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Sample records for extremely halophilic archaebacterium

  1. 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.

  2. ATP Synthesis in the Extremely Halophilic Bacteria

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    Hochstein, Lawrence I.; Morrison, David (Technical Monitor)

    1994-01-01

    The proton-translocating ATPases are multimeric enzymes that carry out a multitude of essential functions. Their origin and evolution represent a seminal event in the early evolution of life. Amino acid sequences of the two largest subunits from archaeal ATPases (A-ATPases), vacuolar ATPases (V-ATPases), and FOF1-ATP syntheses (FATPases) suggest these ATPases evolved from an ancestral vacuolar-like ATP syntheses. A necessary consequence of this notion is that the A-ATPases are ATP syntheses. With the possible exception of the A-ATPase from Halobacterium salinarium. no A-ATPase has been demonstrated to synthesize ATP. The evidence for this case is dubious since ATP synthesis occurs only when conditions are distinctively unphysiological. We demonstrated that ATP synthesis in H.saccharovorum is inconsistent with the operation of an A-type ATPase. In order to determine if this phenomenon was unique to H. saccharovorum, ATP synthesis was examined in various extremely halophilic bacteria with the goal of ascertaining if it resembled what occurred in a. saccharovorum, or was consistent with the operation of an A-type ATPase. A-, V-, and F-type ATPases respond singularly to certain inhibitors. Therefore, the effect of these inhibitors on ATP synthesis in several extreme halophiles was determined. Inhibitors that either blocked or collapsed proton-gradients inhibited the steady state synthesis of ATP thus verifying that synthesis took place at the expense of a proton gradient. Azide, an inhibitor of F-ATPases inhibited ATP synthesis. Since the arginine-dependent synthesis of ATP, which occurs by way of substrate-level phosphorylation, was unaffected by azide, it was unlikely that azide acted as an "uncoupler." N -ethylmaleimide and nitrate, which inhibit V- and A-ATPases, either did not inhibit ATP synthesis or resulted in higher steady-state levels of ATP. These results suggest there are two types of proton-motive ATPases in the extreme halophiles (and presumably in other

  3. 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.

  4. Dynamic Experiments for Bioprocess Parameter Optimization with Extreme Halophilic Archaea

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    Bettina Lorantfy

    2013-11-01

    Full Text Available The to-date studies on extreme halophiles were focused on shake flask cultivations. Bioreactor technology with quantitative approaches can offer a wide variety of biotechnological applications to exploit the special biochemical features of halophiles. Enabling industrial use of Haloferax mediterranei, finding the optima of cultivation parameters is of high interest. In general, process parameter optimizations were mainly carried out with laborious and time-consuming chemostat cultures. This work offers a faster alternative for process parameter optimization by applying temperature ramps and pH shifts on a halophilic continuous bioreactor culture. Although the hydraulic equilibrium in continuous culture is not reached along the ramps, the main effects on the activity from the dynamic studies can still be concluded. The results revealed that the optimal temperature range may be limited at the lower end by the activity of the primary metabolism pathways. At the higher end, the mass transfer of oxygen between the gaseous and the liquid phase can be limiting for microbial growth. pH was also shown to be a key parameter for avoiding overflow metabolism. The obtained experimental data were evaluated by clustering with multivariate data analyses. Showing the feasibility on a halophilic example, the presented dynamic methodology offers a tool for accelerating bioprocess development.

  5. Life at extreme limits: the anaerobic halophilic alkalithermophiles.

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    Mesbah, Noha M; Wiegel, Juergen

    2008-03-01

    The ability of anaerobic microorganisms to proliferate under extreme conditions is of widespread importance for microbial physiology, remediation, industry, and evolution. The halophilic alkalithermophiles are a novel group of polyextremophiles. Tolerance to alkaline pH, elevated NaCl concentrations, and high temperatures necessitates mechanisms for cytoplasmic pH acidification; permeability control of the cell membrane; and stability of proteins, the cell wall, and other cellular constituents to multiple extreme conditions. Although it is generally assumed that extremophiles growing at more than one extreme combine adaptive mechanisms for each individual extreme, adaptations for individual extremes often counteract each other. However, in alkaline, hypersaline niches heated via intense solar irradiation, culture-independent analyses have revealed the presence of an extensive diversity of aerobic and anaerobic microorganisms belonging to Bacteria and Archaea that survive and grow under multiple harsh conditions. Thus, polyextremophiles must have developed novel adaptive strategies enabling them to grow and proliferate under multiple extreme conditions. The recent isolation of two novel anaerobic, halophilic alkalithermophiles, Natranaerobius thermophilus and Halonatronum saccharophilum, will provide a platform for detailed biochemical, genomic, and proteomic experiments, allowing a greater understanding of the novel adaptive mechanisms undoubtedly employed by polyextremophiles. In this review, we highlight growth characteristics, ecology, and phylogeny of the anaerobic halophilic alkalithermophiles isolated. We also describe the bioenergetic and physiological problems posed by growth at the multiple extreme conditions of alkaline pH, high NaCl concentration, and elevated temperature under anoxic conditions and highlight recent findings and unresolved problems regarding adaptation to multiple extreme conditions.

  6. Uracil phosphoribosyltransferase from the extreme thermoacidophilic archaebacterium Sulfolobus shibatae is an allosteric enzyme, activated by GTP and inhibited by CTP

    DEFF Research Database (Denmark)

    Linde, Lise; Jensen, Kaj Frank

    1996-01-01

    -fold without much effect on Km for the substrates. The concentration of GTP required for half-maximal activation was about 80 µM. CTP was a strong inhibitor and acted by raising the concentration of GTP needed for half-maximal activation of the enzyme. We conclude that uracil phosphoribosyltransferase......Uracil phosphoribosyltransferase, which catalyses the formation of UMP and pyrophosphate from uracil and 5-phosphoribosyl a-1-pyrophosphate (PRPP), was partly purified from the extreme thermophilic archaebacterium Sulfolobus shibatae. The enzyme required divalent metal ions for activity...... and it showed the highest activity at pH 6.4. The specific activity of the enzyme was 50-times higher at 95°C than at 37°C, but the functional half-life was short at 95°C. The activity of uracil phosphoribosyltransferase was strongly activated by GTP, which increased Vmax of the reaction by approximately 20...

  7. Halobacterium denitrificans sp. nov., an extremely halophilic denitrifying bacterium

    Science.gov (United States)

    Tomlinson, G. A.; Jahnke, L. L.; Hochstein, L. I.

    1986-01-01

    Halobacterium denitrificans was one of several carbohydrate-utilizing, denitrifying, extremely halophilic bacteria isolated by anaerobic enrichment in the presence of nitrate. Anaerobic growth took place only when nitrate (or nitrite) was present and was accompanied by the production of dinitrogen. In the presence of high concentrations of nitrate (i.e., 0.5 percent), nitrous oxide and nitrite were also detected. When grown aerobically in a mineral-salts medium containing 0.005 percent yeast extract, H. denitrificans utilized a variety of carbohydrates as sources of carbon and energy. In every case, carbohydrate utilization was accompanied by acid production.

  8. Halobacterium denitrificans sp. nov. - An extremely halophilic denitrifying bacterium

    Science.gov (United States)

    Tomlinson, G. A.; Jahnke, L. L.; Hochstein, L. I.

    1986-01-01

    Halobacterium denitrificans was one of several carbohydrate-utilizing, denitrifying, extremely halophilic bacteria isolated by anaerobic enrichment in the presence of nitrate. Anaerobic growth took place only when nitrate (or nitrite) was present and was accompanied by the production of dinitrogen. In the presence of high concentrations of nitrate (i.e., 0.5 percent), nitrous oxide and nitrite were also detected. When grown aerobically in a mineral-salts medium containing 0.005 percent yeast extract, H. denitrificans utilized a variety of carbohydrates as sources of carbon and energy. In every case, carbohydrate utilization was accompanied by acid production.

  9. Energy metabolism of a thermoacidophilic archaebacterium,Sulfolobus acidocaldarius

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    Wakagi, Takayoshi; Oshima, Tairo

    1987-09-01

    To elucidate the phylogenic status of the archaebacterium and mechanisms of acidophily, membrane bound ATPase, cytochromes and NADH dehydrogenase of a thermoacidophilic archaebacterium,Sulfolobus acidocaldarius, were studied. Typea cytochrome was found in the membrane. The organism was sensitive to cyanide and azide, and though cytochromec is lacking in this organism, these respiratory poisons inhibited a terminal oxidase, when assayed with cytochromec from other sources. NADH dehydrogenase was highly purified from the crude extract of the cells. The enzyme was able to transfer electrons from NADH to caldariellaquinone, a unique benzothiophenequinone in the genusSulfolobus. Thus, the enzyme is a possible member of the respiratory chain. Membrane fraction contained two types of ATPase, one was active at neutral pH and slightly activated by sulfate; the other was an acid apyrase and inhibited by sulfate. Typical characteristics of F0F1ATPase could not be found in these enzymes. These results suggest that (1) the thermoacidophilic archaebacteria are phylogenically distant from both eubacteria and eukaryotes, (2) the archaebacterial thermoacidophiles can be classified in a different subgroup from methanogens and extreme halophiles, and (3) in spite of the aerobic nature of the organism, the energy yielding mechanisms appear quite unique, when compared to those of other aerobes and mitochondria.

  10. 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

    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 f...

  11. Life under multiple extreme conditions: diversity and physiology of the halophilic alkalithermophiles.

    Science.gov (United States)

    Mesbah, Noha M; Wiegel, Juergen

    2012-06-01

    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.

  12. A Novel Denitrifying Extreme Halophile That Grows in a Simple Mineral Salts Medium

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    Hochstein, L. I.; Oremland, R. S.; Gherna, R.; Cote, R.; Chang, Sherwood (Technical Monitor)

    1995-01-01

    An extremely halophilic bacterium (strain CH-1) was isolated from a saltern adjacent to San Francisco Bay. It grew in a mineral salts medium with ammonium and glucose as sole sources of nitrogen and carbon as well as energy, respectively Cells lysed at less than 10% NaCl and growth was most rapid in medium containing 20% NaCl. Cells were pieomorphic ranging from disc to ovoid-shaved and used a variety of carbohydrates as sole carbon sources. the utilization of certain carbon sources was controlled by temperature with some used at 37 degrees but not 45 C. CH-1 grew between 30 degrees and 50 C with the optimum at 45 C in the presence of 20% NaCl. CH-1 contained 2,3-di-O-isoprenyl glcerol diethers and was sensitive to aphidicofin. The major polar lipid was glucosyl-mannosyl-alucosyl diether, which is diagnostic of the Haloarcula. Thus CH-1 is an extreme halophile and a member of this genus. Among the novel characteristics of this organism was its ability to grow anaerobically in synthetic medium when nitrate was present which was only reduced to nitrous oxide. This organism should prove useful for studying denitrification and carbohydrate metabolism in the extreme halophiles; and to be a valuable resource for generic studies.

  13. Extremely halophilic archaea from ancient salt sediments and their long term survival.

    Science.gov (United States)

    Stan-Lotter, Helga; Fendrihan, Sergiu; Dornmayr-Pfaffenhuemer, Marion

    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 rock salt of great geological age (195-250 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. When simulating the embedding process of haloarchaea in laboratory-grown salt crystals, cells accumulated preferentially in fluid inclusions, as could be demonstrated by pre-staining with fluorescent dyes. The issue of extreme long term microbial survival in rock salt has considerable implications for the search for extraterrestrial life. Halite has been found in Martian meteorites, salts are present on the Martian surface and there is good evidence for a salty ocean on the Jovian moon Europa. Therefore the search for halophilic prokaryotic life in such environments appears plausible. The development of detection methods for subsurface haloarchaea, which might also be applicable to samples from future missions to space, is important and some examples such as fluorescence microscopy methods with novel dyes will be described. (1) Fendrihan, S., Legat, A., Gruber, C., Pfaffenhuemer, M., Weidler, G., Gerbl, F., Stan- Lotter, H. (2006) Extremely halophilic archaea and the issue of long term microbial survival. Reviews in Environmental Science and Bio/technology 5, 1569-1605.

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

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    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.

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

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    Naziri, Davood; Hamidi, Masoud; Hassanzadeh, Salar; Tarhriz, Vahideh; Maleki Zanjani, Bahram; Nazemyieh, Hossein; Hejazi, Mohammd Amin; Hejazi, Mohammad Saeid

    2014-01-01

    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. PMID:24409411

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

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    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.

  17. Exploring the diversity of extremely halophilic archaea in food-grade salts.

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    Henriet, Olivier; Fourmentin, Jeanne; Delincé, Bruno; Mahillon, Jacques

    2014-11-17

    Salting is one of the oldest means of food preservation: adding salt decreases water activity and inhibits microbial development. However, salt is also a source of living bacteria and archaea. The occurrence and diversity of viable archaea in this extreme environment were assessed in 26 food-grade salts from worldwide origin by cultivation on four culture media. Additionally, metagenomic analysis of 16S rRNA gene was performed on nine salts. Viable archaea were observed in 14 salts and colony counts reached more than 10(5)CFU per gram in three salts. All archaeal isolates identified by 16S rRNA gene sequencing belonged to the Halobacteriaceae family and were related to 17 distinct genera among which Haloarcula, Halobacterium and Halorubrum were the most represented. High-throughput sequencing generated extremely different profiles for each salt. Four of them contained a single major genus (Halorubrum, Halonotius or Haloarcula) while the others had three or more genera of similar occurrence. The number of distinct genera per salt ranged from 21 to 27. Halorubrum had a significant contribution to the archaeal diversity in seven salts; this correlates with its frequent occurrence in crystallization ponds. On the contrary, Haloquadratum walsbyi, the halophilic archaea most commonly found in solar salterns, was a minor actor of the food-grade salt diversity. Our results indicate that the occurrence and diversity of viable halophilic archaea in salt can be important, while their fate in the gastrointestinal tract after ingestion remains largely unknown.

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

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    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.

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

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    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.

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

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    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

  1. Characterization of alcohol dehydrogenase (ADH12) from Haloarcula marismortui, an extreme halophile from the Dead Sea.

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    Timpson, Leanne M; Alsafadi, Diya; Mac Donnchadha, Cillín; Liddell, Susan; Sharkey, Michael A; Paradisi, Francesca

    2012-01-01

    Haloarchaeal alcohol dehydrogenases are of increasing interest as biocatalysts in the field of white biotechnology. In this study, the gene adh12 from the extreme halophile Haloarcula marismortui (HmADH12), encoding a 384 residue protein, was cloned into two vectors: pRV1 and pTA963. The resulting constructs were used to transform host strains Haloferax volcanii (DS70) and (H1209), respectively. Overexpressed His-tagged recombinant HmADH12 was purified by immobilized metal-affinity chromatography (IMAC). The His-tagged protein was visualized by SDS-PAGE, with a subunit molecular mass of 41.6 kDa, and its identity was confirmed by mass spectrometry. Purified HmADH12 catalyzed the interconversion between alcohols and aldehydes and ketones, being optimally active in the presence of 2 M KCl. It was thermoactive, with maximum activity registered at 60°C. The NADP(H) dependent enzyme was haloalkaliphilic for the oxidative reaction with optimum activity at pH 10.0. It favored a slightly acidic pH of 6.0 for catalysis of the reductive reaction. HmADH12 was significantly more tolerant than mesophilic ADHs to selected organic solvents, making it a much more suitable biocatalyst for industrial application.

  2. Growth Kinetics of Extremely Halophilic Archaea (Family Halobacteriaceae) as Revealed by Arrhenius Plots

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    Robinson, Jessie L.; Pyzyna, Brandy; Atrasz, Rachelle G.; Henderson, Christine A.; Morrill, Kira L.; Burd, Anna Mae; DeSoucy, Erik; Fogleman, Rex E.; Naylor, John B.; Steele, Sarah M.; Elliott, Dawn R.; Leyva, Kathryn J.; Shand, Richard F.

    2005-01-01

    Members of the family Halobacteriaceae in the domain Archaea are obligate extreme halophiles. They occupy a variety of hypersaline environments, and their cellular biochemistry functions in a nearly saturated salty milieu. Despite extensive study, a detailed analysis of their growth kinetics is missing. To remedy this, Arrhenius plots for 14 type species of the family were generated. These organisms had maximum growth temperatures ranging from 49 to 58°C. Nine of the organisms exhibited a single temperature optimum, while five grew optimally at more than one temperature. Generation times at these optimal temperatures ranged from 1.5 h (Haloterrigena turkmenica) to 3.0 h (Haloarcula vallismortis and Halorubrum saccharovorum). All shared an inflection point at 31 ± 4°C, and the temperature characteristics for 12 of the 14 type species were nearly parallel. The other two species (Natronomonas pharaonis and Natronorubrum bangense) had significantly different temperature characteristics, suggesting that the physiology of these strains is different. In addition, these data show that the type species for the family Halobacteriaceae share similar growth kinetics and are capable of much faster growth at higher temperatures than those previously reported. PMID:15659670

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

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    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.

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

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    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.

  5. 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.

  6. Antimicrobial Activity and Mechanism of Inhibition of Silver Nanoparticles against Extreme Halophilic Archaea.

    Science.gov (United States)

    Thombre, Rebecca S; Shinde, Vinaya; Thaiparambil, Elvina; Zende, Samruddhi; Mehta, Sourabh

    2016-01-01

    Haloarchaea are salt-loving halophilic microorganisms 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 300-400 μg/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 program. 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.

  7. Antimicrobial Activity and Mechanism of Inhibition of Silver Nanoparticles against Extreme Halophilic Archaea

    Science.gov (United States)

    Thombre, Rebecca S.; Shinde, Vinaya; Thaiparambil, Elvina; Zende, Samruddhi; Mehta, Sourabh

    2016-01-01

    Haloarchaea are salt-loving halophilic microorganisms 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 300–400 μg/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 program. 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. PMID:27679615

  8. Lentibacillus kimchii sp. nov., an extremely halophilic bacterium isolated from kimchi, a Korean fermented vegetable.

    Science.gov (United States)

    Oh, Young Joon; Lee, Hae-Won; Lim, Seul Ki; Kwon, Min-Sung; Lee, Jieun; Jang, Ja-Young; Lee, Jong Hee; Park, Hae Woong; Nam, Young-Do; Seo, Myung-Ji; Roh, Seong Woon; Choi, Hak-Jong

    2016-06-01

    A Gram-positive, aerobic, non-motile and extremely halophilic bacterial strain, designated K9(T), was isolated from kimchi, a Korean fermented food. The strain was observed as endospore-forming rod-shaped cells showing oxidase and catalase activity. It was found to grow at 10.0-30.0 % (w/v) NaCl (optimum, 15.0-20.0 %), pH 7.0-8.0 (optimum, pH 7.5) and 15-40 °C (optimum, 30 °C). The polar lipids of strain K9(T) were identified as phosphatidylglycerol, three unidentified phospholipids and an unidentified glycolipid. The isoprenoid quinone was identified as menaquinone-7. The major cellular fatty acids (>20 % of the total) were found to be anteisio-C15:0 and anteisio-C17:0. The cell wall peptidoglycan composition was determined to contain meso-diaminopimelic acid. The G + C content of genomic DNA was determined to be 48.2 mol %. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that the isolated strain is closely related to Lentibacillus salinarum AHS-1(T) (96.7 % sequence similarity). Based on its phenotypic, chemotaxonomic and phylogenetic data, strain K9(T) is considered to represent a novel species of the genus Lentibacillus, for which the name Lentibacillus kimchii sp. nov., is proposed. The type strain is K9(T) (=KACC 18490(T) = JCM 30234(T)).

  9. 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.

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

    Science.gov (United States)

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

    2009-03-01

    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.

  11. Investigating the Effects of Simulated Martian Ultraviolet Radiation on Halococcus dombrowskii and Other Extremely Halophilic Archaebacteria

    Science.gov (United States)

    Fendrihan, Sergiu; Bérces, Attila; Lammer, Helmut; Musso, Maurizio; Rontó, György; Polacsek, Tatjana K.; Holzinger, Anita; Kolb, Christoph; Stan-Lotter, Helga

    2009-02-01

    The isolation of viable extremely halophilic archaea from 250-million-year-old rock salt suggests the possibility of their long-term survival under desiccation. Since halite has been found on Mars and in meteorites, haloarchaeal survival of martian surface conditions is being explored. Halococcus dombrowskii H4 DSM 14522T was exposed to UV doses over a wavelength range of 200-400 nm to simulate martian UV flux. Cells embedded in a thin layer of laboratory-grown halite were found to accumulate preferentially within fluid inclusions. Survival was assessed by staining with the LIVE/DEAD kit dyes, determining colony-forming units, and using growth tests. Halite-embedded cells showed no loss of viability after exposure to about 21 kJ/m2, and they resumed growth in liquid medium with lag phases of 12 days or more after exposure up to 148 kJ/m2. The estimated D37 (dose of 37% survival) for Hcc. dombrowskii was ≥ 400 kJ/m2. However, exposure of cells to UV flux while in liquid culture reduced D37 by 2 orders of magnitude (to about 1 kJ/m2); similar results were obtained with Halobacterium salinarum NRC-1 and Haloarcula japonica. The absorption of incoming light of shorter wavelength by color centers resulting from defects in the halite crystal structure likely contributed to these results. Under natural conditions, haloarchaeal cells become embedded in salt upon evaporation; therefore, dispersal of potential microscopic life within small crystals, perhaps in dust, on the surface of Mars could resist damage by UV radiation.

  12. Draft Genome Sequence of Bacillus sp. Strain SB47, an Obligate Extreme Halophile Isolated from a Salt Pan of the Little Rann of Kutch, India

    Science.gov (United States)

    Dey, Rinku; Thomas, Manesh; Sherathia, Dharmesh; Dalsania, Trupti; Patel, Ilaxi; Savsani, Kinjal; Ghorai, Sucheta; Vanpariya, Sejal; Sukhadiya, Bhoomika; Mandaliya, Mona; Rupapara, Rupal; Rawal, Priya; Saxena, Anil Kumar

    2013-01-01

    Here, we report the 4.46-Mbp draft genome sequence of Bacillus sp. strain SB47, an extreme halophile isolated from a salt pan of the Little Rann of Kutch, India. Exploring the genome of this organism will facilitate the understanding and isolation of the gene(s) involved in its extreme osmotolerance. PMID:24115544

  13. Draft Genome Sequence of the Extremely Halophilic Bacillus sp. Strain SB49, Isolated from a Salt Crystallizer Pond of the Little Rann of Kutch, India

    Science.gov (United States)

    Dey, Rinku; Thomas, Manesh; Sherathia, Dharmesh; Dalsania, Trupti; Patel, Ilaxi; Savsani, Kinjal; Ghorai, Sucheta; Vanpariya, Sejal; Sukhadiya, Bhoomika; Mandaliya, Mona; Rupapara, Rupal; Rawal, Priya

    2013-01-01

    Here we report the draft whole-genome sequence (3.72 Mbp) of Bacillus sp. strain SB49, an extremely halophilic bacterium isolated from a salt crystallizer pond of the Little Rann of Kutch in India. Unraveling the genome of this organism will facilitate understanding and isolation of the genes involved in imparting extreme osmotolerance. PMID:24136852

  14. The sequence of Methanospirillum hungatei 23S rRNA confirms the specific relationship between the extreme halophiles and the Methanomicrobiales

    Science.gov (United States)

    Burggraf, S.; Ching, A.; Stetter, K. O.; Woese, C. R.

    1991-01-01

    We have determined the sequence of the 23S rRNA from the methanogenic archaeon Methanospirillum hungatei. This is the first such sequence from a member of the Methanomicrobiales. Moreover, it brings additional evidence to bear on the possible specific relationship between this particular group of methanogens and the extreme halophiles. Such evidence is critical in that several new (and relatively untested) methods of phylogenetic inference have lead to the controversial conclusion that the extreme halophiles are either not related to the archaea, or are only peripherally so. Analysis of the Methanospirillum hungatei 23S rRNA sequence shows the Methanomicrobiales are indeed a sister group of the extreme halophiles, further strengthening the conclusions reached from analysis of 16S rRNA sequences.

  15. 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.

  16. 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.

  17. 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

  18. Thiohalorhabdus denitrificans gen. nov., sp. nov., an extremely halophilic, sulfur-oxidizing, deep-lineage gammaproteobacterium from hypersaline habitats.

    Science.gov (United States)

    Sorokin, Dimitry Yu; Tourova, Tatjana P; Galinski, Erwin A; Muyzer, Gerard; Kuenen, J Gijs

    2008-12-01

    Seven strains of extremely halophilic and obligately chemolithoautotrophic sulfur-oxidizing bacteria (SOB) were enriched and isolated at 4 M NaCl from sediments of hypersaline inland lakes in south-eastern Siberia and a Mediterranean sea solar saltern. Cells of the novel isolates were spindle-like, long and non-motile rods with a Gram-negative type of cell wall. They were obligately chemolithoautotrophic SOB using thiosulfate and tetrathionate as electron donors and represent the first example of extremely halophilic chemolithoautotrophs that are able to grow anaerobically with nitrate as electron acceptor. The characteristic feature of the group was the production of large amounts of tetrathionate as an intermediate during the oxidation of thiosulfate to sulfate. With thiosulfate, the novel strains grew within the pH range from 6.5 to 8.2 (optimum at pH 7.5-7.8) and at NaCl concentrations from 1.5 to 4.0 M (optimum at 3.0 M). Cells grown at 4 M NaCl accumulated extremely high concentrations of glycine betaine as a compatible solute. The dominant cellular fatty acids were 10MeC(16 : 0) and C(16 : 0). Based on the DNA-DNA relatedness values, the isolates consisted of a single genomic species and had a similar phenotype. Phylogenetic analysis placed the novel bacteria in the class Gammaproteobacteria as an independent lineage with no significant relationship to any other genera in this class. On the basis of phenotypic and genotypic analysis, the group is proposed to represent a new genus, Thiohalorhabdus gen. nov., with Thiohalorhabdus denitrificans gen. nov., sp. nov. as the type species (type strain HL 19(T)=DSM 15699(T)=UNIQEM U223(T)).

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

    Directory of Open Access Journals (Sweden)

    Ashagrie Gibtan

    2017-05-01

    Full Text Available 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.

  20. Halanaerobium sehlinense sp. nov., an extremely halophilic, fermentative, strictly anaerobic bacterium from sediments of the hypersaline lake Sehline Sebkha.

    Science.gov (United States)

    Abdeljabbar, Hedi; Cayol, Jean-Luc; Ben Hania, Wajdi; Boudabous, Abdellatif; Sadfi, Najla; Fardeau, Marie-Laure

    2013-06-01

    A strictly anaerobic, extremely halophilic, Gram-positive, rod-shaped bacterium was isolated from the hypersaline (>20% NaCl) surface sediments of Sehline Sebkha in Tunisia. The strain, designated 1Sehel(T), was strictly halophilic and proliferated at NaCl concentrations of between 5% and 30% (saturation), with optimal growth at 20% NaCl. Strain 1Sehel(T) was non-spore-forming, non-motile, appearing singly or in pairs, or occasionally as long chains and measured 0.5-0.8 µm by 3-10 µm. Strain 1Sehel(T) grew optimally at pH values of 7.4 but had a very broad pH range for growth (pH 5.2-9.4). It grew at temperatures between 20 and 50 °C with an optimum at 43 °C. Strain 1Sehel(T) required yeast extract for growth. The isolate fermented glucose, galactose, fructose, glycerol, mannose, maltose, ribose, pyruvate and sucrose. The fermentation products from glucose utilization were lactate, acetate, formate, ethanol, CO2 and H2. The G+C ratio of the DNA was 32.7 mol%. The major fatty acids were C15:1ω6c/7c, C16:1ω7c, C16:0 and C15:0. On the basis of phylogenetic and physiological properties, strain 1Sehel(T) (=DSM 25582(T)=JCM 18213(T)) is proposed as the type strain of Halanaerobium sehlinense sp. nov., within the family Halanaerobiaceae.

  1. Delignification and detoxification of peanut shell bio-waste using an extremely halophilic laccase from an Aquisalibacillus elongatus isolate.

    Science.gov (United States)

    Rezaie, Rezvan; Rezaei, Shahla; Jafari, Nasrin; Forootanfar, Hamid; Khoshayand, Mohammad Reza; Faramarzi, Mohammad Ali

    2017-09-05

    Lignocellulose bioconversion is a harsh process requiring the use of surfactants and organic solvents. Consequently, the incorporation of laccases in this bioconversion requires the bioprospecting of enzymes that can remain stable under extreme conditions. An extracellular, highly stable laccase was produced by the halophilic isolate Aquisalibacillus elongatus in submerged liquid culture fermentation. Statistical and non-statistical strategies gave the highest enzymatic activity (8.02 U mL(-1)) following addition of glucose (1.7 g L(-1)), copper sulfate (0.8 g L(-1)), urea (15 g L(-1)), and CaCl2 (0.8 g L(-1)). The enzyme, after purification using a synthetic affinity support, delignified a peanut shell substrate by 45%. A pH of 8.0 and a temperature of 35 °C were optimal for delignification of this bio-waste material. Addition of [Bmim][PF6], 1,4-dioxane, acetone, and HBT promoted this bio-waste delignification. Bio-treatment in the presence of 50% [Bmim][PF6] gave a maximal lignin removal of 87%. The surfactants tested had no significant effects on the delignification yield. The laccase also detoxified the toxic phenols found in peanut shell waste. The high catalytic efficiency of this enzyme against a lignocellulosic sample under extreme conditions suggests the suitability of this laccase for industrial applications.

  2. Systems analysis of bioenergetics and growth of the extreme halophile Halobacterium salinarum.

    Directory of Open Access Journals (Sweden)

    Orland Gonzalez

    2009-04-01

    Full Text Available Halobacterium salinarum is a bioenergetically flexible, halophilic microorganism that can generate energy by respiration, photosynthesis, and the fermentation of arginine. In a previous study, using a genome-scale metabolic model, we have shown that the archaeon unexpectedly degrades essential amino acids under aerobic conditions, a behavior that can lead to the termination of growth earlier than necessary. Here, we further integratively investigate energy generation, nutrient utilization, and biomass production using an extended methodology that accounts for dynamically changing transport patterns, including those that arise from interactions among the supplied metabolites. Moreover, we widen the scope of our analysis to include phototrophic conditions to explore the interplay between different bioenergetic modes. Surprisingly, we found that cells also degrade essential amino acids even during phototropy, when energy should already be abundant. We also found that under both conditions considerable amounts of nutrients that were taken up were neither incorporated into the biomass nor used as respiratory substrates, implying the considerable production and accumulation of several metabolites in the medium. Some of these are likely the products of forms of overflow metabolism. In addition, our results also show that arginine fermentation, contrary to what is typically assumed, occurs simultaneously with respiration and photosynthesis and can contribute energy in levels that are comparable to the primary bioenergetic modes, if not more. These findings portray a picture that the organism takes an approach toward growth that favors the here and now, even at the cost of longer-term concerns. We believe that the seemingly "greedy" behavior exhibited actually consists of adaptations by the organism to its natural environments, where nutrients are not only irregularly available but may altogether be absent for extended periods that may span several years

  3. Damage Avoidance and Repair Mechanisms of Extreme Halophiles to Ionizing Radiation

    Science.gov (United States)

    2013-07-01

    tolerance   to   desiccation  that...abilities.   Early   work   on   the   desiccation   resistance   of   extremely   radiation-­‐resistant   bacteria   revealed...imparts  IR  resistance  to  these  organisms.  The  distribution  of  extremely   IR  and   desiccation

  4. The halophilic alkalithermophile Natranaerobius thermophilus adapts to multiple environmental extremes using a large repertoire of Na(K)/H antiporters.

    Science.gov (United States)

    Mesbah, Noha M; Cook, Gregory M; Wiegel, Juergen

    2009-10-01

    Natranaerobius thermophilus is an unusual extremophile because it is halophilic, alkaliphilic and thermophilic, growing optimally at 3.5 M Na(+), pH(55 degrees C) 9.5 and 53 degrees C. Mechanisms enabling this tripartite lifestyle are essential for understanding how microorganisms grow under inhospitable conditions, but remain unknown, particularly in extremophiles growing under multiple extremes. We report on the response of N. thermophilus to external pH at high salt and elevated temperature and identify mechanisms responsible for this adaptation. N. thermophilus exhibited cytoplasm acidification, maintaining an unanticipated transmembrane pH gradient of 1 unit over the entire extracellular pH range for growth. N. thermophilus uses two distinct mechanisms for cytoplasm acidification. At extracellular pH values at and below the optimum, N. thermophilus utilizes at least eight electrogenic Na(+)(K(+))/H(+) antiporters for cytoplasm acidification. Characterization of these antiporters in antiporter-deficient Escherichia coli KNabc showed overlapping pH profiles (pH 7.8-10.0) and Na(+) concentrations for activity (K(0.5) values 1.0-4.4 mM), properties that correlate with intracellular conditions of N. thermophilus. As the extracellular pH increases beyond the optimum, electrogenic antiport activity ceases, and cytoplasm acidification is achieved by energy-independent physiochemical effects (cytoplasmic buffering) potentially mediated by an acidic proteome. The combination of these strategies allows N. thermophilus to grow over a range of extracellular pH and Na(+) concentrations and protect biomolecules under multiple extreme conditions.

  5. 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

  6. Research on metabolic network of extremely halophilic archaea%极端嗜盐古菌代谢网络研究

    Institute of Scientific and Technical Information of China (English)

    丁德武

    2012-01-01

    Extremely halophilic archaea belonging to the euryarchaeota halobium branch, it is a typical population in archaea, and very important to microbial resources. In this article, we mainly study the structure and function of metabolic network about one extremely halophilic archaea: Halobacterium salinarum Rl. We obtain a list of all metabolic reactions in Halobacterium salinarum Rl from published high-quality metabolic models, and represent it with metabolite graph. We analyze functional modules and hubs of the network, and discussed their biological signification.%极端嗜盐古菌(extremely thermophilic archaea)属于广域古菌界盐杆菌科,是古菌域中的典型生理类群,也是重要的极端微生物资源.文章主要对一种极端嗜盐古菌——盐沼盐杆菌(Halobacterium salinarum R1)——代谢网络的结构与功能进行了分析.对高质量盐沼盐杆菌代谢网络数据进行整理,构建了其中所有的代谢反应列表,并用代谢物图来表示.分析了该网络的功能模块和关键节点,并讨论了它们的生物学功能意义.

  7. 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.

  8. 极端嗜盐古菌蛋白类抗生素——嗜盐菌素%Halocin:Protein Antibiotics Produced by Extremely Halophilic Archaea

    Institute of Scientific and Technical Information of China (English)

    厉云; 向华; 谭华荣

    2002-01-01

    @@ 古菌(Archaea)是一类与细菌及真核生物显著不同的生命的第三种形式[1],大多生活在极端或特殊环境,主要包括产甲烷古菌(Methanogenic Achaea)、极端嗜盐古菌(Extremely Halophilic Archaea)和极端嗜热古菌(Extremely Thermophilic Archaea)等三大类.极端古菌是极端环境微生物的重要成员,也是极端环境微生物资源开发的重要领域.其中,嗜盐古菌可产生一类蛋白类抗生素,称为嗜盐菌素(halocin).

  9. 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+.

  10. Response of the extremely halophilic Halococcus dombrowskii strain H4 to UV radiation and space conditions in the EXPOSE -ADAPT project on the International Space Station

    Science.gov (United States)

    Fendrihan, Sergiu; Grosbacher, Michael; Stan-Lotter, Helga

    2010-05-01

    The international project ADAPT focuses on the response of different microorganisms to outer space conditions. In 2007, the European Space Agency (ESA) has installed the Columbus laboratory and the exposure facility EXPOSE-E on the International Space Station (ISS). One of the microorganisms that were exposed for 18 months on the ISS is Halococcus dombrowskii strain H4, an extremely halophilic archaeon which was isolated from about 250 million years old alpine salt deposits (1). Ground experiments with Hcc. dombrowskii included irradiation with different wavelengths and doses of UV, using a Hg low pressure lamp, a solar simulator SOL2 (both at the DLR, Cologne) and a Mars UV simulation lamp (2). Cells were embedded in halite crystals which were formed on quartz discs by evaporation of high salt buffers. Methods for analyzing the effects of exposure on Hcc. dombrowskii include the estimation of colony forming units (CFUs), staining for viability with the BacLight LIVE/DEAD kit (2), establishing long term liquid cultures and determination of the formation of cyclobutane pyrimidine dimers (CPDs) with specific antibodies (3). Counting of viable (green) and dead (red) cells showed an apparent preservation of viability following exposure to about 21 kJ/m2 in ground experiments, but the calculated D37 (dose of 37 % survival) for Hcc. dombrowskii was about 400 kJ/m2 in salt crystals (2). CPDs were detected in about 6-8% of cells of Hcc. dombrowskii following exposure to a dose of 3000 kJ/m2 (200-400 nm). Preliminary results with the samples of Hcc. dombrowskii from the ISS suggested preservation of cellular morphology and stainability with the fluorescent dyes of the LIVE/DEAD kit, as well as formation of CPDs in about 2-3 % of the cells. The determination of the survival of cells by measuring proliferation requires months of incubation; data can be expected in May or June 2010. (1) Stan-Lotter H, Pfaffenhuemer M, Legat A, Busse H-J, Radax C, Gruber C (2002) Halococcus

  11. 青海茶卡盐湖中极端嗜盐碱真菌分离的研究%Separation of Extreme Halophilic and Alkaliphilic Fungi from Qinghai Chaka Lake

    Institute of Scientific and Technical Information of China (English)

    洒威; 焦迎春

    2012-01-01

    [Objective]The research aimed to separate extreme halophilic and alkaliphilic fungi from the soil samples in Qinghai Chaka Lake.[Method] The spread plate method and streaking were adopted.[Result]Two fungal, five bacteria and three actinomyces were separated. The maximum growth of two fungal was appeared at the first eight days. The halophilic and alkaliphilic of two fungal were studied.[Conclusion] CF12-1 grew at 15% salinity was the extreme halophile. CF12-2 stopped growth at 12% and 15% salinity was the moderate halophile. CF12-1 and CF12-2 grew under pH 10 were the extreme alhallphiles.%[目的]为了从青海茶卡盐湖中分离极端嗜盐碱真菌.[方法]采用平板涂布、划线分离法.[结果]分离得到可培养真菌2株、细菌5株、放线菌3株.2株真菌均在第8天达到最大生长量.同时,对2株真菌的嗜盐碱性进行了研究.[结论] CF12-1在15%盐度时能生长,为极端啫盐菌;CF12-2在12%和15%盐度时停止生长,为中度啫盐菌;CF12-1与CF12-2在pH 10时均能生长,为极端啫碱菌.

  12. Isolation of an extremely halophilic arhaeon Natrialba sp. C21 able to degrade aromatic compounds and to produce stable biosurfactant at high salinity.

    Science.gov (United States)

    Khemili-Talbi, Souad; Kebbouche-Gana, Salima; Akmoussi-Toumi, Siham; Angar, Yassmina; Gana, Mohamed Lamine

    2015-11-01

    Natrialba sp. strain C21 was isolated from oil contaminated saline water in Ain Salah (Algeria) and has exhibited a good potential for degrading phenol (3% v/v), naphthalene (3% v/v), and pyrene (3% v/v) at high salinity with high growth, enzymatic activity and biosurfactant production. Successful metabolism of aromatic hydrocarbon compounds of the strain Natrialba sp. C21 appears to require the ortho-cleavage pathway. Indeed, assays of the key enzymes involved in the ring cleavage of catechol 1, 2-dioxygenase indicated that degradation of the phenol, naphthalene and pyrene by strain Natrialba sp. C21 was via the ortho-cleavage pathway. Cells grown on aromatic hydrocarbons displayed greater ortho-activities mainly towards catechol, while the meta-activity was very low. Besides, biosurfactants derived from the strain C21 were capable of effectively emulsifying both aromatic and aliphatic hydrocarbons and seem to be particularly promising since they have particular adaptations like the increased stability at high temperature and salinity conditions. This study clearly demonstrates for the first time that strain belonging to the genera Natrialba is able to grow at 25% (w/v) NaCl, utilizing phenol, naphthalene, and pyrene as the sole carbon sources. The results suggest that the isolated halophilic archaeon could be a good candidate for the remediation process in extreme environments polluted by aromatic hydrocarbons. Moreover, the produced biosurfactant offers a multitude of interesting potential applications in various fields of biotechnology.

  13. Genomic Analysis of the Extremely Halophilic Archaeon Halobacterium noricense CBA1132 Isolated from Solar Salt That Is an Essential Material for Fermented Foods.

    Science.gov (United States)

    Lim, Seul Ki; Kim, Joon Yong; Song, Hye Seon; Kwon, Min-Sung; Lee, Jieun; Oh, Young Jun; Nam, Young-Do; Seo, Myung-Ji; Lee, Dong-Gi; Choi, Jong-Soon; Yoon, Changmann; Sohn, Eunju; Rahman, Md Arif-Ur; Roh, Seong Woon; Choi, Hak-Jong

    2016-08-28

    The extremely halophilic archaeon Halobacterium noricense is a member of the genus Halobacterium. Strain CBA1132 (= KCCM 43183, JCM 31150) was isolated from solar salt. The genome of strain CBA1132 assembled with 4 contigs, including three rRNA genes, 44 tRNA genes, and 3,208 open reading frames. Strain CBA1132 had nine putative CRISPRs and the genome contained genes encoding metal resistance determinants: copper-translocating P-type ATPase (CtpA), arsenical pump-driving ATPase (ArsA), arsenate reductase (ArsC), and arsenical resistance operon repressor (ArsR). Strain CBA1132 was related to Halobacterium noricense, with 99.2% 16S rRNA gene sequence similarity. Based on the comparative genomic analysis, strain CBA1132 has distinctly evolved; moreover, essential genes related to nitrogen metabolism were only detected in the genome of strain CBA1132 among the reported genomes in the genus Halobacterium. This genome sequence of Halobacterium noricense CBA1132 may be of use in future molecular biological studies.

  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. Screening and isolation of halophilic bacteria producing industrially important enzymes

    Directory of Open Access Journals (Sweden)

    Sumit Kumar

    2012-12-01

    Full Text Available 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.

  16. 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.

  17. Halophilic adaptation of enzymes.

    Science.gov (United States)

    Madern, D; Ebel, C; Zaccai, G

    2000-04-01

    It is now clear that the understanding of halophilic adaptation at a molecular level requires a strategy of complementary experiments, combining molecular biology, biochemistry, and cellular approaches with physical chemistry and thermodynamics. In this review, after a discussion of the definition and composition of halophilic enzymes, the effects of salt on their activity, solubility, and stability are reviewed. We then describe how thermodynamic observations, such as parameters pertaining to solvent-protein interactions or enzyme-unfolding kinetics, depend strongly on solvent composition and reveal the important role played by water and ion binding to halophilic proteins. The three high-resolution crystal structures now available for halophilic proteins are analyzed in terms of haloadaptation, and finally cellular response to salt stress is discussed briefly.

  18. 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.

  19. Salt-bridge energetics in halophilic proteins.

    Directory of Open Access Journals (Sweden)

    Arnab Nayek

    Full Text Available 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

  20. Halophilic life on Mars ?

    Science.gov (United States)

    Stan-Lotter, Helga; Fendrihan, Sergiu; Dornmayr-Pfaffenhuemer, Marion; Holzinger, Anita; Polacsek, Tatjana K.; Legat, Andrea; Grösbacher, Michael; Weigl, Andreas

    2010-05-01

    Background: The search for extraterrestrial life has been declared as a goal for the 21th century by several space agencies. Potential candidates are microorganisms on or in the surface of moons and planets, such as Mars. Extremely halophilic archaea (haloarchaea) are of astrobiological interest since viable strains have been isolated from million years old salt deposits (1) and halite has been found in Martian meteorites and in surface pools. Therefore, haloarchaeal responses to simulated and real space conditions were explored. Immuno assays for a potential Life Marker Chip experiment were developed with antisera against the universal enzyme ATP synthase. Methods: The focus of these studies was on the application of fluorescent probes since they provide strong signals, and detection devices are suitable for miniaturization. Viability of haloarchaeal strains (Halococcus dombrowskii and Halobacterium salinarum NRC-1) was probed with the LIVE/DEAD BacLight™ kit and the BacLight™ Bacterial Membrane Potential kit. Cyclobutane pyrimidine dimers (CPD) in the DNA, following exposure to simulated and real space conditions (UV irradiation from 200 - 400 nm; 18 months exposure on the International Space Station [ISS] within the ADAPT experiment by Dr. P. Rettberg), were detected with fluorescent Alexa-Fluor-488-coupled antibodies. Immuno assays with antisera against the A-ATPase subunits from Halorubrum saccharovorum were carried out with the highly sensitive Immun-Star ™ WesternC ™ chemiluminescent kit (Bio-Rad). Results: Using the LIVE/DEAD BacLight™ kit, the D37 (dose of 37% survival) for Hcc. dombrowskii and Hbt. salinarum NRC-1, following exposure to UV (200-400 nm) was about 400 kJ/m2, when cells were embedded in halite and about 1 kJ/m2, when cells were in liquid cultures. Fluorescent staining indicated a slightly higher cellular activity than that which was derived from the determination of colony forming units. Assessment of viability with the Bac

  1. 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.

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

    Directory of Open Access Journals (Sweden)

    Romain eTalon

    2014-02-01

    Full Text Available Protein-solvent interactions govern the behaviour of proteins isolated from extreme halophiles. In this work, we compared the solvent envelopes of two orthologous tetrameric malate dehydrogenases from halophilic and non-halophilic bacteria. The crystal structure of the malate dehydrogenase 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 malate dehydrogenase 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 organisation 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 behaviour in solution

  3. Chromosome map of the thermophilic archaebacterium Thermococcus celer

    Science.gov (United States)

    Noll, K. M.; Woese, C. R. (Principal Investigator)

    1989-01-01

    A physical map for the chromosome of the thermophilic archaebacterium Thermococcus celer Vu13 has been constructed. Thirty-four restriction endonucleases were tested for their ability to generate large restriction fragments from the chromosome of T. celer. Of these, the enzymes NheI, SpeI, and XbaI yielded the fewest fragments when analyzed by pulsed-field electrophoresis. NheI and SpeI each gave 5 fragments, while XbaI gave 12. The size of the T. celer chromosome was determined from the sum of the apparent sizes of restriction fragments derived from single and double digests by using these enzymes and was found to be 1,890 +/- 27 kilobase pairs. Partial and complete digests allowed the order of all but three small (less than 15 kilobase pairs) fragments to be deduced. These three fragments were assigned positions by using hybridization probes derived from these restriction fragments. The positions of the other fragments were confirmed by using hybridization probes derived in the same manner. The positions of the 5S, 16S, and 23S rRNA genes as well as the 7S RNA gene were located on this map by using cloned portions of these genes as hybridization probes. The 5S rRNA gene was localized 48 to 196 kilobases from the 5' end of the 16S gene. The 7S RNA gene was localized 190 to 504 kilobases from the 3' end of the 23S gene. These analyses demonstrated that the chromosome of T. celer is a single, circular DNA molecule. This is the first such demonstration of the structure of an archaebacterial chromosome.

  4. 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

    Cellulare, UniversitA di Roma, Roma, Italy ’Centro de Biologia Molecular , CSIC -UAM, Cantoblanco, Madrid 34, Spain The ribosomes of extremely halophilic...JD-A275 842 THE TWELFTH EDMOND DE ROTHSCHILD SCHOOL IN MOLECULAR BIOPHYSICS MODERN ASPECTS DTIC OF 0 ELECTEOFFEB 0 3,1994 HALOPHILISM SFE’, PROGRAM...Copy THE TWELFTH EDMOND DE ROTHSCHILD SCHOOL IN MOLECULAR BIOPHYSICS MODERN ASPECTS I CRAMSDTIC TAB 1 OF HALOPHILISM u .............. PROGRAM Dist

  5. Metatranscriptomic analysis of extremely halophilic viral communities

    National Research Council Canada - National Science Library

    Santos, Fernando; Moreno-Paz, Mercedes; Meseguer, Inmaculada; López, Cristina; Rosselló-Mora, Ramon; Parro, Víctor; Antón, Josefa

    2011-01-01

    .... In this work, we analyzed the viral expression in one crystallizer using a metatranscriptomic approach in which clones from a metaviromic library were immobilized in a microarray and used as probes...

  6. 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.

  7. 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.

    2015-01-01

    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. PMID:27682089

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

    Directory of Open Access Journals (Sweden)

    Michaela Weissgram

    2015-06-01

    Full Text Available 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.

  9. Isolation,Identification and Characterization of Extremely Halophilic C50 Carotenoid-Producing Archaeon%1株产C50类胡萝卜素极端嗜盐古菌的筛选鉴定及特性分析

    Institute of Scientific and Technical Information of China (English)

    刘良森; 邓元告; 隋丽英

    2014-01-01

    An extremely halophilic C50 carotenoid-producing red archaeon was isolated from the crystalli-zer ponds in solar saltworks.The isolated strain is Gram-negative and short rod.The optimum salinity and pH for growth is 250 and 7,respectively.Phenotypic and molecular analyses of this strain indicated that it belonged to extremely halophilic archaea genus Halorubrum and named Halorubrum Sp1 (16S rRNA Genbank registration number KF697239).UV-visible scanning spectrum showed that C50 carote-noid was the major pigments presented in this strain.Pigment accumulation was maximizing at pH 8. In the salinity range of 150~300,increasing salinity resulted in declined pigment accumulation.%从日晒盐场结晶池中筛选到1株产C50类胡萝卜素的红色极端嗜盐古菌。该菌株为革兰氏阴性菌,短棒状,最适生长盐度为250,最适生长pH 为7。表型鉴定方法结合16S rDNA序列分析判定,该菌属于极端嗜盐古菌盐红菌属 Halorubrum,命名为 Halorubrum sp.Sp1(16S rRNA Genbank 登录号为KF697239)。根据紫外-可见光扫描特征光谱,确定该菌株主要色素为 C50类胡萝卜素。pH 8时单位细胞色素积累量最大,在盐度150~300范围内随盐度升高,单位细胞色素积累量逐渐降低。

  10. 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)

    2012-01-01

    Background 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 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

  11. Purification and characterization of the oxygen-sensitive acetohydroxy acid synthase from the archaebacterium Methanococcus aeolicus.

    OpenAIRE

    Xing, R.; Whitman, W B

    1994-01-01

    Acetohydroxy acid synthase (EC 4.1.3.18) of the archaebacterium Methanococcus aeolicus was purified 1,150-fold to homogeneity. The molecular weight of the purified enzyme was 125,000, and it contained only one type of subunit (M(r) = 58,000). The amino-terminal sequence had 46 to 57% similarity to those of the large subunits of the eubacterial anabolic enzymes and 37 to 43% similarity to those of the yeast and plant enzymes. The methanococcal enzyme had a pH optimum of 7.6. The pI, estimated ...

  12. Circular chromosomal DNA in the sulfur-dependent archaebacterium Sulfolobus acidocaldarius.

    OpenAIRE

    Yamagishi, A; Oshima, T

    1990-01-01

    The shape of the chromosomal DNA of the sulfur-dependent archaebacterium Sulfolobus acidocaldarius was analyzed by the pulsed-field gel electrophoresis(PFGE). S.acidocaldarius DNA digested with Notl showed two DNA bands at around 1.0 Mbp and 2.1 Mbp. Notl-linking clones were isolated from the library of S.acidocaldarius chromosomal DNA. It contained two Notl sites. Both 1.0 and 2.1 Mbp DNA band separated by PFGE were hybridized with the two independent Notl-linking fragment. Each right and le...

  13. The Function of Gas Vesicles in Halophilic Archaea and Bacteria: Theories and Experimental Evidence

    Directory of Open Access Journals (Sweden)

    Aharon Oren

    2012-12-01

    Full Text Available 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.

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

    Science.gov (United States)

    Oren, Aharon

    2016-01-01

    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. PMID:27187481

  15. 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.

  16. Halophilic microorganism resources and their applications in industrial and environmental biotechnology

    Directory of Open Access Journals (Sweden)

    Hakuto Kageyama

    2016-03-01

    Full Text Available Hypersaline environments are extreme habitats on the planet and have a diverse microbial population formed by halophilic microorganisms. They are considered to be actual or potential sources for discovery bioactive compounds, compatible solutes including novel and/or extraordinarily enzymes. To date, a number of bioactive compounds for the use in various fields of biotechnology which show assorted biological activities ranging from antioxidant, sunscreen and antibiotic actions have been reported. In addition, some halophilic microorganisms are capable of producing massive amounts of compatible solutes that are useful as stabilizers for biomolecules or stress-protective agents. The present review will impart knowledge and discuss on (i potential biotechnological applications of bioactive compounds, compatible solutes and some novel hydrolytic enzymes; (ii recent efforts on discovery and utilization of halophiles for biotechnological interest; (iii future perspective of aforementioned points.

  17. On the Response of Halophilic Archaea to Space Conditions

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    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.

