lignin biomass recalcitrane
Post on 14-Sep-2014
2.759 views
DESCRIPTION
Lignin is one of the major substance in the world. This slide presented lignin, role in the plant, biosynthesis, lignin evolution, and bioengineering or lignin.TRANSCRIPT
LIGNIN
A Twenty-first Century Challenge
Isroi (http://isroi.com)
BIOMASS RECALCITRANE
Cell Wall Model: Cellulose, Hemicellulose and Lignin
Cell Wall Model: Cellulose, Hemicellulose and Lignin
Cell Wall Model: Cellulose, Hemicellulose and Lignin
Pseudocolor SEM micrograph of lignin redeposited on cellulose (10,000X).
www.nrel.gov/.../technology.cfm/tech=18
Lignin:
• Nature’s second abundant organic substances
• Product of phenylpropanoid pathway
• Lignin – monolignol/lignin-forming pathway steps evolved during transition (evolution) of plants from the water habitat to the land habitat.
Plant evolution
LIGNIN: Moleculer Basis and role in plant adaptation
Diagram showing changes in cell wall
composition during the course of
evolution.
Sarkar P et al. J. Exp. Bot. 2009;60:3615-3635
© The Author [2009]. Published by Oxford University Press [on behalf of the Society for Experimental Biology]. All rights
reserved. For Permissions, please e-mail: [email protected]
Sarkar P et al. J. Exp. Bot. 2009;60:3615-3635
Figure 3. Phylogenetic tree
showing the distribution of
lignin monomer composition
across major lineages. *, S-
units are only found in cell
cultures of Ginkgo, not in wood
(Novo Uzal et al., 2009). **,
Lignin-like structures are
reported in some mosses and
green algae, but the presence of
real lignin in these nonvascular
species remains questionable;
red algae have been barely
studied (Weng et al., 2008b;
Martone et al., 2009).
Vanholme R. et.al. Plant Physiol. 2010:153:895-905
Copyright © 2010. © 2010 American Society of Plant Biologists. All rights reserved.
LIGNIN: Moleculer Basis and role in plant adaptation
Red Seaweed
Like many land plants, this red seaweed produces lignin, a primary component of wood. (Credit: Kathy Ann Miller)
http://www.science20.com/news_releases/biofuels_research_makes_a_plant_evolution_discovery
Selaginela
Selaginela
http://esciencenews.com/
Both lignin and cellulose are found in the rigid cell walls of the xylem cells (those that conduct water) in the primitive plant, Selaginella. (Credit: Zina Deretsky, National Science Foundation; Selaginella cross section SEM by Jing-Ke Weng, Clint Chapple, Purdue University; Lignin structure from Wout Bergjan, John Ralph, Marie Baucher (Annual Review of Plant Biology, Vol. 54:519-546, June 2003); Cellulose structure from http://www.chusa.jussieu.fr/disc/bio_cell/)
Fossil Ginkgo leaves from the Jurassic of England. Some 160 million years ago.
Modern Ginkgo leaves.
Corn Stover
Wood
http://siteresources.worldbank.org
Softwood Hardwood
• Larger, longer cells • Water transported by cells
• Contains large-diameter vessels • Water transported by these vessels
Lignin: Major monolignols of lignins.
Hatfield R., Vermerris W. Plant Physiol. 2001:126:1351-1357
H-unit P-hydroxyphenyl
G-unit guaiacyl
S-unit syringyl
Lignin: Major monolignols of lignins.
(A) Monolignol esters 30-32 found in grasses.
(D) Several dominant substructures present in native lignins.
Lignin Structure:
Freudenbrerg (1965)
Brunow et al. 1998
Lignin Structure:
Lignin Structure:
Lignin Biosynthesis Pathway
Lignin Pathway Evolution
Humphreys, J. M., C. C. S. Chapple. 2002. Rewriting the lignin roadmap. Plant Bio. 5, 224–229.
