Oleyl oleate synthesis by immobilized lipase from Candida sp.1619

The effect of 14 different lipases on oleyl oleate synthesis were compared. The lipase from Candida sp.1619 had the highest esterification activity. The lipase was immobilized by adsorbing it on celite with 0.1 (w/w) coconut oil, Tween 80, and 1% (w/w) MgSO4 as coimmobilizing agents. The initial esterification velocity of the immobilized lipase was 1.5 times faster than the one without co-immobilized agents added. The optimum temperature for oleyl oleate synthesis was 30 degrees C. The final esterification rates were over 90%, while the reaction temperature ranged from 0 degrees C to 60 degrees C. It attained 10.25% esterification activity even at 100 degrees C. The optimum pH for esterification was 6.0. By means of dehydration, the final esterification rate reached 99%. Among 23 kinds of organic solvents added, hydrophobic alkanes promoted esterification, especially isooctane, n-nonane, and n-hexane. In batch reaction, half-lives of the immobilized lipase was 990 hours at 28 degrees C. The esterification rate remained 78% after running in continuous-flow column reactor at 28 degrees C for 1,000 hours.