Utilizing Electricity-Producing Bacteria for Powering Programmable ‘Biohybrid’ Systems
It is thought that one day, bacteria combined with electronic devices could be used in biosensors and bioreactors to produce electricity.
Before this is achieved, scientists must first develop materials that can efficiently and controllably harvest the electricity that is generated.
Now, researchers have reported the development of one such material that has allowed them to create a so-called “biohybrid” system that conducts electrons from exoelectrogenic bacteria—electricity-producing bacteria.
These bacteria are capable of producing electrons, moving them across their outer membrane, and then away from their cell.
Developing the Biohybrid Structure
The team’s research has been published in ACS Applied Materials & Interfaces and explains how the researchers developed the biohybrid by making a porous hydrogel made from carbon nanotubes and silica nanoparticles, bound together by strands of DNA. To this structure, they then added exoelectrogenic bacteria along with a nutritional culture medium.
This structure, unlike many other conductive materials, provides a suitable “home” where the bacteria can thrive, with results from the research demonstrating that not only was electron conduction from the bacteria to an electrode highly efficient but also that bacteria were able to grow well enough on the material to completely penetrate it. To stop the flow of electrons, the researchers used an enzyme that snipped DNA strands, causing the material to fall apart.
A nanocomposite material (purple) conducts electrons released by exoelectrogenic bacteria (green) to generate electricity. Image used courtesy of ACS Applied Materials & Interfaces 2020
Developing Biohybrid Electronics
Using this bacterial structure could be especially useful for developing programmable biohybrid electronics and systems because the DNA strands that hold the material together can be manipulated by varying their sequence and size, thus enabling the manipulation of conductivity and other key properties.
The Potential of Biohybrid Materials
With research indicating that the bacterial structure remains stable for several days, it is thought that the application possibilities of this and other such biohybrid materials could stretch beyond biosensors and bioreactors as it is developed further, finding use in industrial applications like fuel cells and electronic power systems.
