title: Collective motion and nonequilibrium cluster formation in colonies of gliding bacteria.
abstract: We characterize cell motion in experiments and show that the transition to collective motion in colonies of gliding bacterial cells confined to a monolayer appears through the organization of cells into larger moving clusters. Collective motion by nonequilibrium cluster formation is detected for a critical cell packing fraction around 17%. This transition is characterized by a scale-free power-law cluster-size distribution, with an exponent 0.88±0.07, and the appearance of giant number fluctuations. Our findings are in quantitative agreement with simulations of self-propelled rods. This suggests that the interplay of self-propulsion and the rod shape of bacteria is sufficient to induce collective motion.
authors.affiliation: Laboratoire J.A. Dieudonné, Université de Nice Sophia-Antipolis, UMR CNRS 7351, Parc Valrose, F-06108 Nice Cedex 02, France.
authors.forename: Fernando
authors.initials: F
authors.lastname: Peruani
authors.forename: Jörn
authors.initials: J
authors.lastname: Starruss
authors.forename: Vladimir
authors.initials: V
authors.lastname: Jakovljevic
authors.forename: Lotte
authors.initials: L
authors.lastname: Søgaard-Andersen
authors.forename: Andreas
authors.initials: A
authors.lastname: Deutsch
authors.forename: Markus
authors.initials: M
authors.lastname: Bär
mesh_terms: D016000:Cluster Analysis; D015169:Colony Count, Microbial; D009068:Movement / Q000502:physiology; D016940:Myxococcus / Q000166:cytology* / Q000254:growth & development*