title: Motility of Electric Cable Bacteria.
abstract: Cable bacteria are filamentous bacteria that electrically couple sulfide oxidation and oxygen reduction at centimeter distances, and observations in sediment environments have suggested that they are motile. By time-lapse microscopy, we found that cable bacteria used gliding motility on surfaces with a highly variable speed of 0.5 ± 0.3 μm s(-1) (mean ± standard deviation) and time between reversals of 155 ± 108 s. They frequently moved forward in loops, and formation of twisted loops revealed helical rotation of the filaments. Cable bacteria responded to chemical gradients in their environment, and around the oxic-anoxic interface, they curled and piled up, with straight parts connecting back to the source of sulfide. Thus, it appears that motility serves the cable bacteria in establishing and keeping optimal connections between their distant electron donor and acceptors in a dynamic sediment environment.
  
  
  
  This study reports on the motility of cable bacteria, capable of transmitting electrons over centimeter distances. It gives us a new insight into their behavior in sediments and explains previously puzzling findings. Cable bacteria greatly influence their environment, and this article adds significantly to the body of knowledge about this organism.
authors.affiliation: Center for Geomicrobiology, Department of Bioscience, Aarhus University, Aarhus, Denmark Section for Microbiology, Department of Bioscience, Aarhus University, Aarhus, Denmark jjbjerg@bios.au.dk.
authors.forename: Jesper Tataru
authors.initials: JT
authors.lastname: Bjerg
authors.affiliation: Section for Microbiology, Department of Bioscience, Aarhus University, Aarhus, Denmark.
authors.forename: Lars Riis
authors.initials: LR
authors.lastname: Damgaard
authors.affiliation: Section for Microbiology, Department of Bioscience, Aarhus University, Aarhus, Denmark.
authors.forename: Simon Agner
authors.initials: SA
authors.lastname: Holm
authors.affiliation: Center for Geomicrobiology, Department of Bioscience, Aarhus University, Aarhus, Denmark Section for Microbiology, Department of Bioscience, Aarhus University, Aarhus, Denmark.
authors.forename: Andreas
authors.initials: A
authors.lastname: Schramm
authors.affiliation: Center for Geomicrobiology, Department of Bioscience, Aarhus University, Aarhus, Denmark Section for Microbiology, Department of Bioscience, Aarhus University, Aarhus, Denmark.
authors.forename: Lars Peter
authors.initials: LP
authors.lastname: Nielsen
mesh_terms: D020564:Deltaproteobacteria / Q000378:metabolism / Q000502:physiology*; D019015:Geologic Sediments / Q000382:microbiology; D008124:Locomotion; D008853:Microscopy; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism; D013440:Sulfides / Q000378:metabolism; D059008:Time-Lapse Imaging
chemical_list: D013440:Sulfides; D010100:Oxygen