Brown algae are key components of coastal ecosystems worldwide, also providing significant environmental and economic value to society through the development of sustainable seaweed mariculture for food and biomass production. They also make a substantial contribution to primary production and carbon sequestration, burying several megatons of carbon from the atmosphere per year, comparable to that reported for terrestrial forests.
Due to their early diverging position in the eukaryotic tree, brown algae are an outstanding source of original biosynthetic pathways, most of which are still unknown so far. Among them, the biosynthetic pathways of storage sugars (i.e. mannitol and laminarin), which represent a substantial part of algal biomass, have been poorly described so far. Therefore, this project aimed to functionally decipher the storage carbohydrate biosynthetic pathways in brown algae.
Based on functional genetics and heterologous expression approaches, we have successfully started the functional characterization of enzymes involved in mannitol biosynthesis and transport. This project has laid a solid foundation for the development of this new research topic in the BIAM (sugar and lipid metabolism in brown macroalgae), with recent fundings from the CEA and the ANR.