[Systematic study of Saccharomyces: oxidases and vitamin requirements]

A study of the genus Saccharomyces by new biocharacters demonstrates indirectly the genotype of each species; intracellular osidases (lactose - maltose -cellobiase - melibiase - invertase - trehalase) and vitamin requirements (biotin-folic acid-inositol-niacine-pantothénate-para-aminobenzoic acid-pyridozine-thiamine) reveal some phylogenetic links between the species. It appears that Van der Walt's group I is very homogeneous and must be restricted to only 7 species. The torulospora group seems very similar to the genus Debaryomyces when vitamin needs and osidases are considered; the relations between the 2 groups are discussed. When other biocharacters are studied (nitrite reductase-immunological properties, etc. ...) the value in the GC content (4-5% lower in Debaryomyces) will be established. These results confirm that intracellular oxidases and vitamin needs are very valuable tools for systematic criteria.