Regulating, Measuring, and Modeling the Viscoelasticity of Bacterial Biofilms

Abstract

Biofilms occur in a broad range of environments under heterogeneous physicochemical conditions, such as in bioremediation plants, on surfaces of biomedical implants, and in the lungs of cystic fibrosis patients. In these scenarios, biofilms are subjected to shear forces, but the mechanical integrity of these aggregates often prevents their disruption or dispersal. Biofilms' physical robustness is the result of the multiple biopolymers secreted by constituent microbial cells which are also responsible for numerous biological functions. A better understanding of the role of these biopolymers and their response to dynamic forces is therefore crucial for understanding the interplay between biofilm structure and function. In this paper, we review experimental techniques in rheology, which help quantify the viscoelasticity of biofilms, and modeling approaches from soft matter physics that can assist our understanding of the rheological properties. We describe how these methods could be combined with synthetic biology approaches to control and investigate the effects of secreted polymers on the physical properties of biofilms. We argue that without an integrated approach of the three disciplines, the links between genetics, composition, and interaction of matrix biopolymers and the viscoelastic properties of biofilms will be much harder to uncover.

Biofilm mechanics: Implications in infection and survival

“…Those pertinent to this review will be briefly discussed here, however for a more compressive review of mechanical methodology refer to Refs. [ [5] , [6] , [7] , [8] ]. For analyses using mechanical indentation, a normal force is applied to the biofilm surface and can be analyzed both at the macro (rheometer or indenter) and micro (atomic force microscopy) scale ( Fig.…”

Biofilm and swarming emergent behaviours controlled through the aid of biophysical understanding and tools

“…Tuning frequency and amplitude of surface waves can control biofilm formation [85][86][87][88][89][90]92] Shear flows High shear flows lead to more compact biofilm formation and changes in its mechanical properties [48,92,93,103] Biofilms, sessile microbial communities embedded in EPS, also emerge on surfaces, but the conditions favourable for biofilm formation are distinct from those for swarming. Biofilms are prominent on solid-liquid, solid-air and liquid-air phase boundaries, and are recalcitrant to almost all types of biological and biochemical stresses.…”

Incorporating Cellular Stochasticity in Solid–Fluid Mixture Biofilm Models

“…To identify the relevant scales governing the evolution of the agar-biofilm interface we nondimensionalize (24) and (25). Making the change of variablesx =…”