Effect of protease and phytase on the physiological state of alcoholic yeast in cultivation

Abstract

Saccharomyces cerevisiae yeast is used in the production of ethyl alcohol. The main requirements for yeast used in the production of ethyl alcohol from starch-containing raw materials: alcohol yeast used in the processing of starchy raw materials must have high fermentation activity; complete fermentability of sugars, resistance to metabolic products, resistance to the development of extraneous microflora. Proteolytic enzyme preparation Prolive BS Liquid was used as a source of protease. Kingphos enzyme preparation was used as a source of phytase. The effect of the enzyme preparations of the neutral protease Prolive BS Liquid and Phytase Kingphos on the fermentation activity of alcohol yeast Saccharomyces cerevisiae race XII was studied. The maximum fermentation activity is possessed by yeast cultivated on the wort, obtained using protease and phytase. The duration of the exponential growth phase in the experiment is 14–16 hours, in the control -18–20 hours. The exponential phase is described by the Mono equation. Compared to the yeast in the control, the yeast in the experiment multiplies more intensively, and by 14–16 hours of growth, about 170 million yeast cells accumulate in the culture medium, and the yeast in the control-about 95 million yeast cells by 18–20 h of growth. The specific growth rate was maximum in the logarithmic phase and amounted to 0.35 million cells / cm3 • h in the experimental samples and 0.25 million cells / cm3 • h in the control. It was found that the maximum accumulation of yeast cells was observed when the neutral enzyme Prolive BS Liquid was added to the wort with a dosage of 0.2 units. PS/g of starch and enzyme preparation Phytase Kingfos with a dosage of 0.5 units. FS/g of starch, the yeast cell content in mature yeast reached 170 million cells / cm3 by 16-18 hours of cultivation, the yeast has a high fermentation activity.