Microbes In Human Welfare

Microbes in Human Welfare: A Summary

Microbes are tiny organisms that can be found in almost every environment, including our bodies. While some microbes can cause diseases, many others have beneficial applications for humans.

Beneficial Applications of Microbes

1. Food Production:
   
   • Fermentation: Microorganisms are used in the fermentation of various foods, such as yogurt, bread, cheese, and alcoholic beverages.
   • Biopreservation: Microbes can be used to preserve food by inhibiting the growth of spoilage organisms.
2. Biotechnology:
   
   • Genetic Engineering: Microbes are used as tools in genetic engineering to produce valuable products like insulin, human growth hormone, and vaccines.
   • Bioremediation: Microbes can be used to clean up pollution and environmental contaminants.
3. Pharmaceutical Industry:
   
   • Antibiotics: Many antibiotics are derived from microorganisms, such as Penicillium and Streptomyces.
   • Vaccines: Vaccines are often produced using weakened or killed microorganisms to induce immunity.
4. Biofuel Production: Microorganisms can be used to convert biomass into biofuels like ethanol and biogas.
   
5. Industrial Processes: Microbes are used in various industrial processes, such as the production of enzymes, detergents, and chemicals.

Microbes as Biocontrol Agents

• Pest Control: Microbes can be used to control pests in agriculture and horticulture.
• Disease Control: Some microbes can be used to treat diseases, such as the use of bacteriophages to combat antibiotic-resistant bacteria.

Challenges and Considerations

• Pathogenicity: While many microbes are beneficial, some can cause diseases. It is essential to understand the potential risks and benefits of using microbes in various applications.
• Ethical Considerations: The use of microbes in biotechnology and other fields raises ethical questions, such as the potential for unintended consequences and the patenting of life forms.

Exercise

1. Bacteria cannot be seen with the naked eyes, but these can be seen with the help of a microscope. If you have to carry a sample from your home to your biology laboratory to demonstrate the presence of microbes with the help of a microscope, which sample would you carry and why?

Ans : 

I would carry a sample of yogurt or curd to demonstrate the presence of microbes using a microscope.

Here’s why:

• High Microbial Content: Yogurt and curd are rich in beneficial bacteria, such as Lactobacillus and Bifidobacterium. These bacteria are responsible for the fermentation process that gives yogurt and curd their characteristic texture and flavor.
• Easy to Obtain: Yogurt and curd are readily available in most households, making them convenient samples to collect.
• Visible Microorganisms: When observed under a microscope, the bacteria in yogurt or curd can often be seen as tiny, rod-shaped organisms.
• Safe to Handle: Yogurt and curd are generally safe to handle and do not pose a significant health risk.

2. Give examples to prove that microbes release gases during metabolism

Ans : 

Yeast and Fermentation: Yeast is a type of fungus that undergoes fermentation to produce alcohol and carbon dioxide gas. This process is used in the production of bread, beer, wine, and other alcoholic beverages.

Bacteria and Decomposition: Many bacteria release gases like methane, carbon dioxide, and hydrogen sulfide during the decomposition of organic matter.

Intestinal Bacteria: The bacteria in our intestines produce gases like hydrogen, methane, and carbon dioxide as a byproduct of their metabolism. These gases contribute to flatulence.

Methanogens: They are found in anaerobic environments, such as swamps, landfills, and the digestive tracts of ruminants.

Denitrifying Bacteria: These bacteria reduce nitrate to nitrogen gas as part of the nitrogen cycle. This process is important for maintaining the balance of nitrogen in the environment.

3. In which food would you find lactic acid bacteria? Mention some of their useful applications.

Ans : 

Lactic acid bacteria (LAB) are commonly found in fermented foods such as:

• Yogurt: The sour taste of yogurt is due to the production of lactic acid by LAB.
• Cheese: LAB are used in the production of various types of cheese, such as cheddar, Swiss, and mozzarella.
• Pickles: LAB are used to ferment vegetables and produce pickles.
• Sauerkraut: This fermented cabbage dish is made using LAB.
• Kimchi: This Korean fermented vegetable dish is also made using LAB.

Useful applications of lactic acid bacteria:

• Probiotics: LAB are often used as probiotics to improve gut health and digestion.
• Food Preservation: LAB can inhibit the growth of spoilage organisms, extending the shelf life of food products.
• Health Benefits: Some LAB strains have been shown to have health benefits, such as reducing the risk of infections, improving lactose tolerance, and boosting immunity.
• Biotechnology: LAB are used in biotechnology for the production of various products, including enzymes, antibiotics, and food additives.

4. Name some traditional Indian foods made of wheat, rice and Bengal gram (or their products) which involve use of microbes.

