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Journal of Bacteriology Oct 2006The moderately halophilic, chloride-dependent bacterium Halobacillus halophilus produces glutamate and glutamine as main compatible solutes at external salinities of 1.0...
Biochemical and molecular characterization of the biosynthesis of glutamine and glutamate, two major compatible solutes in the moderately halophilic bacterium Halobacillus halophilus.
The moderately halophilic, chloride-dependent bacterium Halobacillus halophilus produces glutamate and glutamine as main compatible solutes at external salinities of 1.0 to 1.5 M NaCl. The routes for the biosynthesis of these solutes and their regulation were examined. The genome contains two genes potentially encoding glutamate dehydrogenases and two genes for the small subunit of a glutamate synthase, but only one gene for the large subunit. However, the expression of these genes was not salt dependent, nor were the corresponding enzymatic activities detectable in cell extracts of cells grown at different salinities. In contrast, glutamine synthetase activity was readily detectable in H. halophilus. Induction of glutamine synthetase activity was strictly salt dependent and reached a maximum at 3.0 M NaCl; chloride stimulated the production of active enzyme by about 300%. Two potential genes encoding a glutamine synthetase, glnA1 and glnA2, were identified. The expression of glnA2 but not of glnA1 was increased up to fourfold in cells adapted to high salt, indicating that GlnA2 is the glutamine synthetase involved in the synthesis of the solutes glutamate and glutamine. Furthermore, expression of glnA2 was stimulated twofold by the presence of chloride ions. Chloride exerted an even more pronounced effect on the enzymatic activity of preformed enzyme: in the absence of chloride in the assay buffer, glutamine synthetase activity was decreased by as much as 90%. These data demonstrate for the first time a regulatory role of a component of common salt, chloride, in the biosynthesis of compatible solutes.
Topics: Bacillaceae; Chlorides; DNA, Bacterial; Enzyme Induction; Gene Expression Regulation; Gene Expression Regulation, Bacterial; Genes, Bacterial; Glutamate Dehydrogenase; Glutamate Synthase; Glutamate-Ammonia Ligase; Glutamic Acid; Glutamine; Molecular Sequence Data; Sequence Analysis, DNA; Sodium Chloride
PubMed: 16980483
DOI: 10.1128/JB.00781-06 -
Frontiers in Microbiology 2017The aim of the study was to explore the halophile metabolome in building materials using untargeted metabolomics which allows for broad metabolome coverage. For this...
The aim of the study was to explore the halophile metabolome in building materials using untargeted metabolomics which allows for broad metabolome coverage. For this reason, we used high-performance liquid chromatography interfaced to high-resolution mass spectrometry (HPLC/HRMS). As an alternative to standard microscopy techniques, we introduced pioneering Coherent Anti-stokes Raman Scattering Microscopy (CARS) to non-invasively visualize microbial cells. Brick samples saturated with salt solution (KCl, NaCl (two salinity levels), MgSO, Mg(NO)), were inoculated with the mixture of preselected halophilic microorganisms, i.e., bacteria: , and yeast: and stored at 28°C and 80% relative humidity for a year. Metabolites were extracted directly from the brick samples and measured via HPLC/HRMS in both positive and negative ion modes. Overall, untargeted metabolomics allowed for discovering the interactions of halophilic microorganisms with buildings materials which together with CARS microscopy enabled us to elucidate the biodeterioration process caused by halophiles. We observed that halophile metabolome was differently affected by different salt solutions. Furthermore, we found indications for haloadaptive strategies and degradation of brick samples due to microbial pigment production as a salt stress response. Finally, we detected changes in lipid content related to changes in the structure of phospholipid bilayers and membrane fluidity.
PubMed: 29321766
DOI: 10.3389/fmicb.2017.02448 -
Bioscience, Biotechnology, and... Jun 2006A halophilic bacterium was isolated from fish sauce, classified, and named Halobacillus sp. SR5-3. A purified 43-kDa proteinase produced by this bacterium showed optimal...
A halophilic bacterium was isolated from fish sauce, classified, and named Halobacillus sp. SR5-3. A purified 43-kDa proteinase produced by this bacterium showed optimal activity at 50 degrees C and pH 9-10 in 20% NaCl. The activity of the enzyme was enhanced about 2.5-fold by the addition of 20-35% NaCl, and the enzyme was highly stabilized by NaCl. It was found to be a serine proteinase related to either chymotrypsin or subtilisin. It absolutely preferred Ile at the P(2) position of substrates. Thus, the enzyme was found to be a halophilic serine proteinase with unique substrate specificity.
Topics: Amino Acid Sequence; Bacillaceae; Enzyme Inhibitors; Enzyme Stability; Fish Products; Hydrogen-Ion Concentration; Molecular Sequence Data; Serine Endopeptidases; Sodium Chloride; Substrate Specificity; Thailand
PubMed: 16794319
DOI: 10.1271/bbb.50658 -
Journal of Microbiology and... Dec 2018A total of 108 marine bacteria were isolated from the deep sea sediment of Bay of Bengal, India. Of which, 15 bacteria showed antimicrobial activity against human...
