How to determine control of growth rate in a chemostat. Using metabolic control analysis to resolve the paradox.

The chemostat makes it possible to study microbial physiology at steady state. However, because growth rate in a chemostat is set by the experimenter, it seems impossible to employ the chemostat to study the control of microbial growth by processes within the microorganism. In this paper we show how, paradoxically, one can determine control of growth rate, of growth yield and of other fluxes in a chemostat. We develop metabolic control analysis for the chemostat. This analysis does not depend on the particular way in which specific growth rate varies with the concentration of the growth limiting substrate.