Fungi are one of the most important groups of
organisms on the planet. This is easy to overlook, given their largely hidden, unseen
actions and growth. They are important in an enormous variety of ways.
- Recycling
Fungi, together with bacteria, are responsible for most of the recycling which returns
dead material to the soil in a form in which it can be reused. Without fungi, these
recycling activities would be seriously reduced. We would effectively be lost under piles
many metres thick, of dead plant and animal remains.
- Mycorrhizae and plant growth
Fungi are vitally important for the good growth of most plants, including crops, through
the development of mycorrhizal associations. As
plants are at the base of most food chains, if their growth was limited, all animal life,
including human, would be seriously reduced through starvation.
- Food
Fungi are also important directly as food for humans. Many mushrooms are edible and
different species are cultivated for sale worldwide. While this is a very small proportion
of the actual food that we eat, fungi are also widely used in the production of many foods
and drinks. These include cheeses, beer and wine, bread, some cakes, and some soya bean
products.
While a great many wild fungi are edible, it can be difficult to correctly identify them.
Some mushrooms are deadly if they are eaten. Fungi with names such as 'Destroying Angel'
and 'Death Cap' give us some indication that it would not be a terribly good idea to eat
them! In some countries, collecting wild mushrooms to eat is a popular activity. It is
always wise to be totally sure that what you have collected is edible and not a poisonous
look-a-like.
- Medicines
Penicillin, perhaps the most famous of all antibiotic drugs, is derived from a
common fungus called Penicillium. Many other fungi also produce antibiotic
substances, which are now widely used to control diseases in human and animal populations.
The discovery of antibiotics revolutionized health care worldwide.
Some fungi which parasitise caterpillars have also been traditionally used as medicines.
The Chinese have used a particular caterpillar fungus as a tonic for hundreds of years.
Certain chemical compounds isolated from the fungus may prove to be useful treatments for
certain types of cancer.
A fungus which parasitises Rye crops causes a disease known as Ergot. The fungus can occur
on a variety of grasses. It produces small hard structures, known as sclerotia. These
sclerotia can cause poisoning in humans and animals which have eaten infected material.
However, these same sclerotia are also the source of a powerful and important drug which
has uses in childbirth.
- Biocontrol
Fungi such as the Chinese caterpillar fungus, which parasitise insects, can be
extremely useful for controlling insect pests of crops. The
spores of the fungi are sprayed on the crop pests. Fungi have been used to control
Colorado potato beetles, which can devastate potato crops. Spittlebugs, leaf hoppers and
citrus rust mites are some of the other insect pests which have been controlled using
fungi. This method is generally cheaper and less damaging to the environment than using
chemical pesticides.
- Crop Diseases
Fungal parasites may be useful in biocontrol, but they can also have enormous negative
consequences for crop production. Some fungi are parasites of plants. Most of our common
crop plants are susceptible to fungal attack of one kind or another. Spore production and
dispersal is enormously efficient in fungi and plants of the same species crowded together
in fields are ripe for attack. Fungal diseases can on occasion result in the loss of
entire crops if they are not treated with antifungal agents.
- Animal Disease
Fungi can also parasitise domestic animals causing diseases, but this is not usually a
major economic problem. A wide range of fungi also live on and in humans, but most coexist
harmlessly. Athletes foot and Candida infections are examples of human fungal infections.
- Food Spoilage
It has already been noted that fungi play a major role in recycling organic
material. The fungi which make our bread and jam go mouldy are only recycling organic
matter, even though in this case, we would prefer that it didn't happen! Fungal damage can
be responsible for large losses of stored food, particularly food which contains any
moisture. Dry grains can usually be stored successfully, but the minute they become damp,
moulds are likely to render them inedible. This is obviously a problem where large
quantities of food are being produced seasonally and then require storage until they are
needed.
Looking at the above list, it
is clear that fungi play a role in just about every part of our daily lives! |
