Microbes in Human Welfare

Key Concepts

Microbes in Household Products

Microbes or their products are part of our daily lives.

Benefits of LAB Lactic Acid Bacteria (LAB) not only convert milk to curd but also improve its nutritional quality by increasing Vitamin B12. In our stomach, LAB play a beneficial role in checking disease-causing microbes.

Curd: Lactobacillus (LAB - Lactic Acid Bacteria) converts milk to curd, increases Vitamin B12, and checks disease-causing microbes in the stomach.
Dough: Puffed-up appearance of dosa/idli dough is due to CO2 production by bacteria. Bread is fermented using Baker’s yeast (Saccharomyces cerevisiae).
Toddy: Traditional drink made by fermenting palm sap.
Cheese:
- Swiss Cheese: Large holes due to CO2 from Propionibacterium sharmanii.
- Roquefort Cheese: Ripened by specific fungi for flavour.

Microbes in Industrial Products

Requires large vessels called fermentors.

Fermented Beverages: Brewer’s yeast (S. cerevisiae) is used for ethanol production from malted cereals/fruit juices. (Distilled: Whisky, Brandy, Rum; Undistilled: Wine, Beer).
Antibiotics: Chemical substances produced by microbes to kill/retard other microbes.
- Penicillin: First antibiotic, discovered by Alexander Fleming (from Penicillium notatum). Chain and Florey established its full potential.
Chemicals and Enzymes:
- Citric Acid: Aspergillus niger (fungus).
- Acetic Acid: Acetobacter aceti (bacterium).
- Butyric Acid: Clostridium butylicum (bacterium).
- Lipases: Used in detergents (remove oil stains).
- Pectinases/Proteases: Clarify bottled fruit juices.
- Streptokinase: 'Clot buster' for heart attack patients.
Bioactive Molecules:
- Cyclosporin A: Immunosuppressive agent from Trichoderma polysporum.

How Statins Work Statins act by competitively inhibiting the enzyme responsible for synthesis of cholesterol. They are produced by the yeast Monascus purpureus.

Statins: Blood-cholesterol lowering agents from Monascus purpureus.

Microbes in Sewage Treatment

Primary Treatment: Physical removal of particles (filtration and sedimentation). Supernatant forms the effluent.
Secondary (Biological) Treatment:
- Effluent passed to aeration tanks; aerobic microbes form flocs.
- Microbes consume organic matter, reducing BOD (Biochemical Oxygen Demand).

Significance of BOD BOD refers to the amount of oxygen that would be consumed if all the organic matter in one liter of water were oxidized by bacteria. The greater the BOD of waste water, more is its polluting potential.

Greater BOD = More polluting potential.
Activated Sludge: Sedimented flocs.
Anaerobic Sludge Digesters: Anaerobic bacteria produce Biogas (CH4, H2S, CO2).

Microbes in Biogas Production

Methanogens: e.g., Methanobacterium. Produce methane anaerobically on cellulosic material.
Found in anaerobic sludge and the rumen of cattle (helps digest cellulose).
Biogas Plant: Uses cattle dung (gobar) to produce gas for cooking and lighting.

Microbes as Biocontrol Agents

Use of biological methods to control pests/diseases, reducing chemical use.

Bacillus thuringiensis (Bt): Controls butterfly caterpillars (toxin released in larvae gut).
Trichoderma: Free-living fungi in root ecosystems; control several plant pathogens.
Baculoviruses (Nucleopolyhedrovirus): Species-specific, narrow-spectrum insecticidal application; no harm to non-target organisms.

Microbes as Biofertilisers

Organisms that enrich soil nutrient quality.

Bacteria: Rhizobium (symbiotic in legume nodules), Azospirillum, Azotobacter (free-living).
Fungi: Glomus forms Mycorrhiza; absorbs phosphorus and provides resistance to root pathogens/drought.
Cyanobacteria: Anabaena, Nostoc, Oscillatoria. Fix atmospheric nitrogen, important in paddy fields.

