A novel, Gram-positive, spore-forming actinomycete, designated strain 7K107T, was isolated from a soil sample collected from the Karakum Desert, Turkmenistan. Strain 7K107T forms extensively branched substrate mycelia and aerial mycelia which differentiate into short chains of spores. The novel strain contains meso-diaminopimelic acid as the diagnostic wall amino acid and glucose, galactose, madurose and ribose as whole cell sugars. The predominant menaquinones were identified as MK-10(H4), MK-9(H4), MK-10(H6) and MK-9(H6). The polar lipids were found to be diphosphatidylglycerol, phosphatidylethanolamine, glycolipids, phospholipids, unidentified lipids and an aminolipid. Major fatty acids were identified as C17:0 10-methyl and C14:0. The G + C content of the genomic DNA was determined to be 70.8%. Phylogenetic analysis based on 16S rRNA gene sequences showed that the strain is a member of the family Streptosporangiaceae. The strain shares high 16S rRNA gene sequence similarity (96.2%) with Sphaerisporangium album YIM 48782T followed by Sphaerisporangium corydalis NEAU-YHS15T (96.0%) and Nonomuraea candida HMC10T (95.9%). However, phylogenetic analyses based on 16S rRNA and gyrB genes, as well as whole genome comparison, confirmed the distinctiveness of the strain from closely related type strains of the genera Sphaerisporangium, Nonomuraea and Thermostaphylospora. On the basis of morphological, chemotaxonomic and phylogenetic as well as genomic analyses, strain 7K107T is concluded to represent a new genus within the family Streptosporangiaceae, for which the name Desertiactinospora gelatinilytica gen. nov., sp. nov is proposed. The type strain of D. gelatinilytica is 7K107T (= DSM 107423T = JCM 32585T = KCTC 49108T).
Keywords: 16S rRNA; Desertiactinospora; Polyphasic taxonomy; The Karakum Desert; gyrB.