Pakistan Journal of Biological Sciences1028-88801812-5735Asian Network for Scientific Information10.3923/pjbs.2000.862.865Escherichia coli]]>ArshadRubina Salih AhmadMuhammad 5200035Penicillin G acylase (PGA) is one of the most widely used enzymes at an industrial scale. It is used to hydrolyze penicillin G to produce 6-aminopenicillanic acid (6-APA), a required intermediate in the production of semi-synthetic penicillins. Escherichia coli is the most abundantly used organism for PGA production. Present study was focused on the kinetics of growth and PGA production of three local E. coli isolates, FH6-NIAB, FMu2-NIAB and FD25-NIAB. Optimal enzyme production was reached after 18 hr. For longer incubations, the enzymatic activity decreased slightly. PGA activity was detectable after about 6 hours of incubation.
For the selected isolates, PGA production was determined for various concentrations of glucose and phenylacetic acid in the medium. PGA production by E. coli isolates was completely repressed by glucose concentration above 5 g/l. Production of PGA by E. coli isolates was completely dependent upon the presence of PAA in the medium and optimal enzyme activity was obtained between 1 g/l and 2 g/l of PAA. Enzyme activity was found to be highest when PAA was used as an inducer. PGA production by our local E. coli isolates was completely inducible.]]>Ahmad, M.S., M. Saba and R. Arshad,1999Escherichia coli producing penicillin g acylase from dung of horse, donkey and mule.]]>31141145Goluh, E.I. and A.M. Bei'Kind,1977Escherichia coli.]]>46363365Illanes, A., F. Acevedo, J.C. Gentina, I. Reyes and R. Torres et al.,1994Bacillus megaterium in complex and defined media.]]>29263270Kaufmann, W., K. Bauer and H.A. Offe,19601960pp: 1-5pp: 1-5Klein, J. and F. Wagner,19801980pp: 335-345pp: 335-345McVey, C.E., S.P. Tolley, S.H. Done, J.A. Brannigan and K.S. Wilson,1997Escherichia coli.]]>53777779Robas, N., H. Zouheiry, G. Branlant and C. Branlant,1993Escherichia coli ATCC 11105.]]>411424Saba, M., R. Arshad and M.S. Ahmad,1998Escherichia coli from faeces of vertebrates for penicillin G acylase and betalactamase.]]>3597103Savidge, T. and M. Cole,19751975pp: 705-721pp: 705-721Vandamme, E.,19881988pp: 261-286pp: 261-286Vojtisek, V. and J. Slezak,1975Escherichia coli: II. Synthesis of the enzyme, kinetics and specificity of its induction and the effect of O2.]]>20289297Vojtisek, V. and J. Slezak,1975Escherichia coli: III. Catabolite repression, diauxie, effect of cAMP and nature of the enzyme induction.]]>20298306Wojskowicz, J.,1981Escherichia coli.]]>301323