Spirulina is a food of high nutritional value. It contains a variety of bioactive nutrients such as high biological value protein, iron, gamma-linolenic acid (GLA), beta-carotene, (provitamin A), vitamin B complex, vitamin E etc.
Spirulina is a prokaryotic organism consisted of united cells, which form helicoid fibers. The spiral shape gave rise to its name – Spirulina.
The characteristic blue-green color of spirulina is attributed to the natural colorants that it contains and more specifically to chlorophyll (green color) and phycocyanin (blue color).
In contrast to other plant cells, which contain a hard cellulosic wall, spirulina's cell wall is formed by four numbered layers, from the inner most outward as: LI, LII, LIII and LIV. All these layers are very weak, except for layer LII which is made up of peptidoglycan, a substance responsible for the wall’s ridigity. The protein and lipopolysaccharide nature of the LII layer contributes to the easy human digestion of Spirulina.
The blue-green algae (cyanobacteria) are the first group of bacteria that evolved and could fix atmospheric carbon dioxide into organic carbon compounds using water as an electron donor and thereby evolving oxygen. We owe the present oxygen-rich environment partially to the millions of years of photosynthetic activity by Cyanaobacteria that made it possible for other oxygen dependent life forms to evolve. Indeed it is this same ability to fix carbon dioxide and produce organic matter that we are presently utilizing in the mass cultivation of these organisms for food.
In its commercial use, the common name, Spirulina, refers to the dried biomass of the cyanobacterium, Arthrospira platensis, and is a product of biological origin. In its taxonomic use, Spirulina is a name used to describe mainly two species of Cyanobacteria, A. platensis and A. maxima, which are commonly used as food, dietary supplement, and feed supplement.
It should be pointed out that the name Spirulina is used commonly as a name of commerce. As a matter of fact, studies of morphological, physiological, and biochemical examination of representatives of Spirulina and Arthrospira genera have shown that these two genera are distinctively different. However, this site will use the name Spirulina with the understanding that all the edible forms that are under commercial cultivation and sold as “Spirulina” actually belong to the Genus Arthrospira, and more specifically to the species Arthrospira Platensis.