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 292.50 mg L−1 d−1, 78.73 mg L−1 d−1 (38.9% lipid content per dry weight of biomass), and 549.90 mg L−1 d−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.