Positive solution and stability of the unstirred chemostat with variable yield.

In this paper, we are mainly concerned with the unstirred chemostat model with variable yield. We first study positive steady‐state solution and its stability of the model by bifurcation theory and the fixed point index theory. Then we focus on the model with perturbation on diffusion rates, nonconstant yield rate, and nonzero death rate to obtain the existence and stability of the unique positive solution, whenever the constants are perturbed from the critical point. [ABSTRACT FROM AUTHOR]