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Journal of Applied Microbiology Feb 2001Characterization of a bacterial isolate (strain MAE2) from intertidal beach sediment capable of degrading linear and branched alkanes.
Isolation and characterization of a novel hydrocarbon-degrading, Gram-positive bacterium, isolated from intertidal beach sediment, and description of Planococcus alkanoclasticus sp. nov.
AIMS
Characterization of a bacterial isolate (strain MAE2) from intertidal beach sediment capable of degrading linear and branched alkanes.
METHODS AND RESULTS
A Gram-positive, aerobic, heterotrophic bacterium (strain MAE2), that was capable of extensive degradation of alkanes in crude oil but had a limited capacity for the utilization of other organic compounds, was isolated from intertidal beach sediment. MAE2 had an obligate requirement for NaCl but could not tolerate high salt concentrations. It was capable of degrading branched and n-alkanes in crude oil from C11 to C33, but was unable to degrade aromatic hydrocarbons. Comparative 16S rRNA sequence analysis placed the isolate with members of the genus Planococcus. That finding was corroborated by chemotaxonomic and physiological data. The fatty acid composition of strain MAE2 was very similar to the type species of the genus Planococcus, P. citreus (NCIMB 1493T) and P. kocurii (NCIMB 629T), and was dominated by branched acids, mainly a15:0. However, the 16S rRNA of strain MAE2 had less than 97% sequence identity with the type strains of P. citreus (NCIMB 1439T), P. kocurii (NCIMB 629T) and two Planococcus spp. (strain MB6-16 and strain ICO24) isolated from Antarctic sea ice. This indicated that strain MAE2 represented a separate species from these planococci. Morphologically, the isolate resembled P. okeanokoites (NCIMB 561T) and P. mcmeekinii S23F2 (ATCC 700539T). The cellular fatty acid composition of P. okeanokoites and P. mcmeekinii was considerably different from strain MAE2, and the mol % G + C content of P. mcmeekinii was far lower than that of MAE2.
CONCLUSION
On the basis of phenotypic and genotypic data, it is proposed that strain MAE2 is a new species of Planococcus, Planococcus alkanoclasticus sp. nov., for which the type strain is P. alkanoclasticus MAE2 (NCIMB 13489T).
SIGNIFICANCE AND IMPACT OF THE STUDY
Planococcus species are abundant members of the bacterial community in a variety of marine environments, including some in sensitive Antarctic ecosystems. The occurrence of hydrocarbon-degrading Planococcus spp. is potentially of importance in controlling the impact of hydrocarbon contamination in sensitive marine environments.
Topics: Alkanes; Base Composition; Fatty Acids; Genes, rRNA; Geologic Sediments; Gram-Positive Bacteria; Molecular Sequence Data; Phenotype; Phylogeny; Polymerase Chain Reaction; RNA, Ribosomal, 16S; Seawater; Sequence Analysis, DNA
PubMed: 11168727
DOI: 10.1046/j.1365-2672.2001.01241.x -
Microbial Biotechnology May 2021Microbially induced calcite precipitation (MICP), secreted through biological metabolic activity, secured an imperative position in remedial measures within the...
Microbially induced calcite precipitation (MICP), secreted through biological metabolic activity, secured an imperative position in remedial measures within the construction industry subsequent to ecological, environmental and economical returns. However, this contemporary recurrent healing system is susceptible to microbial depletion in the highly alkaline cementitious environment. Therefore, researchers are probing for alkali resistant calcifying microbes. In the present study, alkaliphilic microbes were isolated from different soil sources and screened for probable CaCO precipitation. Non-ureolytic pathway (oxidation of organic carbon) was adopted for calcite precipitation to eliminate the production of toxic ammonia. For this purpose, calcium lactate Ca(C H O ) and calcium acetate Ca(CH COO) were used as CaCO precipitation precursors. The quantification protocol for precipitated CaCO was established to select potent microbial species for implementation in the alkaline cementitious systems as more than 50% of isolates were able to precipitate CaCO . Results suggested 80% of potent calcifying strains isolated in this study, portrayed higher calcite precipitation at pH 10 when compared to pH 7. Ten superlative morphologically distinct isolates capable of CaCO production were identified by 16SrRNA sequencing. Sequenced microbes were identified as species of Bacillus, Arthrobacter, Planococcus, Chryseomicrobium and Corynebacterium. Further, microstructure of precipitated CaCO was inspected through scanning electron microscopy (SEM), X-ray diffraction (XRD) and thermal gravimetric (TG) analysis. Then, the selected microbes were investigated in the cementitious mortar to rule out any detrimental effects on mechanical properties. These strains showed maximum of 36% increase in compressive strength and 96% increase in flexural strength. Bacillus, Arthrobacter, Corynebacterium and Planococcus genera have been reported as CaCO producers but isolated strains have not yet been investigated in conjunction with cementitious mortar. Moreover, species of Chryseomicrobium and Glutamicibacter were reported first time as calcifying strains.
