New research at Michigan State University and published in the current issue of Nature Communications shows how Geobacter bacteria grow as films on electrodes and generate electricity – a process that’s ready to be scaled up to industrial levels.
The thick biofilm, a gelatin microbial dynamo of sorts, is a combination of cells loaded with cytochromes, metal-based proteins, and pili, hairlike protein filaments discovered and patented by MSU’s Gemma Reguera, associate professor of microbiology.
The biofilms are comparable to an electrical grid. Each cell is a power plant, generating electrical discharges that are delivered to the underlying electrode using a network of cytochromes and pili. The cytochromes are the transformers and towers supplying electricity to the city. The pili represent the sparse-but-mighty powerlines that connect the towers, even those far away from the power plant, to the grid.
Cytochromes and pili work together for shorter ranges – the first 10 layers of cells or so closest to the electrode. As more cells stack on the electrode, the efficiency of the cytochrome as electron carrier diminishes, and the pili do all of the work – discharging electrons 1,000 times faster than normal.
“The pili do all of the work after the first 10 layers, and allow the cells to continue to grow on the electrode, sometimes beyond 200 cell layers, while generating electricity,” said Reguera, who co-published the paper with MSU graduate student Rebecca Steidl and MSU postdoctoral student Sanela Lampa-Pastirk, who work in Reguera’s lab. “This is the first study to show how electrons can travel such long distances across thick biofilms; the pili are truly like powerlines, at the nanoscale.”
The cytochromes lose their transfer speed once they get farther away. Without the wires, you can’t continue to grow the biofilm on the electrode, she added.
The methodical approach to dissect the contribution and interactions between the cytochromes and the pili was the key to this discovery. The researchers used a genetic approach to eliminate key electron carriers in the biofilms, cytochromes and conductive pili, and studied the effect of the mutations in the growth of the biofilm and ability to generate electricity. They also constructed a mutant that produced pili with reduced conductivity.
“We used the mutants to grow biofilms of precise thickness and capacity to produce electricity,” Reguera said. “This information allows us to reconstruct the paths – cytochromes or pili – used by the cells to discharge electrons across the biofilm and to the underlying electrode.”
How the biofilm is mechanistically stratified as it grows in thickness on the electrode without compromising electricity generation was a revelation.
“We went from constructing the cell equivalent of a 10-story building to a 15- and a 20-story building and demonstrated the coordinated action of cytochromes and pili in the bottom floors and the need to discharge electrons via the wires in the upper floors to grid,” Reguera said. “We know that we can build 200-story buildings, which really opens up opportunities for which these biofilms can be used.”
In their natural state, microbes have a taste for waste, she added. Reguera’s bioelectrodes also have a big appetite for waste and are ready to be scaled up and used to cleanup industrial sites while producing electricity as a byproduct. The next phase of this research will explore potential spinoff company options to bring the bioelectrodes to market.
The Latest on: Bioelectrodes
via Google News
The Latest on: Bioelectrodes
- Electrospun CNT embedded ZnO nanofiber based biosensor for electrochemical detection of Atrazine: a step closure to single molecule detectionon January 12, 2020 at 3:15 pm
Deactivation of unbounded sites is done by using the blocker BSA. Protocol for fabrication of bioelectrodes has explained in detail in Annexure H of Supplementary Material. For better understanding, ...
- Elastic kirigami patch for electromyographic analysis of the palm muscle during baseball pitchingon December 27, 2019 at 6:41 am
The wearable device contained kirigami-based stretchable wirings and conductive polymer nanosheet-based ultraconformable bioelectrodes. The research team designed the device to address the ...
- Evaluation of polypyrrole-modified bioelectrodes in a chemical absorption-bioelectrochemical reduction integrated system for NO removalon September 10, 2019 at 2:23 am
A Chemical absorption-bioelectrochemical reduction (CABER) system is based on Chemical absorption-biological reduction (CABR) system, which aims at NO removal and has been studied in many of our ...
- Artificial muscles powered by glucoseon June 19, 2019 at 8:57 am
The scientists behind the study decided instead to use the technology behind bioelectrodes, which can convert chemical energy into electrical energy with the aid of enzymes. They have used ...
- Improving the Lifetime of Bioelectrodes For Solar Energy Conversionon April 26, 2019 at 11:03 am
The use of proteins involved in the photosynthetic process enables the development of affordable and efficient devices for energy conversion. The use of proteins involved in the photosynthetic process ...
- Improving the lifetime of bioelectrodes for solar energy conversionon April 26, 2019 at 7:18 am
Therefore, the design of bioelectrodes operating in an oxygen-free environment was suggested. An important step towards the application Now, operation of the bioelectrode under the exclusion of ...
- 10-023 - Organelle bioelectrodes and methods of makingon July 14, 2018 at 4:33 pm
This invention describes a method of monitoring the metabolic state of an organelle in the presence of a potential organelle modulating agent which comprises the steps of providing at least a first ...
- Why bioelectrodes for energy conversion are not stableon May 26, 2018 at 7:35 am
Researchers have discovered why bioelectrodes containing the photosynthesis protein complex photosystem I are not stable in the long term. Such electrodes could be useful for converting light ...
- Why bioelectrodes for energy conversion are not stableon May 25, 2018 at 7:05 am
Researchers at the Ruhr-Universität Bochum have discovered why bioelectrodes containing the photosynthesis protein complex photosystem I are not stable in the long term. Such electrodes could be ...
- Why bioelectrodes for energy conversion are not stableon May 24, 2018 at 5:00 pm
(Nanowerk News) Researchers at the Ruhr-Universität Bochum have discovered why bioelectrodes containing the photosynthesis protein complex photosystem I are not stable in the long term. Such ...
via Bing News