The search for the microorganisms responsible for sulfide formation and corrosion of steel equipment in the oil fields of Tatarstan (Russia) resulted in the isolation of a new halotolerant strictly anaerobic sulfate-reducing bacterium, strain 5S69. The cells were motile curved Gram-negative rods. Optimal growth was observed in the presence of 2.
View Article and Find Full Text PDFThe reserves of light conditional oil in reservoirs with low-salinity formation water are decreasing worldwide, necessitating the extraction of heavy oil from petroleum reservoirs with high-salinity formation water. As the first stage of defining the microbial-enhanced oil recovery (MEOR) strategies for depleted petroleum reservoirs, microbial community composition was studied for petroleum reservoirs with high-salinity formation water located in Tatarstan (Russia) using metagenomic and culture-based approaches. Bacteria of the phyla , , , , and were revealed using 16S rRNA-based high-throughput sequencing in halophilic microbial communities.
View Article and Find Full Text PDFBurning coal seams, characterized by massive carbon monoxide (CO) emissions, the presence of secondary sulfates, and high temperatures, represent suitable environments for thermophilic sulfate reduction. The diversity and activity of dissimilatory sulfate reducers in these environments remain unexplored. In this study, using metagenomic approaches, activity measurements with a radioactive tracer, and cultivation we have shown that members of the genus are responsible for the extremely high sulfate reduction rate (SRR) in burning lignite seams in the Altai Mountains.
View Article and Find Full Text PDFThe strain WBS, an anaerobic, psychro- and halotolerant bacterium belonging to the genus , was isolated from the littoral bottom sediments of the White Sea, Arctic, Russia. WBS grew at temperatures between 8 and 32 °C (optimum growth at 18-20 °C), pH between 5.2 and 8.
View Article and Find Full Text PDFThe natural combustion of underground coal seams leads to the formation of gas, which contains molecular hydrogen and carbon monoxide. In places where hot coal gases are released to the surface, specific thermal ecosystems are formed. Here, 16S rRNA gene profiling and shotgun metagenome sequencing were employed to characterize the taxonomic diversity and genetic potential of prokaryotic communities of the near-surface ground layer near hot gas vents in an open quarry heated by a subsurface coal fire.
View Article and Find Full Text PDFThe diversity and activity of sulfate-reducing bacteria (SRB) in the camel gut remains largely unexplored. An abundant SRB community has been previously revealed in the feces of Bactrian camels (). This study aims to combine the 16S rRNA gene profiling, sulfate reduction rate (SRR) measurement with a radioactive tracer, and targeted cultivation to shed light on SRB activity in the camel gut.
View Article and Find Full Text PDFBottom sediments at methane discharge sites of the Laptev Sea shelf were investigated. The rates of microbial methanogenesis and methane oxidation were measured, and the communities responsible for these processes were analyzed. Methane content in the sediments varied from 0.
View Article and Find Full Text PDFThe microbial community of subsurface environments remains understudied due to limited access to deep strata and aquifers. Coal-bed methane (CBM) production is associated with a large number of wells pumping water out of coal seams. CBM wells provide access to deep biotopes associated with coal-bed water.
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View Article and Find Full Text PDFThe metagenome of foulings from sulfidic spring "Serovodorodny" (Tatarstan, Russia), where members of the genus was observed, was sequenced. Representatives of the phyla , and dominated in the microbial community. The complete genome of sp.
View Article and Find Full Text PDFIn the bottom sediments from a number of the Barents Sea sites, including coastal areas of the Novaya Zemlya, Franz Josef Land, and Svalbard archipelagos, sulphate reduction rates were measured and the phylogenetic composition of sulphate-reducing bacterial (SRB) communities was analysed for the first time. Molecular genetic analysis of the sequences of the 16S rRNA and dsrB genes (the latter encodes the β-subunit of dissimilatory (bi)sulphite reductase) revealed significant differences in the composition of bacterial communities in different sampling stations and sediment horizons of the Barents Sea depending on the physicochemical conditions. The major bacteria involved in reduction of sulphur compounds in Arctic marine bottom sediments belonged to Desulfobulbaceae, Desulfobacteraceae, Desulfovibrionaceae, Desulfuromonadaceae, and Desulfarculaceae families, as well as to uncultured clades SAR324 and Sva0485.
View Article and Find Full Text PDFMicrobial communities in wastewater treatment plants (WWTPs) play a key role in water purification. Microbial communities of activated sludge (AS) vary extensively based on plant operating technology, influent characteristics and WWTP capacity. In this study we performed 16S rRNA gene profiling of AS at nine large-scale WWTPs responsible for the treatment of municipal sewage from the city of Moscow, Russia.
