Microalgae encompass a wide diversity of organisms and have attracted increasing interest due to their ability to produce biomolecules of biotechnological and industrial relevance. In particular, they can accumulate oil within lipid droplets (LDs) in response to abiotic stresses such as nitrogen deprivation. This oil accumulation holds great potential for biofuel production.We recently demonstrated that knockout of the gene encoding Seipin, a protein involved in LD biogenesis, leads to a strong oil accumulation in the diatom Phaeodactylum tricornutum. Moreover, this accumulation appears to result from an absence of LD degradation in the Seipin-deficient mutants. These findings suggest that, in this diatom, LDs are programmed to undergo degradation soon after their formation, thus inhibiting LD degradation could prove a promising strategy to increase their oil content.This project aims to elucidate the mechanisms underlying LD degradation and, more specifically, the connections between their biogenesis and degradation. Three main research axes will be pursued:
1. Identify PtSeipin interaction partners involved in LD degradation, using both candidate-based and unbiased approaches.
2. Characterize the LD degradation pathways disrupted in PtSeipin knockout mutants by combining electron microscopy with transcriptomic and proteomic analyses.
3. Investigate how microalgae utilize oil during the recovery phase after stress, through fluxomic approaches.