The researchers demonstrated that the enzyme, called Huc, converts hydrogen gas into an electric current.
Australian scientists have discovered an enzyme that can convert air into energy.
Australian researchers have discovered an enzyme capable of converting air into energy. The study, which was recently published in the prestigious journal Nature, shows that the enzyme utilizes small amounts of hydrogen in the air to generate an electric current. This breakthrough paves the way for the development of devices that can literally generate energy from thin air.
The discovery was made by a team of researchers led by Dr. Rhys Grinter, Ashleigh Kropp, a Ph.D. student and Professor Chris Greening from the Monash University Biomedicine Discovery Institute in Melbourne, Australia. The team produced and studied a hydrogen-consuming enzyme derived from a bacterium commonly found in soil.
Recent work from 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 trace amounts of hydrogen in the air as an energy source to help them grow and survive, including in Antarctic soil, volcanic craters and the deep ocean,” Professor Greening said. “But we didn’t know how they did this until now.”
Here Nature paper, the researchers extracted the enzyme responsible for using atmospheric hydrogen from a bacterium called Mycobacterium smegmatis. They showed that this enzyme, called Huc, converts hydrogen gas into an electric current.
Dr. Grinter notes, “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.”
The researchers used several cutting-edge methods to reveal the molecular blueprint for atmospheric hydrogen oxidation. They used advanced microscopy (cryo-EM) to determine its atomic structure and electrical pathways, pushing boundaries to produce the most resolved enzyme structure reported by this method to date. They also used a technique called electrochemistry to demonstrate that the purified enzyme creates electricity at small hydrogen concentrations.
Laboratory work carried out by Mrs Kropp shows that it is possible to store purified Huc for long periods.
“It is amazingly stable. It is possible to freeze the enzyme or heat it to 80 degrees Celsius, and it retains its power to generate energy,” said Ms. Body. “This reflects that this enzyme helps bacteria survive in the most extreme environments.”
Huc is a “natural battery” that produces a continuous electric current from air or added hydrogen. While this research is at an early stage, the discovery of Huc has significant potential for developing small air-powered devices, for example as an alternative to solar-powered devices.
The bacteria that produce enzymes like Huc are common and can be grown in large quantities, meaning we have access to a sustainable source of the enzyme. Dr. Grinter says a key goal for future work is to scale up 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, 08 Mar 2023, Nature.
DOI: 10.1038/s41586-023-05781-7