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1.
Microbes Environ ; 35(1)2020.
Artigo em Inglês | MEDLINE | ID: mdl-31932538

RESUMO

Accretionary prisms are thick masses of sedimentary material scraped from the oceanic crust and piled up at convergent plate boundaries found across large regions of the world. Large amounts of anoxic groundwater and natural gas, mainly methane (CH4), are contained in deep aquifers associated with these accretionary prisms. To identify the subsurface environments and potential for CH4 production by the microbial communities in deep aquifers, we performed chemical and microbiological assays on groundwater and natural gas derived from deep aquifers associated with an accretionary prism and its overlying sedimentary layers. Physicochemical analyses of groundwater and natural gas suggested wide variations in the features of the six deep aquifers tested. On the other hand, a stable carbon isotope analysis of dissolved inorganic carbon in the groundwater and CH4 in the natural gas showed that the deep aquifers contained CH4 of biogenic or mixed biogenic and thermogenic origins. Live/dead staining of microbial cells contained in the groundwater revealed that the cell density of live microbial cells was in the order of 104 to 106| |cells| |mL-1, and cell viability ranged between 7.5 and 38.9%. A DNA analysis and anoxic culture of microorganisms in the groundwater suggested a high potential for CH4 production by a syntrophic consortium of hydrogen (H2)-producing fermentative bacteria and H2-utilizing methanogenic archaea. These results suggest that the biodegradation of organic matter in ancient sediments contributes to CH4 production in the deep aquifers associated with this accretionary prism as well as its overlying sedimentary layers.


Assuntos
Sedimentos Geológicos/microbiologia , Água Subterrânea/microbiologia , Metano/biossíntese , Consórcios Microbianos , Anaerobiose , Archaea/classificação , Archaea/genética , Archaea/isolamento & purificação , Archaea/metabolismo , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Carbono/análise , Sedimentos Geológicos/química , Água Subterrânea/química , Hidrogênio/metabolismo , Japão , Metano/análise , Gás Natural/análise , RNA Ribossômico 16S/genética
2.
Fitoterapia ; 140: 104406, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31698061

RESUMO

One new quinoline alkaloid (1), two new bisabolane-type sesquiterpene derivatives (2 and 3), and a new natural product (4) along with ten known compounds (514) were isolated from the deep sea-derived fungus Aspergillus sp. SCSIO06786 which cultured on solid rice medium. Three new structures were elucidated by analysis of 1D/2D NMR data and HR-ESI-MS. The absolute configurations of 2 and 3 were established by comparison of the experimental and reported ECD values. Compounds 11-13 exhibited moderate selective inhibitory activities against the tested pathogenic bacteria with MIC values among 3.13-12.5 µg/mL.


Assuntos
Alcaloides/isolamento & purificação , Aspergillus/química , Quinolinas/isolamento & purificação , Água do Mar/microbiologia , Sesquiterpenos/isolamento & purificação , Alcaloides/farmacologia , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Sedimentos Geológicos/microbiologia , Oceano Índico , Testes de Sensibilidade Microbiana , Estrutura Molecular , Quinolinas/farmacologia , Sesquiterpenos/farmacologia
3.
Chemosphere ; 239: 124796, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31520972

RESUMO

In July 2013, a fatal train derailment led to an explosion and fire in the town of Lac-Mégantic (LM), Quebec, and the crude oil contamination of regional surface water, soil, and sediment in the adjacent Lake Mégantic. This study investigated the degradation potential of the spilled crude oil by using the sediments from the incident site as the source of microorganisms. Two light crude oils (LM source oil and Alberta Sweet Mixed Blend (ASMB)) were tested at 22 °C for 4 weeks and 4 °C for 8 weeks, respectively. The post-incubation biological and chemical information of the samples were analysed. There was no marked difference in degradation efficacy and biological activities for both the LM and ASMB oils, although the biodegradation potential differed between the two incubations. Higher temperature favoured the growth of microorganisms, thus for the degradation of all petroleum hydrocarbons, except for some conservative biomarkers. The degradation of both oils followed the order of resolved components > total saturated hydrocarbons (TSH) > unresolved complex mixture (UCM) >total aromatic hydrocarbons (TAH). Normal alkanes were generally degraded more significantly than branched ones, and polycyclic aromatic hydrocarbons (PAHs). Degradation of polycyclic aromatic hydrocarbons (PAHs) and their alkylated congeners (APAHs) for both incubations generally decreased as the number of aromatic rings, and the degree of alkylation increased. This study showed that the LM sediments can biodegrade the petroleum hydrocarbons efficaciously if appropriate ambient temperatures are generated to favour the growth of autochthonous microorganisms.


