiotics and ultraviolet radiation on the halophilic blue-green alga

    International Nuclear Information System (INIS)

    Yopp, J.H.; Albright, G.; Miller, D.M.; Southern Illinois Univ., Carbondale

    1979-01-01

    The effects of a variety of antibiotics, ultraviolet radiation and N-methyl-N-nitro-N-nitro-N-nitrosoguanidine (NTG) on the survival and mutability of the halophilic blue-green alga, Aphanothece halophytica, were determined. The halophile was found extremely sensitive to penicillin G and bacitracin; moderately sensitive to novobiocin, amino acid analogs, chloramphenicol and streptomycin; and tolerant to actidione and hydroxyurea. Ultraviolet and NTG killing curves and photoreactivation capabilities were seimilar to those reported for other members of the Chroococcales. Three stable morphological mutants were obtained by ultraviolet and NTG treatment, the latter being much more efficient in the production of mutants. (orig.)

  3. Structural evidence for solvent-stabilisation by aspartic acid as a mechanism for halophilic protein stability in high salt concentrations.

    Science.gov (United States)

    Lenton, Samuel; Walsh, Danielle L; Rhys, Natasha H; Soper, Alan K; Dougan, Lorna

    2016-07-21

    Halophilic organisms have adapted to survive in high salt environments, where mesophilic organisms would perish. One of the biggest challenges faced by halophilic proteins is the ability to maintain both the structure and function at molar concentrations of salt. A distinct adaptation of halophilic proteins, compared to mesophilic homologues, is the abundance of aspartic acid on the protein surface. Mutagenesis and crystallographic studies of halophilic proteins suggest an important role for solvent interactions with the surface aspartic acid residues. This interaction, between the regions of the acidic protein surface and the solvent, is thought to maintain a hydration layer around the protein at molar salt concentrations thereby allowing halophilic proteins to retain their functional state. Here we present neutron diffraction data of the monomeric zwitterionic form of aspartic acid solutions at physiological pH in 0.25 M and 2.5 M concentration of potassium chloride, to mimic mesophilic and halophilic-like environmental conditions. We have used isotopic substitution in combination with empirical potential structure refinement to extract atomic-scale information from the data. Our study provides structural insights that support the hypothesis that carboxyl groups on acidic residues bind water more tightly under high salt conditions, in support of the residue-ion interaction model of halophilic protein stabilisation. Furthermore our data show that in the presence of high salt the self-association between the zwitterionic form of aspartic acid molecules is reduced, suggesting a possible mechanism through which protein aggregation is prevented.

  4. Microbial culturomics to isolate halophilic bacteria from table salt: genome sequence and description of the moderately halophilic bacterium Bacillus salis sp. nov.

    Directory of Open Access Journals (Sweden)

    E.H. Seck

    2018-05-01

    Full Text Available Bacillus salis strain ES3T (= CSUR P1478 = DSM 100598 is the type strain of B. salis sp. nov. It is an aerobic, Gram-positive, moderately halophilic, motile and spore-forming bacterium. It was isolated from commercial table salt as part of a broad culturomics study aiming to maximize the culture conditions for the in-depth exploration of halophilic bacteria in salty food. Here we describe the phenotypic characteristics of this isolate, its complete genome sequence and annotation, together with a comparison with closely related bacteria. Phylogenetic analysis based on 16S rRNA gene sequences indicated 97.5% similarity with Bacillus aquimaris, the closest species. The 8 329 771 bp long genome (one chromosome, no plasmids exhibits a G+C content of 39.19%. It is composed of 18 scaffolds with 29 contigs. Of the 8303 predicted genes, 8109 were protein-coding genes and 194 were RNAs. A total of 5778 genes (71.25% were assigned a putative function. Keywords: Bacillus salis, culturomics, genome, halophilic bacteria, human gut, taxonogenomics

  5. Complete Genome Sequence of the Halophilic Methylotrophic Methanogen Archaeon Methanohalophilus portucalensis Strain FDF-1T

    KAUST Repository

    L’Haridon, Stéphane

    2018-01-17

    We report here the complete genome sequence (2.08 Mb) of Methanohalophilus portucalensis strain FDF-1T, a halophilic methylotrophic methanogen isolated from the sediment of a saltern in Figeria da Foz, Portugal. The average nucleotide identity and DNA-DNA hybridization analyses show that Methanohalophilus mahii, M. halophilus, and M. portucalensis are three different species within the Methanosarcinaceae family.

  6. Evaluation of biodecolorization of the textile azo dye by halophilic archaea

    Directory of Open Access Journals (Sweden)

    Masoomeh Selseleh Hassan-Kiadehi

    2017-09-01

    Discussion and conclusion: In conclusion, our results indicate that halophilic archaea have very high potential to decolorize azo dyes. Regarding high amounts of salts in textile wastewaters, using such microorganisms which can tolerate the harsh environment in order to decolorize azo dyes, could be a new approach in this field.

  7. Life under Multiple Extreme Conditions: Diversity and Physiology of the Halophilic Alkalithermophiles

    Science.gov (United States)

    Wiegel, Juergen

    2012-01-01

    Around the world, there are numerous alkaline, hypersaline environments that are heated either geothermally or through intense solar radiation. It was once thought that such harsh environments were inhospitable and incapable of supporting a variety of life. However, numerous culture-dependent and -independent studies revealed the presence of an extensive diversity of aerobic and anaerobic bacteria and archaea that survive and grow under these multiple harsh conditions. This diversity includes the halophilic alkalithermophiles, a novel group of polyextremophiles that require for growth and proliferation the multiple extremes of high salinity, alkaline pH, and elevated temperature. Life under these conditions undoubtedly involves the development of unique physiological characteristics, phenotypic properties, and adaptive mechanisms that enable control of membrane permeability, control of intracellular osmotic balance, and stability of the cell wall, intracellular proteins, and other cellular constituents. This minireview highlights the ecology and growth characteristics of the extremely halophilic alkalithermophiles that have been isolated thus far. Biochemical, metabolic, and physiological properties of the extremely halophilic alkalithermophiles are described, and their roles in resistance to the combined stressors of high salinity, alkaline pH, and high temperature are discussed. The isolation of halophilic alkalithermophiles broadens the physicochemical boundaries for life and extends the boundaries for the combinations of the maximum salinity, pH, and temperature that can support microbial growth. PMID:22492435

  8. First characterization of extremely halophilic 2-deoxy-D-ribose-5-phosphate aldolase.

    Science.gov (United States)

    Ohshida, Tatsuya; Hayashi, Junji; Satomura, Takenori; Kawakami, Ryushi; Ohshima, Toshihisa; Sakuraba, Haruhiko

    2016-10-01

    2-Deoxy-d-ribose-5-phosphate aldolase (DERA) catalyzes the aldol reaction between two aldehydes and is thought to be a potential biocatalyst for the production of a variety of stereo-specific materials. A gene encoding DERA from the extreme halophilic archaeon, Haloarcula japonica, was overexpressed in Escherichia coli. The gene product was successfully purified, using procedures based on the protein's halophilicity, and characterized. The expressed enzyme was stable in a buffer containing 2 M NaCl and exhibited high thermostability, retaining more than 90% of its activity after heating at 70 °C for 10 min. The enzyme was also tolerant to high concentrations of organic solvents, such as acetonitrile and dimethylsulfoxide. Moreover, H. japonica DERA was highly resistant to a high concentration of acetaldehyde and retained about 35% of its initial activity after 5-h' exposure to 300 mM acetaldehyde at 25 °C, the conditions under which E. coli DERA is completely inactivated. The enzyme exhibited much higher activity at 25 °C than the previously characterized hyperthermophilic DERAs (Sakuraba et al., 2007). Our results suggest that the extremely halophilic DERA has high potential to serve as a biocatalyst in organic syntheses. This is the first description of the biochemical characterization of a halophilic DERA. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Bipyrimidine Signatures as a Photoprotective Genome Strategy in G + C-rich Halophilic Archaea.

    Science.gov (United States)

    Jones, Daniel L; Baxter, Bonnie K

    2016-09-02

    Halophilic archaea experience high levels of ultraviolet (UV) light in their environments and demonstrate resistance to UV irradiation. DNA repair systems and carotenoids provide UV protection but do not account for the high resistance observed. Herein, we consider genomic signatures as an additional photoprotective strategy. The predominant forms of UV-induced DNA damage are cyclobutane pyrimidine dimers, most notoriously thymine dimers (T^Ts), which form at adjacent Ts. We tested whether the high G + C content seen in halophilic archaea serves a photoprotective function through limiting T nucleotides, and thus T^T lesions. However, this speculation overlooks the other bipyrimidine sequences, all of which capable of forming photolesions to varying degrees. Therefore, we designed a program to determine the frequencies of the four bipyrimidine pairs (5' to 3': TT, TC, CT, and CC) within genomes of halophilic archaea and four other randomized sample groups for comparison. The outputs for each sampled genome were weighted by the intrinsic photoreactivities of each dinucleotide pair. Statistical methods were employed to investigate intergroup differences. Our findings indicate that the UV-resistance seen in halophilic archaea can be attributed in part to a genomic strategy: high G + C content and the resulting bipyrimidine signature reduces the genomic photoreactivity.

  10. DNA Repair and Photoprotection: Mechanisms of Overcoming Environmental Ultraviolet Radiation Exposure in Halophilic Archaea.

    Science.gov (United States)

    Jones, Daniel L; Baxter, Bonnie K

    2017-01-01

    Halophilic archaea push the limits of life at several extremes. In particular, they are noted for their biochemical strategies in dealing with osmotic stress, low water activity and cycles of desiccation in their hypersaline environments. Another feature common to their habitats is intense ultraviolet (UV) radiation, which is a challenge that microorganisms must overcome. The consequences of high UV exposure include DNA lesions arising directly from bond rearrangement of adjacent bipyrimidines, or indirectly from oxidative damage, which may ultimately result in mutation and cell death. As such, these microorganisms have evolved a number of strategies to navigate the threat of DNA damage, which we differentiate into two categories: DNA repair and photoprotection. Photoprotection encompasses damage avoidance strategies that serve as a "first line of defense," and in halophilic archaea include pigmentation by carotenoids, mechanisms of oxidative damage avoidance, polyploidy, and genomic signatures that make DNA less susceptible to photodamage. Photolesions that do arise are addressed by a number of DNA repair mechanisms that halophilic archaea efficiently utilize, which include photoreactivation, nucleotide excision repair, base excision repair, and homologous recombination. This review seeks to place DNA damage, repair, and photoprotection in the context of halophilic archaea and the solar radiation of their hypersaline environments. We also provide new insight into the breadth of strategies and how they may work together to produce remarkable UV-resistance for these microorganisms.

  11. Halophilic Bacteria of Lunsu Produce an Array of Industrially Important Enzymes with Salt Tolerant Activity

    Directory of Open Access Journals (Sweden)

    Sonika Gupta

    2016-01-01

    Full Text Available The halophilic bacterial isolates SS1, SS2, SS3, SS5, and SS8 were characterized for production of industrially important enzymes like amylase, protease, lipase, and glutaminase. Halophilic bacterial isolates SS1 and SS3 exhibited salt dependent extracellular amylase and protease activities. Both the halophilic isolates SS1 and SS3 exhibited maximum amylase and protease activities in the presence of 1.5 and 1.0 M NaCl, respectively, with the optimum pH 8 and temperature 40°C. SS2 showed maximum extracellular protease and lipase activities in the presence of 0.75 M NaCl, at optimum pH of 7, and temperature 37°C. The glutaminase activity of SS3 increased with increase in concentration of NaCl up to 2.5 M. The optimum pH and temperature for L-glutaminase activity of SS3 was 8 and 40°C, respectively. The combined hydrolytic activities of these halophilic bacterial isolates can be used for bioconversion of organic materials to useful products.

  12. Survival of Halophilic Archaea in the Stratosphere as a Mars Analog: A Transcriptomic Approach

    Science.gov (United States)

    DasSarma, S.; DasSarma, P.; Laye, V.; Harvey, J.; Reid, C.; Shultz, J.; Yarborough, A.; Lamb, A.; Koske-Phillips, A.; Herbst, A.; Molina, F.; Grah, O.; Phillips, T.

    2016-05-01

    On Earth, halophilic Archaea tolerate multiple extreme conditions similar to those on Mars. In order to study their survival, we launched live cultures into Earth’s stratosphere on helium balloons. The effects on survival and transcriptomes were interrogated in the lab.

  13. Complete Genome Sequence of the Anaerobic Halophilic Alkalithermophile Natranaerobius thermophilus JW/NM-WN-LFT

    Energy Technology Data Exchange (ETDEWEB)

    Mesbah, Noha [University of Georgia, Athens, GA; Dalin, Eileen [U.S. Department of Energy, Joint Genome Institute; Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Nolan, Matt [U.S. Department of Energy, Joint Genome Institute; Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Chertkov, Olga [Los Alamos National Laboratory (LANL); Han, James [U.S. Department of Energy, Joint Genome Institute; Larimer, Frank W [ORNL; Land, Miriam L [ORNL; Hauser, Loren John [ORNL; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Wiegel, Juergen [University of Georgia, Athens, GA

    2011-01-01

    The genome of the anaerobic halophilic alkalithermophile Natranaerobius thermophiles consists of one chromosome and two plasmids.The present study is the first to report the completely sequenced genome of polyextremophile and the harboring genes harboring genes associated with roles in regulation of intracellular osmotic pressure, pH homeostasis, and thermophilic stability.

  14. Halophilic Bacteria of Lunsu Produce an Array of Industrially Important Enzymes with Salt Tolerant Activity.

    Science.gov (United States)

    Gupta, Sonika; Sharma, Parul; Dev, Kamal; Sourirajan, Anuradha

    2016-01-01

    The halophilic bacterial isolates SS1, SS2, SS3, SS5, and SS8 were characterized for production of industrially important enzymes like amylase, protease, lipase, and glutaminase. Halophilic bacterial isolates SS1 and SS3 exhibited salt dependent extracellular amylase and protease activities. Both the halophilic isolates SS1 and SS3 exhibited maximum amylase and protease activities in the presence of 1.5 and 1.0 M NaCl, respectively, with the optimum pH 8 and temperature 40°C. SS2 showed maximum extracellular protease and lipase activities in the presence of 0.75 M NaCl, at optimum pH of 7, and temperature 37°C. The glutaminase activity of SS3 increased with increase in concentration of NaCl up to 2.5 M. The optimum pH and temperature for L-glutaminase activity of SS3 was 8 and 40°C, respectively. The combined hydrolytic activities of these halophilic bacterial isolates can be used for bioconversion of organic materials to useful products.

  15. Bactericidal effect of lactoferrin and lactoferrin chimera against halophilic Vibrio parahaemolyticus

    NARCIS (Netherlands)

    Leon-Sicairos, N.; Canizalez-Roman, A.; de la Garza, M.; Reyes-Lopez, M.; Zazueta-Beltran, J.; Nazmi, K.; Gomez-Gil, B.; Bolscher, J.G.

    2009-01-01

    Infections caused by Vibrio parahaemolyticus, an halophilic member of the genus Vibrio, have increased globally in the last 5 years. Diarrhea caused by V. parahaemolyticus results from eating raw or undercooked seafood. The aim of this work was to investigate whether lactoferrin and some

  16. Characterization of the promising poly(3-hydroxybutyrate) producing halophilic bacterium Halomonas halophila

    Czech Academy of Sciences Publication Activity Database

    Kučera, D.; Pernicová, I.; Kovalčik, A.; Koller, M.; Müllerová, L.; Sedláček, P.; Mravec, F.; Nebesářová, Jana; Kalina, M.; Márová, I.; Krzyžánek, Vladislav; Obruča, S.

    2018-01-01

    Roč. 256, May (2018), s. 552-556 ISSN 0960-8524 R&D Projects: GA MŠk(CZ) LM2015062; GA ČR(CZ) GA15-20645S Institutional support: RVO:68081731 Keywords : Halomonas halophila * halophiles * lignocellulose hydrolysates * morphology of bacterial cells * polyhydroxyalkanoates Impact factor: 5.651, year: 2016

  17. Complete Genome Sequence of the Halophilic Methylotrophic Methanogen Archaeon Methanohalophilus portucalensis Strain FDF-1T

    KAUST Repository

    L’ Haridon, Sté phane; Corre, Erwan; Guan, Yue; Vinu, Manikandan; La Cono, Violetta; Yakimov, Michail; Stingl, Ulrich; Toffin, Laurent; Jebbar, Mohamed

    2018-01-01

    We report here the complete genome sequence (2.08 Mb) of Methanohalophilus portucalensis strain FDF-1T, a halophilic methylotrophic methanogen isolated from the sediment of a saltern in Figeria da Foz, Portugal. The average nucleotide identity and DNA-DNA hybridization analyses show that Methanohalophilus mahii, M. halophilus, and M. portucalensis are three different species within the Methanosarcinaceae family.

  18. DNA Repair and Photoprotection: Mechanisms of Overcoming Environmental Ultraviolet Radiation Exposure in Halophilic Archaea

    Directory of Open Access Journals (Sweden)

    Daniel L. Jones

    2017-09-01

    Full Text Available Halophilic archaea push the limits of life at several extremes. In particular, they are noted for their biochemical strategies in dealing with osmotic stress, low water activity and cycles of desiccation in their hypersaline environments. Another feature common to their habitats is intense ultraviolet (UV radiation, which is a challenge that microorganisms must overcome. The consequences of high UV exposure include DNA lesions arising directly from bond rearrangement of adjacent bipyrimidines, or indirectly from oxidative damage, which may ultimately result in mutation and cell death. As such, these microorganisms have evolved a number of strategies to navigate the threat of DNA damage, which we differentiate into two categories: DNA repair and photoprotection. Photoprotection encompasses damage avoidance strategies that serve as a “first line of defense,” and in halophilic archaea include pigmentation by carotenoids, mechanisms of oxidative damage avoidance, polyploidy, and genomic signatures that make DNA less susceptible to photodamage. Photolesions that do arise are addressed by a number of DNA repair mechanisms that halophilic archaea efficiently utilize, which include photoreactivation, nucleotide excision repair, base excision repair, and homologous recombination. This review seeks to place DNA damage, repair, and photoprotection in the context of halophilic archaea and the solar radiation of their hypersaline environments. We also provide new insight into the breadth of strategies and how they may work together to produce remarkable UV-resistance for these microorganisms.

  19. Structural characteristics of alkaline phosphatase from the moderately halophilic bacterium Halomonas sp. 593

    International Nuclear Information System (INIS)

    Arai, Shigeki; Yonezawa, Yasushi; Ishibashi, Matsujiro; Matsumoto, Fumiko; Adachi, Motoyasu; Tamada, Taro; Tokunaga, Hiroko; Blaber, Michael; Tokunaga, Masao; Kuroki, Ryota

    2014-01-01

    In order to clarify the structural basis of the halophilic characteristics of an alkaline phosphatase derived from the moderate halophile Halomonas sp. 593 (HaAP), the tertiary structure of HaAP was determined to 2.1 Å resolution by X-ray crystallography. The structural properties of surface negative charge and core hydrophobicity were shown to be intermediate between those characteristic of halophiles and non-halophiles, and may explain the unique functional adaptation to a wide range of salt concentrations. Alkaline phosphatase (AP) from the moderate halophilic bacterium Halomonas sp. 593 (HaAP) catalyzes the hydrolysis of phosphomonoesters over a wide salt-concentration range (1–4 M NaCl). In order to clarify the structural basis of its halophilic characteristics and its wide-range adaptation to salt concentration, the tertiary structure of HaAP was determined by X-ray crystallography to 2.1 Å resolution. The unit cell of HaAP contained one dimer unit corresponding to the biological unit. The monomer structure of HaAP contains a domain comprised of an 11-stranded β-sheet core with 19 surrounding α-helices similar to those of APs from other species, and a unique ‘crown’ domain containing an extended ‘arm’ structure that participates in formation of a hydrophobic cluster at the entrance to the substrate-binding site. The HaAP structure also displays a unique distribution of negatively charged residues and hydrophobic residues in comparison to other known AP structures. AP from Vibrio sp. G15-21 (VAP; a slight halophile) has the highest similarity in sequence (70.0% identity) and structure (C α r.m.s.d. of 0.82 Å for the monomer) to HaAP. The surface of the HaAP dimer is substantially more acidic than that of the VAP dimer (144 exposed Asp/Glu residues versus 114, respectively), and thus may enable the solubility of HaAP under high-salt conditions. Conversely, the monomer unit of HaAP formed a substantially larger hydrophobic interior comprising 329

  20. Structural characteristics of alkaline phosphatase from the moderately halophilic bacterium Halomonas sp. 593

    Energy Technology Data Exchange (ETDEWEB)

    Arai, Shigeki; Yonezawa, Yasushi [Japan Atomic Energy Agency, 2-4 Shirakata-shirane, Tokai, Ibaraki 319-1195 (Japan); Ishibashi, Matsujiro [Faculty of Agriculture, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065 (Japan); Matsumoto, Fumiko; Adachi, Motoyasu; Tamada, Taro [Japan Atomic Energy Agency, 2-4 Shirakata-shirane, Tokai, Ibaraki 319-1195 (Japan); Tokunaga, Hiroko [Faculty of Agriculture, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065 (Japan); Blaber, Michael [Florida State University, 1115 West Call Street, Tallahassee, FL 32306-4300 (United States); Tokunaga, Masao [Faculty of Agriculture, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065 (Japan); Kuroki, Ryota, E-mail: kuroki.ryota@jaea.go.jp [Japan Atomic Energy Agency, 2-4 Shirakata-shirane, Tokai, Ibaraki 319-1195 (Japan)

    2014-03-01

    In order to clarify the structural basis of the halophilic characteristics of an alkaline phosphatase derived from the moderate halophile Halomonas sp. 593 (HaAP), the tertiary structure of HaAP was determined to 2.1 Å resolution by X-ray crystallography. The structural properties of surface negative charge and core hydrophobicity were shown to be intermediate between those characteristic of halophiles and non-halophiles, and may explain the unique functional adaptation to a wide range of salt concentrations. Alkaline phosphatase (AP) from the moderate halophilic bacterium Halomonas sp. 593 (HaAP) catalyzes the hydrolysis of phosphomonoesters over a wide salt-concentration range (1–4 M NaCl). In order to clarify the structural basis of its halophilic characteristics and its wide-range adaptation to salt concentration, the tertiary structure of HaAP was determined by X-ray crystallography to 2.1 Å resolution. The unit cell of HaAP contained one dimer unit corresponding to the biological unit. The monomer structure of HaAP contains a domain comprised of an 11-stranded β-sheet core with 19 surrounding α-helices similar to those of APs from other species, and a unique ‘crown’ domain containing an extended ‘arm’ structure that participates in formation of a hydrophobic cluster at the entrance to the substrate-binding site. The HaAP structure also displays a unique distribution of negatively charged residues and hydrophobic residues in comparison to other known AP structures. AP from Vibrio sp. G15-21 (VAP; a slight halophile) has the highest similarity in sequence (70.0% identity) and structure (C{sup α} r.m.s.d. of 0.82 Å for the monomer) to HaAP. The surface of the HaAP dimer is substantially more acidic than that of the VAP dimer (144 exposed Asp/Glu residues versus 114, respectively), and thus may enable the solubility of HaAP under high-salt conditions. Conversely, the monomer unit of HaAP formed a substantially larger hydrophobic interior

  1. Identification of Residues Important for the Activity of Haloferax volcanii AglD, a Component of the Archaeal N-Glycosylation Pathway

    Directory of Open Access Journals (Sweden)

    Lina Kaminski

    2010-01-01

    Full Text Available In Haloferax volcanii, AglD adds the final hexose to the N-linked pentasaccharide decorating the S-layer glycoprotein. Not knowing the natural substrate of the glycosyltransferase, together with the challenge of designing assays compatible with hypersalinity, has frustrated efforts at biochemical characterization of AglD activity. To circumvent these obstacles, an in vivo assay designed to identify amino acid residues important for AglD activity is described. In the assay, restoration of AglD function in an Hfx. volcanii aglD deletion strain transformed to express plasmid-encoded versions of AglD, generated through site-directed mutagenesis at positions encoding residues conserved in archaeal homologues of AglD, is reflected in the behavior of a readily detectable reporter of N-glycosylation. As such Asp110 and Asp112 were designated as elements of the DXD motif of AglD, a motif that interacts with metal cations associated with nucleotide-activated sugar donors, while Asp201 was predicted to be the catalytic base of the enzyme.

  2. Identification of residues important for the activity of Haloferax volcanii AglD, a component of the archaeal N-glycosylation pathway.

    Science.gov (United States)

    Kaminski, Lina; Eichler, Jerry

    2010-05-06

    In Haloferax volcanii, AglD adds the final hexose to the N-linked pentasaccharide decorating the S-layer glycoprotein. Not knowing the natural substrate of the glycosyltransferase, together with the challenge of designing assays compatible with hypersalinity, has frustrated efforts at biochemical characterization of AglD activity. To circumvent these obstacles, an in vivo assay designed to identify amino acid residues important for AglD activity is described. In the assay, restoration of AglD function in an Hfx. volcanii aglD deletion strain transformed to express plasmid-encoded versions of AglD, generated through site-directed mutagenesis at positions encoding residues conserved in archaeal homologues of AglD, is reflected in the behavior of a readily detectable reporter of N-glycosylation. As such Asp110 and Asp112 were designated as elements of the DXD motif of AglD, a motif that interacts with metal cations associated with nucleotide-activated sugar donors, while Asp201 was predicted to be the catalytic base of the enzyme.

  3. Halophilic biohydrogen and 1,3-propanediol production from raw glycerol: A genomic perspective

    Energy Technology Data Exchange (ETDEWEB)

    Kivisto, A.

    2013-11-01

    Glycerol is produced in large amounts as a by-product in biodiesel industry (10 kg per 100 kg biodiesel). By-products and waste materials are typically economical substrates for bioprocesses. Furthermore, microorganisms are able to combine the degradation of organic material with production of a wide range of metabolites and other cellular products. The current biotechnological interest of industrial glycerol lies on bioprocesses yielding environmentally friendly energy carrier molecules (hydrogen, methane, ethanol, butanol) and reduced chemicals (1,3-propanediol, dihydroxyacetone). Industrial glycerol also called as raw or crude glycerol, however, is a challenging substrate for microorganisms due to its impurities including alcohol, soaps, salts and metals. Halophiles (the salt-loving microorganisms) require salt for growth and heavy metal resistances have been characterized for numerous halophiles. Therefore, halophiles are potentially useful for the utilization of raw glycerol from biodiesel waste streams without pre-processing. Another challenge for large-scale microbial bioprocesses is a potential contamination with unfavorable microorganisms. For example, H{sub 2}-producing systems tend to get contaminated with H{sub 2}-consuming microorganisms. Extremophiles are organisms that have been adapted for life under extreme conditions, such as high salinity, high or low temperature, asidic or basic pH, dryness or high pressure. For extremophilic pure cultures contamination and thus the need to ensure a sterile environment might not be a problem due to the extreme process conditions that efficiently prevent the growth of most other bacteria. In addition, hypersaline environments (above 12 % NaCl) do not support the growth of H{sub 2} utilizing methanogens due to bioenergetic reasons. Halophilic fermentative H{sub 2} producers, on the other hand, have been shown to be active up to near salt saturation. The aims of the present study can be divided into two categories

  4. Application of lipopeptide biosurfactant isolated from a halophile: Bacillus tequilensis CH for inhibition of biofilm.

    Science.gov (United States)

    Pradhan, Arun Kumar; Pradhan, Nilotpala; Mall, Gangotri; Panda, Himadri Tanaya; Sukla, Lala Behari; Panda, Prasanna Kumar; Mishra, Barada Kanta

    2013-11-01

    Biosurfactants are amphiphilic molecules having hydrophobic and hydrophilic moieties produced by various microorganisms. These molecules trigger the reduction of surface tension or interfacial tension in liquids. A biosurfactant-producing halophile was isolated from Lake Chilika, a brackish water lake of Odisha, India (19°41'39″N, 85°18'24″E). The halophile was identified as Bacillus tequilensis CH by biochemical tests and 16S rRNA gene sequencing and assigned accession no. KC851857 by GenBank. The biosurfactant produced by B. tequilensis CH was partially characterized as a lipopeptide using thin-layer chromatography, Fourier transform infrared spectroscopy, and nuclear magnetic resonance techniques. The minimum effective concentration of a biosurfactant for inhibition of pathogenic biofilm (Escherichia coli and Streptococcus mutans) on hydrophilic and hydrophobic surfaces was found to be 50 μg ml(-1). This finding has potential for a variety of applications.

  5. Lipids of the ultra-thin square halophilic archaeon Haloquadratum walsbyi

    Directory of Open Access Journals (Sweden)

    Simona LoBasso

    2008-01-01

    Full Text Available The lipid composition of the extremely halophilic archaeon Haloquadratum walsbyi was investigated by thin-layer chromatography and electrospray ionization-mass spectrometry. The analysis of neutral lipids showed the presence of vitamin MK-8, squalene, carotene, bacterioruberin and several retinal isomers. The major polar lipids were phosphatidylglycerophosphate methyl ester, phosphatidylglycerosulfate, phosphatidylglycerol and sulfated diglycosyl diether lipid. Among cardiolipins, the tetra-phytanyl or dimeric phospholipids, only traces of bisphosphatidylglycerol were detected. When the cells were exposed to hypotonic medium, no changes in the membrane lipid composition occurred. Distinguishing it from other extreme halophiles of the Halobacteriaceae family, the osmotic stress did not induce the neo-synthesis of cardiolipins in H. walsbyi. The difference may depend on the three-laminar structure of the cell wall, which differs significantly from that of other Haloarchaea.

  6. Bacterioruberin and salinixanthin carotenoids of extremely halophilic Archaea and Bacteria: A Raman spectroscopic study

    Science.gov (United States)

    Jehlička, J.; Edwards, H. G. M.; Oren, A.

    2013-04-01

    Laboratory cultures of a number of red extremely halophilic Archaea (Halobacterium salinarum strains NRC-1 and R1, Halorubrum sodomense, Haloarcula valismortis) and of Salinibacter ruber, a red extremely halophilic member of the Bacteria, have been investigated by Raman spectroscopy using 514.5 nm excitation to characterize their carotenoids. The 50-carbon carotenoid α-bacterioruberin was detected as the major carotenoid in all archaeal strains. Raman spectroscopy also detected bacterioruberin as the main pigment in a red pellet of cells collected from a saltern crystallizer pond. Salinibacter contains the C40-carotenoid acyl glycoside salinixanthin (all-E, 2'S)-2'-hydroxy-1'-[6-O-(methyltetradecanoyl)-β-D-glycopyranosyloxy]-3',4'-didehydro-1',2'-dihydro-β,ψ-carotene-4-one), for which the Raman bands assignments of are given here for the first time.

  7. Genomic adaptations of the halophilic Dead Sea filamentous fungus Eurotium rubrum.

    Science.gov (United States)

    Kis-Papo, Tamar; Weig, Alfons R; Riley, Robert; Peršoh, Derek; Salamov, Asaf; Sun, Hui; Lipzen, Anna; Wasser, Solomon P; Rambold, Gerhard; Grigoriev, Igor V; Nevo, Eviatar

    2014-05-09

    The Dead Sea is one of the most hypersaline habitats on Earth. The fungus Eurotium rubrum (Eurotiomycetes) is among the few species able to survive there. Here we highlight its adaptive strategies, based on genome analysis and transcriptome profiling. The 26.2 Mb genome of E. rubrum shows, for example, gains in gene families related to stress response and losses with regard to transport processes. Transcriptome analyses under different salt growth conditions revealed, among other things differentially expressed genes encoding ion and metabolite transporters. Our findings suggest that long-term adaptation to salinity requires cellular and metabolic responses that differ from short-term osmotic stress signalling. The transcriptional response indicates that halophilic E. rubrum actively counteracts the salinity stress. Many of its genes encode for proteins with a significantly higher proportion of acidic amino acid residues. This trait is characteristic of the halophilic prokaryotes as well, supporting the theory of convergent evolution under extreme hypersaline stress.

  8. Production of poly-3-(hydroxybutyrate-co-hydroxyvalerate) by Haloferax mediterranei using rice-based ethanol stillage with simultaneous recovery and re-use of medium salts.

    Science.gov (United States)

    Bhattacharyya, Anirban; Saha, Jayeeta; Haldar, Saubhik; Bhowmic, Asit; Mukhopadhyay, Ujjal Kumar; Mukherjee, Joydeep

    2014-03-01

    Haloferax mediterranei holds promise for competitive industrial-scale production of polyhydroxyalkanoate (PHA) because cheap carbon sources can be used thus lowering production costs. Although high salt concentration in production medium permits a non-sterile, low-cost process, salt disposal after process completion is a problem as current environmental standards do not allow total dissolved solids (TDS) above 2000 mg/l in discharge water. As the first objective of this work, the waste product of rice-based ethanol industry, stillage, was used for the production of PHA by H. mediterranei in shake flasks. Utilization of raw stillage led to 71 ± 2% (of dry cell weight) PHA accumulation and 16.42 ± 0.02 g/l PHA production. The product yield coefficient was 0.35 while 0.17 g/l h volumetric productivity was attained. Simultaneous reduction of BOD5 and COD values of stillage by 83% was accomplished. The PHA was isolated by osmotic lysis of cells, purification by sodium dodecyl sulfate and organic solvents. The biopolymer was identified as poly-3-(hydroxybutyrate-co-15.4 mol%-hydroxyvalerate) (PHBV). This first report on utilization of rice-based ethanol stillage for PHBV production by H. mediterranei is currently the most cost effective. As the second objective, directional properties of decanoic acid together with temperature dependence of water solubility in decanoic acid were applied for two-stage desalination of the spent stillage medium. We report for the first time, recovery and re-use of 96% of the medium salts for PHA production thus removing the major bottleneck in the potential application of H. mediterranei for industrial production of PHBV. Final discharge water had TDS content of 670 mg/l.

  9. Molecular interactions within the halophilic, thermophilic, and mesophilic prokaryotic ribosomal complexes: clues to environmental adaptation.

    Science.gov (United States)

    Mallik, Saurav; Kundu, Sudip

    2015-01-01

    Using the available crystal structures of 50S ribosomal subunits from three prokaryotic species: Escherichia coli (mesophilic), Thermus thermophilus (thermophilic), and Haloarcula marismortui (halophilic), we have analyzed different structural features of ribosomal RNAs (rRNAs), proteins, and of their interfaces. We have correlated these structural features with the environmental adaptation strategies of the corresponding species. While dense intra-rRNA packing is observed in thermophilic, loose intra-rRNA packing is observed in halophilic (both compared to mesophilic). Interestingly, protein-rRNA interfaces of both the extremophiles are densely packed compared to that of the mesophilic. The intersubunit bridge regions are almost devoid of cavities, probably ensuring the proper formation of each bridge (by not allowing any loosely packed region nearby). During rRNA binding, the ribosomal proteins experience some structural transitions. Here, we have analyzed the intrinsically disordered and ordered regions of the ribosomal proteins, which are subjected to such transitions. The intrinsically disordered and disorder-to-order transition sites of the thermophilic and mesophilic ribosomal proteins are simultaneously (i) highly conserved and (ii) slowly evolving compared to rest of the protein structure. Although high conservation is observed at such sites of halophilic ribosomal proteins, but slow rate of evolution is absent. Such differences between thermophilic, mesophilic, and halophilic can be explained from their environmental adaptation strategy. Interestingly, a universal biophysical principle evident by a linear relationship between the free energy of interface formation, interface area, and structural changes of r-proteins during assembly is always maintained, irrespective of the environmental conditions.

  10. Comparison of two extreme halophilic Halobacterium noricense strains on DNA and protein level

    Energy Technology Data Exchange (ETDEWEB)

    Bader, Miriam; Cherkouk, Andrea [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). HZDR Young Investigator Group; Flemming, Katrin [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Biogeochemistry; Swanson, J.S. [Los Alamos National Laboratory, Carlsbad, NM (United States)

    2017-06-01

    Two strains of the halophilic archaeon Halobacterium noricense isolated from rock salt of different locations were used for interaction studies with uranium. It was found that both strains showed similar, atypical bioassociation kinetics accompanied by cell agglomeration as a stress response. The 16S rRNA gene sequences of both strains had a high similarity (> 99 %). However, differences in the whole protein pattern were apparent.

  11. Comparison of two extreme halophilic Halobacterium noricense strains on DNA and protein level

    International Nuclear Information System (INIS)

    Bader, Miriam; Cherkouk, Andrea

    2017-01-01

    Two strains of the halophilic archaeon Halobacterium noricense isolated from rock salt of different locations were used for interaction studies with uranium. It was found that both strains showed similar, atypical bioassociation kinetics accompanied by cell agglomeration as a stress response. The 16S rRNA gene sequences of both strains had a high similarity (> 99 %). However, differences in the whole protein pattern were apparent.

  12. Biodeterioration Risk Threatens the 3100 Year Old Staircase of Hallstatt (Austria): Possible Involvement of Halophilic Microorganisms.

    Science.gov (United States)

    Piñar, Guadalupe; Dalnodar, Dennis; Voitl, Christian; Reschreiter, Hans; Sterflinger, Katja

    2016-01-01

    The prosperity of Hallstatt (Salzkammergut region, Austria) is based on the richness of salt in the surrounding mountains and salt mining, which is documented as far back as 1500 years B.C. Substantial archaeological evidence of Bronze and Iron Age salt mining has been discovered, with a wooden staircase (1108 B.C.) being one of the most impressive and well preserved finds. However, after its discovery, fungal mycelia have been observed on the surface of the staircase, most probably due to airborne contamination after its find. As a basis for the further preservation of this valuable object, the active micro-flora was examined to investigate the presence of potentially biodegradative microorganisms. Most of the strains isolated from the staircase showed to be halotolerant and halophilic microorganisms, due to the saline environment of the mine. Results derived from culture-dependent assays revealed a high fungal diversity, including both halotolerant and halophilic fungi, the most dominant strains being members of the genus Phialosimplex (synonym: Aspergillus). Additionally, some typical cellulose degraders, namely Stachybotrys sp. and Cladosporium sp. were detected. Numerous bacterial strains were isolated and identified as members of 12 different genera, most of them being moderately halophilic species. The most dominant isolates affiliated with species of the genera Halovibrio and Marinococcus. Halophilic archaea were also isolated and identified as species of the genera Halococcus and Halorubrum. Molecular analyses complemented the cultivation assays, enabling the identification of some uncultivable archaea of the genera Halolamina, Haloplanus and Halobacterium. Results derived from fungi and bacteria supported those obtained by cultivation methods, exhibiting the same dominant members in the communities. The results clearly showed the presence of some cellulose degraders that may become active if the requirements for growth and the environmental conditions

  13. Halophilic and halotolerant actinomycetes from a marine saltern of Goa, India producing anti-bacterial metabolites.

    Science.gov (United States)

    Ballav, Shuvankar; Kerkar, Savita; Thomas, Sabu; Augustine, Nimmy

    2015-03-01

    Marine salterns are estuarine ecosystems in Goa, receiving inputs from riverine and marine waters. The Salinity fluctuates between 0 and 300 psu which makes it a conducive niche for salt tolerant and salt loving Actinomycetales. Halotolerant and halophilic Actinomycetales producing anti-bacterial metabolites were studied from crystallizer pond sediments of Ribandar saltern, Goa. Three media viz. Starch casein, R2A and Inorganic salt starch agar at four different salinities (35, 50, 75 and 100 psu) were used for isolation. R2A agar at 35 psu was the most preferred by hypersaline actinomycetes. The dominant group was halotolerant Streptomyces spp. others being rare actinomycetes viz. Nocardiopsis, Micromonospora and Kocuria spp. More than 50% of the isolates showed anti-bacterial activity against one or more of the fifteen human pathogens tested. Eight strains from 4 genera showed consistent anti-bacterial activity and studied in detail. Most halotolerant isolates grew from 0 to 75 psu, with optimum antibiotic production at 35 psu whereas halophiles grew at 20 to 100 psu with optimum antibiotic production at 35 psu. Four Streptomyces strains showed multiple inhibition against test organisms while four rare actinomycetes were specific in their inhibitory activity. This is the first report of a halophilic Kocuria sp., Nocardiopsis sp., and halotolerant Micromonospora sp. producing anti-bacterial compound(s) against Staphylococcus aureus, Staphylococcus citreus, and Vibrio cholerae, respectively. Sequential extraction with varying polarity of organic solvents showed that the extracts inhibited different test pathogens. These results suggest that halophilic and halotolerant actinomycetes from marine salterns are a potential source of anti-bacterial compounds. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  14. DNA Repair and Photoprotection: Mechanisms of Overcoming Environmental Ultraviolet Radiation Exposure in Halophilic Archaea

    OpenAIRE

    Daniel L. Jones; Bonnie K. Baxter

    2017-01-01

    Halophilic archaea push the limits of life at several extremes. In particular, they are noted for their biochemical strategies in dealing with osmotic stress, low water activity and cycles of desiccation in their hypersaline environments. Another feature common to their habitats is intense ultraviolet (UV) radiation, which is a challenge that microorganisms must overcome. The consequences of high UV exposure include DNA lesions arising directly from bond rearrangement of adjacent bipyrimidine...

  15. Biodegradation of benzene by halophilic and halotolerant bacteria under aerobic conditions.

    Science.gov (United States)

    Nicholson, Carla A; Fathepure, Babu Z

    2004-02-01

    A highly enriched halophilic culture was established with benzene as the sole carbon source by using a brine soil obtained from an oil production facility in Oklahoma. The enrichment completely degraded benzene, toluene, ethylbenzene, and xylenes within 1 to 2 weeks. Also, [14C]benzene was converted to 14CO2, suggesting the culture's ability to mineralize benzene. Community structure analysis revealed that Marinobacter spp. were the dominant members of the enrichment.

  16. Biodeterioration Risk Threatens the 3100 Year Old Staircase of Hallstatt (Austria: Possible Involvement of Halophilic Microorganisms.

    Directory of Open Access Journals (Sweden)

    Guadalupe Piñar

    Full Text Available The prosperity of Hallstatt (Salzkammergut region, Austria is based on the richness of salt in the surrounding mountains and salt mining, which is documented as far back as 1500 years B.C. Substantial archaeological evidence of Bronze and Iron Age salt mining has been discovered, with a wooden staircase (1108 B.C. being one of the most impressive and well preserved finds. However, after its discovery, fungal mycelia have been observed on the surface of the staircase, most probably due to airborne contamination after its find.As a basis for the further preservation of this valuable object, the active micro-flora was examined to investigate the presence of potentially biodegradative microorganisms.Most of the strains isolated from the staircase showed to be halotolerant and halophilic microorganisms, due to the saline environment of the mine. Results derived from culture-dependent assays revealed a high fungal diversity, including both halotolerant and halophilic fungi, the most dominant strains being members of the genus Phialosimplex (synonym: Aspergillus. Additionally, some typical cellulose degraders, namely Stachybotrys sp. and Cladosporium sp. were detected. Numerous bacterial strains were isolated and identified as members of 12 different genera, most of them being moderately halophilic species. The most dominant isolates affiliated with species of the genera Halovibrio and Marinococcus. Halophilic archaea were also isolated and identified as species of the genera Halococcus and Halorubrum. Molecular analyses complemented the cultivation assays, enabling the identification of some uncultivable archaea of the genera Halolamina, Haloplanus and Halobacterium. Results derived from fungi and bacteria supported those obtained by cultivation methods, exhibiting the same dominant members in the communities.The results clearly showed the presence of some cellulose degraders that may become active if the requirements for growth and the environmental

  17. Microbial culturomics unravels the halophilic microbiota repertoire of table salt: description of Gracilibacillus massiliensis sp. nov.

    Directory of Open Access Journals (Sweden)

    Awa Diop

    2016-10-01

    Full Text Available Background: Microbial culturomics represents an ongoing revolution in the characterization of environmental and human microbiome. Methods: By using three media containing high salt concentration (100, 150, and 200 g/L, the halophilic microbial culturome of a commercial table salt was determined. Results: Eighteen species belonging to the Terrabacteria group were isolated including eight moderate halophilic and 10 halotolerant bacteria. Gracilibacillus massiliensis sp. nov., type strain Awa-1T (=CSUR P1441=DSM 29726, is a moderately halophilic gram-positive, non-spore-forming rod, and is motile by using a flagellum. Strain Awa-1T shows catalase activity but no oxidase activity. It is not only an aerobic bacterium but also able to grow in anaerobic and microaerophilic atmospheres. The draft genome of G. massiliensis is 4,207,226 bp long, composed of 13 scaffolds with 36.05% of G+C content. It contains 3,908 genes (3,839 protein-coding and 69 RNA genes. At least 1,983 (52% orthologous proteins were not shared with the closest phylogenetic species. Hundred twenty-six genes (3.3% were identified as ORFans. Conclusions: Microbial culturomics can dramatically improve the characterization of the food and environmental microbiota repertoire, deciphering new bacterial species and new genes. Further studies will clarify the geographic specificity and the putative role of these new microbes and their related functional genetic content in environment, health, and disease.

  18. Global transcriptome analysis of Halolamina sp. to decipher the salt tolerance in extremely halophilic archaea.

    Science.gov (United States)

    Kurt-Kızıldoğan, Aslıhan; Abanoz, Büşra; Okay, Sezer

    2017-02-15

    Extremely halophilic archaea survive in the hypersaline environments such as salt lakes or salt mines. Therefore, these microorganisms are good sources to investigate the molecular mechanisms underlying the tolerance to high salt concentrations. In this study, a global transcriptome analysis was conducted in an extremely halophilic archaeon, Halolamina sp. YKT1, isolated from a salt mine in Turkey. A comparative RNA-seq analysis was performed using YKT1 isolate grown either at 2.7M NaCl or 5.5M NaCl concentrations. A total of 2149 genes were predicted to be up-regulated and 1638 genes were down-regulated in the presence of 5.5M NaCl. The salt tolerance of Halolamina sp. YKT1 involves the up-regulation of genes related with membrane transporters, CRISPR-Cas systems, osmoprotectant solutes, oxidative stress proteins, and iron metabolism. On the other hand, the genes encoding the proteins involved in DNA replication, transcription, translation, mismatch and nucleotide excision repair were down-regulated. The RNA-seq data were verified for seven up-regulated genes as well as six down-regulated genes via qRT-PCR analysis. This comprehensive transcriptome analysis showed that the halophilic archaeon canalizes its energy towards keeping the intracellular osmotic balance minimizing the production of nucleic acids and peptides. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. An Extremely Halophilic Proteobacterium Combines a Highly Acidic Proteome with a Low Cytoplasmic Potassium Content*

    Science.gov (United States)

    Deole, Ratnakar; Challacombe, Jean; Raiford, Douglas W.; Hoff, Wouter D.

    2013-01-01

    Halophilic archaea accumulate molar concentrations of KCl in their cytoplasm as an osmoprotectant and have evolved highly acidic proteomes that function only at high salinity. We examined osmoprotection in the photosynthetic Proteobacteria Halorhodospira halophila and Halorhodospira halochloris. Genome sequencing and isoelectric focusing gel electrophoresis showed that the proteome of H. halophila is acidic. In line with this finding, H. halophila accumulated molar concentrations of KCl when grown in high salt medium as detected by x-ray microanalysis and plasma emission spectrometry. This result extends the taxonomic range of organisms using KCl as a main osmoprotectant to the Proteobacteria. The closely related organism H. halochloris does not exhibit an acidic proteome, matching its inability to accumulate K+. This observation indicates recent evolutionary changes in the osmoprotection strategy of these organisms. Upon growth of H. halophila in low salt medium, its cytoplasmic K+ content matches that of Escherichia coli, revealing an acidic proteome that can function in the absence of high cytoplasmic salt concentrations. These findings necessitate a reassessment of two central aspects of theories for understanding extreme halophiles. First, we conclude that proteome acidity is not driven by stabilizing interactions between K+ ions and acidic side chains but by the need for maintaining sufficient solvation and hydration of the protein surface at high salinity through strongly hydrated carboxylates. Second, we propose that obligate protein halophilicity is a non-adaptive property resulting from genetic drift in which constructive neutral evolution progressively incorporates weakly stabilizing K+-binding sites on an increasingly acidic protein surface. PMID:23144460

  20. Isolation and characterization of two novel halotolerant Catechol 2, 3-dioxygenases from a halophilic bacterial consortium

    Science.gov (United States)

    Guo, Guang; Fang, Tingting; Wang, Chongyang; Huang, Yong; Tian, Fang; Cui, Qijia; Wang, Hui

    2015-12-01

    Study of enzymes in halophiles will help to understand the mechanism of aromatic hydrocarbons degradation in saline environment. In this study, two novel catechol 2,3-dioxygenases (C23O1 and C23O2) were cloned and overexpressed from a halophilic bacterial consortium enriched from an oil-contaminated saline soil. Phylogenetic analysis indicated that the novel C23Os and their relatives formed a new branch in subfamily I.2.A of extradiol dioxygenases and the sequence differences were further analyzed by amino acid sequence alignment. Two enzymes with the halotolerant feature were active over a range of 0-30% salinity and they performed more stable at high salinity than in the absence of salt. Surface electrostatic potential and amino acids composition calculation suggested high acidic residues content, accounting for their tolerance to high salinity. Moreover, two enzymes were further characterized. The enzymes activity both increased in the presence of Fe3+, Fe2+, Cu2+ and Al3+ and showed no significant inhibition by other tested metal ions. The optimal temperatures for the C23Os were 40 °C and 60 °C and their best substrates were catechol and 4-methylcatechol respectively. As the firstly isolated and characterized catechol dioxygenases from halophiles, the two halotolerant C23Os presented novel characteristics suggesting their potential application in aromatic hydrocarbons biodegradation.

  1. Solid-state fermentation as a potential technique for esterase/lipase production by halophilic archaea.

    Science.gov (United States)

    Martin del Campo, Martha; Camacho, Rosa M; Mateos-Díaz, Juan C; Müller-Santos, Marcelo; Córdova, Jesus; Rodríguez, Jorge A

    2015-11-01

    Halophilic archaea are extremophiles, adapted to high-salt environments, showing a big biotechnological potential as enzyme, lipids and pigments producers. Four inert supports (perlite, vermiculite, polyurethane foam and glass fiber) were employed for solid-state fermentation (SSF) of the halophilic archaeon Natronococcus sp. TC6 to investigate biomass and esterase production. A very low esterase activity and high water activity were observed when perlite, vermiculite and polyurethane were used as supports. When glass fiber was employed, an important moisture loss was observed (8.6%). Moreover, moisture retention was improved by mixing polyurethane and glass fiber, resulting in maximal biomass and esterase production. Three halophilic archaea: Natronococcus sp. TC6, Halobacterium sp. NRC-1 and Haloarcula marismortui were cultured by submerged fermentation (SmF) and by SSF; an improvement of 1.3- to 6.2-fold was observed in the biomass and esterase production when SSF was used. Growth was not homogeneous in the mixture, but was predominant in the glass fiber thus was probably because the glass fiber provides a holder to the cells, while the polyurethane acts as an impregnation medium reservoir. To the best of our knowledge, this work is the first report on haloarchaea cultivation by SSF aiming biomass and esterase/lipase activity production.

  2. Analysis of metagenomic data reveals common features of halophilic viral communities across continents.

    Science.gov (United States)

    Roux, Simon; Enault, Francois; Ravet, Viviane; Colombet, Jonathan; Bettarel, Yvan; Auguet, Jean-Christophe; Bouvier, Thierry; Lucas-Staat, Soizick; Vellet, Agnès; Prangishvili, David; Forterre, Patrick; Debroas, Didier; Sime-Ngando, Telesphore

    2016-03-01

    Microbial communities from hypersaline ponds, dominated by halophilic archaea, are considered specific of such extreme conditions. The associated viral communities have accordingly been shown to display specific features, such as similar morphologies among different sites. However, little is known about the genetic diversity of these halophilic viral communities across the Earth. Here, we studied viral communities in hypersaline ponds sampled on the coast of Senegal (8-36% of salinity) using metagenomics approach, and compared them with hypersaline viromes from Australia and Spain. The specificity of hyperhalophilic viruses could first be demonstrated at a community scale, salinity being a strong discriminating factor between communities. For the major viral group detected in all samples (Caudovirales), only a limited number of halophilic Caudovirales clades were highlighted. These clades gather viruses from different continents and display consistent genetic composition, indicating that they represent related lineages with a worldwide distribution. Non-tailed hyperhalophilic viruses display a greater rate of gene transfer and recombination, with uncharacterized genes conserved across different kind of viruses and plasmids. Thus, hypersaline viral communities around the world appear to form a genetically consistent community that are likely to harbour new genes coding for enzymes specifically adapted to these environments. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  3. Purification and Characterization of Haloalkaline, Organic Solvent Stable Xylanase from Newly Isolated Halophilic Bacterium-OKH

    Science.gov (United States)

    Sanghvi, Gaurav; Jivrajani, Mehul; Patel, Nirav; Jivrajani, Heta; Bhaskara, Govinal Badiger; Patel, Shivani

    2014-01-01

    A novel, alkali-tolerant halophilic bacterium-OKH with an ability to produce extracellular halophilic, alkali-tolerant, organic solvent stable, and moderately thermostable xylanase was isolated from salt salterns of Mithapur region, Gujarat, India. Identification of the bacterium was done based upon biochemical tests and 16S rRNA sequence. Maximum xylanase production was achieved at pH 9.0 and 37°C temperature in the medium containing 15% NaCl and 1% (w/v) corn cobs. Sugarcane bagasse and wheat straw also induce xylanase production when used as carbon source. The enzyme was active over a range of 0–25% sodium chloride examined in culture broth. The optimum xylanase activity was observed at 5% sodium chloride. Xylanase was purified with 25.81%-fold purification and 17.1% yield. Kinetic properties such as Km and Vmax were 4.2 mg/mL and 0.31 μmol/min/mL, respectively. The enzyme was stable at pH 6.0 and 50°C with 60% activity after 8 hours of incubation. Enzyme activity was enhanced by Ca2+, Mn2+, and Mg2+ but strongly inhibited by heavy metals such as Hg2+, Fe3+, Ni2+, and Zn2+. Xylanase was found to be stable in organic solvents like glutaraldehyde and isopropanol. The purified enzyme hydrolysed lignocellulosic substrates. Xylanase, purified from the halophilic bacterium-OKH, has potential biotechnological applications. PMID:27350996

  4. Microbial culturomics unravels the halophilic microbiota repertoire of table salt: description of Gracilibacillus massiliensis sp. nov.

    Science.gov (United States)

    Diop, Awa; Khelaifia, Saber; Armstrong, Nicholas; Labas, Noémie; Fournier, Pierre-Edouard; Raoult, Didier; Million, Matthieu

    2016-01-01

    Microbial culturomics represents an ongoing revolution in the characterization of environmental and human microbiome. By using three media containing high salt concentration (100, 150, and 200 g/L), the halophilic microbial culturome of a commercial table salt was determined. Eighteen species belonging to the Terrabacteria group were isolated including eight moderate halophilic and 10 halotolerant bacteria. Gracilibacillus massiliensis sp. nov., type strain Awa-1 T (=CSUR P1441=DSM 29726), is a moderately halophilic gram-positive, non-spore-forming rod, and is motile by using a flagellum. Strain Awa-1 T shows catalase activity but no oxidase activity. It is not only an aerobic bacterium but also able to grow in anaerobic and microaerophilic atmospheres. The draft genome of G. massiliensis is 4,207,226 bp long, composed of 13 scaffolds with 36.05% of G+C content. It contains 3,908 genes (3,839 protein-coding and 69 RNA genes). At least 1,983 (52%) orthologous proteins were not shared with the closest phylogenetic species. Hundred twenty-six genes (3.3%) were identified as ORFans. Microbial culturomics can dramatically improve the characterization of the food and environmental microbiota repertoire, deciphering new bacterial species and new genes. Further studies will clarify the geographic specificity and the putative role of these new microbes and their related functional genetic content in environment, health, and disease.

  5. Characterization of the proteasome from the extremely halophilic archaeon Haloarcula marismortui

    Directory of Open Access Journals (Sweden)

    B. Franzetti

    2002-01-01

    Full Text Available A 20S proteasome, comprising two subunits α and β, was purified from the extreme halophilic archaeon Haloarcula marismortui, which grows only in saturated salt conditions. The three-dimensional reconstruction of the H. marismortui proteasome (Hm proteasome, obtained from negatively stained electron micrographs, is virtually identical to the structure of a thermophilic proteasome filtered to the same resolution. The stability of the Hm proteasome was found to be less salt-dependent than that of other halophilic enzymes previously described. The proteolytic activity of the Hm proteasome was investigated using the malate dehydrogenase from H. marismortui (HmMalDH as a model substrate. The HmMalDH denatures when the salt concentration is decreased below 2 M. Under these conditions, the proteasome efficiently cleaves HmMalDH during its denaturation process, but the fully denatured HmMalDH is poorly degraded. These in vitro experiments show that, at low salt concentrations, the 20S proteasome from halophilic archaea eliminates a misfolded protein.

  6. Reversible Activation of Halophilic β-lactamase from Methanol-Induced Inactive Form: Contrast to Irreversible Inactivation of Non-Halophilic Counterpart.

    Science.gov (United States)

    Tokunaga, Hiroko; Maeda, Junpei; Arakawa, Tsutomu; Tokunaga, Masao

    2017-06-01

    Effects of a water-miscible organic solvent, methanol, on the structure and activity of halophilic β-lactamase derived from Chromohalobacter sp.560 (HaBla), were investigated by means of circular dichroism (CD) measurement and enzymatic activity determination. Beta-lactamase activity was enhanced about 1.2-fold in the presence of 10-20% methanol. CD measurement of HaBla revealed different structures depending on the methanol concentration: native-like active form (Form I) in 10-20% methanol and methanol-induced inactive form at higher concentration (Form II in 40-60% and Form III in 75-80% methanol). Incubation of HaBla with 40% methanol led to the complete loss of activity within ~80 min accompanied by the formation of Form II, whose activity was recovered promptly up to ~80% of full activity upon dilution of the methanol concentration to 10%. In addition, when the protein concentration was sufficiently high (e.g., 0.7 mg/ml), HaBla activity of Form III in 75% methanol could be recovered in the same way (with slightly slower recovery rate), upon dilution of the methanol concentration. In contrast, non-halophilic β-lactamase from Escherichia coli K12 strain MG1655 (EcBla) was irreversibly denatured in the presence of 40% methanol. HaBla showed remarkable ability to renature from the methanol-induced inactive states.

  7. Microbial culturomics to isolate halophilic bacteria from table salt: genome sequence and description of the moderately halophilic bacterium Bacillus salis sp. nov.

    Science.gov (United States)

    Seck, E H; Diop, A; Armstrong, N; Delerce, J; Fournier, P-E; Raoult, D; Khelaifia, S

    2018-05-01

    Bacillus salis strain ES3 T (= CSUR P1478 = DSM 100598) is the type strain of B. salis sp. nov. It is an aerobic, Gram-positive, moderately halophilic, motile and spore-forming bacterium. It was isolated from commercial table salt as part of a broad culturomics study aiming to maximize the culture conditions for the in-depth exploration of halophilic bacteria in salty food. Here we describe the phenotypic characteristics of this isolate, its complete genome sequence and annotation, together with a comparison with closely related bacteria. Phylogenetic analysis based on 16S rRNA gene sequences indicated 97.5% similarity with Bacillus aquimaris, the closest species. The 8 329 771 bp long genome (one chromosome, no plasmids) exhibits a G+C content of 39.19%. It is composed of 18 scaffolds with 29 contigs. Of the 8303 predicted genes, 8109 were protein-coding genes and 194 were RNAs. A total of 5778 genes (71.25%) were assigned a putative function.

  8. Effect of UVC Radiation on Hydrated and Desiccated Cultures of Slightly Halophilic and Non-Halophilic Methanogenic Archaea: Implications for Life on Mars.

    Science.gov (United States)

    Sinha, Navita; Kral, Timothy A

    2018-05-12

    Methanogens have been considered models for life on Mars for many years. In order to survive any exposure at the surface of Mars, methanogens would have to endure Martian UVC radiation. In this research, we irradiated hydrated and desiccated cultures of slightly halophilic Methanococcus maripaludis and non-halophilic Methanobacterium formicicum for various time intervals with UVC (254 nm) radiation. The survivability of the methanogens was determined by measuring methane concentrations in the headspace gas samples of culture tubes after re-inoculation of the methanogens into their growth-supporting media following exposure to UVC radiation. Hydrated M. maripaludis survived 24 h of UVC exposure, while in a desiccated condition they endured for 16 h. M. formicicum also survived UVC radiation for 24 h in a liquid state; however, in a desiccated condition, the survivability of M. formicicum was only 12 h. Some of the components of the growth media could have served as shielding agents that protected cells from damage caused by exposure to ultraviolet radiation. Overall, these results suggest that limited exposure (12⁻24 h) to UVC radiation on the surface of Mars would not necessarily be a limiting factor for the survivability of M. maripaludis and M. formicicum .

  9. Production of surfactant and detergent-stable, halophilic, and alkalitolerant alpha-amylase by a moderately halophilic Bacillus sp. Strain TSCVKK.

    Science.gov (United States)

    Kiran, Kondepudi Kanthi; Chandra, T S

    2008-01-01

    A moderately halophilic alkalitolerant Bacillus sp. Strain TSCVKK, with an ability to produce extracellular halophilic, alkalitolerant, surfactant, and detergent-stable alpha-amylase was isolated from soil samples obtained from a salt-manufacturing industry in Chennai. The culture conditions for higher amylase production were optimized with respect to NaCl, substrate, pH, and temperature. Maximum amylase production of 592 mU/ml was achieved in the medium at 48 h with 10% NaCl, 1% dextrin, 0.4% yeast extract, 0.2% tryptone, and 0.2% CaCl(2) at pH 8.0 at 30 degrees C. The enzyme activity in the culture supernatant was highest with 10% NaCl at pH 7.5 and 55 degrees C. The amylase that was partially purified by acetone precipitation was highly stable in various surfactants and detergents. Glucose, maltose, and maltooligosaccharides were the main end products of starch hydrolysis indicating that it is an alpha-amylase.

  10. Catalytic properties of thermophilic lactate dehydrogenase and halophilic malate dehydrogenase at high temperature and low water activity.

    Science.gov (United States)

    Hecht, K; Wrba, A; Jaenicke, R

    1989-07-15

    Thermophilic lactate dehydrogenases from Thermotoga maritima and Bacillus stearothermophilus are stable up to temperature limits close to the optimum growth temperature of their parent organisms. Their catalytic properties are anomalous in that Km shows a drastic increase with increasing temperature. At low temperatures, the effect levels off. Extreme halophilic malate dehydrogenase from Halobacterium marismortui exhibits a similar anomaly. Increasing salt concentration (NaCl) leads to an optimum curve for Km, oxaloacctate while Km, NADH remains constant. Previous claims that the activity of halophilic malate dehydrogenase shows a maximum at 1.25 M NaCl are caused by limiting substrate concentration; at substrate saturation, specific activity of halophilic malate dehydrogenase reaches a constant value at ionic strengths I greater than or equal to 1 M. Non-halophilic (mitochondrial) malate dehydrogenase shows Km characteristics similar to those observed for the halophilic enzyme. The drastic decrease in specific activity of the mitochondrial enzyme at elevated salt concentrations is caused by the salt-induced increase in rigidity of the enzyme, rather than gross structural changes.

  11. Approach toward enhancement of halophilic protease production by Halobacterium sp. strain LBU50301 using statistical design response surface methodology.

    Science.gov (United States)

    Chuprom, Julalak; Bovornreungroj, Preeyanuch; Ahmad, Mehraj; Kantachote, Duangporn; Dueramae, Sawitree

    2016-06-01

    A new potent halophilic protease producer, Halobacterium sp. strain LBU50301 was isolated from salt-fermented fish samples ( budu ) and identified by phenotypic analysis, and 16S rDNA gene sequencing. Thereafter, sequential statistical strategy was used to optimize halophilic protease production from Halobacterium sp. strain LBU50301 by shake-flask fermentation. The classical one-factor-at-a-time (OFAT) approach determined gelatin was the best nitrogen source. Based on Plackett - Burman (PB) experimental design; gelatin, MgSO 4 ·7H 2 O, NaCl and pH significantly influenced the halophilic protease production. Central composite design (CCD) determined the optimum level of medium components. Subsequently, an 8.78-fold increase in corresponding halophilic protease yield (156.22 U/mL) was obtained, compared with that produced in the original medium (17.80 U/mL). Validation experiments proved the adequacy and accuracy of model, and the results showed the predicted value agreed well with the experimental values. An overall 13-fold increase in halophilic protease yield was achieved using a 3 L laboratory fermenter and optimized medium (231.33 U/mL).

