The cyanobacteria are a fascinating group of bacteria that have adapted to colonize almost every environment on the planet. They are the only prokaryotes capable of oxygenic photosynthesis, responsible for up to 20-30% of Earth's photosynthetic productivity. They can attune their light-harvesting systems to changes in available light conditions, fix nitrogen, and have circadian rhythms. In addition, many cyanobacteria species exhibit gliding mobility and can differentiate into specialized cell types called heterocysts, and some are symbiotic. Thanks to their simple nutritional requirements, th