Description of Catellibacterium caeni sp. nov., reclassification of Rhodobacter changlensis Anil Kumar et al. 2007 as Catellibacterium changlense comb. nov. and emended description of the genus Catellibacterium

A novel non-sporulating, non-motile, catalase- and oxidase-positive, strictly aerobic, Gram-negative, rod-shaped bacterial strain, designated DCA-1T, was isolated from activated sludge collected from a butachlor wastewater treatment facility. The strain was able to degrade about 85 % of 100 mg butachlor l−1 within 5 days of incubation. Growth occurred in the presence of 0–6 % (w/v) NaCl [optimum, 1 % (w/v) NaCl] and at pH 5.5–9.0 (optimum, pH 7.0) and 15–35 °C (optimum, 25–30 °C). Vesicular internal membrane structures and photoheterotrophic growth were not observed. The major respiratory quinone was ubiquinone 10 (Q-10) and the major cellular fatty acids were C18 : 1ω7c and 11-methyl C18 : 1ω7c. The genomic DNA G+C content of strain DCA-1T was 62.5 mol%. Phylogenetic analysis based on 16S rRNA gene sequence comparison revealed that strain DCA-1T was a member of the family Rhodobacteraceae and was related most closely to the type strain of Catellibacterium aquatile (96.5 % sequence similarity). The combination of phylogenetic analysis, phenotypic characteristics and chemotaxonomic data supports the suggestion that strain DCA-1T represents a novel species of the genus Catellibacterium, for which the name Catellibacterium caeni sp. nov. is proposed. The type strain is DCA-1T ( = CGMCC 1.7745T  = DSM 21823T). In addition, based on the characterization data obtained in this study, it is proposed that Rhodobacter changlensis should be reclassified as Catellibacterium changlense comb. nov. (type strain JA139T  = DSM 18774T  = CCUG 53722T  = JCM 14338T). An emended description of the genus Catellibacterium is also presented.