A novel specific DNA marker in Saccharomyces bayanus for species identification of the Saccharomyces sensu stricto complex

This study was based on RAPD fingerprinting for species identification of the Saccharomyces sensu stricto complex. 40 random primers were used for RAPD analysis. The results showed that one of these primers, OPT-18, produced a 974 bp species-specific band, which was only found in the tested S. bayanus. Afterward this specific fragment was isolated from agarose gel and ligated into vector for DNA sequencing. A pair of primer SpeOPT18Sbay-F2 and SpeOPT18Sbay-R2 were designed according to the cloned species-specific sequence, which was employed for PCR with the template DNA of the S. sensu stricto strains, single 779 bp species-specific band was only found in S. bayanus. Therefore, we conclude that our novel species DNA marker could be used to rapidly and accurately identify the species of S. bayanus from S. sensu stricto complex by direct PCR.