A novel cellulase-producing actinobacterium, designated strain NEAU-L178T, was isolated from soil sample collected from Qiqihaer, Heilongjiang Province, PR China. A polyphasic study was carried out to determine the taxonomic status of the strain. On the basis of 16S rRNA gene sequence analysis, strain NEAU-L178T should be classified into the genus Nonomuraea and is closely related to Nonomuraea cavernae SYSU K10005T (99.31 % 16S rRNA gene sequence similarity), Nonomuraea glycinis NEAU-BB2C19T (98.75 %), Nonomuraea guangzhouensis NEAU-ZJ3T (98.75 %) and 'Nonomuraea rhizosphaerae' NEAU-mq18T (98.34 %). The digital DNA-DNA hybridization values between them are 27.1, 26.1, 42.0 and 30.9 %, and the whole-genome average nucleotide identity values between them are 83.1, 82.3, 90.3 and 85.8 %, respectively. The whole-cell hydrolysates contained glucose, ribose, arabinose and madurose. The menaquinones were identified as MK-9(H0), MK-9(H4) and MK-9(H2). The major fatty acids were C16 : 0, iso-C17 : 0 and C17 : 0 10-methyl. The detected polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, hydroxy-phosphatidylethanolamine, phosphatidylinositol and three unidentified phospholipids. The genomic DNA G+C content was 69.7 mol%. In addition, whole-genome analysis indicated that strain NEAU-L178T had the potential to degrade cellulose. Based on the phenotypic, genotypic, chemotaxonomic and phylogenetic data, strain NEAU-L178T can be differentiated from its close phylogenetic relatives and represents a novel species of the genus Nonomuraea, for which the name Nonomuraea aurantiaca sp. nov. is proposed. The type strain is NEAU-L178T (=JCM 34799T=CGMCC 4.7741T).
Keywords: 16S rRNA gene; Nonomuraea aurantiaca sp. nov.; cellulase-producing actinobacterium; genome; polyphasic approach.