Economic importance of fungi
- 1. Economic importance of Fungi. Vaishali S.Patil Professor, Department of Botany Shri Shivaji College of Arts, Commerce & Science Akola
- 2. 1. Role of Fungi in Medicine: Some fungi produce substances which help to cure diseases caused by the pathogenic microorganisms. These substances are called the antibiotics. The term antibiotic, therefore, denotes an organic substance, produced by a microorganism, which inhibits the growth of certain other microorganisms. The most important antibiotics are produced by the moulds, actinomycetes or bacteria. They are used to combat the evil effects of pathogenic bacteria and viruses. The use of antibiotics is not limited to disease treatment. The discovery of antibiotic agents as drugs is comparatively a recent history. The role of fungi producing antibiotic substances was first established by Sir Alexander Fleming in 1929. He extracted the great antibiotic drug Penicillin from Penicillium notatum.
- 3. 1.Penicillin was the first antibiotic to be widely used. Penicillin is an organic substance lethal to microbes. It is far more effective than ordinary drugs and germicides. It has no adverse effect on human protoplasm but kills bacteria especially gram-positive type.
- 4. 2.The addition to certain antibiotics in small amounts to the feed of slaughter animals promotes rapid growth and improves the quality of the meat products. 3. Application of an antibiotic to surface of freshly killed poultry preserves the fresh- killed taste during long periods of refrigeration. 4.Aureomycin, inhibit the growth of many pathogenic bacteria and are also used successfully in the treatment of various virus diseases. Many animal and human diseases which do not respond readily to other antibiotics are effectively cured by aureomycin.
- 5. 5. The plasmodia of certain species of Myxogastres have been reported to yield soluble antibiotics. These check the growth of certain bacteria and yeasts in culture. The antibiotics play an important role to combat plant diseases as well. 6. A numbers of antibiotics have also been extracted from Aspergillus cultures. 7.Griseofulvin which is recovered from mycelium of Penicillium griseofulvum and many other species has antifungal properties. It is effective against fungal skin diseases such as ringworms and athlete’s foot disease.
- 6. 8.Claviceps purpurea produces sclerotia in the ovaries of the flowers of grasses such as rye The sclerotium is called the ergot of rye. Ergot is used in veterinary and human medicine. It contains a mixture of alkaloids which cause rapid and powerful contractions of the uterus. The medicine is thus used to control bleeding during child birth. Ergot is highly poisonous. A derivative of ergot known by the name of lysergic acid (LSD) is used in experimental psychiatry. 9.The giant puff ball Clavatia contains an anti-cancer substance calvacin. The eating of these fungi prevents stomach tumours.
- 7. 2. Role of Fungi in Industry: (i) Alcoholic fermentation-(a) Brewing (Fermentation of sugar solutions by yeasts produces ethyl alcohol and carbon dioxide.) The yeasts secrete the enzyme complex called zymase which brings about conversion of sugar into alcohol. In producing industrial alcohol moulds are employed as starters to bring about scarification of the starch. They secrete a whole range of enzymes and thus bring about fermentation of complex carbohydrates.eg. Mucor racemosus, M, rouxii, Rhizopus sp., Aspergillus flavus. Carbon dioxide is also considered a valuable by-product. It is collected, solidified and sold as “dry ice”. (b) In the baking or bread- making industry CO2 is the useful product. It causes the dough to rise & makes the bread light.
- 8. (ii) Enzyme preparations: Various enzymes produced by Aspergillus flavus-oryzae. Digestin, Polyzime, Taka diastase, etc. are used for dextrinization of starch and desiring of textiles. Aspergillus niger and A. oryzae produces enzyme amylase. Invertase is extracted from Saccharoymces cerevisiae.
- 9. (iii) Preparation of organic acids: oxalic acid is the fermentation product of Aspergillus niger. citric acid is made by mould fermentation, eg Penicillium species. gluconic acid- The moulds chiefly employed for this purpose eg, Penicillium and Aspergillus. gallic acid is the fermentation product of an extract of tannin by Aspergillus gallomyces. fumaric acid is found bolete mushrooms (specifically Boletus fomentarius var. pseudo-igniarius), lichen.
