By Beth Mole
A lone bacterium, genetically tweaked, can demolish switchgrass and ferment the sugary rubble to ethanol in one fell swoop. The microbe’s one-step conversion of the crop eliminates the need for expensive plant-digesting treatments, offering the potential for cheaper biofuels.
Plucked from hot springs, the bacterium Caldicellulosiruptor bescii grows around 80° Celsius, and naturally wrecks tough, complex plant molecules such as cellulose. Breaking down such roughage into fermentable sugars is one of the trickiest feats for converting plants to ethanol fuel, says geneticist Janet Westpheling of the University of Georgia in Athens. Standard methods require extra steps or costly combinations of enzymes.