The Gas Bug

Bacteria + Sugarcane = Diesel Hybrid Medical Animation/Photo Researchers; Getty Images; Don Mason/Corbis

E. coli has earned a nasty reputation for upsetting stomachs and killing people. But now scientists at LS9, a start-up in South San Francisco, are putting the bad bug to good use, genetically engineering it to excrete biodiesel. The fuel "burns just like diesel," says Greg Pal, the senior director at LS9 [see Breeding the Oil Bug, about the rise of microbial biofuels].

In September, LS9 made headlines with the launch of a pilot plant in its hometown that turns out hundreds of gallons of the biodiesel a week. The plant mixes modified E. coli with sugarcane in large vats of water. The microbes metabolize the sugars and excrete fatty acids that have the same hydrocarbon configuration as petroleum. Unlike other biodiesel setups, LS9's fuel is easy to collect -- it floats to the top of the water and is skimmed off like cream from milk -- and can go straight into your gas tank.

For the full story check out the November issue of Popular Science, out now!