- 10. (iv) Gibberellins: are plant hormones produced by the fungus Gibberella fujikuroi which cause a disease of rice accompanied by abnormal elongation. Gibberellin is used to accelerate growth of several horticultural crops. (v) Cheese Industry: (a) Camembert and Brie types. They are soft. The moulds concerned are Penicillium camemberti and P. caseicolum (b) Roquefort Gorgonzola and Stilton types. The moulds concerned are P. Roqueforti.
- 11. (vi) Manufacture of Proteins: The yeast (Saccharomyces cerevisiae and Candida utilis) contain high percentage of protein of great nutritive value. (vii) Vitamins: The yeasts, are the best source of vitamin B complex. A number of moulds and yeasts are utilised in the synthesis of Ergosterol which contains Vitamin D. Riboflavin—another vitamin useful both in human and animal food—is obtained from a filamentous yeast, Ashby gossypii.
- 12. (viii) Synthesize fat from carbohydrates: Endomyces vernalis, Penicillium javanicum and Oidium lactis have a high fat content. (ix) Antibiotics: Certain fungi form an important basis of fermentation of Cocaobeans. Lichens are used in dyes and reagents. Roccella lichen is used as an indicator to determine the acidity or alkalinity of a solution.
- 13. (X) Preparation of dyes- Pigment Fungus Atromentin Paxillus atromentosus Catenerin Heliminthosporium sp. Phoenicin Penicillium phoenicum Neocercosporin Cercospora kikuchi (xi)In commercial production of single cell protein- eg. Yeasts, Candida utilis, C. Lipolytica. (xii)Luminescences- Armillaria mellea have ability to produce visible light in the dark.
- 14. 3. Role of Fungi in Agriculture: A. Negative Role: They cause fungal diseases to crop, fruit and other economic plants and form tremendous economic losses. i) Damping off disease: eg. tomatoes, com, cotton, mustard, peas, beans, tobacco, spinach etc. caused by Pythium. ii) The potato blight: eg. Potato, egg plants, tomatoes, etc. caused by Phytophthora infestans. (iii) Downy mildews of grapes: eg. Grapes caused by Plasmopara viticola
- 15. (iv) Ergot disease of rye: eg.rye caused by Claviceps (v) Apple scab: eg. Apple .Caused by Venturia inaequalis
- 16. (vi) Brown rot of stone fruits: eg.apricots, cherries, plums and peaches caused by Monilinia fructicola (vii) Smut diseases of corn, wheat, oat and other cereal crops- caused by Ustilago nuda
- 17. (viii) Red rot disease of sugarcane: caused by Colletotrichum falcatum (ix) Rust diseases: black stem rust, yellow rust and orange rust of cereal crops and forest timber, caused by Puccinia graminis (x)Wilt and root rot of cotton: Fusarium oxysporum f. sp. vasinfectum, Rhizoctonia bataticola
- 21. 2.Destruction of timber: Caused by Polyporus, Serpula lacrymans, Fusarium negundi, Coniophora cerebella, Lentinus lapidens and Penicillium divaricatum 3. Destruction of textiles: Alternaria, Penicillum, Aspergillus, Mucor and Fusarium. Spp. Chaetomium globosum
- 22. 4.Leather goods are destroyed by fungi such as Aspergillus niger, Penicilium and Paecilomyces. 5. Rubber products are spoiled by Aspergillus candidus, A.niger, A.tereus and Penicillium sp. 6.Many fungi such as Aspergillus, Penicillum, Cladosporium, Pullularia are responsible for the mold spotting or discoloration of painted surfaces. 7. Amorphotheca resinae grow in storage tanks and fuel tanks of aircrafts containing kerosene based fuel.
