Purdue University scientists have improved a strain of yeast that can produce more biofuel from cellulosic plant material by fermenting all five types of the plant’s sugars.

The researchers used genes from a fungus to re-engineer a yeast strain developed at Purdue. The new yeast can ferment the sugar arabinose in addition to the other sugars found in plant material such as corn stalks, straw, switchgrass and other crop residues.

The addition of new genes to the yeast strain should increase the amount of ethanol that can be produced from cellulosic material. Arabinose makes up about 10 percent of the sugars contained in those plants.

In addition to creating this new arabinose-fermenting yeast, the scientists also were able to develop strains that are more resistant to acetic acid, which gets into yeast cells and slows the fermentation process, adding to the cost of ethanol production.