Assuntos
Sedimentos Geológicos/microbiologia , Hidrocarbonetos/química , Hidrocarbonetos/metabolismo , Petróleo/metabolismo , Poluentes Químicos da Água/metabolismo , Alcanos/química , Alcanos/metabolismo , Biodegradação Ambiental , Lagos/microbiologia , Poluição por Petróleo , Hidrocarbonetos Policíclicos Aromáticos/química , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Quebeque , Temperatura Ambiente , Poluentes Químicos da Água/química
4.
World J Microbiol Biotechnol ; 35(12): 196, 2019 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-31784839

RESUMO

In this research, the dynamics of nitrogen transformation and bacterial community in malodorous river were investigated with different aeration depths. Computational flow dynamics (CFD) and Reynolds number (Re) were specially used to characterize the hydrodynamics condition under different aeration depths. The results indicated that aeration depth had vital impact on nitrogen transformation and bacterial community structure. It was found that a range of aeration depth (0.20-0.45 m above sediment-water interface) facilitated the removal of NH4+-N and TN with Re ranging between 6211 and 8930. Proteobacteria took over Firmicutes to become the predominant phylum (36-78%) under aeration, and the main subdivisions of γ-, ß- and δ-Proteobacteria also varied greatly with different aeration depths. Interestingly, there was a marked shift of the inferentially identified dominant functional role within Proteobacteria from organic-matter degradation to nitrogen metabolism and then to sulfur metabolism as well as the coupling of nitrogen and sulfur with the increase of disturbance. The redundancy analysis (RDA) further confirmed the importance of aeration disturbance in shaping bacterial community. These findings help to gain improved understanding of endogenous N-behavior and aquatic microbial ecology, and underline the need for integrating the hydrodynamics factors with microbial community.


Assuntos
Bactérias/metabolismo , Microbiota/fisiologia , Nitrogênio/metabolismo , Rios/química , Rios/microbiologia , Bactérias/classificação , Bactérias/genética , China , Sedimentos Geológicos/microbiologia , Oxigênio/metabolismo , Filogenia , RNA Ribossômico 16S , Enxofre/metabolismo
5.
Huan Jing Ke Xue ; 40(6): 2753-2763, 2019 Jun 08.
Artigo em Chinês | MEDLINE | ID: mdl-31854668

RESUMO

In order to study the relationship between the vertical distribution of nutrients and bacterial community structures in sediment interstitial waters of stratified reservoirs with different water temperatures, MiSeq high-throughput sequencing was used to analyze and compare the structural characteristics of sediment bacterial communities after reservoirs were built. Additionally, redundancy analysis (RDA) was used to assess the bacterial communities and environmental factors with Cannoco software. The results showed that the temperature difference between the surface and bottom layer of the Xiaowan Reservoir was 3.3℃, and the maximum thermal gradient was 0.2℃·m-1; thus, it was a typical stratified reservoir. The temperature difference between the surface and bottom layer of the Manwan Reservoir was 0.1℃; thus, it was a typical mixed reservoir. The average concentrations of NH4+-N and NO3--N in sediment interstitial waters of the Xiaowan Reservoir were 2.233 mg·L-1 and 0.030 mg·L-1, while those of Manwan were 2.569 mg·L-1 and 0.016 mg·L-1, respectively. In the different reservoirs, the concentrations of NH4+-N showed upward trends, and while variation of NO3--N was not obvious, the content of NO3--N reached a minimum value in the deep layer. In comparisons between reservoirs, only NO3--N showed a significant difference, in which Xiaowan had obviously higher concentrations than Manwan. The bacterial community structures in the Xiaowan and Manwan reservoir sediments had the same dominant bacteria at the phylum, class, and genus levels. The differences of water temperature stratification had no significant effect on nutrients and microorganisms in the sediments. Under the influence of other factors, the denitrifying bacteria in the Manwan Reservoir sediments were more abundant than those in the Xiaowan Reservoir, and the nitrifying bacteria and anammox bacteria in the Xiaowan Reservoir sediments were more abundant than those in the Manwan Reservoir. In the same reservoir, the denitrifying bacteria in the bottom of the sediments were more abundant, and the organic degradation bacteria, nitrifying bacteria, anammox bacteria, and phosphate-solubilizing bacteria were less abundant in this zone. These trends contributed to the differences of nutrients vertically in the different reservoirs.


