Enantioselective production of levofloxacin by immobilized porcine liver esterase

Porcine liver esterase, which cleaves ofloxacin butyl ester enantioselectiv ely to levofloxacin, was successfully immobilized in calcium alginate and p olyacrylamide gel. Immobilized esterase in 5% (w/v) calcium alginate exhibi ted 58% immobilization efficiency and could be reused five times without se vere loss of enzyme activity. On the other hand, entrapped esterase in poly acrylamide gel, composed of 20% of total monomer and 8.3% of cross-linking agent, could be reused 10 times, and 51% of enzyme activity remained after the 10th batch without decrease of enantioselectivity. Compared with entrap ped methods, significant reduction of enzyme activity was found in the case of physical adsorption on to QAE-Sephadex.