%0 Journal Article %A Szabó, I. %A Marton, M. %T Comments on the first results of the international cooperative work on criteria used in characterization of Streptomycetes %D 1964 %J International Journal of Systematic and Evolutionary Microbiology, %V 14 %N 1 %P 17-38 %@ 1466-5034 %R https://doi.org/10.1099/0096266X-14-1-17 %I Microbiology Society, %X SUMMARY In the characterization of the taxonomic criteria of Streptomyces species, or so-called “species groups,” the property in question is to be defined considering the extreme polymorphism of these organisms, and taking into account all sources of error, and problems which may arise in the course of identification. Based upon their own investigations and analysing the summarised data of the cooperative work, the authors came to the conclusion that the properties assigned by the Subcommittee to be studied can be separated with certainty only according to the following scheme: Morphology of sporophores: 1. Rectus flexibilis. 2. Spira. 3, Verticiilatus rectus flexibilis. 4, Verticillatus spira. Colour of substratum mycelia: 1, Yellowbrown. 2, Yellow-brown + red. 3, Yellow-brown + blue (blue or violet or red-blue with indicator-character). 4, Yellow-brown + green. Colour of aerial mycelium (more precisely that of spores): 1, Niveus (snow-white). 2, Griseus (yellowish to greenish - grey). 3, Venetus (blue-grey to blue-green to green-grey). 4, Cinereus (ash-grey). 5, Cinnamoneus (light carmine to brownish). The possible confusion of the spore-colours “griseus” and “venetus” may be eliminated by the simultaneous study of four other properties (i. e. structure of sporophores, melanin - reaction, habits of the aerial mycelium, spore surface), as the latter occur in characteristic combinations with these spore colour-groups. %U https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/0096266X-14-1-17