What does chemoautotrophy mean?
Chemoautotrophy is a form of biological self-nourishment in which organisms obtain energy by carrying out chemical reactions rather than by capturing sunlight. Chemoautotrophic organisms typically oxidize inorganic substances, such as hydrogen sulfide or ammonia, and use the released energy to fix carbon dioxide into organic compounds. This process is especially significant in environments where light is unavailable, including deep-sea hydrothermal vents, caves, sediments, and certain mineral-rich soils. The organisms that practice it form the energetic foundation of complex food webs in such places. Chemoautotrophy is closely related to chemolithoautotrophy, a more specific term commonly applied when inorganic compounds serve as the electron donors. Its principal contrast is with photoautotrophy, in which light supplies the energy. For general readers, the word illustrates the central role of microorganisms in ecosystems that function independently of sunlight.
nounThe biological process by which organisms obtain energy from chemical reactions, typically by oxidizing inorganic substances, and use carbon dioxide to synthesize organic compounds. It is a form of autotrophy that does not depend on light.
- The biological mode of nutrition in which energy is obtained from chemical reactions and carbon is fixed from carbon dioxide, especially by organisms that oxidize inorganic substances.
"The remarkable chemoautotrophy of vent-dwelling bacteria supports an entire ecosystem without sunlight."
"Chemoautotrophy is especially important in environments where sunlight cannot reach, such as deep-sea vents and submerged sediments."
"The researchers identified genes associated with chemoautotrophy in bacteria collected from the hydrothermal field."
The process is discussed in the singular, with the definite article when referring to a particular phenomenon.
"Scientists continue to investigate the importance of chemoautotrophy in the deep ocean."
At deep-sea hydrothermal vents, chemoautotrophic bacteria build a thriving food web in complete darkness.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does chemoautotrophy come from?
The word was formed in scientific English by combining chemo-, from the GreekRoot for “chemical,” with auto-, from Greek for “self,” and trophē, a Greek term associated with nourishment or growth. Its components reflect the process it names: self-nourishment powered by chemical reactions. The root trophē also appears in related biological terms such as autotroph, heterotroph, and phototroph.
Related word forms
How chemoautotrophy is actually used
This is a specialized biological term used chiefly in microbiology, ecology, geochemistry, and astrobiology. It is normally treated as an uncountable noun and is commonly used attributively.
Easily confused with chemoautotrophy
Photoautotrophy uses light as the primary energy source, whereas chemoautotrophy derives energy from chemical reactions.
Chemoautotrophs obtain carbon from carbon dioxide, while chemoheterotrophs obtain organic carbon from other organisms or organic material.