Pseudodesulfovibrio sediminis sp. nov., a mesophilic and neutrophilic sulfate-reducing bacterium isolated from sediment of a brackish lake

Abstract

A novel mesophilic and neutrophilic sulfate-reducing bacterium, strain SF6T, was isolated from sediment of a brackish lake in Japan. Cells of strain SF6T were motile and rod-shaped with length of 1.2-2.5μm and width of 0.6-0.9μm. Growth was observed at 10-37°C with an optimum growth temperature of 28°C. The pH range for growth was 5.8-8.2 with an optimum pH of 7.0. The most predominant fatty acid was anteiso-C15:0. Under sulfate-reducing conditions, strain SF6T utilized lactate, ethanol and glucose as growth substrate. Chemolithoautotrophic growth on H2 was not observed, although H2 was used as electron donor. Fermentative growth occurred on pyruvate. As electron acceptor, sulfate, sulfite, thiosulfate and nitrate supported heterotrophic growth of the strain. The complete genome of strain SF6T is composed of a circular chromosome with length of 3.8Mbp and G+C content of 54mol%. Analyses of the 16S rRNA gene and whole genome sequence indicated that strain SF6T belongs to the genus Pseudodesulfovibrio but distinct form all existing species in the genus. On the basis of its genomic and phenotypic properties, strain SF6T (= DSM111931T = NBRC 114895T) is proposed as the type strain of a new species, with name of Pseudodesulfovibrio sediminis sp. nov.