UofM researchers find microbial cocktail best for isobutanol production

In Michigan, researchers at the University of Michigan discovered that fungus and E. coli bacteria have joined forces to turn tough, waste plant material into isobutanol, a biofuel that matches gasoline’s properties better than ethanol. While much previous research has focused on trying to create a “superbug” that could tackle the whole job of processing waste plant materials into biofuels, the group argues that a team of microbial specialists can do better.

The fungus E. coli is already very good at breaking down tough plant material into sugars. Escherichia coli, meanwhile, is relatively easy for researchers to genetically modify. A researcher at the University of California-Los Angeles provided E. coli bacteria that had been engineered to convert sugars into isobutanol.

The fungi turned the roughage into sugars that fed both microbe species with enough left over to produce isobutanol. The team managed to get 1.88 grams of isobutanol per liter of fluid in the ecosystem, the highest concentration reported to date for turning tough plant materials into biofuels. They also converted a large proportion of the energy locked in the corn stalks and leaves to isobutanol—62 percent of the theoretical maximum.