Modeling the Effect of Biofilm Production in the Development of Plant Diseases

• Other Authors: Donahue, Matthew (authoraut)
• Format: Others
• Language: English; English
• Published: Florida State University
• Subjects: Mathematics
• Online Access: http://purl.flvc.org/fsu/fd/FSU_migr_etd-8973

Despite multiple bacterial infections causing widespread damage to the citrus, wine, and other fruit industries, there has been little attention paid to modeling the development and progression of the structures formed by the bacteria within these diseases. A biology primer describing the processes involved in biofilm formation will be followed by a description of bacterial infections within plants. To model these diseases a multiphase framework of partial differential equations will be used to examine the dynamic behavior and fluid/structure interactions of the biological system. Perturbation analysis will be used to determine potential causes and tendencies of patterns developed by biofilm formed within microfluidic chambers. These patterns represent a dominant mode of instability within the system, and the model equations capture this instability through the use of dispersion relationships. Numerical simulations of the nonlinear system will follow that are consistent with linear results. Further numerical studies will be used to investigate dynamics on a finite domain resembling the behavior of the system in vitro and in planta. First, a simulation using a constant inflow velocity will be used to mimic the properties of biofilms grown in the lab. These simulations also include the effects of added material, such as calcium. Second, a constant pressure drop will be imposed on the fluid similar to the transpiration pressure experienced by the xylem fluid within the plant. In these simulations, the growth of biomass causes a decrease in the flux of fluid able to move through the chamber. These results may provide insight into the ability of biofilm to successfully occlude xylem vessels. === A Dissertation submitted to the Department of Mathematics in partial fulfillment of the requirements for the degree of Doctor of Philosophy. === Summer Semester, 2014. === July 11, 2012. === Biofilm, Biofluids, Multiphase, Pierce's Disease, Xylella fastidiosa === Includes bibliographical references. === Nicholas Cogan, Professor Directing Dissertation; Xiaoqiang Wang, University Representative; Monica Hurdal, Committee Member; Mark Sussman, Committee Member.