Fundamental Research Division
The DRF at the CEA assemble approximately 6,000 scientists since January 2016.
Scientific result | Photosynthesis
Researchers from the CEA-IRTSV and their partners have revised our understanding of the cellular mechanisms behind the impressive photosynthetic capacity of the unicellular marine organisms known as diatoms. The scientists discovered an unexpected interaction between photosynthesis and respiration, which could inspire promising developments in biotechnology.
Whereas terrestrial plants provide photosynthetic activity on land, in the oceans photosynthesis is performed by microscopic unicellular organisms known as phytoplankton. Dominating this community, diatoms (comprising thousands of marine species) are at the origin of the food chain in these environments. They capture and sequester atmospheric CO2 in the depths, and provide about 20% of the planetary photosynthesis. How were diatoms able to reach this level and dominate the phytoplankton community? As part of an international collaboration (including Belgium, France, the USA and Italy), a French team involving the CEA-IRTSV, CNRS, INRA, INSERM, the Ecole Normale Supérieure, the universities of Joseph Fourier, Paris-Sud, and Pierre et Marie Curie, and the Fermentalg company has decrypted the characteristics of the photosynthetic process in diatoms at the molecular level. Decrypting the photosynthetic mechanism of diatoms The fixation of CO2 by photosynthesis requires the production of energy (ATP molecules) and reducing power (NADPH molecules) in the chloroplast, and in well-defined proportions. In diatoms, the molecular mechanisms that work to manage the ATP/NADPH ratio occur through ongoing exchanges between the chloroplast and the mitochondrion (the cellular compartment dedicated to respiration). This process, which helps to optimize photosynthesis, has certainly contributed to the ecological success of diatoms in the world's oceans. The discovery of this coupling mechanism between photosynthesis and respiration in diatoms makes it possible to imagine unprecedented biotechnological applications, such as increasing the production of biomass to produce molecules of interest, by acting on the simultaneous use of light (for photosynthesis) and carbon sources (for respiration).
Energetic coupling between plastids and mitochondria drives CO2 assimilation in diatoms | Nature
CEA is a French government-funded technological research organisation in four main areas: low-carbon energies, defense and security, information technologies and health technologies. A prominent player in the European Research Area, it is involved in setting up collaborative projects with many partners around the world.