Abstract: Seven carriers were investigated for immobilization of the lipase from Serratia marcescens ECU1010, and diatomite and Eupergit C were found to be ideal supports. The thermal and storage stability of the lipase was significantly improved after being immobilized onto these two supports. After heating at 50 ℃ for 6 h, only a small decrease in the activity was observed for the diatomite-adsorbed lipase. About 50% of the initial activity was retained when the two immobilized enzyme samples were storaged at 4 ℃ for 180 days. Operational stability tests indicated that the half-life of the lipase immobilized on Eupergit C was about 2-fold longer than that of the diatomite-immobilized lipase. The crosslinking with glutaraldehyde had no significant effect on the activity of the Eupergit C-immobilized lipase, whereas the reusability of the crosslinked diatomite-immobilized enzyme was slightly improved. Using the crosslinked diatomite-immobilized lipase, an up-scaled bioresolution of (±)-3-(4’-methoxyphenyl)glycidic acid methyl ester ((±)-MPGM) was performed in a 500-ml emulsion reactor with 200 ml biphasic solution (toluene∶water=1∶1) at 30 ℃ and 0.5 mol/L of (±)-MPGM in toluene. After 5 batches of reaction, crystalline (2R,3S)-(-)-MPGM with a chemical purity of 100% and optical purity of>99% enantiomeric excess was obtained in a yield of 37.2%.

Key words: Serratia marcescens, lipase, immobilization, enantioselective hydrolysis, 3-(4’-methoxyphenyl)glycidic acid ester, diatomite, epoxy resin, Eupergit C