**5. Conclusions**

*Microalgae - From Physiology to Application*

and accelerated wound healing [48].

presented 15.29 ± 0.01 μg/g dry mass.

and humans [53, 54].

useful for supporting some diets.

supplements (protein and vitamin, in the form of powder, capsules, pills or tablets). These are usually incorporated into foods such as pasta, cookies, bread, candies, yogurts, soft drinks, among others. It is currently estimated that approximately 30% of the microalgae produced in the world is used in human nutrition due to its high protein content [48]. Therefore, *Arthrospira*-based nutraceutical compounds with anti-cancer protection properties are being commercialized due to their high content of β-carotene [12], the prevention of malnutrition in vitamin A and blood sugar levels, the stimulation of certain prostaglandins, prevention of degenerative diseases,

Recent research has shown that human consumption of microalgae is limited to few species due to strict control over food safety, commercial factors, market demand, and specific preparation for consumption, since the most prominent genera are *Chlorella*, *Arthrospira,* and *Dunaliella*, which are marketed as a food supplement [49, 50]. Studies on nutraceutical substances have been carried out almost exclusively in algae and microalgae, identifying more than 600 naturally occurring carotenoids in plants, animals, and fungi, of which 400 have been isolated and characterized [51], but of these, only a small number are commercially used among them B-carotene and astaxanthin, being only two species of marine microalgae recognized commercial sources of carotenoids: *Dunaliella salina* and *Haematococcus pluvialis* [52]. Recently, our team has registered that *Spirulina maxima* presented 269.54 ± 0.021 μg/g dry mass of β-carotene and *Scenedesmus* sp.

In addition, microalgae have the ability to increase the nutritional content of traditional foods and even positively affect both human health and animal health. This is due to its original chemical composition, since the high protein content in some species is one of the main reasons to consider them as a source of unconventional protein. In turn, the amino acid profile of almost all microalgae is more favorable than compared to conventional sources. The carbohydrates in the microalgae can be found in the form of starch, glucose, sugars or other polysaccharides. Its digestibility is high, so there is no limitation of use in food preparations for both animals

Many microalgal species are marketed for their medicinal value, as *Chlorella* protects against kidney failure and promotes the growth of *Lactobacillus*. In addition, it favors the decrease in blood cholesterol concentration [49, 55], increases the level of antioxidants in the body [56], and stimulates collagen synthesis, supporting tissue regeneration and wrinkle reduction [50]. *Dunaliella* is marketed for its high content of β-carotene [49, 55]. *Haematococcus pluvialis* is the only microalgae that have been commercially exploited for the production of astaxanthin [57, 58]. Today, microalgae are used to feed livestock, and human consumption is increasing, particularly in food supplements [59]. Algae dietary supplements can be particularly

Therefore, the microalgae native to the Peruvian Amazon have been characterized in order to determine their application and use from a biotechnological point of view, due to the abundant source of antioxidants that microalgae possess, which makes them candidates for use in biological processes (aging), as well as in the degenerative changes of different organs [60]. In addition, the beneficial effects of nutraceuticals have been attributed to polyphenols, polyunsaturated fatty acids, terpenes, chlorophyll, and accessory pigments of the photosynthetic apparatus of microalgae and are therefore considered excellent sources of proteins, small peptides, and amino acids that contribute to providing high amount of phosphorus to fight hypertension and lower cholesterol levels, help in the formation and regeneration of blood cells together with iron and stimulate the release of substances that

**62**

control satiety.

The native microalgae of the Peruvian Amazon have biotechnological potential and are therefore promising for the production of both biodiesel and nutraceuticals. Various species of microalgae were identified, isolated, cultured, and characterized using biochemical, nutraceutical, and molecular techniques, the isolation stage being the starting point to achieve various biotechnological applications. *Ankistrodesmus* sp. is one of the microalgae with potential for the production of biodiesel and microalgae such as *Haematococcus pluvialis*, *Scenedesmus* sp., and *Chlorella* sp., among others demonstrated a high potential for nutraceutical production. The stress conditions to which microalgae are subjected are being a determining factor for the production of biodiesel and nutraceuticals.

## **Acknowledgments**

This work was supported by the Scientific University of Peru (UCP) and the National Fund for Technological Scientific Development and Technological Innovation (FONDECYT) with grant contract No. 213-2015-FONDECYT.

## **Conflict of interest**

The authors declare no conflict of interest.
