Kinetics, mechanism, and time course analysis of lipase-catalyzed hydrolysis of high concentration olive oil in AOT-isooctane reversed micelles

Candida rugosa lipase has been used to investigate the hydrolysis of high concentration olive oil in the AOT-isooctane reversed micellar system at w(o) = 10, pH 7.1, and 37 degrees C. Results from this work show the hydrolytic reaction obeys Michaelis-Menten kinetics up to the initial substrate concentration of 1.37 M, with turnover number k(cat) and Michaelis constant Km of 67.1 micromoles/min mg enzyme and 0.717 M, respectively. A competitive inhibition by the main product, oleic acid, has been found with a dissociation constant Ki for the complex EP( ) of 0.089 M. The rate equation was further analyzed in the time course reaction and was found in agreement with the experimental results for lower substrate concentrations, up to 0.341 M. Large deviations occurred at high substrate concentrations, which may be due to the effects of large consumption of water on kinetics, on the formation of glycerol, and on the deactivation of lipase in the hydrolysis reaction as well.