Nannochloropsis is a fast-growing microalga of major biotechnological interest due to its high biomass productivity and ability to accumulate valuable lipids, notably the omega-3 fatty acid eicosapentaenoic acid (EPA). A deeper understanding of its cellular biology is therefore essential to fully exploit its potential. In particular, the mechanisms governing cell wall development remain poorly characterized. Nannochloropsis cell walls contain algaenan, a highly recalcitrant and hydrophobic biopolymer composed of long-chain (C₃₀–C₃₂) alkyl diols linked by ether bonds, which confers exceptional resistance to chemical and biological degradation. Recent observations indicate that red bodies (specialized plastid-derived structures) may contribute to the synthesis, degradation, or transport of algaenan precursors and associated enzymes to the cell surface.

To identify enzymes involved in algaenan biosynthesis and degradation, eight candidate genes encoding proteins accumulating in red bodies were selected for characterization. Knockout and overexpression lines were generated in Nannochloropsis oceanica, and confirmed mutants will undergo biochemical and structural characterization to evaluate changes in cell wall composition and algaenan assembly. This project will provide new insights into algaenan synthesis and may ultimately facilitate the biotechnological exploitation of Nannochloropsis by improving access to valuable intracellular compounds that are shielded by the highly recalcitrant algaenan-based cell wall.