Microbiological corrosion which ensuing loss of metal caused by biological organisms, can occur in any aqueous environments.Because of the omni present nature of microbes in fluid systems, this corrosion is a commonly occurring phenomenon. It is a common problem in industrial processes due to the presence of microbes, adequate nutrients and corrosive byproducts.

Steels, copper alloys etc. tend to corrode generally over the entire surface in the absence of crevices or galvanic effects. In such cases, corrosion is determinated by the rate at which dissolved oxygen can be delivered to the metal surface. Biological organisms present in the aqueous medium often have the potential to increase or decrease oxygen transport to the surface; consequently, these organisms have a role in increasing or decreasing general corrosion. Most MIC manifests as localized corrosion because of organisms do not form in a continuous film on the metal surface.

The highly localized corrosion shown in the figure is typical of that resulting from microbial action. One of the features of this type of attack are the elongated pits(Pit was one of several located near the gas/water interface), which tunnel into the specimen often in an irregular manner. The pipeline was left for a prolonged period in a shut-in (static) condition. It promoted the growth of bacteria and highly localized corrosive attack. Sulfate reducing bacteria were suspected due to the combination of sulfate species in the water and anaerobic conditions. The corrosion was mitigated by a closer control of operating conditions and chemical treatment.