(334d) Bacterial Hopping and Trapping in 3D Porous Media

Diverse applications, ranging from bioremediation to drug delivery, rely on bacterial migration through three-dimensional porous media; however, how pore-scale confinement alters bacterial motility is unknown. Using a novel experimental platform, we demonstrate that the paradigm of run-and-tumble motility is dramatically altered in a porous medium. Instead, we find a new form of motility in which cells are intermittently and transiently trapped as they navigate the pore space. Moreover, we find that the trapping duration and the length of “hops” between traps together can predict the long-time bacterial translational diffusivity. Our work thus provides a revised picture of bacterial motility in complex media and yields principles for predicting cellular migration over large length and time scales, with implications for healthcare, agriculture, and bioremediation.