ABSTRACT DYNAMICS OF PLASMID CONTAINING CELLS IN A CHEMOSTAT UNDER TRANSIENT CONDITIONS

One of the major concerns in the utilization of plasmid-containing organisms in fermentation processes is the stability of the plasmid. In general, it is observed that two parameters, the probability of plasmid loss due to faulty segregation and the difference in the specific growth rate between the recombinant and reverted cells, govern the dynamics of the reactor. These two parameters are affected by a number of factors: the genetic make-up of the host cells and the plasmid and the reactor operating parameters such as temperature, pH, dilution rate, and growth medium. It is speculated that by manipulating these factors it may be possible to enhance the stability of the plasmid-containing population. In this work the effects of well-defined perturbations in reactor conditions on plasmid maintenance and gen