The aim of this master thesis was to characterize brewing strains that could effectively ferment buckwheat and millet wort in comparison with barley wort under brewing conditions. In this research we selected thirteen genetically diverse Saccharomyces pastorianus strains and twelve hybrid strains of the genus Saccharomyces isolated from spontaneous fermentations of cider. The hybrid nature of the strains isolated from cider was determined by species-specific PCR primers for the species of genus Saccharomyces. Further, we determined growth kinetics of the strains on different fermentable sugars and types of worts in microtiter plates. S. pastorianus brewing strains were more efficient in maltotriose assimilation, whereas Saccharomyces spp. strains isolated from cider were more efficient in maltose and raffinose assimilation. We also determined the rate of attenuation of different worts and the formation of ethanol and glycerol by the strains in conical mini-fermenters at 14 °C. The S. pastorianus brewing strains most effectively fermented barley wort, whereas Saccharomyces spp. strains isolated from cider more effectively fermented millet and buckwheat worts. After the fermentations were completed, we determined the rate of flocculation using HELM test. The hybrid strains isolated from cider, flocculated better in buckwheat wort in comparison with the brewing strains. Based on the results, we conclude that we were able to select brewing strains and strains isolated from cider that have desirable technological properties for fermentation of buckwheat and millet wort.
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