-
International Journal of Systematic and... May 2022Three strains of members of the family , which can inhibit the growth of some Gram-stain-positive strains, designated M4U3P1, HD4P25 and RD4P76, were isolated from...
Three strains of members of the family , which can inhibit the growth of some Gram-stain-positive strains, designated M4U3P1, HD4P25 and RD4P76, were isolated from halophytes in Baotou, Inner Mongolia, PR China. A phylogenetic analysis based on the 16S rRNA gene and the whole genome sequences revealed that HD4P25 clustered with YIM 93174 with a similarity of 98.4 %, and RD4P76 shared the highest similarity of 16S rRNA gene with SA4 (97.5 %). M4U3P1 clustered with strains of genera and based on whole-genome sequence analyses, but its 16S rRNA gene had the highest similarity to '' EGI 80668 (96.1 %). The average nucleotide's identity by blast (ANIb) and digital DNA-DNA hybridization (dDDH) values of the three isolated strains to their close relatives were well below the threshold value for identifying a novel species.On the basis of the phylogenetic, physiological and phenotypic results, gen. nov., sp. nov. [type strain M4U3P1 (=CGMCC 1.17076=JCM 33851)] sp. nov. [type strain HD4P25 (=CGMCC 1.18651 =JCM 34524)] and sp. nov. [type strain RD4P76 (=CGMCC 1.18659=JCM 34525)] were proposed, respectively. All three species are ubiquitous in the bulk saline-alkaline soils, but only the species represented by strain RD4P76 was widely distributed in the rhizosphere soil, the above-ground part and the roots of . The species represented by M4U3P1 can be detected in the roots of , and rarely detected in the above-ground parts of . The species represented by HD4P25 was rarely detected in the interior of . The three strains could inhibit some of the Gram-stain-positive bacteria (i.e. members of the genera , and ) in the saline-alkali soil. A genomic analysis of these three strains revealed that they can synthesize different antagonistic compounds, such as aminobenzoate and bacitracin or subtilisin.
Topics: Bacillaceae; Bacillus; Bacterial Typing Techniques; Base Composition; Chenopodiaceae; DNA, Bacterial; Fatty Acids; Phospholipids; Phylogeny; RNA, Ribosomal, 16S; Salt-Tolerant Plants; Sequence Analysis, DNA; Soil
PubMed: 35550242
DOI: 10.1099/ijsem.0.005337 -
ELife Aug 2017Gut bacteria occupy the interface between the organism and the external environment, contributing to homeostasis and disease. Yet, the causal role of the gut microbiota...
Gut bacteria occupy the interface between the organism and the external environment, contributing to homeostasis and disease. Yet, the causal role of the gut microbiota during host aging is largely unexplored. Here, using the African turquoise killifish (), a naturally short-lived vertebrate, we show that the gut microbiota plays a key role in modulating vertebrate life span. Recolonizing the gut of middle-age individuals with bacteria from young donors resulted in life span extension and delayed behavioral decline. This intervention prevented the decrease in microbial diversity associated with host aging and maintained a young-like gut bacterial community, characterized by overrepresentation of the key genera and . Our findings demonstrate that the natural microbial gut community of young individuals can causally induce long-lasting beneficial systemic effects that lead to life span extension in a vertebrate model.
Topics: Aging; Animals; Fundulidae; Gastrointestinal Microbiome; Gastrointestinal Tract; Longevity
PubMed: 28826469
DOI: 10.7554/eLife.27014 -
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 -
Journal of Food Protection May 1981Selected biochemical and microbial changes in Penaeus shrimp inoculated with Planococcus citreus were examined to determine the potential of this organism to contribute...
Selected biochemical and microbial changes in Penaeus shrimp inoculated with Planococcus citreus were examined to determine the potential of this organism to contribute to spoilage of shrimp. Biochemical and microbial studies were conducted following storage of Penaeus shrimp at 5 C for 0, 4, 8, 12 and 16 days. Three samples, a control (raw shrimp), an irradiated (600 Krad) control and an irradiated (600 Krad) sample inoculated with P. citreus , were analyzed for changes in aerobic plate count, pH, total volatile nitrogen/amino acid nitrogen (TVN/AA-N) ratio, trimethyl amine-nitrogen (TMN) and total extractable protein (TEP). P. citreus counts increased in the inoculated shrimp from 3.0 × 10 bacteria/gram at 0 day to 1.5 × 10 bacteria/gram at the 16th day. By the 16th day of storage, the pH of the inoculated shrimp was significantly higher than the pH of the other samples. P. citreus inoculated onto irradiated shrimp was able to produce a TVN/AA-N ratio of 1.3 by the 10th day of storage, about the same time as that developed by the natural flora on raw shrimp. The increase in TMN content of the control (raw shrimp) and the inoculated sample were not significantly different. P. citreus was also able to bring about a significant decrease in the percent TEP of shrimp during storage. These changes indicate the capabilities of P. citreus in lowering the overall quality of Penaeus shrimp.
