Chitinophaga ginsengisegetis sp. nov. and Chitinophaga ginsengisoli sp. nov., isolated from soil of a ginseng field in South Korea

Abstract

Two novel strains belonging to the phylum Bacteroidetes [formerly the Cytophaga–Flexibacter–Bacteroides (CFB) group], designated Gsoil 040T and Gsoil 052T, were isolated from the soil of a ginseng field in Pocheon province, South Korea. A polyphasic approach was used to characterize the taxonomic position of the novel strains. Both strains were Gram-negative, aerobic, non-motile, non-spore-forming and rod-shaped. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the novel isolates belong to the genus Chitinophaga but are clearly separated from the recognized species of this genus; gene sequence similarities between the novel isolates and type strains of recognized species ranged from 91.2 to 96.5 %. One exception was found; strain Gsoil 052T and the type strain of Chitinophaga filiformis had a gene sequence similarity of 99.6 % but had a DNA–DNA relatedness value of 38 %. Phenotypic and chemotaxonomic data (major menaquinone, MK-7; major fatty acids, iso-C15 : 0 and C16 : 1 ω5c; major hydroxy fatty acid, iso-C17 : 0 3-OH and major polyamine, homospermidine) supported the affiliation of both strains Gsoil 040T and Gsoil 052T to the genus Chitinophaga. The results of physiological and biochemical tests enabled the genotypic and phenotypic differentiation of the novel strains from the other recognized species of the genus Chitinophaga. Therefore, it is suggested that the new isolates represent two novel species, for which the names Chitinophaga ginsengisegetis sp. nov. [type strain Gsoil 040T (=KCTC 12654T=DSM 18108T)] and Chitinophaga ginsengisoli sp. nov. [type strain Gsoil 052T (=KCTC 12592T=DSM 18017T)] are proposed.