Development of Synechocystis sp. PCC 6803 as a Phototrophic Cell Factory

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Fuzhong Zhang

2013-08-01

Full Text Available Cyanobacteria (blue-green algae play profound roles in ecology and biogeochemistry. One model cyanobacterial species is the unicellular cyanobacterium Synechocystis sp. PCC 6803. This species is highly amenable to genetic modification. Its genome has been sequenced and many systems biology and molecular biology tools are available to study this bacterium. Recently, researchers have put significant efforts into understanding and engineering this bacterium to produce chemicals and biofuels from sunlight and CO2. To demonstrate our perspective on the application of this cyanobacterium as a photosynthesis-based chassis, we summarize the recent research on Synechocystis 6803 by focusing on five topics: rate-limiting factors for cell cultivation; molecular tools for genetic modifications; high-throughput system biology for genome wide analysis; metabolic modeling for physiological prediction and rational metabolic engineering; and applications in producing diverse chemicals. We also discuss the particular challenges for systems analysis and engineering applications of this microorganism, including precise characterization of versatile cell metabolism, improvement of product rates and titers, bioprocess scale-up, and product recovery. Although much progress has been achieved in the development of Synechocystis 6803 as a phototrophic cell factory, the biotechnology for “Compounds from Synechocystis” is still significantly lagging behind those for heterotrophic microbes (e.g., Escherichia coli.

Improved sugar-free succinate production by Synechocystis sp. PCC 6803 following identification of the limiting steps in glycogen catabolism

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Tomohisa Hasunuma

2016-12-01

Full Text Available Succinate produced by microorganisms can replace currently used petroleum-based succinate but typically requires mono- or poly-saccharides as a feedstock. The cyanobacterium Synechocystis sp. PCC6803 can produce organic acids such as succinate from CO2 not supplemented with sugars under dark anoxic conditions using an unknown metabolic pathway. The TCA cycle in cyanobacteria branches into oxidative and reductive routes. Time-course analyses of the metabolome, transcriptome and metabolic turnover described here revealed dynamic changes in the metabolism of Synechocystis sp. PCC6803 cultivated under dark anoxic conditions, allowing identification of the carbon flow and rate-limiting steps in glycogen catabolism. Glycogen biosynthesized from CO2 assimilated during periods of light exposure is catabolized to succinate via glycolysis, the anaplerotic pathway, and the reductive TCA cycle under dark anoxic conditions. Expression of the phosphoenolpyruvate (PEP carboxylase gene (ppc was identified as a rate-limiting step in succinate biosynthesis and this rate limitation was alleviated by ppc overexpression, resulting in improved succinate excretion. The sugar-free succinate production was further enhanced by the addition of bicarbonate. In vivo labeling with NaH13CO3 clearly showed carbon incorporation into succinate via the anaplerotic pathway. Bicarbonate is in equilibrium with CO2. Succinate production by Synechocystis sp. PCC6803 therefore holds significant promise for CO2 capture and utilization. Keywords: Autofermentation, Cyanobacteria, Dynamic metabolic profiling, Metabolomics, Succinate, Synechocystis

Toxic effects of amoxicillin on the photosystem II of Synechocystis sp. characterized by a variety of in vivo chlorophyll fluorescence tests

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Pan Xiangliang; Deng Chunnuan; Zhang Daoyong; Wang Jianlong; Mu Guijin; Chen Ying

2008-01-01

Amoxicillin is one of the widely used antibiotics of environmental concern. This study shows that amoxicillin has toxic effects on the photosynthesis of Synechocystis sp. Its inhibitory effects on photosystem II (PSII) of Synechocystis sp. were investigated by using a variety of in vivo chlorophyll fluorescence tests. The inhibitory effects of amoxicillin on PSII activity of Synechocystis sp. are concentration-dependent. Amoxicillin exposure leads to slowing down of electron transport on both donor side and acceptor side and causes accumulation of P680 + . Q A - reoxidation test revealed that amoxicillin hinders electron transfer from Q A - to Q B /Q B - and more Q A - is oxidized through S 2 (Q A Q B ) - charge recombination. Analysis of PSII heterogeneity demonstrated that an exposure to amoxicillin increases the proportion of inactive PSII (PSII X ) centers and the proportion of PSII centers with small antenna (PSIIβ). These changes finally result in deterioration of full photosynthesis performance

Radiation characteristics and effective optical properties of dumbbell-shaped cyanobacterium Synechocystis sp

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Heng, Ri-Liang; Pilon, Laurent

2016-01-01

This study presents experimental measurements of the radiation characteristics of unicellular freshwater cyanobacterium Synechocystis sp. during their exponential growth in F medium. Their scattering phase function at 633 nm average spectral absorption and scattering cross-sections between 400 and 750 nm were measured. In addition, an inverse method was used for retrieving the spectral effective complex index of refraction of overlapping or touching bispheres and quadspheres from their absorption and scattering cross-sections. The inverse method combines a genetic algorithm and a forward model based on Lorenz–Mie theory, treating bispheres and quadspheres as projected area and volume-equivalent coated spheres. The inverse method was successfully validated with numerically predicted average absorption and scattering cross-sections of suspensions consisting of bispheres and quadspheres, with realistic size distributions, using the T-matrix method. It was able to retrieve the monomers' complex index of refraction with size parameter up to 11, relative refraction index less than 1.3, and absorption index less than 0.1. Then, the inverse method was applied to retrieve the effective spectral complex index of refraction of Synechocystis sp. approximated as randomly oriented aggregates consisting of two overlapping homogeneous spheres. Both the measured absorption cross-section and the retrieved absorption index featured peaks at 435 and 676 nm corresponding to chlorophyll a, a peak at 625 nm corresponding to phycocyanin, and a shoulder around 485 nm corresponding to carotenoids. These results can be used to optimize and control light transfer in photobioreactors. The inverse method and the equivalent coated sphere model could be applied to other optically soft particles of similar morphologies. - Highlights: • Radiation characteristics of Synechocystis sp. were measured during exponential growth. • This unicellular freshwater cyanobacterium features an interesting

Photoautotrophic Polyhydroxybutyrate Granule Formation Is Regulated by Cyanobacterial Phasin PhaP in Synechocystis sp. Strain PCC 6803

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Hauf, Waldemar; Watzer, Björn; Roos, Nora; Klotz, Alexander

2015-01-01

Cyanobacteria are photoautotrophic microorganisms which fix atmospheric carbon dioxide via the Calvin-Benson cycle to produce carbon backbones for primary metabolism. Fixed carbon can also be stored as intracellular glycogen, and in some cyanobacterial species like Synechocystis sp. strain PCC 6803, polyhydroxybutyrate (PHB) accumulates when major nutrients like phosphorus or nitrogen are absent. So far only three enzymes which participate in PHB metabolism have been identified in this organism, namely, PhaA, PhaB, and the heterodimeric PHB synthase PhaEC. In this work, we describe the cyanobacterial PHA surface-coating protein (phasin), which we term PhaP, encoded by ssl2501. Translational fusion of Ssl2501 with enhanced green fluorescent protein (eGFP) showed a clear colocalization to PHB granules. A deletion of ssl2501 reduced the number of PHB granules per cell, whereas the mean PHB granule size increased as expected for a typical phasin. Although deletion of ssl2501 had almost no effect on the amount of PHB, the biosynthetic activity of PHB synthase was negatively affected. Secondary-structure prediction and circular dichroism (CD) spectroscopy of PhaP revealed that the protein consists of two α-helices, both of them associating with PHB granules. Purified PhaP forms oligomeric structures in solution, and both α-helices of PhaP contribute to oligomerization. Together, these results support the idea that Ssl2501 encodes a cyanobacterial phasin, PhaP, which regulates the surface-to-volume ratio of PHB granules. PMID:25911471

Identification of a New Target slr0946 of the Response Regulator Sll0649 Involving Cadmium Tolerance in Synechocystis sp. PCC 6803

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Tao Sun

2017-08-01

Full Text Available Survival of photosynthetic cyanobacteria is challenged by environmental contaminations like heavy metals. Among them, deciphering the regulatory mechanisms for cadmium (Cd in cyanobacteria would facilitate the construction of Cd-resistant strains. In this study, the DNA-Affinity-Purified-chromatin immunoprecipitation assay was employed to identify the direct targets of Sll0649, which was a Cd2+-related response regulator identified in our previous work in model cyanobacteria Synechocystis sp. PCC 6803. As a result, the promoter region of slr0946 encoding the arsenate reductase was enriched fourfolds by quantitative real time PCR analysis. Further, deletion of slr0946 led to a sensitive phenotype to Cd2+ stress compared with the wild type (WT and the sensitive phenotype of Δslr0946 could be rescued by complementation assay via introducing slr0946 back into Δslr0946. Finally, individually overexpression of slr0946 as well as two Cd2+-related genes identified priviously (i.e., sll1598 and slr0798 in WT could significantly improve the tolerance of Synechocystis sp. PCC 6803 to Cd2+. This study provided a better understanding of the tolerance mechanism to Cd2+ in cyanobacteria and also feasible strategies for tolerance modifications to heavy metals in the future.

Synechocystis sp. PCC 6803 CruA (sll0147) encodes lycopene cyclase and requires bound chlorophyll a for activity.

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Xiong, Wei; Shen, Gaozhong; Bryant, Donald A

2017-03-01

The genome of the model cyanobacterium, Synechococcus sp. PCC 7002, encodes two paralogs of CruA-type lycopene cyclases, SynPCC7002_A2153 and SynPCC7002_A0043, which are denoted cruA and cruP, respectively. Unlike the wild-type strain, a cruA deletion mutant is light-sensitive, grows slowly, and accumulates lycopene, γ-carotene, and 1-OH-lycopene; however, this strain still produces β-carotene and other carotenoids derived from it. Expression of cruA from Synechocystis sp. PCC 6803 (cruA 6803 ) in Escherichia coli strains that synthesize either lycopene or γ-carotene did not lead to the synthesis of either γ-carotene or β-carotene, respectively. However, expression of this orthologous cruA 6803 gene (sll0147) in the Synechococcus sp. PCC 7002 cruA deletion mutant produced strains with phenotypic properties identical to the wild type. CruA 6803 was purified from Synechococcus sp. PCC 7002 by affinity chromatography, and the purified protein was pale yellow-green due to the presence of bound chlorophyll (Chl) a and β-carotene. Native polyacrylamide gel electrophoresis of the partly purified protein in the presence of lithium dodecylsulfate at 4 °C confirmed that the protein was yellow-green in color. When purified CruA 6803 was assayed in vitro with either lycopene or γ-carotene as substrate, β-carotene was synthesized. These data establish that CruA 6803 is a lycopene cyclase and that it requires a bound Chl a molecule for activity. Possible binding sites for Chl a and the potential regulatory role of the Chl a in coordination of Chl and carotenoid biosynthesis are discussed.

Integration vector for the cyanobacteria Synechocystis sp. 6803

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Shestakov, S.V.; Elanskaya, I.V.; Bibikova, M.V.

1985-01-01

The authors have constructed recombinant plasmid DNA molecules with fragments of chromosomal DNA of the cyanobacterium Synechocystis 6803 in the vector plasmid pACYC 184, carrying markers for resistance against tetracycline (TC/sup r/) and chloramphenicol (Cm/sup r/). The authors also present their scheme of constructing integration vectors for Synechocystis 6803. To demonstrate integration of the recombinant plasmids of pSIS and pSIB series into the chromosomes of cyanobacteria, chromosomal DNA was isolated from the Cm/sup r/ transformants of Synechocystis 6803, and used for blot-hybridization using P 32-labeled plasmid DNA of pACYC 184. The hybridization results show that the chromosomal DNA isolated from the Cm/sup r/ transformants of cyanobacteria carries a region homologous with plasmid pACYC 184, whereas the DNA from wild type cells does not hybridize with pACYC 184. The transformation frequency of the Synechocystis 6803 cells by chromosomal DNA from the Cm/sup r/ clones of cyanobacteria was 3-7 x 10 -5 , which corresponds to the frequency of chromosomal transformation for other markers

[Increasing reductant NADPH content via metabolic engineering of PHB synthesis pathway in Synechocystis sp. PCC 6803].

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Xie, Juan; Zhou, Jie; Zhang, Haifeng; Li, Yin

2011-07-01

Cyanobacteria have become attractive hosts for renewable chemicals production. The low productivity, however, prevents it from industrial application. Reductant NAD(P)H availability is a chief hurdle for the production of reductive metabolites in microbes. To increase NADPH content in Synechocystis sp. PCC 6803, PHB synthase encoding gene phaC and phaE in Synechocystis was inactivated by replacing phaC&E genes with chloromycetin resistance cassette via homologous recombination. PCR analysis showed that mutant S.delta phaC&E with complete genome segregation was generated. The comparison between growth curves of S.wt and S.delta phaC&E indicated the knockout of phaC & phaE genes did not affect obviously the cell growth. Gas chromatography analysis showed that the accumulation of PHB in wild type was about 2.3% of the dry cell weight, whereas no PHB was detected in the mutant S.delta phaC&E. The data indicated that inactivation of PHB synthase gene phaC and phaE interrupted the synthesis of PHB. Further comparative study of wild type and mutant demonstrated that NADPH content in S.delta phaC&E was obviously increased. On the third day, the NADPH content in S.delta phaC&E was up to 1.85 fold higher than that in wild type. These results indicated that deleting PHB synthase gene phaC and phaE not only can block the synthesis of PHB, but also can save NADPH to contribute reductant sink in cyanobacteria. Hence, the engineered cyanobacterial strain S.delta phaC&E, in which carbon flux was redirected and NADPH was increased, will be a potential host strain for chemicals production in cyanobacteria.

Characterization of three bioenergetically active respiratory terminal oxidases in the cyanobacterium Synechocystis sp. strain PCC 6803.

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Pils, D; Schmetterer, G

2001-09-25

Synechocystis sp. PCC 6803 contains three respiratory terminal oxidases (RTOs): cytochrome c oxidase (Cox), quinol oxidase (Cyd), and alternate RTO (ARTO). Mutants lacking combinations of the RTOs were used to characterize these key enzymes of respiration. Pentachlorophenol and 2-heptyl-4-hydroxy-quinoline-N-oxide inhibited Cyd completely, but had little effect on electron transport to the other RTOs. KCN inhibited all three RTOs but the in vivo K(I) for Cox and Cyd was quite different (7 vs. 27 microM), as was their affinity for oxygen (K(M) 1.0 vs. 0.35 microM). ARTO has a very low respiratory activity. However, when uptake of 3-O-methylglucose, an active H+ co-transport, was used to monitor energization of the cytoplasmic membrane, ARTO was similarly effective as the other RTOs. As removal of the gene for cytochrome c(553) had the same effects as removal of ARTO genes, we propose that the ARTO might be a second Cox. The possible functions, localization and regulation of the RTOs are discussed.

Increasing the Photoautotrophic Growth Rate of Synechocystis sp. PCC 6803 by Identifying the Limitations of Its Cultivation.

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van Alphen, Pascal; Abedini Najafabadi, Hamed; Branco Dos Santos, Filipe; Hellingwerf, Klaas J

2018-03-25

Many conditions have to be optimized in order to be able to grow the cyanobacterium Synechocystis sp. PCC 6803 (Synechocystis) for an extended period of time under physiologically well-defined and constant conditions. It is still poorly understood what limits growth of this organism in batch and continuous cultures in BG-11, the standard medium used to grow Synechocystis. Through a series of batch experiments in flasks and continuous mode experiments in advanced photobioreactors, it is shown that the limiting nutrient during batch cultivation is sulfate, the depletion of which leads to ROS formation and rapid bleaching of pigments after entry into stationary phase. In continuous mode, however, the limiting nutrient is iron. Optimizing these growth conditions resulted in a so far highest growth rate of 0.16 h -1 (4.3 h doubling time), which is significantly higher than the textbook value of 0.09 h -1 (8 h doubling time). An improved medium, BG-11 for prolonged cultivation (BG-11-PC) is introduced, that allows for controlled, extended cultivation of Synechocystis, under well-defined physiological conditions. The data present here have implications for mass-culturing of cyanobacteria. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Reconstruction and comparison of the metabolic potential of cyanobacteria Cyanothece sp. ATCC 51142 and Synechocystis sp. PCC 6803.

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Rajib Saha

Full Text Available Cyanobacteria are an important group of photoautotrophic organisms that can synthesize valuable bio-products by harnessing solar energy. They are endowed with high photosynthetic efficiencies and diverse metabolic capabilities that confer the ability to convert solar energy into a variety of biofuels and their precursors. However, less well studied are the similarities and differences in metabolism of different species of cyanobacteria as they pertain to their suitability as microbial production chassis. Here we assemble, update and compare genome-scale models (iCyt773 and iSyn731 for two phylogenetically related cyanobacterial species, namely Cyanothece sp. ATCC 51142 and Synechocystis sp. PCC 6803. All reactions are elementally and charge balanced and localized into four different intracellular compartments (i.e., periplasm, cytosol, carboxysome and thylakoid lumen and biomass descriptions are derived based on experimental measurements. Newly added reactions absent in earlier models (266 and 322, respectively span most metabolic pathways with an emphasis on lipid biosynthesis. All thermodynamically infeasible loops are identified and eliminated from both models. Comparisons of model predictions against gene essentiality data reveal a specificity of 0.94 (94/100 and a sensitivity of 1 (19/19 for the Synechocystis iSyn731 model. The diurnal rhythm of Cyanothece 51142 metabolism is modeled by constructing separate (light/dark biomass equations and introducing regulatory restrictions over light and dark phases. Specific metabolic pathway differences between the two cyanobacteria alluding to different bio-production potentials are reflected in both models.

Ethylene Regulates the Physiology of the Cyanobacterium Synechocystis sp. PCC 6803 via an Ethylene Receptor.

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Lacey, Randy F; Binder, Brad M

2016-08-01

Ethylene is a plant hormone that plays a crucial role in the growth and development of plants. The ethylene receptors in plants are well studied, and it is generally assumed that they are found only in plants. In a search of sequenced genomes, we found that many bacterial species contain putative ethylene receptors. Plants acquired many proteins from cyanobacteria as a result of the endosymbiotic event that led to chloroplasts. We provide data that the cyanobacterium Synechocystis (Synechocystis sp. PCC 6803) has a functional receptor for ethylene, Synechocystis Ethylene Response1 (SynEtr1). We first show that SynEtr1 directly binds ethylene. Second, we demonstrate that application of ethylene to Synechocystis cells or disruption of the SynEtr1 gene affects several processes, including phototaxis, type IV pilus biosynthesis, photosystem II levels, biofilm formation, and spontaneous cell sedimentation. Our data suggest a model where SynEtr1 inhibits downstream signaling and ethylene inhibits SynEtr1. This is similar to the inverse-agonist model of ethylene receptor signaling proposed for plants and suggests a conservation of structure and function that possibly originated over 1 billion years ago. Prior research showed that SynEtr1 also contains a light-responsive phytochrome-like domain. Thus, SynEtr1 is a bifunctional receptor that mediates responses to both light and ethylene. To our knowledge, this is the first demonstration of a functional ethylene receptor in a nonplant species and suggests that that the perception of ethylene is more widespread than previously thought. © 2016 American Society of Plant Biologists. All Rights Reserved.

CyanoEXpress: A web database for exploration and visualisation of the integrated transcriptome of cyanobacterium Synechocystis sp. PCC6803.

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Hernandez-Prieto, Miguel A; Futschik, Matthias E

2012-01-01

Synechocystis sp. PCC6803 is one of the best studied cyanobacteria and an important model organism for our understanding of photosynthesis. The early availability of its complete genome sequence initiated numerous transcriptome studies, which have generated a wealth of expression data. Analysis of the accumulated data can be a powerful tool to study transcription in a comprehensive manner and to reveal underlying regulatory mechanisms, as well as to annotate genes whose functions are yet unknown. However, use of divergent microarray platforms, as well as distributed data storage make meta-analyses of Synechocystis expression data highly challenging, especially for researchers with limited bioinformatic expertise and resources. To facilitate utilisation of the accumulated expression data for a wider research community, we have developed CyanoEXpress, a web database for interactive exploration and visualisation of transcriptional response patterns in Synechocystis. CyanoEXpress currently comprises expression data for 3073 genes and 178 environmental and genetic perturbations obtained in 31 independent studies. At present, CyanoEXpress constitutes the most comprehensive collection of expression data available for Synechocystis and can be freely accessed. The database is available for free at http://cyanoexpress.sysbiolab.eu.

The role of Slr0151, a tetratricopeptide repeat protein from Synechocystis sp. PCC 6803, during Photosystem II assembly and repair

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Anna eRast

2016-05-01

Full Text Available The assembly and repair of photosystem II (PSII is facilitated by a variety of assembly factors. Among those, the tetratricopeptide repeat (TPR protein Slr0151 from Synechocystis sp. PCC 6803 (hereafter Synechocystis has previously been assigned a repair function under high light conditions (Yang et al., 2014, J. Integr. Plant Biol. 56, 1136-50. Here, we show that inactivation of Slr0151 affects thylakoid membrane ultrastructure even under normal light conditions. Moreover, the level and localization of Slr0151 are affected in a variety of PSII-related mutants. In particular, the data suggest a close functional relationship between Slr0151 and Sll0933, which interacts with Ycf48 during PSII assembly and is homologous to PAM68 in Arabidopsis thaliana. Immunofluorescence analysis revealed a punctate distribution of Slr0151 within several different membrane types in Synechocystis cells.

Mutation of Gly195 of the ChlH subunit of Mg-chelatase reduces chlorophyll and further disrupts PS II assembly in a Ycf48-deficient strain of Synechocystis sp. PCC 6803

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Tim Crawford

2016-07-01

Full Text Available Biogenesis of the photosystems in oxygenic phototrophs requires co-translational insertion of chlorophyll a. The first committed step of chlorophyll a biosynthesis is the insertion of a Mg2+ ion into the tetrapyrrole intermediate protoporphyrin IX, catalyzed by Mg-chelatase. We have identified a Synechocystis sp. PCC 6803 strain with a spontaneous mutation in chlH that results in a Gly195 to Glu substitution in a conserved region of the catalytic subunit of Mg-chelatase. Mutant strains containing the ChlH Gly195 to Glu mutation were generated using a two-step protocol that introduced the chlH gene into a putative neutral site in the chromosome prior to deletion of the native gene. The Gly195 to Glu mutation resulted in strains with decreased chlorophyll a. Deletion of the PS II assembly factor Ycf48 in a strain carrying the ChlH Gly195 to Glu mutation did not grow photoautotrophically. In addition, the ChlH-G195E:ΔYcf48 strain showed impaired PS II activity and decreased assembly of PS II centers in comparison to a ΔYcf48 strain. We suggest decreased chlorophyll in the ChlH-G195E mutant provides a background to screen for the role of assembly factors that are not essential under optimal growth conditions.

Role of phosphatidylglycerol in the function and assembly of Photosystem II reaction center, studied in a cdsA-inactivated PAL mutant strain of Synechocystis sp. PCC6803 that lacks phycobilisomes

Czech Academy of Sciences Publication Activity Database

Laczkó-Dobos, H.; Ughy, B.; Tóth, S. Z.; Komenda, Josef; Zsiros, O.; Domonkos, I.; Párducz, A.; Bogos, B.; Komura, M.; Itoh, S.; Gombos, Z.

2008-01-01

Roč. 1777, č. 9 (2008), s. 1184-1194 ISSN 0005-2728 R&D Projects: GA AV ČR IAA400200801 Grant - others:HU(HU) OTKA T60109; HU(HU) OTKA T68692 Institutional research plan: CEZ:AV0Z50200510 Keywords : synechocystis sp. pcc6803 * phosphatidylglycerol * photosystem II Subject RIV: EE - Microbiology, Virology Impact factor: 4.447, year: 2008

Gene expression patterns of sulfur starvation in Synechocystis sp. PCC 6803

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Pendse Ninad D

2008-07-01

Full Text Available Abstract Background The unicellular cyanobacterium Synechocystis sp. PCC 6803 is a model microbe for studying biochemistry, genetics and molecular biology of photobiological processes. Importance of this bacterium in basic and applied research calls for a systematic, genome-wide description of its transcriptional regulatory capacity. Characteristic transcriptional responses to changes in the growth environment are expected to provide a scaffold for describing the Synechocystis transcriptional regulatory network as well as efficient means for functional annotation of genes in the genome. Results We designed, validated and used Synechocystis genome-wide oligonucleotide (70-mer microarray (representing 96.7% of all chromosomal ORFs annotated at the time of the beginning of this project to study transcriptional activity of the cyanobacterial genome in response to sulfur (S starvation. The microarray data were verified by quantitative RT-PCR. We made five main observations: 1 Transcriptional changes upon sulfate starvation were relatively moderate, but significant and consistent with growth kinetics; 2 S acquisition genes encoding for a high-affinity sulfate transporter were significantly induced, while decreased transcription of genes for phycobilisome, photosystems I and II, cytochrome b6/f, and ATP synthase indicated reduced light-harvesting and photosynthetic activity; 3 S starvation elicited transcriptional responses associated with general growth arrest and stress; 4 A large number of genes regulated by S availability encode hypothetical proteins or proteins of unknown function; 5 Hydrogenase structural and maturation accessory genes were not identified as differentially expressed, even though increased hydrogen evolution was observed. Conclusion The expression profiles recorded by using this oligonucleotide-based microarray platform revealed that during transition from the condition of plentiful S to S starvation, Synechocystis undergoes

Identification of a transporter Slr0982 involved in ethanol tolerance in cyanobacterium Synechocystis sp. PCC 6803

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Yanan eZhang

2015-05-01

Full Text Available Cyanobacteria have been engineered to produce ethanol through recent synthetic biology efforts. However, one major challenge to the cyanobacterial systems for high-efficiency ethanol production is their low tolerance to the ethanol toxicity. With a major goal to identify novel transporters involved in ethanol tolerance, we constructed gene knockout mutants for 58 transporter-encoding genes of Synechocystis sp. PCC 6803 and screened their tolerance change under ethanol stress. The efforts allowed discovery of a mutant of slr0982 gene encoding an ATP-binding cassette transporter which grew poorly in BG11 medium supplemented with 1.5% (v/v ethanol when compared with the wild type, and the growth loss could be recovered by complementing slr0982 in the ∆slr0982 mutant, suggesting that slr0982 is involved in ethanol tolerance in Synechocystis. To decipher the tolerance mechanism involved, a comparative metabolomic and network-based analysis of the wild type and the ethanol-sensitive ∆slr0982 mutant was performed. The analysis allowed the identification of four metabolic modules related to slr0982 deletion in the ∆slr0982 mutant, among which metabolites like sucrose and L-pyroglutamic acid which might be involved in ethanol tolerance, were found important for slr0982 deletion in the ∆slr0982 mutant. This study reports on the first transporter related to ethanol tolerance in Synechocystis, which could be a useful target for further tolerance engineering. In addition, metabolomic and network analysis provides important findings for better understanding of the tolerance mechanism to ethanol stress in Synechocystis.

Quantitative iTRAQ LC-MS/MS proteomics reveals metabolic responses to biofuel ethanol in cyanobacterial Synechocystis sp. PCC 6803.

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Qiao, Jianjun; Wang, Jiangxin; Chen, Lei; Tian, Xiaoxu; Huang, Siqiang; Ren, Xiaoyue; Zhang, Weiwen

2012-11-02

Recent progress in metabolic engineering has led to autotrophic production of ethanol in various cyanobacterial hosts. However, cyanobacteria are known to be sensitive to ethanol, which restricts further efforts to increase ethanol production levels in these renewable host systems. To understand the mechanisms of ethanol tolerance so that engineering more robust cyanobacterial hosts can be possible, in this study, the responses of model cyanobacterial Synechocystis sp. PCC 6803 to ethanol were determined using a quantitative proteomics approach with iTRAQ LC-MS/MS technologies. The resulting high-quality proteomic data set consisted of 24,887 unique peptides corresponding to 1509 identified proteins, a coverage of approximately 42% of the predicted proteins in the Synechocystis genome. Using a cutoff of 1.5-fold change and a p-value less than 0.05, 135 and 293 unique proteins with differential abundance levels were identified between control and ethanol-treated samples at 24 and 48 h, respectively. Functional analysis showed that the Synechocystis cells employed a combination of induced common stress response, modifications of cell membrane and envelope, and induction of multiple transporters and cell mobility-related proteins as protection mechanisms against ethanol toxicity. Interestingly, our proteomic analysis revealed that proteins related to multiple aspects of photosynthesis were up-regulated in the ethanol-treated Synechocystis cells, consistent with increased chlorophyll a concentration in the cells upon ethanol exposure. The study provided the first comprehensive view of the complicated molecular mechanisms against ethanol stress and also provided a list of potential gene targets for further engineering ethanol tolerance in Synechocystis PCC 6803.

RNA-seq based identification and mutant validation of gene targets related to ethanol resistance in cyanobacterial Synechocystis sp. PCC 6803

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Wang Jiangxin

2012-12-01

Full Text Available Abstract Background Fermentation production of biofuel ethanol consumes agricultural crops, which will compete directly with the food supply. As an alternative, photosynthetic cyanobacteria have been proposed as microbial factories to produce ethanol directly from solar energy and CO2. However, the ethanol productivity from photoautotrophic cyanobacteria is still very low, mostly due to the low tolerance of cyanobacterial systems to ethanol stress. Results To build a foundation necessary to engineer robust ethanol-producing cyanobacterial hosts, in this study we applied a quantitative transcriptomics approach with a next-generation sequencing technology, combined with quantitative reverse-transcript PCR (RT-PCR analysis, to reveal the global metabolic responses to ethanol in model cyanobacterial Synechocystis sp. PCC 6803. The results showed that ethanol exposure induced genes involved in common stress responses, transporting and cell envelope modification. In addition, the cells can also utilize enhanced polyhydroxyalkanoates (PHA accumulation and glyoxalase detoxication pathway as means against ethanol stress. The up-regulation of photosynthesis by ethanol was also further confirmed at transcriptional level. Finally, we used gene knockout strains to validate the potential target genes related to ethanol tolerance. Conclusion RNA-Seq based global transcriptomic analysis provided a comprehensive view of cellular response to ethanol exposure. The analysis provided a list of gene targets for engineering ethanol tolerance in cyanobacterium Synechocystis.

Phosphoproteome of the cyanobacterium Synechocystis sp. PCC 6803 and its dynamics during nitrogen starvation.

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Philipp eSpät

2015-03-01

Full Text Available Cyanobacteria have shaped the earth’s biosphere as the first oxygenic photoautotrophs and still play an important role in many ecosystems. The ability to adapt to changing environmental conditions is an essential characteristic in order to ensure survival. To this end, numerous studies have shown that bacteria use protein post-translational modifications such as Ser/Thr/Tyr phosphorylation in cell signalling, adaptation and regulation. Nevertheless, our knowledge of cyanobacterial phosphoproteomes and their dynamic response to environmental stimuli is relatively limited. In this study, we applied gel-free methods and high accuracy mass spectrometry towards the unbiased detection of Ser/Thr/Tyr phosphorylation events in the model cyanobacterium Synechocystis sp. PCC 6803. We could identify over 300 phosphorylation events in cultures grown on nitrate as exclusive nitrogen source. Chemical dimethylation labelling was applied to investigate proteome and phosphoproteome dynamics during nitrogen starvation. Our dataset describes the most comprehensive (phosphoproteome of Synechocystis to date, identifying 2,382 proteins and 183 phosphorylation events and quantifying 2,111 proteins and 148 phosphorylation events during nitrogen starvation. Global protein phosphorylation levels were increased in response to nitrogen depletion after 24 hours. Among the proteins with increased phosphorylation, the PII signalling protein showed the highest fold-change, serving as positive control. Other proteins with increased phosphorylation levels comprised functions in photosynthesis and in carbon and nitrogen metabolism. This study reveals dynamics of Synechocystis phosphoproteome in response to environmental stimuli and suggests an important role of protein Ser/Thr/Tyr phosphorylation in fundamental mechanisms of homeostatic control in cyanobacteria.

An alternative methionine aminopeptidase, MAP-A, is required for nitrogen starvation and high-light acclimation in the cyanobacterium Synechocystis sp. PCC 6803.

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Drath, Miriam; Baier, Kerstin; Forchhammer, Karl

2009-05-01

Methionine aminopeptidases (MetAPs or MAPs, encoded by map genes) are ubiquitous and pivotal enzymes for protein maturation in all living organisms. Whereas most bacteria harbour only one map gene, many cyanobacterial genomes contain two map paralogues, the genome of Synechocystis sp. PCC 6803 even three. The physiological function of multiple map paralogues remains elusive so far. This communication reports for the first time differential MetAP function in a cyanobacterium. In Synechocystis sp. PCC 6803, the universally conserved mapC gene (sll0555) is predominantly expressed in exponentially growing cells and appears to be a housekeeping gene. By contrast, expression of mapA (slr0918) and mapB (slr0786) genes increases during stress conditions. The mapB paralogue is only transiently expressed, whereas the widely distributed mapA gene appears to be the major MetAP during stress conditions. A mapA-deficient Synechocystis mutant shows a subtle impairment of photosystem II properties even under non-stressed conditions. In particular, the binding site for the quinone Q(B) is affected, indicating specific N-terminal methionine processing requirements of photosystem II components. MAP-A-specific processing becomes essential under certain stress conditions, since the mapA-deficient mutant is severely impaired in surviving conditions of prolonged nitrogen starvation and high light exposure.

Ethylene Regulates the Physiology of the Cyanobacterium Synechocystis sp. PCC 6803 via an Ethylene Receptor1[OPEN

Science.gov (United States)

2016-01-01

Ethylene is a plant hormone that plays a crucial role in the growth and development of plants. The ethylene receptors in plants are well studied, and it is generally assumed that they are found only in plants. In a search of sequenced genomes, we found that many bacterial species contain putative ethylene receptors. Plants acquired many proteins from cyanobacteria as a result of the endosymbiotic event that led to chloroplasts. We provide data that the cyanobacterium Synechocystis (Synechocystis sp. PCC 6803) has a functional receptor for ethylene, Synechocystis Ethylene Response1 (SynEtr1). We first show that SynEtr1 directly binds ethylene. Second, we demonstrate that application of ethylene to Synechocystis cells or disruption of the SynEtr1 gene affects several processes, including phototaxis, type IV pilus biosynthesis, photosystem II levels, biofilm formation, and spontaneous cell sedimentation. Our data suggest a model where SynEtr1 inhibits downstream signaling and ethylene inhibits SynEtr1. This is similar to the inverse-agonist model of ethylene receptor signaling proposed for plants and suggests a conservation of structure and function that possibly originated over 1 billion years ago. Prior research showed that SynEtr1 also contains a light-responsive phytochrome-like domain. Thus, SynEtr1 is a bifunctional receptor that mediates responses to both light and ethylene. To our knowledge, this is the first demonstration of a functional ethylene receptor in a nonplant species and suggests that that the perception of ethylene is more widespread than previously thought. PMID:27246094

Bioinformatic evaluation of L-arginine catabolic pathways in 24 cyanobacteria and transcriptional analysis of genes encoding enzymes of L-arginine catabolism in the cyanobacterium Synechocystis sp. PCC 6803

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Pistorius Elfriede K

2007-11-01

Full Text Available Abstract Background So far very limited knowledge exists on L-arginine catabolism in cyanobacteria, although six major L-arginine-degrading pathways have been described for prokaryotes. Thus, we have performed a bioinformatic analysis of possible L-arginine-degrading pathways in cyanobacteria. Further, we chose Synechocystis sp. PCC 6803 for a more detailed bioinformatic analysis and for validation of the bioinformatic predictions on L-arginine catabolism with a transcript analysis. Results We have evaluated 24 cyanobacterial genomes of freshwater or marine strains for the presence of putative L-arginine-degrading enzymes. We identified an L-arginine decarboxylase pathway in all 24 strains. In addition, cyanobacteria have one or two further pathways representing either an arginase pathway or L-arginine deiminase pathway or an L-arginine oxidase/dehydrogenase pathway. An L-arginine amidinotransferase pathway as a major L-arginine-degrading pathway is not likely but can not be entirely excluded. A rather unusual finding was that the cyanobacterial L-arginine deiminases are substantially larger than the enzymes in non-photosynthetic bacteria and that they are membrane-bound. A more detailed bioinformatic analysis of Synechocystis sp. PCC 6803 revealed that three different L-arginine-degrading pathways may in principle be functional in this cyanobacterium. These are (i an L-arginine decarboxylase pathway, (ii an L-arginine deiminase pathway, and (iii an L-arginine oxidase/dehydrogenase pathway. A transcript analysis of cells grown either with nitrate or L-arginine as sole N-source and with an illumination of 50 μmol photons m-2 s-1 showed that the transcripts for the first enzyme(s of all three pathways were present, but that the transcript levels for the L-arginine deiminase and the L-arginine oxidase/dehydrogenase were substantially higher than that of the three isoenzymes of L-arginine decarboxylase. Conclusion The evaluation of 24

Open reading frame ssr2016 is required for antimycin A-sensitive photosystem I-driven cyclic electron flow in the cyanobacterium Synechocystis sp. PCC 6803

NARCIS (Netherlands)

Yeremenko, Nataliya; Jeanjean, Robert; Prommeenate, Peerada; Krasikov, Vladimir; Nixon, Peter J.; Vermaas, Wim F. J.; Havaux, Michel; Matthijs, Hans C. P.

2005-01-01

Open reading frame ssr2016 encodes a protein with substantial sequence similarities to PGR5 identified as a component of the antimycin A-sensitive ferredoxin:plastoquinone reductase (FQR) in PSI cyclic photophosphorylation in Arabidopsis thaliana. We studied cyclic electron flow in Synechocystis sp.

An Integrative Approach to Energy, Carbon, and Redox Metabolism in the Cyanobacterium Synechocystis sp. PCC 6803. Special Report

Energy Technology Data Exchange (ETDEWEB)

Overbeek, R.

2003-06-30

The main objectives for the first year were to produce a detailed metabolic reconstruction of synechocystis sp. PCC 6803 especially in interrelated areas of photosynthesis, respiration, and central carbon metabolism to support a more complete understanding and modeling of this organism. Additionally, Integrated Genomics, Inc., provided detailed bioinformatic analysis of selected functional systems related to carbon and energy generation and utilization, and of the corresponding pathways, functional roles and individual genes to support wet lab experiments by collaborators.

Transcription and Regulation of the Bidirectional Hydrogenase in the Cyanobacterium Nostoc sp. Strain PCC 7120▿

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Sjöholm, Johannes; Oliveira, Paulo; Lindblad, Peter

2007-01-01

The filamentous, heterocystous cyanobacterium Nostoc sp. strain PCC 7120 (Anabaena sp. strain PCC 7120) possesses an uptake hydrogenase and a bidirectional enzyme, the latter being capable of catalyzing both H2 production and evolution. The completely sequenced genome of Nostoc sp. strain PCC 7120 reveals that the five structural genes encoding the bidirectional hydrogenase (hoxEFUYH) are separated in two clusters at a distance of approximately 8.8 kb. The transcription of the hox genes was examined under nitrogen-fixing conditions, and the results demonstrate that the cluster containing hoxE and hoxF can be transcribed as one polycistronic unit together with the open reading frame alr0750. The second cluster, containing hoxU, hoxY, and hoxH, is transcribed together with alr0763 and alr0765, located between the hox genes. Moreover, alr0760 and alr0761 form an additional larger operon. Nevertheless, Northern blot hybridizations revealed a rather complex transcription pattern in which the different hox genes are expressed differently. Transcriptional start points (TSPs) were identified 66 and 57 bp upstream from the start codon of alr0750 and hoxU, respectively. The transcriptions of the two clusters containing the hox genes are both induced under anaerobic conditions concomitantly with the induction of a higher level of hydrogenase activity. An additional TSP, within the annotated alr0760, 244 bp downstream from the suggested translation start codon, was identified. Electrophoretic mobility shift assays with purified LexA from Nostoc sp. strain PCC 7120 demonstrated specific interactions between the transcriptional regulator and both hox promoter regions. However, when LexA from Synechocystis sp. strain PCC 6803 was used, the purified protein interacted only with the promoter region of the alr0750-hoxE-hoxF operon. A search of the whole Nostoc sp. strain PCC 7120 genome demonstrated the presence of 216 putative LexA binding sites in total, including recA and rec

Resistance, accumulation and transformation of selenium by the cyanobacterium Synechocystis sp. PCC 6803 after exposure to inorganic SeVI or SeIV

International Nuclear Information System (INIS)

Gouget, B.; Avoscan, L.; Collins, R.; Carriere, M.; Sarret, G.

2005-01-01

Our purpose was to investigate the ability of Synechocystis sp. PCC 6803, a photosynthetic prokaryote isolated from fresh water, to resist, incorporate and reduce the oxidized forms of selenium including selenite and selenate, the major selenium species present in aquatic systems. Selenium speciation and the chemical intermediates during selenium transformation were determined by X-ray absorption near edge structure (XANES) spectroscopy. The possible internalisation pathways involving selenium and the metabolic fate of selenate and selenite were examined. Selenate metabolism seemed to proceed via the sulfate reduction pathway resulting in the formation of the R-Se-H, R-Se-R and R-Se-Se-R species. The transformation of selenate to toxic amino acids may explain the high sensitivity of Synechocystis to selenate. Several mechanisms of selenium reduction seem to complete during selenite assimilation. A specific mechanism may transform internalised selenite into selenide and, subsequently induce the biosynthesis of selenoproteins. A non-specific mechanism may interfere with thiols, such as glutathione in the cell cytoplasm, or with proteins in the periplasm of the bacteria, notably thioredoxins. Several hypotheses concerning the complex transformation of selenium in Synechocystis could therefore be proposed. (orig.)

CopM is a novel copper-binding protein involved in copper resistance in Synechocystis sp. PCC 6803

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Giner-Lamia, Joaquín; López-Maury, Luis; Florencio, Francisco J

2015-01-01

Copper resistance system in the cyanobacterium Synechocystis sp. PCC 6803 comprises two operons, copMRS and copBAC, which are expressed in response to copper in the media. copBAC codes for a heavy-metal efflux–resistance nodulation and division (HME-RND) system, while copMRS codes for a protein of unknown function, CopM, and a two-component system CopRS, which controls the expression of these two operons. Here, we report that CopM is a periplasmic protein able to bind Cu(I) with high affinity (KD ∼3 × 10−16). Mutants lacking copM showed a sensitive copper phenotype similar to mutants affected in copB, but lower than mutants of the two-component system CopRS, suggesting that CopBAC and CopM constitute two independent resistance mechanisms. Moreover, constitutive expression of copM is able to partially suppress the copper sensitivity of the copR mutant strain, pointing out that CopM per se is able to confer copper resistance. Furthermore, constitutive expression of copM was able to reduce total cellular copper content of the copR mutant to the levels determined in the wild-type (WT) strain. Finally, CopM was localized not only in the periplasm but also in the extracellular space, suggesting that CopM can also prevent copper accumulation probably by direct copper binding outside the cell. PMID:25545960

Proteomic analysis reveals resistance mechanism against biofuel hexane in Synechocystis sp. PCC 6803

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Liu Jie

2012-09-01

Full Text Available Abstract Background Recent studies have demonstrated that photosynthetic cyanobacteria could be an excellent cell factory to produce renewable biofuels and chemicals due to their capability to utilize solar energy and CO2 as the sole energy and carbon sources. Biosynthesis of carbon-neutral biofuel alkanes with good chemical and physical properties has been proposed. However, to make the process economically feasible, one major hurdle to improve the low cell tolerance to alkanes needed to be overcome. Results Towards the goal to develop robust and high-alkane-tolerant hosts, in this study, the responses of model cyanobacterial Synechocystis PCC 6803 to hexane, a representative of alkane, were investigated using a quantitative proteomics approach with iTRAQ - LC-MS/MS technologies. In total, 1,492 unique proteins were identified, representing about 42% of all predicted protein in the Synechocystis genome. Among all proteins identified, a total of 164 and 77 proteins were found up- and down-regulated, respectively. Functional annotation and KEGG pathway enrichment analyses showed that common stress responses were induced by hexane in Synechocystis. Notably, a large number of transporters and membrane-bound proteins, proteins against oxidative stress and proteins related to sulfur relay system and photosynthesis were induced, suggesting that they are possibly the major protection mechanisms against hexane toxicity. Conclusion The study provided the first comprehensive view of the complicated molecular mechanism employed by cyanobacterial model species, Synechocystis to defend against hexane stress. The study also provided a list of potential targets to engineer Synechocystis against hexane stress.

An integrative approach to energy, carbon, and redox metabolism in the cyanobacterium Synechocystis sp. PCC 6803

Energy Technology Data Exchange (ETDEWEB)

Overbeek, Ross; Fonstein, Veronika; Osterman, Andrei; Gerdes, Svetlana; Vassieva, Olga; Zagnitko, Olga; Rodionov, Dmitry

2005-02-15

The team of the Fellowship for Interpretation of Genomes (FIG) under the leadership of Ross Overbeek, began working on this Project in November 2003. During the previous year, the Project was performed at Integrated Genomics Inc. A transition from the industrial environment to the public domain prompted us to adjust some aspects of the Project. Notwithstanding the challenges, we believe that these adjustments had a strong positive impact on our deliverables. Most importantly, the work of the research team led by R. Overbeek resulted in the deployment of a new open source genomic platform, the SEED (Specific Aim 1). This platform provided a foundation for the development of CyanoSEED a specialized portal to comparative analysis and metabolic reconstruction of all available cyanobacterial genomes (Specific Aim 3). The SEED represents a new generation of software for genome analysis. Briefly, it is a portable and extendable system, containing one of the largest and permanently growing collections of complete and partial genomes. The complete system with annotations and tools is freely available via browsing or via installation on a user's Mac or Linux computer. One of the important unique features of the SEED is the support of metabolic reconstruction and comparative genome analysis via encoding and projection of functional subsystems. During the project period, the FIG research team has validated the new software by developing a significant number of core subsystems, covering many aspects of central metabolism (Specific Aim 2), as well as metabolic areas specific for cyanobacteria and other photoautotrophic organisms (Specific Aim 3). In addition to providing a proof of technology and a starting point for further community-based efforts, these subsystems represent a valuable asset. An extensive coverage of central metabolism provides the bulk of information required for metabolic modeling in Synechocystis sp.PCC 6803. Detailed analysis of several subsystems

Absorption and emission spectroscopic characterization of BLUF protein Slr1694 from Synechocystis sp. PCC6803 with roseoflavin cofactor.

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Zirak, P; Penzkofer, A; Mathes, T; Hegemann, P

2009-11-09

The wild-type BLUF protein Slr1694 from Synechocystis sp. PCC6803 (BLUF=blue-light sensor using FAD) has flavin adenosine dinucleotide (FAD) as natural cofactor. This light sensor causes positive phototaxis of the marine cyanobacterium. In this study the FAD cofactor of the wild-type Slr1694 was replaced by roseoflavin (RoF) and the roseoflavin derivatives RoFMN and RoFAD during heterologous expression in a riboflavin auxotrophic E. coli strain. An absorption and emission spectroscopic characterization of the cofactor-exchanged-Slr1694 (RoSlr) was carried out both under dark conditions and under illuminated conditions. The behaviour of RoF embedded in RoSlr in aqueous solution at pH 8 is compared with the behaviour of RoF in aqueous solution. The fluorescence of RoF and RoSlr is quenched by photo-induced twisted intra-molecular charge transfer at room temperature with stronger effect for RoF. The fluorescence quenching is diminished at liquid nitrogen temperature. Light exposure of RoSlr causes irreversible conversion of the protein embedded roseoflavins to 8-methylamino-flavins, 8-dimethylamino-lumichrome and 8-methylamino-lumichrome.

Mechanisms of High Temperature Resistance of Synechocystis sp. PCC 6803: An Impact of Histidine Kinase 34

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Jan Červený

2015-03-01

Full Text Available Synechocystis sp. PCC 6803 is a widely used model cyanobacterium for studying responses and acclimation to different abiotic stresses. Changes in transcriptome, proteome, lipidome, and photosynthesis in response to short term heat stress are well studied in this organism, and histidine kinase 34 (Hik34 is shown to play an important role in mediating such response. Corresponding data on long term responses, however, are fragmentary and vary depending on parameters of experiments and methods of data collection, and thus are hard to compare. In order to elucidate how the early stress responses help cells to sustain long-term heat stress, as well as the role of Hik34 in prolonged acclimation, we examined the resistance to long-term heat stress of wild-type and ΔHik34 mutant of Synechocystis. In this work, we were able to precisely control the long term experimental conditions by cultivating Synechocystis in automated photobioreactors, measuring selected physiological parameters within a time range of minutes. In addition, morphological and ultrastructural changes in cells were analyzed and western blotting of individual proteins was used to study the heat stress-affected protein expression. We have shown that the majority of wild type cell population was able to recover after 24 h of cultivation at 44 °C. In contrast, while ΔHik34 mutant cells were resistant to heat stress within its first hours, they could not recover after 24 h long high temperature treatment. We demonstrated that the early induction of HspA expression and maintenance of high amount of other HSPs throughout the heat incubation is critical for successful adaptation to long-term stress. In addition, it appears that histidine kinase Hik34 is an essential component for the long term high temperature resistance.

Mechanisms of High Temperature Resistance of Synechocystis sp. PCC 6803: An Impact of Histidine Kinase 34.

Science.gov (United States)

Červený, Jan; Sinetova, Maria A; Zavřel, Tomáš; Los, Dmitry A

2015-03-02

Synechocystis sp. PCC 6803 is a widely used model cyanobacterium for studying responses and acclimation to different abiotic stresses. Changes in transcriptome, proteome, lipidome, and photosynthesis in response to short term heat stress are well studied in this organism, and histidine kinase 34 (Hik34) is shown to play an important role in mediating such response. Corresponding data on long term responses, however, are fragmentary and vary depending on parameters of experiments and methods of data collection, and thus are hard to compare. In order to elucidate how the early stress responses help cells to sustain long-term heat stress, as well as the role of Hik34 in prolonged acclimation, we examined the resistance to long-term heat stress of wild-type and ΔHik34 mutant of Synechocystis. In this work, we were able to precisely control the long term experimental conditions by cultivating Synechocystis in automated photobioreactors, measuring selected physiological parameters within a time range of minutes. In addition, morphological and ultrastructural changes in cells were analyzed and western blotting of individual proteins was used to study the heat stress-affected protein expression. We have shown that the majority of wild type cell population was able to recover after 24 h of cultivation at 44 °C. In contrast, while ΔHik34 mutant cells were resistant to heat stress within its first hours, they could not recover after 24 h long high temperature treatment. We demonstrated that the early induction of HspA expression and maintenance of high amount of other HSPs throughout the heat incubation is critical for successful adaptation to long-term stress. In addition, it appears that histidine kinase Hik34 is an essential component for the long term high temperature resistance.

Isobutanol production in Synechocystis PCC 6803 using heterologous and endogenous alcohol dehydrogenases

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Rui Miao

2017-12-01

Full Text Available Isobutanol is a flammable compound that can be used as a biofuel due to its high energy density and suitable physical and chemical properties. In this study, we examined the capacity of engineered strains of Synechocystis PCC 6803 containing the α-ketoisovalerate decarboxylase from Lactococcus lactis and different heterologous and endogenous alcohol dehydrogenases (ADH for isobutanol production. A strain expressing an introduced kivd without any additional copy of ADH produced 3 mg L−1 OD750−1 isobutanol in 6 days. After the cultures were supplemented with external addition of isobutyraldehyde, the substrate for ADH, 60.8 mg L−1 isobutanol was produced after 24 h when OD750 was 0.8. The in vivo activities of four different ADHs, two heterologous and two putative endogenous in Synechocystis, were examined and the Synechocystis endogenous ADH encoded by slr1192 showed the highest efficiency for isobutanol production. Furthermore, the strain overexpressing the isobutanol pathway on a self-replicating vector with the strong Ptrc promoter showed significantly higher gene expression and isobutanol production compared to the corresponding strains expressing the same operon introduced on the genome. Hence, this study demonstrates that Synechocystis endogenous AHDs have a high capacity for isobutanol production, and identifies kivd encoded α-ketoisovalerate decarboxylase as one of the likely bottlenecks for further isobutanol production.

The exposed N-terminal tail of the D1 subunit is required for rapid D1 degradation during Photosystem II repair in Synechocystis sp

Czech Academy of Sciences Publication Activity Database

Komenda, Josef; Tichý, Martin; Prášil, Ondřej; Knoppová, Jana; Kuviková, Stanislava; de Vries, R.; Nixon, P. J.

2007-01-01

Roč. 19, - (2007), s. 2839-2854 ISSN 1040-4651 R&D Projects: GA MŠk LN00A141; GA ČR GA203/04/0800; GA ČR GA206/06/0322 Institutional research plan: CEZ:AV0Z50200510 Keywords : photosystem II * cyanobacterium * synechocystis sp. pcc 6803 Subject RIV: EE - Microbiology, Virology Impact factor: 9.653, year: 2007

Enhanced accumulation of glycogen, lipids and polyhydroxybutyrate under optimal nutrients and light intensities in the cyanobacterium Synechocystis sp. PCC 6803.

Science.gov (United States)

Monshupanee, T; Incharoensakdi, A

2014-04-01

Glycogen (GL) and lipids (LP) are efficient biofuel substrates, whereas polyhydroxybutyrate (PHB) is a potent biodegradable plastic. This study aimed to increase accumulation of these three compounds in Synechocystis sp. PCC 6803. Under autophototrophic growth, co-accumulation of the three compounds reached maximum level in a mid-stationary phase at 39·2% of dry weight (22·7% GL, 14·1% LP and 2·4% PHB). Nitrogen deprivation increased this to 61·5% (36·8% GL, 11·2% LP and 13·5% PHB), higher than that achieved by phosphorus, sulfur, iron or calcium deprivation. Combining nitrogen deprivation with 0·4% (w/v) glucose addition for heterophototrophic growth and optimizing the light intensity (200 μmol photons m(-2) s(-1) ) synergistically enhanced combined accumulation to 71·1% of biomass (41·3% GL, 16·7% LP and 13·1% PHB), a higher level than previously reported in Synechocystis. However, the maximum coproductivity of GL, LP and PHB (at 0·72 g l(-1) ) was obtained in the 12-day heterophototrophic culture without nitrogen deprivation. Accumulation of GL, LP and PHB was enhanced under both autophototrophic and heterophototrophic conditions by optimizations of nutrient and light supplies. This study provides a means for increasing co-production of potent bioenergy substrates and useful biomaterials in Synechocystis which may also be applicable to other cyanobacteria. © 2013 The Society for Applied Microbiology.

The Multiple Functions of Common Microbial Carbon Polymers, Glycogen and PHB, during Stress Responses in the Non-Diazotrophic Cyanobacterium Synechocystis sp. PCC 6803.

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Damrow, Ramon; Maldener, Iris; Zilliges, Yvonne

2016-01-01

Classical microbial carbon polymers such as glycogen and polyhydroxybutyrate (PHB) have a crucial impact as both a sink and a reserve under macronutrient stress conditions. Most microbial species exclusively synthesize and degrade either glycogen or PHB. A few bacteria such as the phototrophic model organism Synechocystis sp. PCC 6803 surprisingly produce both physico-chemically different polymers under conditions of high C to N ratios. For the first time, the function and interrelation of both carbon polymers in non-diazotrophic cyanobacteria are analyzed in a comparative physiological study of single- and double-knockout mutants (ΔglgC; ΔphaC; ΔglgC/ΔphaC), respectively. Most of the observed phenotypes are explicitly related to the knockout of glycogen synthesis, highlighting the metabolic, energetic, and structural impact of this process whenever cells switch from an active, photosynthetic 'protein status' to a dormant 'glycogen status'. The carbon flux regulation into glycogen granules is apparently crucial for both phycobilisome degradation and thylakoid layer disassembly in the presence of light. In contrast, PHB synthesis is definitely not involved in this primary acclimation response. Moreover, the very weak interrelations between the two carbon-polymer syntheses indicate that the regulation and role of PHB synthesis in Synechocystis sp. PCC 6803 is different from glycogen synthesis.

Sll0528, a Site-2-Protease, Is Critically Involved in Cold, Salt and Hyperosmotic Stress Acclimation of Cyanobacterium Synechocystis sp. PCC 6803

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Haijin Lei

2014-12-01

Full Text Available Site-2-proteases (S2Ps mediated proteolysis of transmembrane transcriptional regulators is a conserved mechanism to regulate transmembrane signaling. The universal presence of S2P homologs in different cyanobacterial genomes suggest conserved and fundamental functions, though limited data has been available. Here we provide the first evidence that Sll0528, a site-2-protease in Synechocystis sp. PCC 6803 is crucial for salt, cold and hyperosmotic stress acclimation. Remarkable induction of sll0528 gene expression was observed under salt, cold and hyperosmotic stress, much higher than induction of the other three S2Ps. Knock-out of sll0528 gene in wild type Synechocystis sp. PCC 6803 increased their sensitivity to salt, cold and hyperosmotic stress, as revealed by retarded growth, reduced pigments and disrupted photosystems. The sll0528 gene was induced to a much smaller extent by high light and mixotrophic growth with glucose. Similar growth responses of the sll0528 knockout mutant and wild type under high light and mixotrophic growth indicated that sll0528 was dispensable for these conditions. Recombinant Sll0528 protein could cleave beta-casein into smaller fragments. These results together suggest that the Sll0528 metalloprotease plays a role in the stress response and lays the foundation for further investigation of its mechanism, as well as providing hints for the functional analysis of other S2Ps in cyanobacteria.

Involvement of sulfoquinovosyl diacylglycerol in DNA synthesis in Synechocystis sp. PCC 6803

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Aoki Motohide

2012-02-01

Full Text Available Abstract Background Sulfoquinovosyl diacylglycerol (SQDG is present in the membranes of cyanobacteria and their postulated progeny, plastids, in plants. A cyanobacterium, Synechocystis sp. PCC 6803, requires SQDG for growth: its mutant (SD1 with the sqdB gene for SQDG synthesis disrupted can grow with external supplementation of SQDG. However, upon removal of SQDG from the medium, its growth is retarded, with a decrease in the cellular content of SQDG throughout cell division, and finally ceases. Concomitantly with the decrease in SQDG, the maximal activity of photosynthesis at high-light intensity is repressed by 40%. Findings We investigated effects of SQDG-defect on physiological aspects in Synechocystis with the use of SD1. SD1 cells defective in SQDG exhibited normal photosynthesis at low-light intensity as on culturing. Meanwhile, SD1 cells defective in SQDG were impaired in light-activated heterotrophic growth as well as in photoautotrophic growth. Flow cytometric analysis of the photoautotrophically growing cells gave similar cell size histograms for the wild type and SD1 supplemented with SQDG. However, the profile of SD1 defective in SQDG changed such that large part of the cell population was increased in size. Of particular interest was the microscopic observation that the mitotic index, i.e., population of dumbbell-like cells with a septum, increased from 14 to 29% in the SD1 culture without SQDG. Flow cytometric analysis also showed that the enlarged cells of SD1 defective in SQDG contained high levels of Chl, however, the DNA content was low. Conclusions Our experiments strongly support the idea that photosynthesis is not the limiting factor for the growth of SD1 defective in SQDG, and that SQDG is responsible for some physiologically fundamental process common to both photoautotrophic and light-activated heterotrophic growth. Our findings suggest that the SQDG-defect allows construction of the photosynthetic machinery at an

Statistical evaluation of nutritional components impacting phycocyanin production in Synechocystis SP

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Devendra V. Deshmukh

2012-03-01

Full Text Available Alkaliphilic cyanobacterial cultures were isolated from Lonar lake (MS, India. Among the set of cultures, Synechocystis sp, was studied for phycocyanin production. A maximum yield was obtained in BG-11 medium at optimized conditions (pH 10 and 16 h light. In order to increase the phycocyanin yield media optimization based on the eight media components a Plackett-Burman design of the 12 experimental trials was used. As per the analysis CaCl2.2H2O and Na2CO3 have been found to be the most influencing media components at 95% significance. Further the optimum concentrations of these components were estimated following a Box Wilson Central Composite Design (CCD with four star points and five replicates at the center points for each of two factors was adopted for optimization of these two media components. The results indicated that there was an interlinked influence of CaCl2.2H2O and Na2CO3 on 98% significance. The maximum yield of phycocyanin (12% of dry wt could be obtained at 0.058 g/l and 0.115 g/l of CaCl2.2H2O and Na2CO3, respectively.

Unicellular cyanobacteria synechocystis accommodate heterotrophic bacteria with varied enzymatic and metal resistance properties

Digital Repository Service at National Institute of Oceanography (India)

Anas, A.; Sageer, S.; Jasmin, C.; Vijayan, V.; Pavanan, P.; Athiyanathil, S.; Nair, S.

unicellular cyanobacterium Synechocystis sp. that came from a heavy metal contaminated region of Cochin estuary, southwest coast of India. Based on 16S rRNA gene sequence similarities, the heterotrophic bacteria were grouped into three phyla: namely...

Acetylome analysis reveals the involvement of lysine acetylation in photosynthesis and carbon metabolism in the model cyanobacterium Synechocystis sp. PCC 6803.

Science.gov (United States)

Mo, Ran; Yang, Mingkun; Chen, Zhuo; Cheng, Zhongyi; Yi, Xingling; Li, Chongyang; He, Chenliu; Xiong, Qian; Chen, Hui; Wang, Qiang; Ge, Feng

2015-02-06

Cyanobacteria are the oldest known life form inhabiting Earth and the only prokaryotes capable of performing oxygenic photosynthesis. Synechocystis sp. PCC 6803 (Synechocystis) is a model cyanobacterium used extensively in research on photosynthesis and environmental adaptation. Posttranslational protein modification by lysine acetylation plays a critical regulatory role in both eukaryotes and prokaryotes; however, its extent and function in cyanobacteria remain unexplored. Herein, we performed a global acetylome analysis on Synechocystis through peptide prefractionation, antibody enrichment, and high accuracy LC-MS/MS analysis; identified 776 acetylation sites on 513 acetylated proteins; and functionally categorized them into an interaction map showing their involvement in various biological processes. Consistent with previous reports, a large fraction of the acetylation sites are present on proteins involved in cellular metabolism. Interestingly, for the first time, many proteins involved in photosynthesis, including the subunits of phycocyanin (CpcA, CpcB, CpcC, and CpcG) and allophycocyanin (ApcA, ApcB, ApcD, ApcE, and ApcF), were found to be lysine acetylated, suggesting that lysine acetylation may play regulatory roles in the photosynthesis process. Six identified acetylated proteins associated with photosynthesis and carbon metabolism were further validated by immunoprecipitation and Western blotting. Our data provide the first global survey of lysine acetylation in cyanobacteria and reveal previously unappreciated roles of lysine acetylation in the regulation of photosynthesis. The provided data set may serve as an important resource for the functional analysis of lysine acetylation in cyanobacteria and facilitate the elucidation of the entire metabolic networks and photosynthesis process in this model cyanobacterium.

Quantitative proteomics reveals dynamic responses of Synechocystis sp. PCC 6803 to next-generation biofuel butanol.

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Tian, Xiaoxu; Chen, Lei; Wang, Jiangxin; Qiao, Jianjun; Zhang, Weiwen

2013-01-14

Butanol is a promising biofuel, and recent metabolic engineering efforts have demonstrated the use of photosynthetic cyanobacterial hosts for its production. However, cyanobacteria have very low tolerance to butanol, limiting the economic viability of butanol production from these renewable producing systems. The existing knowledge of molecular mechanism involved in butanol tolerance in cyanobacteria is very limited. To build a foundation necessary to engineer robust butanol-producing cyanobacterial hosts, in this study, the responses of Synechocystis PCC 6803 to butanol were investigated using a quantitative proteomics approach with iTRAQ - LC-MS/MS technologies. The resulting high-quality dataset consisted of 25,347 peptides corresponding to 1452 unique proteins, a coverage of approximately 40% of the predicted proteins in Synechocystis. Comparative quantification of protein abundances led to the identification of 303 differentially regulated proteins by butanol. Annotation and GO term enrichment analysis showed that multiple biological processes were regulated, suggesting that Synechocystis probably employed multiple and synergistic resistance mechanisms in dealing with butanol stress. Notably, the analysis revealed the induction of heat-shock protein and transporters, along with modification of cell membrane and envelope were the major protection mechanisms against butanol. A conceptual cellular model of Synechocystis PCC 6803 responses to butanol stress was constructed to illustrate the putative molecular mechanisms employed to defend against butanol stress. Copyright © 2012 Elsevier B.V. All rights reserved.

Development of a high-frequency in vivo transposon mutagenesis system for Synechocystis sp. PCC 6803 and Synechococcus elongatus PCC 7942.

