cyanobaktéria

Cyanobacteria, also known as blue-green algae, are a phylum of bacteria within the domain Bacteria. They are ubiquitous in nature, found in a wide variety of habitats including oceans, freshwater, soil, and even in extreme environments like hot springs and deserts. Their name comes from the characteristic blue-green pigment, phycocyanin, which they possess alongside chlorophyll.

These microorganisms are photoautotrophic, meaning they produce their own food using sunlight through photosynthesis. This process is particularly significant as cyanobacteria were among the first organisms to evolve oxygenic photosynthesis, fundamentally altering Earth's atmosphere by releasing oxygen as a byproduct. This ancient evolutionary event is believed to have paved the way for the development of more complex life forms.

Cyanobacteria play crucial roles in ecosystems. They are primary producers, forming the base of many food webs. Some species are capable of nitrogen fixation, converting atmospheric nitrogen into a usable form for plants, thus enriching soil. However, under certain conditions, excessive growth of cyanobacteria can lead to harmful algal blooms (HABs) in aquatic environments. These blooms can produce toxins that are harmful to humans, animals, and aquatic life, and can also deplete oxygen levels, creating dead zones. Despite these potential downsides, cyanobacteria are vital for global biogeochemical cycles and have been subjects of scientific research for their photosynthetic mechanisms and potential applications in biotechnology.