[LINK] Life

[Stephen Loosley]

Biologists discover bacteria that eat pure electrons, redefining life

By Sebastian Anthony on July 18, 2014  www.extremetech.com/extreme

Some intrepid biologists at the University of Southern California (USC) have discovered bacteria that survives on nothing but electricity — rather than food, they eat and excrete pure electrons.

Some of these bacteria also have the curious ability to form into ‘biocables,’ microbial nanowires that are centimeters long and conduct electricity as well as copper wires — a capability that might one day be tapped to build long, self-assembling networks.

As you may recall from high school biology, almost every living organism consumes sugar to survive. When it gets right down to it, everything you eat is ultimately converted or digested into single molecules of glucose. These sugars have excess electrons — and the oxygen you breathe really wants those electrons. By ferrying electrons from sugar to oxygen, a flow of electrons — i.e. energy — is created, which is then used to carry out various vital tasks around your body (triggering electrons, beating your heart, etc.)

These special bacteria found, however, don’t need no poxy sugars — instead, they cut out the middleman and feed directly on electrons. 

To discover these bacteria, and to cultivate them in the lab, the USC biologists quite simply scooped up some sediment from the ocean, took it back to the lab, stuck some electrodes into it, and then turned on the power. When higher voltages are pumped into the water, the bacteria “eats” electrons from the electrode; when a lower voltage is present, the bacteria “exhales” electrons onto the electrode, creating an electrical current. 

The USC study very carefully controlled for other sources of nutrition — these bacteria were definitely eating electrons directly.

All told, various researchers around the world have now discovered upwards of 10 different kinds of bacteria that feed on electricity — and, interestingly, they’re not from the same family.

Kenneth Nealson of USC, speaking to New Scientist about his team’s discovery, said: “This is huge. What it means is that there’s a whole part of the microbial world that we don’t know about.”

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Cheers,
Stephen