Improved specific productivity in cephalexin synthesis by immobilized PGA in silica magnetic micro-particles.

摘要: There is a marked trend in pharmaceutical industry towards the replacement of classical organic methods by “green” alternatives that minimize or eliminate generation waste and avoid, where possible, use toxic and/or hazardous reagents solvents. In this work kinetically controlled synthesis cephalexin soluble penicillin G acylase immobilized sol–gel micro-particles with magnetic properties was performed aqueous media PGME 7-ADCA as substrates, at different concentrations substrate, temperature, pH, enzyme to substrate ratio acyl donor nucleophile ratio. Excess had strong effect on productivity. A PGME/7-ADCA 3 considered optimum. maximum specific productivity 160 mM 7-ADCA, 480 mM low 32.5 U mmol−1 obtained PGA full medium, suggesting diffusional limitations were minimized when compared other commercial biocatalysts. half-life 133 h for biocatalyst estimated during presence 100 mM 300 mM PGME, 50 mM Tris/HCl pH 7.2 14°C. These results compare quite favorably those previously reported cephalexin. Biotechnol. Bioeng. 2010;107: 753–762. © 2010 Wiley Periodicals, Inc.