Desulfonatronum lacustre gen. nov., sp. nov.: A new alkaliphilic sulfate-reducing bacterium utilizing ethanol

A new obligately alkaliphilic sulfate-reducing bacterium, strain Z-7951, growing in a pH range of 8-10 with an optimum at pH 9.5, was isolated from the alkaline Lake Khadyn (Tuva, Central Asia). The bacterium is obligately dependent on sodium and carbonate ions and does not require NaCl. It is mesophilic, with a growth optimum at 37-40 degrees C. Cells are vibrios motile by means of a single polar flagellum. The electron donors for the bacterium are Hz, formate, and ethanol. Growth is possible only in the presence of an electron acceptor: sulfate, sulfite, or thiosulfate. The bacterium can bring about dismutation of sulfite and thiosulfate. The G+C content of DNA is 57.3 mol %. The analysis of 16S rDNA sequence showed that strain Z-7951 represents a new lineage of a generic level within the delta subclass of Proteobacteria. The suggested name is Desulfonatronum lacustre gen. nov., sp. nov., with the type strain Z-7951(T) (= DSM 10312).