Importance of Fungi

Fungi are agents of biodegradation and biodeterioration:
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SAPROTROPHIC fungi utilise dead organic materials as sources of nutrients and are responsible for the biodegradation of organic materials in our environment, particularly plant materials in the form of leaf litter and other plant debris. Such fungi play a vital role in recycling essential elements, particularly carbon. [CLICK TO VIEW BASIDIOCARPS OF A WOOD-ROTTING FUNGUS DEVELOPING ON A TREE STUMP - 51KB]
Fungi are very effective and efficient biodegraders because of the wide range of EXTRACELLULAR ENZYMES they produce, which are capable of degrading complex polymers, such as cellulose, proteins and lignins.
Unfortunately, their excellent biodegradative abilities mean that many saprotrophic fungi are capable of contaminating our food sources or destroying many consumer goods we manufacture from natural raw organic materials.
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For example, some saprotrophic fungi are particulalry dangerous contaminants of seeds and grains because they produce metabolites known as MYCOTOXINS (fungal toxins). When ingested mycotoxins cause toxic or carcinogenic symptoms in humans and other animals. Some Aspergillus species produce a group of chemically related mycotoxins called AFLATOXINS. [CLICK TO VIEW SEEDS AND GRAINS SUSCEPTIBLE TO CONTAMINATION BY MYCOTOXINS - 57KB]
A second example is provided by the 'dry rot' fungus, Serpula lacrymans, which attacks wood and can be a very costly, potentially dangerous and certainly most unwelcome visitor when it attacks timbers used in the construction of buildings (e.g. floor and wall joists or roof timbers).
Fungi are responsible for the majority of plant diseases and several diseases of animals (including humans):
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For example, Phytophthora infestans is the causal agent of late blight disease in potatoes. The disease reached epidemic proportions across Europe in the mid 19th century and resulted in the Irish potato famine. [CLICK TO VIEW POTATO TUBERS EXHIBITING SYMPTOMS OF LATE BLIGHT DISEASE - 46KB]
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Some fungi are actively parasitic in humans and other animals, while others induce severe allergic reactions if their spores are inhaled - resulting in attacks of asthma or hay-fever. [CLICK TO VIEW SYMPTOMS OF A 'RINGWORM' INFECTION CAUSED BY TRICHOPHYTON SPECIES - 22KB]
Fungi are used in industrial fermentation processes:
Yeasts and mycelial fungi are used in a variety of industrial fermentation processes. For example, Saccharomyces species are used extensively in brewing beers and wines, as well as in bread-making.
Fungi are also used in the commercial production of many biochemicals:
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For example, Aspergillus niger is used in the large-scale commercial production of citric acid. [CLICK TO VIEW A COLONY OF ASPERGILLUS NIGER - 23KB]
Many fungi provide us with a direct source of food:
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Some yeasts and mycelial fungi are cultured on a large scale and then undergo further processing to provide various protein-rich food products for human or livestock consumption. For example, Quorn™ mycoprotein is produced commercially from the mycelial fungus Fusarium venanatum. The mycelium is harvested and processed to provide a protein-rich meat substitute in a range of convenience foods. [CLICK TO VIEW A VARIETY OF QUORN™ PRODUCTS - 46KB]
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Some species are cultivated for their edible fruiting bodies, e.g. the basidiocarps of Agaricus bisporus. [CLICK TO VIEW COMMERCIAL MUSHROOM PRODUCTION - 51KB]
Fungi are used in bioremediation:
Some species of yeasts and mycelial fungi are used in processes aimed at reducing the concentrations and toxicities of waste materials, particularly from industrial processes, before those wastes are released into the environment - a process known as bioremediation.
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For example, Aspergillus niger is used to breakdown tannins in tannery effluents to less toxic compounds. [CLICK TO VIEW ASEXUAL SPORULATION IN ASPERGILLUS - 40KB]
Some fungi prove highly beneficial in agriculture, horticulture and forestry:
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For example, some species form symbiotic relationships with the roots of plants, known as MYCORRHIZAS. Mycorrhizas significantly improve plant growth and vigour, resulting in increased yields in crop plants. [CLICK TO VIEW A BASIDIOCARP OF AMANITA MUSCARIA - AN ECTOMYCORRHIZAL FUNGUS - 40KB]
Other fungal species are used in the biological control of insect and nematode pests, weeds and pathogenic microorganisms. For example, the fungus Beauvaria bassiana is used to control a number of insect pests.


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