California (CNN) (07/17/20) — Scientists have discovered a type of bacteria that eats and gets its calories from metal, after suspecting they exist for more than a hundred years but never proving it.

Now microbiologists from the California Institute of Technology (or Caltech) accidentally discovered the bacteria after performing unrelated experiments using a chalk-like type of manganese, a commonly found chemical element.

Dr. Jared Leadbetter, professor of environmental microbiology at Caltech in Pasadena, left a glass jar covered with the substance to soak in tap water in his office sink, and left the vessel for several months when he went to work off campus.