Acetogenesis

Acetogenesis is a process through which acetate is produced by anaerobic bacteria from a variety of energy (for example, hydrogen) and carbon (for example, carbon dioxide) sources. The different bacterial species that are capable of acetogenesis are collectively termed acetogens.

Chemical equation
2 CO2 (aq) + 4H2 (aq) = CH3COOH (aq) + 2H2O

Acetogenesis and anaerobic digestion
Acetogenesis is the third stage of anaerobic digestion
 * Hydrolysis: Particulates are solubilised and large polymers, converted into simpler monomers;
 * Acidogenesis: Simple monomers are converted into volatile fatty acids;
 * Acetogenesis: Volatile fatty acids are converted into acetic acid, carbon dioxide, and hydrogen; and
 * Methanogenesis: Acetate are converted into methane and carbon dioxide, while hydrogen is consumed.