将优化后的枯草芽孢杆菌碱性蛋白酶(serine alkaline protease，SAP)基因克隆到酿酒酵母表达载体pYES2上，在酿酒酵母Whu2d中进行表达。发酵酿酒酵母工程菌，对重组碱性蛋白酶酶学性质和降解豆粕中蛋白类抗营养因子效果进行研究。结果显示：工程菌发酵液中碱性蛋白酶酶活比出发菌株高55.2%。其最适反应温度和pH分别为45 ℃和8.0，在pH值为7.0～10.5时具有较好的稳定性，相对酶活可以保持在80%以上。与出发菌株相比，工程菌发酵后豆粕培养基中酸溶蛋白含量提高42.1%，粗蛋白和β-伴大豆球蛋白含量无显著差异，大豆球蛋白和胰蛋白酶抑制因子的含量分别降低41.9%和57.4%。以上结果表明：该碱性蛋白酶酿酒酵母工程菌可以用于饲料、食品等富含蛋白原料的加工。

The optimized serine alkaline protease (SAP) gene was cloned into expression vector pYES2 and expressed in Saccharomyces cerevisiae Whu2d. The S. cerevisiae engineering bacteria was used to study the enzymatic properties of recombinant alkaline protease and the effect of degrading protein anti-nutritional factors in soybean meal. The results indicated that the activity of alkaline protease in the fermentation broth of recombinant S. cerevisiae was 55.2% higher than that of the original strain. The optimum reaction temperature and pH were 45 ℃ and 8 respectively, and the stability was good at pH 7-10.5, where the relative enzyme activity could be maintained above 80%. Compared with the original strain, the content of acid soluble protein in soybean meal increased by 42.1% and the content of crude protein and β-conglycinin had no significant difference. The contents of glycinin and trypsin inhibitor were reduced by 41.9% and 57.4%. The results showed that the S. cerevisiae engineering bacteria could be used for the processing of feed, food and other protein-rich materials.