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Watabe, Kazuyuki; Mimuro, Mamoru; Tsuchiya, Tohru

2014-11-01

Synechocystis sp. PCC 6803 (Synechocystis) is the first sequenced photosynthetic organism and has two advantages: natural transformation and light-activated heterotrophic growth. Such characteristics have mainly promoted reverse genetic analysis in this organism, however, to date approximately 50% of genes are still annotated as 'unknown protein' or 'hypothetical protein'. Therefore, forward genetic analysis is required for the identification of significant genes responsible for photosynthesis and other physiological phenomena among the genes of unknown function. The in vivo transposon mutagenesis system is one of the major methods for random mutagenesis. However, present in vivo transposon mutagenesis systems for cyanobacteria face problems such as relatively low frequency of transposition and repeated transposition in the host cells. In this study, we constructed vectors based on a mini-Tn5-derived vector that was designed to prevent repeated transposition. Our vectors carry a hyperactive transposase and optimized recognition sequence of transposase, which were reported to enhance frequency of transposition. Using the vector, we succeeded in highly frequent transposition (9×10(-3) per recipient cell) in Synechocystis. Transposon insertion sites of 10 randomly selected mutants indicated that the insertion sites spread throughout the genome with low sequence dependency. Furthermore, one of the 10 mutants exhibited the slow-growing phenotype, and the mutant was functionally complemented by using our expression vector. Our system also worked with another model cyanobacterium, Synechococcus elongatus PCC 7942, with high frequency. These results indicate that the developed system can be applied to the forward genetic analysis of a broad range of cyanobacteria. © The Author 2014. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Metabolic flux analysis of the hydrogen production potential in Synechocystis sp. PCC6803

Energy Technology Data Exchange (ETDEWEB)

Navarro, E. [Departamento de Lenguajes y Ciencias de la Computacion, Campus de Teatrinos, Universidad de Malaga, 29071 Malaga (Spain); Montagud, A.; Fernandez de Cordoba, P.; Urchueguia, J.F. [Instituto Universitario de Matematica Pura y Aplicada, Universidad Politecnica de Valencia, Camino de Vera 14, 46022 Valencia (Spain)

2009-11-15

Hydrogen is a promising energy vector; however, finding methods to produce it from renewable sources is essential to allow its wide-scale use. In that line, biological hydrogen production, although it is considered as a possible alternative, requires substantial improvements to overcome its present low yields. In that direction, genetic manipulation probably will play a central role and from that point of view metabolic flux analysis (MFA) constitutes an important tool to guide a priori most suitable genetic modifications oriented to a hydrogen yield increase. In this work MFA has been applied to analyze hydrogen photoproduction of Synechocystis sp. PCC6803. Flux analysis was carried out based on literature data and several basic fluxes were estimated in different growing conditions of the system. From this analysis, an upper limit for hydrogen photoproduction has been determined indicating a wide margin for improvement. MFA was also used to find a feasible operating space for hydrogen production, which avoids oxygen inhibition, one of the most important limitations to make hydrogen production cost effective. In addition, a set of biotechnological strategies are proposed that would be consistent with the performed mathematical analysis. (author)

Lipid and carotenoid cooperation-driven adaptation to light and temperature stress in Synechocystis sp. PCC6803.

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Zakar, Tomas; Herman, Eva; Vajravel, Sindhujaa; Kovacs, Laszlo; Knoppová, Jana; Komenda, Josef; Domonkos, Ildiko; Kis, Mihaly; Gombos, Zoltan; Laczko-Dobos, Hajnalka

2017-05-01

Polyunsaturated lipids are important components of photosynthetic membranes. Xanthophylls are the main photoprotective agents, can assist in protection against light stress, and are crucial in the recovery from photoinhibition. We generated the xanthophyll- and polyunsaturated lipid-deficient ROAD mutant of Synechocystis sp. PCC6803 (Synechocystis) in order to study the little-known cooperative effects of lipids and carotenoids (Cars). Electron microscopic investigations confirmed that in the absence of xanthophylls the S-layer of the cellular envelope is missing. In wild-type (WT) cells, as well as the xanthophyll-less (RO), polyunsaturated lipid-less (AD), and the newly constructed ROAD mutants the lipid and Car compositions were determined by MS and HPLC, respectively. We found that, relative to the WT, the lipid composition of the mutants was remodeled and the Car content changed accordingly. In the mutants the ratio of non-bilayer-forming (NBL) to bilayer-forming (BL) lipids was found considerably lower. Xanthophyll to β-carotene ratio increased in the AD mutant. In vitro and in vivo methods demonstrated that saturated, monounsaturated lipids and xanthophylls may stabilize the trimerization of Photosystem I (PSI). Fluorescence induction and oxygen-evolving activity measurements revealed increased light sensitivity of RO cells compared to those of the WT. ROAD showed a robust increase in light susceptibility and reduced recovery capability, especially at moderate low (ML) and moderate high (MH) temperatures, indicating a cooperative effect of xanthophylls and polyunsaturated lipids. We suggest that both lipid unsaturation and xanthophylls are required for providing the proper structure and functioning of the membrane environment that protects against light and temperature stress. Copyright © 2017 Elsevier B.V. All rights reserved.

Protein Network Signatures Associated with Exogenous Biofuels Treatments in Cyanobacterium Synechocystis sp. PCC 6803

International Nuclear Information System (INIS)

Pei, Guangsheng; Chen, Lei; Wang, Jiangxin; Qiao, Jianjun; Zhang, Weiwen

2014-01-01

Although recognized as a promising microbial cell factory for producing biofuels, current productivity in cyanobacterial systems is low. To make the processes economically feasible, one of the hurdles, which need to be overcome is the low tolerance of hosts to toxic biofuels. Meanwhile, little information is available regarding the cellular responses to biofuels stress in cyanobacteria, which makes it challenging for tolerance engineering. Using large proteomic datasets of Synechocystis under various biofuels stress and environmental perturbation, a protein co-expression network was first constructed and then combined with the experimentally determined protein–protein interaction network. Proteins with statistically higher topological overlap in the integrated network were identified as common responsive proteins to both biofuels stress and environmental perturbations. In addition, a weighted gene co-expression network analysis was performed to distinguish unique responses to biofuels from those to environmental perturbations and to uncover metabolic modules and proteins uniquely associated with biofuels stress. The results showed that biofuel-specific proteins and modules were enriched in several functional categories, including photosynthesis, carbon fixation, and amino acid metabolism, which may represent potential key signatures for biofuels stress responses in Synechocystis. Network-based analysis allowed determination of the responses specifically related to biofuels stress, and the results constituted an important knowledge foundation for tolerance engineering against biofuels in Synechocystis.

Protein Network Signatures Associated with Exogenous Biofuels Treatments in Cyanobacterium Synechocystis sp. PCC 6803

Energy Technology Data Exchange (ETDEWEB)

Pei, Guangsheng; Chen, Lei; Wang, Jiangxin; Qiao, Jianjun, E-mail: jianjunq@tju.edu.cn; Zhang, Weiwen, E-mail: jianjunq@tju.edu.cn [Laboratory of Synthetic Microbiology, School of Chemical Engineering and Technology, Tianjin University, Tianjin (China); Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin (China); SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin (China)

2014-11-03

Although recognized as a promising microbial cell factory for producing biofuels, current productivity in cyanobacterial systems is low. To make the processes economically feasible, one of the hurdles, which need to be overcome is the low tolerance of hosts to toxic biofuels. Meanwhile, little information is available regarding the cellular responses to biofuels stress in cyanobacteria, which makes it challenging for tolerance engineering. Using large proteomic datasets of Synechocystis under various biofuels stress and environmental perturbation, a protein co-expression network was first constructed and then combined with the experimentally determined protein–protein interaction network. Proteins with statistically higher topological overlap in the integrated network were identified as common responsive proteins to both biofuels stress and environmental perturbations. In addition, a weighted gene co-expression network analysis was performed to distinguish unique responses to biofuels from those to environmental perturbations and to uncover metabolic modules and proteins uniquely associated with biofuels stress. The results showed that biofuel-specific proteins and modules were enriched in several functional categories, including photosynthesis, carbon fixation, and amino acid metabolism, which may represent potential key signatures for biofuels stress responses in Synechocystis. Network-based analysis allowed determination of the responses specifically related to biofuels stress, and the results constituted an important knowledge foundation for tolerance engineering against biofuels in Synechocystis.

Secondary metabolite from Nostoc XPORK14A inhibits photosynthesis and growth of Synechocystis PCC 6803.

Science.gov (United States)

Shunmugam, Sumathy; Jokela, Jouni; Wahlsten, Matti; Battchikova, Natalia; Ateeq ur Rehman; Vass, Imre; Karonen, Maarit; Sinkkonen, Jari; Permi, Perttu; Sivonen, Kaarina; Aro, Eva-Mari; Allahverdiyeva, Yagut

2014-06-01

Screening of 55 different cyanobacterial strains revealed that an extract from Nostoc XPORK14A drastically modifies the amplitude and kinetics of chlorophyll a fluorescence induction of Synechocystis PCC6803 cells.After 2 d exposure to the Nostoc XPORK14A extract, Synechocystis PCC 6803 cells displayed reduced net photosynthetic activity and significantly modified electron transport properties of photosystem II under both light and dark conditions. However, the maximum oxidizable amount of P700 was not strongly affected. The extract also induced strong oxidative stress in Synechocystis PCC 6803 cells in both light and darkness. We identified the secondary metabolite of Nostoc XPORK14A causing these pronounced effects on Synechocystis cells. Mass spectrometry and nuclear magnetic resonance analyses revealed that this compound, designated as M22, has a non-peptide structure. We propose that M22 possesses a dualaction mechanism: firstly, by photogeneration of reactive oxygen species in the presence of light, which in turn affects the photosynthetic machinery of Synechocystis PCC 6803; and secondly, by altering the in vivo redox status of cells, possibly through inhibition of protein kinases.

Optimization of pH and nitrogen for enhanced hydrogen production by Synechocystis sp. PCC 6803 via statistical and machine learning methods.

Science.gov (United States)

Burrows, Elizabeth H; Wong, Weng-Keen; Fern, Xiaoli; Chaplen, Frank W R; Ely, Roger L

2009-01-01

The nitrogen (N) concentration and pH of culture media were optimized for increased fermentative hydrogen (H(2)) production from the cyanobacterium, Synechocystis sp. PCC 6803. The optimization was conducted using two procedures, response surface methodology (RSM), which is commonly used, and a memory-based machine learning algorithm, Q2, which has not been used previously in biotechnology applications. Both RSM and Q2 were successful in predicting optimum conditions that yielded higher H(2) than the media reported by Burrows et al., Int J Hydrogen Energy. 2008;33:6092-6099 optimized for N, S, and C (called EHB-1 media hereafter), which itself yielded almost 150 times more H(2) than Synechocystis sp. PCC 6803 grown on sulfur-free BG-11 media. RSM predicted an optimum N concentration of 0.63 mM and pH of 7.77, which yielded 1.70 times more H(2) than EHB-1 media when normalized to chlorophyll concentration (0.68 +/- 0.43 micromol H(2) mg Chl(-1) h(-1)) and 1.35 times more when normalized to optical density (1.62 +/- 0.09 nmol H(2) OD(730) (-1) h(-1)). Q2 predicted an optimum of 0.36 mM N and pH of 7.88, which yielded 1.94 and 1.27 times more H(2) than EHB-1 media when normalized to chlorophyll concentration (0.77 +/- 0.44 micromol H(2) mg Chl(-1) h(-1)) and optical density (1.53 +/- 0.07 nmol H(2) OD(730) (-1) h(-1)), respectively. Both optimization methods have unique benefits and drawbacks that are identified and discussed in this study. (c) 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009.

Flux Balance Analysis of Cyanobacterial Metabolism.The Metabolic Network of Synechocystis sp. PCC 6803

Czech Academy of Sciences Publication Activity Database

Knoop, H.; Gründel, M.; Zilliges, Y.; Lehmann, R.; Hoffmann, S.; Lockau, W.; Steuer, Ralf

2013-01-01

Roč. 9, č. 6 (2013), e1003081-e1003081 ISSN 1553-7358 R&D Projects: GA MŠk(CZ) EE2.3.20.0256 Institutional support: RVO:67179843 Keywords : SP STRAIN PCC-6803 * SP ATCC 51142 * photoautotrophic metabolism * anacystis-nidulans * reconstructions * pathway * plants * models * growth Subject RIV: EI - Biotechnology ; Bionics Impact factor: 4.829, year: 2013

Monitoring Photosynthesis in Individual Cells of Synechocystis sp. PCC 6803 on a Picosecond Timescale

Science.gov (United States)

Krumova, S.B.; Laptenok, S.P.; Borst, J.W.; Ughy, B.; Gombos, Z.; Ajlani, G.; van Amerongen, H.

2010-01-01

Picosecond fluorescence kinetics of wild-type (WT) and mutant cells of Synechocystis sp. PCC 6803, were studied at the ensemble level with a streak-camera and at the cell level using fluorescence-lifetime-imaging microscopy (FLIM). The FLIM measurements are in good agreement with the ensemble measurements, but they (can) unveil variations between and within cells. The BE mutant cells, devoid of photosystem II (PSII) and of the light-harvesting phycobilisomes, allowed the study of photosystem I (PSI) in vivo for the first time, and the observed 6-ps equilibration process and 25-ps trapping process are the same as found previously for isolated PSI. No major differences are detected between different cells. The PAL mutant cells, devoid of phycobilisomes, show four lifetimes: ∼20 ps (PSI and PSII), ∼80 ps, ∼440 ps, and 2.8 ns (all due to PSII), but not all cells are identical and variations in the kinetics are traced back to differences in the PSI/PSII ratio. Finally, FLIM measurements on WT cells reveal that in some cells or parts of cells, phycobilisomes are disconnected from PSI/PSII. It is argued that the FLIM setup used can become instrumental in unraveling photosynthetic regulation mechanisms in the future. PMID:20858447

Genetic engineering of Synechocystis PCC6803 for the photoautotrophic production of the sweetener erythritol.

Science.gov (United States)

van der Woude, Aniek D; Perez Gallego, Ruth; Vreugdenhil, Angie; Puthan Veetil, Vinod; Chroumpi, Tania; Hellingwerf, Klaas J

2016-04-08

Erythritol is a polyol that is used in the food and beverage industry. Due to its non-caloric and non-cariogenic properties, the popularity of this sweetener is increasing. Large scale production of erythritol is currently based on conversion of glucose by selected fungi. In this study, we describe a biotechnological process to produce erythritol from light and CO2, using engineered Synechocystis sp. PCC6803. By functionally expressing codon-optimized genes encoding the erythrose-4-phosphate phosphatase TM1254 and the erythrose reductase Gcy1p, or GLD1, this cyanobacterium can directly convert the Calvin cycle intermediate erythrose-4-phosphate into erythritol via a two-step process and release the polyol sugar in the extracellular medium. Further modifications targeted enzyme expression and pathway intermediates. After several optimization steps, the best strain, SEP024, produced up to 2.1 mM (256 mg/l) erythritol, excreted in the medium.

The photosynthetic bacteria Rhodobacter capsulatus and Synechocystis sp. PCC 6803 as new hosts for cyclic plant triterpene biosynthesis.

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Anita Loeschcke

Full Text Available Cyclic triterpenes constitute one of the most diverse groups of plant natural products. Besides the intriguing biochemistry of their biosynthetic pathways, plant triterpenes exhibit versatile bioactivities, including antimicrobial effects against plant and human pathogens. While prokaryotes have been extensively used for the heterologous production of other classes of terpenes, the synthesis of cyclic triterpenes, which inherently includes the two-step catalytic formation of the universal linear precursor 2,3-oxidosqualene, is still a major challenge. We thus explored the suitability of the metabolically versatile photosynthetic α-proteobacterium Rhodobacter capsulatus SB1003 and cyanobacterium Synechocystis sp. PCC 6803 as alternative hosts for biosynthesis of cyclic plant triterpenes. Therefore, 2,3-oxidosqualene production was implemented and subsequently combined with different cyclization reactions catalyzed by the representative oxidosqualene cyclases CAS1 (cycloartenol synthase, LUP1 (lupeol synthase, THAS1 (thalianol synthase and MRN1 (marneral synthase derived from model plant Arabidopsis thaliana. While successful accumulation of 2,3-oxidosqualene could be detected by LC-MS analysis in both hosts, cyclase expression resulted in differential production profiles. CAS1 catalyzed conversion to only cycloartenol, but expression of LUP1 yielded lupeol and a triterpenoid matching an oxidation product of lupeol, in both hosts. In contrast, THAS1 expression did not lead to cyclic product formation in either host, whereas MRN1-dependent production of marnerol and hydroxymarnerol was observed in Synechocystis but not in R. capsulatus. Our findings thus indicate that 2,3-oxidosqualene cyclization in heterologous phototrophic bacteria is basically feasible but efficient conversion depends on both the respective cyclase enzyme and individual host properties. Therefore, photosynthetic α-proteo- and cyanobacteria are promising alternative candidates

Effects of selected electron transport chain inhibitors on 24-h hydrogen production by Synechocystis sp. PCC 6803.

Science.gov (United States)

Burrows, Elizabeth H; Chaplen, Frank W R; Ely, Roger L

2011-02-01

One factor limiting biosolar hydrogen (H(2)) production from cyanobacteria is electron availability to the hydrogenase enzyme. In order to optimize 24-h H(2) production this study used Response Surface Methodology and Q2, an optimization algorithm, to investigate the effects of five inhibitors of the photosynthetic and respiratory electron transport chains of Synechocystis sp. PCC 6803. Over 3 days of diurnal light/dark cycling, with the optimized combination of 9.4 mM KCN (3.1 μmol 10(10) cells(-1)) and 1.5 mM malonate (0.5 μmol 10(10) cells(-1)) the H(2) production was 30-fold higher, in EHB-1 media previously optimized for nitrogen (N), sulfur (S), and carbon (C) concentrations (Burrows et al., 2008). In addition, glycogen concentration was measured over 24 h with two light/dark cycling regimes in both standard BG-11 and EHB-1 media. The results suggest that electron flow as well as glycogen accumulation should be optimized in systems engineered for maximal H(2) output. Copyright © 2010 Elsevier Ltd. All rights reserved.

Biocomputional construction of a gene network under acid stress in Synechocystis sp. PCC 6803.

Science.gov (United States)

Li, Yi; Rao, Nini; Yang, Feng; Zhang, Ying; Yang, Yang; Liu, Han-ming; Guo, Fengbiao; Huang, Jian

2014-01-01

Acid stress is one of the most serious threats that cyanobacteria have to face, and it has an impact at all levels from genome to phenotype. However, very little is known about the detailed response mechanism to acid stress in this species. We present here a general analysis of the gene regulatory network of Synechocystis sp. PCC 6803 in response to acid stress using comparative genome analysis and biocomputational prediction. In this study, we collected 85 genes and used them as an initial template to predict new genes through co-regulation, protein-protein interactions and the phylogenetic profile, and 179 new genes were obtained to form a complete template. In addition, we found that 11 enriched pathways such as glycolysis are closely related to the acid stress response. Finally, we constructed a regulatory network for the intricate relationship of these genes and summarize the key steps in response to acid stress. This is the first time a bioinformatic approach has been taken systematically to gene interactions in cyanobacteria and the elaboration of their cell metabolism and regulatory pathways under acid stress, which is more efficient than a traditional experimental study. The results also provide theoretical support for similar research into environmental stresses in cyanobacteria and possible industrial applications. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Responses of Synechocystis sp. PCC 6803 to heterologous biosynthetic pathways

DEFF Research Database (Denmark)

Vavitsas, Konstantinos; Rue, Emil Østergaard; Stefánsdóttir, Lára Kristín

2017-01-01

BACKGROUND: There are an increasing number of studies regarding genetic manipulation of cyanobacteria to produce commercially interesting compounds. The majority of these works study the expression and optimization of a selected heterologous pathway, largely ignoring the wholeness and complexity...... different compounds, the cyanogenic glucoside dhurrin and the diterpenoid 13R-manoyl oxide in Synechocystis PCC 6803. We used genome-scale metabolic modelling to study fluxes in individual reactions and pathways, and we determined the concentrations of key metabolites, such as amino acids, carotenoids...

Photophysiological and photosynthetic complex changes during iron starvation in Synechocystis sp. PCC 6803 and Synechococcus elongatus PCC 7942.

Directory of Open Access Journals (Sweden)

Jared M Fraser

Full Text Available Iron is an essential component in many protein complexes involved in photosynthesis, but environmental iron availability is often low as oxidized forms of iron are insoluble in water. To adjust to low environmental iron levels, cyanobacteria undergo numerous changes to balance their iron budget and mitigate the physiological effects of iron depletion. We investigated changes in key protein abundances and photophysiological parameters in the model cyanobacteria Synechococcus PCC 7942 and Synechocystis PCC 6803 over a 120 hour time course of iron deprivation. The iron stress induced protein (IsiA accumulated to high levels within 48 h of the onset of iron deprivation, reaching a molar ratio of ~42 IsiA : Photosystem I in Synechococcus PCC 7942 and ~12 IsiA : Photosystem I in Synechocystis PCC 6803. Concomitantly the iron-rich complexes Cytochrome b6f and Photosystem I declined in abundance, leading to a decrease in the Photosystem I : Photosystem II ratio. Chlorophyll fluorescence analyses showed a drop in electron transport per Photosystem II in Synechococcus, but not in Synechocystis after iron depletion. We found no evidence that the accumulated IsiA contributes to light capture by Photosystem II complexes.

An Integrative Approach to Energy Carbon and Redox Metabolism In Cyanobacterium Synechocystis

Energy Technology Data Exchange (ETDEWEB)

Dr. Ross Overbeek

2003-06-30

The main objectives for the first year were to produce a detailed metabolic reconstruction of synechocystis sp.pcc6803 especially in interrelated arrears of photosynthesis respiration and central carbon metabolism to support a more complete understanding and modeling of this organism. Additionally, IG, Inc. provided detailed bioinformatic analysis of selected functional systems related to carbon and energy generation and utilization, and of the corresponding pathways functional roles and individual genes to support wet lab experiments by collaborators.

Integrative Gene Cloning and Expression System for Streptomyces sp. US 24 and Streptomyces sp. TN 58 Bioactive Molecule Producing Strains

Directory of Open Access Journals (Sweden)

Samiha Sioud

2009-01-01

Full Text Available Streptomyces sp. US 24 and Streptomyces sp. TN 58, two strains producing interesting bioactive molecules, were successfully transformed using E. coli ET12567 (pUZ8002, as a conjugal donor, carrying the integrative plasmid pSET152. For the Streptomyces sp. US 24 strain, two copies of this plasmid were tandemly integrated in the chromosome, whereas for Streptomyces sp. TN 58, the integration was in single copy at the attB site. Plasmid pSET152 was inherited every time for all analysed Streptomyces sp. US 24 and Streptomyces sp. TN 58 exconjugants under nonselective conditions. The growth, morphological differentiation, and active molecules production of all studied pSET152 integrated exconjugants were identical to those of wild type strains. Consequently, conjugal transfer using pSET152 integration system is a suitable means of genes transfer and expression for both studied strains. To validate the above gene transfer system, the glucose isomerase gene (xylA from Streptomyces sp. SK was expressed in strain Streptomyces sp. TN 58. Obtained results indicated that heterologous glucose isomerase could be expressed and folded effectively. Glucose isomerase activity of the constructed TN 58 recombinant strain is of about eighteenfold higher than that of the Streptomyces sp. SK strain. Such results are certainly of importance due to the potential use of improved strains in biotechnological process for the production of high-fructose syrup from starch.

Physical, chemical, and metabolic state sensors expand the synthetic biology toolbox for Synechocystis sp. PCC 6803.

Science.gov (United States)

Immethun, Cheryl M; DeLorenzo, Drew M; Focht, Caroline M; Gupta, Dinesh; Johnson, Charles B; Moon, Tae Seok

2017-07-01

Many under-developed organisms possess important traits that can boost the effectiveness and sustainability of microbial biotechnology. Photoautotrophic cyanobacteria can utilize the energy captured from light to fix carbon dioxide for their metabolic needs while living in environments not suited for growing crops. Various value-added compounds have been produced by cyanobacteria in the laboratory; yet, the products' titers and yields are often not industrially relevant and lag behind what have been accomplished in heterotrophic microbes. Genetic tools for biological process control are needed to take advantage of cyanobacteria's beneficial qualities, as tool development also lags behind what has been created in common heterotrophic hosts. To address this problem, we developed a suite of sensors that regulate transcription in the model cyanobacterium Synechocystis sp. PCC 6803 in response to metabolically relevant signals, including light and the cell's nitrogen status, and a family of sensors that respond to the inexpensive chemical, l-arabinose. Increasing the number of available tools enables more complex and precise control of gene expression. Expanding the synthetic biology toolbox for this cyanobacterium also improves our ability to utilize this important under-developed organism in biotechnology. Biotechnol. Bioeng. 2017;114: 1561-1569. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Absorption and emission spectroscopic characterization of blue-light receptor Slr1694 from Synechocystis sp. PCC6803.

Science.gov (United States)

Zirak, P; Penzkofer, A; Lehmpfuhl, C; Mathes, T; Hegemann, P

2007-01-03

The BLUF protein Slr1694 from the cyanobacterium Synechocystis sp. PCC6803 is characterized by absorption and emission spectroscopy. Slr1694 expressed from E. coli which non-covalently binds FAD, FMN, and riboflavin (called Slr1694(I)), and reconstituted Slr1694 which dominantly contains FAD (called Slr1694(II)) are investigated. The receptor conformation of Slr1694 (dark adapted form Slr1694(r)) is transformed to the putative signalling state (light adapted form Slr1694(s)) with red-shifted absorption and decreased fluorescence efficiency by blue-light excitation. In the dark at 22 degrees C, the signalling state recovers back to the initial receptor state with a time constants of about 14.2s for Slr1694(I) and 17s for Slr1694(II). Quantum yields of signalling state formation of approximately 0.63+/-0.07 for both Slr1694(I) and Slr1694(II) were determined by transient transmission measurements and intensity dependent steady-state transmission measurements. Extended blue-light excitation causes some bound flavin conversion to the hydroquinone form and some photo-degradation, both with low quantum efficiency. The flavin-hydroquinone re-oxidizes slowly back (time constant 5-9 min) to the initial flavoquinone form in the dark. A photo-cycle dynamics scheme is presented.

Phenotypic characterization of Synechocystis sp PCC 6803 substrains reveals differences in sensitivity to abiotic stress

Czech Academy of Sciences Publication Activity Database

Zavřel, Tomáš; Očenášová, Petra; Červený, Jan

2017-01-01

Roč. 12, č. 12 (2017), č. článku e0189130. E-ISSN 1932-6203 R&D Projects: GA MŠk(CZ) LO1415; GA ČR(CZ) GA15-17367S; GA ČR(CZ) GA15-17367S Institutional support: RVO:86652079 Keywords : sp strain pcc-6803 * high-temperature * sp pcc6803 * cyanobacterium * growth * responses * acclimation * gene * photobioreactor * identification Subject RIV: EI - Biotechnology ; Bionics OBOR OECD: Environmental biotechnology Impact factor: 2.806, year: 2016

comparative transcriptomics between Synechococcus PCC 7942 and Synechocystis PCC 6803 provide insights into mechanisms of adaptation to stress.

Energy Technology Data Exchange (ETDEWEB)

Konstantinos, Billis [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); European Bioinformatics Inst., Hinxton, Cambridge (United Kingdom). European Molecular Biology Lab.; Aristotle Univ., Thessaloniki (Greece). Dept. of Genetics; Billini, Maria [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Max Planck Inst. for Terrestrial Microbiology, Marburg (Germany); Tripp, Harry J. [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Kyrpides, Nikos C. [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Mavrommatis, Konstantinos [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Celgene Corp, San Francisco, CA (United States)

2014-03-21

Background: Synechococcus sp. PCC 7942 and Synechocystis sp. PCC 6803 are model cyanobacteria from which the metabolism and adaptive responses of other cyanobacteria are inferred. Here we report the gene expression response of these two strains to a variety of nutrient and environmental stresses of varying duration, using transcriptomics. Our data comprise both stranded and 5? enriched libraries in order to elucidate many aspects of the transcriptome. Results: Both organisms were exposed to stress conditions due to nutrient deficiency (inorganic carbon) or change of environmental conditions (salinity, temperature, pH, light) sampled at 1 and 24 hours after the application of stress. The transcriptome profile of each strain revealed similarities and differences in gene expression for photosynthetic and respiratory electron transport chains and carbon fixation. Transcriptome profiles also helped us improve the structural annotation of the genome and identify possible missed genes (including anti-sense) and determine transcriptional units (operons). Finally, we predicted association of proteins of unknown function biochemical pathways by associating them to well-characterized ones based on their transcript levels correlation. Conclusions: Overall, this study results an informative annotation of those species and the comparative analysis of the response of the two organisms revealed similarities but also significant changes in the way they respond to external stress and the duration of the response

Metagenome-Assembled Genome Sequences of Acetobacterium sp. Strain MES1 and Desulfovibrio sp. Strain MES5 from a Cathode-Associated Acetogenic Microbial Community.

Science.gov (United States)

Ross, Daniel E; Marshall, Christopher W; May, Harold D; Norman, R Sean

2017-09-07

Draft genome sequences of Acetobacterium sp. strain MES1 and Desulfovibrio sp. strain MES5 were obtained from the metagenome of a cathode-associated community enriched within a microbial electrosynthesis system (MES). The draft genome sequences provide insight into the functional potential of these microorganisms within an MES and a foundation for future comparative analyses. Copyright © 2017 Ross et al.

Flux coupling and transcriptional regulation within the metabolic network of the photosynthetic bacterium Synechocystis sp. PCC6803

DEFF Research Database (Denmark)

Montagud, Arnau; Zelezniak, Aleksej; Navarro, Emilio

2011-01-01

networks, surrounded by a stable core of pathways leading to biomass building blocks. This analysis identified potential bottlenecks for hydrogen and ethanol production. Integration of transcriptomic data with the Synechocystis flux coupling networks lead to identification of reporter flux coupling pairs...

Metabolic Engineering of Light and Dark Biochemical Pathways in Wild-Type and Mutant Strains of Synechocystis PCC 6803 for Maximal, 24-Hour Production of Hydrogen Gas

Energy Technology Data Exchange (ETDEWEB)

Ely, Roger L.; Chaplen, Frank W.R.

2014-03-11

enhanced H2 production profiles using selected culture conditions and inhibitors of specific pathways in WT cells and an NDH-1 mutant; 3. Create Synechocystis PCC 6803 mutant strains with modified hydrogenases exhibiting increased O2 tolerance and greater H2 production; and 4. Integrate enhanced hydrogenase mutants and culture and metabolic factor studies to maximize 24-hour H2 production.

Coping with iron limitation: a metabolomic study of Synechocystis sp PCC 6803

Czech Academy of Sciences Publication Activity Database

Rivas-Ubach, A.; Poret-Peterson, A. T.; Penuelas, J.; Sardans, J.; Pérez-Trujillo, M.; Legido-Quigley, C.; Oravec, Michal; Urban, Otmar; Elser, J. J.

2018-01-01

Roč. 40, č. 2 (2018), č. článku 28. ISSN 0137-5881 R&D Projects: GA MŠk(CZ) LO1415; GA MŠk(CZ) LM2015061 Institutional support: RVO:86652079 Keywords : sp strain pcc-6803 * ocean acidification * unicellular cyanobacterium * marine-phytoplankton * foliar metabolomes * nitrogen-fixation * metal homeostasis * oxidative stress * pacific-ocean * responses * Metabolomics * Metallomics * Iron limitation * Cyanobacteria * Ecological stoichiometry Subject RIV: EH - Ecology, Behaviour OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 1.364, year: 2016

Effect of culture density on biomass production and light utilization efficiency of Synechocystis sp. PCC 6803.

Science.gov (United States)

Straka, Levi; Rittmann, Bruce E

2018-02-01

The viability of large-scale microalgae cultivation depends on providing optimal growth conditions, for which a key operational parameter is culture density. Using Synechocystis sp. PCC 6803, we conducted a series of fixed-density, steady-state experiments and one batch-growth experiment to investigate the role of culture density on biomass production and light utilization efficiency. In all cases, the fixed-density, steady-state experiments and batch-growth experiment showed good agreement. The highest biomass production rates (260 mg L -1  d -1 ) and efficiency for converting light energy to biomass (0.80 μg (μmol photons) -1 ) occurred together at a culture density near 760 mg L -1 , which approximately corresponded to the lowest culture density where almost all incident light was absorbed. The ratio of OD 680 /OD 735 increased with culture density up to the point of maximum productivity, where it plateaued (at a value of 2.4) for higher culture densities. This change in OD 680 /OD 735 indicates a photoacclimation effect that depended on culture density. Very high culture densities led to a sharp decline in efficiency of biomass production per photons absorbed, likely due to a combination of increased decay relative to growth, metabolic changes due to cell-cell interactions, and photodamage due to mixing between regions with high light intensity and zero light intensity. © 2017 Wiley Periodicals, Inc.

Photoreactivation and excision repair of UV induced pyrimidine dimers in the unicellular cyanobacterium Gloeocapsa alpicola (Synechocystis PCC 6308)

International Nuclear Information System (INIS)

O'Brien, P.A.; Houghton, J.A.

1982-01-01

The survival curve obtained after UV irradiation of the unicellular cyanobacterium Synechocystis is typical of a DNA repair competent organism. Inhibition of DNA replication, by incubating cells in the dark, increased resistance to the lethal effects of UV at higher fluences. Exposure of irradiated cells to near ultraviolet light (350-500 nm) restored viability to pre-irradiation levels. In order to measure DNA repair activity, techniques have been developed for the chromatographic analysis of pyrimidine dimers in synechocystis. The specificity of this method was established using a haploid strain of Saccharomyces cerevisiae. In accordance with the physiological responses of irradiated cells to photoreactivating light, pyrimidine dimers were not detected after photoreactivation treatment. Incubation of irradiated cells under non-photoreactivating growth conditions for 15h resulted in complete removal of pyrimidine dimers. It is concluded that Synechocystis contains photoreactivation and excision repair systems for the removal of pyrimidine dimers. (author)

Different physiological and photosynthetic responses of three cyanobacterial strains to light and zinc

International Nuclear Information System (INIS)

Xu, Kui; Juneau, Philippe

2016-01-01

Highlights: • The response mechanisms to high zinc was investigated among three cyanobacterial strains grown under two light regimes. • Photosystem II is more sensitive to high zinc compared to Photosystem I in the three studied strains. • High light increases the zinc uptake in two Microcystis aeruginosa strains, but not in Synechocystis sp.. • Combined high light and high zinc treatment is lethal for the toxic M. aeruginosa CPCC299. - Abstract: Zinc pollution of freshwater aquatic ecosystems is a problem in many countries, although its specific effects on phytoplankton may be influenced by other environmental factors. Light intensity varies continuously under natural conditions depending on the cloud cover and the season, and the response mechanisms of cyanobacteria to high zinc stress under different light conditions are not yet well understood. We investigated the effects of high zinc concentrations on three cyanobacterial strains (Microcystis aeruginosa CPCC299, M. aeruginosa CPCC632, and Synechocystis sp. FACHB898) grown under two light regimes. Under high light condition (HL), the three cyanobacterial strains increased their Car/Chl a ratios and non-photochemical quenching (NPQ), with CPCC299 showing the highest growth rate—suggesting a greater ability to adapt to those conditions as compared to the other two strains. Under high zinc concentrations the values of maximal (Φ_M) and operational (Φ'_M) photosystem II quantum yields, photosystem I quantum yield [Y(I)], and NPQ decreased. The following order of sensitivity to high zinc was established for the three strains studied: CPCC299 > CPCC632 > FACHB898. These different sensitivities can be partly explained by the higher internal zinc content observed in CPCC299 as compared to the other two strains. HL increased cellular zinc content and therefore increased zinc toxicity in both M. aeruginosa strains, although to a greater extent in CPCC299 than in CPCC632. Car/Chl a ratios decreased with high

Genome sequencing and annotation of Serratia sp. strain TEL.

Science.gov (United States)

Lephoto, Tiisetso E; Gray, Vincent M

2015-12-01

We present the annotation of the draft genome sequence of Serratia sp. strain TEL (GenBank accession number KP711410). This organism was isolated from entomopathogenic nematode Oscheius sp. strain TEL (GenBank accession number KM492926) collected from grassland soil and has a genome size of 5,000,541 bp and 542 subsystems. The genome sequence can be accessed at DDBJ/EMBL/GenBank under the accession number LDEG00000000.

Genome sequencing and annotation of Serratia sp. strain TEL

Directory of Open Access Journals (Sweden)

Tiisetso E. Lephoto

2015-12-01

Full Text Available We present the annotation of the draft genome sequence of Serratia sp. strain TEL (GenBank accession number KP711410. This organism was isolated from entomopathogenic nematode Oscheius sp. strain TEL (GenBank accession number KM492926 collected from grassland soil and has a genome size of 5,000,541 bp and 542 subsystems. The genome sequence can be accessed at DDBJ/EMBL/GenBank under the accession number LDEG00000000.

Genome sequencing and annotation of Serratia sp. strain TEL

OpenAIRE

Lephoto, Tiisetso E.; Gray, Vincent M.

2015-01-01

We present the annotation of the draft genome sequence of Serratia sp. strain TEL (GenBank accession number KP711410). This organism was isolated from entomopathogenic nematode Oscheius sp. strain TEL (GenBank accession number KM492926) collected from grassland soil and has a genome size of 5,000,541 bp and 542 subsystems. The genome sequence can be accessed at DDBJ/EMBL/GenBank under the accession number LDEG00000000.

Effects of cyanobacteria Synechocystis spp. in the host-parasite model Crassostrea gasar–Perkinsus marinus

International Nuclear Information System (INIS)

Queiroga, Fernando Ramos; Marques-Santos, Luis Fernando; Hégaret, Hélène; Sassi, Roberto; Farias, Natanael Dantas; Santana, Lucas Nunes

2017-01-01

Highlights: • Synechocystis cyanobacteria cause functional weakness of oysters haemocytes. • Synechocystis cyanobacteria cause a strengthening of Perkinsus marinus. • Synechocystis cyanobacteria may contribute to an imbalance of P. marinus–Crassostrea gasar relationship. - Abstract: Perkinsosis is a disease caused by protozoan parasites from the Perkinsus genus. In Brazil, two species, P. beihaiensis and P. marinus, are frequently found infecting native oysters (Crassostrea gasar and C. rhizophorae) from cultured and wild populations in several states of the Northeast region. The impacts of this disease in bivalves from Brazil, as well as the interactions with environmental factors, are poorly studied. In the present work, we evaluated the in vitro effects of the cyanobacteria Synechocystis spp. on trophozoites of P. marinus and haemocytes of C. gasar. Four cyanobacteria strains isolated from the Northeast Brazilian coast were used as whole cultures (WCs) and extracellular products (ECPs). Trophozoites of P. marinus were exposed for short (4 h) and long (48 h and 7 days, the latter only for ECPs) periods, while haemocytes were exposed for a short period (4 h). Cellular and immune parameters, i.e. cell viability, cell count, reactive oxygen species production (ROS) and phagocytosis of inert (latex beads) and biological particles (zymosan and trophozoites of P. marinus) were measured by flow cytometry. The viability of P. marinus trophozoites was improved in response to WCs of Synechocystis spp., which could be a beneficial effect of the cyanobacteria providing nutrients and reducing reactive oxygen species. Long-term exposure of trophozoites to ECPs of cyanobacteria did not modify in vitro cell proliferation nor viability. In contrast, C. gasar haemocytes showed a reduction in cell viability when exposed to WCs, but not to ECPs. However, ROS production was not altered. Haemocyte ability to engulf latex particles was reduced when exposed mainly to ECPs of

Effects of cyanobacteria Synechocystis spp. in the host-parasite model Crassostrea gasar–Perkinsus marinus

Energy Technology Data Exchange (ETDEWEB)

Queiroga, Fernando Ramos [Laboratório de Imunologia e Patologia de Invertebrados (LABIPI), Departamento de Biologia Molecular, Universidade Federal da Paraíba, 58051-900, João Pessoa, Paraíba (Brazil); Marques-Santos, Luis Fernando [Laboratório de Biologia Celular e do Desenvolvimento (LABID), Departamento de Biologia Molecular, Universidade Federal da Paraíba, 58051-900, João Pessoa, Paraíba (Brazil); Hégaret, Hélène [Laboratoire des Sciences de l' Environnement Marin (LEMAR), UMR 6539 CNRS UBO IRD IFREMER, Institut Universitaire Européen de la Mer, Technopôle Brest-Iroise, 29280, Plouzané (France); Sassi, Roberto [Laboratório de Ambientes Recifais e Biotecnologia de Microalgas (LARBIM), Departamento de Sistemática e Ecologia, Universidade Federal da Paraíba, 58051-900, João Pessoa, Paraíba (Brazil); Farias, Natanael Dantas; Santana, Lucas Nunes [Laboratório de Imunologia e Patologia de Invertebrados (LABIPI), Departamento de Biologia Molecular, Universidade Federal da Paraíba, 58051-900, João Pessoa, Paraíba (Brazil); and others

2017-06-15

Highlights: • Synechocystis cyanobacteria cause functional weakness of oysters haemocytes. • Synechocystis cyanobacteria cause a strengthening of Perkinsus marinus. • Synechocystis cyanobacteria may contribute to an imbalance of P. marinus–Crassostrea gasar relationship. - Abstract: Perkinsosis is a disease caused by protozoan parasites from the Perkinsus genus. In Brazil, two species, P. beihaiensis and P. marinus, are frequently found infecting native oysters (Crassostrea gasar and C. rhizophorae) from cultured and wild populations in several states of the Northeast region. The impacts of this disease in bivalves from Brazil, as well as the interactions with environmental factors, are poorly studied. In the present work, we evaluated the in vitro effects of the cyanobacteria Synechocystis spp. on trophozoites of P. marinus and haemocytes of C. gasar. Four cyanobacteria strains isolated from the Northeast Brazilian coast were used as whole cultures (WCs) and extracellular products (ECPs). Trophozoites of P. marinus were exposed for short (4 h) and long (48 h and 7 days, the latter only for ECPs) periods, while haemocytes were exposed for a short period (4 h). Cellular and immune parameters, i.e. cell viability, cell count, reactive oxygen species production (ROS) and phagocytosis of inert (latex beads) and biological particles (zymosan and trophozoites of P. marinus) were measured by flow cytometry. The viability of P. marinus trophozoites was improved in response to WCs of Synechocystis spp., which could be a beneficial effect of the cyanobacteria providing nutrients and reducing reactive oxygen species. Long-term exposure of trophozoites to ECPs of cyanobacteria did not modify in vitro cell proliferation nor viability. In contrast, C. gasar haemocytes showed a reduction in cell viability when exposed to WCs, but not to ECPs. However, ROS production was not altered. Haemocyte ability to engulf latex particles was reduced when exposed mainly to ECPs of

ORF Alignment: NC_000911 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available ... protein - Synechocystis sp. (strain PCC 6803) ... Length = 227 ... Query: 40 ... SRQTIIVATEPTFPPFEMTDE...ATGQLTGFDVDLIQAIGEAAQVTVDIQGYPFDGIIPALQ 99 ... SRQTIIVATEPTFPPFEMTDEATGQLTGFDVDLIQAIGEAAQVTVDIQGYPFDG...IIPALQ Sbjct: 1 ... SRQTIIVATEPTFPPFEMTDEATGQLTGFDVDLIQAIGEAAQVTVDIQGYPFDGIIPALQ 60

Expression of Heterologous Cellulases in Thermotoga sp. Strain RQ2

Directory of Open Access Journals (Sweden)

Hui Xu

2015-01-01

Full Text Available The ability of Thermotoga spp. to degrade cellulose is limited due to a lack of exoglucanases. To address this deficiency, cellulase genes Csac_1076 (celA and Csac_1078 (celB from Caldicellulosiruptor saccharolyticus were cloned into T. sp. strain RQ2 for heterologous overexpression. Coding regions of Csac_1076 and Csac_1078 were fused to the signal peptide of TM1840 (amyA and TM0070 (xynB, resulting in three chimeric enzymes, namely, TM1840-Csac_1078, TM0070-Csac_1078, and TM0070-Csac_1076, which were carried by Thermotoga-E. coli shuttle vectors pHX02, pHX04, and pHX07, respectively. All three recombinant enzymes were successfully expressed in E. coli DH5α and T. sp. strain RQ2, rendering the hosts with increased endo- and/or exoglucanase activities. In E. coli, the recombinant enzymes were mainly bound to the bacterial cells, whereas in T. sp. strain RQ2, about half of the enzyme activities were observed in the culture supernatants. However, the cellulase activities were lost in T. sp. strain RQ2 after three consecutive transfers. Nevertheless, this is the first time heterologous genes bigger than 1 kb (up to 5.3 kb in this study have ever been expressed in Thermotoga, demonstrating the feasibility of using engineered Thermotoga spp. for efficient cellulose utilization.

NblA1/A2-Dependent Homeostasis of Amino Acid Pools during Nitrogen Starvation in Synechocystis sp. PCC 6803.

Science.gov (United States)

Kiyota, Hiroshi; Hirai, Masami Yokota; Ikeuchi, Masahiko

2014-06-30

Nutrient balance is important for photosynthetic growth and biomass production in microalgae. Here, we investigated and compared metabolic responses of amino acid pools to nitrogen and sulfur starvation in a unicellular model cyanobacterium, Synechocystis sp. PCC 6803, and its mutant nblA1/A2. It is known that NblA1/A2-dependent and -independent breakdown of abundant photosynthetic phycobiliproteins and other cellular proteins supply nutrients to the organism. However, the contribution of the NblA1/A2-dependent nutrient supply to amino acid pool homeostasis has not been studied. Our study demonstrates that changes in the pool size of many amino acids during nitrogen starvation can be categorized as NblA1/A2-dependent (Gln, Glu, glutathione, Gly, Ile, Leu, Met, Phe, Pro, Ser, Thr, Tyr and Val) and NblA1/A2-independent (Ala, Asn, Lys, and Trp). We also report unique changes in amino acid pool sizes during sulfur starvation in wild type and the mutant and found a generally marked increase in the Lys pool in cyanobacteria during nutrient starvation. In conclusion, the NblA1/A2-dependent protein turnover contributes to the maintenance of many amino acid pools during nitrogen starvation.

NblA1/A2-Dependent Homeostasis of Amino Acid Pools during Nitrogen Starvation in Synechocystis sp. PCC 6803

Directory of Open Access Journals (Sweden)

Hiroshi Kiyota

2014-06-01

Full Text Available Nutrient balance is important for photosynthetic growth and biomass production in microalgae. Here, we investigated and compared metabolic responses of amino acid pools to nitrogen and sulfur starvation in a unicellular model cyanobacterium, Synechocystis sp. PCC 6803, and its mutant nblA1/A2. It is known that NblA1/A2-dependent and -independent breakdown of abundant photosynthetic phycobiliproteins and other cellular proteins supply nutrients to the organism. However, the contribution of the NblA1/A2-dependent nutrient supply to amino acid pool homeostasis has not been studied. Our study demonstrates that changes in the pool size of many amino acids during nitrogen starvation can be categorized as NblA1/A2-dependent (Gln, Glu, glutathione, Gly, Ile, Leu, Met, Phe, Pro, Ser, Thr, Tyr and Val and NblA1/A2-independent (Ala, Asn, Lys, and Trp. We also report unique changes in amino acid pool sizes during sulfur starvation in wild type and the mutant and found a generally marked increase in the Lys pool in cyanobacteria during nutrient starvation. In conclusion, the NblA1/A2-dependent protein turnover contributes to the maintenance of many amino acid pools during nitrogen starvation.

Different physiological and photosynthetic responses of three cyanobacterial strains to light and zinc

Energy Technology Data Exchange (ETDEWEB)

Xu, Kui; Juneau, Philippe, E-mail: juneau.philippe@uqam.ca

2016-01-15

Highlights: • The response mechanisms to high zinc was investigated among three cyanobacterial strains grown under two light regimes. • Photosystem II is more sensitive to high zinc compared to Photosystem I in the three studied strains. • High light increases the zinc uptake in two Microcystis aeruginosa strains, but not in Synechocystis sp.. • Combined high light and high zinc treatment is lethal for the toxic M. aeruginosa CPCC299. - Abstract: Zinc pollution of freshwater aquatic ecosystems is a problem in many countries, although its specific effects on phytoplankton may be influenced by other environmental factors. Light intensity varies continuously under natural conditions depending on the cloud cover and the season, and the response mechanisms of cyanobacteria to high zinc stress under different light conditions are not yet well understood. We investigated the effects of high zinc concentrations on three cyanobacterial strains (Microcystis aeruginosa CPCC299, M. aeruginosa CPCC632, and Synechocystis sp. FACHB898) grown under two light regimes. Under high light condition (HL), the three cyanobacterial strains increased their Car/Chl a ratios and non-photochemical quenching (NPQ), with CPCC299 showing the highest growth rate—suggesting a greater ability to adapt to those conditions as compared to the other two strains. Under high zinc concentrations the values of maximal (Φ{sub M}) and operational (Φ'{sub M}) photosystem II quantum yields, photosystem I quantum yield [Y(I)], and NPQ decreased. The following order of sensitivity to high zinc was established for the three strains studied: CPCC299 > CPCC632 > FACHB898. These different sensitivities can be partly explained by the higher internal zinc content observed in CPCC299 as compared to the other two strains. HL increased cellular zinc content and therefore increased zinc toxicity in both M. aeruginosa strains, although to a greater extent in CPCC299 than in CPCC632. Car/Chl a ratios

Draft Genome Sequence of Deep-Sea Alteromonas sp. Strain V450 Isolated from the Marine Sponge Leiodermatium sp.

Science.gov (United States)

Wang, Guojun; Barrett, Nolan H; McCarthy, Peter J

2017-02-02

The proteobacterium Alteromonas sp. strain V450 was isolated from the Atlantic deep-sea sponge Leiodermatium sp. Here, we report the draft genome sequence of this strain, with a genome size of approx. 4.39 Mb and a G+C content of 44.01%. The results will aid deep-sea microbial ecology, evolution, and sponge-microbe association studies. Copyright © 2017 Wang et al.

Effect of salt stress on the physiology of Frankia sp strain CcI6

Indian Academy of Sciences (India)

2013-10-01

Oct 1, 2013 ... the strain is closely related to Frankia sp. strain CcI3. ... [Oshone R, Mansour SR and Tisa LS 2013 Effect of salt stress on the physiology of Frankia sp strain CcI6. .... This work was supported in part by US-Egypt Joint Research.

Feather wastes digestion by new isolated strains Bacillus sp. in ...

African Journals Online (AJOL)

Feather wastes digestion by new isolated strains Bacillus sp. in Morocco. ... The most efficient isolated strain selected was compared with Bacillus subtilis ATCC 6633. Results showed ... African Journal of Biotechnology Vol.3(1) 2004: 67-70 ...

40 CFR 180.1120 - Streptomyces sp. strain K61; exemption from the requirement of a tolerance.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Streptomyces sp. strain K61; exemption... FOOD Exemptions From Tolerances § 180.1120 Streptomyces sp. strain K61; exemption from the requirement of a tolerance. The biological pesticide Streptomyces sp. strain K61 is exempted from the requirement...

A Toxin-Antitoxin System VapBC15 from Synechocystis sp. PCC 6803 Shows Distinct Regulatory Features

Directory of Open Access Journals (Sweden)

Qian Fei

2018-03-01

Full Text Available Type II toxin–antitoxin (TA systems play important roles in bacterial stress survival by regulating cell growth or death. They are highly abundant in cyanobacteria yet remain poorly characterized. Here, we report the identification and regulation of a putative type II TA system from Synechocystis PCC6803, VapBC15. The VapBC15 system is encoded by the chromosomal operon vapBC15. Exogenous expression of VapC15 dramatically arrested cell growth of Escherichia coli and reduced the numbers of colony-forming units (CFU. The VapC15 toxicity could be which was counteracted neutralized by simultaneous or delayed production of VapB15. Biochemical analysis demonstrated the formation of VapB15-VapC15 complexes by the physical interaction between VapB15 and VapC15. Notably, the VapB15 antitoxin up-regulated the transcription of the vapBC15 operon by directly binding to the promoter region, and the VapC15 toxin abolished the up-regulatory effect by destabilizing the binding. Moreover, VapB15 can be degraded by the proteases Lons and ClpXP2s from Synechocystis PCC6803, thus activating the latent toxicity of VapBC15. These findings suggest that VapBC15 represents a genuine TA system that utilizes a distinct mechanism to regulate toxin activity.

Improvement of strain Penicillium sp. EZ-ZH190 for tannase production by induced mutation.

Science.gov (United States)

Zakipour-Molkabadi, E; Hamidi-Esfahani, Z; Sahari, M A; Azizi, M H

2013-11-01

In the search for an efficient producer of tannase, Penicillium sp. EZ-ZH190 was subjected to mutagenesis using heat treatment and strain EZ-ZH290 was isolated. The maximum tannase in this mutant strain was 4.32 U/mL with an incubation period of 84 h as compared to wild strain EZ-ZH190 where the incubation period was 96 h with a maximum enzyme activity of 4.33 U/mL. Also, the Penicillium sp. EZ-ZH290 tannase had a maximum activity at 40 °C and pH 5.5. Then, the spores of strain EZ-ZH290 were subjected to γ irradiation mutagenesis and strain EZ-ZH390 was isolated. Strain EZ-ZH390 exhibited higher tannase activity (7.66 U/mL) than the parent strain EZ-ZH290. It was also found that Penicillium sp. EZ-ZH390 tannase had an optimum activity at 35 °C and a broad pH profile with an optimum at pH 5.5. The tannase pH stability of Penicillium sp. EZ-ZH390 and its maximum production of tannase followed the same trend for five generations confirming the occurrence of stable mutant. This paper is shown that γ irradiation can mutate the Penicillium sp. leading to increase the tannase production.

EFEKTIVITAS Bacillus thuringiensis H-14 STRAIN LOKAL DALAM BUAH KELAPA TERHADAP LARVA Anopheles sp dan Culex sp di KAMPUNG LAUT KABUPATEN CILACAP

Directory of Open Access Journals (Sweden)

Blondine Ch. P

2013-07-01

Full Text Available Abstrak Bacillus thuringiensis serotipe H-14 strain lokal adalah bakteri patogen bersifat target spesifiknya larva nyamuk, aman bagi mamalia dan lingkungan. Penelitian bertujuan menentukan efektivitas B. thuringiensis H-14 strain lokal yang dikembangbiakkan dalam buah kelapa untuk pengendalian larva Anopheles sp dan Culex sp. Rancangan eksperimental semu, terdiri dari kelompok perlakuan dan kontrol. Bacillus thuringiensis H-14 strain lokal dikembangbiakan dalam10 buah kelapa umur 6–8 bulan, dengan berat kira-kira 1 kg, telah berisi air kelapa sekitar 400-500 ml/buah kelapa yang diperoleh dari Desa Klaces, Kampung Laut, Kabupaten Cilacap. Diinkubasi selama 14 hari pada temperatur kamar dan ditebarkan di 6 kolam yang menjadi habitat perkembangbiakan larva nyamuk dengan luas berkisar 3–100 m2.Hasil yang diperoleh menunjukkan efektivitas B. thuringiensis H-14 strain lokal terhadap larva Anopheles sp dan Culex sp selama 1 hari sesudah penebaran kematian larva berturut-turut sebesar 80–100% dan 79,31–100%. Sedangkan pada hari ke-14 sebesar 69,30–76,71% dan 67,69–86,04%. Buah kelapa dapat digunakan sebagai media lokal alternatif untuk pengembangbiakan B. thuringiensis H-14 strain lokal Kata kunci: B. thuringiensis H-14,  strain  lokal, buah kelapa, pengendalian larva Abstract Bacillus thuringiensis serotype H-14 local strain is pathogenic bacteria which specific  target to mosquito larvae. It is safe for mammals and enviroment. The aims of this study was to determine the effectivity of B. thuringiensis H-14 local strain which culturing in thecoconut wates against Anopheles sp and Culex sp mosquito larvae. This research is quasi experiment which consist of treated  and control groups. Bacillus thuringiensis H-14 local strain was cultured in 10 coconuts with 6–8 months age with weight around 1 kg that contained were approximately 400-500 ml/coconut were taken from Klaces village, Kampung Laut. After that the coconuts incubated for 14

Bio sorption of strontium from aqueous solution by the new strain of bacillus sp. strain GT-83

International Nuclear Information System (INIS)

Tajer Mohammad Ghazvini, P.; Ghorbanzadeh Mashkani, S.; Mazaheri, M.

2009-01-01

An attempt was made to isolate bacterial strains capable of removing strontium biologically. In this study ten different water samples collected from Neydasht spring in the north of Iran and then the bacterial species were isolated from the water samples. The initial screening of a total of 50 bacterial isolates resulted in selection of one strain.The isolated strain showed a maximum adsorption capacity with 55 milligrams strontium/g dry wt. It was tentatively identified as Bacillus sp. According to the morphological and biochemical properties, and called strain GT-83. Our studies indicated that Bacillus sp. GT-83 is able to grow aerobically in the presence of 50 mM SrCl 2 , but its growth was inhibited at high levels of strontium concentrations. The bio sorption capacity of Bacillus sp. GT-83 depends strongly on the p H solution. Hence the maximum strontium sorption capacity of Bacillus sp. GT-83 was obtained at pah 10, independent of absence or presence of MgCl 2 of different concentrations. Strontium-salt bio sorption studies were also performed at this p H values. The equilibrium bio sorption of strontium was elevated by increasing the strontium concentration, up to 250 milligrams/l for Bacillus sp. GT-83. The maximum bio sorption of strontium was obtained at temperatures in the range of 30-35 d eg C . The Bacillus sp. GT-83 bio sorbed 97 milligrams strontium/g dry wt at 100 milligrams/l initial strontium concentration without MgCl 2 . When MgCl 2 concentration increased to 15%(w/v), these values dropped to 23.6 milligrams strontium/g dry wt at the same conditions. Uptake of strontium within 5 min of incubation was relatively rapid and the absorption continued slowly thereafter

Distinguishing the Roles of Thylakoid Respiratory Terminal Oxidases in the Cyanobacterium Synechocystis sp. PCC 6803.

Science.gov (United States)

Ermakova, Maria; Huokko, Tuomas; Richaud, Pierre; Bersanini, Luca; Howe, Christopher J; Lea-Smith, David J; Peltier, Gilles; Allahverdiyeva, Yagut

2016-06-01

Various oxygen-utilizing electron sinks, including the soluble flavodiiron proteins (Flv1/3), and the membrane-localized respiratory terminal oxidases (RTOs), cytochrome c oxidase (Cox) and cytochrome bd quinol oxidase (Cyd), are present in the photosynthetic electron transfer chain of Synechocystis sp. PCC 6803. However, the role of individual RTOs and their relative importance compared with other electron sinks are poorly understood, particularly under light. Via membrane inlet mass spectrometry gas exchange, chlorophyll a fluorescence, P700 analysis, and inhibitor treatment of the wild type and various mutants deficient in RTOs, Flv1/3, and photosystem I, we investigated the contribution of these complexes to the alleviation of excess electrons in the photosynthetic chain. To our knowledge, for the first time, we demonstrated the activity of Cyd in oxygen uptake under light, although it was detected only upon inhibition of electron transfer at the cytochrome b6f site and in ∆flv1/3 under fluctuating light conditions, where linear electron transfer was drastically inhibited due to impaired photosystem I activity. Cox is mostly responsible for dark respiration and competes with P700 for electrons under high light. Only the ∆cox/cyd double mutant, but not single mutants, demonstrated a highly reduced plastoquinone pool in darkness and impaired gross oxygen evolution under light, indicating that thylakoid-based RTOs are able to compensate partially for each other. Thus, both electron sinks contribute to the alleviation of excess electrons under illumination: RTOs continue to function under light, operating on slower time ranges and on a limited scale, whereas Flv1/3 responds rapidly as a light-induced component and has greater capacity. © 2016 American Society of Plant Biologists. All Rights Reserved.

Growth in coculture stimulates metabolism of the phenylurea herbicide isoproturon by Sphingomonas sp. strain SRS2.

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Sørensen, Sebastian R; Ronen, Zeev; Aamand, Jens

2002-07-01

Metabolism of the phenylurea herbicide isoproturon by Sphingomonas sp. strain SRS2 was significantly enhanced when the strain was grown in coculture with a soil bacterium (designated strain SRS1). Both members of this consortium were isolated from a highly enriched isoproturon-degrading culture derived from an agricultural soil previously treated regularly with the herbicide. Based on analysis of the 16S rRNA gene, strain SRS1 was assigned to the beta-subdivision of the proteobacteria and probably represents a new genus. Strain SRS1 was unable to degrade either isoproturon or its known metabolites 3-(4-isopropylphenyl)-1-methylurea, 3-(4-isopropylphenyl)-urea, or 4-isopropyl-aniline. Pure culture studies indicate that Sphingomonas sp. SRS2 is auxotrophic and requires components supplied by association with other soil bacteria. A specific mixture of amino acids appeared to meet these requirements, and it was shown that methionine was essential for Sphingomonas sp. SRS2. This suggests that strain SRS1 supplies amino acids to Sphingomonas sp. SRS2, thereby leading to rapid metabolism of (14)C-labeled isoproturon to (14)CO(2) and corresponding growth of strain SRS2. Proliferation of strain SRS1 suggests that isoproturon metabolism by Sphingomonas sp. SRS2 provides unknown metabolites or cell debris that supports growth of strain SRS1. The role of strain SRS1 in the consortium was not ubiquitous among soil bacteria; however, the indigenous soil microflora and some strains from culture collections also stimulate isoproturon metabolism by Sphingomonas sp. strain SRS2 to a similar extent.

Strain of Synechocystis PCC 6803 with Aberrant Assembly of Photosystem NN Contains Tandem Duplication of a Large Chromosomal Region

Czech Academy of Sciences Publication Activity Database

Tichý, Martin; Bečková, Martina; Kopečná, Jana; Noda, J.; Sobotka, Roman; Komenda, Josef

2016-01-01

Roč. 7, May 12 (2016), s. 648 ISSN 1664-462X R&D Projects: GA MŠk(CZ) LO1416 Institutional support: RVO:61388971 Keywords : Synechocystis 6803 * chlorophyll * photosystem I Subject RIV: EE - Microbiology, Virology Impact factor: 4.298, year: 2016

Metalaxyl Degradation by Mucorales Strains Gongronella sp. and Rhizopus oryzae.

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Martins, Maria Rosário; Santos, Cledir; Pereira, Pablo; Cruz-Morais, Júlio; Lima, Nelson

2017-12-14

In this study, the degradation of metalaxyl was investigated in the presence of two Mucorales strains, previously isolated from soil subjected to repeated treatments with this fungicide and selected after enrichment technique. Fungal strains were characterised by a polyphasic approach using phylogenetic analysis of the Internal Transcribed Spacer (ITS) gene region, phenotypic characterisation by Matrix-Assisted Laser Desorption Ionization Time-Of-Flight Mass Spectrometry (MALDI-TOF MS) spectral analysis, and growth kinetics experiments. The strains were identified as Gongronella sp. and Rhizopus oryzae . The fungal growth kinetics in liquid cultures containing metalaxyl fits with Haldane model. Under laboratory conditions, the ability of Gongronella sp. and R. oryzae cultures to degrade metalaxyl was evaluated in liquid cultures and soil experiments. Both species were able to: (a) use metalaxyl as the main carbon and energy source; and (b) degrade metalaxyl in polluted soils, with rates around 1.0 mg kg - ¹ d - ¹. This suggests these strains could degrade metalaxyl in soils contaminated with this fungicide.

Metalaxyl Degradation by Mucorales Strains Gongronella sp. and Rhizopus oryzae

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Maria Rosário Martins

2017-12-01

Full Text Available In this study, the degradation of metalaxyl was investigated in the presence of two Mucorales strains, previously isolated from soil subjected to repeated treatments with this fungicide and selected after enrichment technique. Fungal strains were characterised by a polyphasic approach using phylogenetic analysis of the Internal Transcribed Spacer (ITS gene region, phenotypic characterisation by Matrix-Assisted Laser Desorption Ionization Time-Of-Flight Mass Spectrometry (MALDI-TOF MS spectral analysis, and growth kinetics experiments. The strains were identified as Gongronella sp. and Rhizopus oryzae. The fungal growth kinetics in liquid cultures containing metalaxyl fits with Haldane model. Under laboratory conditions, the ability of Gongronella sp. and R. oryzae cultures to degrade metalaxyl was evaluated in liquid cultures and soil experiments. Both species were able to: (a use metalaxyl as the main carbon and energy source; and (b degrade metalaxyl in polluted soils, with rates around 1.0 mg kg−1 d−1. This suggests these strains could degrade metalaxyl in soils contaminated with this fungicide.

Transcriptomes of Frankia sp. strain CcI3 in growth transitions

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Bickhart Derek M

2011-08-01

Full Text Available Abstract Background Frankia sp. strains are actinobacteria that form N2-fixing root nodules on angiosperms. Several reference genome sequences are available enabling transcriptome studies in Frankia sp. Genomes from Frankia sp. strains differ markedly in size, a consequence proposed to be associated with a high number of indigenous transposases, more than 200 of which are found in Frankia sp. strain CcI3 used in this study. Because Frankia exhibits a high degree of cell heterogeneity as a consequence of its mycelial growth pattern, its transcriptome is likely to be quite sensitive to culture age. This study focuses on the behavior of the Frankia sp. strain CcI3 transcriptome as a function of nitrogen source and culture age. Results To study global transcription in Frankia sp. CcI3 grown under different conditions, complete transcriptomes were determined using high throughput RNA deep sequencing. Samples varied by time (five days vs. three days and by culture conditions (NH4+ added vs. N2 fixing. Assembly of millions of reads revealed more diversity of gene expression between five-day and three-day old cultures than between three day old cultures differing in nitrogen sources. Heat map analysis organized genes into groups that were expressed or repressed under the various conditions compared to median expression values. Twenty-one SNPs common to all three transcriptome samples were detected indicating culture heterogeneity in this slow-growing organism. Significantly higher expression of transposase ORFs was found in the five-day and N2-fixing cultures, suggesting that N starvation and culture aging provide conditions for on-going genome modification. Transposases have previously been proposed to participate in the creating the large number of gene duplication or deletion in host strains. Subsequent RT-qPCR experiments confirmed predicted elevated transposase expression levels indicated by the mRNA-seq data. Conclusions The overall pattern of

Discovery of Rare and Highly Toxic Microcystins from Lichen-Associated Cyanobacterium Nostoc sp. Strain IO-102-I

Science.gov (United States)

Oksanen, Ilona; Jokela, Jouni; Fewer, David P.; Wahlsten, Matti; Rikkinen, Jouko; Sivonen, Kaarina

2004-01-01

The production of hepatotoxic cyclic heptapeptides, microcystins, is almost exclusively reported from planktonic cyanobacteria. Here we show that a terrestrial cyanobacterium Nostoc sp. strain IO-102-I isolated from a lichen association produces six different microcystins. Microcystins were identified with liquid chromatography-UV mass spectrometry by their retention times, UV spectra, mass fragmentation, and comparison to microcystins from the aquatic Nostoc sp. strain 152. The dominant microcystin produced by Nostoc sp. strain IO-102-I was the highly toxic [ADMAdda5]microcystin-LR, which accounted for ca. 80% of the total microcystins. We assigned a structure of [DMAdda5]microcystin-LR and [d-Asp3,ADMAdda5]microcystin-LR and a partial structure of three new [ADMAdda5]-XR type of microcystin variants. Interestingly, Nostoc spp. strains IO-102-I and 152 synthesized only the rare ADMAdda and DMAdda subfamilies of microcystin variants. Phylogenetic analyses demonstrated congruence between genes involved directly in microcystin biosynthesis and the 16S rRNA and rpoC1 genes of Nostoc sp. strain IO-102-I. Nostoc sp. strain 152 and the Nostoc sp. strain IO-102-I are distantly related, revealing a sporadic distribution of toxin production in the genus Nostoc. Nostoc sp. strain IO-102-I is closely related to Nostoc punctiforme PCC 73102 and other symbiotic Nostoc strains and most likely belongs to this species. Together, this suggests that other terrestrial and aquatic strains of the genus Nostoc may have retained the genes necessary for microcystin biosynthesis. PMID:15466511

Glutaredoxins are essential for stress adaptation in the cyanobacterium Synechocystis sp. PCC 6803.

