Flavobacterium knui sp. nov., a novel member of the family Flavobacteriaceae

A Gram-stain negative, non-motile, rod-shaped bacterial strain, designated 2-56^T, was isolated from water and characterized taxonomically using a polyphasic approach. Comparative 16S rRNA gene sequence analysis showed that strain 2-56^T belongs to the family Flavobacteriaceae in the phylum Bacteroidetes and is closely related to Flavobacterium paronense KNUS1^T (98.4%) and Flavobacterium collinsense 4-T-2^T (96.7%). The G + C content of the genomic DNA of strain 2-56^T was 33.4 mol%. The isolate contained MK-6 as the predominant respiratory quinone, and iso-C_15:1 G (15.9%), iso-C_15:0 (15.8%), iso-C_17:0 3-OH (10.7%), and iso-C_15:0 3-OH (9.6%) were the major fatty acids. The major polar lipids were phosphatidylethanolamine and an unidentified lipid. The phenotypic and chemotaxonomic data support the affiliation of strain 2-56^T with the genus Flavobacterium. However, the DNA–DNA relatedness between the isolate and F. paronense and F. collinsense were 35.7 and 21.5%, respectively, clearly showing that strain 2-56^T is not related to them at the species level. Strain 2-56^T could be clearly differentiated from its close neighbours on the basis of its phenotypic, genotypic and chemotaxonomic features. Therefore, strain 2-56^T represents a novel species of the genus Flavobacterium, for which the name Flavobacterium knui sp. nov. is proposed. The type strain is 2-56^T (= KCTC 62061^T = JCM 32247^T).