Modelling biofilm formation

Biofilms are communities of bacteria and other microorganisms that stick to each other and onto surfaces, so that they form a slimy layer like the black slime you sometimes get in taps and garden hoses. They can have important implications for health in some circumstances, for example by causing disease or by fouling medical implants. Dental plaque is a biofilm that forms on teeth, and Legionnaires’ disease is caused by Legionella bacteria that can grow in biofilms in air-conditioning systems. Biofilm formation is often modelled using individual-based simulations, as this allows detailed knowledge of formation mechanisms to be included, but it is very slow for macroscopic biofilms owing to the large number of cells involved (a typical cell density in a biofilm might be 10^11/ml and the many interactions between them. Current individual-based models can only simulate lengthscales of a few millimetres at best and over comparatively short timescales. This project is aimed at developing efficient algorithms for aggregating the microscopic features of individual-based biofilm models into system-level models that can predict features of the biofilm on a macroscopic scale.