Solirubrobacter ginsenosidimutans sp nov., isolated from soil of a ginseng field

A Gram-reaction-positive, non-motile, non-spore-forming, aerobic rod, designated BXN5-15(T), was isolated from the soil of a ginseng field on Baekdu Mountain in China. Strain BXN5-15(T) grew optimally at 30 degrees C and pH 6.0-7.0 in the absence of NaCl on R2A agar. Strain BXN5-15T displayed beta-glucosidase activity, which allowed it to transform ginsenoside Rb-1 (one of the dominant active components of ginseng) via Rd to minor ginsenoside F-2. On the basis of 16S rRNA gene sequence analysis, strain BXN5-15T was shown to belong to the genus Solirubrobacter. The closest phylogenetic relatives were Solirubrobacter soli Gsoil 355(T) (98.4% 16S rRNA gene sequence similarity) and Solirubrobacter pauli B33D1(T) (96.4%). Lower sequence similarities (<96.0%) were found with all of the other recognized members of the order Solirubrobacterales. The predominant quinone was MK-7(H-4). The major fatty acids (>10%) were C-18:1 omega 09c, iso-C-16:0 and C-18:3 omega 6,9,12c. The G+C content of the genomic DNA was 70.6 mol%. DNA DNA relatedness between strain BXN5-15(T) and S. soli KCTC 12628(T) was 23.3%. On the basis of genotypic, phenotypic and chemotaxonomic data, strain BXN5-15T represents a novel species within the genus Solirubrobacter, for which the name Solirubrobacter ginsenosidimutans sp. nov. is proposed. The type strain is BXN5-15(T) (=KACC 20671(T) =LMG 24459(T)).