title: Emergent pattern formation in an interstitial biofilm.
abstract: Collective behavior of bacterial colonies plays critical roles in adaptability, survivability, biofilm expansion and infection. We employ an individual-based model of an interstitial biofilm to study emergent pattern formation based on the assumptions that rod-shaped bacteria furrow through a viscous environment and excrete extracellular polymeric substances which bias their rate of motion. Because the bacteria furrow through their environment, the substratum stiffness is a key control parameter behind the formation of distinct morphological patterns. By systematically varying this property (which we quantify with a stiffness coefficient γ), we show that subtle changes in the substratum stiffness can give rise to a stable state characterized by a high degree of local order and long-range pattern formation. The ordered state exhibits characteristics typically associated with bacterial fitness advantages, even though it is induced by changes in environmental conditions rather than changes in biological parameters. Our findings are applicable to a broad range of biofilms and provide insights into the relationship between bacterial movement and their environment, and basic mechanisms behind self-organization of biophysical systems.
authors.affiliation: School of Mathematical and Physical Sciences, University of Technology Sydney, Ultimo, NSW 2007, Australia.
authors.forename: Cameron
authors.initials: C
authors.lastname: Zachreson
authors.affiliation: School of Mathematical and Physical Sciences, University of Technology Sydney, Ultimo, NSW 2007, Australia.
authors.forename: Christian
authors.initials: C
authors.lastname: Wolff
authors.affiliation: The ithree institute, University of Technology Sydney, Ultimo, NSW 2007, Australia.
authors.forename: Cynthia B
authors.initials: CB
authors.lastname: Whitchurch
authors.affiliation: School of Mathematical and Physical Sciences, University of Technology Sydney, Ultimo, NSW 2007, Australia.
authors.forename: Milos
authors.initials: M
authors.lastname: Toth
mesh_terms: D000818:Animals; D018407:Bacterial Physiological Phenomena; D018441:Biofilms / Q000254:growth & development*; D003198:Computer Simulation; D004548:Elasticity; D045604:Extracellular Fluid / Q000382:microbiology*; D010861:Fimbriae, Bacterial / Q000502:physiology; D008954:Models, Biological; D009068:Movement / Q000502:physiology; D014783:Viscosity