title: Multicellular photo-magnetotactic bacteria.
abstract: Multicellular magnetotactic bacteria (MMB) are unique microorganisms typically comprised of 10-40 bacterial cells arranged around a central acellular compartment. Their life cycle has no known unicellular stage and division occurs by separation of a single MMB aggregate into two identical offspring. In this study, South-seeking multicellular magnetotactic bacteria (ssMMB) were enriched from a New England salt marsh. When exposed to light, ssMMB reversed their magnetotactic behaviour to become North-seeking. The exposure time needed to generate the reversal response varied with light wavelength and intensity. Extensive exposure to light appeared to be lethal. This is the first report of a Northern hemisphere MMB displaying South-seeking behaviour and the first time a MMB is found to exhibit photo-magnetotaxis. We suggest that this mechanism enables ssMMB to optimize their location with regard to chemical gradients and light intensities, and propose a model to explain the peculiar balance between photo- and magnetotaxis.
authors.affiliation: Microbial Diversity Course, Marine Biological Laboratory, Woods Hole, MA 02543, USA Department of Biotechnology Engineering, Ben-Gurion University of the Negev, Be'er-Sheva 84105, Israel Department of Microbial Ecology, University of Vienna, Vienna, A-1090, AustriaDepartments of Crop and Soil Sciences Microbiology, Cornell University, Ithaca, NY 14853, USA Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA.
authors.forename: Orr H
authors.initials: OH
authors.lastname: Shapiro
authors.forename: Roland
authors.initials: R
authors.lastname: Hatzenpichler
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Buckley
authors.forename: Stephen H
authors.initials: SH
authors.lastname: Zinder
authors.forename: Victoria J
authors.initials: VJ
authors.lastname: Orphan