Bacteria Colonies Modify Their Shear and Compressive Mechanical Properties in Response to Different Growth Substrates

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 in a manner that depends on the concentration of agar in their growth substrate. These findings highlight that mechanical interactions between bacteria and their microenvironments are an important element in bacteria colony development, which can aid in developing strategies to disrupt or reduce biofilm growth.

Impact of MSMEG5257 Deletion on Mycolicibacterium smegmatis Growth

“…The cell envelope plays a crucial role in mycobacteria pathogenesis, as most virulence factors are exposed to this structure [12]. Furthermore, changes in the cell envelope can also affect the proper transmission of mechanical signals within the local cell membrane, and this malfunction often leads to the development of host diseases [13,14]. For instance, Mtb lipoproteins elicit TLR2-mediated signaling in macrophages, which hinders the IFN-γ-induced expression of MHC-II molecules [15,16].…”