Metal-eating bacteria are a unique group of microorganisms that have the ability to rust or corrode metals for a bunch of environmentally friendly practices. I became interested in these buggers a couple of years ago and ended up writing a book based in reality.
This process is known as “metal respiration” and will have a huge impact in several areas like cleaning up waste sites, mining, and may even produce energy.
This group of bacteria can corrode a range of metals including iron, steel, stainless, nickel, zinc, and more. Each different strain consumes a specific metal. For example, some rusters thrive on iron and manganese while others demolish nickel and cobalt. Some types need more oxygen and some like acidic environments. Others thrive with particular types of nutrients and minerals. One type of bacteria is slowly demolishing the Titanic at the bottom of the ocean.
HOW THEY WORK
Metal-eating bacteria use metal ions (atoms with extra or fewer electrons) kind of like plants use sunlight for photosynthesis and normal bacteria live off of organic matter. The rusters steal electrons from over-charged metals for energy. Another group, like the ones that corrode aluminum and stainless steel, actually do the opposite, giving up electrons.
APPLICATION
Metal-eating bacteria have a variety of uses:
BIOREMEDIATION – Metal-eating bacteria can be used to clean up contaminated soils and groundwater by breaking down metal ions and reducing their toxicity. This process is known as bioremediation and can be used to detox places polluted with dangerous materials like lead, cadmium, and mercury.
MINIG – These microbes can pull valuable metals out of ores and minerals in a process known as bioleaching. This process is more sustainable and environmentally friendly than traditional mining methods as it uses bacteria instead of undesireable chemicals.
ENERGY PRODUCTION – Some bacteria could be used as a source of renewable energy. By harnessing the energy generated by metal respiration, they produce electricity, and form environmentally friendly fuel cells.
THE TAKEAWAY
This fascinating group of microorganisms may soon provide ways to heal environmental damage already done and help us keep from doing as much harm to the world.
MY APOCALYPTIC NOVEL
METAL
By J.F. Lawrence
When a disease begins rusting important metals overnight, Terrance Mathison, a veteran turned bioengineer, must assemble a team to find a cure as society crumbles.
EXAMPLES OF RUSTERS
IRON – Leptospirillum Ferriphilum
MANGANESE – Pseudomonas
ZINC – Acidithiobacillus Ferrooxidans
NICKEL – Alcaligenes Eutrophus
CHROME – Dechloromonas
STEEL – Acidithiobacillus ferrooxidans
ALUMINUM – Bacillus and Pseudomonas
STAINLESS STEEL – Thiomonas
FURTHER READING
"Corrosion and Biofouling Control in Water Distribution Systems" by M. K. Hossain and M. A. A. Karim, CRC Press, 2013.
"Biocorrosion of Aluminum and Its Alloys" by J.W. Moulder and P.J. Schreiner, in Handbook of Corrosion Engineering, 2nd Edition, edited by P. Marcus, Springer, 2013.
"Microbial Corrosion of Stainless Steel: A Review" by B.F. Li and W.Q. Chen, Frontiers of Environmental Science & Engineering, 2012, 6(1):33-45.
"Microbial Corrosion of Metals" by R.N. Ghosh, John Wiley & Sons, 2012.
"Bacterial Corrosion of Metals" edited by M. Schwedt, J. Boon, and P. Marcus, Woodhead Publishing Limited, 2006.
"Metal-reducing bacteria in the environment: importance and applications" (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5922566/)
"Bioremediation of Heavy Metals Using Metal-Reducing Bacteria" (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6514171/)
"Metal Respiration in Bacteria: A Review" (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6733910/)