PubMed: 30836502
DOI: 10.4315/0362-028X-44.5.359 -
Extremophiles : Life Under Extreme... May 2007Protease-producing bacteria isolated from sub-Antarctic marine sediments of Isla de Los Estados (Argentina) were characterized, and the thermal inactivation kinetics of...
Protease-producing bacteria isolated from sub-Antarctic marine sediments of Isla de Los Estados (Argentina) were characterized, and the thermal inactivation kinetics of their extracellular proteases compared. Isolates were affiliated with the genera Pseudoalteromonas, Shewanella, Colwellia, Planococcus, and a strain to the family Flavobacteriaceae. Colwellia strains were moderate psychrophiles (optimal growth at about 15 degrees C, maximum growth temperature at around 25 degrees C). 16S rRNA phylogenetic analysis revealed that these strains and Colwellia aestuarii form a distinct lineage within the genus. The remaining isolates were psychrotolerant and grew optimally between 20 and 25 degrees C; two of them represent potentially novel species or genus (16S rRNA < 97% sequence similarity). The thermostability of the extracellular proteases produced by the isolates was analysed, and the inactivation rate constant (k (in)), the activation energy (Ea(in)) and the activation Gibbs free energy of thermal inactivation (Delta G( * ) (in)) determined. Delta G( * ) (in), calculated at 30 degrees C, varied between 97 and 124 kJ/mol. Colwellia enzyme extracts presented the highest thermosensitivity, while the most thermostable protease activity was shown by Shewanella spp. These results demonstrated that the stability to temperature of these enzymes varies considerably among the isolates, suggesting important variations in the thermal properties of the proteases that can coexist in this environment.
Topics: Antarctic Regions; Argentina; Bacteria; Geologic Sediments; Kinetics; Peptide Hydrolases; Phylogeny
PubMed: 17487446
DOI: 10.1007/s00792-007-0064-3 -
FEMS Microbiology Ecology May 2004The aim of this study was to identify Antarctic microorganisms with the ability to produce cold-active antimicrobial compounds with potential for use in chilled food...
The aim of this study was to identify Antarctic microorganisms with the ability to produce cold-active antimicrobial compounds with potential for use in chilled food preservation. Colonies (4496) were isolated from 12 Antarctic soil samples and tested against Listeria innocua, Pseudomonas fragi and Brochothrix thermosphacta. Thirteen bacteria were confirmed as being growth-inhibitor producers (detection rate 0.29%). When tested against a wider spectrum of eight target organisms, some of the isolates also inhibited the growth of L. monocytogenes and Staphylococcus aureus. Six inhibitor producers were psychrotrophic (growth optima between 18 and 24 degrees C), halotolerant (up to 10% NaCl) and catalase-positive; all but one were Gram-positive and oxidase-positive. The inhibitors produced by four bacteria were sensitive to proteases, suggesting a proteinaceous nature. Four of the inhibitor-producers were shown to be species of Arthrobacter, Planococcus and Pseudomonas on the basis of their 16S rRNA gene sequences and fatty acid compositions. It was concluded that Antarctic soils represent an untapped reservoir of novel, cold-active antimicrobial-producers.
Topics: Antarctic Regions; Anti-Bacterial Agents; Antibiosis; Bacteria; Bacterial Proteins; Catalase; Cluster Analysis; Cold Temperature; DNA, Bacterial; DNA, Ribosomal; Fatty Acids; Food Microbiology; Oxidoreductases; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Soil Microbiology
PubMed: 19712399
DOI: 10.1016/j.femsec.2004.01.001 -
Waste Management (New York, N.Y.) Oct 2023The objective of this study was to investigate the potential effects of thermophilic bacterial consortia on compost efficiency and quality. The application of bacterial...