  12. [Community structure and diversity of culturable moderate halophilic bacteria isolated from Qrhan salt lake on Qinghai-Tibet Plateau].

    Science.gov (United States)

    Shen, Shuo

    2017-04-04

    I studied the community structure and diversity of culturable moderate halophilic bacteria isolated from Qrhan Salt Lake. I isolated and cultured the moderate halophilic bacteria on different selective media. After the 16S rRNA gene sequences was amplified and measured, I constructed the phylogenic tree, analyzed the community structure and calculated the diversity indexes according to the 16S rRNA gene information. A total of 421 moderate halophilic bacteria were isolated from water and mud samples in Qrhan Salt Lake. The 16S rRNA gene information showed that 4 potential novel species belonged to the family Bacillaceae. Eighty-three model strains belonged to 3 phylurms 6 families 16 genus. Among them, Bacillus sp., Oceanobacillus sp. and Halomonas sp. were dominant species. Diversity analysis showed that the diversity of strains isolated from water sample was higher than that from mud sample, but the dominance degree of strains isolated from mud sample was higher than that from water sample. The genetic diversity of moderate halophilic bacteria isolated from Qrhan Salt Lake was abundant. Also, there were dominant and novel species of culturable moderate halophilic bacteria in this lake.

  13. Approach toward enhancement of halophilic protease production by Halobacterium sp. strain LBU50301 using statistical design response surface methodology

    Directory of Open Access Journals (Sweden)

    Julalak Chuprom

    2016-06-01

    Full Text Available A new potent halophilic protease producer, Halobacterium sp. strain LBU50301 was isolated from salt-fermented fish samples (budu and identified by phenotypic analysis, and 16S rDNA gene sequencing. Thereafter, sequential statistical strategy was used to optimize halophilic protease production from Halobacterium sp. strain LBU50301 by shake-flask fermentation. The classical one-factor-at-a-time (OFAT approach determined gelatin was the best nitrogen source. Based on Plackett–Burman (PB experimental design; gelatin, MgSO4·7H2O, NaCl and pH significantly influenced the halophilic protease production. Central composite design (CCD determined the optimum level of medium components. Subsequently, an 8.78-fold increase in corresponding halophilic protease yield (156.22 U/mL was obtained, compared with that produced in the original medium (17.80 U/mL. Validation experiments proved the adequacy and accuracy of model, and the results showed the predicted value agreed well with the experimental values. An overall 13-fold increase in halophilic protease yield was achieved using a 3 L laboratory fermenter and optimized medium (231.33 U/mL.

  14. The effects of salinity on nitrification using halophilic nitrifiers in a Sequencing Batch Reactor treating hypersaline wastewater.

    Science.gov (United States)

    Cui, You-Wei; Zhang, Hong-Yu; Ding, Jie-Ran; Peng, Yong-Zhen

    2016-04-25

    With annual increases in the generation and use of saline wastewater, the need to avoid environmental problems such as eutrophication is critical. A previous study identified ways to start up a halophilic sludge domesticated from estuarine sediments to remove nitrogen from wastewater with a salinity of 30 g/L. This investigation expands that work to explore the impact of salinity on nitrogen removal. This study demonstrated that the mixed halophilic consortia removed nitrogen from wastewater with a salinity of 30-85 g/L. A kinetic analysis showed that halophilic nitrifiers selected based on hypersalinity were characterized by low Ks, μmax and specific ammonium oxidization rates. This explains the decrease in ammonium removal efficiency in the high salinity operational phases. Salinity inhibited ammonia oxidizing bacteria (AOB) activity, as well as the number of dominant AOB, but did not significantly affect the AOB dominant species. Three most dominant AOB lineages in the halophilic sludge were Nitrosomonas marina, Nitrosomonas europaea, and Nitrosococcus mobilis. Nitrosomonas europaea and Nitrosococcus mobilis were mainly affected by salinity, while nitrite accumulation and ammonia loading played the key role in determining the abundance of Nitrosococcus mobilis and Nitrosococcus europaea. The study contributes insights about shifts in halophilic nitrifying bacterial populations.

  15. Shortcut nitrification-denitrification by means of autochthonous halophilic biomass in an SBR treating fish-canning wastewater.

    Science.gov (United States)

    Capodici, Marco; Corsino, Santo Fabio; Torregrossa, Michele; Viviani, Gaspare

    2018-02-15

    Autochthonous halophilic biomass was cultivated in a sequencing batch reactor (SBR) aimed at analyzing the potential use of autochthonous halophilic activated sludge in treating saline industrial wastewater. Despite the high salt concentration (30 g NaCl L -1 ), biological oxygen demand (BOD) and total suspended solids (TSS), removal efficiencies were higher than 90%. More than 95% of the nitrogen was removed via a shortcut nitrification-denitrification process. Both the autotrophic and heterotrophic biomass samples exhibited high biological activity. The use of autochthonous halophilic biomass led to high-quality effluent and helped to manage the issues related to nitrogen removal in saline wastewater treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Draft genome sequence of the extremely halophilic archaeon Haladaptatus cibarius type strain D43(T) isolated from fermented seafood.

    Science.gov (United States)

    Lee, Hae-Won; Kim, Dae-Won; Lee, Mi-Hwa; Kim, Byung-Yong; Cho, Yong-Joon; Yim, Kyung June; Song, Hye Seon; Rhee, Jin-Kyu; Seo, Myung-Ji; Choi, Hak-Jong; Choi, Jong-Soon; Lee, Dong-Gi; Yoon, Changmann; Nam, Young-Do; Roh, Seong Woon

    2015-01-01

    An extremely halophilic archaeon, Haladaptatus cibarius D43(T), was isolated from traditional Korean salt-rich fermented seafood. Strain D43(T) shows the highest 16S rRNA gene sequence similarity (98.7 %) with Haladaptatus litoreus RO1-28(T), is Gram-negative staining, motile, and extremely halophilic. Despite potential industrial applications of extremely halophilic archaea, their genome characteristics remain obscure. Here, we describe the whole genome sequence and annotated features of strain D43(T). The 3,926,724 bp genome includes 4,092 protein-coding and 57 RNA genes (including 6 rRNA and 49 tRNA genes) with an average G + C content of 57.76 %.

  17. Permuting the PGF Signature Motif Blocks both Archaeosortase-Dependent C-Terminal Cleavage and Prenyl Lipid Attachment for the Haloferax volcanii S-Layer Glycoprotein.

    Science.gov (United States)

    Abdul Halim, Mohd Farid; Karch, Kelly R; Zhou, Yitian; Haft, Daniel H; Garcia, Benjamin A; Pohlschroder, Mechthild

    2015-12-28

    For years, the S-layer glycoprotein (SLG), the sole component of many archaeal cell walls, was thought to be anchored to the cell surface by a C-terminal transmembrane segment. Recently, however, we demonstrated that the Haloferax volcanii SLG C terminus is removed by an archaeosortase (ArtA), a novel peptidase. SLG, which was previously shown to be lipid modified, contains a C-terminal tripartite structure, including a highly conserved proline-glycine-phenylalanine (PGF) motif. Here, we demonstrate that ArtA does not process an SLG variant where the PGF motif is replaced with a PFG motif (slg(G796F,F797G)). Furthermore, using radiolabeling, we show that SLG lipid modification requires the PGF motif and is ArtA dependent, lending confirmation to the use of a novel C-terminal lipid-mediated protein-anchoring mechanism by prokaryotes. Similar to the case for the ΔartA strain, the growth, cellular morphology, and cell wall of the slg(G796F,F797G) strain, in which modifications of additional H. volcanii ArtA substrates should not be altered, are adversely affected, demonstrating the importance of these posttranslational SLG modifications. Our data suggest that ArtA is either directly or indirectly involved in a novel proteolysis-coupled, covalent lipid-mediated anchoring mechanism. Given that archaeosortase homologs are encoded by a broad range of prokaryotes, it is likely that this anchoring mechanism is widely conserved. Prokaryotic proteins bound to cell surfaces through intercalation, covalent attachment, or protein-protein interactions play critical roles in essential cellular processes. Unfortunately, the molecular mechanisms that anchor proteins to archaeal cell surfaces remain poorly characterized. Here, using the archaeon H. volcanii as a model system, we report the first in vivo studies of a novel protein-anchoring pathway involving lipid modification of a peptidase-processed C terminus. Our findings not only yield important insights into poorly understood

  18. High quality draft genome sequence of the moderately halophilic bacterium Pontibacillus yanchengensis Y32(T) and comparison among Pontibacillus genomes.

    Science.gov (United States)

    Huang, Jing; Qiao, Zi Xu; Tang, Jing Wei; Wang, Gejiao

    2015-01-01

    Pontibacillus yanchengensis Y32(T) is an aerobic, motile, Gram-positive, endospore-forming, and moderately halophilic bacterium isolated from a salt field. In this study, we describe the features of P. yanchengensis strain Y32(T) together with a comparison with other four Pontibacillus genomes. The 4,281,464 bp high-quality-draft genome of strain Y32(T) is arranged into 153 contigs containing 3,965 protein-coding genes and 77 RNA encoding genes. The genome of strain Y32(T) possesses many genes related to its halophilic character, flagellar assembly and chemotaxis to support its survival in a salt-rich environment.

  19. Identification of halophile bacteria from salt deserts of Iran and study some of their physiological traits

    Directory of Open Access Journals (Sweden)

    Maryam Safdarian

    2017-06-01

    Full Text Available Introduction: Halophiles and halotolerant microorganisms are some of the extremophiles that are able to grow in medium containing sodium chloride and have adapted to life in salinity environments. Halophiles bacteria in saline soils by maintaining the food chain, decomposition of organic matter and improvement of soil structure and fertility improve soil conditions. Materials and methods: In order to isolate the halotoletant bacteria, from the halophyte rhizosphere, four desert areas in Golestan province were sampled. To check the Extremophile of isolates, their resistance was tested for resistant to salinity, drought, temperature and PH. Also, plant growth promoting traits were measured. Results: Fromforty-five strains which were isolated, three strains (G3, G6 and G14 have demonstrated the ability of resistance to 35% salt. Isolates G6 and G3 phosphate solubiliziation power of 301 and 201 ppm, respectively. Isolated G6 micrograms produced auxin 20/7 Mg/ ml. G14 and G6 grow at 50 °C, pH = 10 and osmotic potential -0 /7MPa. While G3 strain grows at 50 °C, pH = 7/ 5 and osmotic potential -0/49. The three strains of the bacterial genera Bacillus and Pseudomonas, respectively. Discussion and conclusion: In this study, isolates due to the growth in concentrations of salt and saturated salt tolerance of extreme environmental conditions and are likely halotolerant or halophile bacteria and its potential for use in various fields of biotechnology including biotech, industrial enzyme production and biological fertilizers for saline soil improvement.

  20. Characterization of exopolysaccharides produced by three moderately halophilic bacteria belonging to the family Alteromonadaceae.

    Science.gov (United States)

    Mata, J A; Béjar, V; Bressollier, P; Tallon, R; Urdaci, M C; Quesada, E; Llamas, I

    2008-08-01

    To study the exopolysaccharides (EPSs) produced by three novel moderately halophilic species belonging to the family Alteromonadaceae to optimize EPS yields, characterize their physical and chemical properties and evaluate possible biotechnological applications for these polymers. EPSs synthesized by Idiomarina fontislapidosi F32(T), Idiomarina ramblicola R22(T) and Alteromonas hispanica F23(T) were collected and analysed under optimum conditions: MY medium supplemented with 7.5% (w/v) salts; 32 degrees C; and 1% (w/v) glucose. Polymers were synthesized mainly during the early stationary growth phase with yields ranging from 1 to 1.5 g l(-1). The Idiomarina species each produced an anionic EPS composed mainly of glucose, mannose and galactose. A. hispanica synthesized an anionic EPS composed mainly of glucose, mannose and xylose. Solutions of all the polymers were low in viscosity and pseudoplastic in their behaviour. They showed emulsifying activity and the capacity to bind some metals. The Alteromonadaceae species studied in this work produced EPSs with physical and chemical properties different from those produced by other halophilic and nonhalophilic bacteria, suggesting that the wide diversity of micro-organisms being encountered nowadays in hypersaline environments offers enormous potential resources for biotechnological applications. We have optimized the EPS production and analysed new biopolymers produced by some recently described, moderately halophilic bacteria. These biopolymers are chemically and physically different from others already in use in biotechnology and offer hopes for new applications, especially in the case of A. hispanica, which may prove to be a viable source of xylo-oligosaccharides.

  1. Extracellular polymer substance synthesized by a halophilic bacterium Chromohalobacter canadensis 28.

    Science.gov (United States)

    Radchenkova, Nadja; Boyadzhieva, Ivanka; Atanasova, Nikolina; Poli, Annarita; Finore, Ilaria; Di Donato, Paola; Nicolaus, Barbara; Panchev, Ivan; Kuncheva, Margarita; Kambourova, Margarita

    2018-04-03

    Halophilic microorganisms are producers of a lot of new compounds whose properties suggest promising perspectives for their biotechnological exploration. Moderate halophilic bacterium Chromohalobacter canadensis 28 was isolated from Pomorie salterns as an extracellular polymer substance (EP) producer. The best carbon source for extracellular polymer production was found to be lactose, a sugar received as a by-product from the dairy industry. After optimization of the culture medium and physicochemical conditions for cultivation, polymer biosynthesis increased more than 2-fold. The highest level of extracellular polymer synthesis by C. canadensis 28 was observed in an unusually high NaCl concentration (15% w/v). Chemical analysis of the purified polymer revealed the presence of an exopolysaccharide (EPS) fraction (14.3% w/w) and protein fraction (72% w/w). HPLC analysis of the protein fraction showed the main presence of polyglutamic acid (PGA) (75.7% w/w). EPS fraction analysis revealed the following sugar composition (% w/w): glucosamine 36.7, glucose 32.3, rhamnose 25.4, xylose 1.7, and not identified sugar 3.9. The hydrogel formed by PGA and EPS fractions showed high swelling behavior, very good emulsifying and stabilizing properties, and good foaming ability. This is the first report for halophilic bacterium able to synthesize a polymer containing PGA fraction. The synthesized biopolymer shows an extremely high hydrophilicity, due to the simultaneous presence of PGA and EPS. The analysis of its functional properties and the presence of glucosamine in the highest proportion in EPS fraction clearly determine the potential of EP synthesized by C. canadensis 28 for application in the cosmetics industry.

  2. Osmoregulation in the Halophilic Bacterium Halomonas elongata: A Case Study for Integrative Systems Biology.

    Science.gov (United States)

    Kindzierski, Viktoria; Raschke, Silvia; Knabe, Nicole; Siedler, Frank; Scheffer, Beatrix; Pflüger-Grau, Katharina; Pfeiffer, Friedhelm; Oesterhelt, Dieter; Marin-Sanguino, Alberto; Kunte, Hans-Jörg

    2017-01-01

    Halophilic bacteria use a variety of osmoregulatory methods, such as the accumulation of one or more compatible solutes. The wide diversity of compounds that can act as compatible solute complicates the task of understanding the different strategies that halophilic bacteria use to cope with salt. This is specially challenging when attempting to go beyond the pathway that produces a certain compatible solute towards an understanding of how the metabolic network as a whole addresses the problem. Metabolic reconstruction based on genomic data together with Flux Balance Analysis (FBA) is a promising tool to gain insight into this problem. However, as more of these reconstructions become available, it becomes clear that processes predicted by genome annotation may not reflect the processes that are active in vivo. As a case in point, E. coli is unable to grow aerobically on citrate in spite of having all the necessary genes to do it. It has also been shown that the realization of this genetic potential into an actual capability to metabolize citrate is an extremely unlikely event under normal evolutionary conditions. Moreover, many marine bacteria seem to have the same pathways to metabolize glucose but each species uses a different one. In this work, a metabolic network inferred from genomic annotation of the halophilic bacterium Halomonas elongata and proteomic profiling experiments are used as a starting point to motivate targeted experiments in order to find out some of the defining features of the osmoregulatory strategies of this bacterium. This new information is then used to refine the network in order to describe the actual capabilities of H. elongata, rather than its genetic potential.

  3. An x-ray absorption spectroscopy study of Cd binding onto a halophilic archaeon

    International Nuclear Information System (INIS)

    Showalter, Allison R; Bunker, Bruce A; Szymanowski, Jennifer E S; Fein, Jeremy B

    2016-01-01

    X-ray absorption spectroscopy (XAS) and cadmium (Cd) isotherm experiments determine how Cd adsorbs to the surface of halophilic archaeon Halobacterium noricense . This archaeon, isolated from the Waste Isolation Pilot Plant (WIPP) near Carlsbad, New Mexico could be involved with the transport of toxic metals stored in the transuranic waste in the salt mine. The isotherm experiments show that adsorption is relatively constant across the tolerable pH range for H. noricense . The XAS results indicate that Cd adsorption occurs predominately via a sulfur site, most likely sulfhydryl, with the same site dominating all measured pH values. (paper)

  4. An x-ray absorption spectroscopy study of Cd binding onto a halophilic archaeon

    Science.gov (United States)

    Showalter, Allison R.; Szymanowski, Jennifer E. S.; Fein, Jeremy B.; Bunker, Bruce A.

    2016-05-01

    X-ray absorption spectroscopy (XAS) and cadmium (Cd) isotherm experiments determine how Cd adsorbs to the surface of halophilic archaeon Halobacterium noricense. This archaeon, isolated from the Waste Isolation Pilot Plant (WIPP) near Carlsbad, New Mexico could be involved with the transport of toxic metals stored in the transuranic waste in the salt mine. The isotherm experiments show that adsorption is relatively constant across the tolerable pH range for H. noricense. The XAS results indicate that Cd adsorption occurs predominately via a sulfur site, most likely sulfhydryl, with the same site dominating all measured pH values.

  5. Methods of hydrolyzing a cellulose using halophilic, thermostable and ionic liquids tolerant cellulases

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Tao; Datta, Supratim; Simmons, Blake A.; Rubin, Edward M.

    2018-01-09

    The present invention provides for an isolated or recombinant polypeptide comprising an amino acid sequence having at least 70% identity with the amino acid sequence of a Halorhabdus utahensis cellulase, such as Hu-CBH1, wherein said amino acid sequence has a halophilic thermostable and/or thermophilic cellobiohydrolase (CBH) activity. In some embodiments, the polypeptide has a CBH activity that is resistant to up to about 20% of ionic liquids. The present invention also provides for compositions comprising and methods using the isolated or recombinant polypeptide.

  6. Isolation and identification of culturable extremely halophilic archaea of Inche-Boroun wetland

    Directory of Open Access Journals (Sweden)

    Mehrnoosh Rasooli

    2013-11-01

    Full Text Available Haloarchaeal diversity of Inche-Boroun wetland in north of Iran in Golestan province was investigated by using culture-dependent methods. Sampling was carried out in May and September 2010. In each sampling, 4 distinct region of wetland were analyzed by using complex media like MGM, JCM168, MH1 and an alkaliphilic medium containing 23% salts. After incubation at 40ºC, a total of 406 isolates were prepared and 2.1×106 CFU/ml were obtained in culture media. Among all isolates, 361 isolates were obtained from MGM and 39 isolates from JCM 168, 3 isolates from MH1 and 3 isolate from alkaliphilic media. Initial morphological, biochemical and physiological tests were performed. According to the results, 45 isolates were selected and phylogenetic analysis of 16S rRNA was performed for them. Among selected strains, 40 isolates belonged to Halobacteriacaea and were related to Haloarcula, Halorubrum, Haloferax, Halobellus, Halogeometricum, Halobacterium, Halolamina, Halorhabdus and Halostagnicola (respectively 30, 27.5, 17.5, 10, 5.2, 2.6, 2.6, 2.6 and 2.6 percent of Haloarchaeal strains. A total of 5 strains belonged to the kingdom of Bacteria and were related to Rhodovibrio, Pseudomonas and Salicola (respectively 40, 40 and 20 percent of bacterial strains. According to our results and the limited numbers of haloarchaeal genera that having been discovered until now, it seemed that the culturable prokaryotic populations in this hypersaline environment was diverse.

  7. Dynamic structure mediates halophilic adaptation of a DNA polymerase from the deep-sea brines of the Red Sea

    KAUST Repository

    Takahashi, Masateru; Takahashi, Etsuko; Joudeh, Luay I.; Marini, Monica; Das, Gobind; Elshenawy, Mohamed; Akal, Anastassja; Sakashita, Kosuke; Alam, Intikhab; Tehseen, Muhammad; Sobhy, Mohamed Abdelmaboud; Stingl, Ulrich; Merzaban, Jasmeen; Di Fabrizio, Enzo M.; Hamdan, Samir

    2018-01-01

    The deep-sea brines of the Red Sea are remote and unexplored environments characterized by high temperatures, anoxic water, and elevated concentrations of salt and heavy metals. This environment provides a rare system to study the interplay between halophilic and thermophilic adaptation in biologic macromolecules. The present article reports the first DNA polymerase with halophilic and thermophilic features. Biochemical and structural analysis by Raman and circular dichroism spectroscopy showed that the charge distribution on the protein’s surface mediates the structural balance between stability for thermal adaptation and flexibility for counteracting the salt-induced rigid and nonfunctional hydrophobic packing. Salt bridge interactions via increased negative and positive charges contribute to structural stability. Salt tolerance, conversely, is mediated by a dynamic structure that becomes more fixed and functional with increasing salt concentration. We propose that repulsive forces among excess negative charges, in addition to a high percentage of negatively charged random coils, mediate this structural dynamism. This knowledge enabled us to engineer a halophilic version of KOD DNA polymerase.—Takahashi, M., Takahashi, E., Joudeh, L. I., Marini, M., Das, G., Elshenawy, M. M., Akal, A., Sakashita, K., Alam, I., Tehseen, M., Sobhy, M. A., Stingl, U., Merzaban, J. S., Di Fabrizio, E., Hamdan, S. M. Dynamic structure mediates halophilic adaptation of a DNA polymerase from the deep-sea brines of the Red Sea.

  8. Application of halophilic nuclease H of Micrococcus varians subsp. halophilus to commercial production of flavoring agent 5'-GMP.

    Science.gov (United States)

    Kamekura, M; Hamakawa, T; Onishi, H

    1982-01-01

    RNA was degraded at 60 degrees C for 24 h by halophilic nuclease H in supernatants from broth cultures of Micrococcus varians subsp. halophilus containing 12% NaCl. Since contaminating 5'-nucleotidase exhibited almost no activity under these conditions, the 5'-GMP formed could be recovered from the reaction mixture, and the yield was 805 mg from 5 g of RNA. PMID:6184020

  9. Dynamic structure mediates halophilic adaptation of a DNA polymerase from the deep-sea brines of the Red Sea.

    Science.gov (United States)

    Takahashi, Masateru; Takahashi, Etsuko; Joudeh, Luay I; Marini, Monica; Das, Gobind; Elshenawy, Mohamed M; Akal, Anastassja; Sakashita, Kosuke; Alam, Intikhab; Tehseen, Muhammad; Sobhy, Mohamed A; Stingl, Ulrich; Merzaban, Jasmeen S; Di Fabrizio, Enzo; Hamdan, Samir M

    2018-01-24

    The deep-sea brines of the Red Sea are remote and unexplored environments characterized by high temperatures, anoxic water, and elevated concentrations of salt and heavy metals. This environment provides a rare system to study the interplay between halophilic and thermophilic adaptation in biologic macromolecules. The present article reports the first DNA polymerase with halophilic and thermophilic features. Biochemical and structural analysis by Raman and circular dichroism spectroscopy showed that the charge distribution on the protein's surface mediates the structural balance between stability for thermal adaptation and flexibility for counteracting the salt-induced rigid and nonfunctional hydrophobic packing. Salt bridge interactions via increased negative and positive charges contribute to structural stability. Salt tolerance, conversely, is mediated by a dynamic structure that becomes more fixed and functional with increasing salt concentration. We propose that repulsive forces among excess negative charges, in addition to a high percentage of negatively charged random coils, mediate this structural dynamism. This knowledge enabled us to engineer a halophilic version of KOD DNA polymerase.-Takahashi, M., Takahashi, E., Joudeh, L. I., Marini, M., Das, G., Elshenawy, M. M., Akal, A., Sakashita, K., Alam, I., Tehseen, M., Sobhy, M. A., Stingl, U., Merzaban, J. S., Di Fabrizio, E., Hamdan, S. M. Dynamic structure mediates halophilic adaptation of a DNA polymerase from the deep-sea brines of the Red Sea.

  10. Exploration, antifungal and antiaflatoxigenic activity of halophilic bacteria communities from saline soils of Howze-Soltan playa in Iran.

    Science.gov (United States)

    Jafari, Samaneh; Aghaei, Seyed-Soheil; Afifi-Sabet, Hossein; Shams-Ghahfarokhi, Masoomeh; Jahanshiri, Zahra; Gholami-Shabani, Mohammadhassan; Shafiei-Darabi, Seyedahmad; Razzaghi-Abyaneh, Mehdi

    2018-01-01

    In the present study, halophilic bacteria communities were explored in saline soils of Howze-Soltan playa in Iran with special attention to their biological activity against an aflatoxigenic Aspergillus parasiticus NRRL 2999. Halophilic bacteria were isolated from a total of 20 saline soils using specific culture media and identified by 16S rRNA sequencing in neighbor-joining tree analysis. Antifungal and antiaflatoxigenic activities of the bacteria were screened by a nor-mutant A. parasiticus NRRL 2999 using visual agar plate assay and confirmed by high-performance liquid chromatography. Among a total of 177 halophilic bacteria belonging to 11 genera, 121 isolates (68.3%) inhibited A. parasiticus growth and/or aflatoxin production. The most potent inhibitory bacteria of the genera Bacillus, Paenibacillus and Staphylococcus were distributed in three main phylogenetic clusters as evidenced by 16S rRNA sequence analysis. A. parasiticus growth was inhibited by 0.7-92.7%, while AFB 1 and AFG 1 productions were suppressed by 15.1-98.9 and 57.0-99.6%, respectively. Taken together, halophilic bacteria identified in this study may be considered as potential sources of novel bioactive metabolites as well as promising candidates to develop new biocontrol agents for managing toxigenic fungi growth and subsequent aflatoxin contamination of food and feed in practice.

  11. Diverse antimicrobial interactions of halophilic archaea and bacteria extend over geographical distances and cross the domain barrier.

    Science.gov (United States)

    Atanasova, Nina S; Pietilä, Maija K; Oksanen, Hanna M

    2013-10-01

    The significance of antimicrobial substances, halocins, produced by halophilic archaea and bacteria thriving in hypersaline environments is relatively unknown. It is suggested that their production might increase species diversity and give transient competitive advances to the producer strain. Halocin production is considered to be common among halophilic archaea, but there is a lack of information about halocins produced by bacteria in highly saline environments. We studied the antimicrobial activity of 68 halophilic archaea and 22 bacteria isolated from numerous geographically distant hypersaline environments. Altogether 144 antimicrobial interactions were found between the strains and aside haloarchaea, halophilic bacteria from various genera were identified as halocin producers. Close to 80% of the interactions were detected between microorganisms from different genera and in few cases, even across the domain boundary. Several of the strains produced halocins with a wide inhibitory spectrum as has been observed before. Most of the antimicrobial interactions were found between strains from distant sampling sites indicating that hypersaline environments around the world have similar microorganisms with the potential to produce wide activity range antimicrobials. © 2013 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  12. Dynamic structure mediates halophilic adaptation of a DNA polymerase from the deep-sea brines of the Red Sea

    KAUST Repository

    Takahashi, Masateru

    2018-01-24

    The deep-sea brines of the Red Sea are remote and unexplored environments characterized by high temperatures, anoxic water, and elevated concentrations of salt and heavy metals. This environment provides a rare system to study the interplay between halophilic and thermophilic adaptation in biologic macromolecules. The present article reports the first DNA polymerase with halophilic and thermophilic features. Biochemical and structural analysis by Raman and circular dichroism spectroscopy showed that the charge distribution on the protein’s surface mediates the structural balance between stability for thermal adaptation and flexibility for counteracting the salt-induced rigid and nonfunctional hydrophobic packing. Salt bridge interactions via increased negative and positive charges contribute to structural stability. Salt tolerance, conversely, is mediated by a dynamic structure that becomes more fixed and functional with increasing salt concentration. We propose that repulsive forces among excess negative charges, in addition to a high percentage of negatively charged random coils, mediate this structural dynamism. This knowledge enabled us to engineer a halophilic version of KOD DNA polymerase.—Takahashi, M., Takahashi, E., Joudeh, L. I., Marini, M., Das, G., Elshenawy, M. M., Akal, A., Sakashita, K., Alam, I., Tehseen, M., Sobhy, M. A., Stingl, U., Merzaban, J. S., Di Fabrizio, E., Hamdan, S. M. Dynamic structure mediates halophilic adaptation of a DNA polymerase from the deep-sea brines of the Red Sea.

  13. Distinct Osmoadaptation Strategies in the Strict Halophilic and Halotolerant Bacteria Isolated from Lunsu Salt Water Body of North West Himalayas.

    Science.gov (United States)

    Vaidya, Shivani; Dev, Kamal; Sourirajan, Anuradha

    2018-07-01

    Two strict halophilic bacterial strains, Halobacillus trueperi SS1, and Halobacillus trueperi SS3, and three halotolerant bacterial strains, Shewanella algae SS2, Halomonas venusta SS5, and Marinomonas sp. SS8 of Lunsu salt water body, Himachal Pradesh, India, were selected to study the mechanism of salt tolerance and the role of osmolytes therein. A combination of flame photometry, chromatographic and colorimetric assays was used to study the mechanism of salt tolerance in the selected strict halophilic and halotolerant bacterial strains. The strict halophiles and, one of the halotolerants, Marinomonas sp. SS8 were found to utilize both "salt-in strategy" and "accumulation of compatible solutes strategy" for osmoregulation in hypersaline conditions. On the contrary, the remaining two halotolerants used "accumulation of compatible solutes strategy" under saline stress and not the "salt-in strategy". The present study suggests towards distinct mechanisms of salt tolerance in the two classes, wherein strict halophiles accumulate compatible solutes as well as adopt salt-in strategy, while the halotolerant bacteria accumulate a range of compatible solutes, except Marinomonas sp. SS8, which utilizes both the strategies to combat salt stress.

  14. Isolation and characterization of halophilic bacteria and archaea from salt ponds in Hangu Saltworks, Tianjin, China

    Science.gov (United States)

    Deng, Yuangao; Xu, Gaochao; Sui, Liying

    2015-07-01

    A total of 26 isolates were obtained from solar salt ponds of different salinities (100, 150, 200, and 250) in Hangu Saltworks Co. Ltd., Tianjin, China. Phylogenetic analysis of 16S rRNA gene sequences indicated that five bacteria genera Halomonas, Salinicoccus, Oceanobacillus, Gracibacillus, and Salimicrobium and one archaea genera Halorubrum were present. The genus Halomonas was predominant with eight strains distributed in a salinity range of 100-200, followed by Halorubrum with six strains in salinity 250. Based on the genus and original sampling salinity, eight bacterial and two archaeal isolates were selected for further morphological, physiological, and biochemical characterization. All of the bacterial strains were moderately halophilic with the optimal salinity for growth being either 50 or 100, while two archaeal strains were extremely halophilic with an optimal growth salinity of 200. Additionally, we put forth strain SM.200-5 as a new candidate Salimicrobium species based on the phylogenic analysis of the 16S rRNA gene sequence and its biochemical characteristics when compared with known related species.

  15. Isolation and characterization of halophilic Bacillus sp. BS3 able to produce pharmacologically important biosurfactants.

    Science.gov (United States)

    Donio, M B S; Ronica, S F A; Viji, V Thanga; Velmurugan, S; Jenifer, J Adlin; Michaelbabu, M; Citarasu, T

    2013-11-01

    To characterize the pharmacological importance of biosurfactants isolated from halophilic Bacillus sp BS3. Halophilic Bacillus sp. BS3 was isolated from solar salt works, identified by 16S rRNA sequencing and was used for screening their biosurfactant production. Characters of the biosurfactant and their anticancer activity were analyzed and performed in mammary epithelial carcinoma cell at different concentrations. The biosurfactant were characterized by TLC, FTIR and GC-MS analysis and identified as lipopeptide type. GC-MS analysis revealed that, the biosurfactant had various compounds including 13-Docosenamide, (Z); Mannosamine, 9- and N,N,N',N'-tetramethyl. Surprisingly the antiviral activity was found against shrimp white spot syndrome virus (WSSV) by suppressing the viral replication and significantly raised shrimp survival (Pbiosurfactants, among the various concentrations of biosurfactants such as 0.000 25, 0.002 5, 0.025, 0.25 and 2.5 μg, the 0.25 μg concentration suppressed the cells significantly (P<0.05) to 24.8%. Based on the findings, the present study concluded that, there is a possibility to develop eco-friendly antimicrobial and anticancer drugs from the extremophilic origin. Copyright © 2013 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

  16. Halophilic archaea on Earth and in space: growth and survival under extreme conditions.

    Science.gov (United States)

    Oren, Aharon

    2014-12-13

    Salts are abundant on Mars, and any liquid water that is present or may have been present on the planet is expected to be hypersaline. Halophilic archaea (family Halobacteriaceae) are the microorganisms best adapted to life at extremes of salinity on Earth. This paper reviews the properties of the Halobacteriaceae that may make the group good candidates for life also on Mars. Many species resist high UV and gamma radiation levels; one species has survived exposure to vacuum and radiation during a space flight; and there is at least one psychrotolerant species. Halophilic archaea may survive for millions of years within brine inclusions in salt crystals. Many species have different modes of anaerobic metabolism, and some can use light as an energy source using the light-driven proton pump bacteriorhodopsin. They are also highly tolerant to perchlorate, recently shown to be present in Martian soils, and some species can even use perchlorate as an electron acceptor to support anaerobic growth. The presence of characteristic carotenoid pigments (α-bacterioruberin and derivatives) makes the Halobacteriaceae easy to identify by Raman spectroscopy. Thus, if present on Mars, such organisms may be detected by Raman instrumentation planned to explore Mars during the upcoming ExoMars mission. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  17. Halophilic archaea cultivated from surface sterilized middle-late eocene rock salt are polyploid.

    Directory of Open Access Journals (Sweden)

    Salla T Jaakkola

    Full Text Available Live bacteria and archaea have been isolated from several rock salt deposits of up to hundreds of millions of years of age from all around the world. A key factor affecting their longevity is the ability to keep their genomic DNA intact, for which efficient repair mechanisms are needed. Polyploid microbes are known to have an increased resistance towards mutations and DNA damage, and it has been suggested that microbes from deeply buried rock salt would carry several copies of their genomes. Here, cultivable halophilic microbes were isolated from a surface sterilized middle-late Eocene (38-41 million years ago rock salt sample, drilled from the depth of 800 m at Yunying salt mine, China. Eight unique isolates were obtained, which represented two haloarchaeal genera, Halobacterium and Halolamina. We used real-time PCR to show that our isolates are polyploid, with genome copy numbers of 11-14 genomes per cell in exponential growth phase. The ploidy level was slightly downregulated in stationary growth phase, but the cells still had an average genome copy number of 6-8. The polyploidy of halophilic archaea living in ancient rock salt might be a factor explaining how these organisms are able to overcome the challenge of prolonged survival during their entombment.

  18. Diversity of Extremely Halophilic Archaeal and Bacterial Communities from Commercial Salts.

    Science.gov (United States)

    Gibtan, Ashagrie; Park, Kyounghee; Woo, Mingyeong; Shin, Jung-Kue; Lee, Dong-Woo; Sohn, Jae Hak; Song, Minjung; Roh, Seong Woon; Lee, Sang-Jae; Lee, Han-Seung

    2017-01-01

    Salting is one of the oldest food preservation techniques. However, salt is also the source of living halophilic microorganisms that may affect human health. In order to determine the microbial communities of commercial salts, an investigation were done using amplicon sequencing approach in four commercial salts: Ethiopian Afdera salt (EAS), Ethiopian rock salt (ERS), Korean Jangpan salt (KJS), and Korean Topan salt (KTS). Using domain-specific primers, a region of the 16S rRNA gene was amplified and sequenced using a Roche 454 instrument. The results indicated that these microbial communities contained 48.22-61.4% Bacteria, 37.72-51.26% Archaea, 0.51-0.86% Eukarya, and 0.005-0.009% unclassified reads. Among bacteria, the communities in these salts were dominated by the phyla Proteobacteria, Bacteroidetes, Actinobacteria , and Firmicutes . Of the archaea, 91.58% belonged to the class Halobacteria , whereas the remaining 7.58, 0.83, and 0.01% were Nanoarchaea, Methanobacteria , and Thermococci , respectively. This comparison of microbial diversity in salts from two countries showed the presence of many archaeal and bacterial genera that occurred in salt samples from one country but not the other. The bacterial genera Enterobacter and Halovibrio were found only in Korean and Ethiopian salts, respectively. This study indicated the occurrence and diversity of halophilic bacteria and archaea in commercial salts that could be important in the gastrointestinal tract after ingestion.

  19. Extracellular proteases of Halobacillus blutaparonensis strain M9, a new moderately halophilic bacterium.

    Science.gov (United States)

    Santos, Anderson F; Valle, Roberta S; Pacheco, Clarissa A; Alvarez, Vanessa M; Seldin, Lucy; Santos, André L S

    2013-12-01

    Halophilic microorganisms are source of potential hydrolytic enzymes to be used in industrial and/or biotechnological processes. In the present study, we have investigated the ability of the moderately halophilic bacterium Halobacillus blutaparonensis (strain M9), a novel species described by our group, to release proteolytic enzymes. This bacterial strain abundantly proliferated in Luria-Bertani broth supplemented with 2.5% NaCl as well as secreted proteases to the extracellular environment. The production of proteases occurred in bacterial cells grown under different concentration of salt, ranging from 0.5% to 10% NaCl, in a similar way. The proteases secreted by H. blutaparonensis presented the following properties: (i) molecular masses ranging from 30 to 80 kDa, (ii) better hydrolytic activities under neutral-alkaline pH range, (iii) expression modulated according to the culture age, (iv) susceptibility to phenylmethylsulphonyl fluoride, classifying them as serine-type proteases, (v) specific cleavage over the chymotrypsin substrate, and (vi) enzymatic stability in the presence of salt (up to 20% NaCl) and organic solvents (e.g., ether, isooctane and cyclohexane). The proteases described herein are promising for industrial practices due to its haloalkaline properties.

  20. Isolation, cloning and characterization of an azoreductase from the halophilic bacterium Halomonas elongata.

    Science.gov (United States)

    Eslami, Maryam; Amoozegar, Mohammad Ali; Asad, Sedigheh

    2016-04-01

    Azo dyes are a major class of colorants used in various industries including textile, paper and food. These dyes are regarded as pollutant since they are not readily reduced under aerobic conditions. Halomonas elongata, a halophilic bacterium, has the ability to decolorize different mono and di-azo dyes in anoxic conditions. In this study the putative azoreductase gene of H. elongata, formerly annotated as acp, was isolated, heterologously expressed in Escherichia coli, purified and characterized. The gene product, AzoH, was found to have a molecular mass of 22 kDa. The enzyme requires NADH, as an electron donor for its activity. The apparent Km was 63 μM for NADH and 12 μM for methyl red as a mono-azo dye substrate. The specific activity for methyl red was 0.27 μmol min(-1)mg(-1). The optimum enzyme activity was achieved in 50mM sodium phosphate buffer at pH 6. Although increased salinity resulted in reduced activity, AzoH could decolorize azo dye at NaCl concentrations up to 15% (w/v). The enzyme was also shown to be able to decolorize remazol black B as a representative of di-azo dyes. This is the first report describing the sequence and activity of an azo-reducing enzyme from a halophilic bacterium. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Analysis of Carotenoid Production by Halorubrum sp. TBZ126; an Extremely Halophilic Archeon from Urmia Lake

    Directory of Open Access Journals (Sweden)

    Davood Naziri

    2014-03-01

    Full Text Available Purpose: Carotenoids are of great interest in many scientific disciplines because of their wide distribution, diverse functions and interesting properties. The present report describes a new natural source for carotenoid production. Methods: Halorubrum sp., TBZ126, an extremely halophilic archaeon, was isolated from Urmia Lack following culture of water sample on marine agar medium and incubation at 30 °C. Then single colonies were cultivated in broth media. After that the cells were collected and carotenoids were extracted with acetone-methanol (7:3 v/v. The identification of carotenoids was performed by UV-VIS spectroscopy and confirmed by thin layer chromatography (TLC in the presence of antimony pentachloride (SbCl5. The production profile was analyzed using liquid-chromatography mass spectroscopy (LC-MS techniques. Phenotypic characteristics of the isolate were carried out and the 16S rRNA gene was amplified using polymerase chain reaction (PCR. Results: LC-MS analytical results revealed that produced carotenoids are bacterioruberin, lycopene and β-carotene. Bacterioruberin was found to be the predominant produced carotenoid. 16S rRNA analysis showed that TBZ126 has 100% similarity with Halorubrum chaoviator Halo-G*T (AM048786. Conclusion: Halorubrum sp. TBZ126, isolated from Urmia Lake has high capacity in the production of carotenoids. This extremely halophilic archaeon could be considered as a prokaryotic candidate for carotenoid production source for future studies.

  2. Discovery of extremely halophilic, methyl-reducing euryarchaea provides insights into the evolutionary origin of methanogenesis

    Science.gov (United States)

    Sorokin, Dimitry Y.; Makarova, Kira S.; Abbas, Ben; Ferrer, Manuel; Golyshin, Peter N.; Galinski, Erwin A.; Ciordia, Sergio; Mena, María Carmen; Merkel, Alexander Y.; Wolf, Yuri I.; van Loosdrecht, Mark C.M.; Koonin, Eugene V.

    2017-01-01

    Methanogenic archaea are major players in the global carbon cycle and in the biotechnology of anaerobic digestion. The phylum Euryarchaeota includes diverse groups of methanogens that are interspersed with non-methanogenic lineages. So far methanogens inhabiting hypersaline environments have been identified only within the order Methanosarcinales. We report the discovery of a deep phylogenetic lineage of extremophilic methanogens in hypersaline lakes, and present analysis of two nearly complete genomes from this group. Within the phylum Euryarchaeota, these isolates form a separate, class-level lineage “Methanonatronarchaeia” that is most closely related to the class Halobacteria. Similar to the Halobacteria, “Methanonatronarchaeia” are extremely halophilic and do not accumulate organic osmoprotectants. The high intracellular concentration of potassium implies that “Methanonatronarchaeia” employ the “salt-in” osmoprotection strategy. These methanogens are heterotrophic methyl-reducers that utilize C1-methylated compounds as electron acceptors and formate or hydrogen as electron donors. The genomes contain an incomplete and apparently inactivated set of genes encoding the upper branch of methyl group oxidation to CO2 as well as membrane-bound heterosulfide reductase and cytochromes. These features differentiates “Methanonatronarchaeia” from all known methyl-reducing methanogens. The discovery of extremely halophilic, methyl-reducing methanogens related to haloarchaea provides insights into the origin of methanogenesis and shows that the strategies employed by methanogens to thrive in salt-saturating conditions are not limited to the classical methylotrophic pathway. PMID:28555626

  3. Purification and characterization of an extreme halothermophilic protease from a halophilic bacterium Chromohalobacter sp. TVSP101

    Directory of Open Access Journals (Sweden)

    Malashetty Vidyasagar

    2009-03-01

    Full Text Available An extreme halophilic bacterium was isolated from solar saltern samples and identified based on biochemical tests and 16S r RNA sequencing as Chromohalobacter sp. strain TVSP101. The halophilic protease was purified using ultrafiltration, ethanol precipitation, hydrophobic interaction column chromatography and gel permeation chromatography to 180 fold with 22% yield. The molecular mass of the protease determined by SDS PAGE was 66 kDa. The purified enzyme was salt dependent for its activity and stability with an optimum of 4.5 M NaCl. The optimum temperature for maximum protease activity was 75°C. The protease was optimally active at pH 8 and retained more than 80% of its activity in the range of pH 7-10. Sucrose and glycine at 10% (w/v were the most effective osmolytes, retained 100% activity in the absence of NaCl. The activity was completely inhibited by ZnCl2 (2 mM, 0.1% SDS and PMSF (1mM. The enzyme was not inhibited by 1mM of pepstatin, EDTA and PCMB. The protease was active and retained 100% it activity in 10% (v/v DMSO, DMF, ethanol and acetone.

  4. Nesterenkonia sp. strain F, a halophilic bacterium producing acetone, butanol, and ethanol under aerobic conditions.

    Science.gov (United States)

    Amiri, Hamid; Azarbaijani, Reza; Parsa Yeganeh, Laleh; Shahzadeh Fazeli, Abolhassan; Tabatabaei, Meisam; Salekdeh, Ghasem Hosseini; Karimi, Keikhosro

    2016-01-04

    The moderately halophilic bacterium Nesterenkonia sp. strain F, which was isolated from Aran-Bidgol Lake (Iran), has the ability to produce acetone, butanol, and ethanol (ABE) as well as acetic and butyric acids under aerobic and anaerobic conditions. This result is the first report of ABE production with a wild microorganism from a family other than Clostridia and also the first halophilic species shown to produce butanol under aerobic cultivation. The cultivation of Nesterenkonia sp. strain F under anaerobic conditions with 50 g/l of glucose for 72 h resulted in the production of 105 mg/l of butanol, 122 mg/l of acetone, 0.2 g/l of acetic acid, and 2.5 g/l of butyric acid. Furthermore, the strain was cultivated on media with different glucose concentrations (20, 50, and 80 g/l) under aerobic and anaerobic conditions. Through fermentation with a 50 g/l initial glucose concentration under aerobic conditions, 66 mg/l of butanol, 125 mg/l of acetone, 291 mg/l of ethanol, 5.9 g/l of acetic acid, and 1.2 g/l of butyric acid were produced. The enzymes pertaining to the fermentation pathway in the strain were compared with the enzymes of Clostridium spp., and the metabolic pathway of fermentation used by Nesterenkonia sp. strain F was investigated.

  5. Anaerobic Oxidation of Methane Coupled to Nitrite Reduction by Halophilic Marine NC10 Bacteria.

    Science.gov (United States)

    He, Zhanfei; Geng, Sha; Cai, Chaoyang; Liu, Shuai; Liu, Yan; Pan, Yawei; Lou, Liping; Zheng, Ping; Xu, Xinhua; Hu, Baolan

    2015-08-15

    Anaerobic oxidation of methane (AOM) coupled to nitrite reduction is a novel AOM process that is mediated by denitrifying methanotrophs. To date, enrichments of these denitrifying methanotrophs have been confined to freshwater systems; however, the recent findings of 16S rRNA and pmoA gene sequences in marine sediments suggest a possible occurrence of AOM coupled to nitrite reduction in marine systems. In this research, a marine denitrifying methanotrophic culture was obtained after 20 months of enrichment. Activity testing and quantitative PCR (qPCR) analysis were then conducted and showed that the methane oxidation activity and the number of NC10 bacteria increased correlatively during the enrichment period. 16S rRNA gene sequencing indicated that only bacteria in group A of the NC10 phylum were enriched and responsible for the resulting methane oxidation activity, although a diverse community of NC10 bacteria was harbored in the inoculum. Fluorescence in situ hybridization showed that NC10 bacteria were dominant in the enrichment culture after 20 months. The effect of salinity on the marine denitrifying methanotrophic culture was investigated, and the apparent optimal salinity was 20.5‰, which suggested that halophilic bacterial AOM coupled to nitrite reduction was obtained. Moreover, the apparent substrate affinity coefficients of the halophilic denitrifying methanotrophs were determined to be 9.8 ± 2.2 μM for methane and 8.7 ± 1.5 μM for nitrite. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  6. Extremely halophilic archaea from ancient salt sediments and their possible survival in halite fluid inclusions

    Science.gov (United States)

    Stan-Lotter, H.; Fendrihan, S.; Gerbl, F. W.; Dornmayr-Pfaffenhuemer, M.; Frethem, C.

    2008-09-01

    Halophilic archaebacteria (haloarchaea) thrive in environments with salt concentrations approaching saturation, such as natural brines, marine solar salterns and alkaline salt lakes; they have also been isolated from ancient subsurface salt sediments of great geological age (195-280 million years) and some of those strains were described as novel species (1). The cells survived perhaps while being enclosed within small fluid inclusions in the halite. The characterization of subsurface microbial life is of astrobiological relevance since extraterrestrial halite has been detected and since microbial life on Mars, if existent, may have retreated into the subsurface. We attempted to simulate the embedding process of extremely halophilic archaea and to analyse any cellular changes which might occur. When enclosing haloarchaea in laboratory grown halite, cells accumulated preferentially in fluid inclusions, as could be demonstrated by pre-staining with fluorescent dyes. With increased time of embedding, rod-shaped cells of Halobacterium salinarum strains were found to assume roundish morphologies. Upon dissolution of the salt crystals, these spheres were stable and viable for months when kept in buffers containing 4 M NaCl. Scanning electron microscopy (SEM) following fixation with glutaraldehyde suggested a potentially gradual transformation from rods to spheres. This notion was supported by fluorescence microscopy of Halobacterium cells, following embedding in halite and staining with SYTO 9. One-dimensional protein patterns of rods and spheres, following SDS polyacrylamide gel electrophoresis, were similar except that the S-layer protein appeared reduced by about 15 - 20 % in spheres. The reddish-orange pigmentation of spheres was much lighter compared to that of rod-shaped cells, suggesting lowered concentrations of carotenoids; this was confirmed by extraction and spectrometry of pigments. The data suggested that Halobacterium cells are capable of forming specific

  7. The effect of high ionic strength on neptunium (V) adsorption to a halophilic bacterium

    Science.gov (United States)

    Ams, David A.; Swanson, Juliet S.; Szymanowski, Jennifer E. S.; Fein, Jeremy B.; Richmann, Michael; Reed, Donald T.

    2013-06-01

    The mobility of neptunium (V) in subsurface high ionic strength aqueous systems may be strongly influenced by adsorption to the cell wall of the halophilic bacteria Chromohalobacter sp. This study is the first to evaluate the adsorption of neptunium (V) to the surface of a halophilic bacterium as a function of pH from approximately 2 to 10 and at ionic strengths of 2 and 4 M. This is also the first study to evaluate the effects of carbonate complexation with neptunium (V) on adsorption to whole bacterial cells under high pH conditions. A thermodynamically-based surface complexation model was adapted to describe experimental adsorption data under high ionic strength conditions where traditional corrections for aqueous ion activity are invalid. Adsorption of neptunium (V) was rapid and reversible under the conditions of the study. Adsorption was significant over the entire pH range evaluated for both ionic strength conditions and was shown to be dependent on the speciation of the sites on the bacterial surface and neptunium (V) in solution. Adsorption behavior was controlled by the relatively strong electrostatic attraction of the positively charged neptunyl ion to the negatively charged bacterial surface at pH below circum-neutral. At pH above circum-neutral, the adsorption behavior was controlled by the presence of negatively charged neptunium (V) carbonate complexes resulting in decreased adsorption, although adsorption was still significant due to the adsorption of negatively charged neptunyl-carbonate species. Adsorption in 4 M NaClO4 was enhanced relative to adsorption in 2 M NaClO4 over the majority of the pH range evaluated, likely due to the effect of increasing aqueous ion activity at high ionic strength. The protonation/deprotonation characteristics of the cell wall of Chromohalobacter sp. were evaluated by potentiometric titrations in 2 and 4 M NaClO4. Bacterial titration results indicated that Chromohalobacter sp. exhibits similar proton buffering

  8. Selection of halophilic bacteria for biological control of tomato gray mould caused by Botrytis cinerea

    Directory of Open Access Journals (Sweden)

    Imane BERRADA

    2013-01-01

    Full Text Available In Morocco, tomato gray mould caused by Botrytis cinerea Pers: Fr. is a serious threat for postharvest storage of tomatoes. Fifteen halophilic bacteria were evaluated for their antagonistic activity against B. cinerea: 11 Gram positive strains assigned to the genera Bacillus (9, Jeotgalibacillus (1 and Planococcus (1 and four Gram negative strains assigned to the genera Salinivibrio (1, Vibrio (2 and Photobacterium (1. In in vitro screening, 12 antifungal isolates secreted diffusible compounds, hydrolytic enzymes or volatile compounds. In vivo screening of the isolates, Bacillus safensis CCMM B582 and Bacillus oceanisediminis CCMM B584 showed permanent antagonistic activity on tomato fruits, with 100% inhibition of B. cinerea after 7 days. These two strains may offer potential for biological control of tomato gray mould.

  9. Kocuria marina BS-15 a biosurfactant producing halophilic bacteria isolated from solar salt works in India

    Science.gov (United States)

    Sarafin, Yesurethinam; Donio, Mariathasan Birdilla Selva; Velmurugan, Subramanian; Michaelbabu, Mariavincent; Citarasu, Thavasimuthu

    2014-01-01

    Biosurfactant screening was made among the eight halophilic bacterial genera isolated from Kovalam solar salt works in Kanyakumari of India. After initial screening, Kocuria sp. (Km), Kurthia sp. (Ku) and Halococcus sp. (Hc) were found to have positive biosurfactant activity. Biosurfactant derived from Kocuria sp. emulsified more than 50% of the crude oil, coconut oil, sunflower oil, olive oil and kerosene when compared to the other strains. Further, Kocuria marina BS-15 derived biosurfactant was purified and characterized by TLC, FTIR and GC–MS analysis. The TLC analysis revealed that, the purified biosurfactants belong to the lipopeptide group. The IR spectrum results revealed that functional groups are R2C 000000000000 000000000000 000000000000 111111111111 000000000000 111111111111 000000000000 000000000000 000000000000 NN, alkenes and N–H. The GC–MS analysis confirmed the compound as Nonanoic acid and Cyclopropane with the retention time of 12.78 and 24.65, respectively. PMID:25473358

  10. Borrelidins C-E: New Antibacterial Macrolides from a Saltern-Derived Halophilic Nocardiopsis sp.

    Science.gov (United States)

    Kim, Jungwoo; Shin, Daniel; Kim, Seong-Hwan; Park, Wanki; Shin, Yoonho; Kim, Won Kyung; Lee, Sang Kook; Oh, Ki-Bong; Shin, Jongheon; Oh, Dong-Chan

    2017-06-06

    Chemical investigation of a halophilic actinomycete strain belonging to the genus Nocardiopsis inhabiting a hypersaline saltern led to the discovery of new 18-membered macrolides with nitrile functionality, borrelidins C-E ( 1 - 3 ), along with a previously reported borrelidin ( 4 ). The planar structures of borrelidins C-E, which are new members of the rare borrelidin class of antibiotics, were elucidated by NMR, mass, IR, and UV spectroscopic analyses. The configurations of borrelidines C-E were determined by the interpretation of ROESY NMR spectra, J-based configuration analysis, a modified Mosher's method, and CD spectroscopic analysis. Borrelidins C and D displayed inhibitory activity, particularly against the Gram-negative pathogen Salmonella enterica , and moderate cytotoxicity against the SNU638 and K562 carcinoma cell lines.

  11. Comparison between the polypeptide profile of halophilic bacteria and salt tolerant plants.

    Science.gov (United States)

    Muñoz, G; González, C; Flores, P; Prado, B; Campos, V

    1997-12-01

    Changes in the polypeptide profile induced by salt stress in halotolerant and halophilic bacteria, isolated from the Atacama desert (northern Chile), were compared with those in the cotyledons of Prosopis chilensis (Leguminoseae) seedlings, a salt tolerant plant. SDS-PAGE analyses show the presence of four predominant polypeptides, with molecular weights around 78, 70, 60 and 44 kDa respectively, both in bacteria and in cotyledons from P. chilensis seedlings raised under salt stress conditions. Moreover, the 60 and 44 kDa polypeptides seem to be salt responsive, since their concentration increases with increasing NaCl in the growth medium. Our results suggest a common mechanism for salt tolerance in prokaryotes and in eukaryotes.

  12. Molecular Mechanisms of Adaptation of the Moderately Halophilic Bacterium Halobacillis halophilus to Its Environment

    Directory of Open Access Journals (Sweden)

    Inga Hänelt

    2013-02-01

    Full Text Available The capability of osmoadaptation is a prerequisite of organisms that live in an environment with changing salinities. Halobacillus halophilus is a moderately halophilic bacterium that grows between 0.4 and 3 M NaCl by accumulating both chloride and compatible solutes as osmolytes. Chloride is absolutely essential for growth and, moreover, was shown to modulate gene expression and activity of enzymes involved in osmoadaptation. The synthesis of different compatible solutes is strictly salinity- and growth phase-dependent. This unique hybrid strategy of H. halophilus will be reviewed here taking into account the recently published genome sequence. Based on identified genes we will speculate about possible scenarios of the synthesis of compatible solutes and the uptake of potassium ion which would complete our knowledge of the fine-tuned osmoregulation and intracellular osmolyte balance in H. halophilus.

  13. PROTEOLYTIC AND FIBRINOLYTIC ACTIVITIES OF HALOPHILIC LACTIC ACID BACTERIA FROM TWO INDONESIAN FERMENTED FOODS

    Directory of Open Access Journals (Sweden)

    Asep A. Prihanto

    2013-04-01

    Full Text Available Exploration of fermented foods as sources of fibrinolytic enzymes is increased in the last decades. Terasi and Jambal roti is Indonesian traditional fermented fish products, which were famous in Java Island. Both are important products in Indonesian dishes, especially in Java. Investigation on halophilic lactic acid bacteria using MRS and M-17 agar obtained seventy four isolated strains. Their proteolytic and fibrinolytic activities were determined using skim milk agar and plasminogen-free fibrin plate. Twenty five isolates showed protease activities, while only four of them secreted fibrinolitic enzyme. The highest proteolytic and fibrinolytic activity was shown by TB1 strain, which is identified as Bacillus coagulans. The 16s rDNA is still in investigating to confirm the TB1 strain identity.

  14. Yield emulsifiers exopolysaccharides produced by native halophilic bacteria concentrations molasses three Saccharum officinarum L. "sugarcane"

    Directory of Open Access Journals (Sweden)

    Ángel Fuentes, Carmen Carreño

    2013-06-01

    Full Text Available The microbial exopolysaccharide with emulsifying properties are an alternative to polymers and chemicals from algae and plants. Its production in molasses as carbon source lowers costs and generates added value to this byproduct of the sugar industry, so the aim of this study was to determine the performance and productivity of EPS emulsifiers by native halophilic bacteria in 20, 30 and 40 gL-1 of molasses. In MY synthetic medium with 5 % w/v of salts, 138 isolates of bacteria obtained from soil samples of salt water and in the districts of San Jose and Santa Rosa, in Lambayeque. In 10.8 % of these gummy colony forming bacteria and grown on glucose as carbon source EPS recovered whose maximum values of the mixtures in water emulsion - oil phase were 63.3 and 56.6 % after 1 and 24 hours, respectively. The M5 bacteria identified as Halomonas C1 10-1 sp. M5 EPS synthesized emulsifiers molasses broth, reaching yields Yp/s of 0.296 gg-1 and 0.200 gg-1 with 20 and 30 gL-1 of molasses respectively, a productivity of 0.016 and 0.017 gL-1 h -1 , not differing significantly between them. With 10 gL-1 glucose was reached Yp/s of 0.171 gg-1 and a productivity of 0.018 gL-1 h -1 . It was shown that the EPS produced native halophilic bacteria utilizing molasses emulsifiers as carbon source.

  15. Biochemical characterization of a halophilic, alkalithermophilic protease from Alkalibacillus sp. NM-Da2.

    Science.gov (United States)

    Abdel-Hamed, Asmaa R; Abo-Elmatty, Dina M; Wiegel, Juergen; Mesbah, Noha M

    2016-11-01

    An extracellular, halophilic, alkalithermophilic serine protease from the halo-alkaliphilic Alkalibacillus sp. NM-Da2 was purified to homogeneity by ethanol precipitation and anion-exchange chromatography. The purified protease was a monomeric enzyme with an approximate molecular mass of 35 kDa and exhibited maximal activity at 2.7 M NaCl, pH 55 °C 9 and 56 °C. The protease showed great temperature stability, retaining greater than 80 % of initial activity after 2 h incubation at 55 °C. The protease was also extremely pH tolerant, retaining 80 % of initial activity at pH 55 °C 10.5 after 30 min incubation. Protease hydrolyzed complex substrates, displaying activity on yeast extract, tryptone, casein, gelatin and peptone. Protease activity was inhibited at casein concentrations greater than 1.2 mg/mL. The enzyme was stable and active in 40 % (v/v) solutions of isopropanol, ethanol and benzene and was stable in the presence of the polysorbate surfactant Tween 80. Activity was stimulated with the oxidizing agent hydrogen peroxide. Inhibition with phenyl methylsulfonylfluoride indicates it is a serine protease. Synthetic saline wastewater treated with the protease showed 50 % protein removal after 5 h. Being halophilic, alkaliphilic and thermophilic, in addition to being resistant to organic solvents, this protease has potential for various applications in biotechnological and pharmaceutical industries.

  16. Adaptation to high salt concentrations in halotolerant/ halophilic fungi: a molecular perspective

    Directory of Open Access Journals (Sweden)

    Ana ePlemenitas

    2014-05-01

    Full Text Available Molecular studies of salt tolerance of eukaryotic microorganisms have until recently been limited to the baker’s yeast Saccharomyces cerevisiae and a few other moderately halotolerant yeast. Discovery of the extremely halotolerant and adaptable fungus Hortaea werneckii and the obligate halophile Wallemia ichthyophaga introduced two new model organisms into studies on the mechanisms of salt tolerance in eukaryotes. H. werneckii is unique in its adaptability to fluctuations in salt concentrations, as it can grow without NaCl as well as in the presence of up to 5 M NaCl. On the other hand, W. ichthyophaga requires at least 1.5 M NaCl for growth, but also grows in up to 5 M NaCl. Our studies have revealed the novel and intricate molecular mechanisms used by these fungi to combat high salt concentrations, which differ in many aspects between the extremely halotolerant H. werneckii and the halophilic W. ichthyophaga. Specifically, the high osmolarity glycerol signalling pathway that is important for sensing and responding to increased salt concentrations is here compared between H. werneckii and W. ichthyophaga. In both of these fungi, the key signalling components are conserved, but there are structural and regulation differences between these pathways in H. werneckii and W. ichthyophaga. We also address differences that have been revealed from analysis of their newly sequenced genomes. The most striking characteristics associated with H. werneckii are the large genetic redundancy, the expansion of genes encoding metal cation transporters, and a relatively recent whole genome duplication. In contrast, the genome of W. ichthyophaga is very compact, as only 4,884 protein-coding genes are predicted, which cover almost three quarters of the sequence. Importantly, there has been a significant increase in their hydrophobins, cell-wall proteins that have multiple cellular functions.

  17. Actinopolyspora biskrensis sp. nov., a novel halophilic actinomycete isolated from Northern Sahara.

    Science.gov (United States)

    Saker, Rafika; Bouras, Noureddine; Meklat, Atika; Zitouni, Abdelghani; Schumann, Peter; Spröer, Cathrin; Klenk, Hans-Peter; Sabaou, Nasserdine

    2015-03-01

    A novel halophilic, filamentous actinomycete, designated H254(T), was isolated from a Saharan soil sample collected from Biskra (Northern Sahara), and subjected to a polyphasic taxonomic characterization. The strain is Gram-positive, aerobic, and halophilic, and the optimum NaCl concentration for growth is 15-20 % (w/v). The cell-wall hydrolysate contained meso-diaminopimelic acid, and the diagnostic whole-cell sugars were arabinose and galactose. The diagnostic phospholipid detected was phosphatidylcholine, and MK-9(H4) was the predominant menaquinone. The major fatty acid profiles were anteiso-C17:0 (32.8 %), C15:0 (28 %), and iso-C17:0 (12.3 %). Comparative analysis of the 16S rRNA gene sequences revealed that the strain H254(T) formed a well-separated sub-branch within the radiation of the genus Actinopolyspora, and the microorganism was most closely related to Actinopolyspora saharensis DSM 45459(T) (99.2 %), Actinopolyspora halophila DSM 43834(T) (99.1 %), and Actinopolyspora algeriensis DSM 45476(T) (99.0 %). Nevertheless, the strain had relatively lower mean values for DNA-DNA relatedness with the above strains (57.2, 68.4, and 45.6 %, respectively). Based on phenotypic features and phylogenetic position, we propose that strain H254(T) represents a novel species of the genus Actinopolyspora, for which the name Actinopolyspora biskrensis sp. nov. is proposed. The type strain of A. biskrensis is strain H254(T) (=DSM 46684(T) =CECT 8576(T)).