  18. Diversity of culturable halophilic sulfur-oxidizing bacteria in hypersaline habitats.

    Science.gov (United States)

    Sorokin, Dimitry Yu; Tourova, Tatjana P; Lysenko, Anatoly M; Muyzer, Gerard

    2006-10-01

    Unexpectedly high culturable diversity of moderately and extremely halophilic obligately chemolithoautotrophic sulfur-oxidizing bacteria (SOB) was discovered in the sediments of various hypersaline habitats, including chloride-sulfate lakes in Mongolia, Russia and Ukraine, a sea saltern in Slovenia and a deep-sea salt brine from the Mediterranean. Six different groups of halophilic SOB, including four new genera, all belonging to the Gammaproteobacteria, were found. Two groups of moderately halophilic strictly aerobic SOB dominated at 2 M NaCl, including representatives of the genus Halothiobacillus (in fully aerobic conditions) and Thiomicrospira (in micro-oxic conditions). Under denitrifying conditions at 2 M NaCl, a group of moderately halophilic and facultatively anaerobic SOB was selected, capable of complete denitrification of nitrate. The group represents a new genus with closest relatives among as yet undescribed marine thiodenitrifying isolates. With thiocyanate as a substrate, an enrichment culture at 2 M NaCl yielded a pure culture of moderately halophilic SOB capable of aerobic growth with thiocyanate and thiosulfate at up to 4 M NaCl. Furthermore, this bacterium also grew anaerobically using nitrite as electron acceptor. It formed a new lineage distantly related to the genus Thiomicrospira. Enrichments at 4 M NaCl resulted in the domination of two different, previously unknown, groups of extremely halophilic SOB. Under oxic conditions, they were represented by strictly aerobic spiral-shaped bacteria, related to the Ectothiorhodospiraceae, while under denitrifying conditions a group of facultatively anaerobic nitrate-reducing bacteria with long rod-shaped cells was selected, distantly related to the genus Acidithiobacillus.

  19. Phytanyl-glycerol ethers and squalenes in the archaebacterium Methanobacterium thermoautotrophicum

    Energy Technology Data Exchange (ETDEWEB)

    Tornabene, T.G. (Colorado State Univ., Fort Collins); Wolfe, R.S.; Balch, W.E.; Holzer, G.; Fox, G.E.; Oro, J.

    1978-01-01

    The lipids of a thermophilic chemolithotroph, Methanobacterium thermoautotrophicum, have been analyzed by chromatographic techniques and identified by infrared spectrometry and combined gas chromatography-mass spectrometry. Of the total chloroform soluble lipids 79% and 21% are polar and non-polar lipids, respectively. The major components of the polar lipids are dialkyl ethers of glycerol or its derivatives. The nature of the glycerol ether alkyl groups was found to be that of the saturated tetraacyclic acyclic isoprenoid hydrocarbon phytane. The non-polar lipids of the chloroform soluble fraction consist principally of three series of C/sub 20/, C/sub 25/ and C/sub 30/ isoprenoid hydrocarbons, the major components being squalene and a continuous range of hydrosqualene derivatives, from dihydrosqualene up to and including dehydrosqualene. These data establish that M. thermoautotrophicum contains predominantly non-saponifiable lipids as do Halobacterium, Halococcus, Sulfolobus and Thermoplasma. In particular, the composition of the chloroform soluble lipids of M. thermoautotrophicum is quite similar to that of Halobacterium cutirubrum. The results strongly support the recent proposal, based on 16S rRNA sequence homologies, that the extreme halophiles and methanogens share a common ancestor. In addition, it is pointed out that the occurrence of phytane and related polyisoprenoid compounds in ancient sediments can no longer be considered unequivocally as indicative of past photosynthetic activity. Finally, speculations are made concerning the possible role of and evolutionary significance of the presence of squalene and hydrosqualenes in these organisms. To our knowledge this is the first report of squalene and hydrosqualenes in a strictly anaerobic microorganism.

  20. 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.

  1. Etude de Pan A et de Pan B : deux protéines régulatrices du protéasome chez les archaea halophiles.

    OpenAIRE

    Chamieh, Hala

    2005-01-01

    Proteasomes are large ATP-dependent proteases implicated in degradation of key regulatory cellular proteins and abnormal cellular proteins. The current work is the first characterization of two AAA-ATPase proteasomal regulatory proteins PAN A and PAN B in halophilic archaea. The first part of the manuscript characterizes the mode of regulation of the two PANs in the extremely halophilic archaoen Halobacterium salinarium. Our experiments show the existence of two isoforms of each PAN proteins ...

  2. Some Biochemical Properties of an Acido-Thermophilic Archae-Bacterium Sulfolobus Acidocaldarius

    Science.gov (United States)

    Oshima, Tairo; Ohba, Masayuki; Wagaki, Takayoshi

    1984-12-01

    To elucidate the phylogenic status of archaebacteria, some basic cellular components of an acido-thermophilic archaebacterium,Sulfolobus acidocaldarius, were studied. Poly(A) containing RNA was present in the cells, and performed the role of mRNA in a cell-free extract of reticulocyte or the archaebacteria. Poly(A) containing RNA was also found in other archaebacterial cells. The absence of cap structure was suggested in these RNAs. The cell-free protein synthesis using the archaebacterial extract was inhibited by anisomycin, a specific inhibitor for eukaryotic ribosomes. Two unique membrane-bound ATPases were detected. Based on resistance to H+-ATPase inhibitors, these enzymes seemed not to be F0F1-ATPase.

  3. Sequence of the 16S Ribosomal RNA from Halobacterium volcanii, an Archaebacterium.

    Science.gov (United States)

    Gupta, R; Lanter, J M; Woese, C R

    1983-08-12

    The sequence of the 16S ribosomal RNA (rRNA) from the archaebacterium Halobacterium volcanii has been determined by DNA sequencing methods. The archaebacterial rRNA is similar to its eubacterial counterpart in secondary structure. Although it is closer in sequence to the eubacterial 16S rRNA than to the eukaryotic 16S-like rRNA, the H. volcanii sequence also shows certain points of specific similarity to its eukaryotic counterpart. Since the H. volcanii sequence is closer to both the eubacterial and the eukaryotic sequences than these two are to one another, it follows that the archaebacterial sequence resembles their common ancestral sequence more closely than does either of the other two versions.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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

  10. Characterization of halophiles isolated from solar salterns in Baja California, Mexico.

    Science.gov (United States)

    Sabet, Shereen; Diallo, Lamine; Hays, Lauren; Jung, Woosung; Dillon, Jesse G

    2009-07-01

    Solar salterns are extreme hypersaline environments that are five to ten times saltier than seawater (150-300 g L(-1) salt concentration) and typically contain high numbers of halophiles adapted to tolerate such extreme hypersalinity. Thirty-five halophile cultures of both Bacteria and Archaea were isolated from the Exportadora de Sal saltworks in Guerrero Negro, Baja California, Mexico. 16S rRNA sequence analysis showed that these cultured isolates included members belonging to the Halorubrum, Haloarcula, Halomonas, Halovibrio, Salicola, and Salinibacter genera and what may represent a new archaeal genus. For the first time, metabolic substrate usage of halophile isolates was evaluated using the non-colorimetric BIOLOG Phenotype MicroArray plates. Unique carbon substrate usage profiles were observed, even for closely related Halorubrum species, with bacterial isolates using more substrates than archaeal cultures. Characterization of these isolates also included morphology and pigmentation analyses, as well as salinity tolerance over a range of 50-300 g L(-1) salt concentration. Salinity optima varied between 50 and 250 g L(-1) and doubling times varied between 1 and 12 h.

  11. Halophilic Archaea: Life with Desiccation, Radiation and Oligotrophy over Geological Times

    Directory of Open Access Journals (Sweden)

    Helga Stan-Lotter

    2015-07-01

    Full Text Available Halophilic archaebacteria (Haloarchaea can survive extreme desiccation, starvation and radiation, sometimes apparently for millions of years. Several of the strategies that are involved appear specific for Haloarchaea (for example, the formation of halomucin, survival in fluid inclusions of halite, and some are known from other prokaryotes (dwarfing of cells, reduction of ATP. Several newly-discovered haloarchaeal strategies that were inferred to possibly promote long-term survival—halomucin, polyploidy, usage of DNA as a phosphate storage polymer, production of spherical dormant stages—remain to be characterized in detail. More information on potential strategies is desirable, since evidence for the presence of halite on Mars and on several moons in the solar system increased interest in halophiles with respect to the search for extraterrestrial life. This review deals in particular with novel findings and hypotheses on haloarchaeal long-term survival.

  12. 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.

  13. Halophilic Aspergillus penicillioides from athalassohaline, thalassohaline, and polyhaline environments

    National Research Council Canada - National Science Library

    Nazareth, Sarita W; Gonsalves, Valerie

    2014-01-01

    Aspergillus penicillioides is a true halophile, present in diverse econiches - from the hypersaline athalassohaline, and thalassohaline environments, to polyhaline systems, and in different geographical locations...

  14. 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.

  15. Identification of several intracellular carbohydrate-degrading activities from the halophilic archaeon Haloferax mediterranei.

    Science.gov (United States)

    Pérez-Pomares, F; Díaz, S; Bautista, V; Pire, C; Bravo, G; Esclapez, J; Zafrilla, B; Bonete, María-José

    2009-07-01

    Three different amylolytic activities, designated AMY1, AMY2, and AMY3 were detected in the cytoplasm of the extreme halophilic archaeon Haloferax mediterranei grown in a starch containing medium. This organism had also been reported to excrete an alpha-amylase into the external medium in such conditions. The presence of these different enzymes which are also able to degrade starch may be related to the use of the available carbohydrates and maltodextrins, including the products obtained by the action of the extracellular amylase on starch that may be transported to the cytoplasm of the organism. The behavior of these intracellular hydrolytic enzymes on starch is reported here and compared with their extracellular counterpart. Two of these glycosidic activities (AMY1, AMY3) have also been purified and further characterized. As with other halophilic enzymes, they were salt dependent and displayed maximal activity at 3 M NaCl, and 50 degrees C. The purification steps and molecular masses have also been reported. The other activity (AMY2) was also detected in extracts from cells grown in media with glycerol instead of starch and in a yeast extract medium. This enzyme was able to degrade starch yielding small oligosaccharides and displayed similar halophilic behavior with salt requirement in the range 1.5-3 M NaCl.

  16. 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

  17. 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.

  18. Osmoadaptation Strategy of the Most Halophilic Fungus, Wallemia ichthyophaga, Growing Optimally at Salinities above 15% NaCl

    OpenAIRE

    Zajc, Janja; Kogej, Tina; Galinski, Erwin A.; Ramos, José; Gunde-Cimerman, Nina

    2014-01-01

    Wallemia ichthyophaga is a fungus from the ancient basidiomycetous genus Wallemia (Wallemiales, Wallemiomycetes) that grows only at salinities between 10% (wt/vol) NaCl and saturated NaCl solution. This obligate halophily is unique among fungi. The main goal of this study was to determine the optimal salinity range for growth of the halophilic W. ichthyophaga and to unravel its osmoadaptation strategy. Our results showed that growth on solid growth media was extremely slow and resulted in sma...

  19. ISOLATION AND CHARACTERIZATION OF HALOPHILIC BACTERIAL STRAINS FROM SALINE WATERS OF KHEWRA SALT MINES ON THE BASIS OF 16S rRNA GENE SEQUENCE

    Directory of Open Access Journals (Sweden)

    Muhammad Kaleem Sarwar

    2014-02-01

    Full Text Available Halophiles are salt loving microbes optimally growing at high concentrations of salt. Khewra salt mines of Pakistan provide extreme saline conditions where enormous halophilic microbial biota thrives. The present study aimed at isolation and molecular identification of bacterial strains from saline waters of Khewra salt mines. Using halophilic media, nine halophilic bacterial strains from saline water bodies were cultured and studied under optimized growth conditions (NaCl, pH and temperature. Bacterial growth at different NaCl concentrations was measured at 600nm wavelength, showing optimal growth at 1.5M NaCl. 769bp size 16S rRNA gene was amplified for molecular identification of bacterial strains. The amplified genes of the strains FA2.2 and FA3.3 were sequenced and their homology with other bacterial strains was analyzed. The results showed FA2.2 shared maximum homology with Bacillus anthracis strain while FA3.3 showed close resemblance with Staphylococcus saprophyticus subsp. bovis. Isolated halophilic bacterial strains possess potential for various biotechnological applications. They could be manipulated for synthesizing transgenic crops tolerating high salinity boosting the agricultural yield. Moreover extremozymes of these bacteria holds great industrial importance.

  20. 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.

  1. 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.

  2. Halophilic Aspergillus penicillioides from athalassohaline, thalassohaline, and polyhaline environments

    OpenAIRE

    Sarita Winifred Nazareth; Valerie eGonsalves

    2014-01-01

    Aspergillus penicillioides is a true halophile, present in diverse econiches – from the hypersaline athalassohaline, and thalassohaline environments, to polyhaline systems, and in different geographical locations. Twenty seven isolates from these environments, were seen to be moderate halophiles, euryhaline in nature. They had an obligate need of a low aw and were unable to grow on a regular defined medium such as Czapek Dox Agar, as well as on varied nutrient rich agar media such as Malt Ext...

  3. 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.

  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. Heavy metal tolerant halophilic bacteria from Vembanad Lake as possible source for bioremediation of lead and cadmium.

    Science.gov (United States)

    Sowmya, M; Rejula, M P; Rejith, P G; Mohan, Mahesh; Karuppiah, Makesh; Hatha, A A Mohamed

    2014-07-01

    Microorganisms which can resist high concentration of toxic heavy metals are often considered as effective tools of bioremediation from such pollutants. In the present study, sediment samples from Vembanad Lake were screened for the presence of halophilic bacteria that are tolerant to heavy metals. A total of 35 bacterial strains belonging to different genera such as Alcaligenes, Vibrio, Kurthia, Staphylococcus and members of the family Enterobacteriaceae were isolated from 21 sediment samples during February to April, 2008. The salt tolerance and optimum salt concentrations of the isolates revealed that most of them were moderate halophiles followed by halotolerant and extremely halotolerant groups. The minimum inhibitory concentrations (MICs) against cadmium and lead for each isolate revealed that the isolates showed higher MIC against lead than cadmium. Based on the resistance limit concentration, most of them were more tolerant to lead than cadmium at all the three salt concentrations tested. Heavy metal removal efficiency of selected isolates showed a maximum reduction of 37 and 99% against cadmium and lead respectively. The study reveals the future prospects of halophilic microorganisms in the field of bioremediation.

  6. 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.

  7. Biodegradation of heavy oils by halophilic bacterium

    Institute of Scientific and Technical Information of China (English)

    Ruixia Hao; Anhuai Lu

    2009-01-01

    A halophilic bacterial strain TM-1 was isolated from the reservoir of the Shengli oil field in East China. Strain TM-1, which was found to be able to degrade crude oils, is a gram-positive non-motile bacterium with a coccus shape that can grow at temperatures of up to 58 ℃ and in 18% NaCl solution. Depending on the culture conditions, the organism may occur in tetrads. In addition, strain TM-1 pro-duced acid from glucose without gas formation and was catalase-negative. Furthermore, strain TM-I was found to be a facultative aer-obe capable of growth under anaerobic conditions. Moreover, it produced butylated hydroxytoluene, 1,2-benzenedicarboxylic acid-bis ester and dibutyl phthalate and could use different organic substrates. Laboratory studies indicated that strain TM-1 affected different heavy oils by degrading various components and by changing the chemical properties of the oils. In addition, growth of the bacterium in heavy oils resulted in the loss of aromatic hydrocarbons, resins and asphaltenes, and enrichment with light hydrocarbons and an overall redistribution of these hydrocarbons.

  8. 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

  9. Endospores of halophilic bacteria of the family Bacillaceae isolated from non-saline Japanese soil may be transported by Kosa event (Asian dust storm)

    OpenAIRE

    Echigo, Akinobu; Hino, Miki; Fukushima, Tadamasa; Mizuki, Toru; Kamekura, Masahiro; Usami, Ron

    2005-01-01

    Background Generally, extremophiles have been deemed to survive in the extreme environments to which they had adapted to grow. Recently many extremophiles have been isolated from places where they are not expected to grow. Alkaliphilic microorganisms have been isolated from acidic soil samples with pH 4.0, and thermophiles have been isolated from samples of low temperature. Numerous moderately halophilic microorganisms, defined as those that grow optimally in media containing 0.5–2.5 Molar (3...

  10. Spherical particles of halophilic archaea correlate with exposure to low water activity – implications for microbial survival in fluid inclusions of ancient halite

    OpenAIRE

    Fendrihan, S.; Dornmayr-Pfaffenhuemer, M; Gerbl, F W; Holzinger, A.; Grösbacher, M; Briza, P; A. Erler; C. Gruber; Plätzer, K; Stan-Lotter, H.

    2012-01-01

    Viable extremely halophilic archaea (haloarchaea) have been isolated from million-year-old salt deposits around the world; however, an explanation of their supposed longevity remains a fundamental challenge. Recently small roundish particles in fluid inclusions of 22 000- to 34 000-year-old halite were identified as haloarchaea capable of proliferation (Schubert BA, Lowenstein TK, Timofeeff MN, Parker MA, 2010, Environmental Microbiology, 12, 440–454). Searching for a method to produce such p...

  11. Genetic analysis of the br gene in halophilic archaea isolated from Xinjiang region, China

    Institute of Scientific and Technical Information of China (English)

    Xiaohong XU; Min WU; Huibin ZHANG; Zhihu LIU

    2008-01-01

    Some novel members of extremely halophilic archaea, strains AJ 11, AJ 12 and AJ 13, were isolated from the Aularz Lake located in the Altun Mountain National Nature Reserve of Xinjiang, Uygur Autonomous Region in China. Partial DNA fragments encoding a bacteriorho-dopsin (BR), as well as for 16S rRNA of isolated strains, were amplified by PCR and their DNA sequences were determined subsequently. On the basis of homology and phylogenetic analysis of the 16S rDNA, we thought that the isolated strains forming a microbiological population are the members of the genus Natrinema. The results of genetic analysis, such as GC content, transition/transver-sion (Ti/Tv) rate ratios and synonymous substitution rates (Ks) indicate that the br fragments, with a high level of genetic divergence, are faced with both purifying selection and bias mutation pressure. The study provides the basis for use of species and BR proteins resources.

  12. 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.

  13. Euryhaline Halophilic Microorganisms From the Suiyo Seamount Hydrothermal Vents.

    Science.gov (United States)

    Okamoto, T.; Kimura, H.; Maruyama, A.; Naganuma, T.

    2002-12-01

    The euryhaline halophilic microorganisms grow in a wide salinity range from 15% NaCl or to even saturation (about 30% NaCl). A number of euryhaline halophiles have been found in a wide range of habitats from oceanic and terrestrial regimes, from deep-sea vents and seeps, and from Antarctic sea ice and terrains. We have isolated the euryhaline strains independently from a Mid-Atlantic Ridge vent fluids and Antarctic terrains are closely related species of the genus Halomonas. Some euryhaline halophiles maintain intracellular osmotic balance by controlling the concentration of compatible solute such as ectoine. This compatible solute not only stabilizes the proteins from denaturation caused by high salt concentration but also serves as a protectant against stresses such as heating, freezing and drying. The sub-seafloor structure of a hydrothermal vent is highly complicated with mosaic heterogeneity of physicochemical parameters such as temperature and salinity. This premise led us to the hypothesis that some euryhaline halophiles including Halomonas species well adapt to a wide salinity-ranged habitat in the sub-vent. To test this hypothesis, isolation and characterization of euryhaline halophiles from the Suiyo Seamount hydrothermal vents were conducted the drill-cored rock samples from the sites APSK-02, 03, and 07 and the filter-trapped fluid particle samples from the sites APSK-01 and 05 were used. For initial cultivation, a heterotrophic bacterial medium of 15% NaCl was used. The samples was added to the medium and incubated under both aerobic and anaerobic conditions at room temperature. A total of 5 euryhaline halophilic strains were obtained and phylogenetically characterized: two strains (both related to Marinobacter) from APSK-02 core section 2; one strain (related to H. meridiana) from APSK-07 core section 3; and two strains (related to H. meridiana and H. variabilis) from APSK-01 trapped particles. In addition, some thermophilic halophiles that grow at 20

  14. Halophilic Aspergillus penicillioides from athalassohaline, thalassohaline, and polyhaline environments.

    Science.gov (United States)

    Nazareth, Sarita W; Gonsalves, Valerie

    2014-01-01

    Aspergillus penicillioides is a true halophile, present in diverse econiches - from the hypersaline athalassohaline, and thalassohaline environments, to polyhaline systems, and in different geographical locations. Twenty seven isolates from these environments, were seen to be moderate halophiles, euryhaline in nature. They had an obligate need of a low aw and were unable to grow on a regular defined medium such as Czapek Dox Agar, as well as on varied nutrient rich agar media such as Malt Extract, Potato Dextrose and Sabouraud Agar; however, growth was obtained on all these media when amended with 10% solar salt. In absence of added salt, the conidia either did not germinate, or when germinated, distortions and lysis were seen in the short mycelial forms; on media with salt, the mycelia and vesicles appeared normal.

  15. Halophilic Aspergillus penicillioides from athalassohaline, thalassohaline and polyhaline environments

    Directory of Open Access Journals (Sweden)

    Sarita Winifred Nazareth

    2014-08-01

    Full Text Available Aspergillus penicillioides is a true halophile, present in diverse econiches – from the hypersaline athalassohaline and thalassohaline environments, to polyhaline systems, and in different geographical locations. Twenty seven isolates from these environments, were seen to be moderate halophiles, euryhaline in nature. They had an obligate need of a low aw and were unable to grow on a regular defined medium such as Czapek Dox Agar, as well as on varied nutrient rich agar media such as Malt Extract, Potato Dextrose and Sabouraud Agar; however, growth was obtained on all these media when amended with 10% solar salt. In absence of added salt, the conidia either did not germinate, or when germinated, distortions and lysis were seen in the short mycelial forms; on media with salt, the mycelia and vesicles appeared normal.

  16. Carotenoid Production by Halophilic Archaea Under Different Culture Conditions.

    Science.gov (United States)

    Calegari-Santos, Rossana; Diogo, Ricardo Alexandre; Fontana, José Domingos; Bonfim, Tania Maria Bordin

    2016-05-01

    Carotenoids are pigments that may be used as colorants and antioxidants in food, pharmaceutical, and cosmetic industries. Since they also benefit human health, great efforts have been undertaken to search for natural sources of carotenoids, including microbial ones. The optimization of culture conditions to increase carotenoid yield is one of the strategies used to minimize the high cost of carotenoid production by microorganisms. Halophilic archaea are capable of producing carotenoids according to culture conditions. Their main carotenoid is bacterioruberin with 50 carbon atoms. In fact, the carotenoid has important biological functions since it acts as cell membrane reinforcement and it protects the microorganism against DNA damaging agents. Moreover, carotenoid extracts from halophilic archaea have shown high antioxidant capacity. Therefore, current review summarizes the effect of different culture conditions such as salt and carbon source concentrations in the medium, light incidence, and oxygen tension on carotenoid production by halophilic archaea and the strategies such as optimization methodology and two-stage cultivation already used to increase the carotenoid yield of these microorganisms.

  17. 中度嗜盐菌的研究进展%Research Progress on Moderately Halophilic Bacteria

    Institute of Scientific and Technical Information of China (English)

    冯二梅; 宿红艳; 王磊

    2009-01-01

    介绍嗜盐微生物的分类,对中度嗜盐菌的研究历史、嗜盐机制、应用进行综述,并对中度嗜盐菌的应用前景进行展望.%The classification of halophilic microbe was introduced. The research history, halophilic mechanism and application of moderately halo-philic bacteria were reviewed. The application foreground of moderately halophilic bacteria was predicted.

  18. 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.

  19. 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.

  20. Low water activity induces the production of bioactive metabolites in halophilic and halotolerant fungi.

    Science.gov (United States)

    Sepcic, Kristina; Zalar, Polona; Gunde-Cimerman, Nina

    2010-12-27

    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.

  1. Useful halophilic, thermostable and ionic liquids tolerant cellulases

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. Halophiles as a source of polyextremophilic α-amylase for industrial applications

    Directory of Open Access Journals (Sweden)

    Sumit Kumar

    2016-02-01

    Full Text Available Halophiles are perceived as an excellent source of novel enzymes possessing inherent ability to function under saline and hypersaline environment conditions. The article covers and puts in perspective the structural and biocatalytic features of α-amylases from halophilic sources. The choice of α-amylase as the target enzyme is based on the fact that this is among the largest selling enzymes. Oligosaccharide synthesis is favored in presence of organic solvents and at high temperature. For this reason, the demand for α-amylases that are functional at high temperature and salt as well as stable towards organic solvents, is on the rise in recent years. Halophilic α-amylases are deemed to possess all the above characteristics. They are generally salt stable. In terms of water activity, saline environments are similar to non-aqueous systems. Therefore halophilic α-amylases also exhibit stability in organic solvents. In this context, the review encompasses α-amylase producing predominant halophilic microorganisms from saline habitats; strategies adopted for purification of halophilic α-amylase; their salient structural features and unique functional characteristics. Halophilic α-amylase applications and future aspects in research are also analyzed.

  3. Halophilic (aerobic) bacterial growth rate of mangrove ecosystem.

    Science.gov (United States)

    Khan, A Saleem; Ali, M Sheik; Baig, I Juned Ahmed

    2009-09-01

    Mangroves are woody specialized trees of tropics and are valuable flora contributing to economical, ecological, scientific and cultural resources. They thrive in salty environments like coastal regions and are aid towards disaster management facing the onslaught of giant waves such as Tsunami. Analysis of mangrove soil on the banks of the Adyar river behind the Theosophical society campus, Adyar, Chennai, India, gave a startling revelation of microorganisms that can tolerate different salinity ranges. Previous studies in Pichavaram delta, have reported bacterial isolates such as nitrogen fixing bacteria, halophiles and several others. However their efficiency in the growth of mangrove forest has been studied to a lesser extent. The present study has been designed and formulated to estimate halophilic (aerobic) bacterial load from mangroves soil sample based on depth and salinity of the soil and further the efficiency if any of these isolates in the growth of mangroves. Results have been correlated and a cohesive conclusion reached for further intensive research. This study throws light on the ecology of the bacterial population in the coastal marine environment inhabited bymangroves and its possible role in disaster mitigation.

  4. Interaction of hexa-His tag with acidic amino acids results in facilitated refolding of halophilic nucleoside diphosphate kinase.

    Science.gov (United States)

    Ishibashi, Matsujiro; Ida, Keiko; Tatsuda, Shuhei; Arakawa, Tsutomu; Tokunaga, Masao

    2011-11-01

    We have previously reported that amino-terminal extension sequence containing hexa-His facilitated refolding and assembly of hexameric nucleoside diphosphate kinase from extremely halophilic archaeon Halobacterium salinarum (NDK). In this study, we made various mutations in both the tag sequence and within NDK molecule. SerNDK, in which hexa-His was replaced with hexa-Ser, showed no facilitated folding. In addition, HisD58GD63G, in which both Asp58 and Asp63 in NDK were replaced with Gly, also showed no refolding enhancement. These results suggest that hexa-His in His-tag interact cooperatively with either Asp58 or Asp63 or both. Furthermore, G114D mutant, which formed a dimer in low salt solution, was strongly stabilized by His-tag to form a stable hexamer.

  5. Role of trehalose in salinity and temperature tolerance in the model halophilic bacterium Chromohalobacter salexigens.

    Directory of Open Access Journals (Sweden)

    Mercedes Reina-Bueno

    Full Text Available The disaccharide trehalose is considered as a universal stress molecule, protecting cells and biomolecules from injuries imposed by high osmolarity, heat, oxidation, desiccation and freezing. Chromohalobacter salexigens is a halophilic and extremely halotolerant γ-proteobacterium of the family Halomonadaceae. In this work, we have investigated the role of trehalose as a protectant against salinity, temperature and desiccation in C. salexigens. A mutant deficient in the trehalose-6-phosphate synthase gene (otsA::Ω was not affected in its salt or heat tolerance, but double mutants ectoine- and trehalose-deficient, or hydroxyectoine-reduced and trehalose-deficient, displayed an osmo- and thermosensitive phenotype, respectively. This suggests a role of trehalose as a secondary solute involved in osmo- (at least at low salinity and thermoprotection of C. salexigens. Interestingly, trehalose synthesis was osmoregulated at the transcriptional level, and thermoregulated at the post-transcriptional level, suggesting that C. salexigens cells need to be pre-conditioned by osmotic stress, in order to be able to quickly synthesize trehalose in response to heat stress. C. salexigens was more sensitive to desiccation than E. coli and desiccation tolerance was slightly improved when cells were grown at high temperature. Under these conditions, single mutants affected in the synthesis of trehalose or hydroxyectoine were more sensitive to desiccation than the wild-type strain. However, given the low survival rates of the wild type, the involvement of trehalose and hydroxyectoine in C. salexigens response to desiccation could not be firmly established.

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

    Directory of Open Access Journals (Sweden)

    Rajeshwari eSinha

    2014-04-01

    Full Text Available Search for new enzymes of industrial relevance, bestowed with novel properties continues to be a desirable pursuit in enzyme research. Halophilism is the unusual existence of life in saline/ hypersaline habitats and haloenzymes, are the proteins from such origin, naturally endowed with unique structural features which enable them to sustain functionality under high salt. Driven by industrial requirements, halophilic enzymes have been explored for their stability and catalytic abilities under harsh operational conditions. These have been documented to withstand high temperature, pH, organic solvents, and chaotropic agents. However, this stability is modulated by salt. Understanding the basis of salt mediated protection amidst a denaturing milieu will add significantly to the existing knowledge about structure function relationships in halophilic proteins. Exploring their protein architecture may provide template for rationale design of stable enzymes. The article encompasses the current level of understanding about haloadaptations in halophiles and structural basis of their stability against classical denaturants.

  7. 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.

  8. A First Record of Obligate Halophilic Aspergilli from the Dead Sea

    OpenAIRE

    Nazareth, Sarita; Gonsalves, Valerie; Nayak, Shweta

    2011-01-01

    The isolation of obligate halophilic aspergilli from the Dead Sea and the range of salt tolerance of halophilic fungi isolated, are reported here for the first time. The mycobiota of the Dead Sea isolated in this study, was dominated by Aspergillus and Penicillium species; Cladosporium were found in lesser numbers. All three genera were obtained from the water sample; however, Aspergillus was the only genus obtained from the sediment. There was significant difference in growth of each isolate...

  9. 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))....

  10. 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%.

  11. A first record of obligate halophilic aspergilli from the dead sea.

    Science.gov (United States)

    Nazareth, Sarita; Gonsalves, Valerie; Nayak, Shweta

    2012-03-01

    The isolation of obligate halophilic aspergilli from the Dead Sea and the range of salt tolerance of halophilic fungi isolated, are reported here for the first time. The mycobiota of the Dead Sea isolated in this study, was dominated by Aspergillus and Penicillium species; Cladosporium were found in lesser numbers. All three genera were obtained from the water sample; however, Aspergillus was the only genus obtained from the sediment. There was significant difference in growth of each isolate at different salt concentrations and intraspecies analysis revealed dissimilarity in response of strains to different salt concentrations in the growth medium The isolates were euryhaline, with halotolerance up to 20-25% solar salt, Aspergillus and Penicillium species showing a higher level of halotolerance, as compared to that of Cladosporium. Halophilic fungi were found in greater numbers in the sediment sample as compared to that in the water sample. Penicillium and Cladosporium species were exclusively facultative halophiles, while some species of Aspergillus were facultative halophiles. All the obligate halophiles isolated, belonged to the genus Aspergillus and were identified as A. penicillioides and A unguis, the latter being a first record of the species from the Dead Sea.

  12. 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.

  13. Halophilic Archaea determined from geothermal steam vent aerosols.

    Science.gov (United States)

    Ellis, Dean G; Bizzoco, Richard W; Kelley, Scott T

    2008-06-01

    Hydrothermal vents, known as 'fumaroles', are ubiquitous features of geothermal areas. Although their geology has been extensively characterized, little is known about the subsurface microbial ecology of fumaroles largely because of the difficulty in collecting sufficient numbers of cells from boiling steam water for DNA extraction and culture isolation. Here we describe the first collection, molecular analysis and isolation of microbes from fumarole steam waters in Russia (Kamchatka) and the USA (Hawaii, New Mexico, California and Wyoming). Surprisingly, the steam vent waters from all the fumaroles contained halophilic Archaea closely related to the Haloarcula spp. found in non-geothermal salt mats, saline soils, brine pools and salt lakes around the world. Microscopic cell counting estimated the cell dispersal rate at approximately 1.6 x 10(9) cells year(-1) from a single fumarole. We also managed to enrich microbes in high-salt media from every vent sample, and to isolate Haloarcula from a Yellowstone vent in a 20% salt medium after a month-long incubation, demonstrating both salt tolerance and viability of cells collected from high-temperature steam. Laboratory tests determined that microbes enriched in salt media survived temperatures greater than 75 degrees C for between 5 and 30 min during the collection process. Hawaiian fumaroles proved to contain the greatest diversity of halophilic Archaea with four new lineages that may belong to uncultured haloarchaeal genera. This high diversity may have resulted from the leaching of salts and minerals through the highly porous volcanic rock, creating a chemically complex saline subsurface.

  14. How extreme are extremes?

    Science.gov (United States)

    Cucchi, Marco; Petitta, Marcello; Calmanti, Sandro

    2016-04-01

    High temperatures have an impact on the energy balance of any living organism and on the operational capabilities of critical infrastructures. Heat-wave indicators have been mainly developed with the aim of capturing the potential impacts on specific sectors (agriculture, health, wildfires, transport, power generation and distribution). However, the ability to capture the occurrence of extreme temperature events is an essential property of a multi-hazard extreme climate indicator. Aim of this study is to develop a standardized heat-wave indicator, that can be combined with other indices in order to describe multiple hazards in a single indicator. The proposed approach can be used in order to have a quantified indicator of the strenght of a certain extreme. As a matter of fact, extremes are usually distributed in exponential or exponential-exponential functions and it is difficult to quickly asses how strong was an extreme events considering only its magnitude. The proposed approach simplify the quantitative and qualitative communication of extreme magnitude

  15. 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.

  16. Opsin-mediated inhibition of bacterioruberin synthesis in halophilic Archaea.

    Science.gov (United States)

    Peck, Ronald F; Pleşa, Alexandru M; Graham, Serena M; Angelini, David R; Shaw, Emily L

    2017-08-07

    Halophilic Archaea often inhabit environments with limited oxygen, and many produce ion-pumping rhodopsin complexes that allow them to maintain electrochemical gradients when aerobic respiration is inhibited. Rhodopsins require a protein, opsin, and an organic cofactor, retinal. We have previously demonstrated that, in Halobacterium salinarum, bacterioopsin (BO), when not bound by retinal, inhibits the production of bacterioruberin, a biochemical pathway that shares intermediates with retinal biosynthesis. In this work, we use heterologous expression in a related halophilic Archaeon, Haloferax volcanii, to demonstrate that BO is sufficient to inhibit bacterioruberin synthesis catalyzed by the H. salinarum lycopene elongase (Lye) enzyme. This inhibition was observed both in liquid cultures and in a novel colorimetric assay to quantify bacterioruberin abundance based on the colony color. Addition of retinal to convert BO to the bacteriorhodopsin complex resulted in a partial rescue of bacterioruberin production. To explore if this regulatory mechanism occurs in other organisms, we expressed a Lye homolog and an opsin from Haloarcula vallismortis in H. volcaniiH. vallismortis cruxopsin expression inhibited bacterioruberin synthesis catalyzed by H. vallismortis Lye, but had no effect when bacterioruberin synthesis was catalyzed by H. salinarum or H. volcanii Lye. Conversely, H. salinarum BO did not inhibit H. vallismortis Lye activity. Together, our data suggest that opsin-mediated inhibition of Lye is potentially widespread and represents an elegant regulatory mechanism that allows organisms to efficiently utilize ion-pumping rhodopsins obtained through lateral gene transfer.Importance Many enzymes are complexes of proteins and non-protein organic molecules called cofactors. To ensure efficient formation of functional complexes, organisms must regulate the production of proteins and cofactors. To study this regulation, we use bacteriorhodopsin from the Archaeon

  17. Halalkalicoccus paucihalophilus sp. nov., a halophilic archaeon from Lop Nur region in Xinjiang, northwest of China.

    Science.gov (United States)

    Liu, Bing-Bing; Tang, Shu-Kun; Zhang, Yong-Guang; Lu, Xin-Hua; Li, Li; Cheng, Juan; Zhang, Yuan-Ming; Zhang, Li-Li; Li, Wen-Jun

    2013-05-01

    Two extremely halophilic archaea, designated YIM 93701(T) and YIM 93664, were isolated from Lop Nur region in Xinjiang Province, northwest of China. The cells of the two strains were observed to be cocci, non-motile and Gram-negative. The organisms were determined to be aerobic and required at least 6 % NaCl for growth (optimum 20-25 % and maximum 35 %). Growth was found to occur in the ranges of 16-50 °C (optimum 37 °C) and pH 6.0-8.5 (optimum 6.5-7.5). Cells did not lyse in distilled water. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the two strains belongs to the genus Halalkalicoccus and possessed 99.3 and 99.5 % similarities with their closest phylogenetic relative Halalkalicoccus tibetensis JCM 11890(T). Major polar lipids of the two strains were determined to be phosphatidylglycerol(PG),phosphatidylglycerol phosphate methyl ester (PGP-Me), phosphatidylglycerol sulfate (PGS) and three unidentified glycolipids. The DNA G+C contents were determined to be 60.0-60.4 mol%. The DNA hybridization between the two strains was 92.0 %. In addition, the hybridizations of both strains to H. tibetensis were 49 and 52 %, respectively, and to Halalkalicoccus jeotali were 38 and 33 %, respectively. On the basis of physiological, biochemical tests and phylogenetic differentiations, strains YIM 93701(T) and YIM 93664 were classified as the same species which represent a novel species in the genus Halalkalicoccus, for which the name Halalkalicoccus paucihalophilus sp. nov. is proposed. The type strain is YIM 93701(T) (=JCM 17505(T) = CCTCC 2012803(T)).

  18. The protein interaction network of a taxis signal transduction system in a Halophilic Archaeon

    Directory of Open Access Journals (Sweden)

    Schlesner Matthias

    2012-11-01

    Full Text Available Abstract Background The taxis signaling system of the extreme halophilic archaeon Halobacterium (Hbt. salinarum differs in several aspects from its model bacterial counterparts Escherichia coli and Bacillus subtilis. We studied the protein interactions in the Hbt. salinarum taxis signaling system to gain an understanding of its structure, to gain knowledge about its known components and to search for new members. Results The interaction analysis revealed that the core signaling proteins are involved in different protein complexes and our data provide evidence for dynamic interchanges between them. Fifteen of the eighteen taxis receptors (halobacterial transducers, Htrs can be assigned to four different groups depending on their interactions with the core signaling proteins. Only one of these groups, which contains six of the eight Htrs with known signals, shows the composition expected for signaling complexes (receptor, kinase CheA, adaptor CheW, response regulator CheY. From the two Hbt. salinarum CheW proteins, only CheW1 is engaged in signaling complexes with Htrs and CheA, whereas CheW2 interacts with Htrs but not with CheA. CheY connects the core signaling structure to a subnetwork consisting of the two CheF proteins (which build a link to the flagellar apparatus, CheD (the hub of the subnetwork, two CheC complexes and the receptor methylesterase CheB. Conclusions Based on our findings, we propose two hypotheses. First, Hbt. salinarum might have the capability to dynamically adjust the impact of certain Htrs or Htr clusters depending on its current needs or environmental conditions. Secondly, we propose a hypothetical feedback loop from the response regulator to Htr methylation made from the CheC proteins, CheD and CheB, which might contribute to adaptation analogous to the CheC/CheD system of B. subtilis.

  19. [Biodiversity and functional enzymes of cultured halophilic archaeon in Lop Nur region].

    Science.gov (United States)

    Liu, Bingbing; Tang, Shukun; Ming, Hong; He, Songtao; Nie, Guoxing; Guan, Tongwei; Zhang, Lili; Li, Wenjun

    2011-09-01

    In order to explore the diversity of cultured halophilic archaeon from hypersaline environments in Lop Nur region and their potential application. Total 13 soil samples were collected from Lop Nur regions. Halophilic archaea strains were isolated and identified by 16S rRNA gene sequence analysis. In addition, 17 strains were selected based on different branches in pylogenetic tree, and their salt concentration tolerance and amylase, protease, esterase activities were further detected by conventional methods. The 16S rRNA gene sequences of 56 selected strains were determined, and the phylogenetic analysis was carried out. These strains were classified into 10 known genera and 5 new potential genera, and the Shannon index was 1.820. The range of salt concentration tolerance of most strains was 10% - 35% (optimum at 20% - 25%). Amylase positive rate was 70.6%, protease positive rate was 35.3% and esterase positive rate was 82.4%. Diverse halophilic archaeon were discovered in Lop Nur regions. The isolation methods that we used were successful for isolating halophilic archaeon from these areas, which provided the technical basis to future explore the resources of halophilic archaeon in Lop Nur regions.

  20. Isolation and Phylogenetic Analysis of Halophilic Archaeon AJ6

    Institute of Scientific and Technical Information of China (English)

    Xu Xiaohong; Wu Min; Cao Yi; Wu Yuehong; Zhang Ting

    2006-01-01

    Halophilic archaeon A J6 was isolated and purified from the Altun Mountain National Nature Reserve of the Xinjiang Uygur Autonomous Region.Strain AJ6 is a Gram-negative rod whose size is 0.2-0.6 by 1.6-4.2 μm,wherein a few cells are globular.The optimum salt concentration for its growth is 20% NaC1 and 0.6% Mg2+,and the optimum pH is 6.0-7.0.Morphological,physiological,and biochemical characteristics of strain AJ6 were observed.The 16S rRNA encoding gene (16S rDNA)sequence of strain A J6 was amplified by PCR,and its nucteotide sequence was determined subsequently."Clustalw"and"PHYLIP"software bags were used to analyze the 16S rDNA sequence;the homology was compared,and then the phylogenetic tree was established.The results indicate that strain AJ6 is a novel species of the genus Natrinema.The GenBank accession number of the 16S rDNA sequences of strain AJ6 is AY277584.

  1. Actinide biocolloid formation in brine by halophilic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Gillow, J.B.; Francis, A.J.; Dodge, C.J. [Brookhaven National Lab., Upton, NY (United States); Harris, R.; Beveridge, T.J. [Univ. of Guelph, Ontario (Canada); Brady, P.V.; Papenguth, H.W. [Sandia National Labs., Albuquerque, NM (United States)

    1998-12-31

    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. 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.B.; PAPENGUTH,H.W.

    1998-11-09

    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.

  3. 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.

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

    Science.gov (United States)

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

    2010-05-01

    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.

  5. 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.

  6. Primary structures of three highly acidic ribosomal proteins S6, S12 and S15 from the archaebacterium Halobacterium marismortui.

    Science.gov (United States)

    Kimura, J; Arndt, E; Kimura, M

    1987-11-16

    The amino acid sequences of three extremely acidic ribosomal proteins, S6, S12, and S15, from Halobacterium marismortui have been determined. The sequences were obtained by the sequence analysis of peptides derived by enzymatic digestion with trypsin. Stapylococcus aureus protease and chymotrypsin, as well as by cleavage with dilute HCl. The proteins, S6, S12 and S15, consist of 116, 147 and 102 amino acid residues, and have molecular masses of 12,251, 16,440 and 11,747 Da, respectively. Comparison of the amino acid sequences of these proteins with ribosomal protein sequences of other organisms revealed that halobacterial protein S12 has homology with the eukaryotic protein S16A from Saccharomyces cerevisiae, while S15 is significantly related to the Xenopus laevis S19 protein. No homology was found between these halobacterial proteins and any eubacterial ribosomal proteins.

  7. 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 lactoferrin

  8. 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

  9. Efficient utilization of ectoine by halophilic Brevibacterium species and Escherichia coli subjected to osmotic downshock.

    Science.gov (United States)

    Nagata, Shinichi; Wang, Chenxiang

    2005-01-01

    Halophilic and non-halophilic bacteria subjected to osmotic downshock, from 0.7 M NaCl to deionized water, were examined for their survival, with the uptake and utilization of the cyclic amino acid ectoine, one of the representative compatible solutes, being taken into account. The uptake of ectoine added externally and survival of the cells were monitored as a function of incubation time in the presence and absence of NaCl. The halophilic Brevibacterium sp. JCM 6894 and B. epidermidis JCM 2593 actively accumulated ectoine regardless of the presence of NaCl, which led to cell survival. Brevibacterium casei JCM 2594 belonging to the same Brevibacterium species, however, revealed Na+-dependence of its uptake activity of ectoine. Non-halophilic Escherichia coli K-12 did not accumulate ectoine, and thereby this strain failed to survive irrespective of whether NaCl was present. The physiological meanings of the downshock procedure are discussed in connection with the uptake and the subsequent utilization of ectoine.

  10. 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.

  11. Draft Genome Sequence of the Moderately Halophilic Bacterium Pseudoalteromonas ruthenica Strain CP76.

    Science.gov (United States)

    de la Haba, Rafael R; Sánchez-Porro, Cristina; León, María José; Papke, R Thane; Ventosa, Antonio

    2013-05-23

    Pseudoalteromonas ruthenica strain CP76, isolated from a saltern in Spain, is a moderately halophilic bacterium belonging to the Gammaproteobacteria. Here we report the draft genome sequence, which consists of a 4.0-Mb chromosome, of this strain, which is able to produce the extracellular enzyme haloprotease CPI.

  12. 氨基酸嗜盐不对称指数与其理化性质的相关性%Halophilic asymmetry index of amino acids and its relationship with the physicochemical properties

    Institute of Scientific and Technical Information of China (English)

    张光亚

    2012-01-01

    了解嗜盐蛋白氨基酸使用的偏好及该偏好与其理化性质之间的联系对探索嗜盐蛋白构效关系具有重要意义.本文选取极端嗜盐细菌Salinibacter ruber和非嗜盐菌Pelodictyon luteolum中362对同源蛋白,统计了52102个氨基酸突变位点,以此计算氨基酸的嗜盐不对称指数( HAI),并与243个理化性质进行相关性分析.结果表明:天冬氨酸的嗜盐性能最强,而异亮氨酸和赖氨酸最弱;243个理化性质中有16个同HAI存在显著相关性,其中5个呈正相关:氨基酸的亲疏水性及β折叠的倾向性是影响HAI值的两种最重要的理化性质.本文提出的氨基酸嗜盐不对称指数为了解嗜盐蛋白稳定性机制提供了新视角.%To get the patterns of molecular adaptations to halophilic environment and its relationship with the physicochemical properties of amino acids is of great significance for understanding the actual structure-function relationship underlying the stability of proteins. In this paper, a comparison was made between 362 orthologous proteins from extreme halophilic bacteria Salinibacter ruber and non-halophilic bacteria Pelodictyon luteolum. The pattern of asymmetries in the 52102 amino aicds substitutions revealed some common trends. The halophilic asymmetry index (HAI) identified the Asp as the most halophilic behavior, and lie and Lys as the least. Among the 243 physicochemical properties of amino acids, there were 16 significantly correlated with the HAI, and five of them were positively correlated. The polarity& hydrophobicity and the tendency to beta-sheet are two major kinds of properties. The HAI we established here would provide a new way to pursue the molecular signatures of haloadaptation.

  13. 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

  14. 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.

  15. Extreme Heat

    Science.gov (United States)

    ... Landslides & Debris Flow Nuclear Blast Nuclear Power Plants Power Outages Pandemic Radiological Dispersion Device Severe Weather Snowstorms & Extreme ... Landslides & Debris Flow Nuclear Blast Nuclear Power Plants Power Outages Pandemic Radiological Dispersion Device Severe Weather Snowstorms & Extreme ...

  16. 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

  17. Mandelbrot's Extremism

    NARCIS (Netherlands)

    Beirlant, J.; Schoutens, W.; Segers, J.J.J.

    2004-01-01

    In the sixties Mandelbrot already showed that extreme price swings are more likely than some of us think or incorporate in our models.A modern toolbox for analyzing such rare events can be found in the field of extreme value theory.At the core of extreme value theory lies the modelling of maxima

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

    National Research Council Canada - National Science Library

    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...

  19. Osmoadaptation Strategy of the Most Halophilic Fungus, Wallemia ichthyophaga, Growing Optimally at Salinities above 15% NaCl

    Science.gov (United States)

    Zajc, Janja; Kogej, Tina; Galinski, Erwin A.; Ramos, José

    2014-01-01

    Wallemia ichthyophaga is a fungus from the ancient basidiomycetous genus Wallemia (Wallemiales, Wallemiomycetes) that grows only at salinities between 10% (wt/vol) NaCl and saturated NaCl solution. This obligate halophily is unique among fungi. The main goal of this study was to determine the optimal salinity range for growth of the halophilic W. ichthyophaga and to unravel its osmoadaptation strategy. Our results showed that growth on solid growth media was extremely slow and resulted in small colonies. On the other hand, in the liquid batch cultures, the specific growth rates of W. ichthyophaga were higher, and the biomass production increased with increasing salinities. The optimum salinity range for growth of W. ichthyophaga was between 15 and 20% (wt/vol) NaCl. At 10% NaCl, the biomass production and the growth rate were by far the lowest among all tested salinities. Furthermore, the cell wall content in the dry biomass was extremely high at salinities above 10%. Our results also showed that glycerol was the major osmotically regulated solute, since its accumulation increased with salinity and was diminished by hypo-osmotic shock. Besides glycerol, smaller amounts of arabitol and trace amounts of mannitol were also detected. In addition, W. ichthyophaga maintained relatively small intracellular amounts of potassium and sodium at constant salinities, but during hyperosmotic shock, the amounts of both cations increased significantly. Given our results and the recent availability of the genome sequence, W. ichthyophaga should become well established as a novel model organism for studies of halophily in eukaryotes. PMID:24162565

  20. 以分子动力组学的方法探究嗜盐酶的嗜盐机理%Halophilic Mechanism of the Halophilic Enzymes Based on the Molecule Dynameomics Method

    Institute of Scientific and Technical Information of China (English)

    王四华; 黄可君; 张光亚

    2013-01-01

    通过分子动力组学的方法,从原子尺度上分析4组嗜盐酶及其同源非嗜盐酶的分子动力学特性.结果发现:嗜盐酶所形成的盐桥和氢键明显多于非嗜盐酶,嗜盐酶的溶剂可及性表面要小于非嗜盐酶.通过比较嗜盐与非嗜盐的均方根偏差、回旋半径及末端距等参数,发现嗜盐酶的结构较非嗜盐酶更具刚性.同时,非嗜盐酶多个部位的氨基酸残基柔性比嗜盐酶的要大很多.研究表明:能形成较多的盐桥、氢键,较小的溶剂可及性表面和整体结构的刚性,很可能是嗜盐酶在高盐环境中维持其结构稳定的主要原因.%We analyzed the dynamics characteristics of the four groups halophilic enzyme and non-halophilic homologs by molecule dynameomics method in the atomistic scale. The results found that; halophilic enzyme can form more salt bridges and hydrogen bonds than non-halophilic enzyme, the solvent accessible surface areas of halophilic enzyme are larger than non-halophilic enzyme. We also found that the structure of halophilic enzyme is more rigid by comparing the root mean square deviation (RMSD), radius of gyration and end distance. Besides, the flexibility of the amino acids of non-halophilic enzyme is more large than halophilic enzyme. It can be supposed that the main factors that halophilic enzymes can maintain their structure stability in high saline conditions are rich in salt bridges and hydrogen bonds, smaller solvent accessible surface area and structure rigidity.

  1. 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.

  2. 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

  3. 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.

  4. Regulatory Factors Associated with Synthesis of the Osmolyte Glycine Betaine in the Halophilic Methanoarchaeon Methanohalophilus portucalensis

    OpenAIRE

    Lai, Mei-Chin; Yang, Daw-Renn; Chuang, Ming-Jen

    1999-01-01

    The halophilic methanoarchaeon Methanohalophilus portucalensis can synthesize de novo and accumulate β-glutamine, Nɛ-acetyl-β-lysine, and glycine betaine (betaine) as compatible solutes (osmolytes) when grown at elevated salt concentrations. Both in vivo and in vitro betaine formation assays in this study confirmed previous nuclear magnetic resonance 13C-labelling studies showing that the de novo synthesis of betaine proceeded from glycine, sarcosine, and dimethylglycine to form betaine throu...

  5. 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

  6. Communities structure of the planktonic halophiles in the solar saltern of Sfax, Tunisia

    Science.gov (United States)

    Elloumi, Jannet; Carrias, Jean-François; Ayadi, Habib; Sime-Ngando, Télesphore; Bouaïn, Abderrahmen

    2009-01-01

    The composition and distribution of the main planktonic halophilic micro-organisms (heterotrophic and autotrophic picoplankton, nanoplankton, phytoplankton, ciliates) and metazooplankton were investigated in six ponds of increasing salinity in the solar salt works of Sfax, Tunisia, from January to December 2003. Marked changes in the composition and biomass of the communities were found along the salinity gradient, especially at salinities of 150 and 350. Autotrophic picoplankton, nanoplankton, diatoms, dinoflagellates and ciliates characterized the less salted ponds. Planktonic biomass was the highest at intermediate salinity as a consequence of a bloom of Ochromonas. Species richness of phytoplankton, ciliates and zooplankton greatly decrease above a salinity of 150 and typical halophiles ( Dunaliella salina, cyanobacteria, Fabrea salina and Artemia salina) were found between 150 and 350 salinity. In this environment, F. salina appeared more adapted than the brine shrimp to survive during phytoplankton blooms. The halophilic plankton was however almost entirely composed of heterotrophic prokaryotes in the crystallizers. We thus observed a progressive disappearance of the autotrophic planktonic communities along the salinity gradient. Multivariate analysis of the communities provides evidence that ponds represent discrete aquatic ecosystems within this salt works.

