IMPORTANCE & LOSSES OF FUNGI

IMPORTANCE & LOSSES OF FUNGI

IMPORTANCE OF FUNGI

Ecological Importance: Fungi have great ecological importance. They are very important as decomposer and symbionts.

1. The decomposing fungi (with bacteria) play an important role in the recycling of inorganic nutrients in the ecosystem. All the essential nutrients will accumulate in the form of dead bodies of animals and plants without decomposers. So these nutrients will be unavailable for the use of organisms. It will end life on earth.

2. Mycorrhizal fungi improve the growth of the plants. 95 % of all kinds of vascular plants have this association.

3. Lichens grow on rocks. They break the rock and make it suitable of

ecological succession.

4. Lichen are very good bioindicators of air quality as they are very sensitive to pollution.

5. Some fungi are used for bioremediation. They degrade the environmental pollutants. Bioremediation means degrading or removing environmental poisons/ pollutants by organisms.

COMMERCIAL IMPORTANCE

Fungi cause economic gains and losses.

Economic Gains Due to Fungi

1. Edible fungi

Certain fungi are edible. About 200 species of mushrooms (Agaricus sp.) are used as food. For example:

➤ Morels: e. g. Morchella esculenta.

➤ Truffles: Underground fruiting bodies of some Ascomycetes, e. g. Tuber sp).

➤ Reindeer moss (lichen) is used as food for reindeer and some other animals in arctic sub arctic or boreal regions (conifer forests). Some mushrooms are poisonous. The poisonous mushrooms are called toadstools, e. g. death cap/death angel (Amanita) and Jack-O' lantern.

2. Use in food industry 

Certain fungi are used in food industry.

➤ Yeasts can cause fermentation. So yeasts (Saccharomyces cerevisiae) are

used in production of bread and liquor.

➤ Pencillium species are used for giving flavour, aroma and characteristic colour to some cheese.

➤ Some species of Aspergillus are used for fermenting and producing soya sauce and soya paste from soya beans.

➤ Citric acid is also obtained from some Aspergillus species.

3. Antibiotics and other drugs

Some fungi are source of antibiotics and other drugs.

➤ Penicillin was first antibiotic. It was discovered by A. Fleming in 1928. Penicillin is obtained from Pencillium notatum.

➤ Lovastatin is used for lowering the blood cholesterol.

➤ Cyclosporine is obtained from soil fungus. It is used in organ transplantation (like kidney). It prevents the transplant rejection.

➤ Ergotine is used to relieve headache by migraine.

➤ Griseofulvin is used to inhibit fungal growth.

4. Natural dyes

Some natural dyes are obtained from lichens. These are used in textile industry.

5. Use in biological research

Some fungi are use in biological research:

➤ Yeasts are used in genetic and biological research. Yeasts produce new generations rapidly. They increase the genetic pool (total genes) and biochemical information.
➤ Yeasts were the first eukaryote which was used in genetic engineering. In 1983, functional artificial chromosome was made in Saccharomyces cerevisiae. The same yeast was the first eukaryote whose genomic sequence was completely studied in 1996.
➤ Yeasts are being studied for the production of some hormones.
➤ Neurospora (pink mold) has been used for genetic research.

Economic Losses Due to Fungi

1.  Plant diseases

Fungi produce several enzymes that can breakdown cellulose, lignin and cutin. Thus fungi cause many serious plant diseases. They can affect all the plants.

➤ Rust and Smuts: These diseases have caused extensive damages in wheat,

corn and rice crops. So it has caused massive displacement, starvation and death of many people.

➤ Powdery mildew on grapes, rose, wheat etc.

➤ Ergot of rye.

➤ Red rot of sugar cane.

➤ Potato wilt. 

➤ Cotton root rot .

➤  Apple scab.

➤ Brown rot in peaches, plums, apricots and cherries.

2.  Animal diseases

Fungi also cause certain animal disease:

(i) Ringworm and Athlete's foot: These are common infectious disease of fungi. These diseases are caused by certain imperfect fungi.

(ii) Candidiasis or candidosis: These are oral or vaginal thrush. These are caused by Candida albicans.

(iii) Histoplasmosis: It is a serious infection of lungs. It is caused by inhaling spores of a fungus. This fungus is common in soil contaminated with bird's feces. Sometimes, this infection may spread into blood stream and then to other organs. In this case, it may be serious and fatal,

(iv) Aspergillosis: It is also a lung infection. It is caused by Aspergillus fumigatus. This disease is caused only in persons with defective immune system as AIDS. It may cause death. 

(v) Aflatoxins: Aflatoxin 'is a myotoxin, i. e. a toxin produced by fungi Aspergillus flavus Aflatoxins are carcinogenic. Aspergillus contaminates improperly stored grains like peanuts and corn etc, milk, egg and meat. These infected things may have some traces of aflatoxins.

(vi) Ergotism: It is caused by eating bread, made from purple ergot- contaminated rye flour. The poisonous material in the ergot causes nervous spasm.  Convulsion, psychotic delusion and gangrene (decay of tissues due to stoppage of blood supply.

Saprophytic fungi

One hand the saprophytic fungi are useful recycler. But on the other hand, they decompose the food, wood, fibres, leather and cause severe damages.

➤ 15 to 50% of world's fruit is lost each year due to fungal attacks.

➤ They cause wood rotting. Fungi destroy living trees and structural wood. Bracket or shelf fungi damages the stored cut lumber and stands of timber of living trees. 

➤ pink yeast (Rhodotorula) grows on shower curtains and other moist surfaces.