The influence of oriented external electric field on lipase catalyzed triglyceride hydrolysis

Abstract

The use of microbial lipases for the hydrolysis of natural oils such as triglyceride esters is a green alternative to conventional processes to produce high value-added chemicals. Biocatalysis using lipases in aqueous solutions is limited often by instabilities, slow kinetics due to mass transfer limitations, and by challenges of economic lipase recycling. Prior work has shown that mass transfer rates and reaction rates can be intensified by increasing interfacial area using electrostatic spray reactors. However, the possible effect of oriented external electrical field on the lipase catalytic activity has hitherto not been considered. In this study, the performance of microbial lipase derived from Candida rugosa in aqueous solutions was analyzed in the presence of a steady DC externally applied electrical voltage. The reaction was conducted in three different batch type reactors, quiescent (fixed interface), stirred tank, and tubular flow system. In each of the three reactor systems it was concluded that the oriented external electrical field has a positive effect on reaction independently of interfacial area. Further studies conducted using reverse polarity, increased electrode distance and for an immobilized lipase system have shown that lipase undergoes conformational changes due to an oriented external electrical field is the main driving mechanism for this enhanced performance.