Question

Name the agent which decomposes animal dung into biogas. Name the constituent of biogas that makes it an excellent fuel. How is the spent dung slurry used?

Answer 1

Anaerobic bacteria:

The agent which decomposes animal dung into biogas is Anaerobic bacteria. The main constituent of biogas which makes it an excellent fuel is methane.
The spent slurry is used as manure or fertilizer. The bacteria have digested all of the organic materials into simple molecules that can be used as manure by plants that can readily absorb the digested simple biomolecules.