Biofilm formation and its interaction with surfactants and solvents : a physico-biological approach
Abstract/Contents
- Abstract
- Bacteria tend to aggregate on surfaces and form biofilms that are characterized by an extracellular polymeric matrix consisting of proteins and polysaccharides. The unique structure of biofilms prevents bacteria from harsh environmental conditions so they can survive in a broad range of conditions. While this ability is beneficial to the bacteria's survival, biofilms are implicated in most infectious diseases such as catheter infections, cystic fibrosis, endocarditis, and urinary tract infections. Successful treatments of these diseases require thorough understanding of the biochemical and physico-chemical properties of biofilms that relate to function. In this thesis, we combined conventional biofilm research methods with interfacial science techniques including interfacial rheometry and tensiometry to study air-liquid interface biofilm (pellicle) formation by uropathogenic E. coli, which produces an amyloid-fiber called "curli" to develop a biofilm network. We analyzed the bacteria cell growth, adhesion ability, and curli expression, and relate them to the interfacial viscoelasticity during biofilm formation. Our results showed that over-expressed curli content leads to more robust biofilms with higher tenacity. Nonionic surfactant-biofilm interaction was also studied, and the results showed that biofilm formation was very sensitive to surfactant concentration. Below the critical micelle concentration (CMC), the surface was dominated by bacteria-degradable proteins from the nutrient broth, and pellicle formation was observed with delayed inception at increasing surfactant concentration. Above the CMC, the surface was dominated by surfactants, and biofilm formation was inhibited. Our studies demonstrated a unique approach to comprehensively examine air-liquid interface biofilm formation and investigated the influence of curli content and surfactants on amyloid-integrated biofilm formation. The application of this approach is extensible to studies of amyloid-integrated biofilm formation among other microorganisms as well as interactions of surfactant-protein and surfactant-polymer at air-liquid and oil-liquid interfaces.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2012 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Wu, Cynthia Fangliang |
|---|---|
| Associated with | Stanford University, Department of Chemical Engineering |
| Primary advisor | Fuller, Gerald G |
| Thesis advisor | Fuller, Gerald G |
| Thesis advisor | Cegelski, Lynette |
| Thesis advisor | Dunn, Alexander Robert |
| Thesis advisor | Swartz, James R |
| Advisor | Cegelski, Lynette |
| Advisor | Dunn, Alexander Robert |
| Advisor | Swartz, James R |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Cynthia Fangliang Wu. |
|---|---|
| Note | Submitted to the Department of Chemical Engineering. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2012. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2012 by Cynthia Fangliang Wu
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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