Temperature, pH, and cations affect the ability of Escherichia coli to mobilize plasmids in L broth and synthetic wastewater.

Coincubations of plasmid donor and recipient cells in L broth and in synthetic wastewater demonstrated that a large number of environmental factors must be taken into account when measuring the potential for the dissemination of plasmid-encoded genes in natural environments. These include salts and detergents in the medium as well as other factors, e.g., pH and temperature. Complex interactions between and among agents were observed, indicating that simple additive effects may not be assumed. Mobilization of genetically engineered nonconjugative plasmid pHSV106 was inhibited by the same compounds that affected conjugative plasmid movement.