Transient response simulations of recombinant microbial populations.
An asynchronous bacterial population has been approximated using a finite number of "computer" cells, each based on a complex single-cell model for Escherichia coli. This formulation correctly simulates the transient responses of protein and total cell mass synthesis rate to the sudden increase in the concentration of limiting energy source in the growth medium. Experimentally observed responses of rRNA and mRNA synthesis rates to growth rate shifts are qualitatively mirrored by the model. Simulation trends following those of a rel(-) mutant suggest that model modifications are needed to describe the dynamics of the stringent response. Simulations of the responses of recombinant populations to plasmid amplification or plasmid promoter induction also result in behavior similar to that determined experimentally. The calculated responses for recombinant populations subjected to constant promoter induction or cyclic induction-noninduction lead to the conclusion that inducible systems give greater productivity than those with fixed promoter strength. This formulation may be utilized as a basis for exploring other aspects of recombinant population dynamics.
Peretti
S W
SW
Department of Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA.
Bailey
J E
JE