STABILIZATION OF D-AMINO-ACID OXIDASE FROM YEAST TRIGONOPSIS-VARIABILIS USED FOR PRODUCTION OF GLUTARYL-7-AMINOCEPHALOSPORANIC ACID FROM CEPHALOSPORIN-C

The studies to improve the production of glutaryl-7-ACA from cephalosporin C are described in this paper. During the conversion of cephalosporin C to keto-adipyl-7-amino-cephalosporonic acid by D-amino acid oxidase (D-AAO), with the simultaneous production of equimolar amount of hydrogen peroxide, an incomplete nonenzymatic conversion of the keto form into the glutaryl form occurs, where cephalosporin C as well as D-AAO are partly destroyed in the presence of hydrogen peroxide. D-AAO was immobilized to different carriers in order to achieve better enzyme stability. The activity of immobilized D-AAO on manganese oxide remained above 100% during the first 9 h of a semicontinuous conversion of cephalosporin C. The presence of catalase co-immobilized with D-AAO and coupled to CNBr-activated Sepharose 4B improved the operation stability of D-AAO. An additional approach for the continuous transformation of cephalosporin C used whole cells of Trigonopsis variabilis, containing D-AAO, immobilized to magnetic iron oxide particles.