The biophysics of bacterial biofilms facilitate surface survival in moving fluids
Location:216 DeBartolo Hall
Bacterial biofilms are microscopic assemblages of bacterial cells, attached to a surface and held together by an extracellular polymeric slime (EPS) matrix. Biofilms are ubiquitous in the environment. They also are problematic in industry and medicine, causing corrosion, fouling, and infections. The EPS matrix protects the bacteria from antibiotics, chemical challenges, and host immunity. Mass transfer through the EPS is dominated by diffusion which, allows the development of gradients in nutrients, waste products and cell signals. The highly localized and heterogeneous chemical microenvironment can promote antibiotic tolerant populations. The bulk mechanical properties of biofilms can facilitate survival by allowing the biofilm to respond to fluid shear stresses over very short (ms) and very long (days to weeks) time scales. Creep and relaxation tests show that biofilms behave as viscoelastic liquids. However, recent observations of high velocity impacts with water droplets suggest they rapidly form interfacial instabilities, allowing them to flow over surfaces with velocities of meters per second. Biofilm structures in fossil record suggests that such behavior might be an early adaptation to life on surfaces. A better understanding of how bacterial biofilms respond to fluid flow provides new opportunities to develop more effective control strategies.
Department of Microbial Infection and Immunity, Orthopaedics and Microbiology,
The Ohio State University