Economic importance of fungi SMG

A general account of economic importance of Fungi

1. ECONOMIC IMPORTANCE OF FUNGI Dr. Saji Mariam George Associate Professor Assumption College Autonomous Changanacherry .

2. ECONOMIC IMPORTANCE OF FUNGI Fungi are achlorophyllous thallophytes . They are eukaryotic organisms Include unicellular Yeasts and multicellular , filamentous Moulds . Fungi has both beneficial & harmful aspects

3. I : Beneficial aspects of Fungi 1 ) Edible fungi (Fungi as source of food) i ) Mushrooms Fleshy fruiting bodies of higher Fungi Ascomycetes and Basidiomycetes . Some mushrooms are edible – contain high amounts of proteins, vitamins, carbohydrates, minerals, dietary fiber , aminoacids etc. e.g. Agaricus bisporus (Button mushroom) Agaricus campestris (Field Mushrooms) Pleurotus ostreatus (Oyster mushrooms) Calocybe   indica (Milky mushroom) Volvariella volvacea (Paddy straw mush room) Morchella esculenta (Morels) Tuber melanosporum (Black truffle) Lentinula edodes (Shiitake ) etc.

4. Agaricus bisporus (Button mushroom) Agaricus campestris (Field Mushroom) Image: https://www.mykotroph.com/agaricus-bisporus-en.html

5. Pleurotus ostreatus ( Oyster mushrooms) Image:https :// www.healthbenefitstimes.com /oyster-mushroom/ Calocybe   indica (Milky mushroom)

6. Volvariella volvacea (Paddy straw mush room) Morchella esculenta ( Morels)

7. Tuber melanosporum (Black truffle) Lentinula edodes ( Shiitake )

8. ii ) Yeasts Important sources of proteins, vitamins D and B complex . E.g. Saccharomyces cerevisiae (baker’s yeast, brewer's yeasts ) Yeasts have health-promoting effects due to their rich vitamin (especially B-complex) and mineral content, as well as their role in the production of microbial proteins. Yeasts are used to leaven bread and dough for various food items.

9. iii ) Fungi as Single Cell Protein Dried biomass of certain fungi are consumed as a protein source. Such fungal biomass is called fungal protein or mycoprotein . Many yeasts are consumed as single cell protein e.g. Saccharomyces cerevisiae , Candida utilis , Torulopsis etc. Quorn  , a meat substitute product contain mycoprotein as an ingredient , which is derived from the fungus Fusarium venenatum .

10. iv ) Mouldy cheeses e.g. - Blue cheese contain the mold Penicillium . E.g. Roquefort  cheese contain Penicillium roqueforti Camembert cheese contain P.  camemberti .   Image:https ://www.pinterest.com/pin/546835579734865020/

11. v ) Fermented foods : e.g. Tempeh - legume seeds with  Rhizopus oligosporus Tempeh bean balls [ Photograph: FotoosVanRobin on Flickr ]

12. Miso - fermented soybean paste with Aspergillus oryzae . 

13. 2. Fungi in Industry i ) Fungi in Brewery : Yeasts , Saccharomyces cerevisiae is used in Brewing for the production of Beer, Wine etc. ii) Fungi in Baking : S. cerevisiae is also used in baking industry for the production of several bakery products like bread , cake etc. Fermentation of carbohydrates by yeast produce ethyl alcohol and carbon dioxide which help in leavening the batter. iii) Fungi in cheese industry : Penicillium roqueforti and Penicillium camemberti are used in the production of cheese (Roquefort cheese and camembert cheese). Both proteolytic and lipolytic enzymes produced by the fungus help in cheese ripening and give distinct flavor. iv) Thamnidium elegans is used industrially for improving the taste and tenderness of beef.

14. v) Fungi in commercial production of Single cell protein : Yeasts , Saccharomyces cerevisiae , Candida utilis , Candida lipolytica   etc. are used for the production of single cell protein. vi) Industrial production of organic acids : Citric acid : Produced by fermenting sucrose and molasses by Aspergillus niger and A. wentii . Itaconic acid : Produced by fermentation of sugars by Aspergillus itaconium , A. terreus etc. Gluconic acid : Produced by fermenting sugars by Aspergillus niger and Penicillium purpurogenum .

