13 results on '"Slobodkina, Galina B."'
Search Results
2. Diversity, Methane Oxidation Activity, and Metabolic Potential of Microbial Communities in Terrestrial Mud Volcanos of the Taman Peninsula.
- Author
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Slobodkin, Alexander I., Rusanov, Igor I., Slobodkina, Galina B., Stroeva, Aleksandra R., Chernyh, Nikolay A., Pimenov, Nikolai V., and Merkel, Alexander Y.
- Subjects
MUD volcanoes ,MICROBIAL communities ,METHANOTROPHS ,RADIOACTIVE tracers ,METHANE - Abstract
Microbial communities of terrestrial mud volcanoes are involved in aerobic and anaerobic methane oxidation, but the biological mechanisms of these processes are still understudied. We have investigated the taxonomic composition, rates of methane oxidation, and metabolic potential of microbial communities in five mud volcanoes of the Taman Peninsula, Russia. Methane oxidation rates measured by the radiotracer technique varied from 2.0 to 460 nmol CH
4 cm−3 day−1 in different mud samples. This is the first measurement of high activity of microbial methane oxidation in terrestrial mud volcanos. 16S rRNA gene amplicon sequencing has shown that Bacteria accounted for 65–99% of prokaryotic diversity in all samples. The most abundant phyla were Pseudomonadota, Desulfobacterota, and Halobacterota. A total of 32 prokaryotic genera, which include methanotrophs, sulfur or iron reducers, and facultative anaerobes with broad metabolic capabilities, were detected in relative abundance >5%. The most highly represented genus of aerobic methanotrophs was Methyloprofundus reaching 36%. The most numerous group of anaerobic methanotrophs was ANME-2a-b (Ca. Methanocomedenaceae), identified in 60% of the samples and attaining relative abundance of 54%. The analysis of the metagenome-assembled genomes of a community with high methane oxidation rate indicates the importance of CO2 fixation, Fe(III) and nitrate reduction, and sulfide oxidation. This study expands current knowledge on the occurrence, distribution, and activity of microorganisms associated with methane cycle in terrestrial mud volcanoes. [ABSTRACT FROM AUTHOR]- Published
- 2024
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3. Microbial diversity and autotrophic activity in Kamchatka hot springs
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Merkel, Alexander Yu., Pimenov, Nikolay V., Rusanov, Igor I., Slobodkin, Alexander I., Slobodkina, Galina B., Tarnovetckii, Ivan Yu., Frolov, Evgeny N., Dubin, Arseny V., Perevalova, Anna A., and Bonch-Osmolovskaya, Elizaveta A.
- Published
- 2017
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4. Composition and Metabolic Potential of Fe(III)-Reducing Enrichment Cultures of Methanotrophic ANME-2a Archaea and Associated Bacteria.
- Author
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Slobodkin, Alexander I., Ratnikova, Nataliya M., Slobodkina, Galina B., Klyukina, Alexandra A., Chernyh, Nikolay A., and Merkel, Alexander Y.
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MUD volcanoes ,ARCHAEBACTERIA ,ELECTRON donors ,CHARGE exchange ,METALLIC oxides ,ELECTROPHILES - Abstract
The key microbial group involved in anaerobic methane oxidation is anaerobic methanotrophic archaea (ANME). From a terrestrial mud volcano, we enriched a microbial community containing ANME-2a, using methane as an electron donor, Fe(III) oxide (ferrihydrite) as an electron acceptor, and anthraquinone-2,6-disulfonate as an electron shuttle. Ferrihydrite reduction led to the formation of a black, highly magnetic precipitate. A significant relative abundance of ANME-2a in batch cultures was observed over five subsequent transfers. Phylogenetic analysis revealed that, in addition to ANME-2a, two bacterial taxa belonging to uncultured Desulfobulbaceae and Anaerolineaceae were constantly present in all enrichments. Metagenome-assembled genomes (MAGs) of ANME-2a contained a complete set of genes for methanogenesis and numerous genes of multiheme c-type cytochromes (MHC), indicating the capability of methanotrophs to transfer electrons to metal oxides or to a bacterial partner. One of the ANME MAGs encoded respiratory arsenate reductase (Arr), suggesting the potential for a direct coupling of methane oxidation with As(V) reduction in the single microorganism. The same MAG also encoded uptake [NiFe] hydrogenase, which is uncommon for ANME-2. The MAG of uncultured Desulfobulbaceae contained genes of dissimilatory sulfate reduction, a Wood–Ljungdahl pathway for autotrophic CO
2 fixation, hydrogenases, and 43 MHC. We hypothesize that uncultured Desulfobulbaceae is a bacterial partner of ANME-2a, which mediates extracellular electron transfer to Fe(III) oxide. [ABSTRACT FROM AUTHOR]- Published
- 2023
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5. Biodiversity of thermophilic prokaryotes with hydrolytic activities in hot springs of Uzon Caldera, Kamchatka (Russia)
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Kublanov, Ilya V., Perevalova, Anna A., Slobodkina, Galina B., Lebedinsky, Aleksander V., Bidzhieva, Salima K., Kolganova, Tatyana V., Kaliberda, Elena N., Rumsh, Lev D., Haertle, Thomas, and Bonch-Osmolovskaya, Elizaveta A.
