APPLICATIONS OF TECHNOLOGY:
- Biofuels: reduced cell wall recalcitrance and lignin polymerization in feedstocks (e.g., poplar, eucalyptus, switchgrass, miscanthus)
- Paper production: reduced pulping cost associated with delignification
- Forage: increased digestibility of crops used as animal feed (e.g., alfalfa)
- Increased saccharification efficiency with milder pretreatment
- No interference with plant growth or defense mechanisms
- Can be directly applied to monocots and dicots
Dominique Loqué and Aymerick Eudes of the Joint BioEnergy Institute (JBEI) have developed a technology that overcomes lignin recalcitrance without negatively affecting plant growth and development.
The JBEI researchers produced novel monolignols called “stoppers” that, when incorporated in lignin chains, reduce the incorporation of additional monolignols in the chain. (Monolignols are the building blocks of lignin). As a result, the size and degree of polymerization of the lignin polymer is reduced. This technology is designed to produce the stoppers only in lignified woody tissues, i.e., vessels and fibers, to avoid any interference with plant defense mechanisms against pathogens and UV stress.
In Arabidopsis model plants, researchers demonstrated a more than 60% increase in saccharification efficiency of biomass using several different pretreatments. The JBEI technology focuses on biosynthetic modifications that remove the propanoid tail of the monolignols containing sites for polymerization. By using a dominant approach—one that involves dominant traits and uses precursors and promoters that are conserved between plant species—the researchers anticipate that the specific secondary cell wall promoter used for this strategy can also be used in other dicot plants such as poplar and eucalyptus. Furthermore, the dominant strategy is also transferable to bioenergy grasses using monocot-specific promoters.
Lignin is the primary source of cell wall recalcitrance and the main factor limiting efficient conversion of biomass to biofuel, digestibility of forage, and pulping efficiency in the paper production industry. In the past, lignin recalcitrance has been overcome by reducing lignin content in plants. However, this strategy can impact plant growth, development and pathogen resistance. By modifying the lignin structure rather than reducing lignin content, the JBEI approach represents a significant advance in the field.
The Joint BioEnergy Institute (JBEI, www.jbei.org) is a scientific partnership led by the Lawrence Berkeley National Laboratory and including the Sandia National Laboratories, the University of California campuses of Berkeley and Davis, the Carnegie Institution for Science and the Lawrence Livermore National Laboratory. JBEI’s primary scientific mission is to advance the development of the next generation of biofuels.
DEVELOPMENT STAGE: Proven principle. Validated in Arabidopsis.
STATUS: Patent pending. Available for licensing or collaborative research.
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REFERENCE NUMBER: EIB-2929