Promicromonospora xylanilytica sp. nov., an endophytic actinomycete isolated from surface-sterilized leaves of the medicinal plant Maytenus austroyunnanensis.

A novel xylan-degrading actinomycete, strain YIM 61515(T), was isolated from surface-sterilized leaves of the medicinal plant Maytenus austroyunnanensis. Cells were Gram-positive and non-spore-forming, produced primary branches and formed white to yellowish white colonies on the media tested. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain YIM 61515(T) was most similar to Promicromonospora aerolata V54A(T) and Promicromonospora vindobonensis V45(T) (99.4 and 99.1% sequence similarity, respectively). The isolate formed a separate lineage in a cluster containing P. aerolata V54A(T). 16S rRNA gene sequence similarity between the isolate and other members of the genus Promicromonospora ranged from 96.3 to 98.4%. Chemotaxonomic data, including major menaquinones, fatty acid compositions and polar lipid profiles, supported the placement of strain YIM 61515(T) in the genus Promicromonospora. DNA-DNA relatedness, physiological and biochemical data showed that strain YIM 61515(T) could be distinguished from members of all known species of the genus Promicromonospora and therefore represented a novel species. The name Promicromonospora xylanilytica sp. nov. is proposed, with YIM 61515(T) (=DSM 21603(T)=CCTCC AA 208046(T)) as type strain.