Our Mission

All ecosystems on planet Earth are populated by microbes, which are massively entangled in all biogeochemical cycles. In ecosystems relevant to human society, microbes fulfill important functions, resulting in ecosystem services. One important ecosystem service is carbon fixation, i.e., the conversion of inorganic carbon into organic molecules necessary for life. Ecosystem services are a central aspect of ecosystem health, one of the three pillars of the One Health concept.

The Probst Lab focuses on healthy and diseased ecosystems and the role that microbes play therein. We are particularly interested in bacteria, archaea, small eukarya, and viruses that infect these organisms. Since most microbes escape cultivation techniques in the laboratory, we use a community sequencing approach called metagenomics (also environmental genomics) to determine the DNA sequences of entire communities, which we disentangle at the (population) genome level. We bioinformatically pair metagenomics with other techniques like RNA sequencing, proteomics, or lipidomics. The combination of these ‘omics techniques provides information on the status of different microbes in healthy and diseased ecosystems. To investigate the ecophysiology of microbes in situ, we also apply metagenomics-informed correlative microscopy techniques, including fluorescence in situ hybridization (FISH) to visualize specific viruses.

Our research questions are mostly related to aquatic ecosystems and how microbes interact with and mediate nutrient turnover therein. Our favorite ecosystems include rivers, lakes, deep and shallow groundwater, oil reservoirs, and deep sediments.



ERC | European Research Council

Archean Park

This project focuses on life under extremely high-CO2 concentrations to ultimately learn about new biotechnological applications.
Ongoing until 2029


DFG | German Research Foundation


We investigate the evolution of microbes in deep groundwater.
Ongoing until 2027


Lundin Petrolium


Here we investigate indigenous microbes and their functions in oil reservoirs via metagenomics approaches.
Ongoing until 2024


European Union’s Horizon 2020 research and innovation programme


We use ‘omics techniques to predict the location of uncharted marine oil reservoirs to protect the ocean floor from unnecessary and destructive drilling.

For more information see:
Ongoing until 2024




We here design a new bioreactor for cultivating previously uncultivated microbes from aquatic ecosystems.

For more information see:
Ongoing until 2024


DFG | German Research Foundation | CRC 1439


We investigate the effect of multiple stressors on river sediment microbiomes; we also coordinate the research data management in this project

For more information see: Project A01 and Z-INF of CRC RESIST.
Ongoing until 2024


Finished Projects


DFG | German Research Foundation


Here, we investigated previously undiscovered viruses of archaea from the deep biosphere and established new microscopy techniques to detect them.
Finished 2023


Minsterium für Kultur und Wissenschaft NRW

NRW return award: eSym

We investigated symbioses between microbes in the deep biosphere.
Finished 2022




We investigated the dispersal of microbes and viruses in deserts and from the ocean to continents.
Finished 2021



MultiKulti (exploratory phase)

This project was the definition phase for MultiKulti 1.0 (see above).
Finished 2020


Sloan Foundation Subaward Deep Life

Deep Life - novel autotrophs in aquifers rich in carbon dioxide

We developed a method to detect novel autotrophs in the deep biosphere.
Finished  2019