Desulfopila aestuarii gen. nov., sp nov., a Gram-negative, rod-like, sulfate-reducing bacterium isolated from an estuarine sediment in Japan

A strictly anaerobic, mesophilic, sulfate-reducing bacterial strain (MSL86 T) isolated from an estuarine sediment in the Sea of Japan (around the Japanese islands) was characterized phenotypically and phylogenetically. The cells were found to be Gram-negative, motile, non-spore-forming rods. Catalase was not detected. The optimum NaCl concentration for growth was 1.0 % (w/v) and the optimum temperature was 35 degrees C. Strain MSL86(T) was slightly alkaliphilic, with optimum growth at pH 7.5-7.6. Organic electron donors were incompletely oxidized to (mainly) acetate. Strain MSL86 T utilized formate, pyruvate, lactate, fumarate, ethanol, propanol, butanol and glycerol as electron donors for sulfate reduction and did not use acetate, propionate, butyrate, succinate, malate, methanol, glycine, alanine, serine, aspartate, glutamate or H-2. Sulfite, thiosulfate and fumarate were used as electron acceptors with lactate as an electron donor. Without electron acceptors, the strain fermented pyruvate and fumarate. The genomic DNA G + C content was 54.4 mol%. Menaquinone MK-8(H-4) was the major respiratory quinone. The major cellular fatty acids were C-16:0, C(16:1)w7, C(16:1)w5and C(17:1)w6. A phylogenetic analysis based on the 16S rRNA gene sequence placed the strain in the class Deltaproteobacteria. The recognized bacterium most closely related to strain MSL86(T) was [Desulfobacterium] catecholicum DSM 3882(T) (sequence similarity 94.4%), and the next most closely related recognized species were Desulfotalea psychrophila (94.2% sequence similarity with the type strain) and Desulfotalea arctica (93.7%). As the physiological and chemotaxonomic characteristics of MSL86 T were distinctly different from those of any related species, a novel genus and species Desulfopila aestuarii gen. nov., sp. nov. are proposed to accommodate the strain. The type strain of Desulfopila aestuarii is MSL86(T) (=JCM 14042(T) =DSM 18488(T)).