Dresden 2009 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 23: Physics of Bacteria and Viruses
BP 23.1: Vortrag
Donnerstag, 26. März 2009, 17:15–17:30, ZEU 260
Membrane fluidity guides bacterial surface motility — •Claudia Holz1, Berenike Maier1, Jan Mehlich2, and Bart Jan Ravoo2 — 1Universität Münster, Institut für allgemeine Zoologie und Genetik, Schlossplatz 5, 48149 Münster — 2Universität Münster, Organisch-Chemisches Institut, Corrensstrasse 40, 48149 Münster
Bacterial surface motility enables bacteria to form microcolonies, colonise human host cells and abiotic surfaces, and is often required for biofilm formation. Twitching motility is powered by polymeric cell appendages called type IV pili. They act as grappling hooks that support motility by a cycle of pilus elongation, surface adhesion and retraction. It is very poorly understood how bacteria control the velocity and direction of twitching.
We investigated twitching motility of the human pathogen Neisseria gonorrhoeae on different surfaces including glass-supported membranes to mimic cell surfaces. We found that bacteria twitch with a velocity of ~1μm/sec and that movement is persistent on a time scale of around 8sec. Velocity and persistence increased with decreasing fluidity of solid supported membranes. On micropatterned surfaces, bacterial movement was confined to the least fluid regions, i.e. we found that motility was guided by surface fluidity. Our experiments reveal an unprecedented physical mechanism for controlling the direction of twitching motility and we hypothesize that this mechanism is involved in formation of microcolonies during infection.