Bioconversion of organic carbon to CH4 and CO2

The activities of populations in complex anaerobic microbial communities that perform complete bioconversion of organic matter to CH₄ and CO₂ are reviewed. Species of eubacteria produce acetate, H₂, and CO₂ from organic substrates, and methanogenic species of archaebacteria transform the acetate, H₂, and CO₂ to CH₄. The characteristics and activities of the methanogenic bacteria are described. The impact of the use of H₂ by methanogens on the fermentations that produce acetate, H₂, and CO₂ and the importance of syntrophy in complete bioconversion are discussed.