FunCON:
Kohlenstoffsequestrierung in A-Auflösung - CONCENTRATE
- Duration:
- 01.10.2025 - 30.06.2029
- Project coordinated by:
- Universität Greifswald
- Contact (IOW):
- Isabell Klawonn
- Funding:
- DFG - Deutsche Forschungsgemeinschaft
- Research area:
- Partners:
Marine algae annually convert about five times as much carbon dioxide into structurally diverse polysaccharides or glycans as modern human society emits by burning fossil fuels. Bacteria possess thousands of enzymes to degrade these glycans, converting the captured carbon back into carbon dioxide. Yet, surprisingly, we find enormous amounts of glycans accumulating in the global oceans, suggesting there are unknown factors that stabilize glycan structures. As long as the ratio of glycan biosynthesis exceeds glycan consumption, carbon is captured and stored in the oceans, both on short-term (days) and long-term (geological) time scales. This fundamental marine process, termed carbon sequestration, regulates the amount of carbon dioxide in the atmosphere and contributes to a stabilized climate. Our previous work suggests that unknown factors prevent marine bacteria from decomposing algal glycans into carbon dioxide, which promotes carbon sequestration. To identify the unknown controls that limit microbial degradation of glycans, we propose the TRR CONCENTRATE, in which we will conduct “test tube” experiments and environmental measurements with bacteria, fungi, algae and their glycans and proteins. Our main objective is to mechanistically understand, how marine microorganisms interact and sequester carbon in the form of glycans, with a focus on relevant processes and reactions at sub-nanometer (Ångström, Å) resolution. We will concentrate on protein-based machineries that interact with glycans with key-lock specificity and enzyme active sites at a high level of resolution. We aim to discover and unravel the unknown biotic and abiotic factors that render glycans stable against degradation. We will focus on the sunlit surface ocean as the primary hotspot of algal glycan biosynthesis. Our investigated time scales of glycan stability will span from days to years to assess the contribution of different factors. The TRR 420 aims to deconstruct the complexity of glycan sequestration in the ocean and to understand and mimic the underlying processes that control the balance between degradation and sequestration. The discovery of unknown agents that protect glycans from degradation will lead to an advanced understanding of ocean functioning, potentially including key knowledge to counter increasing atmospheric carbon dioxide levels. Switching between the test tube and the sea, we will iteratively decouple the cycle of algal glycan synthesis and microbial degradation until we obtain mechanistic details of the interplay between organismic and molecular-level processes down to Ångström resolution.