Applied Math Seminar I Hermann Eberl, Spatially implicit and spatially explicit models of bacterial cellulose degradation

MC 6460

Speaker

Hermann Eberl  | Department of Mathematics and Statistics, University of Guelph

Title

Spatially implicit and spatially explicit models of bacterial cellulose degradation

 Abstract

Cellulosic ethanol is a biofuel that is produced from non-edible plants and plant materials, such switchgrass and corn stover. It can have a positive net energy output with a reduction in green house gas emissions that is drastically lower than that of cornbased ethanol and fossil fuels. Clostridium thermocellum is a bacteria that is able to directly convert cellulose into ethanol (and other by products). These bacteria colonize cellulose material and degrade cellulose by "chewing" their way through their substrate. In this talk we first present a very simple, spatially implicit reactor scale model for cellulose degradation by C.thermocellum biofilms. This ODE can be studied with elementary techniques and quantitatively compared against experimental data. However, it does not allow for a detailed description of the spatial effects as the bacteria break down their substratum. To address this, we formulate then a spatially explicit model, which consists of a highly degenrate diffusion-reaction equation for bacterial biomas that is couled with an oridnary differential equation for the growth limiting substrate. We study this model numerically and qualitatively compare simulation results against experimental observations. The simulations suggest the existence of a traveling wave; time permitting we investigate those in a simplified setting in more detail.