Christoph Schmidt, Duke University

Bacterial cell wall mechanics, experiments and modeling

Abstract:

Bacteria mechanically protect themselves by covalently linked peptidoglycan (PG) cell walls that preserve cellular morphology and contain high osmotic pressures, controlled by mechanosensitive membrane channels. As a bacterium grows, the cell wall undergoes continuous expansion. Despite a good understanding of the molecular components and the assembly machineries of the cell wall, it remains largely unknown how the mesoscopic mechanical properties of the cell wall emerge from the properties and arrangement of molecular components. I will introduce our AFM-based experimental approach to probe bacterial mechanics and I will introduce a coarse-grained physical model of the bacterial cell wall, consisting of a 2D spring network, with parameters and geometry based on known molecular details, that predicts the mesoscopic mechanical response of the cell wall for the Gram-negative bacterium Escherichia coli.

Speaker: Christoph Schmidt, Duke University

Christoph Schmidt’s interests are in experimental soft matter physics and biophysics. His group, at the moment, works on active materials, polymer networks, bacterial and animal cell mechanics and tissue mechanics, as well as on mechanosensory processes in biology. He started his academic career as a postdoc at Harvard and the Rowland Institute for Science in Boston, achieved tenure in the Physics Department and the Biophysics Research Division of the University of Michigan, and then moved to the Vrije Universiteit Amsterdam in the Netherlands. After seven years in Amsterdam he followed a call to head the Third Institute of Physics of the University of Göttingen in Germany. Recently he joined the Physics Department of Duke University and co-founded the Duke Soft Matter Center as part of the Duke Materials Initiative. Christoph Schmidt is a Fellow of the American Physical Society and a Member of the Göttingen Academy of Sciences and Humanities. 

Host: Sergei Sukharev

Seminars start at 4:00 pm, and refreshments will be served at 3:45 pm. All seminars are held in the Conference Room (1116) of the Institute for Physical Science and Technology (IPST) Building (Bldg #085) unless otherwise noted.