Effect of Cell Concentration on Acylation of Penicillin G Enzymatic Reaction in Immobilized Cells


1 Department of Chemical and Petrochemical Engineering,Sharif University of Technology

2 Department of Chemical and Petroleum Engineering,Sharif University of Technology

3 Biotechnology Group,Azad University


E.coli was immobilized by entrapment within calcium alginate beads using cell suspensions of different concentrations. The immobilization procedure resulted in beads with a homogeneous cell distribution referred to as Non-overlapping Cell (NC) configuration. If cells within the beads are allowed to grow, the NC configuration would transform into a Clustered Cell (CC) configuration as a result of cell growth. Enzyme activity and substrate conversion were obtained for NC and CC configurations of different cell density using penicillin G acylation by penicillin G acylase to produce 6-amino penicillanic acid. Enzyme activity and conversion were found to depend on both cell concentration and configuration. Beads with NC configuration resulted in higher enzyme activity and conversion compared with CC configurations of similar cell density.