Expression of tetracycline resistance in pBR322 derivatives reduces the reproductive fitness of plasmid-containing Escherichia coli.

摘要: Plasmid pBR322 and its numerous derivatives are used extensively for research in biotechnology. The tetracycline-resistance (TcR) genes these plasmids expressed constitutively cells carrying resistant to tetracycline. We have shown that expression of the TcR gene has an adverse effect on reproductive fitness plasmid-containing bacteria both glucose-limited batch chemostat cultures. If inactivated at any one three different restriction sites, mixed cultures plasmid-free grow same rate.