Assuntos
Bactérias/classificação , Água Doce/química , Sedimentos Geológicos/microbiologia , Temperatura Ambiente , Microbiologia da Água , China , Água Doce/microbiologia
6.
J Microbiol ; 57(12): 1095-1104, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31758395

RESUMO

Subglacial ecosystems harbor diverse chemoautotrophic microbial communities in areas with limited organic carbon, and lithological H2 produced during glacial erosion has been considered an important energy source in these ecosystems. To verify the H2-utilizing potential there and to identify the related energy-converting metabolic mechanisms of these communities, we performed metagenomic analysis on subglacial sediment samples from East Antarctica with and without H2 supplementation. Genes coding for several [NiFe]-hydrogenases were identified in raw sediment and were enriched after H2 incubation. All genes in the dissimilatory nitrate reduction and denitrification pathways were detected in the subglacial community, and the genes coding for these pathways became enriched after H2 was supplied. Similarly, genes transcribing key enzymes in the Calvin cycle were detected in raw sediment and were also enriched. Moreover, key genes involved in H2 oxidization, nitrate reduction, oxidative phosphorylation, and the Calvin cycle were identified within one metagenome-assembled genome belonging to a Polaromonas sp. As suggested by our results, the microbial community in the subglacial environment we investigated consisted of chemoautotrophic populations supported by H2 oxidation. These results further confirm the importance of H2 in the cryosphere.


Assuntos
Sedimentos Geológicos/microbiologia , Hidrogênio/metabolismo , Metagenoma , Microbiota/fisiologia , Regiões Antárticas , Archaea/classificação , Archaea/enzimologia , Archaea/genética , Archaea/metabolismo , Bactérias/classificação , Bactérias/enzimologia , Bactérias/genética , Bactérias/metabolismo , Ciclo do Carbono , Crescimento Quimioautotrófico , Comamonadaceae/enzimologia , Comamonadaceae/metabolismo , Genes Arqueais/genética , Genes Bacterianos/genética , Hidrogenase/classificação , Hidrogenase/genética , Hidrogenase/isolamento & purificação , Redes e Vias Metabólicas , Microbiota/genética , Nitratos/metabolismo , Fosforilação Oxidativa , Fotossíntese , Análise de Sequência de DNA
7.
Emerg Microbes Infect ; 8(1): 1688-1700, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31749408

RESUMO

Resistance to ß-lactams is one of the most serious problems associated with Gram-negative infections. ß-Lactamases are able to hydrolyze ß-lactams such as cephalosporins and/or carbapenems. Evolutionary origin of metallo-ß-lactamases (MBLs), conferring critical antibiotic resistance threats, remains unknown. We discovered PNGM-1, the novel subclass B3 MBL, in deep-sea sediments that predate the antibiotic era. Here, our phylogenetic analysis suggests that PNGM-1 yields insights into the evolutionary origin of subclass B3 MBLs. We reveal the structural similarities between tRNase Zs and PNGM-1, and demonstrate that PNGM-1 has both MBL and tRNase Z activities, suggesting that PNGM-1 is thought to have evolved from a tRNase Z. We also show kinetic and structural comparisons between PNGM-1 and other proteins including subclass B3 MBLs and tRNase Zs. These comparisons revealed that the B3 MBL activity of PNGM-1 is a promiscuous activity and subclass B3 MBLs are thought to have evolved through PNGM-1 activity.


Assuntos
Bactérias/enzimologia , Proteínas de Bactérias/genética , Evolução Molecular , Sedimentos Geológicos/microbiologia , beta-Lactamases/genética , Sequência de Aminoácidos , Bactérias/química , Bactérias/classificação , Bactérias/genética , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Domínio Catalítico , Filogenia , beta-Lactamases/química , beta-Lactamases/metabolismo
8.
Environ Sci Pollut Res Int ; 26(34): 35131-35139, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31680200

RESUMO

Water column and sediment samples were collected in the southern Gulf of Mexico (GoMex) during 3 oceanographic cruises: XIXIMI-04 (September 2015), XIXIMI-05 (June 2016), and XIXIMI-06 (August 2017). DNA that was extracted from the samples was analyzed by qPCR to detect and quantify bacterial groups that have been reported to metabolize alkanes (Alcanivorax) and aromatic hydrocarbons (Cycloclasticus) and are involved in methane production (Methanomicrobiales). The results were then analyzed with regard to the water masses that are currently detected in the GoMex. Generally, we observed a decrease in the proportion of Alcanivorax and a rise in those of Cycloclasticus and Methanomicrobiales in samples from the surface to deep waters and in sediment samples. Scatterplots of the results showed that the relative abundance of the 3 groups was higher primarily from the surface to 1000 m, but the levels of Cycloclasticus and Methanomicrobiales were high in certain water samples below 1000 m and in sediments. In conclusion, oil-degrading bacteria are distributed widely from the surface to deep waters and sediments throughout the southern GoMex, representing a potential inoculum of bacteria for various hydrocarbon fractions that are ready for proliferation and degradation in the event of an oil spill from the seafloor or along the water column.


