Class 12 Biology Chapter 8 Microbes in Human Welfare Notes (Short and Handwritten Notes PDF)

Hi students,

If you are a class 12 student and looking for a nice and simple notes for chapter 8 “Microbes in Human Welfare” then you are at the right place. This chapter is very important for board exams, and our notes will make your preparation extremely easy.

These notes are specially created by analyzing NCERT latest syllabus and last 10 years board exam question papers.

In this article, we have given complete notes of Class 12 Biology Chapter 8 Microbes in Human Welfare (NCERT Class 12 Biology). In this note, every point is written in easy language so that you can understand this lesson easily. This note is based on NCERT. That is, this note is useful for all those children who study NCERT in English medium.

Here we have given the Notes in PDF format which you can download so that you can print it and save your time. To download, click on the given Download PDF link.

Microbes in Human Welfare Notes PDF Download

Important topics covered in the notes

• Microbes in Household Products
  • Production of curd, cheese, and other fermented foods.
  • Use of microbes in making bread.
  • Traditional drinks and foods.
• Antibiotics
  • The discovery of Penicillin.
• Chemicals, Enzymes and other Bioactive Molecules
  • Production of organic acids (Citric acid, etc.).
  • Production of alcohol.
  • Enzymes (Lipases, Proteases, etc.).
  • Bioactive molecules (Cyclosporin A, Statins).
• Microbes in Sewage Treatment
  • Primary treatment.
  • Secondary treatment or Biological treatment.
  • Activated sludge.
• Microbes in Production of Biogas
  • Biogas plant.
  • Methanogens.
• Microbes as Biocontrol Agents
  • Biological control of pests and diseases.
  • Examples: Bacillus thuringiensis, Trichoderma, Baculoviruses.
• Microbes as Biofertilisers
  • Bacteria (e.g., Rhizobium).
  • Fungi (e.g., Mycorrhiza).
  • Cyanobacteria.

Microbes in Human Welfare Notes- lesson summary

1. Microbes: Microbes are the major components of biological systems on this earth.
2. Microbes in household products
   • Production of curd
   • Fermentation
   • Production of cheese
3. Microbes in industrial products: Production on an industrial scale, requires growing microbes in very large vessels called fermenters
4. Fermented beverages: Microbes are used for the production of beverages like wine, beer, whiskey, brandy or rum.
5. Antibiotics: Antibiotics are the chemical substances which are produced by some microbes and can kill or stop the growth of other microbes.
6. Microbes in sewage treatment: Municipal waste-water which contains large amounts of organic matter is called sewage. Sewage treatment is carried out in two stages.
7. Microbes in the production of biogas: Biogas is a mixture of gases (containing predominantly methane) produced by the microbial activity.
8. Microbes as biocontrol agents: Biocontrol refers to the use of biological methods for controlling plant diseases and pests.
9. Microbes as biofertilizers: Biofertilizers are organisms that enrich the nutrient quality of the soil.
10. Some microbes used as biofertilizers are
    • Rhizobium from root nodules in leguminous plants and fix atmospheric nitrogen into organic forms, which is used by the plant as a nutrient
    • Free living bacteria like Azospirilium and Azotobacter fix atmospheric nitrogen, hence increasing nitrogen content of the soil.

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