Cyanobacteria filament

Cyanobacteria are photosynthetic microorganisms inhabiting aquatic and terrestrial environments, playing a crucial role in oxygen production and nitrogen cycling.

About this subject

Cyanobacteria, also known as blue-green algae, are prokaryotes that perform oxygenic photosynthesis. They are among the oldest organisms on Earth, with fossils dating back 3.5 billion years. Their ability to fix atmospheric nitrogen makes them essential for aquatic ecosystems and soils, especially in nutrient-poor environments.

In freshwater bodies like lakes and reservoirs, cyanobacteria can form harmful algal blooms (HABs) when excess nutrients, particularly phosphorus and nitrogen, are present from agricultural runoff or urban pollution. These blooms can produce toxins (cyanotoxins) harmful to humans and animals, causing taste and odor issues, fish kills, and health risks. Common genera include Microcystis and Cylindrospermopsis, found worldwide.

Despite risks, cyanobacteria have biotechnological uses: they are sources of pigments like phycocyanin (natural dye), dietary supplements (Spirulina), and biofuels. Research focuses on bloom control and harnessing their sustainable potential. Monitoring water bodies is critical to prevent toxic outbreaks.

Frequently Asked Questions

What are cyanobacteria?

They are prokaryotic photosynthetic microorganisms found in freshwater, marine, and moist soils. Some produce dangerous toxins.

Why do cyanobacteria form blooms?

Due to excess nutrients (phosphorus and nitrogen), warm water, and low turbulence. Eutrophication is the main cause.

Are all cyanobacteria harmful?

No. Many are beneficial, such as Spirulina used as a food supplement. Only certain species produce toxins under specific conditions.