SUMMARY: Four hundred and seventy-five strains, which included 394 type cultures of and representatives of 14 other actinomycete genera, were studied. Overall similarities of these strains for 139 unit characters were determined by the and 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 coefficient at the 70.1% similarity () level and by the coefficient at the 50% -level. Clusters were distinguished at the 77.5% and 63% -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 and should be reduced to synonyms of while and remained as distinct genera in the family also showed strong phenetic affinity to despite its chemotaxonomic differences. was phenetically distinguishable from and was recognized as a taxon distinct from both these genera and from

Most of the type cultures fell into one large cluster-group. At the 77.5% -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 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.


Article metrics loading...

Loading full text...

Full text loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error