脂肪酶Palatase M.miehei的固定化及催化菜籽油水解研究

Immobilization of lipase Palatase M.miehei and hydrolysis of rapeseed oil catalyzed by this immobilized enzyme

采用10种树脂对脂肪酶Palatase M.miehei进行了吸附法固定化,并将其用于催化菜籽油水解.结果发现,大孔吸附树脂LX-8的固定化效果最好,固定化率达91.2%,其得到的固定化酶(IM-PM)酶活为731.1U/g.经米氏常数测定,相比游离酶而言,IM-PM的米氏常数增大,反应速率降低;采用IM-PM催化菜籽油水解,得到了最适水解工艺为:反应时间3h、底物摩尔比(水/油)70∶1、搅拌转速250r/min、温度55℃、加酶量1.5%,最终水解液酸价可达83.2mg·KOH/g.经重复使用6次,IM-PM残余催化活力仍可达70%.

Ten types of resins were employed as carriers for immobilization of lipase Palatase M. miehei ^ and the obtained immobilized lipase was used for hydrolysis of rapeseed oil. The result showed that macroporous resin LX-8 was the optimal carrier for Palatase M. miehei ,which performed the highest immobilizing efiiciency （91. 2 % ） And the activity of the immobilized Palatase M. miehei （IM-PM） was 731. 1 U/g. Compared with free enzyme, the Michealis constant of IM-PM increased and the reaction rates decreased . This IM-PM was employed to catalyze the hydrolysis of rapeseed oil, and the suitable hydrolysis conditions were as follows：reaction time of 3 h, substrate molar ratio （water to oil） of 70 ： 1 , stirring speed of 250 r/min, temperature of 55 ℃ ,and enzyme load of 1. 5 %. Under these conditions, the acid value of final hydrolyzates reached 83. 2 mg · KOH/g. After six times reuse,the re-mained activity of IM-PM was 70%.