title: Thiofractor thiocaminus gen. nov., sp. nov., a novel hydrogen-oxidizing, sulfur-reducing epsilonproteobacterium isolated from a deep-sea hydrothermal vent chimney in the Nikko Seamount field of the northern Mariana Arc.
abstract: A novel chemolithoautotrophic hydrogen-oxidizing and sulfur-reducing bacterium, strain 496Chim(T), was isolated from a deep-sea hydrothermal vent chimney collected from the hydrothermal field at the summit of Nikko Seamount field, in the Mariana Arc. Cells were rods or curved rods, motile by means of a single polar flagellum. Growth was observed between 15 and 45 °C (optimum 37 °C; doubling time, 2.1 h) and between pH 5.3 and 8.0 (optimum pH 6.0). The isolate was a strictly anaerobic, obligate chemolithoautotroph capable of growth using molecular hydrogen as the sole energy source, carbon dioxide as the sole carbon source, ammonium or nitrate as the sole nitrogen source, and elemental sulfur as the electron acceptor. The G+C content of genomic DNA was 35 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the new isolate belonged to the class Epsilonproteobacteria, but the isolate was distantly related to the previously described Epsilonproteobacteria species potentially at the genus level (<90 %). On the basis of its physiological and molecular characteristics, strain 496Chim(T) (=DSM 22050(Τ) = JCM 15747(Τ) = NBRC 105224(Τ)) represents the sole species of a new genus, Thiofractor, for which the name Thiofractor thiocaminus is proposed.
authors.affiliation: Subsurface Geobiology and Advanced Research Project, Extremobiosphere Research Program, Institute of Biogeosciences, Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima-cho, Yokosuka 237-0061, Japan. makita@jamstec.go.jp
authors.forename: Hiroko
authors.initials: H
authors.lastname: Makita
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nakagawa
authors.forename: Masayuki
authors.initials: M
authors.lastname: Miyazaki
authors.forename: Ko-ichi
authors.initials: K
authors.lastname: Nakamura
authors.forename: Fumio
authors.initials: F
authors.lastname: Inagaki
authors.forename: Ken
authors.initials: K
authors.lastname: Takai
mesh_terms: D001482:Base Composition; D020565:Epsilonproteobacteria / Q000145:classification* / Q000302:isolation & purification / Q000502:physiology* / Q000648:ultrastructure; D006863:Hydrogen-Ion Concentration; D060086:Hydrothermal Vents / Q000382:microbiology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D011809:Quinones / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012623:Seawater / Q000382:microbiology; D013045:Species Specificity; D016999:Sulfur-Reducing Bacteria / Q000145:classification / Q000302:isolation & purification / Q000502:physiology; D013696:Temperature
chemical_list: D011809:Quinones; D012336:RNA, Ribosomal, 16S