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).