  18. Purification and characterization of halophilic lipase of Chromohalobacter sp. from ancient salt well.

    Science.gov (United States)

    Ai, Li; Huang, Yaping; Wang, Chuan

    2018-06-04

    A halophilic lipase (LipS2) was produced by Chromohalobacter canadensis strain which was isolated from ancient salt well of Zigong, China. LipS2 was purified to homogeneity and showed a single band with molecular mass of 58 kDa by SDS-PAGE. LipS2 preferred middle-to-long acyl chain esters with C14 triglycerides as optimum substrate. It was noteworthy that LipS2 displayed efficient hydrolysis activity to some vegetable oils which were composed of polyunsaturated fatty acid. LipS2 showed high activity in range of 2.5-3.5 M NaCl, no activity without salt. Optimum temperature and pH were 55 °C and pH 8.5, respectively. Notably, the thermostability and pH stability of LipS2, varying with salt concentration, reached optimum in the presence of 3.0 M NaCl. LipS2 was stimulated by Ca 2+ and Mg 2+ , inhibited by Zn 2+ , Cu 2+ , Mn 2+ , Fe 2+ , and Hg 2+ . Moreover, LipS2 displayed significant tolerance to organic solvents including methanol, ethanol, ethyl acetate and acetone, especially, LipS2 activity was enhanced markedly by the hexane and benzene. Non-ionic surfactants increased LipS2 activity, while ionic surfactants decreased activity. This was the first report on halophilic lipase of Chromohalobacter from ancient salt well. The results suggested that LipS2 may have considerable potential for biotechnological applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Genome sequence of the moderately halophilic bacterium Salinicoccus carnicancri type strain Crm(T) (= DSM 23852(T)).

    Science.gov (United States)

    Hyun, Dong-Wook; Whon, Tae Woong; Cho, Yong-Joon; Chun, Jongsik; Kim, Min-Soo; Jung, Mi-Ja; Shin, Na-Ri; Kim, Joon-Yong; Kim, Pil Soo; Yun, Ji-Hyun; Lee, Jina; Oh, Sei Joon; Bae, Jin-Woo

    2013-01-01

    Salinicoccus carnicancri Jung et al. 2010 belongs to the genus Salinicoccus in the family Staphylococcaceae. Members of the Salinicoccus are moderately halophilic and originate from various salty environments. The halophilic features of the Salinicoccus suggest their possible uses in biotechnological applications, such as biodegradation and fermented food production. However, the genus Salinicoccus is poorly characterized at the genome level, despite its potential importance. This study presents the draft genome sequence of S. carnicancri strain Crm(T) and its annotation. The 2,673,309 base pair genome contained 2,700 protein-coding genes and 78 RNA genes with an average G+C content of 47.93 mol%. It was notable that the strain carried 72 predicted genes associated with osmoregulation, which suggests the presence of beneficial functions that facilitate growth in high-salt environments.

  20. Immobilization of halophilic Bacillus sp. EMB9 protease on functionalized silica nanoparticles and application in whey protein hydrolysis.

    Science.gov (United States)

    Sinha, Rajeshwari; Khare, S K

    2015-04-01

    The present work targets the fabrication of an active, stable, reusable enzyme preparation using functionalized silica nanoparticles as an effective enzyme support for crude halophilic Bacillus sp. EMB9 protease. The immobilization efficiency under optimized conditions was 60%. Characterization of the immobilized preparation revealed marked increase in pH and thermal stability. It retained 80% of its original activity at 70 °C while t 1/2 at 50 °C showed a five-fold enhancement over that for the free protease. Kinetic constants K m and V max were indicative of a higher reaction velocity along with decreased affinity for substrate. The preparation could be efficiently reused up to 6 times and successfully hydrolysed whey proteins with high degree of hydrolysis. Immobilization of a crude halophilic protease on a nanobased scaffold makes the process cost effective and simple.

  1. Proteomic characterization of the outer membrane vesicle of the halophilic marine bacterium Novosphingobium pentaromativorans US6-1.

    Science.gov (United States)

    Yun, Sung Ho; Lee, Sang-Yeop; Choi, Chi-Won; Lee, Hayoung; Ro, Hyun-Joo; Jun, Sangmi; Kwon, Yong Min; Kwon, Kae Kyoung; Kim, Sang-Jin; Kim, Gun-Hwa; Kim, Seung Il

    2017-01-01

    Novosphingobium pentaromativorans US6-1 is a Gram-negative halophilic marine bacterium able to utilize several polycyclic aromatic hydrocarbons such as phenanthrene, pyrene, and benzo[a]pyrene. In this study, using transmission electron microscopy, we confirmed that N. pentaromativorans US6-1 produces outer membrane vesicles (OMVs). N. pentaromativorans OMVs (hereafter OMV Novo ) are spherical in shape, and the average diameter of OMV Novo is 25-70 nm. Proteomic analysis revealed that outer membrane proteins and periplasmic proteins of N. pentaromativorans are the major protein components of OMV Novo . Comparative proteomic analysis with the membrane-associated protein fraction and correlation analysis demonstrated that the outer membrane proteins of OMV Novo originated from the membrane- associated protein fraction. To the best of our knowledge, this study is the first to characterize OMV purified from halophilic marine bacteria.

  2. Neptunium (V) Adsorption to a Halophilic Bacterium Under High Ionic Strength Conditions: A Surface Complexation Modeling Approach

    Energy Technology Data Exchange (ETDEWEB)

    Ams, David A [Los Alamos National Laboratory

    2012-06-11

    Rationale for experimental design: Np(V) -- important as analog for Pu(V) and for HLW scenarios; High ionic strength -- relevant to salt-based repositories such as the WIPP; Halophilic microorganisms -- representative of high ionic strength environments. For the first time showed: Significant adsorbant to halophilic microorganisms over entire pH range under high ionic strength conditions; Strong influence of ionic strength with increasing adsorption with increasing ionic strength (in contrast to trends of previous low ionic strength studies); Effect of aqueous Np(V) and bacterial surface site speciation on adsorption; and Developed thermodynamic models that can be incorporated into geochemical speciation models to aid in the prediction of the fate and transport of Np(V) in more complex systems.

  3. Characterization of a novel chitinase from a moderately halophilic bacterium, Virgibacillus marismortui strain M3-23

    OpenAIRE

    Essghaier, Badiaa; Hedi, Abdeljabbar; Bajji, Mohammed; Jijakli, Haissam; Boudabous, Abdellatif; Sadfi-Zouaoui, Najla

    2012-01-01

    A new chitinase produced by the moderately halophilic bacterium Virgibacillus marismortui strain M3- 23 was identified and characterized. Distinguishable characteristics of high activity and stability at different pH, temperatures and salinity of M3-23 chitinase are reported. Analysis of the catalytic domain sequence from the enzyme highlighted its relationship to glycosyl hydrolase family 18. Comparison of the deduced chitinase sequence from strain M3-23 to known chitinases from Bacillus spe...

  4. Adaptations to High Salt in a Halophilic Protist: Differential Expression and Gene Acquisitions through Duplications and Gene Transfers

    Science.gov (United States)

    Harding, Tommy; Roger, Andrew J.; Simpson, Alastair G. B.

    2017-01-01

    The capacity of halophiles to thrive in extreme hypersaline habitats derives partly from the tight regulation of ion homeostasis, the salt-dependent adjustment of plasma membrane fluidity, and the increased capability to manage oxidative stress. Halophilic bacteria, and archaea have been intensively studied, and substantial research has been conducted on halophilic fungi, and the green alga Dunaliella. By contrast, there have been very few investigations of halophiles that are phagotrophic protists, i.e., protozoa. To gather fundamental knowledge about salt adaptation in these organisms, we studied the transcriptome-level response of Halocafeteria seosinensis (Stramenopiles) grown under contrasting salinities. We provided further evolutionary context to our analysis by identifying genes that underwent recent duplications. Genes that were highly responsive to salinity variations were involved in stress response (e.g., chaperones), ion homeostasis (e.g., Na+/H+ transporter), metabolism and transport of lipids (e.g., sterol biosynthetic genes), carbohydrate metabolism (e.g., glycosidases), and signal transduction pathways (e.g., transcription factors). A significantly high proportion (43%) of duplicated genes were also differentially expressed, accentuating the importance of gene expansion in adaptation by H. seosinensis to high salt environments. Furthermore, we found two genes that were lateral acquisitions from bacteria, and were also highly up-regulated and highly expressed at high salt, suggesting that this evolutionary mechanism could also have facilitated adaptation to high salt. We propose that a transition toward high-salt adaptation in the ancestors of H. seosinensis required the acquisition of new genes via duplication, and some lateral gene transfers (LGTs), as well as the alteration of transcriptional programs, leading to increased stress resistance, proper establishment of ion gradients, and modification of cell structure properties like membrane

  5. Diversity and enumeration of halophilic and alkaliphilic bacteria in Spanish-style green table-olive fermentations.

    Science.gov (United States)

    Lucena-Padrós, Helena; Ruiz-Barba, José Luis

    2016-02-01

    The presence and enumeration of halophilic and alkaliphilic bacteria in Spanish-style table-olive fermentations was studied. Twenty 10-tonne fermenters at two large manufacturing companies in Spain, previously studied through both culture dependent and independent (PCR-DGGE) methodologies, were selected. Virtually all this microbiota was isolated during the initial fermentation stage. A total of 203 isolates were obtained and identified based on 16S rRNA gene sequences. They belonged to 13 bacterial species, included in 11 genera. It was noticeable the abundance of halophilic and alkaliphilic lactic acid bacteria (HALAB). These HALAB belonged to the three genera of this group: Alkalibacterium, Marinilactibacillus and Halolactibacillus. Ten bacterial species were isolated for the first time from table olive fermentations, including the genera Amphibacillus, Natronobacillus, Catenococcus and Streptohalobacillus. The isolates were genotyped through RAPD and clustered in a dendrogram where 65 distinct strains were identified. Biodiversity indexes found statistically significant differences between both patios regarding genotype richness, diversity and dominance. However, Jaccard similarity index suggested that the halophilic/alkaliphilic microbiota in both patios was more similar than the overall microbiota at the initial fermentation stage. Thus, up to 7 genotypes of 6 different species were shared, suggesting adaptation of some strains to this fermentation stage. Morisita-Horn similarity index indicated a high level of codominance of the same species in both patios. Halophilic and alkaliphilic bacteria, especially HALAB, appeared to be part of the characteristic microbiota at the initial stage of this table-olive fermentation, and they could contribute to the conditioning of the fermenting brines in readiness for growth of common lactic acid bacteria. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Adaptations to High Salt in a Halophilic Protist: Differential Expression and Gene Acquisitions through Duplications and Gene Transfers

    Directory of Open Access Journals (Sweden)

    Tommy Harding

    2017-05-01

    Full Text Available The capacity of halophiles to thrive in extreme hypersaline habitats derives partly from the tight regulation of ion homeostasis, the salt-dependent adjustment of plasma membrane fluidity, and the increased capability to manage oxidative stress. Halophilic bacteria, and archaea have been intensively studied, and substantial research has been conducted on halophilic fungi, and the green alga Dunaliella. By contrast, there have been very few investigations of halophiles that are phagotrophic protists, i.e., protozoa. To gather fundamental knowledge about salt adaptation in these organisms, we studied the transcriptome-level response of Halocafeteria seosinensis (Stramenopiles grown under contrasting salinities. We provided further evolutionary context to our analysis by identifying genes that underwent recent duplications. Genes that were highly responsive to salinity variations were involved in stress response (e.g., chaperones, ion homeostasis (e.g., Na+/H+ transporter, metabolism and transport of lipids (e.g., sterol biosynthetic genes, carbohydrate metabolism (e.g., glycosidases, and signal transduction pathways (e.g., transcription factors. A significantly high proportion (43% of duplicated genes were also differentially expressed, accentuating the importance of gene expansion in adaptation by H. seosinensis to high salt environments. Furthermore, we found two genes that were lateral acquisitions from bacteria, and were also highly up-regulated and highly expressed at high salt, suggesting that this evolutionary mechanism could also have facilitated adaptation to high salt. We propose that a transition toward high-salt adaptation in the ancestors of H. seosinensis required the acquisition of new genes via duplication, and some lateral gene transfers (LGTs, as well as the alteration of transcriptional programs, leading to increased stress resistance, proper establishment of ion gradients, and modification of cell structure properties like

  7. Alleviation of salt stress by halotolerant and halophilic plant growth-promoting bacteria in wheat (Triticum aestivum

    Directory of Open Access Journals (Sweden)

    Furkan Orhan

    Full Text Available ABSTRACT In the current study, 18 halotolerant and halophilic bacteria have been investigated for their plant growth promoting abilities in vitro and in a hydroponic culture. The bacterial strains have been investigated for ammonia, indole-3-acetic acid and 1-aminocyclopropane-1-carboxylate-deaminase production, phosphate solubilisation and nitrogen fixation activities. Of the tested bacteria, eight were inoculated with Triticum aestivum in a hydroponic culture. The investigated bacterial strains were found to have different plant-growth promoting activities in vitro. Under salt stress (200 mM NaCl, the investigated bacterial strains significantly increased the root and shoot length and total fresh weight of the plants. The growth rates of the plants inoculated with bacterial strains ranged from 62.2% to 78.1%.Identifying of novel halophilic and halotolerant bacteria that promote plant growth can be used as alternatives for salt sensitive plants. Extensive research has been conducted on several halophilic and halotolerant bacterial strains to investigate their plant growth promoting activities. However, to the best of my knowledge, this is the first study to inoculate these bacterial strains with wheat.

  8. [Comparative analysis of clustered regularly interspaced short palindromic repeats (CRISPRs) loci in the genomes of halophilic archaea].

    Science.gov (United States)

    Zhang, Fan; Zhang, Bing; Xiang, Hua; Hu, Songnian

    2009-11-01

    Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) is a widespread system that provides acquired resistance against phages in bacteria and archaea. Here we aim to genome-widely analyze the CRISPR in extreme halophilic archaea, of which the whole genome sequences are available at present time. We used bioinformatics methods including alignment, conservation analysis, GC content and RNA structure prediction to analyze the CRISPR structures of 7 haloarchaeal genomes. We identified the CRISPR structures in 5 halophilic archaea and revealed a conserved palindromic motif in the flanking regions of these CRISPR structures. In addition, we found that the repeat sequences of large CRISPR structures in halophilic archaea were greatly conserved, and two types of predicted RNA secondary structures derived from the repeat sequences were likely determined by the fourth base of the repeat sequence. Our results support the proposal that the leader sequence may function as recognition site by having palindromic structures in flanking regions, and the stem-loop secondary structure formed by repeat sequences may function in mediating the interaction between foreign genetic elements and CAS-encoded proteins.

  9. Using extremely halophilic bacteria to understand the role of surface charge and surface hydration in protein evolution, folding, and function

    Science.gov (United States)

    Hoff, Wouter; Deole, Ratnakar; Osu Collaboration

    2013-03-01

    Halophilic Archaea accumulate molar concentrations of KCl in their cytoplasm as an osmoprotectant, and have evolved highly acidic proteomes that only function at high salinity. We examine osmoprotection in the photosynthetic Proteobacteria Halorhodospira halophila. We find that H. halophila has an acidic proteome and accumulates molar concentrations of KCl when grown in high salt media. Upon growth of H. halophila in low salt media, its cytoplasmic K + content matches that of Escherichia coli, revealing an acidic proteome that can function in the absence of high cytoplasmic salt concentrations. These findings necessitate a reassessment of two central aspects of theories for understanding extreme halophiles. We conclude that proteome acidity is not driven by stabilizing interactions between K + ions and acidic side chains, but by the need for maintaining sufficient solvation and hydration of the protein surface at high salinity through strongly hydrated carboxylates. We propose that obligate protein halophilicity is a non-adaptive property resulting from genetic drift in which constructive neutral evolution progressively incorporates weakly stabilizing K + binding sites on an increasingly acidic protein surface.

  10. Alleviation of salt stress by halotolerant and halophilic plant growth-promoting bacteria in wheat (Triticum aestivum).

    Science.gov (United States)

    Orhan, Furkan

    2016-01-01

    In the current study, 18 halotolerant and halophilic bacteria have been investigated for their plant growth promoting abilities in vitro and in a hydroponic culture. The bacterial strains have been investigated for ammonia, indole-3-acetic acid and 1-aminocyclopropane-1-carboxylate-deaminase production, phosphate solubilisation and nitrogen fixation activities. Of the tested bacteria, eight were inoculated with Triticum aestivum in a hydroponic culture. The investigated bacterial strains were found to have different plant-growth promoting activities in vitro. Under salt stress (200mM NaCl), the investigated bacterial strains significantly increased the root and shoot length and total fresh weight of the plants. The growth rates of the plants inoculated with bacterial strains ranged from 62.2% to 78.1%. Identifying of novel halophilic and halotolerant bacteria that promote plant growth can be used as alternatives for salt sensitive plants. Extensive research has been conducted on several halophilic and halotolerant bacterial strains to investigate their plant growth promoting activities. However, to the best of my knowledge, this is the first study to inoculate these bacterial strains with wheat. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  11. A novel halophilic lipase, LipBL, showing high efficiency in the production of eicosapentaenoic acid (EPA.

    Directory of Open Access Journals (Sweden)

    Dolores Pérez

    Full Text Available BACKGROUND: Among extremophiles, halophiles are defined as microorganisms adapted to live and thrive in diverse extreme saline environments. These extremophilic microorganisms constitute the source of a number of hydrolases with great biotechnological applications. The interest to use extremozymes from halophiles in industrial applications is their resistance to organic solvents and extreme temperatures. Marinobacter lipolyticus SM19 is a moderately halophilic bacterium, isolated previously from a saline habitat in South Spain, showing lipolytic activity. METHODS AND FINDINGS: A lipolytic enzyme from the halophilic bacterium Marinobacter lipolyticus SM19 was isolated. This enzyme, designated LipBL, was expressed in Escherichia coli. LipBL is a protein of 404 amino acids with a molecular mass of 45.3 kDa and high identity to class C β-lactamases. LipBL was purified and biochemically characterized. The temperature for its maximal activity was 80°C and the pH optimum determined at 25°C was 7.0, showing optimal activity without sodium chloride, while maintaining 20% activity in a wide range of NaCl concentrations. This enzyme exhibited high activity against short-medium length acyl chain substrates, although it also hydrolyzes olive oil and fish oil. The fish oil hydrolysis using LipBL results in an enrichment of free eicosapentaenoic acid (EPA, but not docosahexaenoic acid (DHA, relative to its levels present in fish oil. For improving the stability and to be used in industrial processes LipBL was immobilized in different supports. The immobilized derivatives CNBr-activated Sepharose were highly selective towards the release of EPA versus DHA. The enzyme is also active towards different chiral and prochiral esters. Exposure of LipBL to buffer-solvent mixtures showed that the enzyme had remarkable activity and stability in all organic solvents tested. CONCLUSIONS: In this study we isolated, purified, biochemically characterized and immobilized a

  12. Halotolerant and halophilic bacteria in the oceans of the icy satellites

    Science.gov (United States)

    Ramirez, S. I.; Montoya, L.; Avendaño, R.

    2013-05-01

    Halotolerant and halophilic prokaryotes require salt concentrations equal to or higher than those present at terrestrial oceans (Rothschild and Mancinelli, 2001). They are a particular kind of extremophiles and as expected, their halotolerance is mainly expressed in terms of a certain NaCl percentage, at least on Earth. With the discovery of putative salty liquid oceans beneath the iced surfaces of some of the satellites of Jupiter and Saturn (Mueller and McKinnon, 1988; Kargel et al., 2000; Zolotov, 2007), information about the impact of other types of salts, different from NaCl, on the growth of complex biological systems is necessary. We have found that when three specific bacteria strains are growing in media enriched with salts containing chaotropic and kosmotropic ions, their specific optimal growth value is modified (Montoya et al., 2010). The changes can be broadly explained in terms of the Hofmeister series (Zhang and Cremer, 2006). These results can be used to infer an extension in the limits of biological activity. For terrestrial organisms there is scarce information to determine the impact of another salt in the growth of an organism. In these sense we have found that when media enriched with magnesium sulfate (MgSO4) at water activity values (aw) similar to those reported as optimal for NaCl, their growth and tolerance is considerably enhanced. On the other hand, the combination of chaotropic and kosmotropic ions result in salts of astrobiological importance such as the sulphate already mentioned, carbonates or chlorides that can tentatively exist in the putative ocean of Europa, Ganymedes, or Enceladus or even at the subsurface of Mars. In this frame, we studied the growth rate of Halomonas halodurans, H. magadiensis and Bacillus pumillus when exposed to media enriched with NaCl, MgSO4, Mg(NO3)2, MgCl2, Na2SO4 and NH4SO4. Equivalent values of water activity (aw) for each salt were compared and correlated with microbial activity (Montoya et al., 2010

  13. Solution Behavior and Activity of a Halophilic Esterase under High Salt Concentration

    Science.gov (United States)

    Rao, Lang; Zhao, Xiubo; Pan, Fang; Li, Yin; Xue, Yanfen; Ma, Yanhe; Lu, Jian R.

    2009-01-01

    Background Halophiles are extremophiles that thrive in environments with very high concentrations of salt. Although the salt reliance and physiology of these extremophiles have been widely investigated, the molecular working mechanisms of their enzymes under salty conditions have been little explored. Methodology/Principal Findings A halophilic esterolytic enzyme LipC derived from archeaon Haloarcula marismortui was overexpressed from Escherichia coli BL21. The purified enzyme showed a range of hydrolytic activity towards the substrates of p-nitrophenyl esters with different alkyl chains (n = 2−16), with the highest activity being observed for p-nitrophenyl acetate, consistent with the basic character of an esterase. The optimal esterase activities were found to be at pH 9.5 and [NaCl] = 3.4 M or [KCl] = 3.0 M and at around 45°C. Interestingly, the hydrolysis activity showed a clear reversibility against changes in salt concentration. At the ambient temperature of 22°C, enzyme systems working under the optimal salt concentrations were very stable against time. Increase in temperature increased the activity but reduced its stability. Circular dichroism (CD), dynamic light scattering (DLS) and small angle neutron scattering (SANS) were deployed to determine the physical states of LipC in solution. As the salt concentration increased, DLS revealed substantial increase in aggregate sizes, but CD measurements revealed the maximal retention of the α-helical structure at the salt concentration matching the optimal activity. These observations were supported by SANS analysis that revealed the highest proportion of unimers and dimers around the optimal salt concentration, although the coexistent larger aggregates showed a trend of increasing size with salt concentration, consistent with the DLS data. Conclusions/Significance The solution α-helical structure and activity relation also matched the highest proportion of enzyme unimers and dimers. Given that

  14. Compatible Solute Synthesis and Import by the Moderate Halophile Spiribacter salinus: Physiology and Genomics

    Directory of Open Access Journals (Sweden)

    María J. León

    2018-02-01

    Full Text Available Members of the genus Spiribacter are found worldwide and are abundant in ecosystems possessing intermediate salinities between seawater and saturated salt concentrations. Spiribacter salinus M19-40 is the type species of this genus and its first cultivated representative. In the habitats of S. salinus M19-40, high salinity is a key determinant for growth and we therefore focused on the cellular adjustment strategy to this persistent environmental challenge. We coupled these experimental studies to the in silico mining of the genome sequence of this moderate halophile with respect to systems allowing this bacterium to control its potassium and sodium pools, and its ability to import and synthesize compatible solutes. S. salinus M19-40 produces enhanced levels of the compatible solute ectoine, both under optimal and growth-challenging salt concentrations, but the genes encoding the corresponding biosynthetic enzymes are not organized in a canonical ectABC operon. Instead, they are scrambled (ectAC; ectB and are physically separated from each other on the S. salinus M19-40 genome. Genomes of many phylogenetically related bacteria also exhibit a non-canonical organization of the ect genes. S. salinus M19-40 also synthesizes trehalose, but this compatible solute seems to make only a minor contribution to the cytoplasmic solute pool under osmotic stress conditions. However, its cellular levels increase substantially in stationary phase cells grown under optimal salt concentrations. In silico genome mining revealed that S. salinus M19-40 possesses different types of uptake systems for compatible solutes. Among the set of compatible solutes tested in an osmostress protection growth assay, glycine betaine and arsenobetaine were the most effective. Transport studies with radiolabeled glycine betaine showed that S. salinus M19-40 increases the pool size of this osmolyte in a fashion that is sensitively tied to the prevalent salinity of the growth medium

  15. Bacillus marismortui sp. nov., a new moderately halophilic species from the Dead Sea.

    Science.gov (United States)

    Arahal, D R; Márquez, M C; Volcani, B E; Schleifer, K H; Ventosa, A

    1999-04-01

    A group of 91 moderately halophilic, Gram-positive, rod-shaped strains were isolated from enrichments prepared from Dead Sea water samples collected 57 years ago. These strains were examined for 117 morphological, physiological, biochemical, nutritional and antibiotic susceptibility characteristics. All strains formed endospores and were motile, strictly aerobic and positive for catalase and oxidase. They grew in media containing 5-25% (w/v) total salts, showing optimal growth at 10% (w/v). Eighteen strains were chosen as representative isolates and were studied in more detail. All these strains had mesodiaminopimelic acid in the cell wall and a DNA G + C content of 39.0-42.8 mol%; they constitute a group with levels of DNA-DNA similarity of 70-100%. The sequences of the 16S rRNA genes of three representative strains (strains 123T, 557 and 832) were almost identical (99.9%), and placed the strains in the low G + C content Gram-positive bacteria. On the basis of their features, these isolates should be regarded as members of a new species of the genus Bacillus, for which the name Bacillus marismortui sp. nov. is proposed. The type strain is strain 123T (= DSM 12325T = ATCC 700626T = CIP 105609T = CECT 5066T).

  16. Isolation, characterization and phylogenetic analysis of halophilic archaea from a salt mine in central Anatolia (Turkey).

    Science.gov (United States)

    Yildiz, Evrim; Ozcan, Birgul; Caliskan, Mahmut

    2012-01-01

    The haloarchaeal diversity of a salt mine, a natural cave in central Anatolia, was investigated using convential microbiological and molecular biology methods. Eight halophilic archaeal isolates selected based on their colony morphology and whole cell protein profiles were taxonomically classified on the basis of their morphological, physiological, biochemical properties, polar lipid and protein profiles and 16S rDNA sequences. From the 16S rDNA sequences comparisons it was established that the isolates CH2, CH3 and CHC resembled Halorubrum saccharovorum by 98.8%, 98.9% and 99.5%, respectively. There was a 99.7% similarity between the isolate CH11 and Halobacterium noricense and 99.2% between the isolate CHA1 and Haloarcula argentinensis. The isolate CH8K and CH8B revealed a similarity rate of 99.8% and 99.3% to Halococcus dombrowskii, respectively. It was concluded that the isolates named CH2, CH3 and CHC were clustered in the genus Halorubrum and that CHA1 and CH7 in the genus Haloarcula, CH8K and CH8B in the genus Halococcus and CH11 in the genus Halobacterium.

  17. Structure of halophilic malate dehydrogenase in multimolar KCl solutions from neutron scattering and ultracentrifugation

    International Nuclear Information System (INIS)

    Calmettes, P.

    1987-01-01

    The structure and solvent interactions of malate dehydrogenase from Halobacterium marismortui in multimolar KCl solvents are found to be similar to those in multimolar NaCl solvents reported previously (G. Zaccai, E. Wachtel and H. Eisenberg, J. Mol. Biol. 190 (1986) 97). KCl rather than NaCl is predominant in physiological medium. At salt concentrations up to about 3.0 M, the protein (a dimer of M 87000 g/mol) can be considered to occupy an invariant volume in which it is associated with about 4100 molecules of water and about 520 molecules of salt. At very low resolution, the enzyme particle appears to have a compact protein core and protruding protein parts in interaction with the water and salt components, structural features that are not observed in non-halophilic mitochondrial malate dehydrogenase. The above conclusions were drawn from the analysis of neutron scattering and ultracentrifugation data, and the complementarity of these approaches is discussed extensively. 24 refs.; 7 figs.; 4 tabs

  18. Gracilibacillus aidingensis sp. nov., a novel moderately halophilic bacterium isolated from Aiding salt lake.

    Science.gov (United States)

    Guan, Tong-Wei; Tian, Lei; Li, En-Yuan; Tang, Shu-Kun; Zhang, Xiao-Ping

    2017-11-01

    A novel Gram-positive, aerobe, moderately halophilic bacterium was isolated from saline soil of Aiding lake in Xinjiang, north-west of China, designated strain YIM 98001 T . Cells were rod-shaped, motile and grew at 5-20% (w/v) NaCl (optimum 10%), pH 6-10 (optimum pH 7.0) and 4-45 °C (optimum 37 °C). The major cellular fatty acids were anteiso C 15:0 , anteiso C 17:0 , iso C 15:0 . The predominant respiratory quinone was MK-7. Diphosphatidylglycerol, phosphatidylglycerol, phosphoglycolipid were the major polar lipids. Meso-diaminopimelic acid was the diagnostic diamino acid of the cell-wall peptidoglycan. The G+C content was 36.46 mol%. 16S rRNA gene sequence analysis showed that the strain belongs to the family Bacillaceae, with the highest sequence similarity to the type strain Gracilibacillus thailandensis TP2-8 T (96.84%), followed by Gracilibacillus saliphilus YIM 91119 T (96.78%) and Gracilibacillus ureilyticus MF38 T (96.57%), thus confirming the affiliation of strain YIM 98001 T to the genus Gracilibacillus. The polyphasic approach indicates that strain YIM 98001 T represents a novel species of the genus Gracilibacillus, for which the name Gracilibacillus aidingensis is proposed. The type strain is YIM 98001 T (=KCTC 42683 T  = DSMZ 104330 T ).

  19. Production and properties of an exopolysaccharide synthesized by the extreme halophilic archaeon Haloterrigena turkmenica.

    Science.gov (United States)

    Squillaci, Giuseppe; Finamore, Rosario; Diana, Paola; Restaino, Odile Francesca; Schiraldi, Chiara; Arbucci, Salvatore; Ionata, Elena; La Cara, Francesco; Morana, Alessandra

    2016-01-01

    We have isolated a novel exopolysaccharide (EPS) produced by the extreme halophilic archaeon Haloterrigena turkmenica. Some features, remarkable from an industrial point of view, such as emulsifying and antioxidant properties, were investigated. H. turkmenica excreted 20.68 mg of EPS per 100 ml of culture medium when grown in usual medium supplemented with glucose. The microorganism excreted the biopolymer mainly in the middle exponential growth phase and reached the maximal production in the stationary phase. Analyses by anion exchange chromatography and SEC-TDA Viscotek indicated that the EPS was composed of two main fractions of 801.7 and 206.0 kDa. It was a sulfated heteropolysaccharide containing glucose, galactose, glucosamine, galactosamine, and glucuronic acid. Studies performed utilizing the mixture of EPS anionic fractions showed that the biopolymer had emulsifying activity towards vegetable oils comparable or superior to that exhibited by the controls, moderate antioxidant power when tested with 2,2'-diphenyl-1-picrylhydrazyl (DPPH(·)), and moisture-retention ability higher than hyaluronic acid (HA). The EPS from H. turkmenica is the first exopolysaccharide produced by an archaea to be characterized in terms of properties that can have potential biotechnological applications.

  20. Quantitative Proteomics Reveals Membrane Protein-Mediated Hypersaline Sensitivity and Adaptation in Halophilic Nocardiopsis xinjiangensis.

    Science.gov (United States)

    Zhang, Yao; Li, Yanchang; Zhang, Yongguang; Wang, Zhiqiang; Zhao, Mingzhi; Su, Na; Zhang, Tao; Chen, Lingsheng; Wei, Wei; Luo, Jing; Zhou, Yanxia; Xu, Yongru; Xu, Ping; Li, Wenjun; Tao, Yong

    2016-01-04

    The genus Nocardiopsis is one of the most dominant Actinobacteria that survives in hypersaline environments. However, the adaptation mechanisms for halophilism are still unclear. Here, we performed isobaric tags for relative and absolute quantification based quantitative proteomics to investigate the functions of the membrane proteome after salt stress. A total of 683 membrane proteins were identified and quantified, of which 126 membrane proteins displayed salt-induced changes in abundance. Intriguingly, bioinformatics analyses indicated that these differential proteins showed two expression patterns, which were further validated by phenotypic changes and functional differences. The majority of ABC transporters, secondary active transporters, cell motility proteins, and signal transduction kinases were up-regulated with increasing salt concentration, whereas cell differentiation, small molecular transporter (ions and amino acids), and secondary metabolism proteins were significantly up-regulated at optimum salinity, but down-regulated or unchanged at higher salinity. The small molecule transporters and cell differentiation-related proteins acted as sensing proteins that played a more important biological role at optimum salinity. However, the ABC transporters for compatible solutes, Na(+)-dependent transporters, and cell motility proteins acted as adaptive proteins that actively counteracted higher salinity stress. Overall, regulation of membrane proteins may provide a major protection strategy against hyperosmotic stress.

  1. Low Water Activity Induces the Production of Bioactive Metabolites in Halophilic and Halotolerant Fungi

    Directory of Open Access Journals (Sweden)

    Nina Gunde-Cimerman

    2010-12-01

    Full Text Available The aim of the present study was to investigate indigenous fungal communities isolated from extreme environments (hypersaline waters of solar salterns and subglacial ice, for the production of metabolic compounds with selected biological activities: hemolysis, antibacterial, and acetylcholinesterase inhibition. In their natural habitats, the selected fungi are exposed to environmental extremes, and therefore the production of bioactive metabolites was tested under both standard growth conditions for mesophilic microorganisms, and at high NaCl and sugar concentrations and low growth temperatures. The results indicate that selected halotolerant and halophilic species synthesize specific bioactive metabolites under conditions that represent stress for non-adapted species. Furthermore, adaptation at the level of the chemical nature of the solute lowering the water activity of the medium was observed. Increased salt concentrations resulted in higher hemolytic activity, particularly within species dominating the salterns. The appearance of antibacterial potential under stress conditions was seen in the similar pattern of fungal species as for hemolysis. The active extracts exclusively affected the growth of the Gram-positive bacterium tested, Bacillus subtilis. None of the extracts tested showed inhibition of acetylcholinesterase activity.

  2. Production of an extracellular thermohalophilic lipase from a moderately halophilic bacterium, Salinivibrio sp. strain SA-2.

    Science.gov (United States)

    Amoozegar, Mohammad Ali; Salehghamari, Ensieh; Khajeh, Khosro; Kabiri, Mahbube; Naddaf, Saied

    2008-06-01

    Fifty strains of moderately halophilic bacteria were isolated from various salty environments in Iran. A strain designated as SA-2 was shown to be the best producer of extracellular lipase and was selected for further studies. Biochemical and physiological characterization along with 16S rDNA sequence analysis placed SA-2 in the genus Salinivibrio. The optimum salt, pH, temperature and aeration for enzyme production were 0.1 M KCl, pH 8, 35 degrees C and 150 rpm, respectively. The enzyme production was synchronized bacterial growth and reached a maximum level during the early-stationary phase in the basal medium containing 1 M NaCl. Triacylglycerols enhanced lipase production, while carbohydrates had inhibitory effects on it. The maximum lipase activity was obtained at pH 7.5, 50 degrees C and CaCl(2) concentration of 0.01 M. The enzyme was stable at pH range of 7.5-8 and retained 90% of its activity at 80 degrees C for 30 min. Different concentrations of NaNO(3), Na(2)SO(4), KCl and NaCl had no affect on lipase stability for 3 h. These results suggest that the lipase secreted by Salinivibrio sp. strain SA-2 is industrially important from the perspective of its tolerance to a broad temperature range, its moderate thermoactivity and its high tolerance to a wide range of salt concentrations (0-3 M NaCl).

  3. Partial characterization of an extracellular polysaccharide produced by the moderately halophilic bacterium Halomonas xianhensis SUR308.

    Science.gov (United States)

    Biswas, Jhuma; Ganguly, J; Paul, A K

    2015-01-01

    A moderately halophilic bacterium, Halomonas xianhensis SUR308 (Genbank Accession No. KJ933394) was isolated from a multi-pond solar saltern at Surala, Ganjam district, Odisha, India. The isolate produced a significant amount (7.87 g l(-1)) of extracellular polysaccharides (EPS) when grown in malt extract-yeast extract medium supplemented with 2.5% NaCl, 0.5% casein hydrolysate and 3% glucose. The EPS was isolated and purified following the conventional method of precipitation and dialysis. Chromatographic analysis (paper, GC and GC-MS) of the hydrolyzed EPS confirmed its heteropolymeric nature and showed that it is composed mainly of glucose (45.74 mol%), galactose (33.67 mol %) and mannose (17.83 mol%). Fourier-transform infrared spectroscopy indicated the presence of methylene and carboxyl groups as characteristic functional groups. In addition, its proton nuclear magnetic resonance spectrum revealed functional groups specific for extracellular polysaccharides. X-ray diffraction analysis revealed the amorphous nature (CIxrd, 0.56) of the EPS. It was thermostable up to 250 °C and displayed pseudoplastic rheology and remarkable stability against pH and salts. These unique properties of the EPS produced by H. xianhensis indicate its potential to act as an agent for detoxification, emulsification and diverse biological activities.

  4. Production of beta-xylanase and beta-xylosidase by the extremely halophilic archaeon Halorhabdus utahensis

    DEFF Research Database (Denmark)

    Wainø, M.; Ingvorsen, K.

    2003-01-01

    -xylosidase stabilities, approximately 55% and 83% of the initial beta-xylanase and beta-xylosidase activities, respectively, remained after 24 h incubation at 20% NaCl. The enzymes were also shown to be slightly thermophilic: P-xylanase activity exhibiting two optima at 55degrees and 70degreesC, while beta......The extremely halophilic archaeon, Halorhabdus utahensis, isolated from the Great Salt Lake, Utah, produced beta-xylanase and beta-xylosidase activities. Both enzymes were active over a broad NaCl range from near zero to 30% NaCl when tested with culture broth. A broad NaCl optimum was observed...... for beta-xylanase activity between 5% and 15% NaCl, while beta-xylosidase activity was highest at 5% NaCl. Almost half of the maximum activities remained at 27%-30% NaCl for both enzyme activities. When dialyzed culture supernatant and culture broth were employed for determination of beta-xylanase and beta...

  5. THE EXTREMELY HALOPHILIC MICROORGANISMS, A POSSIBLE MODEL FOR LIFE ON OTHER PLANETS

    Directory of Open Access Journals (Sweden)

    Sergiu Fendrihan

    2017-12-01

    Full Text Available Abstract The group of halophilic Archaea was discovered in the beginning of XX th century. They are able to live in more than 2-3 M of sodium chloride concentration that can be found in hypersaline natural lakes, in alkaline saline lakes, in man-made hypersaline mats, in rock salt, in very salted foods, on salted fish, on salted hides, in stromatolites, in saline soils. Their adaptations consist in resistance to high ionic contents with internal accumulation of K ions in order to face high Na ion content from the near environment. They belong to the Halobacteriaceae family. Their adaptation and their resistance to UV radiation and their resistance in oligotrophic conditions in rock salt, apparently over geological times, increase the possibility to find similar microorganisms in the Martian subsurface and in meteorites, and to support the panspermia theory. Some of the research of a working group in this field of activity and their possible uses are shortly reviewed here.

  6. Halorubrum depositum sp. nov., a Novel Halophilic Archaeon Isolated from a Salt Deposit.

    Science.gov (United States)

    Chen, Shaoxing; Sun, Siqi; Xu, Yao; Lv, Jinting; Chen, Linan; Liu, Liu

    2018-06-01

    A non-motile, pleomorphic rod-shaped or oval, red-pigmented (nearly scarlet), extremely halophilic archaeon, strain Y78 T , was isolated from a salt deposit of Yunnan salt mine, China. Analysis of the 16S rRNA gene sequence showed that it was phylogenetically related to species of the genus Halorubrum, with a close relationship to Halorubrum rutilum YJ-18-S1 T (98.6%), Halorubrum yunnanense Q85 T (98.3%), and Halorubrum lipolyticum 9-3 T (98.1%). The temperature, NaCl, and pH ranges for growth were 25-50 °C, 12-30% (w/v), and 6.5-9.0, respectively. Mg 2+ was required for growth. The polar lipids of strain Y78 T were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate, and a sulfated diglycosyl diether. The DNA G+C content was 66.6 mol%. DNA-DNA hybridization values between strain Y78 T and two closely related species of the genus Halorubrum were far below 70%. Based on the data presented in this study, strain Y78 T represents a novel species for which the name Halorubrum depositum sp. nov. is proposed; the type strain is Y78 T (= CGMCC 1.15456 T  = JCM 31272 T ).

  7. Characterization of detergent compatible protease from halophilic Virgibacillus sp. CD6.

    Science.gov (United States)

    Lam, Ming Quan; Nik Mut, Nik Nurhidayu; Thevarajoo, Suganthi; Chen, Sye Jinn; Selvaratnam, Chitra; Hussin, Huszalina; Jamaluddin, Haryati; Chong, Chun Shiong

    2018-02-01

    A halophilic bacterium, Virgibacillus sp. strain CD6, was isolated from salted fish and its extracellular protease was characterized. Protease production was found to be highest when yeast extract was used as nitrogen source for growth. The protease exhibited stability at wide range of salt concentration (0-12.5%, w/v), temperatures (20-60 °C), and pH (4-10) with maximum activity at 10.0% (w/v) NaCl, 60 °C, pH 7 and 10, indicating its polyextremophilicity. The protease activity was enhanced in the presence of Mg 2+ , Mn 2+ , Cd 2+ , and Al 3+ (107-122% relative activity), and with retention of activity > 80% for all of other metal ions examined (K + , Ca 2+ , Cu 2+ , Co 2+ , Ni 2+ , Zn 2+ , and Fe 3+ ). Both PMSF and EDTA inhibited protease activity, denoting serine protease and metalloprotease properties, respectively. High stability (> 70%) was demonstrated in the presence of organic solvents and detergent constituents, and the extracellular protease from strain CD6 was also found to be compatible in commercial detergents. Proteinaceous stain removal efficacy revealed that crude protease of strain CD6 could significantly enhance the performance of commercial detergent. The protease from Virgibacillus sp. strain CD6 could serve as a promising alternative for various applications, especially in detergent industry.

  8. Purification and characterization of an extracellular halophilic and organic solvent-tolerant amylopullulanase from a haloarchaeon, Halorubrum sp. strain Ha25.

    Directory of Open Access Journals (Sweden)

    Mostafa Fazeli

    2013-01-01

    Full Text Available Introduction: Halophiles, especially haloarchaea are one of the most important groups of extremophiles. Halophilic hydrolases have been studied worldwide and have been considered for biotechnology and industrial technologies. This study is the first report in amylopullulanase production in halophilic microorganisms.Materials and methods: A halophilic archaeon, Halorubrum sp. strain Ha25, produced extracellular halophilic organic solvent-tolerant amylopullulanase. The enzyme was purified using ethanol precipitation and anion exchange chromatography method. Molecular mass of purified enzyme was determined by SDS–PAGE method. After purification, the enzyme was characterized. To study the effects of organic solvents in the stability of the enzyme, the enzyme solution was incubated in the presence of various organic compounds and then, residual enzyme activity was measured. Mode of action of the enzyme was determined by thin-layer chromatography.Results: Molecular weight of the purified enzyme was estimated to be 140 kDa by SDS–PAGE method. Optimum temperature for amylolitic and pullulytic activities was 50 °C. Optimum pH for amylolitic activity was 7.0 and for pullulytic activity was 7.5. This enzyme was active over a wide range of concentrations (0-4.5 M of NaCl. The effect of organic solvents on the amylolitic and pullulytic activities showed that this enzyme was more stable in the presence of non-polar organic solvents than polar solvents. The enzyme solely hydrolyzed pullulan and soluble starch to glucose.Discussion and conclusion: Halorubrum sp. strain Ha25 produces thermophilic and extremely halophilic amylopullulanase. The catalytic function under multi extreme condition of high temperature, high salinity, and low water activity might possess biotechnological and commercial values such as treatment waste solutions with starch residues, high salt content and solvents.

  9. Multistage bioassociation of uranium onto an extremely halophilic archaeon revealed by a unique combination of spectroscopic and microscopic techniques

    Energy Technology Data Exchange (ETDEWEB)

    Bader, Miriam; Müller, Katharina; Foerstendorf, Harald; Drobot, Björn [Helmholtz-Zentrum Dresden – Rossendorf, Institute of Resource Ecology, Bautzner Landstraße 400, 01328 Dresden (Germany); Schmidt, Matthias; Musat, Niculina [Helmholtz Centre for Environmental Research–UFZ, Department of Isotope Biogeochemistry, Permoserstraße 15, 04318 Leipzig (Germany); Swanson, Juliet S.; Reed, Donald T. [Los Alamos National Laboratory, Repository Science and Operations, 1400 University Drive, Carlsbad, NM, 88220 (United States); Stumpf, Thorsten [Helmholtz-Zentrum Dresden – Rossendorf, Institute of Resource Ecology, Bautzner Landstraße 400, 01328 Dresden (Germany); Cherkouk, Andrea, E-mail: a.cherkouk@hzdr.de [Helmholtz-Zentrum Dresden – Rossendorf, Institute of Resource Ecology, Bautzner Landstraße 400, 01328 Dresden (Germany)

    2017-04-05

    Highlights: • First prolonged kinetics study of uranium to halophilic archaea was performed. • An atypical time-dependent bioassociation behavior of uranium was observed. • Unique combination of spectroscopic and microscopic methods was used. • In situ ATR FT-IR showed association of U(VI) to phosphoryl and carboxylate groups. • Time-dependent changes of U(VI) localization could be monitored by SEM/EDX. - Abstract: The interactions of two extremely halophilic archaea with uranium were investigated at high ionic strength as a function of time, pH and uranium concentration. Halobacterium noricense DSM-15987 and Halobacterium sp. putatively noricense, isolated from the Waste Isolation Pilot Plant repository, were used for these investigations. The kinetics of U(VI) bioassociation with both strains showed an atypical multistage behavior, meaning that after an initial phase of U(VI) sorption, an unexpected interim period of U(VI) release was observed, followed by a slow reassociation of uranium with the cells. By applying in situ attenuated total reflection Fourier-transform infrared spectroscopy, the involvement of phosphoryl and carboxylate groups in U(VI) complexation during the first biosorption phase was shown. Differences in cell morphology and uranium localization become visible at different stages of the bioassociation process, as shown with scanning electron microscopy in combination with energy dispersive X-ray spectroscopy. Our results demonstrate for the first time that association of uranium with the extremely halophilic archaeon is a multistage process, beginning with sorption and followed by another process, probably biomineralization.

  10. Investigating the Effects of Simulated Space conditions on Novel Extremely Halophilic Archaea: Halovarius Luteus gen. nov., sp. nov.

    Science.gov (United States)

    Feshangsaz, Niloofar; Van Loon, ing.. Jack J. W. A.; Nazmi, Kamran; Semsarha, Farid

    2016-07-01

    Studying halophiles from different environments of Earth provide new insights into our search for life in the universe. Haloarchaea show some unique characteristics and physiological adaptations like acidic proteins against harsh environments such as natural brine with salt concentration approaching saturation (5 M) and regions with low active water. These properties make haloarchaea interesting candidate for astrobiological studies. Halovarius luteus gen. nov., sp. nov. a novel extremely halophilic archaeon from Urmia salt lake, in Iran has been chosen to explore its resistance against a series of extreme conditions. The aim of this study is to assess the resistance of strain DA50T under the effects of simulated space conditions like simulated microgravity, hypergravity, and desiccation. In this paper we will discuss the results of these studies where we specifically focus on changes in carotenoid pigments production and whole cell proteome. This is the first report of very novel Iranian archaea in response to extreme space conditions. The pigments were extracted by acetone and methanol. Pigments were analyzed by scanning the absorbance spectrum in the UV-VIS spectrophotometer. And they were separated by TLC. Whole protein from cell lysate supernatant was extracted after lysis with Bacterial Protein Extraction Reagent and fractionated by RP-HPLC using C18 column. Proteome analyzed by electrophoresis (SDS-PAGE), and MALDI-TOF. Carotenoid pigments are formed under different extreme conditions such as dry environment and gravitational changes. Also the protein composition exhibits alterations after exposure to the same conditions. Our conclusion is that pigments and proteins formation depend on the growth circumstances. Halophiles use this as an adaptation to survive under different environmental conditions.

  11. Cloning, Characterization and Analysis of cat and ben Genes from the Phenol Degrading Halophilic Bacterium Halomonas organivorans

    Science.gov (United States)

    Moreno, Maria de Lourdes; Sánchez-Porro, Cristina; Piubeli, Francine; Frias, Luciana; García, María Teresa; Mellado, Encarnación

    2011-01-01

    Background Extensive use of phenolic compounds in industry has resulted in the generation of saline wastewaters that produce significant environmental contamination; however, little information is available on the degradation of phenolic compounds in saline conditions. Halomonas organivorans G-16.1 (CECT 5995T) is a moderately halophilic bacterium that we isolated in a previous work from saline environments of South Spain by enrichment for growth in different pollutants, including phenolic compounds. PCR amplification with degenerate primers revealed the presence of genes encoding ring-cleaving enzymes of the β-ketoadipate pathway for aromatic catabolism in H. organivorans. Findings The gene cluster catRBCA, involved in catechol degradation, was isolated from H. organivorans. The genes catA, catB, catC and the divergently transcribed catR code for catechol 1,2-dioxygenase (1,2-CTD), cis,cis-muconate cycloisomerase, muconolactone delta-isomerase and a LysR-type transcriptional regulator, respectively. The benzoate catabolic genes (benA and benB) are located flanking the cat genes. The expression of cat and ben genes by phenol and benzoic acid was shown by RT-PCR analysis. The induction of catA gene by phenol and benzoic acid was also probed by the measurement of 1,2-CTD activity in H. organivorans growth in presence of these inducers. 16S rRNA and catA gene-based phylogenies were established among different degrading bacteria showing no phylogenetic correlation between both genes. Conclusions/Significance In this work, we isolated and determined the sequence of a gene cluster from a moderately halophilic bacterium encoding ortho-pathway genes involved in the catabolic metabolism of phenol and analyzed the gene organization, constituting the first report characterizing catabolic genes involved in the degradation of phenol in moderate halophiles, providing an ideal model system to investigate the potential use of this group of extremophiles in the decontamination of

  12. Cloning and Molecular Characterization of an Alpha-Glucosidase (MalH) from the Halophilic Archaeon Haloquadratum walsbyi.

    Science.gov (United States)

    Cuebas-Irizarry, Mara F; Irizarry-Caro, Ricardo A; López-Morales, Carol; Badillo-Rivera, Keyla M; Rodríguez-Minguela, Carlos M; Montalvo-Rodríguez, Rafael

    2017-11-21

    We report the heterologous expression and molecular characterization of the first extremely halophilic alpha-glucosidase (EC 3.2.1.20) from the archaeon Haloquadratum walsbyi . A 2349 bp region ( Hqrw_2071 ) from the Hqr. walsbyi C23 annotated genome was PCR-amplified and the resulting amplicon ligated into plasmid pET28b(+), expressed in E. coli Rosetta cells, and the resulting protein purified by Ni-NTA affinity chromatography. The recombinant protein showed an estimated molecular mass of 87 kDa, consistent with the expected value of the annotated protein, and an optimal activity for the hydrolysis of α-PNPG was detected at 40 °C, and at pH 6.0. Enzyme activity values were the highest in the presence of 3 M NaCl or 3-4 M KCl. However, specific activity values were two-fold higher in the presence of 3-4 M KCl when compared to NaCl suggesting a cytoplasmic localization. Phylogenetic analyses, with respect to other alpha-glucosidases from members of the class Halobacteria, showed that the Hqr. walsbyi MalH was most similar (up to 41%) to alpha-glucosidases and alpha-xylosidases of Halorubrum . Moreover, computational analyses for the detection of functional domains, active and catalytic sites, as well as 3D structural predictions revealed a close relationship with an E. coli YicI-like alpha-xylosidase of the GH31 family. However, the purified enzyme did not show alpha-xylosidase activity. This narrower substrate range indicates a discrepancy with annotations from different databases and the possibility of specific substrate adaptations of halophilic glucosidases due to high salinity. To our knowledge, this is the first report on the characterization of an alpha-glucosidase from the halophilic Archaea, which could serve as a new model to gain insights into carbon metabolism in this understudied microbial group.

  13. The potential of halophilic and halotolerant bacteria for the production of antineoplastic enzymes: L-asparaginase and L-glutaminase.

    Science.gov (United States)

    Shirazian, Pejman; Asad, Sedigheh; Amoozegar, Mohammad Ali

    2016-01-01

    L-asparaginase and L-glutaminase can be effectively used for the treatment of patients who suffer from accute lymphoblastic leukemia and tumor cells. Microbial sources are the best source for the bulk production of these enzymes. However, their long-term administration may cause immunological responses, so screening for new enzymes with novel properties is required. Halophilic and halotolerant bacteria with novel enzymatic characteristics can be considered as a potential source for production of enzymes with different immunological properties. In this study, L-asparaginase and L-glutaminase production by halophilic bacteria isolated from Urmia salt lake was studied. Out of the 85 isolated halophilic and halotolerant bacterial strains, 16 (19 %) showed L-asparaginase activity and 3 strains (3.5 %) showed L-glutaminase activity. Strains with the highest activities were selected for further studies. Based on 16S rDNA sequence analysis, it was shown that the selected isolates for L-asparaginase and L-glutaminase production belong to the genus Bacillus and Salicola, respectively. Both enzymes were produced extracellularly. The strain with the most L-asparaginase production did not show L-glutaminase production which is medically important. The effects of key parameters including temperature, initial pH of the solution, and concentrations of glucose, asparagine or glutamine, and sodium chloride were evaluated by means of response surface methodology (RSM) to optimize enzymes production. Under the obtained optimal conditions, L-asparaginase and L-glutaminase production was increased up to 1.5 (61.7 unit/mL) and 2.6 fold (46.4 unit/mL), respectively.

  14. Multistage bioassociation of uranium onto an extremely halophilic archaeon revealed by a unique combination of spectroscopic and microscopic techniques

    International Nuclear Information System (INIS)

    Bader, Miriam; Müller, Katharina; Foerstendorf, Harald; Drobot, Björn; Schmidt, Matthias; Musat, Niculina; Swanson, Juliet S.; Reed, Donald T.; Stumpf, Thorsten; Cherkouk, Andrea

    2017-01-01

    Highlights: • First prolonged kinetics study of uranium to halophilic archaea was performed. • An atypical time-dependent bioassociation behavior of uranium was observed. • Unique combination of spectroscopic and microscopic methods was used. • In situ ATR FT-IR showed association of U(VI) to phosphoryl and carboxylate groups. • Time-dependent changes of U(VI) localization could be monitored by SEM/EDX. - Abstract: The interactions of two extremely halophilic archaea with uranium were investigated at high ionic strength as a function of time, pH and uranium concentration. Halobacterium noricense DSM-15987 and Halobacterium sp. putatively noricense, isolated from the Waste Isolation Pilot Plant repository, were used for these investigations. The kinetics of U(VI) bioassociation with both strains showed an atypical multistage behavior, meaning that after an initial phase of U(VI) sorption, an unexpected interim period of U(VI) release was observed, followed by a slow reassociation of uranium with the cells. By applying in situ attenuated total reflection Fourier-transform infrared spectroscopy, the involvement of phosphoryl and carboxylate groups in U(VI) complexation during the first biosorption phase was shown. Differences in cell morphology and uranium localization become visible at different stages of the bioassociation process, as shown with scanning electron microscopy in combination with energy dispersive X-ray spectroscopy. Our results demonstrate for the first time that association of uranium with the extremely halophilic archaeon is a multistage process, beginning with sorption and followed by another process, probably biomineralization.

  15. Cloning and Molecular Characterization of an Alpha-Glucosidase (MalH from the Halophilic Archaeon Haloquadratum walsbyi

    Directory of Open Access Journals (Sweden)

    Mara F. Cuebas-Irizarry

    2017-11-01

    Full Text Available We report the heterologous expression and molecular characterization of the first extremely halophilic alpha-glucosidase (EC 3.2.1.20 from the archaeon Haloquadratum walsbyi. A 2349 bp region (Hqrw_2071 from the Hqr. walsbyi C23 annotated genome was PCR-amplified and the resulting amplicon ligated into plasmid pET28b(+, expressed in E. coli Rosetta cells, and the resulting protein purified by Ni-NTA affinity chromatography. The recombinant protein showed an estimated molecular mass of 87 kDa, consistent with the expected value of the annotated protein, and an optimal activity for the hydrolysis of α-PNPG was detected at 40 °C, and at pH 6.0. Enzyme activity values were the highest in the presence of 3 M NaCl or 3–4 M KCl. However, specific activity values were two-fold higher in the presence of 3–4 M KCl when compared to NaCl suggesting a cytoplasmic localization. Phylogenetic analyses, with respect to other alpha-glucosidases from members of the class Halobacteria, showed that the Hqr. walsbyi MalH was most similar (up to 41% to alpha-glucosidases and alpha-xylosidases of Halorubrum. Moreover, computational analyses for the detection of functional domains, active and catalytic sites, as well as 3D structural predictions revealed a close relationship with an E. coli YicI-like alpha-xylosidase of the GH31 family. However, the purified enzyme did not show alpha-xylosidase activity. This narrower substrate range indicates a discrepancy with annotations from different databases and the possibility of specific substrate adaptations of halophilic glucosidases due to high salinity. To our knowledge, this is the first report on the characterization of an alpha-glucosidase from the halophilic Archaea, which could serve as a new model to gain insights into carbon metabolism in this understudied microbial group.

  16. Reconstruction of the High-Osmolarity Glycerol (HOG) Signaling Pathway from the Halophilic Fungus Wallemia ichthyophaga in Saccharomyces cerevisiae.

    Science.gov (United States)

    Konte, Tilen; Terpitz, Ulrich; Plemenitaš, Ana

    2016-01-01

    The basidiomycetous fungus Wallemia ichthyophaga grows between 1.7 and 5.1 M NaCl and is the most halophilic eukaryote described to date. Like other fungi, W. ichthyophaga detects changes in environmental salinity mainly by the evolutionarily conserved high-osmolarity glycerol (HOG) signaling pathway. In Saccharomyces cerevisiae, the HOG pathway has been extensively studied in connection to osmotic regulation, with a valuable knock-out strain collection established. In the present study, we reconstructed the architecture of the HOG pathway of W. ichthyophaga in suitable S. cerevisiae knock-out strains, through heterologous expression of the W. ichthyophaga HOG pathway proteins. Compared to S. cerevisiae, where the Pbs2 (ScPbs2) kinase of the HOG pathway is activated via the SHO1 and SLN1 branches, the interactions between the W. ichthyophaga Pbs2 (WiPbs2) kinase and the W. ichthyophaga SHO1 branch orthologs are not conserved: as well as evidence of poor interactions between the WiSho1 Src-homology 3 (SH3) domain and the WiPbs2 proline-rich motif, the absence of a considerable part of the osmosensing apparatus in the genome of W. ichthyophaga suggests that the SHO1 branch components are not involved in HOG signaling in this halophilic fungus. In contrast, the conserved activation of WiPbs2 by the S. cerevisiae ScSsk2/ScSsk22 kinase and the sensitivity of W. ichthyophaga cells to fludioxonil, emphasize the significance of two-component (SLN1-like) signaling via Group III histidine kinase. Combined with protein modeling data, our study reveals conserved and non-conserved protein interactions in the HOG signaling pathway of W. ichthyophaga and therefore significantly improves the knowledge of hyperosmotic signal processing in this halophilic fungus.

  17. Halomonas sp. BS4, A biosurfactant producing halophilic bacterium isolated from solar salt works in India and their biomedical importance

    OpenAIRE

    Donio, Mariathason Birdilla Selva; Ronica, Fernando Arul; Viji, Vijayaragavan Thanga; Velmurugan, Subramanian; Jenifer, John Selesteen Charles Adlin; Michaelbabu, Mariavincent; Dhar, Prasenjit; Citarasu, Thavasimuthu

    2013-01-01

    Halophilic bacteria were isolated from Thamaraikulam solar salt works in India. After routine biosurfactant screening by various methods, the biosurfactant producing bacteria, Halomonas sp BS4 was confirmed by 16?S rRNA sequencing. The growth optimization of Halomonas sp BS4 revealed their optimum growth at 8% NaCl and 6-8?pH in the growth medium. Further the partially purified biosurfactants were characterized by TLC, FTIR and GC-MS analysis. GC-MS results revealed that, the partial purified...

  18. Complete genome sequence of the halophilic and highly halotolerant Chromohalobacter salexigens type strain (1H11T)

    Energy Technology Data Exchange (ETDEWEB)

    Copeland, A [U.S. Department of Energy, Joint Genome Institute; O' Connor, Kathleen [Purdue University; Lucas, Susan [U.S. Department of Energy, Joint Genome Institute; Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute; Berry, Kerrie W. [United States Department of Energy Joint Genome Institute; Detter, J. Chris [U.S. Department of Energy, Joint Genome Institute; Glavina Del Rio, Tijana [U.S. Department of Energy, Joint Genome Institute; Hammon, Nancy [U.S. Department of Energy, Joint Genome Institute; Dalin, Eileen [U.S. Department of Energy, Joint Genome Institute; Tice, Hope [U.S. Department of Energy, Joint Genome Institute; Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Bruce, David [Los Alamos National Laboratory (LANL); Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Han, Cliff [Los Alamos National Laboratory (LANL); Tapia, Roxanne [Los Alamos National Laboratory (LANL); Saunders, Elizabeth H [Los Alamos National Laboratory (LANL); Schmutz, Jeremy [Stanford University; Brettin, Thomas S [ORNL; Larimer, Frank W [ORNL; Land, Miriam L [ORNL; Hauser, Loren John [ORNL; Vargas, Carmen [University of Seville; Nieto, Joaquin J. [University of Seville; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Goker, Markus [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Klenk, Hans-Peter [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Csonka, Laszlo N. [Purdue University; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute

    2011-01-01

    Chromohalobacter salexigens is one of nine currently known species of the genus Chromoha- lobacter in the family Halomonadaceae. It is the most halotolerant of the so-called mod- erately halophilic bacteria currently known and, due to its strong euryhaline phenotype, it is an established model organism for prokaryotic osmoadaptation. C. salexigens strain 1H11T and Halomonas elongata are the first and the second members of the family Halomonada- ceae with a completely sequenced genome. The 3,696,649 bp long chromosome with a total of 3,319 protein-coding and 93 RNA genes was sequenced as part of the DOE Joint Genome Institute Program DOEM 2004.

  19. Noncontiguous finished genome sequence and description of Planococcus massiliensis sp. nov., a moderately halophilic bacterium isolated from the human gut

    Directory of Open Access Journals (Sweden)

    E.H. Seck

    2016-03-01

    Full Text Available We propose the main phenotypic characteristics and the complete genome sequence and annotation of Planococcus massiliensis strain ES2T (= CSUR P1103 = DSM 28915, the type strain of P. massiliensis sp. nov., isolated from a faeces sample collected from a healthy Senegalese man. It is an aerobic, Gram-positive, moderately halophilic, motile and rod-shaped bacterium. The 3 357 017 bp long genome exhibits a G+C content of 46.0% and contains 3357 protein-coding genes and 48 RNA genes.

  20. Integration of poly-3-(hydroxybutyrate-co-hydroxyvalerate) production by Haloferax mediterranei through utilization of stillage from rice-based ethanol manufacture in India and its techno-economic analysis.

