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

A novel actinomycete, designated strain NEAU-D10(T), was isolated from rhizosphere soil of wheat (Triticum aestivum L.) collected from Northeast Agricultural University in Harbin, Heilongjiang Province, north-east China. A polyphasic approach was employed to determine the status of strain NEAU-D10(T). Morphological and chemotaxonomic characteristics were consistent with those of members of the genus Streptomyces. The menaquinones detected were MK-9 (H-6), MK-9 (H-8) and MK-9 (H-4). The phospholipid profile consisted of diphosphatidylglycerol, phosphatidylethanola mine, hydroxy- phosphatidylethanolamine, phosphatidylinositol and three unidentified lipids. The major fatty acids were identified as iso-C-16:0, C-16:0, anteiso-C-18:0 and iso-C-14:0. Analysis of the 16S rRNA gene sequence showed that strain NEAU-D10(T) belongs to the genus Streptomyces with high sequence similarity to Streptomyces sioyaensis DSM 40032(T) (99.0 %) and Streptomyces auratus DSM 41897(T) (98.8 %). Moreover, multilocus sequence analysis based on five other housekeeping genes (atpD, gyrB, rpoB, recAand trpB) and the low level of DNA-DNA relatedness and phenotypic differences allowed the novel isolate to be differentiated from its most closely related strains, S. sioyaensis DSM 40032(T) and S. auratus DSM 41897(T). It is concluded that the organism can be classified as representing a novel species of the genus Streptomyces, for which the name Streptomyces inhibens sp. nov. is proposed. The type strain is NEAU-D10(T) (=CGMCC 4.7469(T) =DSM 106197(T)).