Mathematical Investigation for Two-Bacteria Competition in Presence of a Pathogen With Leachate Recirculation

This paper provides a thorough exploration of two-species competition in a continuous bioreactor when adding a pathogen that affects only one species and with leachate recirculation inside the reactor. The dynamics is modelled by a well-constructed system of nonlinear differential equations extending the classical model of the chemostat by adding more realism, enhancing its applicability. The nonnegativity and boundedness of trajectories, the determination of steady states and their local stability strengthens the credibility of the proposed system. The global stability analysis was conducted using uniform persistence theory. The coexistence of both species under somewhat natural assumptions is a key finding, contradicting the well-known competitive exclusion principle. Several numerical examples offer a practical demonstration of the theoretical concepts.