The objective of this study was to investigate the potential effects of thermophilic bacterial consortia on compost efficiency and quality. The application of bacterial consortia resulted in an earlier onset of the thermophilic period (THP), an increased upper temperature limit, and an extended duration of the THP by 3-5 days compared to the control group (CK). Microbial inoculation significantly improved the efficiency of organic matter degradation, as well as the content of water-soluble nitrogen (WSN) and humic acid-carbon (HAC). In the case of consortium Ⅱ inoculation (T2), the activities of cellobiohydrolase, β-glucosidase, and protease were increased by 81.81 %, 70.13 %, and 74.09 % at the THP respectively compared to CK. During the maturation stage, T2 also exhibited the highest P, n/P, n value (1.33) and HAC content (39.53 mg·g), indicating that inoculation of consortium Ⅱ effectively promoted substrate maturity and product quality. Moreover, this inoculation effectively optimized the bacterial communities, particularly the growth of Planococcus, Chelatococcus, and Chelativorans during the composting, which were involved in carbon and nitrogen conversion or HAC synthesis. Carbohydrate and amino acid metabolism, and membrane transport were predominant in the consortia-inoculated samples, with an increased gene abundance, suggesting that inoculation contributed to promoting the biodegradation of lignocellulose and the exchange of favorable factors. In conclusion, this study demonstrates that inoculating thermophilic bacterial consortia has a positive impact on enhancing the resource utilization efficiency of agricultural waste and improving the quality of compost products.
PubMed: 37748282
DOI: 10.1016/j.wasman.2023.09.023 -
Extremophiles : Life Under Extreme... Jul 2014Bauxite residue (red mud), generated during the extraction of alumina from bauxite ore is characterized by high pH, high concentrations of soluble ions with low or...
Bauxite residue (red mud), generated during the extraction of alumina from bauxite ore is characterized by high pH, high concentrations of soluble ions with low or virtually no organic matter. These extreme conditions along with numerous nutrient deficiencies, limit the microbial growth and vegetation establishment. In the present study, diversity of both cultivable and non-cultivable bacteria present in the red mud was investigated by 16S rDNA sequence analyses. The cultivable bacteria were identified as Agromyces indicus, Bacillus litoralis, B. anthracis, Chungangia koreensis, Kokuria flava, K. polaris, Microbacterium hominis, Planococcus plakortidis, Pseudomonas alcaliphila and Salinococcus roseus based on their 16S rDNA sequence analysis. These isolates were alkali tolerant, positive for one or more of the enzyme activities tested, able to produce organic acids and oxidize wide range of carbon substrates. For non-cultivable diversity of bacteria, DNA was extracted from the bauxite residue samples and 16S rDNA clone library was constructed. The 16S rDNA clones of this study showed affiliation to three major phyla predominant being betaproteobacteria (41.1%) followed by gammaproteobacteria (37.5%) and bacteroidetes (21.4%). We are reporting for the first time about the bacterial diversity of this unique and extreme environment.
Topics: Alkalies; Aluminum Oxide; Bacteroidetes; Betaproteobacteria; Gammaproteobacteria; Industrial Waste; Microbiota; Ponds; RNA, Ribosomal, 16S
PubMed: 24817611
DOI: 10.1007/s00792-014-0647-8 -
Journal of Hazardous Materials Jul 2021Long-term exposure of anammox process to 1,4-dioxane was investigated using periodic anammox baffled reactor (PABR) under different 1,4-dioxane concentrations. The...
Long-term exposure of anammox process to 1,4-dioxane was investigated using periodic anammox baffled reactor (PABR) under different 1,4-dioxane concentrations. The results generally indicated that PABR (composed of 4 compartments) has robust resistance to 10 mg-dioxane/L. The 1 compartment acted as a shield to protect subsequent compartments from 1,4-dioxane toxicity through secretion of high extracellular polymeric substance (EPS) of 152.9 mg/gVSS at 10 mg-dioxane/L. However, increasing 1,4-dioxane to 50 mg/L significantly inhibited anammox bacteria; e.g., ~ 93% of total nitrogen removal was lost within 14 days. The inhibition of anammox process at this dosage was most likely due to bacterial cell lysis, resulting in the decrease of EPS secretion and specific anammox activity (SAA) to 105.9 mg/gVSS and 0.04 mg N/gVSS/h, respectively, in the 1 compartment. However, anammox bacteria were successfully self-recovered within 41 days after the cease of 1,4-dioxane exposure. The identification of microbial compositions further emphasized the negative impacts of 1,4-dioxane on abundance of C. Brocadia among samples. Furthermore, the development of genus Planococcus in the 1 compartment, where removal of 1,4-dioxane was consistently observed, highlights its potential role as anoxic 1,4-dioxane degrader. Overall, long-term exposure to 1,4-dioxane should be controlled not exceeding 10 mg/L for a successful application.
Topics: Anaerobiosis; Bioreactors; Dioxanes; Extracellular Polymeric Substance Matrix; Fatigue; Humans; Kinetics; Microbial Consortia; Nitrogen; Oxidation-Reduction
PubMed: 34030408
DOI: 10.1016/j.jhazmat.2021.125533 -
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