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Frontiers in Microbiology 2021Commercial table salt is a condiment with food preservative properties by decreasing water activity and increasing osmotic pressure. Salt is also a source of halophilic...
Commercial table salt is a condiment with food preservative properties by decreasing water activity and increasing osmotic pressure. Salt is also a source of halophilic bacteria and archaea. In the present research, the diversity of halotolerant and halophilic microorganisms was studied in six commercial table salts by culture-dependent and culture-independent techniques. Three table salts were obtained from marine origins: Atlantic Ocean, Mediterranean (Ibiza Island), and Odiel marshes (supermarket marine salt). Other salts supplemented with mineral and nutritional ingredients were also used: Himalayan pink, Hawaiian black, and one with dried vegetables known as Viking salt. The results of 16S rRNA gene sequencing reveal that the salts from marine origins display a similar archaeal taxonomy, but with significant variations among genera. Archaeal taxa , , , , , , , and were prevalent in those three marine salts. Furthermore, the most abundant archaeal genera present in all salts were , , , , , , and uncultured . sp. was the most frequent bacteria, represented almost in all salts. Other genera such as , , and were the most frequent taxa in the Viking, Himalayan pink, and black salts, respectively. Interestingly, the genus was detected only in marine-originated salts. A collection of 76 halotolerant and halophilic bacterial and haloarchaeal species was set by culturing on different media with a broad range of salinity and nutrient composition. Comparing the results of 16S rRNA gene metataxonomic and culturomics revealed that culturable bacteria , , , , , , , , , , , , , and also Archaea , , and were identified at least in one sample by both methods. Our results show that salts from marine origins are dominated by Archaea, whereas salts from other sources or salt supplemented with ingredients are dominated by bacteria.
PubMed: 34777272
DOI: 10.3389/fmicb.2021.714110 -
Archives of Microbiology Dec 2021Understanding the salt tolerance of microbial communities may help to elucidate the effects of salt concentration and other environmental factors on soil biodiversity....
Understanding the salt tolerance of microbial communities may help to elucidate the effects of salt concentration and other environmental factors on soil biodiversity. Here, high-throughput sequencing of 16S rDNA and ITS was combined to investigate the distribution and salt tolerance of microbial communities in coastal soils and sediments near the Yinggehai saltern field of Hainan Island, China. The microbial communities in the soils and sediments of the land zone (YGHLS), the intertidal zone (YGHIS), and the inshore zone (YGHWS) were compared. PCoA of weighted and unweighted UniFrac distance revealed obvious differences in soil microbial community among different samples. ANOSIM analysis could clearly separate the three samples from each other. Three halotolerant bacteria, including Halomonas, Halobacillus and Wallemia, were found in the samples, which accounted for 0.0335 ± 0.0586%, 0.0241 ± 0.0304%, and 0.0308 ± 0.0445% of the total microbial community, respectively. The relative abundance of Trk system potassium uptake protein, Kdp operon response regulator, and Na/H antiporter in the samples exceeded 0.09%, 0.06%, and 0.02%, respectively, indicating that the Trk system plays a major role in the salt tolerance of halotolerant bacteria in Yinggehai coastal soils and sediments.
Topics: Bacteria; Biodiversity; China; Geologic Sediments; RNA, Ribosomal, 16S; Salt Tolerance; Soil; Soil Microbiology
PubMed: 34586467
DOI: 10.1007/s00203-021-02461-w -
Current Microbiology Oct 2021In the current study, fourteen bacterial strains were obtained in salt contaminated soils. The identification and characterization of the bacterial strains were...
In the current study, fourteen bacterial strains were obtained in salt contaminated soils. The identification and characterization of the bacterial strains were performed by conventional and molecular techniques. According to the results of 16S rRNA gene sequence analysis, five genera (Bacillus, Staphylococcus, Oceanobacillus, Exiguobacterium, and Halobacillus) were identified with a homology of equal to 99% or higher similarity. Afterward, these fourteen halotolerant/halophilic bacterial strains were investigated for their plant growth promoting (PGP) traits including production of indole-3-acetic acid (IAA) and siderophore, activity of 1-aminocyclopropane-1-carboxylate (ACC) deaminase, fixation of nitrogen, and phosphate solubilization potential. Five of the bacterial strains possessing PGP traits were tested for their effects on the growth of a salt sensitive plant (wheat) in a hydroponic system under salt stress (200 mM). Inoculation of five bacterial strains under salt stress significantly enhanced plant weight (Triticum aestivum) ranged from 71.18 to 89.04%. Salt stress amelioration potential of Oceanobacillus picturae and Staphylococcus succinus on T. aestivum has been shown for the first time in this study. In non-saline soil, the promising effect of plant growth bacteria is clear; however, in saline soil, the use of PGP halophilic and halotolerant bacteria can increase the productivity of salt sensitive plants. Therefore, the novel halophilic and halotolerant bacteria that promote plant growth can be developed for agricultural uses in saline soils.