    Science.gov (United States)

    Bhattacharyya, Anirban; Jana, Kuntal; Haldar, Saubhik; Bhowmic, Asit; Mukhopadhyay, Ujjal Kumar; De, Sudipta; Mukherjee, Joydeep

    2015-05-01

    Haloferax mediterranei has potential for economical industrial-scale production of polyhydroxyalkanoate (PHA) as it can utilize cheap carbon sources, has capacity for nonsterile cultivation and allows simple product recovery. Molasses-based Indian distilleries are converting themselves to cereal-based distilleries. Waste stillage (14 l) of rice-based ethanol industry was used for the production of PHA by H. mediterranei in the simple plug-flow reactor configuration of the activated sludge process. Cells utilized stillage and accumulated 63 ± 3 % PHA of dry cell weight and produced 13.12 ± 0.05 g PHA/l. The product yield coefficient was 0.27 while 0.14 g/l h volumetric productivity was reached. Simultaneous lowering of 5-day biochemical oxygen demand and chemical oxygen demand values of stillage by 82 % was attained. The biopolymer was characterized as poly-3-(hydroxybutyrate-co-17.9 mol%-hydroxyvalerate) (PHBV). Directional properties of decanoic acid jointly with temperature-dependent water solubility in decanoic acid were employed for two-step desalination of the spent stillage medium in a cylindrical baffled-tank with an immersed heater and a stirrer holding axial and radial impellers. 99.3 % of the medium salts were recovered and re-used for PHA production. The cost of PHBV was estimated as US$2.05/kg when the annual production was simulated as 1890 tons. Desalination contributed maximally to the overall cost. Technology and cost-analysis demonstrate that PHA production integrated with ethanol manufacture is feasible in India. This study could be the basis for construction of a pilot plant.

  1. A complex of Cas proteins 5, 6, and 7 is required for the biogenesis and stability of clustered regularly interspaced short palindromic repeats (crispr)-derived rnas (crrnas) in Haloferax volcanii.

    Science.gov (United States)

    Brendel, Jutta; Stoll, Britta; Lange, Sita J; Sharma, Kundan; Lenz, Christof; Stachler, Aris-Edda; Maier, Lisa-Katharina; Richter, Hagen; Nickel, Lisa; Schmitz, Ruth A; Randau, Lennart; Allers, Thorsten; Urlaub, Henning; Backofen, Rolf; Marchfelder, Anita

    2014-03-07

    The clustered regularly interspaced short palindromic repeats/CRISPR-associated (CRISPR-Cas) system is a prokaryotic defense mechanism against foreign genetic elements. A plethora of CRISPR-Cas versions exist, with more than 40 different Cas protein families and several different molecular approaches to fight the invading DNA. One of the key players in the system is the CRISPR-derived RNA (crRNA), which directs the invader-degrading Cas protein complex to the invader. The CRISPR-Cas types I and III use the Cas6 protein to generate mature crRNAs. Here, we show that the Cas6 protein is necessary for crRNA production but that additional Cas proteins that form a CRISPR-associated complex for antiviral defense (Cascade)-like complex are needed for crRNA stability in the CRISPR-Cas type I-B system in Haloferax volcanii in vivo. Deletion of the cas6 gene results in the loss of mature crRNAs and interference. However, cells that have the complete cas gene cluster (cas1-8b) removed and are transformed with the cas6 gene are not able to produce and stably maintain mature crRNAs. crRNA production and stability is rescued only if cas5, -6, and -7 are present. Mutational analysis of the cas6 gene reveals three amino acids (His-41, Gly-256, and Gly-258) that are essential for pre-crRNA cleavage, whereas the mutation of two amino acids (Ser-115 and Ser-224) leads to an increase of crRNA amounts. This is the first systematic in vivo analysis of Cas6 protein variants. In addition, we show that the H. volcanii I-B system contains a Cascade-like complex with a Cas7, Cas5, and Cas6 core that protects the crRNA.

  2. A Complex of Cas Proteins 5, 6, and 7 Is Required for the Biogenesis and Stability of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-derived RNAs (crRNAs) in Haloferax volcanii*

    Science.gov (United States)

    Brendel, Jutta; Stoll, Britta; Lange, Sita J.; Sharma, Kundan; Lenz, Christof; Stachler, Aris-Edda; Maier, Lisa-Katharina; Richter, Hagen; Nickel, Lisa; Schmitz, Ruth A.; Randau, Lennart; Allers, Thorsten; Urlaub, Henning; Backofen, Rolf; Marchfelder, Anita

    2014-01-01

    The clustered regularly interspaced short palindromic repeats/CRISPR-associated (CRISPR-Cas) system is a prokaryotic defense mechanism against foreign genetic elements. A plethora of CRISPR-Cas versions exist, with more than 40 different Cas protein families and several different molecular approaches to fight the invading DNA. One of the key players in the system is the CRISPR-derived RNA (crRNA), which directs the invader-degrading Cas protein complex to the invader. The CRISPR-Cas types I and III use the Cas6 protein to generate mature crRNAs. Here, we show that the Cas6 protein is necessary for crRNA production but that additional Cas proteins that form a CRISPR-associated complex for antiviral defense (Cascade)-like complex are needed for crRNA stability in the CRISPR-Cas type I-B system in Haloferax volcanii in vivo. Deletion of the cas6 gene results in the loss of mature crRNAs and interference. However, cells that have the complete cas gene cluster (cas1–8b) removed and are transformed with the cas6 gene are not able to produce and stably maintain mature crRNAs. crRNA production and stability is rescued only if cas5, -6, and -7 are present. Mutational analysis of the cas6 gene reveals three amino acids (His-41, Gly-256, and Gly-258) that are essential for pre-crRNA cleavage, whereas the mutation of two amino acids (Ser-115 and Ser-224) leads to an increase of crRNA amounts. This is the first systematic in vivo analysis of Cas6 protein variants. In addition, we show that the H. volcanii I-B system contains a Cascade-like complex with a Cas7, Cas5, and Cas6 core that protects the crRNA. PMID:24459147

  3. Marinospirillum insulare sp. nov., a novel halophilic helical bacterium isolated from kusaya gravy.

    Science.gov (United States)

    Satomi, M; Kimura, B; Hayashi, M; Okuzumi, M; Fujii, T

    2004-01-01

    A novel species that belongs to the genus Marinospirillum is described on the basis of phenotypic characteristics, phylogenetic analysis of 16S rRNA and gyrB gene sequences and DNA-DNA hybridization. Four strains of helical, halophilic, Gram-negative, heterotrophic bacteria were isolated from kusaya gravy, which is fermented brine that is used for the production of traditional dried fish in the Izu Islands of Japan. All of the new isolates were motile by means of bipolar tuft flagella, of small cell size, coccoid-body-forming and aerophilic; it was concluded that they belong to the same bacterial species, based on DNA-DNA hybridization values (>70% DNA relatedness). DNA G+C contents of the new strains were 42-43 mol% and they had isoprenoid quinone Q-8 as the major component. Phylogenetic analysis of 16S rRNA gene sequences indicated that the new isolates were members of the genus Marinospirillum; sequence similarity of the new isolates to Marinospirillum minutulum, Marinospirillum megaterium and Marinospirillum alkaliphilum was 98.5, 98.2 and 95.2%, respectively. Phylogenetic analysis based on the gyrB gene indicated that the new isolates had enough phylogenetic distance from M. minutulum and M. megaterium to be regarded as different species, with 84.7 and 78.7% sequence similarity, respectively. DNA-DNA hybridization showed that the new isolates had <36% DNA relatedness to M. minutulum and M. megaterium, supporting the phylogenetic conclusion. Thus, a novel species is proposed: Marinospirillum insulare sp. nov. (type strain, KT=LMG 21802T=NBRC 100033T).

  4. The Genome-Based Metabolic Systems Engineering to Boost Levan Production in a Halophilic Bacterial Model.

    Science.gov (United States)

    Aydin, Busra; Ozer, Tugba; Oner, Ebru Toksoy; Arga, Kazim Yalcin

    2018-03-01

    Metabolic systems engineering is being used to redirect microbial metabolism for the overproduction of chemicals of interest with the aim of transforming microbial hosts into cellular factories. In this study, a genome-based metabolic systems engineering approach was designed and performed to improve biopolymer biosynthesis capability of a moderately halophilic bacterium Halomonas smyrnensis AAD6 T producing levan, which is a fructose homopolymer with many potential uses in various industries and medicine. For this purpose, the genome-scale metabolic model for AAD6 T was used to characterize the metabolic resource allocation, specifically to design metabolic engineering strategies for engineered bacteria with enhanced levan production capability. Simulations were performed in silico to determine optimal gene knockout strategies to develop new strains with enhanced levan production capability. The majority of the gene knockout strategies emphasized the vital role of the fructose uptake mechanism, and pointed out the fructose-specific phosphotransferase system (PTS fru ) as the most promising target for further metabolic engineering studies. Therefore, the PTS fru of AAD6 T was restructured with insertional mutagenesis and triparental mating techniques to construct a novel, engineered H. smyrnensis strain, BMA14. Fermentation experiments were carried out to demonstrate the high efficiency of the mutant strain BMA14 in terms of final levan concentration, sucrose consumption rate, and sucrose conversion efficiency, when compared to the AAD6 T . The genome-based metabolic systems engineering approach presented in this study might be considered an efficient framework to redirect microbial metabolism for the overproduction of chemicals of interest, and the novel strain BMA14 might be considered a potential microbial cell factory for further studies aimed to design levan production processes with lower production costs.

  5. Purification and characterisation of a salt-stable protease from the halophilic archaeon Halogranum rubrum.

    Science.gov (United States)

    Gao, Ruichang; Shi, Tong; Liu, Xiangdong; Zhao, Mengqin; Cui, Henglin; Yuan, Li

    2017-03-01

    Because proteases play an important role in the fermentation of fish sauce, the purification and characterisation of an extracellular protease from the halophilic archaeon Halogranum rubrum was investigated. The molecular mass of the protease was estimated to be approximately 47 kDa based on sodium dodecyl sulfate-polyacrylamide gel electropheresis (SDS-PAGE) and native-PAGE analysis. The optimum conditions for catalytic activity were pH 8.0 and 50°C. The protease showed alkaline stability (pH 7.0-10.0). The protease also exhibited novel catalytic ability over a broad range of salinity (NaCl 0-3 mol L -1 ). Calcium ion enhanced the proteolytic activity of the enzyme. The K m and V max values of the purified protease for casein were calculated to be 4.89 mg mL -1 and 1111.11 U mL -1 , respectively. The protease was strongly inhibited by ethylenediamine tetraacetic acid (EDTA) and phenylmethanesulfonyl fluoride (PMSF). Meanwhile, the protease was stable in the presence of Triton X-100, isopropanol, ethanol or dithio-bis-nitrobenzoic (DTNB), but was inhibited by sodium dodecyl sulfate (SDS), dimethyl sulfoxide (DMSO) or methanol. MALDI -TOF/TOF MS analysis revealed that the protease shared some functional traits with protease produced by Halogranum salarium. Furthermore, it exhibited high hydrolytic activity on silver carp myosin protein. The protease is an alkaline and salt-tolerant enzyme that hydrolyses silver carp myosin with high efficiency. These excellent characteristics make this protease an attractive candidate for industrial use in low-salt fish sauce fermentation. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  6. Resistance of the Extreme Halophile Halobacterium sp. NRC-1 to Multiple Stresses

    International Nuclear Information System (INIS)

    Gygli, Patrick E.; Prajapati, Surendra; DeVeaux, Linda C.; DasSarma, Shiladitya; DasSarma, Priya; Mestari, Mohammed Amine; Wells, Douglas P.

    2009-01-01

    The model Archaeon Halobacterium sp. NRC-1 is an extreme halophile known for its resistance to multiple stressors, including electron-beam and ultraviolet radiation. It is a well-developed system with a completely sequenced genome and extensive post-genomic tools for the study of a variety of biological processes. To further understand the mechanisms of Halobacterium's, radiation resistance, we previously reported the selection for multiple independent highly resistant mutants using repeated exposure to high doses of 18-20 MeV electrons using a medical S-band Linac. Molecular analysis of the transcriptional profile of several of these mutants revealed a single common change: upregulation of the rfa3 operon. These genes encode proteins homologous to the subunits of eukaryotic Replication Protein A (RPA), a DNA binding protein with major roles in DNA replication, recombination, and repair. This operon has also been implicated in a somewhat lesser role in resistance of wild type Halobacterium to ultraviolet radiation, suggesting common mechanisms for resistance. To further understand the mechanism of radiation resistance in the mutant strains, we measured the survival after exposure to both electron-beam and ultraviolet radiation, UV-A, B, and C All mutant strains showed increased resistance to electrons when compared with the parent. However, the mutant strains do not display increased UV resistance, and in one case is more sensitive than the parent strain. Thus, the protective role of increased RPA expression within a cell may be specific to the DNA damage caused by the different physical effects induced by high energy electron-beam radiation.

  7. Nesterenkonia pannonica sp. nov., a novel alkaliphilic and moderately halophilic actinobacterium.

    Science.gov (United States)

    Borsodi, Andrea K; Szili-Kovács, Tibor; Schumann, Peter; Spröer, Cathrin; Márialigeti, Károly; Tóth, Erika

    2017-10-01

    An alkaliphilic and moderately halophilic bacterial strain characterized by optimal growth at pH 9.0-10.0 and with 5-7 % (w/v) NaCl, designated BV-35 T , was isolated from water of a soda pan located in Kiskunság National Park, Hungary. Cells of the orange-pigmented colony were Gram-stain-positive, non-motile and non-endospore-forming coccoid rods. The isolate was strictly aerobic, catalase-positive and oxidase-negative. Strain BV-35 T displayed a peptidoglycan similar to type A4α, l-Lys-l-Glu (A11.54 according to www.peptidoglycan-types.info) but containing additionally 4-aminobutyric acid. Menaquinone-7 (MK-7) was the predominant isoprenoid quinone, and anteiso-C15 : 0 and anteiso-C17 : 0 were its major cellular fatty acids. The DNA G+C content of strain BV-35 T was 65.4 mol%. Based on 16S rRNA gene sequence similarities, the novel isolate showed the closest relationship to Nesterenkonia populi GP 10-3 T (97.9 %). The DNA-DNA relatedness between BV-35 T and N. populi was 46.7 %. The distinguishing phenotypic and genetic results of this polyphasic study revealed that strain BV-35 T represents a novel member of the genus Nesterenkonia, for which the name Nesterenkonia pannonica sp. nov. is proposed. The type strain is BV-35 T (=DSM 29786 T =NCAIM B 02606 T ).

  8. Lentibacillus amyloliquefaciens sp. nov., a halophilic bacterium isolated from saline sediment sample.

    Science.gov (United States)

    Wang, Jing-Li; Ma, Ke-Dong; Wang, Yan-Wei; Wang, Hui-Min; Li, Yan-Bin; Zhou, Shan; Chen, Xiao-Rong; Kong, De-Long; Guo, Xiang; He, Ming-Xiong; Ruan, Zhi-Yong

    2016-02-01

    A Gram-stain positive, non-motile, non-sporogenous, aerobic, rod-shaped and halophilic bacterium, designated LAM0015(T), was isolated from a saline sediment sample collected from Yantai City in China. The isolate was found to be able to grow at NaCl concentrations of 5-25 % (w/v) (optimum: 7-12 %), 15-45 °C (optimum: 35 °C) and pH 5.0-9.0 (optimum: 7.0). The major fatty acids were determined to be anteiso-C15:0 and anteiso-C17:0. The predominant respiratory quinone was identified as MK-7. The cell wall peptidoglycan was determined to contain meso-diaminopimelic acid. The polar lipids were found to be diphosphatidyglycerol, phosphatidylglycerol, five phospholipids and one glycolipid. The DNA G+C content was 43.1 mol% as determined by the T m method. Analysis of the 16S rRNA gene sequence indicated that the isolate belongs within the genus Lentibacillus and is closely related to Lentibacillus persicus DSM 22530(T), Lentibacillus salicampi JCM 11462(T) and Lentibacillus jeotgali JCM 15795(T) with 97.3, 96.7 and 96.4 % sequence similarity, respectively. The DNA-DNA hybridization value between LAM0015(T) and L. persicus DSM 22530(T) was 51.2 ± 1.4 %. Based on its phenotypic, phylogenetic and chemotaxonomic characteristics, strain LAM0015(T) is concluded to represent a novel species of the genus Lentibacillus, for which the name Lentibacillus amyloliquefaciens sp. nov. is proposed. The type strain is LAM0015(T) (=ACCC 06401(T) = JCM 19838(T)).

  9. Isolation and initial characterization of the tellurite reducing moderately halophilic bacterium, Salinicoccus sp. strain QW6.

    Science.gov (United States)

    Amoozegar, Mohammad Ali; Ashengroph, Morahem; Malekzadeh, Feridon; Reza Razavi, Mohamad; Naddaf, Saied; Kabiri, Mahboubeh

    2008-01-01

    Among the 49 strains of moderately halophilic bacteria isolated from the salty environments of Iran, a Gram-positive coccus designated as strain QW6 showed high capacity in the removal of toxic oxyanions of tellurium in a wide range of culture medium factors including pH (5.5-10.5), temperature (25-45 degrees C), various salts including NaCl, KCl, and Na(2)SO(4) (0.5-4 M), selenooxyanions (2-10 mM), and at different concentrations of potassium tellurite (0.5-1 mM) under aerobic condition. Phenotypic characterization and phylogenetic analyses based on 16S rDNA sequence comparisons indicated that this strain was a member of the genus Salinicoccus. The maximum tellurite removal was exhibited in 1.5M NaCl at 35 degrees C, while the activity reduced by 53% and 47% at 25 and 45 degrees C, respectively. The optimum pH for removal activity was shown to be 7.5, with 90% and 83% reduced removal capacities at the two extreme values of 5.5 and 10, respectively. The impact of different concentrations of selenooxyanions (2-10 mM) on tellurite removal by strain QW6 was evaluated. The ability of strain QW6 in the removal of tellurite in the presence of 6mM selenite increased by 25%. The concentration of toxic potassium tellurite in the supernatant of the bacterial culture medium decreased by 99% (from 0.5 to 0.005 mM) after 6 days and the color of the medium changed to black due to the formation of less toxic elemental tellurium.

  10. Spiribacter roseus sp. nov., a moderately halophilic species of the genus Spiribacter from salterns.

    Science.gov (United States)

    León, María José; Vera-Gargallo, Blanca; Sánchez-Porro, Cristina; Ventosa, Antonio

    2016-10-01

    Four pink-pigmented, non-motile, Gram-staining-negative and moderately halophilic curved rods, designated strains SSL50T, SSL25, SSL97 and SSL4, were isolated from a saltern located in Isla Cristina, Huelva, south-west Spain. Phylogenetic analyses based on 16S rRNA gene sequences showed that they were members of the genus Spiribacter, most closely related to Spiribacter curvatus UAH-SP71T (99.3-99.5 % sequence similarity) and Spiribacter salinus M19-40T (96.5-96.7 %). Other related strains were Alkalilimnicola ehrlichii MLHE-1T (95.1-95.3 %), Arhodomonas recens RS91T (95.1-95.2 %) and Arhodomonas aquaeolei ATCC 49307T (95.0-95.1 %), all members of the family Ectothiorhodospiraceae. The major fatty acids were C18 : 1ω6c and/or C18 : 1ω7c, C16 : 0 and C12 : 0. The DNA G+C range was 64.0-66.3 mol%. The DNA-DNA hybridization values between strains SSL50T, SSL25, SSL97, SSL4 and S. piribacter. curvatus UAH-SP71T were 37-49 %. The average nucleotide identity (ANIb) values between the genome of strain SSL50T and those of the two other representatives of the genus Spiribacter, S. curvatus UAH-SP71T and S. salinus M19-40T, were 82.4 % and 79.1 %, respectively, supporting the proposal of a novel species of the genus Spiribacter. On the basis of the polyphasic analysis, the four new isolates are considered to represent a novel species of the genus Spiribacter, for which the name Spiribacter roseus sp. nov. is proposed. The type strain is SSL50T (=CECT 9117T=IBRC-M 11076T).

  11. Copper-resistant halophilic bacterium isolated from the polluted Maruit Lake, Egypt.

    Science.gov (United States)

    Osman, O; Tanguichi, H; Ikeda, K; Park, P; Tanabe-Hosoi, S; Nagata, S

    2010-04-01

    To isolate and characterize copper-resistant halophilic bacteria from the polluted Maruit Lake, Egypt and identify the role of plasmids in toxic metal resistance. We isolated strain MA2, showing high copper resistance up to the 1.5 mmol l(-1) concentration; it was also resistant to other metals such as nickel, cobalt and zinc and a group of antibiotics. Partial 16S rRNA analysis revealed that strain MA2 belonged to the genus Halomonas. Copper uptake, measured by atomic absorption spectrophotometery, was higher in the absence of NaCl than in the presence of 0.5-1.0 mol l(-1) NaCl during 5-15 min of incubation. Cell fractionation and electron microscopic observation clarified that most of the copper accumulated in the outer membrane and periplasmic fractions of the cells. Plasmid screening yielded two plasmids: pMA21 (11 kb) and pMA22 (5 kb). Plasmid curing resulted in a strain that lost both the plasmids and was sensitive to cobalt and chromate but not copper, nickel and zinc. This cured strain also showed weak growth in the presence of 0.5-1.0 mol l(-1) NaCl. Partial sequencing of both plasmids led to the identification of different toxic metals transporters but copper transporters were not identified. The highest cell viability was found in the presence of 1.0 mol l(-1) NaCl at different copper concentrations, and copper uptake was optimal in the absence of NaCl. Plasmid pMA21 encoded chromate, cobalt, zinc and cadmium transporters, whereas pMA22 encoded specific zinc and RND (resistance, nodulation, cell division) efflux transporters as well as different kinds of metabolic enzymes. Copper resistance was mainly incorporated in the chromosome. Strain MA2 is a fast and efficient tool for copper bioremediation and the isolated plasmids show significant characteristics of both toxic metal and antibiotic resistance.

  12. Chloride and organic osmolytes: a hybrid strategy to cope with elevated salinities by the moderately halophilic, chloride-dependent bacterium Halobacillus halophilus.

    Science.gov (United States)

    Saum, Stephan H; Pfeiffer, Friedhelm; Palm, Peter; Rampp, Markus; Schuster, Stephan C; Müller, Volker; Oesterhelt, Dieter

    2013-05-01

    Salt acclimation in moderately halophilic bacteria is the result of action of a grand interplay orchestrated by signals perceived from the environment. To elucidate the cellular players involved in sensing and responding to changing salinities we have determined the genome sequence of Halobacillus halophilus, a Gram-positive moderate halophilic bacterium that has a strict requirement for the anion chloride. Halobacillus halophilus synthesizes a multitude of different compatible solutes and switches its osmolyte strategy with the external salinity and growth phase. Based on the emerging genome sequence, the compatible solutes glutamate, glutamine, proline and ectoine have already been experimentally studied. The biosynthetic routes for acetyl ornithine and acetyl lysine are also delineated from the genome sequence. Halobacillus halophilus is nutritionally very versatile and most compatible solutes cannot only be produced but also used as carbon and energy sources. The genome sequence unravelled isogenes for many pathways indicating a fine regulation of metabolism. Halobacillus halophilus is unique in integrating the concept of compatible solutes with the second fundamental principle to cope with salt stress, the accumulation of molar concentrations of salt (Cl(-)) in the cytoplasm. Extremely halophilic bacteria/archaea, which exclusively rely on the salt-in strategy, have a high percentage of acidic proteins compared with non-halophiles with a low percentage. Halobacillus halophilus has an intermediate position which is consistent with its ability to integrate both principles. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

  13. Halomonas indalinina sp.nov., a moderately halophilic bacterium isolated from a solar saltern in Cabo de Gata, Al,eria, southern Spain

    NARCIS (Netherlands)

    Cabrera, A.; Aguilera, M.; Fuentes Enriquez de Salamanca, S.; Incerti, C.; Russell, N.J.; Ramos-Cormenzana, A.; Monteoliva-Sanchez, M.

    2007-01-01

    moderately halophilic bacterium, strain CG2.1T, isolated from a solar saltern at Cabo de Gata, a wildlife reserve located in the province of Almería, southern Spain, was subjected to a polyphasic taxonomic study. This organism was an aerobic, motile, Gram-negative rod that produced orange-pigmented

  14. Chloride Activated Halophilic α-Amylase from Marinobacter sp. EMB8: Production Optimization and Nanoimmobilization for Efficient Starch Hydrolysis

    Directory of Open Access Journals (Sweden)

    Sumit Kumar

    2015-01-01

    Full Text Available Halophiles have been perceived as potential source of novel enzymes in recent years. The interest emanates from their ability to catalyze efficiently under high salt and organic solvents. Present work encompasses production optimization and nanoimmobilization of an α-amylase from moderately halophilic Marinobacter sp. EMB8. Media ingredients and culture conditions were optimized by “one-at-a-time approach.” Starch was found to be the best carbon source at 5% (w/v concentration. Glucose acted as catabolic repressor for amylase production. Salt proved critical for amylase production and maximum production was attained at 5% (w/v NaCl. Optimization of various culture parameters resulted in 48.0 IU/mL amylase production, a 12-fold increase over that of unoptimized condition (4.0 IU/mL. α-Amylase was immobilized on 3-aminopropyl functionalized silica nanoparticles using glutaraldehyde as cross-linking agent. Optimization of various parameters resulted in 96% immobilization efficiency. Starch hydrolyzing efficiency of immobilized enzyme was comparatively better. Immobilized α-amylase retained 75% of its activity after 5th cycle of repeated use.

  15. Characterization of halophilic C50 carotenoid-producing archaea isolated from solar saltworks in Bohai Bay, China

    Science.gov (United States)

    Sui, Liying; Liu, Liangsen; Deng, Yuangao

    2014-11-01

    Halophilic archaea comprise the majority of microorganisms found in hypersaline environments. C50 carotenoids accumulated in archaea cells are considered potential biotechnological products and possess a number of biological functions. Ten red colonies were isolated from brine water in a saltern crystallizer pond of the Hangu Saltworks, China. 16S rRNA gene sequence analysis showed that the colonies belonged to the extremely halophilic archaea genera Halobacterium and Halorubrum. Two representative strains, Halobacterium strain SP-2 and Halorubrum strain SP-4, were selected for further study on the phenotypic characteristics and effects of salinity and pH on accumulation and composition of pigments in their cells. The archaeal strains were isolated and grown in a culture medium prepared by dissolving yeast extract (10 g/L) and acid-hydrolyzed casein (7.5 g/L) into brine water obtained from a local salt pond. Their optimum salinity and pH for growth were 250 and 7, respectively, although pigment accumulation (OD490 / mL broth) was highest at pH 8. In addition, at 150-300 salinity, increasing salinity resulted in decreasing pigment accumulation. Analysis of the UV-Vis spectrum, TLC and HLPC chromatograms showed that C50 carotenoid bacterioruberin is the major pigment in both strains.

  16. High-Throughput Screening for a Moderately Halophilic Phenol-Degrading Strain and Its Salt Tolerance Response

    Science.gov (United States)

    Lu, Zhi-Yan; Guo, Xiao-Jue; Li, Hui; Huang, Zhong-Zi; Lin, Kuang-Fei; Liu, Yong-Di

    2015-01-01

    A high-throughput screening system for moderately halophilic phenol-degrading bacteria from various habitats was developed to replace the conventional strain screening owing to its high efficiency. Bacterial enrichments were cultivated in 48 deep well microplates instead of shake flasks or tubes. Measurement of phenol concentrations was performed in 96-well microplates instead of using the conventional spectrophotometric method or high-performance liquid chromatography (HPLC). The high-throughput screening system was used to cultivate forty-three bacterial enrichments and gained a halophilic bacterial community E3 with the best phenol-degrading capability. Halomonas sp. strain 4-5 was isolated from the E3 community. Strain 4-5 was able to degrade more than 94% of the phenol (500 mg·L−1 starting concentration) over a range of 3%–10% NaCl. Additionally, the strain accumulated the compatible solute, ectoine, with increasing salt concentrations. PCR detection of the functional genes suggested that the largest subunit of multicomponent phenol hydroxylase (LmPH) and catechol 1,2-dioxygenase (C12O) were active in the phenol degradation process. PMID:26020478

  17. Multistage bioassociation of uranium onto an extremely halophilic archaeon revealed by a unique combination of spectroscopic and microscopic techniques.

    Science.gov (United States)

    Bader, Miriam; Müller, Katharina; Foerstendorf, Harald; Drobot, Björn; Schmidt, Matthias; Musat, Niculina; Swanson, Juliet S; Reed, Donald T; Stumpf, Thorsten; Cherkouk, Andrea

    2017-04-05

    The interactions of two extremely halophilic archaea with uranium were investigated at high ionic strength as a function of time, pH and uranium concentration. Halobacterium noricense DSM-15987 and Halobacterium sp. putatively noricense, isolated from the Waste Isolation Pilot Plant repository, were used for these investigations. The kinetics of U(VI) bioassociation with both strains showed an atypical multistage behavior, meaning that after an initial phase of U(VI) sorption, an unexpected interim period of U(VI) release was observed, followed by a slow reassociation of uranium with the cells. By applying in situ attenuated total reflection Fourier-transform infrared spectroscopy, the involvement of phosphoryl and carboxylate groups in U(VI) complexation during the first biosorption phase was shown. Differences in cell morphology and uranium localization become visible at different stages of the bioassociation process, as shown with scanning electron microscopy in combination with energy dispersive X-ray spectroscopy. Our results demonstrate for the first time that association of uranium with the extremely halophilic archaeon is a multistage process, beginning with sorption and followed by another process, probably biomineralization. Copyright © 2016. Published by Elsevier B.V.

  18. Purification and characterization of an extracellular haloalkaline serine protease from the moderately halophilic bacterium, Bacillus iranensis (X5B).

    Science.gov (United States)

    Ghafoori, Hossein; Askari, Mansoure; Sarikhan, Sajjad

    2016-03-01

    This study reports the purification and characterization of an extracellular haloalkaline serine protease from the moderately halophilic bacterium, Bacillus iranensis, strain X5B. The enzyme was purified to homogeneity by acetone precipitation, ultrafiltration and carboxymethyl (CM) cation exchange chromatography, respectively. The purified protease was a monomeric enzyme with a relative molecular mass of 48-50 kDa and it was inhibited by PMSF indicating that it is a serine-protease. The optimum pH, temperature and NaCl concentration were 9.5, 35 °C and 0.98 M, respectively. The enzyme showed a significant tolerance to salt and alkaline pH. It retained approximately 50% of activity at 2.5 M NaCl and about 70% of activity at highly alkaline pH of 11.0; therefore, it was a moderately halophilic and also can be activated by metals, especially by Ca(2+). The specific activity of the purified protease was measured to be 425.23 μmol of tyrosine/min per mg of protein using casein as a substrate. The apparent K m and V max values were 0.126 mM and 0.523 mM/min, respectively and the accurate value of k cat was obtained as 3.284 × 10(-2) s(-1). These special and important characteristics make this serine protease as valuable tool for industrial applications.

  19. Antagonistic interactions and production of halocin antimicrobial peptides among extremely halophilic prokaryotes isolated from the solar saltern of Sfax, Tunisia.

    Science.gov (United States)

    Ghanmi, Fadoua; Carré-Mlouka, Alyssa; Vandervennet, Manon; Boujelben, Ines; Frikha, Doniez; Ayadi, Habib; Peduzzi, Jean; Rebuffat, Sylvie; Maalej, Sami

    2016-05-01

    Thirty-five extremely halophilic microbial strains isolated from crystallizer (TS18) and non-crystallizer (M1) ponds in the Sfax solar saltern in Tunisia were examined for their ability to exert antimicrobial activity. Antagonistic assays resulted in the selection of eleven strains that displayed such antimicrobial activity and they were further characterized. Three cases of cross-domain inhibition (archaea/bacteria or bacteria/archaea) were observed. Four archaeal strains exerted antimicrobial activity against several other strains. Three strains, for which several lines of evidence suggested the antimicrobial activity was, at least in part, due to peptide/protein agents (Halobacterium salinarum ETD5, Hbt. salinarum ETD8, and Haloterrigena thermotolerans SS1R12), were studied further. Optimal culture conditions for growth and antimicrobial production were determined. Using DNA amplification with specific primers, sequencing and RT-PCR analysis, Hbt. salinarum ETD5 and Hbt. salinarum ETD8 were shown to encode and express halocin S8, a hydrophobic antimicrobial peptide targeting halophilic archaea. Although the gene encoding halocin H4 was amplified from the genome of Htg. thermotolerans SS1R12, no transcript could be detected and the antimicrobial activity was most likely due to multiple antimicrobial compounds. This is also the first report that points to four different strains isolated from different geographical locations with the capacity to produce identical halocin S8 proteins.

  20. Isolation and identification of poly-extremophilic alkalophilic, halophilic and halotolerant bacteria from alkaline thalassohaline Gomishan wetland

    Directory of Open Access Journals (Sweden)

    Azadeh Shahinpei

    2013-06-01

    Full Text Available Gomishan wetland is a natural ecosystem located in 35 km north west of Gorgan, in the west vicinity of Khajeh Nafas city and Gomishan. Twice sampling from 3 different geographic positions in dry and rainy seasons, led to the isolation of 224 isolates. For 57 isolates, halophilic and halotolerant behaviors and also optimum and growth range in different pH and temperatures were determined. Most of the moderately halophilic and halotolerant strains were capable of growing optimally in media with pH 8.5-9 and optimum growth temperatures ranging from <4 to 40 °C. The isolates were examined for hydrolytic enzymes production. Most of the isolates showed lipase activites and a total of 15, 7 and 3 strains produced amylases, proteases and DNases, respectively. The enzymes could be useful in some industrial processes. 16S rDNA phylogenetic analysis were done for 55 strains. According to this analysis, strains were placed in 22 different genera: Achromobacter, Aeromicrobium, Altererythrobacter, Bacillus, Caenispirillum, Cyclobacterium, Erythrobacter, Halobacillus, Halomonas, Idiomarina, Jonesia, Marinobacter, Martelella, Nesiotobacter, Paenibacillus, Planococcus, Pseudomonas, Rheinheimera, Saccharospirillum, Stappia, Thalassospira and Vibrio. 23% of these strains were haloalkalophilic bacteria and belonged to the Bacillus, Halobacillus, Halomonas, Idiomarina and Marinobacter. This was the first study on the culturable bacteria at Gomishan wetland, an area of considerable alkaline thalassohaline ecosystem.

  1. Sporosalibacterium faouarense gen. nov., sp. nov., a moderately halophilic bacterium isolated from oil-contaminated soil.

    Science.gov (United States)

    Rezgui, Raja; Ben Ali Gam, Zouhaier; Ben Hamed, Said; Fardeau, Marie-Laure; Cayol, Jean-Luc; Maaroufi, Abderrazak; Labat, Marc

    2011-01-01

    A novel strictly anaerobic, moderately halophilic and mesophilic bacterium, designated strain SOL3f37(T), was isolated from a hydrocarbon-polluted soil surrounding a deep petroleum environment located in south Tunisia. Cells of strain SOL3f37(T) stained Gram-positive and were motile, straight and spore-forming. Strain SOL3f37(T) had a typical Gram-positive-type cell-wall structure, unlike the thick, multilayered cell wall of its closest relative Clostridiisalibacter paucivorans. The major fatty acids were iso-C(15 : 0) (41 %), iso-C(14 : 0) 3-OH and/or iso-C(15 : 0) dimethyl acetal (21.6 %), iso-C(13 : 0) (4.4 %), anteiso-C(15 : 0) (3.9 %) and iso-C(15 : 1) (2.8 %). Strain SOL3f37(T) grew between 20 and 48 °C (optimum 40 °C) and at pH 6.2-8.1 (optimum pH 6.9). Strain SOL3f37(T) required at least 0.5 NaCl l(-1) and grew in the presence of NaCl concentrations up to 150 g l(-1) (optimum 40 g l(-1)). Yeast extract (2 g l(-1)) was required for degradation of pyruvate, fumarate, fructose, glucose and mannitol. Also, strain SOL3f37(T) grew heterotrophically on yeast extract, peptone and bio-Trypticase, but was unable to grow on Casamino acids. Sulfate, thiosulfate, sulfite, elemental sulfur, fumarate, nitrate and nitrite were not reduced. The DNA G+C content was 30.7 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain SOL3f37(T) was a member of the family Clostridiaceae in the order Clostridiales; strain SOL3f37(T) was related to members of various genera of the family Clostridiaceae. It exhibited highest 16S rRNA gene sequence similarity (93.4 %) with Clostridiisalibacter paucivorans 37HS60(T), 91.8 % with Thermohalobacter berrensis CTT3(T) and 91.7 % with Caloranaerobacter azorensis MV1087(T). On the basis of genotypic, phenotypic and phylogenetic data, it is suggested that strain SOL3f37(T) represents a novel species in a new genus. The name Sporosalibacterium faouarense gen. nov., sp. nov. is

  2. Haloplanus salinarum sp. nov., an extremely halophilic archaeon isolated from a solar saltern.

    Science.gov (United States)

    Hwang, Han-Bit; Kim, Ye-Eun; Koh, Hyeon-Woo; Song, Hye Seon; Roh, Seong Woon; Kim, So-Jeong; Nam, Seung Won; Park, Soo-Je

    2017-11-01

    An extremely halophilic archaeal strain SP28 T was isolated from the Gomso solar saltern, Republic of Korea. Cells of the new strain SP28 T were pleomorphic and Gram stain negative, and produced red-pigmented colonies. These grew in medium with 2.5-4.5 M NaCl (optimum 3.1 M) and 0.05-0.5 M MgCl2 (optimum 0.1 M), at 25-50 °C (optimum 37 °C) and at a pH of 6.5-8.5 (optimum pH 8.0). Mg 2+ was required for growth. A concentration of at least 2 M NaCl was required to prevent cell lysis. Polar lipids included phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate and one glycolipid chromatographically identical to sulfated mannosyl glucosyl diether. 16S rRNA and rpoB' gene sequence analyses showed that strain SP28 T is closely related to Haloplanus ruber R35 T (97.3 and 94.1 %, 16S rRNA and rpoB' gene sequence similarity, respectively), Haloplanus litoreus GX21 T (97.0 and 92.1 %), Haloplanus salinus YGH66 T (96.0 and 91.9 %), Haloplanus vescus RO5-8 T (95.9 and 90.9 %), Haloplanus aerogenes TBN37 T (95.6 and 90.3 %) and Haloplanus natans RE-101 T (95.3 and 89.8 %). The DNA G+C content of the novel strain SP28 T was 66.2 mol%, which is slightly higher than that of Hpn.litoreus GX21 T (65.8 mol%) and Hpn.ruber R35 T (66.0 mol%). DNA-DNA hybridization values betweenHpn.ruber R35 T and strain SP28 T and between Hpn.litoreus GX21 T and strain SP28 T were about 24.8 and 20.7 %, respectively. We conclude that strain SP28 T represents a novel species of the genus Haloplanus and propose the name Haloplanus salinarum sp. nov. The type strain is SP28 T (=JCM 31424 T =KCCM 43210 T ).

  3. Lanthanide behavior in hypersaline evaporation ponds at Guerrero Negro, Baja California, Mexico - an environment with halophiles

    Science.gov (United States)

    Choumiline, K.; López-Cortés, A.; Grajeda-Muñoz, M.; Shumilin, E.; Sapozhnikov, D.

    2013-12-01

    Lanthanides are known, in some cases, to be sensitive to changes in water column or sediment chemistry, a fact that allows them to be used as environmental fingerprints. Nevertheless, the behavior of these elements in hypersaline environments is insufficiently understood, especially in those colonized by bacteria, archaea and eukarya halophiles. Extreme environments like the mentioned exist in the artificially-controlled ponds of the 'Exportadora de Sal' salt-producing enterprise located in Guerrero Negro (Baja California, Mexico). Sediment cores from various ponds were collected, subsampled and measured by ICP-MS and INAA. This allowed differencing the behavior of lanthanides and trace elements under a water column salinity gradient along the evaporation sequence of ponds. Sediment profiles (30 mm long), obtained in Pond 5, dominated by Ca and Mg precipitation and at the same time rich in organic matter due to bacterial mat presence, showed highs and lows of the shale-normalized patterns along different in-core depths. Two groups of elements could be distinguished with similar trends: set A (La, Ce, Pr and Nd) and set B (Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu). The first 'group A' had two prominent peaks at 15 mm and around 22 mm, whereas the 'group B' showed only slight increase at 15 mm and none at 22 mm. Microscopic analyses of prokaryotic cells of a stratified mat in Pond 5 (collected in 2004) showed filamentous bacteria and cyanobacteria with a cell abundance and morphotype richness maxima of prokaryotic cells in a chemocline from 3 mm to 7 mm depth which co-exists nine morphotypes of aerobic and anaerobic prokaryotes Microcoleus chthonoplastes, Leptolyngbya, Cyanothece, Geitlerinema, Spirulina, Chloroflexus, Beggiatoa, Chromatium and Thioploca. Below the 7 mm depth, oxygenic photosynthesis depletes and sulfur reducing compounds increase. The highs of the shale-normalized lanthanide contents of the 'group A' (at 15 mm depth) seem to correlate with the

  4. Planococcus salinus sp. nov., a moderately halophilic bacterium isolated from a saline-alkali soil.

    Science.gov (United States)

    Gan, Longzhan; Zhang, Heming; Tian, Jiewei; Li, Xiaoguang; Long, Xiufeng; Zhang, Yuqin; Dai, Yumei; Tian, Yongqiang

    2018-02-01

    A novel aerobic, Gram-stain-positive, motile, moderately halophilic and coccoid bacterial strain, designated LCB217 T , was isolated from a saline-alkali soil in north-western China and identified using a polyphasic taxonomic approach. Growth occurred with 3-15 % (w/v) NaCl (optimum 3-5 %), at 10-45 °C (optimum 30 °C) and at pH 7.0-9.0 (optimum pH 9.0). Strain LCB217 T contained MK-7 and MK-8 as the predominant menaquinones and anteiso-C15 : 0, iso-C14 : 0 and iso-C16 : 0 as the major fatty acids. The polar lipids from strain LCB217 T consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, one unidentified phospholipid, one unidentified aminophospholipid and one unidentified lipid. The peptidoglycan type was A4α (l-Lys-d-Glu). Phylogenetic analysis of the 16S rRNA gene sequence showed that strain LCB217 T belonged to the genus Planococcus and was closely related to the type strains Planococcus plakortidis AS/ASP6 (II) T (98.2 % similarity), Planococcus maitriensis S1 T (97.7 %) and Planococcus salinarum ISL-16 T (97.2 %). The G+C content of the genomic DNA was 49.4 mol%. DNA-DNA relatedness values between strain LCB217 T andPlanococcusplakortidis AS/ASP6 (II) T , Planococcusmaitriensis S1 T andPlanococcussalinarum ISL-16 T were 29.5, 38.1 and 39.5 %, respectively. On the basis of the phenotypic, phylogenetic and genomic data, strain LCB217 T represents a novel species of the genus Planococcus, for which the name Planococcus salinus sp. nov. is proposed. The type strain is LCB217 T (=CGMCC 1.15685 T =KCTC 33861 T ).

  5. Extreme Halophiles and Carbon Monoxide: Looking Through Windows at Earth's Past and Towards a Future on Mars

    Science.gov (United States)

    King, G.

    2015-12-01

    Carbon monoxide, which is ubiquitous on Earth, is the 2nd most abundant molecule in the universe. Members of the domain Bacteria have long been known to oxidize it, and activities of CO oxidizers in soils have been known for several decades to contribute to tropospheric CO regulation. Nonetheless, the diversity of CO oxidizers and their evolutionary history remain largely unknown. A molybdenum-dependent dehydrogenase (Mo-CODH) couples CO oxidation by most terrestrial and marine bacteria to either O2 or nitrate. Molybdenum dependence, the requirement for O2 and previous phylogenetic inferences have all supported a relatively late evolution for "aerobic" CO oxidation, presumably after the Great Oxidation Event (GOE) about 2.3 Gya. Although conundrums remain, recent discoveries suggest that Mo-CODH might have evolved before the GOE, and prior to the Bacteria-Archaea split. New phylogenetic analyses incorporating sequences from extremely halophilic CO-oxidizing Euryarchaeota isolated from salterns in the Atacama Desert, brines on Hawai`i and from the Bonneville Salt Flat suggest that Mo-CODH was present in an ancestor shared by Bacteria and Archaea. This observation is consistent with results of phylogenetic histories of genes involved in Mo-cofactor synthesis, and findings by others that Mo-nitrogenase was likely active > 3 Gya. Thus, analyses of Mo-dependent CO oxidizers provide a window on the past by raising questions about the availability of Mo and non-O2 electron acceptors. Extremely halophilic CO oxidizers also provide insights relevant for understanding the potential for extraterrestrial life. CO likely occurred at high concentrations in Mars' early atmosphere, and it occurs presently at about 800 ppm. At such high concentrations, CO represents one of the most abundant energy sources available for near-surface regolith. However, use of CO by an extant or transplanted Mars microbiota would require tolerance of low water potentials and high salt concentrations

  6. Cloning, characterization and analysis of cat and ben genes from the phenol degrading halophilic bacterium Halomonas organivorans.

    Directory of Open Access Journals (Sweden)

    Maria de Lourdes Moreno

    Full Text Available BACKGROUND: Extensive use of phenolic compounds in industry has resulted in the generation of saline wastewaters that produce significant environmental contamination; however, little information is available on the degradation of phenolic compounds in saline conditions. Halomonas organivorans G-16.1 (CECT 5995(T is a moderately halophilic bacterium that we isolated in a previous work from saline environments of South Spain by enrichment for growth in different pollutants, including phenolic compounds. PCR amplification with degenerate primers revealed the presence of genes encoding ring-cleaving enzymes of the β-ketoadipate pathway for aromatic catabolism in H. organivorans. FINDINGS: The gene cluster catRBCA, involved in catechol degradation, was isolated from H. organivorans. The genes catA, catB, catC and the divergently transcribed catR code for catechol 1,2-dioxygenase (1,2-CTD, cis,cis-muconate cycloisomerase, muconolactone delta-isomerase and a LysR-type transcriptional regulator, respectively. The benzoate catabolic genes (benA and benB are located flanking the cat genes. The expression of cat and ben genes by phenol and benzoic acid was shown by RT-PCR analysis. The induction of catA gene by phenol and benzoic acid was also probed by the measurement of 1,2-CTD activity in H. organivorans growth in presence of these inducers. 16S rRNA and catA gene-based phylogenies were established among different degrading bacteria showing no phylogenetic correlation between both genes. CONCLUSIONS/SIGNIFICANCE: In this work, we isolated and determined the sequence of a gene cluster from a moderately halophilic bacterium encoding ortho-pathway genes involved in the catabolic metabolism of phenol and analyzed the gene organization, constituting the first report characterizing catabolic genes involved in the degradation of phenol in moderate halophiles, providing an ideal model system to investigate the potential use of this group of extremophiles in

  7. The Structure of the Lipid A from the Halophilic Bacterium Spiribacter salinus M19-40T

    Directory of Open Access Journals (Sweden)

    Clara Barrau

    2018-04-01

    Full Text Available The study of the adaptation mechanisms that allow microorganisms to live and proliferate in an extreme habitat is a growing research field. Directly exposed to the external environment, lipopolysaccharides (LPS from Gram-negative bacteria are of great appeal as they can present particular structural features that may aid the understanding of the adaptation processes. Moreover, through being involved in modulating the mammalian immune system response in a structure-dependent fashion, the elucidation of the LPS structure can also be seen as a fundamental step from a biomedical point of view. In this paper, the lipid A structure of the LPS from Spiribacter salinus M19-40T, a halophilic gamma-proteobacteria, was characterized through chemical analyses and matrix-assisted laser desorption ionization (MALDI mass spectrometry. This revealed a mixture of mono- and bisphosphorylated penta- to tri-acylated species with the uncommon 2 + 3 symmetry and bearing an unusual 3-oxotetradecaonic acid.

  8. Identification and characterization of a novel biodiesel producing halophilic Aphanothece halophytica and its growth and lipid optimization in various media

    International Nuclear Information System (INIS)

    Monisha Miriam, L.R.; Edwin Raj, R.; Kings, Ajith J.; Adhi Visvanathan, M.

    2017-01-01

    Highlights: • Halophilic microalgae, Aphanothece halophytica is a new candidate for third generation biodiesel source. • This species is robust, resilient, stable and non-susceptible to environmental conditions. • Novel media, seaweed extract and micronutrient are tested, compared and optimized. • High lipid productivity with low free fatty acid content confirms its potential for biodiesel production. - Abstract: The choice of precise strain is a crucial parameter to the success of algal oil industry. A novel halophilic microalgae, Aphanothece halophytica is selected as a potential source to satisfy the enormous energy needs. This species is highly resilient to environmental changes and can effectively utilize both organic and inorganic nutrients. Commercialization of biodiesel production is hindered by its production cost which necessitates advances in quantitative and qualitative microalgae cultivation. In this work, the salinity and major nutrient sources such as nitrogen, phosphorous and potassium of the standard Jaworski’s medium are replaced with commercial agricultural fertilizers like urea (N), single super phosphate (P) and muriate of potash (K) respectively and its concentrations optimized for the growth rate. The result showed maximum growth at 60 ppt salinity, 0.05 g l"−"1 (N), 0.5 g l"−"1 (P) and 0.5 g l"−"1 (K). Then a novel attempt is made to identify a low cost media, involving organic–inorganic (seaweed extract + NPK), inorganic (micronutrients + NPK), organic (vermicompost medium) for maximizing growth rate and lipid productivity, which is then compared with the standard Jaworski’s medium. A. halophytica gave the highest cell density of 21.6 × 10"6 ± 0.17 cells ml"−"1 on the 20th day with a lipid content of 29 ± 0.1% by dry weight in seaweed extract + NPK medium. It’s potentiality for biodiesel production is further confirmed by the gas chromatography analysis of the lipid.

  9. Carbon monoxide as a metabolic energy source for extremely halophilic microbes: implications for microbial activity in Mars regolith.

    Science.gov (United States)

    King, Gary M

    2015-04-07

    Carbon monoxide occurs at relatively high concentrations (≥800 parts per million) in Mars' atmosphere, where it represents a potentially significant energy source that could fuel metabolism by a localized putative surface or near-surface microbiota. However, the plausibility of CO oxidation under conditions relevant for Mars in its past or at present has not been evaluated. Results from diverse terrestrial brines and saline soils provide the first documentation, to our knowledge, of active CO uptake at water potentials (-41 MPa to -117 MPa) that might occur in putative brines at recurrent slope lineae (RSL) on Mars. Results from two extremely halophilic isolates complement the field observations. Halorubrum str. BV1, isolated from the Bonneville Salt Flats, Utah (to our knowledge, the first documented extremely halophilic CO-oxidizing member of the Euryarchaeota), consumed CO in a salt-saturated medium with a water potential of -39.6 MPa; activity was reduced by only 28% relative to activity at its optimum water potential of -11 MPa. A proteobacterial isolate from hypersaline Mono Lake, California, Alkalilimnicola ehrlichii MLHE-1, also oxidized CO at low water potentials (-19 MPa), at temperatures within ranges reported for RSL, and under oxic, suboxic (0.2% oxygen), and anoxic conditions (oxygen-free with nitrate). MLHE-1 was unaffected by magnesium perchlorate or low atmospheric pressure (10 mbar). These results collectively establish the potential for microbial CO oxidation under conditions that might obtain at local scales (e.g., RSL) on contemporary Mars and at larger spatial scales earlier in Mars' history.

  10. Anti-methicillin Resistant Staphylococcus aureus Compound Isolation from Halophilic Bacillus amyloliquefaciens MHB1 and Determination of Its Mode of Action Using Electron Microscope and Flow Cytometry Analysis

    OpenAIRE

    Jeyanthi, Venkadapathi; Velusamy, Palaniyandi

    2016-01-01

    The aim of this study was to purify, characterize and evaluate the antibacterial activity of bioactive compound against methicillin-resistant Staphylococcus aureus (MRSA). The anti-MRSA compound was produced by a halophilic bacterial strain designated as MHB1. The MHB1 strain exhibited 99��% similarity to Bacillus amyloliquefaciens based on 16S rRNA gene analysis. The culture conditions of Bacillus amyloliquefaciens MHB1 were optimized using nutritional and environmental parameters for enhanc...

  11. Amyloid fibril formation in vitro from halophilic metal binding protein: Its high solubility and reversibility minimized formation of amorphous protein aggregations

    Science.gov (United States)

    Tokunaga, Yuhei; Matsumoto, Mitsuharu; Tokunaga, Masao; Arakawa, Tsutomu; Sugimoto, Yasushi

    2013-01-01

    Halophilic proteins are characterized by high net negative charges and relatively small fraction of hydrophobic amino acids, rendering them aggregation resistant. These properties are also shared by histidine-rich metal binding protein (HP) from moderate halophile, Chromohalobacter salexigens, used in this study. Here, we examined how halophilic proteins form amyloid fibrils in vitro. His-tagged HP, incubated at pH 2.0 and 58°C, readily formed amyloid fibrils, as observed by thioflavin fluorescence, CD spectra, and transmission or atomic force microscopies. Under these low-pH harsh conditions, however, His-HP was promptly hydrolyzed to smaller peptides most likely responsible for rapid formation of amyloid fibril. Three major acid-hydrolyzed peptides were isolated from fibrils and turned out to readily form fibrils. The synthetic peptides predicted to form fibrils in these peptide sequences by Waltz software also formed fibrils. Amyloid fibril was also readily formed from full-length His-HP when incubated with 10–20% 2,2,2-trifluoroethanol at pH 7.8 and 25°C without peptide bond cleavage. PMID:24038709

  12. New insight in the structural features of haloadaptation in α-amylases from halophilic Archaea following homology modeling strategy: folded and stable conformation maintained through low hydrophobicity and highly negative charged surface

    Science.gov (United States)

    Zorgani, Mohamed Amine; Patron, Kevin; Desvaux, Mickaël

    2014-07-01

    Proteins from halophilic archaea, which live in extreme saline conditions, have evolved to remain folded, active and stable at very high ionic strengths. Understanding the mechanism of haloadaptation is the first step toward engineering of halostable biomolecules. Amylases are one of the main enzymes used in industry. Yet, no three-dimensional structure has been experimentally resolved for α-amylases from halophilic archaea. In this study, homology structure modeling of α-amylases from the halophilic archaea Haloarcula marismortui, Haloarcula hispanica, and Halalkalicoccus jeotgali were performed. The resulting models were subjected to energy minimization, evaluation, and structural analysis. Calculations of the amino acid composition, salt bridges and hydrophobic interactions were also performed and compared to a set of non-halophilic counterparts. It clearly appeared that haloarchaeal α-amylases exhibited lower propensities for helix formation and higher propensities for coil-forming regions. Furthermore, they could maintain a folded and stable conformation in high salt concentration through highly negative charged surface with over representation of acidic residues, especially Asp, and low hydrophobicity with increase of salt bridges and decrease in hydrophobic interactions on the protein surface. This study sheds some light on the stability of α-amylases from halophilic archaea and provides strong basis not only to understand haloadaptation mechanisms of proteins in microorganisms from hypersalines environments but also for biotechnological applications.

  13. An extreme-halophile archaebacterium possesses the interlock type of prephenate dehydratase characteristic of the Gram-positive eubacteria

    Science.gov (United States)

    Jensen, R. A.; d'Amato, T. A.; Hochstein, L. I.

    1988-01-01

    The focal point of phenylalanine biosynthesis is a dehydratase reaction which in different organisms may be prephenate dehydratase, arogenate dehydratase, or cyclohexadienyl dehydratase. Gram-positive, Gram-negative, and cyanobacterial divisions of the eubacterial kingdom exhibit different dehydratase patterns. A new extreme-halophile isolate, which grows on defined medium and is tentatively designated as Halobacterium vallismortis CH-1, possesses the interlock type of prephenate dehydratase present in Gram-positive bacteria. In addition to the conventional sensitivity to feedback inhibition by L-phenylalanine, the phenomenon of metabolic interlock was exemplified by the sensitivity of prephenate dehydratase to allosteric effects produced by extra-pathway (remote) effectors. Thus, L-tryptophan inhibited activity while L-tyrosine, L-methionine, L-leucine and L-isoleucine activated the enzyme. L-Isoleucine and L-phenylalanine were effective at micromolar levels; other effectors operated at mM levels. A regulatory mutant selected for resistance to growth inhibition caused by beta-2-thienylalanine possessed an altered prephenate dehydratase in which a phenomenon of disproportionately low activity at low enzyme concentration was abolished. Inhibition by L-tryptophan was also lost, and activation by allosteric activators was diminished. Not only was sensitivity to feedback inhibition by L-phenylalanine lost, but the mutant enzyme was now activated by this amino acid (a mutation type previously observed in Bacillus subtilis). It remains to be seen whether this type of prephenate dehydratase will prove to be characteristic of all archaebacteria or of some archaebacterial subgroup cluster.

  14. Biosynthesis and characterization of polyhydroxyalkanoates produced by an extreme halophilic bacterium, Halomonas nitroreducens, isolated from hypersaline ponds.

    Science.gov (United States)

    Cervantes-Uc, J M; Catzin, J; Vargas, I; Herrera-Kao, W; Moguel, F; Ramirez, E; Rincón-Arriaga, S; Lizama-Uc, G

    2014-10-01

    Morphological, biochemical and genotypic characterization of a halophilic bacterium isolated from hypersaline ponds located at Las Coloradas (Río Lagartos, Yucatán, Mexico). Characterization of polymer produced by this strain was also performed. Twenty strains were isolated from water samples of salt ponds and selected based on both morphological features and their PHA storage capacity, which were determined by SEM and staining methods with Nile red and Nile blue, respectively; strains were also analysed by the fluorescence imaging technique. Among them, JCCOL25.8 strain showed the highest production of PHA's reason why phenotypic and genotypic characterization was performed; this strain was identified as Halomonas nitroreducens. Polymer produced by this strain was characterized by FTIR, DSC, GPC and EDX spectroscopy. Results indicated that the biosynthesized polymer was polyhydroxybutyrate (PHB) which had a melting peak at 170°C and a crystallinity percentage of about 36%. Based on phenotypic and genotypic aspects, JCCOL25.8 strain was identified as H. nitroreducens and it was capable to accumulate PHB. To our knowledge, there is only one study published on the biosynthesis of PHA's by H. nitroreducens strains, although the characterization of the obtained polymer was not reported. © 2014 The Society for Applied Microbiology.

  15. Halomonas sp. BS4, A biosurfactant producing halophilic bacterium isolated from solar salt works in India and their biomedical importance.

    Science.gov (United States)

    Donio, Mariathason Birdilla Selva; Ronica, Fernando Arul; Viji, Vijayaragavan Thanga; Velmurugan, Subramanian; Jenifer, John Selesteen Charles Adlin; Michaelbabu, Mariavincent; Dhar, Prasenjit; Citarasu, Thavasimuthu

    2013-12-01

    Halophilic bacteria were isolated from Thamaraikulam solar salt works in India. After routine biosurfactant screening by various methods, the biosurfactant producing bacteria, Halomonas sp BS4 was confirmed by 16 S rRNA sequencing. The growth optimization of Halomonas sp BS4 revealed their optimum growth at 8% NaCl and 6-8 pH in the growth medium. Further the partially purified biosurfactants were characterized by TLC, FTIR and GC-MS analysis. GC-MS results revealed that, the partial purified biosurfactants contain 1, 2-Ethanediamine N, N, N', N'-tetra, 8-Methyl-6-nonenamide, (Z)-9-octadecenamide and a fatty acid derivative. Pharmacological screening of antibacterial, antifungal, antiviral and anticancer assays revealed that, the biosurfactant extracted from Halomonas sp BS4 effectively controlled the human pathogenic bacteria and fungi an aquaculturally important virus, WSSV. The biosurfactant also suppressed the proliferation of mammary epithelial carcinoma cell by 46.77% at 2.5 μg concentration. Based on these findings, the present study concluded that, there is a possibility to develop eco-friendly antimicrobial and anticancer drugs from the extremophilic origin.

  16. Widespread secondary contact and new glacial refugia in the halophilic rotifer Brachionus plicatilis in the Iberian Peninsula.

    Science.gov (United States)

    Campillo, Sergi; Serra, Manuel; Carmona, María José; Gómez, Africa

    2011-01-01

    Small aquatic organisms harbour deep phylogeographic patterns and highly structured populations even at local scales. These patterns indicate restricted gene flow, despite these organisms' high dispersal abilities, and have been explained by a combination of (1) strong founder effects due to rapidly growing populations and very large population sizes, and (2) the development of diapausing egg banks and local adaptation, resulting in low effective gene flow, what is known as the Monopolization hypothesis. In this study, we build up on our understanding of the mitochondrial phylogeography of the halophilic rotifer Brachionus plicatilis in the Iberian Peninsula by both increasing the number of sampled ponds in areas where secondary contact is likely and doubling sample sizes. We analyzed partial mitochondrial sequences of 252 individuals. We found two deep mitochondrial DNA lineages differing in both their genetic diversity and the complexity of their phylogeographic structure. Our analyses suggest that several events of secondary contact between clades occurred after their expansion from glacial refugia. We found a pattern of isolation-by-distance, which we interpret as being the result of historical colonization events. We propose the existence of at least one glacial refugium in the SE of the Iberian Peninsula. Our findings challenge predictions of the Monopolization hypothesis, since coexistence (i.e., secondary contact) of divergent lineages in some ponds in the Iberian Peninsula is common. Our results indicate that phylogeographic structures in small organisms can be very complex and that gene flow between diverse lineages after population establishment can indeed occur.

  17. Widespread secondary contact and new glacial refugia in the halophilic rotifer Brachionus plicatilis in the Iberian Peninsula.

    Directory of Open Access Journals (Sweden)

    Sergi Campillo

    Full Text Available Small aquatic organisms harbour deep phylogeographic patterns and highly structured populations even at local scales. These patterns indicate restricted gene flow, despite these organisms' high dispersal abilities, and have been explained by a combination of (1 strong founder effects due to rapidly growing populations and very large population sizes, and (2 the development of diapausing egg banks and local adaptation, resulting in low effective gene flow, what is known as the Monopolization hypothesis. In this study, we build up on our understanding of the mitochondrial phylogeography of the halophilic rotifer Brachionus plicatilis in the Iberian Peninsula by both increasing the number of sampled ponds in areas where secondary contact is likely and doubling sample sizes. We analyzed partial mitochondrial sequences of 252 individuals. We found two deep mitochondrial DNA lineages differing in both their genetic diversity and the complexity of their phylogeographic structure. Our analyses suggest that several events of secondary contact between clades occurred after their expansion from glacial refugia. We found a pattern of isolation-by-distance, which we interpret as being the result of historical colonization events. We propose the existence of at least one glacial refugium in the SE of the Iberian Peninsula. Our findings challenge predictions of the Monopolization hypothesis, since coexistence (i.e., secondary contact of divergent lineages in some ponds in the Iberian Peninsula is common. Our results indicate that phylogeographic structures in small organisms can be very complex and that gene flow between diverse lineages after population establishment can indeed occur.

  18. Draft genome sequence of Dethiosulfovibrio salsuginis DSM 21565T an anaerobic, slightly halophilic bacterium isolated from a Colombian saline spring.

    Science.gov (United States)

    Díaz-Cárdenas, Carolina; López, Gina; Alzate-Ocampo, José David; González, Laura N; Shapiro, Nicole; Woyke, Tanja; Kyrpides, Nikos C; Restrepo, Silvia; Baena, Sandra

    2017-01-01

    A bacterium belonging to the phylum Synergistetes , genus Dethiosulfovibrio was isolated in 2007 from a saline spring in Colombia. Dethiosulfovibrio salsuginis USBA 82 T ( DSM 21565 T = KCTC 5659 T ) is a mesophilic, strictly anaerobic, slightly halophilic, Gram negative bacterium with a diderm cell envelope. The strain ferments peptides, amino acids and a few organic acids. Here we present the description of the complete genome sequencing and annotation of the type species Dethiosulfovibrio salsuginis USBA 82 T . The genome consisted of 2.68 Mbp with a 53.7% G + C . A total of 2609 genes were predicted and of those, 2543 were protein coding genes and 66 were RNA genes. We detected in USBA 82 T genome six Synergistetes conserved signature indels (CSIs), specific for Jonquetella, Pyramidobacter and Dethiosulfovibrio . The genome of D. salsuginis contained, as expected, genes related to amino acid transport, amino acid metabolism and thiosulfate reduction. These genes represent the major gene groups of Synergistetes , related with their phenotypic traits, and interestingly, 11.8% of the genes in the genome belonged to the amino acid fermentation COG category. In addition, we identified in the genome some ammonification genes such as nitrate reductase genes. The presence of proline operon genes could be related to de novo synthesis of proline to protect the cell in response to high osmolarity. Our bioinformatics workflow included antiSMASH and BAGEL3 which allowed us to identify bacteriocins genes in the genome.

