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BP: Fachverband Biologische Physik

BP 22: Bacterial Biophysics II

BP 22.4: Talk

Wednesday, March 20, 2024, 15:45–16:00, H 0112

Amyloid fibers in biofilms: structure adaptation to environmental cues — •Macarena Siri, Agustín Mangiarotti, Mónica Vázquez-Dávila, and Cécile Bidan — Max Planck Institute of Colloids and Interfaces, Potsdam, Germany

E. coli biofilms consist of bacteria embedded in a self-produced matrix mainly made of protein fibers and polysaccharides. Not only the extracellular matrix plays a major role in achieving biofilm stability under different environmental conditions, but also is sensitive to their surroundings. The curli amyloid fibers found in the E. coli matrix determine the architecture and stiffness of their biofilms. They are promising versatile building blocks to design sustainable bio-sourced materials. To exploit their potential, it is crucial to understand how environmental cues during biofilm growth influence the molecular structure of these amyloid fibers, and how this translates at higher length scales. We studied the effect of water and nutrient content in the substrate on both biofilm materials properties and the structure and properties of curli amyloid fibers extracted from the biofilms. We used micro-indentation to measure the rigidity of the biofilms grown under different conditions, followed by microscopy and spectroscopy to characterize the amyloid fibers purified from the respective biofilms. The purified curli amyloid fibers present differences in the structure and functional properties upon different biofilm growth conditions. Our study highlights how E. coli biofilm growth conditions impact curli structure and functions contributing to macroscopic materials properties.

Keywords: Amyloids; E coli; Biofilms; Spectroscopy; Protein strcuture