Development of immobilized enzyme system for chiral resolution.

摘要

Lipase from Pseudomonas cepacia was used for the chiral resolution of racemic (;It was also found that the addition of a polar organic solvent to the reaction affects the stereoselectivity (E) of the lipase for this chiral reaction. It was observed, in general, that the activity increases with the increase in the polarity of the solvent whereas the stereoselectivity decreases. Among the six solvents chosen i.e. dimethyl sulfoxide (DMSO), 1,4-dioxane, dimethyl formamide (DMF), acetone, 1-propanol, and tetrahydrofuran (THF), maximum activity and minimum stereoselectivity was obtained with DMSO, whereas minimum activity and maximum stereoselectivity was obtained with THF.;To develop an immobilized enzyme preparation suitable for use with hydrophobic substrates and also stable in long term operations, ;In subsequent studies involving immobilized lipase in a fixed bed reactor, the enzyme was found to be at least 3 times more stereoselective than the native form used in a batch reactor. The fixed bed reactor with the beads could be operated with high concentrations (35%) of the polar organic solvent for one month without a significant loss of enzyme activity. A strategy for optimizing the reactor productivity with respect to one chiral component is discussed and a tanks-in-series model is used to simulate a non-ideal fixed bed reactor.