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Brazilian Journal of Microbiology :... Jan 2019Microbes from hypersaline environments are useful in biotechnology as sources of novel enzymes and proteins. The current study aimed to characterize halophilic bacteria...
Microbes from hypersaline environments are useful in biotechnology as sources of novel enzymes and proteins. The current study aimed to characterize halophilic bacteria from the rhizosphere of halophytes (Salsola stocksii and Atriplex amnicola), non-rhizospheric, and brine lake-bank soils collected from Khewra Salt Mine and screening of these bacterial strains for industrially important enzymes. A total of 45 bacterial isolates from the rhizosphere of Salsola, 38 isolates from Atriplex, 24 isolates from non-rhizospheric, and 25 isolates from lake-bank soils were identified by using 16S rRNA gene analysis. Phylogenetic analysis showed that bacterial strains belonging to Bacillus, Halobacillus, and Kocuria were dominant in the rhizosphere of halophytes (Salsola and Atriplex), and Halobacillus and Halomonas were dominating genera from non-rhizospheric and lake-bank soils. Mostly identified strains were moderately halophilic bacteria with optimum growth at 1.5-3.0 M salt concentrations. Most of the bacterial exhibited lipase, protease, cellulase, amylase, gelatinase, and catalase activities. Halophilic and halotolerant Bacilli (AT2RP4, HL1RS13, NRS4HaP9, and LK3HaP7) identified in this study showed optimum lipase, protease, cellulase, and amylase activities at 1.0-1.5 M NaCl concentration, pH 7-8, and temperature 37 °C. These results indicated that halophilic and halotolerant bacteria can be used for bioconversion of organic compounds to useful products under extreme conditions.
Topics: Atriplex; Bacteria; Bacterial Proteins; Biodiversity; Cellulases; Hydrolases; Lakes; Lipase; Peptide Hydrolases; Phylogeny; Rhizosphere; Sodium Chloride; Soil Microbiology
PubMed: 30623303
DOI: 10.1007/s42770-019-00044-y -
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 -
Data in Brief Dec 2018We present the draft genome sequence of sp. BBL2006, a moderately halophilic, gram positive bacterium isolated from a sulfidic salt spring in Big Bone Lick State Park,...
We present the draft genome sequence of sp. BBL2006, a moderately halophilic, gram positive bacterium isolated from a sulfidic salt spring in Big Bone Lick State Park, Boone County, Kentucky. The genome of sp. BBL2006 was 3,988,138 bp in length with a GC content of 41.6%. Genome analysis identified 4331 open reading frames including genes for antibiotic resistance and tolerance to heavy metals. The draft genome was deposited at DDBJ/EMBL/GenBank (DNA Databank of Japan/European Molecular Biology Laboratory/Genbank) (JRNX00000000).
PubMed: 30547067
DOI: 10.1016/j.dib.2018.11.076 -
Journal of Health & Pollution Sep 2018Polycyclic aromatic hydrocarbons (PAHs) are common environmental contaminants which are highly toxic due to their carcinogenic and mutagenic effects. They are released...
BACKGROUND
Polycyclic aromatic hydrocarbons (PAHs) are common environmental contaminants which are highly toxic due to their carcinogenic and mutagenic effects. They are released into the environment by incomplete combustion of solid and liquid fuels, accidental spillage of oils and seepage from industrial activities. One of the promising processes mitigating PAHs is through biodegradation. However, conventional microbiological treatment processes do not function well at high salt concentrations. Hence, utilization of halophilic bacteria should be considered.
OBJECTIVES
This study aimed to assess the ability of halophilic bacteria isolated from local salt beds in Pangasinan and Cavite, the Philippines, to degrade PAHs pyrene, fluorene and fluoranthene.
METHODS
Polycyclic aromatic hydrocarbon-tolerant halophilic bacteria collected from two sampling sites were phenotypically characterized, molecularly identified and tested to determine their potential to degrade the PAHs pyrene, fluorene and fluoranthene at a hypersaline condition. Best PAH degraders were then assayed to identify the optimal degradation using such parameters as pH, temperature and PAH concentration. Testing for enzyme degradation was also done to determine their baseline information. Extraction and analysis of degraded PAHs were performed using centrifugation and UV-vis spectrophotometry.