  19. Characterization of a halophilic heterotrophic nitrification-aerobic denitrification bacterium and its application on treatment of saline wastewater.

    Science.gov (United States)

    Duan, Jinming; Fang, Hongda; Su, Bing; Chen, Jinfang; Lin, Jinmei

    2015-03-01

    A novel halophilic bacterium capable of heterotrophic nitrification-aerobic denitrification was isolated from marine sediments and identified as Vibrio diabolicus SF16. It had ability to remove 91.82% of NH4(+)-N (119.77 mg/L) and 99.71% of NO3(-)-N (136.43 mg/L). The nitrogen balance showed that 35.83% of initial NH4(+)-N (119.77 mg/L) was changed to intracellular nitrogen, and 53.98% of the initial NH4(+)-N was converted to gaseous denitrification products. The existence of napA gene further proved the aerobic denitrification ability of strain SF16. The optimum culture conditions were salinity 1-5%, sodium acetate as carbon source, C/N 10, and pH 7.5-9.5. When an aerated biological filter system inoculated with strain SF16 was employed to treat saline wastewater, the average removal efficiency of NH4(+)-N and TN reached 97.14% and 73.92%, respectively, indicating great potential of strain SF16 for future full-scale applications. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Virgibacillus ainsalahensis sp. nov., a Moderately Halophilic Bacterium Isolated from Sediment of a Saline Lake in South of Algeria.

    Science.gov (United States)

    Amziane, Meriam; Darenfed-Bouanane, Amel; Abderrahmani, Ahmed; Selama, Okba; Jouadi, Lydia; Cayol, Jean-Luc; Nateche, Farida; Fardeau, Marie-Laure

    2017-02-01

    A Gram-positive, moderately halophilic, endospore-forming bacterium, designated MerV T , was isolated from a sediment sample of a saline lake located in Ain Salah, south of Algeria. The cells were rod shaped and motile. Isolate MerV T grew at salinity interval of 0.5-25% NaCl (optimum, 5-10%), pH 6.0-12.0 (optimum, 8.0), and temperature between 10 and 40 °C (optimum, 30 °C).The polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol, a glycolipid, a phospholipid, and two lipids, and MK-7 is the predominant menaquinone. The predominant cellular fatty acids were anteiso C 15:0 and anteiso C 17:0 . The DNA G+C content was 45.3 mol%. Phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that strain MerV T was most closely related to Virgibacillus halodenitrificans (gene sequence similarity of 97.0%). On the basis of phenotypic, chemotaxonomic properties, and phylogenetic analyses, strain MerV T (=DSM = 28944 T ) should be placed in the genus Virgibacillus as a novel species, for which the name Virgibacillus ainsalahensis is proposed.

  1. Reverse micelles in organic solvents: a medium for the biotechnological use of extreme halophilic enzymes at low salt concentration

    Directory of Open Access Journals (Sweden)

    Frutos C. Marhuenda-Egea

    2002-01-01

    Full Text Available Alkaline p-nitrophenylphosphate phosphatase (pNPPase from the halophilic archaeobacterium Halobacterium salinarum (previously halobium was solubilized at low salt concentration in reverse micelles of hexadecyltrimethylammoniumbromide in cyclohexane with 1-butanol as cosurfactant. The enzyme maintained its catalytic properties under these conditions. The thermodynamic “solvation–stabilization hypothesis” has been used to explain the bell-shaped dependence of pNPPase activity on the water content of reverse micelles, in terms of protein–solvent interactions. According to this model, the stability of the folded protein depends on a network of hydrated ions associated with acidic residues at the protein surface. At low salt concentration and low water content (the ratio of water concentration to surfactant concentration; w0, the network of hydrated ions within the reverse micelles may involve the cationic heads of the surfactant. The bell-shaped profile of the relationship between enzyme activity and w0 varied depending on the concentrations of NaCl and Mn2+.

  2. Aspergillus atacamensis and A. salisburgensis: two new halophilic species from hypersaline/arid habitats with a phialosimplex-like morphology.

    Science.gov (United States)

    Martinelli, Livia; Zalar, Polona; Gunde-Cimerman, Nina; Azua-Bustos, Armando; Sterflinger, Katja; Piñar, Guadalupe

    2017-07-01

    Halophilic fungal strains isolated from historical wooden staircase in a salt mine in Austria, and from wall biofilm and soil of a cave in the Coastal Range of the hyperarid Atacama Desert in Chile were characterised and described newly as Aspergillus salisburgensis and Aspergillus atacamensis. Morphological characters including solitary phialides producing solitary conidia and conidia in chains and/or heads suggested affinity to Aspergillus subgenus Polypaecilum. Strains required salt for growth, grew optimally on media with 10-25% NaCl and at 15-28 °C. These values are similar to those observed for Aspergillus salinarus comb. nov. (Phialosimplex salinarum), while the ex-type strains of Aspergillus sclerotialis, Aspergillus chlamydosporus and Aspergillus caninus (all belonging to Aspergillus subgen. Polypaecilum) grew optimally at 0-5% NaCl and showed fastest growth at 28-37 °C. Phylogenetic analyses on the basis of rDNA sequences, RAPD-PCR fingerprint patterns, and cellobiohydrolase gene (cbh-I) polymorphism clustered the strains into three groups and supported their taxonomic recognition as A. salinarus, A. atacamensis and A. salisburgensis. On the basis of phylogenetic inferences, also Sagenomella keratitidis is newly combined as Aspergillus keratitidis and inferred as a species of Aspergillus subgenus Polypaecilum.

  3. Characterization of novel Bacillus strain N31 from mariculture water capable of halophilic heterotrophic nitrification-aerobic denitrification.

    Science.gov (United States)

    Huang, Fei; Pan, Luqing; Lv, Na; Tang, Xianming

    2017-11-01

    The development of an intensive aquaculture industry has been accompanied by increasing environmental impacts, especially nitrogen pollution. In this study, a novel halophilic bacterium capable of heterotrophic nitrification and aerobic denitrification was isolated from mariculture water and identified as Bacillus litoralis N31. The efficiency of ammonium, nitrite and nitrate removal by N31 were 86.3%, 89.3% and 89.4%, respectively, after a 48-h cultivation in sole N-source medium with initial nitrogen approximately 20 mg/L. However, ammonium was removed preferentially, and no obvious nitrite accumulated during the simultaneous nitrification and denitrification process in mixed N-source media. The existence of hao, napA and nirS genes further proved the heterotrophic nitrification-aerobic denitrification capability of N31. The optimal conditions for ammonium removal were 30°C, initial pH 7.5-8.5, C/N ratio 5-20 and salinity 30-40‰, and the nitrification rate of N31 increased with increasing initial [Formula: see text] from 10 to 250 mg/L. Biosecurity assessment with shrimp indicated that strain N31 could be applied in the marine aquaculture industry safely for culture water remediation and effluent treatment. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  4. Bioremediation of oil-based drill cuttings by a halophilic consortium isolated from oil-contaminated saline soil.

    Science.gov (United States)

    Rezaei Somee, Maryam; Shavandi, Mahmoud; Dastgheib, Seyed Mohammad Mehdi; Amoozegar, Mohammad Ali

    2018-05-01

    Oil-based drill cuttings are hazardous wastes containing complex hydrocarbons, heavy metals, and brine. Their remediation is a crucial step before release to the environment. In this work, we enriched a halophilic consortium, from oil-polluted saline soil, which is capable of degrading diesel as the main pollutant of oil-based drill cuttings. The degradation ability of the consortium was evaluated in microcosms using two different diluting agents (fine sand and biologically active soil). During the bioremediation process, the bacterial community dynamics of the microcosms was surveyed using PCR amplification of a fragment of 16S rRNA gene followed by denaturing gradient gel electrophoresis (DGGE). The diesel degradation rates were monitored by total petroleum hydrocarbon (TPH) measurement and the total count of heterotrophic and diesel-degrading bacteria. After 3 months, the microcosm containing fine sand and drill cuttings with the ratio of 1:1 (initial TPH of 36,000 mg/kg) showed the highest TPH removal (40%) and its dominant bacterial isolates belonged to the genera Dietzia, Arthrobacter , and Halomonas . DGGE results also confirmed the role of these genera in drill cuttings remediation. DGGE analysis of the bacterial diversity showed that Propionibacterium, Salinimicrobium, Marinobacter , and Dietzia are dominant in active soil microcosm; whereas Bacillus, Salinibacillus , and Marinobacter are abundant in sand microcosm. Our results suggest that the bioaugmentation strategy would be more successful if the diluting agent does not contain a complex microbial community.

  5. Taxonomic study and partial characterization of antimicrobial compounds from a moderately halophilic strain of the genus Actinoalloteichus

    Directory of Open Access Journals (Sweden)

    Farida Boudjelal

    2011-09-01

    Full Text Available A moderately halophilic actinomycete strain designated AH97 was isolated from a saline Saharan soil, and selected for its antimicrobial activities against bacteria and fungi. The AH97 strain was identified by morphological, chemotaxonomic and phylogenetic analyses to the genus Actinoalloteichus. Analysis of the 16S rDNA sequence of strain AH97 showed a similarity level ranging between 95.8% and 98.4% within Actinoalloteichus species, with A. hymeniacidonis the most closely related. The comparison of the physiological characteristics of AH97 with those of known species of Actinoalloteichus showed significant differences. Strain AH97 showed an antibacterial and antifungal activity against broad spectrum of microorganisms known to be human and plant pathogens. The bioactive compounds were extracted from the filtrate culture with n-butanol and purified using thin layer chromatography and high pressure liquid chromatography procedures. Two active products were isolated, one hydrophilic fraction (F1 and another hydrophobic (F2. Ultraviolet-visible, infrared, mass and ¹H and 13C nuclear magnetic resonance spectroscopy studies suggested that these molecules were the dioctyl phthalate (F2 and an aminoglycosidic compound (F1.

  6. Identification of moderately halophilic bacteria from Thai fermented fish ( pla-ra ) and proposal of Virgibacillus siamensis sp. nov.

    Science.gov (United States)

    Tanasupawat, Somboon; Chamroensaksri, Nitcha; Kudo, Takuji; Itoh, Takashi

    2010-10-01

    Forty-one isolates of moderately halophilic bacteria were isolated from fermented fish (pla-ra) in Thailand. On the basis of their phenotypic and chemotaxonomic characteristics, DNA-DNA relatedness and 16S rRNA gene sequences analyses, they were divided into six groups. The isolates in Group I to V were Gram-positive rod-shaped bacteria. They contained meso-diaminopimelic acid in the cell-wall peptidoglycan and menaquinone with seven isoprene units (MK-7). An isolate in Group VI was a Gram-negative rod-shaped bacterium. The DNA G+C contents of tested strains ranged from 36.5-63 mol%. Ten strains (Group I) were identified as Virgibacillus dokdonensis, 13 isolates (Group II) as V. halodenitrificans, 14 isolates (Group III) as V. marismortui, 1 isolate (Group IV) as Virgibacillus sp., 2 isolates (Group V) as Bacillus vietnamnensis, and 1 isolate (Group VI) as Chromohalobacter salexigens. Isolate MS3-4 in Group IV was closely related to V. carmonensis KCTC 3819(T) (95.9%). This strain contained anteiso-C(15:0) (55.8%) and anteiso-C(17:0) (17.7%) as major cellular fatty acids and had phosphatidylglycerol, diphosphatidylglycerol and an unidentified glycolipid as polar lipids. The DNA G+C content of MS3-4 was 38.0 mol%. The strain from Group IV is proposed as Virgibacillus siamensis sp. nov. and MS3-4(T) is the type strain (JCM 15395(T) =PCU 312(T) =TISTR 1957(T)).

  7. Building a Geochemical View of Microbial Salt Tolerance: Halophilic Adaptation of Marinococcus in a Natural Magnesium Sulfate Brine

    Directory of Open Access Journals (Sweden)

    Mark G. Fox-Powell

    2018-04-01

    Full Text Available Current knowledge of life in hypersaline habitats is mostly limited to sodium and chloride-dominated environments. This narrow compositional window does not reflect the diversity of brine environments that exist naturally on Earth and other planetary bodies. Understanding the limits of the microbial biosphere and predicting extraterrestrial habitability demands a systematic effort to characterize ionic specificities of organisms from a representative range of saline habitats. Here, we investigated a strain of Marinococcus isolated from the magnesium and sulfate-dominated Basque Lakes (British Columbia, Canada. This organism was the sole isolate obtained after exposure to exceptionally high levels of Mg2+ and SO42- ions (2.369 and 2.840 M, respectively, and grew at extremes of ionic strength not normally encountered in Na+/Cl- brines (12.141 mol liter-1. Its association at the 16S rDNA level with bacterial halophiles suggests that ancestral halophily has allowed it to adapt to a different saline habitat. Growth was demonstrated in media dominated by NaCl, Na2SO4, MgCl2, and MgSO4, yet despite this plasticity the strain was still restricted; requiring either Na+ or Cl- to maintain short doubling times. Water activity could not explain growth rate differences between media, demonstrating the importance of ionic composition for dictating microbial growth windows. A new framework for understanding growth in brines is required, that accounts for the geochemical history of brines as well as the various stresses that ions impose on microbes. Studies such as this are required to gain a truly universal understanding of the limits of biological ion tolerance.

  8. A novel NhaD-type Na+/H+ antiporter from the moderate halophile and alkaliphile Halomonas alkaliphila.

    Science.gov (United States)

    Wang, Yanhong; Song, Na; Yang, Lina; Abdel-Motaal, Heba; Zhang, Rui; Zhang, Zhenglai; Meng, Fankui; Jiang, Juquan

    2017-07-01

    In this study, a NhaD-type Na + /H + antiporter gene designated Ha-nhaD was obtained by selection of genomic DNA from the moderate halophile and alkaliphile Halomonas alkaliphila in Escherichia coli KNabc lacking 3 major Na + /H + antiporters. The presence of Ha-NhaD conferred tolerance of E. coli KNabc to NaCl up to 0.6 mol·L -1 and to LiCl up to 0.2 mol·L -1 and to an alkaline pH. pH-dependent Na + (Li + )/H + antiport activity was detected from everted membrane vesicles prepared from E. coli KNabc/pUC-nhaD but not those of KNabc/pUC18. Ha-NhaD exhibited Na + (Li + )/H + antiport activity over a wide pH range from 7.0 to 9.5, with the highest activity at pH 9.0. Protein sequence alignment and phylogenetic analysis revealed that Ha-NhaD is significantly different from the 7 known NhaD-type Na + /H + antiporters, including Dw-NhaD, Dl-NhaD, Vp-NhaD, Vc-NhaD, Aa-NhaD, He-NhaD, and Ha-NhaD1. Although Ha-NhaD showed a closer phylogenetic relationship with Ha-NhaD2, a significant difference in pH-dependent activity profile exists between Ha-NhaD and Ha-NhaD2. Taken together, Ha-nhaD encodes a novel pH-dependent NhaD-type Na + /H + antiporter.

  9. Methylohalobius crimeensis gen. nov., sp. nov., a moderately halophilic, methanotrophic bacterium isolated from hypersaline lakes of Crimea.

    Science.gov (United States)

    Heyer, Jürgen; Berger, Ursula; Hardt, Martin; Dunfield, Peter F

    2005-09-01

    A novel genus and species are proposed for two strains of methanotrophic bacteria isolated from hypersaline lakes in the Crimean Peninsula of Ukraine. Strains 10Ki(T) and 4Kr are moderate halophiles that grow optimally at 1-1.5 M (5.8-8.7%, w/v) NaCl and tolerate NaCl concentrations from 0.2 M up to 2.5 M (1.2-15%). This optimum and upper limit are the highest for any methanotrophic bacterium known to date. The strains are Gram-negative, aerobic, non-pigmented, motile, coccoid to spindle-shaped bacteria that grow on methane or methanol only and utilize the ribulose monophosphate pathway for carbon assimilation. They are neutrophilic (growth occurs only in the range pH 6.5-7.5) and mesophilic (optimum growth occurs at 30 degrees C). On the basis of 16S rRNA gene sequence phylogeny, strains 10Ki(T) and 4Kr represent a type I methanotroph within the 'Gammaproteobacteria'. However, the 16S rRNA gene sequence displays <91.5 % identity to any public-domain sequence. The most closely related methanotrophic bacterium is the thermophilic strain HB. The DNA G+C content is 58.7 mol%. The major phospholipid fatty acids are 18:1omega7 (52-61%), 16:0 (22-23%) and 16:1omega7 (14-20%). The dominance of 18:1 over 16:0 and 16:1 fatty acids is unique among known type I methanotrophs. The data suggest that strains 10Ki(T) and 4Kr should be considered as belonging to a novel genus and species of type I methanotrophic bacteria, for which the name Methylohalobius crimeensis gen. nov., sp. nov. is proposed. Strain 10Ki(T) (=DSM 16011(T)=ATCC BAA-967(T)) is the type strain.

  10. Natronolimnobius aegyptiacus sp. nov., an extremely halophilic alkalithermophilic archaeon isolated from the athalassohaline Wadi An Natrun, Egypt.

    Science.gov (United States)

    Zhao, Baisuo; Hu, Qingping; Guo, Xiaomeng; Liao, Ziya; Sarmiento, Felipe; Mesbah, Noha M; Yan, Yanchun; Li, Jun; Wiegel, Juergen

    2018-02-01

    An obligately aerobic extremely halophilic alkalithermophilic archaeon, strain JW/NM-HA 15 T , was isolated from the sediments of Wadi An Natrun in Egypt. Phylogenetic analysis based on 16S rRNA and rpoB' gene sequences indicated that it belongs to the family Natrialbaceae of the order Natrialbales. The closest relatives were Natronolimnobius baerhuensis IHC-005 T and Natronolimnobius innermongolicus N-1311 T (95.3 and 94.5 % 16S rRNA gene sequence similarity, respectively). Genome relatedness between strain JW/NM-HA 15 T and its neighbours was evaluated using average nucleotide identity, digital DNA-DNA hybridization and average amino acid identity with the values of 75.7-85.0, 18.1-20.0, and 70.2-71.0%, respectively. Cells were obligately aerobic, rod-shaped, non-motile, Gram-stain-negative and chemo-organotrophic. The strain grew in the presence of 2.57 M to saturating Na + (optimum 3.25-4.60 M Na + ), at pH 55 °C 7.5-10.5 (optimum pH 55 °C 9.0-9.5), and at 30-56 °C (optimum 52 °C). The major polar lipids consisted of phosphatidylglycerol, methylated phosphatidylglycerolphosphate and two phospholipids. The complete genome size of strain JW/NM-HA 15 T is approximately 3.93 Mb, with a DNA G+C content of 64.1 mol%. On the basis of phylogenetic features, genomic relatedness, phenotypic and chemotaxonomic data, strain JW/NM-HA 15 T was thus considered to represent a novel species within the genus Natronolimnobius, for which the name Natronolimnobius aegyptiacus sp. nov. is proposed. The type strain is JW/NM-HA 15 T (=ATCC BAA-2088 T =DSM 23470 T ).

  11. Haloprofundus marisrubri gen. nov., sp. nov., an extremely halophilic archaeon isolated from a brine-seawater interface.

    Science.gov (United States)

    Zhang, Guishan; Gu, Jingang; Zhang, Ruifu; Rashid, Mamoon; Haroon, Mohamed Fauzi; Xun, Weibing; Ruan, Zhiyong; Dong, Xiuzhu; Stingl, Ulrich

    2017-01-01

    We isolated a Gram-stain-negative, pink-pigmented, motile, pleomorphic, extremely halophilic archaeon from the brine-seawater interface of Discovery Deep in the Saudi Arabian Red Sea. This strain, designated SB9T, was capable of growth within a wide range of temperatures and salinity, but required MgCl2. Cells lysed in distilled water, but at 7.0 % (w/v) NaCl cell lysis was prevented. The major polar lipids from strain SB9T were phosphatidylglycerol, phosphatidylglycerolphosphate methyl ester, sulfated mannosyl glucosyl diether, mannosyl glucosyl diether, an unidentified glycolipid and two unidentified phospholipids. The major respiratory quinones of strain SB9T were menaquinones MK8 (66 %) and MK8 (VIII-H2) (34 %). Analysis of the 16S rRNA gene sequence revealed that strain SB9T was closely related to species in the genera Halogranum and Haloplanus; in particular, it shared highest sequence similarity with the type strain of Halogranum rubrum (93.4 %), making it its closest known relative. The unfinished draft genome of strain SB9Twas 3 931 127 bp in size with a total G+C content of 62.53 mol% and contained 3917 ORFs, 50 tRNAs and eight rRNAs. Based on comparisons with currently available genomes, the highest average nucleotide identity value was 83 % to Halogranum salarium B-1T (GenBank accession no. GCA_000283335.1). These data indicate that this new isolate cannot be classified into any recognized genera of the family Haloferacaceae, and therefore strain SB9T is considered to be a representative of a novel species of a new genus within this family, for which the name Haloprofundus marisrubri gen. nov., sp. nov. is proposed. The type strain of Haloprofundus marisrubri is SB9T (=JCM 19565T=CGMCC 1.14959T).

  12. Building a Geochemical View of Microbial Salt Tolerance: Halophilic Adaptation of Marinococcus in a Natural Magnesium Sulfate Brine.

    Science.gov (United States)

    Fox-Powell, Mark G; Cockell, Charles S

    2018-01-01

    Current knowledge of life in hypersaline habitats is mostly limited to sodium and chloride-dominated environments. This narrow compositional window does not reflect the diversity of brine environments that exist naturally on Earth and other planetary bodies. Understanding the limits of the microbial biosphere and predicting extraterrestrial habitability demands a systematic effort to characterize ionic specificities of organisms from a representative range of saline habitats. Here, we investigated a strain of Marinococcus isolated from the magnesium and sulfate-dominated Basque Lakes (British Columbia, Canada). This organism was the sole isolate obtained after exposure to exceptionally high levels of Mg 2+ and SO 4 2- ions (2.369 and 2.840 M, respectively), and grew at extremes of ionic strength not normally encountered in Na + /Cl - brines (12.141 mol liter -1 ). Its association at the 16S rDNA level with bacterial halophiles suggests that ancestral halophily has allowed it to adapt to a different saline habitat. Growth was demonstrated in media dominated by NaCl, Na 2 SO 4 , MgCl 2 , and MgSO 4 , yet despite this plasticity the strain was still restricted; requiring either Na + or Cl - to maintain short doubling times. Water activity could not explain growth rate differences between media, demonstrating the importance of ionic composition for dictating microbial growth windows. A new framework for understanding growth in brines is required, that accounts for the geochemical history of brines as well as the various stresses that ions impose on microbes. Studies such as this are required to gain a truly universal understanding of the limits of biological ion tolerance.

  13. Anti-methicillin Resistant Staphylococcus aureus Compound Isolation from Halophilic Bacillus amyloliquefaciens MHB1 and Determination of Its Mode of Action Using Electron Microscope and Flow Cytometry Analysis.

    Science.gov (United States)

    Jeyanthi, Venkadapathi; Velusamy, Palaniyandi

    2016-06-01

    The aim of this study was to purify, characterize and evaluate the antibacterial activity of bioactive compound against methicillin-resistant Staphylococcus aureus (MRSA). The anti-MRSA compound was produced by a halophilic bacterial strain designated as MHB1. The MHB1 strain exhibited 99 % similarity to Bacillus amyloliquefaciens based on 16S rRNA gene analysis. The culture conditions of Bacillus amyloliquefaciens MHB1 were optimized using nutritional and environmental parameters for enhanced anti-MRSA compound production. The pure bioactive compound was isolated using silica gel column chromatography and Semi-preparative High-performance liquid chromatography (Semi-preparative HPLC). The Thin layer chromatography, Fourier transform infrared spectroscopy and proton NMR ((1)H NMR) analysis indicated the phenolic nature of the compound. The molecular mass of the purified compound was 507 Da as revealed by Liquid chromatography-mass spectrometry (LC-MS) analysis. The compound inhibited the growth of MRSA with minimum inhibitory concentration (MIC) of 62.5 µg mL(-1). MRSA bacteria exposed to 4× MIC of the compound and the cell viability was determined using flow cytometric analysis. Scanning electron microscope and Transmission electron microscope analysis was used to determine the ultrastructural changes in bacteria. This is the first report on isolation of anti-MRSA compound from halophilic B. amyloliquefaciens MHB1 and could act as a promising biocontrol agent.

  14. Subsurface Halophilic Microbial Communities in the Hyperarid Core of the Atacama Desert: An Analog for Possible Subsurface Life in Regolith on Mars

    Science.gov (United States)

    Oren, A.; Warren-Rhodes, K.; Rainey, F. T.; Ewing, S.; McKay, C. P.

    2003-12-01

    The Atacama Desert in its driest portion provides an interesting analog for possible past or present life in the Martian regolith. In the hyperarid core of the Atacama, surface soils are virtually abiotic, with no plants and "near sterile" concentrations of heterotrophic bacteria (i.e., exceedingly low densities of approximately 100 colony forming units per gram soil). The dearth of microbial life at the surface is likely maintained through extremely low water availability, low organic content and the highly oxidizing nature of the soil. In marked contrast to the surface, however, extremely halophilic microorganisms exist in salt layers 1.2-1.5m below the surface. Mineralogical analyses indicate the layers are predominantly halite (70% NaCl) but also contain sodium nitrate (5% NaNO3). Culturing and polar lipid analyses suggest the halophiles are archaeal Halobacterium-like motile rods. Microclimate monitoring at 1m indicates a soil relative humidity of 20% which is stable year-round even during decadal rain events such as that experienced in July 2002. This suggests the layers are isolated from even significant moisture influxes at the surface. Although further research is necessary, important parallels exist between this Earthly desert analog and the possible existence and detection of subsurface life on Mars despite harsh abiotic conditions at the surface.

  15. Characterization of an organic solvent-tolerant thermostable glucoamylase from a halophilic isolate, Halolactibacillus sp. SK71 and its application in raw starch hydrolysis for bioethanol production.

    Science.gov (United States)

    Yu, Hui-Ying; Li, Xin

    2014-01-01

    A halophilic bacterium Halolactibacillus sp. SK71 producing extracellular glucoamylase was isolated from saline soil of Yuncheng Salt Lake, China. Enzyme production was strongly influenced by the salinity of growth medium with maximum in the presence of 5% NaCl. The glucoamylase was purified to homogeneity with a molecular mass of 78.5 kDa. It showed broad substrate specificity and raw starch hydrolyzing activity. Analysis of hydrolysis products from soluble starch by thin-layer chromatography revealed that glucose was the sole end-product, indicating the enzyme was a true glucoamylase. Optimal enzyme activity was found to be at 70°C, pH 8.0, and 7.5% NaCl. In addition, it was highly active and stable over broad ranges of temperature (0-100°C), pH (7.0-12.0), and NaCl concentration (0-20%), showing excellent thermostable, alkali stable, and halotolerant properties. Furthermore, it displayed high stability in the presence of hydrophobic organic solvents. The purified glucoamylase was applied for raw corn starch hydrolysis and subsequent bioethanol production using Saccharomyces cerevisiae. The yield in terms of grams of ethanol produced per gram of sugar consumed was 0.365 g/g, with 71.6% of theoretical yield from raw corn starch. This study demonstrated the feasibility of using enzymes from halophiles for further application in bioenergy production. © 2014 American Institute of Chemical Engineers.

  16. Using a portable Raman spectrometer to detect carotenoids of halophilic prokaryotes in synthetic inclusions in NaCl, KCl, and sulfates.

    Science.gov (United States)

    Jehlička, Jan; Culka, Adam; Mana, Lilly; Oren, Aharon

    2018-05-03

    Cell suspensions of the haloarchaea Halorubrum sodomense and Halobacterium salinarum and the extremely halophilic bacterium Salinibacter ruber (Bacteroidetes) in saturated solutions of chlorides and sulfates (NaCl, KCl, MgSO 4 ·7H 2 O, K 2 SO 4 , and (NH 4 )Al(SO 4 ) 2 ·12H 2 O) were left to evaporate to produce micrometric inclusions in laboratory-grown crystals. Raman spectra of these pinkish inclusions were obtained using a handheld Raman spectrometer with green excitation (532 nm). This portable instrument does not include any microscopic tool. Acceptable Raman spectra of carotenoids were obtained in the range of 200-4000 cm -1 . This detection achievement was related to the mode of illumination and collection of scattered light as well as due to resonance Raman enhancement of carotenoid signals under green excitation. The position of diagnostic Raman carotenoid bands corresponds well to those specific carotenoids produced by a given halophile. To our best knowledge, this is the first study of carotenoids included in the laboratory in crystalline chlorides and sulfates, using a miniature portable Raman spectrometer. Graphical abstract ᅟ.

  17. Isolation and characterization of halophilic lactic acid bacteria acting as a starter culture for sauce fermentation of the red alga Nori (Porphyra yezoensis).

    Science.gov (United States)

    Uchida, M; Miyoshi, T; Yoshida, G; Niwa, K; Mori, M; Wakabayashi, H

    2014-06-01

    A screening test was conducted for environmental samples to isolate halophilic lactic acid bacteria (HLAB) that can act as a starter in a Nori (Porphyra yezoensis)-sauce culture. After 9 months of incubation of enrichment cultures added with 25 kinds of environmental samples, growth of HLAB-like microorganisms was observed in six cultures salted at a 15% w/w level, including culture samples originally from mesopelagic water taken from 321 m-depth and from mountain snow taken at 2450 m-height. Ten strains were isolated and characterized as Tetragenococcus halophilus based on sequence analysis of the 16S rRNA gene. The isolates were inoculated into a newly prepared Nori-sauce culture and were confirmed to be able to act as a starter culture while three reference strains of T. halophilus obtained from a culture collection could not grow in the same culture. Halophilic lactic acid bacteria strains that can make growth in a highly salted Nori-sauce culture were isolated from environmental samples for the first time. All the isolates were identified as T. halophilus. The isolated strains are expected to be utilized as a starter culture for manufacturing fermented seaweed-sauce, which will be the first fermented food products obtained from algae. © 2014 The Society for Applied Microbiology.

  18. Isolation, one-step affinity purification, and characterization of a polyextremotolerant laccase from the halophilic bacterium Aquisalibacillus elongatus and its application in the delignification of sugar beet pulp.

    Science.gov (United States)

    Rezaei, Shahla; Shahverdi, Ahmad Reza; Faramarzi, Mohammad Ali

    2017-04-01

    The aim of the present work was to study the ability of a halophilic bacterial laccase to efficient delignification in extreme conditions. Here, a highly stable extracellular laccase showing ligninolytic activity from halophilic Aquisalibacillus elongatus is described. The laccase production was strongly influenced by NaCl and CuSO 4 and under optimal conditions reached 4.8UmL -1 . The monomeric enzyme of 75kDa was purified by a synthetic affinity column with 68.2% yield and 99.8-fold purification. The enzyme showed some valuable features viz. stability against a wide range of organic solvents, salts, metals, inhibitors, and surfactants and specificity to a wide spectrum of substrates diverse in structure and redox potential. It retained more than 50% of the original activity at 25-75°C and pH 5.0-10.0. Furthermore, the enzyme was found to be effective in the delignification of sugar beet pulp in an ionic liquid that makes it useful for industrial applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. An efficient thermotolerant and halophilic biosurfactant-producing bacterium isolated from Dagang oil field for MEOR application

    Science.gov (United States)

    Wu, Langping; Richnow, Hans; Yao, Jun; Jain, Anil

    2014-05-01

    Dagang Oil field (Petro China Company Limited) is one of the most productive oil fields in China. In this study, 34 biosurfactant-producing strains were isolated and cultured from petroleum reservoir of Dagang oil field, using haemolytic assay and the qualitative oil-displacement test. On the basis of 16S rDNA analysis, the isolates were closely related to the species in genus Pseudomonas, Staphylococcus and Bacillus. One of the isolates identified as Bacillus subtilis BS2 were selected for further study. This bacterium was able to produce a type of biosurfactant with excessive foam-forming properties at 37ºC as well as at higher temperature of 55ºC. The biosurfactant produced by the strain BS2 could reduce the surface tension of the culture broth from 70.87 mN/m to 28.97 mN/m after 8 days of incubation at 37ºC and to 36.15 mN/m after 20 days of incubation at 55ºC, respectively. The biosurfactant showed stability at high temperature (up to 120ºC), a wide range of pH (2 to 12) and salt concentrations (up to 12%) offering potential for biotechnology. Fourier transform infrared (FT-IR) spectrum of extracted biosurfactant tentatively characterized the produced biosurfactant as glycolipid derivative. Elemental analysis of the biosurfactant by energy dispersive X-ray spectroscopy (EDS) reveals that the biosurfactant was anionic in nature. 15 days of biodegradation of crude oil suggested a preferential usage of n-alkane upon microbial metabolism of BS2 as a carbon substrate and consequently also for the synthesis of biosurfactants. Core flood studies for oil release indicated 9.6% of additional oil recovery over water flooding at 37ºC and 7.2% of additional oil recovery at 55 ºC. Strain BS2 was characterized as an efficient biosurfactant-producing, thermotolerant and halophillic bacterium and has the potential for application for microbial enhanced oil recovery (MEOR) through water flooding in China's oil fields even in situ as adapted to reservoir chemistry and

  20. Essential and non-essential DNA replication genes in the model halophilic Archaeon, Halobacterium sp. NRC-1

    Directory of Open Access Journals (Sweden)

    DasSarma Shiladitya

    2007-06-01

    Full Text Available Abstract Background Information transfer systems in Archaea, including many components of the DNA replication machinery, are similar to those found in eukaryotes. Functional assignments of archaeal DNA replication genes have been primarily based upon sequence homology and biochemical studies of replisome components, but few genetic studies have been conducted thus far. We have developed a tractable genetic system for knockout analysis of genes in the model halophilic archaeon, Halobacterium sp. NRC-1, and used it to determine which DNA replication genes are essential. Results Using a directed in-frame gene knockout method in Halobacterium sp. NRC-1, we examined nineteen genes predicted to be involved in DNA replication. Preliminary bioinformatic analysis of the large haloarchaeal Orc/Cdc6 family, related to eukaryotic Orc1 and Cdc6, showed five distinct clades of Orc/Cdc6 proteins conserved in all sequenced haloarchaea. Of ten orc/cdc6 genes in Halobacterium sp. NRC-1, only two were found to be essential, orc10, on the large chromosome, and orc2, on the minichromosome, pNRC200. Of the three replicative-type DNA polymerase genes, two were essential: the chromosomally encoded B family, polB1, and the chromosomally encoded euryarchaeal-specific D family, polD1/D2 (formerly called polA1/polA2 in the Halobacterium sp. NRC-1 genome sequence. The pNRC200-encoded B family polymerase, polB2, was non-essential. Accessory genes for DNA replication initiation and elongation factors, including the putative replicative helicase, mcm, the eukaryotic-type DNA primase, pri1/pri2, the DNA polymerase sliding clamp, pcn, and the flap endonuclease, rad2, were all essential. Targeted genes were classified as non-essential if knockouts were obtained and essential based on statistical analysis and/or by demonstrating the inability to isolate chromosomal knockouts except in the presence of a complementing plasmid copy of the gene. Conclusion The results showed that ten

  1. Haladaptatus pallidirubidus sp. nov., a halophilic archaeon isolated from saline soil samples in Yunnan and Xinjiang, China.

    Science.gov (United States)

    Liu, Bing-Bing; Zhao, Wan-Yu; Chu, Xiao; Hozzein, Wael N; Prabhu, Deene Manik; Wadaan, Mohammed A M; Tang, Shu-Kun; Zhang, Li-Li; Li, Wen-Jun

    2014-11-01

    Two extremely halophilic archaea, designated YIM 90917 and YIM 93656(T), were isolated from saline soils in Yunnan province and Lup nur region in Xinjiang province, western China, respectively. Colonies of the two strains were observed to be pink-pigmented. The cells were found to be Gram-stain negative, coccoid and non-motile. The organisms were found to be aerobic and could grow in an NaCl range of 6-35 % (optimum 18 %), temperatures ranging from 25 to 50 °C (optimum 37-42 °C), pH range from 6.0-8.5 (optimum pH 7.0-7.5) and Mg(2+) range from 0 to 1.5 M (optimum 0.5-1.0 M); Mg(2+) was not necessary for growth. Cells were not observed to lyse in distilled water. Strains YIM 90917 and YIM 93656(T) showed the highest 16S rRNA gene sequence similarities to Haladaptatus cibarius JCM 15962(T) (97.6 and 97.9 %, respectively). In addition, the DNA-DNA hybridizations of strains YIM 90917 and YIM 93656(T) with type strains H. cibarius JCM 15962(T), Haladaptatus litoreus JCM 15771(T) and Haladaptatus paucihalophilus JCM 13897(T) were 37.2 and 38.2 %, 36.6 and 39.0 % and 27.9 and 27.7 %, respectively. The DNA G+C contents of strains YIM 90917 and YIM 93656(T) were determined to be 56.0 and 57.4 mol%. The major polar lipids of the two strains were identified as phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate, sulfated mannosyl glucosyl diether and other four unidentified glycolipids. On the basis of physiological, chemotaxonomic data and phylogenetic analysis, the strains YIM 90917 and YIM 93656(T) can be classified as a novel species of the genus Haladaptatus, for which the name Haladaptatus pallidirubidus sp. nov. is proposed. The type strain is YIM 93656(T) (=JCM 17504(T) = CCTCC AB2010454(T)).

  2. Interaction of Extreme Halophilic Archaea With the Evaporites of the Solar Salterns Guerrero Negro Baja California, Mexico

    Science.gov (United States)

    Tamez, P.; Lopez-Cortés, A.

    2008-12-01

    Hypersaline environments have been significant reservoirs for the long-term evolution of specifically adapted microorganisms. Characterized to have higher salt concentrations (up to 35 g/L), they are worldwide distributed and have a commercial significance. Exportadora de Sal, Guerrero Negro, Mexico has a multipond salterns system designed to harvest common salt (NaCl) from sea water. To achieve this purpose, sea water is pumped through a set of shallow ponds where water evaporates and salts concentrate. Sequential precipitation of CaCO3, CaSO4 2H2O and NaCl occurs in a mineral formations call it evaporites. In the interior of those gypsum-encrusted and halite-encrusted minerals, communities of extremely salt-loving archaea prosper. Previous studies have showed the influence of Haloarchaeal cells in the formation of larger fluid inclusions than crystals formed in sterile salt solutions. S-layer envelopes and cells of Haloarcula strain SP8807 contributed to the nucleation of new crystals of NaCl. Given the significance of the scope in phylogenetic archaeal diversity research, this study had a polyphasic approach. SEM micrographs from a 21- 31% (w/v) gradient salt multipond system evaporites, gave an insight profile of the extreme halophilic archaeal communities thriving in the surface of the gypsum and halite evaporites. Halite crystals were form after 21 days of incubation in solid medium with archaeal cells. Both culture and non-culture dependent methods, Nested-PCR-DGGE analysis and sequencing of 16S rDNA amplified fragment genes from environmental samples and isolated strains were used for this purpose. We isolate three strains from Pond 9 (21.07% total salt concentration) and one strain from Cristallizer 20 (25.15% total salt concentration). 16S rDNA signaling gave 99% of similarity with Halogeometricum borinquense, sequence AF002984, two other strains were 99% of similarity with Halobacterium salinarum, sequence AJ496185 these strains shown different colony

  3. Structure of a highly acidic β-lactamase from the moderate halophile Chromohalobacter sp. 560 and the discovery of a Cs{sup +}-selective binding site

    Energy Technology Data Exchange (ETDEWEB)

    Arai, Shigeki; Yonezawa, Yasushi; Okazaki, Nobuo; Matsumoto, Fumiko; Shibazaki, Chie; Shimizu, Rumi; Yamada, Mitsugu; Adachi, Motoyasu; Tamada, Taro [Japan Atomic Energy Agency, 2-4 Shirakata-shirane, Tokai, Ibaraki 319-1195 (Japan); Kawamoto, Masahide [Kyushu Synchrotron Light Research Center, 8-7 Yayoigaoka, Tosu, Saga 841-0005 (Japan); Tokunaga, Hiroko; Ishibashi, Matsujiro [Faculty of Agriculture, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065 (Japan); Blaber, Michael [Japan Atomic Energy Agency, 2-4 Shirakata-shirane, Tokai, Ibaraki 319-1195 (Japan); Florida State University, 1115 West Call Street, Tallahassee, FL 32306-4300 (United States); Tokunaga, Masao [Faculty of Agriculture, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065 (Japan); Kuroki, Ryota, E-mail: kuroki.ryota@jaea.go.jp [Japan Atomic Energy Agency, 2-4 Shirakata-shirane, Tokai, Ibaraki 319-1195 (Japan)

    2015-03-01

    The tertiary structure of a β-lactamase derived from the halobacterium Chromohalobacter sp. 560 (HaBLA) was determined by X-ray crystallography. Three unique Sr{sup 2+}-binding sites and one Cs{sup +}-binding site were discovered in the HaBLA molecule. Environmentally friendly absorbents are needed for Sr{sup 2+} and Cs{sup +}, as the removal of the radioactive Sr{sup 2+} and Cs{sup +} that has leaked from the Fukushima Nuclear Power Plant is one of the most important problems in Japan. Halophilic proteins are known to have many acidic residues on their surface that can provide specific binding sites for metal ions such as Cs{sup +} or Sr{sup 2+}. The crystal structure of a halophilic β-lactamase from Chromohalobacter sp. 560 (HaBLA) was determined to resolutions of between 1.8 and 2.9 Å in space group P3{sub 1} using X-ray crystallography. Moreover, the locations of bound Sr{sup 2+} and Cs{sup +} ions were identified by anomalous X-ray diffraction. The location of one Cs{sup +}-specific binding site was identified in HaBLA even in the presence of a ninefold molar excess of Na{sup +} (90 mM Na{sup +}/10 mM Cs{sup +}). From an activity assay using isothermal titration calorimetry, the bound Sr{sup 2+} and Cs{sup +} ions do not significantly affect the enzymatic function of HaBLA. The observation of a selective and high-affinity Cs{sup +}-binding site provides important information that is useful for the design of artificial Cs{sup +}-binding sites that may be useful in the bioremediation of radioactive isotopes.

  4. Structure of a highly acidic β-lactamase from the moderate halophile Chromohalobacter sp. 560 and the discovery of a Cs+-selective binding site

    International Nuclear Information System (INIS)

    Arai, Shigeki; Yonezawa, Yasushi; Okazaki, Nobuo; Matsumoto, Fumiko; Shibazaki, Chie; Shimizu, Rumi; Yamada, Mitsugu; Adachi, Motoyasu; Tamada, Taro; Kawamoto, Masahide; Tokunaga, Hiroko; Ishibashi, Matsujiro; Blaber, Michael; Tokunaga, Masao; Kuroki, Ryota

    2015-01-01

    The tertiary structure of a β-lactamase derived from the halobacterium Chromohalobacter sp. 560 (HaBLA) was determined by X-ray crystallography. Three unique Sr 2+ -binding sites and one Cs + -binding site were discovered in the HaBLA molecule. Environmentally friendly absorbents are needed for Sr 2+ and Cs + , as the removal of the radioactive Sr 2+ and Cs + that has leaked from the Fukushima Nuclear Power Plant is one of the most important problems in Japan. Halophilic proteins are known to have many acidic residues on their surface that can provide specific binding sites for metal ions such as Cs + or Sr 2+ . The crystal structure of a halophilic β-lactamase from Chromohalobacter sp. 560 (HaBLA) was determined to resolutions of between 1.8 and 2.9 Å in space group P3 1 using X-ray crystallography. Moreover, the locations of bound Sr 2+ and Cs + ions were identified by anomalous X-ray diffraction. The location of one Cs + -specific binding site was identified in HaBLA even in the presence of a ninefold molar excess of Na + (90 mM Na + /10 mM Cs + ). From an activity assay using isothermal titration calorimetry, the bound Sr 2+ and Cs + ions do not significantly affect the enzymatic function of HaBLA. The observation of a selective and high-affinity Cs + -binding site provides important information that is useful for the design of artificial Cs + -binding sites that may be useful in the bioremediation of radioactive isotopes

  5. Egibacter rhizosphaerae gen. nov., sp. nov., an obligately halophilic, facultatively alkaliphilic actinobacterium and proposal of Egibaceraceae fam. nov. and Egibacterales ord. nov.

    Science.gov (United States)

    Zhang, Yong-Guang; Wang, Hong-Fei; Yang, Ling-Ling; Zhou, Xing-Kui; Zhi, Xiao-Yang; Duan, Yan-Qing; Xiao, Min; Zhang, Yuan-Ming; Li, Wen-Jun

    2016-01-01

    A novel obligately halophilic, facultatively alkaliphilic actinobacterium, designated EGI 80759T, was isolated from the rhizosphere of Tamarix hispida Willd, Karamay, Xinjiang province, north-west China. Cells of strain EGI 80759T were Gram-stain-positive, non-motile and non-endospore-forming rods. Strain EGI 80759T showed obligately halophilic growth with a tolerance to 8-25 % (w/v) NaCl (optimum growth at 10-12 %, w/v) and facultatively alkaliphilic growth within the pH range 7.0-11.0 (optimum growth at pH 9.0-10.0). Cell-wall hydrolysates of the isolate contained meso-diaminopimelic acid (peptidoglycan type A1γ), with glucose, glucosamine, ribose and mannose as the major sugars. The major fatty acids identified were 10-methyl-C17 : 0, C17 : 1ω8c and C17 : 0. The predominant menaquinone was MK-9(H4). The G+C content of the genomic DNA was 72.1 mol%. Phylogenetic analysis, based on 16S rRNA gene sequences, revealed that strain EGI 80759T clustered with members of the class Nitriliruptoria and showed highest 16S rRNA gene sequence similarities with Euzebya tangerina F10T (90.3 %) and Nitriliruptor alkaliphilus ANL-iso2T (88.1 %). On the basis of the data obtained from phenotypic and chemotaxonomic studies and the phylogenetic analysis, the isolate is proposed to be a representative of a novel genus and a novel species, Egibacter rhizosphaerae gen. nov., sp. nov., of a proposed novel family, Egibacteraceae fam. nov., and order, Egibacterales ord. nov., within the class Nitriliruptoria. The type strain of the type species, Egibacter rhizosphaerae, is EGI 80759T ( = CGMCC 1.14997T = KCTC 39588T).

  6. Use of a mixed culture strategy to isolate halophilic bacteria with antibacterial and cytotoxic activity from the Manaure solar saltern in Colombia.

    Science.gov (United States)

    Conde-Martínez, Natalia; Acosta-González, Alejandro; Díaz, Luis E; Tello, Edisson

    2017-12-08

    Water evaporation in solar salterns creates salinity gradients that promote the adaptation of microbial species to different salinities. This competitive habitat challenges the metabolic capabilities of microorganisms and promotes alterations in their production of secondary metabolites. Thus, solar salterns are a potentially important source of new natural products. In Colombia, the most important and representative solar saltern is located in Manaure (La Guajira) in the north of Colombia. The aim of this study was to develop an alternative screening strategy to select halophilic bacteria as producers of bioactive compounds from mixed microbial cultures rather than individual environmental isolates. Brine and sediment samples from different ponds (across a salinity gradient) were inoculated in seven different culture media to grow bacteria and archaea, allowing for a total of 40 different mixed cultures. An organic extract from each mixed culture was obtained and tested against multidrug resistant pathogens, including Klebsiella pneumoniae, vancomycin-resistant Enterococcus faecium, methicillin-resistant Staphylococcus aureus and Bacillus subtilis. In addition, the extracts were tested against two human cancer cell lines, cervical adenocarcinoma (SiHa) and lung carcinoma (A-549). Twenty-four of the forty extracts from mixed cultures obtained from brine and sediment samples from the Manaure solar saltern showed antibacterial activity against Bacillus subtilis. Two extracts, referred to as A1SM3-29 and A1SM3-36, were also active against a methicillin-resistant Staphylococcus aureus, with the latter extract also showing slight cytotoxic activity against the assayed human lung cancer cell line. From this mixed culture, nine isolates were cultivated, and their extracts were tested against the same pathogens, resulting in the identification of a Vibrio sp. strain (A1SM3-36-8) with antimicrobial activity that was similar to that observed for the mixed culture extract

  7. Draft genome of Haloarcula rubripromontorii strain SL3, a novel halophilic archaeon isolated from the solar salterns of Cabo Rojo, Puerto Rico

    Directory of Open Access Journals (Sweden)

    Rubén Sánchez-Nieves

    2016-03-01

    Full Text Available The genus Haloarcula belongs to the family Halobacteriaceae which currently has 10 valid species. Here we report the draft genome sequence of strain SL3, a new species within this genus, isolated from the Solar Salterns of Cabo Rojo, Puerto Rico. Genome assembly performed using NGEN Assembler resulted in 18 contigs (N50 = 601,911 bp, the largest of which contains 1,023,775 bp. The genome consists of 3.97 MB and has a GC content of 61.97%. Like all species of Haloarcula, the genome encodes heterogeneous copies of the small subunit ribosomal RNA. In addition, the genome includes 6 rRNAs, 48 tRNAs, and 3797 protein coding sequences. Several carbohydrate-active enzymes genes were found, as well as enzymes involved in the dihydroxyacetone processing pathway which are not found in other Haloarcula species. The NCBI accession number for this genome is LIUF00000000 and the strain deposit number is CECT9001. Keywords: Halophilic archaea, Henome sequence, Puerto Rico

  8. Investigations on ideal mode of cell disruption in extremely halophilic Actinopolyspora halophila (MTCC 263 for efficient release of glycine betaine and trehalose

    Directory of Open Access Journals (Sweden)

    Jayaranjan R. Kar

    2015-03-01

    Full Text Available Actinopolyspora halophila produces glycine betaine and trehalose intracellularly in considerable quantities. These biomolecules are commercially important as they have applications in food, pharmaceuticals, and agricultural sector. Development of an efficient cell disruption technique is an important step for the release of these biomolecules. In this study, various cell disruption methods such as chemical, enzymatic, physico-mechanical and physical methods were evaluated. Cell disruption by osmotic shock was found to be the best suited method for A. halophila which also has a potential to be industrially scaled up. Cell bursting pressure that is generated during osmotic shock in A. halophila was computed using Morse equation and was found to be π = 238.37 ± 29.54 atm or 2.35 ± 0.29 kPa. In addition, it was found that osmotic shock followed a first order release rate kinetics in A. halophila. The findings can be used for commercially important biomolecules from other halophilic and/or halotolerant microbes.

  9. Characterization of detergent compatible protease of a halophilic Bacillus sp. EMB9: differential role of metal ions in stability and activity.

    Science.gov (United States)

    Sinha, Rajeshwari; Khare, S K

    2013-10-01

    A moderately halophilic protease producer, Bacillus sp. strain isolated from sea water is described. The protease is purified to homogeneity by ammonium sulphate precipitation and CM cellulose chromatography. The serine protease has a molecular mass of 29 kDa. Enzymatic characterization of protease revealed K(m) 2.22 mg mL(-1), Vmax 1111.11 U mL(-1), pH optimum 9.0, t1/2 190 min at 60°C and salt optima 1% (w/v) NaCl. The protease is remarkably stable in hydrophilic and hydrophobic solvents at high concentrations. The purified preparation is unstable at room temperature. Ca(2+) ions are required for preventing this loss of activity. Interestingly, the activity and stability are modulated differentially. Whereas, divalent cation Ca(2+) are involved in maintaining stability in solution at room temperature by preventing unfolding, monovalent Na(+) and K(+) ions participate in regulating the activity and assist in refolding of the enzyme. Application of the protease is shown in efficient removal of blood stain. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Sediminibacillus massiliensis sp. nov., a moderately halophilic, Gram-positive bacterium isolated from a stool sample of a young Senegalese man.

    Science.gov (United States)

    Senghor, Bruno; Bassène, Hubert; Khelaifia, Saber; Robert, Catherine; Fournier, Pierre-Edouard; Ruimy, Raymond; Sokhna, Cheikh; Raoult, Didier; Lagier, Jean-Christophe

    2018-07-01

    A Gram-positive, moderately halophilic bacterium, referred to as strain Marseille-P3518 T , was isolated from a stool sample with 2% NaCl concentration from a healthy 15-year-old male living in Dielmo, a village in Senegal. Cells are aerobic, rod-shaped and motile and display endospore formation. Strain Marseille-P3518 T can grow in a medium with 0-20% (w/v) sodium chloride (optimally at 5-7.5% w/v). The major fatty acids were 12-methyl-tetradecanoic acid (45.8%), 13-methyl-tetradecanoic acid (26.9%) and 12-methyl-tridecanoic acid (12.8%). The genome is 4,347,479 bp long with 42.1% G+C content. It contains 4282 protein-coding and 107 RNA genes. Phylogenetic analysis based on 16S rRNA gene sequence comparisons showed that strain Marseille-P3518 T is a member of the Bacillaceae family and is closely related to Sediminibacillus albus (97.4% gene sequence similarity). Strain Marseille-P3518 T was clearly differentiated from its phylogenetic neighbors on the basis of phenotypic and genotypic features. Strain Marseille-P3518 T is, therefore, considered to be a novel representative of the genus Sediminibacillus, for which the name Sediminibacillus massiliensis sp. nov. is proposed, and the type strain is Marseille-P3518 T (CSUR P3518T, DSM69894).

  11. Circular dichroism and fluorescence spectroscopy of cysteinyl-tRNA synthetase from Halobacterium salinarum ssp. NRC-1 demonstrates that group I cations are particularly effective in providing structure and stability to this halophilic protein.

    Directory of Open Access Journals (Sweden)

    Christopher J Reed

    Full Text Available Proteins from extremophiles have the ability to fold and remain stable in their extreme environment. Here, we investigate the presence of this effect in the cysteinyl-tRNA synthetase from Halobacterium salinarum ssp. NRC-1 (NRC-1, which was used as a model halophilic protein. The effects of salt on the structure and stability of NRC-1 and of E. coli CysRS were investigated through far-UV circular dichroism (CD spectroscopy, fluorescence spectroscopy, and thermal denaturation melts. The CD of NRC-1 CysRS was examined in different group I and group II chloride salts to examine the effects of the metal ions. Potassium was observed to have the strongest effect on NRC-1 CysRS structure, with the other group I salts having reduced strength. The group II salts had little effect on the protein. This suggests that the halophilic adaptations in this protein are mediated by potassium. CD and fluorescence spectra showed structural changes taking place in NRC-1 CysRS over the concentration range of 0-3 M KCl, while the structure of E. coli CysRS was relatively unaffected. Salt was also shown to increase the thermal stability of NRC-1 CysRS since the melt temperature of the CysRS from NRC-1 was increased in the presence of high salt, whereas the E. coli enzyme showed a decrease. By characterizing these interactions, this study not only explains the stability of halophilic proteins in extremes of salt, but also helps us to understand why and how group I salts stabilize proteins in general.

  12. A simple laser-based device for simultaneous microbial culture and absorbance measurement

    Science.gov (United States)

    Abrevaya, X. C.; Cortón, E.; Areso, O.; Mauas, P. J. D.

    2013-07-01

    In this work we present a device specifically designed to study microbial growth with several applications related to environmental microbiology and other areas of research as astrobiology. The Automated Measuring and Cultivation device (AMC-d) enables semi-continuous absorbance measurements directly during cultivation. It can measure simultaneously up to 16 samples. Growth curves using low and fast growing microorganism were plotted, including Escherichia coli and Haloferax volcanii, a halophilic archaeon.

  13. Cloning and identification of Group 1 mrp operon encoding a novel monovalent cation/proton antiporter system from the moderate halophile Halomonas zhaodongensis.

    Science.gov (United States)

    Meng, Lin; Hong, Shan; Liu, Henan; Huang, Haipeng; Sun, Hao; Xu, Tong; Jiang, Juquan

    2014-11-01

    The novel species Halomonas zhaodongensis NEAU-ST10-25(T) recently identified by our group is a moderate halophile which can grow at the range of 0-2.5 M NaCl (optimum 0.5 M) and pH 6-12 (optimum pH 9). To explore its halo-alkaline tolerant mechanism, genomic DNA was screened from NEAU-ST10-25(T) in this study for Na(+)(Li(+))/H(+) antiporter genes by selection in Escherichia coli KNabc lacking three major Na(+)(Li(+))/H(+) antiporters. One mrp operon could confer tolerance of E. coli KNabc to 0.8 M NaCl and 100 mM LiCl, and an alkaline pH. This operon was previously mainly designated mrp (also mnh, pha or sha) due to its multiple resistance and pH-related activity. Here, we will also use mrp to designate the homolog from H. zhaodongensis (Hz_mrp). Sequence analysis and protein alignment showed that Hz_mrp should belong to Group 1 mrp operons. Further phylogenetic analysis reveals that Hz_Mrp system should represent a novel sub-class of Group 1 Mrp systems. This was confirmed by a significant difference in pH-dependent activity profile or the specificity and affinity for the transported monovalent cations between Hz_Mrp system and all the known Mrp systems. Therefore, we propose that Hz_Mrp should be categorized as a novel Group 1 Mrp system.

  14. Characterization of a salt-induced DhAHP, a gene coding for alkyl hydroperoxide reductase, from the extremely halophilic yeast Debaryomyces hansenii

    Directory of Open Access Journals (Sweden)

    Ku Maurice SB

    2009-08-01

    Full Text Available Abstract Background Debaryomyces hansenii is one of the most salt tolerant species of yeast and has become a model organism for the study of tolerance mechanisms against salinity. The goal of this study was to identify key upregulated genes that are involved in its adaptation to high salinity. Results By using forward subtractive hybridization we have cloned and sequenced DhAHP from D. hansenii that is significantly upregulated during salinity stress. DhAHP is orthologous to the alkly hydroperoxide reductase of the peroxiredoxin gene family, which catalyzes the reduction of peroxides at the expense of thiol compounds. The full-lengthed cDNA of DhAHP has 674 bp of nucleotide and contains a 516 bp open reading frame (ORF encoding a deduced protein of 172 amino acid residues (18.3 kDa. D. hansenii Ahp is a cytosolic protein that belongs to the Ahp of the 1-Cys type peroxiredoxins. Phylogentically, the DhAhp and Candida albicans Ahp11 (Swiss-Prot: Q5AF44 share a common ancestry but show divergent evolution. Silence of its expression in D. hansenii by RNAi resulted in decreased tolerance to salt whereas overexpression of DhAHP in D. hansenii and the salt-sensitive yeasts Saccharomyces cereviasiae and Pichia methanolica conferred a higher tolerance with a reduced level of reactive oxygen species. Conclusion In conclusion, for the first time our study has identified alkly hydroperoxide reductase as a key protein involved in the salt tolerance of the extremely halophilic D. hansenii. Apparently, this enzyme plays a multi-functional role in the yeast's adaptation to salinity; it serves as a peroxidase in scavenging reactive oxygen species, as a molecular chaperone in protecting essential proteins from denaturation, and as a redox sensor in regulating H2O2-mediated cell defense signaling.

  15. Antagonistic Properties of Some Halophilic Thermoactinomycetes Isolated from Superficial Sediment of a Solar Saltern and Production of Cyclic Antimicrobial Peptides by the Novel Isolate Paludifilum halophilum

    Science.gov (United States)

    Frikha Dammak, Donyez; Zarai, Ziad; Najah, Soumaya; Abdennabi, Rayed; Belbahri, Lassaad; Rateb, Mostafa E.; Mejdoub, Hafedh

    2017-01-01

    This study has focused on the isolation of twenty-three halophilic actinomycetes from two ponds of different salinity and the evaluation of their ability to exert an antimicrobial activity against both their competitors and several other pathogens. From the 23 isolates, 18 strains showed antagonistic activity, while 19 showed activities against one or more of the seven pathogen strains tested. Six strains exhibited consistent antibacterial activity against Gram-negative and Gram-positive pathogens characterized at the physiological and molecular levels. These strains shared only 94-95% 16S rRNA sequence identity with the closely related species of the Thermoactinomycetaceae family. Among them, the potent strain SMBg3 was further characterized and assigned to a new genus in the family for which the name Paludifilum halophilum (DSM 102817T) is proposed. Sequential extraction of the antimicrobial compounds with ethyl acetate revealed that the crude extract from SMBg3 strain had inhibitory effect on the growth of the plant pathogen Agrobacterium tumefaciens and the human pathogens Staphylococcus aureus, Salmonella enterica, Escherichia coli, and Pseudomonas aeruginosa. Based on the HRESI-MS spectral data, the cyclic lipopeptide Gramicidin S and four cyclic dipeptides (CDPs) named cyclo(L-4-OH-Pro-L-Leu), cyclo(L-Tyr-L-Pro), cyclo(L-Phe-L-Pro), and cyclo(L-Leu-L-Pro) were detected in the fermentation broth of Paludifilum halophilum. To our knowledge, this is the first report on the isolation of these compounds from members of the Thermoactinomycetaceae family. PMID:28819625

  16. Optimization of EPS Production and Characterization by a Halophilic Bacterium, Kocuria rosea ZJUQH from Chaka Salt Lake with Response Surface Methodology.

    Science.gov (United States)

    Gu, Di; Jiao, Yingchun; Wu, Jianan; Liu, Zhengjie; Chen, Qihe

    2017-05-16

    With the rising awareness of microbial exopolysaccharides (EPSs) application in various fields, halophilic microorganisms which produce EPSs have received broad attention. A newly identified Kocuria rosea ZJUQH CCTCC M2016754 was determined to be a moderate halobacterium on account of its successful adaption to the environment containing 10% NaCl. The optimal combination of fermentation medium compositions on EPS production was studied. In this work, a fractional factorial design was adopted to investigate the significant factors that affected EPS production. The factors of KCl and MgSO₄ were found to have a profound impact on EPS production. We utilized central composite design and response surface methodology to derive a statistical model for optimizing the submerged culture medium composition. Judging from these experimental results, the optimum culture medium for producing EPSs was composed of 0.50% casein hydrolysate, 1.00% sodium citrate, 0.30% yeast extract, 0.50% KCl, 0.50% peptone, and 5.80% MgSO₄ (initial pH 7.0). The maximal EPS was 48.01 g/L, which is close to the predicted value (50.39 g/L). In the validation experiment, the highest concentration of 70.64 g/L EPSs was obtained after 120 h under the optimized culture medium in a 5-L bioreactor. EPS from this bacterium was also characterized by differential scanning calorimetry (DSC) and Fourier transform infrared analysis (FT-IR). The findings in this study imply that Kocuria rosea ZJUQH has great potential to be exploited as a source of EPSs utilized in food, the pharmaceutical and agriculture industry, and in the biotreatment of hypersaline environments.

  17. MutS and MutL are dispensable for maintenance of the genomic mutation rate in the halophilic archaeon Halobacterium salinarum NRC-1.

    Directory of Open Access Journals (Sweden)

    Courtney R Busch

    Full Text Available BACKGROUND: The genome of the halophilic archaeon Halobacterium salinarum NRC-1 encodes for homologs of MutS and MutL, which are key proteins of a DNA mismatch repair pathway conserved in Bacteria and Eukarya. Mismatch repair is essential for retaining the fidelity of genetic information and defects in this pathway result in the deleterious accumulation of mutations and in hereditary diseases in humans. METHODOLOGY/PRINCIPAL FINDINGS: We calculated the spontaneous genomic mutation rate of H. salinarum NRC-1 using fluctuation tests targeting genes of the uracil monophosphate biosynthesis pathway. We found that H. salinarum NRC-1 has a low incidence of mutation suggesting the presence of active mechanisms to control spontaneous mutations during replication. The spectrum of mutational changes found in H. salinarum NRC-1, and in other archaea, appears to be unique to this domain of life and might be a consequence of their adaption to extreme environmental conditions. In-frame targeted gene deletions of H. salinarum NRC-1 mismatch repair genes and phenotypic characterization of the mutants demonstrated that the mutS and mutL genes are not required for maintenance of the observed mutation rate. CONCLUSIONS/SIGNIFICANCE: We established that H. salinarum NRC-1 mutS and mutL genes are redundant to an alternative system that limits spontaneous mutation in this organism. This finding leads to the puzzling question of what mechanism is responsible for maintenance of the low genomic mutation rates observed in the Archaea, which for the most part do not have MutS and MutL homologs.

