title: Stability of colicin plasmids in continuous culture: mathematical model and analysis.
abstract: Bacteriocin plasmids may be useful in preventing plasmid instability because the bacteriocin they produce selectively kills otherwise identical bacterial cells lacking the plasmid. This capability may allow plasmid-bearing cells to persist despite the problems of growth rate depression and segregational plasmid loss which often lead to displacement by plasmid-free cells.In order to determine the conditions under which bacteriocin plasmids can prevent instability, we develop and analyze a mathematical model for the growth of colicin plasmid-bearing E. coli in continuous culture. Model behavior compares successfully with experimental results of Adams et al. (1979) [1]. Dependence of the system dynamic behavior on key parameters is elucidated and a simple parameter criterion for prevention of plasmid instability is derived. The possibility of instability prevention is found to be extremely sensitive to dilution rate.
authors.affiliation: Department of Chemical Engineering University of Pennsylvania Philadelphia, PA 19104.
authors.forename: D A
authors.initials: DA
authors.lastname: Lauffenburger