Quotes About Cyanobacteria

modern plants. Early in the earth's history, cyanobacteria also generated the planet's first oxygen atmosphere, making the world livable. And since then, they had adapted to millions of ecological niches.

The cyanobacteria, a group of photosynthetic bacteria tinted blue-green by chlorophyll and other pigments, harvest sunlight and fix CO2 much like eukaryotic algae and land plants. However, when hydrogen sulfide (H2S, well known for its "rotten egg" smell) is present, many cyanobacteria use this gas rather than water to supply the electrons needed for photosynthesis. Sulfur and sulfate are formed as by-products, but oxygen is not.

Over the next 400 million years, the cyanobacteria—taking in carbon dioxide and giving back oxygen—turned the sky from

stromatolites—a kind of living rock made by billions and billions of microscopic cyanobacteria. The tiny respirations of these organisms over millions of years largely created Earth's oxygen-rich atmosphere, paving the way for more complex living things.

This symbiosis was fantastically improbable. In 3.5 billion years of history and trillions of trillions of interactions between protozoa and cyanobacteria it seems to have happened exactly once. But this single incident had huge effects—it is responsible for the existence of plants.