Bacterial Chemotaxis in Porous Media
Chemotactic migration of bacteria—their ability to direct multicellular motion along chemical gradients—is central to processes in agriculture, the environment, and medicine. However, studies are typically performed in bulk liquid, despite the fact that most bacteria inhabit heterogeneous porous media such as soils, sediments, and biological gels. By using direct visualization and 3D bioprinting, we find that cellular chemotaxis drives collective migration while confinement in a porous medium fundamentally alters chemotactic migration in two ways. First, cells bias their motion through a different primary mechanism in confinement than in bulk liquid. Second, confinement markedly alters the dynamics and morphology of the migrating population—features that can be described by a continuum model, but only when standard motility parameters are substantially altered from their bulk liquid values. Our work thus provides a framework to predict and control the migration of bacteria, and active matter in general, in heterogeneous environments. Read more about this work here.