15. Kojic acid : Produced by the fermentation of sugars by Aspergillus oryzae Gallic acid : Produced by hydrolysis of gallotannin of gallnuts (or nutgalls) - is a plant excretion produced when irritants are released by the larvae of gall insects - by Penicillium glaucum and Aspergillus gallomyces . Fumaric acid : Produced by the fermentation of sugars by Rhizopus stolonifer . Lactic acid , oxalic acid , Succinic acid : Some species of Mucor , Rhizopus etc. are used in the production of Lactic acid, oxalic acid and Succinic acid .

16. vii) Fungi in industrial production of fermented foods : Tempeh - legume seeds with  Rhizopus oligosporus Miso - fermented soybean paste with Aspergillus oryzae . Soy sauce - Aspergillus oryzae or Aspergillus sojae are used in the industrial production of Soy sauce.

17. viii) Fungi in Antibiotic production : Penicillium notatum or Penicillium chrysogenum - used for the commercial production of antibiotic Penicillin. ix) Production of useful chemicals : Vitamins – B group of vitamins from Streptomyces , Mycorrhizha etc. Glycerol – produced from Aspergillus wentii Alkaloids – Ergotamine from Ergot fungus Claviceps purpurea . Plant hormones – Gibberellins from the fungus Gibberella fujikuroi .

18. x) Fungi in enzyme production : Invertase - Yeasts , Saccharomyces cerevisiae are used for the extraction of enzyme invertase which is used to hydrolyse sugars into glucose and fructose . It is used in confectionery and paper industries. Zymase - Yeasts , Saccharomyces cerevisiae are used for the extraction of enzyme Zymase which is used in the preparation of ethyl alcohol by the fermentation of carbohydrates. Amylase - Aspergillus niger and A. oryzae are used for the production of amylase used in alcohol industry. Cellulase – Trichoderma reesei is used for the production of cellulase used in the saccharification of cellulosic and lignocellulosic wastes. Fungi are also used in the production of other enzymes like lipases, pectinases , proteases etc.

19. xi) Fungi and pigment production : Penicillium chrysogenum exuding yellow pigment Chrysogine the same Penicillium chrysogenum colony, reverse side, exuding yellow chrysogenin pigment, an indicator Images: https://botit.botany.wisc.edu/toms_fungi/nov2003.html

20. Cercospora kikuchii produces a reddish – violet pigment called Neocercosporin Purple stain ( Cercospora kikuchii ) characteristic damage to soya seeds

21. A maroon pigment is obtained from Aspergillus fumigatus . A brown pigment Atromentin is obtained from Paxillus atromentosus . An yellow pigment Citrinin is obtained from Penicillium citrinin .

22. 3. Fungi in Medicine Many fungi are used to produce medically important substances. i ) Antibiotics : Antibacterial agents that inhibit their growth and multiplication. Penicillin - produced from Penicillium notatum or P. chrysogenum . – useful against most of the pathogenic bacteria - tonsillitis is caused by Streptococcus pyogenes , pneumonia , chronic bronchitis etc. Griseofulvin – produced from Penicillium griseofulvum - used to treat infections of the skin, scalp, nails, feet etc. Cephalosporins -produced from the fungus Cephalosporium acremonium – used to treat respiratory tract, skin and urinary tract infections.

23. Cyclosporin – from the fungus Tolypocladium inflatum   is widely used as an immunosuppressant and greatly improves the success rate of transplant operations. Gliotoxin from Aspergillus fumigatus regulate the immune system and may also be useful for postoperative management of transplant patients. Mevinolin – ( source of Statins ) produced by the fungus Aspergillus terreus acts as a cholesterol-lowering agent.

24. ii) Ergot alkaloids Produced by the ergot fungus Claviceps purpurea that infect Rye , Wheat etc. Ergot is the sclerotium of Claviceps purpurea Produce many alkaloids like Ergotinine , Ergotinic acid, Ergobasine , Ergotetrine , Lysergic Acid Diethylamide (LSD ) Image:http ://www.botany.hawaii.edu/faculty/wo ng/BOT135/LECT12.HTM

25. Lysergic Acid Diethylamide ( LSD) – a hallucinogen - therapeutic use as an anti -anxiety agent, the use  in actual practice warrants a lot of expertise, caution and ethical considerations. Ergonovine - used to hasten labor and prevent postpartum bleeding. Ergotamine- is a powerful vasoconstrictor, which constricts the blood vessels and thus the blood flow - useful in migraine.  

