Nutrient composition of culture media induces different patterns of CO2 fixation from biogas and biomass production by the microalga Scenedesmus obliquus U169.

Microalgae are considered as a promising biotechnological strategy to capture CO2 from biogas, producing biomass with valuable energetic compounds. This study has evaluated the biotechnological potential to fix CO2 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 (CH4) of biogas during CO2 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 CO2 fixation from biogas and biomass production in S. obliquus. The highest CO2 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 CH4 of biogas did not affect CO2 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 CO2 from biogas.