Abstract:

The immobilization of Arthrobacter sp. lipase on magnetic porous microspheres was investigated. The magnetic porous microspheres was characterized with FTIR，XRD，SEM，TEM，BET，TGA and VSM，and the effect of immobilization time，pH，and lipase amount on the catalytic performance of the immobilized lipase in an organic system was studied. The results showed that the core of microsphere was Fe₃O₄，the surface was porous，the surface area of microsphere was 12.16 m²/g，average pore diameter was 171.7 nm，its magnetic content was 38% and it was super-paramagnetic. The optimal immobilization conditions were determined to be pH 8.0 with the lipase/carrier ratio of 1 to 1（m/m）and immobilization time of 6 h. The activity recovery was as high as 2.4 fold of the free lipase in the resolution of 4-hydroxy-3-methyl-2-（2-propenyl）-2-cyclopenten-1-one. Furthermore，the operational stability of the immobilized enzyme was greatly enhanced compared to the free enzyme. The residual activity was kept at 74.5% after 30 batch reactions，while that of the free enzyme was just 37.1% after 7 batch reactions.

摘要：

开发了以磁性多孔微粒作为载体固定化脂肪酶的方法，进行了载体的FTIR、XRD、SEM、TEM、BET、TGA和VSM等测定与分析，考察了固定化时间、酶载量和缓冲液pH值等因素对固定化酶在有机相中催化烯丙醇酮转酯化反应性能的影响。结果表明，制备的磁性微粒是以Fe₃O₄为磁核，呈现多孔，比表面积12.16 m²/g，平均孔径为171.7 nm，磁铁含量38%并为超顺磁性；在酶与载体质量比为1∶1、pH值8.0及固定化时间6 h制得固定化酶的效果最佳，固定化酶的活力回收率可达240%。以其作为载体制备获得固定化酶操作稳定性得到显著提高，重复利用30批次后残余活力为74.5%，而游离酶7批次后仅为37.1%。