The potential for production of penicillin G-acylase (PGA), encoded by the chromosomal gene pgai, of four strains belonging to a genealogical line derived from the strain Escherichia coli W, was evaluated in a medium with and without the inducer phenylacetic acid (PA). These strains were used as hosts of the recombinant plasmid pKA18, in which the structural gene pgac isolated from the strain RE3, the best host strain of a line giving the highest production, was cloned. The presence of the inducer reduced the copy number of the plasmid in all recombinant strains. Only in recombinant strain RE3 (pKA18) the reduction of the gene dosage of pgac resulted also in the reduction of the amount of PGA synthesized by the cells. The reduced activity of the cells did not result from a segregation of plasmid-free clones. Also the growth rate was decreased by 20 and 40% in the host and recombinant strains, respectively. The host strain RE3 showing the highest production of PGA was also the best host of the recombinant plasmid in terms of the segregational stability and copy number (198 copies per chromosome). The recombinant strain RE3 (pKA18) also provided the highest production of PGA.

• MeSH
• Escherichia coli classification   genetics   metabolism   MeSH
• Cloning, Molecular MeSH
• Penicillin Amidase biosynthesis   genetics   MeSH
• Plasmids genetics   MeSH
• Gene Expression Regulation, Bacterial MeSH
• DNA, Recombinant MeSH
• Recombinant Proteins biosynthesis   MeSH
• Publication type
• Journal Article MeSH
• Evaluation Study MeSH
• Names of Substances
• Penicillin Amidase MeSH
• DNA, Recombinant MeSH
• Recombinant Proteins MeSH

Escherichia coli strain which contains a marker of tetracycline resistance gene (TcR) placed by P1 transduction beside the chromosomal deletion of ampC gene (delta ampC) coding for beta-lactamase was constructed. Such introduction of TcR marker permits a fast and simple selection for the transfer of delta ampC by P1 transduction into industrial E. coli strains. This approach was used for constructing an E. coli strain suitable for penicillin acylase production.

• MeSH
• Genes, Bacterial * MeSH
• Bacterial Proteins * MeSH
• Bacteriophage P1 genetics   MeSH
• beta-Lactamases genetics   MeSH
• Gene Deletion MeSH
• Escherichia coli drug effects   enzymology   genetics   MeSH
• Genetic Markers MeSH
• Penicillin Amidase biosynthesis   genetics   MeSH
• Plasmids genetics   MeSH
• Recombinant Proteins biosynthesis   genetics   MeSH
• Tetracycline Resistance genetics   MeSH
• Transduction, Genetic MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• AmpC beta-lactamases MeSH Browser
• Bacterial Proteins * MeSH
• beta-Lactamases MeSH
• Genetic Markers MeSH
• Penicillin Amidase MeSH
• Recombinant Proteins MeSH