Department of Genetics In Ecology

AOA: Metabolic and Genomic Studies of Ammonia Oxidizing Archaea from Soil

Duration: 01.11.2010 - 31.10.2013

FUNDING

PARTICIPANTS

Nitrification is a process solely performed by microorganisms, that plays a central role in the global cycling of nitrogen and is of economic importance in agriculture and wastewater treatment. The first step in nitrification is performed by ammonia oxidising microorganisms that convert ammonia into nitrite ions. Thanks to their discovery by S. Winogradsky, nitrifying bacteria have been known for more than hundred years. Only recently, it has been recognized that microorganisms of the domain archaea are also able to perform this process. This group of archaea outnumber the known bacterial nitrifiers by orders of magnitude in the marine plankton, as well as in many soils, sediments and estuarines. Although present in very large numbers, very little is known about the physiology of ammonia oxidizing archaea. Their chemolithoautotrophic growth mode has so far been shown only for a single cultivated isolate from a marine aquarium and for two enrichments from hot environments. Therefore, the physiology of ammonia oxidizing archaea in particular of those from soil has remained elusive and their contribution to nitrification has been debated.
We have recently isolated a chemolithoautotrophic ammonia oxidizing archaeon from a garden soil in Vienna that is stably growing in laboratory cultures for three years now. The overall goal of this project is to get a deeper insight into the physiology, general activities, evolution and genomic potential of Candidatus Nitrososphaera viennensis and thus to develop it into a model organism for ammonia oxidizing archaea from soil. For this purpose we will perform detailed physiological characterisations, as well as genomic and functional genomic studies. The project will be performed in collaboration with the Department of Molecular Systems Biology (W. Weckwerth) and the Department of Chemical Ecology and Ecosystems Research (A. Richter).
In total we expect to get a deeper insight into this widely distributed and potentially ecologically significant group of archaea.