Microalgae are one of the most promising sources of raw material for biofuel production and derivatives since its high yield of biomass and metabolites possess a low environmental impact. However, its implementation on large scale facilites still faces challenges such as the optimisation of lipid production (due to strain capacity and environmental factors) and downstream processes (extraction and separation of the lipidic fraction). The objective of the present investigation was to determine the potential of the carbon/nitrogen ratio as a technical tool for the improvement of total lipids on Scenedesmus obliquus. The carbon/nitrogen ratio was evaluated using a non-factorial design coupled with surface response methodology with sodium bicarbonate and sodium nitrate as carbon and nitrogen source. Results showed that the optimal conditions that enhanced the lipid deposition (up to 66% w/w) were 1.5 g L−1 sodium bicarbonate and 0,125 g L−1 of sodium nitrate. Finally, the results of the fatty acid profile shown the presence of stearic acid (C18: 0) with 22.63% and elaidic acid (C18:1) with 77.38%, with the absence of fatty acids of two or more double bonds. In conclusion, the adjustment in the carbon/nitrogen ratio favours the final deposition of lipids in Scenedesmus obliquus which is emerging as a possible candidate for the production of lipids of interest for the generation of biodiesel.

Microalgae have been studied in recent years for various reasons, one among them being their potential in the production of biofuels. Biofuels are considered as a renewable source that does not compete with the food industry, and their production results in a reduced environmental footprint. The objective of the present study was to evaluate the different culture conditions that influence the productivity of the microalgae Chlorella vulgaris and Scenedesmus obliquus as a potential source for the production of biodiesel. Bold, Bristol, and modified Algal Assay Procedure (AAP) culture media were evaluated to determine which of them can provide the best conditions that favor biomass production and lipid deposition. The results indicated that S. obliquus cultivated in Bold medium exhibited a higher production of biomass after 30 days (1.730 g/l), while C. vulgaris showed a higher production in the modified AAP medium (1.880 g/l). Although the cultures grown in the AAP medium showed a more significant percentage of biomass comprising lipids than those in the other two media, between the two microalgae, the highest final lipid production was obtained by growing S. obliquus in Bold medium (0.685 g/l, 39.60% of biomass). N, P, Fe, and Mo were the elements added to the growth media, and depending on their concentration in the media, there were differences in the production of lipids. Thus, it can be concluded that S. obliquus cultivated in Bold medium has the highest potential in the production of lipids for biodiesel, but it is necessary to further optimize the cultivation of biomass to obtain a greater quantity of lipids, while interfering as little as possible in its synthesis capacity.