Chemioautotrofie

Chemioautotrofie refers to a metabolic process where organisms obtain energy from the oxidation of inorganic chemical compounds rather than from light energy. These organisms, known as chemoautotrophs, utilize this energy to synthesize organic molecules from carbon dioxide, similar to how photoautotrophs use sunlight for photosynthesis. This process is fundamental to certain ecosystems, particularly in environments devoid of sunlight such as deep-sea hydrothermal vents, the subsurface of the Earth, and within rocks.

The energy sources for chemoautotrophs are diverse and typically involve the oxidation of reduced inorganic compounds like hydrogen sulfide (H2S), ammonia (NH3), ferrous iron (Fe2+), or hydrogen gas (H2). For instance, some bacteria and archaea living near hydrothermal vents oxidize hydrogen sulfide to produce ATP, which is then used to fix carbon dioxide into organic matter. This forms the base of the food web in these extreme environments, supporting communities of organisms that do not rely on solar energy.

Chemioautotrophy plays a significant role in biogeochemical cycles, such as the nitrogen cycle and sulfur cycle, by converting inorganic compounds into forms that can be utilized by other organisms. The discovery and study of chemoautotrophic life have expanded our understanding of the limits of life and the potential for life on other planets where sunlight may be scarce.