View Article and Find Full Text PDFLarge areas in the northern hemisphere are covered by extensive wetlands, which represent a complex mosaic of raised bogs, eutrophic fens, and aapa mires all in proximity to each other. Aapa mires differ from other types of wetlands by their concave surface, heavily watered by the central part, as well as by the presence of large-patterned string-flark complexes. In this paper, we characterized microbial diversity patterns in the surface peat layers of the neighboring string and flark structures located within the mire site in the Vologda region of European North Russia, using 16S rRNA gene sequencing.
View Article and Find Full Text PDFThe sulphate-reducing bacteria (SRB) of genus are a group of prokaryotes associated with autism spectrum disorders (ASD). The connection between the elevated numbers of in the gut of children with ASD compared with healthy children remains unresolved. A conceivable consequence of SRB overgrowth in the gut is the conversion of bioavailable iron into low-soluble crystalline iron sulphides, causing iron deficiency in the organism.
View Article and Find Full Text PDFA combination of physicochemical and radiotracer analysis, high-throughput sequencing of the 16S rRNA, and particulate methane monooxygenase subunit A () genes was used to link a microbial community profile with methane, sulfur, and nitrogen cycling processes. The objects of study were surface sediments sampled at five stations in the northern part of the Barents Sea. The methane content in the upper layers (0-5 cm) ranged from 0.
View Article and Find Full Text PDFThermal ecosystems associated with areas of underground burning coal seams are rare and poorly understood in comparison with geothermal objects. We studied the microbial communities associated with gas vents from the coal-fire in the mining wastes in the Kemerovo region of the Russian Federation. The temperature of the ground heated by the hot coal gases and steam coming out to the surface was 58 °C.
View Article and Find Full Text PDFTo get insights into microbial diversity and biogeochemical processes in the terrestrial deep subsurface aquifer, we sequenced the metagenome of artesian water collected at a 2.8 km deep oil exploration borehole 5P in Western Siberia, Russia. We obtained 71 metagenome-assembled genomes (MAGs), altogether comprising 93% of the metagenome.
View Article and Find Full Text PDFAcidophilic archaea of the archaeal Richmond Mine acidophilic nanoorganisms (ARMAN) group from the uncultured candidate phylum " Micrarchaeota" have small genomes and cell sizes and are known to be metabolically dependent and physically associated with their hosts. However, phylogenetically diverse " Micrarchaeota" are widely distributed in various nonacidic environments, and it remains uncertain because of the lack of complete genomes whether they are also devoted to a partner-dependent lifestyle. Here, we obtained nine metagenome-assembled genomes of " Micrarchaeota" from the sediments of a meromictic freshwater lake, including a complete, closed 1.
View Article and Find Full Text PDFMud volcanoes are prominent geological structures where fluids and gases from the deep subsurface are discharged along a fracture network in tectonically active regions. Microbial communities responsible for sulfur and methane cycling and organic transformation in terrestrial mud volcanoes remain poorly characterized. Using a metagenomics approach, we analyzed the microbial community of bubbling fluids retrieved from an active mud volcano in eastern Crimea.
View Article and Find Full Text PDFMost microorganisms from deep terrestrial subsurface remain yet uncultured. Recent achievements in recovery of metagenome-assembled genomes (MAG) provide clues for improving cultivation via metabolic reconstructions and other genomic characteristics. Here we report the isolation in pure culture of a thermophilic spirochete with the use of MAGs binned from metagenomes of the deep (>2 km) aquifers broached by two artesian boreholes in Western Siberia.
View Article and Find Full Text PDFMicrobiological, molecular ecological, biogeochemical, and isotope geochemical research was carried out at the polar Lake Bol'shie Khruslomeny at the coast of the Kandalaksha Bay, White Sea in March and September 2017. The uppermost mixolimnion was oxic, with low salinity (3-5%). The lower chemocline layer was brown-green colored, with very high content of particulate organic matter (up to 11.
View Article and Find Full Text PDFLarge areas in Northern Russia are covered by extensive mires, which represent a complex mosaic of ombrotrophic raised bogs, minerotrophic and eutrophic fens, all in a close proximity to each other. In this paper, we compared microbial diversity patterns in the surface peat layers of the neighbouring raised bogs and eutrophic fens that are located within two geographically remote mire sites in Vologda region using 16S rRNA gene sequencing. Regardless of location, the microbial communities in raised bogs were highly similar to each other but were clearly distinct from those in eutrophic fens.
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