Sphingosinicella ginsenosidimutans sp. nov., with ginsenoside converting activity

The Gram-reaction-negative, strictly aerobic, non-motile, nonspore-forming, and rod-shaped bacterial strain designated BS11ᵀ was isolated from the compost and its taxonomic position was investigated by using a polyphasic approach. Strain BS11ᵀ grew optimally at 30–37°C and at pH 7.0 in the absence of NaCl on nutrient agar. Strain BS11ᵀ displayed β-glucosidase activity that was responsible for its ability to transform ginsenoside Rb1 (one of the dominant active components of ginseng) to Rd. On the basis of 16S rRNA gene sequence similarity, strain BS11ᵀ was shown to belong to the family Sphingomonadaceae and was related to Sphingosinicella vermicomposti YC7378ᵀ (96.3% sequence similarity), S. xenopeptidilytica 3–2W4ᵀ (96.2%), S. microcystinivorans Y2ᵀ (96.1%), and S. soli KSL-125ᵀ (95.9%). The G+C content of the genomic DNA was 64.9%. The major menaquinone was Q-10 and the major fatty acids were summed feature 7 (comprising C₁₈:₁ ω7c/ω9t/ω12t; 40.6%), C₁₆:₀ (22.5%), C₁₇:₁ ω6c (13.7%) and C₁₇:₀ (9.1%). DNA and chemotaxonomic data supported the affiliation of strain BS11ᵀ to the genus Sphingosinicella. Strain BS11ᵀ could be differentiated genotypically and phenotypically from the recognized species of the genus Sphingosinicella. The novel isolate therefore represents a novel species, for which the name Sphingosinicella ginsenosidimutans sp. nov. is proposed, with the type strain BS11ᵀ (=KACC 16619T =JCM 18201ᵀ).