A novel Gram-stain-negative, non-motile, non-spore-forming, rod-shaped, strictly aerobic bacterium, designated strain 13T, was isolated from an activated sludge wastewater treatment plant in Beijing, China. 16S rRNA gene sequence analysis placed this organism within the genus Chitinophaga of the class Bacteroidetes, with Chitinophaga skermanii CC-SG1B (92.4 % gene sequence similarity) and Chitinophaga rupis CS5-B1 (91.2 %) as its closest relatives. This isolate contained meso-diaminopimelic acid as the diagnostic diamino acid and the whole-cell hydrolysate was ribose. Phosphatidylethanolamine was the predominant polar lipid. The major cellular fatty acids were iso-C15 : 0, C16 : 1ω5c and iso-C17 : 0 3-OH. Menaquinone-7 was the only isoprenoid quinone present. The complete genome of the novel strain was sequenced; the size of the genome was 5.28 Mb and the genomic DNA G+C content was 42.5 mol%. The phenotypic, chemotaxonomic and phylogenetic data showed that strain 13T represents a novel species of the genus Chitinophaga, for which the name Chitinophaga caeni sp. nov. is proposed. The type strain is 13T (=CICC 24262T=KCTC 62265T).
Keywords: Chitinophaga caeni; activated sludge.