Berlin 2018 – scientific program
BP 18: Focus Session: Physics of Microbial Systems - organized by Tobias Bollenbach and Benedikt Sabass
BP 18.9: Talk
Wednesday, March 14, 2018, 12:00–12:15, H 2013
Pili-mediated substrate motility of bacteria — •Wolfram Pönisch1, Christoph A. Weber1,2, and Vasily Zaburdaev1 — 1Max Planck Institut für Physik Komplexer Systeme, Dresden, Germany — 2Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, USA
Most bacteria live in complex multicellular communities, known as biofilms, colonizing various surfaces. A wide range of bacteria use cell appendages, so called type IV pili, to bind to a substrate and generate pulling forces, enabling the cells to actively move. The attachment of bacteria to a surface and surface associated motility represent the first steps of biofilm formation.
For Neisseria gonorrhoeae (NG) bacteria, it was shown that its motility could be described as a persistent random walk with a characteristic length scale that exceeded the average pili length. Previously, it has been suggested that such behavior would require a mechanism of directional memory in pili attachments. Here, we develop a stochastic model demonstrating that the persistent motion arises naturally from the force-dependent detachment rate of pili and the geometric properties of the cell and its pili, but does not require any directional memory of the pili. We confirm this result with the help of a computational model of NG cells interacting with a substrate via its multiple individual pili. Furthermore, in agreement with experimental data, both model describes the dependence of cell motility on the total number of pili per cell.