Rhodococcus kronopolitis sp. nov., a novel actinobacterium isolated from a millipede (Kronopolites svenhedind Verhoeff).

Abstract

A novel actinobacterium, designated strain NEAU-ML12(T), was isolated from a millipede (Kronopolites svenhedind Verhoeff), which was collected from Fenghuang Mountain in Wuchang, Heilongjiang Province, north China. The strain was characterized using a polyphasic approach. Strain NEAU-ML12(T) was found to have morphological and chemotaxonomic characteristics typical of the members of the genus Rhodococcus. 16S rRNA gene sequence similarity analysis showed that the strain NEAU-ML12(T) belongs to the genus Rhodococcus, and was most closely related to Rhodococcus tukisamuensis Mb8(T) (98.9 %) and Rhodococcus koreensis DNP505(T) (97.7 %). Phylogenetic analysis based on 16S rRNA gene sequences also demonstrated that strain NEAU-ML12(T) should be classified in the genus Rhodococcus, forming a distinct clade with R. tukisamuensis Mb8(T) supported by a 99 % bootstrap value. However, the DNA-DNA relatedness between strain NEAU-ML12(T) and R. tukisamuensis Mb8(T) was found to be 41.9 ± 0.7 %. Furthermore, strain NEAU-ML12(T) could also be differentiated from R. tukisamuensis Mb8(T) and other closely related strains (R. koreensis DNP505(T) and Rhodococcus maanshanensis M712(T)) by morphological and physiological characteristics. Therefore, it is proposed that strain NEAU-ML12(T) represents a novel species of the genus Rhodococcus, for which the name Rhodococcus kronopolitis sp. nov. is proposed. The type strain is NEAU-ML12(T) (=CGMCC 4.7145(T) = DSM 46702(T)).