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

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    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.

  8. 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.

  9. Genome-scale reconstruction of metabolic network for a halophilic extremophile, Chromohalobacter salexigens DSM 3043

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    Oner Ebru

    2011-01-01

    Full Text Available Abstract Background Chromohalobacter salexigens (formerly Halomonas elongata DSM 3043 is a halophilic extremophile with a very broad salinity range and is used as a model organism to elucidate prokaryotic osmoadaptation due to its strong euryhaline phenotype. Results C. salexigens DSM 3043's metabolism was reconstructed based on genomic, biochemical and physiological information via a non-automated but iterative process. This manually-curated reconstruction accounts for 584 genes, 1386 reactions, and 1411 metabolites. By using flux balance analysis, the model was extensively validated against literature data on the C. salexigens phenotypic features, the transport and use of different substrates for growth as well as against experimental observations on the uptake and accumulation of industrially important organic osmolytes, ectoine, betaine, and its precursor choline, which play important roles in the adaptive response to osmotic stress. Conclusions This work presents the first comprehensive genome-scale metabolic model of a halophilic bacterium. Being a useful guide for identification and filling of knowledge gaps, the reconstructed metabolic network iOA584 will accelerate the research on halophilic bacteria towards application of systems biology approaches and design of metabolic engineering strategies.

  10. Biodegradation of organic pollutants in saline wastewater by halophilic microorganisms: a review.

    Science.gov (United States)

    Castillo-Carvajal, Laura C; Sanz-Martín, José Luis; Barragán-Huerta, Blanca E

    2014-01-01

    Agro-food, petroleum, textile, and leather industries generate saline wastewater with a high content of organic pollutants such as aromatic hydrocarbons, phenols, nitroaromatics, and azo dyes. Halophilic microorganisms are of increasing interest in industrial waste treatment, due to their ability to degrade hazardous substances efficiently under high salt conditions. However, their full potential remains unexplored. The isolation and identification of halophilic and halotolerant microorganisms from geographically unrelated and geologically diverse hypersaline sites supports their application in bioremediation processes. Past investigations in this field have mainly focused on the elimination of polycyclic aromatic hydrocarbons and phenols, whereas few studies have investigated N-aromatic compounds, such as nitro-substituted compounds, amines, and azo dyes, in saline wastewater. Information regarding the growth conditions and degradation mechanisms of halophilic microorganisms is also limited. In this review, we discuss recent research on the removal of organic pollutants such as organic matter, in terms of chemical oxygen demand (COD), dyes, hydrocarbons, N-aliphatic and N-aromatic compounds, and phenols, in conditions of high salinity. In addition, some proposal pathways for the degradation of aromatic compounds are presented.

  11. 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.

  12. Genetic and Biochemical Aspects of Ectoine Biosynthesis in Moderately Halophilic and Halotolerant Methylotrophic Bacteria

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    Valentina N. Khmelenina

    2010-01-01

    Full Text Available Problem statement: The cyclic imino acid ectoine is a widely distributed compatible solute synthesizing by halophilic and halotolerant bacteria to prevent osmotic stress at high external salinity. This water-keeping compound is used in a variety of commercial cosmetics and therapeutic products. Approach: Development of integrated, predictive functional model of the metabolic and regulatory netwoks of ectoine-producing microbes is an active area of research. In this article we present a brief overview of the current knowledge on genetic and biochemical aspects of ectoine biosynthesis in aerobic halophilic and halotolerant bacteria utilizing C1 compounds (methylotrophs. Although enzymology and genetics of the ectoine biosynthesis in methylotrophs are similar to other halophilic bacteria, the regulatory patterns are different. In all methylotrophic bacteria studied, the genes coding for specific enzymes of ectoine biosynthesis: Diaminobutyric Acid (DABA aminotransferase (EctB, DABA acetyltransferase (EctA and ectoine synthase (EctC are organized into ectABC or ectABC-ask, whith is linked to gene encoding Aspartokinase isozyme (Ask. Results: Remarkably, the methylotrophic bacteria possessing a four-gene cluster showed higher halotolerance and accumulated more ectoine than bacteria with a cluster composed of three genes. The DABA acetyltransferases from three methylotrophic species have been comparatively characterized. The properties of the enzymes correlate with eco-physiological and metabolic particularities of the host. Some elements of the regulatory system governing the ectoine pathway operation have been revealed in both methane and methanol utilizing bacteria. In Methylomicrobium alcaliphilum transcription of the ectABC-ask operon is initiated from two σ70-like promoters and controlled by the EctR, a MarR-type negative regulator. EctR orthologs were identified in genomes of several heterotrophic halophilic bacteria. Here

  13. Extreme cosmos

    CERN Document Server

    Gaensler, Bryan

    2011-01-01

    The universe is all about extremes. Space has a temperature 270°C below freezing. Stars die in catastrophic supernova explosions a billion times brighter than the Sun. A black hole can generate 10 million trillion volts of electricity. And hypergiants are stars 2 billion kilometres across, larger than the orbit of Jupiter. Extreme Cosmos provides a stunning new view of the way the Universe works, seen through the lens of extremes: the fastest, hottest, heaviest, brightest, oldest, densest and even the loudest. This is an astronomy book that not only offers amazing facts and figures but also re

  14. 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.

  15. Draft Genome Sequence of a Moderately Halophilic Bacillus megaterium Strain, MSP20.1, Isolated from a Saltern of the Little Rann of Kutch, India

    Science.gov (United States)

    Dey, Rinku; Sherathia, Dharmesh; Vanpariya, Sejal; Patel, Ilaxi; Dalsania, Trupti; Savsani, Kinjal; Sukhadiya, Bhoomika; Mandaliya, Mona; Thomas, Manesh; Ghorai, Sucheta; Rupapara, Rupal; Rawal, Priya; Shah, Abhi; Bhayani, Sharmila

    2014-01-01

    The 4.37-Mbp draft genome of a moderately halophilic Bacillus megaterium strain, MSP20.1, isolated from a saltern of the Little Rann of Kutch, India, is reported here. To understand the mechanism(s) of moderate halophilism and to isolate the gene(s) involved in osmotolerance and adaptation, the genome of MSP20.1 was sequenced. PMID:24407642

  16. Draft Genome Sequence of the Obligate Halophilic Bacillus sp. Strain NSP22.2, Isolated from a Seasonal Salt Marsh of the Great Rann of Kutch, India

    Science.gov (United States)

    Pal, Kamal Krishna; Sherathia, Dharmesh; Vanpariya, Sejal; Patel, Ilaxi; Dalsania, Trupti; Savsani, Kinjal; Sukhadiya, Bhoomika; Mandaliya, Mona; Thomas, Manesh; Ghorai, Sucheta; Rupapara, Rupal; Rawal, Priya

    2013-01-01

    Here, we report the 4.0-Mbp draft genome of an obligate halophile, Bacillus sp. strain NSP22.2, isolated from a seasonal salt marsh of the Great Rann of Kutch, India. To understand the mechanism(s) of obligate halophilism and to isolate the relevant gene(s), the genome of Bacillus sp. NSP22.2 was sequenced. PMID:24356848

  17. Draft Genome Sequence of an Obligate and Moderately Halophilic Bacterium, Thalassobacillus devorans Strain MSP14, the First Draft Genome of the Genus Thalassobacillus

    Science.gov (United States)

    Dey, Rinku; Sherathia, Dharmesh; Sukhadiya, Bhoomika; Dalsania, Trupti; Patel, Ilaxi; Savsani, Kinjal; Thomas, Manesh; Vanpariya, Sejal; Mandaliya, Mona; Rupapara, Rupal; Rawal, Priya; Ghorai, Sucheta; Bhayani, Sharmila; Shah, Abhi; Saxena, Anil Kumar

    2013-01-01

    We report the 3.93-Mbp first draft genome sequence of a species of the genus Thalassobacillus, Thalassobacillus devorans strain MSP14, a moderate but obligate halophile, isolated from a salt crystallizer of the Little Rann of Kutch, India. Exploring the genome of this organism will facilitate understanding the mechanism(s) of its obligate halophilism. PMID:24371204

  18. Extracellular production of beta-amylase by a halophilic isolate, Halobacillus sp. LY9.

    Science.gov (United States)

    Li, Xin; Yu, Hui-Ying

    2011-11-01

    A moderately halophilic strain LY9 with high amylolytic activity was isolated from soil sample obtained from Yuncheng, China. Biochemical and physiological characterization along with 16S rRNA sequence analysis placed the isolate in the genus Halobacillus. Amylase production started from the post-exponential phase of bacterial growth and reached a maximum level during the early-stationary phase. The isolate LY9 was found to secrete the amylase, the production of which depended on the salinity of the growth medium. Maximum amylase production was observed in the presence of 10% KCl or 10% NaCl. Maltose was the main product of soluble starch hydrolysis, indicating a β-amylase activity. The enzyme showed optimal activity at 60°C, pH 8.0, and 10-12.5% of NaCl. It was highly active over broad temperature (50-70°C), NaCl concentration (5.0-20.0%), and pH (4.0-12.0) ranges, indicating its thermoactive and alkali-stable nature. However, activity dropped off dramatically at low NaCl concentrations, showing the amylase was halophilic. Ca(2+) was found to stimulate the β-amylase activity, whereas ethylenediaminetetraacetic acid (EDTA), phenylarsine oxide (PAO), and diethyl pyrocarbonate (DEPC) strongly inhibited the enzyme, indicating it probably was a metalloenzyme with cysteine and histidine residues located in its active site. Moreover, the enzyme exhibited remarkable stability towards sodium dodecyl sulfate (SDS) and Triton X-100. This is the first report of β-amylase production from moderate halophiles. The present study indicates that the extracellular β-amylase of Halobacillus sp. LY9 may have considerable potential for industrial application owing to its properties.

  19. Lead Biosorption by a Moderately Halophile Penicillium sp. Isolated from Çamalti Saltern in Turkey

    OpenAIRE

    AYDIN KURÇ, MİNE; GÜVEN, KIYMET; KORCAN, ELİF; GÜVEN, Alaettin; MALKOC, Semra

    2016-01-01

    Owing the importance of biosorption of heavy metals by different organisms, a moderately halophilic fungus isolated from Çamalti saltern was first time investigated for its potential for biosorption. Different heavy metals namely, lead [(Pb(NO3)2], nickel (NiCl2), chromium (K2CrO4), zinc (ZnCl2), cadmium (CdCl2.H2O), copper (CuSO4) and cobalt (CoCl2.6H2O) were screened for resistance and the most tolerated heavy metal by Penicillium sp. was chosen in biosorption assay.The heavy metal toleranc...

  20. 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.

  1. 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.

  2. 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.

  3. Decolorization of textile azo dyes by newly isolated halophilic and halotolerant bacteria.

    Science.gov (United States)

    Asad, S; Amoozegar, M A; Pourbabaee, A A; Sarbolouki, M N; Dastgheib, S M M

    2007-08-01

    Studies were carried out on the decolorization of textile azo dyes by newly isolated halophilic and halotolerant bacteria. Among the 27 strains of halophilic and halotolerant bacteria isolated from effluents of textile industries, three showed remarkable ability in decolorizing the widely utilized azo dyes. Phenotypic characterization and phylogenetic analysis based on 16S rDNA sequence comparisons indicate that these strains belonged to the genus Halomonas. The three strains were able to decolorize azo dyes in a wide range of NaCl concentration (up to 20%w/v), temperature (25-40 degrees C), and pH (5-11) after 4 days of incubation in static culture. They could decolorize the mixture of dyes as well as pure dyes. These strains also readily grew in and decolorized the high concentrations of dye (5000 ppm) and could tolerate up to 10,000 ppm of the dye. UV-Vis analyses before and after decolorization and the colorless bacterial biomass after decolorization suggested that decolorization was due to biodegradation, rather than inactive surface adsorption. Analytical studies based on HPLC showed that the principal decolorization was reduction of the azo bond, followed by cleavage of the reduced bond.

  4. 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.

    2013-01-01

    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. PMID:24688526

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

    Directory of Open Access Journals (Sweden)

    Anderson F. Santos

    2013-12-01

    Full Text Available 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.

  6. Isolation and characterization of halophilic Bacillussp. BS3 able to produce pharmacologically important biosurfactants

    Institute of Scientific and Technical Information of China (English)

    MBS Donio; SFA Ronica; V Thanga Viji; S Velmurugan; J Adlin Jenifer; M Michaelbabu; T Citarasu

    2013-01-01

    Objective:To characterize the pharmacological importance of biosurfactants isolated from halophilicBacillus spBS3.Methods:HalophilicBacillus sp.BS3 was isolated from solar salt works, identified by16S 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.Results:The biosurfactant were characterized byTLC,FTIR andGC-MS analysis and identified as lipopeptide type.GC-MS analysis revealed that, the biosurfactant had various compounds including13-Docosenamide,(Z);Mannosamine,9- andN,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(P<0.01).Anticancer activity performed in the mammary epithelial carcinoma cell at different concentrations of biosurfactants, among the various concentrations of biosurfactants such as0.00025,0.0025,0.025,0.25 and2.5μg, the 0.25 μg concentration suppressed the cells significantly(P<0.05) to24.8%.Conclusions: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.

  7. Membrane fluidity of halophilic ectoine-secreting bacteria related to osmotic and thermal treatment.

    Science.gov (United States)

    Bergmann, Sven; David, Florian; Clark, Wiebke; Wittmann, Christoph; Krull, Rainer

    2013-12-01

    In response to sudden decrease in osmotic pressure, halophilic microorganisms secrete their accumulated osmolytes. This specific stress response, combined with physiochemical responses to the altered environment, influence the membrane properties and integrity of cells, with consequent effects on growth and yields in bioprocesses, such as bacterial milking. The aim of this study was to investigate changes in membrane fluidity and integrity induced by environmental stress in ectoine-secreting organisms. The halophilic ectoine-producing strains Alkalibacillus haloalkaliphilus and Chromohalobacter salexigens were treated hypo- and hyper-osmotically at several temperatures. The steady-state anisotropy of fluorescently labeled cells was measured, and membrane integrity assessed by flow cytometry and ectoine distribution. Strong osmotic downshocks slightly increased the fluidity of the bacterial membranes. As the temperature increased, the increasing membrane fluidity encouraged more ectoine release under the same osmotic shock conditions. On the other hand, combined shock treatments increased the number of disintegrated cells. From the ectoine release and membrane integrity measurements under coupled thermal and osmotic shock conditions, we could optimize the secretion conditions for both bacteria.

  8. 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

    A new moderately halophilic, strictly aerobic, Gram-negative bacterium, strain SX15T, was isolated from hypersaline surface sediment of the southern arm of Great Salt Lake (Utah, USA). The strain grew on a number of carbohydrates and carbohydrate polymers such as xylan, starch, carboxymethyl...

  9. Spherical particles of halophilic archaea correlate with exposure to low water activity--implications for microbial survival in fluid inclusions of ancient halite.

    Science.gov (United States)

    Fendrihan, S; Dornmayr-Pfaffenhuemer, M; Gerbl, F W; Holzinger, A; Grösbacher, M; Briza, P; Erler, A; Gruber, C; Plätzer, K; Stan-Lotter, H

    2012-09-01

    Viable extremely halophilic archaea (haloarchaea) have been isolated from million-year-old salt deposits around the world; however, an explanation of their supposed longevity remains a fundamental challenge. Recently small roundish particles in fluid inclusions of 22 000- to 34 000-year-old halite were identified as haloarchaea capable of proliferation (Schubert BA, Lowenstein TK, Timofeeff MN, Parker MA, 2010, Environmental Microbiology, 12, 440-454). Searching for a method to produce such particles in the laboratory, we exposed rod-shaped cells of Halobacterium species to reduced external water activity (a(w)). Gradual formation of spheres of about 0.4 μm diameter occurred in 4 M NaCl buffer of a(w) ≤ 0.75, but exposure to buffered 4 M LiCl (a(w) ≤ 0.73) split cells into spheres within seconds, with concomitant release of several proteins. From one rod, three or four spheres emerged, which re-grew to normal rods in nutrient media. Biochemical properties of rods and spheres were similar, except for a markedly reduced ATP content (about 50-fold) and an increased lag phase of spheres, as is known from dormant bacteria. The presence of viable particles of similar sizes in ancient fluid inclusions suggested that spheres might represent dormant states of haloarchaea. The easy production of spheres by lowering a(w) should facilitate their investigation and could help to understand the mechanisms for microbial survival over geological times.

  10. Great Salt Lake halophilic microorganisms as models for astrobiology: evidence for desiccation tolerance and ultraviolet irradiation resistance

    Science.gov (United States)

    Baxter, Bonnie K.; Eddington, Breanne; Riddle, Misty R.; Webster, Tabitha N.; Avery, Brian J.

    2007-09-01

    Great Salt Lake (GSL) is home to halophiles, salt-tolerant Bacteria and Archaea, which live at 2-5M NaCl. In addition to salt tolerance, GSL halophiles exhibit resistance to both ultraviolet (UV) irradiation and desiccation. First, to understand desiccation resistance, we sought to determine the diversity of GSL halophiles capable of surviving desiccation in either recently formed GSL halite crystals or GSL Artemia (brine shrimp) cysts. From these desiccated environments, surviving microorganisms were cultured and isolated, and genomic DNA was extracted from the individual species for identification by 16S rRNA gene homology. From the surface-sterilized cysts we also extracted DNA of the whole microbial population for non-cultivation techniques. We amplified the archaeal or bacterial 16S rRNA gene from all genomic DNA, cloned the cyst population amplicons, and sequenced. These sequences were compared to gene databases for determination of closest matched species. Interestingly, the isolates from the crystal dissolution are distinct from those previously isolated from GSL brine. The cyst population results reveal species not found in crystals or brine, and may indicate microorganisms that live as endosymbionts of this hypersaline arthropod. Second, we explored UV resistance in a GSL haloarchaea species, "H. salsolis." This strain resists UV irradiation an order of magnitude better than control species, all of which have intact repair systems. To test the hypothesis that halophiles have a photoprotection system, which prevents DNA damage from occurring, we designed an immunoassay to detect thymine dimers following UV irradiation. "H. salsolis" showed remarkable resistance to dimer formation. Evidence for both UV and desiccation resistance in these salt-tolerant GSL halophiles makes them well-suited as models for Astrobiological studies in pursuit of questions about life beyond earth.

  11. Life at extreme conditions: Neutron scattering studies of biological molecules suggest that evolution selected dynamics

    Indian Academy of Sciences (India)

    Joseph (Giuseppe) Zaccai

    2008-10-01

    The short review concentrates on recent work performed at the neutrons in biology laboratories of the Institut Laue Langevin and Institut de Biologie Structurale in Grenoble. Extremophile organisms have been discovered that require extreme conditions of temperature, pressure or solvent environment for survival. The existence of such organisms poses a significant challenge in understanding the physical chemistry of their proteins, in view of the great sensitivity of protein structure and stability to the aqueous environment and to external conditions in general. Results of neutron scattering measurements on the dynamics of proteins from extremophile organisms, in vitro as well as in vivo, indicated remarkably how adaptation to extreme conditions involves forces and fluctuation amplitudes that have been selected specifically, suggesting that evolutionary macromolecular selection proceeded via dynamics. The experiments were performed on a halophilic protein, and membrane adapted to high salt, a thermophilic enzyme adapted to high temperature and its mesophilic (adapted to 37°C) homologue; and in vivo for psychrophilic, mesophilic, thermophilic and hyperthermophilic bacteria, adapted respectively to temperatures of 4°C, 37°C, 75°C and 85°C. Further work demonstrated the existence of a water component of exceptionally low mobility in an extreme halophile from the Dead Sea, which is not present in mesophile bacterial cells.

  12. Purification and Characterization of a Polyextremophilic α -Amylase from an Obligate Halophilic Aspergillus penicillioides Isolate and Its Potential for Souse with Detergents

    National Research Council Canada - National Science Library

    Ali, Imran; Akbar, Ali; Anwar, Mohammad; Prasongsuk, Sehanat; Lotrakul, Pongtharin; Punnapayak, Hunsa

    2015-01-01

    An extracellular α-amylase from the obligate halophilic Aspergillus penicillioides TISTR3639 strain was produced and enriched to apparent homogeneity by ammonium sulfate precipitation and Sephadex G100 gel filtration...

  13. Ribulose-1,5-bisphosphate carboxylase/oxygenase genes as a functional marker for chemolithoautotrophic halophilic sulfur-oxidizing bacteria in hypersaline habitats

    National Research Council Canada - National Science Library

    Tourova, Tatjana P; Kovaleva, Olga L; Sorokin, Dimitry Yu; Muyzer, Gerard

    2010-01-01

    ...) (a key enzyme of the Calvin-Benson cycle of autotrophic CO(2) assimilation) were investigated in pure cultures of seven genera of halophilic chemolithoautotrophic sulfur-oxidizing bacteria (SOB...

  14. Understanding the Adaptation of Halobacterium Species NRC-1 to Its Extreme Environment through Computational Analysis of Its Genome Sequence

    Science.gov (United States)

    Kennedy, Sean P.; Ng, Wailap Victor; Salzberg, Steven L.; Hood, Leroy; DasSarma, Shiladitya

    2001-01-01

    The genome of the halophilic archaeon Halobacterium sp. NRC-1 and predicted proteome have been analyzed by computational methods and reveal characteristics relevant to life in an extreme environment distinguished by hypersalinity and high solar radiation: (1) The proteome is highly acidic, with a median pI of 4.9 and mostly lacking basic proteins. This characteristic correlates with high surface negative charge, determined through homology modeling, as the major adaptive mechanism of halophilic proteins to function in nearly saturating salinity. (2) Codon usage displays the expected GC bias in the wobble position and is consistent with a highly acidic proteome. (3) Distinct genomic domains of NRC-1 with bacterial character are apparent by whole proteome BLAST analysis, including two gene clusters coding for a bacterial-type aerobic respiratory chain. This result indicates that the capacity of halophiles for aerobic respiration may have been acquired through lateral gene transfer. (4) Two regions of the large chromosome were found with relatively lower GC composition and overrepresentation of IS elements, similar to the minichromosomes. These IS-element-rich regions of the genome may serve to exchange DNA between the three replicons and promote genome evolution. (5) GC-skew analysis showed evidence for the existence of two replication origins in the large chromosome. This finding and the occurrence of multiple chromosomes indicate a dynamic genome organization with eukaryotic character. PMID:11591641

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

    Science.gov (United States)

    Hänelt, Inga; Müller, Volker

    2013-01-01

    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. PMID:25371341

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

    Directory of Open Access Journals (Sweden)

    Jungwoo Kim

    2017-06-01

    Full Text Available 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.

  17. Efficient proteolysis and application of an alkaline protease from halophilic Bacillus sp. EMB9.

    Science.gov (United States)

    Sinha, Rajeshwari; Srivastava, A K; Khare, S K

    2014-10-03

    A salt-stable alkaline protease from moderately halophilic Bacillus sp. EMB9, isolated from the western coast of India, is described. This protease was capable of efficiently removing silver from used/waste X-Ray films, as well as hydrolyzing defatted soy flour with 31% degree of hydrolysis (DH). Production of the protease was optimized by using response surface methodology. Ca(2+) and NaCl were the most critical factors in enhancing the yield. Under optimized culture conditions, a maximum of 369 U protease/mL was obtained, which is quite comparable to the yields of commercial proteases. The elevated production level coupled with ability to efficiently hydrolyze protein-laden soy flour and complete recovery of silver from used X-Ray films makes it a prospective industrial enzyme.

  18. Biocalcification by halophilic bacteria for remediation of concrete structures in marine environment.

    Science.gov (United States)

    Bansal, Roohi; Dhami, Navdeep Kaur; Mukherjee, Abhijit; Reddy, M Sudhakara

    2016-11-01

    Microbial carbonate precipitation has emerged as a promising technology for remediation and restoration of concrete structures. Deterioration of reinforced concrete structures in marine environments is a major concern due to chloride-induced corrosion. In the current study, halophilic bacteria Exiguobacterium mexicanum was isolated from sea water and tested for biomineralization potential under different salt stress conditions. The growth, urease and carbonic anhydrase production significantly increased under salt stress conditions. Maximum calcium carbonate precipitation was recorded at 5 % NaCl concentration. Application of E. mexicanum on concrete specimens significantly increased the compressive strength (23.5 %) and reduced water absorption about five times under 5 % salt stress conditions compared to control specimens. SEM and XRD analysis of bacterial-treated concrete specimens confirmed the precipitation of calcite. The present study results support the potential of this technology for improving the strength and durability properties of building structures in marine environments.

  19. Structural Insight of a Trimodular Halophilic Cellulase with a Family 46 Carbohydrate-Binding Module.

    Directory of Open Access Journals (Sweden)

    Huaidong Zhang

    Full Text Available Cellulases are the key enzymes used in the biofuel industry. A typical cellulase contains a catalytic domain connected to a carbohydrate-binding module (CBM through a flexible linker. Here we report the structure of an atypical trimodular cellulase which harbors a catalytic domain, a CBM46 domain and a rigid CBM_X domain between them. The catalytic domain shows the features of GH5 family, while the CBM46 domain has a sandwich-like structure. The catalytic domain and the CBM46 domain form an extended substrate binding cleft, within which several tryptophan residues are well exposed. Mutagenesis assays indicate that these residues are essential for the enzymatic activities. Gel affinity electrophoresis shows that these tryptophan residues are involved in the polysaccharide substrate binding. Also, electrostatic potential analysis indicates that almost the entire solvent accessible surface of CelB is negatively charged, which is consistent with the halophilic nature of this enzyme.

  20. 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.

  1. Production of Extracellular Polymeric Substances by Halophilic Bacteria of Solar Salterns

    Directory of Open Access Journals (Sweden)

    Jhuma Biswas

    2014-01-01

    Full Text Available Moderately halophilic aerobic bacteria were isolated from 31 soil and 18 water samples collected from multipond solar salterns of Gujarat, Orissa, and West Bengal, India. A total of 587 bacterial isolates with distinct morphological features were obtained from these samples following dilution and plating on MH agar medium supplemented with NaCl. The isolates were screened for growth associated extracellular polymeric substances (EPS production in MY medium under batch culture. In all, 20 isolates were selected as potent ones producing more than 1 g/L of EPS. These EPS producing isolates were characterized in detail for their morphological, physiological, and biochemical features and tentatively identified as members belonging to the genera Halomonas, Salinicoccus, Bacillus, Aidingimonas, Alteromonas, and Chromohalobacter. Apart from EPS production, these isolates also hold promise towards the production of various biomolecules of industrial importance.

  2. Cold-active halophilic bacteria from the ice-sealed Lake Vida, Antarctica.

    Science.gov (United States)

    Mondino, Lindsay J; Asao, Marie; Madigan, Michael T

    2009-10-01

    Lake Vida is a large, permanently ice-covered lake in the Victoria Valley of the McMurdo Dry Valleys, Antarctica and is unique among Dry Valley lakes because it is ice-sealed, with an ice-cover of nearly 19 m. Enrichment cultures of melt-water from Lake Vida 15.9 m ice yielded five pure cultures of aerobic, heterotrophic bacteria. Of these, one strain grew at -8 degrees C and the four others at -4 degrees C. All isolates were either halotolerant or halophilic, with two strains capable of growth at 15% NaCl. Phylogenetic analysis revealed the Lake Vida isolates to be Gammaproteobacteria, related to species of Psychrobacter and Marinobacter. This is the first report of pure cultures of bacteria from Lake Vida, and the isolates displayed a phenotype consistent with life in a cold hypersaline environment.

  3. Diversity and phylogeny of the ectoine biosynthesis genes in aerobic, moderately halophilic methylotrophic bacteria.

    Science.gov (United States)

    Reshetnikov, Alexander S; Khmelenina, Valentina N; Mustakhimov, Ildar I; Kalyuzhnaya, Marina; Lidstrom, Mary; Trotsenko, Yuri A

    2011-11-01

    The genes of ectoine biosynthesis pathway were identified in six species of aerobic, slightly halophilic bacteria utilizing methane, methanol or methylamine. Two types of ectoine gene cluster organization were revealed in the methylotrophs. The gene cluster ectABC coding for diaminobutyric acid (DABA) acetyltransferase (EctA), DABA aminotransferase (EctB) and ectoine synthase (EctC) was found in methanotrophs Methylobacter marinus 7C and Methylomicrobium kenyense AMO1(T). In methanotroph Methylomicrobium alcaliphilum ML1, methanol-utilizers Methylophaga thalassica 33146(T) , Methylophaga alcalica M8 and methylamine-utilizer Methylarcula marina h1(T), the genes forming the ectABC-ask operon are preceded by ectR, encoding a putative transcriptional regulatory protein EctR. Phylogenetic relationships of the Ect proteins do not correlate with phylogenetic affiliation of the strains, thus implying that the ability of methylotrophs to produce ectoine is most likely the result of a horizontal transfer event.

  4. [Isolation and characteristic of a moderately halophilic bacterium accumulated ectoine as main compatible solute].

    Science.gov (United States)

    He, Jian; Wang, Ting; Sun, Ji-Quan; Gu, Li-Feng; Li, Shun-Peng

    2005-12-01

    A moderately halophilic bacterium(designated strain I15) was isolated from lawn soil. Based on the analysis of 16S rDNA (GenBank accession number DQ010162), morphology, physiological and biochemical characteristics, strain I15 was identified as Virgibacillus marismortuii. This strain was capable of growing under 0% approximately 25% NaCl, and exhibited an optimum NaCl concentration of 10% and an optimum temperature of 30 degrees C and an optimum pH of 7.5 - 8.0 for its growth, respectively. Under hyperosmotic stress, strain 115 accumulated ectoine as the main compatible solute. Under 15% NaCl conditions the intracellar ectoine can reach to 1.608 mmol/(g x cdw), accounted for 89.6% of the total compatible solutes. The biosynthesis of ectoine was under the control of osmotic, and the accumulated ectoine synthesized intraceilularly can released under hypoosmotic shocks and resynthesis under hyperosmotic shock rapidly.

  5. 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.

  6. 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.

  7. 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)).

  8. 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.

  9. Interplay between Iron Homeostasis and the Osmotic Stress Response in the Halophilic Bacterium Chromohalobacter salexigens▿ †

    Science.gov (United States)

    Argandoña, Montserrat; Nieto, Joaquín J.; Iglesias-Guerra, Fernando; Calderón, Maria Isabel; García-Estepa, Raúl; Vargas, Carmen

    2010-01-01

    In this study, the connection between iron homeostasis and the osmostress response in the halophile Chromohalobacter salexigens was investigated. A decrease in the requirement for both iron and histidine and a lower level of siderophore synthesis were observed at high salinity, and these findings were correlated with a lower protein content in salt-stressed cells. A six-gene operon (cfuABC-fur-hisI-orf6 operon) located downstream of the ectABC ectoine synthesis genes was characterized. A fur strain (in which the ferric iron uptake regulator Fur was affected) had the Mn resistance phenotype typical of fur mutants, was deregulated for siderophore production, and displayed delayed growth under iron limitation conditions, indicating that fur encodes a functional iron regulator. hisI was essential for histidine synthesis, which in turn was necessary for siderophore production. Fur boxes were found in the promoters of the cfuABC-fur-hisI-orf6 and ectABC operons, suggesting that Fur directly interacts with DNA in these regions. Fur mediated the osmoregulated inhibition of cfuABC-fur-hisI-orf6 operon expression by iron and functioned as a positive regulator of the ectABC genes under high-salinity conditions, linking the salt stress response with iron homeostasis. Excess iron led to a higher cytoplasmic hydroxyectoine content, suggesting that hydroxyectoine protects against the oxidative stress caused by iron better than ectoine. This study provides the first evidence of involvement of the iron homeostasis regulator Fur as part of the complex circuit that controls the response to osmotic stress in halophilic bacteria. PMID:20363778

  10. 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.

  11. 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.

  12. 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 OMVNovo) are spherical in shape, and the average diameter of OMVNovo is 25-70 nm. Proteomic analysis revealed that outer membrane proteins and periplasmic proteins of N. pentaromativorans are the major protein components of OMVNovo. Comparative proteomic analysis with the membrane-associated protein fraction and correlation analysis demonstrated that the outer membrane proteins of OMVNovo 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.

  13. Purification and characterization of a halophilic α-amylase with increased activity in the presence of organic solvents from the moderately halophilic Nesterenkonia sp. strain F.

    Science.gov (United States)

    Shafiei, Mohammad; Ziaee, Abed-Ali; Amoozegar, Mohammad Ali

    2012-07-01

    An extracellular halophilic α-amylase was purified from Nesterenkonia sp. strain F using 80 % ethanol precipitation and Q-Sepharose anion exchange chromatography. The enzyme showed a single band with an apparent molecular weight of 110 kDa by SDS-PAGE. The amylase exhibited maximal activity at pH 7-7.5, being relatively stable at pH 6.5-7.5. Optimal temperature for the amylase activity and stability was 45 °C. The purified enzyme was highly active in the broad range of NaCl concentrations (0-4 M) with optimal activity at 0.25 M NaCl. The amylase was highly stable in the presence of 3-4 M NaCl. Amylase activity was not influenced by Ca²⁺, Rb⁺, Li⁺, Cs⁺, Mg²⁺ and Hg²⁺, whereas Fe³⁺, Cu²⁺, Zn²⁺ and Al³⁺) strongly inhibited the enzyme activity. The α-amylase was inhibited by EDTA, but was not inhibited by PMSF and β-mercaptoethanol. K(m) value of the amylase for soluble starch was 6.6 mg/ml. Amylolytic activity of the enzyme was enhanced not only by 20 % of water-immiscible organic solvents but also by acetone, ethanol and chloroform. Higher concentration (50 %) of the water-miscible organic solvents had no significant effect on the amylase activity. To the best of our knowledge, this is the first report on increased activity of a microbial α-amylase in the presence of organic solvents.

  14. 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.

  15. 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.

  16. Solution behavior and activity of a halophilic esterase under high salt concentration.

    Directory of Open Access Journals (Sweden)

    Lang Rao

    Full Text Available 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 degrees C. Interestingly, the hydrolysis activity showed a clear reversibility against changes in salt concentration. At the ambient temperature of 22 degrees 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 alpha-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 alpha-helical structure and activity relation also matched the highest proportion of enzyme unimers

  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. Extremely Preterm Birth

    Science.gov (United States)

    ... Events Advocacy For Patients About ACOG Extremely Preterm Birth Home For Patients Search FAQs Extremely Preterm Birth ... Spanish FAQ173, June 2016 PDF Format Extremely Preterm Birth Pregnancy When is a baby considered “preterm” or “ ...

  19. Protein solvent and weak protein protein interactions in halophilic malate dehydrogenase

    Science.gov (United States)

    Ebel, Christine; Faou, Pierre; Zaccai, Giuseppe

    1999-01-01

    With the aim to correlate the solvation, stability and solubility properties of halophilic malate dehydrogenase, we characterized its weak interparticle interactions by small-angle neutron scattering in various solvents. The protein concentration dependence of the apparent radius of gyration and forward scattered intensity extrapolated from Guinier plots, and thus the second virial coefficient, A2, were determined for each solvent condition. In NaCl 1M+2-methylpentane-2,4-diol 30%, a solvent that promotes protein crystallization, A2 is negative, -0.4×10 -4 ml mol g -2 and indicating attractive interactions; in ammonium sulfate 3M, in which the protein precipitates at high concentrations, A2˜0. In 2-5M NaCl, 1-3.5M NaOAc, 1-4.5M KF or 1-2M (NH 4) 2SO 4, in which the protein is very soluble, A2 is positive with a value of the order of 0.4×10 -4 ml mol g -2 which decreases with increasing salt concentration. In MgCl 2 however, A2 increases with increasing salt concentration from 0.2 to 1.3M.

  20. Identification of salt-inducible peptide with putative kinase activity in halophilic bacterium Virgibacillus halodenitrificans.

    Science.gov (United States)

    Rafiee, Mahmoud-Reza; Sokhansanj, Ashrafaddin; Yoosefi, Mitra; Naghizadeh, Mohammad-Ali

    2007-09-01

    Strain XII, a moderately halophilic bacterium, expressed a peptide in response to saline media. This peptide was designated as salt-inducible factor (Sif-A). The purpose of this study is to describe Sif-A, which might be involved in the osmoresistance mechanism of strain XII. The complete sequence of sif-A was determined using PCR. sif-A codes for a polypeptide of 20.518 kDa. The polypeptide has a putative signal peptide of 27 amino acids (2.667 kDa) preceding the mature protein (17.869 kDa). Motif analysis of the deduced amino acid sequence indicated that there is a p-loop NTPase domain on the C-terminal of the peptide, which might correlate with its function. The sequence of the 16S rRNA gene was analyzed phylogenetically to classify strain XII. This organism was found to have the closest association with Virgibacillus halodenitrificans, which was proven by its phenotypic characteristics.

  1. Model organisms for genetics in the domain Archaea: methanogens, halophiles, Thermococcales and Sulfolobales.

    Science.gov (United States)

    Leigh, John A; Albers, Sonja-Verena; Atomi, Haruyuki; Allers, Thorsten

    2011-07-01

    The tree of life is split into three main branches: eukaryotes, bacteria, and archaea. Our knowledge of eukaryotic and bacteria cell biology has been built on a foundation of studies in model organisms, using the complementary approaches of genetics and biochemistry. Archaea have led to some exciting discoveries in the field of biochemistry, but archaeal genetics has been slow to get off the ground, not least because these organisms inhabit some of the more inhospitable places on earth and are therefore believed to be difficult to culture. In fact, many species can be cultivated with relative ease and there has been tremendous progress in the development of genetic tools for both major archaeal phyla, the Euryarchaeota and the Crenarchaeota. There are several model organisms available for methanogens, halophiles, and thermophiles; in the latter group, there are genetic systems for Sulfolobales and Thermococcales. In this review, we present the advantages and disadvantages of working with each archaeal group, give an overview of their different genetic systems, and direct the neophyte archaeologist to the most appropriate model organism.

  2. Thermostable alkaline halophilic-protease production by Natronolimnobius innermongolicus WN18.

    Science.gov (United States)

    Selim, Samy; Hagagy, Nashwa; Abdel Aziz, Mohamed; El-Meleigy, El Syaed; Pessione, Enrica

    2014-01-01

    This study reports the production and biochemical characterisation of a thermostable alkaline halophilic protease from Natronolimnobius innermongolicus WN18 (HQ658997), isolated from soda Lake of Wadi An-Natrun, Egypt. The enzyme was concentrated by spinning through a centriplus, centrifugal ultrafiltration Millipore membrane with a total yield of 25%. The relative molecular mass of this protease determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis ranged from 67 to 43 kDa. The extracellular protease of N. innermongolicus WN18 was dependent on high salt concentrations for activity and stability, and it had an optimum temperature of 60°C in the presence of 2.5 M NaCl. This enzyme was stable in a broad pH range (6-12) with an optimum pH of 9-10 for azocasein hydrolysis. This extracellular protease, therefore, could be defined as thermostable and haloalkaliphilic with distinct properties that make the enzyme applicable for different industrial purposes.

  3. Phenol degradation by halophilic fungal isolate JS4 and evaluation of its tolerance of heavy metals.

    Science.gov (United States)

    Jiang, Yu; Shang, Yu; Yang, Kai; Wang, Hongyu

    2016-02-01

    Phenol is one of the most common pollutants in many kinds of industrial wastewater, some of which are in high salinity, resulting in more difficulties of biodegradation. In this work, a halophilic strain capable of utilizing phenol as sole source of carbon and energy in both hypersaline and no-salt media was isolated and identified as genus Debaryomyces. The optimization of environmental parameters including phenol concentration, pH, dissolved oxygen as well as salinity was carried out and tolerance of heavy metals by the strain was evaluated. The strain Debaryomyces sp. was able to grow in culture when initial phenol concentration, pH, agitation and salinity were at wide ranges (0-1200 mg L(-1), 4.0-10.0, 50-200 rpm, 0 %-15 %, respectively). High removal efficiency was hardly affected in the presence of 5 mM of Zn (II) and Mn (II). Under optimal conditions (pH 6.0, 200 rpm, 1 % of salinity without heavy metals), 500 mg L(-1) of phenol could be completely degraded within 32 h. The high removal efficiency of phenol by the strain with significant variations of process parameters might contribute to the bioremediation of phenol-polluted environments under hypersaline or no-salt conditions.

  4. Halophilic properties of metal binding protein characterized by high histidine content from Chromohalobacter salexigens DSM3043.

    Science.gov (United States)

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

    2012-02-01

    Periplasmic metal binding protein characterized by high histidine content was cloned from moderate halophile, Chromohalobacter salexigens. The protein, termed histidine-rich metal binding protein (HP), was expressed in and purified from E. coli as a native form. HP bound to Ni- and Cu-loaded chelate columns with high affinity, and Co- and Zn-columns with moderate affinity. Although the secondary structure was not grossly altered by the addition of 0.2-2.0 M NaCl, the thermal transition pattern was considerably shifted to higher temperature with increasing salt concentration: melting temperature was raised by ~20 °C at 2.0 M NaCl over the melting temperature at 0.2 M NaCl. HP showed reversible refolding from thermal melting in 0.2-1.15 M NaCl, while it formed irreversible aggregates upon thermal melting at 2 M NaCl. Addition of 0.01-0.1 mM NiSO₄ stabilized HP against thermal melting with high reversibility, while addition above 0.5 mM resulted in irreversible melting due to aggregation.

  5. Antibacterial activity of halophilic bacterial bionts from marine invertebrates of Mandapam-India

    Directory of Open Access Journals (Sweden)

    Sheryanne Velho-Pereira

    2012-01-01

    Full Text Available Marine ecosystem and its organisms, particularly the invertebrates are recent targets of bioprospecting and mining for a large group of structurally unique natural products encompassing a wide variety of chemical classes such as terpenes, polyketides, acetogenins, peptides and alkaloids of varying structures, having pronounced pharmacological activities. In view of the limited reports on the antibacterials produced by bacteria, isolated from marine sponges, corals and bivalves of Indian origin, the present study is aimed at investigating the antagonistic activities of 100 heterotrophic, halophilic bacterial bionts isolated from 9 sponges, 5 corals and one bivalve. Culture broths of 46 of these bionts were active against human pathogenic bacteria namely Staphylococcus citreus, Proteus vulgaris, Serratio marcesans, Salmonella typhi, Aerobacter aerogenes and Escherichia coli. Further, the ethyl acetate extracts of cell free supernatant confirmed the presence of extracellular bioactive factor, by agar cup diffusion method. Interestingly, highest number of bionts having activity was isolated from corals followed by sponges and bivalve. The study clearly demonstrates that bacterial bionts of marine invertebrates are a rich source of bioactive secondary metabolites against human bacterial pathogens.

  6. 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.

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

    Science.gov (United States)

    Prunetti, Laurence; Graf, Michael; Blaby, Ian K; Peil, Lauri; Makkay, Andrea M; Starosta, Agata L; Papke, R Thane; Oshima, Tairo; Wilson, Daniel N; de Crécy-Lagard, Valérie

    2016-01-01

    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. Arhodomonas aquaeolei gen. nov., sp. nov., an aerobic, halophilic bacterium isolated from a subterranean brine.

    Science.gov (United States)

    Adkins, J P; Madigan, M T; Mandelco, L; Woese, C R; Tanner, R S

    1993-07-01

    Arhodomonas aquaeolei gen. nov., sp. nov., isolated from a petroleum reservoir production fluid, is described. The single isolate was an obligately halophilic, aerobic, gram-negative, oval rod-shaped bacterium that was actively motile by means of a single polar flagellum. It was catalase and oxidase positive. The isolate had a specific requirement for NaCl; growth occurred at NaCl concentrations between 6 and 20%, and optimal growth occurred in the presence of 15% NaCl. This species metabolized primarily organic acids and required biotin for growth. The name Arhodomonas is proposed for the new genus, which was placed in the gamma subclass of the Proteobacteria on the basis of the results of a 16S rRNA sequence analysis. Although A. aquaeolei is most closely related to purple sulfur bacteria (the genera Ectothiorhodospira and Chromatium), it is not a phototrophic microorganism, which is consistent with its isolation from a subterranean environment. The major components of its cellular fatty acids were C16:0, C18:1, C19:0, C16:1, and C18:0 acids. The DNA base composition of the type strain is 67 mol% G+C. The type and only strain is strain HA-1 (= ATCC 49307).

  9. Haloanaerobium kushneri sp. nov., an obligately halophilic, anaerobic bacterium from an oil brine

    Science.gov (United States)

    Bhupathiraju, V. K.; McInerney, M. J.; Woese, C. R.; Tanner, R. S.

    1999-01-01

    Three strains, designated VS-751T, VS-511 and VS-732, of a strictly anaerobic, moderately halophilic, Gram-negative, rod-shaped bacterium were isolated from a highly saline (15-20%) brine from an oil reservoir in central Oklahoma, USA. The optimal concentration of NaCl for growth of these three strains was 2 M (12%), and the strains also grew in the presence of an additional 1 M MgCl2. The strains were mesophilic and grew at a pH range of 6-8. Carbohydrates used by all three strains included glucose, fructose, arabinose, galactose, maltose, mannose, cellobiose, sucrose and inulin. Glucose fermentation products included ethanol, acetate, H2 and CO2, with formate produced by two of the three strains. Differences were noted among strains in the optimal temperature and pH for growth, the maximum and minimum NaCl concentration that supported growth, substrate utilization and cellular fatty acid composition. Despite the phenotypic differences among the three strains, analysis of the 16S rRNA gene sequences and DNA-DNA hybridizations showed that these three strains were members of the same genospecies which belonged to the genus Haloanaerobium. The phenotypic and genotypic characteristics of strains VS-751T, VS-511 and VS-732 are different from those of previously described species of Haloanaerobium. It is proposed that strain VS-751T (ATCC 700103T) be established as the type strain of a new species, Haloanaerobium kushneri.

  10. Isolation and characterization of aniline degradation slightly halophilic bacterium, Erwinia sp. Strain HSA 6.

    Science.gov (United States)

    Li, Junmin; Jin, Zexin; Yu, Binbin

    2010-07-20

    The isolated strain HSA6 is classified as Erwinia amylovora based on 16S rDNA sequence and the morphological and physiological properties. Strain HSA6 is the first reported E. amylovora in pure culture growing with aniline as sole electron donor and carbon source. The suitable pH for strain HSA6 is wide (from 5 to 11). Strain HSA6 is slightly halophilic with growth occurring at 0-10% (v/v) NaCl, and the suitable NaCl concentration for strain HSA6 is from 0% to 6%. The number of bacteria appeared to decrease with an increase in aniline concentration. The number of bacteria appeared to be constant as the wastewater concentration increased from 0% to 20%. However, the number of cells decreased with an increase in wastewater concentration from 30% to 50% and grew very slowly at 50%. The degradation rate of aniline was 100% at 0.5% aniline concentration after 24 h culture. The degradation rate of aniline was found to descend as the concentration of aniline increased from 0.5% to 3% and rose as the culture time increased. Strain HSA6 contains a plasmid with molecular weight higher than 42 kDA. Plasmid curing test and quantitative degradation test showed that strain requires the plasmid for aniline degradation. The gene cluster degrading aniline was determined in the plasmid by PCR amplification.

  11. Isolation and characteristics of halophile microorganisms from Lake Qinghai%青海湖嗜盐微生物筛选分离与生长特性

    Institute of Scientific and Technical Information of China (English)

    沈国平; 朱德锐; 刘建; 韩睿; 龙启福

    2012-01-01

    The main objective of the project is to obtain completely halophile germplasm resources from Lake Qinghai, to construct stocks phyletic evolution tree of halophilic bacterium and determine the evolution position. 35 strains were isolated from 20 water samples taken from Lake Qinghai using the high salty medium. Resistant to salt gradient experiment shows that moderate halophilic bacteria account for about 62. 85% in the water, mild halophilic bacteria account for about 22. 85% , non halophilic bacteria and salt resistance bacteria account for 14.28% . Moderate halophilic bacteria could grow in the temperature of 10~45℃ and pH 5.5-11.0, which is related to the local salinization environment and has characteristic of hasophilic microorganisms.%为全面获得青海湖嗜盐菌种质资源,构建种群系统发育树和确定种群进化定位.采用高盐选择性培养基筛选,分离从20份青海湖水样中获得35株青海湖嗜盐微生物.耐盐梯度实验表明:水体中以中度嗜盐菌为主,约占62.85%,轻度嗜盐菌约占22.85%,非嗜盐菌与耐盐菌约占14.28%.青海湖中度嗜盐微生物能在10 ~ 45℃,pH5.5~11.0的范围内生长,与地区盐碱化环境相关,具有嗜盐兼嗜碱微生物的特性.

  12. 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...... euryarchaeon Haloferax volcanii, the gene for which was apparently acquired by Hfx.volcanii through lateral gene transfer (LGT) from a halophilic eubacterium. Genetic studies show that the LGT-acquired LigN enzyme shares an essential function with the native Hfx.volcanii ATP-dependent DNA ligase protein Lig...

  13. Multidimensional extremal dependence coefficients

    OpenAIRE

    2017-01-01

    Extreme values modeling has attracting the attention of researchers in diverse areas such as the environment, engineering, or finance. Multivariate extreme value distributions are particularly suitable to model the tails of multidimensional phenomena. The analysis of the dependence among multivariate maxima is useful to evaluate risk. Here we present new multivariate extreme value models, as well as, coefficients to assess multivariate extremal dependence.

  14. 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. PMID:27330530

  15. The European Extreme Right and Religious Extremism

    Directory of Open Access Journals (Sweden)

    Jean-Yves Camus

    2007-12-01

    Full Text Available The ideology of the Extreme Right in Western Europe is rooted in Catholic fundamentalism and Counter-Revolutionary ideas. However, the Extreme Right, like all other political families, has had to adjust to an increasingly secular society. The old link between religion and the Extreme Right has thus been broken and in fact already was when Fascism overtook Europe: Fascism was secular, sometimes even anti-religious, in its essence. Although Catholic fundamentalists still retain strong positions within the apparatus of several Extreme Right parties (Front National, the vote for the Extreme Right is generally weak among regular churchgoers and strong among non-believers. In several countries, the vote for the Extreme Right is stronger among Protestant voters than among Catholics, since while Catholics may support Christian-Democratic parties, there are very few political parties linked to Protestant churches. Presently, it also seems that Paganism is becoming the dominant religious creed within the Extreme Right. In a multicultural Europe, non-Christian forms of religious fundamentalism such as Islamism also exist with ideological similarities to the Extreme Right, but this is not sufficient to categorize Islamism as a form of Fascism. Some Islamist groups seek alliances with the Extreme Right on the basis of their common dislike for Israel and the West, globalization and individual freedom of thought.

  16. 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.

  17. Structural characterization of the N-linked pentasaccharide decorating glycoproteins of the halophilic archaeon Haloferax volcanii.

    Science.gov (United States)

    Kandiba, Lina; Lin, Chia-Wei; Aebi, Markus; Eichler, Jerry; Guerardel, Yann

    2016-07-01

    N-Glycosylation is a post-translational modification performed in all three domains of life. In the halophilic archaea Haloferax volcanii, glycoproteins such as the S-layer glycoprotein are modified by an N-linked pentasaccharide assembled by a series of Agl (archaeal glycosylation) proteins. In the present study, mass spectrometry (MS) and nuclear magnetic resonance spectroscopy were used to define the structure of this glycan attached to at least four of the seven putative S-layer glycoprotein N-glycosylation sites, namely Asn-13, Asn-83, Asn-274 and Asn-279. Such approaches detected a trisaccharide corresponding to glucuronic acid (GlcA)-β1,4-GlcA-β1,4-glucose-β1-Asn, a tetrasaccharide corresponding to methyl-O-4-GlcA-β-1,4-galacturonic acid-α1,4-GlcA-β1,4-glucose-β1-Asn, and a pentasaccharide corresponding to hexose-1,2-[methyl-O-4-]GlcA-β-1,4-galacturonic acid-α1,4-GlcA-β1,4-glucose-β1-Asn, with previous MS and radiolabeling experiments showing the hexose at the non-reducing end of the pentasaccharide to be mannose. The present analysis thus corrects the earlier assignment of the penultimate sugar as a methyl ester of a hexuronic acid, instead revealing this sugar to be a methylated GlcA. The assignments made here are in good agreement with what was already known of the Hfx. volcanii N-glycosylation pathway from previous genetic and biochemical efforts while providing new insight into the process.

