Wired Cover Story: One Molecule Could Cure Our Addiction to Oil

By Evan Ratliff 09.24.07 | 2:00 PM

Prologue
The Chemistry

On a blackboard, it looks so simple: Take a plant and extract the cellulose. Add some enzymes and convert the cellulose molecules into sugars. Ferment the sugar into alcohol. Then distill the alcohol into fuel. One, two, three, four — and we're powering our cars with lawn cuttings, wood chips, and prairie grasses instead of Middle East oil.

Unfortunately, passing chemistry class doesn't mean acing economics. Scientists have long known how to turn trees into ethanol, but doing it profitably is another matter. We can run our cars on lawn cuttings today; we just can't do it at a price people are willing to pay.

The problem is cellulose. Found in plant cell walls, it's the most abundant naturally occurring organic molecule on the planet, a potentially limitless source of energy. But it's a tough molecule to break down. Bacteria and other microorganisms use specialized enzymes to do the job, scouring lawns, fields, and forest floors, hunting out cellulose and dining on it. Evolution has given other animals elegant ways to do the same: Cows, goats, and deer maintain a special stomach full of bugs to digest the molecule; termites harbor hundreds of unique microorganisms in their guts that help them process it. For scientists, though, figuring out how to convert cellulose into a usable form on a budget driven by gas-pump prices has been neither elegant nor easy. To tap that potential energy, they're harnessing nature's tools, tweaking them in the lab to make them work much faster than nature intended.

Wired Magazine, Sept. 24, 2007