Can we use 'reverse photosynthesis' to make biofuels?

Scientists have discovered that the same process that helps plants grow also helps enzymes break down plants faster in the production of biofuel.

Elise Amendola/AP/File
Gas station attendant Carlos Macar pumps gas in Andover, Mass. Artificial photosynthesis is enticing more researchers looking for alternative transportation fuels, according to a recent report.
Tony Avelar/The Christian Science Monitor
Postdoctoral scholar Shane Ardo uses light to produce hydrogen gas (the bubbles) in water at the California Institute of Technology. There, at the Joint Center for Artificial Photosynthesis, scientists are trying to harness sunlight to generate chemical fuel, specifically by splitting water to generate hydrogen.

German scientists say they have discovered a way to significantly speed up the process of making fuel from biomass, which includes non-food plant material such as wood or grass.

Researchers have discovered that monooxygenases, enzymes already widely used to make bioplastics and biofuel — a clean-burning fuel, or ethanol, made from agricultural waste instead of petroleum — work significantly faster and more efficiently when exposed to sunlight. The enzymes break down biomass to release sugars from plant fibers which are then fermented into ethanol. But without sunlight, the process takes a long time.

"They've [the enzymes] been surprisingly slow," Claus Felby, a professor from University of Copenhagen, told The Christian Science Monitor in an interview.

"The reason is that we didn't provide them with the right condition, because they appear to be light driven," he says.

By using sunlight as a catalyst for the enzymes that break down biomass, and adding chlorophyll, a molecule in plants that helps convert sunlight into energy, the enzymes were able to do their work 100 times faster, Professor Felby and other scientists say in a paper published Monday in the journal Nature Communications. A process that typically takes enzymes a full day of work took only 10 minutes in the team's lab experiments.

"Introducing lights opens up so much more energy and it doesn't cost you a dime," Felby says.

The researchers call their newly discovered technique "reverse photosynthesis," since instead of helping plants grow, as in traditional photosynthesis, the new process boosts the work of the enzymes by helping them break plants down faster.

Now, the scientists are working with a Danish biotech company to try the process in a production facility. If the technique were to be used commercially, said Felby, fuel and plastics production facilities would need to be redesigned to allow sunlight — and the right amount of it — inside.

"Introducing light into these processes turns a lot of things upside down," says Felby.

You've read  of  free articles. Subscribe to continue.

Dear Reader,

About a year ago, I happened upon this statement about the Monitor in the Harvard Business Review – under the charming heading of “do things that don’t interest you”:

“Many things that end up” being meaningful, writes social scientist Joseph Grenny, “have come from conference workshops, articles, or online videos that began as a chore and ended with an insight. My work in Kenya, for example, was heavily influenced by a Christian Science Monitor article I had forced myself to read 10 years earlier. Sometimes, we call things ‘boring’ simply because they lie outside the box we are currently in.”

If you were to come up with a punchline to a joke about the Monitor, that would probably be it. We’re seen as being global, fair, insightful, and perhaps a bit too earnest. We’re the bran muffin of journalism.

But you know what? We change lives. And I’m going to argue that we change lives precisely because we force open that too-small box that most human beings think they live in.

The Monitor is a peculiar little publication that’s hard for the world to figure out. We’re run by a church, but we’re not only for church members and we’re not about converting people. We’re known as being fair even as the world becomes as polarized as at any time since the newspaper’s founding in 1908.

We have a mission beyond circulation, we want to bridge divides. We’re about kicking down the door of thought everywhere and saying, “You are bigger and more capable than you realize. And we can prove it.”

If you’re looking for bran muffin journalism, you can subscribe to the Monitor for $15. You’ll get the Monitor Weekly magazine, the Monitor Daily email, and unlimited access to CSMonitor.com.