NONISOTHERMAL BIOREACTORS UTILIZING CATALYTIC TEFLON MEMBRANES

A hydrophobic and catalytic membrane has been obtained by grafting wit h gamma-radiations a Teflon membrane in presence of methylmethacrylate solution and by immobilizing on it, after treatment with glutaraldehy de, the beta P-Galactosidase enzyme. When employed in a non-isothermal bioreactor, the membrane showed an increase in catalytic activity pro portional to the applied temperature gradients. The results have been explained in terms of distinct contributions from the process of therm odialysis and the conformational changes induced in the dynamic struct ure of the enzyme by the presence of heat flow. The increase of the yi eld of the process has been evaluated in terms of a coefficient alpha representing the percent increase of enzyme activity when a temperatur e difference of 1 degrees C is applied across the membrane. The cataly tic Teflon membrane used here gave values of 20%, which are comparable to those obtained with other membrane systems, making this kind of me mbrane useful for practical applications in industrial processes. (C) 1998 Elsevier Science B.V. All rights reserved.