Class 9
Created by Titas Mallick
Biology Teacher • M.Sc. Botany • B.Ed. • CTET (CBSE) • CISCE Examiner
Created by Titas Mallick
Biology Teacher • M.Sc. Botany • B.Ed. • CTET (CBSE) • CISCE Examiner
Note on Economic Importance of Bacteria
Bacteria are microscopic, single-celled organisms that are found everywhere on Earth. While they are often associated with diseases, bacteria play a crucial role in various aspects of our lives, both beneficial and harmful. Their economic importance stems from their diverse metabolic activities, which have been harnessed by humans for centuries in medicine, agriculture, and industry.
Bacteria are indispensable in the medical field, particularly in the production of vital substances that fight diseases.
Antibiotics: These are chemical substances produced by microorganisms (including bacteria) that can kill or inhibit the growth of other microorganisms. They are one of the most significant discoveries in medicine.
Serums: A serum is the clear, liquid part of blood that contains antibodies. In medicine, serums (or antisera) are prepared by injecting a specific antigen (like a toxin or a virus) into an animal (e.g., a horse). The animal's immune system produces antibodies against that antigen. The blood is then drawn, and the serum containing these antibodies is separated.
Vaccines: A vaccine is a biological preparation that provides active acquired immunity to a particular infectious disease. It typically contains a weakened or killed form of the disease-causing microorganism, its toxins, or one of its surface proteins.
Bacteria are vital for soil fertility and plant growth, primarily through their role in the Nitrogen Cycle. Nitrogen is an essential component of proteins and nucleic acids, but plants cannot use the abundant nitrogen gas (N₂) from the atmosphere directly.
Legumes and Soil Fertility Farmers often rotate crops with leguminous plants (like peas or clover) because the Rhizobium bacteria in their roots naturally enrich the soil with nitrogen, reducing the need for chemical fertilizers.
Bacteria's metabolic processes are harnessed in various industrial applications.
Curing of Tea: The characteristic flavor and aroma of cured tea leaves are developed through a fermentation process. After the leaves are harvested and withered, they are rolled to break the cells and release enzymes. Bacteria, such as Bacillus megaterium, then act on the leaves, causing chemical changes that produce the final product's unique qualities.
Tanning of Leather: Tanning is the process of treating animal hides and skins to produce leather. In the initial stages, hides are soaked in water to clean them and remove hair and flesh. Specific bacteria help in the decomposition of soft, non-collagenous proteins and fats, making the hide softer and more receptive to the tanning agents. This bacterial action is a crucial step in producing high-quality leather.
Bacteria are major culprits in food spoilage. They decompose the organic matter in food, leading to changes in taste, smell, and texture, making it unfit for consumption.
Pathogenic bacteria are a significant cause of diseases in living organisms.
Diseases in Humans:
Diseases in Plants:
A bio-weapon, or biological agent, is a microorganism (like a bacterium, virus, or fungus) or a toxin that is released deliberately to cause disease and death in humans, animals, or plants.
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