PLP 150C1 1st Edition Lecture 14 Outline of Last Lecture I. Toxigenic fungiII. AflatoxinIII. Mushrooms & ReligionA. AmanitaB. PsilocybeOutline of Current Lecture I. TricothecenesA. T-2 & DON toxinsII. Alternaria toxinsIII. PenicilliumIV. Locoweed and LocoismCurrent LectureEcology of microbial toxins• Many have phytotoxic properties◦ Help colonize plants where there is food• Most have antimicrobial properties◦ Aid in competition against other microbes living in microbial film that covers everything on the planet.Tricothecenes• Very nasty toxins produced on moldy grain• T-2 toxin - implicated in the Plague of Athens. Came through grain shipments from Africa, killed 1/3 of the population. Implicated in “yellow rain” during the Vietnam War, and in the Gulf War Syndrome during the Iraq War.• Deoxynivalenol (DON) - Trashed the victorious Russian army on their return home following their triumph over the Nazi army in Germany during WWII.Alternaria toxins• What we’re most commonly exposed to.• Since the species is common on fruits and vegetables, they’re usually found on fresh fruits or in processed foods.Penicillium mycotoxins• A genus of mold-forming fungi that grow on stored feed, fruits, and damp indoor spaces.• Some types contaminated humans that eat contaminated yellow rice• Some types contaminate grapes that are used for wine• Some types contaminate apple juice and apple sauce• Many of these concentrate in our livestockWhat is LD50?• A measure of toxicity, the dose that kills 50% of the animals tested.• Important: the measure is dependent upon the animals and the means of exposureLocoweed• In the legume family• Grow in mountains, foothills & plains throughout western U.S. from Montana to south Texas• Perennial with long taproot, and grows in clumps 8-30 cm high.• Flowers in early Spring, and seeds remain viable after 40+ years in the soil• Toxic to livestock causing losses of $30+ million per year in the western U.S.◦ Locoism: Animals exhibit depression, hard to walk, lack of muscular coordination, difficulty eating & drinking▪ Toxicity varies between species, locations, and among plants at a location▪ Don’t know how to control it, other than removing LocoweedSick building syndrome• When molds grow in our homes/offices• Key problem areas are moist areas under sinks, or A/C systems, leaky roofs• May be obvious, but may
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