Showing papers on "Penicillin amidase published in 1981"
TL;DR: Immobilization of the enzyme in polyelectrolyte complex particles leads to the appearance of new properties of the biocatalyst; immobilized penicillin amidase can be reversibly converted to the insoluble state with a slight change in pH and ionic strength of the solution.
39 citations
Journal Article•
TL;DR: Penicillin amidase from Proteus rettgeri was purified 580-fold by a four-step chromatographic procedure and it was found that the purified preparation contains 53% of the enzyme.
Abstract: 1. Penicillin amidase from Proteus rettgeri was purified 580-fold by a four-step chromatographic procedure. Titration with phenylmethanesulphonyl fluoride showed that the purified preparation contains 53% of the enzyme. 2. The molecular weight of the amidase was found to be 65.000. The enzyme is strongly inhibited by N-bromosuccinimide and zinc ions. It hydrolyses penicillins, cephalosporins and some synthetic substrates, and in addition it catalyses synthesis of ampicillin from methyl ester of phenylglycine and 6-aminopenicillanic acid. 3. The immobilized amidase obtained by copolymerization of the chemically modified enzyme with acrylamide was applied for preparative hydrolysis of benzylpenicillin.
15 citations
01 Jan 1981
TL;DR: Escherichia coli strains synthetizing endoenzymes - hyperproducing, constitutive strains and strains resistant to catabolite repression under different selection pressure were accumulated in a chemostat and the stability of individual strains differed remarkably.
Abstract: Escherichia coli strains synthetizing endoenzymes - hyperproducing, constitutive strains and strains resistant to catabolite repression under different selection pressure were accumulated in a chemostat. The selection pressure was brought about by different carbon and nitrogen sources in synthetic medium in growth limiting concentration and by changes of dilution rate and temperature. In this manner the selected strains had a manifold higher specific activity of individual enzymes, in comparison with the original strains: β-galactosidase 30-fold, D-serine deaminase 25-fold, ribitoldehydrogenase 12-fold and penicillin amidase 20-fold. The stability of individual strains differed remarkably. The high specific activity of strains producing β-galactosidase and ribitol dehydrogenase can be maintained only in continuous culture by substrate limitation.
2 citations
01 Jan 1981
TL;DR: The enzyme production was markedly increased by the optimization by the media composition and several factors affecting the engyme production during fermentation as compared with those previously reported.
Abstract: To maximize the production of penicillin amidase from Estherichia coli (ATCC 9637), the media composition and several factors affecting the engyme production during fermentation were studied. The optimal media composition was found to be; 3.5% tryptone, 1.5% monosodium glutamate and 0.5% yeast extract. The addition of 0.15% phenylacetic acid as an enzyme inducer at the initial stage of cultivation increased the engyme productivity about 5 fold. It was found that the engyme activity reached maximum within 16hr of cultivation. The maximum production of the enzyme obtained was about 102.5 units/l broth under the optimized condition. The enzyme production was markedly increased by the optimization as compared with those previously reported.
2 citations