离子交换树脂固定接枝脂肪酶

Lipase Immobilization Through Ion Exchange Resins

酶法是制取生物柴油的一种新型方法,而酶的重复利用率直接影响该法的运行成本。本文采用吸附法将碱性脂肪酶L4固定在4种不同树脂上,对比了利用不同树脂和在不同酶液浓度条件下的固定化效果,然后采用吸附-交联法将脂肪酶固定在树脂DK110上,考查交联方式和交联剂浓度对酶固定化的影响以及固定化酶的重复使用稳定性。结果表明,大孔型离子交换树脂DK110的固定化效果最好,酶液浓度对脂肪酶固定化影响显著。交联方式对固定化效果有显著影响,酶液先与戊二醛混合后加入树脂载体(JL1)所获得的酶活最大(340U/g),酶液、戊二醛与树脂载体同时混合(JL2)重复使用稳定性最好。该研究为固定酶法制取生物柴油奠定了基础。

IA lipase was immobilized on four kinds of resins by adsorption, involving ion exchange resins and macroporous resins. The influences of carriers and lipase concentrations on the adsorption amounts and activities of immobilized lipases were investigated. Then the IA Lipase was immobilized on ion exchange resin （DK110） by a method so called adsorption and cross-linking, in which glutaraldehyde is used as the cross-linking agent. The influences of glutaraldehyde concentration and cross-linking methods on the lipase immobilization were also investigated. The results show that macroporous ion exchange resin （DKll0） is proved to be the most suitable immobilization supporter; the activity of the immobilized lipase is 292U/g when the lipase concentration is controlled at 50mg/mL. Lipase concentrations and cross-linking methods have a great impact on the immobilization of lipase, either strengthen or weaken. Under the same conditions, lipases immobilized by adsorption and cross-linking treatment exhibit higher activities compared with the lipases immobilized by simple adsorption. Furthermore, lipases immobilized by JL1 exhibit the highest activities, which are 340U/g, and lipases immobilized by JL2 are very much stable in repeated usage, they remain 53% of the initial activity after six cycles. This research might lay the foundation for the further study on bio-diesel based on the immobilized lipases.