D-塔格糖3-差向异构酶的固定化研究

Study on immobilization of D-tagatose 3-epimerase

从14种离子交换树脂和吸附树脂中,筛选出固定化效果较好的大孔弱碱性苯乙烯系阴离子交换树脂D301-Ⅲ为载体,以戊二醛为交联剂,通过先吸附后交联的方法对D-塔格糖3-差向异构酶的固定化进行研究。结果表明,最佳固定化条件为:加酶量为2.00mL/g(粗酶液/树脂),吸附pH7.5,吸附时间为8h,吸附温度为30℃,戊二醛浓度为0.05%,交联时间为3h,固定化酶活回收率可达50%以上。固定化酶重复使用10次,酶活仍能稳定保持在初始酶活的65%以上,具有良好的操作稳定性。

D-tagatose 3-epimerase（DTE）was immobilized on 14 kinds of ion-exchange and adsorption resins,in which D301-Ⅲ was the best material for the immobilization.Then the enzyme was immobilized by cross-linkage of glutaraldehyde.The optimum conditions for the immobilization were as follows：2.00mL/g（liquid enzyme/wet resin）,pH7.5,immobilization temperature 30℃,and immobilization time 8h.The concentration of the crosslinking agent（glutaraldehyde）was 0.05%.The crosslinking time was 3h.The activity recovery yield of immobilized enzyme was above 50%.The remaining activity was more than 65% of the primary enzyme activity after the immobilized enzyme was used repeatedly for 10 times.It showed that the immobilized DTE had good operational stability.