Use of specific PCR primers to identify three important industrial species of Saccharomyces genus: Saccharomyces cerevisiae, Saccharomyces bayanus and Saccharomyces pastorianus

Aim: To develop species-specific primers capable of distinguishing between three important yeast species in alcoholic fermentation: Saccharomyces bayanus, Saccharomyces cerevisiae and Saccharomyces pastorianus. Methods and Results: Two sets of primers with sequences complementary to the HO genes from Saccharomyces sensu stricto species were used. The use of the ScHO primers produced a single amplificon of c. 400 or 300 bp with species S. cerevisiae and S. pastorianus, respectively. The second pair of primers (LgHO) was also constructed, within the HO gene, composed of perfectly conserved sequences common for S. bayanus species, which generate amplicon with 700 bp. No amplification product was observed in the DNA samples from non-Saccharomyces yeasts. Saccharomyces species have also been characterized via electrophoretic karyotyping using pulsed-field gel electrophoresis to demonstrate chromosomal polymorphisms and to determine the evolutionary distances between these species. Conclusions: We conclude that our novel species-specific primers could be used to rapidly and accurately identify of the Saccharomyces species most commonly involved in fermentation processes using a PCR-based assay. Significance and Impact of the Study: The method may be used for routine identification of the most common Saccharomyces sensu stricto yeasts involved in industrial fermentation processes in less than 3 h.