Performance evaluation of an outdoor algal biorefinery for sustainable production of biomass, lipid and lutein valorizing flue-gas carbon dioxide and wastewater cocktail

We evaluated wastewater remediation and CO2 utilization potential of Chlorella minutissima from flue gas in a raceway pond, while synthesizing lutein and lipid for potential healthcare and biofuel application. A mix of 20% kitchen waste, 10 g L-1 of poultry litter waste and 5% flue gas was maintained while cultivating the microalga. Complete removal of nitrate, nitrite and ammonium, 85% carbon and 91% phosphorus was observed. An average areal biomass productivity of 4.06 +/- 0.12 gm(-2) day(-1) with a specific growth rate of 0.34 +/- 0.03 day(-1) was observed within 9 days. Biomass productivity of 6.21 +/- 0.16 gm(-2) day(-1) with a specific growth rate of 0.34 +/- 0.03 day(-1) was achieved during winter. Furthermore, lipid content with appropriate fatty acid composition 1.04: 1 (saturation: unsaturation) increased from 25% to 58%. Additionally, lutein productivity of 1.2 +/- 0.08 mgL(-1) day(-1), while utilizing 80.74 +/- 0.07 mg L-1 day(-1) of CO2 from 5% flue gas was obtained.