豆乳凝固酶产生菌的筛选及其酶学性质的研究

Screening of Soymilk Coagulating Enzyme-producing Strain and Study on Its Enzyme Properties

从黄水中分离到1株分泌胞外豆乳凝固酶的霉菌———毛霉HS-D11,将该菌在30℃、150r/min培养2d,再在25℃静置培养2d^3d,所获得的粗酶液中蛋白酶水解活力仅为0.3U/mL,豆乳凝固活力高达1.16U/mL。该酶最适温度65℃,最适pH5.9,0.5mL粗酶液10min内可使5mL豆乳凝固成型,倒置不流出。

Mucor HS-D11, which could produce soymilk coagulating enzyme was isolated from the soy-whey. The strain was shake-cultured at 30℃and 150 rpm for 2 d and then cultured at 25℃ for 2-3 d. The proteolytic activity of crude enzyme was only 0.3 U/ml, but the soymilk-coagulating activity reached 1.16 U/ml. 5 ml soymilk can be coagulated with 0.5 ml crude enzyme at temperature 65℃and pH 5.9 within 10 min and the curd can not outflow when inversed.