Enhanced lipid production in Scenedesmus obliquus via nitrogen starvation in a two-stage cultivation process and evaluation for biodiesel production

Abstract

The present study amalgamated the high lipid accumulation of Scenedesmus obliquus CCAP 276/3A and a FAME profile suitable for biodiesel production by optimization of nitrate concentration in a flat panel photobioreactor. In the proposed two-stage cultivation process, the nitrogen replete stage I was aimed at maximizing the biomass concentration, followed by a nitrogen deprived stage II for enhancing lipid production. Maximum lipid content was obtained when Scenedesmus obliquus was cultivated for 5 days under nitrogen limited stage II with nitrate concentration of 0.1 g/L. Lipid content ramped up from 33.1% (DCW) in control conditions to 45.1% (DCW) under the identified optimal conditions. The critical properties of biodiesel derived from this lipid were estimated based on the FAME composition; the results established the suitability of Scenedesmus obliquus CCAP 276/3A as a feedstock for biodiesel production. The present study provides important insights into the nitrogen response behavior of Scenedesmus obliquus which can help steer future schemes of lipid enhancement in algae.