(629f) The Influence of Low Voltage Electric Fields on Lipase Catalyzed Triglyceride Hydrolysis (Industry Candidate)

Lipase catalyzed triglyceride hydrolysis is limited often by slow kinetics due to mass transfer limitations and by challenges of economic enzyme recycling. The principle and sole mechanism for the intensification was assumed to be solely on account of increases in interfacial area and some hydrodynamic turbulence. The possible effect of electrical charge on the lipase activity has hitherto not been considered. In this study, rates of reaction for lipase catalyzed hydrolysis of triglycerides in the presence of microbial lipase derived from Candida Rugosa were determined in the presence of steady direct current (DC) electrical field. The reactions were conducted in a fixed rectangular geometry stagnant batch reactor (SBR) fitted with stainless steel planar electrodes. The two immiscible liquid phases, oil and aqueous solution, were located between the electrodes with a quiescent rectangular interface of known area. The rates of percent yield of free fatty acid were determined for applied DC voltages in the range 0-30 Volts imposed between the two electrodes. Comparisons with control conditions in the absence of electrical field, in the absence of enzyme and effect of interface and bulk yield of FFA were also studied. The results showed clear evidence of significant increase in the rates of reaction in the presence of the electrical field. These results also show evidence of an optimum voltage since at the upper end of the voltage range there was significant reduction in the rate enhancement compared with observations at lower voltages. It was concluded that the electric field has a positive effect on reaction rate, independent of interfacial area. This suggested possible changes in enzyme structure due the electrical field, modification of the nature of the enzyme binding at the liquid-liquid interface, or possibly intensification of local transport rates of substrates and reaction products close to the interface. The latter could involve phenomena such as electro-kinetic transport or electro-osmosis.