Sulfate reducing bacteria form one group of sulfate reducing prokaryotes. Main genus is Desulfovibrio. Desulfovibrio desulfuricans is often used to  immobilize dissolved heavy metals as metallic sulfides. SRB are anaerobes that are sustained by organic nutrients.

Generally they require a complete absence of oxygen and a highly reduced environment to function efficiently. Nonetheless, they circulate (probably in a resting state) in aerated waters, including those treated with chlorine and other oxidizers, until they find a "ideal" environment supporting their metabolism and multiplication.

SRB are usually lumped into two nutrient categories, those that can use lactate and those that cannot. The latter generally use acetate and are difficult to grow in the laboratory on any medium. Lactate, acetate, and other short chain fatty acids usable by SRB do not occur naturally in the environment. Therefore, these organisms depend on other organisms to produce such compounds.

SRB reduce sulfate ion (SO₄^-2) to sulfide ion (S^-2), which usually shows up as hydrogen sulfide, with the concomitant oxidation of a carbon source or, if iron is available, as black ferrous sulfide. In the absence of sulfate, some strains can function as fermenters and use organic compounds such as pyruvate to produce acetate, hydrogen, and carbon dioxide. Many SRB strains also contain hydrogenase enzymes, which allow them to consume hydrogen. Most common strains of SRB grow best at temperatures from 25° to 35°C. A few thermophilic strains capable of functioning efficiently at more than 60°C have been reported.

Anaerobic bacteria can convert the sulfate or sulfite present in water handling facilities to hydrogen sulfide (H₂S). This by-product, combined with iron, can form iron sulfide, a scale that is very difficult to remove. SRB occur naturally in surface waters, including seawater. Bacteria accumulation can lead to pitting of steel, and the buildup of H2S increases the corrosiveness of the water, thus increasing the possibility of hydrogen blistering or sulfide-stress cracking.

The lignite, lignin, tannins, cellulose, starches and fatty acids found in many mud systems are carbon food sources for SRB. Where mud is stored, precautions should always be taken when handling or reconditioning water muds containing lignosulfonates, gypsum (sulfate sources) and starches, cellulose, xanthan gum and lignite (food sources). These muds can harbor SRB and can have high sulfide accumulations. Mud filtrate should be tested with the Garrett Gas Train to determine sulfide concentration in a stored mud, followed by treatments with caustic soda to raise pH and zinc-based scavengers to remove sulfides as ZnS. Before storage of mud, treatment with a bactericide can inhibit SRB growth. Also, circulating mud from time to time, with air entrainment, can retard development of anaerobic conditions.

Tests for the presence of SRB have traditionally involved growing the organisms on laboratory media, quite unlike the natural environment in which they were found. These laboratory media will only grow certain strains of SRB, and even then some samples require a long lag time before the organisms will adapt to the new growth conditions. As a result, misleading information has been obtained regarding the presence or absence of SRB in field samples.

SRB have been implicated in the corrosion of cast iron and steel, ferritic stainless steels, 300 series stainless steels (also very highly alloyed stainless steels), copper nickel alloys, and high nickel molybdenum alloys. They are almost always present at corrosion sites because they are in soils, surface water streams and waterside deposits in general. Their mere presence, however, does not mean they are causing corrosion. The key symptom that usually indicates their involvement in the corrosion process of ferrous alloys is localized corrosion filled with black sulfide corrosion products.

Microbiological Induced Corrosion resulted in penetration of this Steel Heating Oil Storage Tank within 4 years. Most commonly the microbes are found to be Sulfate Reducing Bacteria (SRB) which generate a highly acidic environment within and under the colony.(Right picture)

SRB are obligate anaerobes and members of a heterogeneous group of eubacteria and archaebacteria which are able to carry out dissimilatory sulphate reduction. The SRB can be subdivided into two groups depending on their oxidative capability: the genera that completely oxidise the organic substrate to CO2, and the bacteria that oxidise the organic compound incompletely usually with acetate as an end product. The species able to completely oxidise organic carbon sources mainly prefers fatty acids, lactate and succinate as energy sources. Incomplete oxidation is due to the absence of a mechanism for acetyl-Co-A oxidation. Such bacteria generally prefer simple substrates such as hydrogen, lactate and primary alcohols.

SRB can survive in a wide range of pH conditions but commonly have a pH optimum for growth between pH 5-9.