"Bionic leaf" uses Bacteria to Turn Solar Energy into Liquid Fuel

Harvard University's Faculty of Arts and Sciences, Harvard Medical School and the Wyss Institute for Biologically Inspired Engineering at Harvard University have developed a way to produce isopropanol using what they call a "bionic leaf".

The "bionic leaf" uses solar power to split water into hydrogen and oxygen. Then, the hydrogen is fed to a bacterium called Ralstonia eutropha. An enzyme takes the hydrogen back to protons and electrons and combines them with carbon dioxide to replicate. Next, new pathways in the bacterium are metabolically engineered to make isopropanol. The artificial leaf depends on catalysts made from materials that are inexpensive and readily accessible.

"This is a proof of concept that you can have a way of harvesting solar energy and storing it in the form of a liquid fuel," said Pamela Silver, a Core Faculty at the Wyss Institute.

The team's next challenge is to increase the bionic leaf's ability to translate solar energy to biomass by optimizing the catalyst and the bacteria. Their findings are published in PNAS.