Targeted knockout of phospholipase A₂ to increase lipid productivity in Chlamydomonas reinhardtii for biodiesel production

Biofuel derived from microalgae have several advantages over other oleaginous crops, however, still needs to be improved with its cost aspect and can be achieved by developing of a strain with improved lipid productivity. In this study, the CRISPR-Cas9 system was incorporated to carry out a target-specific knockout of the phospholipase A₂ gene in Chlamydomonas reinhardtii. The targeted gene encodes a key enzyme in the Lands cycle. As a result, the mutants showed a characteristic of increased diacylglycerol pool, followed by a higher accumulation of triacylglycerol without being significantly compensated with the cell growth. As a result, the overall lipid productivities of phospholipase A₂ knockout mutants have increased by up to 64.25% (to 80.92 g L⁻¹ d⁻¹). This study can provide crucial information for the biodiesel industry.