Cyanobacteria

Synechococcus

Synechococcus sp.

Synechococcus sp. are cyanobacteria, oxygenic phototrophs that can photolyze either H2O or H2S. Synechococcus is the main source of primary production in oligotrophic, pelagic marine waters. Their can cause destructive blooms, producing neurotoxins. Their growth is generally limited however by the concentration of nutrients and trace metals such as iron and phosphorus.

Microcystis

Mycrocystis aeruginosa is a common unicellular colonial cyanobacteria found in fresh water environments. This bacterium produces harmful toxins that create health risks for populations living and harvesting in contaminated areas where M. aeruginosa blooms. Blooms occur when nutrient levels spike in aquatic environments or nutrient levels are selective toward Microcystis aeruginosa.
The existence of intracellular structures, the gas vesicles, provides cells with buoyancy. These hollow, gas-filled structures can keep Microcystis cells close to the surface of water body, where there is optimal light and oxygen for growth. Thus, when the water column is stable, the colonies can accumulate at the water surface and form surface water blooms.

Anabaena

Anabaena is a genus of filamentous cyanobacteria that exists as plankton. It is known for its nitrogen fixing abilities, and they form symbiotic relationships with certain plants, such as the mosquito fern. They are one of four genera of cyanobacteria that produce neurotoxins, which are harmful to local wildlife, as well as farm animals and pets. Production of these neurotoxins is assumed to be an input into its symbiotic relationships, protecting the plant from grazing pressure.



Spirulina(Arthrospira)

Arthrospira is a genus of free-floating filamentous cyanobacteria characterized by cylindrical, multicellular trichomes in an open left-hand helix. Spirulina occurs naturally in tropical and subtropical lakes with high pH and high concentrations of carbonate and bicarbonate.
Spirulina is a human and animal food or nutritional supplement made primarily from two species of cyanobacteria: Arthrospira platensis and Arthrospira maxima.