APPLICATION OF THE POLYMERASE CHAIN-REACTION TO THE RAPID ANALYSIS OFBREWERY YEAST STRAINS

The rapid discrimination of closely-related Saccharomyces cerevisiae s trains can pose a significant problem to breweries, in particular wher e closely related strains are being used simultaneously to manufacture different products. In this study, two PCR approaches have been exami ned to assess their usefulness for the discrimination of brewery ale a nd lager yeast strains. PCR using arbitrary primers (RAPD PCR) was fou nd unsuitable for such an application since the DNA profiles generated from brewery strains were generally found to be identical, due presum ably to the close genetic relatedness of these yeasts. In contrast, PC R using delta sequence primers could rapidly differentiate between man y ale and lager strains and characteristic profiles for these were gen erated. This method could also be applied directly to yeasts isolated from brewery worts or from active dried yeast preparations. Results of such analyses were available within the working day.