环氧基功能化块体SiO_2大孔材料对漆酶的固定化

Immobilization of laccase on epoxy-functionalized macroporous SiO_2 block materials

采用后嫁接法在溶剂热条件下对新型块体SiO2大孔材料进行环氧基化改性,以环氧基功能化SiO2大孔材料作为载体,通过共价结合法固定化诺维信(Novozymes)工业级漆酶,对固定化条件进行了优化,研究了固定化酶与游离酶的酶学性质。结果表明,在固定化时间为4 h、pH值为4.5、初始酶液浓度为25 mg/mL时,固定化效果最好,固定化漆酶活力达到101.7 U/g;固定化漆酶的最适pH值为4.0,最适温度为50℃,其pH值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43.4%。

A novel macroporous silica block material was epoxy-modified via post-grafting method under solvothermal conditions.The epoxy-functionalized macroporous silica were employed as the supports for immobilization of the commercial Novozymes laccase by using covalent binding method.Immobilization conditions were optimized,the properties of immobilized and free laccase were studied.The optimum conditions for immobilization of laccase were at the immobilization time of 4 h,the buffer of pH 4.5 and the initial laccase concentration of 25 mg /mL,under these conditions,the activity of immobilized laccase reaches 101.7 U /g.The optimum pH and temperature of immobilized laccase were 4.0 and 50 ℃,respectively.The experiments show that the immobilization significantly improves the pH stability and thermal stability of laccase.The immobilized laccase can be used repeatedly,and the remained activity was 43.4% after 10 times of reaction with the substrate.