LIPASE-CATALYZED KINETIC RESOLUTION OF (R,S)-1-PHENYLETHYL PROPIONATEIN AN ENZYME MEMBRANE REACTOR

Enzymatic stereoselective hydrolysis of (R,S)-1-phenylethyl propionate was performed in a stirred tank and in a biphasic enzyme membrane rea ctor. Lipase from Pseudomonas sp. was proved to be a good enantioselec tive catalyst for this reaction. The enzyme was covalently immobilized in a porous polyamide membrane (flat sheet as well as hollow-fibres) via glutaraldehyde. An influence of membrane hydrophobicity on reactor performance was observed. Initial lipase activity and productivity in the processes were equal to 1.05 x 10(-4), 1.3 x 10(-5) and 1.0 x 10( -5) mole/(h x mg of enzyme) in the case of native lipase, in the aroma tic polyamide hydrophobic membrane reactor and in the hydrophilic poly amide-6 membrane reactor, respectively. The influence of some factors such as temperature, pH, buffer concentration, initial substrate conce ntration and addition of P-cyclodextrin derivatives on reaction rate a nd enantioselectivity was investigated and discussed. In the enzyme me mbrane reactor both organic and aqueous phases circulated countercurre ntly on both sides of the membrane. At a conversion degree of under 55 -60%, pure enantiomer of the remaining ester (i.e. >98%) was obtained.