Pseudonocardia xishanensis sp. nov., an endophytic actinomycete isolated from the roots of Artemisia annua L.

A Gram-positive, non-motile, endophytic actinomycete, designated strain YIM 63638(T), was isolated from the surface-sterilized roots of Artemisia annua L. The isolate grew optimally with 1-3 % (w/v) NaCl, at pH 6.0-7.0 and at 20-37 °C. Comparative analysis of the 16S rRNA gene sequence showed that the isolate belonged to the genus Pseudonocardia and showed highest sequence similarity with Pseudonocardia oroxyli D10(T) (98.9 %), Pseudonocardia ailaonensis YIM 45505(T) (98.3 %) and Pseudonocardia halophobica IMSNU 21327(T) (98.0 %). Phylogenetic distance from other type strains of species with validly published names within the genus Pseudonocardia was greater than 2.3 %. Strain YIM 63638(T) had a genomic DNA G+C content of 72.1 mol% and MK-8(H(4)) as the predominant respiratory quinone. The major fatty acids were iso-C(16 : 0) (36.32 %) and 10-methyl-C(16 : 0) (19.78 %). On the basis of phenotypic properties and phylogenetic distinctiveness, strain YIM 63638(T) represents a novel species of the genus Pseudonocardia, for which the name Pseudonocardia xishanensis sp. nov. is proposed. The type strain is YIM 63638(T) ( = JCM 17906(T)  = KCTC 29005(T)).