scholarly journals Lignocellulose pretreatment in a fungus-cultivating termite

2017 ◽  
Vol 114 (18) ◽  
pp. 4709-4714 ◽  
Author(s):  
Hongjie Li ◽  
Daniel J. Yelle ◽  
Chang Li ◽  
Mengyi Yang ◽  
Jing Ke ◽  
...  
Keyword(s):  
Cell Walls ◽  
2D Nmr ◽  
Lignocellulose Degradation ◽  
Plant Cell Walls ◽  
Radical Coupling ◽  
Feeding Experiments ◽  
Starting Point ◽  
Fungus Comb ◽  
Phenolic Polymer ◽  
Lignin Depolymerization

Depolymerizing lignin, the complex phenolic polymer fortifying plant cell walls, is an essential but challenging starting point for the lignocellulosics industries. The variety of ether– and carbon–carbon interunit linkages produced via radical coupling during lignification limit chemical and biological depolymerization efficiency. In an ancient fungus-cultivating termite system, we reveal unprecedentedly rapid lignin depolymerization and degradation by combining laboratory feeding experiments, lignocellulosic compositional measurements, electron microscopy, 2D-NMR, and thermochemolysis. In a gut transit time of under 3.5 h, in young worker termites, poplar lignin sidechains are extensively cleaved and the polymer is significantly depleted, leaving a residue almost completely devoid of various condensed units that are traditionally recognized to be the most recalcitrant. Subsequently, the fungus-comb microbiome preferentially uses xylose and cleaves polysaccharides, thus facilitating final utilization of easily digestible oligosaccharides by old worker termites. This complementary symbiotic pretreatment process in the fungus-growing termite symbiosis reveals a previously unappreciated natural system for efficient lignocellulose degradation.

scholarly journals New Products Generated from the Transformations of Ferulic Acid Dilactone

Biomolecules ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 175 ◽  
Author(s):  
Ying He ◽  
Yuan Jia ◽  
Fachuang Lu
Keyword(s):  
Ferulic Acid ◽  
Succinic Acid ◽  
Plant Cell ◽  
Cell Walls ◽  
New Products ◽  
Plant Cell Walls ◽  
Reaction Conditions ◽  
Radical Coupling ◽  
Naoh Treatment ◽  
Derivatives Of

Various ferulic acid (FA) dimers occurring in plant cell walls, such as 8-5-, 8-O-4-, 5-5-, and 8-8-coupled dimers, are effective antioxidants and potential antimicrobials. It is necessary to access these diferulates as reference compounds to validate those isolated from plants. 3,6-bis(4-hydroxy-3-methoxyphenyl)-tetrahydrofuro-[3,4-c]furan-1,4-dione, a 8-8-coupled FA dilactone generated from ferulic acid via radical coupling, has been used to synthesize 8-8-coupled FA dimers although few reports investigated the distribution of products and mechanisms involved in the transformation of FA dilactone. In this work, the FA dilactone, obtained from FA by a peroxidase-catalyzed radical coupling, was reacted under various base/acid conditions. Effects of reaction conditions and workup procedures on the distribution of products were investigated by GC-MS. The isolated products from such treatments of FA dilactone were characterized by NMR. New derivatives of FA dimer including 2-(4-hydroxy-3-methoxybenzylidene)-3-(hydroxyl-(4-hydroxy-3-methoxyphenyl)methyl)succinic acid and 2-(bis(4-hydroxy-3-methoxyphenyl)-methyl)-succinic acid were produced from NaOH treatment. Another novel 8-8-coupled cyclic FA dimer, diethyl 6-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-7-methoxy-1,2-dihydronaphthalene-2,3-dicarboxylate was identified in products from FA dilactone treated by dry HCl in absolute ethanol. Mechanisms involved in such transformations were proposed.

scholarly journals Synthesis of Vanillin from Lignin

2019 ◽  
pp. 1-5
Author(s):  
Njiema Gitaari ◽  
Kandie Benard ◽  
Joyline Gichuki ◽  
Patrick Kareru
Keyword(s):  
Cell Walls ◽  
Food Industry ◽  
Process Condition ◽  
Dry Weight ◽  
Wood Ash ◽  
Plant Cell Walls ◽  
Wide Range ◽  
Kraft Cooking ◽  
Ft Ir ◽  
Phenolic Polymer

Vanillin (4-hydroxy-3-methoxybenzaldehyde) is the major flavour constituent of vanilla. It has a wide range of applications in food industry and in perfumery. Vanillin is also very useful in the synthesis of several pharmaceutical chemicals. Lignin is a phenolic polymer which is found in plant cell walls with a structure depending strongly on the source of lignin and the process condition, which should be adjusted for different samples. In this work, lignin was extracted from Kraft cooking liquor of wood ash. The amount of extracted lignin was 25.5%, based on oven dry weight of wood ash. The lignin obtained was then reacted with alkaline nitrobenzene and refluxed at 170°C for 3 hours to obtain vanillin. The FT-IR spectrum of vanillin was similar to standard. The yield obtained from oxidation with nitrobenzene was 3.9%.

