A

David

Darling

chemoautotrophs

Chemoautotrophs are autotrophic microorganisms, including many varieties of archaea and bacteria, which are able to synthesize all of the organic compounds they need from inorganic raw materials in the absence of sunlight. The energy required for chemosynthesis is derived from special methods of respiration involving the oxidation of various inorganic materials such as hydrogen sulfide, ammonia, and iron-bearing compounds.