New research at Washington University in St. Louis explains the cellular processes that allow a sun-loving microbe to "eat" electrons to transfer electricity to use carbon dioxide as fuel for their growth.
Under the guidance of Arpita Bose, Assistant Professor of Biology in the Arts and Sciences, and Michael Guzman, a graduate student in her lab, a team from Washington University showed how a naturally occurring strain of Rhodopseudomonas palustris electrons from conductive substances like metal oxides or rust. The work is described in an article of March 22 in the journal Nature Communications .
The study builds on Bose's earlier discovery that R. palustris TIE-1 can pick up electrons from stainless proxies such as filled electrodes, a process called extracellular electron uptake. R. palustris is phototrophic, that is, it uses energy from light to perform certain metabolic processes. The new research explains the cellular sinks in which this microbe discharges the electrons it receives by electricity.
"It clearly shows for the first time how this activity ̵
This mechanistic knowledge can help harness the microbe's natural capabilities for sustainable energy storage or other bioenergy applications – a potential that has earned the attention of the Department of Energy and the Department of Defense.
" R. palustris Tribes are found in wild and exotic locations such as a rusty bridge in Woods Hole, Massachusetts, from which TIE-1 was isolated," said Bose. "Really, you can find these organisms everywhere, which suggests that the uptake of extracellular electrons could be very common."
Guzman added, "The main challenge is that it is an anaerobe, so you need to grow it in an environment that is not." I have oxygen to harvest light energy. But the other side is that these challenges in this organism are confronted with a great versatility that many other organisms do not have. English: emagazine.credit-suisse.com/app/art…7805 & lang = en. German: emagazine.credit-suisse.com/app/art…2934 & lang = DE In a recent study, the researchers showed that electrons from electricity invade proteins responsible for photosynthesis Surprisingly, when they quenched the ability of microbes to capture carbon dioxide, they observed a 90 percent reduced ability to consume electricity.
"It really wants to fix carbon dioxide with this system," Bose said it takes away – this innate ability – it simply does not want to pick up any electrons. "
She said that the reaction is somewhat akin to a rechargeable battery.
Microbe uses electricity to charge her redox pool to store the electrons and greatly reduce, "said Bose. "To empty the cell, the cell reduces carbon dioxide, the energy for all of which comes from sunlight, and the whole process keeps repeating, so the cell can only produce biomolecules with electricity, carbon dioxide, and sunlight."
All The Washington University team has overcome a number of technical hurdles to complete this study. Mark Meacham of the McKelvey School of Engineering helped develop and manufacture the microfluidic devices that enabled researchers to focus on the activities that took place in cells as the bacteria were fed from power sources. The team also relied on the support of partners such as David Fike in the Department of Earth and Planetary Sciences, who helped Bose and Guzman use secondary ion mass spectrometry to determine how the microbe uses carbon dioxide.
The new research answers fundamental scientific questions and offers many opportunities for future bioenergy applications.
"It has long been recognized that microbes can interact with analogues of nearby electrodes – minerals that are also charged," said Guzman. "But no one really knew how this process could be carried out by photoautotrophs, such as those organisms that fix their own carbon and use light to generate energy, and this research closes a barely understood gap in the field."
Bose The lab is working on using these microbes for the production of bioplastics and biofuels.
"We hope that this ability to combine electricity and light to reduce carbon dioxide could help find sustainable solutions to the energy crisis," said Bose.