交联糖化酶聚集体的制备

Preparation of cross-linked glucoamylase aggregates

为了克服游离糖化酶的部分缺点,将游离糖化酶用合适的沉淀剂沉淀后,再用戊二醛作为交联剂进行交联,制备了新型的固定化糖化酶-交联糖化酶聚集体。研究结果表明,糖化酶最适聚集条件为:pH5.6,20℃,5g/L的糖化酶液中加入叔丁醇沉淀,可获得比较理想的糖化酶聚集体;最适交联条件为:向糖化酶聚集体中加入10%戊二醛水溶液交联120min,再经离心、洗涤数次后即得交联糖化酶聚集体,酶活力为游离糖化酶的40.4%。

In order to overcome the disadvantages of free glucoamylase, cross-linked glucoamylase aggregates（CLEAs）, a new immobilized glucoamylase, was produced by using glutaraldehyde as cross-linker after the free glucoamylase was precipitated by the appropriate precipitator. The optimum conditions of glucoamylas aggregation were obtained as followed： the glucoamylase aggregates could be achieved alter adding tert-butyl alcohol into the solution of glucoamylase （5g/L and pH5.6） at 20℃. The optimum crosslinking conditions were as followed： the glutaraldehyde （10%） was introduced into the glucoamylase aggregates and was crosslinked for 120min, the CLEAs were obtained alter centrifuging and washing. The activity of the CLEAs was 40.4% of that of the free glucoamylase.