title: Magnetic properties of the microorganism Candidatus Magnetoglobus multicellularis.
abstract: Magnetotactic microorganisms use the interaction of internal biomineralized nanoparticles with the geomagnetic field to orientate. The movement of the magnetotactic multicellular prokaryote Candidatus Magnetoglobus multicellularis under an applied magnetic field was observed. A method using digital image processing techniques was used to track the organism trajectory to simultaneously obtain its body radius, velocity, U-turn diameter, and the reorientation time. The magnetic moment was calculated using a self-consistent method. The distribution of magnetic moments and radii present two well-characterized peaks at (9 +/- 2) x 10(-15) and (20 +/- 3) x 10(-15) A m(2) and (3.6 +/- 0.1) and (4.3 +/- 0.1) mum, respectively. For the first time, simultaneous determination of the distribution of the organism radii and magnetic moment was obtained from the U-turn method by a new digital imaging processing. The bimodal distributions support an organism reproduction process model based on electron microscopy observations. These results corroborate the prokaryote multicellular hypothesis for Candidatus M. multicellularis.
authors.affiliation: Escola de Engenharia, Universidade Federal do Rio de Janeiro, Cidade Universitária Bloco H, Sala H-220, Ilha do Fundão, 21941-972 Rio de Janeiro, RJ, Brazil.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Perantoni
authors.forename: Darci M S
authors.initials: DM
authors.lastname: Esquivel
authors.forename: Eliane
authors.initials: E
authors.lastname: Wajnberg
authors.forename: Daniel
authors.initials: D
authors.lastname: Acosta-Avalos
authors.forename: Geraldo
authors.initials: G
authors.lastname: Cernicchiaro
authors.forename: Henrique
authors.initials: H
authors.lastname: Lins de Barros
mesh_terms: D001938:Brazil; D020564:Deltaproteobacteria / Q000254:growth & development / Q000502:physiology*; D004574:Electromagnetic Fields; D019015:Geologic Sediments / Q000382:microbiology; D008280:Magnetics; D009068:Movement; D053758:Nanoparticles; D009949:Orientation; D014783:Viscosity; D014871:Water Microbiology