Enhancement of Operational Stability of Immobilized Whole Cell D-Hydantoinase
Dong-Min Kim, Geun-Joong Kim and Hak-Sung Kim
A bacterium Pseudomonas sp. KBEL 101 isolated from soil was immobilized within polyacrylamide gel and used for the synthesis of D-p-hydroxphenylglycine from DL-5-substituted hydantoin. The half-life of immobilized whole cell D-hydantoinase was found to be about 50hrs. In order to increase the operational stability of immobilized whole cell D-hydantoinase, a carbon or nitrogen source was supplied with the reaction mixture in the continuous stirred tank reactor. As a sole source of carbon, glycerol was found to be most effective, and the activity of immobilized whole cell enzyme was maintained stably during 7 days when 0.1%(W/V) glycerol solution was provided. In the case of nitrogen source, supplying of 0.1%(W/V) yeast extract prolonged the half-life of immobilized whole cell D-hydantoinase to about 25 days.