So far it is not clear to which extent essential micronutrients, such as copper and iron, play a limiting role in the aerobic methane oxidation. This research project aims at testing the hypothesis that methanotrophich bacteria strongly depend on Cu and/or Fe supply for the oxidation of methane at the oxic – anoxic boundary in lakes. In order to test this assumption different lake systems with different geochemical conditions are sampled.
Trace-level analysis of labile, dissolved and total metal concentrations are quantified across the redoxcline by two different measurement techniques - diffusion gradient in thin-film gels and voltammetric in situ profiling. For the identification and quantification of the organisms involved in aerobic methane oxidation, microbial tools like PCR and sequencing based on functional genes and specific 16S rRNA sequences will be applied. Finally, analyzing the isotopic composition of Cu and Fe to assess a possible fractionation mechanism during their uptake by methanotrophs will be of high interest.