RESULTS
Twelve isolates from both collection sites tolerated and grew in culture with selected PAHs. These were identified into four genera (Halobacillus, Halomonas, Chromohalobacter, and Pontibacillus). Selected best isolates in a series of biodegradation assays with the above-mentioned parameters were Halobacillus B (Collection of Microbial Strains (CMS) 1802) (=trueperi) (Gram-positive) for pyrene and fluoranthene, and Halomonas A (CMS 1901) (Gram-negative) for fluorene. Degrader biomass and PAH degradation were invariably negatively correlated. Qualitative tests with and without peptone as a nitrogen source implied enzymatic degradation.
DISCUSSION
Polycyclic aromatic hydrocarbons utilized by these halophilic bacteria served as a sole source of carbon and energy. Implications of biodegradation of the two best isolates show that high molecular weight (HMW) (4-ring) pyrene tends to be degraded better by Gram-positive bacteria and low molecular weight (3-ring) fluorene by Gram-negative degraders.
CONCLUSIONS
Halophilic bacteria constitute an untapped natural resource for biotechnology in the Philippines. The present study demonstrated their potential use in bioremediation of recalcitrant hydrocarbons in the environment.
COMPETING INTERESTS
The authors declare no competing financial interests.
PubMed: 30524874
DOI: 10.5696/2156-9614-8.19.180915 -
Heliyon Nov 2018Cultivable halophilic microorganisms were isolated and identified from saline and alkaline-sodic soils: Cuatro Cienegas, Sayula and San Marcos lakes. Physicochemical...
Cultivable halophilic microorganisms were isolated and identified from saline and alkaline-sodic soils: Cuatro Cienegas, Sayula and San Marcos lakes. Physicochemical characteristics of soils were determined to understand the relationship between those and the microorganisms isolated. The Cuatro Cienegas soils had a neutral pH, EC of 2.3-8 dS cm, classified as moderately saline. Whereas, the soils from Sayula and San Marcos lakes, had an alkaline pH, EC 15 to 65 dS m, typical of saline-sodic. We identified 23 cultivable halophilic bacteria using 16s rDNA, being sp., sp., and sp. the predominant genus by culture dependent approach. We found a correlation between the soils anion and cation content with the occurrence of different genus of halophilic bacteria in each studied site. sp. was predominant in Sayula and San Marcos lakes and was related to the high Na content; while sp. and sp. were predominant in Cuatro Cienegas, their occurrence was related to a high content of Ca, Mg, and SO .
PubMed: 30519656
DOI: 10.1016/j.heliyon.2018.e00954 -
Chemosphere Mar 2019Microcystis aeruginosa can cause harmful algal blooms in freshwaters worldwide. It has already seriously affected human lives and prevented the use of water resources....
Microcystis aeruginosa can cause harmful algal blooms in freshwaters worldwide. It has already seriously affected human lives and prevented the use of water resources. Therefore, there is an urgent need to develop ecofriendly and effective methods to control and eliminate M. aeruginosa in aquatic environments. In this study, Halobacillus sp. strain H9, a bacterium that showed high M. aeruginosa flocculation activity, was isolated and selected to assess its potential for the removal of M. aeruginosa. The analyses of flocculation activity and mode indicated that the strain H9 induced M. aeruginosa flocculation by secreting active flocculating substance rather than by directly contacting algal cells. A 5% concentration of the H9 supernatant could efficiently flocculate M. aeruginosa cells with a density of up to 5 × 10 cells/mL. Dramatic increases in the zeta potential indicated that charge neutralization could be the mechanism of the flocculation process. The strain H9 flocculated M. aeruginosa with no damage to the algal cell membrane, and did not result in microcystin being released into the surrounding environment. The flocculated algal culture was less toxic to zebrafish larvae, suggesting an environmentally friendly benefit of the H9 supernatant. In addition to M. aeruginosa, the H9 strain was also able to flocculate two other species causing harmful algal blooms, Phaeocystis globose and Heterosigma akashiwo. Furthermore, the flocculation activity of the H9 supernatant was stable at different temperatures and over a wide pH range. These characteristics give the H9 strain great potential for mitigating the influences of harmful algal blooms.
