Artificial enzymes produce hydrogen gas in cyanobacteria


Hydrogen gas is a promising energy carrier for the sustainable energy systems of the future. Today hydrogen gas is produced almost exclusively from fossil feedstocks, and water splitting through electrolysis is still problematic due to large energy losses and dependence on the precious metal platinum.

In a new study, researchers at Uppsala University report how hydrogen, for the first time, can be produced from photosynthetic cyanobacterial cells using artificial enzymes. The enzymes can utilize the photosynthetic cell’s internal energy production and storage to produce hydrogen gas, using only water and energy from light.

Hydrogen gas is naturally produced and combusted in the metabolism of some green algae and bacteria. The enzymes responsible for this are called hydrogenases. The new study describes how an artificial hydrogenase can be created using a combination of synthetic biology and synthetic chemistry. A synthetic gene, derived from an enzyme in green algae, encoding an inactive form of an efficient hydrogenase was introduced into the cyanobacterial host. The resulting pre-enzyme was then activated via the introduction of a synthetic catalyst. This artificial enzyme becomes fully functional within living cells and interacts with the cellular metabolism under different cultivation conditions.

The reported procedure enables, for the first time, easy acquirement of non-native, non-natural hydrogen producing enzymes within a photosynthetic organism. This opens up unique possibilities to investigate novel enzymes, incorporating designed catalysts prepared on the laboratory bench, in an environment highly interesting for sustainable biofuel production.

The article, “Generation of a functional, semisynthetic [FeFe]-hydrogenase in a photosynthetic microorganism”, was published in Energy & Environmental Science and is available at dx.doi.org/10.1039/C8EE01975D.

For more information, contact:
Gustav Berggren, tel.: +46 73 633 2698, email: gustav.berggren@kemi.uu.se
Peter Lindblad, tel.: +46 70 425 0498, email: peter.lindblad@kemi.uu.se
Adam Wegelius, tel.: +46 70 393 7119, email: adam.wegelius@kemi.uu.se


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