Ans : 

Wheat-based foods:

• Roti: While the dough for roti is made from wheat flour, the leavening agent used is often yeast, a type of fungus that produces carbon dioxide gas, causing the dough to rise.
• Paratha: Similar to roti, paratha also uses yeast or baking soda as a leavening agent.
• Idli: Though made primarily from rice, idli batter often includes a small amount of urad dal (a type of lentil) that is fermented using bacteria to produce carbon dioxide gas.

Rice-based foods:

• Idli: As mentioned above, idli batter often involves fermentation of rice and urad dal using microbes.
• Dosa: Similar to idli, dosa batter is also fermented using microbes.
• Rice Wine: Certain types of rice wine, such as sake, are produced through fermentation by yeast.

Bengal Gram-based foods:

• Tempeh: A fermented soy product that includes Bengal gram (chickpea) as an ingredient. The fermentation process is carried out by fungi, which break down the protein in the beans and give the tempeh its characteristic texture and flavor.
• Hummus: While not traditionally Indian, hummus, a popular Middle Eastern dish made from chickpeas, often involves fermentation using lactic acid bacteria, which can contribute to its flavor and texture.

5. In which way have microbes played a major role in controlling diseases caused by harmful bacteria?

Ans : 

Microbes have played a major role in controlling diseases caused by harmful bacteria through the development of antibiotics.

Many of these antibiotics are derived from microorganisms themselves, such as fungi and bacteria. For example, the antibiotic penicillin was discovered from a mold called Penicillium notatum.

However, the overuse and misuse of antibiotics have led to the emergence of antibiotic-resistant bacteria, which are becoming a major public health concern.

6. Name any two species of fungus, which are used in the production of the antibiotics.

Ans : 

Two species of fungi used in the production of antibiotics are:

1. Penicillium notatum: This species of fungus produces penicillin, one of the most widely used antibiotics.
2. Cephalosporium acremonium: This fungus produces cephalosporins, another class of antibiotics commonly used to treat bacterial infections.

7. What is sewage? In which way can sewage be harmful to us?

Ans : 

Sewage is wastewater that is generated from domestic, commercial, and industrial activities. It typically contains a mixture of human waste, wastewater from household activities, and industrial effluents.

Sewage can be harmful to human health in several ways:

1. Waterborne diseases: If sewage is not treated properly and is allowed to contaminate water sources, it can lead to the spread of waterborne diseases such as cholera, typhoid, and dysentery.
2. Environmental pollution: Untreated sewage can pollute rivers, lakes, and oceans, harming aquatic life and ecosystems. It can also contaminate groundwater, making it unsafe for drinking or irrigation.

8. What is the key difference between primary and secondary sewage treatment?

Ans : 

Primary sewage treatment involves the removal of large solids and debris from wastewater through processes like screening and sedimentation. This step reduces the organic matter and suspended solids in the sewage but does not eliminate all pollutants.

Secondary sewage treatment involves further purification of the wastewater through biological processes, such as activated sludge treatment or trickling filters. These processes break down organic matter into simpler compounds using microorganisms. This step significantly reduces the biochemical oxygen demand (BOD) of the wastewater, which is a measure of its polluting potential.

9. Do you think microbes can also be used as source of energy? If yes, how?

Ans : 

This process is known as bioenergy or microbial fuel production.

Here are some ways microbes can be used for energy production:

1. Biogas: Microorganisms can break down organic matter in the absence of oxygen (anaerobic conditions) to produce biogas, a mixture of methane, carbon dioxide, and other gases. Biogas can be used as a renewable fuel for heating, cooking, and generating electricity.
2. Bioethanol: Microbes can ferment plant materials to produce ethanol, a biofuel that can be blended with gasoline to power vehicles.
3. Hydrogen Production: Some microbes can produce hydrogen gas as a byproduct of their metabolism. Hydrogen is a clean-burning fuel that can be used in fuel cells to generate electricity.

10. Microbes can be used to decrease the use of chemical fertilisers and pesticides. Explain how this can be accomplished. 

Ans : 

 Microbes can be used to decrease the use of chemical fertilizers and pesticides. They can provide plant nutrients at cheaper cost when compared with the chemical fertilizers. e.g.

(i) Use of leguminous plant with Rhizobium.

(ii) Use of sulphur fixing bacteria.

(iii) Use of hydrogen fixing bacterium.

11. Three water samples namely river water, untreated sewage water and secondary effluent discharged from a sewage treatment plant were subjected to BOD test. The samples were labelled A, B and C; but the laboratory attendant did not note which was which. The BOD values of the three samples A, B and C were recorded as 20mg/L, 8mg/L and 400mg/L, respectively. Which sample of the water is most polluted? Can you assign the correct label to each assuming the river water is relatively clean?

