Strains for fermentation of high gravity worts - a review

Abstract

The paper deals with isolation and construction of new strains usable for fermentation of high gravity worts. These worts cause stress for yeasts, and influence their metabolism and fermentation activity. It is reflected in fermentation speed and beer quality. Brewers' yeast with STA2 genome for production of extracellular glucoamylase was obtained by gene manipulations, which is also used in industrial production. Operational experiments were successfully conducted with new strains of yeasts with these characteristics: ethanol-tolerant, osmotolerant, not glucose-repressed, higher flocculation capacity, ability to degrade turbidity-forming substances, influenced production of flavouring substances, but their larger-scale use is prevented by legislation.

Keywords

• brewers' yeasts
• gene manipulations
• hg
• vhg
• stress