Niabella ginsenosidivorans sp. nov., isolated from compost

A Gram-reaction negative, strictly aerobic, non-motile, orange colored, and rod-shaped bacterium (designated BS26^T) isolated from compost, was characterized by a polyphasic approach to clarify its taxonomic position. Strain BS26^T was observed to grow optimally at 25–30°C and at pH 7.0 on R2A and nutrient media. Strain BS26^T 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 BS26^T belongs to the genus Niabella of family Chitinophagaceae and was most closely related to Niabella soli DSM 19437^T (94.5% similarity), N. yanshanensis CCBAU 05354^T (94.3%), and N. aurantiaca DSM 17617^T (93.8%). The G+C content of genomic DNA was 47.3 mol%. Chemotaxonomic data [predominant isoprenoid quinone-MK-7, major fatty acids–iso-C_15:0, iso-C_15:1 G, iso-C_17:0 3-OH, and summed feature 3 (comprising C16:1 ?7c and/or C_16:1?6c)] supported the affiliation of strain BS26^T to the genus Niabella. However, strain BS26^T 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 BS26^T (=KACC 16620^T =JCM 18199^T).