The new experiment comes from Washington University in St. Louis and it relates to a class of bacteria called phototrophes, such as Cyanobacteria, which can transform light energy into an electrochemical gradient of protons across the photosynthetic membrane. However, there are many more types of these bacteria than previously thought. Such organisms have remained hidden for so long because they do not grow well (if at all) in science laboratories on standard culture media.
The new research was conducted on a bacterium called Rhodopseudomonas palustris TIE-1 (a rod-shaped Gram-negative purple non-sulfur bacterium, known for its ability to switch between four different modes of metabolism.) This organism constructs a conduit to accept electrons across its outer membrane, which helps the bacterium to survive under nutrient-scarce conditions.
According to principal scientist Professor Arpita Bose: “The molecular underpinning of this process has been difficult to unravel until our work. This is mostly due to the complex nature of the proteins involved in this process. But now, for the first time, we understand how phototrophic microbes can accept electrons from solid and soluble substances.”
The following video detail the newly discovered process:
The significance of the study is that it will contribute to the design of bacterial platforms. Within this, phototrophic bacteria will be able to feed on electricity and carbon dioxide in order to produce value-added compounds such as biofuels. The researchers also hope to develop a a biological marker that will help them to identify other electricity-eating bacteria in the environment.
The findings have been published in the journal mBio, with the research paper titled “Photoferrotrophs Produce a PioAB Electron Conduit for Extracellular Electron Uptake.”
