Chemoautotrophic

Definition of chemoautotrophic: Chemoautotrophic organisms deriving energy from chemical reactions with inorganic molecules, and use this energy to synthesize all necessary organic compounds from carbon dioxide. This is the common definition for chemoautotrophic, other definitions can be discussed in the article

Chemoautotrophs can use inorganic energy sources such as hydrogen sulfide, elemental sulfur, ferrous iron, molecular hydrogen, and ammonia or organic sources to produce energy. Most chemoautotrophs are extremophiles, bacteria or archaea that live in hostile environments (such as deep sea vents) and are the primary producers in such ecosystems.