Discover ethanol, a cleaner-burning fuel alternative to gasoline, and the efforts to produce it more efficiently in this video from NOVA. 

Today, most ethanol in the United States is made from corn kernels. But converting corn into ethanol requires lots of energy as well as corn, which might otherwise be used to feed people and livestock. 

The video features research efforts to use less valuable plant matter, called cellulosic biomass, and microorganisms that may be able to accomplish the conversion from plant matter to fuel in a single step.