Biofixation of Air Emissions and Biomass Valorization-Evaluation of Microalgal Biotechnology.

This research appraised the simultaneous biofixation, that is not quite common in scientific literature, of carbon dioxide (CO) and nitric oxides (NO) by microalgae species Chlorella vulgaris, Haematococcus pluvialis, and Scenedesmus subspicatus. The experimental design was established by five treatments with gas concentrations between control-0.04% of CO, 5 to 15% of CO, and 30 to 100 ppm of NOx. Parameters such as pH, growth, productivity, lipids, protein, carbon/ nitrogen ratio, and astaxanthin were evaluated. For all species, the maximal growth and productivity were achieved with 5% of CO and 30 ppm of NO. Regarding protein content, for all the three species, better results were obtained at higher concentrations of CO and NOx. These results prove the microalgae capacity for CO and NO biofixation and reuse of biomass as a source of high value-added products, such as lipids, proteins, and astaxanthin. These findings support the indication of these species for flue gas treatment process and use in biorefineries systems.