  18. Amycolatopsis flava sp. nov., a halophilic actinomycete isolated from Dead Sea.

    Science.gov (United States)

    Wei, Xiaomin; Jiang, Yingying; Chen, Xiu; Jiang, Yi; Lai, Hangxian

    2015-10-01

    A novel halophilic, filamentous actinomycete, designated strain AFM 10111(T), was isolated from a sediment sample collected from the Dead Sea of Israel and its taxonomic position was established by using a polyphasic taxonomic approach. The isolate grew at 20-35 °C, pH 5-12 and with 1-30 % NaCl. The substrate mycelium is white or yellow, well developed, branched and fragments into squarish, rod-like elements. The isolate contained meso-diaminopimelic acid as cell-wall diamino acid, and arabinose and galactose as whole-cell sugars. The major menaquinone was MK-9(H4). The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylethanolamine phosphatidylmethylethanolamine and one unidentified phospholipid. Major fatty acids were iso-C16:0, iso-C16:1 H, C17:1 ω6c. The DNA G + C content was 67.7 mol %. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain AFM 10111(T) belongs to the genus Amycolatopsis, and formed a distinct clade with Amycolatopsis marina CGMCC 4.3568(T) and Amycolatopsis palatopharyngis CGMCC 4.1729(T), with the sequence similarity 98.4 and 98.6 %. The level of DNA-DNA relatedness between the strain AFM 10111(T) and A. marina CGMCC 4.3568(T) and A. palatopharyngis CGMCC 4.1729(T) were 46.9 ± 3.08 and 49.4 ± 1.25 %. The combined genotypic and phenotypic data indicate that strain AFM 10111(T) represents a novel species of the genus Amycolatopsis, for which the name Amycolatopsis flava sp. nov. is proposed. The type strain is AFM 10111(T) (= DSM 46658(T) = CGMCC 4.7123(T)).

  19. Development of New Modular Genetic Tools for Engineering the Halophilic Archaeon Halobacterium salinarum.

    Directory of Open Access Journals (Sweden)

    Rafael Silva-Rocha

    Full Text Available Our ability to genetically manipulate living organisms is usually constrained by the efficiency of the genetic tools available for the system of interest. In this report, we present the design, construction and characterization of a set of four new modular vectors, the pHsal series, for engineering Halobacterium salinarum, a model halophilic archaeon widely used in systems biology studies. The pHsal shuttle vectors are organized in four modules: (i the E. coli's specific part, containing a ColE1 origin of replication and an ampicillin resistance marker, (ii the resistance marker and (iii the replication origin, which are specific to H. salinarum and (iv the cargo, which will carry a sequence of interest cloned in a multiple cloning site, flanked by universal M13 primers. Each module was constructed using only minimal functional elements that were sequence edited to eliminate redundant restriction sites useful for cloning. This optimization process allowed the construction of vectors with reduced sizes compared to currently available platforms and expanded multiple cloning sites. Additionally, the strong constitutive promoter of the fer2 gene was sequence optimized and incorporated into the platform to allow high-level expression of heterologous genes in H. salinarum. The system also includes a new minimal suicide vector for the generation of knockouts and/or the incorporation of chromosomal tags, as well as a vector for promoter probing using a GFP gene as reporter. This new set of optimized vectors should strongly facilitate the engineering of H. salinarum and similar strategies could be implemented for other archaea.

  20. Halophilic alkali- and thermostable amylase from a novel polyextremophilic Amphibacillus sp. NM-Ra2.

    Science.gov (United States)

    Mesbah, Noha M; Wiegel, Juergen

    2014-09-01

    Extracellular gluco-amylo-pullulanase from Amphibacillus sp. NM-Ra2 was purified to homogeneity by ethanol precipitation, anion exchange chromatography and gel filtration chromatography. Molecular mass of the enzyme was 50kDa (SDS-PAGE). The enzyme showed maximal activity at 1.9 M NaCl, pH50°C 8.0 and 54°C and was active from 0 to 4.3 M NaCl and 37 to 65°C. The enzyme was inhibited by EDTA and was stable and active in the presence of PMSF, DTT, H2O2, Triton-X-100, Tween 20 and Tween 80. Ca2+ is inessential for activity. The amylase was stimulated with K+ and inhibited with Cu2+ and Mg2+. Hg2+, Zn2+ and Fe2+ had no effect on activity. Amylase was stable and active in the presence of ethanol, methanol and benzene (25%, v/v). The enzyme hydrolyzed linear and branched polysaccharides including pullulan, glycogen and amylopectin, and hydrolyzed raw wheat starch and raw corn starch (14.6% and 13.5% over 2 h). Amylase activity was inhibited by soluble starch concentrations greater than 0.3%. The major products of soluble starch hydrolysis were maltose and maltotriose. The amylase, being halophilic and alkali-thermostable, in addition to being resistant to surfactants, oxidizing agents and organic solvents, can find applications in the starch processing, pharmaceutical, food and paper/pulp industries. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Haloanaerobium salsugo sp. nov., a moderately halophilic, anaerobic bacterium from a subterranean brine

    Energy Technology Data Exchange (ETDEWEB)

    Bhupathiraju, V.K.; Sharma, P.K.; Tanner, R.S.; McInerney, M.J. [Univ. of Oklahoma, Norman, OK (United States). Dept. of Botany and Microbiology; Oren, A. [Hebrew Univ. of Jerusalem (Israel); Woese, C.R. [Univ. of Illinois, Urbana, IL (United States). Dept. of Microbiology

    1994-07-01

    A strictly anaerobic, moderately halophilic, gram-negative bacterium was isolated from a highly saline oil field brine. The bacterium was a non-spore-forming, nonmotile rod, appearing singly, in pairs, or occasionally as long chains, and measured 0.3 to 0.4 by 2.6 to 4 {micro}m. The bacterium had a specific requirement for NaCl and grew at NaCl concentrations of between 6 and 24%, with optimal growth at 9% NaCl. The isolate grew at temperatures of between 22 and 51 C and pH values of between 5.6 and 8.0. The doubling time in a complex medium containing 10% NaCl was 9 h. Growth was inhibited by chloramphenicol, tetracycline, and penicillin but not by cycloheximide or azide. Fermentable substrates were predominantly carbohydrates. The end products of glucose fermentation were acetate, ethanol, CO{sub 2}, and H{sub 2}. The major components of the cellular fatty acids were C{sub 14:0}, C{sub 16:0}, C{sub 16:1}, and C{sub 17:0 cyc} acids. The DNA base composition of the isolate was 34 mol% G+C. Oligonucleotide catalog and sequence analyses of the 16S rRNA showed that strain VS-752{sup T} was most closely related to Haloanaerobium praevalens GSL{sup T} (ATCC 33744), the sole member of the genus Haloanaerobium. The authors propose that strain VS-752 (ATCC 51327) by established as the type strain of a new species, Haloanaerobium salsugo, in the genus Haloanaerobium. 40 refs., 3 figs, 5 tabs.

  2. Haloanaerobium salsugo sp. nov., a moderately halophilic, anaerobic bacterium from a subterranean brine.

    Science.gov (United States)

    Bhupathiraju, V K; Oren, A; Sharma, P K; Tanner, R S; Woese, C R; McInerney, M J

    1994-07-01

    A strictly anaerobic, moderately halophilic, gram-negative bacterium was isolated from a highly saline oil field brine. The bacterium was a non-spore-forming, nonmotile rod, appearing singly, in pairs, or occasionally as long chains, and measured 0.3 to 0.4 by 2.6 to 4 microns. The bacterium had a specific requirement for NaCl and grew at NaCl concentrations of between 6 and 24%, with optimal growth at 9% NaCl. The isolate grew at temperatures of between 22 and 51 degrees C and pH values of between 5.6 and 8.0. The doubling time in a complex medium containing 10% NaCl was 9 h. Growth was inhibited by chloramphenicol, tetracycline, and penicillin but not by cycloheximide or azide. Fermentable substrates were predominantly carbohydrates. The end products of glucose fermentation were acetate, ethanol, CO2, and H2. The major components of the cellular fatty acids were C14:0, C16:0, C16:1, and C17:0 cyc acids. The DNA base composition of the isolate was 34 mol% G+C. Oligonucleotide catalog and sequence analyses of the 16S rRNA showed that strain VS-752T was most closely related to Haloanaerobium praevalens GSLT (ATCC 33744), the sole member of the genus Haloanaerobium. We propose that strain VS-752 (ATCC 51327) be established as the type strain of a new species, Haloanaerobium salsugo, in the genus Haloanaerobium.

  3. Pseudomonas salegens sp. nov., a halophilic member of the genus Pseudomonas isolated from a wetland.

    Science.gov (United States)

    Amoozegar, Mohammad Ali; Shahinpei, Azadeh; Sepahy, Abbas Akhavan; Makhdoumi-Kakhki, Ali; Seyedmahdi, Shima Sadat; Schumann, Peter; Ventosa, Antonio

    2014-10-01

    A novel Gram-stain-negative, aerobic, non-endospore-forming, non-pigmented, rod-shaped, slightly halophilic bacterium, designated GBPy5(T), was isolated from aquatic plants of the Gomishan wetland, Iran. Cells of strain GBPy5(T) were motile. Growth occurred with between 1 and 10% (w/v) NaCl and the isolate grew optimally with 3% (w/v) NaCl. The optimum pH and temperature for growth of the strain were pH 8.0 and 30 °C, respectively, while it was able to grow over a pH range of 6.5-9.0 and a temperature range of 4-35 °C. Phylogenetic analysis, based on 16S rRNA gene sequences, revealed that strain GBPy5(T) is a member of the genus Pseudomonas forming a monophyletic branch. The novel strain exhibited 16S rRNA gene sequence similarity of 95.4% with type strains of Pseudomonas guariconensis PCAVU11(T) and Pseudomonas sabulinigri J64(T), respectively. The major cellular fatty acids of the isolate were C18:1ω7c (37.8%), C16:0 (14.9%), C16:1ω7c (12.9%), C12:0 3-OH (7.1%) and C12:0 (7.0%). The polar lipid pattern of strain GBPy5(T) comprised phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and one phospholipid. Ubiquinone 9 (Q-9) was the predominant lipoquinone. The G+C content of the genomic DNA of strain GBPy5(T) was 59.2 mol%. On the basis of the phenotypic and phylogenetic data, strain GBPY5(T) represents a novel species of the genus Pseudomonas, for which the name Pseudomonas salegens sp. nov. is proposed. The type strain is GBPy5(T) ( = IBRC-M 10762(T) = CECT 8338(T)).

  4. Characteristics of phenol degradation in saline conditions of a halophilic strain JS3 isolated from industrial activated sludge.

    Science.gov (United States)

    Jiang, Yu; Yang, Kai; Wang, Hongyu; Shang, Yu; Yang, Xiaojun

    2015-10-15

    Several halophilic bacteria have been reported to degrade phenol. However, there are a few works about salt-tolerant fungi which can utilize phenol as sole source of carbon. In this study, a halophilic strain JS3 which could degrade phenol with high efficiency was separated and identified. The effect of initial phenol concentration on phenol biodegradation was investigated and optimal pH, temperature, as well as salt-tolerance were evaluated. The isolate could degrade less than 800 mg/L phenol completely in 72 h. It grew well when pH, temperature, and salinity were at values of 4.0-9.0, 30-40°C, and 0-7%, respectively. The optimal pH, temperature and salinity were 6.0, 35°C and 0%. More than 99% of 500 mg/L phenol was degraded in the optimal condition within 24h. The tolerance of wide range of pH, temperature and salinity indicated that strain JS3 was effective for phenol removal in hypersaline wastewaters.

  5. Precipitation of minerals by 22 species of moderately halophilic bacteria in artificial marine salts media: influence of salt concentration.

    Science.gov (United States)

    Rivadeneyra, M A; Delgado, R; Párraga, J; Ramos-Cormenza, A; Delgado, G

    2006-01-01

    Precipitation of minerals was shown by 22 species of moderately halophilic bacteria in both solid and liquid artificial marine salts media at different concentration and different Mg2+-to-Ca2+ ratio. Precipitation of minerals was observed for all the bacteria used. When salt concentration increased, the quantity and the size of bioliths decreased, the time required for precipitation being increased. The precipitated minerals were calcite, magnesian calcite, aragonite, dolomite, monohydrocalcite, hydromagnesite and struvite in variable proportions, depending on the bacterial species, the salinity and the physical state of the medium; the Mg content of the magnesian calcite also varied according to the same parameters. The precipitated minerals do not correspond exactly to those which could be precipitated inorganically according to the saturation indices. Scanning electron microscopy showed that the formation of the bioliths is initiated by grouping of calcified cells and that the dominant final morphologies were spherulitic with fibrous radiated interiors. It was demonstrated that moderately halophilic bacteria play an active role in the precipitation of carbonates and we hypothesize about this process of biomineralization.

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

    Science.gov (United States)

    Kumar, Sumit; Khare, S K

    2015-01-01

    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.

  7. 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.

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

    Directory of Open Access Journals (Sweden)

    Zhi-Yan Lu

    2015-05-01

    Full Text Available 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.

  9. The effect of moderately halophilic bacteria supernatant on proliferation and apoptosis of cancer cells and mesenchymal stem cells.

    Science.gov (United States)

    Sarvari, S; Seyedjafari, E; Amoozgar, M A; Bakhshandeh, B

    2015-06-10

    Many drug discoveries and developing of their applications has originated from microbial metabolites. The most efforts in development of new drugs are concerned with anti—cancer agents that cause better treatment results, less side effects, and more economical production. Several anti—tumor drugs have been recently extracted from natural microbial products. Among these various microbial diversity, Marin bacteria and Archaea have been considered as important and efficient organisms to serve as manufacturers of diverse bioactive compounds. Moderately halophilic microorganisms isolated from saline ponds and lakes of Iran show high capability for production of bioactive compounds like enzymes, dyes and anti—cancer agents. In this research, nine moderately halophilic bacteria isolates were screened to evaluate their anti—cancer agent productivity. After five days of culture on suitable mediums, supernatant samples were tested for in vitro anti—proliferative activity against Human Umbilical Vein Endothelial Cells (HUVEC) while same concentrations of supernatants were examined for evaluating of proliferative activity against Adipose—derived Mesenchymal stem cells (MSCs). Both assessments were carried out by MTT assay and double PI and DAPI staining. GASX17, GBWy6 and GBPX3 isolates just induced HUVEC cell deaths and exhibited anti—proliferative activity while R2S12 not only reduced HUVEC cell proliferation but also enhanced proliferation of MSCs. R2S12 , GASX17, GBWy6 and GBPX3 isolates were characterized biochemically and six hydrophilic components were detected. This research established new bioactive compounds that could be used as an effective treatment in chemotherapy.

  10. Draft Genome Sequence of Salinibacillus aidingensis Strain MSP4, an Obligate Halophilic Bacterium Isolated from a Salt Crystallizer of the Rann of Kutch, India

    Science.gov (United States)

    Dey, Rinku; Sherathia, Dharmesh; Dalsania, Trupti; Savsani, Kinjal; Patel, Ilaxi; Thomas, Manesh; Ghorai, Sucheta; Vanpariya, Sejal; Rupapara, Rupal; Acharya, Namrata; Rawal, Priya; Joshi, Pragnesh; Sukhadiya, Bhoomika; Mandaliya, Mona; Saxena, Anil Kumar

    2013-01-01

    We report the 7.42-Mbp draft whole genome sequence of Salinibacillus aidingensis strain MSP4, an obligate halophilic bacterium, isolated from a salt crystallizer of the Rann of Kutch in India. Analysis of the genome of this organism will lead to a better understanding of the genes and metabolic pathways involved in imparting osmotolerance. PMID:23833129

  11. Draft Genome Sequence of Bacillus sp. Strain NSP9.1, a Moderately Halophilic Bacterium Isolated from the Salt Marsh of the Great Rann of Kutch, India

    Science.gov (United States)

    Pal, Kamal Krishna; Sherathia, Dharmesh; Dalsania, Trupti; Savsani, Kinjal; Patel, Ilaxi; Thomas, Manesh; Ghorai, Sucheta; Vanpariya, Sejal; Rupapara, Rupal; Rawal, Priya; Sukhadiya, Bhoomika; Mandaliya, Mona; Saxena, Anil Kumar

    2013-01-01

    We report the 4.52-Mbp draft genome sequence of Bacillus sp. strain NSP9.1, a moderately halophilic bacterium isolated from the salt marsh of the Great Rann of Kutch, India. Analysis of the genome of this organism will lead to a better understanding of the genes and metabolic pathways involved in imparting osmotolerance. PMID:24115550

  12. Legacy to the extreme

    NARCIS (Netherlands)

    A. van Deursen (Arie); T. Kuipers (Tobias); L.M.F. Moonen (Leon)

    2000-01-01

    textabstractWe explore the differences between developing a system using extreme programming techniques, and maintaining a legacy system. We investigate whether applying extreme programming techniques to legacy maintenance is useful and feasible.

  13. Legacy to the extreme

    NARCIS (Netherlands)

    Deursen, A. van; Kuipers, T.; Moonen, L.M.F.

    2000-01-01

    We explore the differences between developing a system using extreme programming techniques, and maintaining a legacy system. We investigate whether applying extreme programming techniques to legacy maintenance is useful and feasible.

  14. Extreme environment electronics

    CERN Document Server

    Cressler, John D

    2012-01-01

    Unfriendly to conventional electronic devices, circuits, and systems, extreme environments represent a serious challenge to designers and mission architects. The first truly comprehensive guide to this specialized field, Extreme Environment Electronics explains the essential aspects of designing and using devices, circuits, and electronic systems intended to operate in extreme environments, including across wide temperature ranges and in radiation-intense scenarios such as space. The Definitive Guide to Extreme Environment Electronics Featuring contributions by some of the world's foremost exp

  15. Shuttle vectors for the archaebacterium Halobacterium volcanii.

    OpenAIRE

    Lam, W. L.; Doolittle, W F

    1989-01-01

    Progress in archaebacterial molecular biology requires tools for genetic analysis. We describe vectors that can be selected and maintained in either Halobacterium volcanii or Escherichia coli. A genetic determinant for resistance to the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor mevinolin was isolated by "shotgun cloning" into a derivative of the endogenous H. volcanii plasmid pHV2, to form pWL2, which transforms sensitive H. volcanii to mevinolin resistance at high frequency. ...

  16. Deficiently Extremal Gorenstein Algebras

    Indian Academy of Sciences (India)

    Pavinder Singh

    2011-08-01

    The aim of this article is to study the homological properties of deficiently extremal Gorenstein algebras. We prove that if / is an odd deficiently extremal Gorenstein algebra with pure minimal free resolution, then the codimension of / must be odd. As an application, the structure of pure minimal free resolution of a nearly extremal Gorenstein algebra is obtained.

  17. Effect of salinity and acidity on bioleaching activity of mesophilic and extremely thermophilic bacteria

    Institute of Scientific and Technical Information of China (English)

    H.DEVECI; M.A.JORDAN; N.POWELL; I.ALP

    2008-01-01

    The effects of bacterial strain,salinity and pH on the bioleaching of a complex ore using mesophilic and extremely thermophilic bacteria were investigated and the statistical analysis of the results was performed using ERGUN's test.The extreme thermophiles were shown to display superior kinetics of dissolution of zinc compared with the mesophiles as confirmed by the statistical analysis.Bioleaching performance of the extreme thermophiles is found to improve in response to the increase in acidity (pH from 2.0 to 1.0) whilst the activity of the mesophiles is adversely affected by decreasing pH.Statistical analysis of the bioleaching data indicates that the effect of pH is insignificant in the range of pH 1.0-1.2 for the extreme thermophiles and pH 1.4-2.0 for the mesophiles.Salinity is shown to have a suppressing effect on the mesophiles.However,the extreme thermophiles appear to be halophilic in character as they could operate efficiently under saline conditions (1%-4%C1- (w/v)).

  18. Ribulose-1,5-bisphosphate carboxylase/oxygenase genes as a functional marker for chemolithoautotrophic halophilic sulfur-oxidizing bacteria in hypersaline habitats.

    Science.gov (United States)

    Tourova, Tatjana P; Kovaleva, Olga L; Sorokin, Dimitry Yu; Muyzer, Gerard

    2010-07-01

    The presence and diversity of the cbb genes encoding the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) (a key enzyme of the Calvin-Benson cycle of autotrophic CO(2) assimilation) were investigated in pure cultures of seven genera of halophilic chemolithoautotrophic sulfur-oxidizing bacteria (SOB) and in sediments from a hypersaline lake in which such bacteria have been recently discovered. All of the halophilic SOB strains (with the exception of Thiohalomonas nitratireducens) possessed the cbbL gene encoding RuBisCO form I, while the cbbM gene encoding RuBisCO form II was detected only in some of the pure cultures. The general topologies of the CbbL/CbbM trees and the 16S rRNA gene tree were different, but both markers showed that the halophilic SOB genera formed independent lineages in the Gammaproteobacteria. In some cases, such as with several strains of the genus Thiohalospira and with Thioalkalibacter halophilus, the cbbL clustering was incongruent with the positions of these strains on the ribosomal tree. In the cbbM tree, the clustering of Thiohalospira and Thiohalorhabdus strains was incongruent with their branching in both cbbL and 16S rRNA gene trees. cbbL and cbbM genes related to those found in the analysed halophilic SOB were also detected in a sediment from a hypersaline lake in Kulunda Steppe (Russia). Most of the cbbL and cbbM genes belonged to members of the genus Thiohalorhabdus. In the cbbL clone library, sequences related to those of Halothiobacillus and Thiohalospira were detected as minor components. Some of the environmental cbbM sequences belonged to as yet unknown phylotypes, representing deep lineages of halophilic autotrophs.

  19. 极端嗜盐古菌中CRISPR结构的生物信息学分析%Comparative analysis of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPRs) loci in the genomes of halophilic archaea

    Institute of Scientific and Technical Information of China (English)

    张帆; 张兵; 向华; 胡松年

    2009-01-01

    [Objective] Clustered Regularly Interspaeed 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 arehaea, of which the whole genome sequences are available at present time.[Methods] We used bioinformatics methods including alignment, conservation analysis, GC content and RNA structure prediction to analyze the CRISPR structures of 7 haloarehaeal genomes. [Results] 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 halophilie arehaea 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. [Conclusion] 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.%[目的]利用生物信息学方法了解目前拥有全基因组序列的极端嗜盐古菌中CRISPR结构的特征.[方法]通过比对,保守性分析,GC含量分析,RNA结构预测等方法对已有全基因组序列的嗜盐古菌基因组进行研究.[结果]在5株嗜盐古菌基因组中发现CRISPR结构,在leader序列内得到具有回文性质的保守motif.发现在大CRISPR结构内repeat序列具有很强的保守性.同时根据第四位碱基的不同,repeat序列可形成两类不同的RNA二级结构.[结论]leader序列中回文结构的发现对其可能为蛋白结合位点的假设提供了进一步的理论依据.Repeat序列RNA二级结构的形成提示其可能介导外源DNA或RNA与CAS编码蛋白的相互作用.

  20. Bacillus salsus sp. nov., a halophilic bacterium from a hypersaline lake.

    Science.gov (United States)

    Amoozegar, Mohammad Ali; Didari, Maryam; Bagheri, Maryam; Fazeli, Seyed Abolhassan Shahzadeh; Schumann, Peter; Spröer, Cathrin; Sánchez-Porro, Cristina; Ventosa, Antonio

    2013-09-01

    A Gram-staining-positive, endospore-forming, rod-shaped, strictly aerobic, slightly halophilic bacterium, designated strain A24(T), was isolated from the hypersaline lake Aran-Bidgol in Iran. Cells of strain A24(T) were motile rods and produced oval endospores at a terminal position in swollen sporangia. Strain A24(T) was catalase and oxidase positive. Growth occurred with between 0.5 and 7.5% (w/v) NaCl and the isolate grew optimally at 3% (v/w) NaCl. The optimum temperature and pH for growth were 35 °C and pH 8.0, respectively. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain A24(T) belonged to the genus Bacillus within the phylum Firmicutes and showed the closest phylogenetic similarity with the species Bacillus alkalitelluris BA288(T) (97.2%), Bacillus herbersteinensis D-1,5a(T) (96.0%) and Bacillus litoralis SW-211(T) (95.6%). The G+C content of the genomic DNA of this strain was 35.9 mol%. The polar lipid pattern of strain A24(T) consisted of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and two unknown phospholipids. The major cellular fatty acids of strain A24(T) were anteiso-C(15:0) and iso-C(15:0). The respiratory quinones were MK-7 (94%) and MK-6 (4%). The peptidoglycan contained meso-diaminopimelic acid as the diagnostic diamino acid. All these features confirm the placement of isolate A24(T) within the genus Bacillus. DNA-DNA hybridization experiments revealed a relatedness of 8% between strain A24(T) and Bacillus alkalitelluris IBRC-M 10596(T), supporting its placement as a novel species. Phenotypic characteristics, phylogenetic analysis and DNA-DNA relatedness data suggest that this strain represents a novel species of the genus Bacillus, for which the name Bacillus salsus sp. nov. is proposed. The type strain is strain A24(T) ( = IBRC-M 10078 (T) = KCTC 13816(T)).

  1. Bacillus halosaccharovorans sp. nov., a moderately halophilic bacterium from a hypersaline lake.

    Science.gov (United States)

    Mehrshad, Maliheh; Amoozegar, Mohammad Ali; Didari, Maryam; Bagheri, Maryam; Fazeli, Seyed Abolhassan Shahzadeh; Schumann, Peter; Spröer, Cathrin; Sánchez-Porro, Cristina; Ventosa, Antonio

    2013-08-01

    A novel Gram-stain-positive, moderately halophilic bacterium, designated strain E33(T), was isolated from water of the hypersaline lake Aran-Bidgol in Iran and characterized taxonomically using a polyphasic approach. Cells of strain E33(T) were motile rods and produced ellipsoidal endospores at a central or subterminal position in swollen sporangia. Strain E33(T) was a strictly aerobic bacterium, catalase- and oxidase-positive. The strain was able to grow at NaCl concentrations of 0.5-25 % (w/v), with optimum growth occurring at 5-15 % (w/v) NaCl. The optimum temperature and pH for growth were 40 °C and pH 7.5-8.0, respectively. On the basis of 16S rRNA gene sequence analysis, strain E33(T) was shown to belong to the genus Bacillus within the phylum Firmicutes and showed the closest phylogenetic similarity with the species Bacillus niabensis 4T19(T) (99.2 %), Bacillus herbersteinensis D-1-5a(T) (97.3 %) and Bacillus litoralis SW-211(T) (97.2 %). The DNA G+C content of the type strain of the novel species was 42.6 mol%. The major cellular fatty acids of strain E33(T) were anteiso-C15 : 0 and iso-C15 : 0, and the polar lipid pattern consisted of diphosphatidylglycerol, phosphatidylglycerol, two unknown glycolipids, an unknown lipid and an unknown phospholipid. The isoprenoid quinones were MK-7 (97 %), MK-6 (2 %) and MK-8 (0.5 %). The peptidoglycan contained meso-diaminopimelic acid as the diagnostic diamino acid. All these features confirm the placement of isolate E33(T) within the genus Bacillus. DNA-DNA hybridization experiments revealed low levels of relatedness between strain E33(T) and Bacillus niabensis IBRC-M 10590(T) (22 %), Bacillus herbersteinensis CCM 7228(T) (38 %) and Bacillus litoralis DSM 16303(T) (19 %). On the basis of polyphasic evidence from this study, a novel species of the genus Bacillus, Bacillus halosaccharovorans sp. nov. is proposed, with strain E33(T) (= IBRC-M 10095(T) = DSM 25387(T)) as the type strain.

  2. Bacillus persicus sp. nov., a halophilic bacterium from a hypersaline lake.

    Science.gov (United States)

    Didari, Maryam; Amoozegar, Mohammad Ali; Bagheri, Maryam; Mehrshad, Maliheh; Schumann, Peter; Spröer, Cathrin; Sánchez-Porro, Cristina; Ventosa, Antonio

    2013-04-01

    A novel gram-positive, slightly halophilic bacterium, designated strain B48(T), was isolated from soil around the hypersaline lake Aran-Bidgol in Iran and characterized taxonomically using a polyphasic approach. Cells of strain B48(T) were non-motile rods and produced ellipsoidal endospores at a central or subterminal position in swollen sporangia. Strain B48(T) was a strictly aerobic bacterium, catalase- and oxidase-positive. The strain was able to grow at NaCl concentrations of 0.5-10.0 % (w/v), with optimum growth occurring at 2.5 % (w/v) NaCl. The optimum temperature and pH for growth were 35 °C and pH 7.5-8.0, respectively. On the basis of 16S rRNA gene sequence analysis, strain B48(T) was shown to belong to the genus Bacillus within the phylum Firmicutes and showed the closest phylogenetic similarity to the species Bacillus foraminis CV53(T) (97.4 %) and Bacillus purgationiresistens DS22(T) (96.9 %). The DNA G+C content of this new isolate was 40.1 mol%. The major cellular fatty acids of strain B48(T) were iso-C15 : 0 and anteiso-C15 : 0, and its polar lipid pattern consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, an aminophospholipid and two unknown phospholipids. The only quinone present was menaquinone 7 (MK-7). The peptidoglycan contained meso-diaminopimelic acid as the diagnostic diamino acid. All these features confirm the placement of isolate B48(T) within the genus Bacillus. DNA-DNA hybridization experiments revealed a low level of relatedness between strain B48(T) and Bacillus foraminis IBRC-M 10625(T) (8.1 %). On the basis of polyphasic evidence from this study, a new species of the genus Bacillus, Bacillus persicus sp. nov., is proposed, with strain B48(T) ( = IBRC-M 10115(T) = DSM 25386(T) = CECT 8001(T)) as the type strain.

  3. Halomonas songnenensis sp. nov., a moderately halophilic bacterium isolated from saline and alkaline soils.

    Science.gov (United States)

    Jiang, Juquan; Pan, Yuanyuan; Hu, Shaoxin; Zhang, Xiaoxia; Hu, Baozhong; Huang, Haipeng; Hong, Shan; Meng, Jing; Li, Cheng; Wang, Kaibiao

    2014-05-01

    A moderately halophilic bacterium (strain NEAU-ST10-39T) was isolated from saline and alkaline soils in the oilfield of Daqing City, Heilongjiang Province, China. The strain was strictly aerobic, Gram-stain-negative, rod-shaped and motile by peritrichous flagella. Its colonies were yellow. It grew at NaCl concentrations of 0.2-15% (w/v) (optimum 4%, w/v), at temperatures of 4-40 °C (optimum 35 °C) and at pH 5-10 (optimum pH 7). It did not produce acids from sugars or alcohols. Its DNA G+C content was 57.4 mol%. Phylogenetic analyses based on 16S rRNA gene sequences and concatenated 16S rRNA, gyrB and rpoD gene sequences indicated that it belonged to the genus Halomonas in the class Gammaproteobacteria. The most phylogenetically related species were Halomonas axialensis, Halomonas meridiana and Halomonas aquamarina, whose types shared 98.3% (16S rRNA), 82.7% (gyrB) and 83.9-84.5% (rpoD) sequence similarity with strain NEAU-ST10-39T. The results of DNA-DNA hybridization assays showed 20±2%-50±1 % relatedness between strain NEAU-ST10-39T and the most closely related species including Halomonas axialensis DSM 15723T, Halomonas meridiana DSM 5425T, Halomonas aquamarina DSM 30161(T), Halomonas johnsoniae DSM 21197T, Halomonas stevensii DSM 21198T, Halomonas nanhaiensis CCTCC AB 2012911(T), Halomonas hamiltonii DSM 21196T and Halomonas arcis CGMCC 1.6494T. The major fatty acids were C18 : 1ω7c (47.2%), C16:1ω7c and/or C16:1ω6c (18.9%) and C16:0 (16.3%), the only respiratory quinone detected was ubiquinone 9 and polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, two unknown phospholipids and three unknown lipids. The new isolate is proposed to represent a novel species with the name Halomonas songnenensis sp. nov., NEAU-ST10-39T (=CGMCC 1.12152T=DSM 25870T) being the type strain.

  4. Salimicrobium salexigens sp. nov., a moderately halophilic bacterium from salted hides.

    Science.gov (United States)

    de la Haba, Rafael R; Yilmaz, Pinar; Sánchez-Porro, Cristina; Birbir, Meral; Ventosa, Antonio

    2011-09-01

    Two Gram-positive, moderately halophilic bacteria, designated strains 29CMI(T) and 53CMI, were isolated from salted hides. Both strains were non-motile, strictly aerobic cocci, growing in the presence of 3-25% (w/v) NaCl (optimal growth at 7.5-12.5% [w/v] NaCl), between pH 5.0 and 10.0 (optimal growth at pH 7.5) and at temperatures between 15 and 40°C (optimal growth at 37°C). Phylogenetic analysis based on 16S rRNA gene sequence comparison showed that both strains showed a similarity of 98.7% and were closely related to species of the genus Salimicrobium, within the phylum Firmicutes. Strains 29CMI(T) and 53CMI exhibited 16S rRNA gene sequence similarity values of 97.9-97.6% with Salimicrobium album DSM 20748(T), Salimicrobium halophilum DSM 4771(T), Salimicrobium flavidum ISL-25(T) and Salimicrobium luteum BY-5(T). The DNA G+C content was 50.7mol% and 51.5mol% for strains 29CMI(T) and 53CMI, respectively. The DNA-DNA hybridization between both strains was 98%, whereas the values between strain 29CMI(T) and the species S. album CCM 3517(T), S. luteum BY-5(T), S. flavidum ISL-25(T) and S. halophilum CCM 4074(T) were 45%, 28%, 15% and 10%, respectively, showing unequivocally that strains 29CMI(T) and 53CMI constitute a new genospecies. The major cellular fatty acids were anteiso-C(15:0), anteiso-C(17:0), iso-C(15:0) and iso-C(14:0). The main respiratory isoprenoid quinone was MK-7, although small amounts of MK-6 were also found. The polar lipids of the type strain consist of diphosphatidylglycerol, phosphatidylglycerol, one unidentified phospholipid and one glycolipid. The peptidoglycan type is A1γ, with meso-diaminopimelic acid as the diagnostic diamino acid. On the basis of the phylogenetic analysis, and phenotypic, genotypic and chemotaxonomic characteristics, we propose strains 29CMI(T) and 53CMI as a novel species of the genus Salimicrobium, with the name Salimicrobium salexigens sp. nov. The type strain is 29CMI(T) (=CECT 7568(T)=JCM 16414(T)=LMG 25386(T)).

  5. Extreme value distributions

    CERN Document Server

    Ahsanullah, Mohammad

    2016-01-01

    The aim of the book is to give a through account of the basic theory of extreme value distributions. The book cover a wide range of materials available to date. The central ideas and results of extreme value distributions are presented. The book rwill be useful o applied statisticians as well statisticians interrested to work in the area of extreme value distributions.vmonograph presents the central ideas and results of extreme value distributions.The monograph gives self-contained of theory and applications of extreme value distributions.

  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. Different glycosyltransferases are involved in lipid glycosylation and protein N-glycosylation in the halophilic archaeon Haloferax volcanii.

    Science.gov (United States)

    Naparstek, Shai; Vinagradov, Evguenii; Eichler, Jerry

    2010-07-01

    Both the lipid and the protein components of biological membranes can be modified by the covalent addition of polysaccharides. Whereas eukaryal and bacterial pathways of lipid and protein glycosylation are relatively well defined, considerably less is known of the parallel processes in Archaea. Recent efforts have identified glycosyltransferases involved in N-glycosylation of the surface-layer glycoprotein of the halophilic archaeon Haloferax volcanii. In the present study, the involvement of these same glycosyltransferases in the biosynthesis of Hfx. volcanii glycolipids was considered by performing nuclear magnetic resonance analysis of the glycolipid fraction of Hfx. volcanii cells deleted of genes encoding those glycosyltransferases, as well as the oligosaccharyltransferase, AglB. The results reveal that different glycosyltransferases are involved in the biosynthesis of N-linked glycoproteins and glycolipids in Archaea.

  8. Isolation of two strong poly (U binding proteins from moderate halophile Halomonas eurihalina and their identification as cold shock proteins.

    Directory of Open Access Journals (Sweden)

    Usha Kumari Garapati

    Full Text Available Cold shock proteins (Csp are known to be expressed in response to sudden decrease in temperature. They are thought to be involved in a number of cellular processes viz., RNA chaperone activity, translation, transcription, nucleoid condensation. During our studies on ribosomal protein S1 in moderate halophile Halomonas eurihalina, we observed the presence of two strong poly (U binding proteins in abundance in cell extracts from cells grown under normal growth conditions. The proteins can be isolated in a single step using Poly (U cellulose chromatography. The proteins were identified as major cold shock proteins belonging to Csp A family by MALDI-TOF and bioinformatic analysis. Csp 12 kDa was found in both exponential and stationary phases whereas Csp 8 kDa is found only in exponential phase.

  9. 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...... Haloferax volcanii as a model system, we describe the first genetic analysis of archaeal DNA ligase function. We show that the Hfx. volcanii ATP-dependent DNA ligase family member, LigA, is non-essential for cell viability, raising the question of how DNA strands are joined in its absence. We show that Hfx....... 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...

  10. Extreme Velocity Wind Sensor

    Science.gov (United States)

    Perotti, Jose; Voska, Ned (Technical Monitor)

    2002-01-01

    This presentation provides an overview of the development of new hurricane wind sensor (Extreme Velocity Wind Sensor) for the Kennedy Space Center (KSC) which is designed to withstand winds of up to three hundred miles an hour. The proposed Extreme Velocity Wind Sensor contains no moveable components that would be exposed to extreme wind conditions. Topics covered include: need for new hurricane wind sensor, conceptual design, software applications, computational fluid dynamic simulations of design concept, preliminary performance tests, and project status.

  11. How extreme is extreme hourly precipitation?

    Science.gov (United States)

    Papalexiou, Simon Michael; Dialynas, Yannis G.; Pappas, Christoforos

    2016-04-01

    The importance of accurate representation of precipitation at fine time scales (e.g., hourly), directly associated with flash flood events, is crucial in hydrological design and prediction. The upper part of a probability distribution, known as the distribution tail, determines the behavior of extreme events. In general, and loosely speaking, tails can be categorized in two families: the subexponential and the hyperexponential family, with the first generating more intense and more frequent extremes compared to the latter. In past studies, the focus has been mainly on daily precipitation, with the Gamma distribution being the most popular model. Here, we investigate the behaviour of tails of hourly precipitation by comparing the upper part of empirical distributions of thousands of records with three general types of tails corresponding to the Pareto, Lognormal, and Weibull distributions. Specifically, we use thousands of hourly rainfall records from all over the USA. The analysis indicates that heavier-tailed distributions describe better the observed hourly rainfall extremes in comparison to lighter tails. Traditional representations of the marginal distribution of hourly rainfall may significantly deviate from observed behaviours of extremes, with direct implications on hydroclimatic variables modelling and engineering design.

  12. Classifying Returns as Extreme

    DEFF Research Database (Denmark)

    Christiansen, Charlotte

    2014-01-01

    I consider extreme returns for the stock and bond markets of 14 EU countries using two classification schemes: One, the univariate classification scheme from the previous literature that classifies extreme returns for each market separately, and two, a novel multivariate classification scheme tha...

  13. 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...... euryarchaeon Haloferax volcanii, the gene for which was apparently acquired by Hfx.volcanii through lateral gene transfer (LGT) from a halophilic eubacterium. Genetic studies show that the LGT-acquired LigN enzyme shares an essential function with the native Hfx.volcanii ATP-dependent DNA ligase protein Lig......A. Results To characterise the enzymatic properties of the LigN protein, wild-type and three mutant forms of the LigN protein were separately expressed in recombinant form in E.coli and purified to apparent homogeneity by immobilised metal ion affinity chromatography (IMAC). Non-isotopic DNA ligase activity...

  14. Biochemical and Molecular Characterization of the Biosynthesis of Glutamine and Glutamate, Two Major Compatible Solutes in the Moderately Halophilic Bacterium Halobacillus halophilus†

    OpenAIRE

    Saum, Stephan H.; Sydow, Jasmin F.; Palm, Peter; Pfeiffer, Friedhelm; Oesterhelt, Dieter; Müller, Volker

    2006-01-01

    The moderately halophilic, chloride-dependent bacterium Halobacillus halophilus produces glutamate and glutamine as main compatible solutes at external salinities of 1.0 to 1.5 M NaCl. The routes for the biosynthesis of these solutes and their regulation were examined. The genome contains two genes potentially encoding glutamate dehydrogenases and two genes for the small subunit of a glutamate synthase, but only one gene for the large subunit. However, the expression of these genes was not sa...

  15. The ectD Gene, Which Is Involved in the Synthesis of the Compatible Solute Hydroxyectoine, Is Essential for Thermoprotection of the Halophilic Bacterium Chromohalobacter salexigens

    OpenAIRE

    2006-01-01

    The halophilic bacterium Chromohalobacter salexigens synthesizes and accumulates compatible solutes in response to salt and temperature stress. 13C-nuclear magnetic resonance analysis of cells grown in minimal medium at the limiting temperature of 45°C revealed the presence of hydroxyectoine, ectoine, glutamate, trehalose (not present in cells grown at 37°C), and the ectoine precursor, N')'-acetyldiaminobutyric acid. High-performance liquid chromatography analyses showed that the levels of ec...

  16. Moving in extreme environments

    DEFF Research Database (Denmark)

    Lucas, Samuel J E; Helge, Jørn W; Schütz, Uwe H W;

    2016-01-01

    This review addresses human capacity for movement in the context of extreme loading and with it the combined effects of metabolic, biomechanical and gravitational stress on the human body. This topic encompasses extreme duration, as occurs in ultra-endurance competitions (e.g. adventure racing...... and transcontinental races) and expeditions (e.g. polar crossings), to the more gravitationally limited load carriage (e.g. in the military context). Juxtaposed to these circumstances is the extreme metabolic and mechanical unloading associated with space travel, prolonged bedrest and sedentary lifestyle, which may...

  17. Extremal surface barriers

    Energy Technology Data Exchange (ETDEWEB)

    Engelhardt, Netta; Wall, Aron C. [Department of Physics, University of California,Santa Barbara, CA 93106 (United States)

    2014-03-13

    We present a generic condition for Lorentzian manifolds to have a barrier that limits the reach of boundary-anchored extremal surfaces of arbitrary dimension. We show that any surface with nonpositive extrinsic curvature is a barrier, in the sense that extremal surfaces cannot be continuously deformed past it. Furthermore, the outermost barrier surface has nonnegative extrinsic curvature. Under certain conditions, we show that the existence of trapped surfaces implies a barrier, and conversely. In the context of AdS/CFT, these barriers imply that it is impossible to reconstruct the entire bulk using extremal surfaces. We comment on the implications for the firewall controversy.

  18. Extremely 'vanadiphilic' multiply metal-resistant and halophilic aerobic anoxygenic phototrophs, strains EG13 and EG8, from hypersaline springs in Canada.

    Science.gov (United States)

    Csotonyi, J T; Maltman, C; Swiderski, J; Stackebrandt, E; Yurkov, V

    2015-01-01

    Two pinkish peach-colored strains of obligately aerobic phototrophic bacteria, EG13 and EG8, were isolated from a saline spring effluent stream in west central Manitoba, Canada. The strains possessed bacteriochlorophyll a incorporated into a typical purple bacterial light-harvesting complex 1 (870 nm) and reaction center (801 nm). Analysis of 16S rRNA gene sequences indicated 100% identity among the isolates and 99% similarity to Roseovarius tolerans EL-172(T). The strains were physiologically well adapted to high salinity (0-22%), fluctuating pH (7-12) and temperature (7-40 °C) of the exposed hypersaline stream of East German Creek. EG8 and EG13 were also highly resistant to the toxic metal(loid) oxyanions tellurite, selenite and metavanadate (≥1000 μg/ml each). Most intriguingly, growth and pigment production of EG13 on glutamate minimal medium was stimulated by 1000-10000 μg/ml of sodium metavanadate compared to metal-free conditions. Phylogenetic analysis and phenotypic properties such as pigment composition and morphology indicate close relatedness to Roseovarius genus.

  19. Draft genome sequence of the extremely halophilic Halorubrum sp. SAH-A6 isolated from rock salts of the Danakil depression, Ethiopia

    OpenAIRE

    2016-01-01

    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 gen...

  20. 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.

  1. Draft genome sequence of the extremely halophilic Halorubrum sp. SAH-A6 isolated from rock salts of the Danakil depression, Ethiopia.

    Science.gov (United States)

    Gibtan, Ashagrie; Woo, Mingyeong; Oh, Dokyung; Park, Kyounghee; Lee, Han-Seung; Sohn, Jae Hak; Lee, Dong-Woo; Shin, Jung-Kue; Lee, Sang-Jae

    2016-12-01

    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.

  2. Analysis of extreme events

    CSIR Research Space (South Africa)

    Khuluse, S

    2009-04-01

    Full Text Available ) determination of the distribution of the damage and (iii) preparation of products that enable prediction of future risk events. The methodology provided by extreme value theory can also be a powerful tool in risk analysis...

  3. Extreme environments and exobiology.

    Science.gov (United States)

    Friedmann, E I

    1993-01-01

    Ecological research on extreme environments can be applied to exobiological problems such as the question of life on Mars. If life forms (fossil or extant) are found on Mars, their study will help to solve fundamental questions about the nature of life on Earth. Extreme environments that are beyond the range of adaptability of their inhabitants are defined as "absolute extreme". Such environments can serve as terrestrial models for the last stages of life in the history of Mars, when the surface cooled down and atmosphere and water disappeared. The cryptoendolithic microbial community in porous rocks of the Ross Desert in Antarctica and the microbial mats at the bottom of frozen Antarctic lakes are such examples. The microbial communities of Siberian permafrost show that, in frozen but stable communities, long-term survival is possible. In the context of terraforming Mars, selected microorganisms isolated from absolute extreme environments are considered for use in creation of a biological carbon cycle.

  4. Venous Ultrasound (Extremities)

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Ultrasound - Venous (Extremities) Venous ultrasound uses sound waves to ... limitations of Venous Ultrasound Imaging? What is Venous Ultrasound Imaging? Ultrasound is safe and painless, and produces ...

  5. Statistics of extremes

    CERN Document Server

    Gumbel, E J

    2012-01-01

    This classic text covers order statistics and their exceedances; exact distribution of extremes; the 1st asymptotic distribution; uses of the 1st, 2nd, and 3rd asymptotes; more. 1958 edition. Includes 44 tables and 97 graphs.

  6. 嗜盐蛋白高级结构对其稳定性的影响%Influence of Advanced Structures on Protein Halophilic Stability

    Institute of Scientific and Technical Information of China (English)

    张光亚

    2012-01-01

    选择30对具有晶体结构的嗜盐和非嗜盐同源蛋白,通过计算氨基酸所处的结构状态,找出二者在统计学上具有显著差异的氨基酸.研究结果表明:在总的氨基酸组成上,嗜盐蛋白中天冬氨酸含量更多,而苯丙氨酸和赖氨酸含量显著较少.在不同二级结构区域,β-折叠中两种蛋白氨基酸组成差异最大;而在不同溶剂可及表面,两种蛋白在分别表面氨基酸组成差异最大,嗜盐蛋白表面酸性氨基酸显著较多,而碱性氨基酸则较少;48种高级结构结构参数中有4种存在显著差异,这4种结构参数都与可及性表面积有关.%To investigate the structural distribution responsible for protein halophilicity is of great significance for understanding the stability of halophilic protein and would help to develop a practical strategy for designing halophilic proteins. A systematic comparative analysis of 30 pairs of halophilic and non-halophilic proteins was reported. The residue structural states based on secondary structure and solvent accessibility were considered for analyzing the structural patterns of single amino acids. The statistical test revealed that higher frequency in overall of Asp at the expense of Phe and Lys, higher frequency in exposed state of acid amino acids at the expense of alkaline amino acids. The β-sheet and the exposed surface were the regions showed great differences. Among the 48 structure parameters, there were four parameters which showed significant difference between the two kinds of proteins. Interestingly, the four parameters were all related with the accessible surface area.

  7. Identification and characterization of salt-inducible polypeptide in Paenibacillus sp., a moderately halophilic bacterium.

    Science.gov (United States)

    Sokhansanj, Ashrafaddin; Karkhane, Ali Asghar; Jazii, Ferdous Rastgar

    2005-11-01

    In response to salt, Paenibacillus sp. strain XII expresses a 21.4 kDa polypeptide. N-terminal sequencing and sequence homology analysis indicate homology between the N-terminal sequence of the polypeptide and a segment of the N-terminus of the spore coat associated protein CotN of Oceanobacillus iheyensis, an extremely halotolerant bacteria of the deep-sea.

  8. 自贡大公古盐井中嗜盐菌的Na+/H+离子逆转运蛋白基因筛选%Screening a Na+/H+ Antiporter Gene from the Halophiles Colonizing in the Dagong Ancient Brine Well of Zigong City,China

    Institute of Scientific and Technical Information of China (English)

    梁华忠; 刘森; 李可; 张大凤; 车振明; 向文良

    2012-01-01

    grow under alkaline conditions. [Conclusion] The structure and amino acid sequence of M-Nha was different from the previously reported Na+/H+ antiporters, and the m-nha gene disclosed from the Dagong Ancient Brine Well was identified as a novel Na + /H+ antiporter gene. This study was significant in not only helping us understand the necessity of the existence of Na+ /H+ antiporter in the Dagong Ancient Brine Well to maintain the intracellular environment homeostasis for halophiles, but also enriching our knowledge about the different mechanisms of Na+ /H+ antiporter in halophiles in such an extreme environment.

  9. 新疆罗布泊周边地区极端环境嗜盐菌的研究%Physiological and Biochemical Characteristics of Halophilic Archaea Isolated from Lop Nut Surrounding Region in Xinjiang, and Gen Sequence of 16S rRNA, China

    Institute of Scientific and Technical Information of China (English)

    迪丽拜尔·托乎提; 旭格拉; 穆尔特扎; 热则宛古丽; 阿曼古丽; 纪婷; 迪丽乌孜

    2009-01-01

    为了研究分析新疆罗布泊周边地区pH值5~6的盐湖嗜盐古菌资源.从湖中分离筛选出一批嗜盐古菌,对其进行了生理生化特性研究,发现其中6株菌的生理特性和产酶特性比较特殊,并采用PCR方法扩增出其16SrRNA基因(16S rDNA),并测定了基因的核苷酸序列.基于16S rDNA序列的同源性比较以及16S rDNA序列的系统发育学研究表明,菌株B20-RDX是盐盒菌属Haloarchaeon属中新种成员,GenBank登录号为FJ561285,该菌株为革兰氏阴性菌,最适盐浓度25%,最适pH 8.0,能产过氧化氢酶、淀粉酶,对四环素有抗性,能利用精氨酸和丁二酸盐.迄今为止,国内极少有关罗布泊周边地区极端环境微生物研究的报道,该研究可为今后研究同类极端环境中新的物种资源开发应用以及微生物多样性研究提供素材和参考.%Objective:Study and analyze the species resource from a Salt Lake pH5-6 in the LopNur surrounding region,Xinjiang.A group of halophilic archaea strains isolated from a Salt Lake pH5-6 in the LopNur surrounding region,Xinjiang.And their physiological and biochemical characteristics were determined.Based on its morphology and physiological and biochemical features,16S rRNA encoding gene(16S rDNA) from six strains were amplified byPCR,and the nucleotide sequences were determined.The results indicated that the strain B20-RDX was was a novol species of the genus Haloarchaeon,The GenBank accession numbers of the 16S rDNA sequences about strain is FJ561285.The strain B20-RDX is Gram-negative balls,The optimum salt concentration for its growth is 25%,and the optimum pH is at 8.0.The strain B20-RDX produce catalases and amylases,which resistant to tetracycline.B20-RDX make use of arginine and succinate salts.Now,there are few report about Extreme halophiles from Lop Nur surrounding region,in China.The study has offered enlarge the boundary of halophilic archaea diversity and provide halophilic archaea resources for further

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

    Directory of Open Access Journals (Sweden)

    Thomas Geoffrey C

    2011-05-01

    Full Text Available Abstract 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

  11. Extreme Programming: Maestro Style

    Science.gov (United States)

    Norris, Jeffrey; Fox, Jason; Rabe, Kenneth; Shu, I-Hsiang; Powell, Mark

    2009-01-01

    "Extreme Programming: Maestro Style" is the name of a computer programming methodology that has evolved as a custom version of a methodology, called extreme programming that has been practiced in the software industry since the late 1990s. The name of this version reflects its origin in the work of the Maestro team at NASA's Jet Propulsion Laboratory that develops software for Mars exploration missions. Extreme programming is oriented toward agile development of software resting on values of simplicity, communication, testing, and aggressiveness. Extreme programming involves use of methods of rapidly building and disseminating institutional knowledge among members of a computer-programming team to give all the members a shared view that matches the view of the customers for whom the software system is to be developed. Extreme programming includes frequent planning by programmers in collaboration with customers, continually examining and rewriting code in striving for the simplest workable software designs, a system metaphor (basically, an abstraction of the system that provides easy-to-remember software-naming conventions and insight into the architecture of the system), programmers working in pairs, adherence to a set of coding standards, collaboration of customers and programmers, frequent verbal communication, frequent releases of software in small increments of development, repeated testing of the developmental software by both programmers and customers, and continuous interaction between the team and the customers. The environment in which the Maestro team works requires the team to quickly adapt to changing needs of its customers. In addition, the team cannot afford to accept unnecessary development risk. Extreme programming enables the Maestro team to remain agile and provide high-quality software and service to its customers. However, several factors in the Maestro environment have made it necessary to modify some of the conventional extreme

  12. Acidophilic Halophilic Microorganisms in Fluid Inclusions in Halite from Lake Magic, Western Australia

    OpenAIRE

    2013-01-01

    Lake Magic is one of the most extreme of hundreds of ephemeral acid-saline lakes in southern Western Australia. It has pH as low as 1.7, salinity as high as 32% total dissolved solids, temperatures ranging from 0°C to 50°C, and an unusually complex aqueous composition. Optical petrography, UV-vis petrography, and laser Raman spectrometry were used to detect microorganisms and organic compounds within primary fluid inclusions in modern bedded halite from Lake Magic. Rare prokaryotes appear as ...

