Improved enzymatic synthesis of N-carbamoyl-D-phenylalanine with in situ product recovery

D-hydantoinase from Burkholderia cepacia was purified and immobilized onto EAH Sepharose 4B using the carbodiimide method. The enzymatic process for the production of N-carbamoyl-D-phenylalanine via the hydantoinase method was conducted using a special packedbed reactor connected to a DEAE Sepharose FF column for in situ product recovery. This novel apparatus was shown to be effective for pH control, thereby improving the conversion rate. At 40°C, 1.0 g/L substrate concentration, and 10/100 mL adsorbent concentration, the conversion rate of D,L-benzyl hydantoin was 62.7% after the reaction for 14 h, representing an 89.4% increase when compared with that obtained using a packed-bed reactor.