Micromonospora rubida sp. nov., a novel actinobacterium isolated from soil of Harbin

A novel actinobacterium, designated strain NEAU-HG-1^T, was isolated from soil collected from Harbin, Heilongjiang Province, Northeast China and characterised using a polyphasic approach. On the basis of 16S rRNA gene sequence analysis, strain NEAU-HG-1^T belonged to the genus Micromonospora, and shared high sequence similarities with Micromonospora auratinigra DSM 44815^T (98.9%) and Micromonospora coerulea DSM 43143^T (98.7%). Morphological and chemotaxonomic characteristics of the strain also supported its assignment to the genus Micromonospora. Cell wall contained meso-diaminopimelic acid and the whole-cell sugars were arabinose and xylose. The polar lipid contained diphosphatidylglycerol, phosphatidylethanolamine, glycolipid and phosphatidylinositol. The predominant menaquinones were MK-10(H₂), MK-10(H₄) and MK-10(H₆). The major fatty acids were C_17:0 cycle, iso-C_15:0, and iso-C_16:0. Furthermore, strain NEAU-HG-1^T displayed a DNA-DNA relatedness of 33.8 ± 2.2% with M. coerulea DSM 43143^T. The level of digital DNA-DNA hybridization between strain NEAU-HG-1^T and M. auratinigra DSM 44815^T was 27.2% (24.8-29.7%). The value was well below the criteria for species delineation of 70% for dDDH. Whole-genome average nucleotide identity analyses result also indicated that the isolate should be assigned to a new species under the genus Micromonospora. Therefore, it is concluded that strain NEAU-HG-1^T represents a novel species of the genus Micromonospora, for which the name Micromonospora rubida sp. nov. is proposed, with NEAU-HG-1^T (= CGMCC 4.7479^T = JCM 32386^T) as the type strain.