Predator — mediated coexistence in a chemostat: Coexistence and competition reversal

If a system of several populations of microorganisms compete exploitatively for a single nonreproducing limiting nutrient which is introduced into and washed out of the system at a constant rate, then competitive exclusion results, Provided that there are no inhibition effects, the population requiring the lowest “break-even” concentration of nutrient will be the winner. This outcome can be changed if a predator population is introduced into the system. In this paper we explore some of the possibilities of coexistence and competition reversal that may arise.