Streptomyces Tritici Sp Nov., A Novel Actinomycete Isolated From Rhizosphere Soil Of Wheat (Triticum Aestivum L.)

Two novel actinomycete isolates, designated strains NEAU-A4(T) and NEAU-A3, were isolated from rhizosphere soil of wheat (Triticumaestivum L.) and characterized using a polyphasic approach. Morphological and chemotaxonomic characteristics of the two strains coincided with those of the genus Streptomyces. The 16S rRNA gene sequence analysis showed that the two isolates exhibited 99.6% 16S rRNA gene sequence similarity with each other and that they were most closely related to Streptomyces violaceorectus DSM 40279(T) (98.8, 99.0 %). Phylogenetic analysis based on 16S rRNA gene sequences indicated that the two strains clustered together and formed a separate subclade. Furthermore, a combination of DNA-DNA hybridization results and some physiological and biochemical properties demonstrated that the two strains could be distinguished from its closest relative. Therefore, it is proposed that strains NEAU-A4(T) and NEAU-A3 should be classified as representatives of a novel species of the genus Streptomyces, for which the name Streptomyces tritici sp. nov. is proposed. The type strain is NEAU-A4(T) (=CGMCC 4.7393(T)=DSM 104540(T)).