Streptomyces ginkgonis sp. nov., an endophyte from Ginkgo biloba.

A novel endophytic actinomycete strain, designated KM-1-2T, was isolated from seeds of Ginkgo biloba at Yangling, China. A polyphasic approach was used to study the taxonomy of strain KM-1-2T and it was found to show a range of phylogenetic and chemotaxonomic properties consistent with those of members of the genus Streptomyces. The diamino acid of the cell wall peptidoglycan was identified as LL-diaminopimelic acid. No diagnostic sugars were detected in whole cell hydrolysates. The predominant menaquinones were identified as MK-9(H6) and MK-9(H8). The diagnostic phospholipids were found to be phosphatidylethanolamine and phosphatidylcholine. The DNA G + C content of the novel strain was determined to be 72.9 mol%. The predominant cellular fatty acids (> 10.0 %) were identified as iso-C14 : 0, iso-C16 : 0, C16 : 0 and C17 : 0 cyclo. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that the strain is closely related to Streptomyces carpaticus JCM 6915T (99.3%), Streptomyces harbinensis DSM 42076T (98.9%) and Streptomyces cheonanensis JCM 14549T (98.5%). DNA-DNA hybridizations with these three close relatives gave similarity values of 39.1 ± 1.9, 35.8 ± 2.3, and 47.4 ± 2.7%, respectively, which indicated that strain KM-1-2T represents a novel species of the genus Streptomyces. This is consistent with the morphological, physiological and chemotaxonomic data. Cumulatively, these data suggest that strain KM-1-2T represents a novel Streptomyces species, for which the name Streptomyces ginkgonis sp. nov. is proposed, with the type strain KM-1-2T (= CCTCC AA2016004T = KCTC 39801T).