Rhodococcus artemisiae sp. nov., an endophytic actinobacterium isolated from the pharmaceutical plant Artemisia annua L.

A Gram-positive, non-motile actinobacterium, designated YIM 65754(T), was isolated from the stem of Artemisia annua L., collected from Yunnan province, south-west China. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain YIM 65754(T) comprised an evolutionary lineage within the genus Rhodococcus. The isolate clustered with Rhodococcus pyridinivorans PDB9(T), Rhodococcus gordoniae W 4937(T) and Rhodococcus rhodochrous DSM 43241(T), with which it shared 98.4, 97.9 and 97.8% 16S rRNA gene sequence similarities, respectively. However, DNA DNA relatedness demonstrated that strain YIM 65754(T) was distinct from its closest phylogenetic neighbours. The cell-wall peptidoglycan contained meso-diaminopimelic acid, arabinose, galactose, mannose and glucose (cell-wall chemotype The major menaquinone was MK-8(H-2) and the predominant fatty acids were C-16:0 (27.83%), iso-C-15:0 2-OH and/or C-16:1 omega 7c (20.21%) and 10-methyl C-18:0 (17.50%). The DNA G +C content was 66.2 mol%. On the basis of phenotypic, chemotaxonomic and phylogenetic evidence, the isolate represents a novel species of the genus Rhodococcus, for which the name Rhodococcus artemisiae sp. nov. is proposed; the type strain is YIM 65754(T) (=CCTCC AA 209042(T)=DSM 45380(T)).