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Ana M Sánchez-Riego

2013-11-01

Full Text Available Glutaredoxin are small redox proteins able to reduce disulfides and mixed disulfides between GSH and proteins. Synechocystis sp. PCC 6803 contains three genes coding for glutaredoxins: ssr2061 (grxA and slr1562 (grxB code for dithiolic glutaredoxins while slr1846 (grxC codes for a monothiolic glutaredoxin. We have analyzed the expression of these glutaredoxins in response to different stresses, such as high light, H2O2 and heat shock. Analysis of the mRNA levels showed that grxA is only induced by heat while grxC is repressed by heat shock and is induced by high light and H2O2. In contrast, grxB expression was maintained almost constant under all conditions. Analysis of GrxA and GrxC protein levels by western blot showed that GrxA increases in response to high light, heat or H2O2 while GrxC is only induced by high light and H2O2, in accordance with its mRNA levels. In addition, we have also generated mutants that have interrupted one, two or three glutaredoxin genes. These mutants were viable and did not show any different phenotype from the WT under standard growth conditions. Nevertheless, analysis of these mutants under several stress conditions revealed that single grxA mutants grow slower after H2O2, heat and high light treatments, while mutants in grxB are indistinguishable from WT. grxC mutants were hypersensitive to treatments with H2O2, heat, high light and metals. A double grxAgrxC mutant was found to be even more sensitive to H2O2 than each corresponding single mutants. Surprisingly a mutation in grxB suppressed totally or partially the phenotypes of grxA and grxC mutants except the H2O2 sensitivity of the grxC mutant. This suggests that grxA and grxC participate in independent pathways while grxA and grxB participate in a common pathway for H2O2 resistance. The data presented here show that glutaredoxins are essential for stress adaptation in cyanobacteria, although their targets and mechanism of action remain unidentified.

Draft Whole-Genome Sequence of Serratia sp. Strain TEL, Associated with Oscheius sp. TEL-2014 (Nematoda: Rhabditidae) Isolated from a Grassland in South Africa

OpenAIRE

Lephoto, Tiisetso E.; Featherston, Jonathan; Gray, Vincent M.

2015-01-01

Here, we report on the draft genome sequence of Serratia sp. strain TEL, associated with Oscheius sp. TEL-2014 (Nematoda: Rhabditidae, KM492926) isolated from a grassland in Suikerbosrand Nature Reserve near Johannesburg in South Africa. Serratia sp. strain TEL has a genome size of 5,000,541 bp with 4,647 genes and a G+C content of 59.1%.

An assessment of adaptive and antagonistic properties of Trichoderma sp. strains in vegetable waste composts

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Wolna-Maruwka Agnieszka

2017-12-01

Full Text Available The experiment consisted in monitoring the count of moulds and three selected Trichoderma sp. isolates (T1 - Trichoderma atroviride, T2 - Trichoderma harzianum, T3 - Trichoderma harzianum in vegetable (onion and tomato waste composted with additives (straw, pig manure. Additionally, the aim of the study was to determine the type of interaction occurring between autochthonous fungi isolated from composts after the end of the thermophilic phase and Trichoderma sp. strains applied in the experiment. Number of microorganisms was determined by the plate method, next the identification was confirmed. The rating scale developed by Mańka was used to determine the type of interactions occurring between microorganisms. The greatest count of moulds in onion waste composts was noted in the object which had simultaneously been inoculated with two strains T1 - T. atroviride and T3 - T. harzianum. The greatest count of moulds was noted in the tomato waste composts inoculated with T2 - T. harzianum strain. Microscope identification revealed that Penicillum sp., Rhizopus sp., Alternaria sp. and Mucor sp. strains were predominant in onion waste composts. In tomato waste composts Penicillium was the predominant genus, followed by Rhizopus. The test of antagonism revealed the inhibitory effect of Trichoderma isolates on most autochthonous strains of moulds. Tomato waste composts proved to be better substrates for the growth and development of Trichoderma sp. isolates. The results of the study show that vegetable waste can be used in agriculture as carriers of antagonistic microorganisms.

Synthesis of Chlorophyll-Binding Proteins in a Fully Segregated Delta ycf54 Strain of the Cyanobacterium Synechocystis PCC 6803

Czech Academy of Sciences Publication Activity Database

Hollingshead, S.; Kopečná, Jana; Armstrong, D.R.; Bučinská, Lenka; Jackson, P. J.; Chen, G.E.; Dickman, M. J.; Williamson, M.P.; Sobotka, Roman; Hunter, C. N.

2016-01-01

Roč. 7, March 2016 (2016), s. 292 ISSN 1664-462X R&D Projects: GA ČR(CZ) GA14-13967S; GA MŠk(CZ) LO1416 Institutional support: RVO:61388971 Keywords : Ycf54 * Synechocystis 6803 * chlorophyll Subject RIV: EF - Botanics Impact factor: 4.298, year: 2016

Draft Whole-Genome Sequence of Serratia sp. Strain TEL, Associated with Oscheius sp. TEL-2014 (Nematoda: Rhabditidae) Isolated from a Grassland in South Africa.

Science.gov (United States)

Lephoto, Tiisetso E; Featherston, Jonathan; Gray, Vincent M

2015-07-09

Here, we report on the draft genome sequence of Serratia sp. strain TEL, associated with Oscheius sp. TEL-2014 (Nematoda: Rhabditidae, KM492926) isolated from a grassland in Suikerbosrand Nature Reserve near Johannesburg in South Africa. Serratia sp. strain TEL has a genome size of 5,000,541 bp with 4,647 genes and a G+C content of 59.1%. Copyright © 2015 Lephoto et al.

Effect of Indigenous Pseudomonas sp. and Bacillus sp. Strains on Yield and Main Chemical Growth Parameters of Radicchio

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Stanojković-Sebić Aleksandra

2018-03-01

Full Text Available Pseudomonas sp. and Bacillus sp. belong to plant growth promoting rhizobacteria which are able to colonize the plants roots and stimulate growth. In this study, the effect of two indigenous plant growth promoting rhizobacterial strains Pseudomonas sp. Q4 and Bacillus sp. Q10 and their mixture (mix Q4+Q10 on content of the main chemical growth parameters (nitrogen, phosphorus, potassium, calcium and magnesium and the yield of dry biomass of radicchio (Cichorium spp. var. rossa di treviso aerial parts and root, was investigated. The study was carried out with stagnosol type of soil in pot experiments under semi-controlled conditions in the Institute of Soil Science (Belgrade, in the period from July to October in 2013. Phosphorus was determined by spectrophotometer, potassium - by flame emission photometry and total nitrogen and carbon - using elemental CNS analyzer, while calcium and magnesium were determined by AAS. The data on yield of both aerial parts and root dry biomass of radicchio showed that its treatment with Q4 and Q10 strains, as well as with their mixture, caused noticeably increase in this parameter in relation to the control, whereby the strain Q4 was more effective for aerial parts, while mix Q4+Q10 - for roots. The obtained data on the studied chemical parameters of radicchio root and aerial parts were in total accordance with their yield. Concluding, studied strains have a potential in promoting the biomass yield and main chemical growth parameters of both aerial parts and root of radicchio.

Glycogen production for biofuels by the euryhaline cyanobacteria Synechococcus sp. strain PCC 7002 from an oceanic environment.

Science.gov (United States)

Aikawa, Shimpei; Nishida, Atsumi; Ho, Shih-Hsin; Chang, Jo-Shu; Hasunuma, Tomohisa; Kondo, Akihiko

2014-01-01

Oxygenic photosynthetic microorganisms such as cyanobacteria and microalgae have attracted attention as an alternative carbon source for the next generation of biofuels. Glycogen abundantly accumulated in cyanobacteria is a promising feedstock which can be converted to ethanol through saccharification and fermentation processes. In addition, the utilization of marine cyanobacteria as a glycogen producer can eliminate the need for a freshwater supply. Synechococcus sp. strain PCC 7002 is a fast-growing marine coastal euryhaline cyanobacteria, however, the glycogen yield has not yet been determined. In the present study, the effects of light intensity, CO2 concentration, and salinity on the cell growth and glycogen content were investigated in order to maximize glycogen production in Synechococcus sp. strain PCC 7002. The optimal culture conditions for glycogen production in Synechococcus sp. strain PCC 7002 were investigated. The maximum glycogen production of 3.5 g L(-1) for 7 days (a glycogen productivity of 0.5 g L(-1) d(-1)) was obtained under a high light intensity, a high CO2 level, and a nitrogen-depleted condition in brackish water. The glycogen production performance in Synechococcus sp. strain PCC 7002 was the best ever reported in the α-polyglucan (glycogen or starch) production of cyanobacteria and microalgae. In addition, the robustness of glycogen production in Synechococcus sp. strain PCC 7002 to salinity was evaluated in seawater and freshwater. The peak of glycogen production of Synechococcus sp. strain PCC 7002 in seawater and freshwater were 3.0 and 1.8 g L(-1) in 7 days, respectively. Glycogen production in Synechococcus sp. strain PCC 7002 maintained the same level in seawater and half of the level in freshwater compared with the optimal result obtained in brackish water. We conclude that Synechococcus sp. strain PCC 7002 has high glycogen production activity and glycogen can be provided from coastal water accompanied by a fluctuation

Retinal is formed from apo-carotenoids in Nostoc sp. PCC7120: in vitro characterization of an apo-carotenoid oxygenase

Science.gov (United States)

Scherzinger, Daniel; Ruch, Sandra; Kloer, Daniel P.; Wilde, Annegret; Al-Babili, Salim

2006-01-01

The sensory rhodopsin from Anabaena (Nostoc) sp. PCC7120 is the first cyanobacterial retinylidene protein identified. Here, we report on NosACO (Nostoc apo-carotenoid oxygenase), encoded by the ORF (open reading frame) all4284, as the candidate responsible for the formation of the required chromophore, retinal. In contrast with the enzymes from animals, NosACO converts β-apo-carotenals instead of β-carotene into retinal in vitro. The identity of the enzymatic products was proven by HPLC and gas chromatography–MS. NosACO exhibits a wide substrate specificity with respect to chain lengths and functional end-groups, converting β-apo-carotenals, (3R)-3-hydroxy-β-apo-carotenals and the corresponding alcohols into retinal and (3R)-3-hydroxyretinal respectively. However, kinetic analyses revealed very divergent Km and Vmax values. On the basis of the crystal structure of SynACO (Synechocystis sp. PCC6803 apo-carotenoid oxygenase), a related enzyme showing similar enzymatic activity, we designed a homology model of the native NosACO. The deduced structure explains the absence of β-carotene-cleavage activity and indicates that NosACO is a monotopic membrane protein. Accordingly, NosACO could be readily reconstituted into liposomes. To localize SynACO in vivo, a Synechocystis knock-out strain was generated expressing SynACO as the sole carotenoid oxygenase. Western-blot analyses showed that the main portion of SynACO occurred in a membrane-bound form. PMID:16759173

Antimicrobial and cytotoxic assessment of marine cyanobacteria - Synechocystis and Synechococcus.

Science.gov (United States)

Martins, R F; Ramos, M F; Herfindal, L; Sousa, J A; Skaerven, K; Vasconcelos, V M

2008-01-22

Aqueous extracts and organic solvent extracts of isolated marine cyanobacteria strains were tested for antimicrobial activity against a fungus, Gram-positive and Gram-negative bacteria and for cytotoxic activity against primary rat hepatocytes and HL-60 cells. Antimicrobial activity was based on the agar diffusion assay. Cytotoxic activity was measured by apoptotic cell death scored by cell surface evaluation and nuclear morphology. A high percentage of apoptotic cells were observed for HL-60 cells when treated with cyanobacterial organic extracts. Slight apoptotic effects were observed in primary rat hepatocytes when exposed to aqueous cyanobacterial extracts. Nine cyanobacteria strains were found to have antibiotic activity against two Gram-positive bacteria, Clavibacter michiganensis subsp. insidiosum and Cellulomonas uda. No inhibitory effects were found against the fungus Candida albicans and Gram-negative bacteria. Marine Synechocystis and Synechococcus extracts induce apoptosis in eukaryotic cells and cause inhibition of Gram-positive bacteria. The different activity in different extracts suggests different compounds with different polarities.

Antimicrobial and Cytotoxic Assessment of Marine Cyanobacteria - Synechocystis and Synechococcus

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Vitor M. Vasconcelos

2008-01-01

Full Text Available Aqueous extracts and organic solvent extracts of isolated marine cyanobacteria strains were tested for antimicrobial activity against a fungus, Gram-positive and Gram-negative bacteria and for cytotoxic activity against primary rat hepatocytes and HL-60 cells. Antimicrobial activity was based on the agar diffusion assay. Cytotoxic activity was measured by apoptotic cell death scored by cell surface evaluation and nuclear morphology. A high percentage of apoptotic cells were observed for HL-60 cells when treated with cyanobacterial organic extracts. Slight apoptotic effects were observed in primary rat hepatocytes when exposed to aqueous cyanobacterial extracts. Nine cyanobacteria strains were found to have antibiotic activity against two Gram-positive bacteria, Clavibacter michiganensis subsp. insidiosum and Cellulomonas uda. No inhibitory effects were found against the fungus Candida albicans and Gram-negative bacteria. Marine Synechocystis and Synechococcus extracts induce apoptosis in eukaryotic cells and cause inhibition of Gram-positive bacteria. The different activity in different extracts suggests different compounds with different polarities.

Metabolism of dimethylphthalate by Micrococcus sp. strain 12B.

Science.gov (United States)

Eaton, R W; Ribbons, D W

1982-01-01

During growth of Micrococcus sp. strain 12B with dimethylphthalate, 4-carboxy-2-hydroxymuconate lactone (CHML, X) and 3,4-dihydroxyphthalate-2-methyl ester (XI) were isolated from culture filtrates. CHML is the lactone of intermediate 4-carboxy-2-hydroxymuconate (IX). Accumulation of XI which is not a substrate for 3,4-dihydroxyphthalate-2-decarboxylase in strain 12B afforded an easy access to the preparation of 3,4-dihydroxyphthalate. PMID:7085569

Reduction of molybdate to molybdenum blue by Klebsiella sp. strain hkeem.

Science.gov (United States)

Lim, H K; Syed, M A; Shukor, M Y

2012-06-01

A novel molybdate-reducing bacterium, tentatively identified as Klebsiella sp. strain hkeem and based on partial 16s rDNA gene sequencing and phylogenetic analysis, has been isolated. Strain hkeem produced 3 times more molybdenum blue than Serratia sp. strain Dr.Y8; the most potent Mo-reducing bacterium isolated to date. Molybdate was optimally reduced to molybdenum blue using 4.5 mM phosphate, 80 mM molybdate and using 1% (w/v) fructose as a carbon source. Molybdate reduction was optimum at 30 °C and at pH 7.3. The molybdenum blue produced from cellular reduction exhibited absorption spectrum with a maximum peak at 865 nm and a shoulder at 700 nm. Inhibitors of electron transport system such as antimycin A, rotenone, sodium azide, and potassium cyanide did not inhibit the molybdenum-reducing enzyme. Mercury, silver, and copper at 1 ppm inhibited molybdenum blue formation in whole cells of strain hkeem. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The antisense RNA As1_flv4 in the Cyanobacterium Synechocystis sp. PCC 6803 prevents premature expression of the flv4-2 operon upon shift in inorganic carbon supply.

Science.gov (United States)

Eisenhut, Marion; Georg, Jens; Klähn, Stephan; Sakurai, Isamu; Mustila, Henna; Zhang, Pengpeng; Hess, Wolfgang R; Aro, Eva-Mari

2012-09-28

The functional relevance of natural cis-antisense transcripts is mostly unknown. Here we have characterized the association of three antisense RNAs and one intergenically encoded noncoding RNA with an operon that plays a crucial role in photoprotection of photosystem II under low carbon conditions in the cyanobacterium Synechocystis sp. PCC 6803. Cyanobacteria show strong gene expression dynamics in response to a shift of cells from high carbon to low levels of inorganic carbon (C(i)), but the regulatory mechanisms are poorly understood. Among the most up-regulated genes in Synechocystis are flv4, sll0218, and flv2, which are organized in the flv4-2 operon. The flavodiiron proteins encoded by this operon open up an alternative electron transfer route, likely starting from the Q(B) site in photosystem II, under photooxidative stress conditions. Our expression analysis of cells shifted from high carbon to low carbon demonstrated an inversely correlated transcript accumulation of the flv4-2 operon mRNA and one antisense RNA to flv4, designated as As1_flv4. Overexpression of As1_flv4 led to a decrease in flv4-2 mRNA. The promoter activity of as1_flv4 was transiently stimulated by C(i) limitation and negatively regulated by the AbrB-like transcription regulator Sll0822, whereas the flv4-2 operon was positively regulated by the transcription factor NdhR. The results indicate that the tightly regulated antisense RNA As1_flv4 establishes a transient threshold for flv4-2 expression in the early phase after a change in C(i) conditions. Thus, it prevents unfavorable synthesis of the proteins from the flv4-2 operon.

The Antisense RNA As1_flv4 in the Cyanobacterium Synechocystis sp. PCC 6803 Prevents Premature Expression of the flv4-2 Operon upon Shift in Inorganic Carbon Supply*

Science.gov (United States)

Eisenhut, Marion; Georg, Jens; Klähn, Stephan; Sakurai, Isamu; Mustila, Henna; Zhang, Pengpeng; Hess, Wolfgang R.; Aro, Eva-Mari

2012-01-01

The functional relevance of natural cis-antisense transcripts is mostly unknown. Here we have characterized the association of three antisense RNAs and one intergenically encoded noncoding RNA with an operon that plays a crucial role in photoprotection of photosystem II under low carbon conditions in the cyanobacterium Synechocystis sp. PCC 6803. Cyanobacteria show strong gene expression dynamics in response to a shift of cells from high carbon to low levels of inorganic carbon (Ci), but the regulatory mechanisms are poorly understood. Among the most up-regulated genes in Synechocystis are flv4, sll0218, and flv2, which are organized in the flv4-2 operon. The flavodiiron proteins encoded by this operon open up an alternative electron transfer route, likely starting from the QB site in photosystem II, under photooxidative stress conditions. Our expression analysis of cells shifted from high carbon to low carbon demonstrated an inversely correlated transcript accumulation of the flv4-2 operon mRNA and one antisense RNA to flv4, designated as As1_flv4. Overexpression of As1_flv4 led to a decrease in flv4-2 mRNA. The promoter activity of as1_flv4 was transiently stimulated by Ci limitation and negatively regulated by the AbrB-like transcription regulator Sll0822, whereas the flv4-2 operon was positively regulated by the transcription factor NdhR. The results indicate that the tightly regulated antisense RNA As1_flv4 establishes a transient threshold for flv4-2 expression in the early phase after a change in Ci conditions. Thus, it prevents unfavorable synthesis of the proteins from the flv4-2 operon. PMID:22854963

Complete genome sequence of Paenibacillus sp. strain JDR-2

Science.gov (United States)

Virginia Chow; Guang Nong; Franz J. St. John; John D. Rice; Ellen Dickstein; Olga Chertkov; David Bruce; Chris Detter; Thomas Brettin; James Han; Tanja Woyke; Sam Pitluck; Matt Nolan; Amrita Pati; Joel Martin; Alex Copeland; Miriam L. Land; Lynne Goodwin; Jeffrey B. Jones; Lonnie O. Ingram; Keelnathan T. Shanmugam; James F. Preston

2012-01-01

Paenibacillus sp. strain JDR-2, an aggressively xylanolytic bacterium isolated from sweetgum (Liquidambar styraciflua) wood, is able to efficiently depolymerize, assimilate and metabolize 4-O-methylglucuronoxylan, the predominant structural component of hardwood hemicelluloses. A basis for this capability was first supported by...

Synthesis of chlorophyll-binding proteins in a fully-segregated ∆ycf54 strain of the cyanobacterium Synechocystis PCC 6803

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Sarah eHollingshead

2016-03-01

Full Text Available In the chlorophyll (Chl biosynthesis pathway the formation of protochlorophyllide is catalyzed by Mg-protoporphyrin IX methyl ester (MgPME cyclase. The Ycf54 protein was recently shown to form a complex with another component of the oxidative cyclase, Sll1214 (CycI, and partial inactivation of the ycf54 gene leads to Chl deficiency in cyanobacteria and plants. The exact function of the Ycf54 is not known, however, and further progress depends on construction and characterisation of a mutant cyanobacterial strain with a fully inactivated ycf54 gene. Here, we report the complete deletion of the ycf54 gene in the cyanobacterium Synechocystis 6803; the resulting ycf54 strain accumulates huge concentrations of the cyclase substrate MgPME together with another pigment, which we identified using nuclear magnetic resonance as 3-formyl MgPME. The detection of a small amount (~13% of Chl in the ycf54 mutant provides clear evidence that the Ycf54 protein is important, but not essential, for activity of the oxidative cyclase. The greatly reduced formation of protochlorophyllide in the ycf54 strain provided an opportunity to use 35S protein labelling combined with 2D electrophoresis to examine the synthesis of all known Chl-binding protein complexes under drastically restricted de novo Chl biosynthesis. We show that although the ycf54 strain synthesizes very limited amounts of photosystem I and the CP47 and CP43 subunits of photosystem II (PSII, the synthesis of PSII D1 and D2 subunits and their assembly into the reaction centre (RCII assembly intermediate were not affected. Furthermore, the levels of other Chl complexes such as cytochrome b6f and the HliD– Chl synthase remained comparable to wild-type. These data demonstrate that the requirement for de novo Chl molecules differs completely for each Chl-binding protein. Chl traffic and recycling in the cyanobacterial cell as well as the function of Ycf54 are discussed.

Identification of OmpR-family response regulators interacting with thioredoxin in the Cyanobacterium Synechocystis sp. PCC 6803.

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Taro Kadowaki

Full Text Available The redox state of the photosynthetic electron transport chain is known to act as a signal to regulate the transcription of key genes involved in the acclimation responses to environmental changes. We hypothesized that the protein thioredoxin (Trx acts as a mediator connecting the redox state of the photosynthetic electron transport chain and transcriptional regulation, and established a screening system to identify transcription factors (TFs that interact with Trx. His-tagged TFs and S-tagged mutated form of Trx, TrxMC35S, whose active site cysteine 35 was substituted with serine to trap the target interacting protein, were co-expressed in E. coli cells and Trx-TF complexes were detected by immuno-blotting analysis. We examined the interaction between Trx and ten OmpR family TFs encoded in the chromosome of the cyanobacterium Synechocystis sp. PCC 6803 (S.6803. Although there is a highly conserved cysteine residue in the receiver domain of all OmpR family TFs, only three, RpaA (Slr0115, RpaB (Slr0947 and ManR (Slr1837, were identified as putative Trx targets [corrected].The recombinant forms of wild-type TrxM, RpaA, RpaB and ManR proteins from S.6803 were purified following over-expression in E. coli and their interaction was further assessed by monitoring changes in the number of cysteine residues with free thiol groups. An increase in the number of free thiols was observed after incubation of the oxidized TFs with Trx, indicating the reduction of cysteine residues as a consequence of interaction with Trx. Our results suggest, for the first time, the possible regulation of OmpR family TFs through the supply of reducing equivalents from Trx, as well as through the phospho-transfer from its cognate sensor histidine kinase.

Quantitative proteomic analysis of ibuprofen-degrading Patulibacter sp. strain I11

DEFF Research Database (Denmark)

Almeida, Barbara; Kjeldal, Henrik; Lolas, Ihab Bishara Yousef

2013-01-01

was identified and quantified by gel based shotgun-proteomics. In total 251 unique proteins were quantitated using this approach. Biological process and pathway analysis indicated a number of proteins that were up-regulated in response to active degradation of ibuprofen, some of them are known to be involved...... in the degradation of aromatic compounds. Data analysis revealed that several of these proteins are likely involved in ibuprofen degradation by Patulibacter sp. strain I11.......Ibuprofen is the third most consumed pharmaceutical drug in the world. Several isolates have been shown to degrade ibuprofen, but very little is known about the biochemistry of this process. This study investigates the degradation of ibuprofen by Patulibacter sp. strain I11 by quantitative...

Draft Genome Sequence of the Microbispora sp. Strain ATCC-PTA-5024, Producing the Lantibiotic NAI-107

DEFF Research Database (Denmark)

Sosio, M.; Gallo, G.; Pozzi, R.

2014-01-01

We report the draft genome sequence of Microbispora sp. strain ATCC-PTA-5024, a soil isolate that produces NAI-107, a new lantibiotic with the potential to treat life-threatening infections caused by multidrug-resistant Gram-positive pathogens. The draft genome of strain Microbispora sp. ATCC...

The use of fluorescence microscopy and image analysis for rapid detection of non-producing revertant cells of Synechocystis sp. PCC6803 and Synechococcus sp. PCC7002.

Science.gov (United States)

Schulze, Katja; Lang, Imke; Enke, Heike; Grohme, Diana; Frohme, Marcus

2015-04-17

Ethanol production via genetically engineered cyanobacteria is a promising solution for the production of biofuels. Through the introduction of a pyruvate decarboxylase and alcohol dehydrogenase direct ethanol production becomes possible within the cells. However, during cultivation genetic instability can lead to mutations and thus loss of ethanol production. Cells then revert back to the wild type phenotype. A method for a rapid and simple detection of these non-producing revertant cells in an ethanol producing cell population is an important quality control measure in order to predict genetic stability and the longevity of a producing culture. Several comparable cultivation experiments revealed a difference in the pigmentation for non-producing and producing cells: the accessory pigment phycocyanin (PC) is reduced in case of the ethanol producer, resulting in a yellowish appearance of the culture. Microarray and western blot studies of Synechocystis sp. PCC6803 and Synechococcus sp. PCC7002 confirmed this PC reduction on the level of RNA and protein. Based on these findings we developed a method for fluorescence microscopy in order to distinguish producing and non-producing cells with respect to their pigmentation phenotype. By applying a specific filter set the emitted fluorescence of a producer cell with a reduced PC content appeared orange. The emitted fluorescence of a non-producing cell with a wt pigmentation phenotype was detected in red, and dead cells in green. In an automated process multiple images of each sample were taken and analyzed with a plugin for the image analysis software ImageJ to identify dead (green), non-producing (red) and producing (orange) cells. The results of the presented validation experiments revealed a good identification with 98 % red cells in the wt sample and 90 % orange cells in the producer sample. The detected wt pigmentation phenotype (red cells) in the producer sample were either not fully induced yet (in 48 h induced

Biodegradation of 2-nitrotoluene by Micrococcus sp. strain SMN-1.

Science.gov (United States)

Mulla, Sikandar I; Hoskeri, Robertcyril S; Shouche, Yogesh S; Ninnekar, Harichandra Z

2011-02-01

A bacterial consortium capable of degrading nitroaromatic compounds was isolated from pesticide-contaminated soil samples by selective enrichment on 2-nitrotoluene as a sole source of carbon and energy. The three different bacterial isolates obtained from bacterial consortium were identified as Bacillus sp. (A and C), Bacillus flexus (B) and Micrococcus sp. (D) on the basis of their morphological and biochemical characteristics and by phylogenetic analysis based on 16S rRNA gene sequences. The pathway for the degradation of 2-nitrotoluene by Micrococcus sp. strain SMN-1 was elucidated by the isolation and identification of metabolites, growth and enzymatic studies. The organism degraded 2-nitrotoluene through 3-methylcatechol by a meta-cleavage pathway, with release of nitrite.

Studies on Nitrobenzene Metabolism by a Comamonas sp. Strain JS7651

National Research Council Canada - National Science Library

Gibson, David

2000-01-01

.... The nitrobenzene dioxygenase enzyme system shares high amino acid homology with other identified nitroarene dioxygenase enzymes, in particular the 2-nitrotoluene dioxygenase system from Pseudomonas sp. strain JS42...

Unraveling the mechanism responsible for the contrasting tolerance of Synechocystis and Synechococcus to Cr(VI): Enzymatic and non-enzymatic antioxidants

Energy Technology Data Exchange (ETDEWEB)

Gupta, Alka [Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Ballal, Anand, E-mail: aballal@barc.gov.in [Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 40085 (India)

2015-07-15

Highlights: • Cr(VI) accumulation generates higher ROS in Synechocystis than in Synechococcus. • Synechococcus exhibits better photosynthetic activity in response to Cr(VI). • Synechococcus has higher enzymatic/non-enzymatic antioxidants than Synechocystis. • Synechococcus shows better tolerance to other oxidative stresses than Synechocystis. • Differential detoxification of ROS is responsible for the contrasting tolerance to Cr(VI) - Abstract: Two unicellular cyanobacteria, Synechocystis and Synechococcus, showed contrasting tolerance to Cr(VI); with Synechococcus being 12-fold more tolerant than Synechocystis to potassium dichromate. The mechanism responsible for this differential sensitivity to Cr(VI) was explored in this study. Total content of photosynthetic pigments as well as photosynthetic activity decreased at lower concentration of Cr(VI) in Synechocystis as compared to Synechococcus. Experiments with {sup 51}Cr showed Cr to accumulate intracellularly in both the cyanobacteria. At lower concentrations, Cr(VI) caused excessive ROS generation in Synechocystis as compared to that observed in Synechococcus. Intrinsic levels of enzymatic antioxidants, i.e., superoxide dismutase, catalase and 2-Cys-peroxiredoxin were considerably higher in Synechococcus than Synechocystis. Content of total thiols (both protein as well as non-protein) and reduced glutathione (GSH) was also higher in Synechococcus as compared to Synechocystis. This correlated well with higher content of carbonylated proteins observed in Synechocystis than Synechococcus. Additionally, in contrast to Synechocystis, Synechococcus exhibited better tolerance to other oxidative stresses like high intensity light and H{sub 2}O{sub 2}. The data indicate that the disparity in the ability to detoxify ROS could be the primary mechanism responsible for the differential tolerance of these cyanobacteria to Cr(VI)

Genome Sequence of Gluconacetobacter sp. Strain SXCC-1, Isolated from Chinese Vinegar Fermentation Starter▿

OpenAIRE

Du, Xin-jun; Jia, Shi-ru; Yang, Yue; Wang, Shuo

2011-01-01

Gluconacetobacter strains are prominent bacteria during traditional vinegar fermentation. Here, we report a draft genome sequence of Gluconacetobacter sp. strain SXCC-1. This strain was isolated from a fermentation starter (Daqu) used for commercial production of Shanxi vinegar, the best-known vinegar of China.

Complete Genome Sequence of Photobacterium sp. Strain J15, Isolated from Seawater of Southwestern Johor, Malaysia.

Science.gov (United States)

Roslan, Noordiyanah Nadhirah; Sabri, Suriana; Oslan, Siti Nurbaya; Baharum, Syarul Nataqain; Leow, Thean Chor

2016-07-28

Here, we report the genome sequences of Photobacterium sp. strain J15, isolated from seawater in Johor, Malaysia, with the ability to produce lipase and asparaginase. The PacBio genome sequence analysis of Photobacterium sp. strain J15 generated revealed its potential in producing enzymes with different catalytic functions. Copyright © 2016 Roslan et al.

Downstream Processing of Synechocystis for Biofuel Production

Science.gov (United States)

Sheng, Jie

Lipids and free fatty acids (FFA) from cyanobacterium Synechocystis can be used for biofuel (e.g. biodiesel or renewable diesel) production. In order to utilize and scale up this technique, downstream processes including culturing and harvest, cell disruption, and extraction were studied. Several solvents/solvent systems were screened for lipid extraction from Synechocystis. Chloroform + methanol-based Folch and Bligh & Dyer methods were proved to be "gold standard" for small-scale analysis due to their highest lipid recoveries that were confirmed by their penetration of the cell membranes, higher polarity, and stronger interaction with hydrogen bonds. Less toxic solvents, such as methanol and MTBE, or direct transesterification of biomass (without preextraction step) gave only slightly lower lipid-extraction yields and can be considered for large-scale application. Sustained exposure to high and low temperature extremes severely lowered the biomass and lipid productivity. Temperature stress also triggered changes of lipid quality such as the degree of unsaturation; thus, it affected the productivities and quality of Synechocystis-derived biofuel. Pulsed electric field (PEF) was evaluated for cell disruption prior to lipid extraction. A treatment intensity > 35 kWh/m3 caused significant damage to the plasma membrane, cell wall, and thylakoid membrane, and it even led to complete disruption of some cells into fragments. Treatment by PEF enhanced the potential for the low-toxicity solvent isopropanol to access lipid molecules during subsequent solvent extraction, leading to lower usage of isopropanol for the same extraction efficiency. Other cell-disruption methods also were tested. Distinct disruption effects to the cell envelope, plasma membrane, and thylakoid membranes were observed that were related to extraction efficiency. Microwave and ultrasound had significant enhancement of lipid extraction. Autoclaving, ultrasound, and French press caused significant

Biodegradation of cypermethrin by immobilized cells of Micrococcus sp. strain CPN 1.

Science.gov (United States)

Tallur, Preeti N; Mulla, Sikandar I; Megadi, Veena B; Talwar, Manjunatha P; Ninnekar, Harichandra Z

2015-01-01

Pyrethroid pesticide cypermethrin is a environmental pollutant because of its widespread use, toxicity and persistence. Biodegradation of such chemicals by microorganisms may provide an cost-effective method for their detoxification. We have investigated the degradation of cypermethrin by immobilized cells of Micrococcus sp. strain CPN 1 in various matrices such as, polyurethane foam (PUF), polyacrylamide, sodium alginate and agar. The optimum temperature and pH for the degradation of cypermethrin by immobilized cells of Micrococcus sp. were found to be 30 °C and 7.0, respectively. The rate of degradation of 10 and 20 mM of cypermethrin by freely suspended cells were compared with that of immobilized cells in batches and semi-continuous with shaken cultures. PUF-immobilized cells showed higher degradation of cypermethrin (10 mM and 20 mM) than freely suspended cells and cells immobilized in other matrices. The PUF-immobilized cells of Micrococcus sp. strain CPN 1 were retain their degradation capacity. Thus, they can be reused for more than 32 cycles, without losing their degradation capacity. Hence, the PUF-immobilized cells of Micrococcus sp. could potentially be used in the bioremediation of cypermethrin contaminated water.

Biodegradation of cypermethrin by immobilized cells of Micrococcus sp. strain CPN 1

Directory of Open Access Journals (Sweden)

Preeti N. Tallur

2015-09-01

Full Text Available Pyrethroid pesticide cypermethrin is a environmental pollutant because of its widespread use, toxicity and persistence. Biodegradation of such chemicals by microorganisms may provide an cost-effective method for their detoxification. We have investigated the degradation of cypermethrin by immobilized cells of Micrococcus sp. strain CPN 1 in various matrices such as, polyurethane foam (PUF, polyacrylamide, sodium alginate and agar. The optimum temperature and pH for the degradation of cypermethrin by immobilized cells of Micrococcus sp. were found to be 30 °C and 7.0, respectively. The rate of degradation of 10 and 20 mM of cypermethrin by freely suspended cells were compared with that of immobilized cells in batches and semi-continuous with shaken cultures. PUF-immobilized cells showed higher degradation of cypermethrin (10 mM and 20 mM than freely suspended cells and cells immobilized in other matrices. The PUF-immobilized cells of Micrococcus sp. strain CPN 1 were retain their degradation capacity. Thus, they can be reused for more than 32 cycles, without losing their degradation capacity. Hence, the PUF-immobilized cells of Micrococcus sp. could potentially be used in the bioremediation of cypermethrin contaminated water.

Finding novel relationships with integrated gene-gene association network analysis of Synechocystis sp. PCC 6803 using species-independent text-mining.

Science.gov (United States)

Kreula, Sanna M; Kaewphan, Suwisa; Ginter, Filip; Jones, Patrik R

2018-01-01

The increasing move towards open access full-text scientific literature enhances our ability to utilize advanced text-mining methods to construct information-rich networks that no human will be able to grasp simply from 'reading the literature'. The utility of text-mining for well-studied species is obvious though the utility for less studied species, or those with no prior track-record at all, is not clear. Here we present a concept for how advanced text-mining can be used to create information-rich networks even for less well studied species and apply it to generate an open-access gene-gene association network resource for Synechocystis sp. PCC 6803, a representative model organism for cyanobacteria and first case-study for the methodology. By merging the text-mining network with networks generated from species-specific experimental data, network integration was used to enhance the accuracy of predicting novel interactions that are biologically relevant. A rule-based algorithm (filter) was constructed in order to automate the search for novel candidate genes with a high degree of likely association to known target genes by (1) ignoring established relationships from the existing literature, as they are already 'known', and (2) demanding multiple independent evidences for every novel and potentially relevant relationship. Using selected case studies, we demonstrate the utility of the network resource and filter to ( i ) discover novel candidate associations between different genes or proteins in the network, and ( ii ) rapidly evaluate the potential role of any one particular gene or protein. The full network is provided as an open-source resource.

Copper tolerance in Frankia sp. strain EuI1c involves surface binding and copper transport.

Science.gov (United States)

Rehan, Medhat; Furnholm, Teal; Finethy, Ryan H; Chu, Feixia; El-Fadly, Gomaah; Tisa, Louis S

2014-09-01

Several Frankia strains have been shown to be copper-tolerant. The mechanism of their copper tolerance was investigated for Frankia sp. strain EuI1c. Copper binding was shown by binding studies. Unusual globular structures were observed on the surface of the bacterium. These globular structures were composed of aggregates containing many relatively smaller "leaf-like" structures. Scanning electron microscopy with energy-dispersive X-ray (SEM-EDAX) analysis of these structures indicated elevated copper and phosphate levels compared to the control cells. Fourier transform infrared spectroscopy (FTIR) analysis indicated an increase in extracellular phosphate on the cell surface of copper-stressed cells. Bioinformatics' analysis of the Frankia sp. strain EuI1c genome revealed five potential cop genes: copA, copZ, copC, copCD, and copD. Experiments with Frankia sp. strain EuI1c using qRT-PCR indicated an increase in messenger RNA (mRNA) levels of the five cop genes upon Cu(2+) stress. After 5 days of Cu(2+) stress, the copA, copZ, copC, copCD, and copD mRNA levels increased 25-, 8-, 18-, 18-, and 25-fold, respectively. The protein profile of Cu(2+)-stressed Frankia sp. strain EuI1c cells revealed the upregulation of a 36.7 kDa protein that was identified as FraEuI1c_1092 (sulfate-binding periplasmic transport protein). Homologues of this gene were only present in the genomes of the Cu(2+)-resistant Frankia strains (EuI1c, DC12, and CN3). These data indicate that copper tolerance by Frankia sp. strain EuI1c involved the binding of copper to the cell surface and transport proteins.

Antagonistic activities of some Bifidobacterium sp. strains isolated from resident infant gastrointestinal microbiota on Gram-negative enteric pathogens.

Science.gov (United States)

Delcaru, Cristina; Alexandru, Ionela; Podgoreanu, Paulina; Cristea, Violeta Corina; Bleotu, Coralia; Chifiriuc, Mariana Carmen; Bezirtzoglou, Eugenia; Lazar, Veronica

2016-06-01

The gastrointestinal microbiota contributes to the consolidation of the anti-infectious barrier against enteric pathogens. The purpose of this study was to investigate the influence of Bifidobacterium sp. strains, recently isolated from infant gastrointestinal microbiota on the in vitro growth and virulence features expression of enteropathogenic bacterial strains. The antibacterial activity of twelve Bifidobacterium sp. strains isolated from human feces was examined in vitro against a wide range of Gram negative pathogenic strains isolated from 30 infant patients (3 days to 5 years old) with diarrhea. Both potential probiotic strains (Bifidobacterium longum, Bifidobacterium pseudocatenulatum, Bifidobacterium catenulatum, Bifidobacterium breve, Bifidobacterium ruminantium) and enteropathogenic strains (EPEC, EIEC, Klebsiella pneumoniae, Salmonella sp., Yersinia enterocolitica, Pseudomonas aeruginosa) were identified by MALDI-TOF and confirmed serologically when needed. The bactericidal activity, growth curve, adherence to the cellular HEp-2 substratum and production of soluble virulence factors have been assessed in the presence of different Bifidobacterium sp. cultures and fractions (whole culture and free-cell supernatants). Among the twelve Bifidobacterium sp. strains, the largest spectrum of antimicrobial activity against 9 of the 18 enteropathogenic strains was revealed for a B. breve strain recently isolated from infant intestinal feces. The whole culture and free-cell supernatant of B. breve culture decreased the multiplication rate, shortened the log phase and the total duration of the growth curve, with an earlier entrance in the decline phase and inhibited the adherence capacity to a cellular substratum and the swimming/swarming motility too. These results indicate the significant probiotic potential of the B. breve strain. Copyright © 2016 Elsevier Ltd. All rights reserved.

Genome Sequence of Carbon Dioxide-Sequestering Serratia sp. Strain ISTD04 Isolated from Marble Mining Rocks

OpenAIRE

Kumar, Manish; Gazara, Rajesh Kumar; Verma, Sandhya; Kumar, Madan; Verma, Praveen Kumar; Thakur, Indu Shekhar

2016-01-01

The Serratia sp. strain ISTD04 has been identified as a carbon dioxide (CO2)-sequestering bacterium isolated from marble mining rocks in the Umra area, Rajasthan, India. This strain grows chemolithotrophically on media that contain sodium bicarbonate (NaHCO3) as the sole carbon source. Here, we report the genome sequence of 5.07?Mb Serratia sp. ISTD04.

Strategy for improving extracellular lipolytic activities by a novel thermotolerant Staphylococcus sp. strain

Directory of Open Access Journals (Sweden)

Cherif Slim

2011-11-01

Full Text Available Abstract Background Extracellular bacterial lipases received much attention for their substrate specificity and their ability to function under extreme environments (pH, temperature.... Many staphylococci produced lipases which were released into the culture medium. Reports of extracellular thermostable lipases from Staphylococcus sp. and active in alkaline conditions are not previously described. Results This study focused on novel strategies to increase extracellular lipolytic enzyme production by a novel Staphylococcus sp. strain ESW. The microorganism needed neutral or alkaline pH values between 7.0 and 12.0 for growth. For pH values outside this range, cell growth seemed to be significantly inhibited. Staphylococcus sp. culture was able to grow within a wide temperature range (from 30 to 55°C. The presence of oils in the culture medium leaded to improvements in cells growth and lipolytic enzyme activity. On the other hand, although chemical surfactants leaded to an almost complete inhibition of growth and lipolytic enzyme production, their addition along the culture could affect the location of the enzyme. In addition, our results showed that this novel Staphylococcus sp. strain produced biosurfactants simultaneously with lipolytic activity, when soapstock (The main co-product of the vegetable oil refining industry, was used as the sole carbon source. Conclusion A simultaneous biosurfactant and extracellular lipolytic enzymes produced bacterial strain with potential application in soap stock treatment

Benomyl-resistant mutant strain of Trichoderma sp. with increased mycoparasitic activity.

Science.gov (United States)

Olejníková, P; Ondrusová, Z; Krystofová, S; Hudecová, D

2010-01-01

Application of UV radiation to the strain Trichoderma sp. T-bt (isolated from lignite) resulted in the T-brm mutant which was resistant to the systemic fungicide benomyl. The tub2 gene sequence in the T-brm mutant differed from the parent as well as the collection strain (replacing tyrosine with histidine in the TUB2 protein). Under in vitro conditions this mutant exhibited a higher mycoparasitic activity toward phytopathogenic fungi.

Cyanide binding to hexacoordinate cyanobacterial hemoglobins: hydrogen-bonding network and heme pocket rearrangement in ferric H117A Synechocystis hemoglobin.

Science.gov (United States)

Vu, B Christie; Nothnagel, Henry J; Vuletich, David A; Falzone, Christopher J; Lecomte, Juliette T J

2004-10-05

The truncated hemoglobin (Hb) from the cyanobacterium Synechocystis sp. PCC 6803 is a bis-histidyl hexacoordinate complex in the absence of exogenous ligands. This protein can form a covalent cross-link between His117 in the H-helix and the heme 2-vinyl group. Cross-linking, the physiological importance of which has not been established, is avoided with the His117Ala substitution. In the present work, H117A Hb was used to explore exogenous ligand binding to the heme group. NMR and thermal denaturation data showed that the replacement was of little consequence to the structural and thermodynamic properties of ferric Synechocystis Hb. It did, however, decelerate the association of cyanide ions with the heme iron. Full complexation required hours, instead of minutes, of incubation at optical and NMR concentrations. At neutral pH and in the presence of excess cyanide, binding occurred with a first-order dependence on cyanide concentration, eliminating distal histidine decoordination as the rate-limiting step. The cyanide complex of the H117A variant was characterized for the conformational changes occurring as the histidine on the distal side, His46 (E10), was displaced. Extensive rearrangement allowed Tyr22 (B10) to insert in the heme pocket and Gln43 (E7) and Gln47 (E11) to come in contact with it. H-bond formation to the bound cyanide was identified in solution with the use of (1)H(2)O/(2)H(2)O mixtures. Cyanide binding also resulted in a change in the ratio of heme orientational isomers, in a likely manifestation of heme environment reshaping. Similar observations were made with the related Synechococcus sp. PCC 7002 H117A Hb, except that cyanide binding was rapid in this protein. In both cases, the (15)N chemical shift of bound cyanide was reminiscent of that in peroxidases and the orientation of the proximal histidine was as in other truncated Hbs. The ensemble of the data provided insight into the structural cooperativity of the heme pocket scaffold and pointed

集胞藻PCC6803基因slr2049定点突变及其体内重组功能研究%Site-directed mutation of the gene slr2049 from Synechocy-stis sp.PCC 6803 and the study on the function

Institute of Scientific and Technical Information of China (English)

朱超; 陈思礼

2013-01-01

在Synechocystis sp.PCC 6803中找到与cpeS具有高度同源性的基因slr2049.采用PCR从Synechocystis sp.PCC 6803 DNA中扩增出cpcB,slr2049,hol,pcyA 4个基因；定点突变试剂盒构建8个突变体slr2049 (H21S)、slr2049 (L23S)、slr2049 (A24S)、slr2049 (F25S)、slr2049(W72L)、slr2049(G84S)、slr2049(R107S)和slr2049(Y124S)；将它们与表达载体pCDFDuet-1和pET-23a(+)相连构建pCDF-cpcB-slr2049野生型和pCDF-cpcB-slr2049突变体以及pET-ho1-pcyA,进行高效表达,用亲和层析柱纯化,产物用SDS-PAGE和光谱检测.研究表明:突变体slr2049(H21S)、slr2049(L23S)、slr2049(F25S)、slr2049 (W72L)、slr2049 (G84S)、slr2049(Y124S)与野生型slr2049催化获得的重组藻蓝蛋白β亚基具有与天然藻蓝蛋白β亚基相似的光谱特性,其他2个突变体slr2049 (A24S)和slr2049(R107S)催化的产物则没有光谱特性.由此推测,第24位丙氨酸和第107位精氨酸可能是slr2049酶活性的必需氨基酸,其所处位置是slr2049的活性位点.%We have found gene slr2049 in Synechocystis sp.PCC 6803 which was homol ogous to the bilin lyase gene cpeS by some softwares for homologous analysis.Four genes were amplifed from DNA of Synechocystis sp.PCC 6803 by PCR.Eight mutants which were slr2049 (H21S),slr2049 (L23S),slr2049 (A24S),slr2049 (F25S),slr2049 (W72L),slr2049(G84S),slr2049(R107S)and sl-r2049(Y124S)were constructed by Mutan BEST Kit.pCDF-cpcB-slr2049,pCDF-cpcB-slr2049 mutants and pET-ho1-pcyA were formed from the linkage of four genes and mutants with pCDFDuet-land pET-23a (+).They were expressed and purified by affinity column.Proteins were detected by SDS-PAGE,absorption and fluorescence spectra.The results showed that phycocyanin β-subunit which had the same spectral characteristic with native phycocyanin β-subunit were catalysed by the protein encoded by gene slr2049 and mutants slr2049 (H21S),slr2049(L23S),slr2049(F25S),slr2049 (W72L),slr2049 (G84S),slr2049 (Y124S).The rest of mutants slr2049(A24S

Moniliella sojae sp. nov., a species of black yeasts isolated from Vietnamese soy paste (tuong), and reassignment of Moniliella suaveolens strains to Moniliella pyrgileucina sp. nov., Moniliella casei sp. nov. and Moniliella macrospora emend. comb. nov.

Science.gov (United States)

Thanh, Vu Nguyen; Duc Hien, Dinh; Yaguchi, Takashi; Sampaio, Jose Paulo; Lachance, Marc-André

2018-05-01

The presence of yeasts at different steps of Vietnamese soy paste production was studied. Yeast growth occurred during primary soybean fermentation, with the cell density reaching 4.10 6 c.f.u. ml -1 , and terminated during brine fermentation. The dominant species were Pichia kudriavzevii and Millerozyma farinosa. Over the span of 14 years, nine strains of Moniliella were isolated. The strains had identical PCR fingerprints generated with primer (GAC)5 and identical D1/D2 and internal transcribed spacer (ITS) sequences. A D1/D2-based phylogeny indicated that the strains were closest to a group of four previously assigned as Moniliella suaveolens strains. Together they form a new lineage that is well separated from all known species, including M. suaveolens (over 12.7 % divergence). ITS sequences indicated the presence of four species differing from each other by 9-57 nt. The name Moniliella sojae sp. nov. is proposed to accommodate the strains isolated from Vietnamese soy paste, Moniliella pyrgileucina sp. nov. is proposed for PYCC 6800 and Moniliella casei sp. nov. is proposed for CBS 157.58. An emended combination Moniliella macrospora is proposed for CBS 221.32 and CBS 223.32. The type strains and MycoBank numbers are: M. sojae sp. nov., SS 4.2 T =CBS 126448 T =NRRL Y-48680 T and MB 822871; M. pyrgileucina sp. nov., PYCC 6800 T =CBS 15203 T and MB 823030; M. casei sp. nov., CBS 157.58 T =IFM 60348 T and MB 822872; M. macrospora emend. comb. nov., CBS 221.32 T (=MUCL 11527 T ) and MB 822874.

Desulfurization of dibenzothiophene by Corynebacterium sp. strain SY1

International Nuclear Information System (INIS)

Omori, Toshio; Monna, L.; Saiki, Yuko; Kodama, Tohru

1992-01-01

Strain SY1, identified as a Corynebacterium sp., was isolated on the basis of the ability to utilize dibenzothiophene (DBT) as a sole source of sulfur. Strain SY1 could utilize a wide range of organic and inorganic sulfur compounds, such as DBT sulfone, dimethyl sulfide, dimethyl sulfoxide, dimethyl sulfone, CS 2 , FeS 2 , and even elemental sulfur. Strain SY1 metabolized DBT to dibenzothiophene-5-oxide, DBT sulfone, and 2-hydroxybiphenyl, which was subsequently nitrated to produce at least two different hydroxynitrobiphenyls during cultivation. These metabolites were separated by silica gel column chromatography and identified by nuclear magnetic resonance, UV, and mass spectral techniques. Resting cells of SY1 desulfurized toluenesulfonic acid and released sulfite anion. On the basis of these results, a new DBT degradation pathway is proposed

Genome Sequence of Carbon Dioxide-Sequestering Serratia sp. Strain ISTD04 Isolated from Marble Mining Rocks.

Science.gov (United States)

Kumar, Manish; Gazara, Rajesh Kumar; Verma, Sandhya; Kumar, Madan; Verma, Praveen Kumar; Thakur, Indu Shekhar

2016-10-20

The Serratia sp. strain ISTD04 has been identified as a carbon dioxide (CO 2 )-sequestering bacterium isolated from marble mining rocks in the Umra area, Rajasthan, India. This strain grows chemolithotrophically on media that contain sodium bicarbonate (NaHCO 3 ) as the sole carbon source. Here, we report the genome sequence of 5.07 Mb Serratia sp. ISTD04. Copyright © 2016 Kumar et al.

Biodegradation of hexavalent chromium (Cr+6) in wastewater using Pseudomonas sp. and Bacillus sp. bacterial strains

Energy Technology Data Exchange (ETDEWEB)

Qasim, Muhammad [Department of Chemical Engineering, American University of Sharjah (United Arab Emirates)

2013-07-01

The recovery of toxic metal compounds is a deep concern in all industries. Hexavalent chromium is particularly worrying because of its toxic influence on human health. In this paper, biodegradation of hexavalent chromium (Cr+6) present in wastewater has been studied using two different bacterial strains; Pseudomonas sp. and Bacillus sp. A chemostat (with and without recycle of cells) with 10 L liquid culture volume was used to study the substrate and the biomass cell concentrations with time. Also, the degree of substrate conversion was studied by the varying the dilution rate as an independent parameter. The dilution rate (ratio of feed flow rate to the culture volume) was varied by varying the feed volumetric rate from 110-170 mL/h for inlet hexavalent chromium concentrations of 70 mg/dm3. The results show that a chemostat with recycle gives a better performance in terms of substrate conversion than a chemostat without a recycle. Moreover, the degree of substrate conversion decreases as the dilution rate is increased. Also, Bacillus sp. was found to give higher conversions compared to pseudomonas sp.

Lack of Phosphatidylglycerol Inhibits Chlorophyll Biosynthesis at Multiple Sites and Limits Chlorophyllide Reutilization in Synechocystis sp Strain PCC 6803

Czech Academy of Sciences Publication Activity Database

Kopečná, Jana; Pilný, Jan; Krynická, Vendula; Tomčala, Aleš; Kis, M.; Gombos, Z.; Komenda, Josef; Sobotka, Roman

2015-01-01

Roč. 169, č. 2 (2015), s. 1307-1317 ISSN 0032-0889 R&D Projects: GA MŠk LO1416; GA MŠk EE2.3.30.0059; GA ČR GBP501/12/G055 Institutional support: RVO:61388971 ; RVO:60077344 Keywords : II REACTION-CENTER * PHOTOSYSTEM-II * SP PCC-6803 Subject RIV: CE - Biochemistry Impact factor: 6.280, year: 2015

Isolation and Characterization of an Atypical Metschnikowia sp. Strain from the Skin Scraping of a Dermatitis Patient.

Directory of Open Access Journals (Sweden)

Chee Sian Kuan

Full Text Available A yeast-like organism was isolated from the skin scraping sample of a stasis dermatitis patient in the Mycology Unit Department of Medical Microbiology, University Malaya Medical Centre (UMMC, Kuala Lumpur, Malaysia. The isolate produced no pigment and was not identifiable using chromogenic agar and API 20C AUX. The fungus was identified as Metschnikowia sp. strain UM 1034, which is close to that of Metschnikowia drosophilae based on ITS- and D1/D2 domain-based phylogenetic analysis. However, the physiology of the strain was not associated to M. drosophilae. This pathogen exhibited low sensitivity to all tested azoles, echinocandins, 5-flucytosine and amphotericin B. This study provided insight into Metschnikowia sp. strain UM 1034 phenotype profiles using a Biolog phenotypic microarray (PM. The isolate utilized 373 nutrients of 760 nutrient sources and could adapt to a broad range of osmotic and pH environments. To our knowledge, this is the first report of the isolation of Metschnikowia non-pulcherrima sp. from skin scraping, revealing this rare yeast species as a potential human pathogen that may be misidentified as Candida sp. using conventional methods. Metschnikowia sp. strain UM 1034 can survive in flexible and diverse environments with a generalist lifestyle.

Awakening of a Dormant Cyanobacterium from Nitrogen Chlorosis Reveals a Genetically Determined Program

Czech Academy of Sciences Publication Activity Database

Klotz, A.; Georg, J.; Bučinská, Lenka; Watanabe, S.; Reimann, V.; Januszewski, W.; Sobotka, Roman; Jendrossek, D.; Hess, W. R.; Forchhammer, K.

2016-01-01

Roč. 26, č. 21 (2016), s. 2862-2872 ISSN 0960-9822 R&D Projects: GA MŠk(CZ) LO1416 Institutional support: RVO:61388971 Keywords : SP PCC 6803 * SYNECHOCYSTIS STRAIN PCC-6803 * STARVATION-INDUCED CHLOROSIS Subject RIV: EE - Microbiology, Virology Impact factor: 8.851, year: 2016

Co-ordination of NDH and Cup proteins in CO2 uptake in cyanobacterium Synechocystis sp. PCC 6803.

Science.gov (United States)

Han, Xunling; Sun, Nan; Xu, Min; Mi, Hualing

2017-06-01

High and low affinity CO2-uptake systems containing CupA (NDH-1MS) and CupB (NDH-1MS'), respectively, have been identified in Synechocystis sp. PCC 6803, but it is yet unknown how the complexes function in CO2 uptake. In this work, we found that deletion of cupB significantly lowered the growth of cells, and deletion of both cupA and cupB seriously suppressed the growth below pH 7.0 even under 3% CO2. The rate of photosynthetic oxygen evolution was decreased slightly by deletion of cupA but significantly by deletion of cupB and more severely by deletion of both cupA and cupB, especially in response to changed pH conditions under 3% CO2. Furthermore, we found that assembly of CupB into NDH-1MS' was dependent on NdhD4 and NdhF4. NDH-1MS' was not affected in the NDH-1MS-degradation mutant and NDH-1MS was not affected in the NDH-1MS'-degradation mutants, indicating the existence of independent CO2-uptake systems under high CO2 conditions. The light-induced proton gradient across thylakoid membranes was significantly inhibited in ndhD-deletion mutants, suggesting that NdhDs functions in proton pumping. The carbonic anhydrase activity was suppressed partly in the cupA- or cupB-deletion mutant but severely in the mutant with both cupA and cupB deletion, indicating that CupA and CupB function in conversion of CO2 to HCO3-. In turn, deletion of cup genes lowered the transthylakoid membrane proton gradient and deletion of ndhDs decreased the CO2 hydration. Our results suggest that NDH-1M provides an alkaline region to activate Cup proteins involved in CO2 uptake. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Isolation and characterization of Dehalobacter sp. strain UNSWDHB capable of chloroform and chlorinated ethane respiration.

Science.gov (United States)

Wong, Yie K; Holland, Sophie I; Ertan, Haluk; Manefield, Mike; Lee, Matthew

2016-09-01

Dehalobacter sp. strain UNSWDHB can dechlorinate up to 4 mM trichloromethane at a rate of 0.1 mM per day to dichloromethane and 1,1,2-trichloroethane (1 mM, 0.1 mM per day) with the unprecedented product profile of 1,2-dichloroethane and vinyl chloride. 1,1,1-trichloroethane and 1,1-dichloroethane were slowly utilized by strain UNSWDHB and were not completely removed, with minimum threshold concentrations of 0.12 mM and 0.07 mM respectively under growth conditions. Enzyme kinetic experiments confirmed strong substrate affinity for trichloromethane and 1,1,2-trichloroethane (Km  = 30 and 62 µM respectively) and poor substrate affinity for 1,1,1-trichloroethane and 1,1-dichloroethane (Km  = 238 and 837 µM respectively). Comparison of enzyme kinetic and growth data with other trichloromethane respiring organisms (Dehalobacter sp. strain CF and Desulfitobacterium sp. strain PR) suggests an adaptation of strain UNSWDHB to trichloromethane. The trichloromethane RDase (TmrA) expressed by strain UNSWDHB was identified by BN-PAGE and functionally characterized. Amino acid comparison of homologous RDases from all three organisms revealed only six significant amino acid substitutions/deletions, which are likely to be crucial for substrate specificity. Furthermore, strain UNSWDHB was shown to grow without exogenous supply of cobalamin confirming genomic-based predictions of a fully functional cobalamin synthetic pathway. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

Novel Pathway of Salicylate Degradation by Streptomyces sp. Strain WA46

OpenAIRE

Ishiyama, Daisuke; Vujaklija, Dusica; Davies, Julian

2004-01-01

A novel salicylate-degrading Streptomyces sp., strain WA46, was identified by UV fluorescence on solid minimal medium containing salicylate; trace amounts of gentisate were detected by high-pressure liquid chromatography when strain WA46 was grown with salicylate. PCR amplification of WA46 DNA with degenerate primers for gentisate 1,2-dioxygenase (GDO) genes produced an amplicon of the expected size. Sequential PCR with nested GDO primers was then used to identify a salicylate degradation gen...

Draft Genome Sequence of Hoeflea sp. Strain BAL378, a Potential Producer of Bioactive Compounds

DEFF Research Database (Denmark)

Bentzon-Tilia, Mikkel; Riemann, Lasse; Gram, Lone

2014-01-01

Some phytoplankton-associated marine bacteria produce bioactive compounds. Members of the genus Hoeflea may be examples of such bacteria; however, data describing their metabolisms are scarce. Here, we report the draft genome sequence of Hoeflea sp. strain BAL378, a putative producer of bacterioc......Some phytoplankton-associated marine bacteria produce bioactive compounds. Members of the genus Hoeflea may be examples of such bacteria; however, data describing their metabolisms are scarce. Here, we report the draft genome sequence of Hoeflea sp. strain BAL378, a putative producer...

ABC Transporter for Corrinoids in Halobacterium sp. Strain NRC-1†

OpenAIRE

Woodson, Jesse D.; Reynolds, April A.; Escalante-Semerena, Jorge C.

2005-01-01

We report evidence for the existence of a putative ABC transporter for corrinoid utilization in the extremely halophilic archaeon Halobacterium sp. strain NRC-1. Results from genetic and nutritional analyses of Halobacterium showed that mutants with lesions in open reading frames (ORFs) Vng1370G, Vng1371Gm, and Vng1369G required a 105-fold higher concentration of cobalamin for growth than the wild-type or parent strain. The data support the conclusion that these ORFs encode orthologs of the b...

Discovery of Rare and Highly Toxic Microcystins from Lichen-Associated Cyanobacterium Nostoc sp. Strain IO-102-I

OpenAIRE

Oksanen, Ilona; Jokela, Jouni; Fewer, David P.; Wahlsten, Matti; Rikkinen, Jouko; Sivonen, Kaarina

2004-01-01

The production of hepatotoxic cyclic heptapeptides, microcystins, is almost exclusively reported from planktonic cyanobacteria. Here we show that a terrestrial cyanobacterium Nostoc sp. strain IO-102-I isolated from a lichen association produces six different microcystins. Microcystins were identified with liquid chromatography-UV mass spectrometry by their retention times, UV spectra, mass fragmentation, and comparison to microcystins from the aquatic Nostoc sp. strain 152. The dominant micr...

Targeted Gene Disruption of the Cyclo (L-Phe, L-Pro Biosynthetic Pathway in Streptomyces sp. US24 Strain

Directory of Open Access Journals (Sweden)

Samiha Sioud

2007-01-01

Full Text Available We have previously isolated a new actinomycete strain from Tunisian soil called Streptomyces sp. US24, and have shown that it produces two bioactive molecules including a Cyclo (L-Phe, L-Pro diketopiperazine (DKP. To identify the structural genes responsible for the synthesis of this DKP derivative, a PCR amplification (696 bp was carried out using the Streptomyces sp. US24 genomic DNA as template and two degenerate oligonucleotides designed by analogy with genes encoding peptide synthetases (NRPS. The detection of DKP derivative biosynthetic pathway of the Streptomyces sp. US24 strain was then achieved by gene disruption via homologous recombination using a suicide vector derived from the conjugative plasmid pSET152 and containing the PCR product. Chromatography analysis, biological tests and spectroscopic studies of supernatant cultures of the wild-type Streptomyces sp. US24 strain and three mutants obtained by this gene targeting disruption approach showed that the amplified DNA fragment is required for Cyclo (L-Phe, L-Pro biosynthesis in Streptomyces sp. US24 strain. This DKP derivative seems to be produced either directly via a nonribosomal pathway or as a side product in the course of nonribosomal synthesis of a longer peptide.

Draft genome sequence of Serratia sp. strain M24T3, isolated from pinewood disease nematode Bursaphelenchus xylophilus.

Science.gov (United States)

Proença, Diogo Neves; Espírito Santo, Christophe; Grass, Gregor; Morais, Paula V

2012-07-01

Here we report the draft genome sequence of Serratia sp. strain M24T3, which is associated with pinewood nematode Bursaphelenchus xylophilus, the causative agent of pine wilt disease. Serratia sp. strain M24T3 has been identified as a bionematocide for B. xylophilus in vitro, and multiple genes potentially involved in virulence and nematotoxity were identified.

Draft Genome Sequence of Serratia sp. Strain M24T3, Isolated from Pinewood Disease Nematode Bursaphelenchus xylophilus

OpenAIRE

Proença, Diogo Neves; Espírito Santo, Christophe; Grass, Gregor; Morais, Paula V.

2012-01-01

Here we report the draft genome sequence of Serratia sp. strain M24T3, which is associated with pinewood nematode Bursaphelenchus xylophilus, the causative agent of pine wilt disease. Serratia sp. strain M24T3 has been identified as a bionematocide for B. xylophilus in vitro, and multiple genes potentially involved in virulence and nematotoxity were identified.

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.

