Finding ways to produce clean energy and sources that generate green electricity tend to be complex, long-winded, and generally not as easy as simply pulling energy out of thin air. Yet, a group of researchers in Australia has demonstrated just that after discovering an enzyme that can quite literally convert air into energy.
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The team, led by Greening and his colleagues Dr. Rhys Grinter and Ph.D. student Ashleigh Kropp at Monash, recently published their findings in the journal Nature, describing how the enzyme, dubbed ‘Huc,’ is able to convert hydrogen gas into an electrical current.
While certain soil-based bacteria are known to convert hydrogen into energy, how this process works was not completely understood. That was until the Monash team discovered Huc.
Using bacteria found in certain soils, the team was able to produce the Huc enzyme that consumes hydrogen.
We’ve known for some time that bacteria can use the trace hydrogen in the air as a source of energy to help them grow and survive, including in Antarctic soils, volcanic craters, and the deep ocean… But we didn’t know how they did this, until now.
Professor Greening, Monash University Biomedicine Discovery Institute (BDI), Melbourne, Australia
Huc: Nature’s Very Own Battery
To take bacteria from special soil samples and develop the hydrogen-consuming enzyme Huc, the team applied a series of innovative techniques such as cryo-EM imaging advanced microscopy to expose “the molecular blueprint of atmospheric hydrogen oxidation.”
Using cryo-EM imaging to observe the atomic structure and electrical pathways, the team also applied protein film electrochemistry to show how the enzyme, when purified, is able to create electricity from minute hydrogen concentrations.
Each test was conducted at ambient conditions (room temperature and pressure), ensuring results reflected real-world application potential.
In addition to its ability to produce an electrical current from ambient air, the fact that the enzyme is robust and stable makes it particularly promising.
Huc can also be stored for prolonged periods of time, meaning it truly can be considered nature’s battery.
It is astonishingly stable. It is possible to freeze the enzyme or heat it to 80 degrees celsius, and it retains its power to generate energy… This reflects that this enzyme helps bacteria to survive in the most extreme environments.
Ashleigh Kropp, Ph.D. Student, Monash University
After extracting the Huc enzyme from Mycobacterium smegmatis, the team also discovered that the enzyme was capable of producing an electrical current from minute amounts of hydrogen, even at less than atmospheric concentrations.
Huc is extraordinarily efficient. Unlike all other known enzymes and chemical catalysts, it even consumes hydrogen below atmospheric levels – as little as 0.00005% of the air we breathe.
Dr. Rhys Grinter, Monash University
Clean Energy For a Cleaner Future
The Huc-producing bacteria are abundant and can even be grown in relatively large quantities, which makes the enzyme sustainable. According to Dr. Grinter, one of the primary objectives for ensuring clean energy for a cleaner future is to scale up Huc production.
Once we produce Huc in sufficient quantities, the sky is quite literally the limit for using it to produce clean energy.
Dr. Rhys Grinter, Monash University
If scale-up is successful, the team believes that this discovery could pave the way for the development of sophisticated devices with catalysts that oxidize H2 in ambient air, resulting in the self-sufficient generation of electricity.
While there is still a long way to go before even considering the possibility of supporting an entire city or national grid, the hope is that the long-term impact of this cutting-edge enzyme could alleviate stresses on national grids if the theoretical framework can be adopted into practical applications.
This is particularly promising and relevant today as governments and policymakers look to smart, clean energy solutions to address the climate crisis. Being able to pluck energy out of the air using Huc could potentially be a game changer when it comes to combatting climate change.
References and Further Reading
Grinter, R. et al. (2023) “Structural basis for bacterial energy extraction from atmospheric hydrogen,” Nature, 615(7952), pp. 541–547. Available at: https://doi.org/10.1038/s41586-023-05781-7
Scientists discover an enzyme that turns air into electricity, providing a new clean source of energy (2023) Monash Biomedicine Discovery Institute. Available at: https://www.monash.edu/discovery-institute/news-and-events/news/2023-articles/scientists-discover-an-enzyme-that-turns-air-into-electricity-providing-a-new-clean-source-of-energy