Assuntos
Biodegradação Ambiental , Sedimentos Geológicos/microbiologia , Microbiologia da Água , Alcanivoraceae , Alcanos/análise , Bactérias/metabolismo , Monitoramento Ambiental , Golfo do México , Hidrocarbonetos/análise , Methanomicrobiales , Petróleo/metabolismo , Poluição por Petróleo/análise , Poluentes Químicos da Água/análise
9.
Int J Syst Evol Microbiol ; 69(12): 3740-3744, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31693473

RESUMO

A novel actinobacterium producing biosurfactant, designated OTB305T, was isolated from marine sediment sampled at Otsuchi Bay, Iwate Prefecture, Japan and its taxonomic position was examined using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences exhibited that strain OTB305T was closely related to Streptomyces bohaiensis JCM 19630T (98.8 %) and Streptomyces lonarensis DSM 42084T (98.8 %). The chemotaxonomic characteristics of strain OTB305T corresponded to those of the genus Streptomyces as follows: the diamino acid of the cell-wall peptidoglycan was ll-diaminopimelic acid; whole-cell hydrolysates contained glucose and lacked characteristic major sugars; the predominant isoprenoid quinones were MK-9(H8) and MK-9(H6); the polar lipids were phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and an unidentified phospholipid; the major cellular fatty acids were iso-C16 : 0, C16 : 0 and C16 : 1 ω7c; and the genomic DNA G+C content was 72.83 mol%. However, genomic relatedness analysis based on the average nucleotide identity and some phenotypic characteristics revealed that strain OTB305T was distinguished from closely related Streptomyces species. Therefore, strain OTB305T represents a novel species of the genus Streptomyces, for which the name Streptomyces otsuchiensis sp. nov. is proposed. The type strain is OTB305T (=NBRC 113255T=TBRC 9682T).


Assuntos
Sedimentos Geológicos/microbiologia , Filogenia , Água do Mar/microbiologia , Streptomyces/classificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Graxos/química , Japão , Peptidoglicano/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Streptomyces/isolamento & purificação , Vitamina K 2/análogos & derivados , Vitamina K 2/química
10.
Int J Syst Evol Microbiol ; 69(12): 3723-3727, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31693474

RESUMO

A Gram-stain-negative, non-motile bacterial strain, designated SW125T, was isolated from a deep-sea vsediment sample collected from the Indian Ocean. Cells were aerobic, catalase-positive and oxidase-positive. The strain grew at 4-42 °C (optimum, 30 °C), at pH 5.0-10.0 (optimum, pH 7.0-7.6) and in the presence of 0.5-9.0 % (w/v) NaCl (optimum, 2.0-3.0 %). Comparative analyses of the 16S rRNA gene sequence showed that strain SW125T was grouped in the vicinity of the genus Negadavirga with the highest sequence similarity of 91.6 % to the type strain of Negadavirga shengliensis. The quinone system contained menaquinone MK-7 as the predominant component. The predominant cellular fatty acids of strain SW125T were iso-C15 : 0, iso-C17 : 0 3-OH and summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c). Strain SW125T contained phosphatidylethanolamine as the major polar lipid. The genomic DNA G+C content of strain SW125T was 43.2 mol%. On the basis of its phenotypic characteristics and phylogenetic data, strain SW125T represents a novel species of a new genus, for which the name Pleomorphovibrio marinus gen. nov., sp. nov. is proposed. The type strain is SW125T (=CGMCC 1.16172T=DSM 107180T=KCTC 62636T).


Assuntos
Bacteroidetes/classificação , Sedimentos Geológicos/microbiologia , Filogenia , Água do Mar/microbiologia , Técnicas de Tipagem Bacteriana , Bacteroidetes/isolamento & purificação , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Oceano Índico , Fosfatidiletanolaminas/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
11.
J Microbiol ; 57(11): 991-996, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31659685

RESUMO

A Gram-stain-positive, aerobic, motile, and rod-shaped bacterial strain designated TGS2-1T was isolated from sediment soil in the Nakdong River, Republic of Korea. The optimal growth of strain TGS2-1T was observed at 28°C and pH 7.0 without NaCl supplementation. Strain TGS2-1T revealed antibiosis against various bacteria, including Staphylococcus aureus KCCM 4051, CCARM 3089 (methicillin resistant strains), Enterococcus faecalis KCCM 11814, Escherichia coli KCTC 2443, Candida albicans KACC 7270, and Filobasidium neoformans KCTC 7902. Phylogenetic analyses based on the 16S rRNA gene sequences indicated that strain TGS2-1T belonged to the genus Brevibacillus and shared 93.8-99.7% sequence similarity with Brevibacillus species. Whole-genome sequencing of strain TGS2-1T revealed a genome size of 6.2 Mbp and DNA G + C content of 47.0 mol%. The TGS2-1T genome shared an average nucleotide identity and digital DNA-DNA hybridization of 74.6-93.3% and 18.6-67.1%, respectively, with six related Brevibacillus genomes. The major fatty acid constituents of strain TGS2-1T were anteiso-C15:0 (62.3%) and anteiso-C17:0 (10.8%). Cells of strain TGS2-1T contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, seven unidentified aminophospholipids, and five unidentified lipids. The isoprenoid quinone detected in the strain was menaquinone-7 (MK-7). Based on data obtained from this polyphasic taxonomic study, strain TGS2-1T represents a novel species belonging to genus Brevibacillus, for which the name B. antibioticus sp. nov. is proposed. The type strain is TGS2-1T (= KCCM 90326T = NBRC 113840T = FBCC-B2501).


