What does mesophilic mean?
Mesophilic is a technical adjective describing organisms, particularly bacteria and archaea, that grow best at moderate temperatures. Such organisms commonly inhabit environments such as soil, fresh water, compost, and the human body, where temperatures are neither extremely cold nor extremely hot. The word is useful in microbiology because temperature preference helps classify microorganisms and explains where they can be found and how they behave. It is related to the contrasting terms psychrophilic, for organisms that favor cold, and thermophilic, for those that favor high temperatures. In scientific and technical writing, mesophilic usually indicates an optimum growth range, not merely the ability to survive outside that range.
adjectiveMesophilic describes organisms, especially microorganisms, that grow best at moderate temperatures rather than very cold or very hot temperatures. The term is commonly used for bacteria and archaea in microbiology.
- Relating to or denoting organisms that grow optimally at moderate temperatures.
"The bacterium is mesophilic, thriving at temperatures commonly found in soil and freshwater."
"Mesophilic bacteria are commonly found in soils, compost, and freshwater."
"The researchers compared the growth of several mesophilic cultures under controlled laboratory conditions."
Mesophiles live in the temperature zone that many familiar microorganisms call home: warm enough to thrive, but far from boiling or freezing extremes.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of mesophilic
The word combines the Greek mesos, meaning “middle” or “moderate,” with -philic, from philos, meaning “loving.” The resulting term developed in biological usage to describe microorganisms whose preferred growth temperatures lie in a moderate range. The related noun mesophile denotes an organism of this kind, while mesophily refers to the characteristic or condition itself.
Related word forms
How mesophilic is actually used
This is primarily a technical term in microbiology, ecology, and food science. It is usually used of microorganisms and is more specific than simply describing an organism that tolerates a range of temperatures: mesophilic organisms have a relatively narrow optimum in the moderate-temperature range.