These special bacteria, geobacter metallireducens bacterium, doesn't need sugars but their life process by definition, eat AND excrete electricity or electrons. With advanced genetic engineering, they could be bred into nano wires, nano-sized electrical circuits or even fully operational nano-machines!
Biologists discover electric bacteria that eat pure electrons rather than sugar, redefining the tenacity of life | ExtremeTech
Scientists Reveal How Microbe 'Eats' Electricity | IFLScience