CO utilization in the production of biomass and biocompounds by three different microalgae.

The atmospheric CO increase is considered the main cause of global warming. Microalgae are photosynthetic microorganisms that can help in CO mitigation and at the same time produce value-added compounds. In this study, , , and were cultivated under 0.035 (air), 5 and 10% (v/v) of CO concentrations in air to evaluate the performance of the microalgae in terms of kinetic growth parameters, theoretical CO biofixation rate, and biomass composition. Among the microalgae studied, presented the highest values of specific growth rate ( = 1.28 d), maximum productivities ( = 0.28 g Ld), and theoretical CO biofixation rates (0.56 g Ld) at 10% CO. The highest oil content was found at 5% CO, and the fatty acid profile was not influenced by the concentration of CO in the inflow gas mixture and was in compliance with EN 14214, being suitable for biodiesel purposes. The impact of the CO on cells' viability/cell membrane integrity evaluated by the flow cytometry is quite innovative and fast, and revealed that 86.4% of the cells were damaged/permeabilized in cultures without the addition of CO.