Cyanobacterial

Cyanobacteria are a phylum of bacteria that obtain their energy through photosynthesis. They are often referred to as blue-green algae, even though they are prokaryotes, not algae. Cyanobacteria are a significant component of the marine ecosystem, contributing to primary production and the global carbon and nitrogen cycles.

History

Cyanobacteria are among the oldest known life forms, with fossil evidence dating back over 3.5 billion years. They are believed to have been the first organisms to perform oxygenic photosynthesis, which led to the rise of atmospheric oxygen and the subsequent evolution of aerobic life.

Morphology

Cyanobacteria exhibit a wide range of morphologies, including unicellular, colonial, and filamentous forms. Some species form specialized cells called heterocysts that are involved in nitrogen fixation. Others form akinetes, which are resistant spores that can survive adverse environmental conditions.

Metabolism

Cyanobacteria are capable of photosynthesis, using sunlight to convert carbon dioxide and water into glucose and oxygen. They also perform nitrogen fixation, converting atmospheric nitrogen into ammonia, which can be used by other organisms. Some cyanobacteria can switch to heterotrophic metabolism when light is unavailable.

Ecological Role

Cyanobacteria play a crucial role in the global carbon and nitrogen cycles. They are primary producers in many ecosystems, providing food and oxygen for other organisms. Cyanobacteria can also form harmful algal blooms, which can produce toxins and deplete oxygen in the water, leading to the death of aquatic life.

Human Uses

Cyanobacteria have been used by humans for various purposes. They are a source of nutraceuticals and biofuels, and have potential applications in bioremediation. Some species are also used as a source of dietary protein in certain cultures.

See Also

• Algae
• Photosynthesis
• Nitrogen fixation
• Harmful algal bloom
• Bioremediation