  13. Microcystin congeners contribute to toxicity in the halophilic cyanobacterium Aphanothece halophytica

    Directory of Open Access Journals (Sweden)

    Vishwakarma Rashi

    2014-01-01

    Full Text Available Aphanothece halophytica is an extremely saline cyanobacterium. This study investigates the toxic nature of the organism and presents the first report of hepatotoxic cyclic heptapeptide microcystin analogs. The activity of the crude extract was investigated in mice. Results showed acute toxicity with mice death at about 4 h. Histopathological examination indicated massive alveolar hemorrhage and extensive congestion in liver cells. Increases in the levels of serum enzymes, i.e., AST (aspartate aminotransferase, ALT (alanine aminotransferase and LDH (lactate dehydrogenase, provide further evidence of cell injury. An ELISA-based immunological detection kit confirmed the presence of microcystin analogs.

  14. Statistics of Extremes

    KAUST Repository

    Davison, Anthony C.

    2015-04-10

    Statistics of extremes concerns inference for rare events. Often the events have never yet been observed, and their probabilities must therefore be estimated by extrapolation of tail models fitted to available data. Because data concerning the event of interest may be very limited, efficient methods of inference play an important role. This article reviews this domain, emphasizing current research topics. We first sketch the classical theory of extremes for maxima and threshold exceedances of stationary series. We then review multivariate theory, distinguishing asymptotic independence and dependence models, followed by a description of models for spatial and spatiotemporal extreme events. Finally, we discuss inference and describe two applications. Animations illustrate some of the main ideas. © 2015 by Annual Reviews. All rights reserved.

  15. Extremely deformable structures

    CERN Document Server

    2015-01-01

    Recently, a new research stimulus has derived from the observation that soft structures, such as biological systems, but also rubber and gel, may work in a post critical regime, where elastic elements are subject to extreme deformations, though still exhibiting excellent mechanical performances. This is the realm of ‘extreme mechanics’, to which this book is addressed. The possibility of exploiting highly deformable structures opens new and unexpected technological possibilities. In particular, the challenge is the design of deformable and bi-stable mechanisms which can reach superior mechanical performances and can have a strong impact on several high-tech applications, including stretchable electronics, nanotube serpentines, deployable structures for aerospace engineering, cable deployment in the ocean, but also sensors and flexible actuators and vibration absorbers. Readers are introduced to a variety of interrelated topics involving the mechanics of extremely deformable structures, with emphasis on ...

  16. Precursors of extreme increments

    CERN Document Server

    Hallerberg, S; Holstein, D; Kantz, H; Hallerberg, Sarah; Altmann, Eduardo G.; Holstein, Detlef; Kantz, Holger

    2006-01-01

    We investigate precursors and predictability of extreme events in time series, which consist in large increments within successive time steps. In order to understand the predictability of this class of extreme events, we study analytically the prediction of extreme increments in AR(1)-processes. The resulting strategies are then applied to predict sudden increases in wind speed recordings. In both cases we evaluate the success of predictions via creating receiver operator characteristics (ROC-plots). Surprisingly, we obtain better ROC-plots for completely uncorrelated Gaussian random numbers than for AR(1)-correlated data. Furthermore, we observe an increase of predictability with increasing event size. Both effects can be understood by using the likelihood ratio as a summary index for smooth ROC-curves.

  17. A predicted geranylgeranyl reductase reduces the ω-position isoprene of dolichol phosphate in the halophilic archaeon, Haloferax volcanii.

    Science.gov (United States)

    Naparstek, Shai; Guan, Ziqiang; Eichler, Jerry

    2012-06-01

    In N-glycosylation in both Eukarya and Archaea, N-linked oligosaccharides are assembled on dolichol phosphate prior to transfer of the glycan to the protein target. However, whereas only the α-position isoprene subunit is saturated in eukaryal dolichol phosphate, both the α- and ω-position isoprene subunits are reduced in the archaeal lipid. The agents responsible for dolichol phosphate saturation remain largely unknown. The present study sought to identify dolichol phosphate reductases in the halophilic archaeon, Haloferax volcanii. Homology-based searches recognize HVO_1799 as a geranylgeranyl reductase. Mass spectrometry revealed that cells deleted of HVO_1799 fail to fully reduce the isoprene chains of H. volcanii membrane phospholipids and glycolipids. Likewise, the absence of HVO_1799 led to a loss of saturation of the ω-position isoprene subunit of C(55) and C(60) dolichol phosphate, with the effect of HVO_1799 deletion being more pronounced with C(60) dolichol phosphate than with C(55) dolichol phosphate. Glycosylation of dolichol phosphate in the deletion strain occurred preferentially on that version of the lipid saturated at both the α- and ω-position isoprene subunits.

  18. 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 C15:0 and anteiso C17:0. 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.

  19. Thiocyanate hydrolase, the primary enzyme initiating thiocyanate degradation in the novel obligately chemolithoautotrophic halophilic sulfur-oxidizing bacterium Thiohalophilus thiocyanoxidans.

    Science.gov (United States)

    Bezsudnova, Ekaterina Yu; Sorokin, Dimitry Yu; Tikhonova, Tamara V; Popov, Vladimir O

    2007-12-01

    Thiohalophilus thiocyanoxidans is a first halophilic sulfur-oxidizing chemolithoautotrophic bacterium capable of growth with thiocyanate as an electron donor at salinity up to 4 M NaCl. The cells, grown with thiocyanate, but not with thiosulfate, contained an enzyme complex hydrolyzing thiocyanate to sulfide and ammonia under anaerobic conditions with carbonyl sulfide as an intermediate. Despite the fact of utilization of the , high cyanase activity was also detected in thiocyanate-induced cells. Three-stage column chromotography resulted in a highly purified thiocyanate-hydrolyzing protein with an apparent molecular mass of 140 kDa that consists of three subunits with masses 17, 19 and 29 kDa. The enzyme is a Co,Fe-containing protein resembling on its function and subunit composition the enzyme thiocyanate hydrolase from the Betaproteobacterium Thiobacillus thioparus. Cyanase, copurified with thiocyanate hydrolase, is a bisubstrate multisubunit enzyme with an apparent subunit molecular mass of 14 kDa. A possible role of cyanase in thiocyanate degradation by T. thiocyanoxidans is discussed.

  20. Chromohalobacter salarius sp. nov., a moderately halophilic bacterium isolated from a solar saltern in Cabo de Gata, Almeria, southern Spain.

    Science.gov (United States)

    Aguilera, Margarita; Cabrera, Antonio; Incerti, Claudia; Fuentes, Susana; Russell, Nick J; Ramos-Cormenzana, Alberto; Monteoliva-Sánchez, Mercedes

    2007-06-01

    A moderately halophilic, Gram-negative bacterium (strain CG4.1(T)), which was 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 rod that produced colonies with a yellow pigment. Strain CG4.1(T) grew at salinities of 3-25 % (w/v), at 15-45 degrees C and at pH 5-9. The organism reduced nitrate, hydrolysed starch and had phenylalanine deaminase activity. The major fatty acids were C(18 : 1)omega7c, C(16 : 0) and C(19 : 0) cyclo omega8c. The DNA G+C content was 63.6 mol%. On the basis of phenotypic and phylogenetic data, strain CG4.1(T) appears to be a member of the genus Chromohalobacter and clustered closely with Chromohalobacter species, with 95-96 % similarity between their 16S rRNA gene sequences. However, DNA-DNA relatedness between the isolate and the type strains of Chromohalobacter species was low. Therefore, it is proposed that strain CG4.1(T) represents a novel species, Chromohalobacter salarius sp. nov. The type strain is strain CG4.1(T) (=CECT 5903(T)=LMG 23626(T)).

  1. Production, purification and characterization of halophilic organic solvent tolerant protease from marine crustacean shell wastes and its efficacy on deproteinization.

    Science.gov (United States)

    Maruthiah, Thirumalai; Somanath, Beena; Jasmin, Jebamonydhas Vijila; Immanuel, Grasian; Palavesam, Arunachalam

    2016-12-01

    The quantum of marine fish wastes produced by fish processing industries has necessitated to search new methods for its disposal. Hence, this study is focused on production and purification of halophilic organic solvent tolerant protease (HOSP) from marine Alcaligenes faecalis APCMST-MKW6 using marine shell wastes as substrate. The candidate bacterium was isolated from the marine sediment of Manakudi coast and identified as A. faecalis APCMST-MKW6. The purified protease showed 16.39-fold purity, 70.34 U/mg specific activity with 21.67 % yield. The molecular weight of the purified alkaline protease was 49 kDa. This purified protease registered maximum activity at pH 9 and it was stable between pH 8-9 after 1.30 h of incubation. The optimum temperature registered was 60 °C and it was stable between 50 and 60 °C even after 1.30 h of incubation. This enzyme also showed maximum activity at 20 % NaCl concentration. Further, manganese chloride, magnesium chloride, calcium chloride and barium chloride influenced this enzyme activity remarkably and it was also found to be enhanced by many of the tested surfactants and solvents. The candidate bacterium effectively deproteinized the shrimp shell waste compared to the other tested crustaceans shell wastes and also attained maximum antioxidant activity.

  2. 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.

  3. 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.

  4. Characterization of lignocellulolytic activities from a moderate halophile strain of Aspergillus caesiellus isolated from a sugarcane bagasse fermentation.

    Directory of Open Access Journals (Sweden)

    Ramón Alberto Batista-García

    Full Text Available A moderate halophile and thermotolerant fungal strain was isolated from a sugarcane bagasse fermentation in the presence of 2 M NaCl that was set in the laboratory. This strain was identified by polyphasic criteria as Aspergillus caesiellus. The fungus showed an optimal growth rate in media containing 1 M NaCl at 28°C and could grow in media added with up to 2 M NaCl. This strain was able to grow at 37 and 42°C, with or without NaCl. A. caesiellus H1 produced cellulases, xylanases, manganese peroxidase (MnP and esterases. No laccase activity was detected in the conditions we tested. The cellulase activity was thermostable, halostable, and no differential expression of cellulases was observed in media with different salt concentrations. However, differential band patterns for cellulase and xylanase activities were detected in zymograms when the fungus was grown in different lignocellulosic substrates such as wheat straw, maize stover, agave fibres, sugarcane bagasse and sawdust. Optimal temperature and pH were similar to other cellulases previously described. These results support the potential of this fungus to degrade lignocellulosic materials and its possible use in biotechnological applications.

  5. In vivo characterization of the homing endonuclease within the polB gene in the halophilic archaeon Haloferax volcanii.

    Directory of Open Access Journals (Sweden)

    Adit Naor

    Full Text Available Inteins are parasitic genetic elements, analogous to introns that excise themselves at the protein level by self-splicing, allowing the formation of functional non-disrupted proteins. Many inteins contain a homing endonuclease (HEN gene, and rely on its activity for horizontal propagation. In the halophilic archaeon, Haloferax volcanii, the gene encoding DNA polymerase B (polB contains an intein with an annotated but uncharacterized HEN. Here we examine the activity of the polB HEN in vivo, within its natural archaeal host. We show that this HEN is highly active, and able to insert the intein into both a chromosomal target and an extra-chromosomal plasmid target, by gene conversion. We also demonstrate that the frequency of its incorporation depends on the length of the flanking homologous sequences around the target site, reflecting its dependence on the homologous recombination machinery. Although several evolutionary models predict that the presence of an intein involves a change in the fitness of the host organism, our results show that a strain deleted for the intein sequence shows no significant changes in growth rate compared to the wild type.

  6. Quaternary ammonium salt containing soybean oil: an efficient nanosize gene delivery carrier for halophile green microalgal transformation.

    Science.gov (United States)

    Akbari, Fariba; Yari Khosroushahi, Ahmad; Yeganeh, Hamid

    2015-01-01

    Dunaliella salina, a halophile green microalga, is considered a robust photobioreactor and a remarkable cost beneficial system for the production of therapeutic recombinant proteins. In this study, with low overall cost, a proper cationic lipid was synthesized from renewable soybean oil as an efficient gene delivery carrier for D. salina cells to create appropriate protein-producing transformed cell lines. To obtain an effective carrier, quaternary ammonium salt containing soybean oil (QASSO) was synthesized through the ring opening reaction of the epoxy groups of epoxidized soybean oil with diethylamine. QASSO was characterized using nuclear magnetic resonance and Fourier-transform infrared instruments. QASSO was used to prepare nanolipoplex construct using plasmid DNA molecules containing green fluorescent protein (GFP) as reporter gene. These nanolipoplexes (QASSO-pGFP, N/P=3) and QASSO had diameter of 63.62 and 110.63 nm, and zeta potential of -68.89 and 48.25 mV at pH 7.0, respectively. Results indicated the GFP gene expression and cytoplasmic accumulation of GFP protein in the transformants after incubation under desirable conditions for 48 h and 1 week. The transformation efficiency was quantitatively assayed by flow cytometry, which yielded transformations of 58.87% and 48.34% for QASSO and 38.32% and a negligible percentage for Polyfect® after 48 h and 1 week incubation, respectively.

  7. Weather and Climate Extremes.

    Science.gov (United States)

    1997-09-01

    Antarctica’s highest (New Zealand Antarctic Society, 1974). This extreme exceeded the record of 58°F (14.4°C) that occurred on 20 October 1956 at Esperanza ... Esperanza (also known as Bahia Esperanza , Hope Bay) was in operation from 1945 through the early 1960s. Meteorological/Climatological Factors: This extreme...cm) Location: Grand Ilet, La R’eunion Island [21°00’S, 55°30’E] Date: 26 January 1980 WORLD’S GREATEST 24-HOUR RAINFALL 72 in (182.5 cm

  8. Adventure and Extreme Sports.

    Science.gov (United States)

    Gomez, Andrew Thomas; Rao, Ashwin

    2016-03-01

    Adventure and extreme sports often involve unpredictable and inhospitable environments, high velocities, and stunts. These activities vary widely and include sports like BASE jumping, snowboarding, kayaking, and surfing. Increasing interest and participation in adventure and extreme sports warrants understanding by clinicians to facilitate prevention, identification, and treatment of injuries unique to each sport. This article covers alpine skiing and snowboarding, skateboarding, surfing, bungee jumping, BASE jumping, and whitewater sports with emphasis on epidemiology, demographics, general injury mechanisms, specific injuries, chronic injuries, fatality data, and prevention. Overall, most injuries are related to overuse, trauma, and environmental or microbial exposure.

  9. Extremal graph theory

    CERN Document Server

    Bollobas, Bela

    2004-01-01

    The ever-expanding field of extremal graph theory encompasses a diverse array of problem-solving methods, including applications to economics, computer science, and optimization theory. This volume, based on a series of lectures delivered to graduate students at the University of Cambridge, presents a concise yet comprehensive treatment of extremal graph theory.Unlike most graph theory treatises, this text features complete proofs for almost all of its results. Further insights into theory are provided by the numerous exercises of varying degrees of difficulty that accompany each chapter. A

  10. Extremity perfusion for sarcoma

    NARCIS (Netherlands)

    Hoekstra, Harald Joan

    2008-01-01

    For more than 50 years, the technique of extremity perfusion has been explored in the limb salvage treatment of local, recurrent, and multifocal sarcomas. The "discovery" of tumor necrosis factor-or. in combination with melphalan was a real breakthrough in the treatment of primarily irresectable ext

  11. Hydrological extremes and security

    Science.gov (United States)

    Kundzewicz, Z. W.; Matczak, P.

    2015-04-01

    Economic losses caused by hydrological extremes - floods and droughts - have been on the rise. Hydrological extremes jeopardize human security and impact on societal livelihood and welfare. Security can be generally understood as freedom from threat and the ability of societies to maintain their independent identity and their functional integrity against forces of change. Several dimensions of security are reviewed in the context of hydrological extremes. The traditional interpretation of security, focused on the state military capabilities, has been replaced by a wider understanding, including economic, societal and environmental aspects that get increasing attention. Floods and droughts pose a burden and serious challenges to the state that is responsible for sustaining economic development, and societal and environmental security. The latter can be regarded as the maintenance of ecosystem services, on which a society depends. An important part of it is water security, which can be defined as the availability of an adequate quantity and quality of water for health, livelihoods, ecosystems and production, coupled with an acceptable level of water-related risks to people, environments and economies. Security concerns arise because, over large areas, hydrological extremes - floods and droughts - are becoming more frequent and more severe. In terms of dealing with water-related risks, climate change can increase uncertainties, which makes the state's task to deliver security more difficult and more expensive. However, changes in population size and development, and level of protection, drive exposure to hydrological hazards.

  12. Acute lower extremity ischaemia

    African Journals Online (AJOL)

    tend to impact at arterial bifurcations, the commonest site being the ... Other ominous signs of advanced ischaemia include bluish ... Recommended standards for lower extremity ischaemia*. Doppler signals ... of the embolectomy procedure. An ... in a cath-lab or angio-suite under local ... We serially measure the aPTT and.

  13. Extremity perfusion for sarcoma

    NARCIS (Netherlands)

    Hoekstra, Harald Joan

    2008-01-01

    For more than 50 years, the technique of extremity perfusion has been explored in the limb salvage treatment of local, recurrent, and multifocal sarcomas. The "discovery" of tumor necrosis factor-or. in combination with melphalan was a real breakthrough in the treatment of primarily irresectable

  14. Statistics of Local Extremes

    DEFF Research Database (Denmark)

    Larsen, Gunner Chr.; Bierbooms, W.; Hansen, Kurt Schaldemose

    2003-01-01

    . A theoretical expression for the probability density function associated with local extremes of a stochasticprocess is presented. The expression is basically based on the lower four statistical moments and a bandwidth parameter. The theoretical expression is subsequently verified by comparison with simulated...

  15. de Sitter Extremal Surfaces

    CERN Document Server

    Narayan, K

    2015-01-01

    We study extremal surfaces in de Sitter space in the Poincare slicing in the upper patch, anchored on spatial subregions at the future boundary ${\\cal I}^+$, restricted to constant boundary Euclidean time slices (focussing on strip subregions). We find real extremal surfaces of minimal area as the boundaries of past lightcone wedges of the subregions in question: these are null surfaces with vanishing area. We find also complex extremal surfaces as complex extrema of the area functional, and the area is not always real-valued. In $dS_4$ the area is real and has some structural resemblance with entanglement entropy in a dual $CFT_3$. There are parallels with analytic continuation from the Ryu-Takayanagi expressions for holographic entanglement entropy in $AdS$. We also discuss extremal surfaces in the $dS$ black brane and the de Sitter "bluewall" studied previously. The $dS_4$ black brane complex surfaces exhibit a real finite cutoff-independent extensive piece. In the bluewall geometry, there are real surface...

  16. Moving in extreme environments

    DEFF Research Database (Denmark)

    Lucas, Samuel J E; Helge, Jørn W; Schütz, Uwe H W

    2016-01-01

    and transcontinental races) and expeditions (e.g. polar crossings), to the more gravitationally limited load carriage (e.g. in the military context). Juxtaposed to these circumstances is the extreme metabolic and mechanical unloading associated with space travel, prolonged bedrest and sedentary lifestyle, which may...

  17. 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.

  18. Alkalibacillus halophilus subsp.hitensis subsp.nov.:A new subspecies of moderately halophilic bacterium isolated from a chemical plant in China

    Institute of Scientific and Technical Information of China (English)

    LI Wei-guo; MA Fang; WEI Li; LI Li-ping; SU Jun-feng

    2009-01-01

    In order to develop halophilic microorganism resources to improve environment,a Gram-positive,strictlv aerobic and moderately halophilic bacterial strain JSAI Was obtained from the waste water sample col-lected from Jinhong Chemical Plant at Weihai city,by the methods of quick isolation and screening of halophilic bacteria.Systematic studies on it were carried out.Results show that the strain JSAl is bacillus.The temperature range most suitable for its growth is 29-35℃and the most suitable pH is 6.5-9.0.It Can grow well at the salt mass concentration of 30-150 g/L.The C+G mole fraction of its DNA is 37.5%.The analytical result of 16S rRNA gene sequence reveals that this strain has the closest relationship with Alkalibacillus halophihts(DQ359731)of Alkalibacillus.Their similarities are as high as 99%.However,they have obvious differences in aspects of whole-cell main fatty acid components,cell size,cell morphology,motility,oxidase,gelatine liquefication,NaCI tolerance range,pH tolerance range,G+C mole fraction,sole carbon source,sole nitrogen source.antibiotic sensitivity and strain source.Comparing with other species of the same genus,differ-ences of this strain are even more obvious. In view of multiple identification results,we believe this strain iS a new subsDecies of Alkalibacillus halophilus and name it Alkalibacillus halophilus subsp.hitensis subsp.nov.

  19. Halococcus salifodinae sp. nov., an Archaeal Isolate from an Austrian Salt Mine

    Science.gov (United States)

    Denner, Ewald B. M.; McGenity, Terry J.; Busse, Hans-Jurgen; Grant, William D.; Wanner, Gerhard; Stan-Lotter, Helga

    1994-01-01

    A novel extremely halophilic archaeon (archaebacterium) was isolated from rock salt obtained from an Austrian salt mine. The deposition of the salt is thought to have occurred during the Permian period (225 x 106 to 280 x 10(exp 6) years ago). This organism grew over a pH range of 6.8 to 9.5. Electron microscopy revealed cocci in tetrads or larger clusters. The partial 16S rRNA sequences, polar lipid composition, and menaquinone content suggested that this organism was related to members of the genus Halococcus, while the whole-cell protein patterns, the presence of several unknown lipids, and the presence of pink pigmentation indicated that it was different from previously described coccoid halophiles. We propose that this isolate should be recognized as a new species and should be named Halococcus salifodinae. The type strain is Bl(sub p) (= ATCC 51437 = DSM 8989). A chemotaxonomically similar microorganism was isolated from a British salt mine.

  20. Purification and Characterization of a Polyextremophilic α -Amylase from an Obligate Halophilic Aspergillus penicillioides Isolate and Its Potential for Souse with Detergents

    OpenAIRE

    Imran Ali; Ali Akbar; Mohammad Anwar; Sehanat Prasongsuk; Pongtharin Lotrakul; Hunsa Punnapayak

    2015-01-01

    An extracellular α-amylase from the obligate halophilic Aspergillus penicillioides TISTR3639 strain was produced and enriched to apparent homogeneity by ammonium sulfate precipitation and Sephadex G100 gel filtration column chromatography. The mass of the purified amylase was estimated to be 42 kDa by SDS-PAGE. With soluble starch as the substrate it had a specific activity of 118.42 U·mg−1 and V max⁡ and K m values of 1.05 µmol·min−1·mg−1 and 5.41 mg·mL−1, respectively. The enzyme was found ...

  1. Classification and Identification of A Moderately Halophilic Bacterium%一株中度嗜盐菌的分类鉴定

    Institute of Scientific and Technical Information of China (English)

    韩秋菊; 宋旺官

    2011-01-01

    This paper mainly studied the classification and identification of a moderately halophilic bacterium strain HS1. The results showed that strain HS1 belonged to Marinobacter by morphological characteristics,stainning reactions, physiological and biochemical characteristics. And its enzyme-production performance was preliminarily studied also.%通过对一株中度嗜盐菌HS1的形态特征鉴定、染色反应以及生理生化特性鉴定,确定嗜盐菌HSI为海杆菌属(Marinobacter),同时对其产酶特性进行了初步研究.

  2. Non-extremal branes

    Directory of Open Access Journals (Sweden)

    Pablo Bueno

    2015-04-01

    Full Text Available We prove that for arbitrary black brane solutions of generic Supergravities there is an adapted system of variables in which the equations of motion are exactly invariant under electric–magnetic duality, i.e. the interchange of a given extended object by its electromagnetic dual. We obtain thus a procedure to automatically construct the electromagnetic dual of a given brane without needing to solve any further equation. We apply this procedure to construct the non-extremal (p,q-string of Type-IIB String Theory (new in the literature, explicitly showing how the dual (p,q-five-brane automatically arises in this construction. In addition, we prove that the system of variables used is suitable for a generic characterization of every double-extremal Supergravity brane solution, which we perform in full generality.

  3. Tibetans at extreme altitude.

    Science.gov (United States)

    Wu, Tianyi; Li, Shupin; Ward, Michal P

    2005-01-01

    Between 1960 and 2003, 13 Chinese expeditions successfully reached the summit of Chomolungma (Mt Everest or Sagarmatha). Forty-five of the 80 summiteers were Tibetan highlanders. During these and other high-altitude expeditions in Tibet, a series of medical and physiological investigations were carried out on the Tibetan mountaineers. The results suggest that these individuals are better adapted to high altitude and that, at altitude, they have a greater physical capacity than Han (ethnic Chinese) lowland newcomers. They have higher maximal oxygen uptake, greater ventilation, more brisk hypoxic ventilatory responses, larger lung volumes, greater diffusing capacities, and a better quality of sleep. Tibetans also have a lower incidence of acute mountain sickness and less body weight loss. These differences appear to represent genetic adaptations and are obviously significant for humans at extreme altitude. This paper reviews what is known about the physiologic responses of Tibetans at extreme altitudes.

  4. Extremal periodic wave profiles

    Directory of Open Access Journals (Sweden)

    E. van Groesen

    2007-01-01

    Full Text Available As a contribution to deterministic investigations into extreme fluid surface waves, in this paper wave profiles of prescribed period that have maximal crest height will be investigated. As constraints the values of the momentum and energy integrals are used in a simplified description with the KdV model. The result is that at the boundary of the feasible region in the momentum-energy plane, the only possible profiles are the well known cnoidal wave profiles. Inside the feasible region the extremal profiles of maximal crest height are "cornered" cnoidal profiles: cnoidal profiles of larger period, cut-off and periodically continued with the prescribed period so that at the maximal crest height a corner results.

  5. Extreme Photonics & Applications

    CERN Document Server

    Hall, Trevor J; Paredes, Sofia A

    2010-01-01

    "Extreme Photonics & Applications" arises from the 2008 NATO Advanced Study Institute in Laser Control & Monitoring in New Materials, Biomedicine, Environment, Security and Defense. Leading experts in the manipulation of light offered by recent advances in laser physics and nanoscience were invited to give lectures in their fields of expertise and participate in discussions on current research, applications and new directions. The sum of their contributions to this book is a primer for the state of scientific knowledge and the issues within the subject of photonics taken to the extreme frontiers: molding light at the ultra-finest scales, which represents the beginning of the end to limitations in optical science for the benefit of 21st Century technological societies. Laser light is an exquisite tool for physical and chemical research. Physicists have recently developed pulsed lasers with such short durations that one laser shot takes the time of one molecular vibration or one electron rotation in an ...

  6. Extremal Hairy Black Holes

    CERN Document Server

    Gonzalez, P A; Saavedra, Joel; Vasquez, Yerko

    2014-01-01

    We consider a gravitating system consisting of a scalar field minimally coupled to gravity with a self-interacting potential and an U(1) electromagnetic field. Solving the coupled Einstein-Maxwell-scalar system we find exact hairy charged black hole solutions with the scalar field regular everywhere. We go to the zero temperature limit and we study the effect of the scalar field on the near horizon geometry of an extremal black hole. We find that except a critical value of the charge of the black hole there is also a critical value of the charge of the scalar field beyond of which the extremal black hole is destabilized. We study the thermodynamics of these solutions and we find that if the space is flat then at low temperature the Reissner-Nordstr\\"om black hole is thermodynamically preferred, while if the space is AdS the hairy charged black hole is thermodynamically preferred at low temperature.

  7. Religious Extremism in Pakistan

    Science.gov (United States)

    2014-12-01

    Face (July 2008): 32. 21 Ahmed Rashid , Pakistan on the Brink: The Future of America, Pakistan, and Afghanistan (New York: Viking, 2012). 22 Brian J...promoting extremism. Commentators such as Jessica Stern, Alan Richards, Hussain Haqqani, Ahmed Rashid , and Ali Riaz are a few of the scholars who...www.jstor.org/stable/3183558; See also Ahmed Rashid , Descent Into Chaos: The United States and the Failure of Nation Building in Pakistan, Afghanistan, and

  8. USACE Extreme Sea levels

    Science.gov (United States)

    2014-03-14

    report summarising the results of the research, together with a set of recommendations arising from the research. This report describes progress to...Southampton University at HR Wallingford and subsequent teleconference with Heidi Moritz and Kate White. The notes summarising the findings of the...suggestion was made that we may want to begin talking about extreme water levels separate from storms. Ivan mentioned an analysis of storminess which

  9. Extreme geomagnetically induced currents

    Science.gov (United States)

    Kataoka, Ryuho; Ngwira, Chigomezyo

    2016-12-01

    We propose an emergency alert framework for geomagnetically induced currents (GICs), based on the empirically extreme values and theoretical upper limits of the solar wind parameters and of d B/d t, the time derivative of magnetic field variations at ground. We expect this framework to be useful for preparing against extreme events. Our analysis is based on a review of various papers, including those presented during Extreme Space Weather Workshops held in Japan in 2011, 2012, 2013, and 2014. Large-amplitude d B/d t values are the major cause of hazards associated with three different types of GICs: (1) slow d B/d t with ring current evolution (RC-type), (2) fast d B/d t associated with auroral electrojet activity (AE-type), and (3) transient d B/d t of sudden commencements (SC-type). We set "caution," "warning," and "emergency" alert levels during the main phase of superstorms with the peak Dst index of less than -300 nT (once per 10 years), -600 nT (once per 60 years), or -900 nT (once per 100 years), respectively. The extreme d B/d t values of the AE-type GICs are 2000, 4000, and 6000 nT/min at caution, warning, and emergency levels, respectively. For the SC-type GICs, a "transient alert" is also proposed for d B/d t values of 40 nT/s at low latitudes and 110 nT/s at high latitudes, especially when the solar energetic particle flux is unusually high.

  10. Extremes in nature

    CERN Document Server

    Salvadori, Gianfausto; Kottegoda, Nathabandu T

    2007-01-01

    This book is about the theoretical and practical aspects of the statistics of Extreme Events in Nature. Most importantly, this is the first text in which Copulas are introduced and used in Geophysics. Several topics are fully original, and show how standard models and calculations can be improved by exploiting the opportunities offered by Copulas. In addition, new quantities useful for design and risk assessment are introduced.

  11. 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.

  12. Transgenic Arabidopsis expressing osmolyte glycine betaine synthesizing enzymes from halophilic methanogen promote tolerance to drought and salt stress.

    Science.gov (United States)

    Lai, Shu-Jung; Lai, Mei-Chin; Lee, Ren-Jye; Chen, Yu-Hsuan; Yen, Hungchen Emilie

    2014-07-01

    Glycine betaine (betaine) has the highest cellular osmoprotective efficiency which does not accumulate in most glycophytes. The biosynthetic pathway for betaine in higher plants is derived from the oxidation of low-accumulating metabolite choline that limiting the ability of most plants to produce betaine. Halophilic methanoarchaeon Methanohalophilus portucalensis FDF1(T) is a model anaerobic methanogen to study the acclimation of water-deficit stresses which de novo synthesize betaine by the stepwise methylation of glycine, catalyzed by glycine sarcosine N-methyltransferase (GSMT) and sarcosine dimethylglycine N-methyltransferase. In this report, genes encoding these betaine biosynthesizing enzymes, Mpgsmt and Mpsdmt, were introduced into Arabidopsis. The homozygous Mpgsmt (G), Mpsdmt (S), and their cross, Mpgsmt and Mpsdmt (G × S) plants showed increased accumulation of betaine. Water loss from detached leaves was slower in G, S, and G × S lines than wild-type (WT). Pot-grown transgenic plants showed better growth than WT after 9 days of withholding water or irrigating with 300 mM NaCl. G, S, G × S lines also maintained higher relative water content and photosystem II activity than WT under salt stress. This suggests heterologously expressed Mpgsmt and Mpsdmt could enhance tolerance to drought and salt stress in Arabidopsis. We also found a twofold increase in quaternary ammonium compounds in salt-stressed leaves of G lines, presumably due to the activation of GSMT activity by high salinity. This study demonstrates that introducing stress-activated enzymes is a way of avoiding the divergence of primary metabolites under normal growing conditions, while also providing protection in stressful environments.

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

    Science.gov (United States)

    Cabrera, Antonio; Aguilera, Margarita; Fuentes, Susana; Incerti, Claudia; Russell, Nick J; Ramos-Cormenzana, Alberto; Monteoliva-Sánchez, Mercedes

    2007-02-01

    A 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 colonies. Strain CG2.1T was able to grow at salinities of 3-25 % (w/v) and at temperatures of 15-40 degrees C. The pH range for growth was 5-9. Strain CG2.1T was a heterotroph capable of utilizing various carbohydrates as carbon sources. The organism reduced nitrate and showed phenylalanine deaminase activity. The major fatty acids were C(18 : 1)omega7c, C(16 : 0) and C(19 : 0) cyclo omega8c. The DNA G+C content was 60.9 mol%. On the basis of the phenotypic and phylogenetic data, strain CG2.1T appeared to be a member of the genus Halomonas and clustered closely with Halomonas marisflavi (97.1 % 16S rRNA gene sequence similarity). However, the level of DNA-DNA relatedness between the novel isolate and the most closely related Halomonas species was low. On the basis of these data, strain CG2.1T represents a novel member of the genus Halomonas, for which the name Halomonas indalinina is proposed. The type strain is CG2.1T (=CECT 5902T=LMG 23625T).

  14. The Potential Biotechnological Applications of the Exopolysaccharide Produced by the Halophilic Bacterium Halomonas almeriensis

    Directory of Open Access Journals (Sweden)

    Victoria Béjar

    2012-06-01

    Full Text Available We have studied the extracellular polysaccharide (EPS produced by the type strain, M8T, of the halophilic bacterium Halomonas almeriensis, to ascertain whether it might have any biotechnological applications. All the cultural parameters tested influenced both bacterial growth and polysaccharide production. EPS production was mainly growth-associated and under optimum environmental and nutritional conditions M8T excreted about 1.7 g of EPS per litre of culture medium (about 0.4 g of EPS per gram of dry cell weight. Analysis by anion-exchange chromatography and high-performance size-exclusion chromatography indicated that the exopolysaccharide was composed of two fractions, one of 6.3 × 106 and another of 1.5 × 104 Daltons. The monosaccharide composition of the high-molecular-weight fraction was mannose (72% w/w, glucose (27.5% w/w and rhamnose (0.5% w/w. The low-molecular-weight fraction contained mannose (70% w/w and glucose (30% w/w. The EPS has a substantial protein fraction (1.1% w/w and was capable of emulsifying several hydrophobic substrates, a capacity presumably related to its protein content. The EPS produced solutions of low viscosity with pseudoplastic behaviour. It also had a high capacity for binding some cations. It contained considerable quantities of sulphates (1.4% w/w, an unusual feature in bacterial polysaccharides. All these characteristics render it potentially useful as a biological agent, bio-detoxifier and emulsifier.

  15. Virgibacillus albus sp. nov., a novel moderately halophilic bacterium isolated from Lop Nur salt lake in Xinjiang province, China.

    Science.gov (United States)

    Zhang, Yun-Jiao; Zhou, Yu; Ja, Man; Shi, Rong; Chun-Yu, Wei-Xun; Yang, Ling-Ling; Tang, Shu-Kun; Li, Wen-Jun

    2012-11-01

    A Gram-positive, moderately halophilic, strictly aerobic bacterium, designated YIM 93624(T), was isolated from a salt lake in Xinjiang province of China and subjected to a polyphasic taxonomic study. Strain YIM 93624(T) grew at 15-45 °C (optimum 25-30 °C), 1-17% (w/v) NaCl (optimum 5-10 %, w/v) and pH 4.0-9.0 (optimum pH 7.0). The predominant menaquinone was found to be MK-7. The major fatty acids were anteiso-C(15:0) and C(16:0). The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, a glycolipid and two unidentified phospholipids. The cell-wall peptidoglycan contained meso-diaminopimelic acid. The G+C content of the genomic DNA was 37.9 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain YIM 93624(T) was a member of the genus Virgibacillus and exhibited the highest similarity of 97.0 % to Virgibacillus koreensis KCTC 3823(T). However, the level of DNA-DNA relatedness between strain YIM 93624(T) and V. koreensis KCTC 3823(T) was 32.5 %. On the basis of phylogenetic, physiological and chemotaxonomic analysis data, the isolate is concluded to represent a novel species of the genus Virgibacillus, for which the name Virgibacillus albus sp. nov., is proposed, with type strain of YIM 93624(T) (=DSM 23711(T) = JCM 17364(T)).

  16. Bacillus aidingensis sp. nov., a moderately halophilic bacterium isolated from Ai-Ding salt lake in China.

    Science.gov (United States)

    Xue, Yanfen; Ventosa, A; Wang, Xiaowei; Ren, Peigen; Zhou, Peijin; Ma, Yanhe

    2008-12-01

    A Gram-positive, halophilic bacterium was isolated from a sediment sample from Ai-Ding salt lake in China. The isolate, designated strain 17-5(T), grew at salinities of 8-33 % (w/v) NaCl (optimally at 12 %, w/v). The genomic DNA G+C content of strain 17-5(T) was 48.1 mol%. The predominant isoprenoid quinone was MK-7(H(2)) and the cell-wall peptidoglycan contained meso-diaminopimelic acid. The major polar lipids were diphosphatidylglycerol and an unidentified glycolipid. The major cellular fatty acids were anteiso-C(15 : 0), anteiso-C(17 : 0), iso-C(16 : 0) and C(16 : 0). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 17-5(T) was a member of the genus Bacillus, being most closely related to Bacillus qingdaonensis JCM 14087(T) (96.0 % sequence similarity) and Bacillus salarius DSM 16461(T) (95.6 %). The levels of 16S rRNA gene sequence similarity with respect to other Bacillus species were less than 91.7 %. Comparative analysis of the 16S rRNA gene sequence data, chemotaxonomy and phenotypic features of the novel isolate and related species of Bacillus indicated that strain 17-5(T) represents a novel species within the genus Bacillus, for which the name Bacillus aidingensis sp. nov. is proposed. The type strain is 17-5(T) (=CGMCC 1.3227(T)=DSM 18341(T)).

  17. 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.

  18. Ectoine and 5-hydroxyectoine accumulation in the halophile Virgibacillus halodenitrificans PDB-F2 in response to salt stress.

    Science.gov (United States)

    Tao, Ping; Li, Hui; Yu, Yunjiang; Gu, Jidong; Liu, Yongdi

    2016-08-01

    The moderately halophilic bacterium Virgibacillus halodenitrificans PDB-F2 copes with salinity by synthesizing or taking up compatible solutes. The main compatible solutes in this strain were ectoine and hydroxyectoine, as determined by (1)H nuclear magnetic resonance spectroscopy ((1)H-NMR). A high-performance liquid chromatography (HPLC) analysis showed that ectoine was the major solute that was synthesized in response to elevated salinity, while hydroxyectoine was a minor solute. However, the hydroxyectoine/ectoine ratio increased from 0.04 at 3 % NaCl to 0.45 at 15 % NaCl in the late exponential growth phase. A cluster of ectoine biosynthesis genes was identified, including three genes in the order of ectA, ectB, and ectC. The hydroxyectoine biosynthesis gene ectD was not part of the ectABC gene cluster. Reverse transcription-quantitative polymerase chain reactions (RT-qPCR) showed that the expression of the ect genes was salinity dependent. The expression of ectABC reached a maximum at 12 % NaCl, while ectD expression increased up to 15 % NaCl. Ectoine and hydroxyectoine production was growth phase dependent. The hydroxyectoine/ectoine ratio increased from 0.018 in the early exponential phase to 0.11 in the stationary phase at 5 % NaCl. Hydroxyectoine biosynthesis started much later than ectoine biosynthesis after osmotic shock, and the temporal expression of the ect genes differed under these conditions, with the ectABC genes being expressed first, followed by ectD gene. Increased culture salinity triggered ectoine or hydroxyectoine uptake when they were added to the medium. Hydroxyectoine was accumulated preferentially when both ectoine and hydroxyectoine were provided exogenously.

  19. Patterns and determinants of halophilic archaea (class halobacteria) diversity in tunisian endorheic salt lakes and sebkhet systems.

    Science.gov (United States)

    Najjari, Afef; Elshahed, Mostafa S; Cherif, Ameur; Youssef, Noha H

    2015-07-01

    We examined the diversity and community structure of members of the halophilic Archaea (class Halobacteria) in samples from central and southern Tunisian endorheic salt lakes and sebkhet (also known as sebkha) systems using targeted 16S rRNA gene diversity survey and quantitative PCR (qPCR) approaches. Twenty-three different samples from four distinct locations exhibiting a wide range of salinities (2% to 37%) and physical characteristics (water, salt crust, sediment, and biofilm) were examined. A total of 4,759 operational taxonomic units at the 0.03 (species-level) cutoff (OTU0.03s) belonging to 45 currently recognized genera were identified, with 8 to 43 genera (average, 30) identified per sample. In spite of the large number of genera detected per sample, only a limited number (i.e., 2 to 16) usually constituted the majority (≥80%) of encountered sequences. Halobacteria diversity showed a strong negative correlation to salinity (Pearson correlation coefficient = -0.92), and community structure analysis identified salinity, rather than the location or physical characteristics of the sample, as the most important factor shaping the Halobacteria community structure. The relative abundance of genera capable of biosynthesis of the compatible solute(s) trehalose or 2-sulfotrehalose decreased with increasing salinities (Pearson correlation coefficient = -0.80). Indeed, qPCR analysis demonstrated that the Halobacteria otsB (trehalose-6-phosphatase)/16S rRNA gene ratio decreases with increasing salinities (Pearson correlation coefficient = -0.87). The results highlight patterns and determinants of Halobacteria diversity at a previously unexplored ecosystem and indicate that genera lacking trehalose biosynthetic capabilities are more adapted to growth in and colonization of hypersaline (>25% salt) ecosystems than trehalose producers.

  20. Acidophilic Halophilic Microorganisms in Fluid Inclusions in Halite from Lake Magic, Western Australia

    Science.gov (United States)

    Conner, Amber J.

    2013-01-01

    Abstract Lake Magic is one of the most extreme of hundreds of ephemeral acid-saline lakes in southern Western Australia. It has pH as low as 1.7, salinity as high as 32% total dissolved solids, temperatures ranging from 0°C to 50°C, and an unusually complex aqueous composition. Optical petrography, UV-vis petrography, and laser Raman spectrometry were used to detect microorganisms and organic compounds within primary fluid inclusions in modern bedded halite from Lake Magic. Rare prokaryotes appear as 1–3 μm, bright cocci that fluoresce green with UV-vis illumination. Dimpled, 5–7 μm yellow spherules that fluoresce blue with UV-vis illumination are interpreted as Dunaliella algae. Yellow-orange beta-carotene crystals, globules, and coatings are characterized by orange-red fluorescence and three distinct Raman peaks. Because acid saline lakes are good Mars analogues, the documentation of prokaryotes, eukaryotes, and organic compounds preserved in the halite here has implications for the search for life on Mars. Missions to Mars should incorporate such in situ optical and chemical examination of martian evaporites for possible microorganisms and/or organic compounds in fluid inclusions. Key Words: Acid—Extremophiles—Western Australia—Fluid inclusions—Lake Magic—Dunaliella. Astrobiology 13, 850–860. PMID:23971647

  1. Acidophilic halophilic microorganisms in fluid inclusions in halite from Lake Magic, Western Australia.

    Science.gov (United States)

    Conner, Amber J; Benison, Kathleen C

    2013-09-01

    Lake Magic is one of the most extreme of hundreds of ephemeral acid-saline lakes in southern Western Australia. It has pH as low as 1.7, salinity as high as 32% total dissolved solids, temperatures ranging from 0°C to 50°C, and an unusually complex aqueous composition. Optical petrography, UV-vis petrography, and laser Raman spectrometry were used to detect microorganisms and organic compounds within primary fluid inclusions in modern bedded halite from Lake Magic. Rare prokaryotes appear as 1-3 μm, bright cocci that fluoresce green with UV-vis illumination. Dimpled, 5-7 μm yellow spherules that fluoresce blue with UV-vis illumination are interpreted as Dunaliella algae. Yellow-orange beta-carotene crystals, globules, and coatings are characterized by orange-red fluorescence and three distinct Raman peaks. Because acid saline lakes are good Mars analogues, the documentation of prokaryotes, eukaryotes, and organic compounds preserved in the halite here has implications for the search for life on Mars. Missions to Mars should incorporate such in situ optical and chemical examination of martian evaporites for possible microorganisms and/or organic compounds in fluid inclusions.

  2. Extreme Programming Pocket Guide

    CERN Document Server

    Chromatic

    2003-01-01

    Extreme Programming (XP) is a radical new approach to software development that has been accepted quickly because its core practices--the need for constant testing, programming in pairs, inviting customer input, and the communal ownership of code--resonate with developers everywhere. Although many developers feel that XP is rooted in commonsense, its vastly different approach can bring challenges, frustrations, and constant demands on your patience. Unless you've got unlimited time (and who does these days?), you can't always stop to thumb through hundreds of pages to find the piece of info

  3. Mycetoma of lower extremity

    Directory of Open Access Journals (Sweden)

    Sahariah S

    1978-01-01

    Full Text Available Ten cases of mycetoma of the lower extremity were seen and treated at the Postgraduate Institute of Medical Education & Research, Chandigarh, India, during the years 1973 to 1975. Six were treated by conservative method e.g. antibiotics, sulfonamides and immobilization of the part while remaining four were submitted t o surgery. Four out o f six from the first group had recurrence and has been put on second line of therapy. Recurrence occurred in only one case from the second group and he required an above knee amputation while the remaining three are free of disease and are well rehabilitated.

  4. Metagenomics of extreme environments.

    Science.gov (United States)

    Cowan, D A; Ramond, J-B; Makhalanyane, T P; De Maayer, P

    2015-06-01

    Whether they are exposed to extremes of heat or cold, or buried deep beneath the Earth's surface, microorganisms have an uncanny ability to survive under these conditions. This ability to survive has fascinated scientists for nearly a century, but the recent development of metagenomics and 'omics' tools has allowed us to make huge leaps in understanding the remarkable complexity and versatility of extremophile communities. Here, in the context of the recently developed metagenomic tools, we discuss recent research on the community composition, adaptive strategies and biological functions of extremophiles.

  5. Characterizing Extreme Ionospheric Storms

    Science.gov (United States)

    Sparks, L.; Komjathy, A.; Altshuler, E.

    2011-12-01

    Ionospheric storms consist of disturbances of the upper atmosphere that generate regions of enhanced electron density typically lasting several hours. Depending upon the storm magnitude, gradients in electron density can sometimes become large and highly localized. The existence of such localized, dense irregularities is a major source of positioning error for users of the Global Positioning System (GPS). Consequently, satellite-based augmentation systems have been implemented to improve the accuracy and to ensure the integrity of user position estimates derived from GPS measurements. Large-scale irregularities generally do not pose a serious threat to estimate integrity as they can be readily detected by such systems. Of greater concern, however, are highly localized irregularities that interfere with the propagation of a signal detected by a user measurement but are poorly sampled by the receivers in the system network. The most challenging conditions have been found to arise following disturbances of large magnitude that occur only rarely over the course of a solar cycle. These extremely disturbed conditions exhibit behavior distinct from moderately disturbed conditions and, hence, have been designated "extreme storms". In this paper we examine and compare the behavior of the extreme ionospheric storms of solar cycle 23 (or, more precisely, extreme storms occurring between January 1, 2000, and December 31, 2008), as represented in maps of vertical total electron content. To identify these storms, we present a robust means of quantifying the regional magnitude of an ionospheric storm. Ionospheric storms are observed frequently to occur in conjunction with magnetic storms, i.e., periods of geophysical activity as measured by magnetometers. While various geomagnetic indices, such as the disturbance storm time (Dst) and the planetary Kp index, have long been used to rank the magnitudes of distinct magnetic storms, no comparable, generally recognized index exists for

  6. 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.

  7. Bacillus coahuilensis sp. nov., a moderately halophilic species from a desiccation lagoon in the Cuatro Ciénegas Valley in Coahuila, Mexico.

    Science.gov (United States)

    Cerritos, René; Vinuesa, Pablo; Eguiarte, Luis E; Herrera-Estrella, Luis; Alcaraz-Peraza, Luis D; Arvizu-Gómez, Jackeline L; Olmedo, Gabriela; Ramirez, Enrique; Siefert, Janet L; Souza, Valeria

    2008-04-01

    A moderately halophilic, Gram-positive and rod-shaped bacterium, strain m4-4T, was isolated from a Chihuahuan desert lagoon in Cuatro Ciénegas, Coahuila, Mexico. Strain m4-4T was found to grow optimally at 30-37 degrees C, pH 7.0-8.0 and 5 % NaCl and to tolerate from 0.5 % to 10 % NaCl. It was shown to be aerobic. The genomic DNA G+C content was about 37 mol%. Strain m4-4T exhibited minimal or no growth on most sugars tested. Its major cellular fatty acids were C14 : 0, C16 : 0 and C18 : 1. Based on phylogenetic analysis of 16S rRNA and recA gene sequences, we observed that the closest relatives of the isolate are moderately halophilic Bacillus species, with 16S rRNA gene sequence similarity ranging from 96.6 to 97.4 % (Bacillus marisflavi, Bacillus aquimaris and Bacillus vietnamensis). Additionally, using genomic data it was determined that the type strain contains a total of nine rRNA operons with three slightly different sequences. On the basis of phenotypic and molecular properties, strain m4-4T represents a novel species within the genus Bacillus, for which the name Bacillus coahuilensis sp. nov. is proposed, with the type strain m4-4T (=NRRL B-41737T =CECT 7197T).

  8. 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.

  9. Application research on halophilic bacteria in high-salinity wastewater treatment%嗜盐菌在高盐废水处理中的应用研究

    Institute of Scientific and Technical Information of China (English)

    向菲; 王弘宇; 姜宇

    2012-01-01

    Halophilic bacteria is a kind of bacteria with normal growth and metabolism under high-salinity environment. Simultaneously, it has a function of degrading organics, which makes it possible of biological treatment method to processing high-salinity wastewater. The paper discusses the classification, characteristics and mechanism of halophilic bacteria, and overviews the research progress of high-salinity wastewater treatment at home and abroad, and finally makes a prospect about its application.%嗜盐菌是一类能在高盐环境下进行正常生长代谢的细菌,同时其具有降解有机物的功能,这使得生物法处理高盐废水成为可能,论述了嗜盐菌的分类、特性及作用机理,并综述了国内外高盐废水生物处理的研究进展,最后展望了其应用前景。

  10. 嗜盐嗜碱放线菌的研究进展与展望%Research on Progress of Halophilic Basophilic Actinomycetes

    Institute of Scientific and Technical Information of China (English)

    加苏尔·阿不都克里木; 旭格拉; 塔衣尔; 阿不都克里木·热依木; 木尼热木·阿力木江; 迪丽拜尔·托合提

    2015-01-01

    Haloalkaliphilic extremophiles were survied in saline alkali soil. Halophilic basophilic Actinomycetes with the genetic characteristics and the special supersedes way, produced a variety of secondary me⁃tabolites, was one of microbial resources with great application prospect. This paper mainly reviewed Halophilic ba⁃sophilic Actinomycetes Resources, standard classification, distribution, system science, development and utilization prospects.%嗜盐嗜碱极端微生物主要分布于地球上的盐碱土壤中,嗜盐嗜碱放线菌适应并长期生存这一特殊极端环境,已具备独特的遗传特性和新陈代谢途径,能够产生具有开发利用价值的多种次生代谢产物,是一类极具应用前景的微生物资源。文章主要综述了嗜盐嗜碱放线菌的资源、分类标准、分布、系统学及其发展趋势、开发利用前景。

  11. Research on Halophilic Bacteria’s Dispose of High Salinity Oil Extraction Wastewater%嗜盐菌处理高盐度采油废水研究

    Institute of Scientific and Technical Information of China (English)

    程硕

    2016-01-01

    Oil extraction wastewater has not onlyhigh temperature but high salinity and other physical and chemical properties which are easy to pollute soil and water. Currently, the effective governance of oil extraction wastewater is an urgent problem. Halophiles due to its special structure and properties, is often used to control high salinity wastewater. This paper reviews various methods and research progress of halophiles dealing with high salinity oil extraction wastewater, noting current problems and prospects for future development, aiming to provide reference for further research.%采油废水具有高温、高盐度等理化性质,易污染土壤和水源,因此其有效治理是当前急需解决的问题。嗜盐菌由于其特殊的结构和性质,常被用来治理高盐度污水。文章深入分析了嗜盐菌治理高盐度采油废水的各种方法以及研究进展,并指出目前存在的问题和今后发展的前景,对进一步研究具有十分重要的参考意义。

  12. Growth phase-dependent switch in osmolyte strategy in a moderate halophile: ectoine is a minor osmolyte but major stationary phase solute in Halobacillus halophilus.

