Immobilization of Penicillin G Acylase: The Key to Optimum Performance

Penicillin G acylase is a major industrial biocatalyst that is used in the enzymatic production of 20,000 t a −1 of 6‐aminopenicillanic acid, the industrial β‐lactam intermediate, as well as in the enzymatic production of semi‐synthetic β‐lactam antibiotics. Because efficient recovery and reuse of the biocatalyst is a prerequisite for a viable process, much attention has been focused on the immobilization of penicillin G acylase. Methods that have been studied and will be discussed in this review include covalent attachment to porous organic and inorganic carriers, inclusion in and attachment to biopolymer gels and carrier‐free immobilization techniques. Highly active and stable preparations have been developed; mass transfer limitations in the carrier are now a major barrier to further improvement of the biocatalyst performance.