Biochemical conversion of CO2 for cultivation of micro-algae and production of high value-added chemicals

Microalgae is a sustainable and potent source of various bioactive natural compounds, including β-carotene, lutein, astaxanthin, fatty acids. Nowadays, the large-scale cultivation of microalgae for production of various bioactive compounds has gained significant interest with respect to commercial and industrial use for cosmetic, health and nutrition applications. For the enhancement of their exploitation, a suitable extraction method is fundamental to reach high yields, optimal extraction condition, without degrading process caused for high temperature, air and light exposure, and to eliminate trace of hazardous solvents. A well-known innovative method is CO2 supercritical fluid extraction (CO2– SFE) that uses CO2 as safe solvent and operate in mild conditions avoiding degrading process. This method is advantageous for the reduction of solvent use and extraction time, and the yield increase. However the CO2 – SFE of carotenoids from microalgae have still needed to be enhanced to improve the yield and extract quality. For the optimization of this technique, key parameters should be tested on microalgae biomass, as sample matrix pre-treatment, quantity of loaded material, process parameters (temperature and pressure) and entrainer co-solvent. In this work, the recovery and the extraction of astaxanthin from Haematococcus pluvialis biomass and β-carotene, from Dunaliella salina, lutein production from Scenedesmus almeriensis and fatty acids from Nannochloropsis gaditana biomass could be extracted. This study summarize effect of different operative conditions for extraction of high value added chemicals from algal biomass. Acknowledgments This paper has received funding from the Bio Based Industries Joint Undertaking under the European Union’s Horizon 2020 research and innovation program under grant agreement No 745695 (VALUEMAG).