Multiscale models of bacterial populations

We present a hybrid model of the interactions within (multiple-species) populations of bacteria in a developing biofilm which integrates continuum models of population processes (e.g., diffusion of substrates and signalling molecules) with individual-based models of cellular processes (notably growth, division, displacement, and up- regulation). The cell level models combine both aggregated models of continuous processes (growth, division and displacement) for small collections of cells and individual-cell level models of quorum sensing molecule (QSM) sensing, production and up-regulation which encompass both stochastic and discrete processes. The use of both aggregated and individual models of cellular processes allows the resolution of the model to be tailored for a particular modelling problem, while at the same time remaining computationally tractable.