What does aerobe mean?
An aerobe is any organism that depends on free oxygen for its metabolism and survival, a term applied most often to bacteria and other microorganisms but also relevant to plants, animals, and fungi, all of which respire aerobically. Microbiologists distinguish obligate or strict aerobes, which cannot grow without oxygen, from facultative organisms that can switch between oxygenated and oxygen-free conditions. The word entered English in the late nineteenth century, when pioneers such as Louis Pasteur were establishing that microbial life could be classified by its relationship to oxygen — some microbes thriving in it, others being harmed or killed by it. In modern usage, 'aerobe' appears mainly in scientific writing, laboratory reports, and textbooks, usually alongside its opposite, 'anaerobe'. Knowing the term helps make sense of discussions of infection, fermentation, soil ecology, and the history of life on Earth.
nounAn organism, especially a microorganism, that requires oxygen for respiration and growth.
- An organism that needs free oxygen for respiration and growth, especially a bacterium or other microorganism.
"Unlike the bacteria in sealed jars of pickles, most soil microbes are aerobes that need oxygen to thrive."
"Mycobacterium tuberculosis is an obligate aerobe, which is why it favors the oxygen-rich environment of the lungs."
"In the lab, the aerobes grew on the surface of the culture medium while the anaerobes settled at the bottom."
Standard plural; used when referring to multiple oxygen-dependent organisms, e.g. in describing mixed bacterial cultures.
"The pond water sample contained both aerobes and anaerobes."
The word 'aerobe' was born in the age of Pasteur, when scientists first realized that some microbes find oxygen downright poisonous.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of aerobe
The word 'aerobe' was coined in the late nineteenth century from Greek roots: 'aēr', meaning air, and 'bios', meaning life. It emerged during the era of Louis Pasteur's groundbreaking work on fermentation and putrefaction, when scientists first demonstrated that some microorganisms require oxygen while others do not. The same Greek elements gave rise to the related terms 'aerobic' and 'anaerobic', and 'bios' remains a productive root in scientific vocabulary generally.
Related word forms
How aerobe is actually used
A technical term used chiefly in microbiology and biology; rare in everyday speech. Often qualified as 'obligate' (requiring oxygen), 'strict', or 'facultative' (able to survive without it). Plural is 'aerobes'.
Easily confused with aerobe
An aerobe requires oxygen to live, whereas an anaerobe lives without oxygen and may even be killed by it.
Aerobic is an adjective describing processes or organisms that use oxygen, while an aerobe is the noun naming such an organism itself.