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Discover molecular pathways for marine glyco-Carbon sequestration

Project description

Do diatoms sink glycan carbon into the ocean?

Marine microalgae and bacteria form a carbon cycle. Algae convert CO2 into glycan sugar polymers via photosynthesis. Bacteria digest glycans and release the contained carbon CO2 again into the atmosphere. Funded by the European Research Council, the C-Quest project will concentrate on diatom microalgae that convert substantial amounts of CO2 into glycans. The team will test the hypothesis that certain glycans are not digested by bacteria, enabling CO2 containment in the ocean. The structural diversity of glycans creates an analytical barrier, which remains a great challenge to overcome. To break through, the team will use highly specific enzymes and other bioanalytic tools that can identify and quantify algal glycans. Biological counting of glycans will show how much carbon is cycled or sequestered in the ocean.


The scientific frontier project C-Quest will study algal sugar polymers - glycans - in the ocean to resolve their contribution to global carbon cycling and sequestration. C-Quest will explore the hypothesis that marine diatoms, which fix similar amounts of carbon as tropical forests on a global scale, secrete glycan types that are stable, meaning harder to degrade for bacteria than other substrates. This stability results in glyco-carbon sequestration removing the greenhouse gas carbon dioxide from the atmosphere. C-Quest will identify and quantify glycan structural types in seawater, where salt, low glycan concentration and their high molecular diversity challenge classic analytical techniques. With two articles in PNAS (2020) and Nature Communications (2021), implementing bioanalytical strategies to measure glycans in the ocean, we broke through the glyco-carbon challenge setting the stage for testing the glyco-carbon sequestration hypothesis. In the test tube, my team will reveal marine bacterial enzymatic degradation pathways that degrade diatom glycans. Our characterized enzymes will become analytical tools to identify and quantify these glycans across the ocean. In different oceanic regions, we will quantify glycan production during algal blooms, glycan export in sinking particles and glycan burial in sediments to pinpoint the types that have a high potential to sequester carbon. The outcome will be knowledge of glycan contribution to carbon sequestration shedding light into what remains a black box of the global carbon cycle to this day. C-Quest will discover enzymes new to science, explore the potential of glycans for carbon sequestration and reveal molecular principles that govern carbon sequestration in and beyond the ocean.


Host institution

Net EU contribution
€ 2 277 248,00
Bibliothekstrasse 1
28359 Bremen

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Bremen Bremen Bremen, Kreisfreie Stadt
Activity type
Higher or Secondary Education Establishments
Total cost
€ 2 277 248,00

Beneficiaries (1)