Biodegradation of Methyl tert-Butyl Ether by Co-Metabolism with a Pseudomonas sp. Strain

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Shanshan Li

2016-09-01

Full Text Available Co-metabolic bioremediation is supposed to be an impressive and promising approach in the elimination technology of methyl tert-butyl ether (MTBE, which was found to be a common pollutant worldwide in the ground or underground water in recent years. In this paper, bacterial strain DZ13 (which can co-metabolically degrade MTBE was isolated and named as Pseudomonas sp. DZ13 based on the result of 16S rRNA gene sequencing analysis. Strain DZ13 could grow on n-alkanes (C5-C8, accompanied with the co-metabolic degradation of MTBE. Diverse n-alkanes with different carbon number showed a significant influence on the degradation rate of MTBE and accumulation of tert-butyl alcohol (TBA. When Pseudomonas sp. DZ13 co-metabolically degraded MTBE with n-pentane as the growth substrate, a higher MTBE-degrading rate (Vmax = 38.1 nmol/min/mgprotein, Ks = 6.8 mmol/L and lower TBA-accumulation was observed. In the continuous degradation experiment, the removal efficiency of MTBE by Pseudomonas sp. Strain DZ13 did not show an obvious decrease after five times of continuous addition.

The Relationship Between Iron and Nitrogen Fixation in Trichodesmium spp.

Science.gov (United States)

2009-06-01

Genes essential to iron transport in the cyanobacterium Synechocystis sp. strain PCC 6803. J Bacteriol 183: 2779-2784. Keren, N., Aurora , R., and...where surface salinity measurements indicate that we were sampling in the Amazon River plume. At E21, the surface salinity measured by the CTD was 32.5

Large-scale bioreactor production of the herbicide-degrading Aminobacter sp. strain MSH1

DEFF Research Database (Denmark)

Schultz-Jensen, Nadja; Knudsen, Berith Elkær; Frkova, Zuzana

2014-01-01

The Aminobacter sp. strain MSH1 has potential for pesticide bioremediation because it degrades the herbicide metabolite 2,6-dichlorobenzamide (BAM). Production of the BAM-degrading bacterium using aerobic bioreactor fermentation was investigated. A mineral salt medium limited for carbon and with ......The Aminobacter sp. strain MSH1 has potential for pesticide bioremediation because it degrades the herbicide metabolite 2,6-dichlorobenzamide (BAM). Production of the BAM-degrading bacterium using aerobic bioreactor fermentation was investigated. A mineral salt medium limited for carbon...... and with an element composition similar to the strain was generated. The optimal pH and temperature for strain growth were determined using shaker flasks and verified in bioreactors. Glucose, fructose, and glycerol were suitable carbon sources for MSH1 (μ =0.1 h−1); slower growth was observed on succinate and acetic...... acid (μ =0.01 h−1). Standard conditions for growth of theMSH1 strain were defined at pH 7 and 25 °C, with glucose as the carbon source. In bioreactors (1 and 5 L), the specific growth rate of MSH1 increased from μ =0.1 h−1 on traditional mineral salt medium to μ =0.18 h−1 on the optimized mineral salt...

Draft Genome Sequence of the Efficient Bioflocculant-Producing Bacterium Paenibacillus sp. Strain A9

Science.gov (United States)

Liu, Jin-liang; Hu, Xiao-min

2013-01-01

Paenibacillus sp. strain A9 is an important bioflocculant-producing bacterium, isolated from a soil sample, and is pale pink-pigmented, aerobic, and Gram-positive. Here, we report the draft genome sequence and the initial findings from a preliminary analysis of strain A9, which is a novel species of Paenibacillus. PMID:23618713

Transformation of carbon tetrachloride by Pseudomonas sp. strain KC under denitrification conditions

International Nuclear Information System (INIS)

Criddle, C.S.; DeWitt, J.T.; Grbic-Galic, D.; McCarty, P.L.

1990-01-01

A denitrifying Pseudomonas sp. (strain KC) capable of transforming carbon tetrachloride (CT) was isolated from groundwater aquifer solids. Major products of the transformation of 14 C-labeled CT by Pseudomonas strain KC under denitrification conditions were 14 CO 2 and an unidentified water-soluble fraction. Little or no chloroform was produced. Addition of dissolved trace metals, notably, ferrous iron and cobalt, to the growth medium appeared to enhance growth of Pseudomonas strain KC while inhibiting transformation of CT. It is hypothesized that transformation of CT by this organism is associated with the mechanism of trace-metal scavenging

Association of Psb28 and Psb27 Proteins with PSII-PSI Supercomplexes upon Exposure of Synechocystis sp PCC 6803 to High Light

Czech Academy of Sciences Publication Activity Database

Bečková, Martina; Gardian, Zdenko; Yu, J.F.; Koník, Peter; Nixon, P. J.; Komenda, Josef

2017-01-01

Roč. 10, č. 1 (2017), s. 62-72 ISSN 1674-2052 R&D Projects: GA ČR GBP501/12/G055; GA MŠk(CZ) LO1416; GA MŠk(CZ) ED2.1.00/19.0392 Institutional support: RVO:61388971 ; RVO:60077344 Keywords : Psb28 protein s * photosystem I and II * Synechocystis Subject RIV: EE - Microbiology, Virology; CE - Biochemistry (BC-A) OBOR OECD: Microbiology; Biochemistry and molecular biology (BC-A) Impact factor: 8.827, year: 2016

Preliminary Study and Improve the Production of Metabolites with Antifungal Activity by A Bacillus Sp Strain IBA 33

Directory of Open Access Journals (Sweden)

María Antonieta Gordillo

2009-01-01

Full Text Available Bacillus sp strain IBA 33 metabolites, isolated from decaying lemon fruits, were evaluated for the control of pathogenic and non-pathogenic fungi (Penicillium digitatum, Geotrichum candidum, Penicillium expansum, Aspergillus clavatus, Aspergillus flavus, Aspergillus niger, and Fusarium moniliforme. These metabolites were recovered from Landy medium (LM without aminoacids. In order to optimize metabolites production the LM was modified by adding different concentrations and sources of amino acids and carbohydrates at different culture conditions.Bacillus sp strain IBA 33 metabolites efficacy to control fungi were evaluated with in vitro and in vivo assays. A. flavus growth inhibition was 52% with the metabolites of Bacillus sp strain IBA 33 recovered from LM (MBLM in vitro assays. MBLM supplemented with 0.5% glutamic acid, inhibited the growth of P. digitatum, G. candidum, A. clavatus, A. niger and F. moniliforme by 65%, 88.44%, 84%, 34% and 92% respectively. The highest inhibition of P. expansum was 45% with MBLM supplemented with 0.5% aspartic acid. Similar results were obtained in vivo assays. These results showed that Bacillus sp strain IBA 33 metabolites specificity against fungi depended on the composition of the LM.

Preliminary Study and Improve the Production of Metabolites with Antifungal Activity by A Bacillus Sp Strain IBA 33

Directory of Open Access Journals (Sweden)

María Antonieta Gordillo

2009-04-01

Full Text Available Bacillus sp strain IBA 33 metabolites, isolated from decaying lemon fruits, were evaluated for the control of pathogenic and non-pathogenic fungi (Penicillium digitatum, Geotrichum candidum, Penicillium expansum, Aspergillus clavatus, Aspergillus flavus, Aspergillus niger, and Fusarium moniliforme. These metabolites were recovered from Landy medium (LM without aminoacids. In order to optimize metabolites production the LM was modified by adding different concentrations and sources of amino acids and carbohydrates at different culture conditions. Bacillus sp strain IBA 33 metabolites efficacy to control fungi were evaluated with in vitro and in vivo assays. A. flavus growth inhibition was 52% with the metabolites of Bacillus sp strain IBA 33 recovered from LM (MBLM in vitro assays. MBLM supplemented with 0.5% glutamic acid, inhibited the growth of P. digitatum, G. candidum, A. clavatus, A. niger and F. moniliforme by 65%, 88.44%, 84%, 34% and 92% respectively. The highest inhibition of P. expansum was 45% with MBLM supplemented with 0.5% aspartic acid. Similar results were obtained in vivo assays. These results showed that Bacillus sp strain IBA 33 metabolites specificity against fungi depended on the composition of the LM.

Draft genome sequence of Pseudomonas sp. strain M47T1, carried by Bursaphelenchus xylophilus isolated from Pinus pinaster.

Science.gov (United States)

Proença, Diogo Neves; Espírito Santo, Christophe; Grass, Gregor; Morais, Paula V

2012-09-01

The draft genome sequence of Pseudomonas sp. strain M47T1, carried by the Bursaphelenchus xylophilus pinewood nematode, the causative agent of pine wilt disease, is presented. In Pseudomonas sp. strain M47T1, genes that make this a plant growth-promoting bacterium, as well as genes potentially involved in nematotoxicity, were identified.

Sulfur mobilization in cyanobacteria: the catalytic mechanism of L-cystine C-S lyase (C-DES) from synechocystis.

Science.gov (United States)

Campanini, Barbara; Schiaretti, Francesca; Abbruzzetti, Stefania; Kessler, Dorothea; Mozzarelli, Andrea

2006-12-15

Sulfur mobilization represents one of the key steps in ubiquitous Fe-S clusters assembly and is performed by a recently characterized set of proteins encompassing cysteine desulfurases, assembly factors, and shuttle proteins. Despite the evolutionary conservation of these proteins, some degree of variability among organisms was observed, which might reflect functional specialization. L-Cyst(e)ine lyase (C-DES), a pyridoxal 5'-phosphatedependent enzyme identified in the cyanobacterium Synechocystis, was reported to use preferentially cystine over cysteine with production of cysteine persulfide, pyruvate, and ammonia. In this study, we demonstrate that C-DES sequences are present in all cyanobacterial genomes and constitute a new family of sulfur-mobilizing enzymes, distinct from cysteine desulfurases. The functional properties of C-DES from Synechocystis sp. PCC 6714 were investigated under pre-steady-state and steady-state conditions. Single wavelength and rapid scanning stopped-flow kinetic data indicate that the internal aldimine reacts with cystine forming an external aldimine that rapidly decays to a transient quinonoid species and stable tautomers of the alpha-aminoacrylate Schiff base. In the presence of cysteine, the transient formation of a dipolar species precedes the selective and stable accumulation of the enolimine tautomer of the external aldimine, with no formation of the alpha-aminoacrylate Schiff base under reducing conditions. Effective sulfur mobilization from cystine might represent a mechanism that allows adaptation of cyanobacteria to different environmental conditions and to light-dark cycles.

Antibiotic susceptibility profiles of Mycoplasma sp. 1220 strains isolated from geese in Hungary

OpenAIRE

Gr?zner, D?nes; Kreizinger, Zsuzsa; Sulyok, Kinga M.; R?nai, Zsuzsanna; Hrivn?k, Veronika; Turcs?nyi, Ibolya; J?nosi, Szil?rd; Gyuranecz, Mikl?s

2016-01-01

Background Mycoplasma sp. 1220 can induce inflammation primarily in the genital and respiratory tracts of waterfowl, leading to serious economic losses. Adequate housing and appropriate antibiotic treatment are promoted in the control of the disease. The aim of the present study was to determine the in vitro susceptibility to thirteen different antibiotics and an antibiotic combination of thirty-eight M. sp. 1220 strains isolated from geese and a duck in several parts of Hungary, Central Euro...

Molecular characterization of two microalgal strains in Egypt and investigation of the antimicrobial activity of their extracts

Directory of Open Access Journals (Sweden)

El Semary, NA.

2013-01-01

Full Text Available The emergence of new pathogens and the increasing drug-resistance of recognized ones pose a difficult challenge. One way that this challenge is being addressed is through the discovery of new cost-effective drug resources in the form of bioactive compounds. Algae represent a promising source of bioactive compounds in this regard. In the present research, we used molecular and phylogenetic analysis to isolate and identify two microalgal strains. We found that one strain belonged to the phylum chrysophyta and the other to the cyanobacteria. We also investigated the antimicrobial activity of some of the lipophilic extracts of the two microalgal strains. Several fractions showed high individual antimicrobial bioactivity against multidrug-resistant Salmonella sp., Citrobacter sp., Aspergillus niger and Aspergillus flavus. Fraction III from Poterioochromonas malhamensis showed the highest level of activity against two multidrug-resistant bacterial pathogens. The inhibition zone diameter was 1.4 cm for Salmonella and 1.4 cm for Citrobacter. Meanwhile, another lipophilic fraction from the cyanobacterium Synechocystis salina showed broad-spectrum bioactivity (inhibition zone diameter of 0.9 cm for Aspergillus niger, 1 cm for Citrobacter and 0.9 cm for Salmonella. One lipophilic fraction from Aphanizomenon showed antifungal bioactivity against Aspergillus niger and Aspergillus flavus, where the inhibition zone diameter was 1.1 cm and 1.0 cm, respectively. The study highlights the antimicrobial bioactivity of extracts from local microalgae and emphasizes the importance of carrying out screening programs for those microorganisms.

Growth of Chlamydomonas reinhardtii in acetate-free medium when co-cultured with alginate-encapsulated, acetate-producing strains of Synechococcus sp. PCC 7002.

Science.gov (United States)

Therien, Jesse B; Zadvornyy, Oleg A; Posewitz, Matthew C; Bryant, Donald A; Peters, John W

2014-01-01

The model alga Chlamydomonas reinhardtii requires acetate as a co-substrate for optimal production of lipids, and the addition of acetate to culture media has practical and economic implications for algal biofuel production. Here we demonstrate the growth of C. reinhardtii on acetate provided by mutant strains of the cyanobacterium Synechococcus sp. PCC 7002. Optimal growth conditions for co-cultivation of C. reinhardtii with wild-type and mutant strains of Synechococcus sp. 7002 were established. In co-culture, acetate produced by a glycogen synthase knockout mutant of Synechococcus sp. PCC 7002 was able to support the growth of a lipid-accumulating mutant strain of C. reinhardtii defective in starch production. Encapsulation of Synechococcus sp. PCC 7002 using an alginate matrix was successfully employed in co-cultures to limit growth and maintain the stability. The ability of immobilized strains of the cyanobacterium Synechococcus sp. PCC 7002 to produce acetate at a level adequate to support the growth of lipid-accumulating strains of C. reinhartdii offers a potentially practical, photosynthetic alternative to providing exogenous acetate into growth media.

Continuous degradation of trichloroethylene by Xanthobacter sp. strain Py2 during growth on propene.

OpenAIRE

Reij, M W; Kieboom, J; de Bont, J A; Hartmans, S

1995-01-01

Propene-grown Xanthobacter sp. strain Py2 cells can degrade trichloroethylene (TCE), but the transformation capacity of such cells was limited and depended on both the TCE concentration and the biomass concentration. Toxic metabolites presumably accumulated extracellularly, because the fermentation of glucose by yeast cells was inhibited by TCE degradation products formed by strain Py2. The affinity of the propene monooxygenase for TCE was low, and this allowed strain Py2 to grow on propene i...

Exopolysaccharide production by a marine Pseudoalteromonas sp. strain isolated from Madeira Archipelago ocean sediments.

Science.gov (United States)

Roca, Christophe; Lehmann, Mareen; Torres, Cristiana A V; Baptista, Sílvia; Gaudêncio, Susana P; Freitas, Filomena; Reis, Maria A M

2016-06-25

Exopolysaccharides (EPS) are polymers excreted by some microorganisms with interesting properties and used in many industrial applications. A new Pseudoalteromonas sp. strain, MD12-642, was isolated from marine sediments and cultivated in bioreactor in saline culture medium containing glucose as carbon source. Its ability to produce EPS under saline conditions was demonstrated reaching an EPS production of 4.4g/L within 17hours of cultivation, corresponding to a volumetric productivity of 0.25g/Lh, the highest value so far obtained for Pseudoalteromonas sp. strains. The compositional analysis of the EPS revealed the presence of galacturonic acid (41-42mol%), glucuronic acid (25-26mol%), rhamnose (16-22mol%) and glucosamine (12-16mol%) sugar residues. The polymer presents a high molecular weight (above 1000kDa). These results encourage the biotechnological exploitation of strain MD12-642 for the production of valuable EPS with unique composition, using saline by-products/wastes as feedstocks. Copyright © 2016 Elsevier B.V. All rights reserved.

Draft Genome Sequence of the Antitrypanosomally Active Sponge-Associated Bacterium Actinokineospora sp. Strain EG49

KAUST Repository

Harjes, Janno; Ryu, Tae Woo; Abdelmohsen, Usama Ramadan; Moitinho-Silva, Lucas; Horn, Hannes; Ravasi, Timothy; Hentschel, Ute

2014-01-01

The marine sponge-associated bacterium Actinokineospora sp. strain EG49 produces the antitrypanosomal angucycline-like compound actinosporin A. The draft genome of Actinokineospora sp. EG49 has a size of 7.5 megabases and a GC content of 72.8% and contains 6,629 protein-coding sequences (CDS). antiSMASH predicted 996 genes residing in 36 secondary metabolite gene clusters.

Draft Genome Sequence of the Antitrypanosomally Active Sponge-Associated Bacterium Actinokineospora sp. Strain EG49

KAUST Repository

Harjes, Janno

2014-03-06

The marine sponge-associated bacterium Actinokineospora sp. strain EG49 produces the antitrypanosomal angucycline-like compound actinosporin A. The draft genome of Actinokineospora sp. EG49 has a size of 7.5 megabases and a GC content of 72.8% and contains 6,629 protein-coding sequences (CDS). antiSMASH predicted 996 genes residing in 36 secondary metabolite gene clusters.

Draft Genome Sequence of Limnobacter sp. Strain CACIAM 66H1, a Heterotrophic Bacterium Associated with Cyanobacteria

OpenAIRE

da Silva, F?bio Daniel Flor?ncio; Lima, Alex Ranieri Jer?nimo; Moraes, Pablo Henrique Gon?alves; Siqueira, Andrei Santos; Dall?Agnol, Leonardo Teixeira; Bara?na, Anna Rafaella Ferreira; Martins, Luisa Car?cio; Oliveira, Karol Guimar?es; de Lima, Clayton Pereira Silva; Nunes, M?rcio Roberto Teixeira; Vianez-J?nior, Jo?o L?dio Silva Gon?alves; Gon?alves, Evonnildo Costa

2016-01-01

Ecological interactions between cyanobacteria and heterotrophic prokaryotes are poorly known. To improve the genomic studies of heterotrophic bacterium-cyanobacterium associations, the draft genome sequence (3.2 Mbp) of Limnobacter sp. strain CACIAM 66H1, found in a nonaxenic culture of Synechococcus sp. (cyanobacteria), is presented here.

Draft genome sequence of Bradyrhizobium sp. strain BR 3267, an elite strain recommended for cowpea inoculation in Brazil

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Jean Luiz Simões-Araújo

Full Text Available Abstract The strain BR 3267 is a nitrogen-fixing symbiotic bacteria isolated from soil of semi-arid area of Brazilian Northeast using cowpea as the trap plant. This strain is used as commercial inoculant for cowpea and presents high efficient in nitrogen fixation as consequence of its adaptation potential to semi-arid conditions. We report here the draft genome sequence of Bradyrhizobium sp. strain BR 3267, an elite bacterium used as inoculant for cowpea. Whole genome sequencing of BR 3267 using Illumina MiSeq sequencing technology has 55 scaffolds with a total genome size of 7,904,309 bp and C+G 63%. Annotation was added by the RAST prokaryotic genome annotation service and has shown 7314 coding sequences and 52 RNA genes.

Genome Sequence of the Thermophilic Cyanobacterium Thermosynechococcus sp. Strain NK55a.

Energy Technology Data Exchange (ETDEWEB)

Stolyar, Sergey; Liu, Zhenfeng; Thiel, Vera; Tomsho, Lynn P.; Pinel, Nicolas; Nelson, William C.; Lindemann, Stephen R.; Romine, Margaret F.; Haruta, Shin; Schuster, Stephan C.; Bryant, Donald A.; Fredrickson, Jim K.

2014-01-02

The genome of the unicellular cyanobacterium, Thermosynechococcus sp. strain NK55a, isolated from Nakabusa hot spring, comprises a single, circular, 2.5-Mb chromosome. The genome is predicted to encode 2358 protein coding genes, including genes for all typical cyanobacterial photosynthetic and metabolic functions. No genes encoding hydrogenases or nitrogenase were identified.

Draft Genome Sequence of Sphingopyxis sp. Strain MWB1, a Crude-Oil-Degrading Marine Bacterium

Science.gov (United States)

Kim, Jonghyun; Kim, Soo Jung; Kim, Seon Hee; Kim, Seung Il; Moon, Yoon-Jung; Park, Sung-Joon

2014-01-01

Sphingopyxis sp. strain MWB1, which is capable of degrading crude oil, diesel, and kerosene, was isolated from crude oil–contaminated seashore in Tae-an, South Korea. Here, we report the draft genome sequence of this strain, which comprises 3,118,428 bp with a G+C content of 62.85 mol%. PMID:25477411

The Marine Fungi Rhodotorula sp. (Strain CNYC4007) as a Potential Feed Source for Fish Larvae Nutrition

Science.gov (United States)

Barra, M.; Llanos-Rivera, A.; Cruzat, F.; Pino-Maureira, N.; González-Saldía, R. R.

2017-01-01

Fish oil is used in the production of feed for cultured fish owing to its high polyunsaturated fatty acid content (PUFA). The over-exploitation of fisheries and events like “El Niño” are reducing the fish oil supply. Some marine microorganisms are considered potentially as alternative fatty acid sources. This study assesses a strain of Rhodotorula sp. (strain CNYC4007; 27% docosahexaenoic acid (DHA) of total fatty acids), as feed for fish larvae. The total length and ribonucleic acid (RNA)/deoxyribonucleic acid (DNA) ratio of Danio rerio larvae was determined at first feeding at six and 12 days old (post-yolk absorption larvae). Larvae fed with microencapsulated Rhodotorula sp. CNYC4007 had a significantly higher RNA/DNA ratio than control group (C1). At six days post-yolk absorption group, the RNA/DNA ratio of larvae fed with Rhodotorula sp. bioencapsulated in Brachionus sp. was significantly higher than control group fed with a commercial diet high in DHA (C2-DHA). Finally, at 12 days post-yolk absorption, the RNA/DNA ratio was significantly higher in larvae fed with Rhodotorula sp. CNYC4007 and C2-DHA (both bioencapsulated in Artemia sp. nauplii) than in control group (C1). These results suggest that Rhodotorula sp. CNYC4007 can be an alternative source of DHA for feeding fish at larval stage, providing a sustainable source of fatty acids. PMID:29194350

Genome sequence of Shigella flexneri strain SP1, a diarrheal isolate that encodes an extended-spectrum β-lactamase (ESBL).

Science.gov (United States)

Shen, Ping; Fan, Jianzhong; Guo, Lihua; Li, Jiahua; Li, Ang; Zhang, Jing; Ying, Chaoqun; Ji, Jinru; Xu, Hao; Zheng, Beiwen; Xiao, Yonghong

2017-05-12

Shigellosis is the most common cause of gastrointestinal infections in developing countries. In China, the species most frequently responsible for shigellosis is Shigella flexneri. S. flexneri remains largely unexplored from a genomic standpoint and is still described using a vocabulary based on biochemical and serological properties. Moreover, increasing numbers of ESBL-producing Shigella strains have been isolated from clinical samples. Despite this, only a few cases of ESBL-producing Shigella have been described in China. Therefore, a better understanding of ESBL-producing Shigella from a genomic standpoint is required. In this study, a S. flexneri type 1a isolate SP1 harboring bla CTX-M-14 , which was recovered from the patient with diarrhea, was subjected to whole genome sequencing. The draft genome assembly of S. flexneri strain SP1 consisted of 4,592,345 bp with a G+C content of 50.46%. RAST analysis revealed the genome contained 4798 coding sequences (CDSs) and 100 RNA-encoding genes. We detected one incomplete prophage and six candidate CRISPR loci in the genome. In vitro antimicrobial susceptibility testing demonstrated that strain SP1 is resistant to ampicillin, amoxicillin/clavulanic acid, cefazolin, ceftriaxone and trimethoprim. In silico analysis detected genes mediating resistance to aminoglycosides, β-lactams, phenicol, tetracycline, sulphonamides, and trimethoprim. The bla CTX-M-14 gene was located on an IncFII2 plasmid. A series of virulence factors were identified in the genome. In this study, we report the whole genome sequence of a bla CTX-M-14 -encoding S. flexneri strain SP1. Dozens of resistance determinants were detected in the genome and may be responsible for the multidrug-resistance of this strain, although further confirmation studies are warranted. Numerous virulence factors identified in the strain suggest that isolate SP1 is potential pathogenic. The availability of the genome sequence and comparative analysis with other S

Beta Glucan Production from Two Strains of Agrobacterium sp in Medium Containing of Molases and Uracil Combine

Directory of Open Access Journals (Sweden)

KUSMIATI

2007-04-01

Full Text Available Production of β-glucan by Agrobacterium sp is influenced by the composition of nutrition in the fermentation media. Molases has been used successfully by others in the fermentation media of S. cerevisiae to increase the yield of -glucan, and similarly, uracil has been used in the fermentation media of Agrobacterium sp to increase the yield of -glucan. Investigations to increase the yield of -glucan by two strains of Agrobacterium sp, i.e. A1.5 (reference and B4.4 (local strain, have been carried out by addition of various combination of molases and uracil into fermentation media, i.e. 5%(v/v molase-0,05%(b/v uracil; 5% molase-0,025% uracil; 10% molase-0,05% uracil; and 10% molase-0,025% uracil. The β-1,3-glucan and β-1,2-glucan fractions were separated by extraction method. Beta-glucan concentration was determined as the glucose monomer using the phenol-sulphate spectrophotometric method at 490 nm. The protein content was determined by a modified Lowry-spectrophotometric method at 750 nm. The results showed that all combination of molases and uracil in the fermentation media of Agrobacterium sp A1.5 and B4.4 strains have increased both the dry-weight yield of β-glucan (crude and the β¬glucan content, with the highest was in a medium containing 10% molases-0,025% uracil combination. In the above medium, the A1.5 strain produced the highest β-glucan (7,5% with the lowest protein content ( 8,4% in the β-1,3-glucan fraction, while the β-glucan content in the β-1,2-glucan fraction were all lower than in the control media, while the protein content were all higher than in the control media. In the above media, the B4.4 strain produced the highest β-glucan, 7,2% in the β-1,3-glucan fraction, and 13,1% in β-1,2-glucan fraction, while the lowest protein content ( 8,4% was in the β-1,3-glucan fraction. In conclusion, fermentation media of Agrobacterium sp A1.5 strain or B4.4 strain containing molase and uracil combination have increased both

Biofilm formation and indole-3-acetic acid production by two rhizospheric unicellular cyanobacteria.

Science.gov (United States)

Ahmed, Mehboob; Stal, Lucas J; Hasnain, Shahida

2014-08-01

Microorganisms that live in the rhizosphere play a pivotal role in the functioning and maintenance of soil ecosystems. The study of rhizospheric cyanobacteria has been hampered by the difficulty to culture and maintain them in the laboratory. The present work investigated the production of the plant hormone indole-3-acetic acid (IAA) and the potential of biofilm formation on the rhizoplane of pea plants by two cyanobacterial strains, isolated from rice rhizosphere. The unicellular cyanobacteria Chroococcidiopsis sp. MMG-5 and Synechocystis sp. MMG-8 that were isolated from a rice rhizosphere, were investigated. Production of IAA by Chroococcidiopsis sp. MMG-5 and Synechocystis sp. MMG-8 was measured under experimental conditions (pH and light). The bioactivity of the cyanobacterial auxin was demonstrated through the alteration of the rooting pattern of Pisum sativum seedlings. The increase in the concentration of L-tryptophan and the time that this amino acid was present in the medium resulted in a significant enhancement of the synthesis of IAA (r > 0.900 at p = 0.01). There was also a significant correlation between the concentration of IAA in the supernatant of the cyanobacteria cultures and the root length and number of the pea seedlings. Observations made by confocal laser scanning microscopy revealed the presence of cyanobacteria on the surface of the roots and also provided evidence for the penetration of the cyanobacteria in the endorhizosphere. We show that the synthesis of IAA by Chroococcidiopsis sp. MMG-5 and Synechocystis sp. MMG-8 occurs under different environmental conditions and that the auxin is important for the development of the seedling roots and for establishing an intimate symbiosis between cyanobacteria and host plants.

An Alcohol Dehydrogenase Gene from Synechocystis sp. Confers Salt Tolerance in Transgenic Tobacco

Directory of Open Access Journals (Sweden)

So Young Yi

2017-11-01

Full Text Available Synechocystis salt-responsive gene 1 (sysr1 was engineered for expression in higher plants, and gene construction was stably incorporated into tobacco plants. We investigated the role of Sysr1 [a member of the alcohol dehydrogenase (ADH superfamily] by examining the salt tolerance of sysr1-overexpressing (sysr1-OX tobacco plants using quantitative real-time polymerase chain reactions, gas chromatography-mass spectrometry, and bioassays. The sysr1-OX plants exhibited considerably increased ADH activity and tolerance to salt stress conditions. Additionally, the expression levels of several stress-responsive genes were upregulated. Moreover, airborne signals from salt-stressed sysr1-OX plants triggered salinity tolerance in neighboring wild-type (WT plants. Therefore, Sysr1 enhanced the interconversion of aldehydes to alcohols, and this occurrence might affect the quality of green leaf volatiles (GLVs in sysr1-OX plants. Actually, the Z-3-hexenol level was approximately twofold higher in sysr1-OX plants than in WT plants within 1–2 h of wounding. Furthermore, analyses of WT plants treated with vaporized GLVs indicated that Z-3-hexenol was a stronger inducer of stress-related gene expression and salt tolerance than E-2-hexenal. The results of the study suggested that increased C6 alcohol (Z-3-hexenol induced the expression of resistance genes, thereby enhancing salt tolerance of transgenic plants. Our results revealed a role for ADH in salinity stress responses, and the results provided a genetic engineering strategy that could improve the salt tolerance of crops.

Penicillium araracuarense sp. nov., Penicillium elleniae sp. nov., Penicillium penarojense sp. nov., Penicillium vanderhammenii sp. nov. and Penicillium wotroi sp. nov., isolated from leaf litter.

Science.gov (United States)

Houbraken, Jos; López-Quintero, Carlos A; Frisvad, Jens C; Boekhout, Teun; Theelen, Bart; Franco-Molano, Ana Esperanza; Samson, Robert A

2011-06-01

Several species of the genus Penicillium were isolated during a survey of the mycobiota of leaf litter and soil in Colombian Amazon forest. Five species, Penicillium penarojense sp. nov. (type strain CBS 113178(T) = IBT 23262(T)), Penicillium wotroi sp. nov. (type strain CBS 118171(T) = IBT 23253(T)), Penicillium araracuarense sp. nov. (type strain CBS 113149(T) = IBT 23247(T)), Penicillium elleniae sp. nov. (type strain CBS 118135(T) = IBT 23229(T)) and Penicillium vanderhammenii sp. nov. (type strain CBS 126216(T) = IBT 23203(T)) are described here as novel species. Their taxonomic novelty was determined using a polyphasic approach, combining phenotypic, molecular (ITS and partial β-tubulin sequences) and extrolite data. Phylogenetic analyses showed that each novel species formed a unique clade for both loci analysed and that they were most closely related to Penicillium simplicissimum, Penicillium janthinellum, Penicillium daleae and Penicillium brasilianum. An overview of the phylogeny of this taxonomically difficult group is presented, and 33 species are accepted. Each of the five novel species had a unique extrolite profile of known and uncharacterized metabolites and various compounds, such as penicillic acid, andrastin A, pulvilloric acid, paxillin, paspaline and janthitrem, were commonly produced by these phylogenetically related species. The novel species had a high growth rate on agar media, but could be distinguished from each other by several macro- and microscopical characteristics.

Draft Genome Sequence of MCPA-Degrading Sphingomonas sp. Strain ERG5, Isolated from a Groundwater Aquifer in Denmark

DEFF Research Database (Denmark)

Nielsen, Tue Kjærgaard; Kot, Witold; Sørensen, Sebastian R

2015-01-01

Sphingomonas sp. strain ERG5 was isolated from a bacterial community, originating from a groundwater aquifer polluted with low pesticide concentrations. This bacterium degrades 2-methyl-4-chlorophenoxyacetic acid (MCPA) in a wide spectrum of concentrations and has been shown to function in bioaug......Sphingomonas sp. strain ERG5 was isolated from a bacterial community, originating from a groundwater aquifer polluted with low pesticide concentrations. This bacterium degrades 2-methyl-4-chlorophenoxyacetic acid (MCPA) in a wide spectrum of concentrations and has been shown to function...

Mycobacterium eburneum sp. nov., a non-chromogenic, fast-growing strain isolated from sputum.

Science.gov (United States)

Nouioui, Imen; Carro, Lorena; Teramoto, Kanae; Igual, José M; Jando, Marlen; Del Carmen Montero-Calasanz, Maria; Sutcliffe, Iain; Sangal, Vartul; Goodfellow, Michael; Klenk, Hans-Peter

2017-09-01

A polyphasic study was undertaken to establish the taxonomic position of a non-chromogenic, rapidly growing Mycobacterium strain that had been isolated from sputum. The strain, CECT 8775T, has chemotaxonomic and cultural properties consistent with its classification in the genus Mycobacterium and was distinguished from the type strains of closely related mycobacterial species, notably from Mycobacterium paraense DSM 46749T, its nearest phylogenetic neighbour, based on 16S rRNA, hsp65 and rpoB gene sequence data. These organisms were also distinguished by a broad range of chemotaxonomic and phenotypic features and by a digital DNA-DNA relatedness value of 22.8 %. Consequently, the strain is considered to represent a novel species of Mycobacterium for which the name Mycobacterium eburneum sp. nov is proposed; the type strain is X82T (CECT 8775T=DSM 44358T).

Improved Eco-Friendly Recombinant Anabaena sp. Strain PCC7120 with Enhanced Nitrogen Biofertilizer Potential▿

Science.gov (United States)

Chaurasia, Akhilesh Kumar; Apte, Shree Kumar

2011-01-01

Photosynthetic, nitrogen-fixing Anabaena strains are native to tropical paddy fields and contribute to the carbon and nitrogen economy of such soils. Genetic engineering was employed to improve the nitrogen biofertilizer potential of Anabaena sp. strain PCC7120. Constitutive enhanced expression of an additional integrated copy of the hetR gene from a light-inducible promoter elevated HetR protein expression and enhanced functional heterocyst frequency in the recombinant strain. The recombinant strain displayed consistently higher nitrogenase activity than the wild-type strain and appeared to be in homeostasis with compatible modulation of photosynthesis and respiration. The enhanced combined nitrogen availability from the recombinant strain positively catered to the nitrogen demand of rice seedlings in short-term hydroponic experiments and supported better growth. The engineered strain is stable, eco-friendly, and useful for environmental application as nitrogen biofertilizer in paddy fields. PMID:21057013

Improved eco-friendly recombinant Anabaena sp. strain PCC7120 with enhanced nitrogen biofertilizer potential.

Science.gov (United States)

Chaurasia, Akhilesh Kumar; Apte, Shree Kumar

2011-01-01

Photosynthetic, nitrogen-fixing Anabaena strains are native to tropical paddy fields and contribute to the carbon and nitrogen economy of such soils. Genetic engineering was employed to improve the nitrogen biofertilizer potential of Anabaena sp. strain PCC7120. Constitutive enhanced expression of an additional integrated copy of the hetR gene from a light-inducible promoter elevated HetR protein expression and enhanced functional heterocyst frequency in the recombinant strain. The recombinant strain displayed consistently higher nitrogenase activity than the wild-type strain and appeared to be in homeostasis with compatible modulation of photosynthesis and respiration. The enhanced combined nitrogen availability from the recombinant strain positively catered to the nitrogen demand of rice seedlings in short-term hydroponic experiments and supported better growth. The engineered strain is stable, eco-friendly, and useful for environmental application as nitrogen biofertilizer in paddy fields.

Thermodynamic analysis of computed pathways integrated into the metabolic networks of E. coli and Synechocystis reveals contrasting expansion potential.

Science.gov (United States)

Asplund-Samuelsson, Johannes; Janasch, Markus; Hudson, Elton P

2018-01-01

Introducing biosynthetic pathways into an organism is both reliant on and challenged by endogenous biochemistry. Here we compared the expansion potential of the metabolic network in the photoautotroph Synechocystis with that of the heterotroph E. coli using the novel workflow POPPY (Prospecting Optimal Pathways with PYthon). First, E. coli and Synechocystis metabolomic and fluxomic data were combined with metabolic models to identify thermodynamic constraints on metabolite concentrations (NET analysis). Then, thousands of automatically constructed pathways were placed within each network and subjected to a network-embedded variant of the max-min driving force analysis (NEM). We found that the networks had different capabilities for imparting thermodynamic driving forces toward certain compounds. Key metabolites were constrained differently in Synechocystis due to opposing flux directions in glycolysis and carbon fixation, the forked tri-carboxylic acid cycle, and photorespiration. Furthermore, the lysine biosynthesis pathway in Synechocystis was identified as thermodynamically constrained, impacting both endogenous and heterologous reactions through low 2-oxoglutarate levels. Our study also identified important yet poorly covered areas in existing metabolomics data and provides a reference for future thermodynamics-based engineering in Synechocystis and beyond. The POPPY methodology represents a step in making optimal pathway-host matches, which is likely to become important as the practical range of host organisms is diversified. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Draft genome sequence of Agrobacterium sp. strain R89-1, a morphine alkaloid-biotransforming bacterium

Czech Academy of Sciences Publication Activity Database

Zahradník, Jiří; Kyslíková, Eva; Kyslík, Pavel

2016-01-01

Roč. 4, č. 2 (2016), e00196-16 ISSN 2169-8287 Institutional support: RVO:61388971 Keywords : Agrobacterium sp. strain R89-1 * codeine/morphine * phylogenetic lineage Subject RIV: EE - Microbiology, Virology

Polycyclic aromatic hydrocarbon degradation by the white rot fungus Bjerkandera sp. strain BOS55

NARCIS (Netherlands)

Kotterman, M.

1998-01-01

Outline of this thesis
In this thesis the conditions for optimal PAH oxidation by the white rot fungus Bjerkandera sp. strain BOS55 were evaluated. In Chapter 2, culture conditions like aeration and cosubstrate concentrations,

Antibiotic susceptibility profiles of Mycoplasma sp. 1220 strains isolated from geese in Hungary.

Science.gov (United States)

Grózner, Dénes; Kreizinger, Zsuzsa; Sulyok, Kinga M; Rónai, Zsuzsanna; Hrivnák, Veronika; Turcsányi, Ibolya; Jánosi, Szilárd; Gyuranecz, Miklós

2016-08-19

Mycoplasma sp. 1220 can induce inflammation primarily in the genital and respiratory tracts of waterfowl, leading to serious economic losses. Adequate housing and appropriate antibiotic treatment are promoted in the control of the disease. The aim of the present study was to determine the in vitro susceptibility to thirteen different antibiotics and an antibiotic combination of thirty-eight M. sp. 1220 strains isolated from geese and a duck in several parts of Hungary, Central Europe between 2011 and 2015. High MIC50 values were observed in the cases of tilmicosin (>64 μg/ml), oxytetracycline (64 μg/ml), norfloxacin (>10 μg/ml) and difloxacin (10 μg/ml). The examined strains yielded the same MIC50 values with spectinomycin, tylosin and florfenicol (8 μg/ml), while enrofloxacin (MIC50 5 μg/ml), doxycycline (MIC50 5 μg/ml), lincomycin (MIC50 4 μg/ml) and lincomycin-spectinomycin (1:2) combination (MIC50 4 μg/ml) inhibited the growth of the bacteria with lower concentrations. Tylvalosin (MIC50 0.5 μg/ml) and two pleuromutilins (tiamulin MIC50 0.625 μg/ml; valnemulin MIC50 ≤ 0.039 μg/ml) were found to be the most effective drugs against M. sp. 1220. However, strains with elevated MIC values were detected for all applied antibiotics. Valnemulin, tiamulin and tylvalosin were found to be the most effective antibiotics in the study. Increasing resistance was observed in the cases of several antibiotics. The results highlight the importance of testing Mycoplasma species for antibiotic susceptibility before therapy.

The Marine Fungi Rhodotorula sp. (Strain CNYC4007 as a Potential Feed Source for Fish Larvae Nutrition

Directory of Open Access Journals (Sweden)

M. Barra

2017-12-01

Full Text Available Fish oil is used in the production of feed for cultured fish owing to its high polyunsaturated fatty acid content (PUFA. The over-exploitation of fisheries and events like “El Niño” are reducing the fish oil supply. Some marine microorganisms are considered potentially as alternative fatty acid sources. This study assesses a strain of Rhodotorula sp. (strain CNYC4007; 27% docosahexaenoic acid (DHA of total fatty acids, as feed for fish larvae. The total length and ribonucleic acid (RNA/deoxyribonucleic acid (DNA ratio of Danio rerio larvae was determined at first feeding at six and 12 days old (post-yolk absorption larvae. Larvae fed with microencapsulated Rhodotorula sp. CNYC4007 had a significantly higher RNA/DNA ratio than control group (C1. At six days post-yolk absorption group, the RNA/DNA ratio of larvae fed with Rhodotorula sp. bioencapsulated in Brachionus sp. was significantly higher than control group fed with a commercial diet high in DHA (C2-DHA. Finally, at 12 days post-yolk absorption, the RNA/DNA ratio was significantly higher in larvae fed with Rhodotorula sp. CNYC4007 and C2-DHA (both bioencapsulated in Artemia sp. nauplii than in control group (C1. These results suggest that Rhodotorula sp. CNYC4007 can be an alternative source of DHA for feeding fish at larval stage, providing a sustainable source of fatty acids.

Draft Genome Sequence of Limnobacter sp. Strain CACIAM 66H1, a Heterotrophic Bacterium Associated with Cyanobacteria.

Science.gov (United States)

da Silva, Fábio Daniel Florêncio; Lima, Alex Ranieri Jerônimo; Moraes, Pablo Henrique Gonçalves; Siqueira, Andrei Santos; Dall'Agnol, Leonardo Teixeira; Baraúna, Anna Rafaella Ferreira; Martins, Luisa Carício; Oliveira, Karol Guimarães; de Lima, Clayton Pereira Silva; Nunes, Márcio Roberto Teixeira; Vianez-Júnior, João Lídio Silva Gonçalves; Gonçalves, Evonnildo Costa

2016-05-19

Ecological interactions between cyanobacteria and heterotrophic prokaryotes are poorly known. To improve the genomic studies of heterotrophic bacterium-cyanobacterium associations, the draft genome sequence (3.2 Mbp) of Limnobacter sp. strain CACIAM 66H1, found in a nonaxenic culture of Synechococcus sp. (cyanobacteria), is presented here. Copyright © 2016 da Silva et al.

Influence of Carbon Sources and Electron Shuttles on Ferric Iron Reduction by Cellulomonas sp. Strain ES6

Energy Technology Data Exchange (ETDEWEB)

Dr Robin Gerlach; Erin K. Field; Sridhar Viamajala; Brent M. Peyton; William A. Apel; Al B. Cunningham

2011-09-01

Microbially reduced iron minerals can reductively transform a variety of contaminants including heavy metals, radionuclides, chlorinated aliphatics, and nitroaromatics. A number of Cellulomonas spp. strains, including strain ES6, isolated from aquifer samples obtained at the U.S. Department of Energy's Hanford site in Washington, have been shown to be capable of reducing Cr(VI), TNT, natural organic matter, and soluble ferric iron [Fe(III)]. This research investigated the ability of Cellulomonas sp. strain ES6 to reduce solid phase and dissolved Fe(III) utilizing different carbon sources and various electron shuttling compounds. Results suggest that Fe(III) reduction by and growth of strain ES6 was dependent upon the type of electron donor, the form of iron present, and the presence of synthetic or natural organic matter, such as anthraquinone-2,6-disulfonate (AQDS) or humic substances. This research suggests that Cellulomonas sp. strain ES6 could play a significant role in metal reduction in the Hanford subsurface and that the choice of carbon source and organic matter addition can allow for independent control of growth and iron reduction activity.

[EFFICIENCY OF INTRODUCING CAROTENE PRODUCING STRAINS BACILLUS SP. 1.1 AND B. AMYLOLIQUEFACIENS UCM B-5113 INTO THE CHIKENS DIET].

Science.gov (United States)

Nechypurenko, O O; Kharhota M A; Avdeeva, L V

2015-01-01

It was shown the efficiency of carotene producing strains Bacillus sp. 1.1 and B. amyloliquefaciens UCM B-5113 in the diet of chickens. Also it was detected the lowering of the quantitative content of bacterial genera Enterococcus, Staphylococcus, family Enterobacteriaceae in the gut after eating by chickens cross "H&N Brown Nick" fodder with strains Bacillus sp. 1.1 and B. amyloliquefaciens UCM B-5113 alone and in composition in quantities 1 x 10(10) CFU per 1 g of feed. On the 18th day after introduction of cultures Bacillus sp. 1.1, B. amyloliquefaciens UCM B-5113 and their composition in the diet of poultry we revealed the increasing of body weight by 21.6, 7.6 and 22.0%, respectively, comparesing to controls. Also due to Bacillus sp. 1.1 it was detected the restore of intestinal villous structures, tissues of spleen, liver and heart. We found the additive effect of the composition of the investigated strains of bacteria genus Bacillus to the chickens.

Reclassification of rhizosphere bacteria including strains causing corky root of lettuce and proposal of Rhizorhapis suberifaciens gen. nov., comb. nov., Sphingobium mellinum sp. nov., Sphingobium xanthum sp. nov. and Rhizorhabdus argentea gen. nov., sp. nov.

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Francis, Isolde M; Jochimsen, Kenneth N; De Vos, Paul; van Bruggen, Ariena H C

2014-04-01

The genus Rhizorhapis gen. nov. (to replace the illegitimate genus name Rhizomonas) is proposed for strains of Gram-negative bacteria causing corky root of lettuce, a widespread and important lettuce disease worldwide. Only one species of the genus Rhizomonas was described, Rhizomonas suberifaciens, which was subsequently reclassified as Sphingomonas suberifaciens based on 16S rRNA gene sequences and the presence of sphingoglycolipid in the cell envelope. However, the genus Sphingomonas is so diverse that further reclassification was deemed necessary. Twenty new Rhizorhapis gen. nov.- and Sphingomonas-like isolates were obtained from lettuce or sow thistle roots, or from soil using lettuce seedlings as bait. These and previously reported isolates were characterized in a polyphasic study including 16S rRNA gene sequencing, DNA-DNA hybridization, DNA G+C content, whole-cell fatty acid composition, morphology, substrate oxidation, temperature and pH sensitivity, and pathogenicity to lettuce. The isolates causing lettuce corky root belonged to the genera Rhizorhapis gen. nov., Sphingobium, Sphingopyxis and Rhizorhabdus gen. nov. More specifically, we propose to reclassify Rhizomonas suberifaciens as Rhizorhapis suberifaciens gen. nov., comb. nov. (type strain, CA1(T) = LMG 17323(T) = ATCC 49355(T)), and also propose the novel species Sphingobium xanthum sp. nov., Sphingobium mellinum sp. nov. and Rhizorhabdus argentea gen. nov., sp. nov. with the type strains NL9(T) ( = LMG 12560(T) = ATCC 51296(T)), WI4(T) ( = LMG 11032(T) = ATCC 51292(T)) and SP1(T) ( = LMG 12581(T) = ATCC 51289(T)), respectively. Several strains isolated from lettuce roots belonged to the genus Sphingomonas, but none of them were pathogenic.

Reductive dehalogenation of 3,5-dibromo-4-hydroxybenzoate by an aerobic strain of Delftia sp. EOB-17.

Science.gov (United States)

Chen, Kai; Jian, Shanshan; Huang, Linglong; Ruan, Zhepu; Li, Shunpeng; Jiang, Jiandong

2015-12-01

To confirm the reductive dehalogenation ability of the aerobic strain of Delftia sp. EOB-17, finding more evidences to support the hypothesis that reductive dehalogenation may occur extensively in aerobic bacteria. Delftia sp. EOB-17, isolated from terrestrial soil contaminated with halogenated aromatic compounds, completely degraded 0.2 mM DBHB in 28 h and released two equivalents of bromides under aerobic conditions in the presence of sodium succinate. LC-MS analysis revealed that DBHB was transformed to 4-hydroxybenzoate via 3-bromo-4-hydroxybenzoate by successive reductive dehalogenation. Highly conserved DBHB-degrading genes, including reductive dehalogenase gene (bhbA3) and the extra-cytoplasmic binding receptor gene (bhbB3), were also found in strain EOB-17 by genome sequencing. The optimal temperature and pH for DBHB reductive dehalogenation activity are 30 °C and 8, respectively, and 0.1 mM Cd(2+), Cu(2+), Hg(2+) and Zn(2+) strongly inhibited dehalogenation activity. The aerobic strain of Delftia sp. EOB-17 was confirmed to reductively dehalogenate DBHB under aerobic conditions, providing another evidence to support the hypothesis that reductive dehalogenation occurs extensively in aerobic bacteria.

OXIDATION OF BIPHENYL BY A MULTICOMPONENT ENZYME SYSTEM FROM PSEUDOMONAS SP. STRAIN LB400

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Pseudomonas sp. strain LB400 grows on biphenyl as the sole carbon and energy source. This organism also cooxidizes several chlorinated biphenyl congeners. Biphenyl dioxygenase activity in cell extract required addition of NAD(P)H as an electron donor for the conversion of bipheny...

Benzoate Catabolite Repression of the Phthalate Degradation Pathway in Rhodococcus sp. Strain DK17▿

OpenAIRE

Choi, Ki Young; Zylstra, Gerben J.; Kim, Eungbin

2006-01-01

Rhodococcus sp. strain DK17 exhibits a catabolite repression-like response when provided simultaneously with benzoate and phthalate as carbon and energy sources. Benzoate in the medium is depleted to detection limits before the utilization of phthalate begins. The transcription of the genes encoding benzoate and phthalate dioxygenase paralleled the substrate utilization profile. Two mutant strains with defective benzoate dioxygenases were unable to utilize phthalate in the presence of benzoat...

Highly efficient decolorization of Malachite Green by a novel Micrococcus sp. strain BD15.

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Du, Lin-Na; Zhao, Ming; Li, Gang; Zhao, Xiao-Ping; Zhao, Yu-Hua

2011-08-01

Malachite Green (MG) is used for a variety of applications but is also known to be carcinogenic and mutagenic. In this study, a novel Micrococcus sp. (strain BD15) was observed to efficiently decolorize MG. The purposes of this study were to explore the optimal conditions for decolorization and to evaluate the potential use of this strain for MG decolorization. Optical microscope and UV-visible analyses were carried out to determine whether the decolorization was due to biosorption or biodegradation. A Plackett-Burman design was employed to investigate the effect of various parameters on decolorization, and response surface methodology was then used to explore the optimal decolorization conditions. Kinetics analysis and antimicrobial activity tests were also performed. The results indicated that the decolorization by the strain was mainly due to biodegradation. Concentrations of MG, urea, and yeast extract and inoculum size had significantly positive effects on MG decolorization, while concentrations of CuCl(2) and MgCl(2), and temperature had significantly negative effects. The interaction between different parameters could significantly affect decolorization, and the optimal conditions for decolorization were 1.0 g/L urea, 0.9 g/L yeast extract, 100 mg/L MG, 0.1 g/L inoculums (dry weight), and incubation at 25.2°C. Under the optimal conditions, 96.9% of MG was removed by the strain within 1 h, which represents highly efficient microbial decolorization. Moreover, the kinetic data for decolorization fit a second-order model well, and the strain showed a good MG detoxification capability. Based on the results of this study, we propose Micrococcus sp. strain BD15 as an excellent candidate strain for MG removal from wastewater.

Isolation and characterization of an isoproturon mineralizing Sphingomonas sp. strain SH from a French agricultural soil.

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Hussain, Sabir; Devers-Lamrani, Marion; El Azhari, Najoi; Martin-Laurent, Fabrice

2011-06-01

The phenylurea herbicide isoproturon, 3-(4-isopropylphenyl)-1,1-dimethylurea (IPU), was found to be rapidly mineralized in an agricultural soil in France that had been periodically exposed to IPU. Enrichment cultures from samples of this soil isolated a bacterial strain able to mineralize IPU. 16S rRNA sequence analysis showed that this strain belonged to the phylogeny of the genus Sphingomonas (96% similarity with Sphingomonas sp. JEM-14, AB219361) and was designated Sphingomonas sp. strain SH. From this strain, a partial sequence of a 1,2-dioxygenase (catA) gene coding for an enzyme degrading catechol putatively formed during IPU mineralization was amplified. Phylogenetic analysis revealed that the catA sequence was related to Sphingomonas spp. and showed a lack of congruence between the catA and 16S rRNA based phylogenies, implying horizontal gene transfer of the catA gene cluster between soil microbiota. The IPU degrading ability of strain SH was strongly influenced by pH with maximum degradation taking place at pH 7.5. SH was only able to mineralize IPU and its known metabolites including 4-isopropylaniline and it could not degrade other structurally related phenylurea herbicides such as diuron, linuron, monolinuron and chlorotoluron or their aniline derivatives. These observations suggest that the catabolic abilities of the strain SH are highly specific to the metabolism of IPU.

Draft genome sequence of Paenibacillus algorifonticola sp. nov., an antimicrobial-producing strain

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Liying Zhu

2015-09-01

Full Text Available Paenibacillus algorifonticola sp. nov. is isolated from a cold spring sample from Xinjiang Uyghur Autonomous Region (China, a novel strain that can produce antimicrobial substance against human pathogenic bacteria and fungi, including Staphylococcus aureus and Candida albicans. Here we report a 7.60-Mb assembly of its genome sequence and other useful information, including the coding sequences (CDSs responsible for the biosynthesis of antibacterial factors, anaerobic respiration and several immune-associated reactions. Also, prospective studies on P. algorifonticola sp. nov. in the cold spring might offer a potential source for the discovery of bioactive compounds with medical value. The data repository is deposited on the website http://www.ncbi.nlm.nih.gov/nuccore/LAQO00000000 and the accession number is LAQO00000000.

Transcription of the extended hyp-operon in Nostoc sp. strain PCC 7120

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Agervald, Åsa; Stensjö, Karin; Holmqvist, Marie; Lindblad, Peter

2008-01-01

Background The maturation of hydrogenases into active enzymes is a complex process and e.g. a correctly assembled active site requires the involvement of at least seven proteins, encoded by hypABCDEF and a hydrogenase specific protease, encoded either by hupW or hoxW. The N2-fixing cyanobacterium Nostoc sp. strain PCC 7120 may contain both an uptake and a bidirectional hydrogenase. The present study addresses the presence and expression of hyp-genes in Nostoc sp. strain PCC 7120. Results RT-PCRs demonstrated that the six hyp-genes together with one ORF may be transcribed as a single operon. Transcriptional start points (TSPs) were identified 280 bp upstream from hypF and 445 bp upstream of hypC, respectively, demonstrating the existence of several transcripts. In addition, five upstream ORFs located in between hupSL, encoding the small and large subunits of the uptake hydrogenase, and the hyp-operon, and two downstream ORFs from the hyp-genes were shown to be part of the same transcript unit. A third TSP was identified 45 bp upstream of asr0689, the first of five ORFs in this operon. The ORFs are annotated as encoding unknown proteins, with the exception of alr0692 which is identified as a NifU-like protein. Orthologues of the four ORFs asr0689-alr0692, with a highly conserved genomic arrangement positioned between hupSL, and the hyp genes are found in several other N2-fixing cyanobacteria, but are absent in non N2-fixing cyanobacteria with only the bidirectional hydrogenase. Short conserved sequences were found in six intergenic regions of the extended hyp-operon, appearing between 11 and 79 times in the genome. Conclusion This study demonstrated that five ORFs upstream of the hyp-gene cluster are co-transcribed with the hyp-genes, and identified three TSPs in the extended hyp-gene cluster in Nostoc sp. strain PCC 7120. This may indicate a function related to the assembly of a functional uptake hydrogenase, hypothetically in the assembly of the small subunit of

Complete Genome Sequence of Dietzia sp. Strain WMMA184, a Marine Coral-Associated Bacterium

OpenAIRE

Braun, Doug R.; Chevrette, Marc G.; Acharya, Deepa; Currie, Cameron R.; Rajski, Scott R.; Ritchie, Kim B.; Bugni, Tim S.

2018-01-01

ABSTRACT Dietzia sp. strain WMMA184 was isolated from the marine coral Montastraea faveolata as part of ongoing drug discovery efforts. Analysis of the 4.16-Mb genome provides information regarding interspecies interactions as it pertains to the regulation of secondary metabolism and natural product biosynthesis potential.

A Tn5051-like mer-containing transposon identified in a heavy metal tolerant strain Achromobacter sp. AO22

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Bhave Mrinal

2009-03-01

Full Text Available Abstract Background Achromobacter sp. AO22 (formerly Alcaligenes sp. AO22, a bacterial strain isolated from a lead-contaminated industrial site in Australia, was previously found to be resistant to moderate to high levels of mercury, copper and other heavy metals. However, the nature and location of the genetic basis for mercuric ion resistance in this strain, had not been previously identified. Findings Achromobacter sp. AO22 contains a functional mer operon with all four essential genes (merRTPA and shows >99% DNA sequence identity to that of Tn501. The mer operon was present on a transposon, designated TnAO22, captured by introducing a broad-host-range IncP plasmid into Achromobacter sp. AO22 and subsequently transferring it to E. coli recipients. The transposition frequency of TnAO22 was 10-2 to 10-3 per target plasmid transferred. Analysis of TnAO22 sequence revealed it belonged to the Tn21 subgroup of the Tn3 superfamily of transposons, with the transposition module having >99% identity with Tn5051 of a Pseudomonas putida strain isolated from a water sample in New York. Conclusion TnAO22 is thus a new variant of Tn5051 of the Tn3 superfamily and the transposon and its associated mercury resistance system are among the few such systems reported in a soil bacterium. Achromobacter sp. AO22 can thus be exploited for applications such as in situ mercury bioremediation of contaminated sites, or the mobile unit and mer operon could be mobilized to other bacteria for similar purposes.

The ORF slr0091 of Synechocystis sp. PCC6803 encodes a high-light induced aldehyde dehydrogenase converting apocarotenals and alkanals

KAUST Repository

Trautmann, Danika

2013-07-05

Oxidative cleavage of carotenoids and peroxidation of lipids lead to apocarotenals and aliphatic aldehydes called alkanals, which react with vitally important compounds, promoting cytotoxicity. Although many enzymes have been reported to deactivate alkanals by converting them into fatty acids, little is known about the mechanisms used to detoxify apocarotenals or the enzymes acting on them. Cyanobacteria and other photosynthetic organisms must cope with both classes of aldehydes. Here we report that the Synechocystis enzyme SynAlh1, encoded by the ORF slr0091, is an aldehyde dehydrogenase that mediates oxidation of both apocarotenals and alkanals into the corresponding acids. Using a crude lysate of SynAlh1-expressing Escherichia coli cells, we show that SynAlh1 converts a wide range of apocarotenals and alkanals, with a preference for apocarotenals with defined chain lengths. As suggested by in vitro incubations and using engineered retinal-forming E. coli cells, we found that retinal is not a substrate for SynAlh1, making involvement in Synechocystis retinoid metabolism unlikely. The transcript level of SynAlh1 is induced by high light and cold treatment, indicating a role in the stress response, and the corresponding gene is a constituent of a stress-related operon. The assumptions regarding the function of SynAlh are further supported by the surprisingly high homology to human and plant aldehyde dehydrogenase that have been assigned to aldehyde detoxification. SynAlh1 is the first aldehyde dehydrogenase that has been shown to form both apocarotenoic and fatty acids. This dual function suggests that its eukaryotic homologs may also be involved in apocarotenal metabolism, a function that has not been considered so far. Aldehyde dehydrogenases play an important role in detoxification of reactive aldehydes. Here, we report on a cyanbacterial enzyme capable in converting two classes of lipid-derived aldehydes, apocaotenals and alkanals. The corresponding gene is a

Disruption of the ndhF1 gene affects Chl fluorescence through state transition in the Cyanobacterium Synechocystis sp. PCC 6803, resulting in apparent high efficiency of photosynthesis.

Science.gov (United States)

Ogawa, Takako; Harada, Tetsuyuki; Ozaki, Hiroshi; Sonoike, Kintake

2013-07-01

In Synechocystis sp. PCC 6803, the disruption of the ndhF1 gene (slr0844), which encodes a subunit of one of the NDH-1 complexes (NDH-1L complex) serving for respiratory electron transfer, causes the largest change in Chl fluorescence induction kinetics among the kinetics of 750 disruptants searched in the Fluorome, the cyanobacterial Chl fluorescence database. The cause of the explicit phenotype of the ndhF1 disruptant was examined by measurements of the photosynthetic rate, Chl fluorescence and state transition. The results demonstrate that the defects in respiratory electron transfer obviously have great impact on Chl fluorescence in cyanobacteria. The inactivation of NDH-1L complexes involving electron transfer from NDH-1 to plastoquinone (PQ) would result in the oxidation of the PQ pool, leading to the transition to State 1, where the yield of Chl fluorescence is high. Apparently, respiration, although its rate is far lower than that of photosynthesis, could affect Chl fluorescence through the state transition as leverage. The disruption of the ndhF1 gene caused lower oxygen-evolving activity but the estimated electron transport rate from Chl fluorescence measurements was faster in the mutant than in the wild-type cells. The discrepancy could be ascribed to the decreased level of non-photochemical quenching due to state transition. One must be cautious when using the Chl fluorescence parameter to estimate photosynthesis in mutants defective in state transition.

Inhibition of food-related bacteria by antibacterial substances produced by Pseudomonas sp. strains isolated from pasteurized milk

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Ana Beatriz Ferreira Rangel

2013-12-01

Full Text Available In this work, the production of antimicrobial substances by strains of Pseudomonas sp. isolated from pasteurized milk and their potential action against food-related bacteria were investigated. Samples of pasteurized milk were purchased from arbitrarily chosen commercial establishments in the city of Rio de Janeiro, Brazil. Of the four samples analyzed, three presented several typical colonies of Pseudomonas. About 100 colonies were chosen and subjected to biochemical tests for confirmation of their identity. Eighteen strains of the Pseudomonas genus were identified and submitted to tests for the production of antimicrobial substances. Twelve strains (66.7% were identified as Pseudomonas fluorescens, four (22.2% as P. aeruginosa, one (5.5% as P. mendocina and one (5.5% as P. pseudoalcaligenes. Only two P. fluorescens strains were unable to produce any antimicrobial substance against any of the indicator strains tested. Most of the strains presented a broad spectrum of action, inhibiting reference and food-related strains such as Proteus vulgaris, Proteus mirabilis, Hafnia alvei, Yersinia enterocolitica, Escherichia coli and Salmonella typhi. Five antimicrobial substance-producing strains, which presented the broadest spectrum of action, were also tested against Staphylococcus aureus reference strains and 26 Staphylococcus sp. strains isolated from foods, some of which were resistant to antibiotics. The producer strains 8.1 and 8.3, both P. aeruginosa, were able to inhibit all the staphylococcal strains tested. The antimicrobial substances produced by strains 8.1 and 8.3 did not seem to be typical bacteriocins, since they were resistant to the three proteolytic enzymes tested. Experiments involving the characterization of these substances are being carried out in order to evaluate their biotechnological application.

Genome sequence of the agar-degrading marine bacterium Alteromonadaceae sp. strain G7.

Science.gov (United States)

Kwak, Min-Jung; Song, Ju Yeon; Kim, Byung Kwon; Chi, Won-Jae; Kwon, Soon-Kyeong; Choi, Soobeom; Chang, Yong-Keun; Hong, Soon-Kwang; Kim, Jihyun F

2012-12-01

Here, we present the high-quality draft genome sequence of the agar-degrading marine gammaproteobacterium Alteromonadaceae sp. strain G7, which was isolated from coastal seawater to be utilized as a bioresource for production of agar-derived biofuels. The 3.91-Mb genome contains a number of genes encoding algal polysaccharide-degrading enzymes such as agarases and sulfatases.

Genome Sequence of the Agar-Degrading Marine Bacterium Alteromonadaceae sp. Strain G7

OpenAIRE

Kwak, Min-Jung; Song, Ju Yeon; Kim, Byung Kwon; Chi, Won-Jae; Kwon, Soon-Kyeong; Choi, Soobeom; Chang, Yong-Keun; Hong, Soon-Kwang; Kim, Jihyun F.

2012-01-01

Here, we present the high-quality draft genome sequence of the agar-degrading marine gammaproteobacterium Alteromonadaceae sp. strain G7, which was isolated from coastal seawater to be utilized as a bioresource for production of agar-derived biofuels. The 3.91-Mb genome contains a number of genes encoding algal polysaccharide-degrading enzymes such as agarases and sulfatases.

Genome Sequence of Lactobacillus saerimneri 30a (Formerly Lactobacillus sp. Strain 30a), a Reference Lactic Acid Bacterium Strain Producing Biogenic Amines

NARCIS (Netherlands)

Romano, Andrea; Trip, Hein; Campbell-Sills, Hugo; Bouchez, Olivier; Sherman, David; Lolkema, Juke S.; Lucas, Patrick M.

2013-01-01

Lactobacillus sp. strain 30a (Lactobacillus saerimneri) produces the biogenic amines histamine, putrescine, and cadaverine by decarboxylating their amino acid precursors. We report its draft genome sequence (1,634,278 bases, 42.6% G+C content) and the principal findings from its annotation, which

Bifidobacterium reuteri sp. nov., Bifidobacterium callitrichos sp. nov., Bifidobacterium saguini sp. nov., Bifidobacterium stellenboschense sp. nov. and Bifidobacterium biavatii sp. nov. isolated from faeces of common marmoset (Callithrix jacchus) and red-handed tamarin (Saguinus midas).