Assuntos
Antibacterianos/biossíntese , Brevibacillus/classificação , Brevibacillus/isolamento & purificação , Brevibacillus/metabolismo , Filogenia , Rios/microbiologia , Microbiologia do Solo , Bactérias/efeitos dos fármacos , Técnicas de Tipagem Bacteriana , Composição de Bases , Benzoquinonas/química , Brevibacillus/genética , DNA Bacteriano/genética , Ácidos Graxos/química , Sedimentos Geológicos/microbiologia , Testes de Sensibilidade Microbiana , Hibridização de Ácido Nucleico , RNA Ribossômico 16S/genética , República da Coreia , Análise de Sequência de DNA , Solo , Sequenciamento Completo do Genoma
12.
Int J Syst Evol Microbiol ; 69(11): 3362-3367, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31622228

RESUMO

A novel Gram-stain-negative bacterium, designated as SCSIO 06110T, was isolated from a deep-sea sediment of the West Pacific Ocean. Cells were 0.5-0.8 µm in width and 3.0-4.0 µm in length, spore-forming, rod-shaped with peritrichous flagella. Positive for catalase and urease, negative for oxidase and nitrate reduction. Growth occurred at 15-37 °C, pH 6-9 and 1-5 % (w/v) NaCl, with optimum growth at 28 °C, pH 7 and 3 % (w/v) NaCl. MK-7 was the only menaquinone. The strain possessed diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and two unidentified phospholipids. Iso-C16 : 0, iso-C15 : 0 and iso-C14 : 0 were the major fatty acids. The novel isolate clustered with genera in the family Paenibacillaceae, but formed a separated branch with the closest relative Chengkuizengella sediminis J15A17T (91.1 % sequence similarity) when compared in a phylogenetic analysis of 16S rRNA gene sequences. The DNA G+C content of strain SCSIO 06110T was 38.5 mol%. Based on the polyphasic data presented, a new genus, Longirhabdus gen. nov., is proposed in the family Paenibacillaceae with the type species Longirhabdus pacifica sp. nov. and the type strain SCSIO 06110T (=DSM 105158T=CGMCC 1.16550T).


Assuntos
Bacillales/classificação , Sedimentos Geológicos/microbiologia , Fontes Hidrotermais/microbiologia , Filogenia , Bacillales/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Oceano Pacífico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Água do Mar/microbiologia , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
13.
Int J Syst Evol Microbiol ; 69(11): 3644-3649, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31622232

RESUMO

A novel Gram-stain-negative, strictly aerobic bacterium that has a rod-like shape with a single polar flagellum in the exponential phase of growth and a spherical or ovoid shape without a flagellum in the stationary phase was isolated from a mangrove wetland sediment sample collected at Beilun Estuary National Nature Reserve, Guangxi Province, PR China and designated strain ZS-4T. This strain grew optimally at pH 6.0-8.0, at a temperature of 37 °C and in the presence of 3-4 % (w/v) NaCl. Its polar lipid profile included phosphatidylethanolamine, phosphatidylglycerol, one unidentified aminophospholipid and two uncharacterized lipids. Ubiquinone 8 (Q-8) was the sole respiratory quinone and the cellular fatty acids were dominated by C17 : 1ω8c and C16 : 0. A phylogenetic analysis based on the 16S rRNA gene sequence showed that strain ZS-4T exhibited its highest similarities to the type strains Thalassotalea litorea HMF4135T (97.8 %) and Thalassotalea ponticola GJSW-36T (95.9 %). A whole genome-level comparison of strain ZS-4T with T. litorea MCCC 1K03283T revealed an average nucleotide identity value of 75.6 % and a calculated DNA-DNA hybridization value of 19.6 %. In addition, the genomic DNA G+C content of strain ZS-4T was 45.9 mol%. Thus, based on analyses of its morphology, physiology, fatty acid composition and 16S rRNA gene sequence, strain ZS-4T should be considered a novel species of the genus Thalassotalea, with the proposed name Thalassotaleamangrovi sp. nov. The type strain is ZS-4T (=KCTC 72399T=MCCC 1K03630T).


