Toxins from Fungi and Algae

1. Toxins from Fungi and Algae

2. Fungi 2 categories1. Yeasts 2. Moldscertain molds can be found associated with food products which produce toxins that cause acute illness and even death

3. Life cycle of the typical mold (conidia are the spherical structures at the ends of the aerial hyphae

4. Aspergillus flavus, A. parasiticus and A. columnaris ALLproduce aflotoxinA. flavus is found in peanutsA. parasiticus and/or A. columnaris is found associated with barley, rice, rye, wheat, millet, oatscorn, chickpeas, pecans, cassava and yams**aflotoxin is found in the milk of cattle but is converted to a benign form that doesn’t harm humans

5. Peanuts and corn obviously contaminated with Aspergillus A. flavus and A. niger on rotting peanuts Aspergillus flavus sporulating on a peanut seed.Photograph courtesy B. Hornfrom the Compendium of Peanut Diseases, Second Edition. from NCSU Plant Pathology Extension

6. Source of Aspergillus spp. in food1. Grains and foods stored in warm, damp airless environments2. rainy season harvests3. food that comes in contact with the spores in the soil4. harvesting grain before maturity5. growing crops in soil with high levels of fungal growth

7. Aflatoxin iscarcinogenic—causes cancerteratogenic—causes birth defectsandcauses acute illnesses with flu symptomsconvulsionsparalysis coma and death

8. Aflatoxin consumption is correlated with cancer1. liver cancer higher in areas where foods susceptible to Aspergillus contamination are consumed in high quantities. Esp. when foods are harvested and stored under poor conditions.2. Evidence show that aflatoxin alkylates (modifies) proteins (vitaletheine modulaters) that specifically enhance out immune system’s ability to fight off cancer cells

9. Testing for aflatoxins1. ELISA tests on a representative crop2. testing relative weight of foods(I.E. peanuts)A. airblowingB. density gradient testing(premise peanuts infected with Aspergillus are lighter than healthy peanuts)3. Carefully monitor the food yourself (esp. from Farmers’ markets.

10. Claviceps purpurea and Ergot poisoning 1. C. purpurea common in soil 2. In nature this mold grows on the seed heads of wheat, rye, barley oats and corn. 3. Large amounts of growth associated with large amounts of toxin production. 4. Improperly stored grains can lead to fungal growth and toxin production (high humidity and poor ventilation) **Easily seen as black growth on the grain kernels when enough fungal growth is present.

11. Claviceps purpurea infecting rye grains http://www.zoetecnocampo.com/Documentos/cornezuelo/1785.15ergotinbarley.jpg

12. Ergot Toxin—an alkaloidHighly Stable moleculeAlso Heat Stablewithstands long storage withstands brewing processeswithstands boilingTarget organs—brain, nerve & muscle tissue, circulatory and endorcrine systems SymptomsFlu like symptomsmental confusion and hallucinations (LSD)limb paralysisabortionseizures dry gangrene due to vasoconstrictiondeath

13. Controlling C. purpurea1. Most wheat seed planted in the U.S are genetically engineered to be resistant to this mold2. Use substances to prevent the growth of moldsAmmoniaPropionic acidChlorine vapoursSorbic acid

14. Algae, the Red Tide and Shellfish!!Dinoflagellates are marine algaephotosyntheticsomewhat abundanthave two flagelli (motile)Produce a heat stable neuro-toxin that is concentrated in filter feeders and poison humans

15. Only a few species of dinoflagellates cause red tideGlenodium spp., Gymnodinium spp. and Gonyaulax spp.What causes Red tide?When these organisms divide at a high rate causing what looks like rust colored paint poured into the water

16. Dinoflagellates cause Red Tide and infect shellfish www http://courses.bio.psu.edu http://www.agpix.com/catalog www.nmnh.si.edu

17. What causes the dinoflagellates to multiply at a high rate?Increased amounts of nutrients and trace chemicals released into the sea watersewage run-offmarine pollutionwarm sea temperaturesan increase in the duration and intensity of sunlight

18. Symptoms of toxin poisoning by dinoflagellates in humansnumbness and paralysis in tonguelips fingertips and toesburning sensation of face neck and torsoVomiting diarrheadisorientation and short-term memory lossdeath due to asphyxiationIf sublethal amounts of toxin are consumed, symptoms usually fade after 3-4 months

19. Prevention and cureno cureavoid shellfish that have been extracted from the ocean during algal blooms!