19
Industrial
Production and Applications of Hemicellulose:Lignin Etherase: Prototype
Development--Tethys Research, LLC,
Dr. Nancy Gail Kravit, Principal Investigator, ngkravit@tethysresearch.com
Dr. Nancy Gail Kravit, Business Official, ngkravit@tethysresearch.com
DOE Grant No. DE‑FG02‑07ER84788
Amount: $749,728
American forests have the
potential to provide environmentally sustainable, carbon-neutral raw material
for much of the nation’s energy and chemical synthesis needs. However, wood has not been used to produce
chemicals and biofuels because current technology
cannot efficiently separate cellulose, hemicellulose,
and lignin (the major components of wood) for downstream processing. The major difficulty in fractionating wood is
breaking the ether bonds between the lignin and hemicellulose
components. Currently, pulp and paper
mills rely primarily on chemical means to break these bonds, but chemical
methods have many disadvantages: damage to
cellulose fibers; inability to cleanly separate the constituents; and serious
environmental challenges. In this
project, a fluorogenic model compound based on hemicellulose will be used to bioprospect
for enzymes that cleave the ether bonds between lignin and hemicellulose. In Phase I, a microorganism designated B603 that
secretes an enzyme capable of breaking ether bonds has been discovered. The enzyme was isolated, and its activity on
native lignin-hemicellulose complexes was verified. In Phase II, processes will be developed to (1)
apply the enzyme to the pre-treatment of wood chips in pulp mills; and (2) more
efficiently convert wood into chemicals, for use in integrated forest biorefineries.
Finally, molecular biology techniques will be used to facilitate the large
scale production of the enzyme.
Commercial Applications and Other Benefits as described by
the awardee: As a pre-treatment for wood chips in a pulp mill, the new
enzyme should allow previously wasted hemicellulose
to be recovered and added back to the pulp, thereby increasing yield. Alternatively, the hemicellulose
could be converted via fermentation into an array of fine chemicals and energy
products, including ethanol. Broadly
speaking, the technology would allow wood, a renewable resource, to be used to
meet a significant portion of