Microbiologically influenced corrosion: an update

Identification of any mechanism for microbiologically influenced corrosion (MIC) requires an understanding of the specificity of metal/microbe/electrolyte interactions. Recent advancements in our understanding of MIC are related to recognition of the implications of this specificity. For example, under some circumstances, nutrients can accelerate rates of corrosion. In other cases the oxyanions in nutrients can inhibit localised corrosion. In some environments the absence of oxidisable carbon can force a shift in electron donor and may result in more aggressive corrosion than in the presence of oxidisable carbon. Non-corrosive biofilms can become corrosive with subtle changes in the environment, e.g., addition of electron shuttle compounds. The list of electron donors and acceptors related to MIC has been expanded in recognition of the metabolic flexibility that has been demonstrated for microorganisms. Recent research on microbial fuel cells and microbial batteries has added to our understanding of microbial/metal interactions.