Actinomadura roseirufa sp. nov., producer of semduramicin, a polyether ionophore

The taxonomic position of 'Actinomadura roseorufa' LMG 30035(T), a semduramicin-producing mutant of strain ATCC 53666(P), which was isolated from a soil sample collected in Yamae Village, Kamamoto, Japan, was clarified in the present study using a polyphasic approach. This Gram-positive, aerobic actinomycete formed a well-developed, extensively branched, non-fragmenting substrate and aerial mycelia which differentiated into single, smooth-appearing spores. Based on analysis of nearly complete 16S rRNA gene sequence, strain LMG 30035(T) was found to be closely related to the type strains of Actinomadura fibrosa ATCC 49459(T) (98.88 %) and Actinomadura formosensis JCM 7474(T) (98.82 %) (pairwise similarity values in parentheses). Digital DNA-DNA hybridisation experiments revealed unambiguously that strain LMG 30035(T) represents a novel Actinomadura species (OrthoANIu values less than 83.1 %; dDDH values less than 27.2% with type strains of validly named Actinomadura species). Analysis of the cell wall revealed the presence of meso-diaminopimelic acid in the peptidoglycan. The whole-cell sugars were glucose, madurose, galactose, ribose and rhamnose. The major polar lipids included phosphatidylinositol and diphosphatidylglycerol. The predominant menaquinones were MK-9(H-6), MK-9(H-8), MK-9(H-4) and MK-9(H-2). The major fatty acids were C-16 : 00, 10-methyl C-18 : 0, C-18 : 1 omega 9c and C-18 : 00. The DNA G+C content of its genome was 72.5 mol%. In summary, these characteristics distinguish strain LMG 30035(T) from validly named species of the genus Actinomadura, and therefore, we propose to classify this strain formally as the novel species Actinomadura roseirufa sp. nov. with LMG 30035(T) (=CECT 9808(T),=ATCC 53664(T)) as the type strain