Reclassification of Desulfobacterium anilini as Desulfatiglans anilini comb. nov within Desulfatiglans gen. nov., and description of a 4-chlorophenol-degrading sulfate-reducing bacterium, Desulfatiglans parachlorophenolica sp nov.

A strictly anaerobic, mesophilic, sulfate-reducing bacterial strain (DST), isolated from river sediment contaminated with volatile organic compounds, was characterized phenotypically and phylogenetically. Cells were Gram-reaction-negative, non-motile short rods. For growth, optimum NaCl concentration was 0.9 gl(-1), optimum temperature was 30 degrees C and optimum pH was 7.2. Strain DST utilized phenol, benzoate, 4-hydroxybenzoate, 4-methylphenol, 4-chlorophenol, acetate, butyrate and pyruvate as electron donors for sulfate reduction. Electron donors were completely oxidized. Strain DST did not utilize sulfite, thiosulfate-or nitrate as electron acceptors. The genomic DNA G+C content of strain DST was 58.9 mol%. Major cellular fatty acids were iso-C-14:0, anteiso-C-15:0 and C-18:1 omega 7c. Phylogenetic analyses based on the 16S rRNA gene indicated its closest relatives were strains of Desulfobacterium anilini (about 98-99% sequence similarity) but the DNA-DNA hybridization value with Desulfobacterium anilini Anil(T) was around 40%. Although strain DST and its relatives shared most phenotypic and chemotaxonomic characteristics, the utilization of 4-chlorophenol, the range of electron acceptors and the optimum growth conditions differed. Strain DST is closely related to strains of Desulfobacterium anilini, but constitutes a different species within the genus. Based on phylogeny, phenotypic characteristics and chemotaxonomic characteristics, strain DST and Desulfobacterium anilini were clearly different from strains of other species of the genus Desulfobacterium. We thus propose the reclassification of Desulfobacterium anilini within a new genus, Desulfatiglans gen. nov., as Desulfatiglans anilini comb. nov. We also propose Desulfatiglans parachlorophenolica sp. nov. to accommodate strain DST. The type strain is DST (=JCM 19179(T)=DSM 27197(T)).