Delimination of brewing yeast strains using different molecular techniques

In general, the genetic characteristics, the phenotype and the microbial pu rity of the production brewing yeast strains are among the most important f actors in maintaining a consistently good quality of products. Analysis of restriction fragment length polymorphism (RFLP) patterns of 18S rRNA-coding DNA was investigated to group ale and lager strains. All production brewin g yeast strains showed the same RFLP pattern as the type strain and synonym type strains of S. cerevisiae, and were quite different from the type and synonym type strains of S. pastorianus. Based on these data, all production brewing yeast strains investigated in this study appeared to belong to S. cerevisiae. Electrophoretic karyotyping and random amplified polymorphic DN A (RAPD) analysis appeared to be suitable methods for distinguishing not on ly the type and synonym type strain of S. cerevisiae and S. pastorianus, bu t also the ale and the lager strains. (C) 2000 Elsevier Science B.V. All ri ghts reserved.