Description: Das Projekt "Nitrogen elimination pathways and associated isotope effects in Swiss eutrophic Lake Lugano" wird vom Umweltbundesamt gefördert und von Eidgenössische Technische Hochschule Zürich, Institut für Integrative Biologie durchgeführt. Nitrogen isotope ratios can provide important constraints on natural N cycles. In order to use natural abundance stable isotope ratios of dissolved inorganic N species as a means to trace fluxes and transformations of N in aquatic systems, however, it is imperative to understand the isotope effects associated with these specific N transformations. This will also provide information on the transformations themselves. Yet, the possible impact of N2 production processes other than denitrification on global and regional N-isotope budgets has been ignored thus far. Lake Lugano is an excellent model biosystem for an anthropogenically impacted lake. Previous studies have revealed that this lake represents an important sink for fixed N. In addition, they indicate the presence of suboxic consumption of ammonium and, thus, suggest that 'non-traditional' N2 production processes (e.g., anammox) are active in anaerobic portions of the lake. This project addresses the following main research questions: What are the different metabolic pathways of suboxic N2 production in the Lake Lugano water column and in sediments? What are the associated N-isotope effects? What are the respective transformation rates and fluxes? Which microorganisms are responsible for observed N transformations? Combining hydrochemical, microbiological (phylogenetic/molecular genetic analyses, measurements of enzyme activities), with organic-geochemical (anammox lipid analysis) and isotopic techniques (natural abundance of nitrate, ammonium, nitrous oxide isotope ratios, as well as 15N tracer experiments), the project attempts to gain complementary information on specific N transformations and mechanisms of N2 loss in the Lake Lugano water column and sediments, on the microorganisms involved in these transformations, their relevance for the Lake Lugano nitrogen
Types:
SupportProgram
Origin: /Bund/UBA/UFORDAT
Tags: Denitrifikation ? Ammonium ? Stickstoffelimination ? Tierhaltungsanlage ? Zürich ? Ammoniak ? Nitrat ? Seen ? Biomarker ? Lugano ? Anaerobe Bedingungen ? DNA ? Genetik ? Geochemie ? Lipid ? Nitratbestimmung ? Seensediment ? Stickstoff ? Tracer ? Brunnen ? Main ? Schweiz ? Lachgas ? Enzym ? Gebäude ? Wirkung ? Isotop ? Messung ? Konsum ? Produktionstechnik ? Stickstoffkreislauf ? Studie ? Wasseranalyse ? Mikroorganismen ? Sediment ? Wasser ? Wertermittlung ? Schaden ? Wirkung ? Bewässerung ? Biosystem ? Technik ? Forschung ? Globale Aspekte ? Analyse ? Fahrradfahren ? Produktion ? Eutrophie ? SAEULE ? SONSTIG ? GEMEINSCHAFT ? BUDGET ? SPEZIFISCH ? MECHANISMEN ? See [Binnengewässer] ? MICROBIOLOGISCH ? ORTSFEST ? Stall ? VERBRAUCH ? VORGABE ? WICHTIG ? Art [Spezies] ? FRAGE ? PFAD ? PROJEKT ? EINSATZ ? EXPERIMENT ? Erlass [Recht] ? GELOEST ? REGIONAL ?
License: cc-by-nc-nd/4.0
Language: Deutsch
Time ranges: 2010-04-01 - 2013-03-31
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