title: Thermosulfurimonas dismutans gen. nov., sp. nov., an extremely thermophilic sulfur-disproportionating bacterium from a deep-sea hydrothermal vent.
abstract: An extremely thermophilic, anaerobic, chemolithoautotrophic bacterium (strain S95(T)) was isolated from a deep-sea hydrothermal vent chimney located on the Eastern Lau Spreading Center, Pacific Ocean, at a depth of 1910 m. Cells of strain S95(T) were oval to short Gram-negative rods, 0.5-0.6 µm in diameter and 1.0-1.5 µm in length, growing singly or in pairs. Cells were motile with a single polar flagellum. The temperature range for growth was 50-92 °C, with an optimum at 74 °C. The pH range for growth was 5.5-8.0, with an optimum at pH 7.0. Growth of strain S95(T) was observed at NaCl concentrations ranging from 1.5 to 3.5% (w/v). Strain S95(T) grew anaerobically with elemental sulfur as an energy source and bicarbonate/CO(2) as a carbon source. Elemental sulfur was disproportionated to sulfide and sulfate. Growth was enhanced in the presence of poorly crystalline iron(III) oxide (ferrihydrite) as a sulfide-scavenging agent. Strain S95(T) was also able to grow by disproportionation of thiosulfate and sulfite. Sulfate was not used as an electron acceptor. Analysis of the 16S rRNA gene sequence revealed that the isolate belongs to the phylum Thermodesulfobacteria. On the basis of its physiological properties and results of phylogenetic analyses, it is proposed that the isolate represents the sole species of a new genus, Thermosulfurimonas dismutans gen. nov., sp. nov.; S95(T) (=DSM 24515(T)=VKM B-2683(T)) is the type strain of the type species. This is the first description of a thermophilic micro-organism that disproportionates elemental sulfur.
authors.affiliation: Winogradsky Institute of Microbiology, Russian Academy of Sciences, Prospect 60-letiya Oktyabrya 7/2, 117312 Moscow, Russia.
authors.forename: A I
authors.initials: AI
authors.lastname: Slobodkin
authors.affiliation: Department of Biology and Center for Life in Extreme Environments, Portland State University, PO Box 751, Portland, OR 97207-0751, USA.
authors.forename: A-L
authors.initials: AL
authors.lastname: Reysenbach
authors.affiliation: Winogradsky Institute of Microbiology, Russian Academy of Sciences, Prospect 60-letiya Oktyabrya 7/2, 117312 Moscow, Russia.
authors.forename: G B
authors.initials: GB
authors.lastname: Slobodkina
authors.affiliation: Bioengineering Center, Russian Academy of Sciences, Prospect 60-letiya Oktyabrya 7/1, 117312 Moscow, Russia.
authors.forename: R V
authors.initials: RV
authors.lastname: Baslerov
authors.affiliation: Winogradsky Institute of Microbiology, Russian Academy of Sciences, Prospect 60-letiya Oktyabrya 7/2, 117312 Moscow, Russia.
authors.forename: N A
authors.initials: NA
authors.lastname: Kostrikina
authors.affiliation: Department of Biology and Center for Life in Extreme Environments, Portland State University, PO Box 751, Portland, OR 97207-0751, USA.
authors.forename: I D
authors.initials: ID
authors.lastname: Wagner
authors.affiliation: Winogradsky Institute of Microbiology, Russian Academy of Sciences, Prospect 60-letiya Oktyabrya 7/2, 117312 Moscow, Russia.
authors.forename: E A
authors.initials: EA
authors.lastname: Bonch-Osmolovskaya
mesh_terms: D015373:Bacterial Typing Techniques; D001482:Base Composition; D004269:DNA, Bacterial / Q000235:genetics; D006091:Gram-Negative Chemolithotrophic Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D060086:Hydrothermal Vents / Q000382:microbiology*; D008969:Molecular Sequence Data; D010140:Pacific Ocean; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012623:Seawater / Q000382:microbiology; D017422:Sequence Analysis, DNA; D013455:Sulfur / Q000378:metabolism; D016999:Sulfur-Reducing Bacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D013455:Sulfur