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

Abstract

In this study, a novel ginsenoside transforming bacterium, strain W1-2-3T, was isolated from mineral water. The 16S rRNA gene sequence analysis showed that strain W1-2-3T shares 93.7-92.2% sequence similarity with the members of the family Sphingomonadaceae and makes a group with Sphingoaurantiacus capsulatus YLT33T (93.7%) and S. polygranulatus MC 3718T (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°C and at pH 6-10 on R2A agar medium; maximum growth was found to occur at 25°C and pH 7.0. Strain W1-2-3T was found to contain ubiquinone-10 as the predominant quinone and the fatty acids C16:1, C17:1ω6c, C14:0 2-OH, summed feature 3 (C16:1ω6c/C16:1ω7c) and summed feature 8 (C18:1ω6c/C18:1ω7c). The DNA G+C content was determined to be 65.9mol%. Strain W1-2-3T 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 W1-2-3T 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 W1-2-3T 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 W1-2-3T (= KACC 18307T = LMG 28594T).