Streptomyces oryziradicis sp. nov., a novel actinomycete isolated from rhizosphere soil of rice (Oryza sativa L.).

Abstract

A novel actinobacterium, designated strain NEAU-C40T, was isolated from the rhizosphere soil of rice (Oryza sativa L.) collected from Northeast Agricultural University in Harbin, Heilongjiang province, north-east PR China, and was characterized using a polyphasic approach. On the basis of results of 16S rRNA gene sequence analysis, strain NEAU-C40T belongs to the genus Streptomyces, and shares highest sequence similarities with Streptomyces polygonati CGMCC 4.7237T (97.9%) and Streptomyces abietis DSM 42080T (97.9%). Morphological and chemotaxonomic characteristics of the strain also supported its assignment to the genus Streptomyces. Cell walls contained ll-diaminopimelic acid and the whole-cell hydrolysates were glucose, rhamnose and ribose. The major menaquinones were identified as MK-9(H8) and MK-9(H6). The major fatty acids were iso-C16:0, anteiso-C15:0, C16:0 and anteiso-C17:0. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol mannoside and an unidentified lipid. The genomic DNA G+C content of strain NEAU-C40T was 71.8 mol%. Moreover, multilocus sequence analysis based on five other housekeeping genes (atp D, gyr B, rpo B, rec A and trp B) and the low level of DNA-DNA relatedness allowed the isolate to be differentiated from its most closely related strains. On the basis of phenotypic, genotypic and phylogenetic data, strain NEAU-C40T can be characterized to represent a novel species of the genus Streptomyces, for which the name Streptomyces oryziradicis sp. nov. is proposed. The type strain is NEAU-C40T (=DSM 107943T=CCTCC AA 2018038T).