Flavisolibacter ginsenosidimutans sp. nov., with ginsenoside-converting activity isolated from soil used for cultivating ginseng.

A Gram-reaction-negative, aerobic, non-motile and rod-shaped bacterial strain designated Gsoil 636T was isolated from soil of a ginseng cultivation field in Pocheon Province, South Korea and its taxonomic position was investigated using a polyphasic approach. Gsoil 636T grew at 18-30 °C and at pH 6.0-8.0 on R2A medium. Gsoil 636T possessed β-glucosidase activity, which was responsible for its ability to transform ginsenoside Rb1 (ones of the dominant active components of ginseng) to F2. On the basis of 16S rRNA gene sequence similarity, Gsoil 636T was shown to belong to the family Chitinophagaceae and to be related to Flavisolibacter ginsengiterrae Gsoil 492T (96.7 % sequence similarity), Flavisolibacter ginsengisoli Gsoil 643T (96.6 %) and Flavisolibacter rigui 02SUJ3T (96.6 %). The G+C content of the genomic DNA was 48.9 %. The predominant respiratory quinone was MK-7 and the major fatty acids were iso-C15 : 0, summed feature 3 (comprising C16 : 1ω6c and/or C16 : 1ω7c) and iso-C17 : 0 3-OH. DNA and chemotaxonomic data supported the affiliation of Gsoil 636T to the genus Flavisolibacter. Gsoil 636T could be differentiated genotypically and phenotypically from the species of the genus Flavisolibacter with validly published names. The isolate therefore represents a novel species, for which the name Flavisolibacter ginsenosidimutans sp. nov. is proposed, with the type strain Gsoil 636T (KCTC 22818T = JCM 18197T = KACC 14277T).