Keynote Talk  - Friday, 17 September I 9:10 AM (CEST)

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Prof. Dr. Karin Jacobs: "Quantitative bioadhesion studies by SPM and force spectroscopy"

Saarland University, Germany

A successful adhesion of proteins and/or bacteria to surfaces is a crucial step in initial biofilm formation. Using a combined experimental and computational approach, we investigated the adhesion of the pathogenic bacterium Staphylococcus aureus to smooth, hydrophilic and hydrophobic surfaces. We used atomic force microscopy-based single-cell force spectroscopy and Monte Carlo simulations to investigate the similarities and differences in adhesion to hydrophilic and hydrophobic surfaces. Our results show that binding to both types of surfaces is mediated by thermally fluctuating cell wall macromolecules that behave differently on each type of substrate [1]. For nanorough surfaces, we find that as the size of the nanostructures increases, the adhesion forces decrease in a way that can be quantified by the area of the surface that is available for the tethering of cell wall molecules [2]. To be able to quantitatively link surface topography and bacterial adhesion, the surface structures were characterized by a detailed morphometric analysis based on Minkowski functionals. We expect these findings to be important for understanding the adhesion behavior of many bacterial species as well as other microorganisms and even nanoparticles with soft, macromolecular coatings used for biological diagnostics, for example.

[1] E. Maikranz et al., Nanoscale 12 (2020) 19267 DOI: 10.1039/d0nr03134h

[2] C. Spengler et al., Nanoscale 11 (2019) 19713 DOI: 10.1039/C9NR04375F