Topics: Bacillaceae; Bacteria; Plant Roots; RNA, Ribosomal, 16S; Salt Stress; Soil Microbiology; Staphylococcus
PubMed: 34427735
DOI: 10.1007/s00284-021-02637-z -
Journal of Environmental Health Science... Dec 2020In this study, the culturable halophilic and halotolerant bacterial diversity was determined in Aran-Bidgol as a thalassohaline seasonal hypersaline lake in Iran.
PURPOSE
In this study, the culturable halophilic and halotolerant bacterial diversity was determined in Aran-Bidgol as a thalassohaline seasonal hypersaline lake in Iran.
METHODS
Thirty water, soil, sediments, coastal mud, multi-color brines and salt crystals samples were extracted and cultured using different media and incubation conditions. Totally 958 isolates were obtained and 87 isolates were selected for further studies, based on morphological, physiological and biochemical tests, representing different morphotypes.
RESULTS
Based on 16S rRNA gene sequence analyses, the isolates exhibited 94.6-100% sequence similarity to the closest known species of the genera , , , , , , , , , , , , , , , , , , , , , , , , , , and and also, comparison of ARDRA patterns among the sequenced strains, using I, UI and II enzymes showed that these patterns are in accordance with the phylogenetic position of these strains.
CONCLUSION
The PCR-RFLP analyses suggested that ARDRA possess a functional potential for distinguishing halophilic bacteria to be used for further studies in elementary steps of isolation to reduce the tedious duplication of isolates.
PubMed: 33312616
DOI: 10.1007/s40201-020-00519-3 -
Journal, Genetic Engineering &... Oct 2020Halophiles offer an attractive source of genes conferring salt tolerance. Halobacillus trueperi SS1 strain of Lunsu, Himachal Pradesh, India, a strict halophile, was...
BACKGROUND
Halophiles offer an attractive source of genes conferring salt tolerance. Halobacillus trueperi SS1 strain of Lunsu, Himachal Pradesh, India, a strict halophile, was exploited to isolate and clone the genes for salt tolerance. The genomic library of BamH1 digest of H. trueperi SS1 was constructed in pUC19, and recombinants were screened for salt tolerance on an LB medium containing ampicillin (100 μg/ml) and NaCl (0 to 1.5 M).
RESULTS
One recombinant clone named as salt-tolerant clone (STC) conferred salt tolerance to host Escherichia coli/DH5α, which showed growth in the LB medium supplemented with ampicillin and 1.2 M NaCl. Restriction digestion and PCR analysis revealed the presence of an insert of approximately 2000 bp in the STC. DNA sequencing of the 2-kb insert on both strands yielded a sequence of 2301 nucleotides. Protein BLAST analysis of 2301-bp sequence of H. trueperi SS1 present in STC showed 97% identity to multidrug transport ATP binding/permease protein of Halobacillus karajensis. The insert contained in STC was subcloned into pGEX4T2 vector, and the recombinant clone STC/pGEX4T2 conferred salt tolerance to the bacterial host E. coli.
CONCLUSIONS
The present study led to the isolation of salt tolerance gene encoding a putative multidrug transport ATP binding/permease protein from H. trueperi SS1. The salt tolerance gene can be subcloned for transferring salt tolerance traits into agricultural crop plants for cultivation in saline and coastal lands.
PubMed: 33025336
DOI: 10.1186/s43141-020-00070-6 -
Microbial Pathogenesis Dec 2020In recent years, a challenge in clinical treatment has developed due to bacterial resistance to antibiotics. One of the new mechanisms against infections is virulence...
INTRODUCTION
In recent years, a challenge in clinical treatment has developed due to bacterial resistance to antibiotics. One of the new mechanisms against infections is virulence factor inhibition. Many virulence factors are controlled by quorum sensing pathways such as biofilm formation and pyocyanin production. The goal of the present study was to investigate the effect of an obligate halophilic bacterial strain on Pseudomonas aeruginosa and Staphylococcus aureus, due to its halo-tolerant substances and enzymes.
