MARUM Research Academy

Identifying Chemical Signatures of Carbodioxyphilic Microbes in the CO2 Saturated Subsurface of Volcanic Outgassing Sites

One of the most important biosynthetic processes on Earth is the autotrophic CO₂ fixation, which converts inorganic to organic carbon. This process was established during a special period in the history of our Earth, the early Archean Eon, and fueled the evolution of early microbial life. This period was characterized by high levels of CO₂, and it is suggested that these conditions could lead to energetically efficient CO₂ fixation pathways with a great impact on carbon cycling. For this project, we hypothesize that microbes - which we call carbodioxyphiles - that thrive under high CO₂ conditions can still be found today in CO₂-rich subsurface ecosystems.

In the course of my four-year doctoral student position, I will be analyzing the lipidome and metabolites of those microbes using cutting-edge mass spectrometry methods combined with software-assisted targeted and untargeted quantification as well as identification. These are powerful tools to describe microbial communities based on the characteristic structure of their membrane lipids, which therefore can be used as biomarkers. The goal is to find biomarkers for carbodioxyphilic microbes and link those lipids and metabolites to microbial genomes and metabolic pathways.

My doctoral project is funded by the European Research Council (ERC) within the project “Archean Park – Relicts of Ancient Cellular Biochemistry in High-CO₂ Subsurface Ecosystems”.