Objective The largest reservoir for nitrogen on earth is the atmosphere that contains 78 percent nitrogen gas. Until now the only known biological process interacting with elemental nitrogen is the bacterial reduction of nitrogen to ammonia for the build up of biomass (nitrogen fixation). This reaction requires energy and is only carried out in the absence of other nitrogen sources, such as ammonia or nitrate. Thermodynamically, the oxidation of nitrogen to nitrate with oxygen releases reasonable amounts of energy, but no bacterium using this redox couple has been known until today. We have isolated a marine bacterium, which is capable of growing in the dark with nitrogen gas as electron donor and oxygen as electron acceptor while forming nitrate. As this microorganism can also use carbondioxide as a carbon source it basically lives of air. While oxidizing atmospheric nitrogen gas the bacterium releases large amounts of nitrate and thereby enhances the amount of fixed nitrogen available for other organisms. At the moment the apparent flux of elemental nitrogen to the ocean by bacterial nitrogen fixation is much smaller than the loss of nitrogen through bacterial denitrification, suggesting that we are missing a major input of nitrogen. This newly discovered physiology of nitrogen oxidation could close this large gap in our understanding of the nitrogen cycle. The amount of biological available nitrogen determines the amount of biomass that can be build up by living organisms. Therefore, it is crucial to know the nitrogen flux into the biosphere, to understand the balances in the carbon cycle. In this project I propose to study this new bacterial physiology in order to understand, which factors control the activity of nitrogen oxidizing bacteria. We need to know how widespread these bacteria are, to estimate their influence on the global nitrogen cycle, and I propose to investigate the interactions between nitrogen oxidizers and other relevant bacteria of the nitrogen cycle. Fields of science natural sciencesbiological sciencesmicrobiologybacteriologynatural scienceschemical scienceselectrochemistryelectrolysisnatural sciencesearth and related environmental sciencesatmospheric sciencesmeteorologybiospheramedical and health sciencesbasic medicinephysiologyagricultural sciencesagricultural biotechnologybiomass Keywords microbial ecology nitrogen cycle Programme(s) FP7-IDEAS-ERC - Specific programme: "Ideas" implementing the Seventh Framework Programme of the European Community for research, technological development and demonstration activities (2007 to 2013) Topic(s) ERC-SG-PE8 - ERC Starting Grant - Products and process engineering Call for proposal ERC-2007-StG See other projects for this call Funding Scheme ERC-SG - ERC Starting Grant Host institution MAX-PLANCK-GESELLSCHAFT ZUR FORDERUNG DER WISSENSCHAFTEN EV EU contribution € 1 450 673,00 Address HOFGARTENSTRASSE 8 80539 Munchen Germany See on map Region Bayern Oberbayern München, Kreisfreie Stadt Activity type Research Organisations Principal investigator Heide Schulz-Vogt (Dr.) Administrative Contact Heike Wojack (Ms.) Links Contact the organisation Opens in new window Website Opens in new window Total cost No data Beneficiaries (1) Sort alphabetically Sort by EU Contribution Expand all Collapse all MAX-PLANCK-GESELLSCHAFT ZUR FORDERUNG DER WISSENSCHAFTEN EV Germany EU contribution € 1 450 673,00 Address HOFGARTENSTRASSE 8 80539 Munchen See on map Region Bayern Oberbayern München, Kreisfreie Stadt Activity type Research Organisations Principal investigator Heide Schulz-Vogt (Dr.) Administrative Contact Heike Wojack (Ms.) Links Contact the organisation Opens in new window Website Opens in new window Total cost No data