Penicillin G acylase was also immobilized in macro- mesoporous silica spheres prepared with a micro-device. The silica spheres containing PGA were placed into a packed bed reactor in order to perform penicillin G production (Zhao et al. 2011). Macropores of silica spheres allowed high en- zyme loading amount and lower internal mass transfer resis- tance. Immobilized enzymes also showed great stability dur- ing production (Zhao et al. 2011). The production of 6- aminopenicillanic acid was also carried out by isolated bacte- rial cells immobilized on κ-carrageenan. The system allowed the continuous production of 6-APA from penicillin G by repeated use of bacterial cells (Dolui et al. 2011).