  18. Deuterium incorporation experiments from (3R)- and (3S)-[3-2H]leucine into characteristic isoprenoidal lipid-core of halophilic archaea suggests the involvement of isovaleryl-CoA dehydrogenase.

    Science.gov (United States)

    Yamauchi, Noriaki; Tanoue, Ryo

    2017-11-01

    The stereochemical reaction course for the two C-3 hydrogens of leucine to produce a characteristic isoprenoidal lipid in halophilic archaea was observed using incubation experiments with whole cell Halobacterium salinarum. Deuterium-labeled (3R)- and (3S)-[3- 2 H]leucine were freshly prepared as substrates from 2,3-epoxy-4-methyl-1-pentanol. Incorporation of deuterium from (3S)-[3- 2 H]leucine and loss of deuterium from (3R)-[3- 2 H]leucine in the lipid-core of H. salinarum was observed. Taken together with the results of our previous report, involving the incubation of chiral-labeled [5- 2 H]leucine, these results strongly suggested an involvement of isovaleryl-CoA dehydrogenase in leucine conversion to isoprenoid lipid in halophilic archaea. The stereochemical course of the reaction (anti-elimination) might have been the same as that previously reported for mammalian enzyme reactions. Thus, these results suggested that branched amino acids were metabolized to mevalonate in archaea in a manner similar to other organisms.

  19. Methylarcula marina gen. nov., sp. nov. and Methylarcula terricola sp. nov.: novel aerobic, moderately halophilic, facultatively methylotrophic bacteria from coastal saline environments.

    Science.gov (United States)

    Doronina, N V; Trotsenko, Y A; Tourova, T P

    2000-09-01

    A new genus, Methylarcula, with two new species, Methylarcula marina and Methylarcula terricola, are proposed for strains h1T and h37T of moderately halophilic facultatively methylotrophic bacteria isolated from the coastal saline habitats. These methylobacteria are aerobic, Gram-negative, asporogenous, non-motile, colourless rods that multiply by binary fission. Their cellular fatty acids profiles consist primarily of straight-chain unsaturated (C18:1; 70-80%), saturated (C18:0; 14-16%) and cyclopropane (C19:0; 5-6%) acids. The major ubiquinone is Q-10. The dominant phospholipids are phosphatidylethanolamine and phosphatidylcholine. Both strains could use methylamine, some sugars and organic acids as carbon and energy sources. They grew well under optimal conditions (29-35 degrees C, pH 7.5-8.5, 0.5-1.0 M NaCl) and accumulated intracellularly poly-beta-hydroxybutyrate and the compatible solute ectoine. The ectoine pool was found to increase upon increasing the external NaCl concentration and accounted for 18% of the dry cellular weight. Both strains oxidized methylamine by the N-methylglutamate (N-MG) pathway enzymes (gamma-glutamylmethylamide synthetase/lyase and N-MG synthetase/lyase) to formaldehyde and assimilated it via the icl- serine pathway. The DNA G+C content was 60-4 mol% for Methylarcula marina h1T and 57.1 mol% for Methylarcula terricola h37T. The DNA-DNA hybridization value between strains hl and h37 was 25-30%, although they had a low level of DNA relatedness (5-7%) with the type strains of the serine pathway methylobacteria belonging to the genera Methylobacterium, Aminobacter, Methylorhabdus and Methylopila. A comparative 16S rDNA sequence-based phylogenetic analysis placed the two species of Methylarcula into a separate branch of the alpha-3 subclass of the Proteobacteria. The type strains of the new species are Methylarcula marina h1T (= VKM B-2159T) and Methylarcula terricola h37T (= VKM B-2160T).

  20. Marinobacter lacisalsi sp. nov., a moderately halophilic bacterium isolated from the saline-wetland wildfowl reserve Fuente de Piedra in southern Spain.

    Science.gov (United States)

    Aguilera, Margarita; Jiménez-Pranteda, Maria L; Kharroub, Karima; González-Paredes, Ana; Durban, Juan J; Russell, Nick J; Ramos-Cormenzana, Alberto; Monteoliva-Sánchez, Mercedes

    2009-07-01

    A Gram-negative, non-spore-forming, motile, moderately halophilic, aerobic, rod-shaped bacterium, designated strain FP2.5(T), was isolated from the inland hypersaline lake Fuente de Piedra, a saline-wetland wildfowl reserve located in the province of Málaga in southern Spain. Strain FP2.5(T) was subjected to a polyphasic taxonomic study. It produced colonies with a light-yellow pigment. Strain FP2.5(T) grew at salinities of 3-15 % (w/v) and at temperatures of 20-40 degrees C. The pH range for growth was 5-9. Strain FP2.5(T) was able to utilize various organic acids as sole carbon and energy source. Its major fatty acids were C(16 : 0), C(18 : 1)omega9c and C(16 : 1)omega9c. The DNA G+C content was 58.6 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain FP2.5(T) appeared to be a member of the genus Marinobacter and clustered closely with the type strains of Marinobacter segnicrescens, Marinobacter bryozoorum and Marinobacter gudaonensis (levels of 16S rRNA gene sequence similarity of 98.1, 97.4 and 97.2 %, respectively). However, DNA-DNA relatedness between the new isolate and the type strains of its closest related Marinobacter species was low; levels of DNA-DNA relatedness between strain FP2.5(T) and M. segnicrescens LMG 23928(T), M. bryozoorum DSM 15401(T) and M. gudaonensis DSM 18066(T) were 36.3, 32.1 and 24.9 %, respectively. On the basis of phenotypic characteristics, phylogenetic analysis and DNA-DNA relatedness data, strain FP2.5(T) is considered to represent a novel species of the genus Marinobacter, for which the name Marinobacter lacisalsi sp. nov. is proposed. The type strain is FP2.5(T) (=CECT 7297(T)=LMG 24237(T)).

  1. Phenotypic characterization and 16S rDNA identification of culturable non-obligate halophilic bacterial communities from a hypersaline lake, La Sal del Rey, in extreme South Texas (USA).

    Science.gov (United States)

    Phillips, Kristen; Zaidan, Frederic; Elizondo, Omar R; Lowe, Kristine L

    2012-02-02

    La Sal del Rey ("the King's Salt") is one of several naturally-occurring salt lakes in Hidalgo County, Texas and is part of the Lower Rio Grande Valley National Wildlife Refuge. The research objective was to isolate and characterize halophilic microorganisms from La Sal del Rey. Water samples were collected from the lake and a small creek that feeds into the lake. Soil samples were collected from land adjacent to the water sample locations. Sample salinity was determined using a refractometer. Samples were diluted and cultured on a synthetic saline medium to grow halophilic bacteria. The density of halophiles was estimated by viable plate counts. A collection of isolates was selected, gram-stained, tested for catalase, and characterized using API 20E® test strips. Isolates were putatively identified by sequencing the 16S rDNA. Carbon source utilization by the microbial community from each sample site was examined using EcoPlate™ assays and the carbon utilization total activity of the community was determined. Results showed that salinity ranged from 4 parts per thousand (ppt) at the lake water source to 420 ppt in water samples taken just along the lake shore. The density of halophilic bacteria in water samples ranged from 1.2 × 102 - 5.2 × 103 colony forming units per ml (cfu ml-1) whereas the density in soil samples ranged from 4.0 × 105 - 2.5 × 106 colony forming units per gram (cfu g-1). In general, as salinity increased the density of the bacterial community decreased. Microbial communities from water and soil samples were able to utilize 12 - 31 carbon substrates. The greatest number of substrates utilized was by water-borne communities compared to soil-based communities, especially at lower salinities. The majority of bacteria isolated were gram-negative, catalase-positive, rods. Biochemical profiles constructed from API 20E® test strips showed that bacterial isolates from low-salinity water samples (4 ppt) showed the greatest phenotypic diversity

  2. producing halophilic/halotolerant eubacteria

    African Journals Online (AJOL)

    STORAGESEVER

    2010-03-15

    Mar 15, 2010 ... ments has focused on the microbial diversity and ecology of these environments ... number of phylogenetic subgroups. Most of these fall in .... of various protein rich foods including processing of fish ... become non-functional.

  3. Production of biosurfactant on crude date syrup under saline conditions by entrapped cells of Natrialba sp. strain E21, an extremely halophilic bacterium isolated from a solar saltern (Ain Salah, Algeria).

    Science.gov (United States)

    Kebbouche-Gana, Salima; Gana, Mohamed Lamine; Ferrioune, Imen; Khemili, Souad; Lenchi, Nesrine; Akmouci-Toumi, Sihem; Bouanane-Darenfed, Nabila Amel; Djelali, Nacer-Eddine

    2013-11-01

    A bacterial strain E21 was isolated from a sample of water collected in the salt lake located close to Ain Salah, Algeria. The analysis of 16S rRNA gene sequence had indicated that the strain had 93 % sequence similarity with the genus Natrialba sp. strain E21 (GenBank, FR750525.1) and was considered extremely halophilic. Production of biosurfactant by the strain E21 with free and entrapped cells was investigated using soluble starch in the saline conditions. Biosurfactant synthesis was followed by measuring the surface tension and emulsifying index 9 days under optimal conditions (40 °C, pH 7). Some diffusional limitations in alginate and agar beads affected the kinetics of biosurfactant production when compared to that obtained with free cells culture. The minimum values of surface tension were 27 and 30 mN m(-1) achieved after 9 days with free and immobilized cells, respectively, while the corresponding maximum E24 values were 65.3 and 62.3 %, respectively. The re-use of bacterial cells along with the limited cell losses provided by the immobilized system might lead to significant reduction of the biosurfactant production cost.

  4. Halolactibacillus halophilus gen. nov., sp. nov. and Halolactibacillus miurensis sp. nov., halophilic and alkaliphilic marine lactic acid bacteria constituting a phylogenetic lineage in Bacillus rRNA group 1.

    Science.gov (United States)

    Ishikawa, Morio; Nakajima, Kazuyuki; Itamiya, Yuko; Furukawa, Sayumi; Yamamoto, Yasushi; Yamasato, Kazuhide

    2005-11-01

    Eleven novel strains of marine-inhabiting lactic acid bacteria that were isolated from living and decaying marine organisms collected from a temperate area of Japan are described. The isolates were motile with peritrichous flagella and non-sporulating. They lacked catalase, quinones and cytochromes. Fermentation products from glucose were lactate, formate, acetate and ethanol. Lactate yield as percentage conversion from glucose was affected by the pH of the fermentation medium: approximately 55 % at the optimal growth pH of 8.0, greater than approximately 70 % at pH 7.0 and less than approximately 30 % at pH 9.0. The molar ratio of the other three products was the same at each cultivation pH, approximately 2 : 1 : 1. Carbohydrates and related compounds were aerobically metabolized to acetate and pyruvate as well as lactate. The isolates were slightly halophilic, highly halotolerant and alkaliphilic. The optimum NaCl concentration for growth was 2.0-3.0 % (w/v), with a range of 0-25.5 %. The optimum pH for growth was 8.0-9.5, with a range of 6.0-10.0. The G+C content of the DNA was 38.5-40.7 mol%. The isolates constituted two genomic species (DNA-DNA relatedness of less than 41 %) each characterized by sugar fermentation profiles. The cell-wall peptidoglycan of both phenotypes contained meso-diaminopimelic acid. The major cellular fatty acids were C(16 : 0) and a-C(13 : 0). Comparative sequence analysis of the 16S rRNA genes revealed that these isolates represent novel species constituting a phylogenetic unit outside the radiation of typical lactic acid bacteria and an independent line of descent within the group composed of the halophilic/halotolerant/alkaliphilic and/or alkalitolerant species in Bacillus rRNA group 1, with 94.8-95.1 % similarity to the genus Paraliobacillus, 93.7-94.1 % to the genus Gracilibacillus and 93.8-94.2 % to Virgibacillus marismortui. On the basis of possession of physiological and biochemical characteristics common to typical lactic acid

  5. Salinifilum gen. nov., with description of Salinifilum proteinilyticum sp. nov., an extremely halophilic actinomycete isolated from Meighan wetland, Iran, and reclassification of Saccharopolyspora aidingensis as Salinifilum aidingensis comb. nov. and Saccharopolyspora ghardaiensis as Salinifilum ghardaiensis comb. nov.

    Science.gov (United States)

    Moshtaghi Nikou, Mahdi; Ramezani, Mohaddaseh; Harirchi, Sharareh; Makzoom, Somayyeh; Amoozegar, Mohammad Ali; Shahzadeh Fazeli, Seyed Abolhassan; Schumann, Peter; Ventosa, Antonio

    2017-10-01

    A Gram-positive, halophilic actinobacterial strain Miq-12 T was isolated from Meighan wetland in Iran. Strain Miq-12 T was strictly aerobic, catalase positive and oxidase negative. The isolate grew at 12-25 % NaCl, at 30-50 °C and pH 5.5-10.5. The optimum NaCl, temperature and pH for growth were 15-20 %, 40 °C and 7.0-8.0, respectively. The cell wall of strain Miq-12 T contained meso-diaminopimelic acid as diagnostic diamino acid and arabinose as whole-cell sugar. The polar lipid pattern consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine and phosphatidylinositol. It synthesized cellular fatty acids of anteiso and iso-branched types, anteiso-C17 : 0, iso-C17:0, iso-C15:0, iso-C16 : 0. The major respiratory quinone was MK-9(H4). The G+C content of its genomic DNA was 72.1 mol%. Phylogenetic analysis based on 16S rRNA gene sequence comparison revealed that strain Miq-12 T belongs to the family Pseudonocardiaceae, constituted a separate clade, and showed the closest phylogenetic similarity to Saccharopolyspora aidingensis TRM 46074 T (96.99 %) and Saccharopolyspora ghardaiensis CCUG 63370 T (96.92 %). On the basis of phylogenetic analysis, phenotypic and chemotaxonomic characteristics, a novel genus and species of the family Pseudonocardiaceae, Salinifilum proteinilyticum gen. nov., sp. nov., are proposed. The type strain is Miq-12 T (=IBRCM 11033 T =LMG 28390 T ). We also propose that S. aidingensis and S. ghardaiensis should be transferred to this new genus and be named Salinifilum aidingensis comb. nov. and Salinifilum ghardaiensis comb. nov., respectively. The type strain of Salinifilum aidingensis comb. nov. is TRM 46074 T (=CCTCCAA 2012014 T =JCM 30185 T ) and the type strain of Salinifilum ghardaiensis comb. nov. is CCUG 63370 T (=DSM 45606 T =CECT 8304 T ).

  6. Isolation and characterization from solar salterns of North Algeria of a haloarchaeon producing a new halocin.

    Science.gov (United States)

    Mazguene, Souhila; Rossi, Mosè; Gogliettino, Marta; Palmieri, Gianna; Cocca, Ennio; Mirino, Sara; Imadalou-Idres, Nacera; Benallaoua, Said

    2018-03-01

    Halophilic archaea, thriving in hypersaline environments, synthesize antimicrobial substances with an unknown role, called halocins. It has been suggested that halocin production gives transient competitive advantages to the producer strains and represents one of the environmental factors influencing the microbial community composition. Herein, we report on the antibacterial activity of a new haloarchaeon selected from solar salterns of the northern coast of Algeria. A total of 81 halophilic strains, isolated from the microbial consortia, were screened for the production of antimicrobial compounds by interspecies competition test and against a collection of commercial haloarchaea. On the basis of the partial 16S rRNA sequencing, the most efficient halocin producer was recognized as belonging to Haloferax (Hfx) sp., while the best indicator microorganism, showing high sensitivity toward halocin, was related to Haloarcula genus. The main morphological, physiological and biochemical properties of Hfx were investigated and a partial purification of the produced halocin was allowed to identify it as a surface membrane protein with a molecular mass between 30 and 40 kDa. Therefore, in this study, we isolated a new strain belonging to Haloferax genus and producing a promising antimicrobial compound useful for applications in health and food industries.

  7. Fungi living on halophilic plants. II

    Directory of Open Access Journals (Sweden)

    Irena Hołownia

    2014-11-01

    Full Text Available Uromyces saliorniae (DC. de Bary and Uromyces sparsus (Kunze et Schmidt Lev. are species seldom reported from the territory of Europe. From Poland so far only U. sparsus was reported (Busko: in 1964 it was found on a second site in Mątwy near Inowrocław, Uromyces salicorniae was found for the time in Poland in Kołobrzeg in 1966.

  8. Bioprospecting Archaea: Focus on Extreme Halophiles

    KAUST Repository

    Antunes, André ; Simõ es, Marta F.; Grö tzinger, Stefan W.; Eppinger, Jö rg; Braganç a, Judith; Bajic, Vladimir B.

    2016-01-01

    knowledge, and (c) utilization of Archaea in biotechnology. They are increasingly employed in fields as diverse as biocatalysis, biocomputing, bioplastic production, bioremediation, bioengineering, food, pharmaceuticals, and nutraceuticals. This chapter

  9. S-layer and cytoplasmic membrane – exceptions from the typical archaeal cell wall with a focus on double membranes

    Directory of Open Access Journals (Sweden)

    Andreas eKlingl

    2014-11-01

    Full Text Available The common idea of typical cell wall architecture in archaea consists of a pseudo-crystalline proteinaceous surface layer (S-layer, situated upon the cytoplasmic membrane. This is true for the majority of described archaea, hitherto. Within the crenarchaea, the S-layer often represents the only cell wall component, but there are various exceptions from this wall architecture. Beside (glycosylated S-layers in (hyperthermophilic cren- and euryarchaea as well as halophilic archaea, one can find a great variety of other cell wall structures like proteoglycan-like S-layers (Halobacteria, glutaminylglycan (Natronococci, methanochondroitin (Methanosarcina or double layered cell walls with pseudomurein (Methanothermus and Methanopyrus. The presence of an outermost cellular membrane in the crenarchaeal species Ignicoccus hospitalis already gave indications for an outer membrane similar to Gram-negative bacteria. Although there is just limited data concerning their biochemistry and ultrastructure, recent studies on the euryarchaeal methanogen Methanomassiliicoccus luminyensis, cells of the ARMAN group, and the SM1 euryarchaeon delivered further examples for this exceptional cell envelope type consisting of two membranes.

  10. Two Tales of Prokaryotic Genomic Diversity: Escherichia coli and Halophiles

    Directory of Open Access Journals (Sweden)

    Lejla Pašić

    2014-01-01

    Full Text Available Prokaryotes are generally characterized by vast genomic diversity that has been shaped by mutations, horizontal gene transfer, bacteriocins and phage predation. Enormous genetic diversity has developed as a result of stresses imposed in harsh environments and the ability of microorganisms to adapt. Two examples of prokaryotic diversity are presented: on intraspecies level, exemplified by Escherichia coli, and the diversity of the hypersaline environment, with the discussion of food-related health issues and biotechnological potential.

  11. Ecological Performances of Plant Species of Halophilous Hydromorphic Ecosystems

    Directory of Open Access Journals (Sweden)

    Maria Speranza

    2015-12-01

    Full Text Available Coastal wetlands are very special environments, characterized by soils permanently or seasonally saturated by salt or brackish water. They host microorganisms and plants able to adapt to anoxic conditions. This paper proposes a review of recent scientific papers dealing with the study of coastal wetlands from different points of view. Some studies examine the species composition and the pattern of the spatial distribution of plant communities, depending on the depth of the salt water table, as well as on other related factors. A significant number of studies analyse instead the coastal wetlands in their ability for the phytoremediation (phytostabilisation and/or phytoextraction and highlight the importance of interactions between the rhizosphere of the halophytes and the physical environment. Finally, more recent studies consider the plant species of the coastal wetlands as a source of useful products (food, feed, oils and expose the results of promising researches on their cultivation.

  12. Biosynthesis, Characterization, and Hemostasis Potential of Tailor-Made Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Produced by Haloferax mediterranei

    DEFF Research Database (Denmark)

    Han, Jing; Wu, Linping; Hou, Jing

    2015-01-01

    . Consistently, two Tg were observed in the DSC curves of O-PHBV. The "blocky" feature of O-PHBV enhanced crystallinity percentages and improved Young's modulus. Notably, the film of one O-PHBV copolymer, O-PHBV-1, showed unique foveolar cluster-like surface morphology with high hydrophobicity and roughness...

  13. Comparison of four phaC genes from Haloferax mediterranei and their function in different PHBV copolymer biosyntheses in Haloarcula hispanica

    DEFF Research Database (Denmark)

    Han, Jing; Li, Ming; Hou, Jing

    2010-01-01

    , PhaCHme and PhaEHme, has been identified in this strain, and shown to account for the PHBV biosynthesis. RESULTS: With the aid of the genome sequence of Hfx. mediterranei CGMCC 1.2087, three additional phaC genes (designated phaC1, phaC2, and phaC3) were identified, which encoded putative PhaCs. Like......, among the four genes, only phaCHme was transcribed under PHA-accumulating conditions in the wild-type strain. However, heterologous coexpression of phaEHme with each phaC gene in Haloarcula hispanica PHB-1 showed that all PhaCs, except PhaC2, could lead to PHBV accumulation with various 3HV fractions...... meet various application requirements. CONCLUSION: We discover three cryptic phaC genes in Hfx. mediterranei, and demonstrate that genetic engineering of these newly identified phaC genes has biotechnological potential for PHBV production with tailor-made material properties....

  14. Carotenoids from Haloarchaea and Their Potential in Biotechnology

    Science.gov (United States)

    Rodrigo-Baños, Montserrat; Garbayo, Inés; Vílchez, Carlos; Bonete, María José; Martínez-Espinosa, Rosa María

    2015-01-01

    The production of pigments by halophilic archaea has been analysed during the last half a century. The main reasons that sustains this research are: (i) many haloarchaeal species possess high carotenoids production availability; (ii) downstream processes related to carotenoid isolation from haloarchaea is relatively quick, easy and cheap; (iii) carotenoids production by haloarchaea can be improved by genetic modification or even by modifying several cultivation aspects such as nutrition, growth pH, temperature, etc.; (iv) carotenoids are needed to support plant and animal life and human well-being; and (v) carotenoids are compounds highly demanded by pharmaceutical, cosmetic and food markets. Several studies about carotenoid production by haloarchaea have been reported so far, most of them focused on pigments isolation or carotenoids production under different culture conditions. However, the understanding of carotenoid metabolism, regulation, and roles of carotenoid derivatives in this group of extreme microorganisms remains mostly unrevealed. The uses of those haloarchaeal pigments have also been poorly explored. This work summarises what has been described so far about carotenoids production by haloarchaea and their potential uses in biotechnology and biomedicine. In particular, new scientific evidence of improved carotenoid production by one of the better known haloarchaeon (Haloferax mediterranei) is also discussed. PMID:26308012

  15. Carotenoids from Haloarchaea and Their Potential in Biotechnology.

    Science.gov (United States)

    Rodrigo-Baños, Montserrat; Garbayo, Inés; Vílchez, Carlos; Bonete, María José; Martínez-Espinosa, Rosa María

    2015-08-25

    The production of pigments by halophilic archaea has been analysed during the last half a century. The main reasons that sustains this research are: (i) many haloarchaeal species possess high carotenoids production availability; (ii) downstream processes related to carotenoid isolation from haloarchaea is relatively quick, easy and cheap; (iii) carotenoids production by haloarchaea can be improved by genetic modification or even by modifying several cultivation aspects such as nutrition, growth pH, temperature, etc.; (iv) carotenoids are needed to support plant and animal life and human well-being; and (v) carotenoids are compounds highly demanded by pharmaceutical, cosmetic and food markets. Several studies about carotenoid production by haloarchaea have been reported so far, most of them focused on pigments isolation or carotenoids production under different culture conditions. However, the understanding of carotenoid metabolism, regulation, and roles of carotenoid derivatives in this group of extreme microorganisms remains mostly unrevealed. The uses of those haloarchaeal pigments have also been poorly explored. This work summarises what has been described so far about carotenoids production by haloarchaea and their potential uses in biotechnology and biomedicine. In particular, new scientific evidence of improved carotenoid production by one of the better known haloarchaeon (Haloferax mediterranei) is also discussed.

  16. Morphological and structural aspects of the extremely halophilic archaeon Haloquadratum walsbyi.

    Directory of Open Access Journals (Sweden)

    Matilde Sublimi Saponetti

    Full Text Available Ultrathin square cell Haloquadratum walsbyi from the Archaea domain are the most abundant microorganisms in the hypersaline water of coastal salterns and continental salt lakes. In this work, we explore the cell surface of these microorganisms using amplitude-modulation atomic-force microscopy in nearly physiological conditions. We demonstrate the presence of a regular corrugation with a periodicity of 16-20 nm attributed to the surface layer (S-layer protein lattice, striped domains asymmetrically distributed on the cell faces and peculiar bulges correlated with the presence of intracellular granules. Besides, subsequent images of cell evolution during the drying process indicate the presence of an external capsule that might correspond to the giant protein halomucin, predicted by the genome but never before observed by other microscopy studies.

  17. Morphological and structural aspects of the extremely halophilic archaeon Haloquadratum walsbyi.

    Science.gov (United States)

    Sublimi Saponetti, Matilde; Bobba, Fabrizio; Salerno, Grazia; Scarfato, Alessandro; Corcelli, Angela; Cucolo, Annamaria

    2011-04-29

    Ultrathin square cell Haloquadratum walsbyi from the Archaea domain are the most abundant microorganisms in the hypersaline water of coastal salterns and continental salt lakes. In this work, we explore the cell surface of these microorganisms using amplitude-modulation atomic-force microscopy in nearly physiological conditions. We demonstrate the presence of a regular corrugation with a periodicity of 16-20 nm attributed to the surface layer (S-layer) protein lattice, striped domains asymmetrically distributed on the cell faces and peculiar bulges correlated with the presence of intracellular granules. Besides, subsequent images of cell evolution during the drying process indicate the presence of an external capsule that might correspond to the giant protein halomucin, predicted by the genome but never before observed by other microscopy studies.

  18. Morphological and Structural Aspects of the Extremely Halophilic Archaeon Haloquadratum walsbyi

    OpenAIRE

    Sublimi Saponetti, Matilde; Bobba, Fabrizio; Salerno, Grazia; Scarfato, Alessandro; Corcelli, Angela; Cucolo, Annamaria

    2011-01-01

    Ultrathin square cell Haloquadratum walsbyi from the Archaea domain are the most abundant microorganisms in the hypersaline water of coastal salterns and continental salt lakes. In this work, we explore the cell surface of these microorganisms using amplitude-modulation atomic-force microscopy in nearly physiological conditions. We demonstrate the presence of a regular corrugation with a periodicity of 16-20 nm attributed to the surface layer (S-layer) protein lattice, striped domains asymmet...

  19. Bioassay and Molecular Screening of Pectinase Enzyme in halophilic bacteria from Salt Lake, Iran

    Directory of Open Access Journals (Sweden)

    Zohre Nasrollahzadeh

    2018-06-01

    Discussion and conclusion: Quantitative evaluation showed that production and activity of pectinase enzyme in R2S25 strain increased simultaneously with increasing the growth of selected strain in logarithmic phase. Molecular study also showed that the genuses of Martelella, Aeromocrobium, Planococcus, Marinobacter, Virgibacillus, Kocuria and Micrococcus contain the pectinase gene.

  20. Adjusting membrane lipids under salt stress: the case of the moderate halophilic organism Halobacillus halophilus.

    Science.gov (United States)

    Lopalco, Patrizia; Angelini, Roberto; Lobasso, Simona; Köcher, Saskia; Thompson, Melanie; Müller, Volker; Corcelli, Angela

    2013-04-01

    The lipid composition of Halobacillus halophilus was investigated by combined thin-layer chromatography and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analyses of the total lipid extract. Main polar lipids were found to be sulfoquinovosyldiacylglycerol and phosphatidylglycerol, while cardiolipin was a minor lipid together with phosphatidic acid, alanyl-phosphatidylglycerol and two not yet fully identified lipid components. In addition the analyses of residual lipids, associated with denatured proteins after the lipid extraction, revealed the presence of significant amounts of cardiolipin, indicating that it is a not readily extractable phospholipid. Post decay source mass spectrometry analyses allowed the determination of acyl chains of main lipid components. On increasing the culture medium salinity, an increase in the shorter chains and the presence of chain unsaturations were observed. These changes in the lipid core structures might compensate for the increase in packing and rigidity of phospholipid and sulfoglycolipid polar heads in high-salt medium, therefore contributing to the homeostasis of membrane fluidity and permeability in salt stress conditions. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

  1. Halomonas titanicae sp. nov., a halophilic bacterium isolated from the RMS Titanic.

    Science.gov (United States)

    Sánchez-Porro, Cristina; Kaur, Bhavleen; Mann, Henrietta; Ventosa, Antonio

    2010-12-01

    A Gram-negative, heterotrophic, aerobic, non-endospore-forming, peritrichously flagellated and motile bacterial strain, designated BH1(T), was isolated from samples of rusticles, which are formed in part by a consortium of micro-organisms, collected from the RMS Titanic wreck site. The strain grew optimally at 30-37°C, pH 7.0-7.5 and in the presence of 2-8 % (w/v) NaCl. We carried out a polyphasic taxonomic study in order to characterize the strain in detail. Phylogenetic analyses based on 16S rRNA gene sequence comparison indicated that strain BH1(T) clustered within the branch consisting of species of Halomonas. The most closely related type strains were Halomonas neptunia (98.6 % 16S rRNA sequence similarity), Halomonas variabilis (98.4 %), Halomonas boliviensis (98.3 %) and Halomonas sulfidaeris (97.5 %). Other closely related species were Halomonas alkaliphila (96.5 % sequence similarity), Halomonas hydrothermalis (96.3 %), Halomonas gomseomensis (96.3 %), Halomonas venusta (96.3 %) and Halomonas meridiana (96.2 %). The major fatty acids of strain BH1(T) were C(18 : 1)ω7c (36.3 %), C(16 : 0) (18.4 %) and C(19 : 0) cyclo ω8c (17.9 %). The DNA G+C content was 60.0 mol% (T(m)). Ubiquinone 9 (Q-9) was the major lipoquinone. The phenotypic features, fatty acid profile and DNA G+C content further supported the placement of strain BH1(T) in the genus Halomonas. DNA-DNA hybridization values between strain BH1(T) and H. neptunia CECT 5815(T), H. variabilis DSM 3051(T), H. boliviensis DSM 15516(T) and H. sulfidaeris CECT 5817(T) were 19, 17, 30 and 29 %, respectively, supporting the differential taxonomic status of BH1(T). On the basis of the phenotypic, chemotaxonomic and phylogenetic data, strain BH1(T) is considered to represent a novel species, for which the name Halomonas titanicae sp. nov. is proposed. The type strain is BH1(T) (=ATCC BAA-1257(T) =CECT 7585(T) =JCM 16411(T) =LMG 25388(T)).

  2. Marinobacter nitratireducens sp. nov., a halophilic and lipolytic bacterium isolated from coastal surface sea water

    Digital Repository Service at National Institute of Oceanography (India)

    Bhumika, V.; Ravinder, K.; Korpole, S.; Srinivas, T.N.R.; AnilKumar, P.

    A novel Gram-stain-negative, rod-shaped, motile bacterium, designated strain AK21T , was isolated from coastal surface sea water at Visakhapatnam, India. The strain was positive for oxidase, catalase, lipase, L-proline arylamidase...

  3. Adaptation, Ecology, and Evolution of the Halophilic Stromatolite Archaeon Halococcus hamelinensis Inferred through Genome Analyses

    Directory of Open Access Journals (Sweden)

    Reema K. Gudhka

    2015-01-01

    Full Text Available Halococcus hamelinensis was the first archaeon isolated from stromatolites. These geomicrobial ecosystems are thought to be some of the earliest known on Earth, yet, despite their evolutionary significance, the role of Archaea in these systems is still not well understood. Detailed here is the genome sequencing and analysis of an archaeon isolated from stromatolites. The genome of H. hamelinensis consisted of 3,133,046 base pairs with an average G+C content of 60.08% and contained 3,150 predicted coding sequences or ORFs, 2,196 (68.67% of which were protein-coding genes with functional assignments and 954 (29.83% of which were of unknown function. Codon usage of the H. hamelinensis genome was consistent with a highly acidic proteome, a major adaptive mechanism towards high salinity. Amino acid transport and metabolism, inorganic ion transport and metabolism, energy production and conversion, ribosomal structure, and unknown function COG genes were overrepresented. The genome of H. hamelinensis also revealed characteristics reflecting its survival in its extreme environment, including putative genes/pathways involved in osmoprotection, oxidative stress response, and UV damage repair. Finally, genome analyses indicated the presence of putative transposases as well as positive matches of genes of H. hamelinensis against various genomes of Bacteria, Archaea, and viruses, suggesting the potential for horizontal gene transfer.

  4. Radiocarbon analysis of halophilic microbial lipids from an Australian salt lake

    Science.gov (United States)

    Bray, P. Sargent; Jones, Claudia M.; Fallon, Stewart J.; Brocks, Jochen J.; George, Simon C.

    2012-01-01

    Assigning accurate dates to hypersaline sediments opens important terrestrial records of local and regional paleoecologies and paleoclimatology. However, as of yet no conventional method of dating hypersaline systems has been widely adopted. Biomarker, mineralogical, and radiocarbon analyses of sediments and organic extracts from a shallow (13 cm) core from a hypersaline playa, Lake Tyrrell, southeastern Australia, produce a coherent age-depth curve beginning with modern microbial mats and extending to ~ 7500 cal yr BP. These analyses are furthermore used to identify and constrain the timing of the most recent change in hydrological regime at Lake Tyrrell, a shift from a clay deposit to the precipitation of evaporitic sands occurring at some time between ~ 4500 and 7000 yr. These analyses show the potential for widespread dating of hypersaline systems integrating the biomarker approach, reinforce the value of the radiocarbon content of biomarkers in understanding the flow of carbon in modern ecologies, and validate the temporal dimension of data provided by biomarkers when dating late Quaternary sediments.

  5. Discovery of extremely halophilic, methyl-reducing euryarchaea provides insights into the evolutionary origin of methanogenesis

    NARCIS (Netherlands)

    Sorokin, Dimitry Y.; Makarova, Kira S.; Abbas, B.A.; Ferrer, Manuel; Golyshin, Peter N.; Galinski, Erwin A.; Ciordia, Sergio; Mena, María Carmen; Merkel, Alexander Y.; Wolf, Yuri I.; van Loosdrecht, Mark C.M.; Koonin, Eugene V.

    2017-01-01

    Methanogenic archaea are major players in the global carbon cycle and in the biotechnology of anaerobic digestion. The phylum Euryarchaeota includes diverse groups of methanogens that are interspersed with non-methanogenic lineages. So far, methanogens inhabiting hypersaline environments have

  6. Habitability: Where to look for life? Halophilic habitats: Earth analogs to study Mars habitability

    Science.gov (United States)

    Gómez, F.; Rodríguez-Manfredi, J. A.; Rodríguez, N.; Fernández-Sampedro, M.; Caballero-Castrejón, F. J.; Amils, R.

    2012-08-01

    Oxidative stress, high radiation doses, low temperature and pressure are parameters which made Mars's surface adverse for life. Those conditions found on Mars surface are harsh conditions for life to deal with. Life, as we know it on Earth, needs several requirements for its establishment but, the only "sine qua nom" element is water. Extremophilic microorganisms widened the window of possibilities for life to develop in the universe, and as a consequence on Mars. Recently reported results in extreme environments indicate the possibility of presence of "oasys" for life in microniches due to water deliquescence in salts deposits. The compilation of data produced by the ongoing missions (Mars Global Surveyor, Mars Odyssey, Mars Express and Mars Exploration Rover Opportunity) offers a completely different view from that reported by Viking missions: signs of an early wet Mars and rather recent volcanic activity. The discovery of important accumulations of sulfates, and the existence of iron minerals like jarosite, goethite and hematite in rocks of sedimentary origin has allowed specific terrestrial models related with this type of mineralogy to come into focus. Río Tinto (Southwestern Spain, Iberian Pyritic Belt) is an extreme acidic environment, product of the chemolithotrophic activity of microorganisms that thrive in the massive pyrite-rich deposits of the Iberian Pyritic Belt. The high concentration of ferric iron and sulfates, products of the metabolism of pyrite, generate a collection of minerals, mainly gypsum, jarosite, goethite and hematites, all of which have been detected in different regions of Mars. Some particular protective environments or elements could house organic molecules or the first bacterial life forms on Mars surface. Terrestrial analogs could help us to afford its comprehension. We are reporting here some preliminary studies about endolithic niches inside salt deposits used by phototrophs for taking advantage of sheltering particular light wavelengths. These acidic salts deposits located in Río Tinto shelter life forms which are difficult to localize by eye. Techniques for its localization and study during space missions are needed to develop. Extreme environments are good scenarios where to test and train those techniques and where hypothetical astrobiological space missions could be simulated for increasing possibilities of micro niches identification.

  7. Genome sequence of the moderately thermophilic halophile Flexistipes sinusarabici strain (MAS10T)

    Energy Technology Data Exchange (ETDEWEB)

    Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute; Chertkov, Olga [Los Alamos National Laboratory (LANL); Nolan, Matt [U.S. Department of Energy, Joint Genome Institute; Lucas, Susan [U.S. Department of Energy, Joint Genome Institute; Hammon, Nancy [U.S. Department of Energy, Joint Genome Institute; Deshpande, Shweta [U.S. Department of Energy, Joint Genome Institute; Cheng, Jan-Fang [U.S. Department of Energy, Joint Genome Institute; Tapia, Roxanne [Los Alamos National Laboratory (LANL); Han, Cliff [Los Alamos National Laboratory (LANL); Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Liolios, Konstantinos [U.S. Department of Energy, Joint Genome Institute; Pagani, Ioanna [U.S. Department of Energy, Joint Genome Institute; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Huntemann, Marcel [U.S. Department of Energy, Joint Genome Institute; Mavromatis, K [U.S. Department of Energy, Joint Genome Institute; Mikhailova, Natalia [U.S. Department of Energy, Joint Genome Institute; Pati, Amrita [U.S. Department of Energy, Joint Genome Institute; Chen, Amy [U.S. Department of Energy, Joint Genome Institute; Palaniappan, Krishna [U.S. Department of Energy, Joint Genome Institute; Land, Miriam L [ORNL; Hauser, Loren John [ORNL; Brambilla, Evelyne-Marie [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Rohde, Manfred [HZI - Helmholtz Centre for Infection Research, Braunschweig, Germany; Abt, Birte [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Spring, Stefan [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Goker, Markus [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Bristow, James [U.S. Department of Energy, Joint Genome Institute; Eisen, Jonathan [U.S. Department of Energy, Joint Genome Institute; Markowitz, Victor [U.S. Department of Energy, Joint Genome Institute; Hugenholtz, Philip [U.S. Department of Energy, Joint Genome Institute; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Klenk, Hans-Peter [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute

    2011-01-01

    Flexistipes sinusarabici Fiala et al. 2000 is the type species of the genus Flexistipes in the fami- ly Deferribacteraceae. The species is of interest because of its isolated phylogenetic location in a genomically under-characterized region of the tree of life, and because of its origin from a multiply extreme environment; the Atlantis Deep brines of the Red Sea, where it had to struggle with high temperatures, high salinity, and a high concentrations of heavy metals. This is the fourth completed genome sequence to be published of a type strain of the family Deferribacteraceae. The 2,526,590 bp long genome with its 2,346 protein-coding and 53 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

  8. Ponticoccus marisrubri sp. nov., a moderately halophilic marine bacterium of the family Rhodobacteraceae

    KAUST Repository

    Zhang, Guishan; Haroon, Mohamed; Zhang, Ruifu; Dong, Xiaoyan; Liu, Di; Xiong, Qin; Xun, Weibing; Dong, Xiuzhu; Stingl, Ulrich

    2017-01-01

    .5 %), and its major polar lipids are phosphatidylethanolamine, phosphatidylglycerol, phosphocholine, an unknown aminolipid, an unknown phospholipid and two unknown lipids. The genome draft of strain SJ5A-1T as presented here is 4 562 830 bp in size and the DNA G

  9. Bacillus isabeliae sp. nov., a halophilic bacterium isolated from a sea salt evaporation pond.

    Science.gov (United States)

    Albuquerque, Luciana; Tiago, Igor; Taborda, Marco; Nobre, M Fernanda; Veríssimo, António; da Costa, Milton S

    2008-01-01

    A low-G+C, Gram-positive isolate, designated strain CVS-8(T), was isolated from a sea salt evaporation pond on the Island of Sal in the Cape Verde Archipelago. This organism was found to be a catalase- and oxidase-positive, non-motile, spore-forming, aerobic, curved rod-shaped organism with an optimum growth temperature of about 35-37 degrees C and an optimum pH between 7.5 and 8.0. Optimal growth occurred in media containing 4-6% (w/v) NaCl and no growth occurred in medium without NaCl. The cell-wall peptidoglycan was of the A1gamma type with meso-diaminopimelic acid, the major respiratory quinone was MK-7, the major fatty acids were iso-15:0, 16:0, anteiso-15:0 and iso-16:0 and the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and an unidentified aminoglycophospholipid. The G+C content of the DNA was 37.9 mol%. Phylogenetic analysis of the 16S rRNA gene sequence indicated that strain CVS-8(T) represented a novel species of the genus Bacillus, the highest levels of sequence similarity (mean pairwise similarity values of approximately 97.5 %) being found with respect to the type strains of Bacillus shackletonii and Bacillus acidicola. On the basis of the phylogenetic, physiological and biochemical data, strain CVS-8(T) represents a novel species of the genus Bacillus, for which the name Bacillus isabeliae sp. nov. is proposed. The type strain is CVS-8(T) (=LMG 22838(T)=CIP 108578(T)).

  10. Spiribacter curvatus sp. nov., a moderately halophilic bacterium isolated from a saltern.

    Science.gov (United States)

    León, María José; Rodríguez-Olmos, Angel; Sánchez-Porro, Cristina; López-Pérez, Mario; Rodríguez-Valera, Francisco; Soliveri, Juan; Ventosa, Antonio; Copa-Patiño, José Luis

    2015-12-01

    A novel pink-pigmented bacterial strain, UAH-SP71T, was isolated from a saltern located in Santa Pola, Alicante (Spain) and the complete genome sequence was analysed and compared with that of Spiribacter salinus M19-40T, suggesting that the two strains constituted two separate species, with a 77.3% ANI value. In this paper, strain UAH-SP71T was investigated in a taxonomic study using a polyphasic approach. Strain UAH-SP71T was a Gram-stain-negative, strictly aerobic, non-motile curved rod that grew in media containing 5-20% (w/v) NaCl (optimum 10% NaCl), at 5-40 °C (optimum 37 °C) and at pH 5-10 (optimum pH 8). Phylogenetic analysis based on the comparison of 16S rRNA gene sequences revealed thatstrain UAH-SP71T is a member of the genus Spiribacter, showing a sequence similarity of 96.5% with Spiribacter salinus M19-40T. Other related species are also members of the family Ectothiorhodospiraceae, including Arhodomonas recens RS91T (95.5% 16S rRNA gene sequence similarity), Arhodomonas aquaeolei ATCC 49307T (95.4 %) and Alkalilimnicola ehrlichii MLHE-1T (94.9 %). DNA-DNA hybridization between strain UAH-SP71T and Spiribacter salinus M19-40T was 39 %. The major cellular fatty acids of strain UAH-SP71T were C18 : 1ω6c and/or C18 : 1ω7c, C16 : 0, C16 : 1ω6c and/or C16 : 1ω7c, C10 : 0 3-OH and C12 : 0, a pattern similar to that of Spiribacter salinus M19-40T. Phylogenetic, phenotypic and genotypic differences between strain UAH-SP71T and Spiribacter salinus M19-40T indicate that strainUAH-SP71T represents a novel species of the genus Spiribacter, for which the name Spiribacter curvatus sp. nov. is proposed. The type strain is UAH-SP71T (5CECT8396T5DSM 28542T).

  11. Damage Avoidance and Repair Mechanisms of Extreme Halophiles to Ionizing Radiation

    Science.gov (United States)

    2013-07-01

    thermophilic   bacteria   and   archaea   also...manganese  (Mn)  antioxidants  and  coordinated  by   regulatory   networks.  While   ROS-­‐scavenging   enzymes   were   essential...for   resistance   to   chemical  oxidants,   these   enzymes  were  not  necessary   for  H.   salinarum’s  

  12. Effect of halophilic conditions in stabilisation of RNA structure and function at high temperature under radiations.

    Science.gov (United States)

    Maurel, M.-C.

    We have already shown the structural integrity of tRNA at high temperature - 82C for 30h - in high salt concentrations (Tehei et al, 2002). Stability were also performed by measuring the residual specific tRNA charge capacity after heat treatment for 30 h at 82C. RNA molecules are selected (in vitro selection) at high temperature at high salt concentration. We are undergoing studies of such molecules submitted to several stressful conditions, in particular high radiations. These studies provide support for the importance of salt to protect macromolecules against severe cosmic conditions. These could be useful for searching traces of life in planetary objects and space exploration. References : ElAmri, C., Baron, M-H., Maurel, M.-C. ``Adenine adsorption onto and release from meteorite specimens assessed by Surface Enhanced Raman Spectroscopy ''. Journal of Raman Spectroscopy (2004) in press. Meli, M., Vergne, J. and Maurel, M-C. "In vitro selection of adenine-dependent hairpin ribozymes" J. Biol. Chem., (2003), 278, 11, 9835-9842. ElAmri, C., Baron, M-H., Maurel, M.-C. ``Adenine in mineral samples : development of a methodology based on Surface Enhanced Raman Spectroscopy (SERS) for picomole detections ''. Spectrochimica Acta, A, 59, 2645-2654. Tehei, M., Franzetti, B., Maurel, M-C., Vergne, J., Hountondji, C. , Zaccai, G. ``Salt and the Search for Traces of Life '', Extremophiles, (2002), 6 : 427-430. Meli, M., Vergne, J., Décout, J.L., and Maurel, M-C. ``Adenine-Aptamer Complexes. A bipartite RNA site which binds the adenine nucleic base '', J. Biol. Chem., (2002), 277, 3, 2104-2111.

  13. Threonine deaminase from extremely halophilic bacteria - Cooperative substrate kinetics and salt dependence.

    Science.gov (United States)

    Lieberman, M. M.; Lanyi, J. K.

    1972-01-01

    The effect of salt on the activity, stability, and allosteric properties of catabolic threonine deaminase from Halobacterium cutirubrum was studied. The enzyme exhibits sigmoidal kinetics with the substrate, threonine. The Hill slope is 1.55 at pH 10. The enzyme is activated by ADP at low substrate concentrations. In the presence of this effector, sigmoidal kinetics are no longer observed. At pH 10, in the absence of ADP, enzyme activity increases with increasing NaCl concentration from 0 to 4 M.

  14. Ornithinibacillus salinisoli sp. nov., a moderately halophilic bacterium isolated from a saline-alkali soil.

    Science.gov (United States)

    Gan, Longzhan; Zhang, Heming; Long, Xiufeng; Tian, Jiewei; Wang, Zhikuan; Zhang, Yuqin; Dai, Yumei; Tian, Yongqiang

    2018-03-01

    A taxonomic study was performed on strain LCB256 T , which was isolated from a saline-alkali soil sample taken from northwestern China. Cells of strain LCB256 T were Gram-stain-positive, aerobic, rod-shaped and grew at 3-17 % (w/v) NaCl (optimum 10-15 %), 10-52 °C (optimum 25-30 °C) and pH 7.0-9.0 (optimum 8.0). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain LCB256 T was most closely related to the two genera of Ornithinibacillus and Oceanobacillus, showing highest sequence similarity to Oceanobacillus limi KCTC 13823 T (97.8 %) and Ornithinibacillus bavariensis WSBC 24001 T (97.2 %). The peptidoglycan amino acid type was found to be A4β and the major respiratory quinone was determined to be MK-7. The polar lipid profile of strain LCB256 T contained diphosphatidylglycerol, phosphatidylglycerol, one unidentified phospholipid and two unidentified aminolipids. The dominant cellular fatty acids were anteiso-C15 : 0 and iso-C15 : 0. The G+C content of genomic DNA was 39.3 mol%. DNA-DNA relatedness values between strain LCB256 T and Ornithinibacillus halophilus KCTC 13822 T and Oceanobacillus limi KCTC 13823 T were 46.2 and 34.8 %, respectively. Based on this polyphasic taxonomic study, a novel species of the genus Ornithinibacillus, Ornithinibacillussalinisoli sp. nov. is proposed. The type strain is LCB256 T (=CGMCC 1.15809 T =KCTC 33862 T ).

  15. Ponticoccus marisrubri sp. nov., a moderately halophilic marine bacterium of the family Rhodobacteraceae

    KAUST Repository

    Zhang, Guishan

    2017-10-06

    Strain SJ5A-1T, a Gram-stain-negative, coccus-shaped, non-motile, aerobic bacterium, was isolated from the brine-seawater interface of the Erba Deep in the Red Sea, Saudi Arabia. The colonies of strain SJ5A-1T have a beige to pale-brown pigmentation, are approximately 0.5-0.7 µm in diameter, and are catalase and oxidase positive. Growth occurred optimally at 30-33 °C, pH 7.0-7.5, and in the presence of 9.0-12.0 % NaCl (w/v). Phylogenetic analysis of the 16S rRNA gene indicates that strain SJ5A-1T is a member of the genus Ponticoccus within the family Rhodobacteraceae. Ponticoccus litoralis DSM 18986T is the most closely related described species based on 16S rRNA gene sequence identity (96.7 %). The DNA-DNA hybridization value between strain SJ5A-1T and P. litoralis DSM 18986T was 36.7 %. The major respiratory quinone of strain SJ5A-1T is Q-10; it predominantly uses the fatty acids C18 : 1 (54.2 %), C18 : 0 (11.2 %), C16 : 0 (8.6 %), 11-methyl C18 : 1ω7c (7.7 %), C19 : 0cyclo ω8c (3.3 %), and C12 : 1 3-OH (3.5 %), and its major polar lipids are phosphatidylethanolamine, phosphatidylglycerol, phosphocholine, an unknown aminolipid, an unknown phospholipid and two unknown lipids. The genome draft of strain SJ5A-1T as presented here is 4 562 830 bp in size and the DNA G+C content is 68.0 mol %. Based on phenotypic, phylogenetic and genotypic data, strain SJ5A-1T represents a novel species in the genus Ponticoccus, for which we propose the name Ponticoccus marisrubri sp. nov. The type strain of P. marisrubri is SJ5A-1T (=JCM 19520T=ACCC19863T).

  16. Detection of pigments of halophilic endoliths from gypsum: Raman portable instrument and European Space Agency's prototype analysis

    Science.gov (United States)

    Culka, Adam; Osterrothová, Kateřina; Hutchinson, Ian; Ingley, Richard; McHugh, Melissa; Oren, Aharon; Edwards, Howell G. M.; Jehlička, Jan

    2014-01-01

    A prototype instrument, under development at the University of Leicester, for the future European Space Agency (ESA) ExoMars mission, was used for the analysis of microbial pigments within a stratified gypsum crust from a hypersaline saltern evaporation pond at Eilat (Israel). Additionally, the same samples were analysed using a miniaturized Raman spectrometer, featuring the same 532 nm excitation. The differences in the position of the specific bands, attributed to carotenoid pigments from different coloured layers, were minor when analysed by the ESA prototype instrument; therefore, making it difficult to distinguish among the different pigments. The portable Delta Nu Advantage instrument allowed for the discrimination of microbial carotenoids from the orange/green and purple layers. The purpose of this study was to complement previous laboratory results with new data and experience with portable or handheld Raman systems, even with a dedicated prototype Raman system for the exploration of Mars. The latter is equipped with an excitation wavelength falling within the carotenoid polyene resonance region. The ESA prototype Raman instrument detected the carotenoid pigments (biomarkers) with ease, although further detailed distinctions among them were not achieved. PMID:25368354

  17. Production and Characterization of Alkaline Protease from a High Yielding and Moderately Halophilic Strain of SD11 Marine Bacteria

    Directory of Open Access Journals (Sweden)

    Hongxia Cui

    2015-01-01

    Full Text Available A marine bacterium SD11, which was isolated from sea muds (Geziwo Qinhuangdao Sea area, China, was used to produce thermostable alkaline serine nonmetal protease in the skim milk agar plate medium with 10% NaCl. The optimal temperature about the manufacture of the extracellular protease was ~60°C. The crude enzyme was stable at 20–50°C. The activity was retained to 60% and 45% after heating for 1 h at 60 and 70°C, respectively. The protease was highly active in a wide pH scope (8.0–10.0 and maximum protease activity exhibited at pH 10.0. The activity was restrained by phenylmethylsulfonyl fluoride (PMSF but mildly increased (~107% in the presence of ethylenediaminetetraacetic acid (EDTA, indicating that the production contains serine-protease(s and nonmetal protease(s. Moreover, the crude alkaline protease was active with the 5 mM Ca2+, Mn2+, Zn2+, Cu2+, Na+, and K+ that existed separately. In addition, the protease showed superduper stability when exposed to an anionic surfactant (5 mM SDS, an oxidizing agent (1% H2O2, and several organic solvents (methanol, isopropanol, and acetone. These results suggest that the marine bacterium SD11 is significant in the industry from the prospects of its ability to produce thermally stable alkaline protease.

  18. The presence of PHB granules in cytoplasm protects non-halophilic bacterial cells against the harmful impact of hypertonic environments

    Czech Academy of Sciences Publication Activity Database

    Obruča, S.; Sedláček, P.; Mravec, F.; Krzyžánek, Vladislav; Nebesářová, Jana; Samek, Ota; Kučera, D.; Benešová, P.; Hrubanová, Kamila; Milerová, M.; Márová, I.

    2017-01-01

    Roč. 39, OCT (2017), s. 68-80 ISSN 1871-6784 R&D Projects: GA ČR(CZ) GA15-20645S Institutional support: RVO:68081731 ; RVO:60077344 Keywords : Poly(3-hydroxybutyrate) * PHB * cupriavidus necator * hyperosmotic conditions * plasmolysis * stress conditions Subject RIV: BH - Optics, Masers, Lasers; CE - Biochemistry (BC-A) OBOR OECD: Electrical and electronic engineering; Electrical and electronic engineering (BC-A) Impact factor: 3.813, year: 2016

  19. Desulfohalophilus alkaliarsenatis gen. nov., sp. nov., an extremely halophilic sulfate- and arsenate-respiring bacterium from Searles Lake, California

    Science.gov (United States)

    Blum, Jodi Switzer; Kulp, Thomas R.; Han, Sukkyun; Lanoil, Brian; Saltikov, Chad W.; Stolz, John F.; Miller, Laurence G.; Oremland, Ronald S.

    2012-01-01

    A haloalkaliphilic sulfate-respiring bacterium, strain SLSR-1, was isolated from a lactate-fed stable enrichment culture originally obtained from the extreme environment of Searles Lake, California. The isolate proved capable of growth via sulfate-reduction over a broad range of salinities (125–330 g/L), although growth was slowest at salt-saturation. Strain SLSR-1 was also capable of growth via dissimilatory arsenate-reduction and displayed an even broader range of salinity tolerance (50–330 g/L) when grown under these conditions. Strain SLSR-1 could also grow via dissimilatory nitrate reduction to ammonia. Growth experiments in the presence of high borate concentrations indicated a greater sensitivity of sulfate-reduction than arsenate-respiration to this naturally abundant anion in Searles Lake. Strain SLSR-1 contained genes involved in both sulfate-reduction (dsrAB) and arsenate respiration (arrA). Amplicons of 16S rRNA gene sequences obtained from DNA extracted from Searles Lake sediment revealed the presence of close relatives of strain SLSR-1 as part of the flora of this ecosystem despite the fact that sulfate-reduction activity could not be detected in situ. We conclude that strain SLSR-1 can only achieve growth via arsenate-reduction under the current chemical conditions prevalent at Searles Lake. Strain SLSR-1 is a deltaproteobacterium in the family Desulfohalobiacea of anaerobic, haloalkaliphilic bacteria, for which we propose the name Desulfohalophilus alkaliarsenatis gen. nov., sp. nov.

  20. Can the halophilic ciliate Fabrea salina be used as a bio-control of microalgae blooms in solar salterns?

    Science.gov (United States)

    Hong, Hyun Pyo; Choi, Joong Ki

    2015-09-01

    The microlage Dunaliella salina, a major producer in salterns, is a serious problem for salt production. In this study we tried to assess if Fabrea salina can control D. salina. By parameterising numerical and functional response (growth and grazing vs prey abundance, respectively) at 90 psu and 30°C, where the ciliate is abundant and grows well, we developed a predator-prey model. The model is used to explore how change in microalga growth rate affect the dynamics, and the functional response is used in combination with field data to assess the potential impact of F. salina on D. salina. Over the 20 d simulation the ciliate controlled the prey population under all prey growth rates; although once D. salina were exhausted below the threshold level, F. salina died due to starvation, allowing the alga to increase in abundance, resulting in one or two predatorprey cycle, depending on prey growth rate. In general, the model predicted trends observed by others in the field, suggesting that it provided a good prediction of what may occur under the conditions we examined. Likewise we show that the ciliate can have a high impact on microalgal populations in the field. Finally, a literature review indicated that F. salina could be a good competitor with other protozoa and metazoan in salterns, depending on salinity and temperature, which requires further study and attention. In summary, we encourage continued studies on this unique ciliate on solar salterns and suggest that it may be useful in the bio-control of micoalgae.

  1. Isolation of a halophilic bacterium, Bacillus sp. strain NY-6 for organic contaminants removal in saline wastewater on ship

    Science.gov (United States)

    Gao, Jie; Yu, Zhenjiang; Zhang, Xiaohui; Zhao, Dan; Zhao, Fangbo

    2013-06-01

    The objective of this research was to examine if certain strains of Bacillus bacteria, could survive in dry powder products and if so, could the bacteria degrade organic contaminants in saline wastewater on a ship. As part of the study, we isolated 7 domesticated strains named NY1, NY2,..., and NY7, the strain NY6 showed to have the best performance for organic matter degradation and could survive in dry powder more than 3 months. NY6 was identified as Bacillus aerius, based on the morphological and physic-chemical properties. Its optimal growth conditions were as follows: salinity was 2%; temperature was 37°C; pH was in 6.5-7.0; best ratio of C: N: P was 100:5:1. The capability of its dry powder for Chemical Oxygen Demand (COD) removal was 800mg COD/g in synthesized marine wastewater with 2% salinity. The spores in the dry powder were 1.972×108 g -1.

  2. Gammasphaerolipovirus, a newly proposed bacteriophage genus, unifies viruses of halophilic archaea and thermophilic bacteria within the novel family Sphaerolipoviridae.

    Science.gov (United States)

    Pawlowski, Alice; Rissanen, Ilona; Bamford, Jaana K H; Krupovic, Mart; Jalasvuori, Matti

    2014-06-01

    A new family of viruses named Sphaerolipoviridae has been proposed recently. It comprises icosahedral, tailless haloarchaeal viruses with an internal lipid membrane located between the protein capsid and the dsDNA genome. The proposed family Sphaerolipoviridae was divided into two genera: Alphasphaerolipovirus, including Haloarcula hispanica viruses SH1, PH1 and HHIV-2, and Betasphaerolipovirus, including Natrinema virus SNJ1. Here, we propose to expand the family Sphaerolipoviridae to include a group of bacteriophages infecting extreme thermophilic Thermus thermophilus and sharing a number of structural and genomic properties with archaeal sphaerolipoviruses. This new group comprises two members, lytic phage P23-77 and temperate phage IN93, as well as putative members P23-72 and P23-65H. In addition, several related proviruses have been discovered as integrated elements in bacterial genomes of the families Thermus and Meiothermus. Morphology of the virus particles and the overall capsid architecture of these bacteriophages resembles that of archaeal members of the Sphaerolipoviridae, including an unusual capsid arrangement in a T = 28 dextro lattice. Alpha- and betasphaerolipoviruses share with P23-77-like bacteriophages a conserved block of core genes that encode a putative genome-packaging ATPase and the two major capsid proteins (MCPs). The recently determined X-ray structure of the small and large MCPs of P23-77 revealed a single beta-barrel (jelly-roll) fold that is superimposable with the cryo-EM density maps of the SH1 capsomers. Given the common features of these viruses, we propose to include the so far unclassified P23-77-like bacteriophages into a new genus, "Gammasphaerolipovirus", within the family Sphaerolipoviridae.

  3. Noncontiguous finished genome sequence and description of Virgibacillus massiliensis sp. nov., a moderately halophilic bacterium isolated from human gut

    Directory of Open Access Journals (Sweden)

    S. Khelaifia

    2015-11-01

    Full Text Available Strain Vm-5T was isolated from the stool specimen of a 10-year-old Amazonian boy. This bacterium is a Gram-positive, strictly aerobic rod, motile by a polar flagellum. Here we describe its phenotypic characteristics and complete genome sequence. The 4 353 177 bp long genome exhibits a G + C content of 36.87% and contains 4394 protein-coding and 125 predicted RNA genes. Phylogenetically and genetically, strain Vm-c is a member of the genus Virgibacillus but is distinct enough to be classified as a new species. We propose the creation of V. massiliensis sp. nov., whose type strain is strain Vm-5T (CSUR P971 = DSM 28587.

  4. Draft Genome Sequence of Halostagnicola sp. A56, an Extremely Halophilic Archaeon Isolated from the Andaman Islands

    Science.gov (United States)

    Kanekar, Sagar P.; Saxena, Neha; Pore, Soham D.; Arora, Preeti; Kanekar, P. P.

    2015-01-01

    The first draft genome of Halostagnicola sp. A56, isolated from the Andaman Islands is reported here. The A56 genome comprises 3,178,490 bp in 26 contigs with a G+C content of 60.8%. The genome annotation revealed that A56 could have potential applications for the production of polyhydroxyalkanoate or bioplastics. PMID:26564049

  5. [Different NaCl-dependence of the circadian CO2-gas-exchange of some halophil growing coastal plants].

    Science.gov (United States)

    Treichel, Siegfried; Bauer, Peter

    1974-03-01

    CO 2 -exchange, diurnal changes in malate- and ion concentrations of the halophytes Carpobrotus edulis, Crithmum maritimum, Mesembryanthemum nodiflorum, Salicornia fruticosa, Suaeda maritima, and Trifolium fragiferum were investigated after culture at different NaCl concentrations. In Carp. edulis and Mes. nodiflorum the diurnal rhythm of CO 2 -exchange is in accordance with that of crassulacean acid metabolism (CAM), in Sal. fruticosa, Crithm. maritimum, Suaeda maritima, and Trif. fragiferum with that of Benson-Calvin metabolism (C 3 ). Malate concentration and CO 2 uptake in the sap latter group are not influenced. On the other hand, Carp. edulis and Mes. nodiflorum show an accumulation of malate during the night, which can be interpreted as a further indication of CAM.The two species most resistant to NaCl, Carp. edulis and Sal. fruticosa, greatly differ very much in their NaCl content. NaCl concentration in Salicornia is four times higher than in Carpobrotus.The different metabolic properties studied might be of ecological importance for the plants in their natural habitats. The effect of NaCl on metabolic processes is discussed.

  6. Detection of pigments of halophilic endoliths from gypsum: Raman portable instrument and European Space Agency's prototype analysis.

