TAXONOMY: cellular organisms -> Bacteria -> Terrabacteria group -> Cyanobacteria/Melainabacteria group -> Cyanobacteria
Cyanobacteria , also known as Cyanophyta, is a phylum of bacteria that obtain their energy through photosynthesis. The name 'cyanobacteria' comes from the color of the bacteria . They are often called blue-green algae (but some consider that name a misnomer, as cyanobacteria are prokaryotic and algae should be eukaryotic, although other definitions of algae encompass prokaryotic organisms).Cyanobacteria can produce neurotoxins, cytotoxins, endotoxins, and hepatotoxins (i.e. the microcystin-producing bacteria species microcystis), and are called cyanotoxins.Specific toxins include, anatoxin-a, anatoxin-as, aplysiatoxin, cyanopeptolin, cylindrospermopsin, domoic acid, nodularin R (from Nodularia), neosaxitoxin, and saxitoxin. Cyanobacteria reproduce explosively under certain conditions. This results in algal blooms, which can become harmful to other species, and pose a danger to humans and animals, if the cyanobacteria involved produce toxins. Several cases of human poisoning have been documented, but a lack of knowledge prevents an accurate assessment of the risks. Recent studies suggest that significant exposure to high levels of some species of cyanobacteria producing toxins such as BMAA can cause amyotrophic lateral sclerosis (ALS). The Lake Mascoma ALS cluster  and Gulf War veterans' cluster are two notable examples.