Sulfate Reducing Bacteria (SRB) are those bacteria that can obtain energy by oxidizing organic compounds or molecular hydrogen while reducing sulfate to hydrogen sulfide. They are also know as Sulfide Generating Bacteria (SGB) and commonly found in anaerobic environments where they aid in the degradation of organic materials like secondary oil recovery effluents estuarine waters deep wells cooling waters metalworking fluids water-based hydraulic fluids and petroleum based products. They can survive up to 600 DegC and cause pitting corrosion on metal structures that are exposed to sulfate-containing water by cathodic depolarization. They also play a role in the anaerobic oxidation of methane below the seabed in the transition zone which leads to heavy production loss. Since sulfate is also found in some formulations of or the other used in water treatment viz corrosion inhibitors coolants etc.