海藻酸钠固定化环糊精糖基转移酶的研究

Immobilization of Cyclodextrin Glycosyi Transferase in Sodium Alginate

通过单因素分析与正交试验设计确定了海藻酸钠包埋固定环糊精葡萄糖基转移酶(CGTase)的最佳条件。即,海藻酸钠7%(终浓度约为2.3%),CaCl_2浓度3%。海藻酸钠体积与酶液体积比1∶2,固定化时间2.5 h。探讨了固定化CGTase的酶学性质,固定化酶的最适pH及最适温度与游离酶相比没有明显变化,pH稳定性及热稳定性的范围均比游离酶要宽。连续使用7批次操作仍保持75%的酶活力,显示出良好的稳定性。

The optimum conditions for immobilizing CGTase with sodium alginate and the properties of the immobilized enzyme were studied by the single factor and orthogonal design. The results showed thatthe high recovery rate of the immobilized enzyme could be obtained under the conditions of 7 ~ sodium alginate, 3%CAC12, the ratio of sodium alginate and enzyme I ＂ 2, 2. 5 h immobilization time. The optimum pH and temperature of the immobilized enzyme were as the same as free enzyme. It also showed a wider range of re- action pH value and temperature value than free enzyme. The immobilized enzyme showed＇ a high operational stability by retaining almost 75 % of the initial activity at seventh round.