Ammonium Starvation Responses of the Ammonia Oxidizing Archaea Nitrososphaera viennensis

Logan Hodgskiss, Melina Kerou, Pierre Offre, Christa Schleper

Ammonia oxidizing archaea are ubiquitous and abundant in terrestrial environments and contribute considerably to nitrification in soils. However, little is known about their central energy and carbon metabolism and their responses to environmental changes. The first and only available organism from soil that can be grown in pure culture is Nitrososphaera viennensis, isolated from the departmental garden at the University of Vienna. The annotated genome of N. viennensis contains an abundance of genes involved in the regulation of carbon and nitrogen metabolism.
Understanding the interplay and regulation of these metabolic modules in response to environmental cues will help determine how the physiology of N. viennensis has adapted to a complex soil environment. In this context, we applied transcriptomics to gain insight into the ammonium-starvation response of N. viennensis. The experimental setup included starving cultures of ammonium and extracting RNA in a time series upon re-addition of ammonium. The extracted RNA was sequenced on an Illumina HiSeq 2000 and the results are being analyzed to determine the differential expression of genes during culture recovery. The results of this experiment will demonstrate how N. viennensis can respond to varied nitrogen concentrations and limitations found in its natural environment. This will give insights into the role this microorganism plays in the biological turnover of nitrogen in the environment.

Department für Ökogenomik und Systembiologie
ÖFOS 2012
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