Niabella ginsenosidivorans sp. nov., isolated from compost

A Gram-reaction negative, strictly aerobic, non-motile, orange colored, and rod-shaped bacterium (designated BS26ᵀ) isolated from compost, was characterized by a polyphasic approach to clarify its taxonomic position. Strain BS26ᵀ was observed to grow optimally at 25–30°C and at pH 7.0 on R2A and nutrient media. Strain BS26ᵀ showed ß-glucosidase activity that was responsible for its ability to transform ginsenoside Rb₁ (one of the active components of ginseng) to ginsenoside compound-K (C-K). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain BS26ᵀ belongs to the genus Niabella of family Chitinophagaceae and was most closely related to Niabella soli DSM 19437ᵀ (94.5% similarity), N. yanshanensis CCBAU 05354ᵀ (94.3%), and N. aurantiaca DSM 17617ᵀ (93.8%). The G+C content of genomic DNA was 47.3 mol%. Chemotaxonomic data [predominant isoprenoid quinone-MK-7, major fatty acids–iso-C₁₅:₀, iso-C₁₅:₁ G, iso-C₁₇:₀ 3-OH, and summed feature 3 (comprising C16:1 ?7c and/or C₁₆:₁ ?6c)] supported the affiliation of strain BS26ᵀ to the genus Niabella. However, strain BS26ᵀ could be differentiated genotypically and phenotypically from the recognized species of the genus Niabella. The novel isolate therefore represents a novel species, for which the name Niabella ginsenosidivorans sp. nov. is proposed, with the type strain BS26ᵀ (=KACC 16620ᵀ =JCM 18199ᵀ).