METHODS
The effect of Halobacillus karajensis on bacterial growth and production of virulence factors was studied in this work. The obligate halophile cells and supernatant fractions were extracted by the methanol/chloroform method and characterized by Fourier Transform Infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Gas Chromatography-Mass Spectrometry (GC-MS), and zymography. The effects of these fractions were studied on biofilm formation in P. aeruginosa and S. aureus as well as on pyocyanin production in P. aeruginosa. The effective protein in the fraction was analyzed by the SDS-PAGE method, and all protein fragments were studied for pyocyanin inhibition.
RESULTS
The crude supernatant extract, MMS fraction, from H. karajensis was effective for the biofilm reduction in S. aureus (74%) and P. aeruginosa (27%). Two proteases in this fraction, which were recognized by zymography on skim milk, were the probable causes for extracellular polymeric substances (EPS) hydrolysis in the biofilm matrix. Also, halide crystals and branched fatty acids, 12methyl-tetradecanoic acid, in the other fractions decreased the biofilm by 18% in S. aureus. The results showed that a new 25 kD protein, which was obtained from MMS fraction, inhibited pyocyanin production by 60% in P. aeruginosa. The zymogram and bioinformatics studies showed that this protein was a serine alkaline metalloprotease and had an interaction with AHL molecules.
CONCLUSION
The inhibitory effects of the non-toxic natural substances and proteases on biofilm formation and pyocyanin production, specifically the 25 kD protease, are novel in this study and make them a good candidate for infected wound healing and inhibiting the virulence factors.
Topics: Anti-Bacterial Agents; Biofilms; Halobacillus; Peptide Hydrolases; Pseudomonas aeruginosa; Quorum Sensing; Staphylococcus aureus; Virulence Factors
PubMed: 33010361
DOI: 10.1016/j.micpath.2020.104555 -
New Microbes and New Infections Sep 2020Strain Marseille-Q1234 is a new species from the genus that was isolated in 2019 from a stool sample in a healthy Malian child <5 years old. Cells are Gram-positive and...
Strain Marseille-Q1234 is a new species from the genus that was isolated in 2019 from a stool sample in a healthy Malian child <5 years old. Cells are Gram-positive and strictly halophilic bacilli. Strain Marseille-Q1234 exhibits 98.46% 16S rRNA gene sequence similarity to strain JSM 071068 (NR_116505.1), the phylogenetically closely related species with standing in nomenclature. Based on the phenotypic and phylogenetic evidence, OrthoANI values and results of the biochemical tests, the new species is named sp. nov., for which strain Marseille-Q1234 (= CSURQ1234) is proposed as the type strain.
PubMed: 32793353
DOI: 10.1016/j.nmni.2020.100708 -
Folia Microbiologica Oct 2020Halophilic bacterias from saline soil from former Lake Texcoco were isolated, identified based on 16 rRNA and tested to produce glucolytic, nucleolytic, proteolytic and...
Halophilic bacterias from saline soil from former Lake Texcoco were isolated, identified based on 16 rRNA and tested to produce glucolytic, nucleolytic, proteolytic and lipolytic exoenzymes. The Bacillus, Virgibacillus, Kocuria, Salinicoccus, Gracilibacillus, Halobacillus, Tenuibacillus and Nesterekonia genera where identified. Lipase/eserases and proteases from Nesterenkonia sp. and Nesterenkonia aethiopica showed halotolerant characteristics and were selected to synthesize the oleochemical n-butyl oleate and antioxidant peptides from muscle protein of common carp (Cyprinus carpio), respectively. In organic media (2,2,4-Trimethylpentane), the lipase/esterases from Nesterenkonia sp. (0.6 U/mL) and N. aethiopica (1.2 U/mL) achieved a 62.7% and 53.2% of n-butyl oleate conversion, respectively. The protein hydrolysis from muscle of common carp (C. carpio) showed a degree of hydrolysis of 4.5 ± 0.2% and 2.8 ± 0.1% when proteases from Nesterenkonia sp. and N. aethiopica were used, respectively. Three peptidic fractions ranging molecular masses between 254 and 1002 Da [M + H] show antioxidant scavenging activity, and the principal fraction with a peptide of 547.3 Da [M + H] showed an inhibition of 37.7 ± 1.8% and 16.3 ± 0.6%, when 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) were used, respectively. These findings showed that the enzymatic battery of the halophilic bacteria from former lake Texcoco can be used in hydrolysis and synthesis of molecules with applications in different fields as food technology or bioenergy.
