以海藻酸钠为载体制备了固定化碱性蛋白酶Alcalase,并以之为催化剂,研究了醇水体系中玉米蛋白酶促水解反应。结果表明,以海藻酸钠固定Alcalase的最佳条件为:海藻酸钠质量浓度为3%,固定化酶体积分数为2%,固定化时间4 h,CaCl2质量浓度2%。在醇水体系中固定化酶水解玉米蛋白制备多肽的最优条件为:叔丁醇-水体系(体积比1∶1),底物质量浓度5%,加酶量8%(w/v),pH值8.5,温度55℃,水解时间2.5 h,在上述条件下,水解度可达22.7%。对该固定化酶的操作稳定性考察表明,该固定化酶重复使用3批次,酶活力仍保持在50%以上。

Sodium alginate was used as carrier for immobilization of Alcalase.The immobilized conditions of Alcalase and stability of immobilized Alcalase as well as its application in hydrolyzing corn gluten were studied.The results showed that the optimal conditions for immobilizing Alcalase are sodium alginate concentration 3%(w/v),Alcalase concentration 2%(v/v),CaCl2 concentration 2%(w/v).Under these conditions,the optimal conditions for hydrolyzing corn gluten are tertiary butyl alcohol-water system(1∶ 1,v/v),substrate concentration 5%(w/v),dosage of immobilized Alcalase 8%(w/v),pH 8.5,temperature 55℃ and hydrolysis time 2.5h.Under these conditions,the highest hydyolysis degree was 22.7%.After being used for 3 times repeatedly,more than 50% activities of immobilized Alcalase remained.