Bulletin of the American Physical Society
APS March Meeting 2022
Volume 67, Number 3
Monday–Friday, March 14–18, 2022; Chicago
Session T05: Statistical Mechanics of Active Matter and Microbial Ecology
11:30 AM–2:30 PM,
Thursday, March 17, 2022
Room: McCormick Place W-178A
Sponsoring Unit: DBIO
Chair: Marco Polin, Mediterranean Institute for Advanced Studies (IMEDEA UIB-CSIC)
Abstract: T05.00001 : Overcoming physical obstacles: a collective microbial solution to a shared problem*
11:30 AM–12:06 PM
(Univ of Cambridge)
(Univ of Cambridge)
Using time-lapse microscopy on expanding biofilms of B. subtilis crashing against populations of E. coli of variable density and width, we find that the biofilm population exhibits different collective strategies to bypass the barrier on its path, often requiring coordination of cell behaviour across thousands of cells. In particular, while rafts of swarming cells are sufficient to break through thin barriers, large barriers trigger a “vascularization” process during which some cells switch from motile to matrix producers to create protected channels that slowly penetrate the barrier. The two strategies consistently follow a precise chronological order, suggesting that the biofilm behaviour is a response to the increasing mechanical stress generated in the attempt of breaking through the barrier. To test this hypothesis, we perform molecular dynamics simulations of populations of particles that can switch from active to sticky as a function of their local mechanical stress and identify the minimal ingredients necessary to recapitulate the experimental results.
This work is in collaboration with Dr. Luis Ruiz Pestana, University of Miami.
*This work is supported by the Gates Foundation.
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