Streptacidiphilus Fuscans Sp. Nov., A Novel Actinobacterium Isolated From The Root Of Pumpkin (Cucurbita Moschata)

A novel acidophilic actinobacterium, designated strain NEAU-YB345(T), was isolated from a pumpkin root collected from Mudanjiang, Heilongjiang Province, northeast PR China. Based on 16S rRNA gene sequence similarity and chemotaxonomic and morphological properties, the isolate was assigned to the genus Streptacidiphilus, with the high 16S rRNA gene sequence similarities to Streptacidiphilus melanogenes JCM 16224(T) (99.2 %), Streptacidiphilus anmyonensis JCM 16223(T) (99.1 %) and Streptacidiphilus jiangxiensis JCM 12277(T) (98.7 %). Its cell wall contained LL-diaminopimelic acid as the major diamino acid. Rhamnose, ribose, glucose and galactose were the detected sugars from the whole-cell hydrolysates. The phospholipid profile consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside and an unidentified phospholipid. The menaquinones were MK-9(H-8) and MK-9(H-6). Major fatty acids were C-16:0, iso-C-16:0, iso-C-15:0 and anteiso-C-15:0. Phylogenetic analysis using 16S rRNA gene and whole-genome sequences placed the strain in distinct clades but within the genus Streptacidiphilus. The DNA G+C content was 71.2 mol%. Based on DNA-DNA relatedness and physiological and biochemical data, the isolate could be distinguished from its closest relatives. Therefore, strain NEAU-YB345(T) represents a novel species of the genus Streptacidiphilus, for which the name Streptacidiphilus fuscans sp. nov. is proposed. The type strain is NEAU-YB345(T) (=CCTCC AA 2020030(T)=JCM 33976(T)).