How do microalgae fix CO₂?
During photosynthesis, microalgae incorporate carbon dioxide in the Calvin cycle and transform it into sugars and, from these, into the rest of their biomass components. For each unit of biomass produced, a proportional amount of carbon is fixed.
Advantages over other systems
Microalgae can fix CO₂ faster per unit area than many land crops, thanks to their fast growth and the fact that the whole cell is photosynthetic. They can also be grown on land unsuitable for agriculture and with non-potable water.
From CO₂ to useful products
The captured carbon is stored in the biomass, which can be used for food, biofertilizers, biofuels or high-value compounds. In this way, CO₂ capture is combined with obtaining products, rather than being an isolated cost.
Limitations and challenges
The real efficiency of capture depends on the CO₂ source, available light, the cultivation system and the final use of the biomass. A rigorous balance must consider the energy used across the whole process, from cultivation to harvesting and drying.
FAQ
Yes: they fix it through photosynthesis and incorporate it into their biomass. Due to their fast growth they are studied for biological carbon capture.
It remains in the biomass, which can be used for food, biofertilizers, biofuels or high-value compounds.
Sources
- Richmond, A. & Hu, Q. (eds.) (2013). Handbook of Microalgal Culture: Applied Phycology and Biotechnology. Wiley-Blackwell.
- Chisti, Y. (2007). Biodiesel from microalgae. Biotechnology Advances, 25(3), 294–306.
- Spolaore, P. et al. (2006). Commercial applications of microalgae. Journal of Bioscience and Bioengineering, 101(2), 87–96.
- Mata, T.M. et al. (2010). Microalgae for biodiesel production and other applications: A review. Renewable and Sustainable Energy Reviews, 14(1), 217–232.
Scientific outreach based on specialised literature. Scientific review: pending.
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