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Cyanotoxins are toxins produced by bacteria called cyanobacteria (also known as blue-green algae). Cyanobacteria are found almost everywhere, but particularly in lakes and in the ocean where, under certain conditions, they reproduce exponentially to form blooms. Blooming cyanobacteria can produce cyanotoxins in such concentrations that they poison and even kill animals and humans. Cyanotoxins can also accumulate in other animals such as fish and shellfish, and cause poisonings such as shellfish poisoning. Among cyanotoxins are some of the most powerful natural poisons known, including poisons which can cause rapid death by respiratory failure. The toxins include potent neurotoxins, hepatotoxins, cytotoxins, and endotoxins. Recreational exposure to cyanobacteria can result in gastro-intestinal and hay fever symptoms or pruritic skin rashes. Exposure to the cyanobacteria neurotoxin BMAA may be an environmental cause of neurodegenerative diseases such as ALS, Parkinson's Disease and Alzheimer's Disease. There is also an interest in the military potential of biological neurotoxins such as cyanotoxins, which "have gained increasing significance as potential candidates for weaponization." The first published report that blue-green algae or cyanobacteria could have lethal effects appeared in ''Nature'' in 1878. George Francis described the algal bloom he observed in the estuary of the Murray River in Australia, as "a thick scum like green oil paint, some two to six inches thick." Wildlife which drank the water died rapidly and terribly. Most reported incidents of poisoning by microalgal toxins have occurred in freshwater environments, and they are becoming more common and widespread. For example, thousands of ducks and geese died drinking contaminated water in the midwestern United States.〔(Anatoxin ) Neil Edwards, University of Sussex at Brighton. Updated 1 September 1999. Retrieved 19 January 2011.〕 In 2010, for the first time, marine mammals were reported to have died from ingesting cyanotoxins.〔 ==Cyanobacteria== (詳細はcyanobacteria, a phylum of bacteria that obtain their energy through photosynthesis. The prefix ''cyan'' comes from the Greek κύανoς meaning "a dark blue substance",〔(κύανος ), Henry George Liddell, Robert Scott, ''A Greek-English Lexicon'', on Perseus〕 and usually indicates any of a number of colours in the blue/green range of the spectrum. Cyanobacteria are commonly referred to as ''blue-green algae''. Traditionally they were thought of as a form of algae, and were introduced as such in older textbooks. However modern sources tend to regard this as outdated; they are now considered to be more closely related to bacteria,〔Ed. Guiry, M.D., John, D.M., Rindi, F and McCarthy, T.K. 2007. ''New Survey of Clare Island Volume 6: The Freshwater and Terrestrial Algae.'' Royal Irish Academy. ISBN 978-1-904890-31-7〕 and the term for true ''algae'' is restricted to eukaryotic organisms. Like true algae, cyanobacteria are photosynthetic and contain photosynthetic pigments, which is why they are usually green or blue. Cyanobacteria are found almost everywhere; in oceans, lakes and rivers as well as on land. They flourish in Arctic and Antarctic lakes,〔Skulberg OM (1996) "Terrestrial and limnic algae and cyanobacteria". In: ''A Catalogue of Svalvard Plants, Fungi, Algae and Cyanobacteria'', Part 9, A Elvebakk and P Prestud (eds.) Norsk Polarinstitutt Skrifter, 198: 383-395.〕 hotsprings〔Castenholz RA (1973) "Ecology of blue-green algae in hotsprings". In: ''The Biology of Blue-green algae''. NG Carr and BA Whitton (eds), pp. 379-414. Blackwell Scientific Publications, Oxford.〕 and wastewater treatment plants. They even inhabit the fur of polar bears, to which they impart a greenish tinge. Cyanobacteria produce potent toxins, but they also produce helpful bioactive compounds, including substances with antitumour, antiviral, anticancer, antibiotic and antifungal activity, UV protectants and specific inhibitors of enzymes.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Cyanotoxin」の詳細全文を読む スポンサード リンク
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