Microbial Corrosion

Microbial corrosion, also known as microbially influenced corrosion, refers to the degradation of metals and metal alloys caused by the metabolic activities of microbes.

It is most commonly observed on buried or submerged metal structures and predominantly affects iron, steel, copper, and aluminum.

For example, iron corrosion can happen through two mechanisms mediated by sulfate-reducing bacteria.

In one mechanism, molecular hydrogen generated during electrochemical pitting of iron is taken up by bacterial cells, sustaining electron release from the metal and accelerating iron oxidation.

Another mechanism is employed by Desulfopila corrodens, whose cells are embedded within an electroconductive sulfidic corrosion layer.

They accept electrons directly from elemental iron via redox-active proteins to reduce sulfate to sulfide.

The sulfide reacts with iron to form iron sulfide, further promoting localized metal corrosion.

Microbial corrosion can be mitigated using treatments such as biocides, corrosion inhibitors, and biofilm-disrupting biological agents.