April 09 Issue - Employee Monthly Magazine
Piling on to tackle the nation’s energy needs
Laboratory researchers are finding exploitable weaknesses
in plant fibers that could help turn biomass into
biofuels. Image by Donald Montoya
Laboratory researchers have collaborated
in an effort to cost-effectively turn inedible
biomass, such as switch grass or cornhusks,
into alternative fuel in an energy efficient
manner. The problem might seem
simple enough on the surface, but it’s a
lot tougher than it appears.
Plant cellulose—the fibrous material that
makes plants woody—is created when
plants synthesize glucose (sugar) molecules
into long chains. These chains bind
into sheets cemented by hydrogen bonds,
an electrostatic attraction between positively
charged portions of a molecule and
negatively charged portions. The plant
spins these sheets into tough fibers.
If cellulose could be broken down into
sugars using cellulose-attacking enzymes,
the sugars could be fermented into potential
biofuels such as ethanol or butanol.
Unfortunately, the fibers are tough to
crack.
Researchers Tongye Shen and Gnana Gnanakaran
of Theoretical Division and Paul Langan
of Biosciences Division have noted a weakness
in plant cells that could provide a mechanism
to more easily convert plant matter into
simple sugars.
Langan teamed up with colleagues from the
U.S. Department of Agriculture and the French
Center for Vegetable Macromolecule Research
to use neutrons to view the crystalline structure
of cellulose. In separate research, Shen
and Gnanakaran developed a lattice-based
model to examine cellulose structure.
The research showed irregularities in the
hydrogen bond structure of cellulose, and that
the irregularities can be induced at varying
temperatures.
“We have identified a chink in the armor of a
very tough and worthy adversary—the cellulose
fiber,” said Gnanakaran, who leads the theory part of a large multidisciplinary Laboratory
Directed Research and Developmentfunded
biofuels project. Langan, who directs
this project, added that “these results are some
of the first to come from this team and are a
step toward making biofuels from cellulosic
biomass economically effective.”
Shen and Gnanakaran’s work was published
this month in Biophysical Journal, while the
work of Langan and colleagues appeared in
the September 2008 issue of Biomacromolecules.
The complementary research provided
a two-pronged attack on the problem.
--James E. Rickman
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