Science.gov (United States)

Endo, Akihito; Futagawa-Endo, Yuka; Schumann, Peter; Pukall, Rüdiger; Dicks, Leon M T

2012-03-01

Five strains of bifidobacteria were isolated from faeces of a common marmoset (Callithrix jacchus) and a red-handed tamarin (Saguinus midas). The five isolates clustered inside the phylogenetic group of the genus Bifidobacterium but did not show high sequence similarities between the isolates and to known species in the genus by phylogenetic analysis based on 16S rRNA gene sequences. Sequence analyses of dnaJ1 and hsp60 also indicated their independent phylogenetic positions to each other in the Bifidobacterium cluster. DNA G+C contents of the species ranged from 57.3 to 66.3 mol%, which is within the values recorded for Bifidobacterium species. All isolates showed fructose-6-phosphate phosphoketolase activity. Based on the data provided, the five isolates represent five novel species, for which the names Bifidobacterium reuteri sp. nov. (type strain: AFB22-1(T) = JCM 17295(T) = DSM 23975(T)), Bifidobacterium callitrichos sp. nov. (type strain: AFB22-5(T) = JCM 17296(T) = DSM 23973(T)), Bifidobacterium saguini sp. nov. (type strain: AFB23-1(T) = JCM 17297(T) = DSM 23967(T)), Bifidobacterium stellenboschense sp. nov. (type strain: AFB23-3(T) = JCM 17298(T) = DSM 23968(T)) and Bifidobacterium biavatii sp. nov. (type strain: AFB23-4(T) = JCM 17299(T) = DSM 23969(T)) are proposed. Copyright © 2011 Elsevier GmbH. All rights reserved.

Enhanced saturated fatty acids accumulation in cultures of newly-isolated strains of Schizochytrium sp. and Thraustochytriidae sp. for large-scale biodiesel production.

Science.gov (United States)

Wang, Qiuzhen; Sen, Biswarup; Liu, Xianhua; He, Yaodong; Xie, Yunxuan; Wang, Guangyi

2018-08-01

Heterotrophic marine protists (Thraustochytrids) have received increasingly global attention as a renewable, sustainable and alternative source of biodiesel because of their high ability of saturated fatty acids (SFAs) accumulation. Yet, the influence of extrinsic factors (nutrients and environmental conditions) on thraustochytrid culture and optimal conditions for high SFAs production are poorly described. In the present study, two different thraustochytrid strains, Schizochytrium sp. PKU#Mn4 and Thraustochytriidae sp. PKU#Mn16 were studied for their growth and SFAs production profiles under various conditions (carbon, nitrogen, temperature, pH, KH 2 PO 4 , salinity, and agitation speed). Of the culture conditions, substrates (C and N) source and conc., temperature, and agitation speed significantly influenced the cell growth and SFAs production of both strains. Although both the strains were capable of growth and SFAs production in the broad range of culture conditions, their physiological responses to KH 2 PO 4 , pH, and salinity were dissimilar. Under their optimal batch culture conditions, peak SFAs productions of 3.3g/L and 2.2g/L with 62% and 49% SFAs contents (relative to total fatty acids) were achieved, respectively. The results of 5-L fed-batch fermentation under optimal conditions showed a nearly 4.5-fold increase in SFAs production (i.e., 7.5g/L) by both strains compared to unoptimized conditions. Of the two strains, the quality of biodiesel produced from the fatty acids of PKU#Mn4 met the biodiesel standard defined by ASTM6751. This study, to the knowledge of the authors, is the first comprehensive report of optimal fermentation conditions demonstrating enhanced SFAs production by strains belonging to two different thraustochytrid genera and provides the basis for large-scale biodiesel production. Copyright © 2018. Published by Elsevier B.V.

Membrane-aerated biofilm reactor for the removal of 1,2-dichloroethane by Pseudomonas sp strain DCA1

NARCIS (Netherlands)

Hage, J.C.; Houten, R.T.; Tramper, J.; Hartmans, S.

2004-01-01

A membrane-aerated biofilm reactor (MBR) with a biofilm of Pseudomonas sp. strain DCA1 was studied for the removal of 1,2-dichloroethane (DCA) from water. A hydrophobic membrane was used to create a barrier between the liquid and the gas phase. Inoculation of the MBR with cells of strain DCA1 grown

Pesticide lambda-cyhalothrin degradation using mesorhizobium sp. (s1b) and bartonella sp. (s2b) strains isolated from cotton crop

International Nuclear Information System (INIS)

Chumro, W.A.; Phulpoto, A.H.; Mangi, S.; Kanhar, N.A.; Ahmed, S.; Qazi, M.A.; Pirzada, T.

2017-01-01

Lambda-cyhalothrin (LC), synthetic pyrethroid pesticide is used to control a wide range of pests in variety of agricultural fields. Pesticides are potentially harmful environmental pollutants and pose serious threat to human health. Very limited options are available for environment friendly removal of LC. Interestingly, soil microbes have been known to possess remarkable genetic makeup that helps them to perform vital job in cleaning-up harmful pollutants from the environment. In present study, two LC-degrading bacteria viz. Mesorhizobium sp. strain S1B (Accession no. gb|MF471843|) and Bartonella sp. strain S2B (Accession no. b|MF471844|) were isolated by soil enrichment technique from cotton crop soil and characterized taxonomically using conventional methods and molecular PCR-based 16S rRNA sequence homology. The bacterial strains S1B and S2B achieved 29% and 40% removal of LC (conc. 250 mg/L, w/v), with maximum growth absorbance (OD) of 1.19 +- 0.06 and 1.13+- 0.09, respectively, during 20 days of incubation at 30 degree C and agitation 200 rpm under experimental laboratory circumstances. The percent removal of LC was estimated using UV-Vis Spectroscopy at 287 nm (? max) against the standard curve plotted at different LC concentrations. The bacterial isolates of present study have exhibited substantial efficiency for environmental biodegradation of the pesticide. (author)

Experimental infection in Cavia porcellus by infected Amblyomma ovale nymphs with Rickettsia sp. (Atlantic rainforest strain).

Science.gov (United States)

Brustolin, Joice Magali; da Silva Krawczak, Felipe; Alves, Marta Elena Machado; Weiller, Maria Amélia; de Souza, Camila Lopes; Rosa, Fábio Brum; Cadore, Gustavo Cauduro; Dos Anjos Lopes, Sônia Terezinha; Labruna, Marcelo Bahia; Vogel, Fernanda Silveira Flores; de Avila Botton, Sônia; Sangioni, Luís Antônio

2018-03-01

This study describes experimental infection of guinea pigs (Cavia porcellus) infested with naturally infected Amblyomma ovale nymphs with Rickettsia sp. (Atlantic rainforest strain), and the capacity of A. ovale nymphs to transmit this bacterium. Twenty-six guinea pigs were divided into the following groups: G1, 10 animals infested with uninfected A. ovale nymphs; G2, 10 animals infested with nymphs infected with Rickettsia sp. (Atlantic rainforest strain); and G3, 6 animals without tick infestation. Blood samples were taken 7, 14, 21, and 28 days post-infestation for serological and hematological tests. For histopathological analysis and rickettsial DNA detection, fragments of the spleen, lung, brain, and liver were harvested after euthanasia. The average feeding period for nymphs was 6.6 days for G1 and 6 days for G2. Hemolymph and PCR assays, performed to detect the causative agent in ticks, indicated that in G1, all ticks were negative, and in G2, all nymphs were positive by PCR and 80% (8/10) was positive by hemolymph tests. The only clinical change was skin scarring at the tick attachment site. Hematological parameters indicated leukopenia and total plasma protein (TPP) increased with decreased platelets in G1. In G2, leukocytosis, neutrophilia, monocytosis, an increase in platelets, and reduced TPP were observed. Only G2 guinea pigs were seroconverted (80%; 8/10). Histopathology tests indicated mild, diffuse hemosiderosis and mild, multifocal, follicular hyperplasia in the spleen. Molecular analysis did not detect Rickettsia sp. DNA in C. porcellus tissues. We demonstrated the capacity of A. ovale nymphs to transmit Rickettsia sp. (Atlantic rainforest strain) to guinea pigs.

Methyl Red Decolorization Efficiency of a Korea Strain of Aspergillus sp. Immobilized into Different Polymeric Matrices.

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Kim, Beom-Su; Blaghen, Mohamed; Lee, Kang-Min

2017-07-01

  Intensive research studies have revealed that fungal decolorization of dye wastewater is a promising replacement for the current process of dye wastewater decolorization. The authors isolated an Aspergillus sp. from the effluent of a textile industry area in Korea and assessed the effects of a variety of operational parameters on the decolorization of methyl red (MR) by this strain of Aspergillus sp. This Aspergillus sp. was then immobilized by entrapment in several polymeric matrices and the effects of operational conditions on MR decolorization were investigated again. The optimal decolorization activity of this Aspergillus sp. was observed in 1% glucose at a temperature of 37 °C and pH of 6.0. Furthermore, stable decolorization efficiency was observed when fungal biomass was immobilized into alginate gel during repeated batch experiment. These results suggest that the Aspergillus sp. isolated in Korea could be used to treat industrial wastewaters containing MR dye.

Poly(3-Hydroxybutyrate) Synthesis Genes in Azotobacter sp. Strain FA8

OpenAIRE

Pettinari, M. Julia; Vázquez, Gustavo J.; Silberschmidt, Daniel; Rehm, Bernd; Steinbüchel, Alexander; Méndez, Beatriz S.

2001-01-01

Genes responsible for the synthesis of poly(3-hydroxybutyrate) (PHB) in Azotobacter sp. FA8 were cloned and analyzed. A PHB polymerase gene (phbC) was found downstream from genes coding for β-ketothiolase (phbA) and acetoacetyl-coenzyme A reductase (phbB). A PHB synthase mutant was obtained by gene inactivation and used for genetic studies. The phbC gene from this strain was introduced into Ralstonia eutropha PHB-4 (phbC-negative mutant), and the recombinant accumulated PHB when either glucos...

Cellulase production by a strain of Myrothecium sp

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Kassim, E A

1982-01-01

A selected strain of Myrothecium sp. was grown on various carbon sources. Cellulose was found to be the highest inducer of cellulase. CMC resulted in a moderate yield. Cellobiose resulted in a low yield. Glucose, lactose, maltose and soluble starch resulted in negligible amounts. Sucrose, glycerol and salicin were extremely unsuitable. Continuous addition of glucose or cellobiose during fermentation to cellulosic culture media reduced cellulase production, whereas addition of the entire amount of glucose or cellobiose at the beginning did not affect the enzyme production. The enzyme was precipitated from the culture filtrate with ammonium sulfate giving crude cellulase, 3854 units/g. The culture filtrate was concentrated to a one-tenth volume, 97 units/ml. The purified cellulase was prepared by dialysis 6700 units/g of enzyme precipitate.

Selection of microalgae and cyanobacteria strains for bicarbonate-based integrated carbon capture and algae production system.

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Chi, Zhanyou; Elloy, Farah; Xie, Yuxiao; Hu, Yucai; Chen, Shulin

2014-01-01

Using microalgae to capture CO2 from flue gas is an ideal way to reduce CO2 emission, but this is challenged by the high cost of carbon capture and transportation. To address this problem, a bicarbonate-based integrated carbon capture and algae production system (BICCAPS) has been proposed, in which bicarbonate is used for algae culture, and the regenerated carbonate from this process can be used to capture more CO2. High-concentration bicarbonate is obligate for the BICCAPS. Thus, different strains of microalgae and cyanobacteria were tested in this study for their capability to grow in high-concentration NaHCO3. The highest NaHCO3 concentrations they are tolerant to were determined as 0.30 M for Synechocystis sp. PCC6803, 0.60 M for Cyanothece sp., 0.10 M for Chlorella sorokiniana, 0.60 M for Dunaliella salina, and 0.30 M for Dunaliella viridis and Dunaliella primolecta. In further study, biomass production from culture of D. primolecta in an Erlenmeyer flask with either 0.30 M NaHCO3 or 2 % CO2 bubbling was compared, and no significant difference was detected. This indicates BICCAPS can reach the same biomass productivity as regular CO2 bubbling culture, and it is promising for future application.

OXIDATION OF POLYCHLORINATED BIPHENYLS BY PSEUDOMONAS SP. STRAIN LB400 AND PSEUDOMONAS PSEUDOALCALIGENES KF707

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Biphenyl-grown cells and cell extracts prepared from biphenyl-grown cells of Pseudomonas sp. strain LB400 oxidize a much wider range of chlorinated biphenyls than do analogous preparations from Pseudomonas pseudoalcaligenes KF707. These results are attributed to differences in th...

Rhizosphere colonization and arsenic translocation in sunflower (Helianthus annuus L.) by arsenate reducing Alcaligenes sp. strain Dhal-L.

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Cavalca, Lucia; Corsini, Anna; Bachate, Sachin Prabhakar; Andreoni, Vincenza

2013-10-01

In the present study, six arsenic-resistant strains previously isolated were tested for their plant growth promoting characteristics and heavy metal resistance, in order to choose one model strain as an inoculum for sunflower plants in pot experiments. The aim was to investigate the effect of arsenic-resistant strain on sunflower growth and on arsenic uptake from arsenic contaminated soil. Based on plant growth promoting characteristics and heavy metal resistance, Alcaligenes sp. strain Dhal-L was chosen as an inoculum. Beside the ability to reduce arsenate to arsenite via an Ars operon, the strain exhibited 1-amino-cyclopropane-1-carboxylic acid deaminase activity and it was also able to produce siderophore and indole acetic acid. Pot experiments were conducted with an agricultural soil contaminated with arsenic (214 mg kg⁻¹). A real time PCR method was set up based on the quantification of ACR3(2) type of arsenite efflux pump carried by Alcaligenes sp. strain Dhal-L, in order to monitor presence and colonisation of the strain in the bulk and rhizospheric soil. As a result of strain inoculation, arsenic uptake by plants was increased by 53 %, whereas ACR3(2) gene copy number in rhizospheric soil was 100 times higher in inoculated than in control pots, indicating the colonisation of strain. The results indicated that the presence of arsenate reducing strains in the rhizosphere of sunflower influences arsenic mobilization and promotes arsenic uptake by plant.

Gilliamella intestini sp. nov., Gilliamella bombicola sp. nov., Gilliamella bombi sp. nov. and Gilliamella mensalis sp. nov.: Four novel Gilliamella species isolated from the bumblebee gut.

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Praet, Jessy; Cnockaert, Margo; Meeus, Ivan; Smagghe, Guy; Vandamme, Peter

2017-06-01

Spectra of five isolates (LMG 28358 T , LMG 29879 T , LMG 29880 T , LMG 28359 T and R-53705) obtained from gut samples of wild bumblebees of Bombus pascuorum, Bombus lapidarius and Bombus terrestris were grouped into four MALDI-TOF MS clusters. RAPD analysis revealed an identical DNA fingerprint for LMG 28359 T and R-53705 which also grouped in the same MALDI-TOF MS cluster, while different DNA fingerprints were obtained for the other isolates. Comparative 16S rRNA gene sequence analysis of the four different strains identified Gilliamella apicola NCIMB 14804 T as nearest neighbour species. Average nucleotide identity values of draft genome sequences of the four isolates and of G. apicola NCIMB 14804 T were below the 96% threshold value for species delineation and all four strains and G. apicola NCIMB 14804 T were phenotypically distinct. Together, the draft genome sequences and phylogenetic and phenotypic data indicate that the four strains represent four novel Gilliamella species for which we propose the names Gilliamella intestini sp. nov., with LMG 28358 T as the type strain, Gilliamella bombicola sp. nov., with LMG 28359 T as the type strain, Gilliamella bombi sp. nov., with LMG 29879 T as the type strain and Gilliamella mensalis sp. nov., with LMG 29880 T as the type strain. Copyright © 2017 Elsevier GmbH. All rights reserved.

Noncontiguous finished genome sequence and description of Paenibacillus ihumii sp. nov. strain AT5

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A.H. Togo

2016-03-01

Full Text Available Paenibacillus ihumii sp. nov. strain AT5 (= CSUR 1981 = DSM 100664 is the type strain of P. ihumii. This bacterium was isolated from a stool sample from a morbidly obese French patient using the culturomics approach. The genome of this Gram-negative, facultative anaerobic, motile and spore-forming bacillus is 5 924 686 bp long. Genomic analysis identified 253 (5% of 3812 genes as ORFans and at least 2599 (50.03% of 5194 orthologous proteins not shared with the closest phylogenetic species.

Degradation of carbazole, dibenzothiophene, and dibenzofuran at low temperature by Pseudomonas sp. strain C3211.

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Jensen, Anne-Mette; Finster, Kai Waldemar; Karlson, Ulrich

2003-04-01

Pseudomonas sp. strain C3211 was isolated from a temperate climate soil contaminated with creosote. This strain was able to degrade carbazole, dibenzothiophene and dibenzofuran at 10 degrees C with acetone as a co-substrate. When dibenzothiophene was degraded by strain C3211, an orange compound, which absorbed at 472 nm, accumulated in the medium. Degradation of dibenzofuran was followed by accumulation of a yellowish compound, absorbing at 462 nm. The temperature optimum of strain C3211 for degradation of dibenzothiophene and dibenzofuran was at 20 to 21 degrees C, while the maximum temperature for degradation was at 27 degrees C. Both compounds were degraded at 4 degrees C. Degradation at 10 degrees C was faster than degradation at 25 degrees C. This indicates that strain C3211 is adapted to life at low temperatures.

Evaluation of insecticidal activity of a bacterial strain, Serratia sp. EML-SE1 against diamondback moth.

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Jeong, Hyung Uk; Mun, Hye Yeon; Oh, Hyung Keun; Kim, Seung Bum; Yang, Kwang Yeol; Kim, Iksoo; Lee, Hyang Burm

2010-08-01

To identify novel bioinsecticidal agents, a bacterial strain, Serratia sp. EML-SE1, was isolated from a dead larva of the lepidopteran diamondback moth (Plutella xylostella) collected from a cabbage field in Korea. In this study, the insecticidal activity of liquid cultures in Luria-Bertani broth (LBB) and nutrient broth (NB) of a bacterial strain, Serratia sp. EML-SE1 against thirty 3rd and 4th instar larvae of the diamondback moth was investigated on a Chinese cabbage leaf housed in a round plastic cage (Ø 10 x 6 cm). 72 h after spraying the cabbage leaf with LBB and NB cultures containing the bacterial strain, the mortalities of the larvae were determined to be 91.7% and 88.3%, respectively. In addition, the insecticidal activity on potted cabbage containing 14 leaves in a growth cage (165 x 83 x 124 cm) was found to be similar to that of the plastic cage experiment. The results of this study provided valuable information on the insecticidal activity of the liquid culture of a Serratia species against the diamondback moth.

Draft genome sequence of Streptomyces sp. strain F1, a potential source for glycoside hydrolases isolated from Brazilian soil

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Ricardo Rodrigues de Melo

Full Text Available ABSTRACT Here, we show the draft genome sequence of Streptomyces sp. F1, a strain isolated from soil with great potential for secretion of hydrolytic enzymes used to deconstruct cellulosic biomass. The draft genome assembly of Streptomyces sp. strain F1 has 69 contigs with a total genome size of 8,142,296 bp and G + C 72.65%. Preliminary genome analysis identified 175 proteins as Carbohydrate-Active Enzymes, being 85 glycoside hydrolases organized in 33 distinct families. This draft genome information provides new insights on the key genes encoding hydrolytic enzymes involved in biomass deconstruction employed by soil bacteria.

Construction of new synthetic biology tools for the control of gene expression in the cyanobacterium Synechococcus sp. strain PCC 7002.

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Zess, Erin K; Begemann, Matthew B; Pfleger, Brian F

2016-02-01

Predictive control of gene expression is an essential tool for developing synthetic biological systems. The current toolbox for controlling gene expression in cyanobacteria is a barrier to more in-depth genetic analysis and manipulation. Towards relieving this bottleneck, this work describes the use of synthetic biology to construct an anhydrotetracycline-based induction system and adapt a trans-acting small RNA (sRNA) system for use in the cyanobacterium Synechococcus sp. strain PCC 7002. An anhydrotetracycline-inducible promoter was developed to maximize intrinsic strength and dynamic range. The resulting construct, PEZtet , exhibited tight repression and a maximum 32-fold induction upon addition of anhydrotetracycline. Additionally, a sRNA system based on the Escherichia coli IS10 RNA-IN/OUT regulator was adapted for use in Synechococcus sp. strain PCC 7002. This system exhibited 70% attenuation of target gene expression, providing a demonstration of the use of sRNAs for differential gene expression in cyanobacteria. These systems were combined to produce an inducible sRNA system, which demonstrated 59% attenuation of target gene expression. Lastly, the role of Hfq, a critical component of sRNA systems in E. coli, was investigated. Genetic studies showed that the Hfq homolog in Synechococcus sp. strain PCC 7002 did not impact repression by the engineered sRNA system. In summary, this work describes new synthetic biology tools that can be applied to physiological studies, metabolic engineering, or sRNA platforms in Synechococcus sp. strain PCC 7002. © 2015 Wiley Periodicals, Inc.

Draft Genome Sequence of Serratia sp. Strain DD3, Isolated from the Guts of Daphnia magna

OpenAIRE

Poehlein, Anja; Freese, Heike M.; Daniel, Rolf; Simeonova, Diliana D.

2014-01-01

We report the draft genome sequence of Serratia sp. strain DD3, a gammaproteobacterium from the family Enterobacteriaceae. It was isolated from homogenized guts of Daphnia magna. The genome size is 5,274 Mb. peerReviewed

New Genome Sequence of an Echinaceapurpurea Endophyte, Arthrobacter sp. Strain EpSL27, Able To Inhibit Human-Opportunistic Pathogens.

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Miceli, Elisangela; Presta, Luana; Maggini, Valentina; Fondi, Marco; Bosi, Emanuele; Chiellini, Carolina; Fagorzi, Camilla; Bogani, Patrizia; Di Pilato, Vincenzo; Rossolini, Gian Maria; Mengoni, Alessio; Firenzuoli, Fabio; Perrin, Elena; Fani, Renato

2017-06-22

We announce here the draft genome sequence of Arthrobacter sp. strain EpSL27, isolated from the stem and leaves of the medicinal plant Echinacea purpurea and able to inhibit human-pathogenic bacterial strains. The genome sequencing of this strain may lead to the identification of genes involved in the production of antimicrobial molecules. Copyright © 2017 Miceli et al.

Dominant colonization and inheritance of Methylobacterium sp. strain OR01 on perilla plants.

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Mizuno, Masayuki; Yurimoto, Hiroya; Iguchi, Hiroyuki; Tani, Akio; Sakai, Yasuyoshi

2013-01-01

Pink-pigmented facultative methylotrophs (PPFMs) are major inhabitants of the phyllosphere. In a preceding study, we found that perilla plants harbor a dominant population of PPFMs on their leaves and seeds, and that the closest relative of PPFMs (Methylobacterium sp. strain OR01 as representative strain) isolated from red perilla seeds was M. fujisawaense DSM5686(T). In the present study, the specific interaction between red perilla and Methylobacterium species was investigated. All the PPFMs isolated from red perilla seeds harvested in the Ohara area of Kyoto, Japan in 2009, 2010, and 2011 and the PPFMs isolated from red perilla leaves planted at four geographically different places in Japan had 16S rRNA sequences identical to that of strain OR01. Direct transmission of PPFMs from seeds to leaves and the competitiveness of strain OR01 were confirmed. This report is the first step toward understanding the species-level specificity of the interaction between perilla plants and Methylobacterium species.

Antimicrobial susceptibility of Campylobacter sp strains isolated from calves with and without diarrhea in Minas Gerais state, Brazil Susceptibilidade a antimicrobianos de amostras de Campylobacter sp isoladas de bezerros com e sem diarréia, no estado de Minas Gerais, Brasil

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Karina Leite Miranda

2007-06-01

Full Text Available The antimicrobial susceptibility of 25 Campylobacter sp strains isolated from calves with and without diarrhea - 7 C. coli, 16 C. fetus and 2 C. jejuni was studied by the disk diffusion method. Eleven antimicrobial agents were tested amikacin, ampicillin, kanamycin, chloramphenicol, erythromycin, gentamicin, neomycin, nitrofurantoin, penicillin G, tetracycline and sulfamethoxazole-trimethoprim. All Campylobacter sp strains were susceptible to amikacin, ampicillin, chloramphenicol, erythromycin, gentamicin, neomycin and nitrofurantoin. Three strains were moderately susceptible to kanamycin (2 C. coli and 1 C. fetus. All the strains were resistant to penicillin G. Two C. fetus strains were moderately susceptible to sulfamethoxazole-trimethoprim and 1 C. coli, 9 C. fetus and 2 C. jejuni strains were resistant. Two C. fetus strains were moderately susceptible to tetracycline and 3 C. coli, 2 C. fetus and 1 C. jejuni strains were resistant. Eleven strains showed multidrug resistance (2 C. coli, 8 C. fetus and 1 C. jejuni. There was no correlation between resistance of Campylobacter sp strains to antimicrobials and the occurrence of diarrhea in calves. The frequency of resistance and, most importantly, multi drug resistance found among Campylobacter sp strains isolated from calves in Minas Gerais, Brazil, were high and the patterns of resistance observed are related to the antimicrobials agents most largely used in cattle in Brazil.Foi estudado o perfil de susceptibilidade aos antimicrobianos de 25 amostras de Campylobacter sp isoladas de bezerros com e sem diarréia (7 C. coli, 16 C. fetus e 2 C. jejuni. Foram testados pelo método de difusão 11 agentes antimicrobianos: amicacina, ampicilina, canamicina, cloranfenicol, eritromicina, gentamicina, neomicina, nitrofurantoína, penicilina G, tetraciclina e sulfametoxazole-trimetoprim. Todas as amostras de Campylobacter sp foram susceptíveis a amicacina, ampicilina, cloranfenicol, eritromicina

Identification, purification and characterization of laterosporulin, a novel bacteriocin produced by Brevibacillus sp. strain GI-9.

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Pradip Kumar Singh

Full Text Available BACKGROUND: Bacteriocins are antimicrobial peptides that are produced by bacteria as a defense mechanism in complex environments. Identification and characterization of novel bacteriocins in novel strains of bacteria is one of the important fields in bacteriology. METHODOLOGY/FINDINGS: The strain GI-9 was identified as Brevibacillus sp. by 16 S rRNA gene sequence analysis. The bacteriocin produced by strain GI-9, namely, laterosporulin was purified from supernatant of the culture grown under optimal conditions using hydrophobic interaction chromatography and reverse-phase HPLC. The bacteriocin was active against a wide range of Gram-positive and Gram-negative bacteria. MALDI-TOF experiments determined the precise molecular mass of the peptide to be of 5.6 kDa and N-terminal sequencing of the thermo-stable peptide revealed low similarity with existing antimicrobial peptides. The putative open reading frame (ORF encoding laterosporulin and its surrounding genomic region was fished out from the draft genome sequence of GI-9. Sequence analysis of the putative bacteriocin gene did not show significant similarity to any reported bacteriocin producing genes in database. CONCLUSIONS: We have identified a bacteriocin producing strain GI-9, belonging to the genus Brevibacillus sp. Biochemical and genomic characterization of laterosporulin suggests it as a novel bacteriocin with broad spectrum antibacterial activity.

Identification, purification and characterization of laterosporulin, a novel bacteriocin produced by Brevibacillus sp. strain GI-9.

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Singh, Pradip Kumar; Chittpurna; Ashish; Sharma, Vikas; Patil, Prabhu B; Korpole, Suresh

2012-01-01

Bacteriocins are antimicrobial peptides that are produced by bacteria as a defense mechanism in complex environments. Identification and characterization of novel bacteriocins in novel strains of bacteria is one of the important fields in bacteriology. The strain GI-9 was identified as Brevibacillus sp. by 16 S rRNA gene sequence analysis. The bacteriocin produced by strain GI-9, namely, laterosporulin was purified from supernatant of the culture grown under optimal conditions using hydrophobic interaction chromatography and reverse-phase HPLC. The bacteriocin was active against a wide range of Gram-positive and Gram-negative bacteria. MALDI-TOF experiments determined the precise molecular mass of the peptide to be of 5.6 kDa and N-terminal sequencing of the thermo-stable peptide revealed low similarity with existing antimicrobial peptides. The putative open reading frame (ORF) encoding laterosporulin and its surrounding genomic region was fished out from the draft genome sequence of GI-9. Sequence analysis of the putative bacteriocin gene did not show significant similarity to any reported bacteriocin producing genes in database. We have identified a bacteriocin producing strain GI-9, belonging to the genus Brevibacillus sp. Biochemical and genomic characterization of laterosporulin suggests it as a novel bacteriocin with broad spectrum antibacterial activity.

Complete genome sequence of the bioleaching bacterium Leptospirillum sp. group II strain CF-1.

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Ferrer, Alonso; Bunk, Boyke; Spröer, Cathrin; Biedendieck, Rebekka; Valdés, Natalia; Jahn, Martina; Jahn, Dieter; Orellana, Omar; Levicán, Gloria

2016-03-20

We describe the complete genome sequence of Leptospirillum sp. group II strain CF-1, an acidophilic bioleaching bacterium isolated from an acid mine drainage (AMD). This work provides data to gain insights about adaptive response of Leptospirillum spp. to the extreme conditions of bioleaching environments. Copyright © 2016 Elsevier B.V. All rights reserved.

Rapid Aggregation of Biofuel-Producing Algae by the Bacterium Bacillus sp. Strain RP1137

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Powell, Ryan J.

2013-01-01

Algal biofuels represent one of the most promising means of sustainably replacing liquid fuels. However, significant challenges remain before alga-based fuels become competitive with fossil fuels. One of the largest challenges is the ability to harvest the algae in an economical and low-energy manner. In this article, we describe the isolation of a bacterial strain, Bacillus sp. strain RP1137, which can rapidly aggregate several algae that are candidates for biofuel production, including a Nannochloropsis sp. This bacterium aggregates algae in a pH-dependent and reversible manner and retains its aggregation ability after paraformaldehyde fixation, opening the possibility for reuse of the cells. The optimal ratio of bacteria to algae is described, as is the robustness of aggregation at different salinities and temperatures. Aggregation is dependent on the presence of calcium or magnesium ions. The efficiency of aggregation of Nannochloropsis oceanica IMET1 is between 70 and 95% and is comparable to that obtained by other means of harvest; however, the rate of harvest is fast, with aggregates forming in 30 s. PMID:23892750

Cyanobacterial carbon metabolism: Fluxome plasticity and oxygen dependence: Cyanobacterial Carbon Metabolism

Energy Technology Data Exchange (ETDEWEB)

Wan, Ni [Washington Univ., St. Louis, MO (United States); DeLorenzo, Drew M. [Washington Univ., St. Louis, MO (United States); He, Lian [Washington Univ., St. Louis, MO (United States); You, Le [Washington Univ., St. Louis, MO (United States); Immethun, Cheryl M. [Washington Univ., St. Louis, MO (United States); Wang, George [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Baidoo, Edward E. K. [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hollinshead, Whitney [Washington Univ., St. Louis, MO (United States); Keasling, Jay D. [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); Technical Univ. of Denmark, Lyngby (Denmark); Moon, Tae Seok [Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis Missouri 63130; Tang, Yinjie J. [Washington Univ., St. Louis, MO (United States)

2017-03-30

Synechocystis sp. strain PCC 6803 has been widely used as a photo-biorefinery chassis. Based on its genome annotation, this species contains a complete TCA cycle, an Embden-Meyerhof-Parnas pathway (EMPP), an oxidative pentose phosphate pathway (OPPP), and an Entner–Doudoroff pathway (EDP). To evaluate how Synechocystis 6803 catabolizes glucose under heterotrophic conditions, we performed ¹³C metabolic flux analysis, metabolite pool size analysis, gene knockouts, and heterologous expressions. The results revealed a cyclic mode of flux through the OPPP. Small, but non-zero, fluxes were observed through the TCA cycle and the malic shunt. Independent knockouts of 6-phosphogluconate dehydrogenase (gnd) and malic enzyme (me) corroborated these results, as neither mutant could grow under dark heterotrophic conditions. Our data also indicate that Synechocystis 6803 metabolism relies upon oxidative phosphorylation to generate ATP from NADPH under dark or insufficient light conditions. The pool sizes of intermediates in the TCA cycle, particularly acetyl-CoA, were found to be several fold lower in Synechocystis 6803 (compared to E. coli metabolite pool sizes), while its sugar phosphate intermediates were several-fold higher. Moreover, negligible flux was detected through the native, or heterologous, EDP in the wild type or Δgnd strains under heterotrophic conditions. Comparing photoautotrophic, photomixotrophic, and heterotrophic conditions, the Calvin cycle, OPPP, and EMPP in Synechocystis 6803 possess the ability to regulate their fluxes under various growth conditions (plastic), whereas its TCA cycle always maintains at low levels (rigid). This work also demonstrates how genetic profiles do not always reflect actual metabolic flux through native or heterologous pathways. Biotechnol. Bioeng. 2017;114: 1593–1602. © 2017 Wiley Periodicals, Inc.

Small proteins in cyanobacteria provide a paradigm for the functional analysis of the bacterial micro-proteome.

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Baumgartner, Desiree; Kopf, Matthias; Klähn, Stephan; Steglich, Claudia; Hess, Wolfgang R

2016-11-28

Despite their versatile functions in multimeric protein complexes, in the modification of enzymatic activities, intercellular communication or regulatory processes, proteins shorter than 80 amino acids (μ-proteins) are a systematically underestimated class of gene products in bacteria. Photosynthetic cyanobacteria provide a paradigm for small protein functions due to extensive work on the photosynthetic apparatus that led to the functional characterization of 19 small proteins of less than 50 amino acids. In analogy, previously unstudied small ORFs with similar degrees of conservation might encode small proteins of high relevance also in other functional contexts. Here we used comparative transcriptomic information available for two model cyanobacteria, Synechocystis sp. PCC 6803 and Synechocystis sp. PCC 6714 for the prediction of small ORFs. We found 293 transcriptional units containing candidate small ORFs ≤80 codons in Synechocystis sp. PCC 6803, also including the known mRNAs encoding small proteins of the photosynthetic apparatus. From these transcriptional units, 146 are shared between the two strains, 42 are shared with the higher plant Arabidopsis thaliana and 25 with E. coli. To verify the existence of the respective μ-proteins in vivo, we selected five genes as examples to which a FLAG tag sequence was added and re-introduced them into Synechocystis sp. PCC 6803. These were the previously annotated gene ssr1169, two newly defined genes norf1 and norf4, as well as nsiR6 (nitrogen stress-induced RNA 6) and hliR1(high light-inducible RNA 1) , which originally were considered non-coding. Upon activation of expression via the Cu 2+. responsive petE promoter or from the native promoters, all five proteins were detected in Western blot experiments. The distribution and conservation of these five genes as well as their regulation of expression and the physico-chemical properties of the encoded proteins underline the likely great bandwidth of small protein

Transcription of the extended hyp-operon in Nostoc sp. strain PCC 7120

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Lindblad Peter

2008-04-01

Full Text Available Abstract Background The maturation of hydrogenases into active enzymes is a complex process and e.g. a correctly assembled active site requires the involvement of at least seven proteins, encoded by hypABCDEF and a hydrogenase specific protease, encoded either by hupW or hoxW. The N2-fixing cyanobacterium Nostoc sp. strain PCC 7120 may contain both an uptake and a bidirectional hydrogenase. The present study addresses the presence and expression of hyp-genes in Nostoc sp. strain PCC 7120. Results RT-PCRs demonstrated that the six hyp-genes together with one ORF may be transcribed as a single operon. Transcriptional start points (TSPs were identified 280 bp upstream from hypF and 445 bp upstream of hypC, respectively, demonstrating the existence of several transcripts. In addition, five upstream ORFs located in between hupSL, encoding the small and large subunits of the uptake hydrogenase, and the hyp-operon, and two downstream ORFs from the hyp-genes were shown to be part of the same transcript unit. A third TSP was identified 45 bp upstream of asr0689, the first of five ORFs in this operon. The ORFs are annotated as encoding unknown proteins, with the exception of alr0692 which is identified as a NifU-like protein. Orthologues of the four ORFs asr0689-alr0692, with a highly conserved genomic arrangement positioned between hupSL, and the hyp genes are found in several other N2-fixing cyanobacteria, but are absent in non N2-fixing cyanobacteria with only the bidirectional hydrogenase. Short conserved sequences were found in six intergenic regions of the extended hyp-operon, appearing between 11 and 79 times in the genome. Conclusion This study demonstrated that five ORFs upstream of the hyp-gene cluster are co-transcribed with the hyp-genes, and identified three TSPs in the extended hyp-gene cluster in Nostoc sp. strain PCC 7120. This may indicate a function related to the assembly of a functional uptake hydrogenase, hypothetically in the

Comparative evaluation of Amblyomma ovale ticks infected and noninfected by Rickettsia sp. strain Atlantic rainforest, the agent of an emerging rickettsiosis in Brazil.

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Krawczak, Felipe S; Agostinho, Washington C; Polo, Gina; Moraes-Filho, Jonas; Labruna, Marcelo B

2016-04-01

In 2010, a novel spotted fever group rickettsiosis was reported in the Atlantic rainforest coast of Brazil. The etiological agent was identified as Rickettsia sp. strain Atlantic rainforest, and the tick Amblyomma ovale was incriminated as the presumed vector. The present study evaluated under laboratory conditions four colonies of A. ovale: two started from engorged females that were naturally infected by Rickettsia sp. strain Atlantic rainforest (designated as infected groups); the two others started from noninfected females (designated as control groups). All colonies were reared in parallel from F0 engorged female to F2 unfed nymphs. Tick-naïve vesper mice (Calomys callosus) or domestic rabbits were used for feeding of each tick stage. Rickettsia sp. strain Atlantic rainforest was preserved by transstadial maintenance and transovarial transmission in A. ovale ticks for at least 2 generations (from F0 females to F2 nymphs), because nearly 100% of the tested larvae, nymphs, and adults from the infected groups were shown by PCR to contain rickettsial DNA. All vesper mice and rabbits infested by larvae and nymphs, and 50% of the rabbits infested by adults from the infected groups seroconverted, indicating that these tick stages were vector competent for Rickettsia sp. strain Atlantic rainforest. Expressive differences in mortality rates and reproductive performance were observed between engorged females from the infected and control groups, as indicated by 75.0% and 97.1% oviposition success, respectively, and significantly lower egg mass weight, conversion efficiency index, and percentage of egg hatching for the infected groups. Our results indicate that A. ovale can act as a natural reservoir for Rickettsia sp. strain Atlantic rainforest. However, due to deleterious effect caused by this rickettsial agent on engorged females, amplifier vertebrate hosts might be necessary for persistent perpetuation of Rickettsia sp. strain Atlantic rainforest in A. ovale under

Fresh Water Cyanobacteria Geitlerinema sp. CCC728 and Arthrospira sp. CCC729 as an Anticancer Drug Resource

OpenAIRE

Srivastava, Akanksha; Tiwari, Ratnakar; Srivastava, Vikas; Singh, Tej Bali; Asthana, Ravi Kumar

2015-01-01

An increasing number of cancer patients worldwide, especially in third world countries, have raised concern to explore natural drug resources, such as the less explored fresh water filamentous cyanobacteria. Six strains of cyanobacteria (Phormidium sp. CCC727, Geitlerinema sp. CCC728, Arthrospira sp. CCC729, Phormidium sp. CCC731, Phormidium sp. CCC730, and Leptolyngbya sp. CCC732) were isolated (paddy fields and ponds in the Banaras Hindu University, campus) and five strains screened for ant...

Novel Acetone Metabolism in a Propane-Utilizing Bacterium, Gordonia sp. Strain TY-5▿

Science.gov (United States)

Kotani, Tetsuya; Yurimoto, Hiroya; Kato, Nobuo; Sakai, Yasuyoshi

2007-01-01

In the propane-utilizing bacterium Gordonia sp. strain TY-5, propane was shown to be oxidized to 2-propanol and then further oxidized to acetone. In this study, the subsequent metabolism of acetone was studied. Acetone-induced proteins were found in extracts of cells induced by acetone, and a gene cluster designated acmAB was cloned on the basis of the N-terminal amino acid sequences of acetone-induced proteins. The acmA and acmB genes encode a Baeyer-Villiger monooxygenase (BVMO) and esterase, respectively. The BVMO encoded by acmA was purified from acetone-induced cells of Gordonia sp. strain TY-5 and characterized. The BVMO exhibited NADPH-dependent oxidation activity for linear ketones (C3 to C10) and cyclic ketones (C4 to C8). Escherichia coli expressing the acmA gene oxidized acetone to methyl acetate, and E. coli expressing the acmB gene hydrolyzed methyl acetate. Northern blot analyses revealed that polycistronic transcription of the acmAB gene cluster was induced by propane, 2-propanol, and acetone. These results indicate that the acmAB gene products play an important role in the metabolism of acetone derived from propane oxidation and clarify the propane metabolism pathway of strain TY-5 (propane → 2-propanol → acetone → methyl acetate → acetic acid + methanol). This paper provides the first evidence for BVMO-dependent acetone metabolism. PMID:17071761

Engineering Synechocystis PCC6803 for hydrogen production: influence on the tolerance to oxidative and sugar stresses.

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Marcia Ortega-Ramos

Full Text Available In the prospect of engineering cyanobacteria for the biological photoproduction of hydrogen, we have studied the hydrogen production machine in the model unicellular strain Synechocystis PCC6803 through gene deletion, and overexpression (constitutive or controlled by the growth temperature. We demonstrate that the hydrogenase-encoding hoxEFUYH operon is dispensable to standard photoautotrophic growth in absence of stress, and it operates in cell defense against oxidative (H₂O₂ and sugar (glucose and glycerol stresses. Furthermore, we showed that the simultaneous over-production of the proteins HoxEFUYH and HypABCDE (assembly of hydrogenase, combined to an increase in nickel availability, led to an approximately 20-fold increase in the level of active hydrogenase. These novel results and mutants have major implications for those interested in hydrogenase, hydrogen production and redox metabolism, and their connections with environmental conditions.

Genome Sequence of Thermotoga sp. Strain RQ2, a Hyperthermophilic Bacterium Isolated from a Geothermally Heated Region of the Seafloor near Ribeira Quente, the Azores

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Swithers, Kristen S.; DiPippo, Jonathan L.; Bruce, David C.; Detter, Christopher; Tapia, Roxanne; Han, Shunsheng; Saunders, Elizabeth; Goodwin, Lynne A.; Han, James; Woyke, Tanja; Pitluck, Sam; Pennacchio, Len; Nolan, Matthew; Mikhailova, Natalia; Lykidis, Athanasios; Land, Miriam L.; Brettin, Thomas; Stetter, Karl O.; Nelson, Karen E.; Gogarten, J. Peter; Noll, Kenneth M.

2011-01-01

Thermotoga sp. strain RQ2 is probably a strain of Thermotoga maritima. Its complete genome sequence allows for an examination of the extent and consequences of gene flow within Thermotoga species and strains. Thermotoga sp. RQ2 differs from T. maritima in its genes involved in myo-inositol metabolism. Its genome also encodes an apparent fructose phosphotransferase system (PTS) sugar transporter. This operon is also found in Thermotoga naphthophila strain RKU-10 but no other Thermotogales. These are the first reported PTS transporters in the Thermotogales. PMID:21952543

Draft genome sequence of the arsenite-oxidizing strain Aliihoeflea sp. 2WW, isolated from arsenic-contaminated groundwater

NARCIS (Netherlands)

Cavalca, L.; Corsini, A.; Andreoni, V.; Muyzer, G.

2013-01-01

Here, we report the draft genome sequence of the arsenite-oxidizing bacterium Aliihoeflea sp. strain 2WW, which consists of a 4.15-Mb chromosome and contains different genes that are involved in arsenic transformations.

Metabolic Engineering of the Actinomycete Amycolatopsis sp. Strain ATCC 39116 towards Enhanced Production of Natural Vanillin

OpenAIRE

Fleige, Christian; Meyer, Florian; Steinbüchel, Alexander

2016-01-01

The Gram-positive bacterium Amycolatopsis sp. ATCC 39116 is used for the fermentative production of natural vanillin from ferulic acid on an industrial scale. The strain is known for its outstanding tolerance to this toxic product. In order to improve the productivity of the fermentation process, the strain's metabolism was engineered for higher final concentrations and molar yields. Degradation of vanillin could be decreased by more than 90% through deletion of the vdh gene, which codes for ...

Transcriptional analysis of the multicopy hao gene coding for hydroxylamine oxidoreductase in Nitrosomonas sp. strain ENI-11.

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Hirota, Ryuichi; Kuroda, Akio; Ikeda, Tsukasa; Takiguchi, Noboru; Ohtake, Hisao; Kato, Junichi

2006-08-01

The nitrifying bacterium Nitrosomonas sp. strain ENI-11 has three copies of the gene encoding hydroxylamine oxidoreductase (hao(1), hao(2), and hao(3)) on its genome. Broad-host-range reporter plasmids containing transcriptional fusion genes between hao copies and lacZ were constructed to analyze the expression of each hydroxylamine oxidoreductase gene (hao) copy individually and quantitatively. beta-Galactosidase assays of ENI-11 harboring reporter plasmids revealed that all hao copies were transcribed in the wild-type strain. Promoter analysis of hao copies revealed that transcription of hao(3) was highest among the hao copies. Expression levels of hao(1) and hao(2) were 40% and 62% of that of hao(3) respectively. Transcription of hao(1) was negatively regulated, whereas a portion of hao(3) transcription was read through transcription from the rpsT promoter. When energy-depleted cells were incubated in the growth medium, only hao(3) expression increased. This result suggests that it is hao(3) that is responsible for recovery from energy-depleted conditions in Nitrosomonas sp. strain ENI-11.

Whole Genome Sequence Analysis of an Alachlor and Endosulfan Degrading Micrococcus sp. strain 2385 Isolated from Ochlockonee River, Florida.

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Pathak, Ashish; Chauhan, Ashvini; Ewida, Ayman Y I; Stothard, Paul

2016-01-01

We recently isolated Micrococcus sp. strain 2385 from Ochlockonee River, Florida and demonstrated potent biodegradative activity against two commonly used pesticides- alachlor [(2-chloro-2`,6`-diethylphenyl-N (methoxymethyl)acetanilide)] and endosulfan [(6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9methano-2,3,4-benzo(e)di-oxathiepin-3-oxide], respectively. To further identify the repertoire of metabolic functions possessed by strain 2385, a draft genome sequence was obtained, assembled, annotated and analyzed. The genome sequence of Micrococcus sp. strain 2385 consisted of 1,460,461,440 bases which assembled into 175 contigs with an N50 contig length of 50,109 bases and a coverage of 600x. The genome size of this strain was estimated at 2,431,226 base pairs with a G+C content of 72.8 and a total number of 2,268 putative genes. RAST annotated a total of 340 subsystems in the genome of strain 2385 along with the presence of 2,177 coding sequences. A genome wide survey indicated that that strain 2385 harbors a plethora of genes to degrade other pollutants including caprolactam, PAHs (such as naphthalene), styrene, toluene and several chloroaromatic compounds.

Identification of three homologous latex-clearing protein (lcp) genes from the genome of Streptomyces sp. strain CFMR 7.

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Nanthini, Jayaram; Ong, Su Yean; Sudesh, Kumar

2017-09-10

Rubber materials have greatly contributed to human civilization. However, being a polymeric material does not decompose easily, it has caused huge environmental problems. On the other hand, only few bacteria are known to degrade rubber, with studies pertaining them being intensively focusing on the mechanism involved in microbial rubber degradation. The Streptomyces sp. strain CFMR 7, which was previously confirmed to possess rubber-degrading ability, was subjected to whole genome sequencing using the single molecule sequencing technology of the PacBio® RS II system. The genome was further analyzed and compared with previously reported rubber-degrading bacteria in order to identify the potential genes involved in rubber degradation. This led to the interesting discovery of three homologues of latex-clearing protein (Lcp) on the chromosome of this strain, which are probably responsible for rubber degrading activities. Genes encoding oxidoreductase α-subunit (oxiA) and oxidoreductase β-subunit (oxiB) were also found downstream of two lcp genes which are located adjacent to each other. In silico analysis reveals genes that have been identified to be involved in the microbial degradation of rubber in the Streptomyces sp. strain CFMR 7. This is the first whole genome sequence of a clear-zone-forming natural rubber- degrading Streptomyces sp., which harbours three Lcp homologous genes with the presence of oxiA and oxiB genes compared to the previously reported Gordonia polyisoprenivorans strain VH2 (with two Lcp homologous genes) and Nocardia nova SH22a (with only one Lcp gene). Copyright © 2017 Elsevier B.V. All rights reserved.

Characterization of the rcsA Gene from Pantoea sp. Strain PPE7 and Its Influence on Extracellular Polysaccharide Production and Virulence on Pleurotus eryngii

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Min Keun Kim

2017-06-01

Full Text Available RcsA is a positive activator of extracellular polysaccharide (EPS synthesis in the Enterobacteriaceae. The rcsA gene of the soft rot pathogen Pantoea sp. strain PPE7 in Pleurotus eryngii was cloned by PCR amplification, and its role in EPS synthesis and virulence was investigated. The RcsA protein contains 3 highly conserved domains, and the C-terminal end of the open reading frame shared significant amino acid homology to the helix-turn-helix DNA binding motif of bacterial activator proteins. The inactivation of rcsA by insertional mutagenesis created mutants that had decreased production of EPS compared to the wild-type strain and abolished the virulence of Pantoea sp. strain PPE7 in P. eryngii. The Pantoea sp. strain PPE7 rcsA gene was shown to strongly affect the formation of the disease symptoms of a mushroom pathogen and to act as the virulence factor to cause soft rot disease in P. eryngii.

Rhodotorula rosulata sp. nov., Rhodotorula silvestris sp. nov. and Rhodotorula straminea sp. nov., novel myo-inositol-assimilating yeast species in the Microbotryomycetes.

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Golubev, Wladyslav I; Scorzetti, Gloria

2010-10-01

Three novel species are described as Rhodotorula rosulata sp. nov. (type strain VKM Y-2962(T) =CBS 10977(T)), Rhodotorula silvestris sp. nov. (type strain VKM Y-2971(T) =CBS 11420(T)) and Rhodotorula straminea sp. nov. (type strain VKM Y-2964(T) =CBS 10976(T)) based on the study of eight isolates from needle litter. The new species, phylogenetically located within the Microbotryomycetes, are related to glucuronate-assimilating species of the genus Rhodotorula. Sequencing of the D1/D2 domains of the LSU rDNA gene and the internal transcribed spacer (ITS) region, as well as physiological characterization, revealed their distinct taxonomic positions.

Auto-aggregation properties of a novel aerobic denitrifier Enterobacter sp. strain FL.

Science.gov (United States)

Wang, Xia; An, Qiang; Zhao, Bin; Guo, Jin Song; Huang, Yuan Sheng; Tian, Meng

2018-02-01

Enterobacter sp. strain FL was newly isolated from activated sludge and exhibited significant capability of auto-aggregation as well as aerobic denitrification. The removal efficiencies of NO 3 - -N, total nitrogen (TN), and TOC by strain FL in batch culture reached 94.6, 63.9, and 72.5% in 24 h, respectively. The production of N 2 O and N 2 in the presence of oxygen demonstrated the occurrence of aerobic denitrification. The auto-aggregation index of strain FL reached 54.3%, suggesting a high tendency that the cells would agglomerate into aggregates. The production of extracellular polymeric substances (EPSs), which were mainly composed of proteins followed by polysaccharides, was considered to be related to the cell aggregation according to Fourier transform infrared (FT-IR) and confocal laser scanning microscopy (CLSM). The proteins in EPS were evenly and tightly combined to cells and altered the protein secondary structures of cell surface from random coils to β-sheets and three-turn helices. The alteration of protein secondary structures of cell surface caused by the proteins in EPS might play a dominant role in the auto-aggregation of strain FL. To further assess the feasibility of strain FL for synthetic wastewater treatment, a sequencing batch reactor (SBR), solely inoculated with strain FL, was conducted. During the 16 running cycles, the removal efficiency of NO 3 - -N was 90.2-99.7% and the auto-aggregation index was stabilized at 35.0-41.5%. The EPS promoted the biomass of strain FL to aggregate in the SBR.

Enhanced degradation of 2-nitrotoluene by immobilized cells of Micrococcus sp. strain SMN-1.

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Mulla, Sikandar I; Talwar, Manjunatha P; Bagewadi, Zabin K; Hoskeri, Robertcyril S; Ninnekar, Harichandra Z

2013-02-01

Nitrotoluenes are the toxic pollutants of the environment because of their large scale use in the production of explosives. Biodegradation of such chemicals by microorganisms may provide an effective method for their detoxification. We have studied the degradation of 2-nitrotoluene by cells of Micrococcus sp. strain SMN-1 immobilized in various matrices such as polyurethane foam (PUF), sodium alginate (SA), sodium alginate-polyvinyl alcohol (SA-PVA), agar and polyacrylamide. The rate of degradation of 15 and 30 mM 2-nitrotoluene by freely suspended cells and immobilized cells in batches and fed-batch with shaken cultures were compared. The PUF-immobilized cells achieved higher degradation of 15 and 30 mM 2-nitrotoluene than freely suspended cells and the cells immobilized in SA-PVA, polyacrylamide, SA and agar. The PUF-immobilized cells could be reused more than 24 cycles without loosing their degradation capacity and showed more tolerance to pH and temperature changes than freely suspended cells. These results revealed the enhanced rate of degradation of 2-nitrotoluene by PUF-immobilized cells of Micrococcus sp. strain SMN-1. Copyright © 2012 Elsevier Ltd. All rights reserved.

Draft genome sequence of Streptomyces sp. strain F1, a potential source for glycoside hydrolases isolated from Brazilian soil.

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Melo, Ricardo Rodrigues de; Persinoti, Gabriela Felix; Paixão, Douglas Antonio Alvaredo; Squina, Fábio Márcio; Ruller, Roberto; Sato, Helia Harumi

Here, we show the draft genome sequence of Streptomyces sp. F1, a strain isolated from soil with great potential for secretion of hydrolytic enzymes used to deconstruct cellulosic biomass. The draft genome assembly of Streptomyces sp. strain F1 has 69 contigs with a total genome size of 8,142,296bp and G+C 72.65%. Preliminary genome analysis identified 175 proteins as Carbohydrate-Active Enzymes, being 85 glycoside hydrolases organized in 33 distinct families. This draft genome information provides new insights on the key genes encoding hydrolytic enzymes involved in biomass deconstruction employed by soil bacteria. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Legionella clemsonensis sp. nov.: a green fluorescing Legionella strain from a patient with pneumonia.

Science.gov (United States)

Palmer, Allison; Painter, Joseph; Hassler, Hayley; Richards, Vincent P; Bruce, Terri; Morrison, Shatavia; Brown, Ellen; Kozak-Muiznieks, Natalia A; Lucas, Claressa; McNealy, Tamara L

2016-10-01

A novel Legionella species was identified based on sequencing, cellular fatty acid analysis, biochemical reactions, and biofilm characterization. Strain D5610 was originally isolated from the bronchial wash of a patient in Ohio, USA. The bacteria were gram-negative, rod-shaped, and exhibited green fluorescence under long wave UV light. Phylogenetic analysis and fatty acid composition revealed a distinct separation within the genus. The strain grows between 26-45°C and forms biofilms equivalent to L. pneumophila Philadelphia 1. These characteristics suggest that this isolate is a novel Legionella species, for which the name Legionella clemsonensis sp nov. is proposed. © 2016 The Societies and John Wiley & Sons Australia, Ltd.

[Isolation, identification and characterization of a diethylstilbestrol-degrading bacterial strain Serratia sp].

Science.gov (United States)

Xu, Ran-Fang; Sun, Min-Xia; Liu, Juan; Wang, Hong; Li, Xin; Zhu, Xue-Zhu; Ling, Wan-Ting

2014-08-01

Utilizing the diethylstilbestrol (DES)-degrading bacteria to biodegrade DES is a most reliable technique for cleanup of DES pollutants from the environment. However, little information is available heretofore on the isolation of DES-degrading bacteria and their DES removal performance in the environment. A novel bacterium capable of degrading DES was isolated from the activated sludge of a wastewater treatment plant. According to its morphology, physiochemical characteristics, and 16S rDNA sequence analysis, this strain was identified as Serratia sp.. The strain was an aerobic bacterium, and it could degrade 68.3% of DES (50 mg x L(-1)) after culturing for 7 days at 30 degrees C, 150 r x min(-1) in shaking flasks. The optimal conditions for DES biodegradation by the obtained strain were 30 degrees C, 40-60 mg x L(-1) DES, pH 7.0, 5% of inoculation volume, 0 g x L(-1) of added NaCl, and 10 mL of liquid medium volume in 100 mL flask.

Complete genome sequence of cyanobacterium Nostoc sp. NIES-3756, a potentially useful strain for phytochrome-based bioengineering.

Science.gov (United States)

Hirose, Yuu; Fujisawa, Takatomo; Ohtsubo, Yoshiyuki; Katayama, Mitsunori; Misawa, Naomi; Wakazuki, Sachiko; Shimura, Yohei; Nakamura, Yasukazu; Kawachi, Masanobu; Yoshikawa, Hirofumi; Eki, Toshihiko; Kanesaki, Yu

2016-01-20

To explore the diverse photoreceptors of cyanobacteria, we isolated Nostoc sp. strain NIES-3756 from soil at Mimomi-Park, Chiba, Japan, and determined its complete genome sequence. The Genome consists of one chromosome and two plasmids (total 6,987,571 bp containing no gaps). The NIES-3756 strain carries 7 phytochrome and 12 cyanobacteriochrome genes, which will facilitate the studies of phytochrome-based bioengineering. Copyright © 2015. Published by Elsevier B.V.

Mechanism of Biosorption of Nickel Ions from Polluted Effluent by Bacillus sp. Strain MGL-75

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Salman Ahmadi Asbchin

2013-08-01

Full Text Available The aim of this work was to investigate Bacillus sp. strain MGL-75 as biosorbent, for the fixation of Ni ion in batch reactor. Pollution of the environment by toxic metals is a major environmental concern. In a first step, biosorption kinetics and isotherms have been performed at pH 7. The equilibrium time was about 5 min and the adsorption equilibrium data were well described by the Langmuir`s equation. The point of zero net proton charge (PZNPC was found close to pH 5.7. Using the single extrapolation method, three kinds of acidic functional groups with three intrinsic pka were determined at 4.4, 6.9 and 11.2. The maximum capacity has been extrapolated to 0/52 mmol/g. Finally the effect of autoclave, 2, 4 Dinitrophenol (DNF and Na-Azid (NaN3, and the effect of pH values, were studied. These results indicated that the Bacillus sp. strain MGL-75 is an excellent candidate for use in reactor to remove Nickel ions from polluted aqueous effluents.

In-planta Sporulation Capacity Enhances Infectivity and Rhizospheric Competitiveness of Frankia Strains.

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Cotin-Galvan, Laetitia; Pozzi, Adrien C; Schwob, Guillaume; Fournier, Pascale; Fernandez, Maria P; Herrera-Belaroussi, Aude

2016-01-01

Frankia Sp+ strains maintain their ability to sporulate in symbiosis with actinorhizal plants, producing abundant sporangia inside host plant cells, in contrast to Sp- strains, which are unable to perform in-planta sporulation. We herein examined the role of in-planta sporulation in Frankia infectivity and competitiveness for root infection. Fifteen strains belonging to different Sp+ and Sp- phylogenetic lineages were inoculated on seedlings of Alnus glutinosa (Ag) and A. incana (Ai). Strain competitiveness was investigated by performing Sp-/Sp+ co-inoculations. Plant inoculations were standardized using crushed nodules obtained under laboratory-controlled conditions (same plant species, age, and environmental factors). Specific oligonucleotide primers were developed to identify Frankia Sp+ and/or Sp- strains in the resulting nodules. Single inoculation experiments showed that (i) infectivity by Sp+ strains was significantly greater than that by Sp- strains, (ii) genetically divergent Sp+ strains exhibited different infective abilities, and (iii) Sp+ and Sp- strains showed different host preferences according to the origin (host species) of the inocula. Co-inoculations of Sp+ and Sp- strains revealed the greater competitiveness of Sp+ strains (98.3 to 100% of Sp+ nodules, with up to 15.6% nodules containing both Sp+ and Sp- strains). The results of the present study highlight differences in Sp+/Sp- strain ecological behaviors and provide new insights to strengthen the obligate symbiont hypothesis for Sp+ strains.

Rhodotorula bloemfonteinensis sp. nov., Rhodotorula eucalyptica sp. nov., Rhodotorula orientis sp. nov. and Rhodotorula pini sp. nov., yeasts isolated from monoterpene-rich environments.

Science.gov (United States)

Pohl, Carolina H; Smit, Martha S; Albertyn, Jacobus

2011-09-01

Recent rDNA sequencing of 25 isolates from a previous study, during which limonene-utilizing yeasts were isolated from monoterpene-rich environments by using 1,4-disubstituted cyclohexanes as sole carbon sources, led to the identification of four hitherto unknown Rhodotorula species. Analyses of the 26S rDNA D1/D2 region as well as the internal transcribed spacer (ITS) domain indicated that two isolates (CBS 8499(T) and CBS 10736) were identical and were closely related to Rhodotorula cycloclastica, a previously described limonene-utilizing yeast. These novel isolates differed from known yeast species and could be distinguished from R. cycloclastica by standard physiological tests. The other three isolates represent three novel Rhodotorula species, closely related to Sporobolomyces magnisporus. These three species could also be distinguished from other Rhodotorula species by standard physiological tests. Based on these results, we suggest that the new isolates represent novel species, for which the names Rhodotorula eucalyptica sp. nov. (type strain CBS 8499(T)  = NRRL Y-48408(T)), Rhodotorula pini sp. nov. (type strain CBS 10735(T)  = NRRL Y-48410(T)), Rhodotorula bloemfonteinensis sp. nov. (type strain CBS 8598(T)  = NRRL Y-48407(T)) and Rhodotorula orientis sp. nov. (type strain CBS 8594(T)  = NRRL Y-48719(T)) are proposed. R. eucalyptica and R. pini can also utilize limonene.

Methane and Trichloroethylene Oxidation by an Estuarine Methanotroph, Methylobacter sp. Strain BB5.1

OpenAIRE

Smith, Kelly S.; Costello, Andria M.; Lidstrom, Mary E.

1998-01-01

An estuarine methanotroph was isolated from sediment enrichments and designated Methylobacter sp. strain BB5.1. In cells grown on medium with added copper, oxidation of methane and trichloroethylene occurred with similar Ks values, but the Vmax for trichloroethylene oxidation was only 0.1% of the methane oxidation Vmax. Cells grown on low-copper medium did not oxidize trichloroethylene and showed a variable rate of methane oxidation.

Biotransformation of cholesterol and 16,17-alpha epoxypregnenolone by novel Cladosporium sp. strain IS547.

Science.gov (United States)

Pang, Cuiping; Cao, Yuting; Zhu, Xiangdong

2017-01-01

Nowadays, there are a few steroid drugs or intermediates that have been obtained via the transformation of microorganisms, and many strains of transformed steroids have not been found yet. Therefore, it is very significant to screen for the strains that have the abilities to transform steroids to produce valuable products. This study has focused on the screen and identification of strains, the structural identification of converted products, and the optimization of transformation conditions, as well as the establishment of transformation systems. A soil microbiota was screened for strain involved in the biotransformation of steroids. A new isolate IS547 is capable of converting a variety of steroids (such as cholesterol, ergosterol, hydrocortisone, progesterone, pregnenolone, and 16,17-alpha-epoxypregnenolone). Based on the 18S rDNA gene sequence comparison, the isolate IS547 has been demonstrated to be very closely related to Cladosporium sp. genus. Present paper is the first report regarding the microbial transformation by Cladosporium sp. to produce active intermediates, which include 7-hydroxy cholesterol, 20-droxyl-16α,17α-epoxypregna-4-dien-3-one, 7-ketocholesterol, and 7-droxyl-16α,17α-epoxypregna-4-dien-3,20-dione. Under the optimum conditions, the yields of product 3 and product 4 were 20.58 and 17.42%, respectively, higher than that prior to the optimization. The transformation rate increased significantly under the optimum fermentation conditions. This study describes an efficient, rapid, and inexpensive biotransformation system for the production of active pharmaceutical intermediates. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Screening of bacterial strains for pectinolytic activity: characterization of the polygalacturonase produced by Bacillus sp

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Soares Márcia M.C.N.

1999-01-01

Full Text Available One hundred sixty eight bacterial strains, isolated from soil and samples of vegetable in decomposition, were screened for the use of citrus pectin as the sole carbon source. 102 were positive for pectinase depolymerization in assay plates as evidenced by clear hydrolization halos. Among them, 30% presented considerable pectinolytic activity. The cultivation of these strains by submerged and semi-solid fermentation for polygalacturonase production indicated that five strains of Bacillus sp produced high quantities of the enzyme. The physico-chemical characteristics, such as optimum pH of 6.0 - 7.0, optimum temperatures between 45oC and 55oC, stability at temperatures above 40oC and in neutral and alkaline pH, were determined.

Enhanced production of dimethyl phthalate-degrading strain Bacillus sp. QD14 by optimizing fermentation medium

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Jixian Mo

2015-05-01

Conclusion: In this work, the key factors affected by the fermentation of DMP-degrading strain Bacillus sp. QD14 were optimized by PBD, SAM and BBD (RSM; the yield was increased by 57,11% in the conditions in our study. We propose that the conditions optimized in the study can be applied to the fermentation for commercialization production.

Effect of aflatoxin B1 on growth and enzymatic activity of a native strain of Bacillus sp

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Alex Sáez Vega

2004-01-01

Full Text Available The effect of different aflatoxin B1 (AFAB1 concentrations on alkaline protease growth and enzymatic activity was evaluated; a native strain of alkalophilic Bacillus sp cultivated in CSL (Corn Steep Liquor was used. It was found that the effect of AFAB1 on the strain inhibited its growth and enzymatic activity to 1 ppm, showing that the strain is highly sensible to AFAB1, meaning that medium obtained f rom Colombian corn contaminated with this mycotoxin cannot be easily used. Concentrations less than 0.1 ppm did not affect growth and enzymatic activity. Key words: Bacillus, aflatoxin, alkaline proteases.

Effects of nitrogen and carbon sources on the production of inulinase from strain Bacillus sp. SG113

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Gavrailov, Simeon; Ivanova, Viara

2016-03-01

The effects of the carbon and nitrogen substrates on the growth of Bacillus sp. SG113 strain were studied. The use of organic nitrogen sources (peptone, beef extract, yeast extract, casein) leads to rapid cellular growth and the best results for the Bacillus strain were obtained with casein hydrolysate. From the inorganic nitrogen sources studied, the (NH4) 2SO4 proved to be the best nitrogen source. Casein hydrolysate and (NH4) 2SO4 stimulated the invertase synthesis. In the presence of Jerusalem artichoke, onion and garlic extracts as carbon sources the strain synthesized from 6 to 10 times more inulinase.

