Abstract
Corrosion of metals is a natural phenomenon involving the generation and consumption of electrons and, microorganisms actively participate in the corrosion process through the utilization and release of electrons. Anaerobic sulfate-reducing bacteria (SRBs) are known to be especially important in the corrosion of a wide range of industrial structures because the sulfur cycle is linked to microbial metabolism, affecting the integrity of metals. Electrochemically formed H2 on the surface of metals through cathodic depolarization is utilized by microorganisms as a source of electrons. Microbial influence corrosion (MIC) can also take place through microbial exopolymers, by acid production, and by hydrogen metabolism. Recent evidence indicates that both bacteria and archaea can shuttle electrons via organic molecules in the surrounding environment. It is also possible that exopolymeric materials between cells form a linkage between then allowing electron transport. These processes affect the electrochemistry of the local environment and therefore the corrosion of metals. New mechanisms of microbial involvement are also being proposed and tested, but concrete conclusion is not available as this area of research is multidisciplinary and includes biology and also electrochemistry. Elucidation of the mechanisms also requires the characterization of the specific genes and proteins involved and verification of their functions. Prevention of MIC mostly includes the use of biocides and chemicals in industrial applications, and such approaches are likely to be problematic as chemicals not only cause environmental problems but also induce resistance in microorganisms and potentially degradation by them over time of exposure. Future developments may generate new information to enrich our knowledge on the specific involvement of microorganisms in destruction of metals and alloys, and also the effective protection strategies against corrosion.
Original language | English |
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Title of host publication | Encyclopedia of Microbiology |
Publisher | Elsevier |
Pages | 762-771 |
Number of pages | 10 |
ISBN (Electronic) | 9780128117378 |
ISBN (Print) | 9780128117361 |
DOIs | |
State | Published - 1 Jan 2019 |
Externally published | Yes |
Keywords
- Biocide
- Biocide resistance
- Biocorrosion
- Biofilm
- Cathodic polarization
- Degradation
- Deterioration
- Electron shuttling
- Exopolymeric materials
- Hydrogen embrittlement
- Metabolite
- Microbial influenced corrosion
- Organic acid