以介孔分子筛MCM-41作为漆酶固定化的载体,采用物理吸附法进行固定化,考察了时间、pH和给酶量对固定化效果的影响,并对固定化酶的活性及其稳定性进行了研究,讨论了影响固定化过程和固定化酶性质的主要原因。结果显示,在pH为3时,酶和载体比例为625mg·g^-1时吸附12h固定化效果最好,固定化酶活性回收率为50%:与游离漆酶相比,MCM-41固定化漆酶的最适反应pH略有升高,最适温度没有变化,其pH稳定性和热稳定性都显著优于游离漆酶,固定化漆酶具有可重复操作的性质,与底物反应反复操作10批次后剩余活性为40%。以上表明,MCM-41作为固定化漆酶的一种新型载体材料,有利于改善漆酶的稳定性和实用性。
The mesoporous molecular sieve MCM-41 was employed as the support for the immobilization of enzyme laccase, and the laccase was loaded into the MCM-41 by the physical adsorption method. The effects of immobilization time, pH value and the amount of enzyme provided on the immobilization were investigated, and the activity and stability of the immobilized enzyme were also studied. The main factors that influence the immobilization process and properties of the immobilized enzyme were discussed. Under pH=3, the optimum conditions for immobilization of laccase were found as follows: the immobilization time of 12 h and the ratio of enzyme to MCM-41 of 62.5 mg·L^-1, and using them, the activity recovery of the immobilized laccase is 50 %. Comparing with the free laccase, the optimum working pH of the immobilized enzyme is slightly higher, while their most suitable working temperatures are almost the same. The experiments show that the immobilization significantly improves the pH stability and thermal stability of laccase. The immobilized enzyme can be used repeatedly, and the remained activity is 40% after 10 times of reaction with the substrate. The results indicate that using the MCM-41 as a novel support material for laccase immobilization is favorable to the improvement on the stability and practicality of laccase.