Pseudonocardia tropica sp. nov., an endophytic actinomycete isolated from the stem of Maytenus austroyunnanensis.

A novel strain, designated YIM 61452(T), was isolated from the stem of Maytenus austroyunnanensis collected from the tropical rainforest of Xishuangbanna, Yunnan Province, south-west China. The strain was characterized taxonomically by using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain YIM 61452(T) belonged to the genus Pseudonocardia and was most closely related to Pseudonocardia alni IMSNU 20049(T) (99.5 %), Pseudonocardia antarctica DVS 5a1(T) (99.5 %) and Pseudonocardia carboxydivorans Y8(T) (99.4 %). The chemotaxonomic properties of strain YIM 61452(T), for example MK-8(H(4)) as the predominant quinone system and iso-C(16 : 0) and iso-C(16 : 1) H as the major fatty acids, were also consistent with its classification within the genus Pseudonocardia. Strain YIM 61452(T) could be differentiated from closely related species of the genus Pseudonocardia by phenotypic and genotypic analysis. DNA-DNA hybridization experiments between strain YIM 61452(T) and closely related reference strains further confirmed that strain YIM 61452(T) represented a novel taxon of the genus Pseudonocardia. Therefore, strain YIM 61452(T) represents a novel species, for which the name Pseudonocardia tropica sp. nov. is proposed. The type strain is YIM 61452(T) (=DSM 45199(T)=CCTCC AA 208018(T)).