Structure and Habitat
Algae are small unicellular organisms, while cyanobacteria are multicellular organisms and larger in size. Algae are eukaryotic organisms with nucleus, mitochondria and chloroplasts inside each cell. They also have an eye that detects and recognizes light sources and captures the light to generate energy. This process is called photosynthesis. Cyanobacteria lack nuclei and mitochondria. They perform photosynthesis by using water as an electron source and producing oxygen.
Green algae are found in lakes, oceans and freshwater. Some even grow in soil and live in tree trunks. The overall number of green algae is estimated to be over 500 genera and 8500 species. Cyanobacteria are found almost everywhere, including aquatic habitats such as lakes, ponds, and terrestrial areas such as sand, exposed rocks, and moist soil. They breed in extremely high temperatures, up to 60 degrees Celsius and shallow water. The total species of cyanobacteria include 150 species and about 2500 species in the world.
Chlorella can reproduce vegetatively as well as vegetatively. Cyanobacteria reproduce asexually with the process of binary fission, fragmentation or spore production. They have no flagella and therefore lack mobility.
The nutritional value of green algae is similar to that of most green plants. They are rich in vitamins and minerals. They are medically proven necessary food supplements. They are also rich in fatty acids. They have recently been shown to be beneficial biofuels; however, they have not been used commercially due to their economic availability and viability.
Depending on the subspecies, Cyanobacteria are virulent and therapeutic. They can produce certain neurotoxins or cytotoxins. This can cause potential hazards to humans, aquatic animals and animal origin. As lake or pond temperatures increase, cyanobacteria produce large amounts of toxins during the summer, which favors the maximum development of these bacteria. Certain cyanobacteria such as spirulina are beneficial and are a great source of protein, amino acids, vitamins and antioxidants. They are also of high value in antiviral therapy, especially in herpes and HIV.
Both green algae and cyanobacteria evolved from algae. Depending on their structure, they differentiate into prokaryotic cells (cyanobacteria) and eukaryotic cells (green algae). Green algae are symbiotic, which means they can live in symbiosis (harmonious coexistence) with fungi. They are a food source for aquatic microorganisms, while cyanobacteria have been shown to be beneficial or harmful, depending on the subspecies. Cyanobacteria are blue-green bacteria and cannot perform photosynthesis like green algae.