Continuous conversion to optically pure l-methionine from d-enantiomer contaminated preparations by an immobilized enzyme membrane reactor

Abstract

Continuous conversion to optically pure l-methionine from preparations contaminated by a small amount of the d-enantiomer (0.5–1.0%) has been developed with an enzyme membrane reactor system (slurry reactor) containing immobilized d-amino acid oxidase, catalase, and FAD. The optimal pH of the reaction system was from pH 7.0–8.0, and the optimum temperature was 25°C. The average conversion and the space-time yield were > 99% e.e. and nearly 90 g/ l·d, respectively with operation of the reactor for 7 d.