Effect of immobilization by modified ultrastable-Y molecular sieve on the resolution of (R, S)-2-octanol in nonaqueous media by lipase

The lipase from Penicillium expansum PED-03 (PEL) was immobilized into a modified ultrastable-Y molecular sieve and the resolution of (R, S)-2-octanol was carried out in a bioreactor in nonaqueous media by the immobilized lipase to investigate the effect of immobilization on the catalytic property of PEL duing the enzymatic reaction. It was found that the conversion (c), enantiomeric excess (ee), and enantioselectivity (E) of the resolution catalyzed by the PEL immobilized on the modified ultrastable-Y molecular sieve were much higher than those of the reaction catalyzed by free PEL and PEL immobilized on other supports. Being immobilized on the modified Ultrastable-Y molecular sieve, the lipase exhibited obvious activity in a wider pH range and at a much higher temperature than the free PEL, and showed a marked enhancement of stability against thermal inactivation, by which the suitable pH value of the buffer used for immobilization could be "memorized". The conversion of the reaction catalyzed by PEL immobilized on the modified ultrastable-Y molecular sieve reached 97.68% of the theoretical value with excellent enantioselectivity (Average E of 8 batches >460) in nonaqueous media at "memorial" pH 9.5, 50°C for 24 h, which showed a good application potential to the production of optically pure (R, S)-2-octanol.