DESULFONATRONUM LACUSTRE GEN. NOV., SP. NOV - A NEW ALKALIPHILIC SULFATE-REDUCING BACTERIUM UTILIZING ETHANOL

A new obligately alkaliphilic sulfate-reducing bacterium, strain Z-795 1, growing in a pH range of 8-10 with an optimum at pH 9.5, was isolat ed from the alkaline Lake Khadyn (Tuva, Central Asia). The bacterium i s obligately dependent on sodium and carbonate ions and does not requi re NaCl. It is mesophilic, with a growth optimum at 37-40 degrees C. C ells are vibrios motile by means of a single polar flagellum. The elec tron donors for the bacterium are Hz, formate, and ethanol. Growth is possible only in the presence of an electron acceptor: sulfate, sulfit e, or thiosulfate. The bacterium can bring about dismutation of sulfit e 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 lineag e of a generic level within the delta subclass of Proteobacteria. The suggested name is Desulfonatronum lacustre gen. nov., sp. nov., with t he type strain Z-7951(T) (= DSM 10312).