PhD Student (f/m/d)

Project in the field of organosulfur biochemistry, microbiology and bioinformatics.
The project led by Dr. Eileen Kröber aims to investigate the consumption and cycling of organosulfur compounds in marine chemosynthetic symbioses. A wide diversity of chemosynthetic symbioses (these are associations, where the chemosynthetic bacteria provide their eukaryotic hosts with nutrition by assimilating inorganic and organic carbon) inhabit environments which are nutrient limited, such as seagrass meadows, coral reefs or mangroves. However, at the same time these environments are hotspots for the production of organosulfur compounds such as dimethylsulfoniopropionate (DMSP) and dimethylsulfide (DMS). The importance of organosulfur compounds for the biology and ecology of the oceans has only recently become clear. It is now recognized that organosulfur compounds play a key role in biogeochemical cycles, ranging from critical sources of sulfur, carbon and energy for marine microorganisms to affecting the Earth's climate. Despite the realization of their importance, our understanding of how organosulfur compounds are produced, consumed and cycled is still limited. Given that nutrition is often limiting in the environments where chemosynthetic hosts thrive, the ability to use organosulfur compounds can provide a valuable source of energy and carbon to the symbiosis. We aim to determine whether organosulfur compounds, such as DMSP, DMS, DMSO, and MeSH, are important carbon and sulfur sources for marine chemosynthetic symbioses, and how widespread the cycling of these compounds is in diverse marine chemosynthetic symbioses. To achieve these objectives, the candidate will analyze metagenomes, metatranscriptomes, and metaproteomes of various marine chemosynthetic symbioses. The analysis will also focus on determining whether predicted metabolic pathways for organosulfur compounds are expressed and functional in these symbioses. The candidate will also perform functional enzyme characterization and functional genomics to complement the meta'omics analysis. Overall, the project aims to provide insights into the role of organosulfur compounds in marine chemosynthetic symbioses and how they contribute to the carbon and sulfur cycling.