sp. nov. a novel ligninase- producing and cellulose-degrading actinobacterium isolated from soil.

A novel ligninase-producing and cellulose-degrading actinobacterium, designated strain NEAU-A12, was isolated from a soil sample collected from Aohan banner, Chifeng City, Inner Mongolia Autonomous Region, PR China. A polyphasic taxonomic study was used to establish the status of strain NEAU-A12. 16S rRNA gene sequence analysis revealed that strain NEAU-A12 belonged to the genus and showed the highest similarity (98.3 %) to DSM 43940, while showing less than 98.3 % similarity to other members of the genus . The phospholipid profile contained diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol and glycosylphosphatidylinositol. The diagnostic sugars in cell hydrolysates were determined to be arabinose, glucose and xylose. The cell wall contained -diaminopimelic acid as the diagnostic diamino acid. The predominant menaquinones were MK-9(H), MK-9(H) and MK-9(H). The major fatty acids were C, C, C 7 and C. Meanwhile, genomic analysis revealed a genome size of 10 192 524 bp and a DNA G+C content of 70.6 mol%, and indicated that strain NEAU-A12 had the potential to degrade lignin and cellulose, as well as produce bioactive compounds. In addition, the average nucleotide identity values between strain NEAU-A12 and its reference strains DSM 43940, DSM 43151, DSM 43019, DSM 45184 and DSM 43146 were 80.3, 80.3, 84.1, 84.3 and 84.0 %, respectively. The levels of digital DNA-DNA hybridization between them were found to be 23.6 % (21.3-26.1 %), 23.8 % (21.5-26.3 %), 28.3 % (25.9-30.8 %), 28.6 % (26.0-30.9 %) and 28.4 % (26.2-31.1 %), respectively. Based on phenotypic, chemotaxonomic and genotypic data, strain NEAU-A12 is considered to represent a novel species of the genus , for which the name sp. nov. is proposed, with NEAU-A12 (=CCTCC AA 2020039=DSM 112043) as the type strain.