Scenedesmus obliquus CNW-N as a potential candidate for CO₂ mitigation and biodiesel production

This study aimed to achieve higher CO₂ consumption ability and lipid productivity of an indigenous microalgal isolate Scenedesmus obliquus CNW-N by a two-stage cultivation strategy. The microalga strain was first cultivated with 10% CO₂ using a nutrient-rich medium to promote cell growth, which was followed by a nutrient-deficient condition to trigger lipid accumulation. The optimal biomass productivity, lipid productivity, and CO₂ consumption rate were 292.50mgL^-1d^-1, 78.73mgL^-1d^-1 (38.9% lipid content per dry weight of biomass), and 549.90mgL^-1d^-1, respectively. This performance is superior to the results from most of the related studies. Under the nutrient-deficient condition, the microalgal lipid was mainly composed of C16/C18 fatty acids (accounting for 89% of total fatty acids), which is suitable for biodiesel synthesis.