title: Modelling the mechanics and hydrodynamics of swimming E. coli.
abstract: The swimming properties of an E. coli-type model bacterium are investigated by mesoscale hydrodynamic simulations, combining molecular dynamics simulations of the bacterium with the multiparticle particle collision dynamics method for the embedding fluid. The bacterium is composed of a spherocylindrical body with attached helical flagella, built up from discrete particles for an efficient coupling with the fluid. We measure the hydrodynamic friction coefficients of the bacterium and find quantitative agreement with experimental results of swimming E. coli. The flow field of the bacterium shows a force-dipole-like pattern in the swimming plane and two vortices perpendicular to its swimming direction arising from counterrotation of the cell body and the flagella. By comparison with the flow field of a force dipole and rotlet dipole, we extract the force-dipole and rotlet-dipole strengths for the bacterium and find that counterrotation of the cell body and the flagella is essential for describing the near-field hydrodynamics of the bacterium.
authors.affiliation: Theoretical Soft Matter and Biophysics, Institute for Advanced Simulation and Institute of Complex Systems, Forschungszentrum Jülich, D-52425 Jülich, Germany. j.hu@fz-juelich.de g.gompper@fz-juelich.de r.winkler@fz-juelich.de.
authors.forename: Jinglei
authors.initials: J
authors.lastname: Hu
authors.forename: Mingcheng
authors.initials: M
authors.lastname: Yang
authors.forename: Gerhard
authors.initials: G
authors.lastname: Gompper
authors.forename: Roland G
authors.initials: RG
authors.lastname: Winkler
mesh_terms: D001696:Biomechanical Phenomena; D004926:Escherichia coli / Q000737:chemistry* / Q000502:physiology*; D005407:Flagella / Q000737:chemistry / Q000502:physiology; D057446:Hydrodynamics; D007700:Kinetics; D008954:Models, Biological; D056004:Molecular Dynamics Simulation