eng Oriental Scientific Publishing Company Biosciences Biotechnology Research Asia 0973-1245 2016-05-07 9 2 http://dx.doi.org/10.13005/bbra/1050 10029 article Enzymatic Synthesis of Ampicillin by Immobilized Penicillin G acylase of E.coli S.M. Atyabi 1 S. Hatami Gigloo 1 M. Salimi 2 S.B. Momen 1 A. Akbarzadeh 1 D. Nrouzian 1 Department of Pilot Biotechnology, Pasteur Institute of Iran, Tehran 13164, Iran Department of Physiology and Pharmacology, Pasteur Institute of Iran, Tehran13164, Iran. Penicillin G acylase immobilized on to iron oxide nano particle coated with polyethyleneimine was used to synthesize b-lactam antibiotic namely ampicillin through kinetically controlled process. 6-Aminopenicillanic acid (6-APA) and R- phenylglycine methyl ester (PGME) were employed at different molar ratios to synthesis ampicillin batchwise. Lower molar ratio of b-lactam nucleus to higher molar ratio of acyl donor gave highest selectivity either in absence or presence of methanol at 35°C rather than 4°C. Both the selectivity and yields were time dependent. The immobilized enzyme was operationally stable for 6 continuous cycles. https://www.biotech-asia.org/vol9no2/enzymatic-synthesis-of-ampicillin-by-immobilized-penicillin-g-acylase-of-e-coli/ Immobilized penicillin G acylase; Selectivity; Yield; Ampicillin.