The estimated total number of bacteria of the planet is estimated at five nonillion, and the world of bacteria is stocked with potential, including electrical production.
Researchers from the University of California are looking to tap into some of that potential by looking at “electrogenic” bacteria, which generate current as part of their metabolism. The research team has found a new way to mimic that ability upon non-electrogenic bacteria, opening up opportunities for new developments in sustainable electricity generation and wastewater treatment.
“The concept here is that if we just close the lid of the wastewater treatment tank and then give the bacteria an electrode, they can produce electricity while cleaning the water,” says Zach Rengert, co-first author of the study. “And the amount of electricity they produce will never power anything very big, but it can offset the cost of cleaning water.”
This from Science Daily:
The bacteria that inspired this study, Shewanella oneidensis MR-1, live in oxygen-free environments and can breathe in metal minerals and electrodes—instead of air—via current-conducting proteins in their cell membranes. Most bacterial species, however, do not have such proteins and therefore naturally do not produce current. Taking inspiration from S. oneidensis‘ membrane-spanning conductive proteins, the team hypothesized that with the right kind of bio-compatible molecular additive, this electrogenesis might be conferred to bacteria that have not evolved to do so.
[The researchers] built a molecule called DFSO+, which contains an iron atom at its core. To add the DFSO+ to bacteria, the researchers dissolved a small amount of the rust-colored powder into water and added that solution to bacteria. Within a few minutes, the synthetic molecule found its way into the bacteria’s cell membranes and began conducting current through its iron core, providing a new pathway for the bacteria to shuttle electrons from inside to outside the cell.
“It’s a totally different strategy for microbial electrical energy generation,” says Nate Kirchofer, co-author of the study. “Before, we were building these devices, and we were limited to optimizing them by changing reactor materials and architectures or using genetic engineering techniques.”