Thermoactinospora rubra gen. nov., sp. nov., a thermophilic actinomycete isolated from Tengchong, Yunnan province, south–west China

Two novel Gram-positive, spore-forming, thermophilic actinomycetes, designated as strain YIM 77501^T and YIM 77570, were isolated from a sandy soil sample collected at Tengchong National Volcanic Geological Park, Yunnan province, south–west China. Phylogenetic analysis based on the 16S rRNA gene sequences suggested that the two isolates fell within the family Streptosporangiaceae. The strains formed extensively branched substrate and aerial mycelia which carried masses of long, straight or irregular spore chains composed of warty ornamented spores. Cell walls of the two strains contained meso-diaminopimelic acid and glucose, galactose, mannose and ribose were detected as whole-cell sugars. The predominant menaquinones were MK-9(H₄) and MK-9(H₆). The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, N-acetylglucosamine-containing phospholipids and phosphatidylinositol, phosphatidylinositolmannosides. The major cellular fatty acids were iso-C_16:0 and 10-methyl C_17:0. The DNA G+C content was 74–76 mol%. On the basis of the morphological and chemotaxonomic characteristics as well as the phylogenetic analysis, these strains represents a novel species of a new genus within the family Streptosporangiaceae, for which the name Thermoactinospora rubra gen. nov., sp. nov. is proposed. The type strain of T. rubra is YIM 77501^T (=DSM 45614^T = CCTCC AA 2011014^T).