Topics: Bacillus; Bacteria; Calcium Carbonate; Chemical Precipitation; Feasibility Studies
PubMed: 33629805
DOI: 10.1111/1751-7915.13752 -
Astrobiology Sep 2018It is well known that dissolved salts can significantly lower the freezing point of water and thus extend habitability to subzero conditions. However, most...
It is well known that dissolved salts can significantly lower the freezing point of water and thus extend habitability to subzero conditions. However, most investigations thus far have focused on sodium chloride as a solute. In this study, we report on the survivability of the bacterial strain Planococcus halocryophilus in sodium, magnesium, and calcium chloride or perchlorate solutions at temperatures ranging from +25°C to -30°C. In addition, we determined the survival rates of P. halocryophilus when subjected to multiple freeze/thaw cycles. We found that cells suspended in chloride-containing samples have markedly increased survival rates compared with those in perchlorate-containing samples. In both cases, the survival rates increase with lower temperatures; however, this effect is more pronounced in chloride-containing samples. Furthermore, we found that higher salt concentrations increase survival rates when cells are subjected to freeze/thaw cycles. Our findings have important implications not only for the habitability of cold environments on Earth but also for extraterrestrial environments such as that of Mars, where cold brines might exist in the subsurface and perhaps even appear temporarily at the surface such as at recurring slope lineae.
Topics: Chlorides; Cold Temperature; Freezing; Microbial Viability; Osmolar Concentration; Perchlorates; Planococcus Bacteria; Salts; Water
PubMed: 29664686
DOI: 10.1089/ast.2017.1805 -
Foods (Basel, Switzerland) May 2024The composition and continuous succession of natural microbial communities during grape growth play important roles in grape health and flavor quality as well as in...
The composition and continuous succession of natural microbial communities during grape growth play important roles in grape health and flavor quality as well as in characterizing the regional wine terroir. This study explored the diversity and dynamics of fruit epidermal microbes at each growth and developmental stage of Ecolly grapes under an extremely simplified eco-cultivation model, analyzed microbial interactions and associations of weather parameters to specific communities, and emphasized metabolic functional characteristics of microecology. The results indicated that the natural microbial community changed significantly during the grape growth phase. The dominant fungal genera mainly included , , , , , , and , and the dominant bacterial genera mainly contained , , , , , , and . In summary, filamentous fungi gradually shifted to basidiomycetous yeasts along with fruit ripening, with a decline in the number of Gram-negative bacteria and a relative increase in Gram-positive bacteria. The community assembly process reflects the fact that microbial ecology may be influenced by a variety of factors, but the fungal community was more stable, and the bacterial community fluctuated more from year to year, which may reflect their response to weather conditions over the years. Overall, our study helps to comprehensively profile the ecological characteristics of the grape microbial system, highlights the natural ecological viticulture concept, and promotes the sustainable development of the grape and wine industry.
PubMed: 38790880
DOI: 10.3390/foods13101580 -
Frontiers in Microbiology 2020This study aims at exploiting salinity stress as an innovative, simple, and cheap method to enhance the production of antioxidant metabolites and enzymes from bacteria...
