聚乙烯亚胺改性聚丙烯腈中空膜固定脂肪酶

The Modification of Polyacrylonitrile Hollow Membrane by Polyethyleneimine to Immobilize Lipase

聚丙烯腈是富腈基的高分子聚合物,易修饰改性,广泛应用于膜分离应用.我们以聚丙烯腈中空膜为载体,采用化学法交联聚乙烯亚胺并固定脂肪酶,固定过程中引入海藻酸钠,用CaCl_2进行后处理,得到固定化脂肪酶PAN-PEI-SA/E-CaCl_2载酶量为31.70(mg enzyme)/(g support),酶活为50.20 U/(g support),15次重复使用可保留58.77%的酶活,与游离酶相比耐酸性和耐温性有所提高,相同条件下与Nov 435相比,酶活更高,这表明最终得到的固定化脂肪酶有良好的工业应用前景.

Polyacrylonitrile is a nitrile-rich polymer and easy to be surface modified, and it has been widely applied in membrane separation. In this study, polyacrylonitrile hollow membrane was used as a support of enzyme immobilization by chemically cross-linking polyethyleneimine. Sodium alginate was added during immobilization, and the immobilized lipase was post-treated by CaCl2. The amount of loading enzyme of PAN-PEI-SA/E-CaCl2 was 31.70 （mg enzyme）/（g support） and the activity as 50.20 U/（g support）.After 15 cycles of reactions, the immobilized enzyme retained 58.77% of initial enzyme activity, and showed an improvement of heat and acid resistance compared to free lipase. When it is compared to commercialized Nov 435 under same condition, PAN-PEI-SA/E-CaCl2 has higher enzyme activity during 15 cycles of reactions. It shows the immobilized lipase with PAN after surface modification has industrial application prospects.