A microorganism that can live and grow in the absence of oxygen. [G. an- priv. + aer, air, + bios, life]
- facultative a. an a. that either grows in the presence of air or under conditions of reduced oxygen tension.
* * *
* * *
n.
any organism, especially a microbe, that is able to live and grow in the absence of free oxygen. A facultative anaerobe is a microorganism that grows best in the presence of oxygen but is capable of some growth in its absence. An obligate anaerobe can grow only in the absence of free oxygen. Compare aerobe, microaerophilic.
* * *
an·aer·obe (anґə-rōb) [an-1 + aerobe] a microorganism that lives and grows in the complete, or almost complete, absence of molecular oxygen.Medical dictionary. 2011.