Paper Number
GG54
Session
Rheology of Gels, Glasses and Jammed Systems
Title
Self-generating gels: Morphogenesis of growing bacterial communities in polymeric environments
Presentation Date and Time
October 13, 2022 (Thursday) 9:25
Track / Room
Track 3 / Sheraton 5
Authors
- Gonzalez La Corte, Sebastian (Princeton University)
- Bhattacharjee, Tapomoy (Princeton University)
- Royer, Brianna (Princeton University)
- Wingreen, Ned S. (Princeton University)
- Datta, Sujit S. (Princeton University)
Author and Affiliation Lines
Sebastian Gonzalez La Corte, Tapomoy Bhattacharjee, Brianna Royer, Ned S. Wingreen and Sujit S. Datta
Princeton University, Princeton, NJ
Speaker / Presenter
Datta, Sujit S.
Keywords
experimental methods; theoretical methods; computational methods; active matter; bio-fluids; biomaterials; colloids; gels; microscopy; polymer solutions
Text of Abstract
Many bacteria live in polymeric environments, such as mucus in the body, exopolymers in the ocean, and cell-secreted extracellular polymeric substances (EPS) that encapsulate biofilms. However, most studies of bacteria focus on cells in polymer-free fluids. How do interactions with polymers influence the behavior of growing bacterial communities? To address this question, we experimentally probe the growth of non-motile Escherichia coli in solutions of chemically-inert polymers. We find that, when the polymer is sufficiently concentrated, the cells grow in striking “cable-like” morphologies---in stark contrast to the compact morphologies that arise in the conventionally-studied polymer-free case. Experiments and agent-based simulations indicate that these unusual community morphologies arise due to a polymer-induced entropic attraction between pairs of cells---thus, these growing communities can be thought of as self-generating colloidal gels. These results suggest a pivotal role of polymers in regulating microbe-host interactions through physicochemical interactions, e.g., potentially by promoting bacterial exposure to external biochemical groups that protect the host against pathogens. More broadly, this work helps to uncover quantitative soft matter principles governing the morphogenesis of diverse forms of growing active matter in polymeric environments.