Nocardia albiluteola sp. nov., a novel lignin-degrading actinobacterium isolated from rhizosphere soil of pumpkin

A novel lignin-degrading actinobacterium, designated NEAU-G5(T), was isolated from pumpkin rhizosphere soil collected from field in Mudanjiang, Heilongjiang Province, northeast China, and characterized using polyphasic approach. The prior 16S rRNA gene sequence similarities and phylogenic analysis showed that strain NEAU-G5(T) exhibited close phylogenetic relatedness to Nocardia miyunensis NBRC 108239(T) (98.82%), Nocardia nova NBRC 15556(T) (98.75%), Nocardia jiangxiensis NBRC 101359(T) (98.68%) and Nocardia macrotermitis RB20(T) (98.61%). Morphological and chemotaxonomic characteristics indicated that strain NEAU-G5(T) could be assigned to the genus Nocardia. The polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, an unidentified phospholipid and an unidentified lipid. The predominant menaquinone was MK-8(H-4, omega-cycl). The major fatty acids (>10%) were identified as C-16:0, C-18:1 omega 9c. 10-methyl C-18:0 and C-18:0. Mycolic acids were present. The genomic DNA G+C content of strain NEAU-G5(T) was 68mol%. Moreover, based on digital DNA-DNA hybridization and average nucleotide identity values, strain NEAU-G5(T) could be differentiated from its reference strains. In addition, an azure B plate decolorization test and genomic analysis indicated that strain NEAU-G5(T) had the ability to degrade lignin. On the basis of polyphasic characteristics, strain NEAU-G5(T) represents a novel species of the genus Nocardia, with the name Nocardia albiluteola sp. nov. The type strain is NEAU-G5(T) (=CCTCCAA 2021018(T)=DSM 110547(T)).