Rhodococcus yunnanensis sp. nov., a mesophilic actinobacterium isolated from forest soil

Abstract

A Gram-positive, aerobic, non-motile, mesophilic strain, designated YIM 70056T, was isolated from a forest soil sample in Yunnan Province, China. Phylogenetic analysis based on 16S rRNA gene sequences revealed that this isolate had less than 97.0 % similarity to any Rhodococcus species with validly published names, with the exception of Rhodococcus fascians (DSM 20669T), which was found to be its closest neighbour (98.9 % similarity). Chemotaxonomic data, including peptidoglycan type, diagnostic sugar compositions, fatty acid profiles, menaquinones, polar lipids and mycolic acids, were determined for this isolate; the results supported the affiliation of strain YIM 70056T to the genus Rhodococcus. The DNA G+C content was 63.5 mol%. The results of DNA-DNA hybridization with R. fascians DSM 20669T, in combination with chemotaxonomic and physiological data, demonstrated that isolate YIM 70056T represents a novel Rhodococcus species, for which the name Rhodococcus yunnanensis sp. nov. is proposed, with YIM 70056T (=CCTCC AA 204007T=KCTC 19021T=DSM 44837T ) as the type strain.