Some species of bacteria can produce electricity; these are termed electrogenic bacteria. These organisms can produce a current as part of their metabolism. The term exoelectrogen refers to any microorganism with the ability to transfer electrons extracellularly. An example of an organism that can do so is Shewanella oneidensis MR-1. These bacteria reside in oxygen-free environments; here they take in metal minerals and electrodes via current-conducting proteins in their cell membranes. Utilization of exoelectrogens forms part of the development of microbial fuel cells.
As part of plans to create sustainable electricity generation, as well as to assist with wastewater treatment, researchers from University of California, Santa Barbara have discovered the means to confer the ability to generate electricity upon non-electrogenic bacteria. The research used a bio-compatible molecular additive to confer electrogenesis onto bacteria that have not evolved in this way. This was achieved using a synthetic molecule called DFSO+, which contains an iron atom at its core. This molecule was was used to a create solution to which test bacteria were exposed to. This was through creating an addition to the bacterial pathway, something analogous to a prosthetic limb.
In terms of future applications, the research group think the converted bacteria possess the potential to convert organic material like activated sludge from waste water treatment into renewables like ethanol, hydrogen gas, and electric current. In a research note, one of the investigating scientists – Zach Rengert – explains the advantages: “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.”
The research has been published in the journal Chem, under the title “A Ferrocene-Based Conjugated Oligoelectrolyte Catalyzes Bacterial Electrode Respiration.”
In related news, in the quest to find new and efficient means of generating power a research group have developed a battery, resembling a thin sheet of paper, which is powered by microorganisms.
