Regensburg 2013 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 9: Poster I: Statistical Physics in Biological Systems (joint with BP)

DY 9.18: Poster

Monday, March 11, 2013, 17:30–19:30, Poster B2

Swimming patterns of bacteria in confined microchannels with obstacles — •Michael Raatz, Matthias Theves, and Carsten Beta — Institute of Physics and Astronomy, University of Potsdam, Germany

Depending on environmental conditions, single bacteria can irreversibly attach to a solid-liquid or liquid-air interface and form the cores for surface associated growth into aggregates, where cells are embedded in a polymer matrix and become resistive to antibiotic treatment (biofilms). We use microfluidic channels and high-speed time lapse microscopy to investigate the movement of cells which are swimming in close proximity to the wall interface and interact with various arrangements of circular obstacles. Motility statistics show that in the presence of obstacles, the average run length of a bacterium and the probability distribution of turn angles changes when compared to an obstacle-free channel. At small collision angles with the obstacle, the cell trajectory is slightly deflected while large angle collisions can induce reversals in the direction of propagation of a cell. Furthermore, we observe cases where cells move around the obstacle in a circular path, maintaining a stable 'orbit' at a distance of one or two cell diameters from the obstacle surface.