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Biological diversity -- Analysis ,Cladistic analysis -- Usage ,Hydrolysis -- Analysis ,Bacteria, Thermophilic -- Environmental aspects ,Bacteria, Thermophilic -- Physiological aspects ,Biological sciences - Abstract
The in situ enrichment cultures obtained in the presence of different polymeric substrates from hot springs of Uzon Cladera, Kamchatka (Russia), have shown the diversity of thermophilic prokaryotes with hydrolytic activity inhabiting these springs. The evidence has disclosed a competition for substrates between different phylogenetic groups of prokaryotes and has shown a possible ecological function for the widespread but uncultured organisms.
- Published
- 2009
6. PCR-based identification of hyperthermophilic archaea of the family Thermococcaceae
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Slobodkina, Galina B., Chernyh, Nikolai A., Slobodkin, Alexander I., Subbotina, Irina V., Bonch-Osmolovskaya, Elizaveta A, and Lebedinsky, Alexander V.
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Ribosomal RNA -- Research ,Microbiological research ,Biological sciences - Abstract
A method for rapid detection and identification of hyperhtermophilic archaea of the family Thermococcaceae based on PCR amplification of 16 rRNA gene fragments with two primers was developed and used for identification of new isolates.
- Published
- 2004
7. Respiratory Ammonification of Nitrate Coupled to Anaerobic Oxidation of Elemental Sulfur in Deep-Sea Autotrophic Thermophilic Bacteria.
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Slobodkina, Galina B., Mardanov, Andrey V., Ravin, Nikolai V., Frolova, Anastasia A., Chernyh, Nikolay A., Bonch-Osmolovskaya, Elizaveta A., Slobodkin, Alexander I., Hubert, Casey R. J., and Ferdelman, Timothy
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DENITRIFICATION ,SULFUR cycle ,DEEP-sea animals - Abstract
Respiratory ammonification of nitrate is the microbial process that determines the retention of nitrogen in an ecosystem. To date, sulfur-dependent dissimilatory nitrate reduction to ammonium has been demonstrated only with sulfide as an electron donor. We detected a novel pathway that couples the sulfur and nitrogen cycles. Thermophilic anaerobic bacteria Thermosulfurimonas dismutans and Dissulfuribacter thermophilus, isolated from deep-sea hydrothermal vents, grew autotrophically with elemental sulfur as an electron donor and nitrate as an electron acceptor producing sulfate and ammonium. The genomes of both bacteria contain a gene cluster that encodes a putative nitrate ammonification enzyme system. Nitrate reduction occurs via a Nap-type complex. The reduction of produced nitrite to ammonium does not proceed via the canonical Nrf system because nitrite reductase NrfA is absent in the genomes of both microorganisms. The genome of D. thermophilus encodes a complete sulfate reduction pathway, while the Sox sulfur oxidation system is missing, as shown previously for T. dismutans. Thus, in high-temperature environments, nitrate ammonification with elemental sulfur may represent an unrecognized route of primary biomass production. Moreover, the anaerobic oxidation of sulfur compounds coupled to growth has not previously been demonstrated for the members of Thermodesulfobacteria or Deltaproteobacteria, which were considered exclusively as participants of the reductive branch of the sulfur cycle. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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8. Complete Genome Sequence of Strain 1860, a Crenarchaeon of the Genus Pyrobaculum Able To Grow with Various Electron Acceptors.
