Students can go through AP Inter 2nd Year Botany Notes 4th Lesson Microbes in Human Welfare will help students in revising the entire concepts quickly.
AP Inter 2nd Year Botany 4th Lesson Microbes in Human Welfare Notes
→ Microbes are major components of biological systems on Earth, alongside plants and animals.
→ They are present everywhere: in soil, water, air, and inside the bodies of plants and animals.
→ Lactobacillus and other lactic acid bacteria (LAB) convert milk into curd.
→ Curd formation improves nutritional quality by increasing Vitamin B12.
→ Baker’s yeast {Saccharomyces cerevisiae) is specifically used to ferment bread dough.
→ Large holes in Swiss cheese are produced by CO2 from the bacterium Propionibacterium sharmanii.
→ Roquefort cheese is ripened by specific fungi to give it a particular flavor.
→ Whisky, brandy, and rum are produced by the distillation of fermented broth.
→ Antibiotics are chemical substances produced by microbes that kill or retard other pathogens.
→ Penicillin was the first antibiotic discovered, found by chance by Alexander Fleming.
→ Ernest Chain and Howard Florey established the full medical potential of Penicillin.
→ Aspergillus niger (a fungus) is used for the industrial production of citric acid.
→ Acetobacter aceti and Clostridium butylicum produce acetic acid and butyric acid, respectively.
→ Statins, produced by the yeast Monascus purpureus, are used as blood-cholesterol lowering agents.
→ Primary treatment involves the physical removal of large and small particles via filtration and sedimentation.
→ Secondary treatment (biological treatment) involves passing effluent into aeration tanks to grow aerobic microbes.
→ Floes consume organic matter in effluent, significantly reducing the Biochemical Oxygen Demand (BOD).
→ Once BOD is reduced, bacterial floes are allowed to sediment, forming activated sludge.
→ Biogas is a mixture of gases, predominantly methane, produced by microbial activity and used as fuel.
→ Methanogens like Methanobacterium are found in both sewage sludge and the rumen of cattle.
→ Bacillus thuringiensis (Bt) is a microbial agent used to control butterfly caterpillars.
→ Baculoviruses are used for species-specific, narrow-spectrum insecticidal applications in sensitive areas.
→ Biofertilisers, including bacteria (Rhizobium), fungi (Mycorrhiza), and cyanobacteria, enrich soil nutrient quality.
→ The domestic sewage in large cities is processed by aerobic and then anaerobic bacteria in the secondary treatment in Sewage Treatment Plants (STPs).
→ Monascus purpureus is a yeast used commercially in the production of blood cholesterol-lowering statins.
→ An organism used as a biofertiliser for raising soyabean crop is Rhizobium.
→ During sewage treatment, biogas is produced which includes methane, hydrogen sulphide, carbon dioxide.
→ A good producer of citric acid is Aspergillus
→ Large holes in swiss cheese are formed due to production of large amount of CO2 by Propionibacterium.
→ The fungus used for commercial production of citric acid is Aspergillus.
→ Cyclosporin A, used as an immunosuppressive agent in organ transplants, is produced by Trichoderma.
→ Conversion of milk to cure improves its nutritional value by increasing the amount of Vitamin B12.
→ Statin is a commercial blood cholesterol-lowering agent.
→ A commercial blood cholesterol lowering agent is statin.
→ A ‘biocontrol agent’ used in the treatment of plant disease is Trichoderma.
→ Activated sludge is put into anaerobic sludge digester for further sewage treatment.
→ Trichoderma Polysporum is the micro organism responsible for the production of an immunosuppressive molecule cyclosporin A.
→ Streptokinase produced by bacterium strcptococus io used for removing clots from blood vessels.
→ Beer is an example of non-distilled alcoholic beverage produced by yeast.
→ Microbes (bacteria, fungi, viruses, and protozoa) are foundational to human welfare.
- They are essential for producing household foods, life-saving medicines, and sustainable energy.
- Furthermore, they play vital roles in wastewater treatment, agricultural soil enhancement, and natural pest control.
1. Household Products:
- Dairy: Lactobacillus and Lactic Acid Bacteria (LAB) ferment lactose in milk to create curd, increasing its Vitamin B12 content. Other microbes ferment curds to make cheeses like Roquefort and Swiss cheese.
- Baking & Brewing: Baker’s yeast (Saccharomyces cerevisiae) ferments sugars in dough to produce carbon dioxide CO2, making bread and idlis light and fluffy. It is also utilized to brew beers and wines through alcoholic fermentation.
2. Industrial Production
- Antibiotics: Microorganisms produce potent chemicals that restrict the growth of disease-causing pathogens. For instance, Alexander Fleming discovered the first antibiotic, penicillin, from the fungus Penicillium notatum.
- Enzymes & Bioactive Molecules: Fungi like Trichodermapolysporum produce Cyclosporin A, a vital immunosuppressant used in organ transplant patients. Microbes like Monascus purpureus synthesize statins, which act as natural blood-cholesterol-lowering agents.
3. Sewage & Wastewater Treatment:
- Municipal wastewater is treated in Sewage Treatment Plants (STPs) to reduce the Biological Oxygen Demand (BOD).
- Aerobic microbes consume organic waste, and anaerobic bacteria (methanogens) safely digest the remaining sludge, simultaneously producing biogas (a combustible mix of methane and CO2).
4. Agriculture & Biofertilizers
- Biological Control: Microorganisms act as natural eco-friendly pest controllers, replacing toxic chemical pesticides. For example, the bacterium Bacillus thuringiensis (Bt) produces a protein that is toxic to specific insect larvae.
- Nitrogen Fixation: Microbes like Rhizobium (symbiotic in legume roots), Azotobacter, and cyanobacteria (Anabaena, Nostoc) convert atmospheric nitrogen into usable nitrates to naturally enrich soil fertility.