聚合物刷改性的纳米纤维在固定化脂肪酶中的应用

Application of polymer brush modified PMMA-co-PAA nanofibers on lipase immobilization

基于静电纺丝技术制备甲基丙烯酸甲酯-丙烯酸共聚纳米纤维(PMMA-co-PAA),利用壳聚糖(CTS)和甲基丙烯酸钠对纳米纤维改性.以该纳米纤维作为载体固定脂肪酶,研究改性纳米纤维对酶的固载量及稳定性的影响.试验表明,改性纳米纤维的亲水性和纤维直径得到提高,当甲基丙烯酸钠浓度为0.1mol/L时,酶的固载量达到165mg/g.此外,相比于游离酶,固定化脂肪酶有较高的温度和pH值稳定性,pH值在5~9,温度在20~60℃变化时,固定化酶在最低点的相对活性相比游离酶提升了325%和400%;60℃保温10h后,固定化酶的相对活性比游离酶提升170%.

Polymethylmethacrylate-co-polyacrylic acid(PMMA-co-PAA)nanofibers were prepared by electrospinning technique,followed by modification with chitosan(CTS)and sodium methacrylate.The modified nanofibers were explored as the novel support for lipase immobilization,while the influence of enzymatic loading and stability was reached.The study shows that the hydrophilicity and diameter of the modified nanofibers were improved.The enzyme loading reached 165 mg/g while the concentration of sodium methacrylate was 0.1 mol/L.In addition,compared with free lipase,the immobilized lipase showed a better stability resistance to temperature and pH change.at the lowest point,The relative activity of the immobilized lipase was 4.25 times and 5 times higher than that of the free lipase when the pH at 5~9 and temperature changes in the range of 20~60℃.The relative activity of the immobilized enzyme compared with free enzyme up to 2.7 times after storage of 10 h at 60℃.