The heterocyclic ring fission and dehydroxylation of catechins and related compounds by Eubacterium sp. strain SDG-2, a human intestinal bacterium.

Science.gov (United States)

Wang, L Q; Meselhy, M R; Li, Y; Nakamura, N; Min, B S; Qin, G W; Hattori, M

2001-12-01

A human intestinal bacterium, Eubacterium (E.) sp. strain SDG-2, was tested for its ability to metabolize various (3R)- and (3S)-flavan-3-ols and their 3-O-gallates. This bacterium cleaved the C-ring of (3R)- and (3S)-flavan-3-ols to give 1,3-diphenylpropan-2-ol derivatives, but not their 3-O-gallates. Furthermore, E. sp. strain SDG-2 had the ability of p-dehydroxylation in the B-ring of (3R)-flavan-3-ols, such as (-)-catechin, (-)-epicatechin, (-)-gallocatechin and (-)-epigallocatechin, but not of (3S)-flavan-3-ols, such as (+)-catechin and (+)-epicatechin.

Molecular characterization of genes of Pseudomonas sp. strain HR199 involved in bioconversion of vanillin to protocatechuate.

Science.gov (United States)

Priefert, H; Rabenhorst, J; Steinbüchel, A

1997-01-01

The gene loci vdh, vanA, and vanB, which are involved in the bioconversion of vanillin to protocatechuate by Pseudomonas sp. strain HR199 (DSM 7063), were identified as the structural genes of a novel vanillin dehydrogenase (vdh) and the two subunits of a vanillate demethylase (vanA and vanB), respectively. These genes were localized on an EcoRI fragment (E230), which was cloned from a Pseudomonas sp. strain HR199 genomic library in the cosmid pVK100. The vdh gene was identified on a subfragment (HE35) of E230, and the vanA and vanB genes were localized on a different subfragment (H110) of E230. The nucleotide sequences of fragment HE35 and part of fragment H110 were determined, revealing open reading frames of 1062, 951, and 1446 bp, representing vanA, vanB, and vdh, respectively. The vdh gene was organized in one operon together with a fourth open reading frame (ORF2), of 735 bp, which was located upstream of vdh. The deduced amino acid sequences of vanA and vanB exhibited 78.8 and 62.1% amino acid identity, respectively, to the corresponding gene products from Pseudomonas sp. strain ATCC 19151 (F. Brunel and J. Davison, J. Bacteriol. 170:4924-4930, 1988). The deduced amino acid sequence of the vdh gene exhibited up to 35.3% amino acid identity to aldehyde dehydrogenases from different sources. The deduced amino acid sequence of ORF2 exhibited up to 28.4% amino acid identity to those of enoyl coenzyme A hydratases. Escherichia coli strains harboring fragment E230 cloned in pBluescript SK- converted vanillin to protocatechuate via vanillate, indicating the functional expression of vdh, vanA, and vanB in E. coli. High expression of vdh in E. coli was achieved with HE35 cloned in pBluescript SK-. The resulting recombinant strains converted vanillin to vanillate at a rate of up to 0.3 micromol per min per ml of culture. Transfer of vanA, vanB, and vdh to Alcaligenes eutrophus and to different Pseudomonas strains, which were unable to utilize vanillin or vanillate as

Use of combined microscopic and spectroscopic techniques to reveal interactions between uranium and Microbacterium sp. A9, a strain isolated from the Chernobyl exclusion zone

Energy Technology Data Exchange (ETDEWEB)

Theodorakopoulos, Nicolas [CEA, DSV, IBEB, SBVME, LIPM, F-13108 Saint-Paul-lez-Durance (France); CNRS, UMR 7265, F-13108 Saint-Paul-lez-Durance (France); Université d' Aix-Marseille, F-13108 Saint-Paul-lez-Durance (France); IRSN/PRP-ENV/SERIS/L2BT, bat 183, B.P. 3, F-13115 Saint Paul-lez-Durance (France); Chapon, Virginie [CEA, DSV, IBEB, SBVME, LIPM, F-13108 Saint-Paul-lez-Durance (France); CNRS, UMR 7265, F-13108 Saint-Paul-lez-Durance (France); Université d' Aix-Marseille, F-13108 Saint-Paul-lez-Durance (France); Coppin, Fréderic; Floriani, Magali [IRSN/PRP-ENV/SERIS/L2BT, bat 183, B.P. 3, F-13115 Saint Paul-lez-Durance (France); Vercouter, Thomas [CEA, DEN, DANS, DPC SEARS, LANIE, F-91191 Gif-Sur-Yvette Cedex (France); Sergeant, Claire [Univ Bordeaux, CENBG, UMR5797, F-33170 Gradignan (France); CNRS, IN2P3, CENBG, UMR5797, F-33170 Gradignan (France); Camilleri, Virginie [IRSN/PRP-ENV/SERIS/L2BT, bat 183, B.P. 3, F-13115 Saint Paul-lez-Durance (France); Berthomieu, Catherine [CEA, DSV, IBEB, SBVME, LIPM, F-13108 Saint-Paul-lez-Durance (France); CNRS, UMR 7265, F-13108 Saint-Paul-lez-Durance (France); Université d' Aix-Marseille, F-13108 Saint-Paul-lez-Durance (France); Février, Laureline, E-mail: laureline.fevrier@irsn.fr [IRSN/PRP-ENV/SERIS/L2BT, bat 183, B.P. 3, F-13115 Saint Paul-lez-Durance (France)

2015-03-21

Highlights: • Microbacterium sp. A9 develops various detoxification mechanisms. • Microbacterium sp. A9 promotes metal efflux from the cells. • Microbacterium sp. A9 releases phosphate to prevent uranium entrance in the cells. • Microbacterium sp. A9 stores U intracellularly as autunite. - Abstract: Although uranium (U) is naturally found in the environment, soil remediation programs will become increasingly important in light of certain human activities. This work aimed to identify U(VI) detoxification mechanisms employed by a bacteria strain isolated from a Chernobyl soil sample, and to distinguish its active from passive mechanisms of interaction. The ability of the Microbacterium sp. A9 strain to remove U(VI) from aqueous solutions at 4 °C and 25 °C was evaluated, as well as its survival capacity upon U(VI) exposure. The subcellular localisation of U was determined by TEM/EDX microscopy, while functional groups involved in the interaction with U were further evaluated by FTIR; finally, the speciation of U was analysed by TRLFS. We have revealed, for the first time, an active mechanism promoting metal efflux from the cells, during the early steps following U(VI) exposure at 25 °C. The Microbacterium sp. A9 strain also stores U intracellularly, as needle-like structures that have been identified as an autunite group mineral. Taken together, our results demonstrate that this strain exhibits a high U(VI) tolerance based on multiple detoxification mechanisms. These findings support the potential role of the genus Microbacterium in the remediation of aqueous environments contaminated with U(VI) under aerobic conditions.

Genome analysis coupled with physiological studies reveals a diverse nitrogen metabolism in Methylocystis sp. strain SC2.

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Bomba Dam

Full Text Available BACKGROUND: Methylocystis sp. strain SC2 can adapt to a wide range of methane concentrations. This is due to the presence of two isozymes of particulate methane monooxygenase exhibiting different methane oxidation kinetics. To gain insight into the underlying genetic information, its genome was sequenced and found to comprise a 3.77 Mb chromosome and two large plasmids. PRINCIPAL FINDINGS: We report important features of the strain SC2 genome. Its sequence is compared with those of seven other methanotroph genomes, comprising members of the Alphaproteobacteria, Gammaproteobacteria, and Verrucomicrobia. While the pan-genome of all eight methanotroph genomes totals 19,358 CDS, only 154 CDS are shared. The number of core genes increased with phylogenetic relatedness: 328 CDS for proteobacterial methanotrophs and 1,853 CDS for the three alphaproteobacterial Methylocystaceae members, Methylocystis sp. strain SC2 and strain Rockwell, and Methylosinus trichosporium OB3b. The comparative study was coupled with physiological experiments to verify that strain SC2 has diverse nitrogen metabolism capabilities. In correspondence to a full complement of 34 genes involved in N2 fixation, strain SC2 was found to grow with atmospheric N2 as the sole nitrogen source, preferably at low oxygen concentrations. Denitrification-mediated accumulation of 0.7 nmol (30N2/hr/mg dry weight of cells under anoxic conditions was detected by tracer analysis. N2 production is related to the activities of plasmid-borne nitric oxide and nitrous oxide reductases. CONCLUSIONS/PERSPECTIVES: Presence of a complete denitrification pathway in strain SC2, including the plasmid-encoded nosRZDFYX operon, is unique among known methanotrophs. However, the exact ecophysiological role of this pathway still needs to be elucidated. Detoxification of toxic nitrogen compounds and energy conservation under oxygen-limiting conditions are among the possible roles. Relevant features that may stimulate

Improvement of Fish Sauce Quality by Strain CMC5-3-1: A Novel Species of Staphylococcus sp.

Science.gov (United States)

Udomsil, Natteewan; Rodtong, Sureelak; Tanasupawat, Somboon; Yongsawatdigul, Jirawat

2015-09-01

Staphylococcus sp. CMC5-3-1 and CMS5-7-5 isolated from fermented fish sauce at 3 to 7 mo, respectively, showed different characteristics on protein hydrolysis and volatile formation. These Gram-positive cocci were able to grow in up to 15% NaCl with the optimum at 0.5% to 5% NaCl in tryptic soy broth. Based on ribosomal 16S rRNA gene sequences, Staphylococcus sp. CMC5-3-1 and CMS5-7-5 showed 99.0% similarity to that of Staphylococcus piscifermentans JCM 6057(T) , but DNA-DNA relatedness was sauce inoculated with Staphylococcus sp. CMC5-3-1 was 740.5 mM, which was higher than that inoculated by the strain CMS5-7-5 (662.14 mM, P sauce inoculated with Staphylococcus sp. CMC5-3-1 showed the highest content of total glutamic acid (P sauce inoculated with Staphylococcus sp. CMC5-3-1 was 2-methypropanal, contributing to the desirable dark chocolate note. Staphylococcus sp. CMC5-3-1 could be applied as a starter culture to improve the umami and aroma of fish sauce. © 2015 Institute of Food Technologists®

Aerobic degradation of buprofezin via novel degradation intermediates by Rhodococcus sp. strain RX-3

OpenAIRE

Ruixue Li; Chun Dai; Guangli Wang; Shaoxian Wu; Yubao Gong; Yuanyuan Jiang; Zhijia Wang; Naiyue Sun

2016-01-01

Buprofezin is a commonly used chemical with satisfactory efficacy against sucking insect pests, but its disposal causes serious environmental problems. In this study, a bacterial strain RX-3 isolated by continuous enrichment from buprofezin-treated soil was tested for biodegradation of buprofezin. The bacteria were most similar to Rhodococcus sp. based on their morphological, physiological and biochemical characteristics, as well as phylogenetic placement inferred from 16S rRNA gene sequence....

Growth kinetics and biodeterioration of polypropylene microplastics by Bacillus sp. and Rhodococcus sp. isolated from mangrove sediment.

Science.gov (United States)

Auta, H S; Emenike, C U; Jayanthi, B; Fauziah, S H

2018-02-01

Interest in the biodegradation of microplastics is due to their ubiquitous distribution, availability, high persistence in the environment and deleterious impact on marine biota. The present study evaluates the growth response and mechanism of polypropylene (PP) degradation by Bacillus sp. strain 27 and Rhodococcus sp. strain 36 isolated from mangrove sediments upon exposure to PP microplastics. Both bacteria strains were able to utilise PP microplastic for growth as confirmed by the reduction of the polymer mass. The weight loss was 6.4% by Rhodococcus sp. strain 36 and 4.0% by Bacillus sp. strain 27 after 40days of incubation. PP biodegradation was further confirmed using Fourier-transform infrared spectroscopy and scanning electron microscopy analyses, which revealed structural and morphological changes in the PP microplastics with microbial treatment. These analyses showed that the isolates can colonise, modify and utilise PP microplastics as carbon source. Copyright © 2017 Elsevier Ltd. All rights reserved.

Draft Genome Sequence of Lactobacillus sp. Strain TCF032-E4, Isolated from Fermented Radish.

Science.gov (United States)

Mao, Yuejian; Chen, Meng; Horvath, Philippe

2015-07-30

Here, we report the draft genome sequence of Lactobacillus sp. strain TCF032-E4 (= CCTCC AB2015090 = DSM 100358), isolated from a Chinese fermented radish. The total length of the 57 contigs is about 2.9 Mb, with a G+C content of 43.5 mol% and 2,797 predicted coding sequences (CDSs). Copyright © 2015 Mao et al.

Draft Genome Sequence of a Kale (Brassica oleracea L.) Root Endophyte, Pseudomonas sp. Strain C9.

Science.gov (United States)

Laugraud, Aurelie; Young, Sandra; Gerard, Emily; O'Callaghan, Maureen; Wakelin, Steven

2017-04-13

Pseudomonas sp. strain C9 is a plant growth-promoting bacterium isolated from the root tissue of Brassica oleracea L. grown in soil from Marlborough, New Zealand. Its draft genome of 6,350,161 bp contains genes associated with plant growth promotion and biological control. Copyright © 2017 Laugraud et al.

Antimicrobial Susceptibility and Biofilm Production by Salmonella sp. Strains Isolated from Frozen Poultry Carcasses

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MJ Sereno

Full Text Available ABSTRACT The objectives of this study were to evaluate the antimicrobial resistance and the biofilm-producing ability of Salmonella sp. strains isolated from frozen poultry carcasses. Antimicrobial susceptibility was tested by the disk-diffusion method. Biofilm-producing ability was determined in 96-well polystyrene microplates stained with crystal violet at 1%. Out of the 22 strains tested, all were multiresistant, that is, resistant to more than three antimicrobial classes, and 72.7% were able to form biofilms. The highest resistance rates obtained were against sulfonamides, tetracycline, and quinolones. On the other hand, 100% of the strains were sensitive to chloramphenicol. According to the rate of biofilm formation, 3 (13.6% and 13 (59.1% strains were classified as moderate and weak biofilm-producers, respectively, and 27.3% did not form biofilms. Biofilms increase the tolerance of microorganisms to stress, reducing their sensitivity to disinfectants and antimicrobials; favor equipment corrosion; and act as substrates for the adhesion of bacteria with lower biofilm-producing capacity. The results of the present study stress the importance of cleaning procedures in food processing plants and highlight the public health risks related to the emergence of multiresistant strains.

High-quality genome sequence and description of Bacillus ndiopicus strain FF3T sp. nov.

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C.I. Lo

2015-11-01

Full Text Available Strain FF3T was isolated from the skin-flora of a 39-year-old healthy Senegalese man. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry did not allow any identification. This strain exhibited a 16S rRNA sequence similarity of 96.8% with Bacillus massiliensis, the phylogenetically closest species with standing nomenclature. Using a polyphasic study made of phenotypic and genomic analyses, strain FF3T was Gram-positive, aeroanaerobic and rod shaped and exhibited a genome of 4 068 720 bp with a G+C content of 37.03% that coded 3982 protein-coding and 67 RNA genes (including four rRNA operons. On the basis of these data, we propose the creation of Bacillus ndiopicus sp. nov.

Effects of nano bamboo charcoal on PAHs-degrading strain Sphingomonas sp. GY2B.

Science.gov (United States)

She, Bojia; Tao, Xueqin; Huang, Ting; Lu, Guining; Zhou, Zhili; Guo, Chuling; Dang, Zhi

2016-03-01

Nano bamboo charcoal (NBC) has been commonly used in the production of textiles, plastics, paint, etc. However, little is known regarding their effects towards the microorganisms. The effects of NBC on phenanthrene degrading strain Sphingomonas sp. GY2B were investigated in the present study. Results showed that the addition of NBC could improve the phenanthrene removal by Sphingomonas sp. GY2B, with removal efficiencies increased by 10.29-18.56% in comparison to the control at 24h, and phenanthrene was almost completely removed at 48h. With the presence of low dose of NBC (20 and 50mgL(-1)), strain GY2B displayed a better growth at 6h, suggesting that NBC was beneficial to the growth of GY2B and thus resulting in the quick removal of phenanthrene from water. However, the growth of strain GY2B in high dose of NBC (200mgL(-1)) was inhibited at 6h, and the inhibition could be attenuated and eliminated after 12h. NBC-effected phenanthrene solubility experiment suggested that NBC makes a negligible contribution to the solubilization of phenanthrene in water. Results of electronic microscopy analysis (SEM and TEM) indicated NBC may interact with the cell membrane, causing the enhanced membrane permeability and then NBC adsorbed on the membrane would enter into the cells. The findings of this work would provide important information for the future usage and long-term environmental risk assessment of NBC. Copyright © 2015 Elsevier Inc. All rights reserved.

Aerobic degradation of 4-nitroaniline (4-NA) via novel degradation intermediates by Rhodococcus sp. strain FK48

Energy Technology Data Exchange (ETDEWEB)

Khan, Fazlurrahman; Pandey, Janmejay; Vikram, Surendra; Pal, Deepika; Cameotra, Swaranjit Singh, E-mail: ssc@imtech.res.in

2013-06-15

Highlights: • This study reports isolation of a novel bacterium capable of mineralizing 4-nitroaniline (4-NA). • This bacterium has been identified as Rhodococcus sp. strain FK48. • Strain FK48 degrades 4-NA via a novel aerobic degradation pathway that involves 4-AP and 1,2,4-BT. • Subsequent degradation proceeds via ring fission and formation of maleylacetate. • This is the first report showing elucidation of catabolic pathway for microbial degradation 4-NA. -- Abstract: An aerobic strain, Rhodococcus sp. strain FK48, capable of growing on 4-nitroaniline (4-NA) as the sole source of carbon, nitrogen, and energy has been isolated from enrichment cultures originating from contaminated soil samples. During growth studies with non- induced cells of FK48 catalyzed sequential denitrification (release of NO{sub 2} substituent) and deamination (release of NH{sub 2} substituent) of 4-NA. However, none of the degradation intermediates could be identified with growth studies. During resting cell studies, 4-NA-induced cells of strain FK48 transformed 4-NA via a previously unknown pathway which involved oxidative hydroxylation leading to formation of 4-aminophenol (4-AP). Subsequent degradation involved oxidated deamination of 4-AP and formation of 1,2,4-benzenetriol (BT) as the major identified terminal aromatic intermediate. Identification of these intermediates was ascertained by HPLC, and GC–MS analyses of the culture supernatants. 4-NA-induced cells of strain FK48 showed positive activity for 1,2,4-benzenetriol dioxygenase in spectrophotometric assay. This is the first conclusive study on aerobic microbial degradation of 4-NA and elucidation of corresponding metabolic pathway.

Aerobic degradation of 4-nitroaniline (4-NA) via novel degradation intermediates by Rhodococcus sp. strain FK48

International Nuclear Information System (INIS)

Khan, Fazlurrahman; Pandey, Janmejay; Vikram, Surendra; Pal, Deepika; Cameotra, Swaranjit Singh

2013-01-01

Highlights: • This study reports isolation of a novel bacterium capable of mineralizing 4-nitroaniline (4-NA). • This bacterium has been identified as Rhodococcus sp. strain FK48. • Strain FK48 degrades 4-NA via a novel aerobic degradation pathway that involves 4-AP and 1,2,4-BT. • Subsequent degradation proceeds via ring fission and formation of maleylacetate. • This is the first report showing elucidation of catabolic pathway for microbial degradation 4-NA. -- Abstract: An aerobic strain, Rhodococcus sp. strain FK48, capable of growing on 4-nitroaniline (4-NA) as the sole source of carbon, nitrogen, and energy has been isolated from enrichment cultures originating from contaminated soil samples. During growth studies with non- induced cells of FK48 catalyzed sequential denitrification (release of NO 2 substituent) and deamination (release of NH 2 substituent) of 4-NA. However, none of the degradation intermediates could be identified with growth studies. During resting cell studies, 4-NA-induced cells of strain FK48 transformed 4-NA via a previously unknown pathway which involved oxidative hydroxylation leading to formation of 4-aminophenol (4-AP). Subsequent degradation involved oxidated deamination of 4-AP and formation of 1,2,4-benzenetriol (BT) as the major identified terminal aromatic intermediate. Identification of these intermediates was ascertained by HPLC, and GC–MS analyses of the culture supernatants. 4-NA-induced cells of strain FK48 showed positive activity for 1,2,4-benzenetriol dioxygenase in spectrophotometric assay. This is the first conclusive study on aerobic microbial degradation of 4-NA and elucidation of corresponding metabolic pathway

Methylobacterium suomiense sp. nov. and Methylobacterium lusitanum sp. nov., aerobic, pink-pigmented, facultatively methylotrophic bacteria.

Science.gov (United States)

Doronina, Nina V; Trotsenko, Yuri A; Kuznetsov, Boris B; Tourova, Tatjana P; Salkinoja-Salonen, Mirja S

2002-05-01

Two aerobic, pink-pigmented, facultatively methylotrophic bacteria, strains F20T and RXM(T), are described taxonomically. On the basis of their phenotypic and genotypic properties, the isolates are proposed as novel species of the genus Methylobacterium, Methylobacterium suomiense sp. nov. (type strain F20T = VKM B-2238T = NCIMB 13778T) and Methylobacterium lusitanum sp. nov. (type strain RXMT = VKM B-2239T = NCIMB 13779T).

Characterization of a marine-isolated mercury-resistant Pseudomonas putida strain SP1 and its potential application in marine mercury reduction

Energy Technology Data Exchange (ETDEWEB)

Zhang, Weiwei; Chen, Lingxin; Liu, Dongyan [Chinese Academy of Sciences, Yantai, SD (China). Yantai Inst. of Coastal Zone Research (YICCAS); Chinese Academy of Sciences, Yantai, SD (China). Shandong Provincial Key Lab. of Coastal Zone Environmental Processes

2012-02-15

The Pseudomonas putida strain SP1 was isolated from marine environment and was found to be resistant to 280 {mu}M HgCl{sub 2}. SP1 was also highly resistant to other metals, including CdCl{sub 2}, CoCl{sub 2}, CrCl{sub 3}, CuCl{sub 2}, PbCl{sub 2}, and ZnSO{sub 4}, and the antibiotics ampicillin (Ap), kanamycin (Kn), chloramphenicol (Cm), and tetracycline (Tc). mer operon, possessed by most mercury-resistant bacteria, and other diverse types of resistant determinants were all located on the bacterial chromosome. Cold vapor atomic absorption spectrometry and a volatilization test indicated that the isolated P. putida SP1 was able to volatilize almost 100% of the total mercury it was exposed to and could potentially be used for bioremediation in marine environments. The optimal pH for the growth of P. putida SP1 in the presence of HgCl{sub 2} and the removal of HgCl{sub 2} by P. putida SP1 was between 8.0 and 9.0, whereas the optimal pH for the expression of merA, the mercuric reductase enzyme in mer operon that reduces reactive Hg{sup 2+} to volatile and relatively inert monoatomic Hg{sup 0} vapor, was around 5.0. LD50 of P. putida SP1 to flounder and turbot was 1.5 x 10{sup 9} CFU. Biofilm developed by P. putida SP1 was 1- to 3-fold lower than biofilm developed by an aquatic pathogen Pseudomonas fluorescens TSS. The results of this study indicate that P. putida SP1 is a low virulence strain that can potentially be applied in the bioremediation of HgCl{sub 2} contamination over a broad range of pH. (orig.)

Raoultella sp. SM1, a novel iron-reducing and uranium-precipitating strain.

Science.gov (United States)

Sklodowska, Aleksandra; Mielnicki, Sebastian; Drewniak, Lukasz

2018-03-01

The main aim of this study was the characterisation of novel Raoutella isolate, an iron-reducing and uranium-precipitating strain, originating from microbial mats occurring in the sediments of a closed down uranium mine in Kowary (SW Poland). Characterisation was done in the context of its potential role in the functioning of these mats and the possibility to use them in uranium removal/recovery processes. In our experiment, we observed the biological precipitation of iron and uranium's secondary minerals containing oxygen, potassium, sodium and phosphor, which were identified as ningyoite-like minerals. The isolated strain, Raoultella sp. SM1, was also able to dissimilatory reduce iron (III) and uranium (VI) in the presence of citrate as an electron donor. Our studies allowed us to characterise a new strain which may be used as a model microorganism in the study of Fe and U respiratory processes and which may be useful in the bioremediation of uranium-contaminated waters and sediments. During this process, uranium may be immobilised in ningyoite-like minerals and can then be recovered in nano/micro-particle form, which may be easily transformed to uraninite. Copyright © 2017 Elsevier Ltd. All rights reserved.

Analysing the dhaT gene in Colombian Clostridium sp. (Clostridia 1,3-propanediol-producing strains

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Diana Milena Quilaguy-Ayure

2010-04-01

Full Text Available To analyze the dhaT gene, one of the genes responsible for the 1,3-propanediol (1,3-PD production, in two native Clostridiumstrains. Materials and methods: The dhaT gene was amplified by Polimerase Chain Reaction with specific primers designed fromClostridium butyricum VPI1718 operon. Bioinformatics tools like BLASTN, ORF finder, BLASTP and ClustalW were used to determinethe identity of the sequence and to assign a function. Results: DNA amplification products were obtained from Colombian Clostridium sp.native strains (IBUN 13A and IBUN 158B and the Clostridium butyricum DSM 2478 strain, which were sequenced. According to thebioinformatics analysis of the above sequences, a high degree of similarity was found with the dhaT gene of different bacterial species. Thehighest percentage of identity was obtained with the Clostridium butyricum VPI 1718 strain. Conclusion: knowledge of the physicalstructure of the 1,3-PD operon in native strains opens the way for developing genetic and metabolic engineering strategies for improvingprocesses productivity.

Crystallization and preliminary X-ray crystallographic studies of β-transaminase from Mesorhizobium sp. strain LUK

International Nuclear Information System (INIS)

Kim, Bokyung; Park, Ok Kyeung; Bae, Ju Young; Jang, Tae-ho; Yoon, Jong Hwan; Do, Kyoung Hun; Kim, Byung-Gee; Yun, Hyungdon; Park, Hyun Ho

2011-01-01

β-Transaminase from Mesorhizobium sp. strain LUK was crystallized. The crystals were found to belong to the orthorhombic space group C222 1 , with unit-cell parameters a = 90.91, b = 192.17, c = 52.75 Å. The crystals were obtained at 293 K and diffracted to a resolution of 2.5 Å. β-Transaminase (β-TA) catalyzes the transamination reaction between β-aminocarboxylic acids and keto acids. This enzyme is a particularly suitable candidate for use as a biocatalyst for the asymmetric synthesis of enantiochemically pure β-amino acids for pharmaceutical purposes. The β-TA from Mesorhizobium sp. strain LUK (β-TAMs) belongs to a novel class in that it shows β-transaminase activity with a broad and unique substrate specificity. In this study, β-TAMs was overexpressed in Escherichia coli with an engineered C-terminal His tag. β-TAMs was then purified to homogeneity and crystallized at 293 K. X-ray diffraction data were collected to a resolution of 2.5 Å from a crystal that belonged to the orthorhombic space group C222 1 , with unit-cell parameters a = 90.91, b = 192.17, c = 52.75 Å

Enzymic Dehalogenation of 4-Chlorobenzoyl Coenzyme A in Acinetobacter sp. Strain 4-CB1

OpenAIRE

Copley, Shelley D.; Crooks, Gwen P.

1992-01-01

4-Chlorobenzoate degradation in cell extracts of Acinetobacter sp. strain 4-CB1 occurs by initial synthesis of 4-chlorobenzoyl coenzyme A (4-chlorobenzoyl CoA) from 4-chlorobenzoate, CoA, and ATP. 4-Chlorobenzoyl CoA is dehalogenated to 4-hydroxybenzoyl CoA. Following the dehalogenation reaction, 4-hydroxybenzoyl CoA is hydrolyzed to 4-hydroxybenzoate and CoA. Possible roles for the CoA moiety in the dehalogenation reaction are discussed.

Enzymic Dehalogenation of 4-Chlorobenzoyl Coenzyme A in Acinetobacter sp. Strain 4-CB1

Science.gov (United States)

Copley, Shelley D.; Crooks, Gwen P.

1992-01-01

4-Chlorobenzoate degradation in cell extracts of Acinetobacter sp. strain 4-CB1 occurs by initial synthesis of 4-chlorobenzoyl coenzyme A (4-chlorobenzoyl CoA) from 4-chlorobenzoate, CoA, and ATP. 4-Chlorobenzoyl CoA is dehalogenated to 4-hydroxybenzoyl CoA. Following the dehalogenation reaction, 4-hydroxybenzoyl CoA is hydrolyzed to 4-hydroxybenzoate and CoA. Possible roles for the CoA moiety in the dehalogenation reaction are discussed. PMID:16348702

PERFORMA FOTOSINTESIS Kappaphycus sp. (strain Sumba) YANG DIUKUR BERDASARKAN EVOLUSI OKSIGEN TERLARUT PADA BEBERAPA TINGKAT SUHU DAN CAHAYA

OpenAIRE

Lideman Lideman; Asda Laining

2015-01-01

Penelitian ini bertujuan untuk mengetahui pengaruh suhu dan cahaya terhadap laju fotosintesis Kappaphycus sp. (strain Sumba) yang diukur berdasarkan perubahan oksigen terlarut. Pengukuran laju fotosintesis Kappaphycus sp. pertama-tama dilakukan pada suhu 20oC, 24oC, 28oC, dan 32oC pada tingkat cahaya 353 μmol photons m-2 s-1 untuk mendapatkan kurva fotosintesis versus suhu (kurva P-T). Selanjutnya, pengukuran laju fotosintesis dilakukan pada suhu 20oC, 24oC, dan 28oC dengan intensitas cahaya ...

MapA, an iron-regulated, cytoplasmic membrane protein in the cyanobacterium Synechococcus sp. strain PCC7942.

Science.gov (United States)

Webb, R; Troyan, T; Sherman, D; Sherman, L A

1994-08-01

Growth of Synechococcus sp. strain PCC 7942 in iron-deficient media leads to the accumulation of an approximately 34-kDa protein. The gene encoding this protein, mapA (membrane-associated protein A), has been cloned and sequenced (GenBank accession number, L01621). The mapA transcript is not detectable in normally grown cultures but is stably accumulated by cells grown in iron-deficient media. However, the promoter sequence for this gene does not resemble other bacterial iron-regulated promoters described to date. The carboxyl-terminal region of the derived amino acid sequence of MapA resembles bacterial proteins involved in iron acquisition, whereas the amino-terminal end of MapA has a high degree of amino acid identity with the abundant, chloroplast envelope protein E37. An approach employing improved cellular fractionation techniques as well as electron microscopy and immunocytochemistry was essential in localizing MapA protein to the cytoplasmic membrane of Synechococcus sp. strain PCC 7942. When these cells were grown under iron-deficient conditions, a significant fraction of MapA could also be localized to the thylakoid membranes.

Genetic labelling and application of the isoproturon-mineralizing Sphingomonas sp. strain SRS2 in soil and rhizosphere

DEFF Research Database (Denmark)

Kristensen, K.E.; Jacobsen, C.S.; Hansen, L.H.

2006-01-01

AIMS: To construct a luxAB-labelled Sphingomonas sp. strain SRS2 maintaining the ability to mineralize the herbicide isoproturon and usable for monitoring the survival and distribution of strain SRS2 on plant roots in laboratory systems. METHODS AND RESULTS: We inserted the mini-Tn5-luxAB marker...... into strain SRS2 using conjugational mating. In the transconjugant mutants luciferase was produced in varying levels. The mutants showed significant differences in their ability to degrade isoproturon. One luxAB-labelled mutant maintained the ability to mineralize isoproturon and was therefore selected...... for monitoring colonization of barley roots. CONCLUSIONS: We successfully constructed a genetically labelled isoproturon-mineralizing-strain SRS2 and demonstrated its ability to survive in soil and its colonization of rhizosphere. SIGNIFICANCE AND IMPACT OF THE STUDY: The construction of a luxAB-labelled strain...

Draft Genome Sequence of Pseudoalteromonas sp. Strain XI10 Isolated from the Brine-Seawater Interface of Erba Deep in the Red Sea

KAUST Repository

Zhang, Guishan; Haroon, Mohamed; Zhang, Ruifu; Hikmawan, Tyas I.; Stingl, Ulrich

2016-01-01

Pseudoalteromonas sp. strain XI10 was isolated from the brine-seawater interface of Erba Deep in the Red Sea, Saudi Arabia. Here, we present the draft genome sequence of strain XI10, a gammaproteobacterium that synthesizes polysaccharides for biofilm formation when grown in liquid culture.

Draft Genome Sequence of Pseudoalteromonas sp. Strain XI10 Isolated from the Brine-Seawater Interface of Erba Deep in the Red Sea

KAUST Repository

Zhang, Guishan

2016-03-10

Pseudoalteromonas sp. strain XI10 was isolated from the brine-seawater interface of Erba Deep in the Red Sea, Saudi Arabia. Here, we present the draft genome sequence of strain XI10, a gammaproteobacterium that synthesizes polysaccharides for biofilm formation when grown in liquid culture.

Dissecting the hydrogenase expression and activity of transformed escherichia coli with the bidirectional NiFe-hydrogenase from synechocystis sp. PCC 6803

International Nuclear Information System (INIS)

Moon, Yu Ran; Lee, Min Hee; An, Byung Chull; Chung, Byung Yeoup; Kim, Jae Sung; Kim, Jin Hong; Park, Youn Il; Kim, Cha Soon

2009-01-01

Synechocystis bidirectional hydrogenase genes (hoxEFUYH) and their putative promoter regions and transformed into E. coli. The hox genes were transcribed in the E. coli cells carrying the vector construct of pCCIFOS::phox::hox or pCCIFOS::pT7::hox and translated into HoxEFUYH proteins, suggesting that the putative hox promoter can be constitutively activated in E. coli. Accordingly, the total hydrogenase activity was markedly increased up to 192% or 169% in the transformed cells, while the hydrogen uptake was decreased up to about 30% of the negative control. Although the gene expression of LexA, the only one transcription regulator proven for the hox genes, was substantially decreased in the pCCIFOS::phox::hox cells after γ-irradiation of 30 Gy, the expression levels of HoxEFUYH proteins were not altered significantly. Thus, it is also suggested that other transcription regulators as well as LexA might contribute to activation of the hox promoter in E. coli

Isolation and characterization of Staphylococcus sp. strain NBRIEAG-8 from arsenic contaminated site of West Bengal

Energy Technology Data Exchange (ETDEWEB)

Srivastava, Shubhi; Singh, Namrata; Singh, Nandita [CSIR - National Botanical Research Institute, Lucknow, UP (India). Eco-auditing Lab.; Verma, Praveen C.; Singh, Ankit; Mishra, Manisha [CSIR - National Botanical Research Institute, Lucknow, UP (India). Plant Molecular Biology and Genetic Engineering; Sharma, Neeta [Lucknow Univ., UP (India). Plant Pathology Lab.

2012-09-15

Arsenic contaminated rhizospheric soils of West Bengal, India were sampled for arsenic resistant bacteria that could transform different arsenic forms. Staphylococcus sp. NBRIEAG-8 was identified by16S rDNA ribotyping, which was capable of growing at 30,000 mg l{sup -1} arsenate [As(V)] and 1,500 mg l{sup -1} arsenite [As(III)]. This bacterial strain was also characterized for arsenical resistance (ars) genes which may be associated with the high-level resistance in the ecosystems of As-contaminated areas. A comparative proteome analysis was conducted with this strain treated with 1,000 mg l{sup -1} As(V) to identify changes in their protein expression profiles. A 2D gel analysis showed a significant difference in the proteome of arsenic treated and untreated bacterial culture. The change in pH of cultivating growth medium, bacterial growth pattern (kinetics), and uptake of arsenic were also evaluated. After 72 h of incubation, the strain was capable of removing arsenic from the culture medium amended with arsenate and arsenite [12% from As(V) and 9% from As(III)]. The rate of biovolatilization of As(V) was 23% while As(III) was 26%, which was determined indirectly by estimating the sum of arsenic content in bacterial biomass and medium. This study demonstrates that the isolated strain, Staphylococcus sp., is capable for uptake and volatilization of arsenic by expressing ars genes and 8 new upregulated proteins which may have played an important role in reducing arsenic toxicity in bacterial cells and can be used in arsenic bioremediation. (orig.)

Distinct features of C/N balance regulation in Prochlorococcus sp. strain MIT9313.

Science.gov (United States)

Domínguez-Martín, María Agustina; López-Lozano, Antonio; Rangel-Zúñiga, Oriol Alberto; Díez, Jesús; García-Fernández, José Manuel

2018-02-01

The abundance and significant contribution to global primary production of the marine cyanobacterium Prochlorococcus have made it one of the main models in marine ecology. Several conditions known to cause strong effects on the regulation of N-related enzymes in other cyanobacteria lacked such effect in Prochlorococcus. Prochlorococcus sp. strain MIT9313 is one of the most early-branching strains among the members of this genus. In order to further understand the C/N control system in this cyanobacterium, we studied the effect of the absence of three key elements in the ocean, namely N, P and Fe, as well as the effect of inhibitors of the N assimilation or photosynthesis on the N metabolism of this strain. Furthermore, we focused our work in the effect of ageing, as the age of cultures has clear effects on the regulation of some enzymes in Prochlorococcus. To reach this goal, expression of the main three regulators involved in N assimilation in cyanobacteria, namely ntcA, glnB and pipX, as well as that of icd (encoding for isocitrate dehydrogenase) were analysed. Our results show that the control of the main proteins involved in the C/N balance in strain MIT9313 differs from other model Prochlorococcus strains. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Draft Genome Sequence of Exiguobacterium sp. Strain BMC-KP, an Environmental Isolate from Bryn Mawr, Pennsylvania.

Science.gov (United States)

Hyson, Peter; Shapiro, Joshua A; Wien, Michelle W

2015-10-08

Exiguobacterium sp. strain BMC-KP was isolated as part of a student environmental sampling project at Bryn Mawr College, PA. Sequencing of bacterial DNA assembled a 3.32-Mb draft genome. Analysis suggests the presence of genes for tolerance to cold and toxic metals, broad carbohydrate metabolism, and genes derived from phage. Copyright © 2015 Hyson et al.

Characterisation of a detergent-stable alkaline protease from a novel thermophilic strain Paenibacillus tezpurensis sp. nov. AS-S24-II.

Science.gov (United States)

Rai, Sudhir K; Roy, Jetendra K; Mukherjee, Ashis K

2010-02-01

An alkaline-protease-producing bacterial strain (AS-S24-II) isolated from a soil sample in Assam is a Gram-stain-positive, catalase-positive, endospore-forming rod and grows at temperatures ranging from 30 degrees C to 60 degrees C and salinity ranging from 0% to 7% (w/v) NaCl. Phenotypic characterisation, chemotaxonomic properties, presence of Paenibacillus-specific signature sequences, and ribotyping data suggested that the strain AS-S24-II represents a novel species of the genus Paenibacillus, for which the name Paenibacillus tezpurensis sp. nov. (MTCC 8959) is proposed. Phylogenetic analysis revealed that P. lentimorbus strain DNG-14 and P. lentimorbus strain DNG-16 represent the closest phylogenetic neighbour of this novel strain. Alkaline protease production (598 x 10(3) U l(-1)) by P. tezpurensis sp. nov. in SmF was optimised by response surface method. A laundry-detergent-stable, Ca(2+)-independent, 43-kDa molecular weight alkaline serine protease from this strain was purified with a 1.7-fold increase in specific activity. The purified protease displayed optimum activity at pH 9.5 and 45-50 degrees C temperature range and exhibited a significant stability and compatibility with surfactants and most of the tested commercial laundry detergents at room temperature. Further, the protease improved the wash performance of detergents, thus demonstrating its feasibility for inclusion in laundry detergent formulations.

[Effects of nitriles and amides on the growth and the nitrile hydratase activity of the Rhodococcus sp. strain gt1].

Science.gov (United States)

Maksimov, A Iu; Kuznetsova, M V; Ovechkina, G V; Kozlov, S V; Maksimova, Iu G; Demakov, V A

2003-01-01

Effects of some nitriles and amides, as well as glucose and ammonium, on the growth and the nitrile hydratase (EC 4.2.1.84) activity of the Rhodococcus sp. strain gt1 isolated from soil were studied. The activity of nitrile hydratase mainly depended on carbon and nitrogen supply to cells. The activity of nitrile hydratase was high in the presence of glucose and ammonium at medium concentrations and decreased at concentrations of glucose more than 0.3%. Saturated unsubstituted aliphatic nitriles and amides were found to be a good source of nitrogen and carbon. However, the presence of nitriles and amides in the medium was not absolutely necessary for the expression of the activity of nitrile hydratase isolated from the Rhodococcus sp. strain gt1.

A Possible Role of Peptides in the Growth Enhancement of an Industrial Strain of Saccharomyces sp.

Directory of Open Access Journals (Sweden)

Dino Paolo Cortes

2005-06-01

Full Text Available Individual addition of a commercially available nutritional supplement and a methanol extract from an industrial Saccharomyces sp. strain SMC resulted in the enhanced growth of Saccharomyces sp. strain SMC in minimal medium. Isolation of the growth enhancing components from aqueous extracts of the supplement and the cellular extract was performed using reversed-phase, gel filtration, and ion exchange chromatography. Reversed-phase chromatography using Sep-Pak® vac C18 yielded aqueous washes which elicited increased yeast growth. Gel filtration chromatography of the aqueous washes in a group separation mode using Sephadex G25 gave three distinct groups for the nutritional supplement, and four distinct groups for the cellular extract. Fraction groups that exhibited growth enhancing activity also exhibited high absorbances at all three wavelengths of 214, 260, and 280 nm. Two major fractions which tested positive for growth enhancing activity in succeeding experiments were obtained after passing each of the active GFC groups through a Toyopearl SP 550C cation exchanger column. The active component from the cellular extract did not bind to the cation exchanger. The absorbance data at 214 nm (peptide bond experimental absorbance maximum wavelength, the Bradford assay (showing the presence of proteinaceous matter, and the active component’s inclusion in the Sephadex G25 fractionation range of 1-5 kDa (characteristic of small peptides suggest that the growth enhancing components of the nutritional supplement and methanol cell extracts are peptides.

Isolation and characterization of Halomonas sp. strain C2SS100, a hydrocarbon-degrading bacterium under hypersaline conditions.

Science.gov (United States)

Mnif, S; Chamkha, M; Sayadi, S

2009-09-01

To isolate and characterize an efficient hydrocarbon-degrading bacterium under hypersaline conditions, from a Tunisian off-shore oil field. Production water collected from 'Sercina' petroleum reservoir, located near the Kerkennah island, Tunisia, was used for the screening of halotolerant or halophilic bacteria able to degrade crude oil. Bacterial strain C2SS100 was isolated after enrichment on crude oil, in the presence of 100 g l(-1) NaCl and at 37 degrees C. This strain was aerobic, Gram-negative, rod-shaped, motile, oxidase + and catalase +. Phenotypic characters and phylogenetic analysis based on the 16S rRNA gene of the isolate C2SS100 showed that it was related to members of the Halomonas genus. The degradation of several compounds present in crude oil was confirmed by GC-MS analysis. The use of refined petroleum products such as diesel fuel and lubricating oil as sole carbon source, under the same conditions of temperature and salinity, showed that significant amounts of these heterogenic compounds could be degraded. Strain C2SS100 was able to degrade hexadecane (C16). During growth on hexadecane, cells surface hydrophobicity and emulsifying activity increased indicating the production of biosurfactant by strain C2SS100. A halotolerant bacterial strain Halomonas sp. C2SS100 was isolated from production water of an oil field, after enrichment on crude oil. This strain is able to degrade hydrocarbons efficiently. The mode of hydrocarbon uptake is realized by the production of a biosurfactant which enhances the solubility of hydrocarbons and renders them more accessible for biodegradation. The biodegradation potential of the Halomonas sp. strain C2SS100 gives it an advantage for possibly application on bioremediation of water, hydrocarbon-contaminated sites under high-salinity level.

Improved Method for the Isolation of Biosurfactant Glycolipids from Rhodococcus sp. Strain H13A

OpenAIRE

Bryant, Frank O.

1990-01-01

An improved method for the isolation of the biosurfactant glycolipids from Rhodococcus sp. strain H13A by using XM 50 diafiltration and isopropanol precipitation was devised. This procedure was advantageous since it removes protein coisolated when the glycolipids are obtained by organic extraction and silicic acid chromatography. The protein apparently does not contribute any biosurfactant characteristics to the glycolipids. The deacylated glycolipid backbone included only a disaccharide.

A homozygous recA mutant of Synechocystis PCC6803: construction strategy and characteristics eliciting a novel RecA independent UVC resistance in dark.

Science.gov (United States)

Minda, Renu; Ramchandani, Jyoti; Joshi, Vasudha P; Bhattacharjee, Swapan Kumar

2005-12-01

We report here the construction of a homozygous recA460::cam insertion mutant of Synechocystis sp. PCC 6803 that may be useful for plant molecular genetics by providing a plant like host free of interference from homologous recombination. The homozygous recA460::cam mutant is highly sensitive to UVC under both photoreactivating and non-photoreactivating conditions compared to the wild type (WT). The liquid culture of the mutant growing in approximately 800 lx accumulates nonviable cells to the tune of 86% as estimated by colony counts on plates incubated at the same temperature and light intensity. The generation time of recA mutant in standard light intensity (2,500 lx) increases to 50 h compared to 28 h in lower light intensity (approximately 800 lx) that was used for selection, thus explaining the earlier failures to obtain a homozygous recA mutant. The WT, in contrast, grows at faster rate (23 h generation time) in standard light intensity compared to that at approximately 800 lx (26 h). The Synechocystis RecA protein supports homologous recombination during conjugation in recA (-) mutant of Escherichia coli, but not the SOS response as measured by UV sensitivity. It is suggested that using this homozygous recA460::cam mutant, investigations can now be extended to dissect the network of DNA repair pathways involved in housekeeping activities that may be more active in cyanobacteria than in heterotrophs. Using this mutant for the first time we provide a genetic evidence of a mechanism independent of RecA that causes enhanced UVC resistance on light to dark transition.

Reduction of Mo(VI) by the bacterium Serratia sp. strain DRY5.

Science.gov (United States)

Rahman, M F A; Shukor, M Y; Suhaili, Z; Mustafa, S; Shamaan, N A; Syed, M A

2009-01-01

The need to isolate efficient heavy metal reducers for cost effective bioremediation strategy have resulted in the isolation of a potent molybdenum-reducing bacterium. The isolate was tentatively identified as Serratia sp. strain DRY5 based on the Biolog GN carbon utilization profiles and partial 16S rDNA molecular phylogeny. Strain DRY5 produced 2.3 times the amount of Mo-blue than S. marcescens strain Dr.Y6, 23 times more than E. coli K12 and 7 times more than E. cloacae strain 48. Strain DRY5 required 37 degrees C and pH 7.0 for optimum molybdenum reduction. Carbon sources such as sucrose, maltose, glucose and glycerol, supported cellular growth and molybdate reduction after 24 hr of static incubation. The most optimum carbon source that supported reduction was sucrose at 1.0% (w/v). Ammonium sulphate, ammonium chloride, glutamic acid, cysteine, and valine supported growth and molybdate reduction with ammonium sulphate as the optimum nitrogen source at 0. 2% (w/v). Molybdate reduction was optimally supported by 30 mM molybdate. The optimum concentration of phosphate for molybdate reduction was 5 mM when molybdate concentration was fixed at 30 mM and molybdate reduction was totally inhibited at 100 mM phosphate. Mo-blue produced by this strain shows a unique characteristic absorption profile with a maximum peak at 865 nm and a shoulder at 700 nm, Dialysis tubing experiment showed that 95.42% of Mo-blue was found in the dialysis tubing suggesting that the molybdate reduction seen in this bacterium was catalyzed by enzyme(s). The characteristics of isolate DRY5 suggest that it would be useful in the bioremediation ofmolybdenum-containing waste.

Genome sequence of three Psychrobacter sp. strains with potential applications in bioremediation

Directory of Open Access Journals (Sweden)

Aide Lasa

2017-06-01

Full Text Available To date, the genus Psychrobacter consists of 37 recognized species isolated from different sources, however they are more frequently found in cold and other non-polar environments of low water activity. Some strains belonging to the genus have shown different enzymatic activities with potential applications in bioremediation or food industry. In the present study, the whole genome sequences of three Psychrobacter-like strains (C 20.9, Cmf 22.2 and Rd 27.2 isolated from reared clams in Galicia (Spain are described. The sequenced genomes resulted in an assembly size of 3,143,782 bp for C 20.9 isolate, 3,168,467 bp for Cmf 22.2 isolate and 3,028,386 bp for Rd 27.2 isolate. Among the identified coding sequences of the genomes, mercury detoxification and biogeochemistry genes were found, as well as genes related to heavy metals and antibiotic resistance. Also virulence-related features were identified such as the siderophore vibrioferrin or an aerobactin-like siderophore. The phylogenetic analysis of the 16S rRNA gene suggested that these strains may represent novel species of the Psychrobacter genus. The genome sequences of the Psychrobacter sp. strains have been deposited at DDBJ/EMBL/GenBank under the accession numbers MRYA00000000 (Cmf 22.2, MRYB00000000 (Rd 27.2 and MRYC00000000 (C 20.9, and the sequences could be found at the site https://www.ncbi.nlm.nih.gov/bioproject/PRJNA353858.

ORF Sequence: NC_000911 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available Synechocystis sp. PCC 6803] MYFLLVTLVILVFPLLSIALEWTTSGNSQALVDVLARWFVFWGVGVRLFLAGVVQITKPSFTAEKILGVQSQDSLILVKELGIGNLAIASVALGSIFVNAWVLGAALAGGIFYLLAGINHILQPERNAKENYAMATDLFLGLLLGGILFFAWQP

Burkholderia humisilvae sp. nov., Burkholderia solisilvae sp. nov. and Burkholderia rhizosphaerae sp. nov., isolated from forest soil and rhizosphere soil.

Science.gov (United States)

Lee, Jae-Chan; Whang, Kyung-Sook

2015-09-01

Strains Y-12(T) and Y-47(T) were isolated from mountain forest soil and strain WR43(T) was isolated from rhizosphere soil, at Daejeon, Korea. The three strains grew at 10-55 °C (optimal growth at 28-30 °C), at pH 3.0-8.0 (optimal growth at pH 6.0) and in the presence of 0-4.0% (w/v) NaCl, growing optimally in the absence of added NaCl. On the basis of 16S rRNA gene sequence analysis, the three strains were found to belong to the genus Burkholderia, showing the closest phylogenetic similarity to Burkholderia diazotrophica JPY461(T) (97.2-97.7%); the similarity between the three sequences ranged from 98.3 to 98.7%. Additionally, the three strains formed a distinct group in phylogenetic trees based on the housekeeping genes recA and gyrB. The predominant ubiquinone was Q-8, the major fatty acids were C16 : 0 and C17  : 0 cyclo and the DNA G+C content of the novel isolates was 61.6-64.4 mol%. DNA-DNA relatedness among the three strains and the type strains of the closest species of the genus Burkholderia was less than 50%. On the basis of 16S rRNA, recA and gyrB gene sequence similarities, chemotaxonomic and phenotypic data, the three strains represent three novel species within the genus Burkholderia, for which the names Burkholderia humisilvae sp. nov. (type strain Y-12(T)= KACC 17601(T) = NBRC 109933(T) = NCAIM B 02543(T)), Burkholderia solisilvae sp. nov. (type strain Y-47(T) = KACC 17602(T)= NBRC 109934(T) = NCAIM B 02539(T)) and Burkholderia rhizosphaerae sp. nov. (type strain WR43(T) = KACC 17603(T) = NBRC 109935(T) = NCAIM B 02541(T)) are proposed.

Antiviral activity of the exopolysaccharide produced by Serratia sp. strain Gsm01 against Cucumber mosaic virus.

Science.gov (United States)

Ipper, Nagesh S; Cho, Saeyoull; Lee, Seon Hwa; Cho, Jun Mo; Hur, Jang Hyun; Lim, Chun Keun

2008-01-01

The potential of the exopolysaccharide (EPS) from a Serratia sp. strain Gsm01 as an antiviral agent against a yellow strain of Cucumber mosaic virus (CMV-Y) was evaluated in tobacco plants (Nicotiana tabacum cv. Xanthi-nc). The spray treatment of plants using an EPS preparation, 72 before CMV-Y inoculation, protected them against symptom appearance. Fifteen days after challenge inoculation with CMVY, 33.33% of plants showed mosaic symptoms in EPS-treated plants compared with 100% in the control plants. The EPS-treated plants, which showed mosaic symptoms, appeared three days later than the controls. The enzyme-linked immunosorbent assay (ELISA) and reverse transcriptase polymerase chain reaction (RT-PCR) analyses of the leaves of the protected plants revealed that the EPS treatment affected virus accumulation in those plants. Analysis of phenylalanine ammonia lyase, peroxidase, and phenols in protected plants revealed enhanced accumulation of these substances. The pathogenesis-related (PR) genes expression represented by PR-1b was increased in EPS-treated plants. This is the first report of a systemic induction of protection triggered by EPS produced by Serratia sp. against CMV-Y.

Mixotrophic growth of two thermophilic Methanosarcina strains, Methanosarcina thermophila TM-1 and Methanosarcina sp. SO-2P, on methanol and hydrogen/carbon dioxide

DEFF Research Database (Denmark)

Mladenovska, Zuzana; Ahring, Birgitte Kiær

1997-01-01

Two thermophilic strains, Methanosarcina thermophila TM-1 and Methanosarcina sp. SO-2P, were capable of mixotrophic growth on methanol and H-2/CO2. Activated carbon was, however, found to be necessary to support good growth. Both strains used hydrogen and methanol simultaneously. When methanol...

Genetic labelling and application of the isoproturon-mineralizing Sphingomonas sp. strain SRS2 in soil and rhizosphere.

Science.gov (United States)

Kristensen, K E; Jacobsen, C S; Hansen, L H; Aamand, J; Morgan, J A W; Sternberg, C; Sørensen, S R

2006-09-01

To construct a luxAB-labelled Sphingomonas sp. strain SRS2 maintaining the ability to mineralize the herbicide isoproturon and usable for monitoring the survival and distribution of strain SRS2 on plant roots in laboratory systems. We inserted the mini-Tn5-luxAB marker into strain SRS2 using conjugational mating. In the transconjugant mutants luciferase was produced in varying levels. The mutants showed significant differences in their ability to degrade isoproturon. One luxAB-labelled mutant maintained the ability to mineralize isoproturon and was therefore selected for monitoring colonization of barley roots. We successfully constructed a genetically labelled isoproturon-mineralizing-strain SRS2 and demonstrated its ability to survive in soil and its colonization of rhizosphere. The construction of a luxAB-labelled strain SRS2 maintaining the degradative ability, provides a powerful tool for ecological studies serving as the basis for evaluating SRS2 as a bioremediation agent.

Enhanced ferrihydrite dissolution by a unicellular, planktonic cyanobacterium: a biological contribution to particulate iron bioavailability.

Science.gov (United States)

Kranzler, Chana; Kessler, Nivi; Keren, Nir; Shaked, Yeala

2016-12-01

Iron (Fe) bioavailability, as determined by its sources, sinks, solubility and speciation, places severe environmental constraints on microorganisms in aquatic environments. Cyanobacteria are a widespread group of aquatic, photosynthetic microorganisms with especially high iron requirements. While iron exists predominantly in particulate form, little is known about its bioavailability to cyanobacteria. Some cyanobacteria secrete iron solubilizing ligands called siderophores, yet many environmentally relevant strains do not have this ability. This work explores the bioavailability of amorphous synthetic Fe-oxides (ferrihydrite) to the non-siderophore producing, unicellular cyanobacterium, Synechocystis sp PCC 6803. Iron uptake assays with 55 ferrihydrite established dissolution as a critical prerequisite for iron transport. Dissolution assays with the iron binding ligand, desferrioxamine B, demonstrated that Synechocystis 6803 enhances ferrihydrite dissolution, exerting siderophore-independent biological influence on ferrihydrite bioavailability. Dissolution mechanisms were studied using a range of experimental conditions; both cell-particle physical proximity and cellular electron flow were shown to be important determinants of bio-dissolution by Synechocystis 6803. Finally, the effects of ferrihydrite stability on bio-dissolution rates and cell physiology were measured, integrating biological and chemical aspects of ferrihydrite bioavailability. Collectively, these findings demonstrate that Synechocystis 6803 actively dissolves ferrihydrite, highlighting a significant biological component to mineral phase iron bioavailability in aquatic environments. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

The Role of Hydrophobicity and Surface Receptors at Hyphae of Lyophyllum sp. Strain Karsten in the Interaction with Burkholderia terrae BS001 – Implications for Interactions in Soil

Science.gov (United States)

Vila, Taissa; Nazir, Rashid; Rozental, Sonia; dos Santos, Giulia M. P.; Calixto, Renata O. R.; Barreto-Bergter, Eliana; Wick, Lukas Y.; van Elsas, Jan Dirk

2016-01-01

The soil bacterium Burkholderia terrae strain BS001 can interact with varying soil fungi, using mechanisms that range from the utilization of carbon/energy sources such as glycerol to the ability to reach novel territories in soil via co-migration with growing fungal mycelia. Here, we investigate the intrinsic properties of the B. terrae BS001 interaction with the basidiomycetous soil fungus Lyophyllum sp. strain Karsten. In some experiments, the ascomycetous Trichoderma asperellum 302 was also used. The hyphae of Lyophyllum sp. strain Karsten were largely hydrophilic on water-containing media versus hydrophobic when aerial, as evidenced by contact angle analyses (CA). Co-migration of B. terrae strain BS001 cells with the hyphae of the two fungi occurred preferentially along the - presumably hydrophilic - soil-dwelling hyphae, whereas aerial hyphae did not allow efficient migration, due to reduced thickness of their surrounding mucous films. Moreover, the cell numbers over the length of the hyphae in soil showed an uneven distribution, i.e., the CFU numbers increased from minima at the inoculation point to maximal numbers in the middle of the extended hyphae, then decreasing toward the terminal side. Microscopic analyses of the strain BS001 associations with the Lyophyllum sp. strain Karsten hyphae in the microcosms confirmed the presence of B. terrae BS001 cells on the mucous matter that was present at the hyphal surfaces of the fungi used. Cell agglomerates were found to accumulate at defined sites on the hyphal surfaces, which were coined ‘fungal-interactive’ hot spots. Evidence was further obtained for the contention that receptors for a physical bacterium-fungus interaction occur at the Lyophyllum sp. strain Karsten hyphal surface, in which the specific glycosphingolipid ceramide monohexoside (CMH) plays an important role. Thus, bacterial adherence may be mediated by heterogeneously distributed fungal-specific receptors, implying the CMH moieties. This

Potential Role of Diploscapter sp. Strain LKC25, a Bacterivorous Nematode from Soil, as a Vector of Food-Borne Pathogenic Bacteria to Preharvest Fruits and Vegetables

Science.gov (United States)

Gibbs, Daunte S.; Anderson, Gary L.; Beuchat, Larry R.; Carta, Lynn K.; Williams, Phillip L.

2005-01-01

Diploscapter, a thermotolerant, free-living soil bacterial-feeding nematode commonly found in compost, sewage, and agricultural soil in the United States, was studied to determine its potential role as a vehicle of Salmonella enterica serotype Poona, enterohemorrhagic Escherichia coli O157:H7, and Listeria monocytogenes in contaminating preharvest fruits and vegetables. The ability of Diploscapter sp. strain LKC25 to survive on agar media, in cow manure, and in composted turkey manure and to be attracted to, ingest, and disperse food-borne pathogens inoculated into soil or a mixture of soil and composted turkey manure was investigated. Diploscapter sp. strain LKC25 survived and reproduced in lawns of S. enterica serotype Poona, E. coli O157:H7, and L. monocytogenes on agar media and in cow manure and composted turkey manure. Attraction of Diploscapter sp. strain LKC25 to colonies of pathogenic bacteria on tryptic soy agar within 10, 20, 30, and 60 min and 24 h was determined. At least 85% of the worms initially placed 0.5 to 1 cm away from bacterial colonies migrated to the colonies within 1 h. Within 24 h, ≥90% of the worms were embedded in colonies. The potential of Diploscapter sp. strain LKC25 to shed pathogenic bacteria after exposure to bacteria inoculated into soil or a mixture of soil and composted turkey manure was investigated. Results indicate that Diploscapter sp. strain LKC25 can shed pathogenic bacteria after exposure to pathogens in these milieus. They also demonstrate its potential to serve as a vector of food-borne pathogenic bacteria in soil, with or without amendment with compost, to the surface of preharvest fruits and vegetables in contact with soil. PMID:15870330

Stereospecific oxidation of (R)- and (S)-1-indanol by naphthalene dioxygenase from Pseudomonas sp. strain NCIB 9816-4.

OpenAIRE

Lee, K; Resnick, S M; Gibson, D T

1997-01-01

A recombinant Escherichia coli strain which expresses naphthalene dioxygenase (NDO) from Pseudomonas sp. strain NCIB 9816-4 oxidized (S)-1-indanol to trans-(1S,3S)-indan-1,3-diol (95.5%) and (R)-3-hydroxy-1-indanone (4.5%). The same cells oxidized (R)-1-indanol to cis-1,3-indandiol (71%), (R)-3-hydroxy-1-indanone (18.2%), and cis-1,2,3-indantriol (10.8%). Purified NDO oxidized (S)-1-indenol to both syn- and anti-2,3-dihydroxy-1-indanol.

Stereospecific oxidation of (R)- and (S)-1-indanol by naphthalene dioxygenase from Pseudomonas sp. strain NCIB 9816-4.

Science.gov (United States)

Lee, K; Resnick, S M; Gibson, D T

1997-05-01

A recombinant Escherichia coli strain which expresses naphthalene dioxygenase (NDO) from Pseudomonas sp. strain NCIB 9816-4 oxidized (S)-1-indanol to trans-(1S,3S)-indan-1,3-diol (95.5%) and (R)-3-hydroxy-1-indanone (4.5%). The same cells oxidized (R)-1-indanol to cis-1,3-indandiol (71%), (R)-3-hydroxy-1-indanone (18.2%), and cis-1,2,3-indantriol (10.8%). Purified NDO oxidized (S)-1-indenol to both syn- and anti-2,3-dihydroxy-1-indanol.

Deep Sequencing-Identified Kanamycin-Resistant Paenibacillus sp. Strain KS1 Isolated from Epiphyte Tillandsia usneoides (Spanish Moss) in Central Florida, USA.

Science.gov (United States)

Lata, Pushpa; Govindarajan, Subramaniam S; Qi, Feng; Li, Jian-Liang; Sahoo, Malaya K

2017-02-02

Paenibacillus sp. strain KS1 was isolated from an epiphyte, Tillandsia usneoides (Spanish moss), in central Florida, USA. Here, we report a draft genome sequence of this strain, which consists of a total of 398 contigs spanning 6,508,195 bp, with a G+C content of 46.5% and comprising 5,401 predicted coding sequences. Copyright © 2017 Lata et al.

Organization of nif gene cluster in Frankia sp. EuIK1 strain, a symbiont of Elaeagnus umbellata.

Science.gov (United States)

Oh, Chang Jae; Kim, Ho Bang; Kim, Jitae; Kim, Won Jin; Lee, Hyoungseok; An, Chung Sun

2012-01-01

The nucleotide sequence of a 20.5-kb genomic region harboring nif genes was determined and analyzed. The fragment was obtained from Frankia sp. EuIK1 strain, an indigenous symbiont of Elaeagnus umbellata. A total of 20 ORFs including 12 nif genes were identified and subjected to comparative analysis with the genome sequences of 3 Frankia strains representing diverse host plant specificities. The nucleotide and deduced amino acid sequences showed highest levels of identity with orthologous genes from an Elaeagnus-infecting strain. The gene organization patterns around the nif gene clusters were well conserved among all 4 Frankia strains. However, characteristic features appeared in the location of the nifV gene for each Frankia strain, depending on the type of host plant. Sequence analysis was performed to determine the transcription units and suggested that there could be an independent operon starting from the nifW gene in the EuIK strain. Considering the organization patterns and their total extensions on the genome, we propose that the nif gene clusters remained stable despite genetic variations occurring in the Frankia genomes.

Efficient biotransformation of herbicide diuron by bacterial strain Micrococcus sp. PS-1.

Science.gov (United States)

Sharma, Priyanka; Chopra, Adity; Cameotra, Swaranjit Singh; Suri, C Raman

2010-11-01

A Gram-positive, Micrococcus sp. strain PS-1 capable of utilizing phenylurea herbicide diuron as a sole carbon source at a high concentration (up to 250 ppm) was isolated from diuron storage site by selective enrichment study. The taxonomic characterization with 16S rRNA gene sequencing (1,477 bp) identified PS-1 as a member of Micrococcus sp. It was studied for the degradation of diuron and a range of its analogues (monuron, linuron, monolinuron, chlortoluron and fenuron). The shake flasks experiments demonstrated fast degradation of diuron (up to 96% at 250 ppm within 30 h incubation) with the addition of small quantity (0.01%) of non-ionic detergent. The relative degradation profile by the isolate was in the order of fenuron > monuron > diuron > linuron > monolinuron > chlortoluron. Further, the biochemical characterization of catabolic pathway by spectroscopic and chromatographic techniques demonstrated that the degradation proceeded via formation of dealkylated metabolites to form 3,4-dichloroaniline (3,4-DCA). It was the major metabolite formed, associated with profound increase in degradation kinetics in presence of appropriate additive.

Isolation of a bacterial strain, Acinetobacter sp. from centrate wastewater and study of its cooperation with algae in nutrients removal.