    Science.gov (United States)

    Culka, Adam; Osterrothová, Kateřina; Hutchinson, Ian; Ingley, Richard; McHugh, Melissa; Oren, Aharon; Edwards, Howell G M; Jehlička, Jan

    2014-12-13

    A prototype instrument, under development at the University of Leicester, for the future European Space Agency (ESA) ExoMars mission, was used for the analysis of microbial pigments within a stratified gypsum crust from a hypersaline saltern evaporation pond at Eilat (Israel). Additionally, the same samples were analysed using a miniaturized Raman spectrometer, featuring the same 532 nm excitation. The differences in the position of the specific bands, attributed to carotenoid pigments from different coloured layers, were minor when analysed by the ESA prototype instrument; therefore, making it difficult to distinguish among the different pigments. The portable Delta Nu Advantage instrument allowed for the discrimination of microbial carotenoids from the orange/green and purple layers. The purpose of this study was to complement previous laboratory results with new data and experience with portable or handheld Raman systems, even with a dedicated prototype Raman system for the exploration of Mars. The latter is equipped with an excitation wavelength falling within the carotenoid polyene resonance region. The ESA prototype Raman instrument detected the carotenoid pigments (biomarkers) with ease, although further detailed distinctions among them were not achieved. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  7. Bioactivity of a Novel Glycolipid Produced by a Halophilic Buttiauxella sp. and Improving Submerged Fermentation Using a Response Surface Method

    Directory of Open Access Journals (Sweden)

    Abdolrazagh Marzban

    2016-09-01

    Full Text Available An antimicrobial glycolipid biosurfactant (GBS, extracted and identified from a marine bacterium, was studied to inhibit pathogenic microorganisms. Production of the GBS was optimized using a statistical method, a response surface method (RSM with a central composite design (CCD for obtaining maximum yields on a cost-effective substrate, molasses. The GBS-producing bacterium was identified as Buttiauxella Species in terms of biochemical and molecular characteristics. This compound showed a desirable antimicrobial activity against some pathogens such as E. coli, Bacillus subtilis, Bacillus cereus, Candida albicans, Aspergilus niger, Salmonella enterica. The rheological studies described the stability of the GBS at high values in a range of pH (7–8, temperature (20–60 and salinity (0%–3%. The statistical optimization of GBS fermentation was found to be pH 7, temperature 33 °C, Peptone 1%, NaCl 1% and molasses 1%. The potency of the GBS as an effective antimicrobial agent provides evidence for its use against food and human pathogens. Moreover, favorable production of the GBS in the presence of molasses as a cheap substrate and the feasibility of pilot scale fermentation using an RSM method could expand its uses in food, pharmaceutical products and oil industries.

  8. The presence of PHB granules in cytoplasm protects non-halophilic bacterial cells against the harmful impact of hypertonic environments.

    Science.gov (United States)

    Obruca, Stanislav; Sedlacek, Petr; Mravec, Filip; Krzyzanek, Vladislav; Nebesarova, Jana; Samek, Ota; Kucera, Dan; Benesova, Pavla; Hrubanova, Kamila; Milerova, Miluse; Marova, Ivana

    2017-10-25

    Numerous prokaryotes accumulate polyhydroxybutyrate (PHB) intracellularly as a storage material. It has also been proposed that PHB accumulation improves bacterial stress resistance. Cupriavidus necator and its PHB non-accumulating mutant were employed to investigate the protective role of PHB under hypertonic conditions. The presence of PHB granules enhanced survival of the bacteria after exposure to hypertonic conditions. Surprisingly, when coping with such conditions, the bacteria did not utilize PHB to harvest carbon or energy, suggesting that, in the osmotic upshock of C. necator, the protective mechanism of PHB granules is not associated with their hydrolysis. The presence of PHB granules influenced the overall properties of the cells, since challenged PHB-free cells underwent massive plasmolysis accompanied by damage to the cell membrane and the leakage of cytoplasm content, while no such effects were observed in PHB containing bacteria. Moreover, PHB granules demonstrated "liquid-like" properties indicating that they can partially repair and stabilize cell membranes by plugging small gaps formed during plasmolysis. In addition, the level of dehydration and changes in intracellular pH in osmotically challenged cells were less pronounced for PHB-containing cultures, demonstrating the important role of PHB for bacterial survival under hyperosmotic conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Encapsulation of carotenoids extracted from halophilic Archaea in oil-in-water (O/W) micro- and nano-emulsions.

    Science.gov (United States)

    Chaari, Marwa; Theochari, Ioanna; Papadimitriou, Vassiliki; Xenakis, Aristotelis; Ammar, Emna

    2018-01-01

    Carotenoids extracted from halophilc Archaea have potential health benefits. Their poor water-solubility and low bioavailability is a challenge to their incorporation into foods. The aim of this work was the carotenoids encapsulation into two oil-in-water (O/W) dispersions, to increase their use as functional food applications. A nanoemulsion produced by high pressure homogenization and a spontaneously formed microemulsion were conceived. The limonene was the dispersed oil phase, and mixtures of Triton X-100/Tween-80 (3:1) as emulsifiers and of water/glycerol (2:1) as the continuous aqueous phase. The microemulsion monophasic area was determined through the pseudo-ternary phase diagram. Dynamic Light Scattering was used for the structural characterization of the nano- and micro-emulsions in the presence of the carotenoids. Moreover, the radical scavenging activity of the encapsulated carotenoids was examined by Electron Paramagnetic Resonance spectroscopy. The results confirmed the delivery systems design effectiveness to encapsulate and stabilize the carotenoids for food applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Evolutionary consequences of polyploidy in prokaryotes and the origin of mitosis and meiosis.

    Science.gov (United States)

    Markov, Alexander V; Kaznacheev, Ilya S

    2016-06-08

    The origin of eukaryote-specific traits such as mitosis and sexual reproduction remains disputable. There is growing evidence that both mitosis and eukaryotic sex (i.e., the alternation of syngamy and meiosis) may have already existed in the basal eukaryotes. The mating system of the halophilic archaeon Haloferax volcanii probably represents an intermediate stage between typical prokaryotic and eukaryotic sex. H. volcanii is highly polyploid, as well as many other Archaea. Here, we use computer simulation to explore genetic and evolutionary outcomes of polyploidy in amitotic prokaryotes and its possible role in the origin of mitosis, meiosis and eukaryotic sex. Modeling suggests that polyploidy can confer strong short-term evolutionary advantage to amitotic prokaryotes. However, it also promotes the accumulation of recessive deleterious mutations and the risk of extinction in the long term, especially in highly mutagenic environment. There are several possible strategies that amitotic polyploids can use in order to reduce the genetic costs of polyploidy while retaining its benefits. Interestingly, most of these strategies resemble different components or aspects of eukaryotic sex. They include asexual ploidy cycles, equalization of genome copies by gene conversion, high-frequency lateral gene transfer between relatives, chromosome exchange coupled with homologous recombination, and the evolution of more accurate chromosome distribution during cell division (mitosis). Acquisition of mitosis by an amitotic polyploid results in chromosome diversification and specialization. Ultimately, it transforms a polyploid cell into a functionally monoploid one with multiple unique, highly redundant chromosomes. Specialization of chromosomes makes the previously evolved modes of promiscuous chromosome shuffling deleterious. This can result in selective pressure to develop accurate mechanisms of homolog pairing, and, ultimately, meiosis. Emergence of mitosis and the first

  11. Life at extreme conditions: Neutron scattering studies of biological

    Indian Academy of Sciences (India)

    Extremophile bacteria; molecular adaptation; halophile; water dynamics; protein dynamics. ... Results of neutron scattering measurements on the dynamics of proteins ... The experiments were performed on a halophilic protein, and membrane ...

  12. Marinimicrobium haloxylanilyticum sp. nov., a new moderately halophilic, polysaccharide-degrading bacterium isolated from Great Salt Lake, Utah

    DEFF Research Database (Denmark)

    Fogh Møller, Mette; Kjeldsen, Kasper Urup; Ingvorsen, Kjeld

    2010-01-01

    cellulose and galactomannan. The strain grew at salinities ranging from 2 to 22% NaCl (w/v). Optimal growth occurred in the presence of 7–11% NaCl (w/v) at a temperature of 35°C and a pH of 6.7–8.2. Major whole-cell fatty acids were C16:0 (30.5%), C18:0 (14.8%), C18:1ω7c (13.1%) and C12:0 (7.8%). The G...

  13. Screening a novel Na+/H+ antiporter gene from a metagenomic library of halophiles colonizing in the Dagong Ancient Brine Well in China.

    Science.gov (United States)

    Xiang, Wenliang; Zhang, Jie; Li, Lin; Liang, Huazhong; Luo, Hai; Zhao, Jian; Yang, Zhirong; Sun, Qun

    2010-05-01

    Metagenomic DNA libraries constructed from the Dagong Ancient Brine Well were screened for genes with Na(+)/H(+) antiporter activity on the antiporter-deficient Escherichia coli KNabc strain. One clone with a stable Na(+)-resistant phenotype was obtained and its Na(+)/H(+) antiporter gene was sequenced and designated as m-nha. The deduced amino acid sequence of M-Nha protein consists of 523 residues with a calculated molecular weight of 58 147 Da and a pI of 5.50, which is homologous with NhaH from Halobacillus dabanensis D-8(T) (92%) and Halobacillus aidingensis AD-6(T) (86%), and with Nhe2 from Bacillus sp. NRRL B-14911 (64%). It had a hydropathy profile with 10 putative transmembrane domains and a long carboxyl terminal hydrophilic tail of 140 amino acid residues, similar to Nhap from Synechocystis sp. and Aphanothece halophytica, as well as NhaG from Bacillus subtilis. The m-nha gene in the antiporter-negative mutant E. coli KNabc conferred resistance to Na(+) and the ability to grow under alkaline conditions. The difference in amino acid sequence and the putative secondary structure suggested that the m-nha isolated from the Dagong Ancient Brine Well in this study was a novel Na(+)/H(+) antiporter gene.

  14. Complete genome sequence of Acidihalobacter prosperus strain F5, an extremely acidophilic, iron- and sulfur-oxidizing halophile with potential industrial applicability in saline water bioleaching of chalcopyrite.

    Science.gov (United States)

    Khaleque, Himel N; Corbett, Melissa K; Ramsay, Joshua P; Kaksonen, Anna H; Boxall, Naomi J; Watkin, Elizabeth L J

    2017-11-20

    Successful process development for the bioleaching of mineral ores, particularly the refractory copper sulfide ore chalcopyrite, remains a challenge in regions where freshwater is scarce and source water contains high concentrations of chloride ion. In this study, a pure isolate of Acidihalobacter prosperus strain F5 was characterized for its ability to leach base metals from sulfide ores (pyrite, chalcopyrite and pentlandite) at increasing chloride ion concentrations. F5 successfully released base metals from ores including pyrite and pentlandite at up to 30gL -1 chloride ion and chalcopyrite up to 18gL -1 chloride ion. In order to understand the genetic mechanisms of tolerance to high acid, saline and heavy metal stress the genome of F5 was sequenced and analysed. As well as being the first strain of Ac. prosperus to be isolated from Australia it is also the first complete genome of the Ac. prosperus species to be sequenced. The F5 genome contains genes involved in the biosynthesis of compatible solutes and genes encoding monovalent cation/proton antiporters and heavy metal transporters which could explain its abilities to tolerate high salinity, acidity and heavy metal stress. Genome analysis also confirmed the presence of genes involved in copper tolerance. The study demonstrates the potential biotechnological applicability of Ac. prosperus strain F5 for saline water bioleaching of mineral ores. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Salininema proteolyticum gen. nov., sp. nov., a halophilic rare actinomycete isolated from wetland soil, and emended description of the family Glycomycetaceae.

    Science.gov (United States)

    Nikou, Mahdi Moshtaghi; Ramezani, Mohaddaseh; Amoozegar, Mohammad Ali; Rasouli, Mehrnoush; Fazeli, Seyed Abolhassan Shahzadeh; Schumann, Peter; de la Haba, Rafael R; Ventosa, Antonio

    2015-10-01

    A Gram-stain-positive actinobacterial strain, Miq-4T, was isolated from soil around Meighan wetland in the centre of Iran. Strain Miq-4T was strictly aerobic, catalase- and oxidase-positive. The isolate grew in the presence of 3–15 % (w/v) NaCl, at 20–40 °C and pH 6.0–11.0. The optimum NaCl, temperature and pH for growth were 7.0 %, 30 °C and 7.0–8.5, respectively. The cell wall of strain Miq-4T contained meso-diaminopimelic acid as the diamino acid and glucose and ribose as the whole-cell sugars. The polar lipid pattern consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannoside. Strain Miq-4T synthesized cellular fatty acids of anteiso- and iso-branched types, including anteiso-C17 : 0, anteiso- C15 : 0 and iso-C16 : 0, and the major respiratory quinone was MK-9(H4). The G+C content of the genomic DNA was 68.2 mol%. Phylogenetic analysis based on 16S rRNA gene sequences and characteristic patterns of 16S rRNA gene signature nucleotides revealed that strain Miq-4T belongs to the family Glycomycetaceae and showed the closest phylogenetic similarity with Haloglycomyces albus YIM 92370T (94.1 % 16S rRNA gene sequence similarity). On the basis of phylogenetic analysis and phenotypic and chemotaxonomic characteristics, strain Miq-4T represents a novel species of a new genus in the family Glycomycetaceae, for which the name Salininema proteoliyticum gen. nov., sp. nov. is proposed. The type strain of the type species is Miq-4T ( = IBRC-M 10908T = LMG 28391T). An emended description of the family Glycomycetaceae is also proposed in order to include features of the new genus.

  16. Methylophaga natronica sp. nov., a new alkaliphilic and moderately halophilic, restricted-facultatively methylotrophic bacterium from soda lake of the Southern Transbaikal region.

    Science.gov (United States)

    Doronina, Nina; Darmaeva, Tsyregma; Trotsenko, Yuri

    2003-09-01

    A new, moderately haloalkaliphilic and restricted-facultatively methylotrophic bacterium (strain Bur2T) with the ribulose monophosphate pathway of carbon assimilation is described. The isolate, which utilizes methanol, methylamine and fructose, is an aerobic, Gram-negative, asporogenous, motile short rod multiplying by binary fission. It is auxotrophic for vitamin B12, and requires NaHCO3 or NaCl for growth in alkaline medium. Cellular fatty acids profile consists primarily of straight-chain saturated C16:0, unsaturated C16:1 and C18:1 acids. The major ubiquinone is Q-8. The dominant phospholipids are phosphatidylethanolamine and phosphatidylglycerol. Diphosphatidylglycerol is also present. Optimal growth conditions are 25-29 degrees C, pH 8.5-9.0 and 2-3% (w/v) NaCl. Cells accumulate ectoine and glutamate as the main osmoprotectants. The G + C content of the DNA is 45.0 mol%. Based on 16S rDNA sequence analysis and DNA-DNA relatedness (25-35%) with type strains of marine and soda lake methylobacteria belonging to the genus Methylophaga, the novel isolate was classified as a new species of this genus and named Methylophaga natronica (VKM B-2288T).

  17. Marinimicrobium haloxylanilyticum sp. nov., a new moderately halophilic, polysaccharide-degrading bacterium isolated from Great Salt Lake, Utah

    DEFF Research Database (Denmark)

    Fogh Møller, Mette; Kjeldsen, Kasper Urup; Ingvorsen, Kjeld

    2010-01-01

    cellulose and galactomannan. The strain grew at salinities ranging from 2 to 22% NaCl (w/v). Optimal growth occurred in the presence of 7–11% NaCl (w/v) at a temperature of 35°C and a pH of 6.7–8.2. Major whole-cell fatty acids were C16:0 (30.5%), C18:0 (14.8%), C18:1ω7c (13.1%) and C12:0 (7.8%). The G...... species of the genus Marinimicrobium for which the name Marinimicrobium haloxylanilyticum is proposed. The type strain is SX15T (= DSM 23100T = CCUG 59572T)....

  18. Effects of carbon sources on the enrichment of halophilic polyhydroxyalkanoate-storing mixed microbial culture in an aerobic dynamic feeding process

    Science.gov (United States)

    Cui, You-Wei; Zhang, Hong-Yu; Lu, Peng-Fei; Peng, Yong-Zhen

    2016-08-01

    Microbial polyhydroxyalkanoate (PHA) production serves as a substitute for petroleum-based plastics. Enriching mixed microbial cultures (MMCs) with the capacity to store PHA is a key precursor for low-cost PHA production. This study investigated the impact of carbon types on enrichment outcomes. Three MMCs were separately fed by acetate sodium, glucose, and starch as an enriching carbon source, and were exposed to long-term aerobic dynamic feeding (ADF) periods. The PHA production capacity, kinetics and stoichiometry of the enrichments, the PHA composition, and the microbial diversity and community composition were explored to determine carbon and enrichment correlations. After 350-cycle enriching periods under feast-famine (F-F) regimes, the MMCs enriched by acetate sodium and glucose contained a maximum PHA content of 64.7% and 60.5% cell dry weight (CDW). The starch-enriched MMC only had 27.3% CDW of PHA. High-throughput sequencing revealed that non-PHA bacteria survived alongside PHA storing bacteria, even under severe F-F selective pressure. Genus of Pseudomonas and Stappia were the possible PHA accumulating bacteria in acetate-enriched MMC. Genus of Oceanicella, Piscicoccus and Vibrio were found as PHA accumulating bacteria in glucose-enriched MMC. Vibrio genus was the only PHA accumulating bacteria in starch-enriched MMC. The community diversity and composition were regulated by the substrate types.

  19. Changes in growth, carbon and nitrogen enzyme activity and mRNA accumulation in the halophilic microalga Dunaliella viridis in response to NaCl stress

    Science.gov (United States)

    Wang, Dongmei; Wang, Weiwei; Xu, Nianjun; Sun, Xue

    2016-12-01

    Many species of microalga Dunaliella exhibit a remarkable tolerance to salinity and are therefore ideal for probing the effects of salinity. In this work, we assessed the effects of NaCl stress on the growth, activity and mRNA level of carbon and nitrogen metabolism enzymes of D. viridis. The alga could grow over a salinity range of 0.44 mol L-1 to 3.00 mol L-1 NaCl, but the most rapid growth was observed at 1.00 mol L-1 NaCl, followed by 2.00 mol L-1 NaCl. Paralleling these growth patterns, the highest initial and total Rubisco activities were detected in the presence of 1.00 mol L-1 NaCl, decreasing to 37.33% and 26.39% of those values, respectively, in the presence of 3.00 mol L-1 NaCl, respectively. However, the highest extracellular carbonic anhydrase (CA) activity was measured in the presence of 2.00 mol L-1 NaCl, followed by 1.00 mol L-1 NaCl. Different from the two carbon enzymes, nitrate reductase (NR) activity showed a slight change under different NaCl concentrations. At the transcriptional level, the mRNAs of Rubisco large subunit ( rbcL), and small subunit ( rbcS), attained their highest abundances in the presence of 1.00 and 2.00 mol L-1 NaCl, respectively. The CA mRNA accumulation was induced from 0.44 mol L-1 to 3.00 mol L-1 NaCl, but the NR mRNA showed the decreasing tendency with the increasing salinity. In conclusion, the growth and carbon fixation enzyme of Rubisco displayed similar tendency in response to NaCl stress, CA was proved be salt-inducible within a certain salinity range and NR showed the least effect by NaCl in D. viridis.

  20. Complete genome sequence of the halophilic bacterium Spirochaeta africana type strain (Z-7692T) from the alkaline Lake Magadi in the East African Rift

    Energy Technology Data Exchange (ETDEWEB)

    Liolios, Konstantinos [U.S. Department of Energy, Joint Genome Institute; Abt, Birte [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Scheuner, Carmen [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Teshima, Hazuki [Los Alamos National Laboratory (LANL); Held, Brittany [Los Alamos National Laboratory (LANL); Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute; Nolan, Matt [U.S. Department of Energy, Joint Genome Institute; Lucas, Susan [U.S. Department of Energy, Joint Genome Institute; Deshpande, Shweta [U.S. Department of Energy, Joint Genome Institute; Cheng, Jan-Fang [U.S. Department of Energy, Joint Genome Institute; Tapia, Roxanne [Los Alamos National Laboratory (LANL); Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Pagani, Ioanna [U.S. Department of Energy, Joint Genome Institute; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Mavromatis, K [U.S. Department of Energy, Joint Genome Institute; Mikhailova, Natalia [U.S. Department of Energy, Joint Genome Institute; Huntemann, Marcel [U.S. Department of Energy, Joint Genome Institute; Pati, Amrita [U.S. Department of Energy, Joint Genome Institute; Chen, Amy [U.S. Department of Energy, Joint Genome Institute; Palaniappan, Krishna [U.S. Department of Energy, Joint Genome Institute; Land, Miriam L [ORNL; Rohde, Manfred [HZI - Helmholtz Centre for Infection Research, Braunschweig, Germany; Tindall, Brian [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Detter, J. Chris [U.S. Department of Energy, Joint Genome Institute; Goker, Markus [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Bristow, James [U.S. Department of Energy, Joint Genome Institute; Eisen, Jonathan [U.S. Department of Energy, Joint Genome Institute; Markowitz, Victor [U.S. Department of Energy, Joint Genome Institute; Hugenholtz, Philip [U.S. Department of Energy, Joint Genome Institute; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute; Klenk, Hans-Peter [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute

    2013-01-01

    Spirochaeta africana Zhilina et al. 1996 is an anaerobic, aerotolerant, spiral-shaped bacte- rium that is motile via periplasmic flagella. The type strain of the species, Z-7692T, was iso- lated in 1993 or earlier from a bacterial bloom in the brine under the trona layer in a shallow lagoon of the alkaline equatorial Lake Magadi in Kenya. Here we describe the features of this organism, together with the complete genome sequence, and annotation. Considering the pending reclassification of S. caldaria to the genus Treponema, S. africana is only the second 'true' member of the genus Spirochaeta with a genome-sequenced type strain to be pub- lished. The 3,285,855 bp long genome of strain Z-7692T with its 2,817 protein-coding and 57 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

  1. Desulfonatronovibrio halophilus sp. nov., a novel moderately halophilic sulfate-reducing bacterium from hypersaline chloride-sulfate lakes in Central Asia

    NARCIS (Netherlands)

    Sorokin, D.Y.; Tourova, T.P.; Abbas, B.; Suhacheva, M.V.; Muyzer, G.

    2012-01-01

    Four strains of lithotrophic sulfate-reducing bacteria (SRB) have been enriched and isolated from anoxic sediments of hypersaline chloride-sulfate lakes in the Kulunda Steppe (Altai, Russia) at 2 M NaCl and pH 7.5. According to the 16S rRNA gene sequence analysis, the isolates were closely related

  2. Quantum chemical study of halophilic interactions. Communication 3. Non-empirical study of the ways of tetrachloromethane attack by halide ions

    International Nuclear Information System (INIS)

    Kobychev, V.B.; Vitkovskaya, N.M.; Abramov, A.V.; Timokhin, B.V.

    1999-01-01

    It has been shown by means of non-empirical calculations of model reactions between tetrachloromethane and chlorine/iodine anions that in case of attack via carbon atom according to mechanism S N 2 formation of weakly-bound CCl 4 complexes with halide ions is observed at initial state. Further transformation of the complexes is restricted by considerable potential barriers. Attack of nucleophil via chlorine atom with formation of stable complexes CCl 3 -Cl-Hlg - is preferable [ru

  3. Desulfonatronovibrio halophilus sp. nov., a novel moderately halophilic sulfate-reducing bacterium from hypersaline chloride–sulfate lakes in Central Asia

    NARCIS (Netherlands)

    Sorokin, D.Y.; Tourova, T.P.; Abbas, B.; Suhacheva, M.V.; Muyzer, G.

    2012-01-01

    Four strains of lithotrophic sulfate-reducing bacteria (SRB) have been enriched and isolated from anoxic sediments of hypersaline chloride–sulfate lakes in the Kulunda Steppe (Altai, Russia) at 2 M NaCl and pH 7.5. According to the 16S rRNA gene sequence analysis, the isolates were closely related

  4. A novel thermophilic and halophilic esterase from Janibacter sp. R02, the first member of a new lipase family (Family XVII).

    Science.gov (United States)

    Castilla, Agustín; Panizza, Paola; Rodríguez, Diego; Bonino, Luis; Díaz, Pilar; Irazoqui, Gabriela; Rodríguez Giordano, Sonia

    2017-03-01

    Janibacter sp. strain R02 (BNM 560) was isolated in our laboratory from an Antarctic soil sample. A remarkable trait of the strain was its high lipolytic activity, detected in Rhodamine-olive oil supplemented plates. Supernatants of Janibacter sp. R02 displayed superb activity on transesterification of acyl glycerols, thus being a good candidate for lipase prospection. Considering the lack of information concerning lipases of the genus Janibacter, we focused on the identification, cloning, expression and characterization of the extracellular lipases of this strain. By means of sequence alignment and clustering of consensus nucleotide sequences, a DNA fragment of 1272bp was amplified, cloned and expressed in E. coli. The resulting recombinant enzyme, named LipJ2, showed preference for short to medium chain-length substrates, and displayed maximum activity at 80°C and pH 8-9, being strongly activated by a mixture of Na + and K + . The enzyme presented an outstanding stability regarding both pH and temperature. Bioinformatics analysis of the amino acid sequence of LipJ2 revealed the presence of a consensus catalytic triad and a canonical pentapeptide. However, two additional rare motifs were found in LipJ2: an SXXL β-lactamase motif and two putative Y-type oxyanion holes (YAP). Although some of the previous features could allow assigning LipJ2 to the bacterial lipase families VIII or X, the phylogenetic analysis showed that LipJ2 clusters apart from other members of known lipase families, indicating that the newly isolated Janibacter esterase LipJ2 would be the first characterized member of a new family of bacterial lipases. Published by Elsevier Inc.

  5. Draft genome sequence of the extremely halophilic Halorubrum sp. SAH-A6 isolated from rock salts of the Danakil depression, Ethiopia

    Directory of Open Access Journals (Sweden)

    Ashagrie Gibtan

    2016-12-01

    Full Text Available The draft genome sequence of Halorubrum sp. SAH-A6, isolated from commercial rock salts of the Danakil depression, Ethiopia. The genome comprised 3,325,770 bp, with the G + C content of 68.0%. The strain has many genes which are responsible for secondary metabolites biosynthesis, transport and catabolism as compared to other Halorubrum archaea members. Abundant genes responsible for numerous transport systems, solute accumulation, and aromatic/sulfur decomposition were detected. The first genomic analysis encourages further research on comparative genomics, and biotechnological applications. The NCBI accession number for this genome is SAMN04278861 and ID: 4278861 and strain deposited with accession number KCTC 43215.

  6. Characterization of Extracellular Dextranase from a Novel Halophilic Bacillus subtilis NRC-B233b a Mutagenic Honey Isolate under Solid State Fermentation

    Directory of Open Access Journals (Sweden)

    Mona A. Esawy

    2012-01-01

    Full Text Available Bacillus subtilis NRC-B233b was isolated from Libyan honey sample proved to be a potent dextranase producer by applying solid state fermentation and utilizing corn flour as the sole carbon source. The optimized culture conditions for dextranase productions were 37°C, pH 10, 32 h, and 20% (v/w moisture content. A unique character of this isolate is its ability to produce steady dextranase irrespective to the presence of NaCl in the medium. The addition of 0.175 Mm CrCl3 increased the enzyme production by about 4.5 fold. Further improvement in enzyme production was achieved by simple UV mutation which increased the enzyme production up to about 2842 U/g. The crude extract has been partially purified about 112-fold from crude extract by only two purification steps involving ultra-filtration. The partially purified dextranase showed its maximum activity at pH 9.2 and 70°C. It retained full activity (100% at 75°C for one hour. Dextranase activity increased about 4 fold in the presence of 10% NaCl. This enzyme showed variable degradation effect on different types of dextran and its derivatives. The treatment of viscous sugar cane juice with the enzyme preparation resulted in clear visual dextran hydrolysis. These results suggest that the dextranase produced by Bacillus subtilis NRC-B233b is industrially applicable.

  7. Modern Aspects of Halophilism: The Edmond de Rothschild School in Molecular Biophysics (12th) Held in Israel on March 26-April 5, 1989. Program and Abstracts

    Science.gov (United States)

    1989-04-01

    pairs 16:30 CHRISTINE EBEL Study of the stability and activity of the elongation factor Tu from Halobacterlum marismortul at different salt conditions...RELEVANT LITERATURE Alfano RR, Yu W, Govindjee R, Becher B, Ebrey TG (1976). Picosecond kinetics of the fluorescence from the chromophore of the

  8. Ferric Sulfate and Proline Enhance Heavy-Metal Tolerance of Halophilic/Halotolerant Soil Microorganisms and Their Bioremediation Potential for Spilled-Oil Under Multiple Stresses

    Science.gov (United States)

    Al-Mailem, Dina M.; Eliyas, Mohamed; Radwan, Samir S.

    2018-01-01

    The aim of this study was to explore the heavy-metal resistance and hydrocarbonoclastic potential of microorganisms in a hypersaline soil. For this, hydrocarbonoclastic microorganisms were counted on a mineral medium with oil vapor as a sole carbon source in the presence of increasing concentrations of ZnSO4, HgCl2, CdSO4, PbNO3, CuSO4, and Na2HAsO4. The colony-forming units counted decreased in number from about 150 g-1 on the heavy-metal-free medium to zero units on media with 40–100 mg l-1 of HgCl2, CdSO4, PbNO3, or Na2HAsO4. On media with CuSO4 or ZnSO4 on the other hand, numbers increased first reaching maxima on media with 50 mg l-1 CuSO4 and 90 mg l-1 ZnSO4. Higher concentrations reduced the numbers, which however, still remained considerable. Pure microbial isolates in cultures tolerated 200–1600 mg l-1 of HgCl2, CdSO4, PbNO3, CuSO4, and Na2HAsO4 in the absence of crude oil. In the presence of oil vapor, the isolates tolerated much lower concentrations of the heavy metals, only 10–80 mg l-1. The addition of 10 Fe2(SO4)3 and 200 mg l-1 proline (by up to two- to threefold) enhanced the tolerance of several isolates to heavy metals, and consequently their potential for oil biodegradation in their presence. The results are useful in designing bioremediation technologies for oil spilled in hypersaline areas. PMID:29563904

  9. Draft genome sequence of Halorubrum tropicale strain V5, a novel halophilic archaeon isolated from the solar salterns of Cabo Rojo, Puerto Rico.

    Science.gov (United States)

    Sánchez-Nieves, Rubén; Facciotti, Marc T; Saavedra-Collado, Sofía; Dávila-Santiago, Lizbeth; Rodríguez-Carrero, Roy; Montalvo-Rodríguez, Rafael

    2016-03-01

    The genus Halorubrum is a member of the family Halobacteriaceae which currently has the highest number of described species (31) of all the haloarchaea. Here we report the draft genome sequence of strain V5, a new species within this genus that was isolated from the solar salterns of Cabo Rojo, Puerto Rico. Assembly was performed and rendered the genome into 17 contigs (N50 = 515,834 bp), the largest of which contains 1,031,026 bp. The genome consists of 3.57 MB in length with G + C content of 67.6%. In general, the genome includes 4 rRNAs, 52 tRNAs, and 3246 protein-coding sequences. The NCBI accession number for this genome is LIST00000000 and the strain deposit number is CECT9000.

  10. Draft genome of Haloarcula rubripromontorii strain SL3, a novel halophilic archaeon isolated from the solar salterns of Cabo Rojo, Puerto Rico.

    Science.gov (United States)

    Sánchez-Nieves, Rubén; Facciotti, Marc; Saavedra-Collado, Sofía; Dávila-Santiago, Lizbeth; Rodríguez-Carrero, Roy; Montalvo-Rodríguez, Rafael

    2016-03-01

    The genus Haloarcula belongs to the family Halobacteriaceae which currently has 10 valid species. Here we report the draft genome sequence of strain SL3, a new species within this genus, isolated from the Solar Salterns of Cabo Rojo, Puerto Rico. Genome assembly performed using NGEN Assembler resulted in 18 contigs (N50 = 601,911 bp), the largest of which contains 1,023,775 bp. The genome consists of 3.97 MB and has a GC content of 61.97%. Like all species of Haloarcula, the genome encodes heterogeneous copies of the small subunit ribosomal RNA. In addition, the genome includes 6 rRNAs, 48 tRNAs, and 3797 protein coding sequences. Several carbohydrate-active enzymes genes were found, as well as enzymes involved in the dihydroxyacetone processing pathway which are not found in other Haloarcula species. The NCBI accession number for this genome is LIUF00000000 and the strain deposit number is CECT9001.

  11. Biochemical properties and base excision repair complex formation of apurinic/apyrimidinic endonuclease from Pyrococcus furiosus

    OpenAIRE

    Kiyonari, Shinichi; Tahara, Saki; Shirai, Tsuyoshi; Iwai, Shigenori; Ishino, Sonoko; Ishino, Yoshizumi

    2009-01-01

    Apurinic/apyrimidinic (AP) sites are the most frequently found mutagenic lesions in DNA, and they arise mainly from spontaneous base loss or modified base removal by damage-specific DNA glycosylases. AP sites are cleaved by AP endonucleases, and the resultant gaps in the DNA are repaired by DNA polymerase/DNA ligase reactions. We identified the gene product that is responsible for the AP endonuclease activity in the hyperthermophilic euryarchaeon, Pyrococcus furiosus. Furthermore, we detected...

  12. Single-step purification and characterization of an extreme halophilic, ethanol tolerant and acidophilic xylanase from Aureobasidium pullulans NRRL Y-2311-1 with application potential in the food industry.

    Science.gov (United States)

    Yegin, Sirma

    2017-04-15

    An extracellular xylanase from Aureobasidium pullulans NRRL Y-2311-1 produced on wheat bran was purified by a single-step chromatographic procedure. The enzyme had a molecular weight of 21.6kDa. The optimum pH and temperature for xylanase activity were 4.0 and 30-50°C, respectively. The enzyme was stable in the pH range of 3.0-8.0. The inactivation energy of the enzyme was calculated as 218kJmol -1 . The xylanase was ethanol tolerant and kept complete activity in the presence of 10% ethanol. Likewise, it retained almost complete activity at a concentration range of 0-20% NaCl. In general, the enzyme was resistant to several metal ions and reagents. Mg 2+ , Zn 2+ , Cu 2+ , K 1+ , EDTA and β-mercaptoethanol resulted in enhanced xylanase activity. The K m and V max values on beechwood xylan were determined to be 19.43mgml -1 and 848.4Uml -1 , respectively. The enzyme exhibits excellent characteristics and could, therefore, be a promising candidate for application in food and bio-industries. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Adaptation de l'Archaea halophile halobacterium salinarum aux stress environnementaux : mécanismes de survie et rôle de la protéolyse intracellulaire

    OpenAIRE

    Marty , Vincent

    2011-01-01

    Molecular systems described for Archaea show primitive and simple characteristics, compared to their homologous eukaryotes. In addition, extremophilic characteristic results in an hyper-robust which makes in vitro manipulation and structural studies much easier. Thus, Archaea represent good models for understanding complex cellular functions, particularly those that involve large molecular machines, such as those involved in proteolysis. My thesis consisted in understanding the resistance mec...

  14. Charge Segregation and Low Hydrophobicity Are Key Features of Ribosomal Proteins from Different Organisms*

    Science.gov (United States)

    Fedyukina, Daria V.; Jennaro, Theodore S.; Cavagnero, Silvia

    2014-01-01

    Ribosomes are large and highly charged macromolecular complexes consisting of RNA and proteins. Here, we address the electrostatic and nonpolar properties of ribosomal proteins that are important for ribosome assembly and interaction with other cellular components and may influence protein folding on the ribosome. We examined 50 S ribosomal subunits from 10 species and found a clear distinction between the net charge of ribosomal proteins from halophilic and non-halophilic organisms. We found that ∼67% ribosomal proteins from halophiles are negatively charged, whereas only up to ∼15% of ribosomal proteins from non-halophiles share this property. Conversely, hydrophobicity tends to be lower for ribosomal proteins from halophiles than for the corresponding proteins from non-halophiles. Importantly, the surface electrostatic potential of ribosomal proteins from all organisms, especially halophiles, has distinct positive and negative regions across all the examined species. Positively and negatively charged residues of ribosomal proteins tend to be clustered in buried and solvent-exposed regions, respectively. Hence, the majority of ribosomal proteins is characterized by a significant degree of intramolecular charge segregation, regardless of the organism of origin. This key property enables the ribosome to accommodate proteins within its complex scaffold regardless of their overall net charge. PMID:24398678

  15. A Simple Laser-Based Device for Simultaneous Microbial Culture and Absorbance Measurement

    OpenAIRE

    Abrevaya, X. C.; Cortón, E.; Areso, O.; Mauas, P. J. D.

    2012-01-01

    In this work we present a device specifically designed to study microbial growth with several applications related to environmental microbiology and other areas of research as astrobiology. The Automated Measuring and Cultivation device (AMC-d) enables semi-continuous absorbance measurements directly during cultivation. It can measure simultaneously up to 16 samples. Growth curves using low and fast growing microorganism were plotted, including Escherichia coli and Haloferax volcanii, a halop...

  16. Draft Genome of the Marine Gammaproteobacterium Halomonas titanicae

    Science.gov (United States)

    Sánchez-Porro, Cristina; de la Haba, Rafael R.; Cruz-Hernández, Norge; González, Juan M.; Reyes-Guirao, Cristina; Navarro-Sampedro, Laura; Carballo, Modesto

    2013-01-01

    Halomonas titanicae strain BH1 is a heterotrophic, aerobic marine bacterium which was isolated from rusticles of the RMS Titanic wreck. Here we report the draft genome sequence of this halophilic gammaproteobacterium. PMID:23516210

  17. Fungal diversity in deep-sea sediments revealed by culture-dependent and culture-independent approaches

    Digital Repository Service at National Institute of Oceanography (India)

    Singh, P.; Raghukumar, C.; Meena, R.M.; Verma, P.; Shouche, Y.

    dog. Journal of Clinical Microbiology 41: 1722-1725. Gunde-Cimerman N, Zalar P, Hoog Gsde, Plemenitas A, 2000. Hypersaline waters in salterns: natural ecological niches for halophilic black yeasts. FEMS Microbiology Ecology 32: 235–340. Gupta SM...

  18. Optimization of extracellular polysaccharide production in ...

    African Journals Online (AJOL)

    sunny

    2014-11-26

    Nov 26, 2014 ... textiles, detergents, adhesives, cosmetics, pharmaceu- ticals, food additives ... Isolation and identification of EPS producing halophilic bacteria ..... The present study lead to the optimization of key culture conditions with CCD ...

  19. Environmental genomics of "Haloquadratum walsbyi" in a saltern crystallizer indicates a large pool of accessory genes in an otherwise coherent species

    NARCIS (Netherlands)

    Legault, Boris A.; Lopez-Lopez, Arantxa; Alba-Casado, Jose Carlos; Doolittle, W. Ford; Bolhuis, Henk; Rodriguez-Valera, Francisco; Papke, R. Thane

    2006-01-01

    Background: Mature saturated brine (crystallizers) communities are largely dominated (> 80% of cells) by the square halophilic archaeon "Haloquadratum walsbyi". The recent cultivation of the strain HBSQ001 and thesequencing of its genome allows comparison with the metagenome of this taxonomically

  20. Biosignatures of Hypersaline Environments (Salt Crusts) an Analog for Mars

    Science.gov (United States)

    Smith, H. D.; Duncan, A. G.; Davilla, A. F.; McKay, C. P.

    2016-05-01

    Halophilic ecosystems are models for life in extreme environments including planetary surfaces such as Mars. Our research focuses on biosignatures in a salt crusts and the detection of these biomarkers by ground and orbital assests.

  1. Discrimination of Pigments of Microalgae, Bacteria and Yeasts Using Lightweight Handheld Raman Spectrometers: Prospects for Astrobiology

    Science.gov (United States)

    Jehlicka, J.; Osterrothova, K.; Nedbalova, L.; Gunde-Cimerman, N.; Oren, A.

    2014-06-01

    Handheld Raman instrumentation with 532 nm lasers can be used to distinguish carotenoids of autotrophic microalgae, purple sulfur bacteria, halophilic Archaea and pigmented yeasts. Pigments are proposed as biomarkers for astrobiology of Mars.

  2. Disease: H00307 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available thogen of both aquatic animals and humans. In the case of humans, it is often acquired through the consumpti...e halophilic bacterium that naturally inhabits marine and estuarine environments. It is a well-recognized pa

  3. BKR 27(1) pp. xx-xx (Dick et al)

    African Journals Online (AJOL)

    Femi J. Olorunniji

    2015-03-31

    Mar 31, 2015 ... Antibiotic sensitivity profiles of the bacteria (Escherichia coli, Vibrio sp. and Salmonella sp.) ..... of Vibrio parahaemolyticus isolated from cockles in Padang, ... potentially pathogenic Halophilic Vibrios isolated from seafood.

  4. New insights into microbial adaptation to extreme saline environments

    Directory of Open Access Journals (Sweden)

    Vauclare P.

    2014-02-01

    Full Text Available Extreme halophiles are microorganisms adapted to low water activity living at the upper salt concentration that life can tolerate. We review here recent data that specify the main factors, which determine their peculiar salt-dependent biochemistry. The data suggested that evolution proceeds by stage to modify the molecular dynamics properties of the entire proteome. Extreme halophiles therefore represent tractable models to understand how fast and to what extent microorganisms adapt to environmental changes. Halophiles are also robust organisms, capable to resist multiple stressors. Preliminary studies indicated that they have developed a cellular response specifically aimed to survive when the salt condition fluctuates. Because of these properties halophilic organisms deserve special attention in the search for traces of life on other planets.

  5. Differences in lateral gene transfer in hypersaline versus thermal environments.

    Science.gov (United States)

    Rhodes, Matthew E; Spear, John R; Oren, Aharon; House, Christopher H

    2011-07-08

    The role of lateral gene transfer (LGT) in the evolution of microorganisms is only beginning to be understood. While most LGT events occur between closely related individuals, inter-phylum and inter-domain LGT events are not uncommon. These distant transfer events offer potentially greater fitness advantages and it is for this reason that these "long distance" LGT events may have significantly impacted the evolution of microbes. One mechanism driving distant LGT events is microbial transformation. Theoretically, transformative events can occur between any two species provided that the DNA of one enters the habitat of the other. Two categories of microorganisms that are well-known for LGT are the thermophiles and halophiles. We identified potential inter-class LGT events into both a thermophilic class of Archaea (Thermoprotei) and a halophilic class of Archaea (Halobacteria). We then categorized these LGT genes as originating in thermophiles and halophiles respectively. While more than 68% of transfer events into Thermoprotei taxa originated in other thermophiles, less than 11% of transfer events into Halobacteria taxa originated in other halophiles. Our results suggest that there is a fundamental difference between LGT in thermophiles and halophiles. We theorize that the difference lies in the different natures of the environments. While DNA degrades rapidly in thermal environments due to temperature-driven denaturization, hypersaline environments are adept at preserving DNA. Furthermore, most hypersaline environments, as topographical minima, are natural collectors of cellular debris. Thus halophiles would in theory be exposed to a greater diversity and quantity of extracellular DNA than thermophiles.

  6. Novel Insights into the Diversity of Catabolic Metabolism from Ten Haloarchaeal Genomes

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Iain; Scheuner, Carmen; Goker, Markus; Mavromatis, Kostas; Hooper, Sean D.; Porat, Iris; Klenk, Hans-Peter; Ivanova, Natalia; Kyrpides, Nikos

    2011-05-03

    The extremely halophilic archaea are present worldwide in saline environments and have important biotechnological applications. Ten complete genomes of haloarchaea are now available, providing an opportunity for comparative analysis. We report here the comparative analysis of five newly sequenced haloarchaeal genomes with five previously published ones. Whole genome trees based on protein sequences provide strong support for deep relationships between the ten organisms. Using a soft clustering approach, we identified 887 protein clusters present in all halophiles. Of these core clusters, 112 are not found in any other archaea and therefore constitute the haloarchaeal signature. Four of the halophiles were isolated from water, and four were isolated from soil or sediment. Although there are few habitat-specific clusters, the soil/sediment halophiles tend to have greater capacity for polysaccharide degradation, siderophore synthesis, and cell wall modification. Halorhabdus utahensis and Haloterrigena turkmenica encode over forty glycosyl hydrolases each, and may be capable of breaking down naturally occurring complex carbohydrates. H. utahensis is specialized for growth on carbohydrates and has few amino acid degradation pathways. It uses the non-oxidative pentose phosphate pathway instead of the oxidative pathway, giving it more flexibility in the metabolism of pentoses. These new genomes expand our understanding of haloarchaeal catabolic pathways, providing a basis for further experimental analysis, especially with regard to carbohydrate metabolism. Halophilic glycosyl hydrolases for use in biofuel production are more likely to be found in halophiles isolated from soil or sediment.

  7. Diversity of Heterotrophic Protists from Extremely Hypersaline Habitats.

    Science.gov (United States)

    Park, Jong Soo; Simpson, Alastair G B

    2015-09-01

    Heterotrophic protists (protozoa) are a diverse but understudied component of the biota of extremely hypersaline environments, with few data on molecular diversity within halophile 'species', and almost nothing known of their biogeographic distribution. We have garnered SSU rRNA gene sequences for several clades of halophilic protozoa from enrichments from waters of >12.5% salinity from Australia, North America, and Europe (6 geographic sites, 25 distinct samples). The small stramenopile Halocafeteria was found at all sites, but phylogenies did not show clear geographic clustering. The ciliate Trimyema was recorded from 6 non-European samples. Phylogenies confirmed a monophyletic halophilic Trimyema group that included possible south-eastern Australian, Western Australian and North American clusters. Several halophilic Heterolobosea were detected, demonstrating that Pleurostomum contains at least three relatively distinct clades, and increasing known continental ranges for Tulamoeba peronaphora and Euplaesiobystra hypersalinica. The unclassified flagellate Palustrimonas, found in one Australian sample, proves to be a novel deep-branching alveolate. These results are consistent with a global distribution of halophilic protozoa groups (∼ morphospecies), but the Trimyema case suggests that is worth testing whether larger forms exhibit biogeographic phylogenetic substructure. The molecular detection/characterization of halophilic protozoa is still far from complete at the clade level, let alone the 'species level'. Copyright © 2015 Elsevier GmbH. All rights reserved.

  8. AglM and VNG1048G, Two Haloarchaeal UDP-Glucose Dehydrogenases, Show Different Salt-Related Behaviors

    OpenAIRE

    Kandiba, Lina; Eichler, Jerry

    2016-01-01

    Haloferax volcanii AglM and Halobacterium salinarum VNG1048G are UDP-glucose dehydrogenases involved in N-glycosylation in each species. Despite sharing >60% sequence identity and the ability of VNG1048G to functionally replace AglM in vivo, these proteins behaved differently as salinity changed. Whereas AglM was active in 2–4 M NaCl, VNG1048G lost much of its activity when salinity dropped below 3 M NaCl. To understand the molecular basis of this phenomenon, each protein was examined by s...

  9. Complete genome sequence of Halorhodospira halophila SL1

    Energy Technology Data Exchange (ETDEWEB)

    Challacombe, Jean F [ORNL; Majid, Sophia [University of Chicago; Deole, Ratnakar [Oklahoma State University; Brettin, Thomas S. [Argonne National Laboratory (ANL); Bruce, David [Los Alamos National Laboratory (LANL); Delano, Susana [Los Alamos National Laboratory (LANL); Detter, J. Chris [U.S. Department of Energy, Joint Genome Institute; Gleasner, Cheryl D. [Los Alamos National Laboratory (LANL); Han, Cliff [Los Alamos National Laboratory (LANL); Misra, Monica [Los Alamos National Laboratory (LANL); Reitenga, Krista K. [Los Alamos National Laboratory (LANL); Mikhailova, Natalia [U.S. Department of Energy, Joint Genome Institute; Copeland, A [U.S. Department of Energy, Joint Genome Institute; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute; Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Nolan, Matt [U.S. Department of Energy, Joint Genome Institute; Land, Miriam L [ORNL; Saunders, Elizabeth H [Los Alamos National Laboratory (LANL); Tapia, Roxanne [Los Alamos National Laboratory (LANL); Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Hoff, Wouter D. [Oklahoma State University

    2013-01-01

    Halorhodospira halophila is among the most halophilic organisms known. It is an obligately photosynthetic and anaerobic purple sulfur bacterium that exhibits autotrophic growth up to saturated NaCl concentrations. The type strain H. halophila SL1 was isolated from a hypersaline lake in Oregon. Here we report the determination of its entire genome in a single contig. This is the first genome of a phototrophic extreme halophile. The genome consists of 2,678,452 bp, encoding 2493 predicted genes as determined by automated genome annotation. Of the 2407 predicted proteins, 1905 were assigned to a putative function. Future detailed analysis of this genome promises to yield insights into the halophilic adaptations of this organism, its ability for photoautotrophic growth under extreme conditions, and its characteristic sulfur metabolism.

  10. Plutonium interaction with a bacterial strain isolated from the waste isolation pilot plant (WIPP) environment

    International Nuclear Information System (INIS)

    Strietelmeier, B.A.; Kraus, S.M.; Leonard, P.A.; Triay, I.R.

    1996-01-01

    This work was conducted as part of a series of experiments to determine the association and interaction of various actinides with bacteria isolated from the WIPP site. The majority of bacteria that exist at the site are expected to be halophiles, or extreme halophiles, due to the high concentration of salt minerals at the location. Experiments were conducted to determine the toxicity of plutonium-n-239, neptunium-237 and americium-243 to several species of these halophiles and the results were reported elsewhere. As an extension of these experiments, we report an investigation of the type of association that occurs between 239 Pu and the isolate WIPP-1A, isolated by staff at Brookhaven National Laboratory, when grown in a high-salt, defined medium. Using scanning electron microscopy (SEM) techniques, we demonstrate a surface association of the 239 Pu with the bacterial cells

  11. Differences in lateral gene transfer in hypersaline versus thermal environments

    Directory of Open Access Journals (Sweden)

    House Christopher H

    2011-07-01

    Full Text Available Abstract Background The role of lateral gene transfer (LGT in the evolution of microorganisms is only beginning to be understood. While most LGT events occur between closely related individuals, inter-phylum and inter-domain LGT events are not uncommon. These distant transfer events offer potentially greater fitness advantages and it is for this reason that these "long distance" LGT events may have significantly impacted the evolution of microbes. One mechanism driving distant LGT events is microbial transformation. Theoretically, transformative events can occur between any two species provided that the DNA of one enters the habitat of the other. Two categories of microorganisms that are well-known for LGT are the thermophiles and halophiles. Results We identified potential inter-class LGT events into both a thermophilic class of Archaea (Thermoprotei and a halophilic class of Archaea (Halobacteria. We then categorized these LGT genes as originating in thermophiles and halophiles respectively. While more than 68% of transfer events into Thermoprotei taxa originated in other thermophiles, less than 11% of transfer events into Halobacteria taxa originated in other halophiles. Conclusions Our results suggest that there is a fundamental difference between LGT in thermophiles and halophiles. We theorize that the difference lies in the different natures of the environments. While DNA degrades rapidly in thermal environments due to temperature-driven denaturization, hypersaline environments are adept at preserving DNA. Furthermore, most hypersaline environments, as topographical minima, are natural collectors of cellular debris. Thus halophiles would in theory be exposed to a greater diversity and quantity of extracellular DNA than thermophiles.

  12. Low-pass sequencing for microbial comparative genomics

    Directory of Open Access Journals (Sweden)

    Kennedy Sean

    2004-01-01

    Full Text Available Abstract Background We studied four extremely halophilic archaea by low-pass shotgun sequencing: (1 the metabolically versatile Haloarcula marismortui; (2 the non-pigmented Natrialba asiatica; (3 the psychrophile Halorubrum lacusprofundi and (4 the Dead Sea isolate Halobaculum gomorrense. Approximately one thousand single pass genomic sequences per genome were obtained. The data were analyzed by comparative genomic analyses using the completed Halobacterium sp. NRC-1 genome as a reference. Low-pass shotgun sequencing is a simple, inexpensive, and rapid approach that can readily be performed on any cultured microbe. Results As expected, the four archaeal halophiles analyzed exhibit both bacterial and eukaryotic characteristics as well as uniquely archaeal traits. All five halophiles exhibit greater than sixty percent GC content and low isoelectric points (pI for their predicted proteins. Multiple insertion sequence (IS elements, often involved in genome rearrangements, were identified in H. lacusprofundi and H. marismortui. The core biological functions that govern cellular and genetic mechanisms of H. sp. NRC-1 appear to be conserved in these four other halophiles. Multiple TATA box binding protein (TBP and transcription factor IIB (TFB homologs were identified from most of the four shotgunned halophiles. The reconstructed molecular tree of all five halophiles shows a large divergence between these species, but with the closest relationship being between H. sp. NRC-1 and H. lacusprofundi. Conclusion Despite the diverse habitats of these species, all five halophiles share (1 high GC content and (2 low protein isoelectric points, which are characteristics associated with environmental exposure to UV radiation and hypersalinity, respectively. Identification of multiple IS elements in the genome of H. lacusprofundi and H. marismortui suggest that genome structure and dynamic genome reorganization might be similar to that previously observed in the

  13. Problems in identification of Francisella philomiragia associated with fatal bacteremia in a patient with chronic granulomatous disease

    DEFF Research Database (Denmark)

    Friis-Møller, Alice; Lemming, L E; Valerius, Niels Henrik

    2004-01-01

    Francisella philomiragia is a rare gram-negative, halophilic coccobacillus with bizarre spherical forms on primary isolation. A case of F. philomiragia bacteremia in a 24-year-old patient with chronic granulomatous disease is reported. Identification of F. philomiragia was problematic with conven......Francisella philomiragia is a rare gram-negative, halophilic coccobacillus with bizarre spherical forms on primary isolation. A case of F. philomiragia bacteremia in a 24-year-old patient with chronic granulomatous disease is reported. Identification of F. philomiragia was problematic...

  14. Metabolism, Physiology and Biotechnological Applications of Halobacteria

    OpenAIRE

    Oleg Mosin; Ignat Ignatov

    2015-01-01

    Halophiles (lat. “salt-loving”) is the taxonomic group of extreme aerobic obligate Gram-negative microorganisms that live in conditions of high salinity – in the seas, salt lakes, saline soils etc. These microorganisms are known to reddish patina on products, preserved with using large quantities of salt (NaCl). Halophiles were isolated for the first time at the beginning of the XX century from the marine flora estuary mud, but their systematic study was started only at the end of the second ...

  15. The xanthopsins : a new family of eubacterial blue-light photoreceptors

    NARCIS (Netherlands)

    Kort, R; Hoff, W.D.; West, M.E.; Kroon, A R; Hoffer, S.M.; Vlieg, K H; Crielaand, W; van Beeumen, J.; Hellingwerf, K J

    1996-01-01

    Photoactive yellow protein (PYP) is a photoreceptor that has been isolated from three halophilic phototrophic purple bacteria. The PYP from Ectothiorhodospira halophila BN9626 is the only member for which the sequence has been reported at the DNA level. Here we describe the cloning and sequencing of

  16. The Xanthopsins: a new family of eubacterial blue-light photoreceptors

    NARCIS (Netherlands)

    Kort, R.; Hoff, W.D.; van West, W.S.; Kroon, A.R.; Hoffer, S.M.; Vlieg, K.H.; Crielaard, W.; van Beeumen, J.J.; Hellingwerf, K.J.

    1996-01-01

    Photoactive yellow protein (PYP) is a photoreceptor that has been isolated from three halophilic phototrophic purple bacteria. The PYP from Ectothiorhodospira halophila BN9626 is the only member for which the sequence has been reported at the DNA level. Here we describe the cloning and sequencing of

  17. Optimization of extracellular polysaccharide production in ...

    African Journals Online (AJOL)

    sunny

    2014-11-26

    Nov 26, 2014 ... Llamas I (2007). Characterization of exopolysaccharides produced by three moderately halophilic bacteria belonging to the family. Alteromonadaceae. J. Appl. Microbiol. 105:521-528. Mishra, Jha (2013). Microbial Exopolysaccharides In: Rosenberg, E.,. The Prokaryotes –Applied Bacteriology and ...

  18. Complete Genome Sequence of Methanohalophilus halophilus DSM 3094 T , Isolated from a Cyanobacterial Mat and Bottom Deposits at Hamelin Pool, Shark Bay, Northwestern Australia

    KAUST Repository

    L'Haridon, Stéphane

    2017-02-17

    The complete genome sequence of Methanohalophilus halophilus DSM 3094, a member of the Methanosarcinaceae family and the Methanosarcianales order, consists of 2,022,959 bp in one contig and contains 2,137 predicted genes. The genome is consistent with a halophilic methylotrophic anaerobic lifestyle, including the methylotrophic and CO-H methanogensis pathways.

  19. Assessment of four different methods for selecting biosurfactant ...

    African Journals Online (AJOL)

    ... and ease of use to screen biosurfactant producing six extremely halophilic bacteria isolated from saline soil of Chott El Hodna-M'sila (Algeria), which is considered as a thalassohaline environment. Results from screening methods revealed that, CH2 and CH5 strains are potential candidates for biosurfactant production.

  20. Problems in identification of Francisella philomiragia associated with fatal bacteremia in a patient with chronic granulomatous disease

    DEFF Research Database (Denmark)

    Friis-Møller, Alice; Lemming, L E; Valerius, Niels Henrik

    2004-01-01

    Francisella philomiragia is a rare gram-negative, halophilic coccobacillus with bizarre spherical forms on primary isolation. A case of F. philomiragia bacteremia in a 24-year-old patient with chronic granulomatous disease is reported. Identification of F. philomiragia was problematic...

  1. Radiation decontamination and disinfestation of salted dried tilapia ...

    African Journals Online (AJOL)

    Significant reduction in total viable count was observed after treatment with gamma radiation. A least square regression fitted through the data points indicated that 1.3 kGy would be required to reduce the microbial population on the product by one log cycle. Insects and pink colonies of halophilic bacteria were observed on ...

  2. Ruegeria profundi sp. nov. and Ruegeria marisrubri sp. nov., isolated from the brine–seawater interface at Erba Deep in the Red Sea

    KAUST Repository

    Zhang, Guishan; Haroon, Mohamed; Zhang, Ruifu; Dong, Xiaoyan; Wang, Dandan; Liu, Yunpeng; Xun, Weibing; Dong, Xiuzhu; Stingl, Ulrich

    2017-01-01

    Two moderately halophilic marine bacterial strains of the family Rhodobacteraceae, designated ZGT108T and ZGT118T, were isolated from the brine-seawater interface at Erba Deep in the Red Sea (Saudi Arabia). Cells of both strains were aerobic, rod

  3. Draft Genome Sequence of an Obligately Methylotrophic Methanogen, Methanococcoides methylutens, Isolated from Marine Sediment

    KAUST Repository

    Guan, Yue; Ngugi, David; Blom, J.; Ali, Shahjahan; Ferry, J. G.; Stingl, Ulrich

    2014-01-01

    Methanococcoides methylutens, the type species of the genus Methanococcoides, is a slightly halophilic methanogenic archaeon with a methylotrophic metabolism. Here, we present the annotated draft genome sequence of M. methylutens, which comprises 2,508,511 bp with 2,482 coding sequences, 51 tRNA genes, and a G+C content of 42.5%.

  4. Cytomorphology of six halotolerant coccoid cyanobacteria using DAPI fluorescent and transmission electron microscopy, compared with molecular data

    Czech Academy of Sciences Publication Activity Database

    Cepák, Vladislav; Komárek, Jiří

    2010-01-01

    Roč. 10, č. 2 (2010), s. 229-234 ISSN 1802-5439 R&D Projects: GA AV ČR IAA600050704 Institutional research plan: CEZ:AV0Z60050516 Keywords : halophilic cyanobacteria * cytomorphology * molecular evaluation Subject RIV: EF - Botanics Impact factor: 0.978, year: 2010

  5. Mining Halophytes for Plant Growth-Promoting Halotolerant Bacteria to Enhance the Salinity Tolerance of Non-halophytic Crops

    Directory of Open Access Journals (Sweden)

    Hassan Etesami

    2018-02-01

    Full Text Available Salinity stress is one of the major abiotic stresses limiting crop production in arid and semi-arid regions. Interest is increasing in the application of PGPRs (plant growth promoting rhizobacteria to ameliorate stresses such as salinity stress in crop production. The identification of salt-tolerant, or halophilic, PGPRs has the potential to promote saline soil-based agriculture. Halophytes are a useful reservoir of halotolerant bacteria with plant growth-promoting capabilities. Here, we review recent studies on the use of halophilic PGPRs to stimulate plant growth and increase the tolerance of non-halophytic crops to salinity. These studies illustrate that halophilic PGPRs from the rhizosphere of halophytic species can be effective bio-inoculants for promoting the production of non-halophytic species in saline soils. These studies support the viability of bioinoculation with halophilic PGPRs as a strategy for the sustainable enhancement of non-halophytic crop growth. The potential of this strategy is discussed within the context of ensuring sustainable food production for a world with an increasing population and continuing climate change. We also explore future research needs for using halotolerant PGPRs under salinity stress.

  6. Oxynema, a new genus separated from the genus Phormidium (Cyanophyta)

    Czech Academy of Sciences Publication Activity Database

    Chatchawan, T.; Komárek, Jiří; Strunecký, Otakar; Šmarda, J.; Peerapornpisal, Y.

    2012-01-01

    Roč. 33, č. 1 (2012), s. 41-59 ISSN 0181-1568 Institutional research plan: CEZ:AV0Z60050516 Keywords : halophilic habitats * molecular sequencing * Oxynema Subject RIV: EF - Botanics Impact factor: 1.170, year: 2012

  7. Evaluation of Three Automated Genome Annotations for Halorhabdus utahensis

    DEFF Research Database (Denmark)

    Bakke, Peter; Carney, Nick; DeLoache, Will

    2009-01-01

    in databases such as NCBI and used to validate subsequent annotation errors. We submitted the genome sequence of halophilic archaeon Halorhabdus utahensis to be analyzed by three genome annotation services. We have examined the output from each service in a variety of ways in order to compare the methodology...

  8. Salinibater Ruber as a Model for the Habitability of Europa's Ocean

    Science.gov (United States)

    Cardona, M. C.; Ramírez, S. I.

    2017-11-01

    The moon Europa has an ocean enriched with sulfate compounds. This work evaluates the adaptation strategies of Salinibacter ruber, a halophilic bacterium, when subjected to MgSO4 and NaSO4, two of the main salty components of Europás ocean.

  9. Proteolytic activity of recombinant DegP from Chromohalobacter salexigens BKL5

    Directory of Open Access Journals (Sweden)

    Dewi Fitriani

    2017-09-01

    Conclusions: Recombinant DegP from C. salexigens BKL5 showed proteolytic activity when β-casein was used as a substrate. In silico analysis indicated that recombinant DegP had characteristics similar to those of halophilic proteins depending on its amino acid composition.

  10. Draft Genome Sequence of an Obligately Methylotrophic Methanogen, Methanococcoides methylutens, Isolated from Marine Sediment

    KAUST Repository

    Guan, Yue

    2014-11-20

    Methanococcoides methylutens, the type species of the genus Methanococcoides, is a slightly halophilic methanogenic archaeon with a methylotrophic metabolism. Here, we present the annotated draft genome sequence of M. methylutens, which comprises 2,508,511 bp with 2,482 coding sequences, 51 tRNA genes, and a G+C content of 42.5%.

  11. Effect of salinity on cell growth and β-carotene production in ...

    African Journals Online (AJOL)

    Urmia Lake, the second largest hyper-saline lake by area in the world, has fluctuated in salinity over time, but recently, it has reached a maximum of 360 g/l. Dunaliella is a type of halophile green-orange microalgae especially found in lake and salty fields and is known for its antioxidant activity; because of its ability to create ...

  12. Agwu et al (6)

    African Journals Online (AJOL)

    DELL

    Enterobacteriaceae, the bacteria Escherichia coli is regarded as non-halophilic, and cannot tolerate high salt concentrations (Abdulkarim et al., 2009). Nevertheless, some strains of E. coli are halo- tolerant and survive in high salt concentrations. The ability to demonstrate such high osmotic pressure is possibly due to the ...

  13. Structural Analysis and Bioengineering of Thermostable Pyrococcus furiosus Prolidase for the Optimization of Organophosphorus Nerve Agent Detoxification

    Science.gov (United States)

    2012-04-26

    organophosphorus acid anhydrase from a halophilic bacterial isolate. J Bacteriol, 173, 1938-1943. Du, X., Tove, S., Kast -Hutcheson, K. & Grunden, A. M...1938-1943. Du, X., Tove, S., Kast -Hutcheson, K. & Grunden, A. M. 2005. Characterization of the dinuclear metal center of Pyrococcus furiosus

  14. Hypersaline sapropels act as hotspots for microbial dark matter

    Czech Academy of Sciences Publication Activity Database

    Andrei, Adrian-Stefan; Baricz, A.; Robeson, M. S.; Pauşan, M. R.; Tamaş, T.; Chiriac, C.; Szekeres, E.; Barbu-Tudoran, L.; Levei, E. A.; Coman, C.; Podar, M.; Banciu, H.L.