26. Ergotism - the effect of long-term ergot poisoning due to the ingestion of the alkaloids produced by the fungus Claviceps purpurea   in humans and other mammals who consume grains contaminated with its fruiting structure. Ergotism may cause strange hallucinations, the feeling of itchy and burning skin, gangrene(localized death and decomposition of body tissue, resulting from obstructed circulation)  and even death. In low and controlled concentrations Ergot alkaloids can be used as drugs - result in dilation of veins and reduction in blood pressure as well as contraction of smooth muscles.

27. iii) Antitumour agents Shiitake mushroom- ( Lentinula edodes ) contain a polysaccharide lentinan – has anti- tumour potential. Ganoderma lucidum – has polysaccharides that have anticancerous activity. Dietary intake of mushrooms can enhance the immune response of the human body. Ganoderma lucidum

28. iv) Vitamins Saccharomyces cerevisiae produce vitamin B complex . Rhodotorula gracilis  (unicellular pigmented yeasts). produce Vitamin A . Eremothemium ashbyii produce vitamin B 2, B 12 Synthesis of B-group vitamins by mycorrhizal  fungi. The vitamin produced in largest amounts by the mycorrhizal  fungi was thiamin (vitamin B1). Production of vitamin B 12  by various strains of Actinomycetes . Ergosterol , a precursor of vitamin D is synthesized by some yeasts and moulds.

29. v) Production of Steroids : Steroid like cortisone is produced by Aspergillus niger from plant glycosides by fermentation. vi) Yeast mediated synthesis of the L-ephedrine precursor, L- phenylacetylcarbinol - important pharmaceutical products commonly found in anti-asthmatic formulations, nasal decongestant mixtures and sinus preparations.

30. 4. Fungi in Agriculture Fungi play an important role in Agriculture. i ) Fungi as decomposers : Saprophytic fungi secrete enzymes and decompose dead remains of plants and animals . Hence they are called as ‘vegetative vultures of Plant Kingdom.’ During this process, complex organic compounds like cellulose, hemicelluloses, chitin, pectin, lignin etc. are degraded by fungi and produce humus , a nutrient rich material . The humus help to maintain the physical and chemical properties of soil, increases soil fertility and promotes various biological activities in the soil.

31. ii) Fungi as biocontrol agents Some fungi play an important role in the biological control of pests. Trichoderma harzianum is used to control the blight of tomato Blight of tomato(caused by Alternaria solani ) Image: https://www.veggiegardener.com/tips-for-preventing-and-treating-tomato-blights/

32. Trichoderma harzianum is used to control the blight of peanut (ground nut) caused by Sclerotium rolfsii The fungus Gliocladium roseum is used to control white mould , Sclerotinia diseases Blight of Peanut (caused by Sclerotium rolfsii ) Image :uploaded by  Jason E. Woodward

33. Trichoderma lignorum suppresses the growth of the root rot fungus Pythium . Growth of Rhizoctonia solani can be checked by Penicillium vermiculatum .

34. iii) Myconematicide Populations of the cereal cyst nematode may be controlled by two fungi,  Nematophthora gynophila  and  Verticillium chlamydosporium The fungus Nematophthora gynophilia heavily parasitizes the cyst of Heterodera avenae

35. iv) Entomogenous fungi or entomopathogenic fungi (means ‘growing on or in the bodies of insects’) as biocontrol agents. The fungus Beauveria bassiana can be used as a biocontrol agent to control Colorado potato beetle. Image: https://www.codiferro.it/en/beauveria-bassiana-2/ Image: http://www.potatobeetle.org/overview.html

36. The fungus Metarhizium anisopliae as biocontrol agents to control Rhinoceros beetle and Black rice bug. Image: http://www.iucngisd.org/gisd/species.php?sc=173

37. v)Fungi in mycorrhizal association Mycorrhiza is the symbiotic association of some soil fungi with the root system of higher plants. Some plants ( e.g Orchids) can not thrive without mycorrhizal association. Mycorrhizal association helps to enhance the water holding capacity of soil - increase the area of contact of the roots of the plant with the soil and thereby enhances the uptake of water - improve resistance against high temperature, drought etc. It also improves the uptake of nutrients such as Phosphorous - improves the over all growth and development of the host plant and may increase the yield to 30 – 40 % .

38. The secretion of hormones or antibiotic agents by mycorrhizae give better resistance to the host plant against various soil and root – borne pathogens. Plants with mycorrhizal associations also have better tolerance against salinity, heavy metal toxicity etc.

