WEST LAFAYETTE, Ind., June 10 (UPI) -- U.S. biological engineers say they have developed a strain of yeast that is more efficient in producing biofuel from cellulosic plant material.
Purdue University Associate Professor Nathan Mosier, Assistant Professor Miroslav Sedlak and Professor Nancy Ho said they used genes from a fungus to re-engineer a yeast strain Ho developed at Purdue. The researchers said their 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.
"Natural yeast can ferment three sugars: galactose, manose and glucose," Ho said. "The original Ho yeast added xylose to that, and now the fifth, arabinose, has been added."
The scientists said addition of new genes to the Ho yeast strain should increase the amount of ethanol that can be produced from cellulosic material.
In addition, the researchers said they were also able to develop strains that are more resistant to acetic acid, which is released with sugars before the fermentation process during ethanol production. Acetic acid gets into yeast cells and slows the fermentation process, adding to the cost of ethanol production.
The team's findings on acetic acid appear in the journal FEMS Yeast Research. The findings on arabinose are reported in the early online edition of the journal Applied Microbiology and Biotechnology.
