Esterification kinetics of long-chain fatty acids and fatty alcohols with a surfactant-coated lipase in n-hexane

The esterification reaction kinetics of long-chain fatty acids and fatty al cohols catalyzed with a surfactant-coated lipase in a microaqueous n-hexane system were studied. The biocatalytic complex, surfactant-lipase adduct, s howed 40 times the activity after a reaction time of 5 h compared to the un modified lipase in the same reaction system. Various factors that may affec t the activity of the modified lipase were studied; such as the influence o f substrate fatty acid chainlength, water content, and temperature. By vary ing the concentration of each of the two substrates while keeping that of t he other substrate constant, it was found hat the esterification reaction f ollows Michaelis-Menten kinetics. The surfactant-enzyme complex kinetic par ameters were determined with respect to both substrates. It was suggested t hat the kinetics of the lipase-catalyzed esterification reaction model foll ow a Ping-Pong Bi Bi mechanism with no substrate or product inhibition.