Science.gov (United States)

Liu, Hui; Lu, Qian; Wang, Qin; Liu, Wen; Wei, Qian; Ren, Hongyan; Ming, Caibing; Min, Min; Chen, Paul; Ruan, Roger

2017-07-01

Algae were able to grow healthy on bacteria-containing centrate wastewater in a pilot-scale bioreactor. The batch experiment indicated that the co-cultivation of algae and wastewater-borne bacteria improved the removal efficiencies of chemical oxygen demand and total phosphorus in centrate wastewater to 93.01% and 98.78%, respectively. A strain of beneficial aerobic bacteria, Acinetobacter sp., was isolated and its biochemical characteristics were explored. Synergistic cooperation was observed in the growth of algae and Acinetobacter sp. Removal efficiencies of some nutrients were improved significantly by the co-cultivation of algae and Acinetobacter sp. After treatment, residual nutrients in centrate wastewater reached the permissible discharge limit. The cooperation between algae and Acinetobacter sp. was in part attributed to the exchange of carbon dioxide and oxygen between the algae and bacteria. This synergetic relationship between algae and Acinetobacter sp. provided a promising way to treat the wastewater by improving the nutrients removal and biomass production. Copyright © 2017 Elsevier Ltd. All rights reserved.

Pré-seleção de estirpes de Rhizobium sp. para amendoim Preliminary selection of peanut Rhizobium sp. strains

Directory of Open Access Journals (Sweden)

Antonio Roberto Giardini

1984-01-01

Full Text Available Um ensaio foi conduzido em casa de vegetação, com solução nutritiva isenta de N, com o objetivo de selecionar estirpes de Rhizobium eficientes fixadoras de N2, quando associadas com amendoim (Arachis hypogaea L. cultivar Tatu. Foram testadas 35 estirpes de Rhizobium sp., isoladas de quinze diferentes espécies de leguminosas tropicais, e incluído um tratamento de inoculação com solo previamente cultivado com amendoim. Das 35 estirpes testadas, doze formaram nódulos e, entre essas, sete foram eficientes fixadoras de nitrogênio. Das doze estirpes que nodularam, sete foram isoladas de leguminosas da tribo Hedysareae (à qual pertence o género Arachis e, destas, apenas quatro foram eficientes fixadoras de nitrogênio. O peso e o número de nódulos não se mostraram como critérios adequados para avaliação da eficiência.An experiment was carried out in Leonard jars, in the greenhouse, with nitrogen-free nutrient solution to test the efficiency of 35 strains of rhizobia isolated from 15 species of tropical legumes. Twelve of the tested strains were capable of nodule formation in peanut. Seven of those strains were isolated from the trible Hedysareae, which includes the genus Arachis. Only four of the rhizobia strains with inducing nodulation were effective. Dry weight and number of nodules were not good criteria for evaluating effectiveness.

Biodegradation of buprofezin by Rhodococcus sp. strain YL-1 isolated from rice field soil.

Science.gov (United States)

Li, Chao; Zhang, Ji; Wu, Zhi-Guo; Cao, Li; Yan, Xin; Li, Shun-Peng

2012-03-14

A buprofezin-degrading bacterium, YL-1, was isolated from rice field soil. YL-1 was identified as Rhodococcus sp. on the basis of the comparative analysis of 16S rDNA sequences. The strain could use buprofezin as the sole source of carbon and nitrogen for growth and was able to degrade 92.4% of 50 mg L(-1) buprofezin within 48 h in liquid culture. During the degradation of buprofezin, four possible metabolites, 2-tert-butylimino-3-isopropyl-1,3,5-thiadiazinan-4-one, N-tert-butyl-thioformimidic acid formylaminomethyl ester, 2-isothiocyanato-2-methyl-propane, and 2-isothiocyanato-propane, were identified using gas chromatography-mass spectrometry (GC-MS) analysis. The catechol 2,3-dioxygenase activity was strongly induced during the degradation of buprofezin. A novel microbial biodegradation pathway for buprofezin was proposed on the basis of these metabolites. The inoculation of soils treated with buprofezin with strain YL-1 resulted in a higher degradation rate than that observed in noninoculated soils, indicating that strain YL-1 has the potential to be used in the bioremediation of buprofezin-contaminated environments.

Molecular characterization of protease activity in Serratia sp. strain SCBI and its importance in cytotoxicity and virulence.

Science.gov (United States)

Petersen, Lauren M; Tisa, Louis S

2014-11-01

A newly recognized Serratia species, termed South African Caenorhabditis briggsae isolate (SCBI), is both a mutualist of the nematode Caenorhabditis briggsae KT0001 and a pathogen of lepidopteran insects. Serratia sp. strain SCBI displays high proteolytic activity, and because secreted proteases are known virulence factors for many pathogens, the purpose of this study was to identify genes essential for extracellular protease activity in Serratia sp. strain SCBI and to determine what role proteases play in insect pathogenesis and cytotoxicity. A bank of 2,100 transposon mutants was generated, and six SCBI mutants with defective proteolytic activity were identified. These mutants were also defective in cytotoxicity. The mutants were found defective in genes encoding the following proteins: alkaline metalloprotease secretion protein AprE, a BglB family transcriptional antiterminator, an inosine/xanthosine triphosphatase, GidA, a methyl-accepting chemotaxis protein, and a PIN domain protein. Gene expression analysis on these six mutants showed significant downregulation in mRNA levels of several different types of predicted protease genes. In addition, transcriptome sequencing (RNA-seq) analysis provided insight into how inactivation of AprE, GidA, and a PIN domain protein influences motility and virulence, as well as protease activity. Using quantitative reverse transcription-PCR (qRT-PCR) to further characterize expression of predicted protease genes in wild-type Serratia sp. SCBI, the highest mRNA levels for the alkaline metalloprotease genes (termed prtA1 to prtA4) occurred following the death of an insect host, while two serine protease and two metalloprotease genes had their highest mRNA levels during active infection. Overall, these results indicate that proteolytic activity is essential for cytotoxicity in Serratia sp. SCBI and that its regulation appears to be highly complex. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Isolation of a buprofezin co-metabolizing strain of Pseudomonas sp. DFS35-4 and identification of the buprofezin transformation pathway.

Science.gov (United States)

Chen, Kai; Liu, Xiao-Mei; Li, Rong; Liu, Yuan; Hu, Hai; Li, Shun-Peng; Jiang, Jian-Dong

2011-11-01

Buprofezin is a widely used insecticide that has caused environmental pollution in many areas. However, biodegradation of buprofezin by pure cultures has not been extensively studied, and the transformation pathway of buprofezin remains unclear. In this paper, a buprofezin co-metabolizing strain of DFS35-4 was isolated from a buprofezin-polluted soil in China. Strain DFS35-4 was preliminarily identified as Pseudomonas sp. based on its morphological, physiological, and biochemical properties, as well as 16S rRNA gene analysis. In the presence of 2.0 g l(-1) sodium citrate, strain DFS35-4 degraded over 70% of 50 mg l(-1) buprofezin in 3 days. Strain DFS35-4 efficiently degraded buprofezin in the pH range of 5.0-10.0 and at temperatures between 20 and 30°C. Three metabolites, 2-imino-5-phenyl-3-(propan-2-yl)-1,3,5-thiadiazinan-4-one, 2-imino-5-phenyl-1,3,5-thiadiazinan-4-one, and methyl(phenyl) carbamic acid, were identified during the degradation of buprofezin using gas chromatography-mass spectrometry (GC-MS) and tandem mass spectrometry (MS/MS). A partial transformation pathway of buprofezin in Pseudomonas sp. DFS35-4 was proposed based on these metabolites.

Draft Genome Sequence of Sphingomonas sp. Strain Sph1(2015), Isolated from a Fouled Membrane Filter Used To Produce Drinking Water.

Science.gov (United States)

de Vries, Hendrik J; Marshall, Ian P G; Schreiber, Lars; Plugge, Caroline M

2017-06-15

We report here the high-quality draft genome sequence of Sphingomonas sp. strain Sph1(2015), isolated from a fouled reverse osmosis membrane used for the production of high-quality drinking water. The draft sequence provides insights into the modus operandi of this strain to form biofilms on membrane surfaces. This knowledge offers tools to develop novel antifouling strategies. Copyright © 2017 de Vries et al.

Evidence for cooperative mineralization of diuron by Arthrobacter sp. BS2 and Achromobacter sp. SP1 isolated from a mixed culture enriched from diuron exposed environments.

Science.gov (United States)

Devers-Lamrani, Marion; Pesce, Stéphane; Rouard, Nadine; Martin-Laurent, Fabrice

2014-12-01

Diuron was found to be mineralized in buffer strip soil (BS) and in the sediments (SED) of the Morcille river in the Beaujolais vineyard repeatedly treated with this herbicide. Enrichment cultures from BS and SED samples led to the isolation of three bacterial strains transforming diuron to 3,4-dichloroaniline (3,4-DCA) its aniline derivative. 16S rRNA sequencing revealed that they belonged to the genus Arthrobacter (99% of similarity to Arthrobacter globiformis strain K01-01) and were designated as Arthrobacter sp. BS1, BS2 and SED1. Diuron-degrading potential characterized by sequencing of the puhA gene, characterizing the diuron-degradaing potential, revealed 99% similarity to A. globiformis strain D47 puhA gene isolated a decade ago in the UK. These isolates were also able to use chlorotoluron for their growth. Although able to degrade linuron and monolinuron to related aniline derivatives they were not growing on them. Enrichment cultures led to the isolation of a strain from the sediments entirely degrading 3,4-DCA. 16S rRNA sequence analysis showed that it was affiliated to the genus Achromobacter (99% of similarity to Achromobacter sp. CH1) and was designated as Achromobacter sp. SP1. The dcaQ gene encoding enzyme responsible for the transformation of 3,4-DCA to chlorocatechol was found in SP1 with 99% similarity to that of Comamonas testosteroni WDL7. This isolate also used for its growth a range of anilines (3-chloro-4-methyl-aniline, 4-isopropylaniline, 4-chloroaniline, 3-chloroaniline, 4-bromoaniline). The mixed culture composed of BS2 and SP1 strains entirely mineralizes (14)C-diuron to (14)CO2. Diuron-mineralization observed in the enrichment culture could result from the metabolic cooperation between these two populations. Copyright © 2014. Published by Elsevier Ltd.

Isolation of a human intestinal anaerobe, Bifidobacterium sp. strain SEN, capable of hydrolyzing sennosides to sennidins.

OpenAIRE

Akao, T; Che, Q M; Kobashi, K; Yang, L; Hattori, M; Namba, T

1994-01-01

A strictly anaerobic bacterium capable of metabolizing sennosides was isolated from human feces and identified as Bifidobacterium sp., named strain SEN. The bacterium hydrolyzed sennosides A and B to sennidins A and B via sennidin A and B 8-monoglucosides, respectively. Among nine species of Bifidobacterium having beta-glucosidase activity, only Bifidobacterium dentium and B. adolescentis metabolized sennoside B to sennidin B, suggesting that the sennoside-metabolizing bacteria produce a nove...

Cyanobacterial carbon metabolism: Fluxome plasticity and oxygen dependence

DEFF Research Database (Denmark)

Wan, Ni; Delorenzo, Drew M.; He, Lian

2017-01-01

Synechocystis sp. strain PCC 6803 has been widely used as a photo-biorefinery chassis. Based on its genome annotation, this species contains a complete TCA cycle, an Embden-Meyerhof-Parnas pathway (EMPP), an oxidative pentose phosphate pathway (OPPP), and an Entner-Doudoroff pathway (EDP). To eva...... the ability to regulate their fluxes under various growth conditions (plastic), whereas its TCA cycle always maintains at low levels (rigid). This work also demonstrates how genetic profiles do not always reflect actual metabolic flux through native or heterologous pathways....

Strain and culture medium optimization for production enhancement of prodiginines from marine-derived Streptomyces sp. GQQ-10

Science.gov (United States)

Li, Xueping; Zhang, Guojian; Zhu, Tianjiao; Li, Dehai; Gu, Qianqun

2012-09-01

A mutant (GQQ-M6) of a Sponge-Derived streptomyces sp. GQQ-10 obtained by UV-induced mutation was used for producing prodiginines (PGs). Single factor experiments and orthogonal array design (OAD) methods were employed for medium optimization. In the single factor method, the effects of soluble starch, glucose, soybean flour, yeast extract and sodium acetate on PGs production were investigated individually. In the subsequent OAD experiments, the concentrations of these 5 key nutritional components combined with salinity were further adjusted. The mutant strain GQQ-M6 gave a 2.2-fold higher PGs production than that of the parent strain; OAD experiments offered a PGs yield of 61mg L-1, which was 10 times higher than that of the initial GQQ-10 strain under the original cultivation mode.

A new endonuclease recognizing the deoxynucleotide sequence CCNNGG from the cyanobacterium Synechocystis 6701.

Science.gov (United States)

Calléja, F; Tandeau de Marsac, N; Coursin, T; van Ormondt, H; de Waard, A

1985-09-25

A new sequence-specific endonuclease from the cyanobacterium Synechocystis species PCC 6701 has been purified and characterized. This enzyme, SecI, is unique in recognizing the nucleotide sequence: 5' -CCNNGG-3' 3' -GGNNCC-5' and cleaves it at the position indicated by the symbol. Two other restriction endonucleases, SecII and SecIII, found in this organism are isoschizomers of MspI and MstII, respectively.

Enhancement of 2,3-butanediol production from Jerusalem artichoke tuber extract by a recombinant Bacillus sp. strain BRC1 with increased inulinase activity.

Science.gov (United States)

Park, Jang Min; Oh, Baek-Rock; Kang, In Yeong; Heo, Sun-Yeon; Seo, Jeong-Woo; Park, Seung-Moon; Hong, Won-Kyung; Kim, Chul Ho

2017-07-01

A Bacillus sp. strain named BRC1 is capable of producing 2,3-butanediol (2,3-BD) using hydrolysates of the Jerusalem artichoke tuber (JAT), a rich source of the fructose polymer inulin. To enhance 2,3-BD production, we undertook an extensive analysis of the Bacillus sp. BRC1 genome, identifying a putative gene (sacC) encoding a fructan hydrolysis enzyme and characterizing the activity of the resulting recombinant protein expressed in and purified from Escherichia coli. Introduction of the sacC gene into Bacillus sp. BRC1 using an expression vector increased enzymatic activity more than twofold. Consistent with this increased enzyme expression, 2,3-BD production from JAT was also increased from 3.98 to 8.10 g L -1 . Fed-batch fermentation of the recombinant strain produced a maximal level of 2,3-BD production of 28.6 g L -1 , showing a high theoretical yield of 92.3%.

Draft genome sequence of two Shingopyxis sp. strains H107 and H115 isolated from a chloraminated drinking water distriburion system simulator

Data.gov (United States)

U.S. Environmental Protection Agency — Draft genome sequence of two Shingopyxis sp. strains H107 and H115 isolated from a chloraminated drinking water distriburion system simulator. This dataset is...

An Entamoeba sp. strain isolated from rhesus monkey is virulent but genetically different from Entamoeba histolytica.

Science.gov (United States)

Tachibana, Hiroshi; Yanagi, Tetsuo; Pandey, Kishor; Cheng, Xun-Jia; Kobayashi, Seiki; Sherchand, Jeevan B; Kanbara, Hiroji

2007-06-01

An Entamoeba sp. strain, P19-061405, was isolated from a rhesus monkey in Nepal and characterized genetically. The strain was initially identified as Entamoeba histolytica using PCR amplification of peroxiredoxin genes. However, sequence analysis of the 18S rRNA gene showed a 0.8% difference when compared to the reference E. histolytica HM-1:IMSS human strain. Differences were also observed in the 5.8S rRNA gene and the internal transcribed spacer (ITS) regions 1 and 2, and analysis of the serine-rich protein gene from the monkey strain showed unique codon usages compared to E. histolytica isolated from humans. The amino acid sequences of two hexokinases and two glucose phosphate isomerases also differed from those of E. histolytica. Isoenzyme analyses of these enzymes in the monkey strain showed different electrophoretic mobility patterns compared with E. histolytica isolates. Analysis of peroxiredoxin genes indicated the presence of at least seven different types of protein, none of which were identical to proteins in E. histolytica. When the trophozoites from the monkey strain were inoculated into the livers of hamsters, formation of amebic abscesses was observed 7 days after the injection. These results demonstrate that the strain is genetically different from E. histolytica and is virulent. Revival of the name Entamoeba nuttalli is proposed for the organism.

Overexpression, purification, crystallization and preliminary X-ray cystallographic studies of a proline-specific aminopeptidase from Aneurinibacillus sp. strain AM-1

International Nuclear Information System (INIS)

Akioka, Makoto; Nakano, Hiroaki; Horikiri, Aya; Tsujimoto, Yoshiyuki; Matsui, Hiroshi; Shimizu, Tetsuya; Nakatsu, Toru; Kato, Hiroaki; Watanabe, Kunihiko

2006-01-01

Preliminary X-ray crystallographic study of a proline-specific aminopepitdase from Aneurinibacillus sp, strain AM-1 was carried out. To elucidate the structure and molecular mechanism of a characteristic proline-specific aminopeptidase produced by the thermophile Aneurinibacillus sp. strain AM-1, its gene was cloned and the recombinant protein was overexpressed in Escherichia coli, purified and crystallized using the hanging-drop vapour-diffusion method. X-ray diffraction data were collected to 1.8 Å resolution from the recombinant aminopeptidase crystal. The crystals belong to the orthorhombic space group P2 1 2 1 2, with unit-cell parameters a = 93.62, b = 68.20, c = 76.84 Å. A complete data set was also obtained from crystals of SeMet-substituted aminopeptidase. Data in the resolution range 20–2.1 Å from the MAD data set from the SeMet-substituted crystal were used for phase determination

Shewanella hafniensis sp. nov. and Shewanella morhuae sp. nov., isolated from marine fish of the Baltic Sea

DEFF Research Database (Denmark)

Satomi, M.; Vogel, Birte Fonnesbech; Gram, Lone

2006-01-01

Two novel species belonging to the genus Shewanella are described on the basis of their phenotypic characteristics, phylogenetic analyses of 16S rRNA and gyrB gene sequences and levels of DNA-DNA hybridization. A total of 47 strains belonging to two novel Gram-negative, psychrotolerant, H2S-produ...... species, Shewanella hafniensis sp. nov. (type strain P010T=ATCC BAA-1207T=NBRC 100975T) and Shewanella morhuae sp. nov. (type strain U1417T=ATCC BAA-1205T=NBRC 100978T), are described....

Improvement of FK506 Production in the High-Yielding Strain Streptomyces sp. RM7011 by Engineering the Supply of Allylmalonyl-CoA Through a Combination of Genetic and Chemical Approach.

Science.gov (United States)

Mo, SangJoon; Lee, Sung-Kwon; Jin, Ying-Yu; Suh, Joo-Won

2016-02-01

FK506, a widely used immunosuppressant, is a 23-membered polyketide macrolide that is produced by several Streptomyces species. FK506 high-yielding strain Streptomyces sp. RM7011 was developed from the discovered Streptomyces sp. KCCM 11116P by random mutagenesis in our previous study. The results of transcript expression analysis showed that the transcription levels of tcsA, B, C, and D were increased in Streptomyces sp. RM7011 by 2.1-, 3.1-, 3.3-, and 4.1- fold, respectively, compared with Streptomyces sp. KCCM 11116P. The overexpression of tcsABCD genes in Streptomyces sp. RM7011 gave rise to approximately 2.5-fold (238.1 μg/ml) increase in the level of FK506 production compared with that of Streptomyces sp. RM7011. When vinyl pentanoate was added into the culture broth of Streptomyces sp. RM7011, the level of FK506 production was approximately 2.2-fold (207.7 μg/ml) higher than that of the unsupplemented fermentation. Furthermore, supplementing the culture broth of Streptomyces sp. RM7011 expressing tcsABCD genes with vinyl pentanoate resulted in an additional 1.7-fold improvement in the FK506 titer (498.1 μg/ml) compared with that observed under nonsupplemented condition. Overall, the level of FK506 production was increased approximately 5.2-fold by engineering the supply of allylmalonyl-CoA in the high-yielding strain Streptomyces sp. RM7011, using a combination of overexpressing tcsABCD genes and adding vinyl pentanoate, as compared with Streptomyces sp. RM7011 (95.3 μg/ml). Moreover, among the three precursors analyzed, pentanoate was the most effective precursor, supporting the highest titer of FK506 in the FK506 high-yielding strain Streptomyces sp. RM7011.

Complete genome of Pseudomonas sp. strain L10.10, a psychrotolerant biofertilizer that could promote plant growth.

Science.gov (United States)

See-Too, Wah Seng; Lim, Yan-Lue; Ee, Robson; Convey, Peter; Pearce, David A; Yin, Wai-Fong; Chan, Kok Gan

2016-03-20

Pseudomonas sp. strain L10.10 (=DSM 101070) is a psychrotolerant bacterium which was isolated from Lagoon Island, Antarctica. Analysis of its complete genome sequence indicates its possible role as a plant-growth promoting bacterium, including nitrogen-fixing ability and indole acetic acid (IAA)-producing trait, with additional suggestion of plant disease prevention attributes via hydrogen cyanide production. Copyright © 2016 Elsevier B.V. All rights reserved.

DL-7-azatryptophan and citrulline metabolism in the cyanobacterium Anabaena sp. strain 1F

International Nuclear Information System (INIS)

Chen, C.H.; Van Baalen, C.; Tabita, F.R.

1987-01-01

An alternative route for the primary assimilation of ammonia proceeds via glutamine synthetase-carbamyl phosphate synthetase and its inherent glutaminase activity in Anabaena sp. strain 1F, a marine filamentous, heterocystous cyanobacterium. Evidence for the presence of this possible alternative route to glutamate was provided by the use of amino acid analogs as specific enzyme inhibitors, enzymological studies, and radioistopic labeling experiments. The amino acid pool patterns of continuous cultures of Anabaena sp. strain 1F were markedly influenced by the nitrogen source. A relatively high concentration of glutamate was maintained in the amino acid pools of all cultures irrespective of the nitrogen source, reflecting the central role of glutamate in nitrogen metabolism. The addition of 1.0 microM azaserine increased the intracellular pools of glutamate and glutamine. All attempts to detect any enzymatic activity for glutamate synthase by measuring the formation of L-[ 14 C]glutamate from 2-keto-[1- 14 C]glutarate and glutamine failed. The addition of 10 microM DL-7-azatryptophan caused a transient accumulation of intracellular citrulline and alanine which was not affected by the presence of chloramphenicol. The in vitro activity of carbamyl phosphate synthetase and glutaminase increased severalfold in the presence of azatryptophan. Results from radioisotopic labeling experiments with [ 14 C]bicarbonate and L-[1- 14 C]ornithine also indicated that citrulline was formed via carbamyl phosphate synthetase and ornithine transcarbamylase. In addition to its effects on nitrogen metabolism, azatryptophan also affected carbon metabolism by inhibiting photosynthetic carbon assimilation and photosynthetic oxygen evolution

Prauserella endophytica sp. nov., an endophytic actinobacterium isolated from Tamarix taklamakanensis.

Science.gov (United States)

Liu, Jia-Meng; Habden, Xugela; Guo, Lin; Tuo, Li; Jiang, Zhong-Ke; Liu, Shao-Wei; Liu, Xian-Fu; Chen, Li; Li, Rong-Feng; Zhang, Yu-Qin; Sun, Cheng-Hang

2015-06-01

A novel endophytic actinobacterium, designated strain SP28S-3(T), was isolated from a surface-sterilized stem of Tamarix taklamakanensis collected from the southern edge of Taklamakan desert, Xinjiang, China. Strain SP28S-3(T) was found to show chemotaxonomic and morphological properties consistent with its classification in the genus Prauserella. The polar lipids were found to consist of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphoglycolipid, phosphatidylcholine, phosphatidylinositol, a glycolipid, an aminolipid and unidentified phospholipids. The major fatty acids (>10 %) were identified as iso-C16:0 and C16:0. The genomic DNA G+C content was determined to be 69.7 mol%. Phylogenetic analysis of strain SP28S-3(T) clearly showed that the strain had the highest similarity of 16S rRNA gene sequence with Prauserella coralliicola SCSIO 11529(T) (99.9 %), followed by Prauserella marina DSM 45268(T) (97.0 %) and is affiliated with the genus Prauserella. The low level (47.8 ± 5.5 %) of DNA-DNA relatedness between strain SP28S-3(T) and P. coralliicola SCSIO 11529(T) combined with other polyphasic taxonomic evidence clearly support the conclusion that strain SP28S-3(T) represents a novel Prauserella species, for which the name Prauserella endophytica sp. nov. is proposed. The type strain is SP28S-3(T) (=DSM 46655(T) = CGMCC 4.7182 (T)).

Detection of a Rickettsia Closely Related to Rickettsia aeschlimannii, “Rickettsia heilongjiangensis,” Rickettsia sp. Strain RpA4, and Ehrlichia muris in Ticks Collected in Russia and Kazakhstan

OpenAIRE

Shpynov, Stanislav; Fournier, Pierre-Edouard; Rudakov, Nikolay; Tankibaev, Marat; Tarasevich, Irina; Raoult, Didier

2004-01-01

Using PCR, we screened 411 ticks from four genera collected in Russia and Kazakhstan for the presence of rickettsiae and ehrlichiae. In Russia, we detected “Rickettsia heilongjiangensis,” Rickettsia sp. strain RpA4, and Ehrlichia muris. In Kazakhstan, we detected Rickettsia sp. strain RpA4 and a rickettsia closely related to Rickettsia aeschlimannii. These agents should be considered in a differential diagnosis of tick-borne infections in these areas.

Acquired thermotolerance and heat shock in the extremely thermophilic archaebacterium Sulfolobus sp. strain B12.

OpenAIRE

Trent, J D; Osipiuk, J; Pinkau, T

1990-01-01

The extreme thermophile Sulfolobus sp. strain B12 exhibits an acquired thermotolerance response. Thus, survival of cells from a 70 degrees C culture at the lethal temperature of 92 degrees C was enhanced by as much as 6 orders of magnitude over a 2-h period if the culture was preheated to 88 degrees C for 60 min or longer before being exposed to the lethal temperature. In eubacteria and eucaryotes, acquired thermotolerance correlates with the induced synthesis of a dozen or so proteins known ...

Fresh Water Cyanobacteria Geitlerinema sp. CCC728 and Arthrospira sp. CCC729 as an Anticancer Drug Resource.

Directory of Open Access Journals (Sweden)

Akanksha Srivastava

Full Text Available An increasing number of cancer patients worldwide, especially in third world countries, have raised concern to explore natural drug resources, such as the less explored fresh water filamentous cyanobacteria. Six strains of cyanobacteria (Phormidium sp. CCC727, Geitlerinema sp. CCC728, Arthrospira sp. CCC729, Phormidium sp. CCC731, Phormidium sp. CCC730, and Leptolyngbya sp. CCC732 were isolated (paddy fields and ponds in the Banaras Hindu University, campus and five strains screened for anticancer potential using human colon adenocarcinoma (HT29 and human kidney adenocarcinoma (A498 cancer cell lines. Geitlerinema sp. CCC728 and Arthrospira sp. CCC729 were the most potent as determined by examination of morphological features and by inhibition of growth by graded concentrations of crude extracts and thin-layer chromatography (TLC eluates. Cell cycle analysis and multiplex assays using cancer biomarkers also confirmed Geitlerinema sp. CCC728 and Arthrospira sp. CCC729 as cancer drug resources. Apoptotic studies in the cells of A498 (cancer and MCF-10A (normal human epithelial exposed to crude extracts and TLC fractions revealed no significant impact on MCF-10A cells emphasizing its importance in the development of anticancer drug. Identification of biomolecules from these extracts are in progress.

Fresh Water Cyanobacteria Geitlerinema sp. CCC728 and Arthrospira sp. CCC729 as an Anticancer Drug Resource.

Science.gov (United States)

Srivastava, Akanksha; Tiwari, Ratnakar; Srivastava, Vikas; Singh, Tej Bali; Asthana, Ravi Kumar

2015-01-01

An increasing number of cancer patients worldwide, especially in third world countries, have raised concern to explore natural drug resources, such as the less explored fresh water filamentous cyanobacteria. Six strains of cyanobacteria (Phormidium sp. CCC727, Geitlerinema sp. CCC728, Arthrospira sp. CCC729, Phormidium sp. CCC731, Phormidium sp. CCC730, and Leptolyngbya sp. CCC732) were isolated (paddy fields and ponds in the Banaras Hindu University, campus) and five strains screened for anticancer potential using human colon adenocarcinoma (HT29) and human kidney adenocarcinoma (A498) cancer cell lines. Geitlerinema sp. CCC728 and Arthrospira sp. CCC729 were the most potent as determined by examination of morphological features and by inhibition of growth by graded concentrations of crude extracts and thin-layer chromatography (TLC) eluates. Cell cycle analysis and multiplex assays using cancer biomarkers also confirmed Geitlerinema sp. CCC728 and Arthrospira sp. CCC729 as cancer drug resources. Apoptotic studies in the cells of A498 (cancer) and MCF-10A (normal human epithelial) exposed to crude extracts and TLC fractions revealed no significant impact on MCF-10A cells emphasizing its importance in the development of anticancer drug. Identification of biomolecules from these extracts are in progress.

Alternating Current-Dielectrophoresis Collection and Chaining of Phytoplankton on Chip: Comparison of Individual Species and Artificial Communities

Directory of Open Access Journals (Sweden)

Coralie Siebman

2017-01-01

Full Text Available The capability of alternating current (AC dielectrophoresis (DEP for on-chip capture and chaining of the three species representative of freshwater phytoplankton was evaluated. The effects of the AC field intensity, frequency and duration on the chaining efficiency and chain lengths of green alga Chlamydomonas reinhardtii, cyanobacterium Synechocystis sp. and diatom Cyclotella meneghiniana were characterized systematically. C. reinhardtii showed an increase of the chaining efficiency from 100 Hz to 500 kHz at all field intensities; C. meneghiniana presented a decrease of chaining efficiency from 100 Hz to 1 kHz followed by a significant increase from 1 kHz to 500 kHz, while Synechocystis sp. exhibited low chaining tendency at all frequencies and all field intensities. The experimentally-determined DEP response and cell alignment of each microorganism were in agreement with their effective polarizability. Mixtures of cells in equal proportion or 10-times excess of Synechocystis sp. showed important differences in terms of chaining efficiency and length of the chains compared with the results obtained when the cells were alone in suspension. While a constant degree of chaining was observed with the mixture of C. reinhardtii and C. meneghiniana, the presence of Synechocystis sp. in each mixture suppressed the formation of chains for the two other phytoplankton species. All of these results prove the potential of DEP to discriminate different phytoplankton species depending on their effective polarizability and to enable their manipulation, such as specific collection or separation in freshwater.

Spiribacter curvatus sp. nov., a moderately halophilic bacterium isolated from a saltern.

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León, María José; Rodríguez-Olmos, Angel; Sánchez-Porro, Cristina; López-Pérez, Mario; Rodríguez-Valera, Francisco; Soliveri, Juan; Ventosa, Antonio; Copa-Patiño, José Luis

2015-12-01

A novel pink-pigmented bacterial strain, UAH-SP71T, was isolated from a saltern located in Santa Pola, Alicante (Spain) and the complete genome sequence was analysed and compared with that of Spiribacter salinus M19-40T, suggesting that the two strains constituted two separate species, with a 77.3% ANI value. In this paper, strain UAH-SP71T was investigated in a taxonomic study using a polyphasic approach. Strain UAH-SP71T was a Gram-stain-negative, strictly aerobic, non-motile curved rod that grew in media containing 5-20% (w/v) NaCl (optimum 10% NaCl), at 5-40 °C (optimum 37 °C) and at pH 5-10 (optimum pH 8). Phylogenetic analysis based on the comparison of 16S rRNA gene sequences revealed thatstrain UAH-SP71T is a member of the genus Spiribacter, showing a sequence similarity of 96.5% with Spiribacter salinus M19-40T. Other related species are also members of the family Ectothiorhodospiraceae, including Arhodomonas recens RS91T (95.5% 16S rRNA gene sequence similarity), Arhodomonas aquaeolei ATCC 49307T (95.4 %) and Alkalilimnicola ehrlichii MLHE-1T (94.9 %). DNA-DNA hybridization between strain UAH-SP71T and Spiribacter salinus M19-40T was 39 %. The major cellular fatty acids of strain UAH-SP71T were C18 : 1ω6c and/or C18 : 1ω7c, C16 : 0, C16 : 1ω6c and/or C16 : 1ω7c, C10 : 0 3-OH and C12 : 0, a pattern similar to that of Spiribacter salinus M19-40T. Phylogenetic, phenotypic and genotypic differences between strain UAH-SP71T and Spiribacter salinus M19-40T indicate that strainUAH-SP71T represents a novel species of the genus Spiribacter, for which the name Spiribacter curvatus sp. nov. is proposed. The type strain is UAH-SP71T (5CECT8396T5DSM 28542T).

Isolation and characterization of a novel 2-methyl-4-chlorophenoxyacetic acid-degrading Enterobacter sp. strain SE08.

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Tan, Lin; Hu, Qiulong; Xiong, Xingyao; Su, Xiaojun; Huang, Yanning; Jiang, Ziwei; Zhou, Qingming; Zhao, Songyi; Zeng, Wei-ai

2013-10-01

A bacterial strain (SE08) capable of utilizing 2-methyl-4-chlorophenoxy acetic acid (MCPA) as the sole carbon and energy source for growth was isolated by continuous enrichment culturing in minimal salt medium (MSM) from a long term MCPA exposed soil. This bacterial strain was identified as Enterobacter sp. based on morphological, physiological and biochemical tests, as well as 16S rRNA sequence analysis. Its ability to degrade MCPA was determined using high performance liquid chromatography. The strain SE08 can tolerate unusually high MCPA concentrations (125-2000mg/L). The influences of culturing factors (initial concentration, pH, and temperature) on the bacterial growth and substrate degradation were studied. The results showed that the optimal MCPA degradation occurred at an MCPA concentration of 500mg/L, 30°C and pH 6.0. Under these conditions, 68.5 percent of MCPA in MSM was degraded by SE08, and the OD600nm reached 0.64 after culturing for 72h. The degradation of MCPA could be enhanced by addition of both carbon and nitrogen sources. At an initial MCPA concentration of 500mg/L, when 5g/L glucose and 2.5g/L yeast extract were added into the MSM media, the MCPA degradation was significantly increased to 83.8 percent, and OD600nm was increased to 1.09 after incubation at 30°C and pH 6.0 for 72h. This is the first study showing that an Enterobacter sp. strain is capable of degrading MCPA, which might provide a new approach for the remediation of MCPA contaminated soil and contribute to the limited knowledge about the function of Enterobacter species. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

CrdR function in a curdlan-producing Agrobacterium sp. ATCC31749 strain.

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Yu, Xiaoqin; Zhang, Chao; Yang, Liping; Zhao, Lamei; Lin, Chun; Liu, Zhengjie; Mao, Zichao

2015-02-10

Agrobacterium sp. ATCC31749 is an efficient curdlan producer at low pH and under nitrogen starvation. The helix-turn-helix transcriptional regulatory protein (crdR) essential for curdlan production has been analyzed, but whether crdR directly acts to cause expression of the curdlan biosynthesis operon (crdASC) is uncertain. To elucidate the molecular function of crdR in curdlan biosynthesis, we constructed a crdR knockout mutant along with pBQcrdR and pBQNcrdR vectors with crdR expression driven by a T5 promoter and crdR native promoter, respectively. Also, we constructed a pAG with the green fluorescent protein (GFP) gene driven by a curdlan biosynthetic operon promoter (crdP) to measure the effects of crdR expression on curdlan biosynthesis. Compared with wild-type (WT) strain biomass production, the biomass of the crdR knockout mutant was not significantly different in either exponential or stationary phases of growth. Mutant cells were non-capsulated and planktonic and produced significantly less curdlan. WT cells were curdlan-capsulated and aggregated in the stationery phase. pBQcrdR transformed to the WT strain had a 38% greater curdlan yield and pBQcrdR and pBQNcrdR transformed to the crdR mutant strain recovered 18% and 105% curdlan titers of the WT ATCC31749 strain, respectively. Consistent with its function of promoting curdlan biosynthesis, curdlan biosynthetic operon promoter (crdP) controlled GFP expression caused the transgenic strain to have higher GFP relative fluorescence in the WT strain, and no color change was observed with low GFP relative fluorescence in the crdR mutant strain as evidenced by fluorescent microscopy and spectrometric assay. q-RT-PCR revealed that crdR expression in the stationary phase was greater than in the exponential phase, and crdR overexpression in the WT strain increased crdA, crdS, and crdC expression. We also confirmed that purified crdR protein can specifically bind to the crd operon promoter region, and we inferred

Evidence for Increased Aggressiveness in a Recent Widespread Strain of Puccinia striiformis f. sp. tritici Causing Stripe Rust of Wheat

DEFF Research Database (Denmark)

Milus, Eugene A; Kristensen, Kristian; Hovmøller, Mogens S

2009-01-01

Stripe rust (yellow rust) of wheat, caused by Puccinia striiformis f. sp. tritici, has become more severe in eastern United States, Australia, and elsewhere since 2000. Recent research has shown that this coincided with a global spread of two closely related strains that were similar based on vir...... that wheat rust fungi can adapt to warmer temperatures and cause severe disease in previously unfavorable environments......Stripe rust (yellow rust) of wheat, caused by Puccinia striiformis f. sp. tritici, has become more severe in eastern United States, Australia, and elsewhere since 2000. Recent research has shown that this coincided with a global spread of two closely related strains that were similar based...... regimes for latent period, lesion length, lesion width, lesion area, and spore production on adult plants of a susceptible wheat cultivar with no known genes for resistance to stripe rust. "New" isolates (since 2000) were significantly more aggressive than "old" isolates (before 2000) for all variables...

Draft Genome Sequence of Zobellia sp. Strain OII3, Isolated from the Coastal Zone of the Baltic Sea.

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Harms, Henrik; Poehlein, Anja; Thürmer, Andrea; König, Gabriele M; Schäberle, Till F

2017-09-07

Zobellia sp. strain OII3 was isolated from a marine environmental sample due to its heterotrophic lifestyle, i.e., using Escherichia coli cells as prey. It shows strong agar-lytic activity. The genome was assembled into 41 contigs with a total size of 5.4 Mb, revealing the genetic basis for natural product biosynthesis. Copyright © 2017 Harms et al.

Mutation of the murC and murB Genes Impairs Heterocyst Differentiation in Anabaena sp. Strain PCC 7120

OpenAIRE

Videau, Patrick; Rivers, Orion S.; Ushijima, Blake; Oshiro, Reid T.; Kim, Min Joo; Philmus, Benjamin; Cozy, Loralyn M.

2016-01-01

To stabilize cellular integrity in the face of environmental perturbations, most bacteria, including cyanobacteria, synthesize and maintain a strong, flexible, three-dimensional peptidoglycan lattice. Anabaena sp. strain PCC 7120 is a filamentous cyanobacterium capable of differentiating morphologically distinct nitrogen-fixing heterocyst cells in a periodic pattern. While heterocyst development has been shown to require proper peptidoglycan remodeling, the role of peptidoglycan synthesis has...

[Influence of staphylococcin T on Enterococcus sp. growth].

Science.gov (United States)

Białucha, Agata; Kozuszko, Sylwia; Gospodarek, Eugenia; Bugalski, Roman Marian; Gierlotka, Krzysztof

2007-01-01

Bacteriocins are ribosomally synthesised, extracellular bacterial products. Generally, spectrum of inhibition is limited to the same or closely related species to bacteriocin producer. Staphylococcin T is produced by Staphylococcus cohnii strain. The present study concerns influence of StT to 267 Enterococcus sp. strains growth isolated between 2003 and 2006 in Department of Microbiology University Hospital of dr. A. Jurasz in Bydgoszcz. S. cohnii T antagonistic ability evaluated towards bacteries on Mueller-Hinton Agar (bio Mérieux) in aerobic conditions. After 24 and 48 hours tested enterococci suspensions were plated perpendiculary. Susceptibility to antibiotics was assessed by disc diffusion method according to the guideless of Clinical and Laboratory Standards Institute and National Reference Centre for Antimicrobial Susceptibility. Among Enterococcus sp. strains tested 7.1% were sensitive to StT. The highest percentage of sensitive enterococci isolated from wound swabs, urine, blood and pus. Enterococcus faecium strains dominated (63.2%) among enterococci sensitive to StT. Moderate inhibition degree on S. cohnii T bacteriocin action was observed in majority sensitive enterococci strains. Enterococcus sp. sensitive to StT strains were frequently multidrug resistant (68.4%). According to the study results and increasing resistance to antibiotics, StT could be an alternative agent used to treat infections caused by Enterococcus sp.

Penicillium sp. strain that efficiently adsorbs lignosulfonate in the presence of sulfate ion.

Science.gov (United States)

Aoyama, Akihisa; Kurane, Ryuichiro; Nagai, Kazuo

2013-03-01

Lignin is one of the major water insoluble substances that support the physical properties of plants and can be solubilized by sulfite or alkaline treatment in accordance with pulpification. The lignin derivatives produced by both the sulfite and the kraft processes are called lignosulfonate (LS) and kraft lignin (KL), respectively, and both derivatives show a broad spectrum of optical absorbance from ultraviolet to visible light. When the spore suspension of an isolated Penicillium sp., Penicillium sp. A, was inoculated to a medium containing 0.1% commercial LS, absorbance at 480 nm (A480) almost completely disappeared after 5 days of cultivation. Maximum decolorization of the culture broth was observed when the microbe was cultured in the 0.8% LS medium reaching 88%, and the amount of LS removed was calculated to be 7 g/L. In a similar assay with the dark-liquid containing KL, 80% of the A480 of a 20% (v/v) dark-liquid medium disappeared after 5 days of culturing and the amount of KL removed was calculated to be 2.9 g/L. These values significantly exceeded the previously reported amounts with respect to substrate concentration and decolorization. Furthermore, since similar results were obtained in the cases of both LS and KL, it is expected that the present strain is able to non-specifically adsorb a wide range of lignin derivatives, because most of the colored substances were recovered in the culture sediments. Thus, the strain can be used to clean up waste fluids containing water soluble lignin derivatives, adsorb lignin derivatives in waste fluids before dehydration. Copyright © 2012 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Thermococcus guaymasensis sp. nov. and Thermococcus aggregans sp. nov., two novel thermophilic archaea isolated from the Guaymas Basin hydrothermal vent site.

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Canganella, F; Jones, W J; Gambacorta, A; Antranikian, G

1998-10-01

Thermococcus strains TYST and TYT isolated from the Guaymas Basin hydrothermal vent site and previously described were compared by DNA-DNA hybridization analysis with the closest Thermococcus species in terms of physiology and nutritional aspects. On the basis of the new data and taking into consideration the molecular, physiological and morphological traits published previously, it is proposed that strains TYT and TYST should be classified as new species named Thermococcus aggregans sp. nov. and Thermococcus guaymasensis sp. nov., respectively. The type strain of T. aggregans is strain TYT (= DSM 10597T) and the type strain of T. guaymasensis is strain TYST (= DSM 11113T).

Herbaspirillum canariense sp. nov., Herbaspirillum aurantiacum sp. nov. and Herbaspirillum soli sp. nov., isolated from volcanic mountain soil, and emended description of the genus Herbaspirillum.

Science.gov (United States)

Carro, Lorena; Rivas, Raúl; León-Barrios, Milagros; González-Tirante, María; Velázquez, Encarna; Valverde, Angel

2012-06-01

Three Gram-negative, motile and slightly curved rod-shaped bacteria, strains SUEMI03(T), SUEMI08(T) and SUEMI10(T), were isolated from an old volcanic mountain soil on Tenerife (Canary Islands). The three strains were related phylogenetically to Herbaspirillum seropedicae. 16S rRNA gene sequence similarity was 99.2-99.6 % among strains SUEMI03(T), SUEMI08(T) and SUEMI10(T), which presented 97.5, 97.8 and 97.7 % identity, respectively, with respect to H. seropedicae DSM 6445(T). The three strains grew optimally in TSB at 28 °C and contained summed features 3 (C(16:1)ω6c and/or C(16:1)ω7c) and 8 (C(18:1)ω6c and/or C(18:1)ω7c) and C(16:0) as major cellular fatty acids. The DNA G+C contents of strains SUEMI03(T), SUEMI08(T) and SUEMI10(T) were 61.6, 60.4 and 61.9 mol%, respectively. Strains SUEMI03(T), SUEMI08(T) and SUEMI10(T) presented less than 60 % interstrain DNA relatedness and less than 30 % relatedness with respect to H. seropedicae DSM 6445(T). In spite of their common geographical origin, the three strains isolated in this study presented several phenotypic differences, presenting phenotypic profiles highly divergent from that of H. seropedicae. Therefore, we propose that the strains isolated in this study represent three novel species of the genus Herbaspirillum, named Herbaspirillum canariense sp. nov. (type strain SUEMI03(T) = LMG 26151(T) = CECT 7838(T)), Herbaspirillum aurantiacum sp. nov. (type strain SUEMI08(T) = LMG 26150(T) = CECT 7839(T)) and Herbaspirillum soli sp. nov. (type strain SUEMI10(T) = LMG 26149(T) = CECT 7840(T)).

Mesorhizobium shonense sp. nov., Mesorhizobium hawassense sp. nov. and Mesorhizobium abyssinicae sp. nov., isolated from root nodules of different agroforestry legume trees.

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Degefu, Tulu; Wolde-Meskel, Endalkachew; Liu, Binbin; Cleenwerck, Ilse; Willems, Anne; Frostegård, Åsa

2013-05-01

A total of 18 strains, representing members of the genus Mesorhizobium, obtained from root nodules of woody legumes growing in Ethiopia, have been previously shown, by multilocus sequence analysis (MLSA) of five housekeeping genes, to form three novel genospecies. In the present study, the phylogenetic relationship between representative strains of these three genospecies and the type strains of their closest phylogenetic neighbours Mesorhizobium plurifarium, Mesorhizobium amorphae, Mesorhizobium septentrionale and Mesorhizobium huakuii was further evaluated using a polyphasic taxonomic approach. In line with our earlier MLSA of other housekeeping genes, the phylogenetic trees derived from the atpD and glnII genes grouped the test strains into three well-supported, distinct lineages that exclude all defined species of the genus Mesorhizobium. The DNA-DNA relatedness between the representative strains of genospecies I-III and the type strains of their closest phylogenetic neighbours was low (≤59 %). They differed from each other and from their closest phylogenetic neighbours by the presence/absence of several fatty acids, or by large differences in the relative amounts of particular fatty acids. While showing distinctive features, they were generally able to utilize a wide range of substrates as sole carbon and nitrogen sources. The strains belonging to genospecies I, II and III therefore represent novel species for which we propose the names Mesorhizobium shonense sp. nov., Mesorhizobium hawassense sp. nov. and Mesorhizobium abyssinicae sp. nov. The isolates AC39a(T) ( = LMG 26966(T) = HAMBI 3295(T)), AC99b(T) ( = LMG 26968(T) = HAMBI 3301(T)) and AC98c(T) ( = LMG 26967(T) = HAMBI 3306(T)) are proposed as type strains for the respective novel species.

Influence of growth medium on cometabolic degradation of polycyclic aromatic hydrocarbons by Sphingomonas sp. strain PheB4

Energy Technology Data Exchange (ETDEWEB)

Zhong Yin; Wang Xiaowei [Sun Yat-Sen Univ., Guangzhou (China). State Key Lab. of Biocontrol; Futian-CityU Mangrove Research and Development Centre, Shenzhen (China). Futian National Nature Reserve; Luan Tiangang; Lan Chongyu [Sun Yat-Sen Univ., Guangzhou (China). State Key Lab. of Biocontrol; Tam, N.F.Y. [Futian-CityU Mangrove Research and Development Centre, Shenzhen (China). Futian National Nature Reserve; City Univ. of Hong Kong, Kowloon (China). Dept. of Biology and Chemistry

2007-05-15

The influence of growth medium on cometabolic degradation of polycyclic aromatic hydrocarbons (PAHs) was investigated when Sphingomonas sp. strain PheB4 isolated from surface mangrove sediments was grown in either phenanthrene-containing mineral salts medium (PMSM) or nutrient broth (NB). The NB-grown culture exhibited a more rapid cometabolic degradation of single and mixed non-growth substrate PAHs compared to the PMSM-grown culture. The concentrations of PAH metabolites were also lower in NB-grown culture than in PMSM-grown culture, suggesting that NB-grown culture removed metabolites at a faster rate, particularly, for metabolites produced from cometabolic degradation of a binary mixture of PAHs. Cometabolic pathways of single PAH (anthracene, fluorene, or fluoranthene) in NB-grown culture showed similarity to that in PMSM-grown culture. However, cometabolic pathways of mixed PAHs were more diverse in NB-grown culture than that in PMSM-grown culture. These results indicated that nutrient rich medium was effective in enhancing cometabolic degradation of mixed PAHs concomitant with a rapid removal of metabolites, which could be useful for the bioremediation of mixed PAHs contaminated sites using Sphingomonas sp. strain PheB4. (orig.)

Oscillating behavior of carbohydrate granule formation and dinitrogen fixation in the cyanobacterium Cyanothece sp. strain ATCC 51142

Science.gov (United States)

Schneegurt, M. A.; Sherman, D. M.; Nayar, S.; Sherman, L. A.; Mitchell, C. A. (Principal Investigator)

1994-01-01

It has been shown that some aerobic, unicellular, diazotrophic cyanobacteria temporally separate photosynthetic O2 evolution and oxygen-sensitive N2 fixation. Cyanothece sp. ATCC strain 51142 is an aerobic, unicellular, diazotrophic cyanobacterium that fixes N2 during discrete periods of its cell cycle. When the bacteria are maintained under diurnal light-dark cycles, N2 fixation occurs in the dark. Similar cycling is observed in continuous light, implicating a circadian rhythm. Under N2-fixing conditions, large inclusion granules form between the thylakoid membranes. Maximum granulation, as observed by electron microscopy, occurs before the onset of N2 fixation, and the granules decrease in number during the period of N2 fixation. The granules can be purified from cell homogenates by differential centrifugation. Biochemical analyses of the granules indicate that these structures are primarily carbohydrate, with some protein. Further analyses of the carbohydrate have shown that it is a glucose polymer with some characteristics of glycogen. It is proposed that N2 fixation is driven by energy and reducing power stored in these inclusion granules. Cyanothece sp. strain ATCC 51142 represents an excellent experimental organism for the study of the protective mechanisms of nitrogenase, metabolic events in cyanobacteria under normal and stress conditions, the partitioning of resources between growth and storage, and biological rhythms.

Isolation of a human intestinal anaerobe, Bifidobacterium sp. strain SEN, capable of hydrolyzing sennosides to sennidins.

Science.gov (United States)

Akao, T; Che, Q M; Kobashi, K; Yang, L; Hattori, M; Namba, T

1994-01-01

A strictly anaerobic bacterium capable of metabolizing sennosides was isolated from human feces and identified as Bifidobacterium sp., named strain SEN. The bacterium hydrolyzed sennosides A and B to sennidins A and B via sennidin A and B 8-monoglucosides, respectively. Among nine species of Bifidobacterium having beta-glucosidase activity, only Bifidobacterium dentium and B. adolescentis metabolized sennoside B to sennidin B, suggesting that the sennoside-metabolizing bacteria produce a novel type of beta-glucosidase capable of hydrolyzing sennosides to sennidins. PMID:8161172

Borrelia bissettiae sp. nov. and Borrelia californiensis sp. nov. prevail in diverse enzootic transmission cycles.

Science.gov (United States)

Margos, Gabriele; Lane, Robert S; Fedorova, Natalia; Koloczek, Johannes; Piesman, Joseph; Hojgaard, Andrias; Sing, Andreas; Fingerle, Volker

2016-03-01

Two species of the genus Borrelia , Borrelia bissettiae sp. nov. and Borrelia californiensis sp. nov., were first described by Postic and co-workers on the basis of genetic analyses of several loci. Multilocus sequence analysis of eight housekeeping loci confirmed that these two Borrelia genomospecies are distinct members of the Borrelia burgdorferi sensu lato complex. B. bissettiae sp. nov. was initially described in transmission cycles involving Neotoma fuscipes wood rats and Ixodes pacificus ticks in California, and Neotoma mexicana and Ixodes spinipalpis in Colorado. The preferred host of B. californiensis sp. nov. appears to be the California kangaroo rat, Dipodomys californicus ; Ixodes jellisoni , I. spinipalipis and I. pacificus ticks are naturally infected with it. Thus, the ecological associations of the two genomospecies and their genetic distance from all other known Borrelia genomospecies species justify their description as separate genomospecies: B. bissettiae sp. nov. (type strain DN127 T  = DSM 17990 T  =  CIP 109136 T ) and B. californiensis (type strain CA446 T  = DSM 17989 T  = ATCC BAA-2689 T ).

Nitric Oxide Mediates Biofilm Formation and Symbiosis in Silicibacter sp. Strain TrichCH4B.

Science.gov (United States)

Rao, Minxi; Smith, Brian C; Marletta, Michael A

2015-05-05

Nitric oxide (NO) plays an important signaling role in all domains of life. Many bacteria contain a heme-nitric oxide/oxygen binding (H-NOX) protein that selectively binds NO. These H-NOX proteins often act as sensors that regulate histidine kinase (HK) activity, forming part of a bacterial two-component signaling system that also involves one or more response regulators. In several organisms, NO binding to the H-NOX protein governs bacterial biofilm formation; however, the source of NO exposure for these bacteria is unknown. In mammals, NO is generated by the enzyme nitric oxide synthase (NOS) and signals through binding the H-NOX domain of soluble guanylate cyclase. Recently, several bacterial NOS proteins have also been reported, but the corresponding bacteria do not also encode an H-NOX protein. Here, we report the first characterization of a bacterium that encodes both a NOS and H-NOX, thus resembling the mammalian system capable of both synthesizing and sensing NO. We characterized the NO signaling pathway of the marine alphaproteobacterium Silicibacter sp. strain TrichCH4B, determining that the NOS is activated by an algal symbiont, Trichodesmium erythraeum. NO signaling through a histidine kinase-response regulator two-component signaling pathway results in increased concentrations of cyclic diguanosine monophosphate, a key bacterial second messenger molecule that controls cellular adhesion and biofilm formation. Silicibacter sp. TrichCH4B biofilm formation, activated by T. erythraeum, may be an important mechanism for symbiosis between the two organisms, revealing that NO plays a previously unknown key role in bacterial communication and symbiosis. Bacterial nitric oxide (NO) signaling via heme-nitric oxide/oxygen binding (H-NOX) proteins regulates biofilm formation, playing an important role in protecting bacteria from oxidative stress and other environmental stresses. Biofilms are also an important part of symbiosis, allowing the organism to remain in a

Physiological and Biochemical characterization of Chlamydomonas sp. the Hydrogen Production's Strain

International Nuclear Information System (INIS)

Chader, S.; Belhamel, M.; H Hacene

2006-01-01

The hydrogen produced by biological way became, one of the most interesting subjects of research relating to development the energy system starting from renewable sources. This study describes the closed relation between the physiological behaviour, biochemical and rate of gases produced by Chlamydomonas sp. strain AT14, isolated in the area of Touat (the Sahara Algerian) and cultivated in a toric photo-bioreactor. A considerable growth was noted, where the concentration of the biomass double in only two days after incubation. The micro-algal cells present a 100% of viability, which relocate has satisfactory behaviour in the toric engine. In addition, the displacement water level in the system of measurement implies has gas production (0.1 ml) in coordination with the anaerobic period of the reactional enclosure. The yield of this way of hydrogen production is depending on the species used, the light intensity, and the conditions of culture. (authors)

Substrate Interactions during the Biodegradation of Benzene, Toluene, Ethylbenze, and Xylene (BTEX) Hydrocarbons by the Fungus Cladophialophora sp. Strain T1

NARCIS (Netherlands)

Prenafeta-Boldú, F.X.; Vervoort, J.; Grotenhuis, J.T.C.; Groenestijn, van J.W.

2002-01-01

The soil fungus Cladophialophora sp. strain T1 (= ATCC MYA-2335) was capable of growth on a model water-soluble fraction of gasoline that contained all six BTEX components (benzene, toluene, ethylbenzene, and the xylene isomers). Benzene was not metabolized, but the alkylated benzenes (toluene,

A Novel Method for Culturing of Leptothrix sp. Strain OUMS1 in Natural Conditions

Directory of Open Access Journals (Sweden)

Tomoko Suzuki

2012-05-01

Full Text Available Although some strains of Leptothrix spp. isolated from aquatic environments have been characterized by culturing them in laboratory conditions, they often show morphological and chemical features distinct from those found in natural environments. To resolve this discrepancy, a novel cultivation method was devised for culturing such strains in natural groundwater. Leptothrix sp. strain OUMS1 was pre-cultured in a medium lacking Fe for 2 days, and then injected into a small dialysis tube bag and immersed in a container with continuously flowing groundwater for 1–3 and 14 days. Microscopic analysis of the initial phase of sheath formation and arbitrary comparisons with medium cultures revealed that in groundwater the surface coat of the sheath comprised much thinner fibrils, and an inner sheath wall that was much thinner and more indistinct compared with medium cultures. These differences were probably attributable to poorer secretion from the cell surface in groundwater conditions. A nutrient-rich medium likely activates cell metabolism and promotes secretion, resulting in a thicker inner sheath wall and thicker outer coat fibrils. Aqueous-phase Fe was deposited on immature sheaths in a similar manner in both cultures. These results indicate that laboratory culture of isolated microbes does not always reflect their characteristics in natural environments.

Streptococcus moroccensis sp. nov. and Streptococcus rifensis sp. nov., isolated from raw camel milk.

Science.gov (United States)

Kadri, Zaina; Amar, Mohamed; Ouadghiri, Mouna; Cnockaert, Margo; Aerts, Maarten; El Farricha, Omar; Vandamme, Peter

2014-07-01

Two catalase- and oxidase-negative Streptococcus-like strains, LMG 27682(T) and LMG 27684(T), were isolated from raw camel milk in Morocco. Comparative 16S rRNA gene sequencing assigned these bacteria to the genus Streptococcus with Streptococcus rupicaprae 2777-2-07(T) as their closest phylogenetic neighbour (95.9% and 95.7% similarity, respectively). 16S rRNA gene sequence similarity between the two strains was 96.7%. Although strains LMG 27682(T) and LMG 27684(T) shared a DNA-DNA hybridization value that corresponded to the threshold level for species delineation (68%), the two strains could be distinguished by multiple biochemical tests, sequence analysis of the phenylalanyl-tRNA synthase (pheS), RNA polymerase (rpoA) and ATP synthase (atpA) genes and by their MALDI-TOF MS profiles. On the basis of these considerable phenotypic and genotypic differences, we propose to classify both strains as novel species of the genus Streptococcus, for which the names Streptococcus moroccensis sp. nov. (type strain, LMG 27682(T)  = CCMM B831(T)) and Streptococcus rifensis sp. nov. (type strain, LMG 27684(T)  = CCMM B833(T)) are proposed. © 2014 IUMS.

Endosulfan induced alteration in bacterial protein profile and RNA yield of Klebsiella sp. M3, Achromobacter sp. M6, and Rhodococcus sp. M2.

Science.gov (United States)

Singh, Madhu; Singh, Dileep Kumar

2014-01-30

Three bacterial strains identified as Klebsiella sp. M3, Achromobacter sp. M6 and Rhodococcus sp. M2 were isolated by soil enrichment with endosulfan followed by shake flask enrichment technique. They were efficiently degrading endosulfan in the NSM (non sulfur medium) broth. Degradation of endosulfan was faster with the cell free extract of bacterial cells grown in the sulfur deficient medium (NSM) supplemented with endosulfan than that of nutrient rich medium (Luria Bertani). In the cell free extract of NSM supplemented with endosulfan as sole sulfur source, a unique band was visualized on SDS-PAGE but not with magnesium sulfate as the sole sulfur source in NSM and LB with endosulfan. Expression of a unique polypeptide band was speculated to be induced by endosulfan under sulfur starved condition. These unique polypeptide bands were identified as OmpK35 protein, sulfate binding protein and outer membrane porin protein, respectively, in Klebsiella sp. M3, Achromobacter sp. M6 and Rhodococcus sp. M2. Endosulfan showed dose dependent negative effect on total RNA yield of bacterial strains in nutrient rich medium. Absence of plasmid DNA indicated the presence of endosulfan metabolizing gene on genomic DNA. Copyright © 2013 Elsevier B.V. All rights reserved.

INFLUENCE OF METRONIDAZOLE, CO, CO2, AND METHANOGENS ON THE FERMENTATIVE METABOLISM OF THE ANAEROBIC FUNGUS NEOCALLIMASTIX SP STRAIN L2

NARCIS (Netherlands)

MARVINSIKKEMA, FD; REES, E; KRAAK, MN; GOTTSCHAL, JC; PRINS, RA

The effects of metronidazole, CO, methanogens, and CO, on the fermentation of glucose by the anaerobic fungus Neocallimastix sp. strain L2 were investigated. Both metronidazole and CO caused a shift in the fermentation products from predominantly H-2, acetate, and formate to lactate as the major

Ultrastructure and Development of Pasteuria sp. (S-1 strain), an Obligate Endoparasite of Belonolaimus longicaudatus (Nemata: Tylenchida).

Science.gov (United States)

Giblin-Davis, R M; Williams, D S; Wergin, W P; Dickson, D W; Hewlett, T E; Bekal, S; Becker, J O

2001-12-01

Pasteuria sp., strain S-1, is a gram-positive, obligate endoparasitic bacterium that uses the phytoparasitic sting nematode, Belonolaimus longicaudatus, as its host in Florida. The host attachment of S-1 appears to be specific to the genus Belonolaimus with development occurring only in juveniles and adults of B. longicaudatus. This bacterium is characterized from other described species of Pasteuria using ultrastructure of the mature endospore. Penetration, development, and sporogenesis were elucidated with TEM, LTSEM, and SEM and are similar to other nematode-specific Pasteuria. Recent analysis of 16S rDNA sequence homology confirms its congeneric ranking with other Pasteuria species and strains from nematodes and cladocerans, and corroborates ultrastructural, morphological, morphometric, and host-range evidence suggesting separate species status.

Optimization of biosynthesis conditions and catalitic behavior evaluation of cellulase-free xylanase produced by a new Streptomyces sp. strain

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GABRIELA BAHRIM

2011-07-01

Full Text Available Cellulase-free xylanase by Streptomyces sp.P12-137 was obtained bycultivation on the wheat bran as the sole carbon source. The effect of carbon and nitrogen sources and a ratio of them on the cellulase-free xylanase production was investigated. The new isolate Streptomyces sp. strain was able to grow in submerged system and to produce an increased level of xylanase. Wheat bran induced xylanase biosynthesis yield at a high level (9.27 UA/ml. For economical reasons cultivation was achieved on a cheap fermentative medium represented by agro-industrial wastes. The optima of the pH and temperature of the crude xylanase activity were 5.5 and 70°C,respectively.

Ability of an alkali-tolerant mutant strain of the microalga Chlorella sp. AT1 to capture carbon dioxide for increasing carbon dioxide utilization efficiency.

Science.gov (United States)

Kuo, Chiu-Mei; Lin, Tsung-Hsien; Yang, Yi-Chun; Zhang, Wen-Xin; Lai, Jinn-Tsyy; Wu, Hsi-Tien; Chang, Jo-Shu; Lin, Chih-Sheng

2017-11-01

An alkali-tolerant Chlorella sp. AT1 mutant strain was screened by NTG mutagenesis. The strain grew well in pH 6-11 media, and the optimal pH for growth was 10. The CO 2 utilization efficiencies of Chlorella sp. AT1 cultured with intermittent 10% CO 2 aeration for 10, 20 and 30min at 3-h intervals were approximately 80, 42 and 30%, respectively. In alkaline medium (pH=11) with intermittent 10% CO 2 aeration for 30min at 3-, 6- and 12-h intervals, the medium pH gradually changed to 10, and the biomass productivities of Chlorella sp. AT1 were 0.987, 0.848 and 0.710gL -1 d -1 , respectively. When Chlorella sp. AT1 was aerated with 10% CO 2 intermittently for 30min at 3-h intervals in semi-continuous cultivation for 21days, the biomass concentration and biomass productivity were 4.35gL -1 and 0.726gL -1 d -1 , respectively. Our results show that CO 2 utilization efficiency can be markedly increased by intermittent CO 2 aeration and alkaline media as a CO 2 -capturing strategy for alkali-tolerant microalga cultivation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Function and Regulation of Ferredoxins in the Cyanobacterium, Synechocystis PCC6803: Recent Advances.

Science.gov (United States)

Cassier-Chauvat, Corinne; Chauvat, Franck

2014-11-07

Ferredoxins (Fed), occurring in most organisms, are small proteins that use their iron-sulfur cluster to distribute electrons to various metabolic pathways, likely including hydrogen production. Here, we summarize the current knowledge on ferredoxins in cyanobacteria, the prokaryotes regarded as important producers of the oxygenic atmosphere and biomass for the food chain, as well as promising cell factories for biofuel production. Most studies of ferredoxins were performed in the model strain, Synechocystis PCC6803, which possesses nine highly-conserved ferredoxins encoded by monocistronic or operonic genes, some of which are localized in conserved genome regions. Fed1, encoded by a light-inducible gene, is a highly abundant protein essential to photosynthesis. Fed2-Fed9, encoded by genes differently regulated by trophic conditions, are low-abundant proteins that play prominent roles in the tolerance to environmental stresses. Concerning the selectivity/redundancy of ferredoxin, we report that Fed1, Fed7 and Fed9 belong to ferredoxin-glutaredoxin-thioredoxin crosstalk pathways operating in the protection against oxidative and metal stresses. Furthermore, Fed7 specifically interacts with a DnaJ-like protein, an interaction that has been conserved in photosynthetic eukaryotes in the form of a composite protein comprising DnaJ- and Fed7-like domains. Fed9 specifically interacts with the Flv3 flavodiiron protein acting in the photoreduction of O2 to H2O.

