SPOILAGE POTENTIAL AND BREWING ABILITY OF DIFFERENT SACCHAROMYCES CEREVISIAE VARIETY DIASTATICUS YEAST ISOLATE BY PHENOTYPIC AND PHYSIOLOGICAL CHARACTERIZATION

Saccharomyces cerevisiae var. diastaticus is generally considered to be an obligatory spoilage microorganism and spoilage yeast (i.e. wild yeast) in beer and beer-mixed beverages (Andrews and Gilliland, 2015). A microbiological contamination with S. cerevisiae var. diastaticus can cause economic losses and occasionally expose the consumer to risk of injury. Yeast strains of S. cerevisiae var. diastaticus occur as primary contaminants in the yeast/fermentation cellar and as secondary contaminants in the filling process. A primary contamination can lead to a competition with culture yeast during main fermentation and to a strong increase in the diastaticus cells in the fermentation substrate. Saccharomyces cerevisiae var. diastaticus can lead to changes in flavor but does not give an unpleasant taste to beer (Andrews and Gilliland, 2015). With better knowledge of phenotypic and physiological brewing properties, yeast strains with super-attenuating ability could be further used to produce carbohydrate-reduced and calorie-reduced dealcolyzed beers and beverages.