黏土吸附法固定化脂肪酶的初步研究

为研究天然黏土为载体固定化脂肪酶的可行性,采用羟基化、硅烷化处理,对黏土进行改性,并以此为载体吸附固定化脂肪酶,探讨黏土固定化脂肪酶的条件对酶活及蛋白吸附量的影响,优化固定化脂肪酶条件。研究结果表明:黏土经羟基化、硅烷化改性处理后能显著提高固定化酶活和蛋白固定量,其中硅烷化改性最优;载体固定脂肪酶最优条件为:加酶量50 mg/g,载体粒径180—250μm,pH值为4.0,固定化温度25℃,固定化时间2.0 h;与游离酶相比,固定化酶显示出更广的pH值适应性。黏土固定化脂肪酶重复使用10批次后,仍能保留76.85%的初始活力。以天然黏土为载体固定化脂肪酶,具有较好的实际可应用性及操作稳定性,在较低pH值条件下应用具有一定优势。

Preliminary study on lipase immobilization by clay adsorption

In order to explore the feasibility of lipase immobilization using natural clay as carrier,the clay was modified by hydroxylation and silanization,and the lipase was adsorbed and immobilized with the modified clay.The influence of the immobilization conditions on the enzyme activity and the protein adsorption capacity was investigated.The optimal immobilization conditions were obtained.The results show that the clay modified by hydroxylation and silanization can significantly improve the activity of immobilized enzyme and the capacity of adsorbed protein,and the silanization is the better modification method.The optimal conditions of lipase immobilization with carrier are as follows: the enzyme dosage is 50 mg/g,the carrier particle size is 180-250 μm,the pH value is 4.0,the immobilization temperature is 25 ℃,and the immobilization time is 2.0 h.The immobilized lipase shows a wider range of pH value adaptability in comparison with the free enzyme.The lipase immobilized with the clay can retain 76.85% of the initial activity after reusing 10 times.The method of lipase immobilization using natural clay as carrier has the characteristics of practical application and operational stability,and has certain advantages in the condition of lower pH value.