- 23. 4. Destruction of Paper: Polyporus adustus, Polystictus hirsutus, Chaetomium, Aspergillus, Stachybotrys, Alternaria, Fusarium, C.dematium, Mucor, Cladosporium etc. 5.A few of the mushrooms are fatally poisonous, some cause only discomfort eg. Amanita.
- 24. B. Positive Role of Fungi: 1. soil fungi maintain the fertility of the soil. 2.Some saprophytic fungi particularly in acid soils where bacterial activity is at its minimum cause decay and decomposition of dead bodies of plants and their wastes taking up the complex organic compounds (cellulose and lignin) by secreting enzymes. 3.There are fungi in the soil which produce more ammonia from proteins than the ammonifying bacteria. 4.Many saprophytic fungi of decay maintain the never ending cycle of carbon dioxide which is a most important raw material for plant photosynthesis in nature. 5.They also bring about rot, decay and decomposition of animal and plant remains releasing plant nutrients in a form available to green plants as food. 6.The soil fungi utilize many inorganic salts.
- 25. 7.Some fungi prevented lost from the soil by leaching. 8. Some fungi form mycorrhizal association with the roots of certain plants and help them in their nutrition. 9.Many insect pests can be controlled by the growth of fungi such as Empusa sepulchrasis, Metarrhizium anisopliae, Cordyceps melothac etc. 10. Some common fungal inhabitants such as Trichoderma lignorum and Gliocladium fimbriatum of the soil help to combat diseases caused by soil borne fungi eg Pythium. 11. Some predacious fungi in the soil trap and destroy the nematodes (eel worms) such as Beauveria bassiana against borers, thrips, and aphids. Trichoderma viride and T. harzianum used against a large number of soil-borne pathogens. 12.Fungi are being tested as biopesticides especially as nematicides and as fungicides. 13. Some fungi, such as red bread mold, Neurospora sitophila and others, complete their sexual life cycle in a few days and thus make ideal organisms for the study of the laws of heredity. 14.The slime molds (Physarum polycephalum) are now widely used in research. P. polycephalum has proved an excellent experimental organism for the study of DNA synthesis, meiotic cycle and the mechanism of protoplasmic streaming. To detect the presence and quantity of vitamin B in given sample, Neurospora crassa is commonly used. 15. Aspergillus niger is used for detection of trace elements like zinc, nickel and copper.
- 26. 4. Role of Fungi as Food and as Food Producers: Positive role- About 2000 species of fungi are edible such as the field mushroom Agaricus campestris (dhingri), Podaxon podaxis (Khumb), the honey coloured mushrooms, the fairy ring mushrooms, the puff balls (Lycoperdon and Clavatia), morels (Morchella, guchhi), and truffles. They supply vitamins and are valuable as appetisers. Yeasts and some filamentous fungi are valuable sources of vitamins of the B- complex.
- 27. 2.Negative role- Many fungi are responsible for spoilage of food stuffs. a)Penicillium digitatum causes rotting of citrus fruits. b)Milk and milk products are spoiled and made unfit for human use due to the growth of several fungi such as Mucor, Aspergillus, Penicillium, Oidium and Fusarium. c) Mucor mucedo and spp. of Aspergillus grow on bread and spoil it. d) Oidium lactis develops the fishy odour of butter causing damage to the butter. e) Many fungi such as Mucor sp., Penicillium, Neurospora, Fusarium, Aspergillus etc., grow on meat causing sufficient spoilage. f) Aflatoxins the most potent carcinogenic agent-are produced by Aspergillus flavus, A. fumigatus, A. parasiticus and Penicillium islandicum on dried foods and groundnut meal.
- 28. g) Mushroom toxins are produced by several poisonous mushrooms. These cause diarrhoea vomiting, liver damage, complete unconsciousness etc. Mushroom toxins are commonly produced by Amanita phalloides, spp. of Helvella and some species of Inocybe. h) Ergot toxins produced by Claviceps purpurea cause diarrhoea, abdominal pain, vomiting and psychiatric disturbances.