Thin-film lubrication model for biofilm expansion under strong adhesion
Date
2022
Authors
Tam, A.K.Y.
Harding, B.
Green, J.E.F.
Balasuriya, S.
Binder, B.J.
Editors
Advisors
Journal Title
Journal ISSN
Volume Title
Type:
Journal article
Citation
Physical Review E, 2022; 105(1):1-15
Statement of Responsibility
Alexander K. Y. Tam, Brendan Harding, J. Edward F. Green, Sanjeeva Balasuriya, and Benjamin J. Binder
Conference Name
Abstract
Understanding microbial biofilm growth is important to public health because biofilms are a leading cause of persistent clinical infections. In this paper, we develop a thin-film model for microbial biofilm growth on a solid substratum to which it adheres strongly. We model biofilms as two-phase viscous fluid mixtures of living cells and extracellular fluid. The model explicitly tracks the movement, depletion, and uptake of nutrients and incorporates cell proliferation via a nutrient-dependent source term. Notably, our thin-film reduction is two dimensional and includes the vertical dependence of cell volume fraction. Numerical solutions show that this vertical dependence is weak for biologically feasible parameters, reinforcing results from previous models in which this dependence was neglected. We exploit this weak dependence by writing and solving a simplified one-dimensional model that is computationally more efficient than the full model. We use both the one- and two-dimensional models to predict how model parameters affect expansion speed and biofilm thickness. This analysis reveals that expansion speed depends on cell proliferation, nutrient availability, cell-cell adhesion on the upper surface, and slip on the biofilm-substratum interface. Our numerical solutions provide a means to qualitatively distinguish between the extensional flow and lubrication regimes, and quantitative predictions that can be tested in future experiments.
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Dissertation Note
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Data source: Supplemental material, https://doi.org/10.1103/PhysRevE.105.014408
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© 2022 American Physical Society