Lignin Pathway Evolution
Humphreys, J. M., C. C. S. Chapple. 2002. Rewriting the lignin roadmap. Plant Bio. 5, 224–229.
Vascular Plant Diversification and Lignification
Vascular Plant Diversification and Lignification
Pinus taeda
Medicago sativa
Vascular Plant Diversification and Lignification
Loblolly pine (Pinus taeda)
Tamarack (Larix laricina) Ebony (Diospyros ebenum)
Douglas fir
compression
normal
Black cottonwood
tension
normal
Monilignol Biosynthesis
7.3.2
Monilignol Biosynthesis
7.3.3
Monilignol Biosynthesis
7.3.4
Monilignol Biosynthesis
7.3.5
Monilignol Biosynthesis
7.3.6
Monilignol Biosynthesis
7.3.7
Monilignol Biosynthesis
7.3.8
Monilignol Biosynthesis
http://aob.oxfordjournals.org/content/91/6/673/F3.expansion
Monilignol Biosynthesis
Inherent Shortcomings in lignin analyses: a critical juncture and the urgent need
Lignin Isolation Procedure:
• Strong acid (sulphite pulping proceses) • Strong alkaline (kraft pulping) • Milled wood lignin • Björkman lignin
Figure 2. Representation of a lignin polymer from poplar, as predicted from NMR-based lignin
analysis (adapted from Stewart et al., 2009).
Vanholme R. et.al. Plant Physiol. 2010:153:895-905
Copyright © 2010. © 2010 American Society of Plant Biologists. All rights reserved.
Lignin Structure: Lignin subunit and lignin structural analyses by NMR spectroscopy
Quantification of lignin amounts, lignin degradation protocols, and synthetic dehydropolymerizates
• Klason Lignin Various non-lignin componens, such as tannins, was determined
• Acetyl bromide • Thioglycolic acid
Modulation of monolignol pathway and peroxidase enzymatic step
Lignin, a key component of plant cell walls, is normally synthesized from three simple monolignols (top). The hydroxyl group (OH), shown in red, must remain unmodified for these precursors to link up. Liu's team created a novel enzyme (green "ribbon" structure) that can methylate this specific hydroxyl group. This enzyme may therefore lead to ways to interfere with lignin biosynthesis in plants to make them easier to break down for biofuels.
Chang-Jun Liu
Native Lignin Macromolecular Configuration
Freudenbrerg (1965)
1965
Lignin Structure: 1970s-1980s
Adler (1977)
Lignin Structure:
Lignin Structure:
Partial structure of a hypothetical lignin molecule from European beech (Fagus sylvatica ). The phenylpropanoid units that make up lignin are not linked in a simple, repeating way. The lignin of beech contains units derived from coniferyl alcohol, sinapyl alcohol, and para-coumaryl alcohol in the approximate ratio 100:70:7 and is typical of angiosperm lignin. Gymnosperm lignin contains relatively fewer sinapyl alcohol units. (After Nimz 1974.)
Brunow et al. 1998
Lignin Structure: 1990s and 2000s
Figure 2. Representation of a lignin polymer from poplar, as predicted from NMR-based lignin
analysis (adapted from Stewart et al., 2009).
Vanholme R. et.al. Plant Physiol. 2010:153:895-905
Copyright © 2010. © 2010 American Society of Plant Biologists. All rights reserved.
Lignin Structure: Lignin subunit and lignin structural analyses by NMR spectroscopy
Future Outlook
Future Outlook
1. Monolignol transport to the cell/wall 2. Lignin initiation sites 3. Lignin Primary Sequences/New Chemistries 4. Re-oxidation of the growing lignin chains 5. Monolignol radical and lignin primary chain
interactions, proposed template polymerization, and lignin association
6. Transcriptional control of individual cell wall formation processes, biomechanics, and biodegradation of plant cell walls.
Thanks You
Biomass Recalcitrance
Alkali nitrobenzene oxidation/thioacidolysis/permanganate oxidation degradation procedures