Desulfoferula mesophilus gen. nov. sp. nov., a mesophilic sulfate-reducing bacterium isolated from a brackish lake sediment.

A novel sulfate-reducing bacterium (strain 12FAK) was isolated from sediment sampled from a brackish lake in Japan. Respiratory growth was observed with formate and pyruvate as an electron donor. Sulfate, thiosulfate, elemental sulfur and dimethyl sulfoxide were utilized as an electron acceptor. The isolate grew over a temperature range of 18-42 °C (optimum 35-37 °C), a NaCl concentration range of 50-450 mM (optimum 150-300 mM) and a pH range of 6.6-7.5. The 12FAK genome consists of a circular chromosome with a length of 4.5 Mbp and G + C content of 63.6%. Based on 16S rRNA gene sequence similarity, the closest cultured relative was Desulfarculus baarsii 2st14 (92.2%). Genome-based phylogenetic analysis placed strain 12FAK within the family Desulfarculaceae but did not affiliate the strain with any existing genus. Taken together, we propose a novel species of a novel genus, Desulfoferula mesophilus gen. nov. sp. nov. with the type strain 12FAK (= DSM 115219 = JCM 39399).