Hankyongella ginsenosidimutans gen. nov., sp. nov., isolated from mineral water with ginsenoside coverting activity

In this study, a novel ginsenoside transforming bacterium, strain W1-2-3(T), was isolated from mineral water. The 16S rRNA gene sequence analysis showed that strain W1-2-3(T) shares 93.7-92.2% sequence similarity with the members of the family Sphingomonadaceae and makes a group with Sphingoaurantiacus capsulatus YLT33(T) (93.7%) and S. polygranulatus MC 3718(T) (93.4%). The novel isolate efficiently hydrolyses the ginsenoside Rc to Rd. The genome comprises a single circular 2,880,809, bp chromosome with 3211 genes in total, and 1993 protein coding genes. The isolate was observed to grow at 10-37 degrees C and at pH 6-10 on R2A agar medium; maximum growth was found to occur at 25 degrees C and pH 7.0. Strain W1-2-3(T) was found to contain ubiquinone-10 as the predominant quinone and the fatty acids C-16:1, C-17:1 omega 6c, C-14:0 2-OH, summed feature 3 (C-16:1 omega 6c/C-16:1 omega 7c) and summed feature 8 (C-18:(1)omega 6c/C-18:1 omega 7c). The DNA G+C content was determined to be 65.9 mol%. Strain W1-2-3(T) can be distinguished from the other members of the family Sphingomonadaceae by a number of chemotaxonomic and phenotypic characteristics. The major polar lipids of strain W1-2-3(T) were identified as phosphatidylethanolamine, an unidentified glycolipid and an unidentified polar lipid. The major poly amine was found to be homospermidine. Based on polyphasic taxonomic analysis, strain W1-2-3(T) is concluded to represent a novel species within a new genus, for which the name Hankyongella ginsenosidimutans gen. nov., sp. nov. is proposed. The type strain of Hankyongella ginsenosidimutans is W1-2-3(T) (= KACC 18307(T) = LMG 28594(T)).