The conversion of organic compounds from waste materials to methane is an important strategy for sustainable energy supply.The production of methane involves a consortium of several microorganisms,which undertakes major biological processes such as hydrolysis/acidogenesis,acetogenesis and methanogenesis steps.Fermentative bacteria hydrolyze polymers to simpler monomers and oligomers,which afterward are fermented to alcohols,short-chain fatty acids
(SCFA),carbon dioxide and hydrogen.Then acetogenic bacteria convert the SCFA other than acetate to acetate,carbon dioxide and hydrogen.