Scientists Have Discovered an Enzyme That Converts Air Into Electricity
The scientists demonstrated that the enzyme, called Huc, turns hydrogen gas into an electric current.
Australian researchers have discovered an enzyme that can convert air into energy.
Australian researchers have discovered an enzyme capable of transforming air into energy. The study, which was recently published in the prestigious journal Nature, shows that the enzyme uses small amounts of hydrogen in the air to generate an electric current. This discovery paves the way for the development of devices that can literally generate energy out of thin air.
The discovery was made by a team of scientists led by Dr. Rhys Grinter, Ashleigh Kropp, a Ph.D. student and Professor Chris Greening from the Biomedical Discovery Institute at Monash University in Melbourne, Australia. The team produced and studied a hydrogen-consuming enzyme sourced from a bacterium commonly found in soil.
Recent work by the team has shown that many bacteria use hydrogen from the atmosphere as an energy source in nutrient-poor environments. “We’ve known for some time that bacteria can use traces of hydrogen in the air as an energy source to help them grow and survive, including in Antarctic soils, volcanic craters and the deep ocean,” Professor Greening said. . “But we didn’t know how they did it, until now.”
In this Nature paper, researchers extracted the enzyme responsible for using atmospheric hydrogen from a bacterium called Mycobacterium smegmatis. They showed that this enzyme, called Huc, turns hydrogen gas into an electric current.
Dr. Grinter notes, “Huc is extremely 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.
The researchers used several cutting-edge methods to uncover the molecular blueprint for the oxidation of atmospheric hydrogen. They used advanced microscopy (cryo-EM) to determine its atomic structure and electrical pathways, pushing the boundaries to produce the most resolved structure of the enzyme reported by this method to date. They also used a technique called electrochemistry to demonstrate that the purified enzyme creates electricity at minimal concentrations of hydrogen.
The laboratory work performed by Mrs. Kropp shows that it is possible to store purified Huc for long periods.
“It’s surprisingly durable. It is possible to freeze or heat the enzyme to 80 degrees Celsius and it retains its power to generate energy,” said Ms. Kropp. “This reflects that this enzyme helps bacteria survive in the most extreme environments.”
The Huc is a “natural battery” that produces a steady electric current from added air or hydrogen. While this research is at an early stage, Huc’s discovery has significant potential to develop small air-powered devices, for example as an alternative to solar-powered devices.
Bacteria that produce enzymes like Huc are common and can be grown in large quantities, meaning we have access to a stable source of the enzyme. Dr. Grinter says a key target for future work is increasing Huc production. “Once we produce Huc in sufficient quantities, the sky is literally the limit for using it to produce clean energy.”
Reference: “Structural basis for bacterial energy extraction from atmospheric hydrogen” by Rhys Grinter, Ashleigh Kropp, Hari Venugopal, Moritz Senger, Jack Badley, Princess R. Cabotaje, Ruyu Jia, Zehui Duan, Ping Huang, Sven T. Stripp, Christopher K Barlow, Matthew Belousoff, Hannah S. Shafaat, Gregory M. Cook, Ralf B. Schittenhelm, Kylie A. Vincent, Syma Khalid, Gustav Berggren and Chris Greening, March 8, 2023, Nature.
DOI: 10.1038/s41586-023-05781-7