Topics: Animals; Antioxidants; Bacteria; Bacterial Proteins; Carps; Esterases; Hydrolysis; Lakes; Lipase; Oleic Acids; Peptide Hydrolases; Peptides; Phylogeny; RNA, Ribosomal, 16S; Salt Tolerance; Soil Microbiology
PubMed: 32410069
DOI: 10.1007/s12223-020-00794-5 -
Journal of Materials Chemistry. B Jun 2020In the emerging scenario of increasing antibiotic resistance and pathogen transmission channels, the grave danger posed by bacterial endospores in critical fields like...
In the emerging scenario of increasing antibiotic resistance and pathogen transmission channels, the grave danger posed by bacterial endospores in critical fields like food industry, health and medicine highlights the urgent need to develop efficient probes for their detection; their sturdy and impermeable multilayer coat makes desirable methods like fluorescence imaging extremely difficult. Selective imaging of the endospores in the presence of the bacteria is even more challenging. Furthermore, it is preferable to maintain the dormant state of endospores through the imaging process, if extended monitoring is required; many of the available techniques involve lethal germination or destruction of the endospores. We show that simple zwitterionic diaminodicyanoquinodimethane (DADQ) molecules with selected functionalities are efficient dyes for fluorescence imaging due to their dipolar structure that facilitates the penetration into the endospore system, and the enhanced fluorescence in their rigid/aggregated state. The facile structural tailorability allows DADQs with various appendage moieties to be synthesized; a derivative with ionic substituents (BT), and another with optimally long alkyl chains and the resultant hydrophobic character (BHADQ) are shown to be excellent fluorescent probes for endospores. Nanomolar amounts of dyes provide effective staining; while BT stains bacteria and endospores, most significantly, BHADQ stains endospores selectively. To the best of our knowledge, this is the first example of selective fluorescence imaging of endospores in their dormant state. A range of spectroscopy, microscopy and calorimetry studies provide insight into the molecular level interactions that enable efficient staining and bright images. DADQ fluorophores are photostable and non-cytotoxic, hence useful in practical applications. The versatile structural tailorability of these dye molecules holds great promise for targeted imaging.
Topics: Fluorescent Dyes; Halobacillus; Molecular Structure; Optical Imaging; Particle Size; Spectrum Analysis, Raman; Spores, Bacterial; Surface Properties
PubMed: 32391841
DOI: 10.1039/d0tb00470g -
The Science of the Total Environment May 2020Algicidal behavior is a common interaction between marine microalgae and bacteria, especially in the dissipation phase of algal blooms. The marine bacterium Halobacillus...
Algicidal behavior is a common interaction between marine microalgae and bacteria, especially in the dissipation phase of algal blooms. The marine bacterium Halobacillus sp. P1 was previously isolated and exhibits high algicidal activity against the diatom Skeletonema costatum. However, little is known about the mechanism underlying this algicidal process. Here, a tandem mass tag (TMT)-based proteomic approach was coupled with physiological analysis to investigate the cellular responses of S. costatum when treated with P1 culture supernatant. Among the 4582 proteins identified, 82 and 437 proteins were differentially expressed after treatment for 12 and 24 h, respectively. The proteomic results were in accordance with the results of verification by parallel reaction monitoring (PRM) assays. Proteins involved in reactive oxygen species scavenging, protein degradation and transport were upregulated, while proteins participating in nitrogen metabolism, protein translation, photosynthetic pigment biosynthesis and cell cycle regulation were significantly downregulated (p-value ≤0.05), corresponding to the increasing malondialdehyde content and the decreasing nitrogen, protein and chlorophyll a contents. A nutrient competitive relationship might exist between the bacterium P1 and S. costatum, and the inhibition of nitrogen metabolism by the P1 culture supernatant might be the key lethal factor that results in the dysfunction of S. costatum metabolism. Our study sheds light on the algicidal mechanism of P1 at the molecular level and provides new insights into algae-bacteria interactions.
Topics: Chlorophyll A; Diatoms; Halobacillus; Photosynthesis; Proteomics
PubMed: 32070889
DOI: 10.1016/j.scitotenv.2020.137048