MICROORGANISMS : FRIEND AND FOE | Class 8 Science Notes

Are Microorganisms Useful?

Microorganisms are extremely useful to humans and the environment. They play a vital role in processes such as decomposition, nitrogen fixation, and food production. Decomposers like bacteria and fungi break down dead plants and animals, returning nutrients to the soil, which supports plant growth. Certain bacteria convert atmospheric nitrogen into forms usable by plants, a process called nitrogen fixation. Microorganisms are also used in the production of medicines like antibiotics, vaccines, and enzymes. In the food industry, yeast is used to make bread rise, and bacteria are used in the production of curd, cheese, and vinegar. Moreover, microorganisms help in cleaning the environment by degrading pollutants in sewage treatment plants. This section elaborates on the beneficial roles of microorganisms in nature and human welfare.

📊 Diagram: Diagram showing nitrogen fixation by Rhizobium bacteria in root nodules of leguminous plants and the role of yeast in bread making.

🧪 Activity: Preparation of curd at home to observe the role of bacteria in food production.

🔗 Connection: This section connects to the next, which discusses the harmful effects of microorganisms, providing a balanced view of their impact.