Photobiologic Production of Hydrogene
The purpose of our research is to understand the metabolic pathways and the electron transfer pathways involved in the process of hydrogen photoproduction, to identify the regulatory mechanisms and to propose innovative strategies to optimize the production capacities
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Some microalgae (like Chlamydomonas reinhardtii) or cyanobacteria (such Synechocystis) have the capacity to produce hydrogen thanks to a hydrogenase in interaction with the photosynthetic electron transport chain. In nature, the photobiological production of H2 is a transitory phenomenon, the hydrogenase being strongly sensitive to the oxygen produced by photosynthesis. We develop two complementary strategies to try to break oneself of this major limitation.
The first one consists in separating in time the phases of oxygenic photosynthesis and hydrogen production by playing with the metabolic flexibility and the capacity to accumulate energy storage (starch, lipids) in answer to a mineral deprivation. Genetic approaches are developed in the unicellular alga C. reinhardtii via the search for mutants affected in the photosynthetic conversion or the metabolism of the starch with the aim of identifying key genes allowing the control and the optimization of this process.
The second one, carried out at in the cyanobacteria Synechocystis, aims at reducing by genetic engineering the sensitivity to oxygen of the hydrogenase. The molecular bases of the resistance to oxygen studied on various bacterial models (exploration of the biodiversity) are transposed to the hydrogenase of the cyanobacteria, this organism being particularly adapted to targeted modifications (homologous recombination).