A total of 108 marine bacteria were isolated from the deep sea sediment of Bay of Bengal, India. Of which, 15 bacteria showed antimicrobial activity against human pathogenic bacteria. These antagonistic marine bacteria were characterized phenotypically and their taxonomic affiliations were made on the basis of 16S rRNA gene homology and molecular phylogeny tree analysis, the antagonistic marine bacteria were identified as the species of , , , . The extracts of potent marine bacteria exhibited differential cytotoxicity towards lung (A549), cervical (HeLa), breast (MCF-7) and colon (HT-29) cancer cells. The acridine-orange and ethidium bromide (AO/EB) staining of the extract of strain MB30-treated cancer cells showed typical characteristics of apoptosis such as nuclear condensation, cell shrinkage and formation of apoptotic bodies. Present investigation, reports potent marine bacteria from the deep sea sediment of Bay of Bengal that exhibit broad-spectrum antimicrobial and cytotoxicity potential. Due to their innate bioactive potential, these bacteria can be used as the source of potent molecules.
PubMed: 30602267
DOI: 10.4014/jmb.1811.11010 -
Microbiology Resource Announcements Mar 2019We report here the genome sequence of halophilic Halobacillus trueperi SS1, isolated from the Lunsu saltwater body in India. The bacteria are Gram positive and rod...
We report here the genome sequence of halophilic Halobacillus trueperi SS1, isolated from the Lunsu saltwater body in India. The bacteria are Gram positive and rod shaped. The genome of H. trueperi SS1 has 4.14 Mbp, with 4,329 coding sequences, 35 RNA genes (29 tRNAs, 2 rRNAs, and 4 noncoding RNAs), and 42.15% G+C content.
PubMed: 30863831
DOI: 10.1128/MRA.01710-18 -
New Microbes and New Infections May 2017We report the main characteristics of P3515 sp. nov., P3516 sp. nov., P2481 sp. nov., P3554 sp. nov., P3089 sp. nov., P3587 sp. nov., P3532 sp. nov., P3469 sp....
Description of sp. nov., sp. nov., sp. nov., sp. nov., sp. nov., sp. nov., sp. nov., sp. nov. and sp. nov., nine halophilic new species isolated from human stool.
We report the main characteristics of P3515 sp. nov., P3516 sp. nov., P2481 sp. nov., P3554 sp. nov., P3089 sp. nov., P3587 sp. nov., P3532 sp. nov., P3469 sp. nov. and P3610 sp. nov., that were isolated in 2016 from salty stool samples (≥1.7% NaCl) from healthy Senegalese living at Dielmo and N'diop, two villages in Senegal.
PubMed: 28280541
DOI: 10.1016/j.nmni.2017.01.010 -
Applied and Environmental Microbiology Aug 1997The bacterial populations associated with sea ice sampled from Antarctic coastal areas were investigated by use of a phenotypic approach and a phylogenetic approach...
The bacterial populations associated with sea ice sampled from Antarctic coastal areas were investigated by use of a phenotypic approach and a phylogenetic approach based on genes encoding 16S rRNA (16S rDNA). The diversity of bacteria associated with sea ice was also compared with the bacterial diversity of seawater underlying sea ice. Psychrophilic (optimal growth temperature, < or = 15 degrees C; no growth occurring at 20 degrees C) bacterial diversity was found to be significantly enriched in sea ice samples possessing platelet and bottom ice diatom assemblages, with 2 to 9 distinct (average, 5.6 +/- 1.8) psychrophilic taxa isolated per sample. Substantially fewer psychrophilic isolates were recovered from ice cores with a low or negligible population of ice diatoms or from under-ice seawater samples (less than one distinct taxon isolated per sample). In addition, psychrophilic taxa that were isolated from under-ice seawater samples were in general phylogenetically distinct from psychrophilic taxa isolated from sea ice cores. The taxonomic distributions of psychrotrophic bacterial isolates (optimal growth temperature, > 20 degrees C; growth can occur at approximately 4 degrees C) isolated from sea ice cores and under-ice seawater were quite similar. Overall, bacterial isolates from Antarctic sea ice were found to belong to four phylogenetic groups, the alpha and gamma subdivisions of the Proteobacteria, the gram-positive branch, and the Flexibacter-Bacteroides-Cytophaga phylum. Most of the sea ice strains examined appeared to be novel taxa based on phylogenetic comparisons, with 45% of the strains being psychrophilic. 16S rDNA sequence analysis revealed that psychrophilic strains belonged to the genera Colwellia, Shewanella, Marinobacter, Planococcus, and novel phylogenetic lineages adjacent to Colwellia and Alteromonas and within the Flexibacter-Bacteroides-Cytophaga phylum. Psychrotrophic strains were found to be members of the genera Pseudoalteromonas, Psychrobacter, Halomonas, Pseudomonas, Hyphomonas, Sphingomonas, Arthrobacter, Planococcus, and Halobacillus. From this survey, it is proposed that ice diatom assemblages provide niches conducive to the proliferation of a diverse array of psychrophilic bacterial species.