Ans : 

The BOD (Biochemical Oxygen Demand) test measures the amount of oxygen required by microorganisms to decompose organic matter in a water sample. A higher BOD value indicates a higher concentration of organic pollutants in the water.

Based on the given BOD values:

• Sample C (400mg/L) has the highest BOD value, indicating it is the most polluted water sample.
• Sample A (20mg/L) has the lowest BOD value, suggesting it is the relatively clean river water.
• Sample B (8mg/L) likely represents the secondary effluent from the sewage treatment plant. While it has a lower BOD than the untreated sewage, it still contains some organic matter.

Therefore, the possible labels are:

• Sample A: River water
• Sample B: Secondary effluent
• Sample C: Untreated sewage wate

12. Find out the name of the microbes from which Cyclosporin A (an immunosuppressive drug) and Statins (blood cholesterol lowering agents) are obtained

Ans : 

It is a potent immunosuppressant drug used to prevent organ transplant rejection and in the treatment of autoimmune diseases.

Statins are a class of drugs used to lower cholesterol levels in the blood.

• Aspergillus terreus
• Monascus purpureus
• Penicillium citrinum

These fungi naturally produce statins as secondary metabolites, which can be extracted and purified for use as medications.

13. Find out the role of microbes in the following and discuss it with your teacher. (a) Single cell protein (SCP) (b) Soil

Ans : 

(a) Single-Cell Protein (SCP)

Single-cell protein (SCP) is a food source derived from microorganisms, such as bacteria, yeast, and algae. It is a rich source of protein and can be used as a dietary supplement or as a protein alternative in various food products.

Role of Microbes in SCP Production:

• Rapid Growth: Microorganisms can grow rapidly under controlled conditions, producing large quantities of biomass in a short period.
• Nutrient-Rich: Microbes are rich in protein, vitamins, and minerals, making them valuable sources of nutrition.
• Versatility: Microbes can be grown on a variety of substrates, including agricultural waste products, industrial byproducts, and even carbon dioxide.
• Environmental Benefits: SCP production can help reduce food waste and environmental pollution by utilizing waste materials.

(b) Soil

Microbes play a crucial role in soil health and fertility. They contribute to various processes, including:

• Nutrient Cycling: Microbes decompose organic matter, releasing nutrients that plants can absorb. They also help in the mineralization of inorganic nutrients, making them available to plants.
• Soil Structure: Microbes can influence soil structure by producing substances that bind soil particles together. This improves soil aeration and water retention.
• Bioremediation: Microbes can be used to clean up contaminated soil by degrading pollutants.
• Plant Growth Promotion: Some microbes produce plant growth-promoting substances, such as hormones and antibiotics, that can enhance plant growth and health.

13. Arrange the following in the decreasing order (most important first) of their importance, for the welfare of human society. Give reasons for your answer. 

Biogas, Citric acid, Penicillin and Curd

Ans : 

Importance of Microbes in Human Welfare

Here’s a ranking of the given products based on their importance for human welfare:

1. Penicillin
   
   • Reason: Penicillin is an antibiotic that has saved countless lives by treating bacterial infections.
2. Citric Acid
   
   • Reason: Citric acid is a versatile compound used in a wide range of industries, including food and beverages, pharmaceuticals, and cleaning products. It is essential for the flavor and preservation of many foods.
3. Curd
   
   • Reason: Curd is a nutritious food product that is an excellent source of protein and calcium. It is also fermented using beneficial bacteria, which can improve gut health.
4. Biogas
   
   • Reason: While biogas is a valuable renewable energy source, its importance for human welfare may be considered lower than the other products on this list. It is primarily used for cooking and heating, and its impact on overall human health and well-being is less direct.

15. How do biofertilisers enrich the fertility of the soil?

Ans : 

Biofertilizers are microorganisms that can improve soil fertility by enhancing nutrient availability to plants. They work in several ways:

1. Nitrogen Fixation: Some bacteria, such as Rhizobium and Azotobacter, can fix atmospheric nitrogen into a form that plants can absorb. This reduces the need for chemical nitrogen fertilizers.
2. Phosphate Solubilization: Certain bacteria can solubilize insoluble phosphate compounds in the soil, making phosphorus available to plants.
3. Potassium Mobilization: Some microbes can help release potassium from soil minerals, making it accessible to plants.
4. Organic Matter Decomposition: Microorganisms decompose organic matter, releasing nutrients and improving soil structure.
5. Plant Growth Promotion: Some microbes produce plant growth-promoting substances, such as hormones and antibiotics, that can enhance plant growth and health.