Over a billion years ago, these bacteria oxygenated Earth's atmosphere. So it's thanks to Cyanobacteria that we have air to breathe.
Cyanobacteria are also believed to be the precursors responsible for photosynthesis and multicellularity as a whole.
These photosynthesizing chains of bacteria are found in many environments, including freshwater ecosystems.
Special thanks to Professor Jared Leadbetter at the California Institute of Technology for his invaluable assistance and expertise.