Numerical taxonomy of Actinomadura and related actinomycetes.

One hundred and fifty-six Actinomadura strains, marker strains of related taxa, and related isolates from bagasse and fodder were the subject of numerical phenetic analyses using 90 unit characters. The data were examined using the simple matching (SSM), Jaccard (SJ) and pattern (DP) coefficients and clustering was achieved using both single and average linkage algorithms. Cluster composition was not markedly affected either by the coefficient or clustering algorithms used or by test error, estimated at 4.5%. Actinomadura dassonvillei, Actinomadura madurae and Streptomyces somaliensis formed good taxospecies, but the separation of Actinomadura pelletieri strains into two clusters by SJ and SSM analysis requires further study. The single representatives of Actinomadura helvata, Actinomadura pusilla, Actinomadura roseoviolacea, Actinomadura spadix and Actinomadura verrucosopora seemed to form new centres of variation while Actinomadura citrea and Actinomadura malachitica showed much similarity with Actinomadura madurae. Most of the isolates form bagasse and fodder were recovered in two well-defined phena, provisionally labelled clusters 'A' and 'B' which showed little similarity to either Actinomadura or Nocardia strains. The effect of the different coefficients on the aggregation of clusters is discussed.