RT Journal Article SR Electronic(1) A1 Vetriani, Costantino A1 Speck, Mark D. A1 Ellor, Susan V. A1 Lutz, Richard A. A1 Starovoytov, ValentinYR 2004 T1 Thermovibrio ammonificans sp. nov., a thermophilic, chemolithotrophic, nitrate-ammonifying bacterium from deep-sea hydrothermal vents JF International Journal of Systematic and Evolutionary Microbiology, VO 54 IS 1 SP 175 OP 181 DO https://doi.org/10.1099/ijs.0.02781-0 PB Microbiology Society, SN 1466-5034, AB A thermophilic, anaerobic, chemolithoautotrophic bacterium was isolated from the walls of an active deep-sea hydrothermal vent chimney on the East Pacific Rise at 9° 50′ N. Cells of the organism were Gram-negative, motile rods that were about 1·0 μm in length and 0·6 μm in width. Growth occurred between 60 and 80 °C (optimum at 75 °C), 0·5 and 4·5 % (w/v) NaCl (optimum at 2 %) and pH 5 and 7 (optimum at 5·5). Generation time under optimal conditions was 1·57 h. Growth occurred under chemolithoautotrophic conditions in the presence of H2 and CO2, with nitrate or sulfur as the electron acceptor and with concomitant formation of ammonium or hydrogen sulfide, respectively. Thiosulfate, sulfite and oxygen were not used as electron acceptors. Acetate, formate, lactate and yeast extract inhibited growth. No chemoorganoheterotrophic growth was observed on peptone, tryptone or Casamino acids. The genomic DNA G+C content was 54·6 mol%. Phylogenetic analyses of the 16S rRNA gene sequence indicated that the organism was a member of the domain Bacteria and formed a deep branch within the phylum Aquificae, with Thermovibrio ruber as its closest relative (94·4 % sequence similarity). On the basis of phylogenetic, physiological and genetic considerations, it is proposed that the organism represents a novel species within the newly described genus Thermovibrio. The type strain is Thermovibrio ammonificans HB-1T (=DSM 15698T=JCM 12110T)., UL https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/ijs.0.02781-0