Almost complete 16S rRNA sequences from seven Thermomonospora strains, Thermomonospora curvata, Thermomonospora formosensis, Thermomonospora fusca, Thermomonospora mesophila, Thermomonospora chromogena, Thermomonospora alba and Thermomonospora mesouviformis (a synonym of Thermomonospora alba) were determined and subjected to phylogenetic analysis together with the sequences from all the representative members of the suborder Streptosporangineae. On the basis of phylogenetic, chemotaxonomic and phenotypic evidence, the transfer is proposed of Thermomonospora formosensis to the genus Actinomadura as Actinomadura formosensis comb. nov., Thermomonospora mesophila to the genus Microbispora as Microbispora mesophila comb. nov., and Thermomonospora fusca and Thermomonospora alba to a new genus, Thermobifida gen. nov., which belongs to the family Nocardiopsaceae, as Thermobifida fusca comb. nov. and Thermobifida alba comb. nov. Thermobifida alba is designated the type species of the genus. The transfer is also proposed of all species of the Microtetraspora pusilla group, which were transferred from Actinomadura, to a new genus, Nonomuria gen. nov., as Nonomuria africana comb. nov., Nonomuria angiospora comb. nov., Nonomuria fastidiosa comb. nov., Nonomuria ferruginea comb. nov., Nonomuria flexuosa comb. nov., Nonomuria helvata comb. nov., Nonomuria polychroma comb. nov., Nonomuria pusilla comb. nov., Nonomuria recticatena comb. nov., Nonomuria roseola comb. nov., Nonomuria roseoviolacea comb. nov., Nonomuria rubra comb. nov., Nonomuria salmonea comb. nov., Nonomuria spiralis comb. nov. and Nonomuria turkmeniaca comb. nov. Nonomuria pusilla is designated the type species of the genus.

Two new species of Actinomadura isolated from soil samples of the Turkmen SSR, i.e. Actinomadura fulvescens sp. nov. and Actinomadura turkmeniaca sp. nov. are described. The first species is characterized by formation of short (1-2 turns) spiral spore chains, smooth spores, scanty white aerial mycelium, colourless or yellowish substrate mycelium on synthetic media and brownish-yellow substrate mycelium and soluble pigment of the same colour on organic media. No melanoid pigment is secreted. The type culture is designated as INA 3321. The cultures of A. fulvescens show antibiotic activity. A. turkmeniaca is characterized by formation of short straight or spiral spore chains, smooth spores, scanty white aerial mycelium, substrate mycelium and soluble pigment of pinkish-violet colour, absence of melanoid pigment. The type culture is designated as INA 3344. The strains of this species have low antibiotic activity. The study on the use of carbon sources by the representatives of 7 species (9 strains) of Actinomadura showed that the majority of the cultures (5 species, 7 strains) produced no growth on the Pridham and Gottlieb medium (ISP-9) with various carbon sources, including glucose. Possibly this medium cannot be used as the main medium for investigation of the spectrum of carbohydrate consumption in Actinomadura.