- Author
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Mardanov, Andrey V., Gumerov, Vadim M., Slobodkina, Galina B., Beletsky, Alexey V., Bonch-Osmolovskaya, Elizaveta A., Ravin, Nikolai V., and Skryabin, Konstantin G.
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GLUCOSE metabolism , *ANAEROBIC bacteria , *CARBOXYLIC acids , *OXIDOREDUCTASES , *ELECTRON research - Abstract
Strain 1860, a novel member of the genus Pyrobaculum, is a hyperthermophilic organotrophic crenarchaeon growing anaerobically with various electron acceptors. The complete genome sequence reveals genes for several membrane-bound oxidoreductases, the Embden-Meyerhof and Entner-Doudoroff pathways for glucose metabolism, the tricarboxylic acid cycle, the glyoxylate cycle, and the dicarboxylate/4-hydroxybutyrate cycle. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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9. Thermosulfuriphilus ammonigenes gen. nov., sp. nov., a thermophilic, chemolithoautotrophic bacterium capable of respiratory ammonification of nitrate with elemental sulfur.
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Slobodkina GB, Reysenbach AL, Kolganova TV, Novikov AA, Bonch-Osmolovskaya EA, and Slobodkin AI
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- Bacteria, Anaerobic genetics, Bacteria, Anaerobic isolation & purification, Bacterial Typing Techniques, Base Composition, DNA, Bacterial genetics, Pacific Ocean, RNA, Ribosomal, 16S genetics, Seawater microbiology, Sequence Analysis, DNA, Bacteria, Anaerobic classification, Hydrothermal Vents microbiology, Nitrates metabolism, Phylogeny, Sulfur metabolism
- Abstract
An extremely thermophilic, anaerobic, chemolithoautotrophic bacterium (strain ST65T) was isolated from a deep-sea hydrothermal vent chimney located on the Eastern Lau Spreading Centre in the south-western Pacific Ocean, at a depth of 1870 m. Cells of strain ST65T were non-motile straight or slightly curved short rods, 0.5-0.6 µm in diameter and 0.8-1.5 µm in length. The temperature range for growth was 47-75 °C, with an optimum at 65 °C. The pH range for growth was 5.5-7.5, with an optimum at pH 6.5. Growth of strain ST65T was observed at NaCl concentrations ranging from 1.5 to 4.5 % (w/v), with an optimum at 2.0-2.5 %. Strain ST65T grew anaerobically with inorganic carbon as a carbon source and with elemental sulfur as an electron donor and nitrate as an electron acceptor producing sulfate and ammonium. It was also able to grow by disproportionation of elemental sulfur, thiosulfate and sulfite. Sulfate was not utilized as an electron acceptor. Analysis of the 16S rRNA gene sequence revealed that the isolate belongs to a deep lineage in the phylum Thermodesulfobacteria. On the basis of its physiological properties and results of phylogenetic analyses, it is proposed that the isolate represents a novel species of a new genus, Thermosulfuriphilus ammonigenes gen. nov., sp. nov. ST65T (=DSM 102941T=VKM B-2855T) is the type strain of the type species.
- Published
- 2017
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10. Dissulfurirhabdus thermomarina gen. nov., sp. nov., a thermophilic, autotrophic, sulfite-reducing and disproportionating deltaproteobacterium isolated from a shallow-sea hydrothermal vent.
