Study Reveals Enzyme That Converts Air Into Energy
In an article published in the journal Nature , researchers from the Institute of Biomedicine at Monash University in Melbourne, Australia, discovered an enzyme that uses atmospheric hydrogen to produce energy. The team produced and analyzed the hydrogen-consuming enzyme from a common soil bacterium, Mycobacterium smegmatis .
Bacteria capable of producing energy using hydrogen are common in nature and known for a long time. However, this is one of the first studies capable of identifying one of the enzymes responsible for this process, named Mycobacterium smegmatis hydrogenase Huc. By growing the bacteria in the laboratory, the researchers were able to extract Huc hydrogenase and map its molecular structure. In its pure state, the enzyme was able to create electricity in minute concentrations of hydrogen.
According to Henrique Eisi Toma, a professor at the Institute of Chemistry (IQ) at USP, the finding helps to understand the metabolism of these “impressive bacteria”. In the opinion of the specialist, who did not participate in the study, they stand out for using hydrogen gas as a source of energy. Not by chance, hydrogen is an extremely scarce gas in the Earth’s atmosphere. The professor explains that, “in a balloon of one meter in volume, with 1,000 liters of gas, the amount of hydrogen would be equivalent to a grain of pea”.
Another important element of the discovery is the ability of these bacteria to select hydrogen over atmospheric oxygen. The structure of the Huc enzyme is able to “take the hydrogen, extract its energy, transform the hydrogen into a chemical compound and use it to stay alive.” The professor also points out that, in addition to being scarcer than oxygen, hydrogen is much less energetic.
By capturing atmospheric hydrogen, these bacteria are able to utilize it in a process similar to breathing oxygen. The professor says that “the hydrogenase will activate the entire cycle of biomolecules, similar to what we have in the respiratory chain, it would be like saying that it breathes hydrogen”.
According to the authors of the article, the Huc is a “natural battery” that produces a sustained electrical current from air or added hydrogen. And, although the research is at an early stage, the discovery has considerable potential for small air-powered devices to be developed, for example, as an alternative to solar-powered devices.
Finally, Professor Toma also explains that Huc is related to the study of other bacterial enzymes, in particular nitrogenase. This enzyme is capable of producing energy from nitrogen, generating ammonia and hydrogen as by-products. According to him, the atmospheric balance depends on the capacity of the hydrogenase to capture the excess hydrogen present in the atmosphere, “it consumes any excess hydrogen that comes from the atmosphere”.