Batch production of deacetyl 7-aminocephalosporanic acid by immobilized cephalosporin-C deacetylase

Bacillus subtilis SHS0133 cephalosporin-C deacetylase (CAH) overexpressed in Escherichia coli was immobilized on an anion-exchange resin, KA-890, using glutaraldehyde. The activity yield of immobilized enzyme was approximately 55% of the free enzyme. The pH range for stability of the immobilized enzyme (pH 5-10) was broader than that for free enzyme. The K-m(app) value of immobilized enzyme for 7-aminocephalosporanic acid (7-ACA) was similar to that of the free enzyme. This immobilized enzyme obeyed Michaelis-Menten kinetics similar to those of the free enzyme. A batch-type reactor with a water jacket was employed for deacetylation of 7-ACA using CAH immobilized on KA-890. Ten kilograms of 7-ACA were completely converted to deacetyl 7-ACA at pH 8.0 within 90 min. The reaction kinetics agreed well with a computer simulation model. Moreover, the immobilized enzyme exhibited only a slight loss of the initial activity even after repeated use (52 times ) over a period of 70 days. This reaction will thus be useful for the production of cephalosporin-type antibiotics.