(5b) Active Glassy Dynamics and Its Role in Three-Dimensional Growth of Motile Bacterial Monolayers
AIChE Annual Meeting
2020
2020 Virtual AIChE Annual Meeting
Engineering Sciences and Fundamentals
Active Colloidal Systems I
Monday, November 16, 2020 - 8:15am to 8:30am
One key step in the development of many bacterial colonies and biofilms is a transition from a two-dimensional (2D) monolayer into a three-dimensional (3D) structure. In this talk, we will address the physical state of the bacterial colony at a collective level as a function of cell density, and describe its role in mediating the out-of-plane growth of bacterial monolayers [1]. Our experiments on motile bacterial colonies show that increasing the cell density leads to a cross over from an active swarming state to a kinetically arrested glassy state. Following the trajectories of individual bacteria, we demonstrate that motile monolayers at high densities exhibit characteristic signatures of glassy dynamics, in particular, the dynamic heterogeneity. Combining molecular simulations of active Brownian particle models, we extend the dynamical facilitation theory, which fundamentally takes into account the dynamic heterogeneity, to active colloidal systems, showing universal features of the role of motility in modulating the relaxation behaviors of active glasses. In doing so, we ultimately arrive at a corresponding states for active glassy systems and bacterial monolayers, and calculate an onset pressure (or density) that delineates the boundary between swarming vs. glassy colonies. We will end by discussing the role of the dynamical state diagram on the mechanisms leading to colony growth in the third dimension.
(See accompanying abstract by Dr. Sho C. Takatori, for associated work on a novel motility induced buckling mechanism in bacterial colonies in the swarming state.)
[1] S. C. Takatori, and K. K. Mandadapu, “Motility-induced buckling and glassy dynamics regulate three-dimensional transitions of bacterial monolayersâ€, arXiv:2003.05618 (2020).
(See accompanying abstract by Dr. Sho C. Takatori, for associated work on a novel motility induced buckling mechanism in bacterial colonies in the swarming state.)
[1] S. C. Takatori, and K. K. Mandadapu, “Motility-induced buckling and glassy dynamics regulate three-dimensional transitions of bacterial monolayersâ€, arXiv:2003.05618 (2020).