Biosynthesis od cephaloglycine using whole cell system

Abstract

Cephaloglycin (CEG) was synthesized directly from D-α-phenylglycine methyl ester (PGM) and 7-amino cephalospolanic acid (7-ACA) by whole cell enzyme of the $\mbox{\underline{Xanthomonas}}$ $\mbox{\underline{citri}}$ IFO 3835. To data, cephaloglycin has been manufactured by chemical process involving fairly large number of steps to protect other function group. However, the enzymatic process involves only a single step. The production of CEG with X. citri was identified by the bioassay, the paper chromatography, and the HPLC. The reaction model of CEG synthesis and the inhibition of the product of PG were studied through HPLC. The kinetic constants of PGM hydrolysis, CEG synthesis, and CEG hydrolysis were determined. The $K_m$ values of PGM 7-ACA, and CEG were 16 mM, 30 mM, and 167 mM, and $K_i$ value of PG was 20-22 mM. The optimum condition to synthesize CEG was studied, and the method (enzyme loading and solvent effect) to increase the CEG synthesis was researched.