Results of a comparative study of criteria used in the classification of the Actinomycetes

The results of a comparison of criteria used in characterization of the Actinomycetes under the auspices of the International Subcommittee are reported. Although this first co-operative work carried out on a large scale showed some deficiencies which were caused by the selection of the media and methods and by the type of description, some interesting evidence concerning the value of the used criteria for the classification of Streptomycetes were obtained.

The morphology of sporophores and the shape of spores are significant and constant characteristics so that they can be used as taxonomically useful criteria.

Likewise, the melanin reaction is an unequivocal characteristic and can be applied in a classification. The determination and description of the colours of the aerial as well as of the vegetative mycelium are much more complicated. In principle these results confirm those obtained from a co-operative experiment which was carried out in the USA a short time before (Gottlieb, 1951). In this study organized by the Subcommittee on Actinomycetes of the Committee on Taxonomy of the Society of American Bacteriologists workers ot 11 different laboratories examined 5 different strains by means of 12 morphological as well as physiological criteria

Further studies are necessary to find the most useful criteria and to improve the methods which are suitable for the classification of Streptomycetes. Further co-operative and comparative work could be the best way to solve these taxnomical problems.