    Science.gov (United States)

    Saum, Stephan H; Müller, Volker

    2008-03-01

    The moderately halophilic, chloride-dependent bacterium Halobacillus halophilus switches its osmolyte strategy with the salinity in its environment by the production of different compatible solutes. Ectoine is produced predominantly at very high salinities, along with proline. Interestingly, ectoine production is growth phase dependent which led to a more than 1000-fold change in the ectoine : proline ratio from 0.04 in exponential to 27.4 in late stationary phase cultures. The genes encoding the ectoine biosynthesis pathway were identified on the chromosome in the order ectABC. They form an operon that is expressed in a salinity-dependent manner with low-level expression below 1.5 M NaCl but 10-fold and 23-fold increased expression at 2.5 and 3.0 M NaCl respectively. The temporal expression of genes involved in osmoresponse is different with gdh/gln and pro genes being first, followed by ect genes. Chloride had no effect on expression of ect genes, but stimulated cellular EctC synthesis as well as ectoine production. These data demonstrate, for the first time, a growth-phase dependent switch in osmolyte strategy in a moderate halophile and, additionally, represent another piece of the chloride regulon of H. halophilus.

  13. Denitrification in a binary culture and thiocyanate metabolism in Thiohalophilus thiocyanoxidans gen. nov. sp. nov. - a moderately halophilic chemolithoautotrophic sulfur-oxidizing Gammaproteobacterium from hypersaline lakes.

    Science.gov (United States)

    Sorokin, Dimitry Y; Tourova, Tatjana P; Bezsoudnova, Ekatherina Y; Pol, Arjan; Muyzer, Gerard

    2007-06-01

    Anaerobic enrichment culture with thiocyanate as electron donor and nitrate as electron acceptor at 2 M NaCl inoculated with a mixture of sediments from hypersaline lakes in Kulunda Steppe (Altai, Russia) resulted in a selection of a binary consortium of moderately halophilic, obligately chemolithoautotrophic sulfur-oxidizing bacteria (SOB) capable of complete denitrification of nitrate with thiosulfate as the electron donor. One consortium member, strain HRhD 3sp, was isolated into pure culture with nitrate and thiosulfate using a density gradient. This strain was responsible for the reduction of nitrate to nitrite in the consortium, while a second strain, HRhD 2, isolated under microoxic conditions with thiosulfate as substrate, was capable of anaerobic growth with nitrite and thiosulfate. Nitrite, either as substrate or as product, was already toxic at very low concentrations for both strains. As a result, optimal growth under anaerobic conditions could only be achieved within the consortium. On the basis of phylogenetic analysis, both organisms were identified as new lineages within the Gammaproteobacteria. As well as thiosulfate, strain HRhD 2 can also use thiocyanate as electron donor, representing a first halophilic SOB capable of growth with thiocyanate at 2-4 M NaCl. Product and enzymatic analysis identified the "carbonyl sulfide (COS) pathway" of primary thiocyanate degradation in this new species. On the basis of phenotypic and genetic analysis, strain HRhD 2 is proposed to be assigned to a new genus and species Thiohalophilus thiocyanoxidans.

  14. Winter Storms and Extreme Cold

    Science.gov (United States)

    ... Landslides & Debris Flow Nuclear Blast Nuclear Power Plants Power Outages Pandemic Radiological Dispersion Device Severe Weather Snowstorms & Extreme ... Landslides & Debris Flow Nuclear Blast Nuclear Power Plants Power Outages Pandemic Radiological Dispersion Device Severe Weather Snowstorms & Extreme ...

  15. Factors Contributing to Short-cut Nitrification in Halophilic Activated Sludge Treating Highly Saline Domestic Wastewater%嗜盐污泥处理高盐生活污水的短程硝化及其诱因辨析

    Institute of Scientific and Technical Information of China (English)

    崔有为; 丁洁然; 李晶; 陈叶菲; 苏贺

    2012-01-01

    Halophilic activated sludge was developed by seeding with sediment of the estuary to the sea. During 120d operation, stable short-cut nitrification was achieved in SBRs treating saline domestic wastewater containing 30 ± 2g/L salts. Based on the short-cut nitrification theory of fresh activated sludge, this study evaluated some key process factors possibly contributing to nitrite accumulation such as pH,free ammonium (FA) , temperature, dissolved oxygen ( DO ) and aeration time. The results showed the optimal pH and salinity of halophilic activated sludge was 7.5-9g/L and 10-61 g/L,respectively. Aeration time and FA was not the reasons inducing high nitrite accumulation. Salinity and temperature have impact on both the ammonium oxidizing bacteria(AOB) and the nitrite oxidizing bacteria ( NOB). However, the activity of halophilic AOB remained higher than halophilic NOB during the experiment. Fluorescence in situ hybridization (FISH) for visualizing nitrification community of the sediments and the halophilic activated sludge showed that AOB was the dominant nitrifiers in the both biological systems. The high nitrite accumulation in halophilic activated sludge may be owed to two reasons, one is that halophilic AOB has higher substrate degrading rate than that of halophilic NOB, the other is that the dominant bacterial population is halophilic AOB other than halophilic NOB.%本研究采集入海口河底泥发展嗜盐活性污泥处理高盐生活污水,在SBR工艺连续运行的120d里取得了稳定的短程硝化.为了确定嗜盐污泥短程硝化的成因,研究基于淡水污泥短程硝化理论系统地分析了pH、游离氨(FA)、温度、溶解氧(DO)和曝气时间等关键工艺参数对嗜盐硝化系统内短程硝化的贡献.试验结果表明,嗜盐硝化系统最适宜盐度范围为10-61g/L,最佳pH范围为7.5-9.尽管盐度、温度对氨氧化菌(AOB)和亚硝酸氧化菌(NOB)的活性有一定的影响,但在测试的温度和盐度范围

  16. Molecular Structural Basis of Microbial Halophilic Enzymes Related to Their Haloadaptation%微生物嗜盐酶盐适应性的分子结构基础研究

    Institute of Scientific and Technical Information of China (English)

    阎松; 陈雷; 林秀坤

    2012-01-01

    由高盐环境中生长的微生物里分离出的嗜盐酶在高盐度下仍然具有催化活性,工业上具有良好的应用前景.一些嗜盐酶已被克隆纯化出来,它们的分子结构特点也已经被广泛研究.该文从嗜盐酶的蛋白质序列和结构特征等方面综述了嗜盐酶嗜盐的分子结构基础研究进展,分析了存在的问题并对未来工作提出了展望.研究嗜盐酶盐适应性的分子基础,可以为新的功能蛋白的发展和鉴定提供依据.%Halophilic enzymes are isolated from microorganisms lived in the environment with high salt concentration, and this kind of enzyme only functions under high salt conditions. Halophilic enzymes have been considered to have a variety of industrial applications due to their tolerance on salt. Some halophilic enzymes have been cloned and purified and their molecular structural properties have been widely studied. In the present review, the recent progresses of molecular structural basis of halophilic enzymes related to halophilic characteristics are presented. Some questions and the prospects of future studies are also discussed. This review will contribute to a further understanding of the molecular basis of haloadaptation in halophilic enzymes and will be helpful for developing and identifying functional novel proteins.

  17. Precipitation extremes under climate change

    CERN Document Server

    O'Gorman, Paul A

    2015-01-01

    The response of precipitation extremes to climate change is considered using results from theory, modeling, and observations, with a focus on the physical factors that control the response. Observations and simulations with climate models show that precipitation extremes intensify in response to a warming climate. However, the sensitivity of precipitation extremes to warming remains uncertain when convection is important, and it may be higher in the tropics than the extratropics. Several physical contributions govern the response of precipitation extremes. The thermodynamic contribution is robust and well understood, but theoretical understanding of the microphysical and dynamical contributions is still being developed. Orographic precipitation extremes and snowfall extremes respond differently from other precipitation extremes and require particular attention. Outstanding research challenges include the influence of mesoscale convective organization, the dependence on the duration considered, and the need to...

  18. "Triangular" extremal dilatonic dyons

    CERN Document Server

    Gal'tsov, Dmitri; Orlov, Dmitri

    2014-01-01

    Explicit dyonic dilaton black holes of the four-dimensional Einstein-Maxwell-dilaton theory are known only for two particular values of the dilaton coupling constant $a =1,\\sqrt{3}$, while for other $a$ numerical evidence was presented earlier about existence of extremal dyons in theories with the discrete sequence of dilaton couplings $a=\\sqrt{n(n+1)/2}$ with integer $n$. Apart from the lower members $n=1,\\,2$, this family of theories does not have motivation from supersymmetry or higher dimensions, and so far the above quantization rule has not been derived analytically. We fill this gap showing that this rule follows from analyticity of the dilaton at the $AdS_2\\times S^2$ event horizon with $n$ being the leading dilaton power in the series expansion. We also present generalization for asymptotically anti-de Sitter dyonic black holes with spherical, plane and hyperbolic topology of the horizon.

  19. Extreme skin depth waveguides

    CERN Document Server

    Jahani, Saman

    2014-01-01

    Recently, we introduced a paradigm shift in light confinement strategy and introduced a class of extreme skin depth (e-skid) photonic structures (S. Jahani and Z. Jacob, "Transparent sub-diffraction optics: nanoscale light confinement without metal," Optica 1, 96-100 (2014)). Here, we analytically establish that figures of merit related to light confinement in dielectric waveguides are fundamentally tied to the skin depth of waves in the cladding. We contrast the propagation characteristics of the fundamental mode of e-skid waveguides and conventional waveguides to show that the decay constant in the cladding is dramatically larger in e-skid waveguides, which is the origin of sub-diffraction confinement. Finally, we propose an approach to verify the reduced skin depth in experiment using the decrease in the Goos-H\\"anchen phase shift.

  20. Pulsars and Extreme Physics

    Science.gov (United States)

    Bell-Burnell, Jocelyn

    2004-10-01

    Pulsars were discovered 35 years ago. What do we know about them now, and what have they taught us about the extremes of physics? With an average density comparable to that of the nucleus, magnetic fields around 108 T and speeds close to c these objects have stretched our understanding of the behaviour of matter. They serve as extrememly accurate clocks with which to carry out precision experiments in relativity. Created in cataclysmic explosions, pulsars are a (stellar) form of life after death. After half a billion revolutions most pulsars finally die, but amazingly some are born again to yet another, even weirder, afterlife. Pulsar research continues lively, delivering exciting, startling and almost unbelievable results!

  1. Characterization of halophiles in natural MgSO 4 salts and laboratory enrichment samples: Astrobiological implications for Mars

    Science.gov (United States)

    Foster, Ian S.; King, Penelope L.; Hyde, Brendt C.; Southam, Gordon

    2010-03-01

    The presence of sulfate salts and limited subsurface water (ice) on Mars suggests that any liquid water on Mars today will occur as (magnesium) sulfate-rich brines in regions containing sources of magnesium and sulfur. The Basque Lakes of British Columbia, Canada, represent a hypersaline terrestrial analogue site, which possesses chemical and physical properties similar to those observed on Mars. The Basque Lakes also contain diverse halophilic organisms representing all three Kingdoms of life, growing in surface and near-subsurface environments. Of interest from an astrobiological perspective, crushed magnesium sulfate samples that were analyzed using a modified Lowry protein assay contained biomass in every crystal inspected, with biomass values from 0.078 to 4.21 mg biomass/g salt; average=0.74±0.7 mg biomass/g salt. Bacteria and Archaea cells were easily observed even in low-biomass samples using light microscopy, and bacteria trapped within magnesium sulfate crystals were observed using confocal microscopy. Regions within the salt also contained bacterial pigments, e.g., carotenoids, which were separate from the cells, indicating that cell lysis might have occurred during entrapment within the salt matrix. These biosignatures, cells, and any 'soluble' organic constituents were primarily found trapped within fluid inclusions or fluid-filled void spaces between intergrown crystals. Diffuse reflectance infrared Fourier transform spectroscopy (reflectance IR) analysis of enrichment cultures, containing cyanobacteria, Archaea, or dissimilatory sulfate-reducing bacteria, highlighted molecular biosignature features between 550-1650 and 2400-3000 cm -1. Spectra from natural salts demonstrated that we can detect biomass within salt crystals using the most sensitive biosignatures, which are the 1530-1570 cm -1, C-N, N-H, -COOH absorptions and the 1030-1050 cm -1 C-OH, C-N, PO 43- bond features. The lowest detection limit for a biosignature absorption feature using

  2. 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

  3. 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

  4. Women in extreme poverty.

    Science.gov (United States)

    1994-01-01

    Population is estimated to increase from 5.5 billion in 1990 to 10 billion by 2050; the poverty level is expected to increase from 1 billion to 2-3 billion people. Women in development has been promoted throughout the UN and development system, but women in poverty who perform work in the informal sector are still uncounted, and solutions are elusive. The issue of extreme poverty can not be approached as just another natural disaster with immediate emergency relief. Many people live in precarious economic circumstances throughout their lives. Recent research reveals a greater understanding of the underlying causes and the need for inclusion of poor women in sustainable development. Sanitation, water, housing, health facilities need to be improved. Women must have access to education, opportunities for trading, and loans on reasonable terms. UNESCO makes available a book on survival strategies for poor women in the informal sector. The profile shows common problems of illiteracy, broken marriages, and full time involvement in provision of subsistence level existence. Existence is a fragile balance. Jeanne Vickers' "Women and the World" offers simple, low cost interventions for aiding extremely poor women. The 1992 Commission on the Status of Women was held in Vienna. Excerpts from several speeches are provided. The emphasis is on some global responses and an analysis of solutions. The recommendation is for attention to the gender dimension of poverty. Women's dual role contributes to greater disadvantages. Women are affected differently by macroeconomic factors, and that there is intergenerational transfer of poverty. Social services should be viewed as investments and directed to easing the burdens on time and energy. Public programs must be equipped to deal with poverty and to bring about social and economic change. Programs must be aware of the different distribution of resources within households. Women must be recognized as principal economic providers within

  5. Extreme winds in Denmark

    Energy Technology Data Exchange (ETDEWEB)

    Kristensen, L.; Rathmann, O.; Hansen, S.O.

    1999-02-01

    Wind-speed data from four sites in Denmark have been analyzed in order to obtain estimates of the basic wind velocity which is defined as the 50-year wind speed under standard conditions, i.e. ten-minute averages at the height 10 m over a uniform terrain with the roughness length 0.05 m. The sites are, from west, Skjern (15 years), Kegnaes (7 years), Sprogoe (20 years), and Tystofte (15 years). The data are ten minute averages of wind speed, wind direction, temperature and pressure. The last two quantities are used to determine the air density {rho}. The data are cleaned for terrain effects by means of a slightly modified WASP technique where the sector speed-up factors and roughness lengths are linearly smoothed with a direction resolution of one degree. Assuming geotropic balance, all the wind-velocity data are transformed to friction velocity u{sub *} and direction at standard conditions by means of the geotropic drag law for neutral stratification. The basic wind velocity in 30 deg. sectors are obtained through ranking of the largest values of the friction velocity pressure 1/2{rho}u{sub *}{sup 2} taken both one every two months and once every year. The main conclusion is that the basic wind velocity is significantly larger at Skjern, close to the west coast of Jutland, than at any of the other sites. Irrespective of direction, the present standard estimates of 50-year wind are 25 {+-} 1 m/s at Skern and 22 {+-} 1 m/s at the other three sites. These results are in agreement with those obtained by Jensen and Franck (1970) and Abild (1994) and supports the conclusion that the wind climate at the west coast of Jutland is more extreme than in any other part of the country. Simple procedures to translate in a particular direction sector the standard basic wind velocity to conditions with a different roughness length and height are presented. It is shown that a simple scheme makes it possible to calculate the total 50-year extreme load on a general structure without

  6. Stacked Extreme Learning Machines.

    Science.gov (United States)

    Zhou, Hongming; Huang, Guang-Bin; Lin, Zhiping; Wang, Han; Soh, Yeng Chai

    2015-09-01

    Extreme learning machine (ELM) has recently attracted many researchers' interest due to its very fast learning speed, good generalization ability, and ease of implementation. It provides a unified solution that can be used directly to solve regression, binary, and multiclass classification problems. In this paper, we propose a stacked ELMs (S-ELMs) that is specially designed for solving large and complex data problems. The S-ELMs divides a single large ELM network into multiple stacked small ELMs which are serially connected. The S-ELMs can approximate a very large ELM network with small memory requirement. To further improve the testing accuracy on big data problems, the ELM autoencoder can be implemented during each iteration of the S-ELMs algorithm. The simulation results show that the S-ELMs even with random hidden nodes can achieve similar testing accuracy to support vector machine (SVM) while having low memory requirements. With the help of ELM autoencoder, the S-ELMs can achieve much better testing accuracy than SVM and slightly better accuracy than deep belief network (DBN) with much faster training speed.

  7. Solar extreme events

    CERN Document Server

    Hudson, Hugh S

    2015-01-01

    Solar flares and CMEs have a broad range of magnitudes. This review discusses the possibility of "extreme events," defined as those with magnitudes greater than have been seen in the existing historical record. For most quantitative measures, this direct information does not extend more than a century and a half into the recent past. The magnitude distributions (occurrence frequencies) of solar events (flares/CMEs) typically decrease with the parameter measured or inferred (peak flux, mass, energy etc. Flare radiation fluxes tend to follow a power law slightly flatter than $S^{-2}$, where S represents a peak flux; solar particle events (SPEs) follow a still flatter power law up to a limiting magnitude, and then appear to roll over to a steeper distribution, which may take an exponential form or follow a broken power law. This inference comes from the terrestrial $^{14}$C record and from the depth dependence of various radioisotope proxies in the lunar regolith and in meteorites. Recently major new observation...

  8. Detectors in Extreme Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Blaj, G. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Carini, G. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Carron, S. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Haller, G. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Hart, P. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Hasi, J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Herrmann, S. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Kenney, C. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Segal, J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Tomada, A. [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-06

    Free Electron Lasers opened a new window on imaging the motion of atoms and molecules. At SLAC, FEL experiments are performed at LCLS using 120Hz pulses with 1012 - 1013 photons in 10 femtoseconds (billions of times brighter than the most powerful synchrotrons). This extreme detection environment raises unique challenges, from obvious to surprising. Radiation damage is a constant threat due to accidental exposure to insufficiently attenuated beam, focused beam and formation of ice crystals reflecting the beam onto the detector. Often high power optical lasers are also used (e.g., 25TW), increasing the risk of damage or impeding data acquisition through electromagnetic pulses (EMP). The sample can contaminate the detector surface or even produce shrapnel damage. Some experiments require ultra high vacuum (UHV) with strict design, surface contamination and cooling requirements - also for detectors. The setup is often changed between or during experiments with short turnaround times, risking mechanical and ESD damage, requiring work planning, training of operators and sometimes continuous participation of the LCLS Detector Group in the experiments. The detectors used most often at LCLS are CSPAD cameras for hard x-rays and pnCCDs for soft x-rays.

  9. Extremal almost-Kahler metrics

    CERN Document Server

    Lejmi, Mehdi

    2009-01-01

    We generalize the notion of the Futaki invariant and extremal vector field to the general almost-Kahler case and we prove the periodicity of the extremal vector field when the symplectic form represents an integral cohomology class modulo torsion. We give also an explicit formula of the hermitian scalar curvature which allows us to obtain examples of non-integrable extremal almost-Kahler metrics saturating LeBrun's estimates.

  10. Upper extremity amputations and prosthetics.

    Science.gov (United States)

    Ovadia, Steven A; Askari, Morad

    2015-02-01

    Upper extremity amputations are most frequently indicated by severe traumatic injuries. The location of the injury will determine the level of amputation. Preservation of extremity length is often a goal. The amputation site will have important implications on the functional status of the patient and options for prosthetic reconstruction. Advances in amputation techniques and prosthetic reconstructions promote improved quality of life. In this article, the authors review the principles of upper extremity amputation, including techniques, amputation sites, and prosthetic reconstructions.

  11. Likelihood estimators for multivariate extremes

    KAUST Repository

    Huser, Raphaël

    2015-11-17

    The main approach to inference for multivariate extremes consists in approximating the joint upper tail of the observations by a parametric family arising in the limit for extreme events. The latter may be expressed in terms of componentwise maxima, high threshold exceedances or point processes, yielding different but related asymptotic characterizations and estimators. The present paper clarifies the connections between the main likelihood estimators, and assesses their practical performance. We investigate their ability to estimate the extremal dependence structure and to predict future extremes, using exact calculations and simulation, in the case of the logistic model.

  12. Cel8H, a novel endoglucanase from the halophilic bacterium Halomonas sp. S66-4: molecular cloning, heterogonous expression, and biochemical characterization.

    Science.gov (United States)

    Huang, Xiaoluo; Shao, Zongze; Hong, Yuzhi; Lin, Ling; Li, Chanjuan; Huang, Fei; Wang, Hui; Liu, Ziduo

    2010-06-01

    A recombinant Escherichia coli clone expressing an endoglucanase was identified from a genomic library of the halophilic bacterium Halomonas sp. S66-4, and the enzyme was designated Cel8H. The cel8H gene consisted of 1,053 bp and encoded 350 amino acids sharing the highest identity of 48% to other known endoglucanases. The protein was expressed in E. coli BL21 (DE3) and purified to homogeneity. The purified recombinant enzyme had an optimal activity of 4.9 U/mg at pH 5 and 45 degrees C toward the substrate carboxymethylcellulose. It exhibited extraordinary properties which differed from endoglucanases reported previously at the point of high salt tolerance above 5 M, simultaneously with high pH stability at pH 4-12 and high temperature stability at 40-60 degrees C. Various substrate tests indicated that the enzyme hydrolyzes beta-1,4-glucosidic bonds specifically.

  13. Development of a vector and host system and characterization of replication of plasmid pSQ10 in moderately halophilic Nocardiopsis

    Institute of Scientific and Technical Information of China (English)

    Ana Zeng; Tao Wang; Haiyang Xia; Shiyuan Peng; Weihua Chen; Chenglin Jiang; Lihua Xu

    2011-01-01

    The genus of Nocardiopsis is a new source of antibiotics,chemicals,and enzymes.Here we reported the development of a vector and host system in moderately halophilic Nocardiopsis via an oriT-mediated conjugation.By screening about 80 Nocardiopsis strains,6 of them harbored 8 plasmids (18-80 kb).The complete nucleotide sequence of pSQ10 consisted of 18,219 bp,with 71.9% G + Ccontent,encoding 17 open reading frames,5 of them resembled those of Streptomyces plasmids.A rep locus (iteron within the gene) was identified for replication in Nocardiopsis sp.YIM 90083,and rep protein bound to its iteron sequence.This system may be useful for gene cloning and expression in Nocardiopsis.

  14. 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

    Directory of Open Access Journals (Sweden)

    MacNeill Stuart A

    2006-11-01

    Full Text Available Abstract 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 euryarchaeon Haloferax volcanii, the gene for which was apparently acquired by Hfx.volcanii through lateral gene transfer (LGT from a halophilic eubacterium. Genetic studies show that the LGT-acquired LigN enzyme shares an essential function with the native Hfx.volcanii ATP-dependent DNA ligase protein LigA. Results To characterise the enzymatic properties of the LigN protein, wild-type and three mutant forms of the LigN protein were separately expressed in recombinant form in E.coli and purified to apparent homogeneity by immobilised metal ion affinity chromatography (IMAC. Non-isotopic DNA ligase activity assays using λ DNA restriction fragments with 12 bp cos cohesive ends were used to show that LigN activity was dependent on addition of divalent cations and salt. No activity was detected in the absence of KCl, whereas maximum activity could be detected at 3.2 M KCl, close to the intracellular KCl concentration of Hfx.volcanii cells. Conclusion LigN is unique amongst characterised DNA ligase enzymes in displaying maximal DNA strand joining activity at high (> 3 M salt levels. As such the LigN enzyme has potential both as a novel tool for biotechnology and as a model enzyme for studying the adaptation of proteins to high intracellular salt levels.

  15. 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.

  16. 连云港台北盐场嗜盐古菌多样性研究%Diversity Research on Halophilic Archaea of Taibei Saltern in Lianyungang

    Institute of Scientific and Technical Information of China (English)

    薛梦颖; 殷婷婷; 丁丽燕; 王宇; 齐婕; 杨丽; 温洪宇

    2013-01-01

    For the protection and development of microbial resources ,five halophilic archaea strains numbered 23 ,25 ,40 ,174 and 178 which are Gram-negative and rod-shaped were isolated from Taibei saltern of Lianyun-gang .16S rRNA genes were obtained by PCR with archaea universal primers of 16S rRNA gene .After cloning and sequencing ,compared the nucleotide sequences with closely species were phylogenetic analyzed and phylag-enetic trees were constructed .The results showed that halophilic archaea strains 23 ,40 ,174 and 178 belonged to genus H alorubrum ,and strain 25 belonged to genus H aloarcula .%为了保护和开发微生物资源,从连云港台北盐场采集卤水,通过分离筛选获得5株嗜盐古菌,编号分别为23、25、40、174和178,均为革兰氏阴性,杆状。用嗜盐古菌16 S rRNA基因通用引物进行16 s rRNA基因扩增,克隆后测序,对测序结果进行系统发育学分析研究并构建系统发育树。结果表明:嗜盐古菌菌株23、40、174和178属于盐红杆菌属(Halorubrum),25属于盐盒菌属(Haloarcula)。

  17. Attitude extremity, consensus and diagnosticity

    NARCIS (Netherlands)

    van der Pligt, J.; Ester, P.; van der Linden, J.

    1983-01-01

    Studied the effects of attitude extremity on perceived consensus and willingness to ascribe trait terms to others with either pro- or antinuclear attitudes. 611 Ss rated their attitudes toward nuclear energy on a 5-point scale. Results show that attitude extremity affected consensus estimates. Trait

  18. Gender, Education, Extremism and Security

    Science.gov (United States)

    Davies, Lynn

    2008-01-01

    This paper examines the complex relationships between gender, education, extremism and security. After defining extremism and fundamentalism, it looks first at the relationship of gender to violence generally, before looking specifically at how this plays out in more extremist violence and terrorism. Religious fundamentalism is also shown to have…

  19. Grassland responses to precipitation extremes

    Science.gov (United States)

    Grassland ecosystems are naturally subjected to periods of prolonged drought and sequences of wet years. Climate change is expected to enhance the magnitude and frequency of extreme events at the intraannual and multiyear scales. Are grassland responses to extreme precipitation simply a response to ...

  20. Modeling extreme risks in ecology.

    Science.gov (United States)

    Burgman, Mark; Franklin, James; Hayes, Keith R; Hosack, Geoffrey R; Peters, Gareth W; Sisson, Scott A

    2012-11-01

    Extreme risks in ecology are typified by circumstances in which data are sporadic or unavailable, understanding is poor, and decisions are urgently needed. Expert judgments are pervasive and disagreements among experts are commonplace. We outline approaches to evaluating extreme risks in ecology that rely on stochastic simulation, with a particular focus on methods to evaluate the likelihood of extinction and quasi-extinction of threatened species, and the likelihood of establishment and spread of invasive pests. We evaluate the importance of assumptions in these assessments and the potential of some new approaches to account for these uncertainties, including hierarchical estimation procedures and generalized extreme value distributions. We conclude by examining the treatment of consequences in extreme risk analysis in ecology and how expert judgment may better be harnessed to evaluate extreme risks.

  1. Bioenergetics of halophiles

    Energy Technology Data Exchange (ETDEWEB)

    Lanyi, Janos K. [Univ. of California, Irvine, CA (United States); Balashov, Sergei [Univ. of California, Irvine, CA (United States)

    2016-02-26

    In the last grant period we explored the Na+ binding site of the recently discovered light-driven sodium ion pump. The rationale was that comparison of this novel system to the similar proton pumps and chloride ion pumps would reveal the amazingly (and unexpectedly) wide variety of structural features that govern conversion of light-energy into biologically useful transmembrane gradients and thus production of biomass. A thorough description of this system would establish the basis for continuing our funded research on these proteins.

  2. Spatial dependence of extreme rainfall

    Science.gov (United States)

    Radi, Noor Fadhilah Ahmad; Zakaria, Roslinazairimah; Satari, Siti Zanariah; Azman, Muhammad Az-zuhri

    2017-05-01

    This study aims to model the spatial extreme daily rainfall process using the max-stable model. The max-stable model is used to capture the dependence structure of spatial properties of extreme rainfall. Three models from max-stable are considered namely Smith, Schlather and Brown-Resnick models. The methods are applied on 12 selected rainfall stations in Kelantan, Malaysia. Most of the extreme rainfall data occur during wet season from October to December of 1971 to 2012. This period is chosen to assure the available data is enough to satisfy the assumption of stationarity. The dependence parameters including the range and smoothness, are estimated using composite likelihood approach. Then, the bootstrap approach is applied to generate synthetic extreme rainfall data for all models using the estimated dependence parameters. The goodness of fit between the observed extreme rainfall and the synthetic data is assessed using the composite likelihood information criterion (CLIC). Results show that Schlather model is the best followed by Brown-Resnick and Smith models based on the smallest CLIC's value. Thus, the max-stable model is suitable to be used to model extreme rainfall in Kelantan. The study on spatial dependence in extreme rainfall modelling is important to reduce the uncertainties of the point estimates for the tail index. If the spatial dependency is estimated individually, the uncertainties will be large. Furthermore, in the case of joint return level is of interest, taking into accounts the spatial dependence properties will improve the estimation process.

  3. 舟山盐田环境嗜盐菌和耐盐菌数量分布调查%Investigation on the Numerical Distribution of Halotolerant Bacteria and Halophilic Bacteria from Brine Pan in Zhoushan

    Institute of Scientific and Technical Information of China (English)

    刘雪珠; 汤新潮; 朱斌

    2009-01-01

    The distribution of halotolerant and halophilic bacteria in brine and sediment samples from three salt fields of Dinghai, Zhujiajian and Daishan in Zhoushan was investigated in the winter, spring and summer from 2006 to 2007. Using NaCl as the limiting growth factor, the preliminary identification and culture counting of halophilic bacteria in samples were studied by using three solid media with high salt, moderate salt and low salt. The results showed that the colony morphology, cell shape and numerical distribution of halophilic bacteria in brine pan were different. And the number of halophilic bacteria in sediment was 101-102 higher than that in brine.%2006~2007 年冬春夏3季在舟山定海、朱家尖、岱山盐场盐田中取卤水和底泥样品,对嗜盐菌和耐盐菌的分布状况进行调查.以NaCl为限制性生长因子,主要采用高盐、中盐及低盐3种平板,对样品中的嗜盐菌进行初步鉴定和培养计数研究.结果表明,盐田中的嗜盐菌类群在菌落、个体特征以及数量分布上有所不同,并且底泥中的菌量比卤水中高 1~2个数量级.

  4. [Resistance of microorganisms of coastal ecosystems of the Dead Sea to extremal factors].

    Science.gov (United States)

    Romanovskaia, V A; Avdeeva, L V; Gladka, G V; Pritula, I R; Kharkhota, M A; Tashirev, A B

    2013-01-01

    Such extreme factors as UV radiation, high temperature and salinity, and also the small amount of accessible water have an influence on microorganisms of coastal ecosystems of the Dead Sea. Resistance to these factors of the microorganisms isolated from ecosystems of this region (vertical steep gorge around the Dead Sea, clay-salt plain and black highly mineralized muds) is studied. Aerobic, chemoorganotrophic, thermotolerant, moderately halophilic bacteria which, according to their morphological and physiological properties, are similar to species Gracilibacillus halotolerans, Salimicrobium album and genus Caryophanon have been isolated from these ecosystems. All strains grew at 0-10% of NaCl in the medium (one strain--at 15% of NaCl), in the range of 30-50 degrees C. Resistance to UV radiation has been revealed in all the investigated bacteria Lethal doses of UV (LD90 and LD99.99) for spore-forming strains of genus Gracilibacillus were 100-170 and 1100-1500 J/m2, respectively; for strain Salimicrobium 6t1 (does not form spores)--70 and 400 J/m2; for the strain lt4 (genus Caryophanon), forming filamentous (or trychomes)--150 and 1400 J/m2. Some strains of genus Gracilibacillus had strong antagonistic effect on conditionally pathogenic test cultures Staphylococcus aureus 209p and Candida albicans UCM Y-690. It is conceivable that resistance of microorganisms of coastal ecosystems of the Dead Sea to extreme factors was generated under the influence of abiotic (physical and chemical) factors typical of this region.

  5. Extreme Thrombocytosis and Cardiovascular Surgery

    Science.gov (United States)

    Natelson, Ethan A.

    2012-01-01

    Extreme thrombocytosis is a major risk factor for excessive bleeding and for thrombosis, either of which can complicate cardiovascular surgical and interventional procedures. Extreme thrombocytosis can also cause an unusual syndrome, erythromelalgia, that results in a type of chronic microvascular occlusive arterial disease. We present the differential diagnosis of conditions that may lead to extreme thrombocytosis, 3 cases (each of which illustrates a different potential complication), and a review of the pertinent medical literature. Correcting excessive thrombocytosis is typically not difficult, whether electively or acutely, and effective therapy usually controls thrombosis and excessive hemorrhage postprocedurally. PMID:23304015

  6. 陕西定边盐湖嗜盐菌A393的分离及其种属鉴定%Isolation and Identification of Halophilic Bacteria A393 from Dingbian Salt Lake

    Institute of Scientific and Technical Information of China (English)

    陈锐; 李玥; 韩丽萍; 沈俭; 孙晓宇; 路鹏鹏; 门欣; 黄继红; 沈卫荣

    2012-01-01

    A halophilic bacterial strain A393 was isolated and screened from Dingbian salt lake soil sample using high salt selective culture method and gradient dilution isolation. According to the classic phenotypic characteristics including morphological observation, physiological and bio-chemical characteristics and 16S rDNA sequence analysis of phylogeny it was identified the taxonomic position of the halophilic strain A393. The most suitable growth salt concentration of the strain was at 8% -20% . Its phenotypic features and 16S rDNA sequence analysis results initially characterized it as a moderate halophilic bacterial strain and belonged to the genus of Marinococcus.%采用高盐选择性培养基和稀释平板法,从陕西定边盐湖土壤样本中,分离筛选获得嗜盐菌株A393,通过形态学观察、生理生化特征和系统发育学16S rDNA序列分析鉴定嗜盐菌株A393分类学地位.获得的A393最适生产盐浓度在8%~20%.表型特征和16S rDNA序列分析结果初步鉴定其为中度嗜盐菌,属于海球菌属(Marinococcus sp.)菌株.

  7. Extreme hypertriglyceridemia managed with insulin.

    Science.gov (United States)

    Thuzar, Moe; Shenoy, Vasant V; Malabu, Usman H; Schrale, Ryan; Sangla, Kunwarjit S

    2014-01-01

    Extreme hypertriglyceridemia can lead to acute pancreatitis and rapid lowering of serum triglycerides (TG) is necessary for preventing such life-threatening complications. However, there is no established consensus on the acute management of extreme hypertriglyceridemia. We retrospectively reviewed 10 cases of extreme hypertriglyceridemia with mean serum TG on presentation of 101.5 ± 23.4 mmol/L (8982 ± 2070 mg/dL) managed with insulin. Serum TG decreased by 87 ± 4% in 24 hours in those patients managed with intravenous insulin and fasting and 40 ± 8.4% in those managed with intravenous insulin alone (P = .0003). The clinical course was uncomplicated in all except 1 patient who subsequently developed a pancreatic pseudocyst. Thus, combination of intravenous insulin with fasting appears to be an effective, simple, and safe treatment strategy in immediate management of extreme hypertriglyceridemia. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

  8. Moment methods in extremal geometry

    NARCIS (Netherlands)

    De Laat, D.

    2016-01-01

    In this thesis we develop techniques for solving problems in extremal geometry. We give an infinite dimensional generalization of moment techniques from polynomial optimization. We use this to construct semidefinite programming hierarchies for approximating optimal packing densities and ground state

  9. Moment methods in extremal geometry

    NARCIS (Netherlands)

    De Laat, D.

    2016-01-01

    In this thesis we develop techniques for solving problems in extremal geometry. We give an infinite dimensional generalization of moment techniques from polynomial optimization. We use this to construct semidefinite programming hierarchies for approximating optimal packing densities and ground state

  10. Statistical Model of Extreme Shear

    DEFF Research Database (Denmark)

    Larsen, Gunner Chr.; Hansen, Kurt Schaldemose

    2004-01-01

    In order to continue cost-optimisation of modern large wind turbines, it is important to continously increase the knowledge on wind field parameters relevant to design loads. This paper presents a general statistical model that offers site-specific prediction of the probability density function...... by a model that, on a statistically consistent basis, describe the most likely spatial shape of an extreme wind shear event. Predictions from the model have been compared with results from an extreme value data analysis, based on a large number of high-sampled full-scale time series measurements...... are consistent, given the inevitabel uncertainties associated with model as well as with the extreme value data analysis. Keywords: Statistical model, extreme wind conditions, statistical analysis, turbulence, wind loading, statistical analysis, turbulence, wind loading, wind shear, wind turbines....

  11. Deformations of extremal toric manifolds

    CERN Document Server

    Rollin, Yann

    2012-01-01

    Let $X$ be a compact toric extremal K\\"ahler manifold. Using the work of Sz\\'ekelyhidi, we provide a simple criterion on the fan describing $X$ to ensure the existence of complex deformations of $X$ that carry extremal metrics. As an example, we find new CSC metrics on 4-points blow-ups of $\\C\\P^1\\times\\C\\P^1$.

  12. Large Extremity Peripheral Nerve Repair

    Science.gov (United States)

    2015-10-01

    IL, Kochevar IE, Redmond RW. Large extremity peripheral nerve repair. Military Health System Research Symposium (MHSRS) Fort Lauderdale, FL. August...some notable discoveries that may impact military health care in the near future. There is a clear need in military medicine to improve outcomes in...membranes or “caul” intact was considered extremely lucky. Children were gifted with life-long happiness , the ability to see spirits, and protection

  13. Observed Statistics of Extreme Waves

    Science.gov (United States)

    2006-12-01

    9 Figure 5. An energy stealing wave as a solution to the NLS equation . (From: Dysthe and...shown that nonlinear interaction between four colliding waves can produce extreme wave behavior. He utilized the NLS equation in his numerical ...2000) demonstrated the formation of extreme waves using the Korteweg de Vries ( KdV ) equation , which is valid in shallow water. It was shown in the

  14. Weather Extremes Around the World

    Science.gov (United States)

    1974-04-01

    or ever has occurred. According to M. A. Arkin, "... record extremes must be taken with a grain of salt .... Ř He explains that news of an extreme...the edge of the Danakil Depression, a salt desert. By averaging the annual mean daily maximum temperature of 106°F36 atid the annual mean daily...increased by orographic lifting.1" Asa result of these monsoon disturbances, which are still not fully understood, the eastern Himalayan 105 106

  15. Irrigation mitigates against heat extremes

    Science.gov (United States)

    Thiery, Wim; Fischer, Erich; Visser, Auke; Hirsch, Annette L.; Davin, Edouard L.; Lawrence, Dave; Hauser, Mathias; Seneviratne, Sonia I.

    2017-04-01

    Irrigation is an essential practice for sustaining global food production and many regional economies. Emerging scientific evidence indicates that irrigation substantially affects mean climate conditions in different regions of the world. Yet how this practice influences climate extremes is currently unknown. Here we use gridded observations and ensemble simulations with the Community Earth System Model to assess the impacts of irrigation on climate extremes. While the influence of irrigation on annual mean temperatures is limited, we find a large impact on temperature extremes, with a particularly strong cooling during the hottest day of the year (-0.78 K averaged over irrigated land). The strong influence on hot extremes stems from the timing of irrigation and its influence on land-atmosphere coupling strength. Together these effects result in asymmetric temperature responses, with a more pronounced cooling during hot and/or dry periods. The influence of irrigation is even more pronounced when considering subgrid-scale model output, suggesting that local effects of land management are far more important than previously thought. Finally we find that present-day irrigation is partly masking GHG-induced warming of extreme temperatures, with particularly strong effects in South Asia. Our results overall underline that irrigation substantially reduces our exposure to hot temperature extremes and highlight the need to account for irrigation in future climate projections.

  16. 微波处理对嗜碱和嗜盐海洋放线菌分离效果的影响%Effects of microwave irradiation on isolation of basophilic and halophilic marine actinomycetes

    Institute of Scientific and Technical Information of China (English)

    丁彦博; 蔡超靖; 穆云龙; 单越琦; 路新华; 蒋沁

    2012-01-01

    [Objective] Study the effects of microwave irradiation on isolation of basophilic and halophilic marine actinomycetes. [Methods] Seven marinemud samples were radiated by microwave and then gradient diluted for isolation of basophilic and halophilic marine actinomycetes in three media. [Results] Microwave irradiation could highly significantly increase the total quantity of basophilic and halophilic marine actinomycetes respectively in four and three marinemud samples. The total quantity of basophilic and halophilic marine rare actinomycetes of Micromonospora, Actinoplanes and Nocardia were significantly increased after microwave irradiation. The species of other marine rare actinomycetes such as Catellatospora, Microbispora, Streptosporangium were increased to one to four in different samples. [Conclusion] Microwave irradiation could significantly increase the total quantity of basophilic and halophilic marine actinomycetes and the species of marine rare actinomycetes.%[目的]研究微波处理对于分离嗜碱和嗜盐海洋放线菌的效果.[方法]用微波处理7份海泥样品,梯度稀释后涂布于3种分离培养基,分离具有嗜碱和嗜盐特性的海洋放线菌.[结果]微波处理后的7份样品中,4份样品中嗜碱海洋稀有放线菌和3份样品的嗜盐海洋稀有放线菌数量极显著提高;7份样品中的嗜碱、嗜盐海洋小单孢菌属、游动放线菌属、诺卡氏菌属等稀有放线菌数量均有显著增加,不同样品中新分离到链孢菌属、小双孢菌属、链孢囊菌属及其他未鉴定的海洋稀有放线菌,分离到属的数量提高了1-4个.[结论]微波处理不仅显著提高嗜碱和嗜盐海洋放线菌的分离数量,而且明显增加了海洋稀有放线菌的分离种类.

  17. Assessing Climate Variability using Extreme Rainfall and ...

    African Journals Online (AJOL)

    user1

    As noted by the Bureau of Meteorology, Canada, to examine whether such ... their local climate, a threshold considered extreme in one part of Australia could be ... (extreme frequency); the average intensity of rainfall from extreme events.

  18. Seperation and Identification of a Novel Halophile%一株嗜盐菌新种的分离与鉴定

    Institute of Scientific and Technical Information of China (English)

    白雪冬; 吴敏; 李遂焰

    2011-01-01

    A marine bacterium,designated strain S3-22, was isolated from the ballast water sample from Zhoushan archipelago,China. 16S rDNA sequences similarity of strain S3-22 to all recognized bacterial species was not greater than 97%. The DNA G +C content was 54.9 mol%. The dominant fatty acid was iso-C17:1ω 9c (24.99%). The major respiratory quinine was MK-5. Cells of strain S3-22 were gram-negative. Optimal growth of strain S3-22 was at pH 7.0,30 - 37 ℃ and 3% (w/v) NaCl. It was halophilic and tested positive for catalase,oxidase,amylase,and esterase. In addition,it could deoxidize the nitrate. Based on the evidence of 16S rDNA sequences similarities,phylogenetic analysis and cellular and molecular level identification, the halophile formed a phyletic lineage which was distinct from the known Kordiimonas species. Strain S3-22 represented a novel species in the Kordiimonas, its Genebank Accession number was FJ847942.%从舟山册子岛船舶压载水泥样中分离到一株细菌S3-22,其与已知细菌的16S rDNA序列相似性低于97%,G+C mo1%为54.9 mol%,主要脂肪酸iso-C17:1ω9c(24.99%),细胞醌型为甲基萘醌MK-5.革兰氏染色阴性,最适生长条件为30~37 ℃、pH 7、3%NaCl.嗜盐,氧化酶、接触酶、淀粉酶、酯酶呈阳性,可还原硝酸盐.依据其16S rDNA序列相似性、系统发育学分析及细胞与分子水平的鉴定表明,该菌是Kordiimonas属的一个新种,菌株S3-22的16S rDNA序列登陆号为FJ847942.

  19. 我国近海中度嗜盐菌的分离筛选及其产酶多样性分析%Isolation,screening and enzyme diversity of moderately halophilic bacteria in Chinese coastal waters

    Institute of Scientific and Technical Information of China (English)

    产竹华; 刘洋; 王昭凯; 钟添华; 曾润颖

    2014-01-01

    To investigate phylogenetic and enzyme production diversity of moderately halophilic bacteria ,we got the samples from China's offshore of Tianjing ,Shandong ,Jiangsu ,Fujian and Hainan. 108 moderately halophilic strains were isolated ,26 of which could produce at least one type of enzymes. According to physiological and bio-chemical characteristics ,16S rRNA sequences and phylogenetic analysis ,the 26 moderately halophilic strains be-longed to genera Halomonas ,Idiomarina ,Virgibacillus ,Pontibacillus ,Oceanobacillus ,Halobacillus or Mari-nilactibacillus separately. The sequences had the similarity (97% -100% ) to the type strains of each genera. Some moderately halophilic bacteria might be a novel species. The substrates specific experiment indicated that there were 13 moderately halophilic strains producing protease ,19 strains producing amylase ,13 strains producing ester-ase ,4 strains producing cellulose. And there were 6 strains producing three enzymes and 11 strains producing two enzymes simultaneously. The research indicated that there was not only abundant phylogenetic and enzyme diversi-ty of moderately halophilic bacteria ,but also some unknown bacteria groups existed in China's offshore ,which provided references for reasonable development and utilization of halophilic microbial resources.%为了解我国近海中度嗜盐菌系统发育多样性及产酶特性,从天津、山东、江苏、福建、海南等地近海采集样品为研究对象,分离筛选得到108株中度嗜盐菌,其中有26株至少产一种酶。通过对其形态特征、生理生化、16S rRNA 基因序列及系统进化树进行分析,将26株菌鉴定为细菌域的Halomonas、Idiomarina、Virgibacillus、Pontibacillus、Oceanobacillus、Halobacillus和 Marinilactibacillus属的菌株。它们与相应属的模式菌株16S rRNA基因序列相似性在97%~100%不等,其中有些菌株可能代表不同的分类单元。底物特异性试验表明,分离的26

  20. Are hourly precipitation extremes increasing faster than daily precipitation extremes?

    Science.gov (United States)

    Barbero, Renaud; Fowler, Hayley; Blenkinsop, Stephen; Lenderink, Geert

    2016-04-01

    Extreme precipitation events appear to be increasing with climate change in many regions of the world, including the United States. These extreme events have large societal impacts, as seen during the recent Texas-Oklahoma flooding in May 2015 which caused several billion in damages and left 47 deaths in its path. Better understanding of past changes in the characteristics of extreme rainfall events is thus critical for reliable projections of future changes. Although it has been documented in several studies that daily precipitation extremes are increasing across parts of the contiguous United States, very few studies have looked at hourly extremes. However, this is of primary importance as recent studies on the temperature scaling of extreme precipitation have shown that increases above the Clausius-Clapeyron (~ 7% °C-1) are possible for hourly precipitation. In this study, we used hourly precipitation data (HPD) from the National Climatic Data Center and extracted more than 1,000 stations across the US with more than 40 years of data spanning the period 1950-2010. As hourly measurements are often associated with a range of issues, the data underwent multiple quality control processes to exclude erroneous data. While no significant changes were found in annual maximum precipitation using both hourly and daily resolution datasets, significant increasing trends in terms of frequency of episodes exceeding present-day 95th percentiles of wet hourly/daily precipitation were observed across a significant portion of the US. The fraction of stations with significant increasing trends falls outside the confidence interval range during all seasons but the summer. While less than 12% of stations exhibit significant trends at the daily scale in the wintertime, more than 45% of stations, mostly clustered in central and Northern United States, show significant increasing trends at the hourly scale. This suggests that short-duration storms have increased faster than daily

  1. Rising Precipitation Extremes across Nepal

    Directory of Open Access Journals (Sweden)

    Ramchandra Karki

    2017-01-01

    Full Text Available As a mountainous country, Nepal is most susceptible to precipitation extremes and related hazards, including severe floods, landslides and droughts that cause huge losses of life and property, impact the Himalayan environment, and hinder the socioeconomic development of the country. Given that the countrywide assessment of such extremes is still lacking, we present a comprehensive picture of prevailing precipitation extremes observed across Nepal. First, we present the spatial distribution of daily extreme precipitation indices as defined by the Expert Team on Climate Change Detection, Monitoring and Indices (ETCCDMI from 210 stations over the period of 1981–2010. Then, we analyze the temporal changes in the computed extremes from 76 stations, featuring long-term continuous records for the period of 1970–2012, by applying a non-parametric Mann−Kendall test to identify the existence of a trend and Sen’s slope method to calculate the true magnitude of this trend. Further, the local trends in precipitation extremes have been tested for their field significance over the distinct physio-geographical regions of Nepal, such as the lowlands, middle mountains and hills and high mountains in the west (WL, WM and WH, respectively, and likewise, in central (CL, CM and CH and eastern (EL, EM and EH Nepal. Our results suggest that the spatial patterns of high-intensity precipitation extremes are quite different to that of annual or monsoonal precipitation. Lowlands (Terai and Siwaliks that feature relatively low precipitation and less wet days (rainy days are exposed to high-intensity precipitation extremes. Our trend analysis suggests that the pre-monsoonal precipitation is significantly increasing over the lowlands and CH, while monsoonal precipitation is increasing in WM and CH and decreasing in CM, CL and EL. On the other hand, post-monsoonal precipitation is significantly decreasing across all of Nepal while winter precipitation is decreasing

  2. Book review: Extreme ocean waves

    Science.gov (United States)

    Geist, Eric L.

    2017-01-01

    Extreme Ocean Waves”, edited by E. Pelinovsky and C. Kharif, second edition, Springer International Publishing, 2016; ISBN: 978-3-319-21574-7, ISBN (eBook): 978-3-319-21575-4The second edition of “Extreme Ocean Waves” published by Springer is an update of a collection of 12 papers edited by Efim Pelinovsky and Christian Kharif following the April 2007 meeting of the General Assembly of the European Geosciences Union. In this edition, three new papers have been added and three more have been substantially revised. Color figures are now included, which greatly aids in reading several of the papers, and is especially helpful in visualizing graphs as in the paper on symbolic computation of nonlinear wave resonance (Tobisch et al.). A note on terminology: extreme waves in this volume broadly encompass different types of waves, including deep-water and shallow-water rogue waves (which are alternatively termed freak waves), and internal waves. One new paper on tsunamis (Viroulet et al.) is now included in the second edition of this volume. Throughout the book, the reader will find a combination of laboratory, theoretical, and statistical/empirical treatment necessary for the complete examination of this subject. In the Introduction, the editors underscore the importance of studying extreme waves, documenting a dramatic instance of damaging extreme waves that recently occurred in 2014.

  3. Extreme lattices: symmetries and decorrelation

    Science.gov (United States)

    Andreanov, A.; Scardicchio, A.; Torquato, S.

    2016-11-01

    We study statistical and structural properties of extreme lattices, which are the local minima in the density landscape of lattice sphere packings in d-dimensional Euclidean space {{{R}}d} . Specifically, we ascertain statistics of the densities and kissing numbers as well as the numbers of distinct symmetries of the packings for dimensions 8 through 13 using the stochastic Voronoi algorithm. The extreme lattices in a fixed dimension of space d (d≥slant 8 ) are dominated by typical lattices that have similar packing properties, such as packing densities and kissing numbers, while the best and the worst packers are in the long tails of the distribution of the extreme lattices. We also study the validity of the recently proposed decorrelation principle, which has important implications for sphere packings in general. The degree to which extreme-lattice packings decorrelate as well as how decorrelation is related to the packing density and symmetry of the lattices as the space dimension increases is also investigated. We find that the extreme lattices decorrelate with increasing dimension, while the least symmetric lattices decorrelate faster.

  4. Functional metagenomics of extreme environments.

    Science.gov (United States)

    Mirete, Salvador; Morgante, Verónica; González-Pastor, José Eduardo

    2016-04-01

    The bioprospecting of enzymes that operate under extreme conditions is of particular interest for many biotechnological and industrial processes. Nevertheless, there is a considerable limitation to retrieve novel enzymes as only a small fraction of microorganisms derived from extreme environments can be cultured under standard laboratory conditions. Functional metagenomics has the advantage of not requiring the cultivation of microorganisms or previous sequence information to known genes, thus representing a valuable approach for mining enzymes with new features. In this review, we summarize studies showing how functional metagenomics was employed to retrieve genes encoding for proteins involved not only in molecular adaptation and resistance to extreme environmental conditions but also in other enzymatic activities of biotechnological interest.

