Streptosporangium heterodermiicola sp. nov., a novel actinomycete isolated from the foliose lichen Heterodermia diademata

A novel actinobacterial strain V21-05 T was isolated from the thallus of the foliose lichen Heterodermia diademata collected in Doi Inthanon National Park, Chiang Mai Province, Thailand. Phylogenetic analysis based on the 16S rRNA gene and whole-genome sequences consistently placed strain V21-05 T within the genus Streptosporangium , forming a well-supported clade with Streptosporangium oxazolinicum JCM 17388 T . The draft genome of strain V21-05 T contained 71.1 mol% of G+C content. Strain V21-05 T exhibited digital DNA–DNA hybridization and average nucleotide identity values with S. oxazolinicum JCM 17388 T below the species delineation thresholds. A polyphasic approach revealed differences in physiological characteristics, carbon and nitrogen utilization patterns and enzymatic activity profiles between V21-05 T and the closely related strains. The chemotaxonomic characteristics supported its placement within the genus Streptosporangium , with meso -diaminopimelic acid, MK-9(H 2 ) and MK-9(H 4 ) as predominant menaquinones, and fatty acids including iso-C 16:0 , C 17:1 ω8C, and C 17:0 10-methyl. The polar lipid profile comprised phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, two unidentified glycolipids, two unidentified aminophospholipids and two unidentified phosphoglycolipids. These results support the classification of strain V21-05 T as a representative of a novel species, for which the name Streptosporangium heterodermiicola sp. nov. (type strain =V21-05 T =TBRC 20022 T =NBRC 117251 T ) is proposed. This is the first report of a novel Streptosporangium from a lichen habitat.