Considering the current energetic and environmental issues, there is no doubt about the necessity to replace fossil-derived compounds. Organic wastes arise as renewable feedstock alternatives for the production of biofuels and biochemicals. In this manner, the costs of such bioproducts might be reduced by using a waste as substrate while avoiding wastes treatments.
Microalgae biomass generated during wastewater bioremediation may be considered an attractive low-cost feedstock for bioproducts. Although the most conventional approach for wastewater grown microalgae is the use of this biomass for biogas production purposes, others bioproducts can be also produced.
Volatile fatty acids (VFAs) can be obtained during anaerobic fermentation of microalgae biomass. These compounds exhibit from 2 to 6 carbons (from acetic to caproic acid) and are considered valuable building blocks for the chemical industry. Some microorganisms are able to use VFAs as carbon source and convert them into lipids that have applications in the oleochemical industry. On the other hand, the solid spent from the anaerobic fermentation can be further revalorized via anaerobic digestion into methane, which can be employed as energy carrier. This double approach has been the focus of the Biotechnological Processes Unit at IMDEA Energy willing to maximize product output. The results have been recently published in a scientific article*.
*Llamas, M., Magdalena, J. A., Tomás-Pejó, E., & González-Fernández, C. (2020). Microalgae-based anaerobic fermentation as a promising technology for producing biogas and microbial oils. Energy, 206, 118184. DOI: 10.1016/j.energy.2020.118184
More information: Cristina González-Fernández, Senior Researcher, Biotechnology Processes Unit, firstname.lastname@example.org