  5. Mitochondriogenesis genes and extreme longevity.

    Science.gov (United States)

    Santiago, Catalina; Garatachea, Nuria; Yvert, Thomas; Rodríguez-Romo, Gabriel; Santos-Lozano, Alejandro; Fiuza-Luces, Carmen; Lucia, Alejandro

    2013-02-01

    Genes of the proliferator-activated receptor delta (PPARD)-peroxisome proliferator-activated receptor γ coactivator 1α (PPARGC1A, also termed PGC1-α)-nuclear respiratory factor (NRF)-mitochondrial transcription Factor A (TFAM) mitochondriogenesis pathway can influence health/disease phenotypes, yet their association with extreme longevity is not known. We studied the association of five common polymorphisms in genes of this pathway (rs2267668, rs8192678, rs6949152, rs12594956, rs1937) and extreme longevity using a case (107 centenarians)-control (284 young adults) design. We found no between-group differences in allele/genotype frequencies, except for CC genotype in rs1937 (p=0.003), with no representation in controls (0%), versus 2.8% in centenarians (2 men, 1 woman). In summary, the studied genetic variants of the PPARD-PPARGC1A-NRF-TFAM pathway were not associated with extreme longevity, yet a marginal association could exist for rs1937.

  6. Extreme Conditions Modeling Workshop Report

    Energy Technology Data Exchange (ETDEWEB)

    Coe, R. G.; Neary, V. S.; Lawson, M. J.; Yu, Y.; Weber, J.

    2014-07-01

    Sandia National Laboratories (SNL) and the National Renewable Energy Laboratory (NREL) hosted the Wave Energy Converter (WEC) Extreme Conditions Modeling (ECM) Workshop in Albuquerque, NM on May 13th-14th, 2014. The objective of the workshop was to review the current state of knowledge on how to model WECs in extreme conditions (e.g. hurricanes and other large storms) and to suggest how U.S. Department of Energy (DOE) and national laboratory resources could be used to improve ECM methods for the benefit of the wave energy industry.

  7. Automation Rover for Extreme Environments

    Science.gov (United States)

    Sauder, Jonathan; Hilgemann, Evan; Johnson, Michael; Parness, Aaron; Hall, Jeffrey; Kawata, Jessie; Stack, Kathryn

    2017-01-01

    Almost 2,300 years ago the ancient Greeks built the Antikythera automaton. This purely mechanical computer accurately predicted past and future astronomical events long before electronics existed1. Automata have been credibly used for hundreds of years as computers, art pieces, and clocks. However, in the past several decades automata have become less popular as the capabilities of electronics increased, leaving them an unexplored solution for robotic spacecraft. The Automaton Rover for Extreme Environments (AREE) proposes an exciting paradigm shift from electronics to a fully mechanical system, enabling longitudinal exploration of the most extreme environments within the solar system.

  8. Extreme Weather and Natural Disasters

    CERN Document Server

    Healey, Justin

    2012-01-01

    Australia is a vast land in which weather varies significantly in different parts of the continent. Recent extreme weather events in Australia, such as the Queensland floods and Victorian bushfires, are brutal reminders of nature's devastating power. Is global warming increasing the rate of natural disasters? What part do La Niña and El Niño play in the extreme weather cycle? Cyclones, floods, severe storms, bushfires, landslides, earthquakes, tsunamis - what are the natural and man-made causes of these phenomena, how predictable are they, and how prepared are we for the impacts of natural dis

  9. Uncommon upper extremity compression neuropathies.

    Science.gov (United States)

    Knutsen, Elisa J; Calfee, Ryan P

    2013-08-01

    Hand surgeons routinely treat carpal and cubital tunnel syndromes, which are the most common upper extremity nerve compression syndromes. However, more infrequent nerve compression syndromes of the upper extremity may be encountered. Because they are unusual, the diagnosis of these nerve compression syndromes is often missed or delayed. This article reviews the causes, proposed treatments, and surgical outcomes for syndromes involving compression of the posterior interosseous nerve, the superficial branch of the radial nerve, the ulnar nerve at the wrist, and the median nerve proximal to the wrist. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. Statistical Model of Extreme Shear

    DEFF Research Database (Denmark)

    Hansen, Kurt Schaldemose; Larsen, Gunner Chr.

    2005-01-01

    In order to continue cost-optimisation of modern large wind turbines, it is important to continuously increase the knowledge of wind field parameters relevant to design loads. This paper presents a general statistical model that offers site-specific prediction of the probability density function...... by a model that, on a statistically consistent basis, describes the most likely spatial shape of an extreme wind shear event. Predictions from the model have been compared with results from an extreme value data analysis, based on a large number of full-scale measurements recorded with a high sampling rate...

  11. Manual annotation, transcriptional analysis, and protein expression studies reveal novel genes in the agl cluster responsible for N glycosylation in the halophilic archaeon Haloferax volcanii.

    Science.gov (United States)

    Yurist-Doutsch, Sophie; Eichler, Jerry

    2009-05-01

    While Eukarya, Bacteria, and Archaea are all capable of protein N glycosylation, the archaeal version of this posttranslational modification is the least understood. To redress this imbalance, recent studies of the halophilic archaeon Haloferax volcanii have identified a gene cluster encoding the Agl proteins involved in the assembly and attachment of a pentasaccharide to select Asn residues of the surface layer glycoprotein in this species. However, because the automated tools used for rapid annotation of genome sequences, including that of H. volcanii, are not always accurate, a reannotation of the agl cluster was undertaken in order to discover genes not previously recognized. In the present report, reanalysis of the gene cluster that includes aglB, aglE, aglF, aglG, aglI, and aglJ, which are known components of the H. volcanii protein N-glycosylation machinery, was undertaken. Using computer-based tools or visual inspection, together with transcriptional analysis and protein expression approaches, genes encoding AglP, AglQ, and AglR are now described.

  12. The study of organic removal efficiency and halophilic bacterial mixed liquor characteristics in a membrane bioreactor treating hypersaline produced water at varying organic loading rates.

    Science.gov (United States)

    Sharghi, Elham Abdollahzadeh; Bonakdarpour, Babak

    2013-12-01

    In this study the organic pollutant removal performance and the mixed liquor characteristics of a membrane bioreactor (MBR), employing a halophilic bacterial consortium, for the treatment of hypersaline synthetic produced water - at varying organic loading rates (OLR) from 0.3 to 2.6 kg CODm(-3)d(-1) - were considered. The oil and grease (O&G) and COD removal efficiency were 95-99% and 83-93%, respectively with only transient O&G (mainly polycyclic aromatic hydrocarbons) and soluble microbial products accumulation being observed. With increasing OLR, in the range 0.9-2.6 kg COD m(-3)d(-1), as a result of change in both extracellular polymeric substances (EPS) and zeta potential, bioflocculating ability improved but the compressibility of the flocs decreased resulting in the occurrence of EPS bulking at the highest OLR studied. The latter resulted in a change in the rheology of the mixed liquor from Newtonian to non-Newtonian and the occurrence of significant membrane fouling. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Morphotypes and pigment profiles of halophilic bacteria: Practical data useful for novelty, taxonomic categorization and for describing novel species or new taxa.

    Science.gov (United States)

    Rekadwad, Bhagwan N; Khobragade, Chandrahasya N

    2017-08-01

    Halophilic bacteria were isolated from oil spill samples collected from West-coast of Goa. Bacteria were isolated from oil studded soil, salt marsh and offshore samples (A, A7, CSM, CB and CM) collected along the West coastline in Goa (India) i.e. Arambol beach, Calanguate beach, Candolim beach and Colva beach on Zobell Marine agar, R2A agar, Mannitol salt agar and Blood agar at temperature 22 to 24 °C. Isolates showed growth in the presence of hydrocarbons (1% phenanthrene and 2% bitumen). Diverse profiles of pigments were observed on different nutrient medium. Color of pigments produced on agar media recorded as per standard color chart. All isolates showed different growth pattern. Isolate no 11 (GOACSMMS-11) showed three different morphological features/growth patterns on Zobell Marine Agar and R2A medium in the presence of hydrocarbons. Results obtained yield new information which gives a clear idea about morphological features and pigmented profiles of hydrocarbon resistant morphotypes in the presence different media compositions. The presented datasets will be useful for studies on bacterial species showing high sequence similarity. Hence, generated data serves as a benchmark for to distinguish between genetically similar bacteria and for further research in phenotype based microbial diversity, microbial ecology of microorganisms and microbial systematics and taxonomy in addition to genotype data.

  14. Methanohalophilus levihalophilus sp. nov., a slightly halophilic, methylotrophic methanogen isolated from natural gas-bearing deep aquifers, and emended description of the genus Methanohalophilus.

    Science.gov (United States)

    Katayama, Taiki; Yoshioka, Hideyoshi; Mochimaru, Hanako; Meng, Xian-Ying; Muramoto, Yoshiyuki; Usami, Jun; Ikeda, Hidefumi; Kamagata, Yoichi; Sakata, Susumu

    2014-06-01

    A mesophilic, slightly halophilic, obligately methylotrophic, methanogenic archaeon, designated strain GTA13(T), was isolated from natural gas-bearing confined aquifers in the Minami-Kanto gas field, Japan. The cells were non-motile, slightly irregular cocci, 0.7-1.0 µm in diameter and occurred singly, in pairs or as small aggregates. The cells grew with tri- or dimethylamine but not with H2/CO2, formate, acetate, methanol or dimethyl sulphide. Vitamins, sodium and magnesium were required for growth. Optimal growth occurred at pH 7.0-7.5, 35 °C, 0.35-0.40 M NaCl and 15-50 mM MgCl2. The NaCl range for growth was 0.2-1.3 M. The DNA G+C content was 43.7 mol%. Strain GTA13(T) showed highest levels of 16S rRNA gene sequence similarity with Methanohalophilus portucalensis FDF-1(T) (96.4% sequence similarity) and Methanohalophilus halophilus DSM 3094(T) (96.0%). On the basis of physiological and phylogenetic features, strain GTA13(T) is considered to represent a novel species of the genus Methanohalophilus, for which the name Methanohalophilus levihalophilus sp. nov. is proposed. The type strain is GTA13(T) ( = NBRC 110099(T) = DSM 28452(T)). An emended description of the genus Methanohalophilus is also proposed.

  15. 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.

  16. High quality draft genome sequence of the slightly halophilic bacterium Halomonas zhanjiangensis type strain JSM 078169T (DSM 21076T) from a sea urchin in southern China

    Science.gov (United States)

    Zhou, Yu; Li, Rui; Gao, Xiao-Yang; Lapidus, Alla; Han, James; Haynes, Matthew; Lobos, Elizabeth; Huntemann, Marcel; Pati, Amrita; Ivanova, Natalia N.; Rohde, Manfred; Mavromatis, Konstantinos; Tindall, Brian J.; Markowitz, Victor; Woyke, Tanja; Klenk, Hans-Peter; Kyrpides, Nikos C.; Li, Wen-Jun

    2014-01-01

    Halomonas zhanjiangensis Chen et al. 2009 is a member of the genus Halomonas, family Halomonadaceae, class Gammaproteobacteria. Representatives of the genus Halomonas are a group of halophilic bacteria often isolated from salty environments. The type strain H. zhanjiangensis JSM 078169T was isolated from a sea urchin (Hemicentrotus pulcherrimus) collected from the South China Sea. The genome of strain JSM 078169T is the fourteenth sequenced genome in the genus Halomonas and the fifteenth in the family Halomonadaceae. The other thirteen genomes from the genus Halomonas are H. halocynthiae, H. venusta, H. alkaliphila, H. lutea, H. anticariensis, H. jeotgali, H. titanicae, H. desiderata, H. smyrnensis, H. salifodinae, H. boliviensis, H. elongata and H stevensii. Here, we describe the features of strain JSM 078169T, together with the complete genome sequence and annotation from a culture of DSM 21076T. The 4,060,520 bp long draft genome consists of 17 scaffolds with the 3,659 protein-coding and 80 RNA genes and is a part of Genomic Encyclopedia of Type Strains, Phase I: the one thousand microbial genomes (KMG) project. PMID:25197480

  17. The freshwater cyanobacterium Anabaena doliolum transformed with ApGSMT-DMT exhibited enhanced salt tolerance and protection to nitrogenase activity, but became halophilic.

    Science.gov (United States)

    Singh, Meenakshi; Sharma, Naveen K; Prasad, Shyam Babu; Yadav, Suresh Singh; Narayan, Gopeshwar; Rai, Ashwani K

    2013-03-01

    Glycine betaine (GB) is an important osmolyte synthesized in response to different abiotic stresses, including salinity. The two known pathways of GB synthesis involve: 1) two step oxidation of choline (choline → betaine aldehyde → GB), generally found in plants, microbes and animals; and 2) three step methylation of glycine (glycine → sarcosine → dimethylglycine → GB), mainly found in halophilic archaea, sulphur bacteria and the cyanobacterium Aphanothece (Ap.) halophytica. Here, we transformed a salt-sensitive freshwater diazotrophic filamentous cyanobacterium Anabaena (An.) doliolum with N-methyltransferase genes (ApGSMT-DMT) from Ap. halophytica using the triparental conjugation method. The transformed An. doliolum synthesized and accumulated GB in cells, and showed increased salt tolerance and protection to nitrogenase activity. The salt responsiveness of the transformant was also apparent as GB synthesis increased with increasing concentrations of NaCl in the nutrient solution, and maximal [12.92 µmol (g dry weight)(-1)] in cells growing at 0.5 M NaCl. Therefore, the transformed cyanobacterium has changed its behaviour from preferring freshwater to halophily. This study may have important biotechnological implications for the development of stress tolerant nitrogen-fixing cyanobacteria as biofertilizers for sustainable agriculture.

  18. High quality draft genome sequence of the slightly halophilic bacterium Halomonas zhanjiangensis type strain JSM 078169(T) (DSM 21076(T)) from a sea urchin in southern China.

    Science.gov (United States)

    Zhou, Yu; Li, Rui; Gao, Xiao-Yang; Lapidus, Alla; Han, James; Haynes, Matthew; Lobos, Elizabeth; Huntemann, Marcel; Pati, Amrita; Ivanova, Natalia N; Rohde, Manfred; Mavromatis, Konstantinos; Tindall, Brian J; Markowitz, Victor; Woyke, Tanja; Klenk, Hans-Peter; Kyrpides, Nikos C; Li, Wen-Jun

    2014-06-15

    Halomonas zhanjiangensis Chen et al. 2009 is a member of the genus Halomonas, family Halomonadaceae, class Gammaproteobacteria. Representatives of the genus Halomonas are a group of halophilic bacteria often isolated from salty environments. The type strain H. zhanjiangensis JSM 078169(T) was isolated from a sea urchin (Hemicentrotus pulcherrimus) collected from the South China Sea. The genome of strain JSM 078169(T) is the fourteenth sequenced genome in the genus Halomonas and the fifteenth in the family Halomonadaceae. The other thirteen genomes from the genus Halomonas are H. halocynthiae, H. venusta, H. alkaliphila, H. lutea, H. anticariensis, H. jeotgali, H. titanicae, H. desiderata, H. smyrnensis, H. salifodinae, H. boliviensis, H. elongata and H stevensii. Here, we describe the features of strain JSM 078169(T), together with the complete genome sequence and annotation from a culture of DSM 21076(T). The 4,060,520 bp long draft genome consists of 17 scaffolds with the 3,659 protein-coding and 80 RNA genes and is a part of Genomic Encyclopedia of Type Strains, Phase I: the one thousand microbial genomes (KMG) project.

  19. Sulfate reduction and sulfide oxidation in extremely steep salinity gradients formed by freshwater springs emerging into the Dead Sea.

    Science.gov (United States)

    Häusler, Stefan; Weber, Miriam; Siebert, Christian; Holtappels, Moritz; Noriega-Ortega, Beatriz E; De Beer, Dirk; Ionescu, Danny

    2014-12-01

    Abundant microbial mats, recently discovered in underwater freshwater springs in the hypersaline Dead Sea, are mostly dominated by sulfur-oxidizing bacteria. We investigated the source of sulfide and the activity of these communities. Isotopic analysis of sulfide and sulfate in the spring water showed a fractionation of 39-50‰ indicative of active sulfate reduction. Sulfate reduction rates (SRR) in the spring sediment (Dead Sea water are responsible for the abundant microbial biomass around the springs. The springs flow is highly variable and accordingly the local salinities. We speculate that the development of microbial mats dominated by either Sulfurimonas/Sulfurovum-like or Thiobacillus/Acidithiobacillus-like sulfide-oxidizing bacteria, results from different mean salinities in the microenvironment of the mats. SRR of up to 10 nmol cm(-3) day(-1) detected in the Dead Sea sediment are surprisingly higher than in the less saline springs. While this shows the presence of an extremely halophilic sulfate-reducing bacteria community in the Dead Sea sediments, it also suggests that extensive salinity fluctuations limit these communities in the springs due to increased energetic demands for osmoregulation.

  20. Extreme conditions (p, T, H)

    Energy Technology Data Exchange (ETDEWEB)

    Mesot, J. [Lab. for Neutron Scattering ETH Zurich, Zurich (Switzerland) and Paul Scherrer Institute, Villigen (Switzerland)

    1996-11-01

    The aim of this paper is to summarize the sample environment which will be accessible at the SINQ. In order to illustrate the type of experiments which will be feasible under extreme conditions of temperature, magnetic field and pressure at the SINQ a few selected examples are also given. (author) 7 figs., 14 refs.

  1. Extreme cervical elongation after sacrohysteropexy

    NARCIS (Netherlands)

    Vierhout, M.E.; Futterer, J.J.

    2013-01-01

    We present a case of extreme cervical elongation with a cervix of 12 cm after an unusual operation in which the uterine corpus was directly fixed to the promontory, and which became symptomatic after 8 years. The possible pathophysiology of cervical elongation is discussed. Diagnosing a case of seve

  2. Applied extreme-value statistics

    Energy Technology Data Exchange (ETDEWEB)

    Kinnison, R.R.

    1983-05-01

    The statistical theory of extreme values is a well established part of theoretical statistics. Unfortunately, it is seldom part of applied statistics and is infrequently a part of statistical curricula except in advanced studies programs. This has resulted in the impression that it is difficult to understand and not of practical value. In recent environmental and pollution literature, several short articles have appeared with the purpose of documenting all that is necessary for the practical application of extreme value theory to field problems (for example, Roberts, 1979). These articles are so concise that only a statistician can recognise all the subtleties and assumptions necessary for the correct use of the material presented. The intent of this text is to expand upon several recent articles, and to provide the necessary statistical background so that the non-statistician scientist can recognize and extreme value problem when it occurs in his work, be confident in handling simple extreme value problems himself, and know when the problem is statistically beyond his capabilities and requires consultation.

  3. Astrobiology: Life in Extreme Environments

    Science.gov (United States)

    Kaur, Preeti

    2011-01-01

    Astrobiology is the study of the origin, evolution and distribution of life in the universe. It seeks to answer two important scientific questions: how did we get here and are we alone in the universe? Scientists begin by studying life on Earth and its limits. The discovery of extremophiles on Earth capable of surviving extremes encourages the…

  4. Extreme Energy Events Monitoring report

    CERN Document Server

    Baimukhamedova, Nigina

    2015-01-01

    Following paper reflects the progress I made on Summer Student Program within Extreme Energy Events Monitor project I was working on. During 8 week period I managed to build a simple detector system that is capable of triggering events similar to explosions (sudden change in sound levels) and measuring approximate location of the event. Source codes are available upon request and settings described further.

  5. Generic Hurricane Extreme Seas State

    DEFF Research Database (Denmark)

    Wehmeyer, Christof; Skourup, Jesper; Frigaard, Peter

    2012-01-01

    the US east coast and the Gulf of Mexico (1851 - 2009) and Japanese east coast (1951 -2009) form the basis for Weibull extreme value analyses to determine return period respective maximum wind speeds. Unidirectional generic sea state spectra are obtained by application of the empirical models...

  6. Astrobiology: Life in Extreme Environments

    Science.gov (United States)

    Kaur, Preeti

    2011-01-01

    Astrobiology is the study of the origin, evolution and distribution of life in the universe. It seeks to answer two important scientific questions: how did we get here and are we alone in the universe? Scientists begin by studying life on Earth and its limits. The discovery of extremophiles on Earth capable of surviving extremes encourages the…

  7. Extremal non-BPS black holes and entropy extremization

    CERN Document Server

    Lópes-Cardoso, G; Lust, D; Perz, J; Cardoso, Gabriel Lopes; Grass, Viviane; Lust, Dieter; Perz, Jan

    2006-01-01

    At the horizon, a static extremal black hole solution in N=2 supergravity in four dimensions is determined by a set of so-called attractor equations which, in the absence of higher-curvature interactions, can be derived as extremization conditions for the black hole potential or, equivalently, for the entropy function. We contrast both methods by explicitly solving the attractor equations for a one-modulus prepotential associated with the conifold. We find that near the conifold point, the non-supersymmetric solution has a substantially different behavior than the supersymmetric solution. We analyze the stability of the solutions and the extrema of the resulting entropy as a function of the modulus. For the non-BPS solution the region of attractivity and the maximum of the entropy do not coincide with the conifold point.

  8. Comparative community genomics in the Dead Sea: an increasingly extreme environment.

    Science.gov (United States)

    Bodaker, Idan; Sharon, Itai; Suzuki, Marcelino T; Feingersch, Roi; Shmoish, Michael; Andreishcheva, Ekaterina; Sogin, Mitchell L; Rosenberg, Mira; Maguire, Michael E; Belkin, Shimshon; Oren, Aharon; Béjà, Oded

    2010-03-01

    Owing to the extreme salinity ( approximately 10 times saltier than the oceans), near toxic magnesium levels (approximately 2.0 M Mg(2+)), the dominance of divalent cations, acidic pH (6.0) and high-absorbed radiation flux rates, the Dead Sea represents a unique and harsh ecosystem. Measures of microbial presence (microscopy, pigments and lipids) indicate that during rare bloom events after exceptionally rainy seasons, the microbial communities can reach high densities. However, most of the time, when the Dead Sea level is declining and halite is precipitating from the water column, it is difficult to reliably measure the presence of microorganisms and their activities. Although a number of halophilic Archaea have been previously isolated from the Dead Sea, polar lipid analyses of biomass collected during Dead Sea blooms suggested that these isolates were not the major components of the microbial community of these blooms. In this study, in an effort to characterize the perennial microbial community of the Dead Sea and compare it with bloom assemblages, we performed metagenomic analyses of concentrated biomass from hundreds of liters of brine and of microbial material from the last massive Dead Sea bloom. The difference between the two conditions was reflected in community composition and diversity, in which the bloom was different and less diverse from the residual brine population. The distributional patterns of microbial genes suggested Dead Sea community trends in mono- and divalent cation metabolisms as well as in transposable elements. This may indicate possible mechanisms and pathways enabling these microbes to survive in such a harsh environment.

  9. Performance and influencing factors of halophilic activated sludge in denitrifying of nitrite%嗜盐污泥反硝化亚硝酸盐的性能及其影响因素

    Institute of Scientific and Technical Information of China (English)

    崔有为; 丁洁然; 卢鹏飞; 彭永臻

    2012-01-01

    淡水污泥反硝化高盐废水受到盐度抑制而导致处理的失败.为了突破高盐废水脱氮的技术瓶颈,本研究通过采集人海口河底泥发展嗜盐脱氮生物系统实现了高盐废水的脱氮.本文系统地探讨了盐度、温度、pH和碳源类型等关键影响因素对嗜盐污泥反硝化亚硝酸的影响.试验结果表明:采集人海口底泥发展的嗜盐系统可以以亚硝酸盐作为电子受体进行反硝化.在38 g·L-1盐度下,嗜盐反硝化菌以甲醇作为碳源的最大反硝化速率为3.29 mg N·(g VSS)-1·h-1.系统最适宜盐度为15~51 g· L-1,最佳pH范围为8.0~9.0.反硝化碳源类型影响着反硝化速率.在测试的4种碳源类型中,嗜盐反硝化污泥利用甲醇进行反硝化较快.作为新认知的生物系统,确定高盐废水嗜盐生物处理系统的反硝化特性和影响因素对于实现高盐废水的高效处理具有重要的意义.%It is not successful to denitrify waste-water with high content of salt by freshwater activated sludge because of salinity choking. To overcome this problem, halophilic activated sludge must be developed. In this study, activated sediment at estuary of a river was collected and cultured to get halophilic activated sludge. The effect of key factors, such as salinity, temperature, pH and carbon source etc. , on denitrifying-nitrite performance of the halophilic activated sludge was studied. The results show that nitrite can be denitrified by the halophilic system via utilizing it as electron acceptor. As a result, the halophilic activated sludge is of ability to denitrify highly saline wastewater. At 38 g · L-1 salinity environment,the maximum specific denitrification rate of the biological system is 3. 29 mg N · (g VSS)-1 · h-1. These key operation parameters were optimized for further engineering design; the optimal survival salinity is 15-51 g · L-1 and pH 8. 0-9. 0. Carbon source has a great influence on denitrification rate. Among

  10. On causality of extreme events

    CERN Document Server

    Zanin, Massimiliano

    2016-01-01

    Multiple metrics have been developed to detect causality relations between data describing the elements constituting complex systems, all of them considering their evolution through time. Here we propose a metric able to detect causality within static data sets, by analysing how extreme events in one element correspond to the appearance of extreme events in a second one. The metric is able to detect both linear and non-linear causalities; to analyse both cross-sectional and longitudinal data sets; and to discriminate between real causalities and correlations caused by confounding factors. We validate the metric through synthetic data, dynamical and chaotic systems, and data representing the human brain activity in a cognitive task.

  11. Extreme Conditions Modeling Workshop Report

    Energy Technology Data Exchange (ETDEWEB)

    Coe, Ryan Geoffrey [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Neary, Vincent Sinclair [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Lawon, Michael J. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Yu, Yi-Hsiang [National Renewable Energy Lab. (NREL), Golden, CO (United States); Weber, Jochem [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2014-07-01

    Sandia National Laboratories (SNL) and the National Renewable Energy Laboratory (NREL) hosted the Wave Energy Converter (WEC) Extreme Conditions Modeling (ECM) Workshop in Albuquerque, New Mexico on May 13–14, 2014. The objective of the workshop was to review the current state of knowledge on how to numerically and experimentally model WECs in extreme conditions (e.g. large ocean storms) and to suggest how national laboratory resources could be used to improve ECM methods for the benefit of the wave energy industry. More than 30 U.S. and European WEC experts from industry, academia, and national research institutes attended the workshop, which consisted of presentations from W EC developers, invited keynote presentations from subject matter experts, breakout sessions, and a final plenary session .

  12. Cacti with Extremal PI Index

    Directory of Open Access Journals (Sweden)

    Chunxiang Wang

    2016-12-01

    Full Text Available The vertex PI index PI(G=∑ xy∈E(G [n xy (x‎+‎n xy (y] PI(G=∑xy∈E(G[nxy(x‎+‎nxy(y] is a distance-based molecular structure descriptor‎, ‎where n xy (x nxy(x denotes the number of vertices which are closer to the vertex x x than to the vertex y y and which has been the considerable research in computational chemistry dating back to Harold Wiener in 1947‎. ‎A connected graph is a cactus if any two of its cycles have at most one common vertex‎. ‎In this paper‎, ‎we completely determine the extremal graphs with the greatest and smallest vertex PI indices mong all cacti with a fixed number of vertices‎. ‎As a consequence‎, ‎we obtain the sharp bounds with corresponding extremal cacti and extend a known result‎.

  13. On causality of extreme events

    Directory of Open Access Journals (Sweden)

    Massimiliano Zanin

    2016-06-01

    Full Text Available Multiple metrics have been developed to detect causality relations between data describing the elements constituting complex systems, all of them considering their evolution through time. Here we propose a metric able to detect causality within static data sets, by analysing how extreme events in one element correspond to the appearance of extreme events in a second one. The metric is able to detect non-linear causalities; to analyse both cross-sectional and longitudinal data sets; and to discriminate between real causalities and correlations caused by confounding factors. We validate the metric through synthetic data, dynamical and chaotic systems, and data representing the human brain activity in a cognitive task. We further show how the proposed metric is able to outperform classical causality metrics, provided non-linear relationships are present and large enough data sets are available.

  14. On causality of extreme events

    Science.gov (United States)

    2016-01-01

    Multiple metrics have been developed to detect causality relations between data describing the elements constituting complex systems, all of them considering their evolution through time. Here we propose a metric able to detect causality within static data sets, by analysing how extreme events in one element correspond to the appearance of extreme events in a second one. The metric is able to detect non-linear causalities; to analyse both cross-sectional and longitudinal data sets; and to discriminate between real causalities and correlations caused by confounding factors. We validate the metric through synthetic data, dynamical and chaotic systems, and data representing the human brain activity in a cognitive task. We further show how the proposed metric is able to outperform classical causality metrics, provided non-linear relationships are present and large enough data sets are available. PMID:27330866

  15. Upper Extremity Injuries in Gymnasts.

    Science.gov (United States)

    Wolf, Megan R; Avery, Daniel; Wolf, Jennifer Moriatis

    2017-02-01

    Gymnastics is a unique sport, which loads the wrist and arms as weight-bearing extremities. Because of the load demands on the wrist in particular, stress fractures, physeal injury, and overuse syndromes may be observed. This spectrum of injury has been termed "gymnast's wrist," and incorporates such disorders as wrist capsulitis, ligamentous tears, triangular fibrocartilage complex tears, chondromalacia of the carpus, stress fractures, distal radius physeal arrest, and grip lock injury.

  16. Racial Extremism in the Army

    Science.gov (United States)

    1998-04-01

    example, one soldier has a picture of Martin Luther King ;. another has a picture of Ronald Reagan). What is legal, appropriate action? (1) The particular...degree requirements for the 46h Judge Advocate Officer Graduate Course. 2 Virginia A. White, Killings Tied to Racism , FAYETTEVILLE OBSERVER-TIMES...causes to lure new members to their organizations. Lieutenant Colonel Edwin W. Anderson, Jr ., Right Wing Extremism in America and its Implications for

  17. Typologies of Extreme Longevity Myths

    OpenAIRE

    2010-01-01

    Purpose. Political, national, religious, and other motivations have led the media and even scientists to errantly accept extreme longevity claims prima facie. We describe various causes of false claims of extraordinary longevity. Design and Methods. American Social Security Death Index files for the period 1980–2009 were queried for individuals with birth and death dates yielding ages 110+ years of age. Frequency was compared to a list of age-validated supercentenarians maintained by the Ge...

  18. Promoting Exit from Violent Extremism

    DEFF Research Database (Denmark)

    Dalgaard-Nielsen, Anja

    2013-01-01

    A number of Western countries are currently adding exit programs targeting militant Islamists to their counterterrorism efforts. Drawing on research into voluntary exit from violent extremism, this article identifies themes and issues that seem to cause doubt, leading to exit. It then provides...... the influence attempt as subtle as possible, use narratives and self-affirmatory strategies to reduce resistance to persuasion, and consider the possibility to promote attitudinal change via behavioral change as an alternative to seek to influence beliefs directly....

  19. Moderate and extreme maternal obesity.

    LENUS (Irish Health Repository)

    Abdelmaboud, M O

    2012-05-01

    The aim of this study was to investigate the prevalence of moderate and extreme obesity among an Irish obstetric population over a 10-year period, and to evaluate the obstetric features of such pregnancies. Of 31,869 women delivered during the years 2000-2009, there were 306 women in the study group, including 173 in the moderate or Class 2 obese category (BMI 35-39.9) and 133 in the extreme or Class 3 obese category (BMI > or = 40).The prevalence of obese women with BMI > or = 35 was 9.6 per 1000 (0.96%), with an upward trend observed from 2.1 per 1000 in the year 2000, to 11.8 per 1000 in the year 2009 (P = 0.001). There was an increase in emergency caesarean section (EMCS) risk for primigravida versus multigravid women, within both obese categories (P < 0.001). However, there was no significant difference in EMCS rates observed between Class 2 and Class 3 obese women, when matched for parity. The prevalence of moderate and extreme obesity reported in this population is high, and appears to be increasing. The increased rates of abdominal delivery, and the levels of associated morbidity observed, have serious implications for such women embarking on pregnancy.

  20. Technology improves upper extremity rehabilitation.

    Science.gov (United States)

    Kowalczewski, Jan; Prochazka, Arthur

    2011-01-01

    Stroke survivors with hemiparesis and spinal cord injury (SCI) survivors with tetraplegia find it difficult or impossible to perform many activities of daily life. There is growing evidence that intensive exercise therapy, especially when supplemented with functional electrical stimulation (FES), can improve upper extremity function, but delivering the treatment can be costly, particularly after recipients leave rehabilitation facilities. Recently, there has been a growing level of interest among researchers and healthcare policymakers to deliver upper extremity treatments to people in their homes using in-home teletherapy (IHT). The few studies that have been carried out so far have encountered a variety of logistical and technical problems, not least the difficulty of conducting properly controlled and blinded protocols that satisfy the requirements of high-level evidence-based research. In most cases, the equipment and communications technology were not designed for individuals with upper extremity disability. It is clear that exercise therapy combined with interventions such as FES, supervised over the Internet, will soon be adopted worldwide in one form or another. Therefore it is timely that researchers, clinicians, and healthcare planners interested in assessing IHT be aware of the pros and cons of the new technology and the factors involved in designing appropriate studies of it. It is crucial to understand the technical barriers, the role of telesupervisors, the motor improvements that participants can reasonably expect and the process of optimizing IHT-exercise therapy protocols to maximize the benefits of the emerging technology.

  1. Typologies of Extreme Longevity Myths

    Directory of Open Access Journals (Sweden)

    Robert D. Young

    2010-01-01

    Full Text Available Purpose. Political, national, religious, and other motivations have led the media and even scientists to errantly accept extreme longevity claims prima facie. We describe various causes of false claims of extraordinary longevity. Design and Methods. American Social Security Death Index files for the period 1980–2009 were queried for individuals with birth and death dates yielding ages 110+ years of age. Frequency was compared to a list of age-validated supercentenarians maintained by the Gerontology Research Group who died during the same time period. Age claims of 110+ years and the age validation experiences of the authors facilitated a list of typologies of false age claims. Results. Invalid age claim rates increase with age from 65% at age 110-111 to 98% by age 115 to 100% for 120+ years. Eleven typologies of false claims were: Religious Authority Myth, Village Elder Myth, Fountain of Youth Myth (substance, Shangri-La Myth (geographic, Nationalist Pride, Spiritual Practice, Familial Longevity, Individual and/or Family Notoriety, Military Service, Administrative Entry Error, and Pension-Social Entitlement Fraud. Conclusions. Understanding various causes of false extreme age claims is important for placing current, past, and future extreme longevity claims in context and for providing a necessary level of skepticism.

  2. The Isolation and Enzyme Screening of Moderate Halophilic Bacteria from Tangshan Daqinghe Saltwork%唐山大清河盐场中度嗜盐菌的分离及功能酶的筛选

    Institute of Scientific and Technical Information of China (English)

    胡居猛; 贾瑞雪; 吴乐天; 杜文博; 唐红梅

    2014-01-01

    为了调查唐山大清河盐场的中度嗜盐菌资源,采集晒盐场的盐泥进行嗜盐菌的分离纯化,并进行形态学观察、生理生化特征鉴定和功能酶筛选。结果分离得到14株中度嗜盐菌。这些嗜盐菌的菌落呈黄色或者乳白色,较小,不透明,边缘整齐;细菌多呈杆状,革兰氏染色均呈阴性。生理生化特征鉴定显示,14株菌株中的3株甲基红试验阳性,3株伏-普试验阳性,3株可分解含硫的氨基酸,5株可利用柠檬酸作为碳源。多株菌可释放功能酶,其中6株产淀粉酶,7株产纤维素酶,7株产脂肪酶和6株产蛋白酶。该研究虽然仅获取了少量的中度嗜盐菌,但为开发利用唐山大清河盐场的嗜盐菌资源提供了参考。%The research aims to investigate the resources of moderate halophilic bacteria from Daqinghe saltwork of Tangshan. Mud samples are obtained from it, and 14 halophilic strains are isolated. They are small opaque colonies which are yellow or milky white. The cells of the isolates are mostly rod or cocci shaped and all the strains are gram negative. Physiological biochemical characteristics are analyzed. The important enzymes from these strains are screened subsequently. The results show that 6 strains produced amylase, 7 strains produced cellulose, 7 strains produced lipase and 6 strains produced protease. This research is to obtain a small amount of moderate halophilic bacteria, it provides references for reasonable development and utilization of halophilic microbial resources.

  3. Influence of F/F on PHB production by halophilic activated sludge fed by sodium acetate%F/F对嗜盐污泥以乙酸钠为底物生产PHB能力的影响

    Institute of Scientific and Technical Information of China (English)

    崔有为; 冀思远; 卢鹏飞; 张宏宇

    2015-01-01

    Poly-β-hydroxybutyrate (PHB) production by halophilic mixed consortia has great advantage in cost. PHB production by the two-step production process using halophilic activated sludge cultured from estuary sediment was investigated. During the continuous 300 d, the ability of PHB storage at different F/F was assessed from the performance of the long-term tests, experiments of PHB production and the observed kinetics. The ratio of feast to famine (F/F) as an important parameter directly affected the capacity of the PHB-storing of halophilic activated sludge. At a high F/F the non PHB-storing bacteria became dominant in the enrichment reactor, while a low F/F was in favor of the selection and enrichment of PHB-storing bacteria. Moreover, the culture selected at F/F less than 0.33 showed the best PHB-storing capacity with a PHB content of 46.7%cell dry weight and a PHB yield of 0.358 mg PHB·(mg Ac)−1. The results obtained in the study provided a guidance to the production of PHB by halophilic activated sludge.%嗜盐混合菌生产PHB具有较好的成本优势。本研究接种入海口底泥发展嗜盐活性污泥,利用嗜盐活性污泥以两步法工艺生产PHB。在连续300 d的试验中从长期试验、发酵生产PHB以及表观动力学等方面探索了不同盛宴期/饥饿期(F/F)下筛选菌群的PHB积累能力。研究发现F/F作为重要的参数直接影响嗜盐活性污泥的PHB积累能力。在高F/F下非PHB积累菌群成为优势菌,而低F/F下促进高聚PHB嗜盐菌的选择和富集。在F/F≤0.33条件下筛选的嗜盐活性污泥最大PHB含量可以达到细胞干重的46.7%,PHB产率为0.358 mg PHB·(mg Ac)−1。研究结果将对进一步实现嗜盐污泥生产PHB提供有益的指导。

  4. Outcomes for extremely premature infants.

    Science.gov (United States)

    Glass, Hannah C; Costarino, Andrew T; Stayer, Stephen A; Brett, Claire M; Cladis, Franklyn; Davis, Peter J

    2015-06-01

    Premature birth is a significant cause of infant and child morbidity and mortality. In the United States, the premature birth rate, which had steadily increased during the 1990s and early 2000s, has decreased annually for 7 years and is now approximately 11.39%. Human viability, defined as gestational age at which the chance of survival is 50%, is currently approximately 23 to 24 weeks in developed countries. Infant girls, on average, have better outcomes than infant boys. A relatively uncomplicated course in the intensive care nursery for an extremely premature infant results in a discharge date close to the prenatal estimated date of confinement. Despite technological advances and efforts of child health experts during the last generation, the extremely premature infant (less than 28 weeks gestation) and extremely low birth weight infant (death and disability with 30% to 50% mortality and, in survivors, at least 20% to 50% risk of morbidity. The introduction of continuous positive airway pressure, mechanical ventilation, and exogenous surfactant increased survival and spurred the development of neonatal intensive care in the 1970s through the early 1990s. Routine administration of antenatal steroids during premature labor improved neonatal mortality and morbidity in the late 1990s. The recognition that chronic postnatal administration of steroids to infants should be avoided may have improved outcomes in the early 2000s. Evidence from recent trials attempting to define the appropriate target for oxygen saturation in preterm infants suggests arterial oxygen saturation between 91% and 95% (compared with 85%-89%) avoids excess mortality; however, final analyses of data from these trials have not been published, so definitive recommendations are still pending. The development of neonatal neurocritical intensive care units may improve neurocognitive outcomes in this high-risk group. Long-term follow-up to detect and address developmental, learning, behavioral, and

  5. 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.

  6. Purification and Characterization of a Polyextremophilic α-Amylase from an Obligate Halophilic Aspergillus penicillioides Isolate and Its Potential for Souse with Detergents

    Science.gov (United States)

    Ali, Imran; Akbar, Ali; Anwar, Mohammad; Prasongsuk, Sehanat; Lotrakul, Pongtharin; Punnapayak, Hunsa

    2015-01-01

    An extracellular α-amylase from the obligate halophilic Aspergillus penicillioides TISTR3639 strain was produced and enriched to apparent homogeneity by ammonium sulfate precipitation and Sephadex G100 gel filtration column chromatography. The mass of the purified amylase was estimated to be 42 kDa by SDS-PAGE. With soluble starch as the substrate it had a specific activity of 118.42 U·mg−1 and Vmax⁡ and Km values of 1.05 µmol·min−1·mg−1 and 5.41 mg·mL−1, respectively. The enzyme was found to have certain polyextremophilic characteristics, with an optimum activity at pH 9, 80°C, and 300 g·L−1 NaCl. The addition of CaCl2 at 2 mM was found to slightly enhance the amylase activity, while ZnCl2, FeCl2, or EDTA at 2 mM was strongly or moderately inhibitory, respectively, suggesting the requirement for a (non-Fe2+ or Zn2+) divalent cation. The enzyme retained more than 80% of its activity when incubated with three different laundry detergents and had a better performance compared to a commercial amylase and three detergents in the presence of increasing NaCl concentrations up to 300 g·L−1. Accordingly, it has a good potential for use as an α-amylase in a low water activity (high salt concentration) and at high pH and temperatures. PMID:26180787

  7. Purification and Characterization of a Polyextremophilic α -Amylase from an Obligate Halophilic Aspergillus penicillioides Isolate and Its Potential for Souse with Detergents.

    Science.gov (United States)

    Ali, Imran; Akbar, Ali; Anwar, Mohammad; Prasongsuk, Sehanat; Lotrakul, Pongtharin; Punnapayak, Hunsa

    2015-01-01

    An extracellular α-amylase from the obligate halophilic Aspergillus penicillioides TISTR3639 strain was produced and enriched to apparent homogeneity by ammonium sulfate precipitation and Sephadex G100 gel filtration column chromatography. The mass of the purified amylase was estimated to be 42 kDa by SDS-PAGE. With soluble starch as the substrate it had a specific activity of 118.42 U · mg(-1) and Vmax and Km values of 1.05 µmol · min(-1) · mg(-1) and 5.41 mg · mL(-1), respectively. The enzyme was found to have certain polyextremophilic characteristics, with an optimum activity at pH 9, 80 °C, and 300 g · L(-1) NaCl. The addition of CaCl2 at 2 mM was found to slightly enhance the amylase activity, while ZnCl2, FeCl2, or EDTA at 2 mM was strongly or moderately inhibitory, respectively, suggesting the requirement for a (non-Fe(2+) or Zn(2+)) divalent cation. The enzyme retained more than 80% of its activity when incubated with three different laundry detergents and had a better performance compared to a commercial amylase and three detergents in the presence of increasing NaCl concentrations up to 300 g · L(-1). Accordingly, it has a good potential for use as an α-amylase in a low water activity (high salt concentration) and at high pH and temperatures.

  8. Purification and Characterization of a Polyextremophilic α-Amylase from an Obligate Halophilic Aspergillus penicillioides Isolate and Its Potential for Souse with Detergents

    Directory of Open Access Journals (Sweden)

    Imran Ali

    2015-01-01

    Full Text Available An extracellular α-amylase from the obligate halophilic Aspergillus penicillioides TISTR3639 strain was produced and enriched to apparent homogeneity by ammonium sulfate precipitation and Sephadex G100 gel filtration column chromatography. The mass of the purified amylase was estimated to be 42 kDa by SDS-PAGE. With soluble starch as the substrate it had a specific activity of 118.42 U·mg−1 and Vmax⁡ and Km values of 1.05 µmol·min−1·mg−1 and 5.41 mg·mL−1, respectively. The enzyme was found to have certain polyextremophilic characteristics, with an optimum activity at pH 9, 80°C, and 300 g·L−1 NaCl. The addition of CaCl2 at 2 mM was found to slightly enhance the amylase activity, while ZnCl2, FeCl2, or EDTA at 2 mM was strongly or moderately inhibitory, respectively, suggesting the requirement for a (non-Fe2+ or Zn2+ divalent cation. The enzyme retained more than 80% of its activity when incubated with three different laundry detergents and had a better performance compared to a commercial amylase and three detergents in the presence of increasing NaCl concentrations up to 300 g·L−1. Accordingly, it has a good potential for use as an α-amylase in a low water activity (high salt concentration and at high pH and temperatures.

  9. Ectoine from halophilic microorganisms induces the expression of hsp70 and hsp70B' in human keratinocytes modulating the proinflammatory response.

    Science.gov (United States)

    Buommino, Elisabetta; Schiraldi, Chiara; Baroni, Adone; Paoletti, Iole; Lamberti, Monica; De Rosa, Mario; Tufano, Maria Antonietta

    2005-01-01

    The heat shock proteins (Hsps) have an important role in the cytoprotection and repair of cells and tissues. One potential mechanism of protection is the ability of Hsp to inhibit genetic expression of proinflammatory cytokines, the transcription of which is dependent on nuclear factor-kappa B (NF-kappaB) activation. In this study, we evaluated the ability of ectoine, a novel natural biomolecule produced by halophilic microorganisms, to activate the hsp70 and hsp70B'. By reverse transcriptase-polymerase chain reaction and Western blot analysis, we demonstrated increased hsp70B' gene expression in human keratinocytes treated with ectoine and heat stressed. In contrast, in the absence of heat shock, ectoine was unable to induce hsp70B' but had the ability to induce another member of the Hsp family, the hsp70. The latter is not only elevated in response to stress but is also present at basal level in unstressed cells. In addition, ectoine had no effect on proinflammatory cytokines interleukin (IL)-1alpha, IL-6, IL-8, and tumor necrosis factor-alpha and on NF-kappaB and IkappaB-alpha pathway, whereas it downregulated the expression of cited proinflammatory cytokines, in lipopolysaccharides-treated keratinocytes. These results highlighted the ability of ectoine to protect cells from stress conditions and to prevent cell damage by maintaining an elevated level of the Hsp70. Overall, these data might suggest the use of this compatible solute in cosmetic and even pharmaceutical preparations aiming to activate a cytoprotective heat shock response in human cells.

  10. 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.

  11. Protein glycosylation in Archaea: sweet and extreme.

    Science.gov (United States)

    Calo, Doron; Kaminski, Lina; Eichler, Jerry

    2010-09-01

    While each of the three domains of life on Earth possesses unique traits and relies on characteristic biological strategies, some processes are common to Eukarya, Bacteria and Archaea. Once believed to be restricted to Eukarya, it is now clear that Bacteria and Archaea are also capable of performing N-glycosylation. However, in contrast to Bacteria, where this posttranslational modification is still considered a rare event, numerous species of Archaea, isolated from a wide range of environments, have been reported to contain proteins bearing Asn-linked glycan moieties. Analysis of the chemical composition of the Asn-linked polysaccharides decorating archaeal proteins has, moreover, revealed the use of a wider variety of sugar subunits than seen in either eukaryal or bacterial glycoproteins. Still, although first reported some 30 years ago, little had been known of the steps or components involved in the archaeal version of this universal posttranslational modification. Now, with the availability of sufficient numbers of genome sequences and the development of appropriate experimental tools, molecular analysis of archaeal N-glycosylation pathways has become possible. Accordingly using halophilic, methanogenic and thermophilic model species, insight into the biosynthesis and attachment of N-linked glycans decorating archaeal glycoproteins is starting to amass. In this review, current understanding of N-glycosylation in Archaea is described.

  12. Outcomes for Extremely Premature Infants

    Science.gov (United States)

    Glass, Hannah C.; Costarino, Andrew T.; Stayer, Stephen A.; Brett, Claire; Cladis, Franklyn; Davis, Peter J.

    2015-01-01

    Premature birth is a significant cause of infant and child morbidity and mortality. In the United States, the premature birth rate, which had steadily increased during the 1990s and early 2000s, has decreased annually for four years and is now approximately 11.5%. Human viability, defined as gestational age at which the chance of survival is 50%, is currently approximately 23–24 weeks in developed countries. Infant girls, on average, have better outcomes than infant boys. A relatively uncomplicated course in the intensive care nursery for an extremely premature infant results in a discharge date close to the prenatal EDC. Despite technological advances and efforts of child health experts during the last generation, the extremely premature infant (less than 28 weeks gestation) and extremely low birth weight infant (ELBW) (premature labor improved neonatal mortality and morbidity in the late 1990s. The recognition that chronic postnatal administration of steroids to infants should be avoided may have improved outcomes in the early 2000s. Evidence from recent trials attempting to define the appropriate target for oxygen saturation in preterm infants suggests arterial oxygen saturation between 91–95% (compared to 85–89%) avoids excess mortality. However, final analyses of data from these trials have not been published, so definitive recommendations are still pending The development of neonatal neurocognitive care visits may improve neurocognitive outcomes in this high-risk group. Long-term follow up to detect and address developmental, learning, behavioral, and social problems is critical for children born at these early gestational ages. The striking similarities in response to extreme prematurity in the lung and brain imply that agents and techniques that benefit one organ are likely to also benefit the other. Finally, since therapy and supportive care continue to change, the outcomes of ELBW infants are ever evolving. Efforts to minimize injury, preserve

  13. Gravity and Extreme Magnetism SMEX

    Science.gov (United States)

    2012-01-01

    The Gravity and Extreme Magnetism SMEX mission will be the first mission to catalogue the X-ray polarisation of many astrophysical objects including black-holes and pulsars. This first of its kind mission is enabled by the novel use of a time projection chamber as an X-ray polarimeter. The detector has been developed over the last 5 years, with the current effort charged toward a demonstration of it's technical readiness to be at level 6 prior to the preliminary design review. This talk will describe the design GEMS polarimeter and the results to date from the engineering test unit.

  14. Communication path for extreme environments

    Science.gov (United States)

    Jorgensen, Charles C. (Inventor); Betts, Bradley J. (Inventor)

    2010-01-01

    Methods and systems for using one or more radio frequency identification devices (RFIDs), or other suitable signal transmitters and/or receivers, to provide a sensor information communication path, to provide location and/or spatial orientation information for an emergency service worker (ESW), to provide an ESW escape route, to indicate a direction from an ESW to an ES appliance, to provide updated information on a region or structure that presents an extreme environment (fire, hazardous fluid leak, underwater, nuclear, etc.) in which an ESW works, and to provide accumulated thermal load or thermal breakdown information on one or more locations in the region.

  15. Ionization Chamber Measures Extreme Ultraviolet

    Science.gov (United States)

    Carlson, Robert W.

    1987-01-01

    Ionization chamber operates in nearly total photon absorption as stable, self-calibrating detector of ionizing extreme ultraviolet radiation. Working gas of instrument is neon; photoionization properties well known and readily applicable to absolute measurements. Designed for measurements of solar ultraviolet flux aboard sounding rocket, instrument used on Earth to measure ultraviolet radiation in vacuum systems. Ionization chamber collects positive neon ions and electrons produced by irradiation of neon gas by ultraviolet photons. Approximately one ion produced by each photon; consequently, photoionization current nearly proportional to photon flux.

  16. Extreme Geomagnetic Storms - 1868 - 2010

    Science.gov (United States)

    Vennerstrom, S.; Lefevre, L.; Dumbović, M.; Crosby, N.; Malandraki, O.; Patsou, I.; Clette, F.; Veronig, A.; Vršnak, B.; Leer, K.; Moretto, T.

    2016-05-01

    We present the first large statistical study of extreme geomagnetic storms based on historical data from the time period 1868 - 2010. This article is the first of two companion papers. Here we describe how the storms were selected and focus on their near-Earth characteristics. The second article presents our investigation of the corresponding solar events and their characteristics. The storms were selected based on their intensity in the aa index, which constitutes the longest existing continuous series of geomagnetic activity. They are analyzed statistically in the context of more well-known geomagnetic indices, such as the Kp and Dcx/Dst index. This reveals that neither Kp nor Dcx/Dst provide a comprehensive geomagnetic measure of the extreme storms. We rank the storms by including long series of single magnetic observatory data. The top storms on the rank list are the New York Railroad storm occurring in May 1921 and the Quebec storm from March 1989. We identify key characteristics of the storms by combining several different available data sources, lists of storm sudden commencements (SSCs) signifying occurrence of interplanetary shocks, solar wind in-situ measurements, neutron monitor data, and associated identifications of Forbush decreases as well as satellite measurements of energetic proton fluxes in the near-Earth space environment. From this we find, among other results, that the extreme storms are very strongly correlated with the occurrence of interplanetary shocks (91 - 100 %), Forbush decreases (100 %), and energetic solar proton events (70 %). A quantitative comparison of these associations relative to less intense storms is also presented. Most notably, we find that most often the extreme storms are characterized by a complexity that is associated with multiple, often interacting, solar wind disturbances and that they frequently occur when the geomagnetic activity is already elevated. We also investigate the semiannual variation in storm occurrence

  17. Advances in upper extremity prosthetics.

    Science.gov (United States)

    Zlotolow, Dan A; Kozin, Scott H

    2012-11-01

    Until recently, upper extremity prostheses had changed little since World War II. In 2006, the Defense Advanced Research Projects Agency responded to an increasing number of military amputees with the Revolutionizing Prosthetics program. The program has yielded several breakthroughs both in the engineering of new prosthetic arms and in the control of those arms. Direct brain-wave control of a limb with 22° of freedom may be within reach. In the meantime, advances such as individually powered digits have opened the door to multifunctional full and partial hand prostheses. Restoring sensation to the prosthetic limb remains a major challenge to full integration of the limb into a patient's self-image.

