What produces most of the planet’s oxygen?
They release oxygen as a waste product of photosynthesis. Their net oxygen output is higher than that produced by all the trees and other land-based plants put together.
Ancient algae are also the main constituent of oil and gas. Blue-green algae or cyanobacteria (from Greek kyanos – “dark green-blue”) it is earth’s earliest known life form, with fossils that date back 3.6 billion years.
While some algae are included with the plants in the Eukaryote domain (eu, “true, and karyon, “nut”, referring to their cell’s having true nuclei, which bacteria don’t), the cyanobacteria are now firmly in the Bacteria kingdom with their own phylum.
One form of cyanobacteria, spirulina, yields twenty times more protein per acre than soya beans. It consists of 70 percent protein (compared with beef’s 22 percent), 5 percent fat, no cholesterol, and an impressive array of vitamins and minerals. Hence the increasing popularity of the spirulina smoothie.
It also boosts the immune system, particularly the production of protein interferons, the body’s front-line defense against viruses and tumour cells.
The nutritional and health benefits of spirulina were recognized centuries ago by the Aztecs, sub-Saharan Africans, and flamingos.
Its significance for the future may be that algae can be grown on land that isn’t fertile, using (and recycling) brackish water. It’s a crop that doesn’t cause soil erosion, requires no fertilizers or pesticides, and refreshes the atmosphere more than anything else that grows.