Separating motile and immotile bacteria through confined chemotaxis

The majority of bacteria move in complex porous materials, such as tissues or soil, yet their motion and chemotaxis in confinement is not yet completely understood. We will present a model that couples individual tun-and-tumble bacterial motion to the chemical gradient while the entire colony is inside a simple circular confinement. We will discuss the states observed for various parameters, and also the phase separation in an initially random mixture of motile and immotile bacteria.