摘要
从汾酒厂的酒醅、酒糟、曲粉、曲块和湿曲5种样品中,分离纯化出42株芽孢杆菌。通过在酪蛋白平板上测定透明圈筛选得到1株在高温下产蛋白酶能力很强的菌株,编号为W20。W20的产酶最适温度为55℃,产酶能力随pH值的升高先增大后减小,在pH值为7时产酶能力最强。蛋白酶标准测定法结果也证明W20是1株高产高温蛋白酶芽孢杆菌菌株。55℃时测得的蛋白酶活力高达708.33U/mL。
Forty-two Bacillus strains were isolated from the fermented grains, distilled grains, Daqu powder, Daqu cake and wet Daqu of Chinese Fen liquor. Through determination of the transparent circle on casein plate, strain W20 was selected as a high thermotolerant protease producing Bacillus strain. The optimum protease-producing temperature of W20 was 55℃. Along with the increase of pH, the protease-producing activity of W20 increased firstly and decreased afterwards, and the highest protease-producing activity appeared at pH 7. The results of standard determination of protease also proved W20 was a high thermotolerant protease producing Bacillus strain. The thermotolerant protease activity of W20 reached 708.33 U/ml at 55℃.
出处
《中国酿造》
CAS
北大核心
2009年第1期67-69,共3页
China Brewing
基金
山西杏花村汾酒厂股份有限公司专项基金