Topics: Animals; Flocculation; Fresh Water; Halobacillus; Harmful Algal Bloom; Humans; Microcystis; Zebrafish
PubMed: 30471494
DOI: 10.1016/j.chemosphere.2018.11.082 -
Colloids and Surfaces. B, Biointerfaces Jan 2019In the present study, an attempt has been made to explore the antifouling potential of bioactive compound isolated from sponge associated bacterium Halobacillus...
PYRROLO isolated from marine sponge associated bacterium Halobacillus kuroshimensis SNSAB01 - Antifouling study based on molecular docking, diatom adhesion and mussel byssal thread inhibition.
In the present study, an attempt has been made to explore the antifouling potential of bioactive compound isolated from sponge associated bacterium Halobacillus kuroshimensis SNSAB01. The crude extract of SNSAB01 strongly inhibited the growth of fouling bacterial strains with least minimal inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The bioactive compound was characterized through FT-IR, HPLC, GCMS and NMR predicted as 'pyrrolo". From the mass spectral library, structure was elucidated as pyrrolo [1, 2-a] pyrazine-1, 4-dione, hexahydro. The in silico studies provided encouraging docking scores with two interactions by GLN 200 and GLU 304. The extract inhibited 89% diatom adhesion at 350 μg/ml concentration against Amphora sp. An EC value of 150 μg/ml for 50% inhibition of byssal thread of Perna viridis and LC was found to be 500 μg/ml. The LC/EC ratio of 3.0 indicated nontoxic to nature. The result suggested that pyrrolo[1,2-a]pyrazine-1,4-dione can be used for antifouling coating.
Topics: Acetylglucosamine; Animals; Anti-Infective Agents; Binding Sites; Bivalvia; Complex Mixtures; Diatoms; Extracellular Matrix; Halobacillus; Microbial Sensitivity Tests; Molecular Docking Simulation; Phylogeny; Porifera; Pyrazines; Pyrroles; Symbiosis
PubMed: 30261347
DOI: 10.1016/j.colsurfb.2018.09.044 -
Frontiers in Microbiology 2018Arginine-aspartate-aspartate (RDD) family, representing a category of transmembrane proteins containing one highly conserved arginine and two highly conserved...
Arginine-aspartate-aspartate (RDD) family, representing a category of transmembrane proteins containing one highly conserved arginine and two highly conserved aspartates, has been functionally uncharacterized as yet. Here we present the characterization of a member of this family designated RDD from the moderate halophile NEAU-ST10-40 and report for the first time that RDD should function as a novel Na(Li, K)/H antiporter. It's more interesting whether the highly conserved arginine/aspartate residues among the whole family or between RDD and its selected homologs are related to the protein function. Therefore, we analyzed their roles in the cation-transporting activity through site-directed mutagenesis and found that D154, R124, R129, and D158 are indispensable for Na(Li, K)/H antiport activity whereas neither R35 nor D42 is involved in Na(Li, K)/H antiport activity. As a dual representative of Na(Li, K)/H antiporters and RDD family proteins, the characterization of RDD and the analysis of its important residues will positively contribute to the knowledge of the cation-transporting mechanisms of this novel antiporter and the roles of highly conserved arginine/aspartate residues in the functions of RDD family proteins.
PubMed: 29922240
DOI: 10.3389/fmicb.2018.00807 -
Canadian Journal of Microbiology Aug 2018Salinity is one of the major abiotic stresses; a total of 3% of the world's land mass is affected by salinity. Approximately 6.3 million hectares of land in Pakistan is...
Diversity of Bacillus-like bacterial community in the rhizospheric and non-rhizospheric soil of halophytes (Salsola stocksii and Atriplex amnicola), and characterization of osmoregulatory genes in halophilic Bacilli.
