Continuous penicillin G hydrolysis in an electro-membrane reactor with immobilized penicillin G acylase

Penicillin G (2%, w/v in phosphate buffer, pH 8) was hydrolysed in a flow-through, miniature electro-membrane reactor with the penicillin G acylase immobilized in 5% (w/v) polyacrylamide (diam. 10 mm, thickness 2.6 mm, enzyme activity 24 U ml^–1). The conversion of penicillin G increased from 0.15 to almost 0.5 when the electric current applied to the reactor was changed from –600 to +600 A/m² with a substrate residency of 1 h.Symbols and abbreviationsc_j^p & concentration of component j in product stream (M) c_j^s & concentration of component j in substrate stream (M) c_s^o & substrate concentration at reactor inlet (M) C_j^p=c_j^p/c_S⁰ & scaled concentration of component j in product stream C_j^s=c_j^s/c_S⁰ & scaled concentration of component j in substrate stream i & electric current density (A/m²) j & reaction component, j P, Q or S P & main reaction product (6-aminopenicillanic acid) PGA & penicillin G acylase Q & side reaction product (phenylacetic acid) S & substrate (penicillin G) Y_s=C_P^s+C_P^p & substrate conversion & mean residence time of substrate and product streams in reactor (h) =C_Q^s+C_Q^p+C_S^s+C_S^s & check-sum of scaled concentrations =C_P^p/(C_P^s+C_P^p) & separation factor of 6-aminopenicillanic acid (0 1)