Useful & Harmful microbes

Study Material on useful and harmful Microbes for Class 8 NCERT Science

1. Food and Beverages Industry Lactobacillus – Is a Bacterium that sours milk and is used to make curd from milk . Starter curd multiplies and coverts the milk to curd . It is also used for making Cheese. Yeast - Fungus Used in making Bread , cake , Pastry.

2. Yeast is mixed with sugar for making the bread, bun , cakes etc. This breaks sugar to form alcohol and CO2 is given off. - This process is called as Fermentation The bubbles of CO2 makes the cake dough rise and Makes the cake fluffy and spongy. Same process occurs in Idly and Dhokla Batter Fermentation

3. Alcohol and Alcoholic Drinks Fermentation of Sugar with Yeast produces Alcohol which is used to make Beer and Wine. Wine : Sugar is obtained from Grapes Beer : Sugar is obtained from Barley . Algin : Obtained from Algae to make Jellies and Ice creams etc.

4. Medicines and Vaccines Bacteria & Fungi are used to make Antibiotics Antibiotics are medicines which kill or stop the growth the of disease causing Microbes. Examples are : Penicillin - Penicillium ( Algae) Streptomycin , Erythromycin ,Tetracycline (from Bacteria and Algae )

5. Vaccines Are dead and weakened microbes , they produce antibodies to fight against diseases like Typhoid, Tuberculosis, Hepatitis , small pox, chicken pox , measles , polio etc. Vaccination is also called as Immunization. Vitamin B capsules --- Bacteria & Yeast Insulin -- Bacteria

6. Agriculture & Eco system Rhizobium & Blue Green Algae – Nitrogen Fixing Environment Cleaning : Bacteria , Fungi and Protozoa – Decomposition of dead organism for their food Decomposition of Organic matter – Manure Decomposition of Sewage and Other waste water

7. Some Other Uses Help the animals to digest their food Tanning – In jute , leather Industries Bio Gas Production – Methane CH3

8. Harmful

9. Micro organism

10. Harmful Microorganisms They cause diseases --- Germs Pathogens is the scientific name of Germs. Disease is caused when pathogens enter our body .

11. Mode of Communication Cuts & Wounds

12. Carriers of Diseases Insects and Animals are the Carriers of Pathogens House Fly : Food Poisoning Female Anopheles mosquito- Malaria through the parasite of malaria called  Plasmodium Female Aedes mosquito - Dengu through the dengue virus called Flavivirus

13. Food Poisoning

14. Diseases Caused by Microorganisms in Animals Anthrax:  A dangerous disease that affects human and cattle is caused by a bacterium called  Bacillus Anthracis . Foot and mouth disease in Cattle: It is caused by a virus called  Foot-and-mouth-disease Virus  (FMDV) or Picornavirus .

15. Diseases Caused by Microorganisms in Plants

16. Plant Disease Microorganisms can cause diseases in plants and reduce crop yield.

17. Useful Information

18. By : Kalyani . S