Many microorganisms occurring naturally in waters and soils can cause microbiologically influenced corrosion (MIC) on metal structures. Such microorganisms include sulfate-reducing bacteria (SRB), sulfate-reducing archaea (SRA), acid-producing bacteria (APB), methanogens, metal-oxidizing bacteria, metal-reducing bacteria, and nitrate-reducing bacteria. The activities of individual microbial species or a synergistic group of microbes alter the electrochemical processes on metal surface and produce a broad range of outcomes, such as pitting, crevice corrosion, under-deposit corrosion, and selective dealloying, in addition to an enhanced galvanic and erosion corrosion.