| In this paper, the determination of alcohol degree in wine brewing, screening of wine ADY (Active Dry Yeast) strain, and the control of ADY production technics were studied.A method that can quickly determine wine alcohol degree was selected. It needs less sample and shorter time, and is accurate and suitable for the large amount of assay under the condition of lab.The results of determination of 8 strains' tolerance trait of alcohol, SO2, CO2, high concentration of glucose and wine brewing test showed mat strain A, B, C, F, H have good fermentation characters.The production capability of strain A, B, C, F, H was determined, including suitable culture temperature, specific growth rate, biomass and trehalose accumulation. Strain A was selected as ADY production yeast, its suitable culture temperature was 32 C, specific growth rate was 0.2481/h in malt extract, trehaloase accumulation could reach 8.59% in shake flask.Seed media of strain A was optimized by orthogonal design, and the feeding culture of wine ADY in 5L fermentation jar was conducted with four different technics. The result showed that heat shock technics was the best. In the 13h feeding culture, the temperature was raised from 30 C to 32 C during 9~10h, from 32 C to 34 C during 10~11h and retained 36 C in the last 2h. Under this condition, the biomass could reach 134 g/L and intracellular trehalose content was 19.38%.The feeding culture of wine ADY in 150L fermentation jar was conducted in the factory. The results showed that commodity yeast accorded with the general standard of wine ADY, which further proved the availability of production of wine ADY with the heat shock technics. |
