Iogen Specializes in Producing Ethanol from Cellulosic Material.

Conventional yeast can ferment glucose to ethanol, but it cannot ferment xylose. Xylose makes up about 30 percent of the sugar from agricultural residues, and the inability to ferment xylose would represent a major loss of ethanol yield, Ho said.

The Purdue researchers altered the genetic structure of the yeast so that it now contains three additional genes that make it possible to simultaneously convert glucose and xylose to ethanol. The ability to ferment xylose increases the yield of ethanol from straw by about 40 percent. Read