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

A novel actinobacterium, designated strain NEAU-HG-1, 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 belonged to the genus Micromonospora, and shared high sequence similarities with Micromonospora auratinigra DSM 44815 (98.9%) and Micromonospora coerulea DSM 43143 (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(H), MK-10(H) and MK-10(H). The major fatty acids were C cycle, iso-C, and iso-C. Furthermore, strain NEAU-HG-1 displayed a DNA-DNA relatedness of 33.8 ± 2.2% with M. coerulea DSM 43143. The level of digital DNA-DNA hybridization between strain NEAU-HG-1 and M. auratinigra DSM 44815 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 represents a novel species of the genus Micromonospora, for which the name Micromonospora rubida sp. nov. is proposed, with NEAU-HG-1 (= CGMCC 4.7479 = JCM 32386) as the type strain.