Anaerobic bacteria are micro-organisms that grow in the absence of oxygen. Many anaerobes cannot survive in the presence of oxygen. Their metabolism usually involves inorganic/organic redox reactions, including anaerobic respiration and fermentation reactions, producing VFAs (Volatile Fatty Acids) and gaseous products, such as methane. Anaerobic bacteria are also involved in the digestion process of grazing animals.
Avanish K Panikkar (Lead Author);Jay Gulledge (Topic Editor) "Anaerobic bacteria". In: Encyclopedia of Earth. Eds. Cutler J. Cleveland (Washington, D.C.: Environmental Information Coalition, National Council for Science and the Environment). [First published in the Encyclopedia of Earth August 29, 2008; Last revised Date August 29, 2008; Retrieved June 20, 2013 <http://www.eoearth.org/article/Anaerobic_bacteria>