酵母细胞破碎条件优化及高肽酶菌株筛选

为构建酵母细胞总肽酶活力的测定方法。采用单因素试验和L9(34)正交试验设计，以反应体系中游离氨基酸总量为肽酶活力指标，对酵母细胞破碎条件进行优化。结果表明：最佳破壁条件为：蜗牛酶添加量10mg/mL、超声破碎功率500W、超声时间8min、超声时间间隔5s。在此条件下，对主要源于贵州特色发酵豆制品的61 株酵母菌进行总肽酶活力测定，获得产高肽酶酵母菌4 株，即WCF-5、XWF-1、XWF-7 和YZJ-4。

Optimization of Yeast Cell Disruption and Screening of Strains with High Peptidase Activity

To construct a method for determining total peptidase activity in yeast cells, a L9(34) orthogonal array design generated based on single-factor experiments was employed to optimize conditions for yeast cell disruption. In the optimization, the effects of 4 conditions for yeast cell disruption on total free amino acid amount in reaction system were dealt with. Snailase dose of 10 mg/mL, ultrasonic power of 500 W, ultrasonic treatment time of 8 min and ultrasonic operation interval of 5 s were found optimum. Under these optimum conditions, 61 yeast strains originated from unique Guizhou-style fermented soybean products were subjected to total peptidase activity determination, and 4 of them, namely WCF-5, XWF-1, XWF-7 and YZJ-4, were found have higher pepetidase activity.