Composting Processes And Microbes Involved

Back to: MICROBIOLOGY 400 LEVEL

Welcome to class!

Hello, brilliant mind! It’s always exciting to have you here. Today, we’re learning about something that touches everyday life—from our kitchens to our farms. Our topic is Composting Processes and Microbes Involved. Have you ever seen people turn food waste or farm leftovers into rich black soil? That’s composting, and guess what? Microbes are the heroes behind it. Let’s learn how they do it!

Composting Processes And Microbes Involved

Composting is a natural process that turns organic waste like food scraps, leaves, and farm waste into a nutrient-rich soil material called compost. Compost is great for farming because it improves soil structure and fertility without using chemical fertilisers.

Microbes play a major role in making this transformation happen. They break down the waste into simple materials that plants can use. There are three main stages in the composting process.

1. Mesophilic Stage (Initial Breakdown)

This is the first stage, when the composting process begins.

It lasts for a few days and occurs at moderate temperatures (around 20–45°C).

Microorganisms like Bacillus, Pseudomonas, and some fungi begin breaking down simple sugars and proteins.

Heat is generated as a by-product, causing the temperature to rise.

2. Thermophilic Stage (High-Temperature Breakdown)

This is the second and most active stage, where the temperature rises to 50–70°C.

Thermophilic microbes like Thermus, Streptomyces, and Actinomycetes take over.

They break down more complex materials like fats, cellulose (plant fibres), and proteins.

The high temperature helps kill harmful pathogens and weed seeds, making the compost safe.

3. Maturation or Curing Stage

In this final stage, the temperature starts to drop back to ambient levels.

Mesophilic microbes return to complete the breakdown of any remaining material.

Fungi like Aspergillus and Penicillium help finish the process and stabilise the compost.

The result is dark, earthy-smelling compost rich in nutrients.

Conditions Needed for Good Composting

Oxygen: For aerobic microbes to work effectively.

Moisture: Around 40–60% water is ideal.

Temperature: Must be monitored to allow microbes to thrive.

Carbon to Nitrogen ratio (C:N): Balance between materials like dry leaves (carbon) and food waste (nitrogen).

Real-life Nigerian example: In farming communities in Plateau and Kwara States, farmers use compost made from crop leftovers and animal dung. With the help of local extension officers, they build compost pits that support microbial activity and reduce the cost of fertiliser.

Summary

• Composting is the process of converting organic waste into nutrient-rich compost.
• Microbes break down waste in three stages: mesophilic, thermophilic, and maturation.
• Bacillus and Pseudomonas work in the mesophilic stage.
• Thermus and Actinomycetes dominate the thermophilic stage.
• Fungi like Aspergillus help in the maturation stage.
• Heat generated during composting kills harmful organisms.
• Good composting needs oxygen, moisture, temperature control, and C:N balance.
• Compost improves soil health and crop yield.
• Composting is widely used in Nigerian farming communities.

Evaluation

1. What are the three stages of composting and which microbes are involved in each?
2. Why is the thermophilic stage important in composting?
3. List two benefits of composting for Nigerian farmers.

You’ve just unlocked the secret behind turning waste into wealth using microbes. This knowledge will serve you and your community for years to come. Keep learning with Afrilearn—you are on the path to greatness. See you in our next amazing lesson!