Directional persistence of chemotactic bacteria in a traveling concentration wave

• DOI: 10.1073/pnas.1101996108
• Publication Date: 2011-09-15T08:37:03Z
• Authors: J. Saragosti; V. Calvez; N. Bournaveas; B. Perthame; A. Buguin; P. Silberzan
• Keywords: Persistence (discontinuity)

Chemotactic bacteria are known to collectively migrate towards sources of attractants. In confined convectionless geometries, concentration “waves” swimming Escherichia coli can form and propagate through a self-organized process involving hundreds thousands these microorganisms. These waves observed in particular microcapillaries or microchannels; they result from the interaction between individual chemotactic macroscopic chemical gradients dynamically generated by migrating population. By studying trajectories within propagating wave, we show that, not only mean run length is longer direction propagation, but also that directional persistence larger compared opposite direction. This modulation reorientations significantly improves efficiency collective migration. Moreover, two quantities spatially modulated along profile. We recover quantitatively microscopic observations with dedicated kinetic model.