Aquaculture is the process of cultivation of aquatic organisms, animals or plants, such as fish, shrimp, algae and marine plants. Aquaculture is presented as an alternative to the over exploitation of marine resources, already surpassing fishing activity worldwide. It undoubtedly represents the future of animal protein production of aquatic origin and of polyunsaturated fatty acids Ω3.
Microalgae have been used as food for centuries. Rich in substances beneficial to our health and with great potential to prevent numerous diseases, they are currently used in the form of dry biomass or for the extraction of supplements and natural food colors. The best known species of microalgae for human consumption are Chlorella sp. and Arthrospira (commonly called Spirulina). The natural pigment astaxanthin is extracted from the freshwater species Haematococcus pluvialis, and is the most potent antioxidants known to date, which gives the pink color to salmon, flamingos and crustaceans. The β-carotene pigment, extracted from the Dunaliella sp. is widely used in natural drinks and also as an antioxidant.
Microalgae are attracting strong interest from the agrochemical industry and agricultural producers, due to their biostimulant and biofertilizing properties. Different products based on microalgae are commercially available for use in agriculture as innovative and potential products to improve crop production. Typically, the labels of biostimulants and biofertilizers of microalgae report information regarding their composition, including the concentrations of elementary minerals, the content of amino acids and phytohormones.
Microalgae have mechanisms to absorb inorganic and organic compounds dissolved in water as nutrients for their metabolism. The high adaptability of these organisms and their high growth rate allow them to be used to treat water from anthropogenic industries, or from aquatic systems in need of some kind of remediation.
Nitrogen compounds, phosphates, heavy metals and others can be metabolized or sequestered by microalgae and removed from the water. Microalgae also contribute to greater oxygenation of aquatic systems.
The use of microalgae for the extraction of natural compounds in the cosmetic-pharmaceutical sector is growing. Source of natural pigments, antioxidants and vitamins, various species of microalgae are being used to treat various skin-related problems. They act as humectants, help the regeneration of cells, and are also used in wrinkle treatments.
Mitigation of CO2
Microalgae absorb solar energy and assimilate CO2 from the air and nutrients of aquatic habitats. The photosynthetic capacity of microalgae is 3 to 5 times higher than that of terrestrial plants. Microalgae are responsible for the absorption of at least 60% of all global CO2 emissions. For every kilo of microalgae biomass generated, at least 1.85 kg of CO2 are used. On the other hand, CO2 mitigation based on microalgae has the potential to obtain valuable biomass products that can be used to generate income.