Speaker
Description
In marine environments,bacterial biofilm formation occurs on the surface of plumes of marine snow that serve as moving nutrient hotspots.We develop a mathematical model on bacterial biofilm study that accounts for biomass growth,surface attachment-detachment,diffusive and directed movement of planktonic bacteria and perform a numerical simulation study.The biomass density controls the spatial expansion of biofilm,whereas biomass growth depends on the concentration of two counter-diffusive substrates,carbon and oxygen.Carbon diffuses from surface of marine snow into the domain,while oxygen enters from the opposite boundary.Planktonic bacteria, driven by directed movement,accumulate in regions with favorable growth conditions.The system is described by a one-dimensional set of four highly nonlinear PDEs.The flux-conservative finite volume method is used for space discretization of transport terms corresponding to biomass in biofilm and suspension.Substrate equations are discretized and numerically solved using a time-adaptive method from ‘ReacTran’ library in ‘R’.Simulation results show biofilm expansion toward the aqueous phase and dynamic migration of suspended bacteria toward optimal nutrient zones.A comparative study on uniform and non-uniform grid refinement using the Shishkin mesh and graded mesh is conducted.The interplay between directed movement,attachment-detachment and counter-diffusion is shown to significantly influence biofilm maturation dynamics.
