Rhodococcus kunmingensis sp nov, an actinobacterium isolated from a rhizosphere soil

A Gram-positive, aerobic, non-motile actinobacterium strain, designated YIM 45607(T), was isolated from a rhizosphere soil sample in Kunming, south-west China. Chemotaxonomically, the isolate contained chemical markers that supported its assignment to the genus Rhodococcus. On the basis of 16S rRNA gene sequence similarity analysis, strain YIM 45607(T) formed a new subline within the genus Rhodococcus, with Rhodococcus equi as its closest phylogenetic neighbour (98.2% 16S rRNA gene sequence similarity to the type strain). However, DNA-DNA hybridization demonstrated that strain YIM 45607(T) was different from R. equi DSM 20307(T) (35.4 % relatedness). Based on polyphasic analysis, strain YIM 45607(T) could be clearly distinguished from other species of the genus Rhodococcus. The isolate therefore represents a novel species of Rhodococcus, for which the name Rhodococcus kunmingensis sp. nov. is proposed. The type strain is strain YIM 45607(T) (=KCTC 19149(T) =DSM 45001(T)).