(CNN)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. When he returned, Leadbetter found the jar coated with a dark material.
"I thought, 'What is that?' " Leadbetter explained in a press release. "I started to wonder if long-sought-after microbes might be responsible, so we systematically performed tests to figure that out."
Researchers discovered that the black coating found on the jar was oxidized manganese which had been generated by newly discovered bacteria most likely found in the tap water.
"There is evidence that relatives of these creatures reside in groundwater, and a portion of Pasadena's drinking water is pumped from local aquifers," he said.