摘要
采用复合技术制备出粒径为 １００～３００ｎｍ的磁性淀粉复合微球。以此为载体采用溴化氰共价结合法、戌二醛交联法、物理吸附法固定化ａ一乙酰乳酸脱羧酶。以戌二醛交联法制备的磁性酶为最佳，其活力为１１３８．８Ｕ／ｇ微球，蛋白载量为８９．７ｍｇ／ｇ微球，比活为１２．６Ｕ／ｍｇ蛋白，活性回收率为５９．６％。并对其理化性质进行了研究：磁性酶最适温度３０℃，最适ｐＨ为５．０，热稳定性及酸碱稳定性均有所提高，磁性酶重复使用１０次，其相对活性仍保持在７７．２％。将磁性固定化ＡＬＤＣ用于啤酒发酵，磁性酶用量为 ８０Ｕ／Ｌ麦芽汁，主发酵温度为 １３℃，保持 １０ｄ，发酵后双乙酰含量降到 ０．１３×１０－６以下。
Acetolactate decarboxylase (ALDC) was immobilized on the magnetic starch composite microsphere by adsorption, covalent bond and cross - linking. The conditions of immobilization were studied .The activity of the magnetic immobilized enzyme(MIE) was 1138. 8u/g microsphere. The protein binding capacity was 89. 7mg/g mincrosphere. The specific activity was 12. 6u/mg protein. The activity recovery was 59. 6%. The optimum temperature of MIE was 30℃. The optimum pH value of MIE was 5. 0. MIE had fairly thermal stability and working stability. By using the ALDC in prophase fermentation of beer. It showed that the enzyme could obviously reduce the activity of beer yeast's producing diacetyl.
出处
《广州化工》
CAS
2000年第4期24-27,共4页
GuangZhou Chemical Industry
基金
内蒙古自治区自然科学基金!资助项目(990303-3)
关键词
磁性淀粉复合微球
固定化
乙酰乳酸脱羧酸
啤酒
magnetic starch composite microsphere, immobilization, acetolactate decarboxylase
