Numerical Classification of Streptomyces and Related Genera

• Published in: Journal of general microbiology Vol. 129; no. 6; pp. 1743 - 1813
• Main Authors: Williams, S. T, Goodfellow, M, Alderson, G, Wellington, E. M. H, Sneath, P. H. A, Sackin, M. J
• Format: Journal Article
• Language: English
• Published: England Soc General Microbiol 01.06.1983
• Subjects: Actinomadura; Culture Media; Drug Resistance, Microbial; Nocardia; Pigmentation; Space-Time Clustering; Spores, Bacterial; Streptomyces; Streptomyces - classification; Streptomyces - growth & development; Streptomyces - metabolism; Streptomycetaceae
• ISSN: 0022-1287; 1350-0872; 1465-2080
• DOI: 10.1099/00221287-129-6-1743

Department of Botany, University of Liverpool, Liverpool L69 3BX, U.K. Department of Microbiology, University of Newcastle, Newcastle upon Tyne NE1 7RU, U.K. School of Studies in Medical Sciences, University of Bradford, Bradford BD7 1DP, U.K. Department of Biology, Liverpool Polytechnic, Liverpool L3 3AF, U.K. Department of Microbiology, University of Leicester, Leicester LE1 3RH, U.K. ABSTRACT SUMMARY: Four hundred and seventy-five strains, which included 394 type cultures of Streptomyces and representatives of 14 other actinomycete genera, were studied. Overall similarities of these strains for 139 unit characters were determined by the S SM and S J coefficients and clustering by the UPGMA algorithm. Test error and overlap between the phena defined were within acceptable limits. Cluster-groups were defined by the S SM coefficient at the 70.1% similarity ( S ) level and by the S J coefficient at the 50% S -level. Clusters were distinguished at the 77.5% S SM and 63% S J S -levels. Groupings obtained with the two coefficients were generally similar, but there were some changes in the definition and membership of cluster-groups and clusters. The phenetic data obtained, together with those from previous diverse studies, indicated that the genera Actinopycnidium, Actinosporangium, Chainia, Elytrosporangium, Kitasatoa and Micro-ellobosporia should be reduced to synonyms of Streptomyces, while Intrasporangium, Nocardioides and Streptoverticillium remained as distinct genera in the family Streptomycetaceae. Nocardiopsis dassonvillei also showed strong phenetic affinity to Streptomyces, despite its chemotaxonomic differences. Actinomadura sensu stricto was phenetically distinguishable from Streptomyces and ‘Nocardid’ mediterranea was recognized as a taxon distinct from both these genera and from Nocardia sensu stricto. Most of the Streptomyces type cultures fell into one large cluster-group. At the 77.5% S SM S -level, they were recovered in 19 major and 40 minor clusters, with 18 strains recovered as single member clusters. The status of the latter as species was therefore confirmed. Most of the minor clusters, consisting of two to five strains, can also be regarded as species. The major clusters varied in size (from 6 to 71 strains) and in their homogeneity. Therefore, it is suggested that they be regarded as species-groups until further information is available. The results provide a basis for the reduction of the large number of Streptomyces species which have been described. They also demonstrate that the previous use of a limited number of subjectively chosen characters to define species-groups or species has resulted in artificial classifications.