This study aims at exploiting salinity stress as an innovative, simple, and cheap method to enhance the production of antioxidant metabolites and enzymes from bacteria for potential application as functional additives to foods and pharmaceuticals. We investigated the physiological and biochemical responses of four bacterial isolates, which exhibited high tolerance to 20% NaCl (wt/vol), out of 27 bacterial strains isolated from Aushazia Lake, Qassim region, Saudi Arabia. The phylogenetic analysis of the 16S rRNA genes of these four isolates indicated that strains ST1 and ST2 belong to genus , whereas strains ST3 and ST4 belong to genus . Salinity stress differentially induced oxidative damage, where strains ST3 and ST4 showed increased lipid peroxidation, lipoxygenase, and xanthine oxidase levels. Consequently, high antioxidant contents were produced to control oxidative stress, particularly in ST3 and ST4. These two strains showed increased glutathione cycle, phenols, flavonoids, antioxidant capacity, catalase, and/or superoxide dismutase (SOD). Interestingly, the production of glutathione by strains was some thousand folds greater than by higher plants. On the other hand, the induction of antioxidants in ST1 and ST2 was restricted to phenols, flavonoids, peroxidase, glutaredoxin, and/or SOD. The hierarchical analysis also supported strain-specific responses. This is the first report that exploited salinity stress for promoting the production of antioxidants from bacterial isolates, which can be utilized as postbiotics for promising applications in foods and pharmaceuticals.
PubMed: 33042068
DOI: 10.3389/fmicb.2020.561816 -
Brazilian Journal of Microbiology :... Jul 2012To compensate for stress imposed by salinity, biofilm formation and exopolysaccharide production are significant strategies of salt tolerant bacteria to assist...
To compensate for stress imposed by salinity, biofilm formation and exopolysaccharide production are significant strategies of salt tolerant bacteria to assist metabolism. We hypothesized that two previously isolated salt-tolerant strains Halomonas variabilis (HT1) and Planococcus rifietoensis (RT4) have an ability to improve plant growth, These strains can form biofilm and accumulate exopolysacharides at increasing salt stress. These results showed that bacteria might be involved in developing microbial communities under salt stress and helpful in colonizing of bacterial strains to plant roots and soil particles. Eventually, it can add to the plant growth and soil structure. We investigated the comparative effect of exopolysacharide and biofilm formation in two bacterial strains Halomonas variabilis (HT1) and Planococcus rifietoensis (RT4) in response to varying salt stress. We found that biofilm formation and exopolysaccharide accumulation increased at higher salinity. To check the effect of bacterial inoculation on the plant (Cicer arietinum Var. CM-98) growth and soil aggregation, pot experiment was conducted by growing seedlings under salt stress. Inoculation of both strains increased plant growth at elevated salt stress. Weight of soil aggregates attached with roots and present in soil were added at higher salt concentrations compared to untreated controls. Soil aggregation was higher at plant roots under salinity. These results suggest the feasibility of using above strains in improving plant growth and soil fertility under salinity.
PubMed: 24031943
DOI: 10.1590/S1517-838220120003000046 -
Polish Journal of Microbiology 2015This paper presents the results of the research on the number, taxonomic composition, and biochemical properties of bacterial strains isolated from the alkaline Solvay...
This paper presents the results of the research on the number, taxonomic composition, and biochemical properties of bacterial strains isolated from the alkaline Solvay distillery lime, deposited at the repository in Janikowo (central Poland). Fifteen strains out of 17 were facultative alkaliphiles and moderate halophiles, and two were alkalitolerants and moderate halophiles. The number of aerobic bacteria cultured in alkaline lime was approximately 10(5) CFU ml(-1), and the total number of bacteria was 10(7) cells g(-1). According to 16S rRNA gene sequence analysis, nine strains belonged to the genus Bacillus, six to the genus Halomonas, one to the genus Planococcus, and one to the genus Microcella. Strains that hydrolyse starch and protein were the most numerous. Esterase (C4) and esterase lipase (C8) were detected in the majority of bacterial strains. Twelve strains exhibited α-glucosidase activity and nine, naphtol-AS-BI-phosphohydrolase activity. The present study proves that alkaliphilic bacteria of this type may constitute a source of potentially useful extremozymes.