Function and Regulation of Ferredoxins in the Cyanobacterium, Synechocystis PCC6803: Recent Advances

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Corinne Cassier-Chauvat

2014-11-01

Full Text Available Ferredoxins (Fed, occurring in most organisms, are small proteins that use their iron-sulfur cluster to distribute electrons to various metabolic pathways, likely including hydrogen production. Here, we summarize the current knowledge on ferredoxins in cyanobacteria, the prokaryotes regarded as important producers of the oxygenic atmosphere and biomass for the food chain, as well as promising cell factories for biofuel production. Most studies of ferredoxins were performed in the model strain, Synechocystis PCC6803, which possesses nine highly-conserved ferredoxins encoded by monocistronic or operonic genes, some of which are localized in conserved genome regions. Fed1, encoded by a light-inducible gene, is a highly abundant protein essential to photosynthesis. Fed2-Fed9, encoded by genes differently regulated by trophic conditions, are low-abundant proteins that play prominent roles in the tolerance to environmental stresses. Concerning the selectivity/redundancy of ferredoxin, we report that Fed1, Fed7 and Fed9 belong to ferredoxin-glutaredoxin-thioredoxin crosstalk pathways operating in the protection against oxidative and metal stresses. Furthermore, Fed7 specifically interacts with a DnaJ-like protein, an interaction that has been conserved in photosynthetic eukaryotes in the form of a composite protein comprising DnaJ- and Fed7-like domains. Fed9 specifically interacts with the Flv3 flavodiiron protein acting in the photoreduction of O2 to H2O.

Noncontiguous finished genome sequence and description of Paenibacillus antibioticophila sp. nov. GD11T, the type strain of Paenibacillus antibioticophila

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G. Dubourg

2015-11-01

Full Text Available Paenibacillus antibioticophila strain GD11T sp. nov. is the type strain of a new species within the genus Paenibacillus. This strain, whose genome is described here, was isolated from human faeces of a 63-year-old woman with multidrug-resistant tuberculosis who was receiving numerous antibiotics at the time of stool collection. P. antibioticophila is a Gram-positive aerobic bacterium. We describe here the features of this bacterium, together with the complete genome sequence and annotation. The 5 562 631 bp long genome contains 5084 protein-coding and 71 RNA genes.

Biosorption of cadmium by Brevundimonas sp. ZF12 strain, a novel biosorbent isolated from hot-spring waters in high background radiation areas

International Nuclear Information System (INIS)

Masoudzadeh, Nasrin; Zakeri, Fardideh; Lotfabad, Tayebe bagheri; Sharafi, Hakimeh; Masoomi, Fatemeh; Zahiri, Hoseein Shahbani; Ahmadian, Gholamreza; Noghabi, Kambiz Akbari

2011-01-01

Highlights: ► Isolation and characterization of a novel cadmium-biosorbent (Brevundimonas sp. ZF12) from high background radiation areas. ► Brevundimonas sp. ZF12 caused 50% removal of cadmium at the concentration level of 250 ppm. ► Solution pH values used for the reusability study have powerful desorptive features to recover Cd ions sorbed onto the biomass. ► This is the first study carried out so far for the cadmium removal from aqueous solutions by a novel biosorbent Brevundimonas sp. ZF12. ► In our opinion, the isolate can be an attractive alternative to remove the cadmium-containing wastewaters. - Abstract: The aim of this study is to screen cadmium biosorbing bacterial strains isolated from soils and hot-springs containing high concentrations of radium ( 226 Ra) in Ramsar using a batch system. Brevundimonas sp. ZF12 strain isolated from the water with high 226 Ra content caused 50% removal of cadmium at a concentration level of 250 ppm. The biosorption equilibrium data are fitted well by the Langmuir adsorption isotherm and kinetic studies indicated that the biosorption follows pseudo second-order model. The effect of different physico-chemical parameters like biomass concentration, pH, cadmium concentration, temperature and contact time on cadmium sorption was also investigated using FTIR, SEM and XRD analytical techniques. A high desorption efficiency (above 90%) was obtained using a pH range of 2.0–4.0. Reusability of the biomass was examined under consecutive biosorption–desorption cycles repeated thrice. In conclusion, Brevundimonas sp. ZF12 is proposed as an excellent cadmium biosorbent that may have important applications in Cd removal from wastewaters.

Degradation of ethyl mercaptan and its major intermediate diethyl disulfide by Pseudomonas sp. strain WL2.

Science.gov (United States)

Wang, Xiangqian; Wu, Chao; Liu, Nan; Li, Sujing; Li, Wei; Chen, Jianmeng; Chen, Dongzhi

2015-04-01

A Pseudomonas sp. strain WL2 that is able to efficiently metabolize ethyl mercaptan (EM) into diethyl disulfide (DEDS) through enzymatic oxidation was isolated from the activated sludge of a pharmaceutical wastewater plant. One hundred percent removal of 113.5 mg L(-1) EM and 110.3 mg L(-1) DEDS were obtained within 14 and 32 h, respectively. A putative EM degradation pathway that involved the catabolism via DEDS was proposed, which indicated DEDS were further mineralized into carbon dioxide (CO2), bacterial cells, and sulfate (SO4 (2-)) through the transformation of element sulfur and ethyl aldehyde. Degradation kinetics for EM and DEDS with different initial concentrations by strain WL2 were evaluated using Haldane-Andrews model with maximum specific degradation rates of 3.13 and 1.33 g g(-1) h(-1), respectively, and maximum degradation rate constants of 0.522 and 0.175 h(-1) using pseudo-first-order kinetic model were obtained. Results obtained that aerobic degradation of EM by strain WL2 was more efficient than those from previous studies. Substrate range studies of strain WL2 demonstrated its ability to degrade several mercaptans, disulfides, aldehydes, and methanol. All the results obtained highlight the potential of strain WL2 for the use in the biodegradation of volatile organic sulfur compounds (VOSCs).

Insights into metabolism and sodium chloride adaptability of carbaryl degrading halotolerant Pseudomonas sp. strain C7.

Science.gov (United States)

Trivedi, Vikas D; Bharadwaj, Anahita; Varunjikar, Madhushri S; Singha, Arminder K; Upadhyay, Priya; Gautam, Kamini; Phale, Prashant S

2017-08-01

Pseudomonas sp. strain C7 isolated from sediment of Thane creek near Mumbai, India, showed the ability to grow on glucose and carbaryl in the presence of 7.5 and 3.5% of NaCl, respectively. It also showed good growth in the absence of NaCl indicating the strain to be halotolerant. Increasing salt concentration impacted the growth on carbaryl; however, the specific activity of various enzymes involved in the metabolism remained unaffected. Among various enzymes, 1-naphthol 2-hydroxylase was found to be sensitive to chloride as compared to carbaryl hydrolase and gentisate 1,2-dioxygenase. The intracellular concentration of Cl - ions remained constant (6-8 mM) for cells grown on carbaryl either in the presence or absence of NaCl. Thus the ability to adapt to the increasing concentration of NaCl is probably by employing chloride efflux pump and/or increase in the concentration of osmolytes as mechanism for halotolerance. The halotolerant nature of the strain will be beneficial to remediate carbaryl from saline agriculture fields, ecosystems and wastewaters.

Expression of the neutral protease gene from a thermophilic Bacillus sp BT1 strain in Bacillus subtilis and its natural host : Identification of a functional promoter

NARCIS (Netherlands)

Vecerek, B; Venema, G

The expression of the neutral protease gene (npr) from the thermophilic Bacillus sp. BT1 strain was studied in its natural host and in mesophilic Bacillus subtilis. In the thermophilic BT1 strain, the transcription of the protease gene is initiated from its own promoter, just 5' to the gene. In

Purification, crystallization and preliminary X-ray diffraction of fluorescence recovery protein from Synechocystis PCC 6803

International Nuclear Information System (INIS)

Liu, Ting; Shuai, Yingli; Zhou, Honggang

2011-01-01

Fluorescence recovery protein from Synechocystis PCC 6803 plays a key role in the orange carotenoid protein-related photoprotective mechanism in cyanobacteria. The full-length form and a truncated form were overexpressed, purified and crystallized, and diffraction was observed to 2.75 Å resolution. Fluorescence recovery protein (FRP), which is encoded by the slr1964 gene in Synechocystis PCC 6803, plays a key role in the orange carotenoid protein-related photoprotective mechanism in cyanobacteria. As the crystal structure of FRP may provide information about the biological functions and mechanism of action of the protein, recombinant full-length FRP and a truncated form were overexpressed, purified and crystallized at 291 K using ethylene imine polymer as the precipitant. An FRP data set was collected to a resolution of 2.75 Å at low temperature (100 K). The crystal belonged to space group P4 1 2 1 2, with unit-cell parameters a = b = 61.9, c = 160.7 Å, α = β = γ = 90°. Assuming that the asymmetric unit contains three molecules, the Matthews coefficient was calculated to be 2.1 Å 3 Da −1

Genome Sequence of Pseudomonas sp. Strain Chol1, a Model Organism for the Degradation of Bile Salts and Other Steroid Compounds

KAUST Repository

Holert, Johannes; Alam, Intikhab; Larsen, Michael; Antunes, Andre; Bajic, Vladimir B.; Stingl, Ulrich; Philipp, Bodo

2013-01-01

Bacterial degradation of steroid compounds is of high ecological and biotechnological relevance. Pseudomonas sp. strain Chol1 is a model organism for studying the degradation of the steroid compound cholate. Its draft genome sequence is presented and reveals one gene cluster responsible for the metabolism of steroid compounds.

Genome Sequence of Pseudomonas sp. Strain Chol1, a Model Organism for the Degradation of Bile Salts and Other Steroid Compounds

KAUST Repository

Holert, Johannes

2013-01-15

Bacterial degradation of steroid compounds is of high ecological and biotechnological relevance. Pseudomonas sp. strain Chol1 is a model organism for studying the degradation of the steroid compound cholate. Its draft genome sequence is presented and reveals one gene cluster responsible for the metabolism of steroid compounds.

Bioemulsifier production byMicrobacterium SP. strains isolated from mangrove and their application to remove cadmiun and zinc from hazardous industrial residue

Science.gov (United States)

Aniszewski, Erick; Peixoto, Raquel Silva; Mota, Fábio Faria; Leite, Selma Gomes Ferreira; Rosado, Alexandre Soares

2010-01-01

The contamination of ecosystems with heavy metals is an important issue in current world and remediation technologies should be in according to environmental sustainability concept. Bioemulsifier are promising agents to be used in metal removal and could be effective to many applications in environmental industries. The aims of this work was screening the potential production of bioemulsifier by microorganisms isolated from an oil contaminated mangrove, and evaluate cadmium and zinc removal potential of those strains from a hazardous industrial residue. From that, bioemulsifier-producing bacteria were isolated from urban mangrove sediments. Four isolates were identified as Microbacterium sp by 16S rRNA analysis and were able to reduce up to 53.3% of culture medium surface tension (TS) when using glucose as carbon and energy source and 20.2% when sucrose was used. Suspensions containing bioemulsifier produced by Microbacterium sp. strains show to be able to remove cadmium and zinc from contaminated industrial residue, and its ability varied according carbon source. Significant differences in metal removal were observed by all strains depending on the carbon source. When glucose was used, Cd and Zn removal varied from 17 to 41%, and 14 to 68%, respectively. However, when sucrose was used it was observed only 4 to a maximum of 15% of Cd removal, and 4 to 17% of Zn removal. When the same tests were performed after ethanol precipitation, the results were different: the percentages of removal of Zn (7–27%) and Cd (14–32%) were higher from sucrose cultures. This is the first report of heavy metals removal by bioemulsifier from Microbacterium sp. PMID:24031486

The transporter SynPAM71 is located in the plasma membrane and thylakoids, and mediates manganese tolerance in Synechocystis PCC6803

DEFF Research Database (Denmark)

Gandini, Chiara; Schmidt, Sidsel Birkelund; Husted, Søren

2017-01-01

symptoms were observed in WT cells exposed to excess Mn. Moreover, CyanoP, which is involved in the early steps of PSII assembly, is massively upregulated in ΔSynPAM71. SynPAM71 was detected in both the plasma membrane and, to a lesser extent, the thylakoid membranes. Our results suggest that SynPAM71......Manganese (Mn) is an essential constituent of photosystem II (PSII) and therefore indispensable for oxygenic photosynthesis. Very little is known about how Mn is transported, delivered and retained in photosynthetic cells. Recently, the thylakoid-localized transporter PAM71 has been linked...... to chloroplast Mn homeostasis in Arabidopsis thaliana. Here, we characterize the function of its homolog in Synechocystis (SynPAM71). We used a loss-of-function line (ΔSynPAM71), wild-type (WT) cells exposed to Mn stress and strains expressing a tagged variant of SynPAM71 to characterize the role of SynPAM71...

Karyotype rearrangements and telomere analysis in Myzus persicae (Hemiptera, Aphididae) strains collected on Lavandula sp. plants

Science.gov (United States)

Mandrioli, Mauro; Zanasi, Federica; Manicardi, Gian Carlo

2014-01-01

Abstract Karyotype analysis of nine strains of the peach-potato aphid Myzus persicae (Sulzer, 1776), collected on Lavandula sp. plants, evidenced showed that five of them had a standard 2n = 12 karyotype, one possessed a fragmentation of the X chromosome occurring at the telomere opposite to the NOR-bearing one and three strains had a chromosome number 2n = 11 due to a non-reciprocal translocation of an autosome A3 onto an A1 chromosome. Interestingly, the terminal portion of the autosome A1 involved in the translocation was the same in all the three strains, as evidenced by FISH with the histone cluster as a probe. The study of telomeres in the Myzus persicae strain with the X fission evidenced that telomerase synthesised de novo telomeres at the breakpoints resulting in the stabilization of the chromosomal fragments. Lastly, despite the presence of a conserved telomerase, aphid genome is devoid of genes coding for shelterin, a complex of proteins involved in telomere functioning frequently reported as conserved in eukaryotes. The absence of this complex, also confirmed in the genome of other arthropods, suggests that the shift in the sequence of the telomeric repeats has been accompanied by other changes in the telomere components in arthropods in respect to other metazoans. PMID:25610541

An unusual case of chronic nonhealing periorbital ulceration due to a new species of Corynebacterium sp. strain UCL557

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Bipasa Chakraborty

2016-01-01

Full Text Available Nondiphtherial Corynebacterium (diphtheroids has been related to blood and wound infections but are an uncommon cause for soft tissue infection. We report a case of periorbital soft tissue infection with ulceration caused by multidrug-resistant Corynebacterium spp. in a 9-year-old girl who is apparently immunocompetant. Computed tomography scan showed soft tissue involvement of right periorbital region with no bony destructions or focal calcifications. Vision remained unaffected. Patient was treated by debridement and skin grafting, but condition did not improve. Pus collected from the periorbital ulcerated area was cultured in blood agar and Corynebacterium spp. was isolated from the pure culture, which was identified as a new species Corynebacterium sp. strain UCL557 using 16S rDNA- based molecular technique based on nucleotide homology and phylogenetic analysis. Antibiogram showed multiresistance pattern with sensitivity to ceftriaxone-sulbactum vancomycin and linezolid. After initiation of treatment with vancomycin infusion and oral linezolid, the patient responded well and lesion started to heal. To the best of our knowledge, this is the first ever case report of periorbital ulceration by new species of Corynebacterium sp. strain UCL557.

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

Science.gov (United States)

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

2016-06-01

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

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

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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.

Purification and characterization of a fibrinolytic enzyme produced from Bacillus sp. strain CK 11-4 screened from Chungkook-Jang.

Science.gov (United States)

Kim, W; Choi, K; Kim, Y; Park, H; Choi, J; Lee, Y; Oh, H; Kwon, I; Lee, S

1996-01-01

Bacillus sp. strain CK 11-4, which produces a strongly fibrinolytic enzyme, was screened from Chungkook-Jang, a traditional Korean fermented-soybean sauce. The fibrinolytic enzyme (CK) was purified from supernatant of Bacillus sp. strain CK 11-4 culture broth and showed thermophilic, hydrophilic, and strong fibrinolytic activity. The optimum temperature and pH were 70 degrees C and 10.5, respectively, and the molecular weight was 28,200 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The first 14 amino acids of the N-terminal sequence of CK are Ala-Gin-Thr-Val-Pro-Tyr-Gly-Ile-Pro-Leu-Ile-Lys-Ala-Asp. This sequence is identical to that of subtilisin Carlsberg and different from that of nattokinase, but CK showed a level of fibrinolytic activity that was about eight times higher than that of subtilisin Carlsberg. The amidolytic activity of CK increased about twofold at the initial state of the reaction when CK enzyme was added to a mixture of plasminogen and substrate (H-D-Val-Leu-Lys-pNA). A similar result was also obtained from fibrin plate analysis. PMID:8779587

Methylobacterium pseudosasicola sp. nov. and Methylobacterium phyllostachyos sp. nov., isolated from bamboo leaf surfaces.

Science.gov (United States)

Madhaiyan, Munusamy; Poonguzhali, Selvaraj

2014-07-01

Two strains of Gram-negative, methylotrophic bacteria, isolated because of their abilities to promote plant growth, were subjected to a polyphasic taxonomic study. The isolates were strictly aerobic, motile, pink-pigmented, facultatively methylotrophic, non-spore-forming rods. The chemotaxonomic characteristics of the isolates included the presence of C18 : 1ω7c as the major cellular fatty acid. The DNA G+C contents of strains BL36(T) and BL47(T) were 69.4 and 69.8 mol%, respectively. 16S rRNA gene sequence analysis of strains BL36(T) and BL47(T) placed them under the genus Methylobacterium, with the pairwise sequence similarity between them and the type strains of closely related species ranging from 97.2 to 99.0%. On the basis of their phenotypic and phylogenetic distinctiveness and the results of DNA-DNA hybridization analysis, the isolates represent two novel species within the genus Methylobacterium, for which the names Methylobacterium pseudosasicola sp. nov. (type strain BL36(T) = NBRC 105203(T) = ICMP 17621(T)) and Methylobacterium phyllostachyos sp. nov. (type strain BL47(T) = NBRC 105206(T) = ICMP 17619(T)) are proposed. © 2014 IUMS.

Minimum Requirements of Flagellation and Motility for Infection of Agrobacterium sp. Strain H13-3 by Flagellotropic Bacteriophage 7-7-1

Science.gov (United States)

Yen, Jiun Y.; Broadway, Katherine M.

2012-01-01

The flagellotropic phage 7-7-1 specifically adsorbs to Agrobacterium sp. strain H13-3 (formerly Rhizobium lupini H13-3) flagella for efficient host infection. The Agrobacterium sp. H13-3 flagellum is complex and consists of three flagellin proteins: the primary flagellin FlaA, which is essential for motility, and the secondary flagellins FlaB and FlaD, which have minor functions in motility. Using quantitative infectivity assays, we showed that absence of FlaD had no effect on phage infection, while absence of FlaB resulted in a 2.5-fold increase in infectivity. A flaA deletion strain, which produces straight and severely truncated flagella, experienced a significantly reduced infectivity, similar to that of a flaB flaD strain, which produces a low number of straight flagella. A strain lacking all three flagellin genes is phage resistant. In addition to flagellation, flagellar rotation is required for infection. A strain that is nonmotile due to an in-frame deletion in the gene encoding the motor component MotA is resistant to phage infection. We also generated two strains with point mutations in the motA gene resulting in replacement of the conserved charged residue Glu98, which is important for modulation of rotary speed. A change to the neutral Gln caused the flagellar motor to rotate at a constant high speed, allowing a 2.2-fold-enhanced infectivity. A change to the positively charged Lys caused a jiggly motility phenotype with very slow flagellar rotation, which significantly reduced the efficiency of infection. In conclusion, flagellar number and length, as well as speed of flagellar rotation, are important determinants for infection by phage 7-7-1. PMID:22865074

Draft Genome Sequence of Hymenobacter sp. Strain AT01-02, Isolated from a Surface Soil Sample in the Atacama Desert, Chile

DEFF Research Database (Denmark)

Hansen, Anders Cai Holm; Paulino-Lima, Ivan Glaucio; Fujishima, Kosuke

2016-01-01

Here, we report the 5.09-Mb draft genome sequence of Hymenobacter sp. strain AT01-02, which was isolated from a surface soil sample in the Atacama Desert, Chile. The isolate is extremely resistant to UV-C radiation and is able to accumulate high intracellular levels of Mn/Fe....

Microbial community dynamics during the bioremediation process of chlorimuron-ethyl-contaminated soil by Hansschlegelia sp. strain CHL1.

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Liqiang Yang

Full Text Available Long-term and excessive application of chlorimuron-ethyl has led to a series of environmental problems. Strain Hansschlegelia sp. CHL1, a highly efficient chlorimuron-ethyl degrading bacterium isolated in our previous study, was employed in the current soil bioremediation study. The residues of chlorimuron-ethyl in soils were detected, and the changes of soil microbial communities were investigated by phospholipid fatty acid (PLFA analysis. The results showed that strain CHL1 exhibited significant chlorimuron-ethyl degradation ability at wide range of concentrations between 10μg kg-1 and 1000μg kg-1. High concentrations of chlorimuron-ethyl significantly decreased the total concentration of PLFAs and the Shannon-Wiener indices and increased the stress level of microbes in soils. The inoculation with strain CHL1, however, reduced the inhibition on soil microbes caused by chlorimuron-ethyl. The results demonstrated that strain CHL1 is effective in the remediation of chlorimuron-ethyl-contaminated soil, and has the potential to remediate chlorimuron-ethyl contaminated soils in situ.

Microbial Community Dynamics during the Bioremediation Process of Chlorimuron-Ethyl-Contaminated Soil by Hansschlegelia sp. Strain CHL1

Science.gov (United States)

Yang, Liqiang; Li, Xinyu; Li, Xu; Su, Zhencheng; Zhang, Chenggang; Zhang, Huiwen

2015-01-01

Long-term and excessive application of chlorimuron-ethyl has led to a series of environmental problems. Strain Hansschlegelia sp. CHL1, a highly efficient chlorimuron-ethyl degrading bacterium isolated in our previous study, was employed in the current soil bioremediation study. The residues of chlorimuron-ethyl in soils were detected, and the changes of soil microbial communities were investigated by phospholipid fatty acid (PLFA) analysis. The results showed that strain CHL1 exhibited significant chlorimuron-ethyl degradation ability at wide range of concentrations between 10μg kg-1 and 1000μg kg-1. High concentrations of chlorimuron-ethyl significantly decreased the total concentration of PLFAs and the Shannon-Wiener indices and increased the stress level of microbes in soils. The inoculation with strain CHL1, however, reduced the inhibition on soil microbes caused by chlorimuron-ethyl. The results demonstrated that strain CHL1 is effective in the remediation of chlorimuron-ethyl-contaminated soil, and has the potential to remediate chlorimuron-ethyl contaminated soils in situ. PMID:25689050

Mineralization of a Malaysian crude oil by Pseudomonas sp. and Achromabacter sp. isolated from coastal waters

Energy Technology Data Exchange (ETDEWEB)

Ahmad, J.; Ahmad, M.F.

1995-12-31

Regarded as being a potentially effective tool to combat oil pollution, bioremediation involves mineralization, i.e., the conversion of complex hydrocarbons into harmless CO{sub 2} and water by action of microorganisms. Therefore, in achieving optimum effectiveness from the application of these products on crude oil in local environments, the capability of the bacteria to mineralize hydrocarbons was evaluated. The microbial laboratory testing of mineralization on local oil degraders involved, first, isolation of bacteria found at a port located on the west coast of Peninsular Malaysia. Subsequently, these bacteria were identified by means of Biomereux`s API 20E and 20 NE systems and later screened by their growth on a Malaysian crude oil. Selected strains of Pseudomonas sp. and Achromabacter sp. were then exposed individually to a similar crude oil in a mineralization unit and monitored for 16 days for release of CO{sub 2}. Pseudomonas paucimobilis was found to produce more CO{sub 2} than Achromobacter sp. When tested under similar conditions, mixed populations of these two taxa produced more CO{sub 2} than that produced by any individual strain. Effective bioremediation of local crude in Malaysian waters can therefore be achieved from biochemically developed Pseudomonas sp. strains.

Draft Genome Sequence of an Endophytic Fungus, Gaeumannomyces sp. Strain JS-464, Isolated from a Reed Plant, Phragmites communis.

Science.gov (United States)

Kim, Jung A; Jeon, Jongbum; Kim, Ki-Tae; Choi, Gobong; Park, Sook-Young; Lee, Hyun-Jung; Shim, Sang-Hee; Lee, Yong-Hwan; Kim, Soonok

2017-08-03

An endophytic fungus, Gaeumannomyces sp. strain JS-464, is capable of producing a number of secondary metabolites which showed significant nitric oxide reduction activity. The draft genome assembly has a size of 53,151,282 bp, with a G+C content of 53.11% consisting of 80 scaffolds with an N 50 of 7.46 Mbp. Copyright © 2017 Kim et al.

Accumulation of a Polyhydroxyalkanoate Containing Primarily 3-Hydroxydecanoate from Simple Carbohydrate Substrates by Pseudomonas sp. Strain NCIMB 40135

OpenAIRE

Haywood, Geoffrey W.; Anderson, Alistair J.; Ewing, David F.; Dawes, Edwin A.

1990-01-01

A number of Pseudomonas species have been identified which accumulate a polyhydroxyalkanoate containing mainly 3-hydroxydecanoate monomers from sodium gluconate as the sole carbon source. One of these, Pseudomonas sp. strain NCIMB 40135, was further investigated and shown to accumulate such a polyhydroxyalkanoate from a wide range of carbon sources (C2 to C6); however, when supplied with octanoic acid it produced a polyhydroxyalkanoate containing mainly 3-hydroxyoctanoate monomers. Polymer sy...

Sinorhizobium arboris sp. nov. and Sinorhizobium kostiense sp. nov., isolated from leguminous trees in Sudan and Kenya.

Science.gov (United States)

Nick, G; de Lajudie, P; Eardly, B D; Suomalainen, S; Paulin, L; Zhang, X; Gillis, M; Lindström, K

1999-10-01

SDS-PAGE of total bacterial proteins was applied to the classification of 25 Sudanese and five Kenyan strains isolated from the root nodules of Acacia senegal and Prosopis chilensis. Twenty strains were also studied by multilocus enzyme electrophoresis (MLEE) and the whole 16S rRNA gene was sequenced from two strains representing the two major clusters. These results, together with the previously reported numerical taxonomy analysis, pulsed-field gel electrophoresis studies, DNA-DNA dot-blot hybridization, genomic fingerprinting using repetitive sequence-based PCR, DNA base composition analysis, DNA-DNA reassociation analysis, partial sequencing of the 16S rRNA gene and RFLP analysis of the amplified 16S rRNA gene, showed that all 30 strains belong to the genus Sinorhizobium. Two of the strains grouped with Sinorhizobium saheli and seven with Sinorhizobium terangae, while the rest did not cluster with any of the established species. The majority of the strains formed two phenotypically and genotypically distinct groups and we therefore propose that these strains should be classified as two new species, Sinorhizobium arboris sp. nov. and Sinorhizobium kostiense sp. nov.

Microtwin formation in the α phase of duplex titanium alloys affected by strain rate

International Nuclear Information System (INIS)

Lin, Yi-Hsiang; Wu, Shu-Ming; Kao, Fang-Hsin; Wang, Shing-Hoa; Yang, Jer-Ren; Yang, Chia-Chih; Chiou, Chuan-Sheng

2011-01-01

Research highlights: → The long and dense twins in α phase of SP700 alloy occurring at lower strain rates promote a good ductility. → The deformation in SP700 alloy changed to micro twins-controlled mechanism in α as the strain rate decreases. → The material has time to redistribute the deformed strain between α and β as the strain rate decreases. - Abstract: The effect of tensile strain rate on deformation microstructure was investigated in Ti-6-4 (Ti-6Al-4V) and SP700 (Ti-4.5Al-3V-2Mo-2Fe) of the duplex titanium alloys. Below a strain rate of 10 -2 s -1 , Ti-6-4 alloy had a higher ultimate tensile strength than SP700 alloy. However, the yield strength of SP700 was consistently greater than Ti-6-4 at different strain rates. The ductility of SP700 alloy associated with twin formation (especially at the slow strain rate of 10 -4 s -1 ), always exceeded that of Ti-6-4 alloy at different strain rates. It is caused by a large quantity of deformation twins took place in the α phase of SP700 due to the lower stacking fault energy by the β stabilizer of molybdenum alloying. In addition, the local deformation more was imposed on the α grains from the surrounding β-rich grains by redistributing strain as the strain rate decreased in SP700 duplex alloy.

Methylopila helvetica sp. nov. and Methylobacterium dichloromethanicum sp. nov.--novel aerobic facultatively methylotrophic bacteria utilizing dichloromethane.

Science.gov (United States)

Doronina, N V; Trotsenko, Y A; Tourova, T P; Kuznetsov, B B; Leisinger, T

2000-06-01

Eight strains of Gram-negative, aerobic, asporogenous, neutrophilic, mesophilic, facultatively methylotrophic bacteria are taxonomically described. These icl- serine pathway methylobacteria utilize dichloromethane, methanol and methylamine as well as a variety of polycarbon compounds as the carbon and energy source. The major cellular fatty acids of the non-pigmented strains DM1, DM3, and DM5 to DM9 are C18:1, C16:0, C18:0, Ccy19:0 and that of the pink-pigmented strain DM4 is C18:1. The main quinone of all the strains is Q-10. The non-pigmented strains have similar phenotypic properties and a high level of DNA-DNA relatedness (81-98%) as determined by hybridization. All strains belong to the alpha-subgroup of the alpha-Proteobacteria. 16S rDNA sequence analysis led to the classification of these dichloromethane-utilizers in the genus Methylopila as a new species - Methylopila helvetica sp.nov. with the type strain DM9 (=VKM B-2189). The pink-pigmented strain DM4 belongs to the genus Methylobacterium but differs from the known members of this genus by some phenotypic properties, DNA-DNA relatedness (14-57%) and 16S rDNA sequence. Strain DM4 is named Methylobacterium dichloromethanicum sp. nov. (VKM B-2191 = DSMZ 6343).

‘Khoudiadiopia massiliensis’ gen. nov., sp. nov., strain Marseille-P2746TT, a new bacterial genus isolated from the female genital tract

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A. Diop

2017-09-01

Full Text Available We report the main characteristics of ‘Khoudiadiopia massiliensis’ gen. nov., sp. nov., strain Marseille-P2746T (= CSUR P2746, a new member of the Peptoniphilaceae family isolated from a vaginal swab of a patient suffering from bacterial vaginosis.

Glycomyces scopariae sp. nov. and Glycomyces mayteni sp. nov., isolated from medicinal plants in China.

Science.gov (United States)

Qin, Sheng; Chen, Hua-Hong; Klenk, Hans-Peter; Zhao, Guo-Zhen; Li, Jie; Xu, Li-Hua; Li, Wen-Jun

2009-05-01

Two actinomycete strains, designated YIM 56256(T) and YIM 61331(T), were isolated from the roots of Scoparia dulcis and Maytenus austroyunnanensis, two Chinese medicinal plants, and their taxonomic status was established based on a polyphasic investigation. The organisms were found to have chemical and morphological markers typical of members of the genus Glycomyces. 16S rRNA gene sequence analysis showed that they were closely related to each other and to Glycomyces sambucus E71(T). A battery of physiological characteristics and levels of DNA-DNA relatedness indicated that strains YIM 56256(T) and YIM 61331(T) represent two novel species, clearly different from the related known Glycomyces species. On the basis of the data presented, it is evident that each of these strains represents a novel species of the genus Glycomyces, for which the names Glycomyces scopariae sp. nov. (type strain YIM 56256(T) =KCTC 19158(T) =DSM 44968(T)) and Glycomyces mayteni sp. nov. (type strain YIM 61331(T) =KCTC 19527(T) =CCTCC AA 208004(T)) are proposed.

Genome sequence of the photoarsenotrophic bacterium Ectothiorhodospira sp. strain BSL-9, isolated from a hypersaline alkaline arsenic-rich extreme environment

Science.gov (United States)

Hernandez-Maldonado, Jaime; Stoneburner, Brendon; Boren, Alison; Miller, Laurence; Rosen, Michael R.; Oremland, Ronald S.; Saltikov, Chad W

2016-01-01

The full genome sequence of Ectothiorhodospira sp. strain BSL-9 is reported here. This purple sulfur bacterium encodes an arxA-type arsenite oxidase within the arxB2AB1CD gene island and is capable of carrying out “photoarsenotrophy” anoxygenic photosynthetic arsenite oxidation. Its genome is composed of 3.5 Mb and has approximately 63% G+C content.

SACCHAROTHRIX SP. ABH26, A NEW ACTINOBACTERIAL STRAIN FROM ALGERIAN SAHARAN SOIL: ISOLATION, IDENTIFICATION AND ANTIMICROBIAL ACTIVITY

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Abdelhadi Lahoum

2015-04-01

Full Text Available A new strain of actinobacteria, designated ABH26, was isolated from a Saharan soil in the Adrar region (Algeria, by the dilution agar plating method using a chitin-vitamins B medium supplemented with polymyxin and penicillin. The morphological studies showed that this strain represents a member of the Saccharothrix genus. Phylogenetic analysis showed that this strain had 16S rRNA gene sequence similarities ranging from 97.63% (with Saccharothrix violaceirubra NBRC 102064T to 99.86% (with Saccharothrix xinjiangensis NBRC 101911T. Furthermore, strain ABH26 presented a strong activity against mycotoxigenic and phytopathogenic fungi including Aspergillus carbonarius (M333, A. flavus (NRRL 3251, A. westerdijkiae (ATCC 3174, Fusarium oxysporum f. sp. lini (Fol and F. solani (Fsol. Additionally, the strain exhibited an important antimicrobial activity against many strains of the pathogenic yeast Candida albicans (M2, M3 and IPA200 and against methicillin resistant Staphylococcus aureus (MRSA 639c. Thus, four solvents (n-hexane, dichloromethane, ethyl acetate and n-butanol were used for the extraction of produced antibiotic compounds. The highest antimicrobial activities were obtained using the butanolic extract. The thin layer chromatography (TLC method showed two bioactive spots, named HAD1 and HAD2, which were reveled negatively by using chemical revelators (ninhydrin, naphtoresorcinol-sulfuric acid, ferrous iron chloride and formaldehyde-sulfuric. These results indicated the absence of amine group, sugar, hydroxamic acid, phenol and aromatic compound.

Isolation and characterization of an acrylamide-degrading yeast Rhodotorula sp. strain MBH23 KCTC 11960BP.

Science.gov (United States)

Rahim, M B H; Syed, M A; Shukor, M Y

2012-10-01

As well as for chemical and environmental reasons, acrylamide is widely used in many industrial applications. Due to its carcinogenicity and toxicity, its discharge into the environment causes adverse effects on humans and ecology alike. In this study, a novel acrylamide-degrading yeast has been isolated. The isolate was identified as Rhodotorula sp. strain MBH23 using ITS rRNA analysis. The results showed that the best carbon source for growth was glucose at 1.0% (w/v). The optimum acrylamide concentration, being a nitrogen source for cellular growth, was at 500 mg l(-1). The highest tolerable concentration of acrylamide was 1500 mg l(-1) whereas growth was completely inhibited at 2000 mg l(-1). At 500 mg l(-1), the strain MBH completely degraded acrylamide on day 5. Acrylic acid as a metabolite was detected in the media. Strain MBH23 grew well between pH 6.0 and 8.0 and between 27 and 30 °C. Amides such as 2-chloroacetamide, methacrylamide, nicotinamide, acrylamide, acetamide, and propionamide supported growth. Toxic heavy metals such as mercury, chromium, and cadmium inhibited growth on acrylamide. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Membrane-aerated biofilm reactor for the removal of 1,2-dichloroethane by Pseudomonas sp. strain DCA1.

Science.gov (United States)

Hage, J C; Van Houten, R T; Tramper, J; Hartmans, S

2004-06-01

A membrane-aerated biofilm reactor (MBR) with a biofilm of Pseudomonas sp. strain DCA1 was studied for the removal of 1,2-dichloroethane (DCA) from water. A hydrophobic membrane was used to create a barrier between the liquid and the gas phase. Inoculation of the MBR with cells of strain DCA1 grown in a continuous culture resulted in the formation of a stable and active DCA-degrading biofilm on the membrane. The maximum removal rate of the MBR was reached at a DCA concentration of approximately 80 micro M. Simulation of the DCA fluxes into the biofilm showed that the MBR performance at lower concentrations was limited by the DCA diffusion rate rather than by kinetic constraints of strain DCA1. Aerobic biodegradation of DCA present in anoxic water could be achieved by supplying oxygen solely from the gas phase to the biofilm grown on the liquid side of the membrane. As a result, direct aeration of the water, which leads to undesired coagulation of iron oxides, could be avoided.

ORF Alignment: NC_000911 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available ... thioredoxin [Synechocystis sp. PCC 6803] ... Length = 92 ... Query: 2 ... SLLEITDAEFEQETQGQTKPVLVYFWASWCGPCRLMAPA...IQAIAKDYGDKLKVLKLEVDP 61 ... SLLEITDAEFEQETQGQTKPVLVYFWASWCGPCRLMAPA...IQAIAKDYGDKLKVLKLEVDP Sbjct: 1 ... SLLEITDAEFEQETQGQTKPVLVYFWASWCGPCRLMAPAIQAIAKDYGDKLKVLKLEVDP 60 ...

Characterization and Optimization of Bioflocculant Exopolysaccharide Production by Cyanobacteria Nostoc sp. BTA97 and Anabaena sp. BTA990 in Culture Conditions.

Science.gov (United States)

Tiwari, Onkar Nath; Khangembam, Romi; Shamjetshabam, Minerva; Sharma, Aribam Subhalaxmi; Oinam, Gunapati; Brand, Jerry J

2015-08-01

Bioflocculant exopolysaccharide (EPS) production by 40 cyanobacterial strains during their photoautotrophic growth was investigated. Highest levels of EPS were produced by Nostoc sp. BTA97 and Anabaena sp. BTA990. EPS production was maximum during stationary growth phase, when nitrogenase activity was very low. Maximum EPS production occurred at pH 8.0 in the absence of any combined nitrogen source. The cyanobacterial EPS consisted of soluble protein and polysaccharide that included substantial amounts of neutral sugars and uronic acid. The EPS isolated from Anabaena sp. BTA990 and Nostoc sp. BTA97 demonstrated high flocculation capacity. There was a positive correlation between uronic acid content and flocculation activity. The flocculant bound a cationic dye, Alcian Blue, indicating it to be polyanionic. The 16S rRNA gene sequences for Nostoc sp. BTA97 and Anabaena sp. BTA990 were deposited at NCBI GenBank, and accession numbers were obtained as KJ830951 and KJ830948, respectively. The results of these experiments indicate that strains Anabaena sp. BTA990 and Nostoc sp. BTA97 are good candidates for the commercial production of EPS and might be utilized in industrial applications as an alternative to synthetic and abiotic flocculants.

Pseudomonas lactis sp. nov. and Pseudomonas paralactis sp. nov., isolated from bovine raw milk.

Science.gov (United States)

von Neubeck, Mario; Huptas, Christopher; Glück, Claudia; Krewinkel, Manuel; Stoeckel, Marina; Stressler, Timo; Fischer, Lutz; Hinrichs, Jörg; Scherer, Siegfried; Wenning, Mareike

2017-06-01

Five strains, designated WS 4672T, WS 4998, WS 4992T, WS 4997 and WS 5000, isolated from bovine raw milk formed two individual groups in a phylogenetic analysis. The most similar species on the basis of 16S rRNA gene sequences were Pseudomonas azotoformans IAM 1603T, Pseudomonas gessardii CIP 105469T and Pseudomonas libanensis CIP 105460T showing 99.7-99.6 % similarity. Using rpoD gene sequences Pseudomonas veronii LMG 17761T (93.3 %) was most closely related to strain WS 4672T and Pseudomonas libanensis CIP 105460T to strain WS 4992T (93.3 %). The five strains could be differentiated from their closest relatives and from each other by phenotypic and chemotaxonomic characterization and ANIb values calculated from draft genome assemblies. ANIb values of strains WS 4992T and WS4671T to the closest relatives are lower than 90 %. The major cellular polar lipids of both strains are phosphatidylethanolamine, phosphatidylglycerol, a phospholipid and diphosphatidylglycerol, and their major quinone is Q-9. The DNA G+C content of strains WS 4992T and WS 4672T were 60.0  and 59.7  mol%, respectively. Based on these genotypic and phenotypic traits two novel species of the genus Pseudomonas are proposed: Pseudomonas lactis sp. nov. [with type strain WS 4992T (=DSM 29167T=LMG 28435T) and the additional strains WS 4997 and WS 5000], and Pseudomonasparalactis sp. nov. [with type strain WS 4672T (=DSM 29164T=LMG 28439T) and additional strain WS 4998].

Estimation of the light field inside photosynthetic microorganism cultures through Mittag-Leffler functions at depleted light conditions

Science.gov (United States)

Fuente, David; Lizama, Carlos; Urchueguía, Javier F.; Conejero, J. Alberto

2018-01-01

Light attenuation within suspensions of photosynthetic microorganisms has been widely described by the Lambert-Beer equation. However, at depths where most of the light has been absorbed by the cells, light decay deviates from the exponential behaviour and shows a lower attenuation than the corresponding from the purely exponential fall. This discrepancy can be modelled through the Mittag-Leffler function, extending Lambert-Beer law via a tuning parameter α that takes into account the attenuation process. In this work, we describe a fractional Lambert-Beer law to estimate light attenuation within cultures of model organism Synechocystis sp. PCC 6803. Indeed, we benchmark the measured light field inside cultures of two different Synechocystis strains, namely the wild-type and the antenna mutant strain called Olive at five different cell densities, with our in silico results. The Mittag-Leffler hyper-parameter α that best fits the data is 0.995, close to the exponential case. One of the most striking results to emerge from this work is that unlike prior literature on the subject, this one provides experimental evidence on the validity of fractional calculus for determining the light field. We show that by applying the fractional Lambert-Beer law for describing light attenuation, we are able to properly model light decay in photosynthetic microorganisms suspensions.

Heitmania gen. nov., a new yeast genus in Microbotryomycetes, and description of three novel species: Heitmania litseae sp. nov., Heitmania castanopsis sp. nov. and Heitmania elacocarpi sp. nov.

Science.gov (United States)

Liu, Xin-Zhan; Groenewald, Marizeth; Boekhout, Teun; Bai, Feng-Yan

2017-11-01

Nine anamorphic yeast strains isolated from various plant leaves collected in southern China were phylogenetically characterized based on sequences of the internal transcribed spacer (ITS) region, the D1/D2 domains of the large subunit (LSU) rRNA gene, the small subunit (SSU) rRNA gene, the two subunits of the RNA polymerase II gene (RPB1 and RPB2) and the translation elongation factor 1-α (TEF1). Phylogenetic analysis of the combined sequences of the six genes showed that the new strains formed a distinct clade in the class Microbotryomycetes but could not be assigned to any of the existing genera, families or orders of the class. Three separate groups were consistently resolved from the nine new strains based on the combined sequences of the six genes and single gene sequences of ITS, RPB1, RPB2 and TEF1. The results suggest that the nine yeast strains compared represent three novel species in a novel genus. The names Heitmania gen. nov. (MycoBank registration number MB819987), Heitmania litseae sp. nov. (MB820112, type strain CGMCC 2.5697 T =CBS 14756 T ), Heitmania castanopsis sp. nov. (MB819988, CGMCC 2.5698 T =CBS 14750 T ) and Heitmania elacocarpi sp. nov. (MB820113, CGMCC 2.5695 T =CBS 14752 T ) are proposed for the new taxa.

Description of Leifsonia kafniensis sp. nov. and Leifsonia antarctica sp. nov.

Science.gov (United States)

Pindi, Pavan Kumar; Kishore, K Hara; Reddy, G S N; Shivaji, S

2009-06-01

Strains KFC-22(T) and SPC-20(T) are yellow-pigmented, Gram-positive, aerobic, non-motile, rod-shaped bacteria that were isolated from a soil sample near the Kafni glacier in the Himalayan mountain ranges in India, and from a spade core sediment sample from the Antarctic Ocean at Larsemann Hill, respectively. In both cases, the cell-wall peptidoglycan contained 2,4-diaminobutyric acid as the diamino acid, anteiso-C(15 : 0), anteiso-C(17 : 0) and iso-C(16 : 0) were the predominant fatty acids and MK-11 was the major isoprenoid quinone in the cell membrane. On the basis of the above-mentioned characteristics, both strains can be assigned to the genus Leifsonia. The strains share 16S rRNA gene sequence similarity of 97.7 % and DNA relatedness of only 10 %, indicating that they represent different species. A blast analysis indicated that Leifsonia pindariensis PON10(T) was the closest phylogenetic neighbour of strains SPC-20(T) and KFC-22(T), showing 16S rRNA gene sequence similarities of 97.3 and 97.7 %, respectively. However, at the whole-genome level, strains KFC-22(T) and SPC-20(T) shared 42 and 11 % DNA-DNA relatedness, respectively, with L. pindariensis PON10(T). In addition, both strains exhibited several phenotypic differences with respect to L. pindariensis PON10(T). Thus, on the basis of the differences that the two strains exhibited with respect to L. pindariensis, both were identified as representing novel species of the genus Leifsonia, for which the names Leifsonia kafniensis sp. nov. (type strain KFC-22(T) =NCCB 100216(T) =LMG 24362(T)) and Leifsonia antarctica sp. nov. (type strain SPC-20(T) =NCCB 100227(T) =LMG 24541(T)) are proposed.

Suitable conditions for xylanases activities from Bacillus sp. GA2(1 and Bacillus sp. GA1(6 and their properties for agricultural residues hydrolysis

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Sudathip Chantorn

2016-04-01

Full Text Available Bacillus sp. GA2(1 and Bacillus sp. GA1(6 were isolated from soybean field in Khon Kaen province, Thailand. Crude enzymes from both isolates showed the activities of cellulase, xylanase, and mannanase at 37°C for 24 h. The highest xylanase activities of Bacillus sp. GA2(1 and Bacillus sp. GA1(6 were 1.58±0.25 and 0.82±0.16 U/ml, respectively. The relative xylanase activities from both strains were more than 60% at pH 5.0 to 8.0. The optimum temperature of xylanases was 50°C in both strains. The residual xylanase activities from both strains were more than 70% at 60°C for 60 min. Five agricultural wastes (AWs, namely coffee residue, soybean meal, potato peel, sugarcane bagasse, and corn cobs, were used as substrates for hydrolysis properties. The highest reducing sugar content of 101±1.32 µg/ml was obtained from soybean meal hydrolysate produced by Bacillus sp. GA2(1 xylanase.

Involvement of Potassium Transport Systems in the Response of Synechocystis PCC 6803 Cyanobacteria to External pH Change, High-Intensity Light Stress and Heavy Metal Stress.

Science.gov (United States)

Checchetto, Vanessa; Segalla, Anna; Sato, Yuki; Bergantino, Elisabetta; Szabo, Ildiko; Uozumi, Nobuyuki

2016-04-01

The unicellular photosynthetic cyanobacterium, able to survive in varying environments, is the only prokaryote that directly converts solar energy and CO2 into organic material and is thus relevant for primary production in many ecosystems. To maintain the intracellular and intrathylakoid ion homeostasis upon different environmental challenges, the concentration of potassium as a major intracellular cation has to be optimized by various K(+)uptake-mediated transport systems. We reveal here the specific and concerted physiological function of three K(+)transporters of the plasma and thylakoid membranes, namely of SynK (K(+)channel), KtrB (Ktr/Trk/HKT) and KdpA (Kdp) in Synechocystis sp. strain PCC 6803, under specific stress conditions. The behavior of the wild type, single, double and triple mutants was compared, revealing that only Synk contributes to heavy metal-induced stress, while only Ktr/Kdp is involved in osmotic and salt stress adaptation. With regards to pH shifts in the external medium, the Kdp/Ktr uptake systems play an important role in the adaptation to acidic pH. Ktr, by affecting the CO2 concentration mechanism via its action on the bicarbonate transporter SbtA, might also be responsible for the observed effects concerning high-light stress and calcification. In the case of illumination with high-intensity light, a synergistic action of Kdr/Ktp and SynK is required in order to avoid oxidative stress and ensure cell viability. In summary, this study dissects, using growth tests, measurement of photosynthetic activity and analysis of ultrastructure, the physiological role of three K(+)transporters in adaptation of the cyanobacteria to various environmental changes. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Cloning and recombinant expression of a cellulase from the cellulolytic strain Streptomyces sp. G12 isolated from compost

Directory of Open Access Journals (Sweden)

Amore Antonella

2012-12-01

Full Text Available Abstract Background The use of lignocellulosic materials for second generation ethanol production would give several advantages such as minimizing the conflict between land use for food and fuel production, providing less expensive raw materials than conventional agricultural feedstock, allowing lower greenhouse gas emissions than those of first generation ethanol. However, cellulosic biofuels are not produced at a competitive level yet, mainly because of the high production costs of the cellulolytic enzymes. Therefore, this study was aimed at discovering new cellulolytic microorganisms and enzymes. Results Different bacteria isolated from raw composting materials obtained from vegetable processing industry wastes were screened for their cellulolytic activity on solid medium containing carboxymethylcellulose. Four strains belonging to the actinomycetes group were selected on the basis of their phenotypic traits and cellulolytic activity on solid medium containing carboxymethylcellulose. The strain showing the highest cellulolytic activity was identified by 16S rRNA sequencing as belonging to Streptomyces genus and it was designated as Streptomyces sp. strain G12. Investigating the enzymes responsible for cellulase activity produced by Streptomyces G12 by proteomic analyses, two endoglucanases were identified. Gene coding for one of these enzymes, named CelStrep, was cloned and sequenced. Molecular analysis showed that the celstrep gene has an open reading frame encoding a protein of 379 amino acid residues, including a signal peptide of 37 amino acid residues. Comparison of deduced aminoacidic sequence to the other cellulases indicated that the enzyme CelStrep can be classified as a family 12 glycoside hydrolase. Heterologous recombinant expression of CelStrep was carried out in Escherichia coli, and the active recombinant enzyme was purified from culture supernatant and characterized. It catalyzes the hydrolysis of carboxymethylcellulose

Cloning and recombinant expression of a cellulase from the cellulolytic strain Streptomyces sp. G12 isolated from compost

Science.gov (United States)

2012-01-01

Background The use of lignocellulosic materials for second generation ethanol production would give several advantages such as minimizing the conflict between land use for food and fuel production, providing less expensive raw materials than conventional agricultural feedstock, allowing lower greenhouse gas emissions than those of first generation ethanol. However, cellulosic biofuels are not produced at a competitive level yet, mainly because of the high production costs of the cellulolytic enzymes. Therefore, this study was aimed at discovering new cellulolytic microorganisms and enzymes. Results Different bacteria isolated from raw composting materials obtained from vegetable processing industry wastes were screened for their cellulolytic activity on solid medium containing carboxymethylcellulose. Four strains belonging to the actinomycetes group were selected on the basis of their phenotypic traits and cellulolytic activity on solid medium containing carboxymethylcellulose. The strain showing the highest cellulolytic activity was identified by 16S rRNA sequencing as belonging to Streptomyces genus and it was designated as Streptomyces sp. strain G12. Investigating the enzymes responsible for cellulase activity produced by Streptomyces G12 by proteomic analyses, two endoglucanases were identified. Gene coding for one of these enzymes, named CelStrep, was cloned and sequenced. Molecular analysis showed that the celstrep gene has an open reading frame encoding a protein of 379 amino acid residues, including a signal peptide of 37 amino acid residues. Comparison of deduced aminoacidic sequence to the other cellulases indicated that the enzyme CelStrep can be classified as a family 12 glycoside hydrolase. Heterologous recombinant expression of CelStrep was carried out in Escherichia coli, and the active recombinant enzyme was purified from culture supernatant and characterized. It catalyzes the hydrolysis of carboxymethylcellulose following a Michaelis�

Lactobacillus micheneri sp. nov., Lactobacillus timberlakei sp. nov. and Lactobacillus quenuiae sp. nov., lactic acid bacteria isolated from wild bees and flowers.

Science.gov (United States)

McFrederick, Quinn S; Vuong, Hoang Q; Rothman, Jason A

2018-04-12

Gram-stain-positive, rod-shaped, non-spore forming bacteria have been isolated from flowers and the guts of adult wild bees in the families Megachilidae and Halictidae. Phylogenetic analysis of the 16S rRNA gene indicated that these bacteria belong to the genus Lactobacillus, and are most closely related to the honey-bee associated bacteria Lactobacillus kunkeei (97.0 % sequence similarity) and Lactobacillus apinorum (97.0 % sequence similarity). Phylogenetic analyses of 16S rRNA genes and six single-copy protein coding genes, in situ and in silico DNA-DNA hybridization, and fatty-acid profiling differentiates the newly isolated bacteria as three novel Lactobacillus species: Lactobacillus micheneri sp. nov. with the type strain Hlig3 T (=DSM 104126 T ,=NRRL B-65473 T ), Lactobacillus timberlakei with the type strain HV_12 T (=DSM 104128 T ,=NRRL B-65472 T ), and Lactobacillus quenuiae sp. nov. with the type strain HV_6 T (=DSM 104127 T ,=NRRL B-65474 T ).

Pesticide tolerant and phosphorus solubilizing Pseudomonas sp. strain SGRAJ09 isolated from pesticides treated Achillea clavennae rhizosphere soil.

Science.gov (United States)

Rajasankar, R; Manju Gayathry, G; Sathiavelu, A; Ramalingam, C; Saravanan, V S

2013-05-01

In this study, an attempt was made to identify an effective phosphate solubilizing bacteria from pesticide polluted field soil. Based on the formation of solubilization halo on Pikovskaya's agar, six isolates were selected and screened for pesticide tolerance and phosphate (P) solubilization ability through liquid assay. The results showed that only one strain (SGRAJ09) obtained from Achillea clavennae was found to tolerate maximum level of the pesticides tested and it was phylogenetically identified as Pseudomonas sp. It possessed a wide range of pesticide tolerance, ranging from 117 μg mL(-1) for alphamethrin to 2,600 μg mL(-1) for endosulfan. The available P concentrations increased with the maximum and double the maximum dose of monocrotophos and imidacloprid, respectively. On subjected to FT-IR and HPLC analysis, the presence of organic acids functional group in the culture broth and the production of gluconic acid as dominant acid aiding the P solubilization were identified. On comparison with control broth, monocrotophos and imidacloprid added culture broth showed quantitatively high organic acids production. In addition to gluconic acid production, citric and acetic acids were also observed in the pesticide amended broth. Furthermore, the Pseudomonas sp. strain SGRAJ09 possessed all the plant growth promoting traits tested. In presence of monocrotophos and imidacloprid, its plant growth promoting activities were lower than that of the pesticides unamended treatment.

Isolation and characterization of mesotrione-degrading Bacillus sp. from soil

International Nuclear Information System (INIS)

Batisson, Isabelle; Crouzet, Olivier; Besse-Hoggan, Pascale; Sancelme, Martine; Mangot, Jean-Francois; Mallet, Clarisse; Bohatier, Jacques

2009-01-01

Dissipation kinetics of mesotrione, a new triketone herbicide, sprayed on soil from Limagne (Puy-de-Dome, France) showed that the soil microflora were able to biotransform it. Bacteria from this soil were cultured in mineral salt solution supplemented with mesotrione as sole source of carbon for the isolation of mesotrione-degrading bacteria. The bacterial community structure of the enrichment cultures was analyzed by temporal temperature gradient gel electrophoresis (TTGE). The TTGE fingerprints revealed that mesotrione had an impact on bacterial community structure only at its highest concentrations and showed mesotrione-sensitive and mesotrione-adapted strains. Two adapted strains, identified as Bacillus sp. and Arthrobacter sp., were isolated by colony hybridization methods. Biodegradation assays showed that only the Bacillus sp. strain was able to completely and rapidly biotransform mesotrione. Among several metabolites formed, 2-amino-4-methylsulfonylbenzoic acid (AMBA) accumulated in the medium. Although sulcotrione has a chemical structure closely resembling that of mesotrione, the isolates were unable to degrade it. - A Bacillus sp. strain isolated from soil was able to completely and rapidly biotransform the triketone herbicide mesotrione

Characterization of a novel biosurfactant produced by Staphylococcus sp. strain 1E with potential application on hydrocarbon bioremediation.

Science.gov (United States)

Eddouaouda, Kamel; Mnif, Sami; Badis, Abdelmalek; Younes, Sonia Ben; Cherif, Slim; Ferhat, Samira; Mhiri, Najla; Chamkha, Mohamed; Sayadi, Sami

2012-08-01

A biosurfactant-producing bacterium (Staphylococcus sp. strain 1E) was isolated from an Algerian crude oil contaminated soil. Biosurfactant production was tested with different carbon sources using the surface tension measurement and the oil displacement test. Olive oil produced the highest reduction in surface tension (25.9 dynes cm(-1)). Crude oil presented the best substrate for 1E biosurfactant emulsification activity. The biosurfactant produced by strain 1E reduced the growth medium surface tension below 30 dynes cm(-1). This reduction was also obtained in cell-free filtrates. Biosurfactant produced by strain 1E showed stability in a wide range of pH (from 2 to 12), temperature (from 4 to 55 °C) and salinity (from 0 to 300 g l(-1)) variations. The biosurfactant produced by strain 1E belonged to lipopeptide group and also constituted an antibacterial activity againt the pathogenic bacteria such as Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Bacillus subtilis. Phenanthrene solubility in water was enhanced by biosurfactant addition. Our results suggest that the 1E biosurfactant has interesting properties for its application in bioremediation of hydrocarbons contaminated sites. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Enhancement of the potential to utilize octopine in the nonfluorescent Pseudomonas sp. strain 92

International Nuclear Information System (INIS)

Gill, S.S.; Boivin, R.; Dion, P.

1991-01-01

The nonfluorescent Pseudomonas sp. strain 92 requires the presence of a supplementary carbon source for growth on octopine, whereas the spontaneous mutant RB100 has acquired the capacity to utilize this opine as the sole carbon and nitrogen source. Insertional mutagenesis of RB100 with transposon Tn5 generated mutants which were unable to grow on octopine and others which grew slowly on this substrate. Both types of mutants yielded revertants that had regained the ability to utilize octopine. Some of the revertants had lost the transposon, whereas in others the transposon was retained but with rearrangements of the insertion site. Genes of octopine catabolism from strain 92 were cloned on a cosmid vector to generate pK3. The clone pK3 conferred the ability to utilize octopine as the sole carbon and nitrogen source on the host Pseudomonas putida KT2440. Although they conferred an equivalent growth phenotype, the mutant genes carried by RB100 and the cloned genes on pK3 differed in their regulation. Utilization of [ 14 C]octopine was inducible by octopine in RB100 and was constitutive in KT2440(pK3)

A phycocyanin·phellandrene synthase fusion enhances recombinant protein expression and β-phellandrene (monoterpene) hydrocarbons production in Synechocystis (cyanobacteria).

Science.gov (United States)

Formighieri, Cinzia; Melis, Anastasios

2015-11-01

Cyanobacteria can be exploited as photosynthetic platforms for heterologous generation of terpene hydrocarbons with industrial applications. Transformation of Synechocystis and heterologous expression of the β-phellandrene synthase (PHLS) gene alone is necessary and sufficient to confer to Synechocystis the ability to divert intermediate terpenoid metabolites and to generate the monoterpene β-phellandrene during photosynthesis. However, terpene synthases, including the PHLS, have a slow Kcat (low Vmax) necessitating high levels of enzyme concentration to enable meaningful rates and yield of product formation. Here, a novel approach was applied to increase the PHLS protein expression alleviating limitations in the rate and yield of β-phellandrene product generation. Different PHLS fusion constructs were generated with the Synechocystis endogenous cpcB sequence, encoding for the abundant in cyanobacteria phycocyanin β-subunit, expressed under the native cpc operon promoter. In one of these constructs, the CpcB·PHLS fusion protein accumulated to levels approaching 20% of the total cellular protein, i.e., substantially higher than expressing the PHLS protein alone under the same endogenous cpc promoter. The CpcB·PHLS fusion protein retained the activity of the PHLS enzyme and catalyzed β-phellandrene synthesis, yielding an average of 3.2 mg product g(-1) dry cell weight (dcw) versus the 0.03 mg g(-1)dcw measured with low-expressing constructs, i.e., a 100-fold yield improvement. In conclusion, the terpene synthase fusion-protein approach is promising, as, in this case, it substantially increased the amount of the PHLS in cyanobacteria, and commensurately improved rates and yield of β-phellandrene hydrocarbons production in these photosynthetic microorganisms. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Mutational analysis of the multicopy hao gene coding for hydroxylamine oxidoreductase in Nitrosomonas sp. strain ENI-11.

Science.gov (United States)

Yamagata, A; Hirota, R; Kato, J; Kuroda, A; Ikeda, T; Takiguchi, N; Ohtake, H

2000-08-01

The ammonia-oxidizing bacterium Nitrosomonas sp. strain ENI-11 contains three copies of the hao gene (hao1, hao2, and hao3) coding for hydroxylamine oxidoreductase (HAO). Three single mutants (hao1::kan, hao2::kan, or hao3::kan) had 68 to 75% of the wild-type growth rate and 58 to 89% of the wild-type HAO activity when grown under the same conditions. A double mutant (hao1::kan and hao3::amp) also had 68% of the wild-type growth and 37% of the wild-type HAO activity.

Characterization of a cold-adapted esterase and mutants from a psychotolerant Pseudomonas sp. strain.

Science.gov (United States)

Dong, Juan; Gasmalla, Mohammed A A; Zhao, Wei; Sun, Jingtao; Liu, Wenyu; Wang, Mingming; Han, Liang; Yang, Ruijin

2017-09-01

A cold-adapted esterase-producing strain named T1-39 was isolated from Glacier No. 1, Tianshan, People's Republic of China and identified as Pseudomonas sp. from 16S rRNA sequence analysis. The esterase (EstT1-39) secreted by this strain preferentially hydrolyzed esters of glycerol with short- and medium-chain fatty acids. Mutants of T1-39 were generated by the atmospheric and room temperature plasma method and screened for enhanced esterase activity. Among all the mutants, strain TB11 had 4.45-fold higher esterase productivity than T1-39, with high genetic stability over 10 generations of continuous cultivation. Maximum activity of EstT1-39 and EstTB11 was observed at 30 ℃, pH 9.0 and 25 ℃, pH 8.5, respectively. EstTB11 was thermally more stable (50 ℃ for 1 H) and active over a broader pH range than EstT1-39. EstTB11 also retained 38% of its maximal activity at 0 ℃ and was found to be able to hydrolyze milk fats into short- and medium-chain fatty acids at 4 ℃. The characteristics of EstT1-39 made it a cold-adapted enzyme and the EstTB11 from the mutant, with its higher activity at lower temperatures, may be suitable for the production of aromas and flavors in the dairy industry. © 2016 International Union of Biochemistry and Molecular Biology, Inc.

Relationship between oviposition, virulence gene expression and parasitism success in Cotesia typhae nov. sp. parasitoid strains.

Science.gov (United States)

Benoist, R; Chantre, C; Capdevielle-Dulac, C; Bodet, M; Mougel, F; Calatayud, P A; Dupas, S; Huguet, E; Jeannette, R; Obonyo, J; Odorico, C; Silvain, J F; Le Ru, B; Kaiser, L

2017-12-01

Studying mechanisms that drive host adaptation in parasitoids is crucial for the efficient use of parasitoids in biocontrol programs. Cotesia typhae nov. sp. (Fernández-Triana) (Hymenoptera: Braconidae) is a newly described parasitoid of the Mediterranean corn borer Sesamia nonagrioides (Lefebvre) (Lepidoptera: Noctuidae). Braconidae are known for their domesticated bracovirus, which is injected with eggs in the host larva to overcome its resistance. In this context, we compared reproductive success traits of four Kenyan strains of C. typhae on a French and a Kenyan populations of its host. Differences were found between the four strains and the two most contrasted ones were studied more thoroughly on the French host population. Parasitoid offspring size was correlated with parasitism success and the expression of bracovirus virulence genes (CrV1 and Cystatin) in the host larva after parasitism. Hybrids between these two parasitoid strains showed phenotype and gene expression profiles similar to the most successful parental strain, suggesting the involvement of dominant alleles in the reproductive traits. Ovary dissections revealed that the most successful strain injected more eggs in a single host larva than the less successful one, despite an equal initial ovocyte number in ovaries. It can be expected that the amount of viral particles increase with the number of eggs injected. The ability to bypass the resistance of the allopatric host may in consequence be related to the oviposition behaviour (eggs allocation). The influence of the number of injected eggs on parasitism success and on virulence gene expression was evaluated by oviposition interruption experiments.

Investigation of the Amycolatopsis sp. Strain ATCC 39116 Vanillin Dehydrogenase and Its Impact on the Biotechnical Production of Vanillin

OpenAIRE

Fleige, Christian; Hansen, Gunda; Kroll, Jens; Steinbüchel, Alexander

2013-01-01

The actinomycete Amycolatopsis sp. strain ATCC 39116 is capable of synthesizing large amounts of vanillin from ferulic acid, which is a natural cell wall component of higher plants. The desired intermediate vanillin is subject to undesired catabolism caused by the metabolic activity of a hitherto unknown vanillin dehydrogenase (VDHATCC 39116). In order to prevent the oxidation of vanillin to vanillic acid and thereby to obtain higher yields and concentrations of vanillin, the responsible vani...

Structural studies of the O-specific polysaccharide(s) from the lipopolysaccharide of Azospirillum brasilense type strain Sp7.

Science.gov (United States)

Sigida, Elena N; Fedonenko, Yuliya P; Shashkov, Alexander S; Zdorovenko, Evelina L; Konnova, Svetlana A; Ignatov, Vladimir V; Knirel, Yuriy A

2013-10-18

Lipopolysaccharide was obtained by phenol-water extraction from dried bacterial cells of Azospirillum brasilense type strain Sp7. Mild acid hydrolysis of the lipopolysaccharide followed by GPC on Sephadex G-50 resulted in a polysaccharide mixture, which was studied by composition and methylation analyses, Smith degradation and (1)H and (13)C NMR spectroscopy. The following polysaccharide structures were established, where italics indicate a non-stoichiometric (∼40%) 2-O-methylation of l-rhamnose. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

Science.gov (United States)

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

2017-11-01

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