10.18453/rosdok_id00001600 Berg, Carlo Carlo Berg http://d-nb.info/gnd/1075814022 Universität Rostock 2015 550 Earth sciences 570 Life science 2015 en http://purl.uni-rostock.de/rosdok/id00001600 urn:nbn:de:gbv:28-diss2015-0150-4 In hypoxic waters within the pelagic redox gradients of the Baltic Sea, Thaumarchaeota occur in high abundances but their contributions to the process of nitrification as well as their adaptations to this habitat remained elusive. In the scope of this thesis, metatranscriptomic analyses, biogeochemical rate measurements, and group-specific quantifications in environmental samples as well as investigations of enrichment cultures were carried out to resolve these questions.