Rhodococcus kyotonensis sp nov., a novel actinomycete isolated from soil

A polyphasic study was undertaken to establish the taxonomic position of an isolate, strain DS472(T), from soil in Kyoto, Japan. Phylogenetic analysis, based on the 16S rRNA gene sequences, revealed that this strain constitutes a new subline within the genus Rhodococcus, with Rhodococcus yunnanensis YIM 70056(T) and Rhodococcus fascians DSM 20669(T) as its nearest phylogenetic neighbours (98.2 and 97.8% sequence similarity, respectively). DNA-DNA hybridization experiments revealed 36 and 29% relatedness between the isolate and its phylogenetic relatives, R. yunnanensis and R. fascians, respectively. Chemotaxonomic characteristics, including the major quinone MK-8(H-2), predominant fatty acids C-16:0, C-18:1 omega 9c and 10-methyl C-18:0, the presence of cell-wall chemotype IV and mycolic acids, were consistent with the properties of members of the genus Rhodococcus. The DNA G+C content was 64.5 mol%. On the basis of both phenotypic and genotypic evidence, strain DS472(T) represents a novel species of the genus Rhodococcus, for which the name Rhodococcus kyotonensis sp. nov. is proposed. The type strain is strain DS472(T) (=IAM 15415(T) = CCTCC AB206088(T)).