RAPID CHARACTERIZATION OF 4 SPECIES OF THE SACCHAROMYCES SENSU-STRICTO COMPLEX ACCORDING TO MITOCHONDRIAL-DNA PATTERNS

Several strains of the four sibling species of the genus Saccharomyces (S. bayanus, S. cerevisiae, S. paradoxus, and S. pastorianus) were ch aracterized by using a rapid and simple method of restriction analysis of mitochondrial DNA. Patterns obtained with four-cutter endonuclease s (such as AluI, DdeI, HinfI, and RsaI) made it possible to differenti ate each species. S. cerevisiae and S. paradoxus presented a greater n umber of large fragments than S. pastorianus and S. bayanus with all t he assay enzymes. With AluI and DdeI, species-specific bands clearly p ermitted differentiation between S. pastorianus and S. bayanus. To tes t the resolution of this method, wild Saccharomyces strains were analy zed. The correct assignment of these strains to a known taxon by this rapid method was confirmed by means of electrophoretic karotyping.