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Aminoacylase immobilized on chitosan was applied for optical resolution of DL-amino acids. Optimun pH´s for hydrolysis of N-ac DL Met, N-ac DL Try and N-ac DL Phe by immobilized aminoacylase were 8.0, 7.0, and 7.5, respectively. The pH stability of immobilized aminoacylase was less than that of soluble enzyme, while there was no difference in thermostability between immibilized and soluble enzymes. The reaction rate of immobilized enzyme was maximum, when concentrations of N-ac DL Met, N-ac DL Try and N-ac DL Phe were 0.05, 0.03 and 0.05M, respectively. Continuous resolution of M/20 N-ac DL amino acids with immobilized aminoacylase packed in a column resulted in 100% hydrolysis upto space velocity 2.0 at 45℃, and the half-life of the column at space velocity 5.0 was about 25 days. The yield of L-Met, L-Try and L-Phe recovered from 2 liter of column effluent were 57%, 52% and 52%, respectively
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