Cyan (blue-green) colored photosynthetic aquatic-bacteria are termed as cyanobacteria. Bacteria usually are single celled organism. It is known that cyanobacteria originated 2.5 – 3 billion years ago on planet earth. Since; cyanobacteria prepares its own food (auto-trophic) using sunlight, carbon-dioxide and water in presence of chlorophyll, Edible cyanobacteria are undoubtedly first vegetarian food on earth showing plant like properties with bacterial capabilities.
Natural Spirulina Lake
Endosymbiotic theory proposed by Dr.Lynn Margulis in 1960’s, established that all plants and trees on the earth have evolved from cyanobacteria. It is also well accepted by the scientific fraternity and established through peer reviewed journal like PNAS that cyanobacteria are responsible for the “great oxidation event” on the earth. During photosynthesis, cyanobacteria released oxygen and thus over period of thousands of years, oxygen layer has been formed in the atmosphere. This subsequently has led to the evolution of the oxygen dependent organisms on the planet. Additionally, Spirulina during its photosynthetic activity not only releases oxygen, but also sequesters carbon dioxide thereby reducing atmospheric carbon into carbohydrate enriching compounds in the biosphere. Even today; 70% of oxygen on earth is contributed by such cyanobacterial activities which are significantly more than the oxygen provided by all trees and plants together on earth. Thus, it is considered as most successful organism from the perspective of sustainability. It has originated, thrived and grown in most reducing environment (absence of oxygen) on the earth and transformed the planet’s habitat suitable for many other organisms to survive.
Spirulina was the first food on earth. Currently; it is the best food on the earth. Since, it is the only food containing most of the nutrients popular as the “super food”. Tomorrow; it might be the last food on earth due to its unbeatable capacity to sustain and dietary benefits.
Cyanobacteria are classified on the following criteria:
- Heterocystous [specially compartmentalized cells for nitrogen fixation] – non heterocystous.
- Single cell – Filamentous: Depending upon the number of cells cyanobacteria will be classified as single celled or a colony arranged in filament.
- Edible – non edible: Certain cyanobacteria like Microcystis produces cyanotoxins those make consumption of these organism inedible.
- Examples of cyanobacteria: Nostoc, Oscillatoria, Dunaliella, Microcystis, Anabaena, Chlorella, Arthrospira, Prochlorococcus, Synechococcus.