Many autotrophic archaea are facultative autotrophs or they can co-assimilate organic substrates into cellular building blocks even though they do not use organic substrates as an energy source by oxidizing them to CO2.

How does archaea get nutrition?

Obtaining Food and Energy

Most archaea are chemotrophs and derive their energy and nutrients from breaking down molecules in their environment. A few species of archaea are photosynthetic and capture the energy of sunlight. Some archaea do live within other organisms.

Are archaea photosynthetic?

(No archaea are known to use photosynthesis.) Phototrophic archaea use the sun’s energy to produce chemical energy in the form of ATP. In the Halobacteria, light-activated ion pumps like bacteriorhodopsin produce ion gradients by pumping ions out of the cell through the plasma membrane.

Some archaea, called lithotrophs, obtain energy from inorganic compounds such as sulfur or ammonia. The energy released generates adenosine triphosphate ( ATP ) through chemiosmosis in the same basic process that happens in the mitochondrion of eukaryotic cells.