Abstract
On the basis of morphological and biochemical criteria, Actinomadura das-sonvillei (Brocq-Rousseu) Lechevalier and Lechevalier, the former Nocardia dassonvillei (Brocq-Rousseu) Liegard and Landrieu, is removed from the genus Actinomadura Lechevalier and Lechevalier to a new genus, Nocardiopsis. It is proposed that this new genus harbors aerobic actinomycetes with a nocardioform substrate mycelium, an aerial mycelium, and a cell wall containing meso-2,6-diaminopimelic acid but not madurose or other diagnostically important carbohydrates. The type species is Nocardiopsis dassonvillei (Brocq-Rousseu) comb, nov., for which strain IMRU 509 (= ATCC 23218) is designated as the neotype. An outline of the characters which differentiate the new genus from the genera Nocardia, Actinomadura, and Streptomyces is given.