Speaker
Description
Biofilms are communities of bacteria embedded in a self-secreted extracellular matrix (ECM) that typically exist in either surface-attached or floating structures. The ECM, characterized as viscoelastic, primarily comprises exopolysaccharides and structural proteins that protect the bacteria from environmental stresses. In porous media, such as soils, biofilms develop under hydrodynamic flow, which facilitates their growth by transporting nutrients and dispersing bacteria across available spaces. As biofilms expand into pore spaces, a phenomenon known as bio-clogging, they impede flow within the porous medium. Shear stress from flow can erode biofilms, leading to the formation of preferential flow paths. These interactions between flow and biofilms shape the spatial organization of the biofilms, which varies depending on the flow profile and biofilm rheology. The ECM rheology, which is ultimately determined by its biochemical composition, plays a critical role in clogging dynamics by influencing biofilm deformability, cohesion, and resistance to shear stress. However, the current understanding of matrix composition's role in defining biofilms' spatial organization is largely based on single time-point observations and indirect measurements of the relative abundance of each founder strain, which determine the local matrix composition and rheology.
In this project, we aim to investigate the influence of local biofilm rheology on the colonization patterns and dynamics of biofilms under varying flow conditions in porous media. To precisely tune biofilm rheology, we use bacterial strains engineered to lack the ability to secrete specific ECM components. Specifically, we focus on double-strain biofilms composed of a wild-type strain and a matrix mutant of Bacillus subtilis, a well-established model organism for studying biofilms. While mono-strain biofilm studies can provide insights into the contribution of individual ECM components to the bio-clogging dynamics, co-culture experiments enable us to capture the mutual influence between the two biofilms on their spatial distribution. This approach is critical for understanding biofilm behaviour under flow conditions in porous media. By employing time-lapse imaging and fluorescence intensity quantification, we estimate the local relative abundance of founder cells, providing insight into local matrix composition and its role in shaping biofilm clogging dynamics.
Overall, this study enhances our understanding of biofilm development in porous media by revealing how variations in biofilm rheology influence the spatial distribution of biofilms under varying flow conditions.
| Country | Switzerland |
|---|---|
| Green Housing & Porous Media Focused Abstracts | This abstract is related to Green Housing |
| Student Awards | I would like to submit this presentation into the Earth Energy Science (EES) and Capillarity Student Poster Awards. |
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