Desulfosalsimonas propionicica gen. nov., sp. nov., a halophilic, sulfate-reducing member of the family Desulfobacteraceae isolated from a salt-lake sediment

Abstract

A novel halophilic Gram-negative sulfate-reducing bacterium affiliated with the deltaproteobacterial family Desulfobacteraceae, strain PropA(T), was isolated from the extreme hypersaline sediment of the northern arm of Great Salt Lake, Utah, USA. Comparative 16S rRNA gene sequence analysis showed that strain PropA(T) is the first cultured representative of a clade of phylotypes that have been retrieved from a range of geographically and ecologically distinct hypersaline environments. Strain PropA(T) shared < or =90 % 16S rRNA gene sequence identity with cultured strains within the family Desulfobacteraceae. Cells of strain PropA(T) were rod-shaped and sometimes motile. The strain required NaCl for growth and grew at salinities up to 200 g NaCl l(-1) (optimum 60 g l(-1)). Growth was observed at 15-40 degrees C, optimum growth occurred at about 40 degrees C, while growth was absent at 10 and 45 degrees C. The pH range for growth was pH 6.0-8.3. Yeast extract (0.1 g l(-1)) was required for growth. C(2-4) alcohols, C(3-4) carboxylic acids, yeast extract and H(2)/acetate supported growth with sulfate as electron acceptor. Sulfate, thiosulfate and sulfite served as electron acceptors, but not elemental sulfur, nitrate or fumarate. The DNA G+C content of strain PropA(T) was 54.1 mol%. Based on the genotypic and physiological properties, we propose that strain PropA(T) represents a novel species within a novel genus, Desulfosalsimonas propionicica gen. nov., sp. nov. The type strain of Desulfosalsimonas propionicica is PropA(T) (=DSM 17721(T) =VKM B-2385(T)).