Sulfate-reducing bacteria are those bacteria and archaea that can obtain energy by oxidizing organic compounds or molecular hydrogen (H2) while reducing sulfate (SO2−
4) to hydrogen sulfide (H2S). In a sense, these organisms "breathe" sulfate rather than oxygen, in a form of anaerobic respiration.
Sulfate-reducing bacteria can be traced back to 3.5 billion years ago and are considered to be among the oldest forms of microorganisms, having contributed to the sulfur cycle soon after life emerged on Earth.
Many bacteria reduce small amounts of sulfates in order to synthesize sulfur-containing cell components; this is known as assimilatory sulfate reduction. By contrast, the sulfate-reducing bacteria considered here reduce sulfate in large amounts to obtain energy and expel the resulting sulfide as waste; this is known as dissimilatory sulfate reduction. They use sulfate as the terminal electron acceptor of their electron transport chain. Most of them are anaerobes.
Most sulfate-reducing bacteria can also reduce other oxidized inorganic sulfur compounds, such as sulfite, thiosulfate, or elemental sulfur (which is reduced to sulfide as hydrogen sulfide).
In addition, there are sulfate-reducing bacteria that can reduce fumarate, nitrate and nitrite, iron (Fe(III)) and some other metals, dimethyl sulfoxide and even oxygen.
Other articles related to "bacteria":
... The sulfate-reducing bacteria have been treated as a phenotypic group, together with the other sulfur-reducing bacteria, for identification purposes ... As of 2009, 60 genera containing 220 species of sulfate-reducing bacteria were known ... Among the Deltaproteobacteria the orders of sulfate-reducing bacteria include Desulfobacterales, Desulfovibrionales and Syntrophobacterales ...
Famous quotes containing the word bacteria:
“To the eyes of a god, mankind must appear as a species of bacteria which multiply and become progressively virulent whenever they find themselves in a congenial culture, and whose activity diminishes until they disappear completely as soon as proper measures are taken to sterilise them.”
—Aleister Crowley (18751947)