BIOTRANSFORMATION OF CEPHALOSPORIN-C TO 7-AMINOCEPHALOSPORANIC ACID WITH COIMMOBILIZED BIOCATALYST IN A BATCH BIOREACTOR .1. REACTION-KINETICS AND DIFFUSION EFFECTS

The permeabilized cells of Trigonopsis variabilis CCY 15-1-3 having D- amino acid oxidase (DAAO) activity were used to convert cephalosporin C (CPS-C) into 7-(alpha-ketoadipyl amido) cephalosporanic acid (CO-GL- 7-ACA) in a batch bioreactor with good aeration and stirring during th e process. The deacylation of 7-beta-(4-carboxybutanamido)-cephalospor anic acid (GL-7-ACA) to 7-cephalosporanic acid (7-ACA) by permeabilize d cells of Pseudomonas species 3635 having 4-beta-(4-carboxybutamido) -cephalosporanic acid acylase (GL-7-ACA acylase) activity was performe d in a batch bioreactor. A spectrophotometric method for the determina tion of CO-GL-7-ACA and 7-ACA was proposed. Experimental data were fit ted by non-linear regression with parameters optimization. The sorptio n method (without reaction) was applied for the determination of cepha losporin effective diffusion coefficients in Ca-pectate gel beads. The se beads were prepared by dropping a potassium pectate gel suspension of inactive permeabilized cells of Trigonopsis variabilis and Pseudomo nas species, crosslinked with glutaraldehyde, into a stirred 0.2 M cal cium chloride solution. Concentrations of appropriate cephem component s were measured by the refractive method. Values of effective diffusio n coefficients were calculated by the Fibbonacci optimization method.