Streptomyces roietensis sp. nov., an endophytic actinobacterium isolated from the surface-sterilized stem of jasmine rice, Oryza sativa KDML 105

An endophytic actinobacterium, strain WES2^T, was isolated from the stem of a jasmine rice plant collected from a paddy field in Thung Gura Rong Hai, Roi Et province, Thailand. As a result of a polyphasic study, this strain was identified as representing a novel member of the genus Streptomyces. This strain was a Gram-stain-positive, aerobic actinobacterium with well-developed substrate mycelia and forming chains of looped spores. The closest phylogenetic relations, which shared the highest 16S rRNA gene sequence similarity, were Streptomyces nogalater JCM 4799^T and Streptomyces lavenduligriseus NRRL-ISP 5487^T at 99.1 and 99.0%, respectively. Chemotaxonomic data, including major fatty acids, cell wall components and major menaquinones, confirmed the affiliation of WES2^T to the genus Streptomyces. The data from the phylogenetic analysis, including physiological and biochemical studies and DNA–DNA hybridization, revealed the genotypic and phenotypic differentiation of WES2^T from the most closely related species with validly published names. The name proposed for the novel species is Streptomyces roietensis sp. nov. The type strain is WES2^T (=DSM 101729=NRRL B-65344).