Microalga, Acutodesmus obliquus KGE 30 as a potential candidate for CO2 mitigation and biodiesel production

In this study, the effect of flue gas CO2 on growth, lipid production, and fatty acid composition of a green microalga Acutodesmus obliquus KGE 30 was investigated. The highest growth rate (0.46 g L-1 and mu(max) = 1.09 day(-1)), total inorganic carbon removal (95.9 mg L-1), and lipid productivity (20.1 mg L-1 day L-1) was obtained at 14.1 % CO2 after 4 days of cultivation. In a semicontinuous batch reactor, the highest biomass production (1.19 g L-1) was achieved after 12 days with continuous injection of flue gas CO2. Compared with synthetic CO2, fatty acid methyl ester analysis showed that the amount of unsaturated fatty acid increased by 19.2 % with 14.1 % flue gas CO2. The application of flue gas CO2 improved biomass production and lipid productivity in A. obliquus. The current investigation demonstrated that the use of flue gas CO2 could reduce the cost of microalgae biomass production for better biofuel generation.