Acetogen

An acetogen is a microorganism that generates acetate as a product of anaerobic respiration. This process is known as acetogenesis^[1] and is different from acetate fermentation, although both occur in the absence of oxygen and produce acetate. Although previously thought that only bacteria are acetogens, some archaea can be considered to be acetogens.^[2]

Acetogens are found in a variety of habitats, generally those that are anaerobic (lack oxygen). Acetogens can use a variety of compounds as sources of energy and carbon; the best studied form of acetogenic metabolism involves the use of carbon dioxide as a carbon source and hydrogen as an energy source. Carbon dioxide reduction is carried out by the key enzyme acetyl-CoA synthase. Together with methane-forming archaea, acetogens constitute the last limbs in the anaerobic food web that leads to the production of methane from polymers in the absence of oxygen. Acetogens may represent ancestors of the first bioenergetically active cells in evolution.^[3]

References