A strategy for lipid production in Scenedesmus sp. by multiple stresses induction

Microalgae are rich source of lipids and are one of the promising feedstocks for biofuel production, whereas enhancement of lipid, carbohydrate, and biomass production is crucial for commercialization of algal biofuels. Nutrients/salinity stresses are important to increase the synthesis of lipid. In the present study, Scenedesmus sp. is treated with a varying combination of sodium nitrate (NaNO3), dipotassium hydrogen phosphate (K2HPO4), and sodium chloride (NaCl) to improve lipid accumulation. Results indicate that the modified media comprising of NaCl (100 mM), NaNO3 (0 mM), and K2HPO4 (0.22 mM) (S100N0P0.22) accumulated higher quantities of lipid (385.4 ± 34.2 μg/mg) along with considerable biomass (537.0 ± 22.3 μg/mL), chlorophyll “a” (6.2 ± 0.08 μg/mL), and palmitic acid (32.6%). Apart from biochemical analysis, stress-induced biomarker such as hydrogen peroxide (H2O2) was observed maximum for same combination (10854 μmolH2O2/g), with low lipid peroxidation (3.2 μmol/g). Catalase (CAT) and superoxide dismutase (SOD) activity were further studied to monitor the impact of reactive oxygen species (ROS) on lipid accumulation. This study revealed a better combination in terms of lipid and biomass profile, which can further be investigated for large-scale production. Multi-stress-driven lipid production is one of the significant outputs of the current study, which can further be explored in detail. Insight such interactions may provide directions for economical production of algal biodiesel.