Actinopolymorpha alba sp nov., isolated from a rhizosphere soil

A Gram-positive, milk-white coloured, aerobic strain, YIM 48868(T), was isolated from the rhizosphere soil of Maytenus hookeri Loes in Xishuangbanna, China. 16S rRNA gene sequence similarity studies showed that strain YIM 48868(T) was a member of the genus Actinopolymorpha, showing 96.8% sequence similarity to Actinopolymorpha singaporensis IM 7744(T) and 97.0% similarity to Actinopolymorpha rutila YIM 45725(T). Chemotaxonomic data (peptidoglycan type 1, LL-diaminopimelic acid; sugar pattern C, glucose, rhamnose and ribose; polar lipids PI, diphosphatidylglycerol, phosphaticlylglycerol, phosphatidylinositol mannosides and phosphatidylinositol) were characteristic of the genus Actinopolymorpha. A phylogenetic tree based on 16S rRNA gene sequences showed that strain YIM 48868(T) formed a distinct phylogenetic lineage within the genus Actinopolymorpha. Strain YIM 48868(T) could be differentiated from recognized species by means of phenotypic properties and the predominant menaquinones [MK-9(H-6), MK-9(H-8), MK-10(H-6), MK-10(H-8)]. The DNA G+C content was 66.6 mol%. The DNA-DNA relatedness values between strain YIM 48868(T) and the type strains of A. singaporensis and A. rutila were 48.7% and 53.1%, respectively. These data, in combination with phenotypic and chemotaxonomic data, demonstrate that strain YIM 48868(T) represents a novel species in the genus Actinopolymorpha, for which the name Actinopolymorpha alba sp. nov. is proposed. The type strain is YIM 48868(T) (=CCTCC AA 208030(T) =DSM 45243(T)).