Differentiation and species identification of yeasts using PCR.

A PCR-based method has been developed that permits both intraspecies differentiation and species identification of yeast isolates. Oligonucleotide primers that are complementary to intron splice sites were used to produce PCR fingerprints that display polymorphisms between different species of indigenous wine yeasts. Although polymorphisms existed between isolates of the same species, the banding patterns shared several amplification products that allowed species identification. Importantly, the method was able to distinguish between species of the closely related Saccharomyces sensu stricto yeasts. In two cases where isolates could not be positively identified there was discrepancy between the phenetic and phylogenetic species concept. The method has applications in yeast ecological studies, enabling the rapid grouping of isolates with related genomes and the investigation of population dynamics of strains of the same species.