39. The extension of fungal hyphae into the soil makes the soil more compact and stable. Ectomycorrhizae are used in the establishment of trees in nurseries, in reforestation programs etc. Vesicular Arbuscular Mycorrhizae (VAM fungi) can be used as bioferilizers and hence is useful for reclamation of soil. (VAM fungi - are formed by the symbiotic association between certain phycomycetes and the root system of higher plants. The fungus colonizes the root cortex and form a mycelial network with bladder like vesicles and branched finger like arbuscules ).

40. 5. Fungi in Biological research ( Fungi as test organisms ) i ) Neurospora crassa A type of red bread mold Used in genetic studies because it is a haploid organism and make genetic analysis simple because recessive traits will be expressed in the offsprings . Analysis of genetic recombination (Tetrad analysis) is facilitated by the ordered arrangement ascospores formed after meiosis in the ascus .

41. Neurospora crassa Image: http://www.devbio.biology.gatech.edu/unicellular-model-organisms/neurospora-crassa/ Image: https://www.semanticscholar.org/paper/Neurospora-crassa Copyright  © 2000, W. H. Freeman and Company.

42. Beadle and Tatum proposed one gene, one enzyme hypothesis (one gene encodes one enzyme) based on genetic and biochemical studies on   Neurospora crassa . ii) Aspergillus niger Several strains of Aspergillus niger have been used as a test organism for determining Mg, Cu, Zn and Mo in soils. Image: https://www.timetoast.com/timelines/genetics-timeline--30

43. iii) Physarum polycephalum The slime mold Physarum polycephalum has been used as a model organism to study DNA synthesis, morphogenesis, mitotic cycle, amoeboid movement, cell motility etc .

44. iv) Saccharomyces cerevisiae The yeast  Saccharomyces cerevisiae  is used as a model organism for understanding cellular and molecular processes in eukaryotes. Yeast shares some genes with humans so can also be used to test new drugs. 

45. II. Harmful aspects of Fungi 1. Fungal diseases in plants Many parasitic fungi are pathogens which cause various diseases in plants and animals . i). Rust diseases Diseases caused by fungi of the order Pucciniales . e.g. Wheat stem rust, also known as black rust, is caused by the fungus  Puccinia graminis  . Wheat stem rust Image : https://www.ars.usda.gov/midwest-area/stpaul/cereal-disease-

46. Caused by the fungus Ustilago . It mainly infects inflorescence, flowers, anthers etc. The grains get filled with black powder of teliospores of the fungi. e.g. Loose smut of wheat caused by Ustilago tritici Covered smut of Barley - caused by Ustilago hordei . Grains are replaced by brown-black balls. ii ). Smut diseases

47. Loose smut of wheat caused by Ustilago tritici © 2015 TNAU. Covered smut of Barley by Ustilago hordei Image:https ://www.agric.wa.gov.au/mycrop/diagnosing-covered-smut-barley

48. Caused by several soil borne fungi. Rot diseases are characterised by plant decomposition and putrefaction. The decay may be hard, dry, spongy, watery or slimy and may affect any plant part. E.g. Root rot caused by Phytophthora sps , Pythium sps . Root rot of  Papaya caused by Pythium aphanidermatum  . iii ). Rot diseases

49. iv) . Blast diseases A common disease of paddy , Oryza sativa by the fungus Pyricularia oryzae . Lesions develop on leaf sheaths and on the stems. The weakened stems are easily broken. Image: https://www.greenlife.co.ke/rice-blast/

50. . v). Blight diseases Blight diseases are characterized by a rapid and complete chlorosis , browning and death of plant tissues such as leaves, branches, twigs or floral organs. e.g. Late blight of potato caused by Phytophthora infestans , the disease which led to the great Irish famine. Image:https ://onvegetables.com/2018/08/17/  (©2019 DPIRD) https://www.agric.wa.gov.au/plant-biosecurity/ Andrew Taylor

51. Powdery mildew is caused by fungi of the order Erysiphales . Infected leaves get covered with a white to gray powdery growth. e.g. Powdery mildew of wheat caused by Erisiphae graminis Powdery mildew of peas caused by Erisiphae polygoni . vi) Powdery mildew

52. Powdery mildew of wheat caused by Erisiphae graminis (Photo: Alfredo Martinez.) Image: https://extension.uga.edu/ Powdery mildew of peas caused by Erisiphae polygoni . Image:   Nigel Cattlin   / Alamy  Stock Photohttps://www.alamy.com/powdery-mildew-erysiphe-polygoni-i

