title: Rotation-induced polymorphic transitions in bacterial flagella.
abstract: Bacteria propel themselves with the help of rotating helical flagella. They change their swimming direction during tumbling events in order to increase, for example, their supply of nutrients (chemotaxis). During tumbling a bacterial flagellum assumes different polymorphic states. Based on a continuum model for the motor-flagellum system, we demonstrate that a changing motor torque can initiate these polymorphic transformations. In particular, we investigate the run-and-stop tumble strategy of Rhodobacter sphaeroides which uses a coiled-to-normal transition in its single flagellum. We also show that torque reversal in single-flagellated Escherichia coli generates a normal-to-curly I transition as observed for tumbling E. coli that swim with a bundle of several flagella.
authors.affiliation: Institut für Theoretische Physik, Technische Universität Berlin, Hardenbergstrasse 36, 10623 Berlin, Germany.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Vogel
authors.affiliation: Institut für Theoretische Physik, Technische Universität Berlin, Hardenbergstrasse 36, 10623 Berlin, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Stark
mesh_terms: D004926:Escherichia coli / Q000502:physiology*; D005407:Flagella / Q000502:physiology*; D008954:Models, Biological; D012242:Rhodobacter sphaeroides / Q000502:physiology*; D013550:Swimming / Q000502:physiology; D019415:Torque