3-Oxoacyl acyl carrier protein reductase overexpression reveals its unprecedented roles in biofuel production and high-temperature tolerance in diatom

Due to its high lipid accumulation capability, Phaeodactylum tricornutum has attracted considerable attention as a promising candidate for biofuel production. However, the derived lipid cannot satisfy the industrial biofuel manufacturing requirements given its poor fatty acid characteristics. Genetic engineering, as a prospective approach, has been employed to overcome this bottleneck. Relevant research indicates that the fabG gene plays a crucial role in fatty acid biosynthesis in bacteria, but its significance in microalgae remains unclear. In this study, FabG was successfully introduced, transcribed, and overexpressed in P. tricornutum . FabG overexpression significantly enhanced lipid (1.49-fold) and fatty acid (1.31-fold) biosynthesis without altering growth and photosynthesis, and this method thus exhibits great potential in high-quality biodiesel production. Moreover, increased saturation of fatty acids (e.g., C16:0) and improved antioxidative activities enhanced the tolerance of transgenic P. tricornutum to high temperature stress. To conclude, this study reports a feasible approach for high-quality algae-based biofuel production via the unprecedented roles of FabG retrieved from diatom.