Coexistence and stability of an unstirred chemostat model with Beddington–DeAngelis function

This paper deals with an unstirred chemostat model with the Beddington–DeAngelis functional response. First, a sufficient condition to the existence of positive steady state solutions is established. Second, the effect of the parameter β1β1 in the Beddington–DeAngelis functional response which models mutual interference between species uu is considered. The result shows that if β1β1 is sufficiently large, the solution of this model is determined by a limiting equation. The main tool used here includes the fixed point index theory, the perturbation technique and the bifurcation theory.