Role of killer effect in fermentations conducted by mixed cultures of Saccharomyces cerevisiae

Abstract The present work reports on population dynamics in musts (pH 3.2) inoculated with pairs of Saccharomyces cerevisiae wild strains. Two assays determined the growth of both killer and sensitive strains; the latter were not totally eliminated from the must and non-proliferating populations were detected. Another two were carried out with two killer or two sensitive strains, respectively; the exponential growth of the two populations was observed in both cases. The succession of Saccharomyces cerevisiae strains was seen to be common in the four assays; only one strain proved to have the ability to complete fermentation, whereas the other disappeared after 28 days of fermentation. The most important fermentation compounds were estimated at the end of fermentations.