The Role of Polymer-Mediated Cohesion in Bacterial Suspensions

The ability of some strains of bacteria to self assemble into free-floating aggregates in liquid media has inspired numerous computational and theoretical studies in the field of active matter. Consequently, we have gained a deeper theoretical understanding of how motility, cell shape, and chemical signalling might influence aggregation. Bacteria also modulate their environment via the active secretion of macromolecules. In particular the production of polymers is thought to be crucial for cell-cell cohesion and surface-adhesion in bacterial biofilms, yet there has been little emphasis on the role of such polymers in the formation of suspended bacterial aggregates in liquid media.

In this talk, I will present results from aggregation experiments on the model biofilm organism Pseudomonas aeruginosa and discuss the importance of polymer production in its ability to form free-floating aggregates in liquid media. If time permits, I will also present a simulation model, inspired by polymer-mediated cohesion in this system, that gives rise to some interesting phase separation behaviour.