Salinity is one of the major abiotic stresses; a total of 3% of the world's land mass is affected by salinity. Approximately 6.3 million hectares of land in Pakistan is affected by salinity to varying degrees, and most of the areas are arid to semiarid with low annual precipitation. The aim of the present study is to identify and characterize Bacillus and Bacillus-derived bacterial genera from the rhizospheric and non-rhizospheric soil samples from the Khewra Salt Mine, Pakistan, by using culture-independent and -dependent methods. Seven Bacillus-like bacterial genera, Bacillus, Halobacillus, Virgibacillus, Brevibacillus, Paenibacillus, Tumebacillus, and Lysinibacillus, were detected by using pyrosequencing analysis, whereas only four genera, Bacillus, Halobacillus, Oceanobacillus, and Virgibacillus, were identified by culture-dependent methods. Most of the Bacillus-like isolates identified in this study were moderately halophilic, alkaliphilic, and mesophilic bacteria and were considered a good source of hydrolytic enzymes because of their ability to degrade proteins, carbohydrates, and lipids. Eight Bacillus-like strains from the genera Bacillus, Halobacillus, Oceanobacillus, and Virgibacillus showed positive results for the presence of ectABC gene cluster (ectoine), six strains could synthesize betaine from choline, and six strains tested positive for the synthesis of proline from either glutamate or ornithine by using proline dehydrogenase enzyme.
Topics: Amino Acids, Diamino; Atriplex; Bacillaceae; Biodiversity; DNA, Bacterial; Osmoregulation; Pakistan; Phylogeny; Salsola; Salt-Tolerant Plants; Soil Microbiology
PubMed: 29701484
DOI: 10.1139/cjm-2017-0544 -
Journal of Microbiology (Seoul, Korea) Apr 2018moderately halophilic spore forming, motile, Gram-positive, rod-shaped bacterial strain designated as KGW1 was isolated from water sample of Chilika Lake and...
moderately halophilic spore forming, motile, Gram-positive, rod-shaped bacterial strain designated as KGW1 was isolated from water sample of Chilika Lake and characterized taxonomically using polyphasic approach. The strain grew in the presence of 0-25% (w/v) NaCl in marine salt agar media, hydrolyzes casein, and gelatin and shows presence of alkaline proteases. The major cell wall menaquinone was MK7 and major cellular fatty acids were anteiso-C (44.89%), anteiso-C (6.18%), isoC (19.38%), and iso-C (7.39%). Several chemotaxonomic features conform the isolate be a member of genus Halobacillus. The isolate KGW1 contained A1γ meso-Dpm-direct type of peptidoglycan which is different from its phylogenetically closest neighbours. The 16S rRNA gene sequence based phylogenetic analysis also revealed the strain KGW1 was affiliated to the genus Halobacillus and sequence similarity between the isolated strain and the type strains of Halobacillus species were found closest to, H. dabanensis D-8 DSM 18199 (99.08%) and H. faecis IGA7-4 DSM 21559 (99.01%), H. trueperi SL-5 DSM 10404 (98.94%). The in silico DDH showed that the values in a range of 14.2-17.5% with the most closest strain H. dabanensis D-8 DSM 18199 and other type strains of the genus Halobacillus for which whole genome sequence is reported. DNA-DNA relatedness between strain KGW1 and the closest type strain Halobacillus trueperi DSM 10404 was 11.75% (± 1.15). The draft genome sequence includes 3,683,819 bases and comprises of 3898 predicted coding sequences with a G + C content of 46.98%. Thus, the significant distinctiveness supported by phenotypic and genotypic data with its closest neighbors and other closely related species confirm the strain KGW1 to be classified as a novel species within the genus Halobacillus, for which the name Halobacillus marinus sp. nov. is proposed. The type strain is KGW1 (= DSM 29522 = JCM 30443).
Topics: Bacterial Typing Techniques; Base Composition; DNA, Bacterial; DNA, Ribosomal; Fatty Acids; Genome, Bacterial; Genotype; Halobacillus; India; Lakes; Phenotype; Phylogeny; RNA, Ribosomal, 16S; Salinity; Sequence Analysis, DNA; Water Microbiology
PubMed: 29611137
DOI: 10.1007/s12275-018-7387-x