Topics: Bacteria; Bacterial Physiological Phenomena; Calcium Compounds; DNA, Bacterial; Hydrogen-Ion Concentration; Oxides; Phylogeny; RNA, Bacterial; RNA, Ribosomal, 16S; Soil Microbiology
PubMed: 26999957
DOI: 10.5604/17331331.1185236 -
Marine Drugs Mar 2021With the widespread occurrence of aquaculture diseases and the broad application of antibiotics, drug-resistant pathogens have increasingly affected aquatic animals'...
With the widespread occurrence of aquaculture diseases and the broad application of antibiotics, drug-resistant pathogens have increasingly affected aquatic animals' health. Marine probiotics, which live under high pressure in a saltwater environment, show high potential as a substitute for antibiotics in the field of aquatic disease control. In this study, twenty strains of non-hemolytic bacteria were isolated from the intestine of wild oysters and perch, and a model of infected by was established. Based on the model, ML1206, which showed a 99% similarity of 16S rRNA sequence to , was selected as a potential marine probiotic, with strong antibacterial capabilities and great acid and bile salt tolerance, to protect from being damaged by . Combined with plate counting and transmission electron microscopy, it was found that strain ML1206 could significantly inhibit colonization in the intestinal tract of . Acute oral toxicity tests in mice showed that ML1206 was safe and non-toxic. The real-time qPCR results showed a higher expression level of genes related to the antibacterial peptide () and detoxification (, , and ) in the group of protected by ML1206 compared to the control group. It is speculated that ML1206, as a potential probiotic, may inhibit the infection caused by through stimulating to secrete antibacterial effectors and detoxification proteins. This paper provides a new direction for screening marine probiotics and an experimental basis to support the potential application of ML1206 as a marine probiotic in aquaculture.
Topics: Animals; Aquaculture; Caenorhabditis elegans; Female; Intestines; Male; Mice; Mice, Inbred ICR; Ostreidae; Planococcaceae; Probiotics; RNA, Ribosomal, 16S; Survival; Vibrio; Vibrio Infections
PubMed: 33809116
DOI: 10.3390/md19030150 -
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 -
Journal of Microbiology and... May 2015To enrich the genetic resource of microbial xylanases with high activity and stability under alkaline conditions, a xylanase gene (xynSL4) was cloned from Planococcus...
To enrich the genetic resource of microbial xylanases with high activity and stability under alkaline conditions, a xylanase gene (xynSL4) was cloned from Planococcus sp. SL4, an alkaline xylanase-producing strain isolated from the sediment of soda lake Dabusu. Deduced XynSL4 consists of a putative signal peptide of 29 residues and a catalytic domain (30-380 residues) of glycosyl hydrolase family 10, and shares the highest identity of 77% with a hypothetical protein from Planomicrobium glaciei CHR43. Phylogenetic analysis indicated that deduced XynSL4 is closely related with thermophilic and alkaline xylanases from Geobacillus and Bacillus species. The gene xynSL4 was expressed heterologously in Escherichia coli and the recombinant enzyme showed some superior properties. Purified recombinant XynSL4 (rXynSL4) was highly active and stable over the neutral and alkaline pH range from 6 to 11, with maximum activity at pH 7 and more than 60% activity at pH 11. It had an apparent temperature optimum of 70°C and retained stable at this temperature in the presence of substrate. rXynSL4 was highly halotolerant, retaining more than 55% activity with 0.25-3.0 M NaCl and was stable at the concentration of NaCl up to 4M. The enzyme activity was significantly enhanced by β-mercaptoethanol and Ca(2+) but strongly inhibited by heavy-metal ions and SDS. This thermophilic and alkaline- and salt-tolerant enzyme has great potential for basic research and industrial applications.
Topics: Amino Acid Sequence; Bacterial Proteins; China; Cloning, Molecular; Endo-1,4-beta Xylanases; Enzyme Stability; Geologic Sediments; Lakes; Molecular Sequence Data; Planococcus Bacteria; Sequence Alignment
PubMed: 25381738
DOI: 10.4014/jmb.1408.08062