Invited Paper BI+AS-WeM3
Biofilm Mechanics as a Mechanism for Survival on Surfaces from Medical Device to Ship Hulls

Wednesday, October 23, 2019, 8:40 am, Room A120-121

Bacterial biofilms are microscopic assemblages of bacterial cells usually attached to a surface and held together by a self-produced extracellular polymeric slime (EPS) matrix. Biofilms are ubiquitous in the natural environment and are highly problematic in industry and medicine where they cause corrosion, fouling, contamination and chronic medical and dental infections. The basic biology of bacterial biofilm development and strategies evolved to survive in the environment of the ancient earth are now used by the bacteria to survive on modern man-made materials. Diffusion limitation within the EPS matrix results in sharp gradients as nutrients are consumed by respiring bacteria on the periphery faster than they can diffuse in. Similarly, cell signals (molecules used to co-ordinate behavior between individual cells) and waste products, such as fermentation acids, build up in the interior of the biofilm. Biofilms are mechanically complex showing a range of behaviors from elastic solids to viscous liquids. These viscoelastic properties can facilitate survival on surfaces exposed to high shear stresses and can explain the high pressure drop and frictional losses in pipelines and ship hull fouling. However, the mechanical response may also be exploited to drive antimicrobials into the biofilm for control. The development of microenvironments combined with the structural versatility of the biofilm is the basis for the distinct biofilm phenotype as an emergent property of population of single cells and is a challenge to overcome in their control.