HR: 0800h
AN: B21A-0849    [Abstracts]
TI: Exploring Nitrogen and Oxygen Isotopic Relationships Among Nitrification Products
AU: * Casciotti, K L
EM: kcasciotti@whoi.edu
AF: Woods Hole Oceanographic Institution, 360 Woods Hole Rd. Mail Stop 8, Woods Hole, MA 02543 United States
AB: The process of nitrification plays a central role in the production of nitrite, nitrate, nitric oxide and nitrous oxide in the marine environment. The mass fluxes and isotopic signatures of these compounds are interrelated through various metabolic pathways and intermediates of this process, including interactions between multiple groups of bacteria. In this presentation, simple metabolic network models will be combined with measured isotope effects to explore the nitrogen and oxygen isotopic relationships between nitrification product pools. This work focuses on potential role of ammonia transport and oxygen isotopic exchange in setting the isotopic signatures in nitrite, nitrate, and nitrous oxide produced by marine nitrifiers. Current uncertainties and priorities for future research will be highlighted.
DE: 4805 Biogeochemical cycles (1615)
DE: 4840 Microbiology
DE: 4845 Nutrients and nutrient cycling
DE: 1040 Isotopic composition/chemistry
DE: 0400 Biogeosciences
SC: Biogeosciences [B]
MN: 2004 AGU Fall Meeting