Selection of microalgae for lipid production under high levels carbon dioxide

To select microalgae with a high biomass and lipid productivity, Botryococcus braunii, Chlorella vulgaris, and Scenedesmus sp. were cultivated with ambient air containing 10% CO2 and flue gas. The biomass and lipid productivity for Scenedesmus sp. with 10% CO2 were 217.50 and 20.65 mg L−1 d−1 (9% of biomass), while those for B. braunii were 26.55 and 5.51 mg L−1 d−1 (21% of biomass). With flue gas, the lipid productivity for Scenedesmus sp. and B. braunii was increased 1.9-fold (39.44 mg L−1 d−1) and 3.7-fold (20.65 mg L−1 d−1), respectively. Oleic acid, a main component of biodiesel, occupied 55% among the fatty acids in B. braunii. Therefore, the present results suggested that Scenedesmus sp. is appropriate for mitigating CO2, due to its high biomass productivity and C-fixation ability, whereas B. braunii is appropriate for producing biodiesel, due to its high lipid content and oleic acid proportion.