title: Diversity of magneto-aerotactic behaviors and oxygen sensing mechanisms in cultured magnetotactic bacteria.
abstract: Microorganisms living in gradient environments affect large-scale processes, including the cycling of elements such as carbon, nitrogen or sulfur, the rates and fate of primary production, and the generation of climatically active gases. Aerotaxis is a common adaptation in organisms living in the oxygen gradients of stratified environments. Magnetotactic bacteria are such gradient-inhabiting organisms that have a specific type of aerotaxis that allows them to compete at the oxic-anoxic interface. They biomineralize magnetosomes, intracellular membrane-coated magnetic nanoparticles, that comprise a permanent magnetic dipole that causes the cells to align along magnetic field lines. The magnetic alignment enables them to efficiently migrate toward an optimal oxygen concentration in microaerobic niches. This phenomenon is known as magneto-aerotaxis. Magneto-aerotaxis has only been characterized in a limited number of available cultured strains. In this work, we characterize the magneto-aerotactic behavior of 12 magnetotactic bacteria with various morphologies, phylogenies, physiologies, and flagellar apparatus. We report six different magneto-aerotactic behaviors that can be described as a combination of three distinct mechanisms, including the reported (di-)polar, axial, and a previously undescribed mechanism we named unipolar. We implement a model suggesting that the three magneto-aerotactic mechanisms are related to distinct oxygen sensing mechanisms that regulate the direction of cells' motility in an oxygen gradient.
authors.affiliation: Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany; CEA/CNRS/Aix-Marseille Université, UMR7265 Biologie Végétale et Microbiologie Environnementales, Laboratoire de Bioénergétique Cellulaire, Saint Paul lez Durance, France.
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Lefèvre
authors.affiliation: Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Bennet
authors.affiliation: Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany; Department of Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany.
authors.forename: Livnat
authors.initials: L
authors.lastname: Landau
authors.affiliation: Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Vach
authors.affiliation: CEA/CNRS/Aix-Marseille Université, UMR7265 Biologie Végétale et Microbiologie Environnementales, Laboratoire de Bioénergétique Cellulaire, Saint Paul lez Durance, France.
authors.forename: David
authors.initials: D
authors.lastname: Pignol
authors.affiliation: University of Nevada at Las Vegas, School of Life Sciences, Las Vegas, Nevada.
authors.forename: Dennis A
authors.initials: DA
authors.lastname: Bazylinski
authors.affiliation: Department of Physics, California Polytechnic State University, San Luis Obispo, California.
authors.forename: Richard B
authors.initials: RB
authors.lastname: Frankel
authors.affiliation: Department of Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Klumpp
authors.affiliation: Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany. Electronic address: damien.faivre@mpikg.mpg.de.
authors.forename: Damien
authors.initials: D
authors.lastname: Faivre
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism; D001483:Base Sequence; D002633:Chemotaxis; D042201:Magnetospirillum / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D059346:Magnets; D008969:Molecular Sequence Data; D010100:Oxygen / Q000378:metabolism / Q000494:pharmacology*; D015398:Signal Transduction
chemical_list: D001426:Bacterial Proteins; D010100:Oxygen