Sulfur bacteria are a very common bacterial group found in soil and water environments. The most common sulfur bacteria are those that use sulfates, other forms of oxidized sulfur, and/or elemental sulfur to generate hydrogen sulfide gas. These bacteria are very common in soil and water environments. These bacteria, generally referred to as sulfate-reducing bacteria (SRB), are a real nuisance problem in water because they create smells like rotten eggs, initiate corrosion processes in metal fittings, and react with dissolved metals, such as iron, to generate black deposits in water. These bacteria commonly vent hydrogen sulfide into water when oxygen is absent and sufficient amounts of dissolved organic matter are present. Forcing oxygen into the water eliminates these bacteria since oxygen is toxic to their activities. There are also forms of bacteria that oxidize sulfur to release acidic products, some that utilize hydrogen sulfide and some that use sulfur in photosynthetic reactions. Both sulfur-reducing and sulfur-oxidizing bacteria can cause nuisance problems in drinking water systems, but sulfur-reducing bacteria are better known for drinking water problems and for wastewater treatment because they generate hydrogen sulfide gas. Sulfur oxidizing bacteria are best known for the role they play in acid mine drainage and leaching of ores. These bacteria require oxygen to grow and they convert various sulfides to acidic products, such as sulfuric acid. The most common sulfur reducing anaerobes that use sulfates, other forms of oxidized sulfur, and/or elemental sulfur as an energy source are often involved in co-oxidation of another substance which is usually an organic carbon source. These sulfate reducing bacteria (SRB) breathe sulfate instead of oxygen and are a real nuisance problem in anaerobic water conditions. They are the organisms that create an odor that smells like rotten eggs, which is actually the reduced sulfur compound of hydrogen sulfide.