What they are?
Microalgae are single-celled photosynthetic organisms that can be found in oceans, brackish water, fresh water, rocks, and soils. These microorganisms are microscopic in size and use light, atmospheric carbon dioxide, and inorganic nutrients to produce oxygen and biomass rich in various bioactive compounds of health interest.
Their genetic diversity is very wide and gives them unique characteristics, and they can be grouped into two distinct taxonomic groups, the eukaryotes (such as chlorophytes) and prokaryotes (cyanobacteria). Among their unique nutritional characteristics, one should highlight their biomass for being a rich source of proteins, vitamins, minerals, essential fatty acids (omega 3 and 6), chlorophylls, and carotenoids with great bioactivity.
On the other side, in recent years these microorganisms have been used for the production of natural cosmetics with unique characteristics and investigated as biofactories of new compounds with great applicability in the pharmaceutical industry.
Algae are reported to be the first organisms to appear on Earth, about 3500 million years ago, with an estimated 40,000 to 10 million species, mostly microalgae. In historical terms microalgae date back to the Aztec population, who harvested the species Arthrospira from Lake Texcoco for food. Also, Arthrospira platensis was consumed as a food supplement called "dihe" in the surrounding population of Lake Chad, and is now a major food of this population. On the other hand, species of the genus Nostoc have been used by the Chinese as a food delicacy because of their nutraceutical and bioactive properties for hundreds of years. More recently, the species of the genus Chlorella and Odontella began cultivation and processing in the years 1975 and 1994, and were marketed as a superfood between 2002 and 2003.
Microalgae form the base of the food chain
They play an important role along the food chain, because they are primary producers that serve as a staple food for various aquatic organisms.
Microalgae are the largest producers of oxygen
Microalgae are organisms that perform photosynthesis, producing about 50% of the oxygen present on the planet, which is indispensable to our survival.
Microalgae have a high nutritional value
Microalgae are rich in a number of biomolecules of high nutritional interest and bioactive capacity.
Microalgae are fixers of atmospheric CO2
These microorganisms have the ability to fix atmospheric carbon dioxide, thus contributing to the reduction of greenhouse gases.
Bioactive Compounds from Microalgae
Antiviral and anti-fungal activity
Microalgae (e.g. Chlorella vulgaris) are capable of producing a wide range of organic compounds that have been used in the synthesis of various antibiotics.
They consist of polyunsaturated fatty acids, particularly DHA, which is fundamental for the maintenance and development of brain functions.
Stimulation of immune responses
Vitamins B9 (folic acid) and B12 and minerals (e.g. iron) contribute to the strengthening of the immune system.
They are a great source of omega-3 fatty acids, which contribute to the prevention and treatment of cardiovascular diseases.
Diabetes and hypertension
Regular consumption of microalgae contributes to controlling blood sugar levels and regulating blood pressure.
The antioxidants found in microalgae protect cells from free radicals, which are responsible for skin aging and the onset of certain diseases (cancer).
They present in their constitution vitamin B6 and B12, which are fundamental in the renewal of cells and tissues of the human organism.
Anti-tumor and anti-inflammatory drugs
The β-carotene, astaxanthin, fucoxanthin, and phycocyanin have proven anti-tumor and anti-inflammatory effects.
Hair and skin health
They are rich in vitamins B2, B3 and B7 (biotin) and lutein, which are responsible for maintaining healthy hair and skin.
Lutein is an antioxidant that is not synthesized in the human body and that is essential for its vision-protecting function.
Free of heavy metals, pesticides, and other contaminants.
Reduced ecological footprint
Responsible for removing atmospheric carbon dioxide.
Removal of impurities and heavy metals
Effective in eliminating impurities and heavy metals from the body, which accumulate in certain organs (e.g. liver and kidneys).
The carotenoids and phytosterols present in microalgae contribute to the reduction of cholesterol levels found in blood plasma.
The biomass of the microalgae Chlorella and Spirulina are excellent sources of protein (50-60%), and are alternatives to animal sources. They also provide antioxidant compounds, vitamins and minerals essential for the human body.
Natural products industry
> Fatty acids
Industrial CO2 capture
The Chlorella vulgaris is a green eukaryotic microalgae whose cells are spherical or ellipsoid with a diameter between 2 and 10 µm. Nutritionally it is rich in protein (50-60%), fiber, vitamins, minerals, antioxidants, omega-3 fatty acids, and essential amino acids. Its benefits for human health range from strengthening the immune system, reducing cholesterol levels and blood sugar, the ability to prevent inflammation and maintain muscle mass by its high protein content.
The Arthrospira platensis is a blue-green filamentous prokaryotic cyanobacterium that characteristically grows in aquatic media with a high concentration of bicarbonate, in alkaline conditions (pH 9-10), showing considerable salt tolerance. It is currently the most widely cultivated photosynthetic organism in the world and is usually marketed under the name "Spirulina". It is an excellent source of protein, polyunsaturated fatty acids, essential amino acids, vitamins, and chlorophylls.
The Haematococcus pluvialis is a unicellular freshwater green microalgae that usually, under conditions of stress, nutrient deficit or high light intensities produces in large quantities a molecule with strong antioxidant power, astaxanthin, which has an intense red coloration. The interest in this microalgae is mainly due to this molecule, as it has multiple benefits for human health, such as prevention and treatment of diabetes, prevention of cardiovascular diseases, reduced risk of Alzheimer's disease due to anti-inflammatory properties, increased fertility, and finally a potential gastroprotectant against the Helicobacter pylori bacteria, which is associated with stomach cancer.
Dunaliella salina is a unicellular, green halophilic microalgae that can be found in high salinity environments with high concentrations of sodium chloride. Its ability to survive in these environments is due to the production and accumulation of glycerol as a way to balance the osmotic pressure inside the cell. In these environments Dunaliella salina is also exposed to intense solar radiation that stimulates the production of the β-carotene molecule as a form of protection. This molecule has a high antioxidant power, which allows it to have a wide application, particularly in cosmetics and food supplements.