Assuntos
Gammaproteobacteria/classificação , Sedimentos Geológicos/microbiologia , Filogenia , Áreas Alagadas , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Estuários , Ácidos Graxos/química , Gammaproteobacteria/isolamento & purificação , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Ubiquinona/química
14.
World J Microbiol Biotechnol ; 35(10): 153, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31576426

RESUMO

Karst caves, considering to be the "arks" of biodiversity, often contain high levels of endemism. In the present study, the actinobacterial community in Shuanghe Cave, the longest cave in Asia, was analyzed for the first-time using culture-dependent and -independent (16S rRNA amplicon sequencing) approaches. The amplicon sequencing analysis revealed a broad taxonomic diversity in Shuanghe Cave, including 19 phyla (predominantly Actinobacteria) and 264 different genera. While the culture-dependent method got the unrepresentative but supplemental result, a total of 239 actinomycetes were isolated and were identified to seven genera based on culture features and 16S rRNA tests. Among the three habitats (soil, rock soil, and bat guano), the dominant phyla did not differ significantly, while the dominant genus community varied among different habitats, and the richness in soil and rock soil samples was higher than that in bat guano. Furthermore, 16 isolate strains showed antimicrobial activity, especially, the strain S142 (Streptomyces badius) and S761 (Actinoplanes friuliensis) exhibited the most promising activity against various pathogens. Overall, this work showed the abundant bacterial diversity and the antimicrobial potential of the isolates from the Shuanghe Cave.


Assuntos
Actinobacteria/isolamento & purificação , Cavernas/microbiologia , Actinobacteria/classificação , Actinobacteria/genética , Actinobacteria/crescimento & desenvolvimento , Animais , Ásia , Biodiversidade , Quirópteros/microbiologia , DNA Bacteriano/genética , Ecossistema , Sedimentos Geológicos/microbiologia , Filogenia , RNA Ribossômico 16S/genética , Microbiologia do Solo
15.
Ecotoxicol Environ Saf ; 185: 109722, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31577991

RESUMO

Methylmercury (MeHg) is a toxicant that mainly originates from in situ microbial methylation of inorganic mercury (Hg) in the environment and poses a severe health risk to the public. However, the characteristics of the Hg-methylating microbial community and its relationship with MeHg production in various environments remain to be understood. In the present study, Hg-methylating microbial communities and genes (hgcAB cluster) in the sediments of the Pearl River (PR), Pearl River Estuary (PRE) and South China Sea (SCS) were investigated at a large spatial scale using high-throughput sequencing-based approaches. The results showed that sulfur-reducing bacteria (SRB) and iron-reducing bacteria (IRB) were consistently the dominant microbial strains responsible for the methylation of inorganic Hg in all three regions investigated. The abundance and diversity of Hg-methylating communities and genes were both found to be higher in the PR sediments compared to that in the PRE and SCS sediments, and in good agreement with the spatial distribution of MeHg. Furthermore, a significant correlation was observed between the MeHg concentration and the abundance of both hgcA and hgcB genes in the sediments of the PR, PRE and SCS regions. Overall, the present study suggested that there was the presence of a close link between MeHg and Hg-methylating communities or genes in the ambient aquatic environment, which could be used to reflect the potential of in situ MeHg production.


Assuntos
Estuários , Sedimentos Geológicos , Mercúrio/análise , Compostos de Metilmercúrio/análise , Microbiota/genética , Rios/química , Poluentes Químicos da Água/análise , China , Sedimentos Geológicos/química , Sedimentos Geológicos/microbiologia , Metilação
16.
Ecotoxicol Environ Saf ; 184: 109634, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31520950

