Biology Notes on Microbes – For Class 12th Students (Grade A+)

Summary:

Microbes are major components of the biological system and are found almost everywhere. They contribute to various sectors, such as household and industrial products. Lactic acid bacteria, such as Lactobacillus, convert milk into curd and dough into bread. They are also instrumental in producing various cheeses, alcoholic beverages, and antibiotics. In industry, microbes are harnessed for their chemical-producing abilities, such as the production of citric, acetic, lactic, and butyric acids, as well as enzymes useful in detergent formulations and medical applications.

They are also essential in sewage treatment and are used in biogas production, particularly in rural areas. Microbes are utilised as biocontrol agents, employed in agricultural pest and disease control, and promoting organic farming practices. This is seen in using certain bacteria, beetles, and viruses to manage pests.

Microbes also function as biofertilizers, enriching the soil’s nutrient quality. This is exemplified in the symbiotic relationships between certain bacteria and the roots of leguminous plants, which fix atmospheric nitrogen into organic form. Similarly, the symbiosis between higher plant roots and fungi helps synthesize food and absorb nutrients. Cyanobacteria are autotrophic microbes that enrich soil nutrients, reducing dependence on chemical fertilizers.

Excerpt:

Biology Notes on Microbes

Microbes in Human Welfare
MICROBES: Major Component of Biological system
↓
Are Diverse
1. microscopic animals & Plant viruses
2. Viroids.
3. Prions (proteinaceous Infectious agent)
4. Fungi
5. Protozoa

Present Everywhere :
– Soil
– Aater
– Air
– Inside our bodies
– Other plants & Animals
– Deep inside Geysers
– Deep in the soil
– Under a layer of Snow
– Highly acidic Environment

Bacteria+Many fungi→Grown on Nutritive media
↓
Form Colonies
Microbes in Household Products:
Lactic acid bacteria Eg : Lactobacillus
Converts milk → Curd
Produces acid → Coagulates & partially Digests milk
Improves Nutritional quantity of Vitamin B12
In the stomach, checks disease-causing microbes

DOUGH
~Used to make IDLI & DOSA
~Fermented by Bacteria
~Puffed Up→Due to production on CO2 Gas