CTAB逆胶束体系中Lipex脂肪酶催化合成油酸乙酯

Enzymatic synthesis of ethyl oleate by Lipex lipase in CTAB reverse micellar system

研究了CTAB逆胶束体系的适宜构建条件以及Lipex脂肪酶催化合成油酸乙酯的适宜反应条件。探讨了有机溶剂、底物配比、pH值、水含量W0、酸浓度、反应时间等因素对反应的影响。研究表明,在以CTAB为表面活性剂时,以异辛烷为溶剂,正己醇作助溶剂条件下,能得到较为稳定的逆胶束体系,更有利于Lipex脂肪酶的活性发挥;在该反应体系下反应温度25℃,缓冲液pH7.0,W010,酸醇比1∶4(摩尔比),油酸浓度0.01mol.L-1,摇床转速150r.min-1,反应36h,油酸乙酯产率达到79%。并建立了逆胶束体系中双底物作用的动力学模型,经验证模拟计算结果与实验结果吻合良好。

The optimal conditions of cetyl trimethyl ammonium bromide（CTAB）reverse micellar system,and the most suitable reaction conditions of synthesis of ethyl oleate by Lipex lipase were determined.The influences of organic solvent,ratio of substrates,pH value,water content W0,concentration of oleic acid and reaction time were investigated.As a result,a more stable reverse micellar system was obtained,which led to a better activity of Lipex lipase.The parameters in this condition were optimized as follows：reaction temperature 25 ℃,buffer pH value 7.0,W0 10,ratio of acid to ethanol 1∶4,oleic acid concentration 0.01 mol·L-1,agitation speed 150 r·min-1 and reaction time 36 h,and the yield of ethyl oleate was 79%.The kinetic model of the reverse micellar system influenced by double substrates was established.The simulated result agreed well with the experimental result.