> Research > Programs and projects > Theme 1 & 2

Present and past pathways for ammonium oxidation in the oxygen-depleted waters of the ocean
Program coordinator(s): Prof. dr. ir. M. S. M. Jetten
Theme(s): 1 , 2
Funding date: 11-dec-09

Abstract
Nitrogen is one of the key nutrients in marine waters that may limit primary productivity. Our views on marine N-cycling have undergone significant changes due to the discovery of novel microbial processes such as anaerobic ammonium oxidation (anammox) and strong evidence for aerobic ammonium oxidation by crenarchaea in oxygen depleted ecosystems. Also in the geological past, oxygen depleted conditions may have occurred widespread in the ocean with important consequences for N-cycling. In this project we want to study the marine N-cycle under limiting oxygen conditions that mimic the oxygen-depleted zones of the present and past oceans. The ecophysiology and biomarkers of marine N-cycle organisms will be investigated under controlled conditions in the laboratory with cultures obtained in a previous joint DARWIN project. Field studies will be undertaken in the coastal and open ocean ecosystems to examine relative importance of archaeal nitrification at low oxygen concentrations and to assess which microbes interact in the marine N-cycle using state of the art techniques. Microbial biomarkers will be used to understand past N-cyling. The results of this research will lead to significant new insights into the microbial roots of the global marine N-cycle and will supply new input for biogeochemical modeling.

This program contains the following projects:
3011: Microbial key players in the oxidation of ammonium under oxygen limitation
3012: Lipids as indicators of N-cycling in sub-oxic zones of present and past oceans

Publications
Russ L. Kartal B. Op den Camp H. J. M. Sollai M. Le Bruchec J. Caprais J. C. Godfroy A. Sinninghe Damsté J. S. Jetten M. S. M. (2013). Presence and diversity of anammox bacteria in cold hydrocarbon-rich seeps and hydrothermal vent sediments of the Guaymas Basin. Frontiers in microbiology4: 1-10.
Darwin Center authors: Sinninghe Damsté J. S., Sollai M.

Sollai, M. Hopmans, E.C. Schouten, S. Keil, R.G. Sinninghe Damsté, J.S. (2015). Intact polar lipids of Thaumarchaeota and anammox bacteria as indicators of N cycling in the eastern tropical North Pacific oxygen-deficient zone. Biogeosciences12: 4725-4737.
Darwin Center authors: Hopmans E. C., Schouten S., Sinninghe Damsté J. S., Sollai M.

Sollai M. Hopmans E.C. Schouten S. Keil R.G. Sinninghe Damsté J.S. (2015). Intact polar lipids of Thaumarchaeota and anammox bacteria as indicators of N cycling in the eastern tropical North Pacific oxygen-deficient zone. Biogeosciences12: 4725-4737.
Darwin Center authors: Hopmans E. C., Schouten S., Sinninghe Damsté J. S., Sollai M.