title: Membrane vesicles in magnetotactic bacteria.
abstract: Magnetotactic bacteria are microorganisms that respond to magnetic fields. We have studied the surface ultrastructure of Magnetospirillum magnetotacticum and uncultured magnetotactic bacteria from a marine environment using transmission electron microscopy and freeze-etching. Numerous membrane vesicles were observed on the surface of Magnetospirillum magnetotacticum bacteria. All uncultured magnetotactic bacteria presented membrane vesicles on their surface in addition to an extensive capsular material and an S-layer formed by particles arranged in a hexagonal symmetry. We did not observe any indication of electron-dense precipitation on the surface of these microorganisms. Our results indicate that membrane vesicles are a common characteristic of magnetotactic bacteria in natural sediments.
authors.affiliation: Departamento de Microbiologia Geral, Instituto de Microbiologia Prof. Paulo de Góes, Universidade Federal do Rio de Janeiro, 21941-590, Rio de Janeiro, Brasil. ulins@micro.ufrj.br
authors.forename: Ulysses
authors.initials: U
authors.lastname: Lins
authors.forename: Marcos
authors.initials: M
authors.lastname: Farina
authors.forename: Bechara
authors.initials: B
authors.lastname: Kachar
mesh_terms: D001419:Bacteria / Q000648:ultrastructure*; D002462:Cell Membrane / Q000648:ultrastructure*; D003470:Culture Media; D005290:Ferric Compounds; D005613:Freeze Etching; D008280:Magnetics; D042201:Magnetospirillum / Q000254:growth & development / Q000648:ultrastructure*; D008854:Microscopy, Electron; D014871:Water Microbiology
chemical_list: D003470:Culture Media; D005290:Ferric Compounds