RESUMO

Imidazolium-based ionic liquids (IL) with short-alkyl side chain such as 1-ethyl-3-methyl-imidazolium chloride ([Emim]Cl) and 1-butyl-3-methyl-imidazolium chloride ([Bmim]Cl) has immense application potential including in lignocellulosic bioenergy production. But they are toxic to most microorganisms, and those isolated from different environments as IL-tolerant have salt tolerance capabilities. This study evaluates the relationship between salt and [Emim]Cl tolerance of microorganisms using different salinity sediments (2-19%) and brines (35%) of India's largest inland hypersaline lake, Sambhar in Rajasthan as the model system. While samples with 2% and 35% salinities do not yield any [Emim]Cl (100 mM) tolerant colonies, others have 6-50% colonies tolerant to the IL. Similar trend was observed with 50 mM [Bmim]Cl. Moderate halophilic isolates of genera Halomonas and Bacillus (growth in 0.7-3.0 M NaCl) isolated from the sediments could grow in as high as 375 mM [Emim]Cl, or 125 mM [Bmim]Cl facilitated by higher synthesis, and uptake of organic osmolytes; and up to 1.7-fold increased activity of active efflux pumps. [Bmim]Cl was more toxic than [Emim]Cl in all performed experiments. [Emim]Cl-adapted cells could trounce IL-induced stress. Interestingly, enrichment with 100 mM [Emim]Cl resulted in increase of IL-tolerant colonies in all sediments including the one with 2% salinity. However, the salt saturated brines (35%) do not yield any such colony even after repeated incubations. Extreme halophilic archaea, Natronomonas (growth in 3.0-4.0 M NaCl) isolated from such brines, were exceedingly sensitive to even 5 mM [Emim]Cl, or 1 mM [Bmim]Cl. Two additional extremophilic archaea, namely Haloferax and Haladaptatus were also sensitive to the tested ILs. Archaeal sensitivity is possibly due to the competitive interaction of [Emim]+ with their acidic proteome (15.4-17.5% aspartic and glutamic acids, against 10.7-12.9% in bacteria) that they maintain to stabilize the high amount of K+ ion accumulated by salt-in strategy. Thus, general salt adaptation strategies of moderate halophilic bacteria help them to restrain toxicity of these ILs, but extremophilic archaea are highly sensitive and demands meticulous use of these solvents to prevent environmental contamination.


Assuntos
Halobacteriaceae/efeitos dos fármacos , Halomonas/efeitos dos fármacos , Imidazóis/toxicidade , Líquidos Iônicos/toxicidade , Sedimentos Geológicos/química , Sedimentos Geológicos/microbiologia , Índia , Lagos/química , Lagos/microbiologia , Salinidade , Tolerância ao Sal
17.
Fitoterapia ; 138: 104357, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31521701

RESUMO

Three new 3-hydroxy-N-methyl-2-oxindole (1 and 2) and 4-hydroxy-pyran-2-one (3) derivatives, along with the known 3-hydroxy-N-methyl-2-oxindole (4) and 6-methoxy-N-methylisatin (5) were isolated from a marine Salinispora arenicola strain from sediments of the St. Peter and St. Paul Archipelago, Brazil. The structures of the new compounds were elucidated by a combination of spectroscopic (1D and 2D NMR and HR-ESIMS) data, including single-crystal X-ray diffraction analysis for 2 and 3. Compounds 1 to 5 were assayed for their antimicrobial properties, but only 4 and 5 were active against Enterococcus faecalis with MIC value of 15.6 µg/mL.


Assuntos
Antibacterianos/farmacologia , Sedimentos Geológicos/microbiologia , Micromonosporaceae/química , Oxindois/farmacologia , Antibacterianos/isolamento & purificação , Brasil , Enterococcus faecalis/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Oxindois/isolamento & purificação , Água do Mar/microbiologia
18.
J Microbiol ; 57(11): 976-981, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31555990

RESUMO

A novel, Gram-stain-negative marine bacterium, designated GH2-6T, was isolated from a rhizosphere mudflat of a halophyte (Carex scabrifolia) collected in Gangwha Island, the Republic of Korea. The cells of the organism were strictly aerobic, oxidase- and catalase-positive, non-flagellated rods. Growth occurred at 20-45°C, pH 5-10, and 0.5-9 (w/v) NaCl. The requirement of Na+ for growth (0.5-3%) was observed. The major respiratory quinone was Q-10. The major polar lipids were phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, an aminolipid and a glycolipid. The predominant fatty acids were C18:1ω7c, C18:0, C16:0, C19:0 cyclo ω8c, C18:1ω7c 11-methyl and summed feature 2 (C14:0 3-OH and/or C16:1 iso I). The genome size was 4.45 Mb and the G+C content of the genomic DNA was 61.9 mol%. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain GH2-6T belonged to genus Martelella and formed a tight cluster with M. radicis BM5-7T and M. endophytica YC6887T. Levels of 16S rRNA gene sequence similarity between the novel isolate and members of the genus were 99.3-95.5%, but strain GH2-6T possessed an extended loop (49 nucleotides in length) between positions 187 and 213 of the 16S rRNA gene sequence (E. coli numbering). DDH values in vitro between the novel isolate and the closest relatives were 23.2±12.8-46.3±5.2%. On the basis of polyphasic data presented in this study, the type strain GH2-6T (= KACC 19403T = KCTC 62125T = NBRC 113212T) represents a novel species of the genus Martelella for which the name Martelella lutilitoris sp. nov. is proposed.


