In the beginning, scientists thought photosynthesis was the only foundation for life on Earth, and that sunlight was required for the energy that percolated through the food chain. Then in the 1970s, chemosynthesis was confirmed in life around deep-sea volcanic vents (and more recently, cold seeps). Now researchers have identified several species of bacteria that get energy directly from energy, or electrosynthesis. The bacteria feed on electrons, with no intermediary conversions from matter. Researchers are using batteries in mines to lure electrosynthesizing bacteria so they can culture them and learn how to make bioelectric devices that are cleaner and more efficient than conventional mechanical electricity converters.
Geobacter sulfurreducens breathes by transferring electrons to iron oxides found in soil. (From NOVA Next.)