I am a marine microbiologist and organic geochemist. My research topics involve the reconstruction of marine biogeochemical cycles, in particular the carbon and nitrogen cycles, during periods of past and present global climate change. 

My research currently focuses on the cultivation of 'ancient' algae using continuous-flow systems. During photosynthesis, algae fixate carbon dioxide (CO2) and produce oxygen (O2). Dependent on atmospheric CO2 concentrations, CO2-fixation leaves a 'carbon isotopic signal' in the lipids of the photosynthesizing organism. These 'lipid biomarkers' can be found as molecular fossils in the Earth's sedimentary record and can be used to reconstruct past atmospheric CO2 concentrations. Currently, carbon isotopic fractionation studies have focused on relatively 'recent' algae, that emerged >250 million years ago.  By investigating carbon isotopic fractionation pathways in 'ancient' algae, we aim to acquire a better framework for the reconstruction of atmospheric CO2 in the Paleozoic (<250 million years ago).