In the absence of air, microorganisms produce hydrogen using an enzyme called [FeFe]-hydrogenase, one of the most efficient hydrogen-producing biocatalysts known and a promising tool for green hydrogen energy. However, these enzymes are rapidly destroyed when exposed to air, which has so far limited their industrial use.

Now, joint efforts led by scientists from the Photobiotechnology group and the Center for Theoretical Chemistry at Ruhr University Bochum, Germany, have isolated a new type of oxygen-stable [FeFe]-hydrogenase and revealed its “tricks” for this oxygen-stability.

The results are published in the Journal of the American Chemical Society.

Most biochemistry labs that study DNA isolate it within a water-based solution that allows scientists to manipulate DNA without interacting with other molecules. They also tend to use heat to separate strands, heating the DNA to more than 150°F, a temperature a cell would never naturally reach. By contrast, in a living cell DNA lives in a very crowded environment, and special proteins attach to DNA to mechanically unwind the double helix and then pry it apart.

“The interior of the cell is super crowded with molecules, and most biochemistry experiments are super uncrowded,” said Northwestern professor John Marko. “You can think of extra molecules as billiard balls. They’re pounding against the DNA double helix and keeping it from opening.”