The growing interest in the study of microalgae is due to 3 main pillars, namely: biological, ecological and economic. In biological terms, the value of this group of organisms resides in the structuring of the current Earth’s atmosphere by producing most of the O₂ of the atmosphere, thus making life on the Earth’s surface of aerobic living beings possible. Whereas the fact that they are primary producers gives algae ecological importance as they support life in the seas and oceans, thus playing a fundamental ecological role in the maintenance of these ecosystems. The economic importance, on the other hand, is determined by its diversity in commercial application, not only in the food industry to that of medicines, from immunostimulants to biofuels, but also, from cosmetics to agriculture.
FEATURES
Microalgae are elements of a very heterogeneous group of organisms, they are naturally present in different aquatic / humid environments, including rivers, lakes, oceans and soils. They are organisms with two types of cellular structure: prokaryotes or eukaryotes, which can form colonies, with little or no cell differentiation besides being endowed with pigments, responsible for varied coloration and photoautotrophic metabolism.
They can be grown in different production systems, with volumes ranging from a few liters to billions of liters. The systems commonly used are unsophisticated, since many companies develop crops in the open, under natural lighting and temperature conditions, and with little or no control over these environmental parameters. However, some companies have developed intensive crops using specific equipment called photobioreactors, in which it is possible to control environmental parameters such as lighting, temperature, pH, CO₂, among others, resulting in high productivity.
Photo / Ref .: Aphanocapsa colony uncertain / Phytology Research Center
THE POTENTIAL
Because they reproduce very quickly, they provide a large amount of oil and biomass. This undoubtedly drew the attention of sectors that need large quantities of raw materials. This is because algae biomass has considerable advantages over traditional raw materials:
- High productivity– usually 10 to 100 times higher than traditional agricultural crops
- Highly efficient carbon capture
- High content of lipids or starch, which can be used for the production of biodiesel or ethanol, respectively
- Cultivation in sea water, or brackish water or even in waste water
- Production on non-agricultural land
THE MARKET FOR SEAWEED PRODUCTS
The exact number of microalgae species is still unknown. Namely, citations are currently found reporting that there may be between 200,000 to a few million representatives of this group. Such diversity is also reflected in the biochemical composition and, in this way, microalgae are the source of an unlimited amount of products.
At first, microalgal crops have been developed aiming at the production of biomass, both for use in food preparation, and for obtaining bioactive and medicinal compounds with high value on the world market, such as pigments, polyunsaturated fatty acids, drugs and others, which are of great interest to the food, chemical, pharmaceutical and cosmetics industries. Thus, the main commercially grown microalgae are species of the genera Chlorella and Arthrospira for addition to natural foods (health food), Dunaliella salina for obtaining beta-carotene and Haematococcus pluvialis for obtaining astaxanthin.
| Features | Product | Application |
| Pigments | Astaxanthin / Cataxanthin Phycocyanin |
Biomedical human and animal nutrition (dyes) |
| Polyunsaturated fatty acids | EPA DHA |
Human and animal nutrition Cosmetics (antioxidants) |
| Mycosporin-type amino acids | Porphyra | Cosmetics (sunscreens) |
| Phycocolloid | Carrageenan Agar / Alginate | Biomedical / pharmaceutical foods (stabilizers) |
| Sterols | Phytosteriol | Animal nutrition (aquaculture) Biomedical |
| Amino acids and proteins | Chlorella Spirulina |
Human and animal nutrition |
| Carbohydrates | Ethanol Bioplastic Blocks Chemical Builders |
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| Lipids | Biodisel and biokerosene Surfactants Lubricants Polymers |
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| Biomass | Biogas and energy Fertilizers CO2 biofixation and effluent treatment Functional foods |
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| Enzymes | SOD PGK Luciferase and Luciferin Restriction enzymes |
Health Food Biomedical Research |
Not only the applications listed above, but many studies have been carried out in other fields: in the treatment of waste water from numerous industrial processes, for biological detoxification and removal of heavy metals; as bioindicators, in the detection of nutrients (for microalgae) and toxic substances (detergents, industrial effluents, herbicides, etc.). Furthermore, in agriculture, biomass can be used as a soil biofertilizer. In addition, it can synthesize toxins, microalgae can produce a range of bioactive molecules with antibiotic, anticancer, anti-inflammatory, antiviral, cholesterol-lowering, enzymatic properties and with other pharmacological activities.
In addition, they can be used to mitigate the greenhouse effect by assimilating CO₂, the result of the process of burning fossil fuels and inappropriate agricultural practices (such as burning, for example). Furthermore, they enable the production of biofuels (biodiesel). Finally, microalgae are useful for the production of free hydrogen, by biophotolysis in the elaboration of a natural insecticide, by recombining a DNA sequence of the bacterium Bacillus thuringiensis var. israelensis (Bti) in the genome of a microalgae species, consumed by the malaria mosquito in its larval form.
Photo / Ref .: Submerged Asterocapsa Colony / Research Center in Phycology
THE GREEN FUTURE
Undoubtedly, the amount of compounds of commercial interest that can still be obtained through the cultivation of microalgae is very large. The growing interest in clean, sustainable and organic technologies for obtaining products for human and medicinal consumption, brings the need, not only, for a continuous search for species and / or varieties (strains) capable of synthesizing large quantities of specific compounds , but with knowledge to enhance the synthesis of these products. Thus, research is also needed to develop and, mainly, to improve production systems on a commercial scale in order to make some of the known systems viable. Consequently, it is important to identify products that can be extracted from microalgae
