Hydrogenimonas urashimensis sp. nov., a hydrogen-oxidizing chemolithoautotroph isolated from a deep-sea hydrothermal vent in the Southern Mariana Trough

A novel thermophilic bacterium, strain SSM-sur55T, was isolated from a chimney structure at the Urashima site on Southern Mariana Trough in Pacific Ocean. Growth observed temperatures between 25 and 60 °C (optimum, 55 °C; 180 min doubling time), pH values 5.3 7.2 5.9) presence of 1.6 5.6% (w/v) NaCl 3.2%). The isolate used molecular hydrogen as its sole energy source, carbon dioxide ammonium nitrogen elemental sulfur source. Thiosulfate, oxygen (0.1%, v/v) or utilized electron acceptor. Phylogenetic analysis based 16S rRNA gene sequences indicated that SSM-sur55T belonged to genus Hydrogenimonas class “Campylobacteria”, closest relative thermophila EP1-55-1%T (94.9%). On basis phylogenetic, physiological characteristics, represents species within Hydrogenimonas, for which name urashimensis sp. nov. is proposed, with type (JCM 19825 = KCTC 15926).