Bacteria colonies modify their shear and compressive mechanical properties in response to different growth substrates

TL;DR

This study reveals that bacteria colonies adapt their shear and compressive mechanical properties based on the agar concentration of their growth substrate, highlighting environmental influence on biofilm mechanics.

Contribution

It demonstrates the link between growth substrate properties and bacterial colony mechanics, providing new insights into biofilm development and potential disruption strategies.

Findings

Bacteria colonies modify their mechanical properties in response to substrate stiffness.

Mechanical interactions influence biofilm development.

Results suggest environmental conditions affect biofilm robustness.

Abstract

Bacteria build multicellular communities termed biofilms, which are often encased in a self-secreted extracellular matrix that gives the community mechanical strength and protection against harsh chemicals. How bacteria assemble distinct multicellular structures in response to different environmental conditions remains incompletely understood. Here, we investigated the connection between bacteria colony mechanics and the colony growth substrate by measuring the oscillatory shear and compressive rheology of bacteria colonies grown on agar substrates. We found that bacteria colonies modify their own mechanical properties in response to shear and uniaxial compression with the increasing agar concentration of their growth substrate. These findings highlight that mechanical interactions between bacteria and their microenvironment are an important element in bacteria colony development, which can aid in developing strategies to disrupt or reduce biofilm growth.