Microbial Corrosion of Iron: Unveiling the Invisible Culprits

Corrosion of iron is a pervasive and costly problem in various industries affecting infrastructure, transportation and machinery. 

- Monikandon Sukumaran

While traditional corrosion mechanisms often involve chemical reactions with oxygen, acids or salts there is another culprit lurking in the shadows: microbial corrosion also known as microbiologically influenced corrosion (MIC). This article explores the intriguing world of microbial corrosion of iron shedding light on the invisible yet powerful agents responsible for this form of deterioration.

Understanding Microbial Corrosion

Microbial corrosion as the name suggests is the corrosion of metals driven by the activity of microorganisms. These microorganisms encompass a wide array of bacteria, archaea, fungi and even algae each with unique characteristics and metabolic pathways. Microbes can promote corrosion by altering the chemical environment at the metal's surface and accelerating the deterioration process.

Mechanisms of Microbial Corrosion

Biogenic Sulfide Corrosion: Some microorganisms such as sulfate reducing bacteria (SRB), play a pivotal role in biogenic sulfide corrosion. SRB utilize sulfate as an electron acceptor reducing it to sulfide ions. Sulfide ions can react with iron to form iron sulfides (e.g., FeS and FeS2) which are highly corrosive.