sp. nov., a novel actinobacterium isolated from rhizosphere soil of wheat ( L.).

A novel actinobacterium, designated strain NEAU-D428, was isolated from rhizosphere soil of wheat and characterized using a polyphasic approach. Morphological and chemotaxonomic characteristics of the strain coincided with members of the genus . The 16S rRNA gene sequence analysis showed that the isolate was most closely related to NEAU-TX2-2 (99.2 %). Phylogenetic analysis based on the 16S rRNA gene sequences indicated that the strain clustered with CLES2 (99.1 %), but formed a separate subclade in the phylogenomic tree within the genus . The menaquinones were identified as MK-9(H), MK-9(H) and MK-9(H). The phospholipid profile was found to consist of diphosphatidylglycerol, phosphatidylmonomethylethanolamine, phosphatidylethanolamine, ninhydrin-positive glycophospholipid, phosphatidylinositol and phosphatidylinositol mannoside. The major fatty acids were identified as iso-C, C, 10-methyl C and C. Digital DNA-DNA hybridization and average nucleotide identity values between strain NEAU-D428 and NEAU-TX2-2, 2C-HV3, CLES2, ' Gxj-6 and NEAU-HEGS1-5 were 47.6 and 92.2 %, 47.5 and 92.2 %, 55.9 and 94.0 %, 33.1 and 86.8 %, and 33.6 and 87.1 %, respectively. These results and some physiological and biochemical properties demonstrated that the strain could be distinguished from its closest relatives. Therefore, it is proposed that strain NEAU-D428 should be classified as representative of a novel species of the genus , for which the name sp. nov. is proposed. The type strain is NEAU-D428 (=CGMCC 4.7523=DSM 109822).