Biologist refines ethanol process
Biologist Steven Gorsich is working on the cellular and molecular
level to refine the process of turning lignocellulose waste – corn
stalks, wood chips, and grass clippings – into ethanol.
According to the Michigan Department of Agriculture, there are five corn ethanol plants in Michigan, with another five under construction or proposed. The ethanol industry has drawn sharp criticism worldwide for using food crops for energy – a practice that critics say trades one problem for another.
Gorsich’s focus is on using plant waste products for feasible ethanol production. There are two problems with using plant waste products. A large portion of the sugars are not easily fermentable by yeast, and many growth and fermentation inhibitors are generated during the fermentation process.
The key to success: stronger yeast cells that can metabolize the sugars while withstanding the inhibitors that are generated.
Last summer Gorsich and his team of students finished screening the
6,000 genes in a single yeast cell to find the strongest ones that
stand up best to the lignocellulose-derived inhibitors. These
results have already informed the research team how these inhibitors
affect the cell’s physiology. In the long term, they will engineer
the strongest genes to make stronger yeast cells.
With stronger yeast cells, the ethanol production process using plant waste products will become more efficient and practical.
Gorsich says scientists in labs worldwide are working on this problem. He may not be the one to find the solution, but he expects that someone will soon.
“Within five years, these cells will be ready to go,” he says. “This technology of taking waste products and turning them into ethanol is very near.”
And Gorsich concedes that in the long term, ethanol may not be the answer to the world’s fuel problems – even by using the waste products his work involves. However, he says ethanol can be one of many solutions for the short term.
“Within the next 10 to 20 years, ethanol will likely be the
liquid fuel that will get us over the gap,” he says.
• By Barbara Sutherland Chovanec