- Author
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Slobodkina GB, Kolganova TV, Kopitsyn DS, Viryasov MB, Bonch-Osmolovskaya EA, and Slobodkin AI
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- Autotrophic Processes, Bacterial Typing Techniques, Base Composition, DNA, Bacterial genetics, Deltaproteobacteria genetics, Deltaproteobacteria isolation & purification, Fatty Acids chemistry, RNA, Ribosomal, 16S genetics, Russia, Sequence Analysis, DNA, Sulfites metabolism, Sulfur metabolism, Deltaproteobacteria classification, Hydrothermal Vents microbiology, Phylogeny, Seawater microbiology
- Abstract
A thermophilic, anaerobic, chemolithoautotrophic bacterium, strain SH388
T , was isolated from a shallow, submarine hydrothermal vent (Kuril Islands, Russia). Cells of strain SH388T were Gram-stain-negative short rods, 0.2-0.4 µm in diameter and 1.0-2.5 µm in length, and motile with flagella. The temperature range for growth was 25-58 °C (optimum 50 °C), and the pH range for growth was pH 5.0-7.0 (optimum pH 6.0-6.5). Growth of strain SH388T was observed in the presence of NaCl concentrations ranging from 0.5 to 4.0 % (w/v) (optimum 2.0-2.5 %). The strain grew chemolithoautotrophically with molecular hydrogen as electron donor, sodium sulfite as electron acceptor and bicarbonate/CO2 as a carbon source. It was also able to grow by disproportionation of sulfite and elemental sulfur but not thiosulfate. Sulfate, Fe(III) and nitrate were not used as electron acceptors either with H2 or organic electron donors. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolate belonged to the class Deltaproteobacteria and was most closely related to Dissulfuribacter thermophilus and Dissulfurimicrobium hydrothermale (91.6 % and 90.4 % sequence similarity). On the basis of its physiological properties and results of phylogenetic analyses, strain SH388T is considered to represent a novel species of a new genus, for which the name Dissulfurirhabdus thermomarina gen. nov., sp. nov. is proposed. The type strain of the species is SH388T (=DSM 100025T =VKM B-2960T ). It is the first thermophilic disproportionator of sulfur compounds isolated from a shallow-sea environment.- Published
- 2016
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11. Thermostilla marina gen. nov., sp. nov., a thermophilic, facultatively anaerobic planctomycete isolated from a shallow submarine hydrothermal vent.
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Slobodkina GB, Panteleeva AN, Beskorovaynaya DA, Bonch-Osmolovskaya EA, and Slobodkin AI
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- Bacterial Typing Techniques, Base Composition, DNA, Bacterial genetics, Fatty Acids chemistry, Italy, Nitrification, Planctomycetales genetics, Planctomycetales isolation & purification, RNA, Ribosomal, 16S genetics, Seawater microbiology, Sequence Analysis, DNA, Sulfur, Hydrothermal Vents microbiology, Phylogeny, Planctomycetales classification
- Abstract
A novel thermophilic planctomycete (strain SVX8T) was isolated from a shallow submarine hydrothermal vent, Vulcano Island, Italy. The temperature range for growth was 30-68 °C, with an optimum at 55 °C. The pH range for growth was 5.0-9.0, with an optimum at pH 7.0-8.0. Growth was observed at NaCl concentrations ranging from 0.8 to 4.5 % (w/v) with an optimum at 2.5-3.5 % (w/v). The isolate grew anaerobically using a number of mono-, di- and polysaccharides as electron donors and nitrate or elemental sulfur as electron acceptors or by fermentation. Nitrate was reduced to nitrite; sulfur was reduced to sulfide. Strain SVX8T did not grow at atmospheric concentration of oxygen but grew microaerobically (up to 2 % oxygen in the gas phase). The G+C content of the DNA of strain SVX8T was 58.5 mol%. Based on phylogenetic position and phenotypic features, the new isolate is considered to represent a novel species belonging to a new genus in the order Planctomycetales, for which the name Thermostilla marina gen. nov., sp. nov. is proposed. The type strain of Thermostilla marina is SVX8T ( = JCM 19992T = VKM B-2881T). Strain SVX8T is the first thermophilic planctomycete isolated from a marine environment.
- Published
- 2016
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12. Inmirania thermothiophila gen. nov., sp. nov., a thermophilic, facultatively autotrophic, sulfur-oxidizing gammaproteobacterium isolated from a shallow-sea hydrothermal vent.
