Nejvíce citovaný článek - PubMed ID 1100492
Penicillinamidohydrolase in Escherichia coli. II. Synthesis of the enzyme, kinetics and specificity of its induction and the effect of O2
Intact cells Escherichia coli CCM 2843, exhibiting substantial benzylpenicillin amidase activity, were bound mutually with supporting waste microbial cells, native or treated, to obtain an inexpensive biocatalyst for the production of 6-aminopenicillanic acid (6-APA). The bond was effected by glutaraldehyde (GA) and Sedipur CL-930 (PEI), without any carrier. The optimal concentration of GA was 2%, that of PEI 1%. The optimal biocatalyst was obtained by immobilization of productive cells with their fragments at a mass ratio of 4:1. The cell aggregates were used for hydrolysis of potassium benzyl-penicillin at a concentration of 5% to 6-APA. After 25 repeated batch conversions the degree of conversion did not decrease; its average value was 96.4%.
- MeSH
- bakteriální adheze MeSH
- Escherichia coli enzymologie MeSH
- penicilinamidasa metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- penicilinamidasa MeSH
Synthesis of penicillinamidohydrolase (penicillin acylase, EC 3.5.1.11) in Escherichia coli is subjected to the absolute catabolite repression by glucose and partial repression by acetate. Both types of catabolite repression of synthesis of the enzyme in Escherichia coli are substantially influenced by cyclic 3',5'-adenosinemonophosphate (cAMP). Growth diauxie in a mixed medium containing glucose and phenylacetic acid serving as carbon and energy sources is overcome by cAMP. cAMP does not influence the basal rate of the enzyme synthesis (without the inducer). Derepression of synthesis of penicillinamidohydrolase by cAMP in a medium with glucose and inducer (phenylacetic acid) is associated with utilization of the inducer, due probably to derepression of other enzymes responsible for degradation of phenylacetic acid. Lactate can serve as a "catabolically neutral" source of carbon suitable for the maximum production of penicillinamidohydrolase. The gratuitous induction of the enzyme synthesis in a medium with lactate as the carbon and energy source and with phenylacetic acid is not influenced by cAMP; however, cAMP overcomes completely the absolute catabolite repression of the enzyme synthesis by glucose.
- MeSH
- acetáty farmakologie MeSH
- amidohydrolasy biosyntéza MeSH
- AMP cyklický farmakologie MeSH
- enzymová indukce MeSH
- enzymová represe MeSH
- Escherichia coli enzymologie růst a vývoj MeSH
- fenylacetáty farmakologie MeSH
- glukosa antagonisté a inhibitory farmakologie MeSH
- kinetika MeSH
- kultivační média MeSH
- laktáty farmakologie MeSH
- penicilinamidasa biosyntéza MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- acetáty MeSH
- amidohydrolasy MeSH
- AMP cyklický MeSH
- fenylacetáty MeSH
- glukosa MeSH
- kultivační média MeSH
- laktáty MeSH
- penicilinamidasa MeSH