Nocardiopsis changdeensis sp. nov., an endophytic actinomycete isolated from the roots of Eucommia ulmoides Oliv

Strain Mg02 T was isolated from roots of Eucommia ulmoides Oliv. collected from Changde City, Hunan Province, China. Strain Mg02 T , which exhibited distinct chemotaxonomic characteristics of the genus Nocardiopsis : cell-wall chemotype III/C, i.e., meso -diaminopimelic acid as diagnostic amino acid in whole-cell hydrolysates and menaquinone MK-10 with variable degrees of saturation in the side chain as the predominant isoprenoid quinone, was investigated by a polyphasic approach to determine their taxonomic position. Sequence analysis of the 16S rRNA gene indicated that strain Mg02 T is affiliated to the genus Nocardiopsis , having highest sequence similarity to Nocardiopsis flavescens CGMCC 4.5723 T (99.1%) and <98.7% to other species of the genus Nocardiopsis with validly published names. Phylogenetic analysis of 16S rRNA gene indicated strain Mg02 T formed a separate evolutionary clade, suggesting that it could be a novel Nocardiopsis species. Phylogenomic analysis showed that strain Mg02 T was closely related to N. flavescens CGMCC 4.5723 T and distinct from the latter according to the clustering patterns. The Average Nucleotide Identity and digital DNA-DNA hybridization values between strain Mg02 T and N. flavescens CGMCC 4.5723 T were far below the species-level thresholds. Based on phenotypic, phylogenetic and chemotaxonomic characteristics, we think that strain Mg02 T should represent a novel Nocardiopsis species, for which the name Nocardiopsis changdeensis sp. nov. is proposed. The type strain is Mg02 T (=MCCC 1K06174 T = JCM 34709 T ).