Question

During the acidogenesis stage of biogas production, which of the following is NOT a product generated by fermentative bacteria?

Options

• Methane

• Carbon dioxide

• Acetic acid

• Hydrogen gas

Answer 1

Acidogenesis is Stage II of anaerobic digestion, during which fermentative (acidogenic) bacteria convert monomers into organic acids (such as acetic acid), hydrogen gas (H₂), and carbon dioxide (CO₂). Methane is not produced during acidogenesis; it is the final product of Stage III (methanogenesis) when methanogens convert acetate and hydrogen into methane. The separation of these stages is crucial for understanding the sequential microbial processes.