Bacterial motility is central to several biological processes, including pathogenesis and biofilm formation. Accordingly, understanding how bacteria move through and interact with their surroundings has significant implications for human health and the environment. Though bacterial fitness often depends on the ability to navigate complex landscapes, most investigations of bacterial locomotion are performed in controlled, homogeneous laboratory settings. For instance, the well-characterized ‘run-and-tumble’ motion observed in E. coli has been observed primarily in unconstrained fluid environments.
Recently, experiments performed in confined porous media have uncovered a seemingly novel mode of locomotion, called ‘hop-and-trap’. However, it is unclear if this constitutes a distinct behavior that E. coli adopt when they sense obstacles in their environment or if run-and-tumble and hop-and-trap lie along the same behavioral axis. That is, is the choice of locomotion simply driven by the degree of environmental clutter? Further, do there exist other unknown bacterial locomotive strategies driven by bacterial sensing, spatial confinement, or some combination of the two? This proposal aims to gain a deeper understanding of movement through natural environments, and of how interaction with spatially complex and temporally dynamic mechanical cues shape the space of bacterial motility.