title: Magnetotaxis.
abstract: The ability of magnetotactic bacteria to orientate and navigate along geomagnetic lines is due to intracellular magnetic particles. These are enclosed within a membrane to form a magnetosome, a specialized organelle of magnetotactic organisms. The magnetic crystallite of many of the magnetotactic bacteria and algae is the iron oxide magnetite (Fe3O4) but recently a multicellular bacterial aggregate has been found to contain magnetic iron sulphide. Magnetotactic bacteria are found in regions of low oxygen pressure. Those of the Northern hemisphere are north-seeking while those of the Southern hemisphere are south-seeking. The opposite polarity of their internal magnets enables both types to travel to the deeper, less oxygenated, regions of their aqueous environments.
authors.affiliation: Museu de Astronomia e Ciencias Afins, Sao Cristovao, Rio de Janeiro, Brazil.
authors.forename: H G
authors.initials: HG
authors.lastname: Lins de Barros
authors.forename: D M
authors.initials: DM
authors.lastname: Esquivel
authors.forename: M
authors.initials: M
authors.lastname: Farina
mesh_terms: D018407:Bacterial Physiological Phenomena; D005075:Biological Evolution; D004574:Electromagnetic Fields; D052203:Ferrosoferric Oxide; D006801:Humans; D007501:Iron / Q000378:metabolism; D008280:Magnetics; D010087:Oxides / Q000378:metabolism
chemical_list: D010087:Oxides; D007501:Iron; D052203:Ferrosoferric Oxide