Sulphate API Broth is recommended for detection of sulphate reducing bacteria. Sulphate-reducing bacteria cause corrosion of oil well systems resulting in perforations in the pipes. Sulphate-reducing bacteria convert sulphate to sulphide which with the ferrous ion gives black colour. The insoluble sulphide results in plugging. The detection and estimation of these bacteria is done on the basis of their ability to grow and produce sulphide in this medium.