Nutrient composition of culture media induces different patterns of CO 2 fixation from biogas and biomass production by the microalga Scenedesmus obliquus U169.

Microalgae are considered as a promising biotechnological strategy to capture CO ₂ from biogas, producing biomass with valuable energetic compounds. This study has evaluated the biotechnological potential to fix CO ₂ from biogas and biomass production by Scenedesmus obliquus cultured in four different formulations of culture media, C30, Bristol, Bold 3N, and C30+M, as well as the effect of methane (CH ₄ ) of biogas during CO ₂ fixation and biomass production. The results obtained showed that different nutrient composition and concentration of culture media, mainly micronutrient and vitamin concentrations, induced different patterns of CO ₂ fixation from biogas and biomass production in S. obliquus. The highest CO ₂ fixation (23.03 ± 0.24%) and biomass production (4.63 ± 0.31 g L ^-1 ) were attained in the microalgae growing in C30+M medium, accumulating mainly proteins. Moreover, these results demonstrated that the CH ₄ of biogas did not affect CO ₂ fixation from biogas and biomass production by S. obliquus. Overall, these results demonstrated that a culture medium with a balanced nutrient supply is crucial to increasing the biotechnological potential of microalgae to fix CO ₂ from biogas.