A new genus of the order Actinomycetales, Cryptosporangium gen. nov., with descriptions of Cryptosporangium arvum sp. nov. and Cryptosporangium japonicum sp. nov.

Four strains that form sporangia with motile sporangiospores and mycelia were isolated from soil samples. Their many sporangia were covered by mycelia. They had glutamic acid, glycine, alanine and meso-diaminopimelic acid as cell wall amino acids (wall chemotype II), acofriose (3-O-methylrhamnose) as a characteristic whole-cell sugar, and menaquinone 9(H-6). The taxonomic characteristics of these strains differ from those of the previously described motile actinomycetes. On the basis of the morphological, physiological, chemotaxonomic and phylogenetic analyses, a new genus is proposed, Cryptosporangium, and two new species, Cryptosporangium arvum sp. nov. (type strain IFO 15965(T)) for strain YU 629-21(T) and Cryptosporangium japonicum sp. nov. (type strain IFO 15966(T)) for strains YU 636-3(T), YU 655-31 and YU 656-31.