吸附-聚合物修饰组合固定化Candida antarctica脂肪酶研究

通过吸附法联合PEG非共价修饰,研发了一种固定化南极假丝酵母脂肪酶(Candida antarctica lipase)的新方法,可以有效提高固定化酶在非水介质中的催化活性。最佳固定化条件为硅藻土:酶粉(W/W)=8,PEG4000:酶粉(W/W)=0.6,缓冲液pH7.5。采用三油酸甘油酯与甲醇的转酯化反应,测定了固定化酶的转酯活性。结果表明,固定化酶同时加入PEG进行非共价修饰,可显著提高固定化酶的转酯活力。PEG修饰的固定化酶转酯比活是未经PEG修饰的固定化酶的4.1倍,转酯酶活回收率为604.8%,说明PEG两性分子的特性对制备用于非水介质的固定化酶有重要作用。该固定化方法可显著提高Candida antarctica脂肪酶在非水介质中的催化效率,且固定化方法简单、成本低,具有工业应用价值。

Immobilization of Candida antarctica Lipase by the Combination of Adsorption and Polymer Modification

Using combination of diatomite adsorption and non-covalent modification by poly(ethylene glycol) 4000 (PEG), a novel method of immobilizing Candida antarctica lipase (CAL) to give a high catalytic activity for transesterification reaction in anhydrous organic media was developed. The transesterification activity of the immobilized lipase was assayed in the transesterification reaction between 1,2,3-oleic acid and methanol. The optimum immobilization conditions of the CAL were found as follows: diatomite : lipase = 8, PEG4000 : lipase (W:W)=0.6, pH=7.5, respectively. The results show that the immobilized CAL with PEG modification displays higher transesterification activity than that of the immobilized CAL without PEG modification. The specific transesterification activity of the immobilized CAL with PEG modification is 4.1 times that of the CAL without PEG modification, and the recovery of its transesterification activity is 604.8%. These clearly indicate that the amphiphilic nature of the polymer PEG is important for the preparation of the immobilized lipase used in organic media, and the immobilization method proposed can obviously increase the catalytic efficiency of CAL in non-aqueous medium and has the advantage of easy operation and lower cost. All mentioned above indicate that the method proposed is applicable and promising in industrial immobilization field of lipase.