CELLULAR CARBOHYDRATE COMPOSITION, DNA BASE COMPOSITION, UBIQUINONE SYSTEMS, AND DIAZONIUM BLUE B COLOR TEST IN THE GENERA RHODOSPORIDIUM, LEUCOSPORIDIUM, RHODOTORULA AND RELATED BASIDIOMYCETOUS YEASTS

The cellular carbohydrate composition of the whole cell hydrolysates, the DNA base composition, the ubiquinone systems, and the Diazonium Blue B (DBB) color test were examined in 108 strains of 61 species assigned to the genera Rhodosporidium, Leucosporidium, Rhodotorula, and to other basidiomycetous and ascomycetous yeasts. Taxonomic evaluations of these yeasts were made based upon the data presented. The yeasts were divided into two major groups based upon the presence of xylose in the cells. They had ubiquinone systems, Q-8, Q-9, or Q-10. All basidiomycetous yeasts gave the positive color reaction with DBB except two strains of Rhodotorula glutinis, whereas the ascomycetous ones were all negative. A good correlation was found between the groupings based upon the presence of xylose in the cells, DNA base composition, ubiquinone systems, assimilation of inositol, formation of starch-like compounds, and basidial forms in the Rhodosporidium, Leucosporidium, Cystofilobasidium, Filobasidium, and Filobasidiella. Further, species of the genera Rhodosporidium and Leucosporidium, including their anamorphs Rhodotorula and Candida, should be revised taxonomically on the basis of chemotaxonomy. The presence of xylose in the cells, even in small amounts, is significant taxonomically. The ratio of mannose to glucose is also an indicative index in some strains.