Desulfosporosinus youngiae sp nov., a spore-forming, sulfate-reducing bacterium isolated from a constructed wetland treating acid mine drainage

Strain JW/YJL-B18(T), a spore-forming, sulfate-reducing bacterium, was isolated from constructed wetland sediment. Cells were curved rods, 0.7-1.2 mu m in diameter and 3-7 mu m long. Despite being phylogenetically a member of the Gram-type-positive phylum Firmicutes, cells stained Gram-negative at all growth phases. Strain JW/YJL-B18(T) grew at 8-39 degrees C, with an optimum at 32-35 degrees C and no growth at 4 degrees C or below or at 42 degrees C or above. The pH(25 degrees C) range for growth was 5.7-8.2, with an optimum at pH(25 degrees C) 7.0-7.3, and no growth was detected at or below pH 5.2 or at or above pH 8.4. The salinity range for growth was 0-3% (NaCl/KCl 9:1). Strain JW/YJL-B18(T) utilized as carbon and energy sources beef extract, yeast extract, formate, succinate, lactate, pyruvate, ethanol and toluene. Fumarate, sulfate, sulfite and thiosulfate were reduced in the presence of lactate. Arsenate (V) was not used as an electron acceptor. Strain JW/YJL-B18(T) showed no indication of growth under autotrophic conditions. The predominant cellular fatty acids were C-16:1 and C-16:0. The genomic DNA G+C content was 36.6 mol% (HPLC). 16S rRNA gene sequence analysis indicated that strain JW/YJL-B18(T) fell into the genus Desulfosporosinus, with Desulfosporosinus auripigmenti OREX-4(T) as its closest neighbour with a validly published name (97.9% similarity). Based on molecular genetic evidence and physiological and biochemical characters including differences in the DNA G+C content, we propose to place strain JW/YJL-B18(T) (=DSM 17734(T) =ATCC BAA-1261(T)) as the type strain of a novel species, Desulfosporosinus youngiae sp. nov.