Assuntos
Alphaproteobacteria/classificação , Alphaproteobacteria/isolamento & purificação , Sedimentos Geológicos/microbiologia , Filogenia , Rizosfera , Água do Mar/microbiologia , Alphaproteobacteria/genética , Alphaproteobacteria/fisiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Escherichia coli/genética , Ácidos Graxos/química , Glicolipídeos/química , Ilhas , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , República da Coreia , Plantas Tolerantes a Sal , Análise de Sequência de DNA , Ubiquinona/química
19.
Environ Pollut ; 255(Pt 1): 113069, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31541809

RESUMO

The Bohai Sea, one of the largest marginal seas in China, is extensively influenced by human and industrial activities. The pollutant loads from anthropogenic activities have induced severe ecological problems. The study investigates the physicochemical characteristics of seawater and sediments in Bohai Bay and Laizhou Bay of the Bohai Sea. The diversity and composition of microbial community in sediments are analyzed by 16S rRNA gene amplicon sequencing. The sequencing results present 16 phyla and 31 classes from the samples. Proteobacteria constituted a dominant phylum, of which the classes of Gamma-, Delta-, and Epsilon-are predominant sub-divisions. Nitrogen, phosphorus, and sulfur cycling related microbes present high abundance in both bays. The metabolism of organic matters is the main factor that influences the distribution of microbial communities in Bohai Bay, while the inflow of Yellow River is the dominant factor that influences the distribution of microbial communities in Laizhou Bay. Sulfur oxidizing process is expected to be positively influenced by heavy metals, while ammonia (NH4+) oxidizing process is prone to be negatively affected by heavy metals in both bays. Microbial communities in the offshore sediments of Laizhou Bay and the majority microbial communities in Bohai Bay sediments are subject to similar predominant controlling factors. This phenomenon is likely ascribed to ocean circulation. The results of this study can provide constructive guidelines on ecosystem management of marginal seas in Bohai and elsewhere.


Assuntos
Monitoramento Ambiental/métodos , Sedimentos Geológicos/microbiologia , Metais Pesados/análise , Microbiota/efeitos dos fármacos , Água do Mar/microbiologia , Poluentes Químicos da Água/análise , Baías/química , Baías/microbiologia , China , Sedimentos Geológicos/química , Metais Pesados/toxicidade , Oceanos e Mares , Proteobactérias/isolamento & purificação , RNA Ribossômico 16S , Rios/química , Rios/microbiologia , Água do Mar/química , Poluentes Químicos da Água/toxicidade
20.
J Microbiol ; 57(12): 1065-1072, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31562606

RESUMO

A yellow pigmented, Gram-stain-negative, aerobic bacterium designated A5.7T was studied to evaluate the taxonomic position following the modern polyphasic approach. The strain was isolated from sediments near Zhairuo Island, which is situated in the East China Sea. Cells were non-spore forming rods without flagella but showed motility by gliding. Growth was observed at 15-35°C (optimum 28°C), pH 6.0-9.0 (optimum pH 6.5) and 0-2% (w/v) NaCl (optimum 0-0.5%) in LB broth. The major respiratory quinone of A5.7T was menaquinone 6. The major polar lipid of A5.7T was phosphatidylethanolamine and the predominant fatty acids (> 5%) were iso-C15:0, iso-C17:0 3-OH, C15:1ω6c, iso-C15:0 3-OH, iso-C15:1 G, summed feature 3 (C16:1ω7c and/or C16:1ω6c) and summed feature 9 (iso-C17:1ω9c and/or C16:010-methyl). Phylogenetic analysis based on 16S rRNA gene sequences showed that the isolate belongs to the genus Flavobacterium and shares the highest sequence similarities with Flavobacterium sharifuzzamanii A7.6T (98.5%), Flavobacterium tistrianum GB 56.1T (98.3%), Flavobacterium nitrogenifigens NXU-44T (97.8%), Flavobacterium anhuiense D3T (97.6%), Flavobacterium ginsenosidimutans THG 01T (97.6%), and Flavobacterium foetidum CJ42T (97.6%). Digital DNA-DNA hybridization and average nucleotide identity values between the strain and its closest phylogenetic neighbors showed the ranges from 19.6 to 34.1% and 73.7 to 87.9%, respectively. Therefore, based on polyphasic characteristics, strain A5.7T represents a novel species of the genus Flavobacterium for which the name Flavobacterium zhairuonensis sp. nov. is proposed. The type strain is A5.7T (= KCTC 62406T = MCCC 1K03494T).


Assuntos
Flavobacterium/classificação , Flavobacterium/isolamento & purificação , Sedimentos Geológicos/microbiologia , Filogenia , Água do Mar/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/análise , Flavobacterium/genética , Flavobacterium/fisiologia , Genoma Bacteriano/genética , Concentração de Íons de Hidrogênio , Hibridização de Ácido Nucleico , Fosfatidiletanolaminas/análise , Quinonas/análise , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Cloreto de Sódio , Temperatura Ambiente , Vitamina K 2/análogos & derivados , Vitamina K 2/análise
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