An organism that can live in the absence of free oxygen. Obligate or strict anaerobes cannot live in the presence of free oxygen. Facultative or indifferent anaerobes can grow in the presence of oxygen but do not use it. Such organisms include the denitrifying bacteria and lactic acid bacteria. The term facultative anaerobe may also be used of such organisms as yeasts that can grow under anaerobic conditions but given free oxygen will use it to oxidize the products of anaerobic respiration. They thus grow better with free oxygen. However yeasts and similar organisms could equally well be described as facultative aerobes. Compare aerobe . |