  18. 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.

  19. 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 Km and Vmax 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.

  20. Prevention of Lower Extremity Injuries in Basketball

    OpenAIRE

    2015-01-01

    Context: Lower extremity injuries are common in basketball, yet it is unclear how prophylactic interventions affect lower extremity injury incidence rates. Objective: To analyze the effectiveness of current lower extremity injury prevention programs in basketball athletes, focusing on injury rates of (1) general lower extremity injuries, (2) ankle sprains, and (3) anterior cruciate ligament (ACL) tears. Data Sources: PubMed, MEDLINE, CINAHL, SPORTDiscus, and the Cochrane Register of Controlle...

  1. Dynamics of extremal black holes

    CERN Document Server

    Giddings, Steven B

    1992-01-01

    Particle scattering and radiation by a magnetically charged, dilatonic black hole is investigated near the extremal limit at which the mass is a constant times the charge. Near this limit a neighborhood of the horizon of the black hole is closely approximated by a trivial product of a two-dimensional black hole with a sphere. This is shown to imply that the scattering of long-wavelength particles can be described by a (previously analyzed) two-dimensional effective field theory, and is related to the formation/evaporation of two-dimensional black holes. The scattering proceeds via particle capture followed by Hawking re-emission, and naively appears to violate unitarity. However this conclusion can be altered when the effects of backreaction are included. Particle-hole scattering is discussed in the light of a recent analysis of the two-dimensional backreaction problem. It is argued that the quantum mechanical possibility of scattering off of extremal black holes implies the potential existence of additional ...

  2. EXTREMAL CONTROL FOR PHOTOVOLTAIC PANELS

    Directory of Open Access Journals (Sweden)

    Genevieve DAPHIN TANGUY

    2016-11-01

    Full Text Available In this paper a methodology for extremal control of photovoltaic panels has been designed through the use of an embedded polynomial controller using robust approaches and algorithms. Also, a framework for testing solar trackers in a hard ware in the loop (HIL configuration has been established. Efficient gradient based optimization methods were put in place in order to determine the parameters of the employed photovoltaic panel, as well as for computing the Maximum Power Point (MPP. Further a numerical RST controller has been computed in order to allow the panel to follow the movement of the sun to obtain a maximum energetic efficiency. A robustness analysis and correction procedure has been done on the RST polynomial algorithm. The hardware in the loop configuration allows for the development of a test and development platform which can be used for bringing improvements to the current design and also test different control approaches. For this, a microcontroller based solution was chosen. The achieved performances of the closed loop photovoltaic panel (PP system are validated in simulation using the MATLAB / SIMULINK environment and the WinPim & WinReg dedicated software. As it will be seen further in this paper, the extremal control of this design resides in a sequential set of computations used for obtaining the new Maximum Power Point at each change in the system.

  3. 利用嗜盐及耐盐菌处理高盐废水的现状与展望%Current Status and Prospects of Treatment of Hyperhaline Wastewater by Halophilic Bacteria and Halotolerant Bacteria

    Institute of Scientific and Technical Information of China (English)

    易绣光; 林俊岳

    2012-01-01

    This paper introduced the characteristics of halotolerant and halophilic bacteria, and their application and study status in the treatment of hyperhaline wastewater, pointed out the existing strain loss problem, and suggested replacing common bacterial strains with auto - flocculating halotolerant bacterial strains, which not only could solve the problem of strain loss, but also could produce microbial flocculants, and this was the key technology for the treatment of hyperhaline wastewater by halophilic bacteria and halotolerant bacteria.%介绍了嗜(耐)盐菌的特性及其在高盐废水处理工艺中的应用研究现状,指出了其存在菌种流失的问题,并提出了利用能自絮凝的耐盐菌代替普通菌种,不仅可解决菌种流失的问题,还能产生微生物絮凝剂,这是嗜(耐)盐菌生物处理高盐废水工艺的关键.

  4. Isolation, identification and characteristics of moderately halophilic bacteria in crab paste%蟹酱中度嗜盐菌的分离、鉴定及特性研究

    Institute of Scientific and Technical Information of China (English)

    吕彦; 孙业盈

    2012-01-01

    The aim of this study was to isolate and identify moderately halophilic bacteria from crab paste and investigate its morphological, physiological and biochemical characteristics. Three moderately halophilic bacteria PKY101, PKY102 and PKY103 were isolated. Moderately halophilic bacteria were isolated by Gibbons medium. Morphological tests, biochemical reactions and molecular identifications of 16S rDNA were applied to i-dentify the bacteria with determining growth characterization by spectrophotometry. Three strains were found to be gram-positive, non-sporulating and spherical, and the diameter of the strains was 0.6μm~1.9μm, 0.8μm ~1.0μm and 0.7μm~1.5μm, respectively. 16S rDNA alignment and phylo-genetic anlysis showed that the stain PKY101 had a 99% homology with Staphylococcus succinus, PKY102 had a 99% homology with Staphylococ-cus cohnii and PKY103 had a 99% homology with Staphylococcus equorum. Our result could provided some references for study of halophilic bacteria structure in crab paste and prevention of halophilic bacteria contamination.%从蟹酱中分离纯化鉴定嗜盐菌,对其进行形态学和生理生化特性研究.采用Gibbons培养基分离纯化,通过形态学、生理生化实验进行特性研究,16S rDNA序列比对分析进行鉴定,吸光度法测定生长特性.结果分离得到3株中度嗜盐菌PKY101,PKY102和PKY103,试验结果表明,3种嗜盐菌均为革兰氏阳性菌,不产芽孢,菌体呈球状,直径分别为0.6μm~1.9μm,0.8μm~1.0μm,0.7μm~1.5μm;系统发育分析将3株嗜盐菌鉴定为葡萄球菌属(Staphylococcus)中的3个不同的种,分别为:琥珀葡萄球菌(Staphylococcus succinus)、科氏葡萄球菌(Staphylococcus cohnii)和马胃葡萄球菌(Staphylococcus equorum).本研究将为进一步研究蟹酱中的嗜盐菌的类型及在发酵盐渍类食品中的作用开展了前期的基础工作,为防止嗜盐菌污染食品提供了理论参考.

  5. Nitrification performance of wild halophilic mixed culture in treating highly saline domestic wastewater%野生型嗜盐混合菌群处理高盐生活污水的硝化性能

    Institute of Scientific and Technical Information of China (English)

    崔有为; 丁洁然; 李晶; 苏贺; 陈叶菲

    2011-01-01

    由于渗透压和无机盐生物毒性的影响,淡水活性污泥无法在高盐环境下进行正常的新陈代谢.生物处理高盐废水受到极大的挑战.为了解决这一难题,本研究采集人海口河底泥培养嗜盐活性污泥,并考察了该污泥的硝化性能.研究采用实际高盐生活污水探讨了嗜盐处理系统的启动、氨氮负荷和盐度冲击对系统硝化的影响.实验结果表明:经过9d适应期,嗜盐污泥开始硝化高盐生活污水中的氨氮.氨氮负荷及其负荷的稳定性对氨氮去除率具有显著影响.研究确定了嗜盐硝化系统的耐盐范围为10~60 g·L-1,而最优盐度在40 g· L-1左右.由于该嗜盐混合菌群是由海洋菌和中度嗜盐菌组成的,该系统具有良好的抗盐度冲击能力和硝化活性.尽管实验采用的操作条件不会对亚硝酸氧化菌构成抑制,但是研究中却发现显著的亚硝酸盐积累现象.该研究为实现高盐废水生物处理提供了有益探索.%Due to effects of high osmotic pressure and biological toxicity of inorganic salts, eubolism of activated sludge developing in fresh wastewater can not be carried out in highly saline wastewater. This difficulty could be solved by collecting, studying and culturing halophilic activated sludge from the estuary deposit at the mouth of the river. In this paper the effect of start-up, ammonium-nitrogen loading and salinity on nitrification performance of the halophilic nitrification culture in treating real saline domestic wastewater was studied. The results show that after 9 day adjustment stage, nitrification of ammonium-nitrogen is started. This halophilic system is sensitive to ammonium-nitrogen loading and its fluctuation. Salt tolerance of 10-60 g· L-1 as well as optimum salt of about 40 g· L-1 was established. Comparing with fresh activated sludge and salt-acclimation activated sludge, this system is of advantages of high specific ammonium removal rate and tolerance of salt

  6. Population diversity and phylogeny of halophiles in the Qinghai Lake%青海湖嗜盐微生物系统发育与种群多样性

    Institute of Scientific and Technical Information of China (English)

    朱德锐; 刘建; 韩睿; 沈国平; 杨芳; 龙启福; 刘德立

    2012-01-01

    Qinghai Lake is the largest inland saline lake in China, but the diversity of halophiles within the lake remains unknown. We isolated 35 bacterial strains from different water samples in Qinghai Lake using an Oesterhelt-Stoeckenius medium (OSM). The majority of halophiles in this lake were moderate halophiles (grew at 0.4 to 3.5 M NaCl), accounting for about 62.9% (22 strains) of total bacteria, followed by the slight halophiles (22.9%, 8 strains) which could grow at 0 to 1.0 M NaCl, whereas the halotolerant (grew at 0 to more than 1.0 M NaCl) and nonhalophile (grew at 0 to 1.0 M NaCl) represented 11.4% (4 strains) and 2.9% (1 strain) of total bacteria, respectively. We investigated and analyzed the population diversity and evolutionary relationship based on the 16S rDNA sequences. A total of 35 bacterial strains were sequenced, and ho-mology analysis showed that a majority was affiliated with y-Proteobacteria and Bacilli, which accounted for 68.6% (24 strains) and 17.1% (6 strains) of total bacteria, respectively, whereas Actinobacteridae (3 strains), a-Proteobacteria (1 strain) and Eurotiomycetidae (1 strain) represented a small portion of total bacteria. Based on phylogenetics, 35 strains belonged to 14 different genera. Ten strains of Halomonas in the Oceano-spiri Hales were the most dominant species, whereas 4 strains of Marinomonas represented a minor species component. Overall, Halomonas was the dominant group of moderate halophile, which can likely be attributed to its ability to adapt to relatively low salinity environments.%青海湖是我国境内最大的内陆咸水湖泊,水体中嗜盐微生物的生存现状尚不明确.本研究利用OSM培养基(Oesterhelt-Stoeckenius medium),从湖域生境水样中富集和分离获得嗜盐微生物35株,以中度嗜盐菌为主,约占62.9%(22株);轻度嗜盐菌次之,约占22.9%(8株);耐盐菌与非嗜盐菌分别占11.4%(4株)和2.9%(1株).根据16SrDNA序列的系统发育分析表明,γ-变形

  7. Predictability of extreme values in geophysical models

    Directory of Open Access Journals (Sweden)

    A. E. Sterk

    2012-09-01

    Full Text Available Extreme value theory in deterministic systems is concerned with unlikely large (or small values of an observable evaluated along evolutions of the system. In this paper we study the finite-time predictability of extreme values, such as convection, energy, and wind speeds, in three geophysical models. We study whether finite-time Lyapunov exponents are larger or smaller for initial conditions leading to extremes. General statements on whether extreme values are better or less predictable are not possible: the predictability of extreme values depends on the observable, the attractor of the system, and the prediction lead time.

  8. Proposal of Enhanced Extreme Programming Model

    Directory of Open Access Journals (Sweden)

    M. Rizwan Jameel Qureshi

    2015-01-01

    Full Text Available Extreme programming is one of the commonly used agile methodologies in software development. It is very responsive to changing requirements even in the late phases of the project. However, quality activities in extreme programming phases are implemented sequentially along with the activities that work on the functional requirements. This reduces the agility to deliver increments continuously and makes an inverse relationship between quality and agility. Due to this relationship, extreme programming does not consume enough time on making extensive documentation and robust design. To overcome these issues, an enhanced extreme programming model is proposed. Enhanced extreme programming introduces parallelism in the activities' execution through putting quality activities into a separate execution line. In this way, the focus on delivering increments quickly is achieved without affecting the quality of the final output. In enhanced extreme programming, the quality concept is extended to include refinement of all phases of classical extreme programming and creating architectural design based on the refined design documents.

  9. Interpretation of Extreme Scattering Events

    CERN Document Server

    Walker, M A

    2000-01-01

    Extreme Scattering Events are sometimes manifest in the light-curves of compact radio-quasars at frequencies of a few GHz. These events are not understood. The model which appears to offer the best explanation requires a new population of AU-sized, neutral gas clouds; these clouds would then make up a large fraction of the Galaxy's dark matter. Independent of the question of which theoretical model is correct, if we extrapolate the observed behaviour to low radio-frequencies, we expect that the sky should be criss-crossed by a network of narrow caustics, at frequencies below about 700 MHz. Consequently at these frequencies sources should typically manifest additional, faint images which are substantially delayed with respect to the primary image. Although some examples of this type of behaviour are already known, it is expected that these are just the tip of the iceberg, with strong selection biases having been imposed by the instrumentation employed to date.

  10. QCD matter in extreme environments

    CERN Document Server

    Fukushima, Kenji

    2011-01-01

    We review various theoretical approaches to the states of QCD matter out of quarks and gluons in extreme environments such as the high-temperature states at zero and finite baryon density and the dimensionally reduced state under an intense magnetic field. The topics at high temperature include the Polyakov loop and the 't Hooft loop in the perturbative regime, the Polyakov loop behaviour and the phase transition in some of non-perturbative methods; the strong-coupling expansion, the large-Nc limit and the holographic QCD models. These analyses are extended to hot and dense matter with a finite baryon chemical potential. We point out that the difficulty in the finite-density problem has similarity to that under a strong magnetic field. We make a brief summary of results related to the topological contents probed by the magnetic field and the Chiral Magnetic Effect. We also address the close connection to the (1+1) dimensional system.

  11. Extreme resilience in cochleate nanoparticles.

    Science.gov (United States)

    Bozó, Tamás; Brecska, Richárd; Gróf, Pál; Kellermayer, Miklós S Z

    2015-01-20

    Cochleates, prospective nanoscale drug delivery vehicles, are rolls of negatively charged phospholipid membrane layers. The membrane layers are held together by calcium ions; however, neither the magnitude of membrane interaction forces nor the overall mechanical properties of cochleates have been known. Here, we manipulated individual nanoparticles with atomic force microscopy to characterize their nanomechanical behavior. Their stiffness (4.2-12.5 N/m) and membrane-rupture forces (45.3-278 nN) are orders of magnitude greater than those of the tough viral nanoshells. Even though the fundamental building material of cochleates is a fluid membrane, the combination of supramolecular geometry, the cross-linking action of calcium, and the tight packing of the ions apparently lead to extreme mechanical resilience. The supramolecular design of cochleates may provide efficient protection for encapsulated materials and give clues to understanding biomolecular structures of similar design, such as the myelinated axon.

  12. Extreme ultraviolet Talbot interference lithography.

    Science.gov (United States)

    Li, Wei; Marconi, Mario C

    2015-10-05

    Periodic nanopatterns can be generated using lithography based on the Talbot effect or optical interference. However, these techniques have restrictions that limit their performance. High resolution Talbot lithography is limited by the very small depth of focus and the demanding requirements in the fabrication of the master mask. Interference lithography, with large DOF and high resolution, is limited to simple periodic patterns. This paper describes a hybrid extreme ultraviolet lithography approach that combines Talbot lithography and interference lithography to render an interference pattern with a lattice determined by a Talbot image. As a result, the method enables filling the arbitrary shaped cells produced by the Talbot image with interference patterns. Detailed modeling, system design and experimental results using a tabletop EUV laser are presented.

  13. Weather extremes could affect agriculture

    Science.gov (United States)

    Balcerak, Ernie

    2012-05-01

    As Earth's climate warms, agricultural producers will need to adapt. Changes, especially increases in extreme events, are already having an impact on food production, according to speakers at a 1 May session on agriculture and food security at the AGU Science Policy Conference. Christopher Field, director of the Department of Global Ecology at the Carnegie Institution for Science of Washington, D. C., pointed out the complex factors that come into play in understanding food security, including spatially varying controls and stresses, incomplete models, and the potential for threshold responses. Factors that are likely to cause problems include increasing population; increasing preference for meat, which needs more land and energy inputs to produce; climate change; and increasing use of agricultural lands for biomass energy.

  14. Reach Envelope of Human Extremities

    Institute of Scientific and Technical Information of China (English)

    YANG Jingzhou(杨景周); ZHANG Yunqing(张云清); CHEN Liping(陈立平); ABDEL-MALEK Karim

    2004-01-01

    Significant attention in recent years has been given to obtain a better understanding of human joint ranges, measurement, and functionality, especially in conjunction with commands issued by the central nervous system. While researchers have studied motor commands needed to drive a limb to follow a path trajectory, various computer algorithms have been reported that provide adequate analysis of limb modeling and motion. This paper uses a rigorous mathematical formulation to model human limbs, understand their reach envelope, delineate barriers therein where a trajectory becomes difficult to control, and help visualize these barriers. Workspaces of a typical forearm with 9 degrees of freedom, a typical finger modeled as a 4- degree-of-freedom system, and a lower extremity with 4 degrees of freedom are discussed. The results show that using the proposed formulation, joint limits play an important role in distinguishing the barriers.

  15. Generic Hurricane Extreme Seas State

    DEFF Research Database (Denmark)

    Wehmeyer, Christof; Skourup, Jesper; Frigaard, Peter

    2012-01-01

    Extreme sea states, which the IEC 61400-3 (2008) standard requires for the ultimate limit state (ULS) analysis of offshore wind turbines are derived to establish the design basis for the conceptual layout of deep water floating offshore wind turbine foundations in hurricane affected areas...... data is required for a type specific conceptual design. ULS conditions for different return periods are developed, which can subsequently be applied in siteindependent analysis and conceptual design. Recordings provided by National Oceanic and Atmospheric Administration (NOAA), of hurricanes along...... for hurricane generates seas by Young (1998, 2003, and 2006), requiring maximum wind speeds, forward velocity and radius to maximum wind speed. An averaged radius to maximum sustained wind speeds, according to Hsu et al. (1998) and averaged forward speed of cyclonic storms are applied in the initial state...

  16. Pneumatic tourniquets in extremity surgery.

    LENUS (Irish Health Repository)

    Wakai, A

    2012-02-03

    Pneumatic tourniquets maintain a relatively bloodless field during extremity surgery, minimize blood loss, aid identification of vital structures, and expedite the procedure. However, they may induce an ischemia-reperfusion injury with potentially harmful local and systemic consequences. Modern pneumatic tourniquets are designed with mechanisms to regulate and maintain pressure. Routine maintenance helps ensure that these systems are working properly. The complications of tourniquet use include postoperative swelling, delay of recovery of muscle power, compression neurapraxia, wound hematoma with the potential for infection, vascular injury, tissue necrosis, and compartment syndrome. Systemic complications can also occur. The incidence of complications can be minimized by use of wider tourniquets, careful preoperative patient evaluation, and adherence to accepted principles of tourniquet use.

  17. Acquired Upper Extremity Growth Arrest.

    Science.gov (United States)

    Gauger, Erich M; Casnovsky, Lauren L; Gauger, Erica J; Bohn, Deborah C; Van Heest, Ann E

    2017-01-01

    This study reviewed the clinical history and management of acquired growth arrest in the upper extremity in pediatric patients. The records of all patients presenting from 1996 to 2012 with radiographically proven acquired growth arrest were reviewed. Records were examined to determine the etiology and site of growth arrest, management, and complications. Patients with tumors or hereditary etiology were excluded. A total of 44 patients (24 boys and 20 girls) with 51 physeal arrests who presented at a mean age of 10.6 years (range, 0.8-18.2 years) were included in the study. The distal radius was the most common site (n=24), followed by the distal humerus (n=8), metacarpal (n=6), distal ulna (n=5), proximal humerus (n=4), radial head (n=3), and olecranon (n=1). Growth arrest was secondary to trauma (n=22), infection (n=11), idiopathy (n=6), inflammation (n=2), compartment syndrome (n=2), and avascular necrosis (n=1). Twenty-six patients (59%) underwent surgical intervention to address deformity caused by the physeal arrest. Operative procedures included ipsilateral unaffected bone epiphysiodesis (n=21), shortening osteotomy (n=10), lengthening osteotomy (n=8), excision of physeal bar or bone fragment (n=2), angular correction osteotomy (n=1), and creation of single bone forearm (n=1). Four complications occurred; 3 of these required additional procedures. Acquired upper extremity growth arrest usually is caused by trauma or infection, and the most frequent site is the distal radius. Growth disturbances due to premature arrest can be treated effectively with epiphysiodesis or osteotomy. In this series, the specific site of anatomic growth arrest was the primary factor in determining treatment. [Orthopedics. 2017; 40(1):e95-e103.]. Copyright 2016, SLACK Incorporated.

  18. Extremely red quasars in BOSS

    Science.gov (United States)

    Hamann, Fred; Zakamska, Nadia L.; Ross, Nicholas; Paris, Isabelle; Alexandroff, Rachael M.; Villforth, Carolin; Richards, Gordon T.; Herbst, Hanna; Brandt, W. Niel; Cook, Ben; Denney, Kelly D.; Greene, Jenny E.; Schneider, Donald P.; Strauss, Michael A.

    2017-01-01

    Red quasars are candidate young objects in an early transition stage of massive galaxy evolution. Our team recently discovered a population of extremely red quasars (ERQs) in the Baryon Oscillation Spectroscopic Survey (BOSS) that has a suite of peculiar emission-line properties including large rest equivalent widths (REWs), unusual `wingless' line profiles, large N V/Lyα, N V/C IV, Si IV/C IV and other flux ratios, and very broad and blueshifted [O III] λ5007. Here we present a new catalogue of C IV and N V emission-line data for 216 188 BOSS quasars to characterize the ERQ line properties further. We show that they depend sharply on UV-to-mid-IR colour, secondarily on REW(C IV), and not at all on luminosity or the Baldwin Effect. We identify a `core' sample of 97 ERQs with nearly uniform peculiar properties selected via i-W3 ≥ 4.6 (AB) and REW(C IV) ≥ 100 Å at redshifts 2.0-3.4. A broader search finds 235 more red quasars with similar unusual characteristics. The core ERQs have median luminosity ˜ 47.1, sky density 0.010 deg-2, surprisingly flat/blue UV spectra given their red UV-to-mid-IR colours, and common outflow signatures including BALs or BAL-like features and large C IV emission-line blueshifts. Their SEDs and line properties are inconsistent with normal quasars behind a dust reddening screen. We argue that the core ERQs are a unique obscured quasar population with extreme physical conditions related to powerful outflows across the line-forming regions. Patchy obscuration by small dusty clouds could produce the observed UV extinctions without substantial UV reddening.

  19. The ectD Gene, Which Is Involved in the Synthesis of the Compatible Solute Hydroxyectoine, Is Essential for Thermoprotection of the Halophilic Bacterium Chromohalobacter salexigens

    Science.gov (United States)

    García-Estepa, Raúl; Argandoña, Montserrat; Reina-Bueno, Mercedes; Capote, Nieves; Iglesias-Guerra, Fernando; Nieto, Joaquín J.; Vargas, Carmen

    2006-01-01

    The halophilic bacterium Chromohalobacter salexigens synthesizes and accumulates compatible solutes in response to salt and temperature stress. 13C-nuclear magnetic resonance analysis of cells grown in minimal medium at the limiting temperature of 45°C revealed the presence of hydroxyectoine, ectoine, glutamate, trehalose (not present in cells grown at 37°C), and the ectoine precursor, Nγ-acetyldiaminobutyric acid. High-performance liquid chromatography analyses showed that the levels of ectoine and hydroxyectoine were maximal during the stationary phase of growth. Accumulation of hydroxyectoine was up-regulated by salinity and temperature, whereas accumulation of ectoine was up-regulated by salinity and down-regulated by temperature. The ectD gene, which is involved in the conversion of ectoine to hydroxyectoine, was isolated as part of a DNA region that also contains a gene whose product belongs to the AraC-XylS family of transcriptional activators. Orthologs of ectD were found within the sequenced genomes of members of the proteobacteria, firmicutes, and actinobacteria, and their products were grouped into the ectoine hydroxylase subfamily, which was shown to belong to the superfamily of Fe(II)- and 2-oxoglutarate-dependent oxygenases. Analysis of the ectoine and hydroxyectoine contents of an ectABC ectD mutant strain fed with 1 mM ectoine or hydroxyectoine demonstrated that ectD is required for the main ectoine hydroxylase activity in C. salexigens. Although in minimal medium at 37°C the wild-type strain grew with 0.5 to 3.0 M NaCl, with optimal growth at 1.5 M NaCl, at 45°C it could not cope with the lowest (0.75 M NaCl) or the highest (3.0 M NaCl) salinity, and it grew optimally at 2.5 M NaCl. The ectD mutation caused a growth defect at 45°C in minimal medium with 1.5 to 2.5 M NaCl, but it did not affect growth at 37°C at any salinity tested. With 2.5 M NaCl, the ectD mutant synthesized 38% (at 37°C) and 15% (at 45°C) of the hydroxyectoine produced

  20. Remembrance of ecohydrologic extremes past

    Science.gov (United States)

    Band, L. E.; Hwang, T.

    2013-12-01

    Ecohydrological systems operate at time scales that span several orders of magnitude. Significant processes and feedbacks range from subdaily physiologic response to meteorological drivers, to soil forming and geomorphic processes ranging up through 10^3-10^4 years. While much attention in ecohydrology has focused on ecosystem optimization paradigms, these systems can show significant transience in structure and function, with apparent memory of hydroclimate extremes and regime shifts. While optimization feedbacks can be reconciled with system transience, a better understanding of the time scales and mechanisms of adjustment to increased hydroclimate variability and to specific events is required to understand and predict dynamics and vulnerability of ecosystems. Under certain circumstances of slowly varying hydroclimate, we hypothesize that ecosystems can remain adjusted to changing climate regimes, without displaying apparent system memory. Alternatively, rapid changes in hydroclimate and increased hydroclimate variability, amplified with well expressed non-linearity in the processes controlling feedbacks between water, carbon and nutrients, can move ecosystems far from adjusted states. The Coweeta Hydrological Laboratory is typical of humid, broadleaf forests in eastern North America, with a range of forest biomes from northern hardwoods at higher elevations, to oak-pine assemblages at lower elevations. The site provides almost 80 years of rainfall-runoff records for a set of watersheds under different management, along with multi-decadal forest plot structural information, soil moisture conditions and stream chemistry. An initial period of multi-decadal cooling, was followed by three decades of warming and increased hydroclimate variability. While mean temperature has risen over this time period, precipitation shows no long term trends in the mean, but has had a significant rise in variability with repeated extreme drought and wet periods. Over this latter

  1. Extreme heat and runoff extremes in the Swiss Alps

    Directory of Open Access Journals (Sweden)

    M. Zappa

    2007-06-01

    Full Text Available The hydrological response of Swiss river basins to the 2003 European summer heatwave was evaluated by a combined analysis of historical discharge records and specific applications of distributed hydrological modeling. In the summer of 2003, the discharge from headwater streams of the Swiss Central Plateau was only 40%–60% of the long-term average. For alpine basins runoff was about 60%–80% of the average. Glacierized basins showed the opposite behavior. According to the degree of glacierization, the average summer runoff was close or even above average. The hydrological model PREVAH was applied for the period 1982–2005. Even if the model was not calibrated for such extreme meteorological conditions, it was well able to simulate the hydrological responses of three basins. The aridity index φ describes feedbacks between hydrological and meteorological anomalies, and was adopted as an indicator of hydrological drought. The anomalies of φ and temperature in the summer of 2003 exceeded the 1982–2005 mean by more than 2 standard deviations. Catchments without glaciers showed negative correlations between φ and discharge R. In basins with about 15% glacierization, φ and R were not correlated. River basins with higher glacier percentages showed a positive correlation between φ and R. Icemelt was positively correlated with φ and reduced the variability of discharge with larger amounts of meltwater. Runoff generation from the non-glaciated sub-areas was limited by high evapotranspiration and reduced precipitation. The 2003 summer heatwave could be a precursor to similar events in the near future. Hydrological models and further data analysis will allow the identification of the most sensitive regions where heatwaves may become a recurrent natural hazard with large environmental, social and economical impacts.

  2. Extreme Programming in a Research Environment

    Science.gov (United States)

    Wood, William A.; Kleb, William L.

    2002-01-01

    This article explores the applicability of Extreme Programming in a scientific research context. The cultural environment at a government research center differs from the customer-centric business view. The chief theoretical difficulty lies in defining the customer to developer relationship. Specifically, can Extreme Programming be utilized when the developer and customer are the same person? Eight of Extreme Programming's 12 practices are perceived to be incompatible with the existing research culture. Further, six of the nine 'environments that I know don't do well with XP' apply. A pilot project explores the use of Extreme Programming in scientific research. The applicability issues are addressed and it is concluded that Extreme Programming can function successfully in situations for which it appears to be ill-suited. A strong discipline for mentally separating the customer and developer roles is found to be key for applying Extreme Programming in a field that lacks a clear distinction between the customer and the developer.

  3. Extremely Red Quasars in BOSS

    CERN Document Server

    Hamann, Fred; Ross, Nicholas; Paris, Isabelle; Alexandroff, Rachael M; Villforth, Carolin; Richards, Gordon T; Herbst, Hanna; Brandt, W Niel; Cook, Ben; Denney, Kelly D; Greene, Jenny E; Schneider, Donald P; Strauss, Michael A

    2016-01-01

    Red quasars are candidate young objects in an early transition stage of massive galaxy evolution. Our team recently discovered a population of extremely red quasars (ERQs) in the Baryon Oscillation Spectroscopic Survey (BOSS) that has a suite of peculiar emission-line properties including large rest equivalent widths (REWs), unusual "wingless" line profiles, large NV/Lya, NV/CIV, SiIV/CIV and other flux ratios, and very broad and blueshifted [OIII] 5007. Here we present a new catalog of CIV and NV emission-line data for 216,188 BOSS quasars to characterize the ERQ line properties further. We show that they depend sharply on UV-to-mid-IR color, secondarily on REW(CIV), and not at all on luminosity or the Baldwin Effect. We identify a "core" sample of 97 ERQs with nearly uniform peculiar properties selected via i-W3 > 4.6 (AB) and REW(CIV) > 100 A at redshifts 2.0-3.4. A broader search finds 235 more red quasars with similar unusual characteristics. The core ERQs have median luminosity log L (ergs/s) ~ 47.1, sk...

  4. Living with the extreme demand

    Directory of Open Access Journals (Sweden)

    Teppo Eskelinen

    2013-05-01

    Full Text Available Most of the ethical literature on extreme poverty suggests, that some, if not most, of the incomes of the residents of rich countries ought to be donated to the global poor. Yet complying with this ethical demand becomes increasingly more difficult as the changes in lifestyle in the (postindustrial north demand ever more consumption in order to obtain the necessities for survival in such societies. In this article, I will discuss Peter Singer's famous arguments for the ethical duty to donate one's possessions, and elaborate the conception of needs prevalent in both Singer's theory and the theories of many of his critics. My argument is that we have to recognise a category of needs called 'social necessities' that are neither luxuries nor basic needs. This leads to two main conclusions: first, the space for ethical deliberation on whether to donate to life-saving purposes is socially conditioned; and second, ethical strategies of redistribution ought to be accompanied with institutional changes, which also concern the conditions in wealthy countries.http://dx.doi.org/10.5324/eip.v7i1.1791

  5. Driving Extreme Efficiency to Market

    Science.gov (United States)

    Garbesi, Karina

    2014-03-01

    The rapid development of extremely energy efficient appliances and equipment is essential to curtail catastrophic climate disruption. This will require the on-going development of products that apply all best-practices and that take advantage of the synergies of hybridization and building integration. Beyond that, it requires the development of new disruptive technologies and concepts. To facilitate these goals, in 2011 the Lawrence Berkeley National Laboratory and the U.S. Department of Energy launched the Max Tech and Beyond Design Competition for Ultra-Low-Energy-Use Appliances and Equipment. Now in its third year, the competition supports faculty-lead student design teams at U.S. universities to develop and test new technology prototypes. This talk describes what the competition and the Max Tech Program are doing to drive such rapid technology progress and to facilitate the entry to the market of successful Max Tech prototypes. The talk also initiates a discussion of physicists' unique role in driving that technology progress faster and farther. Emerging Technologies, Building Technologies Office, U.S. Department of Energy.

  6. Magnetic slippery extreme icephobic surfaces

    Science.gov (United States)

    Irajizad, Peyman; Hasnain, Munib; Farokhnia, Nazanin; Sajadi, Seyed Mohammad; Ghasemi, Hadi

    2016-11-01

    Anti-icing surfaces have a critical footprint on daily lives of humans ranging from transportation systems and infrastructure to energy systems, but creation of these surfaces for low temperatures remains elusive. Non-wetting surfaces and liquid-infused surfaces have inspired routes for the development of icephobic surfaces. However, high freezing temperature, high ice adhesion strength, and high cost have restricted their practical applications. Here we report new magnetic slippery surfaces outperforming state-of-the-art icephobic surfaces with a ice formation temperature of -34 °C, 2-3 orders of magnitude higher delay time in ice formation, extremely low ice adhesion strength (~2 Pa) and stability in shear flows up to Reynolds number of 105. In these surfaces, we exploit the magnetic volumetric force to exclude the role of solid-liquid interface in ice formation. We show that these inexpensive surfaces are universal and can be applied to all types of solids (no required micro/nano structuring) with no compromise to their unprecedented properties.

  7. An extremely primitive halo star

    CERN Document Server

    Caffau, E; François, P; Sbordone, L; Monaco, L; Spite, M; Spite, F; Ludwig, H -G; Cayrel, R; Zaggia, S; Hammer, F; Randich, S; Molaro, P; Hill, V; 10.1038/nature10377

    2012-01-01

    The early Universe had a chemical composition consisting of hydrogen, helium and traces of lithium1, almost all other elements were created in stars and supernovae. The mass fraction, Z, of elements more massive than helium, is called "metallicity". A number of very metal poor stars have been found some of which, while having a low iron abundance, are rich in carbon, nitrogen and oxygen. For theoretical reasons and because of an observed absence of stars with metallicities lower than Z=1.5E-5, it has been suggested that low mass stars (M<0.8M\\odot, the ones that survive to the present day) cannot form until the interstellar medium has been enriched above a critical value, estimated to lie in the range 1.5E-8\\leqZ\\leq1.5E-6, although competing theories claiming the contrary do exist. Here we report the chemical composition of a star with a very low Z\\leq6.9E-7 (4.5E-5 of that of the Sun) and a chemical pattern typical of classical extremely metal poor stars, meaning without the enrichment of carbon, nitroge...

  8. 蜢子虾酱中度嗜盐菌的分离、鉴定及特性研究%Isolation, identification and characteristics of moderately halophilic bacteria in shrimp sauce

    Institute of Scientific and Technical Information of China (English)

    孙业盈; 单长民; 武玉永

    2011-01-01

    从蜢子虾酱中分离纯化鉴定了一株中度嗜盐菌MKY20,对其进行了形态学和生理生化特性研究;通过测定其16S rDNA序列并通过系统发育分析对该菌株进行了分子水平的鉴定.试验结果表明,嗜盐菌株MKY20为革兰氏阳性菌,菌体可以产芽孢,呈杆状,菌体大小为(0.6μm~0.8μm)×(2.0μm~4.0μm);生理生化特性研究表明菌株MKY20最适盐度为3%,最适生长温度为28℃~34℃,最适pH值为7.0;系统发育分析将该菌初步鉴定为枝芽孢杆菌属(Virgibacillus)中的盐脱氮枝芽胞杆菌(Virgibacillus halodenitrificans).该研究将为进一步研究虾酱中的嗜盐菌的菌落结构提供参考,为防止嗜盐菌污染食品提供帮助.%A moderately halophilic bacterium MK.Y20 was isolated from shrimp sauce and was identified through its morphological, physiological and biochemical characteristics. The strain MKY20 was gram-positive strain, spore-forming and rods. And it was 0.6μm~0.8|xm wide and 2.0iun~4.0|nn long. The optimal salt concentration, temperature and pH value for MKY20 were 3%, 28℃~34℃ and 7.0, respectively. The result of 16S rDNA alignment and phylogenetic an lysis showed that the stain MKY20 had a 100% homology with Virgibacillus halodenitriGcans. Our result cold provide a reference for studying the structure of halophilic bacteria in shrimp sauce and give some help to prevent halophilic bacteria contamination.

  9. 同步培养驯化嗜盐菌处理纳滤浓水的试验研究%Synchronous Acclimation of Halophilic Bacteria for Treatment of NF Concentrated Water

    Institute of Scientific and Technical Information of China (English)

    李振伟; 王亮; 张宏伟; 于海涛

    2012-01-01

    Halophilic bacteria were acclimated by increasing the salinity concentration gradually in SBR. The salt content in the process of acclimation was increased from 1140 mg/L to 1880 mg/L, and the glucose was decreased from 200 mg/L to 0 mg/L. The treatment efficiency of NF concentrated water by the acclimated halophilic bacteria was investigated. When COD and TN in NF concentrated water were 115 to 160 mg/L and 35 to 55 mg/L respectively, the removal rates of COD and TN were 58% and 67% respectively under the conditions of operation period 8 h, aeration rate 0. 6 L/min, average sludge concentration 4 500 to 5 500 mg/L and sludge retention time 16 d. The acclimated halophilic bacteria could normally grow at a salt concentration of 1 880 mg/L. Changes in the influent organic load had little effect on COD removal efficiency, and the system showed a higher resistance to organic load impact.%在序批式间歇反应器(SBR)中,通过逐步提高含盐量的方法同步驯化出嗜盐菌,驯化过程中含盐量从1 140 mg/L提高到1 880 mg/L,进水的葡萄糖投加量由200 mg,/L降至零.同时考察了该嗜盐菌对纳滤浓水的处理效果.试验结果显示,对于COD为115~ 160 mg/L、TN为35~55 mg/L的纳滤浓水,在运行周期为8h、曝气量为0.6 L/min、污泥浓度为4 500~5 500 mg/L、污泥龄为16 d的条件下,对COD的平均去除率为58%,对TN的平均去除率为67%;驯化出的嗜盐菌能够在含盐量为1 880 mg/L的条件下正常生长;改变进水有机负荷对出水COD的影响不大,该系统的耐有机负荷冲击能力较强.

  10. 岱山盐田中度嗜盐菌的分离及抗菌活性筛选%Isolation and Screening of Antimicrobial Activity of Moderately Halophiles from the Daishan Solar Saltern

    Institute of Scientific and Technical Information of China (English)

    汪雪婷; 杨丹丹; 聂都; 黄晶晶; 陈敏

    2016-01-01

    The aim of this study was to investigate the potential antimicrobial activities of moderately halophiles from solar saltern. A total of 106 halophilic strains were isolated from the soil of Daishan solar saltern by culture-dependent method based on RM medium. All the isolated strains were tested for their antimicrobial activity using the inhibition-zone method. The phylogenetic position of strains was determined by 16S rRNA sequencing. Our results showed that among 106 strains tested, 27 strains showed remarkable activities against Gram-positive bacterium, Gram-negative bacterium and human pathogenic fungi. Phylogenetic analysis indicated that 27 strains belonged to seven genera, Halomonas, Halobacillus, Marinobacter, Microbulbifer, Piscibacillus, Bacillus and Virgibacillus. The results suggest that Daishan saltern environment harbors moderately halophiles, which may be developed as promising sources for the discovery of novel bioactive substances.%从岱山盐田采集土壤样品,利用含不同NaCl浓度的RM培养基分离中度嗜盐菌,并采用抑菌圈法进行抗菌活性筛选。结果共分离得到106株中度嗜盐细菌菌株,其中有27株显示出对革兰氏阳性菌、革兰氏阴性菌和人类病原真菌的有效抗性。通过基于16S rRNA基因序列的系统发育分析,具有抗菌活性的27株菌株分别属于7个属,即嗜盐单胞菌属(Halomonas)、喜盐芽孢杆菌属(Halobacillus)、海杆菌属(Marinobacter)、产微球茎菌属(Microbulbifer)、Piscibacillus属、芽孢杆菌属(Bacillus)和枝芽孢杆菌属(Virgibacillus)。研究结果表明,岱山盐田土壤中存在较丰富的中度嗜盐菌种类,是筛选抗菌活性菌株的潜在资源库。

  11. Involvement of EupR, a response regulator of the NarL/FixJ family, in the control of the uptake of the compatible solutes ectoines by the halophilic bacterium Chromohalobacter salexigens

    Directory of Open Access Journals (Sweden)

    Jebbar Mohamed

    2010-10-01

    Full Text Available Abstract Background Osmosensing and associated signal transduction pathways have not yet been described in obligately halophilic bacteria. Chromohalobacter salexigens is a halophilic bacterium with a broad range of salt tolerance. In response to osmotic stress, it synthesizes and accumulates large amounts of the compatible solutes ectoine and hydroxyectoine. In a previous work, we showed that ectoines can be also accumulated upon transport from the external medium, and that they can be used as carbon sources at optimal, but not at low salinity. This was related to an insufficient ectoine(s transport under these conditions. Results A C. salexigens Tn1732-induced mutant (CHR95 showed a delayed growth with glucose at low and optimal salinities, could not grow at high salinity, and was able to use ectoines as carbon sources at low salinity. CHR95 was affected in the transport and/or metabolism of glucose, and showed a deregulated ectoine uptake at any salinity, but it was not affected in ectoine metabolism. Transposon insertion in CHR95 caused deletion of three genes, Csal0865-Csal0867: acs, encoding an acetyl-CoA synthase, mntR, encoding a transcriptional regulator of the DtxR/MntR family, and eupR, encoding a putative two-component response regulator with a LuxR_C-like DNA-binding helix-turn-helix domain. A single mntR mutant was sensitive to manganese, suggesting that mntR encodes a manganese-dependent transcriptional regulator. Deletion of eupR led to salt-sensitivity and enabled the mutant strain to use ectoines as carbon source at low salinity. Domain analysis included EupR as a member of the NarL/FixJ family of two component response regulators. Finally, the protein encoded by Csal869, located three genes downstream of eupR was suggested to be the cognate histidine kinase of EupR. This protein was predicted to be a hybrid histidine kinase with one transmembrane and one cytoplasmic sensor domain. Conclusions This work represents the first

  12. The Sulfate-Rich and Extreme Saline Sediment of the Ephemeral Tirez Lagoon: A Biotope for Acetoclastic Sulfate-Reducing Bacteria and Hydrogenotrophic Methanogenic Archaea

    Directory of Open Access Journals (Sweden)

    Lilia Montoya

    2011-01-01

    Full Text Available Our goal was to examine the composition of methanogenic archaea (MA and sulfate-reducing (SRP and sulfur-oxidizing (SOP prokaryotes in the extreme athalassohaline and particularly sulfate-rich sediment of Tirez Lagoon (Spain. Thus, adenosine-5′-phosphosulfate (APS reductase α (aprA and methyl coenzyme M reductase α (mcrA gene markers were amplified given that both enzymes are specific for SRP, SOP, and MA, respectively. Anaerobic populations sampled at different depths in flooded and dry seasons from the anoxic sediment were compared qualitatively via denaturing gradient gel electrophoresis (DGGE fingerprint analysis. Phylogenetic analyses allowed the detection of SRP belonging to Desulfobacteraceae, Desulfohalobiaceae, and Peptococcaceae in ∂-proteobacteria and Firmicutes and SOP belonging to Chromatiales/Thiotrichales clade and Ectothiorhodospiraceae in γ-proteobacteria as well as MA belonging to methylotrophic species in Methanosarcinaceae and one hydrogenotrophic species in Methanomicrobiaceae. We also estimated amino acid composition, GC content, and preferential codon usage for the AprA and McrA sequences from halophiles, nonhalophiles, and Tirez phylotypes. Even though our results cannot be currently conclusive regarding the halotolerant strategies carried out by Tirez phylotypes, we discuss the possibility of a plausible “salt-in” signal in SRP and SOP as well as of a speculative complementary haloadaptation between salt-in and salt-out strategies in MA.

  13. Extreme weather events and infectious disease outbreaks

    OpenAIRE

    McMichael, Anthony J.

    2015-01-01

    Human-driven climatic changes will fundamentally influence patterns of human health, including infectious disease clusters and epidemics following extreme weather events. Extreme weather events are projected to increase further with the advance of human-driven climate change. Both recent and historical experiences indicate that infectious disease outbreaks very often follow extreme weather events, as microbes, vectors and reservoir animal hosts exploit the disrupted social and environmental c...

  14. Extreme Learning Machine for land cover classification

    OpenAIRE

    Pal, Mahesh

    2008-01-01

    This paper explores the potential of extreme learning machine based supervised classification algorithm for land cover classification. In comparison to a backpropagation neural network, which requires setting of several user-defined parameters and may produce local minima, extreme learning machine require setting of one parameter and produce a unique solution. ETM+ multispectral data set (England) was used to judge the suitability of extreme learning machine for remote sensing classifications...

  15. Extreme Events in Nature and Society

    CERN Document Server

    Albeverio, Sergio; Kantz, Holger

    2006-01-01

    Significant, and usually unwelcome, surprises, such as floods, financial crisis, epileptic seizures, or material rupture, are the topics of Extreme Events in Nature and Society. The book, authored by foremost experts in these fields, reveals unifying and distinguishing features of extreme events, including problems of understanding and modelling their origin, spatial and temporal extension, and potential impact. The chapters converge towards the difficult problem of anticipation: forecasting the event and proposing measures to moderate or prevent it. Extreme Events in Nature and Society will interest not only specialists, but also the general reader eager to learn how the multifaceted field of extreme events can be viewed as a coherent whole.

  16. Exclusive lower extremity mirror movements and diastematomyelia.

    Science.gov (United States)

    Tubbs, R Shane; Smyth, Matthew D; Dure, Leon S; Oakes, W Jerry

    2004-01-01

    Mirror movements usually seen in the Klippel-Feil syndrome are most commonly appreciated in the upper extremities. Lower extremity involvement is seen rarely and when observed, is found in conjunction with upper extremity mirror movements. We report what we believe to be the first case of mirror movements found exclusively in the lower extremities in a female patient presenting with tethered cord syndrome. Our hopes are that this report will help elucidate mechanisms involved with these anomalous movements, as currently there is no commonly accepted etiology.

  17. Magnetotactic Bacteria from Extreme Environments

    Directory of Open Access Journals (Sweden)

    Christopher T. Lefèvre

    2013-03-01

    Full Text Available Magnetotactic bacteria (MTB represent a diverse collection of motile prokaryotes that biomineralize intracellular, membrane-bounded, tens-of-nanometer-sized crystals of a magnetic mineral called magnetosomes. Magnetosome minerals consist of either magnetite (Fe3O4 or greigite (Fe3S4 and cause cells to align along the Earth’s geomagnetic field lines as they swim, a trait called magnetotaxis. MTB are known to mainly inhabit the oxic–anoxic interface (OAI in water columns or sediments of aquatic habitats and it is currently thought that magnetosomes function as a means of making chemotaxis more efficient in locating and maintaining an optimal position for growth and survival at the OAI. Known cultured and uncultured MTB are phylogenetically associated with the Alpha-, Gamma- and Deltaproteobacteria classes of the phylum Proteobacteria, the Nitrospirae phylum and the candidate division OP3, part of the Planctomycetes-Verrucomicrobia-Chlamydiae (PVC bacterial superphylum. MTB are generally thought to be ubiquitous in aquatic environments as they are cosmopolitan in distribution and have been found in every continent although for years MTB were thought to be restricted to habitats with pH values near neutral and at ambient temperature. Recently, however, moderate thermophilic and alkaliphilic MTB have been described including: an uncultured, moderately thermophilic magnetotactic bacterium present in hot springs in northern Nevada with a probable upper growth limit of about 63 °C; and several strains of obligately alkaliphilic MTB isolated in pure culture from different aquatic habitats in California, including the hypersaline, extremely alkaline Mono Lake, with an optimal growth pH of >9.0.

  18. Archaeal Haloarcula californiae Icosahedral Virus 1 Highlights Conserved Elements in Icosahedral Membrane-Containing DNA Viruses from Extreme Environments

    Directory of Open Access Journals (Sweden)

    Tatiana A. Demina

    2016-07-01

    Full Text Available Despite their high genomic diversity, all known viruses are structurally constrained to a limited number of virion morphotypes. One morphotype of viruses infecting bacteria, archaea, and eukaryotes is the tailless icosahedral morphotype with an internal membrane. Although it is considered an abundant morphotype in extreme environments, only seven such archaeal viruses are known. Here, we introduce Haloarcula californiae icosahedral virus 1 (HCIV-1, a halophilic euryarchaeal virus originating from salt crystals. HCIV-1 also retains its infectivity under low-salinity conditions, showing that it is able to adapt to environmental changes. The release of progeny virions resulting from cell lysis was evidenced by reduced cellular oxygen consumption, leakage of intracellular ATP, and binding of an indicator ion to ruptured cell membranes. The virion contains at least 12 different protein species, lipids selectively acquired from the host cell membrane, and a 31,314-bp-long linear double-stranded DNA (dsDNA. The overall genome organization and sequence show high similarity to the genomes of archaeal viruses in the Sphaerolipoviridae family. Phylogenetic analysis based on the major conserved components needed for virion assembly—the major capsid proteins and the packaging ATPase—placed HCIV-1 along with the alphasphaerolipoviruses in a distinct, well-supported clade. On the basis of its virion morphology and sequence similarities, most notably, those of its core virion components, we propose that HCIV-1 is a member of the PRD1-adenovirus structure-based lineage together with other sphaerolipoviruses. This addition to the lineage reinforces the notion of the ancient evolutionary links observed between the viruses and further highlights the limits of the choices found in nature for formation of a virion.

  19. Isolation of Halophiles from Qinghai Lake and Growth Characteristics of Dominant Strain QHL5%青海湖嗜盐菌的分离与优势菌株QHL5的特性

    Institute of Scientific and Technical Information of China (English)

    朱德锐; 刘建; 刘静静; 沈国平; 龙启福; 高翔; 刘德立

    2012-01-01

    Thirty-five strains of halophiles were isolated from 20 water samples of Qinghai Lake, China by a high saline medium. In all strains tested, the proportion of the moderate halophile was 66.7%, as a dominate group, and the percentage of the slight halophile was 25.7. The nonhalophilc plus halotolerant was however only 8.5%. The dominant strain QHL5 was a moderate halophile, which could grow in a salt concentration from 0.04 to 3.0 mol/L, and its optimal concentration was 0.3-0.9 mol/L. According to colonial morphology and growth characteristics, QHL5 was round or oval, 4.0-6.0 mm, white, gram negative and opaque as a single cell. The optimum pH and cultural temperature were 7.5-8.0 and 35 ℃, respectively. Based on the physiological and biochemical characteristics of bacteria, and phylogenetic analysis using 16S rDNA sequence comparison, QHL5 was primarily identified as a Halomonas ventosae species of Holomonas genus, in Oceanospirillales order of Gammaproteobacteria class. The intracellular compatible solute of QHL5 was extracted with 80% ethanol, then the ectoine accumulated in cell was tested by a TLC method. Fig 6, Tab 1, Ref 28%采用高盐选择性培养基从20份青海湖水样中筛选分离获得35株青海湖嗜盐微生物.耐盐梯度实验分析表明:水体中以中度嗜盐菌为主,约占65.7%;弱嗜盐菌次之,约占25.7%;非嗜盐菌与耐盐菌相对较少,约占8.5%.其中优势菌QHL5的生长盐度耐受范围为0.04~3.0 mol/L,最适生长范围为0.3~0.9 mol/L,隶属于中度嗜盐菌.菌体形态和生长特性分析表明:QHL5菌落大小为4~6 mm,圆形或椭圆形,边缘整齐厚实,乳白色,中间微隆起,不透明,革兰氏染色阴性.显微形态呈杆状,最适生长pH为8.5~9.5,最适生长温度为35℃.生理生化、16S rRNA的全序列Blast和系统发育分析表明:QHL5菌株分类定位于γ变形菌纲海洋螺菌目盐单胞菌属樊氏盐单胞菌(Halomonas ventosae).通过80%乙醇法抽提胞内

  20. One-Loop Corrected Thermodynamics of the Extremal and Non-Extremal Spinning BTZ Black Hole

    CERN Document Server

    Medved, A J M

    2001-01-01

    We consider the one-loop corrected geometry and thermodynamics of a rotating BTZ black hole by way of a dimensionally reduced dilaton model. The analysis begins with a comprehensive study of the non-extremal solution after which two different methods are invoked to study the extremal case. The first approach considers the extremal limit of the non-extremal calculations, whereas the second treatment is based on the following conjecture: extremal and non-extremal black holes ae qualitatively distinct entities. We show that only the latter method yields regularity and consistency at the one-loop level. This is suggestive of a generalized third law of thermodynamics that forbids continuous evolution from non-extremal to extremal black hole geometries.