ARBITRARY PCR - A NEW METHOD FOR PROVIDIN G QUICK EVIDENCE AND QUICK IDENTIFICATION OF BREWING ORGANISMS .1. BREWERY-RELEVANT YEAST STRAINS

Culture yeast is used more especially in breweries for top and bottom fermented beers having different technological properties (i.e. the co urse of the fermentation, break formation, aroma spectrum). Occasional ly contamination occurs with closely associated or remotely associated yeasts. An important aspect of operational control is maintaining the purity and the properties of the appropriate culture yeast. The yeast strains have to be regularly identified for this purpose. As a rule t his is based on numerous physiological and biochemical characteristics the examining of which is generally very complicated and time-consumi ng. Modem methods of identifying organisms are based on molecular biol ogical DNS tests. The polymerase chain reaction technique has gained m ore and more significance in recent years. For some two or three years now a variant of the PCR, the arbitrary PCR, offers the possibility o f characterising microorganisms at genomic level. It is a quick and le ss expensive alternative to conventional identification methods. In th is article this unique method is introduced by bringing an example of some of the yeast strains relevant for brewing as an example and then drawing a comparison with established physiological and genotypical id entification methods in beverage microbiology.