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

Abstract

A novel xylan-degrading actinomycete, strain YIM 61515T, 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 61515T was most similar to Promicromonospora aerolata V54AT and Promicromonospora vindobonensis V45T (99.4 and 99.1 % sequence similarity, respectively). The isolate formed a separate lineage in a cluster containing P. aerolata V54AT. 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 61515T in the genus Promicromonospora. DNA–DNA relatedness, physiological and biochemical data showed that strain YIM 61515T 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 61515T ( = DSM 21603T = CCTCC AA 208046T) as type strain.