Mycology

Importance of Fungi

Fungi has been classifies as plants for several decades However, they differ from plants due to following properties:

  • Fungi lack chlorophyll, while plants have this pigment
  • Fungal cell wall contains a carbohydrate called chitin, plant cell walls have cellulose
  • Most fungi are not truly multicellular as plants
  • Fungi are heterotrophic while plants are autotrophic

 

Importance of fungi

Fungi are important in various facets.

  1. Fungi degrade/ decompose complex plant and animal remains, breaking them down to simpler chemical compounds which on addition increases fertility of the soil.
  2. They are also important in industrial fermentation. E.g. Brewing of beers, Wine production.
  3. Production of food products: Leavening of dough and ripening of some cheese are dependent on fungal activity.
  4. Antibiotics production: Antibiotics such as penicillins are produced by fungi.
  5. Various disease in humans, plants and animals are caused by fungal pathogens.

Decomposition activity of fungi are undesirable when they decompose textiles, food, timber and other materials.

 

Biodegradation in ecosystem and Biodeterioration

  • Degrade complex organic materials in environment.
  • Release C, N, P and other critical constituents of dead organisms and make available to living organisms.
  • Essential for decomposing lignin and other woody substances.
  • Biodeterioration: Dry rot fungus Serpula lacrymans attacks wood and potentially dangerous when it attacks timbers used in construction of buildings.

 

Major cause of disease

  • Parasitic fungi- pathogens
  • Cause diseases in plants, animals and human.
  • In Plants cause diseases such as blights, mildews, rusts, etc.
  • Human: cause mycoses and mycotoxicoses
  • Mycoses classified as superficial, sub cutaneous or systemic.

 

 

Used in industrial fermentation processes

  • Yeasts in making of bread, wine and beer.
  • Preparation of some cheeses (Roquefort cheese contains Penicillium roquefortii)
  • Production of soy sauce using Aspergillus oryzae
  • Production of organic acids (citric, gallic)
  • Production of drugs like ergometrine, cortisone and immunosuppressive drugs like cyclosporine.
  • Production of antibiotics

 

Direct source of food

  • Mushroom (Agaricus bisporus)
  • Commercially produced and industrially processed protein-rich food product for human or livestock consumption (Fusarium venanatum).
  • The mycelium is harvested and processed to provide a protein-rich meat substitute in a range of convenience foods.

 

Use in bioremediation 

  • Some fungi are used in processes aimed at reducing the concentrations and toxicities of waste materials particularly from industrial processes, before releasing waste to environment.
  • Aspergillus niger is used to break down tannins in tannery effluents.

 

Mycorrhiza

  • Many plants form associations called mycorrhizae with fungi that give them access to nutrients in the soil, protecting against disease and toxicities.
  • Specific, mutualistic association of plant roots and fungi
  • Fungi increase absorptive surface of roots and exchange soil minerals
  • Found in 95% of vascular plants
  • Necessary for optimal plant growth

 

 

Ecological Impact of fungi

Ecosystems depend on fungi as decomposers and symbionts: decompose food, wood and even plastics.

Some fungi are pathogens e.g. athlete’s foot, ringworm etc.:

  • Plants are 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