Using a fungus and E. coli bacteria, University of Michigan researchers have turned inedible waste plant material into isobutanol. The waste used in the initial work was corn stalks and leaves. Isobutanol has 82 percent of the energy in gasoline, whereas ethanol has only 67 percent. It also has the added advantage over ethanol of not mixing easily (or absorbing) water. So it is a viable candidate to replace ethanol as a gasoline additive. The fungi turns the plant roughage into sugars that are then converted by escherichia coli to isobutanol. Through bioengineering the researchers believe they can produce a variety of petroleum-based chemicals through this same process.