磁性纳米粒固定化脂肪酶的制备及稳定性研究  

Preparation and stability of immobilized lipase by magnetic nanoparticles

作　　者：茅燕勇[1] 李文谦[1] 王朝宇[1] 时号[1] 

机构地区：[1]淮阴工学院生命科学与食品工程学院,淮安223003

出　　处：《食品科技》2016年第9期45-49,共5页Food Science and Technology

基　　金：淮安市科技支撑计划项目(HAG2011005);淮安市重点研发计划项目(HAG2015031);淮阴工学院科研基金项目(491712034)

摘　　要：高温热解制备磁性Fe_3O_4纳米粒并修饰羧基后作为载体,以EDCl作为游离羧基活化剂、NHS为活性羧基稳定剂,对脂肪酶进行共价固定化和稳定性研究。结果表明:制备的磁性纳米粒直径约21 nm,羧基修饰量为0.90×10^(-4) mmol/mg。优化的固定化条件为:对1 m L含铁5 mg/m L的羧基化Fe_3O_4纳米粒溶液,EDCl和NHS用量均为5.8×10^(-4) mmol,脂肪酶添加量为7 mg,反应时间1 h,得到的固定化酶冻干粉表观比酶活为1.03 U/mg。与游离脂肪酶相比,该固定化酶具有很好的存储、p H和热稳定性,循环水解橄榄油6次后,酶活回收率仍可保持65%。In this study, magnetic Fe3O4 nano-particles were prepared by high temperature pyrolysis method, and were carboxyl-functionalized using dual terminal carboxyl polyethylene glycol to get carboxylPEG-carboxyl-Fe3O4（Fe3O4@PEG-COOH） nano-particles. Then, carbodiimide hydrochloride（EDCl）（stimulator） and N-hydroxyl-succimide（NHS）（stabilizer） were used to immobilize free lipase covalently onto the nano-particles, and stability of immobilized lipase was investigated. Results showed that dimeter of the Fe3O4 nano-particles was approximately 21 nm, and modified quantity of free carboxyl on the Fe3O4@PEG-COOH was 0.90×10-4 mmol/mg. Optimum condition of immobilization were as follows： for 1 m L solution of the Fe3O4@PEG-COOH containing 5 mg/m L iron, amount of the EDCl equal to amount of the NHS was 5.8×10-4 mmol with 7 mg lipase for 1 h coupling reaction. Apparently immobilized lipase lyophilized to be powder had better storage stability, p H and heat endurance than the free lipase, and the specific enzyme activity was 1.03 U/mg. Furthermore, the recovery activity of the immobilized lipase was about 65 percent after 6 cycles of olive oil hydrolysis.

关 键 词：磁性Fe3O4纳米粒 固定化脂肪酶 稳定性 橄榄油 

分 类 号：TS201.25[轻工技术与工程—食品科学]