title: A mathematical model of quorum sensing regulated EPS production in biofilm communities.
abstract: BACKGROUND
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Mathematics and Statistics, University of Guelph, 50 Stone Rd E, Guelph, ON N1G2W1, Canada. mfrederi@uoguelph.ca
authors.forename: Mallory R
authors.initials: MR
authors.lastname: Frederick
authors.forename: Christina
authors.initials: C
authors.lastname: Kuttler
authors.forename: Burkhard A
authors.initials: BA
authors.lastname: Hense
authors.forename: Hermann J
authors.initials: HJ
authors.lastname: Eberl
mesh_terms: D018441:Biofilms / Q000254:growth & development; D018533:Biomass; D015169:Colony Count, Microbial; D003198:Computer Simulation; D005110:Extracellular Space / Q000737:chemistry*; D008954:Models, Biological; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis*; D053038:Quorum Sensing / Q000502:physiology*
chemical_list: D011135:Polysaccharides, Bacterial