Bionic leaf: using bacteria to convert solar energy into fuel

Harvesting sunlight is a trick plants mastered more than a billion years ago, using solar energy to feed themselves from the air and water around them through photosynthesis. Scientists have also figured out how to harness solar energy, using electricity from photovoltaic cells to yield hydrogen that can be later used in fuel cells.
Hydrogen has failed to catch on as a practical fuel for cars or for power generation in a world designed around liquid fuels. Now scientists from a team spanning Harvard University’s Faculty of Arts and Sciences, Harvard Medical School and the Wyss Institute for Biologically Inspired Engineering at Harvard University have created a system that uses bacteria to convert solar energy into a liquid fuel. Their work integrates an "artificial leaf," which uses a catalyst to make sunlight split water into hydrogen and oxygen, with a bacterium engineered to convert carbon dioxide plus hydrogen into the liquid fuel isopropanol.
Pamela Silver, the Elliott T. and Onie H. Adams Professor of Biochemistry and Systems Biology at HMS and an author of the paper, calls the system a bionic leaf, a nod to the artificial leaf invented by the paper’s senior author, Daniel Nocera, the Patterson Rockwood Professor of Energy at Harvard University.
"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 Silver, who is Core Faculty at the Wyss Institute. "Dan’s formidable discovery of the catalyst really set this off, and we had a mission of wanting to interface some kinds of organisms with the harvesting of solar energy. It was a perfect match."