Topics: Antarctic Regions; Bacteria; Gram-Negative Bacteria; Gram-Positive Bacteria; Ice; Molecular Sequence Data; Phylogeny; RNA, Ribosomal, 16S; Seawater; Sequence Analysis, DNA; Water Microbiology
PubMed: 9251193
DOI: 10.1128/aem.63.8.3068-3078.1997 -
International Journal of Microbiology 2009Bacterial and archaeal aerobic communities were recovered from sediments from the shallow El-Djerid salt lake in Tunisia, and their salinity gradient distribution was...
Bacterial and archaeal aerobic communities were recovered from sediments from the shallow El-Djerid salt lake in Tunisia, and their salinity gradient distribution was established. Six samples for physicochemical and microbiological analyses were obtained from 6 saline sites in the lake for physico-chemical and microbiological analyses. All samples studied were considered hypersaline with NaCl concentration ranging from 150 to 260 g/L. A specific halophilic microbial community was recovered from each site, and characterization of isolated microorganisms was performed via both phenotypic and phylogenetic approaches. Only one extreme halophilic organism, domain Archaea, was isolated from site 4 only, whereas organisms in the domain Bacteria were recovered from the five remaining sampling sites that contained up to 250 g/L NaCl. Members of the domain Bacteria belonged to genera Salicola, Pontibacillus, Halomonas, Marinococcus, and Halobacillus, whereas the only member of domain Archaea isolated belonged to the genus Halorubrum. The results of this study are discussed in terms of the ecological significance of these microorganisms in the breakdown of organic matter in Lake El-Djerid and their potential for industry applications.
PubMed: 20066169
DOI: 10.1155/2009/731786 -
Microorganisms Feb 2024Soil salinization is negatively affecting soils globally, and the spread of this problem is of great concern due to the loss of functions and benefits offered by the...
Soil salinization is negatively affecting soils globally, and the spread of this problem is of great concern due to the loss of functions and benefits offered by the soil resource. In the present study, we explored the diversity of halophilic and halotolerant microorganisms in the arable fraction of a sodic-saline soil without agricultural practices and two soils with agricultural practices (one sodic and one saline) near the geothermal area "Los Negritos" in Villamar, Michoacán state. This was achieved through their isolation and molecular identification, as well as the characterization of their potential for the production of metabolites and enzymes of biotechnological interest under saline conditions. Using culture-dependent techniques, 62 halotolerant and moderately halophilic strains belonging to the genera , , , , , , , , , , , , , , , , and were isolated. The different strains synthesized hydrolytic enzymes under 15% (/) of salts, as well as metabolites with plant-growth-promoting (PGP) characteristics, such as indole acetic acid (IAA), under saline conditions. Furthermore, the production of biopolymers was detected among the strains; members of , , , and showed extracellular polymeric substance (EPS) production, and the strain sp. LNSP3E3-1.2 produced polyhydroxybutyrate (PHB) under 10% (/) of total salts.
PubMed: 38543532
DOI: 10.3390/microorganisms12030482 -
Brazilian Journal of Microbiology :... Oct 2012Halophiles are excellent sources of enzymes that are not only salt stable but also can withstand and carry out reactions efficiently under extreme conditions. The aim of...
Halophiles are excellent sources of enzymes that are not only salt stable but also can withstand and carry out reactions efficiently under extreme conditions. The aim of the study was to isolate and study the diversity among halophilic bacteria producing enzymes of industrial value. Screening of halophiles from various saline habitats of India led to isolation of 108 halophilic bacteria producing industrially important hydrolases (amylases, lipases and proteases). Characterization of 21 potential isolates by morphological, biochemical and 16S rRNA gene analysis found them related to Marinobacter, Virgibacillus, Halobacillus, Geomicrobium, Chromohalobacter, Oceanobacillus, Bacillus, Halomonas and Staphylococcus genera. They belonged to moderately halophilic group of bacteria exhibiting salt requirement in the range of 3-20%. There is significant diversity among halophiles from saline habitats of India. Preliminary characterization of crude hydrolases established them to be active and stable under more than one extreme condition of high salt, pH, temperature and presence of organic solvents. It is concluded that these halophilic isolates are not only diverse in phylogeny but also in their enzyme characteristics. Their enzymes may be potentially useful for catalysis under harsh operational conditions encountered in industrial processes. The solvent stability among halophilic enzymes seems a generic novel feature making them potentially useful in non-aqueous enzymology.
PubMed: 24031991
DOI: 10.1590/S1517-838220120004000044