Caminibacter mediatlanticus sp. nov., a thermophilic, hemolithoautotrophic, nitrate-ammonifying bacterium isolated from a deep-sea hydrothermal vent on the Mid-Atlantic Ridge

Abstract

) and pH 4?5 and 7?5 (optimum pH 5?5). Generation time under optimal conditions was 50 min. Growth occurred under chemolithoautotrophic conditions with H 2 as the energy source and CO 2 as the carbon source. Nitrate or sulfur was used as the electron acceptor, with resulting production of ammonium and hydrogen sulfide, respectively. Oxygen, thiosulfate, sulfite, selenate and arsenate were not used as electron acceptors. Growth was inhibited by the presence of acetate, lactate, formate and peptone. The G+C content of the genomic DNA was 25?6 mol%. Phylogenetic analysis of the 16S rRNA gene sequence indicated that this organism is closely related to Caminibacter hydrogeniphilus and Caminibacter profundus (95?9 and 96?3 % similarity, respectively). On the basis of phylogenetic, physiological and genetic considerations, it is proposed that the organism represents a novel species within the genus Caminibacter, Caminibacter mediatlanticus sp. nov. The type strain is TB-2