Use of Stable Emulsion to Improve Stability, Activity, and Enantioselectivity of Lipasi Immobilized in a Membrane Reactor

The enantiocatalytic performance of immobilised lipase in an emulsion membrane reactor using stable emulsion prepared by membrane emulsification technology has been studied. The production of optical pure (S)-naproxen from racemic naproxen methyl ester has been used as model reaction system. The O/W emulsion, containing the substrate in the organic phase, was fed to the enzyme membrane reactor from shell-to-lumen. The enzyme was immobilised in the sponge layer (shell side) of capillary polyamide membrane with 50 kDa cut-off. The results evidenced that lipase maintained stable activity during all the operation time (more than 250 hours), showing an enantiomeric excess (96 ±2%) comparable to the free enzyme (98 ± 1%) and much higher compared to similar lipase-loaded membrane reactors used in two-separate phase systems (90%). The results demonstrate that immobilised enzymes can achieve high stability as well as high catalytic activity and enantioselectivity.