Actinopolymorpha pittospori sp. nov., an endophyte isolated from surface-sterilized leaves of an apricot tree (Pittosporum phylliraeoides)

A member of the genus Actinopolymorpha, designated PIP 143 ^T, was isolated from the leaves of an Australian native apricot tree (Pittosporum phylliraeoides). The isolate was a Gram-reactionpositive, aerobic actinobacterium, with a well-developed substrate mycelium that fragmented into small rods. Phylogenetic evaluation based on 16S rRNA gene sequences placed the isolate in the family Nocardioidaceae. Strain PIP 143 ^T was most closely related to Actinopolymorpha cephalotaxi I06-2230 ^T (98.7 %) and Actinopolymorpha rutila YIM 45725 ^T (98.1 %). Chemotaxonomic data, including cell-wall components, menaquinones and fatty acids, confirmed the affiliation of strain PIP 143 ^T to the genus Actinopolymorpha. Phylogenetic analysis and physiological and biochemical studies, in combination with DNA-DNA hybridization studies, allowed the differentiation of strain PIP 143 ^T from its closest phylogenetic neighbours with validly published names. Therefore, a novel species is proposed, with the name Actinopolymorpha pittospori sp. nov. The type strain is PIP 143 ^T (=DSM 45354 ^T=5ACM 5288 ^T=5NRRL B-24810 ^T).