响应面法优化脂肪酶的固定化条件及其水解橄榄油的特性研究

采用Sepharose CL-4B和7种大孔树脂为载体固定Palatase 20000L脂肪酶，对载体进行筛选，以酶活力为指标，采用响应面法优化固定化条件，并考察所制得固定化酶的稳定性和水解橄榄油的酶学性质。结果表明：以大孔树脂HPD-600为载体制得的固定化酶具有较高的活性和良好的稳定性。其最优的固定化条件为：pH3.9，酶与载体比例为9.1mg/g，吸附时间1.8h。在最优条件下制得固定化酶在最适合条件下测得的酶活力达到1440U/g，酶活回收率大于50%。固定化酶最适作用温度为50℃，最适作用pH值为8.0。固定化酶的Km值为0.130g/mL，高于游离酶的Km(0.069g/mL)。固定化酶的热稳定性有一定程度的提高，其重复操作5次后相对酶活力仍保持在58%以上。

Optimization of Immobilization of Lipase Using Response Surface Methodology and Its Performances in Olive Oil Hydrolysis

Different carriers such as Sepharose CL-4B and seven kinds of macroporous resins were used to immobilize lipase Palatase 20000L.The lipase showed higher activity and better stablity when immpbilized on macroporous resin type HPD-600 compared with other carriers.Ressponse surface methodolgy was employed to optimize key conditions for the immobilization of lipase Palatase 20000L on macroporous resin type HPD-600 to achieve maximum immobilized lipase activity.The optimal immobilization conditions were found as follows: pH 3.9,enzyme-to-carrier ratio 9.1 mg/g,and adsorption time 1.8 h.Under these conditions,the immobilized lipase achieved its maximum activity,1440 U/g and a rantivity ecovery above 50%.The optimal reacton temperature of the immobilized lipase was 50 ℃,the optimal reaction pH 8.0,and the Km value 0.130 g/mL,which was higher than that(0.069 g/mL) of the free form.Moreover,the immobilized lipase showed higher thermal stability and maitained over 58% of its original activity after the fifth repeated use.