Method for modifying lignin structure using monolignol ferulate conjugates
Inventors
Ralph, John • Grabber, John H. • Hatfield, Ronald D. • Lu, Fachuang
Assignees
US Department of Agriculture USDA • Wisconsin Alumni Research Foundation
Publication Number
US-9388285-B2
Publication Date
2016-07-12
Expiration Date
2030-07-06
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Abstract
Described is an isolated lignified plant cell wall including lignin, wherein the lignin includes a ferulate residue incorporated therein, such as from coniferyl ferulate and/or sinapyl ferulate. Also described is a method to make the isolated lignified plant cell wall, and the lignin produced by the method.
Core Innovation
The invention describes isolated lignified plant cell walls containing lignin that incorporates a ferulate residue derived from monolignol-ferulate conjugates such as coniferyl ferulate and sinapyl ferulate. The method of manufacturing modified lignin involves conducting lignin-producing polymerization reactions in the presence of these polymerizable conjugates, allowing at least a portion to incorporate into the resulting lignin polymer. This modification changes lignin structure by introducing ferulate residues into lignin, creating lignins with ester linkages in the backbone that facilitate cleavage and more efficient processing.
The problem solved relates to the complexity and recalcitrance of lignin in plant cell walls, which severely limits forage digestibility, saccharification, and biofuel production. Lignin is indigestible by ruminants and inhibits enzyme accessibility to cell wall polysaccharides, thus impeding sugar release for fermentation. Traditional lignin modification strategies have been insufficient, so there is a need for modifications that improve digestibility and fermentability without causing adverse plant growth effects.
The invention capitalizes on the metabolic malleability of lignification, allowing incorporation of novel monomer conjugates into lignin polymers through radical coupling reactions. Incorporating monolignol-ferulate conjugates into lignin provides cleavable ester inter-unit linkages that enable easier depolymerization under milder conditions, improving delignification and enzymatic hydrolysis. This approach avoids replacing the entire monomer pool, instead strategically introducing monomers that maintain plant viability while enhancing lignin extractability and biomass processing.
Claims Coverage
The patent discloses four claims focusing on isolated lignified plant cell walls containing lignin with ferulate residues derived from sinapyl ferulate and specifically derived from trees or certain tree families and genera. There are two main inventive features identified from the independent claims.
Isolated lignified plant cell wall containing lignin with ferulate residue from sinapyl ferulate
An isolated lignified plant cell wall comprising lignin, wherein the lignin includes a ferulate residue incorporated therein, the ferulate residue being derived from sinapyl ferulate.
Source of the plant cell wall derived from specific tree families and genera
The isolated lignified plant cell wall is derived from a tree, specifically from trees belonging to the families Myrtaceae or Salicaceae, or hybrids thereof, including genera such as Salix, Eucalyptus, Corymbia, and Angophora, or their hybrids.
The claims focus on lignified plant cell walls incorporating ferulate residues from sinapyl ferulate and emphasize the source of the cell walls being specific tree families and genera, establishing intellectual property rights over these modified lignin-containing cell walls derived from those plants.
Stated Advantages
Incorporation of monolignol-ferulate conjugates into lignin enables easier depolymerization due to ester linkages, facilitating mild-condition delignification and improved enzymatic hydrolysis.
Modified lignin improves the digestibility and fermentability of plant cell wall polysaccharides for animal feeds and biofuel production.
The method reduces energy and processing costs during biomass conversion, such as pulping and saccharification, while maintaining plant growth and development.
The modified lignins allow for quantum improvements in biomass processing compared to incremental changes from altering traditional monolignol pathways.
Documented Applications
Production of animal feeds and forages with improved digestibility for ruminants.
Manufacturing pulp for papermaking with easier delignification processes.
Providing fermentable substrates for biofuel and biochemical production via improved saccharification.
Interested in licensing this patent?