Sun Grant/TAES Internal Research Project

Introduction of Cellulosomes into Low Lignin Plants for Improved Cellulose and Hemicellulose Digestion

Neal Stewart, Plant Sciences (PI)
Joe Bozell, Forest Products Center
Nikki Labbe, Forest Products Center
Joshua Yuan, Plant Sciences
Edward Bayer, Weizmann Institute, Israel
Richard Dixon, Noble Foundation

Abstract:
For cellulosic ethanol to become a reality, the cost of production must be drastically decreased.
Considerable savings could potentially be realized by utilizing plant biotechnology to decrease the following costs: feedstock transportation, pretreatment, and hydrolysis. We imagine the production of a low-lignin feedstock in which cell walls are hydrolyzed by cellulosomes on-the-plant. This research will attempt, for the first time, to express and assemble cellulosomes in transgenic, low lignin plants. The cellulosome is composed of a scaffold on which a suite of cellulases and hemicellulases are tethered. Cellulosomes.are naturally produced by a host of plant cell wall digesting microbes. Genetically transforming plants with these engineered molecular machines could result in condensed plant matter for shipment to a biorefinery; matter that is already partially converted to simple sugars for further processing. We will use low lignin and normal lignin tobacco as a model to assess the efficacy of cellulosomes for cell wall digestion. Several hypotheses relating to the additivity and synergy as well as the role of lignin in cell wall digestion will be tested, thus adding to our basic knowledge of materials conversion using biomimetic processes. Following proof-of-concept studies, switchgrass will be engineered with cellulosomes as potentially drastically improved feedstock.

Funded: July, 2007
Projected End Date: July, 2009

Reports and Publications:
None to date