Fragmentation Mechanisms of Bacterial Biofilms of Physiological Relevance

  • Fragmentation Mechanisms of Bacterial Biofilms of Physiological Relevance
  • Biofilms are a phenotype of bacteria in which the organisms are sessile and embedded in an extracellular matrix of polysaccharides. Typically surface adherent and structurally heterogeneous, biofilms arise in natural, industrial and health settings. The biomechanics of biofilms are of fundamental physical science interest because their systemic proliferation is triggered by their mechanical rupture, fracture and fragmentation. This problem involves a complex interplay of molecular, interfacial and viscoelastic interactions, each active on different spatial scales of the biofilm. Yet, because of its scope and complexity, integrated physical science-based modeling and computational approaches have not previously been applied to discover mechanisms of fragmentation. Instead, microbiological approaches that do not directly address the fundamental biomechanics have been more commonly applied. Professor Sureshkumar and colleagues argue that by integrating modern computational methodologies and resources for simulating the non-equilibrium dynamics of polymers and the multiphase flow of viscoelastic fluids, the mechanisms for biofilm fragmentation can be identified. This project is bringing together applied mathematics, non-equilibrium stochastic simulation of polymer dynamics, microbiology and microscale rheology to transform the scientific understanding of bacterial biofilms from one based solely on molecular biology to one that comprehensively addresses the molecular, interfacial and viscoelastic origins of behavior. Our overall approach to tackling this problem is illustrated in the figure below.

    Fragmentation Mechanism Research

    Research approach: fragmentation of bacterial biofilms. (A) S. epidermidis grown at 0.1 Pa shear for 24 hours; (B) Microscopic structure of biofilms, here shown for K. pneumoniae; (C) Stress-induced fragmentation of biofilms; (D) Composite nature of biofilms: interfacial and bulk regions of the extracellular matrix respond to deformation; (E) network model of the fragmentation process shown in (C); (F) density field model of the pair-wise microscopic deformation shown in (D).