A xerophile () is an
extremophilic organism that can grow and reproduce in conditions with a low availability of water, also known as
water activity. Water activity (a
w) is measured as the humidity above a substance relative to the humidity above pure water (Aw = 1.0). Xerophiles are "xerotolerant", meaning tolerant of dry conditions. They can often survive in environments with water activity below 0.8; above which is typical for most life on Earth. Typically xerotolerance is used with respect to matric drying, where a substance has a low water concentration. These environments include arid desert soils. The term
osmotolerance is typically applied to organisms that can grow in solutions with high solute concentrations (salts, sugars), such as
halophiles.
The common
food preservation method of reducing water (
food drying) activities may not prevent the growth of xerophilic organisms, often resulting in
food spoilage. Some
mold and
yeast
Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are estimated to constit ...
species are xerophilic. Mold growth on bread is an example of food spoilage by xerophilic organisms.
Examples of xerophiles include ''
Trichosporonoides nigrescens'',
''
Zygosaccharomyces'', and
cacti.
See also
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Xerocole
A xerocole (), is a general term referring to any animal that is adapted to live in a desert. The main challenges xerocoles must overcome are lack of water and excessive heat. To conserve water they avoid evaporation and concentrate excretions (i. ...
*
Xerophyte
A xerophyte (from Ancient Greek language, Greek ξηρός ''xeros'' 'dry' + φυτόν ''phuton'' 'plant') is a species of plant that has adaptations to survive in an environment with little liquid water, such as a desert such as the Sahara or pl ...
References
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Biology terminology
Ecology terminology
Extremophiles