Virgisporangium aliadipatigenens sp. nov., Isolated from Soil in Iriomote Island and Emended Description of the Genus Virgisporangium

During a study of the distribution of actinomycetes in a subtropical zone in Japan, two strains forming short sporangiophores on the substrate mycelium were isolated from soil. The 16S rRNA gene sequences of the isolates indicated that these organisms formed a monophyletic cluster with members of the genus Virgisporangium in the family Micromonosporaceae. These strains formed narrow sporangia on short sporangiophores directly above the substrate mycelium. The sporangia contained motile spores. The strains contained 3-OH-diaminopimelic acid in the cell wall and glucose, ribose, mannose, galactose, xylose and 3-O-methylmannose as whole-cell sugars. The predominant menaquinones were MK-10(H4) and MK-10(H6). The diagnostic phospholipid was phosphatidylethanolamine. Cis 9 C17:1 and C17:0 were detected as the major cellular fatty acids. The G+C content of the DNA was 71.7 mol%. DNA–DNA relatedness analysis showed that the two isolates represented the same genomic species. The results of morphological, chemotaxonomic and 16S rRNA gene sequence analyses, as well as DNA–DNA hybridization studies, confirmed that these isolates certainly belonged to a new species of the genus Virgisporangium. We propose a novel taxon of the genus Virgisporangium as Virgisporangium aliadipatigenens sp. nov., with the type strain IR20-55T (= NBRC 105644T).