What are methanogens ?

Explanation

### Step-by-Step Solution:

1. **Definition of Methanogens**: Methanogens are a specific type of microorganisms classified as archaebacteria.

2. **Classification**: They belong to the domain Archaea, which is distinct from bacteria and eukaryotes.

3. **Function**: Methanogens play a crucial role in the production of methane-rich biogas. They are involved in anaerobic digestion, where organic matter is broken down in the absence of oxygen.

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