53. vii ) White rust of Crucifers White rust is a disease in plants caused by the fungus Albugo candida  . Symptoms  include  chlorosis  on leaf surfaces, whiteblister -like growths on the underside of leaves and on the stems of the plant, and swelling of the roots. Study Solutions  Copyright © 2019. http://istudy.pk/white-rust-of-crucifers/

54. 2. Fungal diseases in humans Candidiasis Caused by the yeast Candida , the most common of which is   Candida  albicans . Can occur in the mouth and throat, vagina or blood stream. Symptoms of  candidiasis  vary depending on the area of the body that is infected. Candidiasis  that develops in the mouth or throat is called “thrush” or oropharyngeal   candidiasis . Its symptoms include white patches on the inner cheeks, tongue, roof of the mouth, and throat, redness or soreness, cottony feeling in the mouth, loss of taste, pain while eating or swallowing, cracking and redness at the corners of the mouth etc.

55. Candidiasis in the vagina is commonly referred to as a “yeast infection .” The symptoms include vaginal itching, pain or discomfort when urinating, abnormal vaginal discharge etc. In severe infections , redness, swelling, and cracks in the wall of the vagina may occur. Invasive candidiasis  occurs when  Candida  species enter the bloodstream and spread throughout the body.

56. ii ). Athlete’s foot Athlete's foot ( Tinea pedis ) is a fungal infection caused by Trichophyton rubrum that usually begins between the toes. It commonly occurs in people whose feet have become very sweaty while confined within tightfitting shoes. Symptoms  include a scaly rash that usually causes itching, stinging and burning. This  fungal infection is called athlete’s foot because it is commonly seen in athletes.

57. iii ) Ringworm ( Tinea corporis ) This is a common fungal skin infection that looks like a circular rash. Trichophyton , Microsporum , and Epidermophyton are the most common genera of fungi that cause ringworm in humans. Usually occur on the skin of the arms and legs or any part of the body.

58. iv ) Aspergillosis Aspergillosis is  caused by the fungus   Aspergillus . Symptoms include allergic reactions, lung infections, and infections in other organs. Usually occurs in people with weakened immune system.

59. 3. Fungal toxins ( Mycotoxins ) Many fungi produce toxins called mycotoxins (fungal poisons) . Mycotoxins may be food toxins, ergot toxins and mushroom toxins. Food toxins a ) Aflatoxins Toxins produced by Aspergillus flavus , A. fumigatus , Penicillium islandicum . They infect dried food and Ground nut . Cause liver cancer in animals including humans. Carcinogens.

60. b ) Ochratoxins produced by Aspergillus ochraceus and Penicillium viridicatum Infect stored maize, pea nuts, beans etc. Causes tubular necrosis of the kidney, mild degeneration of the liver etc . c) Zearalenone Produced by Fusarium graminearum and F. moniliforme growing in maize. Cause estrogenic symptoms in pigs.

61. d) Trichothecenes Produced by Cephalosporium sps ., Fusarium sps . Trichoderma sps . Cause severe local irritation, inflammation, sub – epidermal haemorrhage and general necrosis .

62. ii ) Ergot toxins Ergot, the sclerotia of Claviceps purpurea contain poisonous alkaloids called ergot toxins – Ergotamine, Ergometrimine , Ergocristine , Ergonovin . Ergot poisoning in humans cause diarrhoea , abdominal pain, vomiting etc. Also affects nerves and cause psychiatric disturbances.

63. iii ) Mushroom toxins. Occasionally, toxic mushrooms  are mistaken for edible species and human poisoning occurs. Mushroom poisoning (mushroom toxicity) occurs after the ingestion of mushrooms that contain toxins. Several mush rooms produce mycotoxins . Amanita phalloides , commonly known as the death cap, is a deadly poisonous basidiomycete fungus produce toxins - amatoxins , phallotoxins etc. The first symptoms are stomach pains, vomiting and diarrhoea . Death is caused by liver failure, often accompanied by kidney failure.

64. Helvella sps . is an ascomycetan fungus. It produces the toxin and carcinogen called Gyromitrin – It  is a gastrointestinal irritant and cause vomiting, abdominal pain and diarrhea, 6 –12 h after ingestion of the poisonous mushroom. Inocybe (Fiber caps) and Citocybe produce an toxin Muscarine , which can be dangerous if ingested.  Muscarine poisoning causes diarrhea, blurred vision, increased salivation, excessive  sweating, bradycardia (low heart rate )etc. Coprinus atramentarius  contains the heat-stable toxin coprine , which only causes toxicity when ethanol is consumed after the mushroom.

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