HR: 1330h
AN: B33C-03    [Abstracts]
TI: Biogeochemistry of phosphorus exchange in magnetic bacteria
AU: * Drennen, C
EM: cdrennen@usc.edu
AF: University of Southern California, Dept of Earth Sciences 3651 Trousdale PKWY SCI 117, Los Angeles, CA 90089-0740
AU: Popa, R
EM: rpopa@usc.edu
AF: University of Southern California, Dept of Earth Sciences 3651 Trousdale PKWY SCI 117, Los Angeles, CA 90089-0740
AU: Nealson, K
EM: knealson@usc.edu
AF: University of Southern California, Dept of Earth Sciences 3651 Trousdale PKWY SCI 117, Los Angeles, CA 90089-0740
AB: Magnetotactic bacteria swim at high relative speeds (5 mm/min) and cross the sediment water interface in an apparent diurnal pattern. We hypothesized that this is part of a migratory life cycle across the oxic anoxic transition zone at the water sediment interface. If true, this migration has important consequences on the exchange of phosphorous, sulfur and iron between water and sediments. Magnetotactic bacteria may also influence biomineralization and the magnetization of sediments. Our results show that the exchange of phosphorus between magnetic bacteria and water is consistent with a periodic life cycle, during which cells accumulated large amounts of phosphate under oxidizing conditions. Under reducing and anaerobic conditions (i.e. sulfidic sediments) cells release phosphorus. This research shows the importance of magnetic bacteria in the exchange of materials across redox interfaces.
DE: 0330 Geochemical cycles
DE: 0400 Biogeosciences
DE: 1099 General or miscellaneous
SC: Biogeosciences [B]
MN: 2005 Joint Assembly