酒精发酵中应用酸性蛋白酶的研究

对酸性蛋白酶在酒精发酵中的应用进行了研究。添加酸性蛋白酶有利于原料中蛋白质的水解，增加醪液中酵母可吸收性氮，促进酵母菌生长繁殖，提高酒精发酵速率。而且，a-氨基氮的增加，减轻了酵母菌细胞氨基酸合成代谢的负荷，使底物（葡萄糖）更多地转向发酵生成乙醇，提高原料出酒率。接种酵母后，在醪液中添加0．01％的酸性蛋白酶，发酵时间由原来的52h缩短到32h，发酵成熟醪酒精含量为10．2％（V）。着延长发酵时间至44h，则发酵成熟醪中酒精含量由原来的9．8％（V）增加到10．7％（V），并对添加酸性蛋白酶和（NH4）2SO4的发酵结果进行了比较，认为酸性蛋白酶是实现高效率酒精发酵的优选促进剂。

The Study on the Application of Acid Proteinase to Ethanol Fermentation

The application of acid proteinase to ethanol fermentation was studied. Acid proteinase couldhydrolyze soluble corn proteins to yeast-assimiable nitrogen in mash,which stimulated yeast growth and ac-celerated the rate of the ethanol fermentation. The increased levels of free amino nitrogen could decreased themetabolism current yeast biosynthesised amino acid. Thus more media (glucose) cou1d be used to produceethanol, which raised the rate of corn utilization. lt was found that 0. 01 % acid proteinase added in mash couldshorten fermentation time from 52h to 32h, producing 10. 2% (v) ethanol in the fermented mash. After 44hof the fermentation, 10. 7 % (v) ethanol was yielded. Whereas,in normal corn mash the ethanol was 9. 8 % (v)until 52h. Comparing the results of adding acid proteinase and ammonium sulphate in mash,acid proteinasewas proved to be the superior high-effectively ethanol fermentation promoter.