Mutant algae may fuel cars

Chemically-modified algae may become key to the production of hydrogen gas which seen by researchers as a next-generation fuel source.

"We believe there is a fundamental advantage in looking at the production of hydrogen by photosynthesis as a renewable fuel," said David Tiede, a senior chemist the U.S. Department of Energy's Argonne National Laboratory. "Right now, ethanol is being produced from corn, but generating ethanol from corn is a thermodynamically much more inefficient process."

Tiede says that the process would work by exploiting hydrogenase, an enzyme that can create small amounts of hydrogen gas. Tiede and his colleagues at Argonne are working to introduce the hydrogen-generating part of the enzyme into the photosynthesis process to create larger amount of hydrogen gas.

"Biology can do it, but it's making it do it at 5-10 percent yield that's the problem," Tiede said. "What we would like to do is take that catalyst out of hydrogenase and put into the photosynthetic protein framework."

Tiede says algae offers a number benefits over corn and other food crops in fuel production.

"If you have terrestrial plants like corn, you are restricted to where you could grow them," Tiede said. "There is a problem now with biofuel crops competing with food crops because they are both using the same space. Algae provides an alternative, which can be grown in a closed photobioreactor analogous to a microbial fermentor that you could move any place."

Tiede says the research is only in its beginning stages and is still a long way from commercialization.

Hydrogen fuel-cell cars are seen by many as a way to improve fuel efficiency and reduce pollution from transportation.