Abstract: “The purpose of this study was to explore the ways that could enhance the productivity of oil by a marine microalga Nannochloropsis sp. Microalgae have the characteristics of rapid growth with ample accumulation of oil in their cells. Algae are photoautotrophs that grow on carbon dioxide. With the yield of oil rich biomass, cultivation of microalgae suits the noble purposes of pollutant reduction and renewable energy production. In this study, Nannochloropsis sp., which is known for its large biomass yield with high cell oil content, was cultured in batch reactors in the Walne medium. Light intensity was controlled at 11000 Lux and culture temperature was set at 32+ 20C. Sodium bicarbonate was the carbon source and sodium nitrate was the nitrogen source, both of which were variables for the determination of maximal oil productivity. pH was held at controlled and un-controlled states. Test results showed that with sodium bicarbonate and sodium nitrate concentration of 12 g-HCO3- L-1 and”

Keywords: biomass oil, renewable energy, microalgae, carbondioxide mitigation, optimization