Methane Production Using Microbial Systems - Methane is produced during anaerobic decomposition of sewage and other organic wastes by bacteria. The methane thus produced is collected and used as fuel in many countries.

The methogenic bacteria are able to utilize acetate, methanol, formate, and Hz + CO2 of the organic wastes for the production of methane gas. The starting materials in the wastes are, however, complex organic molecules such as cellulose, starch, fats and proteins. These are first broken down to simpler substrates such as acetate and H2 + CO2 by other microorganisms.