A mathematical model of quorum sensing regulated EPS production in biofilm communities
1 Department of Mathematics and Statistics, University of Guelph, 50 Stone Rd E, Guelph ON Canada N1G 2W1
2 Center of Mathematical Sciences, Technical University of Munich, Boltzmannstr. 3, 85748 Garching, Germany
3 Institute of Biomathematics and Biometry, HelmholtzCenter Munich, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
Theoretical Biology and Medical Modelling 2011, 8:8 doi:10.1186/1742-4682-8-8Published: 10 April 2011
Biofilms are microbial communities encased in a layer of extracellular polymeric substances (EPS). The EPS matrix provides several functional purposes for the biofilm, such as protecting bacteria from environmental stresses, and providing mechanical stability. Quorum sensing is a cell-cell communication mechanism used by several bacterial taxa to coordinate gene expression and behaviour in groups, based on population densities.
We mathematically model quorum sensing and EPS production in a growing biofilm under various environmental conditions, to study how a developing biofilm impacts quorum sensing, and conversely, how a biofilm is affected by quorum sensing-regulated EPS production. We investigate circumstances when using quorum-sensing regulated EPS production is a beneficial strategy for biofilm cells.
We find that biofilms that use quorum sensing to induce increased EPS production do not obtain the high cell populations of low-EPS producers, but can rapidly increase their volume to parallel high-EPS producers. Quorum sensing-induced EPS production allows a biofilm to switch behaviours, from a colonization mode (with an optimized growth rate), to a protection mode.
A biofilm will benefit from using quorum sensing-induced EPS production if bacteria cells have the objective of acquiring a thick, protective layer of EPS, or if they wish to clog their environment with biomass as a means of securing nutrient supply and outcompeting other colonies in the channel, of their own or a different species.