Saccharothrix yanglingensis sp. nov., an antagonistic endophytic actinomycete isolated from cucumber plant.

An endophytic actinomycete strain, designated Hhs.015(T), was isolated from roots of cucumber seedlings. The endophytic isolate was identified by means of a polyphasic taxonomic approach. On the basis of 16S rRNA gene sequence similarities, strain Hhs.015(T) was closely related to members of the genus Saccharothrix. DNA-DNA hybridization with the four closest relatives, Saccharothrix longispora NRRL B-16116(T), Saccharothrix xinjiangensis NRRL B-24321(T), Saccharothrix autraliensis CGMCC 4.1355(T) and Saccharothrix espanaensis CGMCC 4.1714(T), gave similarity values of 33.8, 28.2, 44.1 and 29.5%, respectively, which indicated that strain Hhs.015(T) represents a novel species of the genus Saccharothrix. This is consistent with the morphological, physiological and chemotaxonomic data. As a whole, these results suggest that strain Hhs.015(T) represents a novel Saccharothrix species. The name Saccharothrix yanglingensis sp. nov. is proposed, with the type strain Hhs.015(T) (=CGMCC 4.5627(T) = KCTC 19722(T)).