Nocardioides panaciterrulae sp. nov., isolated from soil of a ginseng field, with ginsenoside converting activity

A Gram-positive, coccoid to rod-shaped, non-spore-forming bacterium, designated Gsoil 958(T), was isolated from soil of a ginseng field located in Pocheon province in South Korea. This bacterium was characterized in order to determine its taxonomic position by using a polyphasic approach. Strain Gsoil 958(T) was observed to grow well at 25-30 °C and at pH 7.0 on R2A and nutrient agar without NaCl supplementation. Strain Gsoil 958(T) was determined to have β-glucosidase activity and the ability to transform ginsenoside Rb1 (one of the dominant active components of ginseng) to F2 via gypenoside XVII and Rd. On the basis of 16S rRNA gene sequence similarity, strain Gsoil 958(T) was shown to belong to the family Nocardioidaceae and related most closely to Nocardioides koreensis MSL-09(T) (97.6 % 16S rRNA gene sequence similarity), Nocardioides aquiterrae GW-9(T) (97.0 %), and Nocardioides sediminis MSL-01(T) (97.0 %). The sequence similarities with other validly named species within the genus Nocardioides were less than 96.8 %. Strain Gsoil 958(T) was characterized chemotaxonomically as having LL-2,6-diaminopimelic acid in the cell-wall peptidoglycan, MK-8(H4) as the predominant menaquinone, and iso-C16:0, iso-C16:1 H, iso-C14:0, iso-C15:0 were identified as the major fatty acids. The G + C content of genomic DNA was determined to be 70.8 mol %. The chemotaxonomic properties and phenotypic characteristics supported the affiliation of strain Gsoil 958(T) to the genus Nocardioides. The results of both physiological and biochemical tests allowed for differentiation of strain Gsoil 958(T) from the recognized Nocardioides species. Therefore, strain Gsoil 958(T) is considered to represent a novel species of the genus Nocardioides, for which the name Nocardioides panaciterrulae sp. nov. is proposed, with the type strain Gsoil 958(T) (KACC 14271(T) = KCTC 19471(T) = DSM 21350(T)).