Chemoautotroph

Part of speech: noun

Definitions

1. An organism that derives energy by oxidizing inorganic substances and uses carbon dioxide as its carbon source; typically found in environments lacking sunlight; capable of synthesizing organic compounds from inorganic molecules
2. A life form that obtains its energy through chemical reactions involving inorganic compounds and fixes carbon dioxide to produce organic matter; commonly inhabits habitats where photosynthesis is not possible
3. A type of organism that gains energy from the oxidation of inorganic chemicals and assimilates carbon dioxide for growth; usually thrives in ecosystems without light for photosynthetic processes

Etymology: "Chemoautotroph" is a modern scientific compound assembled from three parts: "chemo-", from the Greek "khēmeia" (the root behind "chemistry"), "auto-", from Greek "autos" meaning "self," and "-troph," from Greek "trophē," meaning "nourishment." Put together, the name describes an organism that feeds itself using chemical reactions rather than sunlight. The "autotroph" half is the older and more familiar piece. Biologists use "autotroph" for any organism that makes its own food from simple inorganic materials, a category that includes plants, which photosynthesize. The prefix "chemo-" narrows this down: a chemoautotroph draws its energy from oxidizing inorganic compounds such as hydrogen sulfide, ammonia, or iron, rather than from light. Many of these organisms are bacteria and archaea living in environments without sunlight, such as deep-sea hydrothermal vents. Because the word is a deliberate combination of classical roots, it did not exist in ancient Greek. Its ingredients were available to scientists who needed precise terms for the newly recognized metabolic categories of microbes.

Synonyms: chemolithoautotroph, chemosynthetic organism