Activities

Activity 1: Observing Microbes in Curd

Aim: To demonstrate the presence of Lactic Acid Bacteria (LAB) in curd using a microscope.

Materials:

• A drop of fresh curd or buttermilk.
• Microscope, glass slide, and coverslip.
• Methylene blue stain (optional for better contrast).

Procedure:

1. Place a tiny drop of curd on a clean glass slide.
2. Add a drop of water to dilute it slightly and spread it to form a thin film.
3. (Optional) Add a drop of methylene blue stain and leave for a minute, then wash gently with water.
4. Place a coverslip over the smear and observe under the high-power lens of the microscope.

Observation: Numerous rod-shaped bacteria (Lactobacillus) will be visible, often in clusters.

Conclusion: Curd is a concentrated source of beneficial Lactic Acid Bacteria that are essential for converting milk into a more nutritious form.

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Activity 2: Mapping a Biogas Plant

Aim: To understand the structural components and the working mechanism of a typical biogas plant.

Procedure:

1. Study Figure 8.8 in the textbook.
2. Identify and sketch the following parts:
   • Concrete Tank (Digester): Where bio-wastes and dung slurry are collected.
   • Floating Cover: Which rises as gas is produced.
   • Inlet: For feeding the dung-water slurry.
   • Outlet for Biogas: Connected to pipes for supply.
   • Outlet for Sludge: To collect spent slurry used as fertilizer.
3. Explain the role of methanogens in the anaerobic digestion process.

Conclusion: Biogas plants provide a sustainable and eco-friendly way to manage organic waste while producing fuel and manure.

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Activity 3: Case Study – Ganga and Yamuna Action Plans

Aim: To research the governmental initiatives for river restoration through microbial treatment.

Procedure:

1. Research the Ganga Action Plan (GAP) and Yamuna Action Plan.
2. Find out:
   • When these plans were initiated.
   • The primary objective (e.g., reducing BOD levels).
   • The role of Sewage Treatment Plants (STPs) in these projects.
3. Discuss why millions of gallons of untreated sewage are still a challenge for these rivers despite these plans.

Conclusion: Scaling up microbial sewage treatment is the only effective way to protect our national water resources from urban pollution.

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Activity 4: Local Biofertiliser Inquiry

Aim: To investigate the usage and availability of biofertilisers in local agriculture.

Procedure:

1. Visit a local agricultural supply store or nursery.
2. Check for the availability of biofertiliser packets (e.g., Rhizobium, Azotobacter, Glomus/Mycorrhiza).
3. Read the instructions on the packets:
   • How are they applied to the soil or seeds?
   • What are the claimed benefits (e.g., "Increases nitrogen content", "Promotes root growth")?
4. If possible, talk to a farmer about their experience switching from chemical fertilisers to biofertilisers.

Conclusion: Biofertilisers offer a viable, non-polluting alternative to chemical fertilisers for sustainable organic farming.