Human-Fungus Interactions

• Beneficial Effects of Fungi

  • Decomposition - nutrient and carbon recycling.

  • Biosynthetic factories. Can be used to produce drugs, antibiotics, alcohol, acids, food (e.g., fermented products, mushrooms).

  • Model organisms for biochemical and genetic studies.

• Harmful Effects of Fungi

  • Destruction of food, lumber, paper, and cloth.

  • Animal and human diseases (mycosis), including allergies.

  • Toxins produced by poisonous mushrooms and within food (e.g., grain, cheese, etc.).

  • Plant diseases.

Ecological Impacts of Fungi

• Ecosystems depend on fungi as decomposers and symbionts: they decompose food, wood and even plastics!

• Some fungi are pathogens

  • Plants particularly susceptible (e.g. Dutch elm disease)

  • Ergot - affects cereal crops: causes gangrene, hallucinations and “St. Anthony’s fire”

• Many animals, including humans, eat fungi:

  • In US, mushroom consumption restricted to Agaricus

  • We eat a range of cultivated and wild mushrooms

  • Truffles are underground ascocarps of mycelia that are mycorrhizal on tree roots

Animal-Fungus Symbioses

• Some fungi share their digestive services with animals

• These fungi help break down plant material in the guts of cows and other grazing mammals

• Many species of ants use the digestive power of fungi by raising them in “farms”

Fungus-Plant Mutualisms

• Mycorrhizae are enormously important in natural ecosystems and agriculture

• Plants harbor harmless symbiotic endophytes

  • Endophytes: fungi that live inside leaves or other plant parts

• Endophytes make toxins that deter herbivores and defend against pathogens

• Most endophytes are ascomycetes