title: Cyanobacterial toxins--occurrence, biosynthesis and impact on human affairs.
abstract: Mass developments of cyanobacteria ("blue-green algae") in lakes and brackish waters have repeatedly led to serious concerns due to their frequent association with toxins. Among these are the widespread hepatotoxins microcystin (MC) and nodularin (NOD). Here, we give an overview about the ecostrategies of the diverse toxin-producing species and about the genes and enzymes that are involved in the biosynthesis of the cyclic peptides. We further summarize current knowledge about toxicological mechanisms of MC and NOD, including protein phosphatase inhibition, oxidative stress and their tumor-promoting capabilities. One biotransformation pathway for MC is described. Mechanisms of cyanobacterial neurotoxins (anatoxin-a, homanatoxin-a, and anatoxin-a(s)) are briefly explained. We highlight selected cases of human fatalities related to the toxins. A special focus is given to evident cases of contamination of food supplements with cyanobacterial toxins, and to the necessary precautions.
authors.affiliation: Humboldt University, Institute of Biology, Berlin, Germany. elke.dittmann@rz.hu-berlin.de
authors.forename: Elke
authors.initials: E
authors.lastname: Dittmann
authors.forename: Claudia
authors.initials: C
authors.lastname: Wiegand
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000032:analysis* / Q000096:biosynthesis / Q000633:toxicity*; D002273:Carcinogens; D056486:Chemical and Drug Induced Liver Injury; D000458:Cyanobacteria / Q000254:growth & development / Q000378:metabolism*; D000087522:Cyanobacteria Toxins; D019587:Dietary Supplements; D017753:Ecosystem; D005506:Food Contamination; D006801:Humans; D008387:Marine Toxins / Q000032:analysis* / Q000096:biosynthesis / Q000633:toxicity*; D052998:Microcystins; D018384:Oxidative Stress; D010456:Peptides, Cyclic / Q000737:chemistry / Q000633:toxicity; D010749:Phosphoprotein Phosphatases / Q000037:antagonists & inhibitors; D014326:Tropanes
chemical_list: D001427:Bacterial Toxins; D002273:Carcinogens; D000087522:Cyanobacteria Toxins; D008387:Marine Toxins; D052998:Microcystins; D010456:Peptides, Cyclic; D014326:Tropanes; C063998:nodularin; C078588:microcystin; C509783:anatoxin a; D010749:Phosphoprotein Phosphatases