Arachidicoccus ginsenosidivorans sp. nov., with ginsenoside-converting activity isolated from ginseng cultivating soil

A Gram-reaction-negative, catalase- and oxidase-positive, aerobic, non-motile, light yellow and rod-shaped bacterium (designated Gsoil 809T) isolated from soil of ginseng field, was characterized by a polyphasic approach to clarify its taxonomic position. Strain Gsoil 809T was observed to grow optimally at 30 °C and at pH 7.0 on nutrient agar medium. Strain Gsoil 809T possessed β-glucosidase activity, which was responsible for its ability to transform protopanaxatriol-type ginsenoside Rg1 to ginsenoside Rh1. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain Gsoil 809T belongs to the genus Arachidicoccus of the family Chitinophagaceae and was most closely related to Arachidicoccusrhizosphaerae Vu-144T (98.1 % 16S rRNA gene sequence similarity). The DNA G+C content was 39.4 mol%. The DNA-DNA hybridization value between strain Gsoil 809T and A.rhizosphaerae Vu-144T was 41.27±1.03 %. The major polar lipids were phosphatidylethanolamine and an unknown polar lipid. The predominant quinone was MK-7. The major fatty acids were iso-C15 : 0, iso-C15 : 1 G, iso-C17 : 0 3-OH and summed feature 3, which supported the affiliation of Gsoil 809T to the genus Arachidicoccus. Strain Gsoil 809T contained homospermidineas the major polyamine. Moreover, the physiological and biochemical test results and low DNA-DNA relatedness value allowed the phenotypic and genotypic differentiation of strain Gsoil 809T from recognized species of the genus Arachidicoccus. Therefore, strain Gsoil 809T represents a novel species of the genus Arachidicoccus, for which the name Arachidicoccus ginsenosidivorans sp. nov. is proposed. The type strain is Gsoil 809T (=KCTC 22820T=JCM 30984T).