title: Hydrogenivirga caldilitoris gen. nov., sp. nov., a novel extremely thermophilic, hydrogen- and sulfur-oxidizing bacterium from a coastal hydrothermal field.
abstract: A novel extremely thermophilic, hydrogen- and sulfur-oxidizing bacterium, designated strain IBSK3(T), was isolated from a coastal hot spring in Ibusuki, Kagoshima Prefecture, Japan. The cells were motile, straight to slightly curved rods (1.2-3.0 microm long and 0.3-0.4 microm wide). Strain IBSK3(T) was an obligate chemolithoautotroph growing by respiratory nitrate reduction with H(2), forming N(2)O as an end product. Low concentrations of O(2) (0.4-7.7 %, v/v; optimum 2.0 %, v/v) could serve as an alternative electron acceptor to growth. In addition, strain IBSK3(T) was able to utilize elemental sulfur as a sole electron donor with either nitrate or low concentrations of O(2) as an electron acceptor. Growth was observed between 55 and 77.5 degrees C (optimum 75 degrees C; 2 h doubling time), pH 5.5 and 8.3 (optimum pH 6.5-7.0), and in the presence of 0.5 and 4.0 % NaCl (optimum 2.0 %). The G+C content of the genomic DNA was 49.2 mol%. On the basis of 16S rRNA gene sequence analysis, strain IBSK3(T) belonged to the family Aquificaceae, but it only demonstrated a distant phylogenetic relationship with any recognized species within the family (sequence similarity was less than 92 %). On the basis of the physiological and molecular characteristics of the novel isolate, a new genus and novel species are proposed: the type strain of Hydrogenivirga caldilitoris gen. nov., sp. nov. is IBSK3(T) (=JCM 12173(T)=ATCC BAA-821(T)).
authors.affiliation: Laboratory of Marine Microbiology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nakagawa
authors.affiliation: Laboratory of Marine Microbiology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
authors.forename: Sachiko
authors.initials: S
authors.lastname: Nakamura
authors.affiliation: Subground Animalcule Retrieval (SUGAR) Project, Frontier Research System for Extremophiles, Japan Agency of Marine-Earth Science and Technology 2-15 Natsushima-cho, Yokosuka 237-0061, Japan.
authors.forename: Fumio
authors.initials: F
authors.lastname: Inagaki
authors.affiliation: Subground Animalcule Retrieval (SUGAR) Project, Frontier Research System for Extremophiles, Japan Agency of Marine-Earth Science and Technology 2-15 Natsushima-cho, Yokosuka 237-0061, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Takai
authors.affiliation: Industrial Research Center of Shiga Prefecture, Kamitoyama 232, Ritto 520-3004, Japan.
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Shirai
authors.affiliation: Laboratory of Marine Microbiology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Sako
mesh_terms: D001482:Base Composition; D004269:DNA, Bacterial / Q000737:chemistry / Q000302:isolation & purification; D004275:DNA, Ribosomal / Q000737:chemistry / Q000302:isolation & purification; D020459:Genes, rRNA; D006090:Gram-Negative Bacteria / Q000145:classification* / Q000166:cytology / Q000302:isolation & purification* / Q000378:metabolism; D045482:Hot Springs / Q000382:microbiology*; D006358:Hot Temperature; D006859:Hydrogen / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007287:Inorganic Chemicals / Q000378:metabolism; D007564:Japan; D008969:Molecular Sequence Data; D009068:Movement; D009566:Nitrates / Q000378:metabolism; D009609:Nitrous Oxide / Q000378:metabolism; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism; D010802:Phylogeny; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012462:Saline Solution, Hypertonic; D017422:Sequence Analysis, DNA; D013455:Sulfur / Q000378:metabolism*
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D007287:Inorganic Chemicals; D009566:Nitrates; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D012462:Saline Solution, Hypertonic; D013455:Sulfur; D006859:Hydrogen; D009609:Nitrous Oxide; D010100:Oxygen