Could cyborg bacteria generate clean power in the future? Researchers at UC Berkeley covered bacteria with small semiconductors that function like solar panels in order to see how much of the sun’s energy they could capture. The cyborg bacteria have a solar efficiency of 80% – which is four times greater than commercial solar panels and six times greater than the chlorophyll plants use in photosynthesis.
Researchers in Peidong Yang’s laboratory gave the nonphotosynthetic bacterium Moorella thermoacetica cadmium, and the bacteria’s natural defense allowed it to produce cadmium sulfide crystals which accrued on the outside of their bodies and essentially acted as mini solar panels. The bacteria normally can produce acetic acid – which can be used for fuel, plastics, or pharmaceuticals – with carbon dioxide (CO2). But using their tiny solar panels, they were able to create acetic acid more efficiently with CO2, light, and water.
Kelsey Sakimoto of Harvard University, a past member of Yang’s group, told the BBC, “It’s shamefully simple, we’ve harnessed a natural ability of these bacteria that had never been looked at through this lens…You grow them in their liquid broth and you just add small aliquots of cadmium solution and you wait a couple of days and out pops these photosynthetic organisms. It’s all very simple, mix-in-a-pot chemistry.”
Artificial photosynthesis techniques can be expensive, but big vats of liquid, in which the bacteria can be kept in sunlight, are really all that’s needed for this new process, so it could work well even in rural areas or developing countries. The self-replicating, self-regenerating bacteria offer a zero-waste technology, according to UC Berkeley.