USE OF ALCOHOLS AS COSOLVENTS IN ENZYME-FACILITATED TRANSPORT OF ORGANIC-ACIDS THROUGH A LIQUID MEMBRANE

Further applications and developments were studied for the use of enzy me-facilitated liquid membranes (EFLM). The use of ethanol as a cosolv ent in the aqueous phase of the EFLM enhanced the facilitated transpor t of phenyl-acetic acid by more than 13 times relative to the case whe re water with low butanol concentrations was used, and more than 1000- fold relative to non-facilitated transport in the butanol/water system . This transport enhancement is proposed to result from a favorable sh ift in the equilibrium between phenylacetic acid and its ester (ethyl phenylacetate) which is the species transported across the liquid memb rane. The enhancement goes through a maximum with increasing ethanol c ontent that is proposed to result from the observed denaturing of the enzyme at high ethanol concentrations. A simple model is proposed whic h qualitatively describes the observed enhancement by ethanol blends.