Numerical Classification of Actinomadura and Nocardiopsis

Abstract

We studied 170 strains of Actinomadura, Nocardiopsis, and related taxa. The overall similarities of the test strains were determined by comparing 120 unit characters, using the simple matching and pattern coefficients. Clustering was achieved by using the unweighted pair group method with averages. Cluster composition was not markedly affected by the coefficient used or by test error (estimated at 4.9%). The numerical data, together with results from previous chemical and genetic studies, showed that the genus Actinomadura is markedly heterogeneous. Strains received as Actinomadura fell into two large aggregate groups. One, Actinomadura sensu stricto, contained Actinomadura citrea, Actinomadura coerulea, Actinomadura coeruleoviolacea, Actinomadura cremea, Actinomadura livida, Actinomadura madurae, Actinomadura malachitica, Actinomadura pelletieri, and Actinomadura verrucosospora. Actinomadura kijaniata was not studied, but other genetic data suggest that it should also be included in this group. The other aggregate group encompassed Actinomadura ferruginea, Actinomadura pusilla, Actinomadura roseola, Actinomadura roseoviolacea, Actinomadura rubra, and Actinomadura salmonea. The representatives of Actinomadura helvata, Actinomadura libanotica, Actinomadura luteofluorescens, Actinomadura spadix, and Actinomadura spiralis studied formed distinct clusters separate from both of the aggregate groups. Nocardiopsis strains formed a cluster clearly distinguished from the clusters containing the Actinomadura strains.