Three-Factor Joint Shock Breeding Yeast

through three-factor (high gravity ethanol, high gravity sodium chloride and heat) joint shock test, we found that different yeast species have different sensitivity to temperature. For example, the mutants resulting from 45 degrees C and 50 degrees C shock of rice wine yeast can ferment in medium containing 17% ethanol, and they have similar ethanol production ability; but the mutant resulting from 50 degrees C shock of brewer's yeast can produce more ethanol than mutant resulting from 45 degrees C shock. Through 48 hours fermentation, original rice yeast can produce 2.6% alcohol in mash, while some of the mutants from this yeast can produce 3.1% alcohol; original brewer's yeast can produce 2.9% alcohol in mash, while some of the mutants of brewer's yeast can produce 3.8% alcohol. So the way of three-factor joint shock can improve yeast ability to produce ethanol and ethanol tolerant capacity significantly.