Catellibacterium nanjingense sp. nov., a propanil-degrading bacterium isolated from activated sludge, and emended description of the genus Catellibacterium.

A novel facultatively anaerobic, non-spore-forming, non-motile, catalase- and oxidase-positive, Gram-negative and rod-shaped bacterial strain, designated Y12(T), was isolated from activated sludge of a wastewater bio-treatment facility. The strain was able to degrade about 90% of added propanil (100 mg l(-1)) within 3 days of incubation. Growth occurred in the presence of 0-4.5% (w/v) NaCl (optimum 0.5%), at 10-40 °C (optimum 28 °C) and at pH 5.5-10.0 (optimum pH 7.0). Vesicular internal membrane structures and photoheterotrophic growth were not observed. The major respiratory quinone was ubiquinone-10 and the major cellular fatty acid was summed feature 8 (C(18:1)ω6c and/or C(18:1)ω7c). The genomic DNA G+C content of strain Y12(T) was 63.7 mol%. Phylogenetic analysis based on 16S rRNA gene sequence comparison revealed that strain Y12(T) was a member of the genus Catellibacterium, as it showed highest sequence similarities to Catellibacterium caeni DCA-1(T) (99.1%) and <96.0% similarities with other species of the genus Catellibacterium. Strain Y12(T) showed low DNA-DNA relatedness values with C. caeni DCA-1(T). Based on phenotypic, genotypic and phylogenetic properties, strain Y12(T) represents a novel species of the genus Catellibacterium, for which the name Catellibacterium nanjingense sp. nov. is proposed. The type strain is Y12(T) (=CCTCC AB 2010218(T) =KCTC 23298(T)). An emended description of the genus Catellibacterium is also presented.