Microalgae cultivation in a novel top-lit gas-lift open bioreactor

This work investigated a top-lit open microalgae bioreactor that uses a gas-lift system to enable deeper production depths, thereby significantly reducing the footprint. Growth of Scenedesmus sp. in a one-meter deep system by sparged with 6% CO2-enhanced air was evaluated. The results gave comparable volumetric biomass productivity (0.06 gdw L−1 day−1), but around three-times higher areal productivity (60.0 gdw m−2 day−1) than reported for traditional raceways. The lipid content of the Scenedesmus sp. was increased by 27% with an enhanced level of CO2 in the sparging gas.