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BP: Fachverband Biologische Physik
BP 6: Bacterial Mechanics
BP 6.3: Talk
Monday, March 27, 2023, 15:30–15:45, BAR 0106
Magnetic fields help magnetotactic bacteria navigate complex environments — Agnese Codutti1,2, Mohammad Charsooghi1, Konrad Marx3, Elisa Cerda-Donate1, Omar Munoz3, Paul Zaslansky1, Vitali Telezki3, Tom Robinson1, Damien Faivre1,4, and •Stefan Klumpp3 — 1MPI of Colloids and Interfaces, Potsdam — 2TU Munich — 3University of Göttingen — 4Aix-Marseille Université, CEA, CNRS, BIAM, Saint Paul lez Durance, France
To study swimming of magnetotactic bacteria in a near-realistic sediment environment resembling those in their natural habitat, we produced microfluidic channels that contained sediment-mimicking obstacles. These obstacle channels were produced based on microCT reconstructions of sediment samples. We characterized the swimming of magnetotactic bacteria through these channels and found that swimming throughput was highest for intermediate magnetic fields. This observation was confirmed by extensive computer simulations using an active Brownian particle model, parameterized based on experimental trajectories. The simulations indicate that swimming at strong field is impeded by the trapping of bacteria in corners that require transient swimming against the magnetic field for escape. At weak fields, the direction of swimming is almost random, making the process inefficient as well. We confirmed the trapping effect in our experiments and showed that lowering the field strength allows the bacteria to escape.