摘要
通过悬浮聚合法制备了含环氧基团的聚合物载体高分子磁性多孔微球（GHD），用TEM、SEM和Micromeritics ASAP2010等对聚合物载体进行了表征。考察了载体中交联剂含量、固定化时间、给酶量等因素对固定化脂肪酶催化活性的影响。结果表明，Fe3O3纳米粒子粒径20nm，分布均匀，磁性多孔微球粒径从几十微米到一百多微米，粒子大小大体呈正态分布且分布较窄，平均粒径为110μm，直径在区间80—150μm范围内的粒子占90％以上。微球表面呈皱褶态且呈现多孔性，孔径从几个纳米到几十纳米，为闭孔，且孔间互相贯穿。固定化酶最适条件为给酶量125mg／g，固定化时间7h，此时酶的吸附量为118．5mg／g，比酶活7．56×10^5U／g，酶的活力回收率95％。以GHD为载体制备的固定化脂肪酶最佳反应温度从37℃上升到42℃，最适反应pH从7．2提高到7．5，固定化后酶对温度和pH的敏感性降低，重复使用12次，固定化酶的活力都能保持在92％以上。
A polymer support with epoxy groups for immobilized lipase was synthesized by suspension polymerization by using glyeidyl methacrylete, 2 -hydroxyethyl methaerylate and divinylbenzene as reactive monomers, hexane as pore -forming agent, benzoyl peroxide as initiators; it was characterized by TEM, SEM and Micromeritics ASAP 2010. The effect of crosslinking agent content on immobilization of lipase had been studied. Optimization of immobilization parameters was conducted with respect to immobilization time and lipase loading. The results showed that the magnetic microsphere （GHD） has porous structure in the surface ; the pore size was tens of nanometers beneficial to the immobilization of the CRL. The particle was narrow distributed, the average size was 110μm with size distribution of 50 -180 μm. The optimum immobilized condition is obtained that GHD （40） as carrier, GHD （40） to lipase ratio 125 mg/g, immobilizing time 7 h, and the immobilized lipase has the optimal catalytic activity with total activity, protein binding, specific activity; activity yield of the immobilized lipase were 7.56 × 10^5 U/g, 118.5 mg/g and 0.95 respectively. The optimal temperature after immobilization had raised from 37℃ to 42℃, and the maximum activity increased from pH 7.2 to 7.5. Operational stability tests indicated that the ester yield was still 92% after 12 batch cycles.
出处
《中国粮油学报》
EI
CAS
CSCD
北大核心
2013年第12期68-73,共6页
Journal of the Chinese Cereals and Oils Association
基金
国家科技支撑计划(2011BAD22B04)
