Industrial & Engineering Chemistry Research, Vol.53, No.5, 1947-1953, 2014
Immobilization of Penicillin G Acylase on Mesostructured Cellular Foams through a Cross-Linking Network Method
A novel immobilization method that combines the advantages of physical adsorption and covalent binding was developed for penicillin G acylase (PGA) immobilization. In this method, a polymer network was formed by linear polymer molecules and enzymes were connected to the net-work through multipoint immobilization. This method is different from the conventional covalent binding method that creates chemical bonds between PGA molecules and support. Initially, PGA was physically adsorbed into the support because of the interaction between Si-OH and enzyme molecules. Afterward, chitosan and glutaraldehyde were added to generate a network connected with PGA, thereby successfully preventing enzyme leaching. Using the novel method, the PGA loading amount reached 555.0 mg/g (dry support), the specific activity was up to 27.7 U/mg (enzyme), and 85% activity was retained after five reuses. In addition, the immobilized PGA showed relatively high operation stability in pH and thermal stability.