Lithotroph

Definition

Lithotrophs are microorganisms that obtain energy by oxidizing inorganic compounds. They play a crucial role in various biogeochemical cycles.

5 Must Know Facts For Your Next Test

1. Lithotrophs can use inorganic molecules such as hydrogen sulfide, ammonia, or ferrous iron as electron donors.
2. They are categorized into two groups: chemolithotrophs and photolithotrophs, based on their energy sources.
3. Chemolithoautotrophs use carbon dioxide as their carbon source while obtaining energy from inorganic compounds.
4. Lithotrophic bacteria are vital for nutrient cycling, including the nitrogen and sulfur cycles.
5. Some lithotrophs thrive in extreme environments such as deep-sea hydrothermal vents and hot springs.

Review Questions

• What types of electron donors do lithotrophs utilize?
• How do chemolithoautotrophs differ from photolithotrophs in terms of their metabolic processes?
• Why are lithotrophic bacteria important for biogeochemical cycles?

Related terms

Autotroph: An organism that produces its own food using light or chemical energy.

Chemolithoautotroph: A type of lithotroph that derives energy from inorganic compounds and fixes carbon dioxide.

Photolithoautotroph: An organism that uses light energy to drive the oxidation of inorganic substances and fix carbon dioxide.