- Author
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Slobodkina GB, Baslerov RV, Novikov AA, Viryasov MB, Bonch-Osmolovskaya EA, and Slobodkin AI
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- Autotrophic Processes, Bacterial Typing Techniques, Base Composition, DNA, Bacterial genetics, Fatty Acids chemistry, Gammaproteobacteria genetics, Gammaproteobacteria isolation & purification, Oxidation-Reduction, RNA, Ribosomal, 16S genetics, Russia, Sequence Analysis, DNA, Sulfur Compounds metabolism, Sulfur-Reducing Bacteria classification, Sulfur-Reducing Bacteria genetics, Sulfur-Reducing Bacteria isolation & purification, Gammaproteobacteria classification, Hydrothermal Vents microbiology, Phylogeny
- Abstract
A novel thermophilic, facultatively autotrophic bacterium, strain S2479T, was isolated from a thermal spring located in a tidal zone of a geothermally heated beach (Kuril Islands, Russia). Cells of strain S2479T were rod-shaped and motile with a Gram-negative cell-wall type. The temperature range for growth was 35-68 °C (optimum 65 °C), and the pH range for growth was pH 5.5-8.8 (optimum pH 6.5). Growth of strain S2479T was observed in the presence of NaCl concentrations ranging from 0.5 to 3.5 % (w/v) (optimum 1.5-2.0 %). The strain oxidized sulfur and thiosulfate as sole energy sources for autotrophic growth under anaerobic conditions with nitrate as electron acceptor. Strain S2479T was also capable of heterotrophic growth by reduction of nitrate with oxidation of low-chain fatty acids and a limited number of other carboxylic acids or with complex proteinaceous compounds. Nitrate was reduced to N2. Sulfur compounds were oxidized to sulfate. Strain S2479T did not grow aerobically during incubation at atmospheric concentration of oxygen but was able to grow microaerobically (1 % of oxygen in gas phase). Phylogenetic analysis based on 16S rRNA gene sequences indicated that the strain was a member of the family Ectothiorhodospiraceae, order Chromatiales, class Gammaproteobacteria. On the basis of phylogenetic and phenotypic properties, strain S2479T represents a novel species of a new genus, for which the name Inmirania thermothiophila gen. nov., sp. nov. is proposed. The type strain of the type species is S2479T ( = DSM 100275T = VKM B-2962T).
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- 2016
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13. Thermogutta terrifontis gen. nov., sp. nov. and Thermogutta hypogea sp. nov., thermophilic anaerobic representatives of the phylum Planctomycetes.
- Author
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Slobodkina GB, Kovaleva OL, Miroshnichenko ML, Slobodkin AI, Kolganova TV, Novikov AA, van Heerden E, and Bonch-Osmolovskaya EA
- Subjects
- Bacteria genetics, Bacteria isolation & purification, Bacterial Typing Techniques, DNA, Bacterial genetics, Fatty Acids chemistry, Mining, Molecular Sequence Data, RNA, Ribosomal, 16S genetics, Russia, Sequence Analysis, DNA, South Africa, Water Microbiology, Bacteria classification, Hot Springs microbiology, Phylogeny
- Abstract
Two novel strains of thermophilic planctomycetes were recovered from terrestrial and subterranean habitats. Strain R1(T) was isolated from a hot spring (Kunashir Island, Russia) and strain SBP2(T) was isolated from a deep gold mine (South Africa). Both isolates grew in the temperature range 30-60 °C and pH range 5.0-8.0. Strain R1(T) grew optimally at 60 °C and pH 6.0-6.5; for SBP2(T) optimal conditions were at 52 °C and pH 7.5-8.0. Both strains were capable of anaerobic respiration with nitrate and nitrite as electron acceptors as well as of microaerobic growth. They also could grow by fermentation of mono-, di- and polysaccharides. Based on their phylogenetic position and phenotypic features we suggest that the new isolates represent two novel species belonging to a new genus in the order Planctomycetales, for which the names Thermogutta terrifontis gen. nov., sp. nov. and Thermogutta hypogea sp. nov. are proposed. The type strain of Thermogutta terrifontis, the type species of the genus, is R1(T) ( = DSM 26237(T) = VKM B-2805(T)), and the type strain of Thermogutta hypogea is SBP2(T) ( = JCM 19991(T) = VKM B-2782(T))., (© 2015 IUMS.)
- Published
- 2015
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- View/download PDF
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