新型脂肪酶LipB52催化生物柴油

Production of Biodiesel Catalyzed by a Novel Lipase LipB52 from Pseudomonas fluorescens

一种来源于荧光假单胞菌的新型脂肪酶基因lipB52在大肠杆菌BL21(DE3)中获得表达,并且利用Ni-NTA亲和柱对脂肪酶LipB52进行纯化。采用固定化脂肪酶LipB52催化大豆油与甲醇的转酯反应生产生物柴油。实验考察了温度、底物摩尔比、酶用量、有机溶剂、酶的种类以及油的类型对于反应的影响,结果表明:转酯反应的最佳反应条件为:m(酶)∶m(油)=20∶80,n(油)∶n(甲醇)=1∶4、正庚烷作为溶剂、反应温度为30℃,在此条件下脂肪酶LipB52表现出很高的催化活性,反应40 h后甲酯的产率高达92%。

A novel lipase gene lipB52 from Pseudornonas fluorescens was overexpressed in E. coli BL21 （DE3） and the lipase LipB52 was purified through a Ni-NTA chelated Sepharose column. Immobilized lipase LipB52 was used to catalyze the transesterification of soybean oil and methanol to produce biodiesel. The effects of temperature, substrate molar ratio, lipase dosage, organic solvent, different enzymes and oil type on transesterification were investigated and the optimal conditions of methanolysis were as follows： 20% LipB52 based on oil weight; oil/methanol molar ratio 1 ： 4; n-heptane as solvent and 30 ℃. Under the optimal conditions lipase LipB52 exhibited high catalysis activity and methyl ester yield of transesterification was 92% at 40 h.