Sphingobium jiangsuense sp nov., a 3-phenoxybenzoic acid-degrading bacterium isolated from a wastewater treatment system

A non-sporulating, non-motile, catalase- and oxidase-positive, Gram-negative, rod-shaped bacterial strain, designated BA-3(T), was isolated from activated sludge of a wastewater treatment facility. The strain was able to degrade about 95% of 100 mg 3-phenoxybenzoic acid I-1 within 2 days of incubation. Growth occurred in the presence of 0-2% (w/v) NaCl [optimum, 0.5% (w/v) NaCl], at pH 5.5-9.0 (optimum, pH 7.0) and at 10-37 degrees C (optimum, 28 degrees C). Phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that strain BA-3(T) was a member of the genus Sphingobium; it showed highest gene sequence similarity to Sphingobium qiguonii X23(T) (98.2%), and similarities of <97.0% with strains of other Sphingobium species. The polar lipid pattern, the presence of spermidine and ubiquinone Q-10, the predominance of summed feature 8 (C-18:1 omega 6c and/or C-18:1 omega 7c) in the cellular fatty acid profile and the DNA G+C content also supported affiliation of the isolate to the genus Sphingobium. Strain BA-3(T) showed low DNA-DNA relatedness values (21.3 +/- 0.8%) with Sphingobium qiguonii X23(T). Based on phenotypic, genotypic and phylogenetic data, strain BA-3(T) represents a novel species of the genus Sphingobium, for which the name Sphingobium jiangsuense sp. nov. is proposed; the type strain is BA-3(T) (=CCTCC AB 2010217(T)=KCTC 23196(T)=KACC 16433(T)).