Synthesis of triacylglycerol by lipase in phosphatidylcholine reverse micellar system

Abstract

Abstract Triacylglycerols were synthesized from 1,2‐diacylglycerol and fatty acids by lipase entrapped in phosphatidylcholine reverse micelles in n‐hexane. In the reaction system without reverse micelles, however, 1,2‐diacylglycerol was hydrolyzed into 2‐monoacylglycerol and fatty acid, and triacylglycerol was not synthesized. The maximum activity of synthetic reaction was obtained at Wo=10 (Wo=mol water/mol surfactant), which was the water content of this reverse micellar system. Though the optimal pH of the R. delemar lipase reaction is about pH 5.6 in a bulk water system, the enzyme was active for triacylglycerol synthesis at pH's from 5 to 9 in the reverse micellar system. For the synthesis of triacylglycerols, lauric, myristic, palmitic, stearic, oleic and arachidic acids were effectively used as the fatty acid substrate. 2‐Monoacylglycerol was also effective as a substrate of triacylglycerol synthesis. Furthermore, 1,2‐diacylglycerol could be replaced by several kinds of aliphatic alcohols as fatty acid acceptors in the reverse micellar system. In this case, those alcohols with chain length more than 4 carbons were effectively used for ester formation.