Microbes in Human Welfare

Notes

Introduction

Microbes (Microorganisms) are microscopic organisms that cannot be seen with the naked eye. They include bacteria, fungi, viruses, algae, protozoa, and archaea.

Although some microbes cause diseases, many are beneficial and play an important role in food production, industrial products, medicines, sewage treatment, biogas production, agriculture, and environmental management.

Examples of Useful Microbes

Bacteria

Fungi (Yeast)

Cyanobacteria

Actinomycetes

Methanogens

Uses of Microbes in Human Welfare

Microbes are used in:

Household Products

Industrial Products

Antibiotics

Chemicals, Enzymes & Bioactive Molecules

Sewage Treatment

Biogas Production

Biocontrol Agents

Biofertilizers

I. Microbes in Household Products

1. Curd Formation

Organism

Lactobacillus (Lactic Acid Bacteria - LAB)

Process

Converts lactose into lactic acid.

Lactic acid coagulates milk proteins, converting milk into curd.

Importance

Improves digestion.

Increases Vitamin B12 content.

Prevents harmful microbes in intestine.

Board Point: LAB are probiotic bacteria.

2. Dough Fermentation

Organism

Saccharomyces cerevisiae (Baker's yeast)

Products

Bread

Cake

Idli

Dosa

Bhatura

Process

Yeast ferments sugar and releases:

Carbon dioxide (CO₂)

Alcohol (small amount)

CO₂ makes dough soft and fluffy.

3. Fermented Beverages

Organism

Yeast

Products

Wine

Beer

Whisky

Rum

Process

Alcoholic fermentation converts sugar into ethanol.

II. Microbes in Industrial Products

Industries use microbes to produce valuable products.

Fermented Beverages

Microbe

Saccharomyces cerevisiae

Produces

Ethanol

Wine

Beer

Organic Acids

Acid Microbe

Citric Acid Aspergillus niger

Acetic Acid Acetobacter aceti

Lactic Acid Lactobacillus

Enzymes:

Enzyme Microbe

Lipase Candida

Pectinase Aspergillus

Protease Bacillus

Uses:

Detergents

Fruit juice clarification

Leather industry

III. Antibiotics

Definition

Chemical substances produced by microorganisms that kill or inhibit harmful bacteria.

Discovery

Alexander Fleming (1928)

Discovered Penicillin from

Penicillium notatum

Common Antibiotics:

Antibiotic Produced By

Penicillin Penicillium

Streptomycin Streptomyces

Tetracycline Streptomyces

Uses

Pneumonia

Typhoid

Tuberculosis

Skin infections

IV. Chemicals, Enzymes & Bioactive Molecules

Streptokinase

Produced by

Streptococcus

Use

Dissolves blood clots.

Called:

Clot Buster

Cyclosporin A

Produced by

Trichoderma polysporum

Uses

Immunosuppressant

Organ transplantation

Statins

Produced by

Monascus purpureus

Uses

Reduces blood cholesterol.

V. Sewage Treatment

Sewage

Wastewater from homes…