    2017-01-01

    Roč. 7, č. 1 (2017), č. článku 6150. ISSN 2045-2322 Institutional support: RVO:60077344 Keywords : 16S RIBOSOMAL-RNA * HALOPHILIC ARCHAEA * lake-sediments Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 4.259, year: 2016

  15. Complete Genome Sequence of Methanohalophilus halophilus DSM 3094 T , Isolated from a Cyanobacterial Mat and Bottom Deposits at Hamelin Pool, Shark Bay, Northwestern Australia

    KAUST Repository

    L'Haridon, Sté phane; Corre, Erwan; Guan, Yue; Vinu, Manikandan; La Cono, Violetta; Yakimov, Mickail; Stingl, Ulrich; Toffin, Laurent; Jebbar, Mohamed

    2017-01-01

    The complete genome sequence of Methanohalophilus halophilus DSM 3094, a member of the Methanosarcinaceae family and the Methanosarcianales order, consists of 2,022,959 bp in one contig and contains 2,137 predicted genes. The genome is consistent with a halophilic methylotrophic anaerobic lifestyle, including the methylotrophic and CO-H methanogensis pathways.

  16. Development of a two-step, non-probed multiplex real-time PCR for surveilling Vibrio anguillarum in seawater

    Science.gov (United States)

    Vibrio anguillarum is an aggressive and halophilic bacterial pathogen commonly found in seawater. Its presence in aquaculture facilities causes significant morbidity and mortality among aquaculture species primarily from hemorrhaging of the body and skin of the infected fish that eventually leads t...

  17. Sorption behavior of europium(III) and curium(III) on the cell surfaces of microorganisms

    International Nuclear Information System (INIS)

    Ozaki, T.; Kimura, T.; Ohnuki, T.; Yoshida, Z.; Gillow, J.B.; Francis, A.J.

    2004-01-01

    We investigated the association of europium(III) and curium(III) with the microorganisms Chlorella vulgaris, Bacillus subtilis, Pseudomonas fluorescens, Halomonas sp., Halobacterium salinarum, and Halobacterium halobium. We determined the kinetics and distribution coefficients (K d ) for Eu(III) and Cm(III) sorption at pH 3-5 by batch experiments, and evaluated the number of water molecules in the inner-sphere (N H 2 O ) and the degree of strength of ligand field (R E/M ) for Eu(III) by time-resolved laser-induced fluorescence spectroscopy (TRLFS). Exudates from C. vulgaris, Halomonas sp., and H. halobium had an affinity for Eu(III) and Cm(III). The log K d of Eu(III) and Cm(III) showed that their sorption was not fully due to the exchange with three protons on the functional groups on cell surfaces. The halophilic microorganisms (Halomonas sp., Halobacterium salinarum, H. halobium) showed almost no pH dependence in log K d , indicating that an exchange with Na + on the functional groups was involved in their sorption. The ΔN H 2 O (= 9 - N H 2 O ) for Eu(III) on C. vulgaris was 1-3, while that for the other microorganisms was over 3, demonstrating that the coordination of Eu(III) with C. vulgaris was predominantly an outer-spherical process. The R E/M for Eu(III) on halophilic microorganisms was 2.5-5, while that for non-halophilic ones was 1-2.5. This finding suggests that the coordination environment of Eu(III) on the halophilic microorganisms is more complicated than that on the other three non-halophilic ones. (orig.)

  18. Sorption behavior of europium(III) and curium(III) on the cell surfaces of microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Ozaki, T.; Kimura, T.; Ohnuki, T.; Yoshida, Z. [Advanced Science Research Center, Japan Atomic Energy Research Inst., Ibaraki (Japan); Gillow, J.B.; Francis, A.J. [Environmental Sciences Dept., Brookhaven National Lab., Upton, NY (United States)

    2004-07-01

    We investigated the association of europium(III) and curium(III) with the microorganisms Chlorella vulgaris, Bacillus subtilis, Pseudomonas fluorescens, Halomonas sp., Halobacterium salinarum, and Halobacterium halobium. We determined the kinetics and distribution coefficients (K{sub d}) for Eu(III) and Cm(III) sorption at pH 3-5 by batch experiments, and evaluated the number of water molecules in the inner-sphere (N{sub H{sub 2}O}) and the degree of strength of ligand field (R{sub E/M}) for Eu(III) by time-resolved laser-induced fluorescence spectroscopy (TRLFS). Exudates from C. vulgaris, Halomonas sp., and H. halobium had an affinity for Eu(III) and Cm(III). The log K{sub d} of Eu(III) and Cm(III) showed that their sorption was not fully due to the exchange with three protons on the functional groups on cell surfaces. The halophilic microorganisms (Halomonas sp., Halobacterium salinarum, H. halobium) showed almost no pH dependence in log K{sub d}, indicating that an exchange with Na{sup +} on the functional groups was involved in their sorption. The {delta}N{sub H{sub 2}O} (= 9 - N{sub H{sub 2}O}) for Eu(III) on C. vulgaris was 1-3, while that for the other microorganisms was over 3, demonstrating that the coordination of Eu(III) with C. vulgaris was predominantly an outer-spherical process. The R{sub E/M} for Eu(III) on halophilic microorganisms was 2.5-5, while that for non-halophilic ones was 1-2.5. This finding suggests that the coordination environment of Eu(III) on the halophilic microorganisms is more complicated than that on the other three non-halophilic ones. (orig.)

  19. Direct observation of electrogenic NH4(+) transport in ammonium transport (Amt) proteins.

    Science.gov (United States)

    Wacker, Tobias; Garcia-Celma, Juan J; Lewe, Philipp; Andrade, Susana L A

    2014-07-08

    Ammonium transport (Amt) proteins form a ubiquitous family of integral membrane proteins that specifically shuttle ammonium across membranes. In prokaryotes, archaea, and plants, Amts are used as environmental NH4(+) scavengers for uptake and assimilation of nitrogen. In the eukaryotic homologs, the Rhesus proteins, NH4(+)/NH3 transport is used instead in acid-base and pH homeostasis in kidney or NH4(+)/NH3 (and eventually CO2) detoxification in erythrocytes. Crystal structures and variant proteins are available, but the inherent challenges associated with the unambiguous identification of substrate and monitoring of transport events severely inhibit further progress in the field. Here we report a reliable in vitro assay that allows us to quantify the electrogenic capacity of Amt proteins. Using solid-supported membrane (SSM)-based electrophysiology, we have investigated the three Amt orthologs from the euryarchaeon Archaeoglobus fulgidus. Af-Amt1 and Af-Amt3 are electrogenic and transport the ammonium and methylammonium cation with high specificity. Transport is pH-dependent, with a steep decline at pH values of ∼5.0. Despite significant sequence homologies, functional differences between the three proteins became apparent. SSM electrophysiology provides a long-sought-after functional assay for the ubiquitous ammonium transporters.

  20. Divergent Roles of RPA Homologs of the Model Archaeon Halobacterium salinarum in Survival of DNA Damage.

    Science.gov (United States)

    Evans, Jessica J; Gygli, Patrick E; McCaskill, Julienne; DeVeaux, Linda C

    2018-04-20

    The haloarchaea are unusual in possessing genes for multiple homologs to the ubiquitous single-stranded DNA binding protein (SSB or replication protein A, RPA) found in all three domains of life. Halobacterium salinarum contains five homologs: two are eukaryotic in organization, two are prokaryotic and are encoded on the minichromosomes, and one is uniquely euryarchaeal. Radiation-resistant mutants previously isolated show upregulation of one of the eukaryotic-type RPA genes. Here, we have created deletions in the five RPA operons. These deletion mutants were exposed to DNA-damaging conditions: ionizing radiation, UV radiation, and mitomycin C. Deletion of the euryarchaeal homolog, although not lethal as in Haloferax volcanii , causes severe sensitivity to all of these agents. Deletion of the other RPA/SSB homologs imparts a variable sensitivity to these DNA-damaging agents, suggesting that the different RPA homologs have specialized roles depending on the type of genomic insult encountered.

  1. Expression of gentisate 1,2-dioxygenase (gdoA) genes involved in aromatic degradation in two haloarchaeal genera.

    Science.gov (United States)

    Fairley, D J; Wang, G; Rensing, C; Pepper, I L; Larkin, M J

    2006-12-01

    Gentisate-1,2-dioxygenase genes (gdoA), with homology to a number of bacterial dioxygenases, and genes encoding a putative coenzyme A (CoA)-synthetase subunit (acdB) and a CoA-thioesterase (tieA) were identified in two haloarchaeal isolates. In Haloarcula sp. D1, gdoA was expressed during growth on 4-hydroxybenzoate but not benzoate, and acdB and tieA were not expressed during growth on any of the aromatic substrates tested. In contrast, gdoA was expressed in Haloferax sp. D1227 during growth on benzoate, 3-hydroxybenzoate, cinnamate and phenylpropionate, and both acdB and tieA were expressed during growth on benzoate, cinnamate and phenylpropionate, but not on 3-hydroxybenzoate. This pattern of induction is consistent with these genes encoding steps in a CoA-mediated benzoate pathway in this strain.

  2. Reclassification of Bacillus marismortui as Salibacillus marismortui comb. nov.

    Science.gov (United States)

    Arahal, D R; Márquez, M C; Volcani, B E; Schleifer, K H; Ventosa, A

    2000-07-01

    Recently, the features of a group of strains isolated from Dead Sea enrichments obtained in 1936 by one of us (B. E. Volcani) were described. They were gram-positive, moderately halophilic, spore-forming rods, and were placed in a new species, Bacillus marismortui. At the same time, the new genus Salibacillus was proposed for the halophilic species Bacillus salexigens. B. marismortui and Salibacillus salexigens have similar phenotypic characteristics and the same peptidoglycan type. Phylogenetic analysis based on 16S rRNA sequence comparisons showed that they are sufficiently closely related (96.6% similarity) as to warrant placement in the same genus. However, DNA-DNA hybridization experiments showed that they constitute two separate species (41% DNA similarity). Therefore the reclassification of Bacillus marismortui as Salibacillus marismortui comb. nov. is proposed.

  3. Quality improvement on half-fin anchovy (Setipinna taty) fish sauce by Psychrobacter sp. SP-1 fermentation.

    Science.gov (United States)

    Zheng, Bin; Liu, Yu; He, Xiaoxia; Hu, Shiwei; Li, Shijie; Chen, Meiling; Jiang, Wei

    2017-10-01

    A method of improving fish sauce quality during fermentation was investigated. Psychrobacter sp. SP-1, a halophilic protease-producing bacterium, was isolated from fish sauce with flavor-enhancing properties and non-biogenic amine-producing activity. The performance of Psychrobacter sp. SP-1 in Setipinna taty fish sauce fermentation was investigated further. The inoculation of Psychrobacter sp. SP-1 did not significantly affect pH or NaCl concentration changes (P > 0.05), although it significantly increased total moderately halophilic microbial count, protease activity, total soluble nitrogen content and amino acid nitrogen content, and also promoted the umami taste and meaty aroma (P sauce quality by fermentation. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  4. Microbial reduction of 99Tc (as TcO4-) in anaerobic alkaline conditions

    International Nuclear Information System (INIS)

    Khizhnyak, T.; Simonoff, M.; Sergeant, C.; Simonoff, G.; Medvedeva-Lyalikova, N.N.

    2003-01-01

    The ability of bacteria to reduce pertechnetate in alkaline conditions was investigated using halophilic bacteria isolated from soda-lakes environments. Anaerobic halophilic bacteria were able to reduce as much as 0.25 mM pertechnetate, whereas no reduction took place without bacteria or in the presence of heat-killed bacteria. The results obtained showed reduction of Tc(VII)O 4 - to the Tc(V) and Tc(IV) at pH 10 in the carbonate-bicarbonate medium. About 57% of the total technetium was determined to be Tc(IV), 1-3% as a Tc(V) and 17-20% as a Tc(VII) after 1-3 days of incubation with bacteria. The microbial reduction of Tc(VII) in alkaline conditions has been suggested as a potential mechanism for the removal of Tc from contaminated environments or waste streams. (author)

  5. The Genome Sequence of Methanohalophilus mahii SLPT Reveals Differences in the Energy Metabolism among Members of the Methanosarcinaceae Inhabiting Freshwater and Saline Environments

    Directory of Open Access Journals (Sweden)

    Stefan Spring

    2010-01-01

    Full Text Available Methanohalophilus mahii is the type species of the genus Methanohalophilus, which currently comprises three distinct species with validly published names. Mhp. mahii represents moderately halophilic methanogenic archaea with a strictly methylotrophic metabolism. The type strain SLPT was isolated from hypersaline sediments collected from the southern arm of Great Salt Lake, Utah. Here we describe the features of this organism, together with the complete genome sequence and annotation. The 2,012,424 bp genome is a single replicon with 2032 protein-coding and 63 RNA genes and part of the Genomic Encyclopedia of Bacteria and Archaea project. A comparison of the reconstructed energy metabolism in the halophilic species Mhp. mahii with other representatives of the Methanosarcinaceae reveals some interesting differences to freshwater species.

  6. Metabolic Capabilities of the Members of the Order Halanaerobiales and Their Potential Biotechnological Applications

    Energy Technology Data Exchange (ETDEWEB)

    Roush, Daniel W [Missouri University of Science and Technology; Elias, Dwayne A [ORNL; Mormile, Dr. Melanie R. [Missouri University of Science and Technology

    2014-01-01

    The order Halanaerobiales contains a number of well-studied halophiles that possess great potential for biotechnological applications. The unique halophilic adaptations that these organisms utilize, such as salting-in mechanisms to increase their intercellular concentration of KCl, combined with their ability to ferment simple sugars, provides an excellent platform for biotechnological development over a wide range of salt levels and possible other extreme conditions, such as alkaline conditions. From fermented foods to oil reservoirs, members of Halanaerobiales are found in many environments. The environmental conditions many of these organisms grow are similar to industrially important processes, such as alkaline pre-treated biomass stocks, treatment of crude glycerol from biodiesel production, salty fermented foods, as well as bioremediation of contaminants under extreme conditions of salinity and in some cases, alkalinity. From salt stable enzymes to waste fermentations, bioremediation options, bioenergy, and microbially enhanced oil recovery (MEOR), Halanaerobiales can provide a wide spectrum of environmentally friendly solutions to current problems.

  7. The Genome Sequence of Methanohalophilus mahii SLPT Reveals Differences in the Energy Metabolism among Members of the Methanosarcinaceae Inhabiting Freshwater and Saline Environments

    Energy Technology Data Exchange (ETDEWEB)

    Spring, Stefan [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Scheuner, Carmen [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute; Lucas, Susan [U.S. Department of Energy, Joint Genome Institute; Glavina Del Rio, Tijana [U.S. Department of Energy, Joint Genome Institute; Tice, Hope [U.S. Department of Energy, Joint Genome Institute; Copeland, A [U.S. Department of Energy, Joint Genome Institute; Cheng, Jan-Fang [U.S. Department of Energy, Joint Genome Institute; Chen, Feng [U.S. Department of Energy, Joint Genome Institute; Nolan, Matt [U.S. Department of Energy, Joint Genome Institute; Saunders, Elizabeth H [Los Alamos National Laboratory (LANL); Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Liolios, Konstantinos [U.S. Department of Energy, Joint Genome Institute; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Mavromatis, K [U.S. Department of Energy, Joint Genome Institute; Lykidis, A [U.S. Department of Energy, Joint Genome Institute; Pati, Amrita [U.S. Department of Energy, Joint Genome Institute; Chen, Amy [U.S. Department of Energy, Joint Genome Institute; Palaniappan, Krishna [U.S. Department of Energy, Joint Genome Institute; Land, Miriam L [ORNL; Hauser, Loren John [ORNL; Chang, Yun-Juan [ORNL; Jeffries, Cynthia [Oak Ridge National Laboratory (ORNL); Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Detter, J. Chris [U.S. Department of Energy, Joint Genome Institute; Brettin, Thomas S [ORNL; Rohde, Manfred [HZI - Helmholtz Centre for Infection Research, Braunschweig, Germany; Goker, Markus [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute; Bristow, James [U.S. Department of Energy, Joint Genome Institute; Eisen, Jonathan [U.S. Department of Energy, Joint Genome Institute; Markowitz, Victor [U.S. Department of Energy, Joint Genome Institute; Hugenholtz, Philip [U.S. Department of Energy, Joint Genome Institute; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Klenk, Hans-Peter [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany

    2010-01-01

    Methanohalophilus mahii is the type species of the genus Methanohalophilus, which currently comprises three distinct species with validly published names. Mhp. mahii represents moderately halophilic methanogenic archaea with a strictly methylotrophic metabolism. The type strain SLPT was isolated from hypersaline sediments collected from the southern arm of Great Salt Lake, Utah. Here we describe the features of this organism, together with the complete genome sequence and annotation. The 2,012,424 bp genome is a single replicon with 2032 protein-coding and 63 RNA genes and part of the Genomic Encyclopedia of Bacteria and Archaea project. A comparison of the reconstructed energy metabolism in the halophilic species Mhp. mahii with other representatives of the Methanosarcinaceae reveals some interesting differences to freshwater species.

  8. The Genome Sequence of Methanohalophilus mahii SLPT Reveals Differences in the Energy Metabolism among Members of the Methanosarcinaceae Inhabiting Freshwater and Saline Environments

    Energy Technology Data Exchange (ETDEWEB)

    Spring, Stefan [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Scheuner, Carmen [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Lapidus, Alla L. [Joint Genome Institute, Walnut Creek, California; Lucas, Susan [Joint Genome Institute, Walnut Creek, California; Glavina Del Rio, Tijana [Joint Genome Institute, Walnut Creek, California; Tice, Hope [Joint Genome Institute, Walnut Creek, California; Copeland, A [U.S. Department of Energy, Joint Genome Institute; Cheng, Jan-Fang [Joint Genome Institute, Walnut Creek, California; Chen, Feng [Joint Genome Institute, Walnut Creek, California; Nolan, Matt [Joint Genome Institute, Walnut Creek, California; Saunders, Elizabeth H [Los Alamos National Laboratory (LANL); Pitluck, Samuel [ORNL; Liolios, Konstantinos [Joint Genome Institute, Walnut Creek, California; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Mavromatis, K [U.S. Department of Energy, Joint Genome Institute; Lykidis, A [U.S. Department of Energy, Joint Genome Institute; Pati, Amrita [U.S. Department of Energy, Joint Genome Institute; Chen, Amy [Joint Genome Institute, Walnut Creek, California; Palaniappan, Krishna [Joint Genome Institute, Walnut Creek, California; Land, Miriam L [ORNL; Hauser, Loren John [ORNL; Chang, Yun-Juan [ORNL; Jeffries, Cynthia D [ORNL; Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Detter, J. Chris [Joint Genome Institute, Walnut Creek, California; Brettin, Thomas S [ORNL; Rohde, Manfred [HZI - Helmholtz Centre for Infection Research, Braunschweig, Germany; Goker, Markus [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Woyke, Tanja [ORNL; Bristow, James [Joint Genome Institute, Walnut Creek, California; Eisen, Jonathan [Joint Genome Institute, Walnut Creek, California; Markowitz, Victor [Joint Genome Institute, Walnut Creek, California; Hugenholtz, Philip [U.S. Department of Energy, Joint Genome Institute; Kyrpidis, Nikos C [ORNL; Klenk, Hans-Peter [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany

    2010-12-01

    Methanohalophilus mahii is the type species of the genus Methanohalophilus, which currently comprises three distinct species with validly published names. Mhp. mahii represents moderately halophilic methanogenic archaea with a strictly methylotrophic metabolism. The type strain SLPT was isolated from hypersaline sediments collected from the southern arm of Great Salt Lake, Utah. Here we describe the features of this organism, together with the complete genome sequence and annotation. The 2,012,424 bp genome is a single replicon with 2032 protein-coding and 63 RNA genes and part of the Genomic Encyclopedia of Bacteria and Archaea project. A comparison of the reconstructed energy metabolism in the halophilic species Mhp. mahii with other representatives of the Methanosarcinaceae reveals some interesting differences to freshwater species.

  9. Proteomic properties reveal phyloecological clusters of Archaea.

    Directory of Open Access Journals (Sweden)

    Nela Nikolic

    Full Text Available In this study, we propose a novel way to describe the variety of environmental adaptations of Archaea. We have clustered 57 Archaea by using a non-redundant set of proteomic features, and verified that the clusters correspond to environmental adaptations to the archaeal habitats. The first cluster consists dominantly of hyperthermophiles and hyperthermoacidophilic aerobes. The second cluster joins together halophilic and extremely halophilic Archaea, while the third cluster contains mesophilic (mostly methanogenic Archaea together with thermoacidophiles. The non-redundant subset of proteomic features was found to consist of five features: the ratio of charged residues to uncharged, average protein size, normalized frequency of beta-sheet, normalized frequency of extended structure and number of hydrogen bond donors. We propose this clustering to be termed phyloecological clustering. This approach could give additional insights into relationships among archaeal species that may be hidden by sole phylogenetic analysis.

  10. Salt and alkali stresses reduction in wheat by plant growth promoting haloalkaliphilic bacteria

    OpenAIRE

    Torbaghan, Mehrnoush Eskandari; Lakzian, Amir; Astaraei, Ali Reza; Fotovat, Amir; Besharati, Hossein

    2017-01-01

    Haloalkaliphilic bacteria have plant growth promoting characteristics that can be used to deal with different environmental stresses. To study the effect of haloalkaliphilic bacteria to reduce salinity and alkalinity stress in wheat, 48 isolates were isolated and grouped into halophiles, alkaliphiles and haloalkaliphiles based on growth characteristics. The ammonia, 3-indole acetic acid and ACC (1-aminocyclopropane-1-carboxylate) deaminase production were studied. Wheat yield was evaluated in...

  11. Ecology of Hypersaline Microorganisms

    Digital Repository Service at National Institute of Oceanography (India)

    Kerkar, S.

    of ancient seas. Deep Sea brines are relatively stable as a result of their higher density as reported in the Red Sea and Gulf of Mexico (MacDonald et al, 1990). Preliminary studies have suggested that microbial activity occurs in some Deep Sea hypersaline... partially characterized extreme halophile called ?Halobacterium sp GN101? (GN = Guerrero Negro, Mexico) (Ebert and Goebel, 1985). Hal R1 activity is typical with first activity detected during the transition from exponential to stationary phase...

  12. Draft Genome Sequence of the Polyextremophilic Halorubrum sp. Strain AJ67, Isolated from Hyperarsenic Lakes in the Argentinian Puna

    OpenAIRE

    Burguener, Germán Federico; Maldonado, Marcos Javier; Revale, Santiago; Fernández Do Porto, Darío Augusto; Rascovan, Nicolas; Vazquez, Martin Pablo; Farias, Maria Eugenia; Marti, Marcelo Adrian; Turjanski, Adrian

    2016-01-01

    Halorubrum sp. AJ67, an extreme halophilic, UV resistant archae that was isolated from Laguna Antofalla in the Argentinean Puna. The draft genome sequence suggests potent enzyme candidates that are essential to survive in multiple environmental extreme conditions, as high UV radiation, elevated salinity and the presence of critical arsenic concentration. Fil: Burguener, Germán Federico. Facultad de Ciencias Exactas y Naturales. Instituto de Cálculo. Plataforma de Bioinformática Argentina; ...

  13. Identification of a haloalkaliphilic and thermostable cellulase with improved ionic liquid tolerance

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Tao; Datta, Supratim; Eichler, Jerry; Ivanova, Natalia; Axen, Seth D.; Kerfeld, Cheryl A.; Chen, Feng; Kyrpides, Nikos; Hugenholtz, Philip; Cheng, Jan-Fang; Sale, Kenneth L.; Simmons, Blake; Rubin, Eddy

    2011-02-17

    Some ionic liquids (ILs) have been shown to be very effective solvents for biomass pretreatment. It is known that some ILs can have a strong inhibitory effect on fungal cellulases, making the digestion of cellulose inefficient in the presence of ILs. The identification of IL-tolerant enzymes that could be produced as a cellulase cocktail would reduce the costs and water use requirements of the IL pretreatment process. Due to their adaptation to high salinity environments, halophilic enzymes are hypothesized to be good candidates for screening and identifying IL-resistant cellulases. Using a genome-based approach, we have identified and characterized a halophilic cellulase (Hu-CBH1) from the halophilic archaeon, Halorhabdus utahensis. Hu-CBH1 is present in a gene cluster containing multiple putative cellulolytic enzymes. Sequence and theoretical structure analysis indicate that Hu-CBH1 is highly enriched with negatively charged acidic amino acids on the surface, which may form a solvation shell that may stabilize the enzyme, through interaction with salt ions and/or water molecules. Hu-CBH1 is a heat tolerant haloalkaliphilic cellulase and is active in salt concentrations up to 5 M NaCl. In high salt buffer, Hu-CBH1 can tolerate alkali (pH 11.5) conditions and, more importantly, is tolerant to high levels (20percent w/w) of ILs, including 1-allyl-3-methylimidazolium chloride ([Amim]Cl). Interestingly, the tolerances to heat, alkali and ILs are found to be salt-dependent, suggesting that the enzyme is stabilized by the presence of salt. Our results indicate that halophilic enzymes are good candidates for the screening of IL-tolerant cellulolytic enzymes.

  14. Effect of biowaste sludge maturation on the diversity of thermophilic bacteria and archaea in an anaerobic reactor.

    Science.gov (United States)

    Goberna, M; Insam, H; Franke-Whittle, I H

    2009-04-01

    Prokaryotic diversity was investigated near the inlet and outlet of a plug-flow reactor. After analyzing 800 clones, 50 bacterial and 3 archaeal phylogenetic groups were defined. Clostridia (>92%) dominated among bacteria and Methanoculleus (>90%) among archaea. Significant changes in pH and volatile fatty acids did not invoke a major shift in the phylogenetic groups. We suggest that the environmental filter imposed by the saline conditions (20 g liter(-1)) selected a stable community of halotolerant and halophilic prokaryotes.

  15. Draft Genome Sequence of Nafulsella turpanensis ZLM-10T, a Novel Member of the Family Flammeovirgaceae.

    Science.gov (United States)

    Zhang, Lei; Si, Meiru; Zhu, Lingfang; Li, Changfu; Wei, Yahong; Shen, Xihui

    2014-04-03

    Nafulsella turpanensis ZLM-10(T) is a slightly halophilic, Gram-negative, rod-shaped, gliding, pale-pink-pigmented bacterium in the family Flammeovirgaceae, and it shows resistance to gentamicin, kanamycin, neomycin, and streptomycin. Here, we report the genome sequence of N. turpanensis strain ZLM-10(T), which has a 4.8-Mb genome and a G+C content of 45.67%.

  16. Draft Genome Sequence of Nafulsella turpanensis ZLM-10T, a Novel Member of the Family Flammeovirgaceae

    OpenAIRE

    Zhang, Lei; Si, Meiru; Zhu, Lingfang; Li, Changfu; Wei, Yahong; Shen, Xihui

    2014-01-01

    Nafulsella turpanensis ZLM-10T is a slightly halophilic, Gram-negative, rod-shaped, gliding, pale-pink-pigmented bacterium in the family Flammeovirgaceae, and it shows resistance to gentamicin, kanamycin, neomycin, and streptomycin. Here, we report the genome sequence of N. turpanensis strain ZLM-10T, which has a 4.8-Mb genome and a G+C content of 45.67%.

  17. Draft Genome Sequence of Cyanobacterium sp. Strain HL-69, Isolated from a Benthic Microbial Mat from a Magnesium Sulfate-Dominated Hypersaline Lake

    Energy Technology Data Exchange (ETDEWEB)

    Mobberley, J. M.; Romine, M. F.; Cole, J. K.; Maezato, Y.; Lindemann, S. R.; Nelson, W. C.

    2018-02-08

    ABSTRACT

    The complete genome sequence ofCyanobacteriumsp. strain HL-69 consists of 3,155,247 bp and contains 2,897 predicted genes comprising a chromosome and two plasmids. The genome is consistent with a halophilic nondiazotrophic phototrophic lifestyle, and this organism is able to synthesize most B vitamins and produces several secondary metabolites.

  18. Septicemia caused by Vibrio parahemolyticus: a case report.

    Science.gov (United States)

    Hsu, G J; Young, T; Peng, M Y; Chang, F Y; Chou, M Y

    1993-11-01

    Vibrio parahemolyticus is a halophilic marine vibrio commonly associated with outbreaks of acute gastroenteritis which also sometimes causes serious wound infection. It is an uncommon cause of septicemia. A few reports suggest that patients with chronic liver disease and leukemia are more susceptible. A case of liver cirrhosis with septicemia caused by this organism is discussed. The patient's condition rapidly deteriorated, and he died 12 hours after admission.

  19. ABC Transporter for Corrinoids in Halobacterium sp. Strain NRC-1†

    OpenAIRE

    Woodson, Jesse D.; Reynolds, April A.; Escalante-Semerena, Jorge C.

    2005-01-01

    We report evidence for the existence of a putative ABC transporter for corrinoid utilization in the extremely halophilic archaeon Halobacterium sp. strain NRC-1. Results from genetic and nutritional analyses of Halobacterium showed that mutants with lesions in open reading frames (ORFs) Vng1370G, Vng1371Gm, and Vng1369G required a 105-fold higher concentration of cobalamin for growth than the wild-type or parent strain. The data support the conclusion that these ORFs encode orthologs of the b...

  20. Archaebacterial phylogeny: perspectives on the urkingdoms

    Science.gov (United States)

    Woese, C. R.; Olsen, G. J.

    1986-01-01

    Comparisons of complete 16S ribosomal RNA sequences have been used to confirm, refine and extend earlier concepts of archaebacterial phylogeny. The archaebacteria fall naturally into two major branches or divisions, I--the sulfur-dependent thermophilic archaebacteria, and II--the methanogenic archaebacteria and their relatives. Division I comprises a relatively closely related and phenotypically homogeneous collection of thermophilic sulfur-dependent species--encompassing the genera Sulfolobus, Thermoproteus, Pyrodictium and Desulfurococcus. The organisms of Division II, however, form a less compact grouping phylogenetically, and are also more diverse in phenotype. All three of the (major) methanogen groups are found in Division II, as are the extreme halophiles and two types of thermoacidophiles, Thermoplasma acidophilum and Thermococcus celer. This last species branches sufficiently deeply in the Division II line that it might be considered to represent a separate, third Division. However, both the extreme halophiles and Tp. acidophilum branch within the cluster of methanogens. The extreme halophiles are specifically related to the Methanomicrobiales, to the exclusion of both the Methanococcales and the Methanobacteriales. Tp. acidophilum is peripherally related to the halophile-Methanomicrobiales group. By 16S rRNA sequence measure the archaebacteria constitute a phylogenetically coherent grouping (clade), which excludes both the eubacteria and the eukaryotes--a conclusion that is supported by other sequence evidence as well. Alternative proposals for archaebacterial phylogeny, not based upon sequence evidence, are discussed and evaluated. In particular, proposals to rename (reclassify) various subgroups of the archaebacteria as new kingdoms are found wanting, for both their lack of proper experimental support and the taxonomic confusion they introduce.

  1. The primary structures of ribosomal proteins S14 and S16 from the archaebacterium Halobacterium marismortui. Comparison with eubacterial and eukaryotic ribosomal proteins.

    Science.gov (United States)

    Kimura, J; Kimura, M

    1987-09-05

    The amino acid sequences of two ribosomal proteins, S14 and S16, from the archaebacterium Halobacterium marismortui have been determined. Sequence data were obtained by the manual and solid-phase sequencing of peptides derived from enzymatic digestions with trypsin, chymotrypsin, pepsin, and Staphylococcus aureus protease as well as by chemical cleavage with cyanogen bromide. Proteins S14 and S16 contain 109 and 126 amino acid residues and have Mr values of 11,964 and 13,515, respectively. Comparison of the sequences with those of ribosomal proteins from other organisms demonstrates that S14 has a significant homology with the rat liver ribosomal protein S11 (36% identity) as well as with the Escherichia coli ribosomal protein S17 (37%), and that S16 is related to the yeast ribosomal protein YS22 (40%) and proteins S8 from E. coli (28%) and Bacillus stearothermophilus (30%). A comparison of the amino acid residues in the homologous regions of halophilic and nonhalophilic ribosomal proteins reveals that halophilic proteins have more glutamic acids, asparatic acids, prolines, and alanines, and less lysines, arginines, and isoleucines than their nonhalophilic counterparts. These amino acid substitutions probably contribute to the structural stability of halophilic ribosomal proteins.

  2. The Survival and Resistance of Halobacterium salinarum NRC-1, Halococcus hamelinensis, and Halococcus morrhuae to Simulated Outer Space Solar Radiation.

    Science.gov (United States)

    Leuko, S; Domingos, C; Parpart, A; Reitz, G; Rettberg, P

    2015-11-01

    Solar radiation is among the most prominent stress factors organisms face during space travel and possibly on other planets. Our analysis of three different halophilic archaea, namely Halobacterium salinarum NRC-1, Halococcus morrhuae, and Halococcus hamelinensis, which were exposed to simulated solar radiation in either dried or liquid state, showed tremendous differences in tolerance and survivability. We found that Hcc. hamelinensis is not able to withstand high fluences of simulated solar radiation compared to the other tested organisms. These results can be correlated to significant differences in genomic integrity following exposure, as visualized by random amplified polymorphic DNA (RAPD)-PCR. In contrast to the other two tested strains, Hcc. hamelinensis accumulates compatible solutes such as trehalose for osmoprotection. The addition of 100 mM trehalose to the growth medium of Hcc. hamelinensis improved its survivability following exposure. Exposure of cells in liquid at different temperatures suggests that Hbt. salinarum NRC-1 is actively repairing cellular and DNA damage during exposure, whereas Hcc. morrhuae exhibits no difference in survival. For Hcc. morrhuae, the high resistance against simulated solar radiation may be explained with the formation of cell clusters. Our experiments showed that these clusters shield cells on the inside against simulated solar radiation, which results in better survival rates at higher fluences when compared to Hbt. salinarum NRC-1 and Hcc. hamelinensis. Overall, this study shows that some halophilic archaea are highly resistant to simulated solar radiation and that they are of high astrobiological significance. Halophiles-Solar radiation-Stress resistance-Survival.

  3. Archaea: Essential inhabitants of the human digestive microbiota

    Directory of Open Access Journals (Sweden)

    Vanessa Demonfort Nkamga

    2017-03-01

    Full Text Available Prokaryotes forming the domain of Archaea, named after their first discovery in extreme environments, are acknowledged but still neglected members of the human digestive tract microbiota. In this microbiota, cultured archaea comprise anaerobic methanogens: Methanobrevibacter smithii, Methanobrevibacter oralis, Methanobrevibacter massiliense, Methanosphaera stadtmanae, Methanobrevibacter arboriphilus, Methanobrevibacter millerae and Methanomassiliicoccus luminyensis; along with the non-methanogen halophilic Archaea Halopherax massiliense. Metagenomic analyses detected DNA sequences indicative of the presence of additional methanogenic and non-methanogenic halophilic Archaea in the human intestinal tract and oral cavity. Methanogens specifically metabolize hydrogen produced by anaerobic fermentation of carbohydrates into methane; further transforming heavy metals and metalloids into methylated derivatives, such as trimethylbismuth which is toxic for both human and bacterial cells. However, the role of Archaea as pathogens remains to be established. Future researches will aim to increase the repertoire of the human digestive tract Archaea and to understand their possible association with intestinal and extra-intestinal infections and diseases including weight regulation abnormalities. Keywords: Human-associated Archaea, Methanogens, Halophiles, Oral cavity, Intestinal tract

  4. Biodegradation of glyphosate herbicide by Salinicoccus spp isolated from Qom Hoze-soltan lake, Iran

    Directory of Open Access Journals (Sweden)

    Yaser Sharifi

    2015-01-01

    Full Text Available Background: Glyphosate (N-phosphonomethyl Glycine is an organophosphorus pesticide with dangerous effects on the environment. In this study, the biodegradation of glyphosate herbicide by halophilic bacteria isolated from Qom Hoze-Soltan Lake has been investigated. Methods: After sampling and bacterial isolation, native halophilic strains grown in the presence of glyphosate at a wavelength of 660 nm and also the disappearance of the glyphosate in the plates at a wavelength of 220 nm were determined and the dominant bacteria were isolated. Biochemical, molecular (according to the 16S rRNA sequence, antibiotic, and the Minimum Inhibitory Concentration (MIC test was performed for the dominant bacteria. Analysis of the remaining glyphosate herbicide was performed by HPLC analysis after derivation with FMOC-Cl. Results: According to the results of the biochemical, antibiotic and molecular 16S rRNA tests, the native halophilic isolates with the ability to biodegrade glyphosate were gram positive cocci very similar to Salinicoccusspp. The results of HPLC showed that Salinicoccusspp is able to biodegrade glyphosate herbicide. Conclusion: The native bacteria in Qom Hoze-soltanlake, Iran can be used for biodegradation of glyphosate herbicide.

  5. Survival and death of the haloarchaeon Natronorubrum strain HG-1 in a simulated martian environment

    Science.gov (United States)

    Peeters, Z.; Vos, D.; ten Kate, I. L.; Selch, F.; van Sluis, C. A.; Sorokin, D. Yu.; Muijzer, G.; Stan-Lotter, H.; van Loosdrecht, M. C. M.; Ehrenfreund, P.

    2010-11-01

    Halophilic archaea are of interest to astrobiology due to their survival capabilities in desiccated and high salt environments. The detection of remnants of salty pools on Mars stimulated investigations into the response of haloarchaea to martian conditions. Natronorubrum sp. strain HG-1 is an extremely halophilic archaeon with unusual metabolic pathways, growing on acetate and stimulated by tetrathionate. We exposed Natronorubrum strain HG-1 to ultraviolet (UV) radiation, similar to levels currently prevalent on Mars. In addition, the effects of low temperature (4, -20, and -80 °C), desiccation, and exposure to a Mars soil analogue from the Atacama desert on the viability of Natronorubrum strain HG-1 cultures were investigated. The results show that Natronorubrum strain HG-1 cannot survive for more than several hours when exposed to UV radiation equivalent to that at the martian equator. Even when protected from UV radiation, viability is impaired by a combination of desiccation and low temperature. Desiccating Natronorubrum strain HG-1 cells when mixed with a Mars soil analogue impaired growth of the culture to below the detection limit. Overall, we conclude that Natronorubrum strain HG-1 cannot survive the environment currently present on Mars. Since other halophilic microorganisms were reported to survive simulated martian conditions, our results imply that survival capabilities are not necessarily shared between phylogenetically related species.

  6. Potential for plant growth promotion of rhizobacteria associated with Salicornia growing in Tunisian hypersaline soils.

    Science.gov (United States)

    Mapelli, Francesca; Marasco, Ramona; Rolli, Eleonora; Barbato, Marta; Cherif, Hanene; Guesmi, Amel; Ouzari, Imen; Daffonchio, Daniele; Borin, Sara

    2013-01-01

    Soil salinity and drought are among the environmental stresses that most severely affect plant growth and production around the world. In this study the rhizospheres of Salicornia plants and bulk soils were collected from Sebkhet and Chott hypersaline ecosystems in Tunisia. Depiction of bacterial microbiome composition by Denaturing Gradient Gel Electrophoresis unveiled the occurrence of a high bacterial diversity associated with Salicornia root system. A large collection of 475 halophilic and halotolerant bacteria was established from Salicornia rhizosphere and the surrounding bulk soil, and the bacteria were characterized for the resistance to temperature, osmotic and saline stresses, and plant growth promotion (PGP) features. Twenty Halomonas strains showed resistance to a wide set of abiotic stresses and were able to perform different PGP activities in vitro at 5% NaCl, including ammonia and indole-3-acetic acid production, phosphate solubilisation, and potential nitrogen fixation. By using a gfp-labelled strain it was possible to demonstrate that Halomonas is capable of successfully colonising Salicornia roots in the laboratory conditions. Our results indicated that the culturable halophilic/halotolerant bacteria inhabiting salty and arid ecosystems have a potential to contribute to promoting plant growth under the harsh salinity and drought conditions. These halophilic/halotolerant strains could be exploited in biofertilizer formulates to sustain crop production in degraded and arid lands.

  7. Metabolic Capability of a Predominant Halanaerobium sp. in Hydraulically Fractured Gas Wells and Its Implication in Pipeline Corrosion

    Science.gov (United States)

    Liang, Renxing; Davidova, Irene A.; Marks, Christopher R.; Stamps, Blake W.; Harriman, Brian H.; Stevenson, Bradley S.; Duncan, Kathleen E.; Suflita, Joseph M.

    2016-01-01

    Microbial activity associated with produced water from hydraulic fracturing operations can lead to gas souring and corrosion of carbon-steel equipment. We examined the microbial ecology of produced water and the prospective role of the prevalent microorganisms in corrosion in a gas production field in the Barnett Shale. The microbial community was mainly composed of halophilic, sulfidogenic bacteria within the order Halanaerobiales, which reflected the geochemical conditions of highly saline water containing sulfur species (S2O32-, SO42-, and HS-). A predominant, halophilic bacterium (strain DL-01) was subsequently isolated and identified as belonging to the genus Halanaerobium. The isolate could degrade guar gum, a polysaccharide polymer used in fracture fluids, to produce acetate and sulfide in a 10% NaCl medium at 37°C when thiosulfate was available. To mitigate potential deleterious effects of sulfide and acetate, a quaternary ammonium compound was found to be an efficient biocide in inhibiting the growth and metabolic activity of strain DL-01 relative to glutaraldehyde and tetrakis (hydroxymethyl) phosphonium sulfate. Collectively, our findings suggest that predominant halophiles associated with unconventional shale gas extraction could proliferate and produce sulfide and acetate from the metabolism of polysaccharides used in hydraulic fracturing fluids. These metabolic products might be returned to the surface and transported in pipelines to cause pitting corrosion in downstream infrastructure. PMID:27446028

  8. Structural adaptations of octaheme nitrite reductases from haloalkaliphilic Thioalkalivibrio bacteria to alkaline pH and high salinity.

    Directory of Open Access Journals (Sweden)

    Anna Popinako

    Full Text Available Bacteria Tv. nitratireducens and Tv. paradoxus from soda lakes grow optimally in sodium carbonate/NaCl brines at pH range from 9.5 to 10 and salinity from 0.5 to 1.5 M Na+. Octaheme nitrite reductases (ONRs from haloalkaliphilic bacteria of genus Thioalkalivibrio are stable and active in a wide range of pH (up to 11 and salinity (up to 1 M NaCl. To establish adaptation mechanisms of ONRs from haloalkaliphilic bacteria a comparative analysis of amino acid sequences and structures of ONRs from haloalkaliphilic bacteria and their homologues from non-halophilic neutrophilic bacteria was performed. The following adaptation strategies were observed: (1 strategies specific for halophilic and alkaliphilic proteins (an increase in the number of aspartate and glutamate residues and a decrease in the number of lysine residues on the protein surface, (2 strategies specific for halophilic proteins (an increase in the arginine content and a decrease in the number of hydrophobic residues on the solvent-accessible protein surface, (3 strategies specific for alkaliphilic proteins (an increase in the area of intersubunit hydrophobic contacts. Unique adaptation mechanism inherent in the ONRs from bacteria of genus Thioalkalivibrio was revealed (an increase in the core in the number of tryptophan and phenylalanine residues, and an increase in the number of small side chain residues, such as alanine and valine, in the core.

  9. Potential and limits of Raman spectroscopy for carotenoid detection in microorganisms: implications for astrobiology

    Science.gov (United States)

    Jehlička, Jan; Edwards, Howell G. M.; Osterrothová, Kateřina; Novotná, Julie; Nedbalová, Linda; Kopecký, Jiří; Němec, Ivan; Oren, Aharon

    2014-01-01

    In this paper, it is demonstrated how Raman spectroscopy can be used to detect different carotenoids as possible biomarkers in various groups of microorganisms. The question which arose from previous studies concerns the level of unambiguity of discriminating carotenoids using common Raman microspectrometers. A series of laboratory-grown microorganisms of different taxonomic affiliation was investigated, such as halophilic heterotrophic bacteria, cyanobacteria, the anoxygenic phototrophs, the non-halophilic heterotrophs as well as eukaryotes (Ochrophyta, Rhodophyta and Chlorophyta). The data presented show that Raman spectroscopy is a suitable tool to assess the presence of carotenoids of these organisms in cultures. Comparison is made with the high-performance liquid chromatography approach of analysing pigments in extracts. Direct measurements on cultures provide fast and reliable identification of the pigments. Some of the carotenoids studied are proposed as tracers for halophiles, in contrast with others which can be considered as biomarkers of other genera. The limits of application of Raman spectroscopy are discussed for a few cases where the current Raman spectroscopic approach does not allow discriminating structurally very similar carotenoids. The database reported can be used for applications in geobiology and exobiology for the detection of pigment signals in natural settings. PMID:25368348

  10. Potential for Plant Growth Promotion of Rhizobacteria Associated with Salicornia Growing in Tunisian Hypersaline Soils

    Directory of Open Access Journals (Sweden)

    Francesca Mapelli

    2013-01-01

    Full Text Available Soil salinity and drought are among the environmental stresses that most severely affect plant growth and production around the world. In this study the rhizospheres of Salicornia plants and bulk soils were collected from Sebkhet and Chott hypersaline ecosystems in Tunisia. Depiction of bacterial microbiome composition by Denaturing Gradient Gel Electrophoresis unveiled the occurrence of a high bacterial diversity associated with Salicornia root system. A large collection of 475 halophilic and halotolerant bacteria was established from Salicornia rhizosphere and the surrounding bulk soil, and the bacteria were characterized for the resistance to temperature, osmotic and saline stresses, and plant growth promotion (PGP features. Twenty Halomonas strains showed resistance to a wide set of abiotic stresses and were able to perform different PGP activities in vitro at 5% NaCl, including ammonia and indole-3-acetic acid production, phosphate solubilisation, and potential nitrogen fixation. By using a gfp-labelled strain it was possible to demonstrate that Halomonas is capable of successfully colonising Salicornia roots in the laboratory conditions. Our results indicated that the culturable halophilic/halotolerant bacteria inhabiting salty and arid ecosystems have a potential to contribute to promoting plant growth under the harsh salinity and drought conditions. These halophilic/halotolerant strains could be exploited in biofertilizer formulates to sustain crop production in degraded and arid lands.

  11. Grappling archaea: ultrastructural analyses of an uncultivated, cold-loving archaeon and its biofilm

    Directory of Open Access Journals (Sweden)

    Alexandra ePerras

    2014-08-01

    Full Text Available Similarly to Bacteria, Archaea are microorganisms that interact with their surrounding environment in a versatile manner. To date, interactions based on cellular structure and surface appendages have mainly been documented using model systems of cultivable archaea under laboratory conditions. Here, we report on the microbial interactions and ultrastructural features of the uncultivated SM1 Euryarchaeon, which is highly dominant in its biotope. Therefore, biofilm samples taken from the Sippenauer Moor, Germany, were investigated via transmission electron microscopy (TEM; negative staining, thin-sectioning and scanning electron microscopy (SEM in order to elucidate the fine structures of the microbial cells and the biofilm itself. The biofilm consisted of small archaeal cocci (0.6 µm diameter, arranged in a regular pattern (1.2-2.0 µm distance from cell to cell, whereas each archaeon was connected to 6 other archaea on average. Extracellular polymeric substances (EPS were limited to the close vicinity of the archaeal cells, and specific cell surface appendages (hami, Moissl et al., 2005 protruded beyond the EPS matrix enabling microbial interaction by cell-cell contacts among the archaea and between archaea and bacteria. All analyzed hami revealed their previously described architecture of nano-grappling hooks and barb-wire basal structures. Considering the archaeal cell walls, the SM1 Euryarchaea exhibited a double-membrane, which has rarely been reported for members of this phylogenetic domain. Based on these findings, the current generalized picture on archaeal cell walls needs to be revisited, as archaeal cell structures are more complex and sophisticated than previously assumed, particularly when looking into the uncultivated majority.

  12. Coupling genetic and chemical microbiome profiling reveals heterogeneity of archaeome and bacteriome in subsurface biofilms that are dominated by the same archaeal species.

    Directory of Open Access Journals (Sweden)

    Alexander J Probst

    Full Text Available Earth harbors an enormous portion of subsurface microbial life, whose microbiome flux across geographical locations remains mainly unexplored due to difficult access to samples. Here, we investigated the microbiome relatedness of subsurface biofilms of two sulfidic springs in southeast Germany that have similar physical and chemical parameters and are fed by one deep groundwater current. Due to their unique hydrogeological setting these springs provide accessible windows to subsurface biofilms dominated by the same uncultivated archaeal species, called SM1 Euryarchaeon. Comparative analysis of infrared imaging spectra demonstrated great variations in archaeal membrane composition between biofilms of the two springs, suggesting different SM1 euryarchaeal strains of the same species at both aquifer outlets. This strain variation was supported by ultrastructural and metagenomic analyses of the archaeal biofilms, which included intergenic spacer region sequencing of the rRNA gene operon. At 16S rRNA gene level, PhyloChip G3 DNA microarray detected similar biofilm communities for archaea, but site-specific communities for bacteria. Both biofilms showed an enrichment of different deltaproteobacterial operational taxonomic units, whose families were, however, congruent as were their lipid spectra. Consequently, the function of the major proportion of the bacteriome appeared to be conserved across the geographic locations studied, which was confirmed by dsrB-directed quantitative PCR. Consequently, microbiome differences of these subsurface biofilms exist at subtle nuances for archaea (strain level variation and at higher taxonomic levels for predominant bacteria without a substantial perturbation in bacteriome function. The results of this communication provide deep insight into the dynamics of subsurface microbial life and warrant its future investigation with regard to metabolic and genomic analyses.

  13. An active site–tail interaction in the structure of hexahistidine-tagged Thermoplasma acidophilum citrate synthase

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, Jesse R.; Donini, Stefano; Kappock, T. Joseph, E-mail: kappock@purdue.edu [Purdue University, 175 South University Street, West Lafayette, IN 47907-2063 (United States)

    2015-09-23

    Citrate synthase from the thermophilic euryarchaeon T. acidophilum fused to a hexahistidine tag was purified and biochemically characterized. The structure of the unliganded enzyme at 2.2 Å resolution contains tail–active site contacts in half of the active sites. Citrate synthase (CS) plays a central metabolic role in aerobes and many other organisms. The CS reaction comprises two half-reactions: a Claisen aldol condensation of acetyl-CoA (AcCoA) and oxaloacetate (OAA) that forms citryl-CoA (CitCoA), and CitCoA hydrolysis. Protein conformational changes that ‘close’ the active site play an important role in the assembly of a catalytically competent condensation active site. CS from the thermoacidophile Thermoplasma acidophilum (TpCS) possesses an endogenous Trp fluorophore that can be used to monitor the condensation reaction. The 2.2 Å resolution crystal structure of TpCS fused to a C-terminal hexahistidine tag (TpCSH6) reported here is an ‘open’ structure that, when compared with several liganded TpCS structures, helps to define a complete path for active-site closure. One active site in each dimer binds a neighboring His tag, the first nonsubstrate ligand known to occupy both the AcCoA and OAA binding sites. Solution data collectively suggest that this fortuitous interaction is stabilized by the crystalline lattice. As a polar but almost neutral ligand, the active site–tail interaction provides a new starting point for the design of bisubstrate-analog inhibitors of CS.

  14. An active site–tail interaction in the structure of hexahistidine-tagged Thermoplasma acidophilum citrate synthase

    International Nuclear Information System (INIS)

    Murphy, Jesse R.; Donini, Stefano; Kappock, T. Joseph

    2015-01-01

    Citrate synthase from the thermophilic euryarchaeon T. acidophilum fused to a hexahistidine tag was purified and biochemically characterized. The structure of the unliganded enzyme at 2.2 Å resolution contains tail–active site contacts in half of the active sites. Citrate synthase (CS) plays a central metabolic role in aerobes and many other organisms. The CS reaction comprises two half-reactions: a Claisen aldol condensation of acetyl-CoA (AcCoA) and oxaloacetate (OAA) that forms citryl-CoA (CitCoA), and CitCoA hydrolysis. Protein conformational changes that ‘close’ the active site play an important role in the assembly of a catalytically competent condensation active site. CS from the thermoacidophile Thermoplasma acidophilum (TpCS) possesses an endogenous Trp fluorophore that can be used to monitor the condensation reaction. The 2.2 Å resolution crystal structure of TpCS fused to a C-terminal hexahistidine tag (TpCSH6) reported here is an ‘open’ structure that, when compared with several liganded TpCS structures, helps to define a complete path for active-site closure. One active site in each dimer binds a neighboring His tag, the first nonsubstrate ligand known to occupy both the AcCoA and OAA binding sites. Solution data collectively suggest that this fortuitous interaction is stabilized by the crystalline lattice. As a polar but almost neutral ligand, the active site–tail interaction provides a new starting point for the design of bisubstrate-analog inhibitors of CS

  15. Novel Large Sulfur Bacteria in the Metagenomes of Groundwater-Fed Chemosynthetic Microbial Mats in the Lake Huron Basin.

    Science.gov (United States)

    Sharrar, Allison M; Flood, Beverly E; Bailey, Jake V; Jones, Daniel S; Biddanda, Bopaiah A; Ruberg, Steven A; Marcus, Daniel N; Dick, Gregory J

    2017-01-01

    Little is known about large sulfur bacteria (LSB) that inhabit sulfidic groundwater seeps in large lakes. To examine how geochemically relevant microbial metabolisms are partitioned among community members, we conducted metagenomic analysis of a chemosynthetic microbial mat in the Isolated Sinkhole, which is in a deep, aphotic environment of Lake Huron. For comparison, we also analyzed a white mat in an artesian fountain that is fed by groundwater similar to Isolated Sinkhole, but that sits in shallow water and is exposed to sunlight. De novo assembly and binning of metagenomic data from these two communities yielded near complete genomes and revealed representatives of two families of LSB. The Isolated Sinkhole community was dominated by novel members of the Beggiatoaceae that are phylogenetically intermediate between known freshwater and marine groups. Several of these Beggiatoaceae had 16S rRNA genes that contained introns previously observed only in marine taxa. The Alpena fountain was dominated by populations closely related to Thiothrix lacustris and an SM1 euryarchaeon known to live symbiotically with Thiothrix spp. The SM1 genomic bin contained evidence of H 2 -based lithoautotrophy. Genomic bins of both the Thiothrix and Beggiatoaceae contained genes for sulfur oxidation via the rDsr pathway, H 2 oxidation via Ni-Fe hydrogenases, and the use of O 2 and nitrate as electron acceptors. Mats at both sites also contained Deltaproteobacteria with genes for dissimilatory sulfate reduction ( sat, apr , and dsr ) and hydrogen oxidation (Ni-Fe hydrogenases). Overall, the microbial mats at the two sites held low-diversity microbial communities, displayed evidence of coupled sulfur cycling, and did not differ largely in their metabolic potentials, despite the environmental differences. These results show that groundwater-fed communities in an artesian fountain and in submerged sinkholes of Lake Huron are a rich source of novel LSB, associated heterotrophic and sulfate

  16. Novel Large Sulfur Bacteria in the Metagenomes of Groundwater-Fed Chemosynthetic Microbial Mats in the Lake Huron Basin

    Directory of Open Access Journals (Sweden)

    Allison M. Sharrar

    2017-05-01

    Full Text Available Little is known about large sulfur bacteria (LSB that inhabit sulfidic groundwater seeps in large lakes. To examine how geochemically relevant microbial metabolisms are partitioned among community members, we conducted metagenomic analysis of a chemosynthetic microbial mat in the Isolated Sinkhole, which is in a deep, aphotic environment of Lake Huron. For comparison, we also analyzed a white mat in an artesian fountain that is fed by groundwater similar to Isolated Sinkhole, but that sits in shallow water and is exposed to sunlight. De novo assembly and binning of metagenomic data from these two communities yielded near complete genomes and revealed representatives of two families of LSB. The Isolated Sinkhole community was dominated by novel members of the Beggiatoaceae that are phylogenetically intermediate between known freshwater and marine groups. Several of these Beggiatoaceae had 16S rRNA genes that contained introns previously observed only in marine taxa. The Alpena fountain was dominated by populations closely related to Thiothrix lacustris and an SM1 euryarchaeon known to live symbiotically with Thiothrix spp. The SM1 genomic bin contained evidence of H2-based lithoautotrophy. Genomic bins of both the Thiothrix and Beggiatoaceae contained genes for sulfur oxidation via the rDsr pathway, H2 oxidation via Ni-Fe hydrogenases, and the use of O2 and nitrate as electron acceptors. Mats at both sites also contained Deltaproteobacteria with genes for dissimilatory sulfate reduction (sat, apr, and dsr and hydrogen oxidation (Ni-Fe hydrogenases. Overall, the microbial mats at the two sites held low-diversity microbial communities, displayed evidence of coupled sulfur cycling, and did not differ largely in their metabolic potentials, despite the environmental differences. These results show that groundwater-fed communities in an artesian fountain and in submerged sinkholes of Lake Huron are a rich source of novel LSB, associated heterotrophic

  17. Producción de polihidroxialcanoatos por bacterias halófilas nativas utilizando almidón de cáscaras de Solanum tuberosum L.

    Directory of Open Access Journals (Sweden)

    César Guzmán

    2017-01-01

    Full Text Available The aim of this study was to determine the concentration of starch Solanum tuberosum L. “potato” peels for the production of polyhydroxyalkanoates, PHA, from native halophilic bacteria as an alternative to reduce production costs of these biopolymers, possible replacements for petrochemical plastics. The bacteria were isolated of water samples of eight saline Lamba yeque region and were enriched in HM 1 broth at 30 °C with 5, 10, 15, 20, 25 and 30 g 100 mL - 1 NaCl. Dilutions were performed subsequently, aliquots were taken and plated on HM 1 agar, 203 isolates of halophilic bacteria were obtained, they were grown in HM 2 broth with 10 g.L - 1 glucose as carbon source and the 38.92% of the isolates showed PHA granules stained by Sudan Black B. Twenty bacteria with PHA granules in 65 – 75% over carried to fermentation, reaching between 0.174 to 0.889 g . g - 1 of yield Y (p / x. Three isolates were selected with the highest values among which Halomonas sp M4C1 grew and synthesized PHA in HM 2 broth with 5, 10, 15 and 20 g . L - 1 of starch as carbon source, reaching 0.019; 0.016; 0.007 y 0.006 g . L - 1 of PHA, with 0.177; 0.111; 0.056 an d 0.066 g . L - 1 of biomass after 20, 40, 24 and 16 hours respectively. The highest yield of 0.144 g . g - 1 corresponded to 10 g . L - 1 of starch demonstrating that this concentration is feasible PHA production by native halophilic bacteria.

  18. Influence of weather variables and plant communities on grasshopper density in the Southern Pampas, Argentina.

    Science.gov (United States)

    de Wysiecki, María Laura; Arturi, Marcelo; Torrusio, Sandra; Cigliano, María Marta

    2011-01-01

    A study was conducted to evaluate the influence of weather (precipitation and temperature) and plant communities on grasshopper density over a 14-year period (1996-2009) in Benito Juárez County, Southern Pampas, Argentina. Total density strongly varied among plant communities. Highest values were registered in 2001 and 2003 in highly disturbed pastures and in 2002 and 2009 in halophilous grasslands. Native grasslands had the lowest density values. Seasonal precipitation and temperature had no significant effect on total grasshopper density. Dichroplus elongatus (Giglio-Tos) (Orthoptera: Acridoidea), Covasacris pallidinota (Bruner), Dichroplus pratensis Bruner, Scotussa lemniscata Stål, Borellia bruneri (Rehn) and Dichroplus maculipennis (Blanchard) comprised, on average, 64% of the grasshopper assemblages during low density years and 79% during high density years. Dichroplus elongatus, S. lemniscata and C. pallidinota were the most abundant species in 2001, 2002 and 2003, while D. elongatus, B. brunneri and C. pallidinota in 2009. Dichroplus elongatus and D. pratensis, mixed feeders species, were positively affected by summer rainfall. This suggests that the increase in summer precipitation had a positive effect on the quantity and quality forage production, affecting these grasshopper populations. Scotussa lemniscata and C. pallidinota were negatively affected by winter and fall temperature, possibly affecting the embryonic development before diapause and hatching. Dichroplus elongatus and D. pratensis were associated with highly disturbed pastures, S. lemniscata with pastures and B. bruneri and D. maculipennis with halophilous grasslands. Covasacris pallidinota was closely associated with halophilous grasslands and moderately disturbed pastures. Weather conditions changed over the years, with 2001, 2002 and 2003 having excessive rainfall while 2008 and 2009 were the driest years since the study started. We suggest that although seasonal precipitation and

  19. Effect Of Substrates On The Fractionation Of Hydrogen Isotopes During Lipid-Biosynthesis By Haloarcula marismortui

    Science.gov (United States)

    Dirghangi, S. S.; Pagani, M.

    2010-12-01

    Lipids form an important class of proxies for paleoclimatological research, and hydrogen isotope ratios of lipids are being increasingly used for understanding changes in the hydrological system. Proper understanding of hydrogen isotope fractionation during lipid biosynthesis is therefore important and attention has been directed toward understanding the magnitude of hydrogen isotope fractionation that occurs during lipid biosynthesis in various organisms. Hydrogen isotope ratios of lipids depend on the hydrogen isotopic composition of the ambient water, hydrogen isotopic composition of NADPH used during biosynthesis, growth conditions, pathways of lipid biosynthesis, and substrates in the case of heterotrophic organisms. Recently it has been observed that NADPH contributes a significant part of the hydrogen in fatty acids synthesized by bacteria during heterotrophic growth (Zhang et al, 2009). As NADPH is formed by reduction of NADP+ during metabolism of substrates, different metabolic pathways form NADPH with different D/H ratios, which in turn results in variation in D/H ratios of lipids (Zhang et al, 2009). Therefore, substrates play a significant role in hydrogen isotopic compositions of lipids. For this study, we are investigating the effects of substrates on hydrogen isotope fractionation during biosynthesis of isoprenoidal lipids by heterotrophically growing halophilic archaea. Haloarcula marismortui is a halophilic archaea which synthesizes Archaeol (a diether lipid) and other isoprenoidal lipids. We have grown Haloarcula marismortui in pure cultures on three different substrates and are in the process of evaluating isotopic variability of Archaeol and other lipids associated with substrate and the D/H composition of ambient water. Our results will be helpful for a better understanding of hydrogen isotope fractionations during lipid synthesis by archaea. Also, halophilic archaea are the only source of archaeol in hypersaline environments. Therefore, our

  20. Biogeographical note on Antarctic microflorae: Endemism and cosmopolitanism

    Directory of Open Access Journals (Sweden)

    Waqar Azeem Jadoon

    2013-11-01

    Full Text Available This study deals with the biogeography of Antarctic microflora (Antarctica acts as best model to study microbial biogeography such as cyanobacteria and selected halophiles with special emphasis on Halomonas variabilis and Bacillus licheniformis. Halophiles are known to be resistant not only to salt stress, but also to extreme temperature, pressure, and aridity and they are capable of surviving in harsh environments such as polar regions, deep-sea habitats, and deserts. Many microbes are known to be resistant to hostile environmental conditions, and are capable of surviving in harsh environments. Our group has isolated 444 strains belonging to 28 genera of halophiles from various environments around the world. The 16S rRNA gene sequences revealed that many of the isolated strains from geographically distant habitats having different environmental conditions, were closely related to each other, with some strains possessing 100% identical sequences. Organisms possessing survival mechanism such as spore formation are usually ubiquitous. The genus Halomonas is represented by potentially endemic strains and the ubiquitous H. variabilis, while spore-forming B. licheniformis showed cosmopolitan distribution. One potentially endemic (moderate endemicity that is regional and/or continental distribution strain was reported from Syowa station, East Antarctica, and Mario Zucchelli station, West Antarctica, which are geographically separated by 3000 km. Moreover, 15 strains having 100% similarity with B. licheniformis were considered cosmopolitans. The results of this work provide support for the middle-ground model that some microbes have moderate endemicity and others have cosmopolitan distribution. These results will contribute to a greater understanding of microbial biogeography with special emphasis on Antarctica.