Regensburg 2022 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 10: Cell Adhesion and Multicellular Systems
BP 10.8: Vortrag
Dienstag, 6. September 2022, 12:00–12:15, H13
Self-Buckling of filamentous cyanobacteria reveals gliding forces — •Maximilian Kurjahn1, Antaran Deka1, Antoine Girot1,2, Leila Abbaspour3,4, Stefan Klumpp3,4, Maike Lorenz5, Oliver Bäumchen1,2, and Stefan Karpitschka1 — 1Max Planck Institute for Dynamics and Self-Organization (MPI-DS), Göttingen — 2Experimental Physics V, University of Bayreuth — 3Max Planck School Matter to Life, University of Göttingen — 4Institute for Dynamics of Complex Systems, University of Göttingen — 5Department of Experimental Phycology and SAG Culture Collection of Algae, University of Göttingen
Filamentous cyanobacteria are one of the oldest and today still most abundant lifeforms on earth, with manifold implications in ecology and economics. These phototrophic organisms form long and flexible filaments that do not actively swim in bulk liquid but exhibit gliding motility in contact with solid surfaces. The underlying force generating mechanism of their gliding apparatus is not yet understood. We measure their bending modulus with micropipette force sensors, and investigate how filaments buckle after gliding onto an obstacle. Comparing Kirchhoff theory to the experiments, we derive the active forces and the friction coefficients associated with gliding from the observed critical filament length for buckling. Remarkably, we find that these two quantities are strongly coupled, while dependencies on other observables are largely absent. The critical length also aligns with the peak of their natural length distribution, indicating the importance of buckling for their collective.