Coexistence and dynamical behavior for an unstirred chemostat with variable yield

This paper deals with a PDE model of two species competing for a single limiting nutrient resource in the unstirred chemostat in which one microbial species is of the variable yield. The introduction of the variable yield makes the conservation law fail. We first investigate the uniqueness of positive steady-state solution and dynamical behavior of the single species model. Then we establish the existence and structure of coexistence solutions of two species system. It turns out that the positive bifurcation branch connects two semi-trivial solution branch. Finally, we analyze the dynamical behavior of two species system, and the result shows that the two species system is uniformly persistent.