Characterisation and typing of Saccharomyces strains by DNA fingerprinting

Three different molecular methods, total DNA restriction profile analysis, restriction profile of mitochondrial DNA (mtDNA) and Southern hybridisation of mtDNA, were used to characterise Italian wine yeast strains previously identified using conventional taxonomic techniques. Total DNA restriction profile analysis allowed the typing of all strains and showed that they constitute two well separated genomic taxa, one including the type strain of S. cerevisiae and the other the type strain of S. bayanus. The data obtained by analysing mtDNA restriction profiles and mtDNA Southern hybridisation were consistent with results of total DNA restriction profile analysis. This permitted the taxonomic assignmen t of Italian wine yeast strains and the determination of the interspecific genomic relatedness.