Inhibition and Inactivation of Lipase by Fat Peroxide in the Course of Batch and Continuous Glycerolyses of Fat by Lipase

Abstract

The effects of fat hydroperoxides on the reaction rate and enzyme stability in glycerolysis of safflower oil catalyzed by Pseudomonas fluorescens lipase were investigated. In the batch glycerolysis, the initial reaction rate, r_i, decreased linearly with the increase in the safflower oil's peroxide value (POV).
In the continuous glycerolysis using a microporous hydrophobic membrane bioreactor, the outlet conversions decreased monomolecularly with the elapsed time due to inactivation. The first-order decay constants, K_a, increased with the increase in the safflower oil's POV.
The courses of sodium dodecyl suit ate-pol yacrl lamide gel electrophoresis (PAGE) of the enzyme in the glycerol phase in the continuous glycerolysis showed that the high hydroperoxide content caused polymerization of the lipase. From the activity staining of the bands of the native proteins developed in the PAGE, the highly polymerized lipase was found to have no lipolytic activity.