ECONOMIC IMPORTANCE OF LICHENS (NEW).pptx

MSC 1st semester

1. ECONOMIC IMPORTANCE OF LICHENS ANJANA.K

2. Economic importance of lichens can be classified broadly into two broad categories A. Beneficial aspects B . Harmful aspects 1.

3. Ecological importance of lichen Lichens plays crucial roles in the ecology; it serves as a crucial component of many ecosystems. Some of the key ecological roles of lichens include Biodiversity : Lichens are adverse group of organisms that contribute to the overall biodiversity of an ecosystem. They are found in a wide range of habitats, including forests, tundra, and even urban environments.

4. 1.Lichens are indicators of pollution-free environment Lichens serve as indicators of air pollution Since lichens are very sensitive to environmental changes (pollution), their presence in an area indicate a pollution free environment. Lichens cannot survive in the areas air pollution due to the occurrence of sulphur dioxide . Thus, lichens can act as indicator species for monitoring air quality and other environmental parameters.

5. 2.Lichens are pioneer of ecological succession Lichens are the first serial community (pioneer community) in a xerarch succession . Sequence of stages in xerarch succession are as follows: Lichen stage → Moss stage → Herb stage → Shrub stage → Climax community Example: Caloplaca and Lecanora

6. Lichens assists in soil formation : Lichens release lichen acids which help in the weathering of rock and organic matter that leads to the formation of soil.

7. Lichens can fix atmospheric Nitrogen Lichen that contain cyanobacteria , are capable of fixing atmospheric nitrogen. Nitrogen fixation is essential for maintaining soil fertility.

8. Source of food Lichens have been used as a source of staple food, food colorant, and food preservative for centuries in some traditional cultures, particularly in arctic and sub-arctic regions. In some cultures, lichens are used as a staple food and are collected, dried, and stored for later use. Reindeer moss ( Cladonia rangiferina ) is a common food source for indigenous peoples in the Arctic and is eaten either raw or cooked. The thallus of Umbilicaria has been eaten in arctic regions in danger of striation.

9. Species of Lecanora have been used as food in Western Asia and Northern Africa. Parmelia is used as flavouring agent in some culinary preparations of South India. Some lichens are used as a flavor enhancer in some traditional dishes. Example: Iceland moss ( Cetraria islandica ) is used as a spice in Scandinavian and Icelandic cuisine. Some lichens are used as natural food colorants due to their bright and distinctive pigments.

10. Some lichens have antimicrobial properties , making them useful as natural food preservatives. Example : Usnic acid , extracted from Usnea , has been used to preserve cheese and other dairy products. In France lichen are used for making chocolates, pastries. Endocarpon miniatum used as vegetables.

11. Cetraria islandica (Ice land moss) Usnea

12. Medicinal Importance of Lichens Lichens also have been used for medicinal purposes for centuries in traditional medicine. Some of the most important medicinal uses of lichens are listed below Anti-inflammatory: Some lichens contain compounds that have anti- inflammatory effects, making them useful in the treatment of rheumatoid arthritis and inflammatory bowel disease . Example Parmelia , Usnea .

13. Antimicrobial: Lichens contain a variety of antimicrobial compounds, including usnic acid and barbatic acid, which are effective against many pathogenic bacteria. Anti-oxidant activity : Experimental evidence suggested that barbatic acid (extracted from Usnea and Cladonia ) has antioxidant properties. Anticancer : Some lichen compounds are promising for the treatment of various types of cancer, including breast and colon cancers. Example: Barbatic acid exhibits cytotoxic and genotoxic activity against some tumour cell lines and it has a pro-apoptotic property as well.

14. Wound healing : Lichens have been used for wound healing in traditional medicine. Immune system booster : Lichens have been shown to have immuno stimulatory effects, making them useful for boosting the immune system and preventing infections. Parmelia is used in snake and scorpion bites.

15. industrial uses Some of the most important industrial uses of lichens include 1.In tannin industry Cetraria icelandica , Lobaria pulmonaria used as tannin agent in leather industries. 2. I n fermentation and distillation process : In Russia, Sweden and Siberia liquors are manufactured by fermentation and distillation of lichen like Cladonia rangiferina and Ramalina fraxinea . 3.As culture media Lichens are important constituents of some culture media for the culture of fungi and bacteria in laboratories. 4.Lichens are good source of dyes : Lichens have been used for centuries as a source of natural dyes for textiles and other products

16. Litmus is a pH sensitive dye extracted from many species of Roccella , Lepra , Parmotrema and Parmelia . Litmus is used to test the pH. Orchil or Orcein is a bright purple dye extracted from Roccella tinctoria . Orchil is used to stain cloth and wood . Orchil can also stain chromosomes . Cudbear is a purple dye extracted from orchil lichens used for colouring wool and silk.

17. In cosmetic and perfumery In cosmetic : Lichens have been used as an ingredient in cosmetics and personal care products due to their antimicrobial properties Perfumery: Some lichens produce fragrant compounds that have been used in perfumery for centuries. For example, oakmoss ( Evernia prunastri ), a lichen that grows on oak trees, is a common ingredient in perfumes and fragrances.

18. Bioremediation : Lichens have been used in bioremediation, the process of using living organisms to clean up contaminated environments. Some lichen species are capable of breaking down toxic compounds, such as heavy metals, making them useful in the clean-up of contaminated sites.

19. (B) Harmful Aspects of Lichens Some of the most notable harmful aspects of lichens include: Allergic reactions : Some people can develop allergic reactions to lichens, especially when they are exposed to large amounts of airborne lichen spores. Symptoms of lichen allergies can include itching and sneezing Toxicity: Some lichen species contain toxic compounds, such as usnic acid, which can be harmful to humans and animals if ingested in large amounts. Ingestion of toxic lichens can cause a range of symptoms, including vomiting, diarrhea, and respiratory distress. Building damage : Some lichens can cause damage to buildings and other structures if they are allowed to grow unchecked. For example, lichens can break down roofing materials, cause discoloration of paints

20. Lichens cause loss of the surface of glasses and marble stones. Long threads of pendant lichens like Usnea are inflammable, thus help in spreading forest fire. Lichen like Cladonia cause total destruction to the colonies of mosses by direct parasitic attack.

21. Important questions Write a note on reproductive bodies of lichens. Explain thallus structure of lichen. Write note on classification of lichen. Write an account on asexual reproduction of lichen. Write an account on different groups of lichen based on thallus . Explain the vegetative propagates and economic importance. Write an account on systematic , thallus structure and ecological significance of lichen