Influence of the chemical and textural properties of the support in the immobilization of penicillin G-acylase from Kluyvena citrophila on inorganic supports

Abstract

The influence of the chemical and textural properties of some inorganic supports in the enzymatic activity of covalently bonded penicillin G-acylase is analyzed. A simple and general activation methodology of the inorganic supports is described. Surface area is the main factor in the immobilization process when mesoporous solids (SiO 2 or γ-Al 2O 3) are used. The channel structure of the sepiolite clay and the presence of cations reduce the enzymatic activity of the immobilized derivatives. The enzymatic activity of these derivatives is tested in (i) the hydrolysis of penicillin G; (ii) semisynthesis of penicillin G; (iii) semisynthesis of a cephalosporin model. The yields obtained in the synthesis of β-lactams are 20-35%. The nature of the solid support is important in the hydrolysis of penicillin G but not in the semisynthesis of β-lactamic antibiotics. The enzymatic derivatives can be reused.