A Simulation Model of Biofilms with Autonomous Cells, 2 - Explicit Representation of the Extracellular Polymeric Substance

Biofilms are complex colonies of bacteria that grow in contact with a wall, often in the presence of a water flow. In the current work, biofilm colony growth is investigated using a two-dimensional lattice Monte–Carlo algorithm based on the bond-fluctuation algorithm (BFA). One of the distinguishing characteristics of biofilms, the synthesis and physical properties of the extracellular polymeric substance (EPS) in which the cells are embedded, is explicitly taken into account. Cells are modeled as autonomous closed loops with well-defined mechanical and biological properties, while the EPS is modeled as flexible polymeric chain synthesized by the cells during their growth. By tuning the structural, energy, biological, and morphologic parameters of the model, the cell shapes as well as the growth and maturation of various types of biofilm colonies (including colonies with multiple species) can be controlled.