Atomistic insights into microbial biofilms
Abstract/Contents
- Abstract
- Most microbes live as multi-cellular communities termed biofilms. This lifestyle protects microbes against harsh conditions including antibiotic treatment and host immune responses. Within biofilms, microbial cells are entangled in a self-secreted extracellular matrix (ECM) that is rich in biopolymers such as fibrillar proteins and polysaccharides. This extracellular material is key to the characteristic properties of biofilms. Despite the prevalent roles that biofilms play in infections, a molecular-level understanding of the insoluble matrix components or the interactions between the ECM components has yet to be described. Biofilms and ECM are neither soluble nor crystalline, which poses challenges to analysis by traditional biochemical techniques. Solid-state nuclear magnetic resonance (NMR) is uniquely suited to study such complex systems because it provides quantitative information about chemical composition and also the spatial relationships of the components without requiring degradative sample preparation. Using solid-state NMR, we previously elucidated that the insoluble ECM produced by a uropathogenic strain of Escherichia coli called UTI89 is composed of two biopolymers: a functional amyloid called curli and modified cellulose. The purpose of this study is to elucidate quantitative information about microbial biofilm composition and structural information about biofilm constituents. Additionally, we aim to achieve an understanding of how the chemical and biophysical properties of specific ECM components contribute to the overall ECM architecture. To this end, we pursued three intersecting avenues with a primary focus on the bacterial strain UTI89, although we also determined quantitative parameters of additional microbial biofilms. In the first approach, we explored the dye binding properties of the biofilm constituent and functional amyloid called curli. The ability to specifically stain ECM components has been a key step in traditional investigations of biofilms, and we sought to provide a foundation to similarly study curli. In the second approach, we developed a means to spectroscopically annotate chemically complex ECM composition of the important human pathogens Vibrio cholerae and Aspergillus fumigatus using solid-state NMR. Finally, we provided novel biophysical and structural details of specific ECM components to better understand how these biopolymers interact to form robust ECM networks. Looking forward, we have begun to utilize solid-state NMR to provide a global accounting of the architecture of the UTI89 ECM. Together these studies have provided important quantitative parameters of biofilm composition and structural information of ECM components. Our analysis has wide-ranging implications for understanding the fundamental mechanisms of biofilm formation and for the development of functional biopolymeric materials.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2016 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Reichhardt, Courtney | |
|---|---|---|
| Associated with | Stanford University, Department of Chemistry. | |
| Primary advisor | Cegelski, Lynette | |
| Thesis advisor | Cegelski, Lynette | |
| Thesis advisor | Boxer, Steven G. (Steven George), 1947- | |
| Thesis advisor | Solomon, Edward I | |
| Advisor | Boxer, Steven G. (Steven George), 1947- | |
| Advisor | Solomon, Edward I |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Courtney Reichhardt. |
|---|---|
| Note | Submitted to the Department of Chemistry. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2016. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2016 by Courtney Reichhardt
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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