The eco-friendly fuel ethanol is usually made from grain, but the U.S. Department of Energy (DOE) would like to find other renewable materials that will be cost-effective alternatives, such as paper pulp, sawdust, straw and grain hulls.
A UWM professor recently helped DOE do just that by analyzing the DNA of a bacterium that can break down cellulose, the major structural component of plants that is also found in forestry by-products (including paper) and waste feedstocks.
Mark McBride, a professor of biological sciences, worked with DOE's Joint Genome Institute and scientists at Los Alamos National Laboratory to examine the genes of Cytophaga hutchinsonii that are responsible for the organism's ability to digest cellulose the first step in the carbohydrate's conversion into ethanol.
Sequencing the genome of C. hutchinsonii provides what McBride calls a "parts list" for the microbe, allowing scientists to explore how bacteria use these parts to build and run their key functions some of which have potential uses in bioenergy.
The genome has revealed surprises, he says.
"Microorganisms typically require two kinds of enzymes to efficiently break down cellulose," he says. "One type cuts the long carbohydrate molecule through the middle, while another chews small pieces from the ends."
Not so with C. hutchinsonii. Although it efficiently digests cellulose, in DNA analysis it appears to be lacking one of the usual enzymes, suggesting that it may use either a novel strategy or novel enzymes.
The information McBride reports could help DOE devise mixtures of microorganisms or enzymes that will more efficiently convert cellulose into glucose, and finally into ethanol.
McBride's interest in C. hutchinsonii goes beyond its possible value in bioenergy.
What really intrigues him is that it's a "gliding bacterium," able to crawl rapidly over surfaces by an unknown mechanism, which is the main sub
Contact: Mark McBride
University of Wisconsin - Milwaukee