Key Concepts

Microbes or their products are part of our daily lives.

Curd: Lactobacillus (LAB - Lactic Acid Bacteria) converts milk to curd, increases Vitamin B12, and checks disease-causing microbes in the stomach.

Dough: Puffed-up appearance of dosa/idli dough is due to CO2 production by bacteria. Bread is fermented using Baker’s yeast (Saccharomyces cerevisiae).

Toddy: Traditional drink made by fermenting palm sap.

Cheese:

Swiss Cheese: Large holes due to CO2 from Propionibacterium sharmanii.
Roquefort Cheese: Ripened by specific fungi for flavour.

Requires large vessels called fermentors.

Fermented Beverages: Brewer’s yeast (S. cerevisiae) is used for ethanol production from malted cereals/fruit juices. (Distilled: Whisky, Brandy, Rum; Undistilled: Wine, Beer).

Antibiotics: Chemical substances produced by microbes to kill/retard other microbes.

Penicillin: First antibiotic, discovered by Alexander Fleming (from Penicillium notatum). Chain and Florey established its full potential.

Chemicals and Enzymes:

Citric Acid: Aspergillus niger (fungus).
Acetic Acid: Acetobacter aceti (bacterium).
Butyric Acid: Clostridium butylicum (bacterium).
Lipases: Used in detergents (remove oil stains).
Pectinases/Proteases: Clarify bottled fruit juices.
Streptokinase: 'Clot buster' for heart attack patients.

Bioactive Molecules:

Cyclosporin A: Immunosuppressive agent from Trichoderma polysporum.

How Statins Work Statins act by competitively inhibiting the enzyme responsible for synthesis of cholesterol. They are produced by the yeast Monascus purpureus.

Statins: Blood-cholesterol lowering agents from Monascus purpureus.

Primary Treatment: Physical removal of particles (filtration and sedimentation). Supernatant forms the effluent.

Secondary (Biological) Treatment:

Effluent passed to aeration tanks; aerobic microbes form flocs.
Microbes consume organic matter, reducing BOD (Biochemical Oxygen Demand).

Greater BOD = More polluting potential.

Activated Sludge: Sedimented flocs.

Anaerobic Sludge Digesters: Anaerobic bacteria produce Biogas (CH4, H2S, CO2).

Methanogens: e.g., Methanobacterium. Produce methane anaerobically on cellulosic material.

Found in anaerobic sludge and the rumen of cattle (helps digest cellulose).

Biogas Plant: Uses cattle dung (gobar) to produce gas for cooking and lighting.

Use of biological methods to control pests/diseases, reducing chemical use.

Bacillus thuringiensis (Bt): Controls butterfly caterpillars (toxin released in larvae gut).

Trichoderma: Free-living fungi in root ecosystems; control several plant pathogens.

Baculoviruses (Nucleopolyhedrovirus): Species-specific, narrow-spectrum insecticidal application; no harm to non-target organisms.

Organisms that enrich soil nutrient quality.

Bacteria: Rhizobium (symbiotic in legume nodules), Azospirillum, Azotobacter (free-living).

Fungi: Glomus forms Mycorrhiza; absorbs phosphorus and provides resistance to root pathogens/drought.

Cyanobacteria: Anabaena, Nostoc, Oscillatoria. Fix atmospheric nitrogen, important in paddy fields.

Microbes in Human Welfare

Microbes in Human Welfare

Key Concepts

Microbes in Household Products

Microbes in Industrial Products

Microbes in Sewage Treatment

Microbes in Biogas Production

Microbes as Biocontrol Agents

Microbes as Biofertilisers

On this page

Microbes in Human Welfare

Microbes in Human Welfare

Key Concepts

Microbes in Household Products

Microbes in Industrial Products

Microbes in Sewage Treatment

Microbes in Biogas Production

Microbes as Biocontrol Agents

Microbes as Biofertilisers

On this page