Continuous production of <scp>L</scp>‐aspartic acid by immobilized aspartase

Abstract

Abstract Various methods were tried for the immobilization of aspartase, and the preparation having the highest activity was obtained when partially purified aspartase from Escherichia coli was entrapped into polyacrylamide gel Iattice. Enzymatic properties of the immobilized aspartase were investigated and compared with those of the native aspartase. With regard to optimum pH, temperature, concentration of Mn ++ , kinetic constants and heat stability, no marked difference was observed between the native and immobilized aspartases. By employing an enzyme column packed with the immobilized aspartase, conditions for continuous production of L ‐aspartic acid from ammonium fumarate were investigated. When a solution of 1 M ammonium fumarate (pH 8.5, containing 1m M MnCl 2 ) was passed through the aspartase column at the flow rate of SV = 0.08 at 37°C, the highest rate of reaction was attained. From the column effluents, L‐aspartic acid was obtained in a good yield.