Written by the Fiveable Content Team • Last updated August 2025
Written by the Fiveable Content Team • Last updated August 2025
Definition
Sulfur bacteria are a group of prokaryotic microorganisms that metabolize sulfur compounds, either for energy production or growth. They are often found in environments rich in sulfur, such as hot springs, deep-sea vents, and sulfur-rich sediments.
Sulfur bacteria can be divided into two main groups: photosynthetic and non-photosynthetic.
Photosynthetic sulfur bacteria use light energy to oxidize hydrogen sulfide (H2S) to sulfate (SO4^2-), producing elemental sulfur as an intermediate.
Non-photosynthetic sulfur bacteria include genera like Thiobacillus, which oxidize sulfur compounds to derive energy through chemolithotrophy.
Certain sulfur bacteria play a key role in the biogeochemical cycling of sulfur by converting various forms of sulfur between organic and inorganic states.
Sulfur bacteria can influence their environments significantly; for instance, they can contribute to the corrosion of metal structures due to the production of sulfide.
A form of metabolism in which organisms derive energy from the oxidation of inorganic compounds.
Biogeochemical cycling: The movement of elements or compounds through different compartments of Earth, including the biosphere, atmosphere, hydrosphere, and lithosphere.
Hydrogen Sulfide (H2S): A colorless gas with a characteristic foul odor, used by certain microorganisms as an electron donor in metabolic processes.