Solution-State 2D NMR Spectroscopy of Plant Cell Walls Enabled by a Dimethylsulfoxide-d6/1-Ethyl-3-methylimidazolium Acetate Solvent

2013 ◽  
Vol 85 (6) ◽  
pp. 3213-3221 ◽  
Author(s):  
Kun Cheng ◽  
Hagit Sorek ◽  
Herbert Zimmermann ◽  
David E. Wemmer ◽  
Markus Pauly
Keyword(s):  
Nmr Spectroscopy ◽  
Plant Cell ◽  
Cell Walls ◽  
2D Nmr ◽  
Plant Cell Walls ◽  
2D Nmr Spectroscopy ◽  
Solution State

Exploration of cell wall architecture with the rapid-freeze deep-etch technique

1993 ◽  
Vol 51 ◽  
pp. 128-129
Author(s):  
Béatrice Satiat-Jeunemaitre ◽  
Chris Hawes
Keyword(s):  
Plant Cell ◽  
Cell Walls ◽  
Cell Biology ◽  
Molecular Model ◽  
Three Dimensional ◽  
Secretory Activity ◽  
Wall Structure ◽  
Specimen Preparation ◽  
Molecular Architecture ◽  
Plant Cell Walls

The comprehension of the molecular architecture of plant cell walls is one of the best examples in cell biology which illustrates how developments in microscopy have extended the frontiers of a topic. Indeed from the first electron microscope observation of cell walls it has become apparent that our understanding of wall structure has advanced hand in hand with improvements in the technology of specimen preparation for electron microscopy. Cell walls are sub-cellular compartments outside the peripheral plasma membrane, the construction of which depends on a complex cellular biosynthetic and secretory activity (1). They are composed of interwoven polymers, synthesised independently, which together perform a number of varied functions. Biochemical studies have provided us with much data on the varied molecular composition of plant cell walls. However, the detailed intermolecular relationships and the three dimensional arrangement of the polymers in situ remains a mystery. The difficulty in establishing a general molecular model for plant cell walls is also complicated by the vast diversity in wall composition among plant species.

Quantum Mechanical Calculations Suggest That Lignin Polymerization Is Kinetically Controlled

2019 ◽  
Author(s):  
Terry Gani ◽  
Michael Orella ◽  
Eric Anderson ◽  
Michael Stone ◽  
Fikile Brushett ◽  
...  
Keyword(s):  
Plant Cell ◽  
First Principles ◽  
Plant Cell Wall ◽  
Biological Processes ◽  
Plant Cell Walls ◽  
Biomass Valorization ◽  
Effective Strategies ◽  
Radical Coupling ◽  
Kinetically Controlled ◽  
Atomistic Models

Lignin is an abundant biopolymer important for plant function while holding promise as a renewable source of valuable chemicals. Although the lignification process in plant cell walls has been long-studied, a comprehensive, mechanistic understanding on the molecular scale remains elusive. A better understanding of lignification will lead to improved atomistic models of the plant cell wall that could, in turn, inform effective strategies for biomass valorization. Here, using first-principles quantum chemical calculations, we show that a simple model of kinetically-controlled radical coupling broadly rationalizes qualitative experimental observations of lignin structure across a wide variety of biomass types, thus paving the way for predictive, first-principles models of lignification while highlighting the ability of computational chemistry to help illuminate complex biological processes.

Wheat cell walls and constituent polysaccharides induce similar microbiota profiles upon in vitro fermentation despite different short chain fatty acid end-product levels.

2021 ◽  
Author(s):  
Shiyi Lu ◽  
Deirdre Mikkelsen ◽  
Hong Yao ◽  
Barbara Williams ◽  
Bernadine Flanagan ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Gut Microbiota ◽  
Plant Cell ◽  
Cell Walls ◽  
Short Chain Fatty Acid ◽  
Chain Fatty Acid ◽  
Plant Cell Walls ◽  
Human Gut ◽  
In Vitro Fermentation

Plant cell walls as well as their component polysaccharides in foods can be utilized to alter and maintain a beneficial human gut microbiota, but it is not known whether the...

scholarly journals Plant Cell Wall Hydration and Plant Physiology: An Exploration of the Consequences of Direct Effects of Water Deficit on the Plant Cell Wall

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1263
Author(s):  
David Stuart Thompson ◽  
Azharul Islam
Keyword(s):  
Cell Wall ◽  
Water Content ◽  
Bacterial Cellulose ◽  
Plant Cell ◽  
Cell Walls ◽  
Plant Cell Wall ◽  
Plant Cell Walls ◽  
Cell Wall Polysaccharides ◽  
Degree Of Hydration ◽  
Cellulose Composites

The extensibility of synthetic polymers is routinely modulated by the addition of lower molecular weight spacing molecules known as plasticizers, and there is some evidence that water may have similar effects on plant cell walls. Furthermore, it appears that changes in wall hydration could affect wall behavior to a degree that seems likely to have physiological consequences at water potentials that many plants would experience under field conditions. Osmotica large enough to be excluded from plant cell walls and bacterial cellulose composites with other cell wall polysaccharides were used to alter their water content and to demonstrate that the relationship between water potential and degree of hydration of these materials is affected by their composition. Additionally, it was found that expansins facilitate rehydration of bacterial cellulose and cellulose composites and cause swelling of plant cell wall fragments in suspension and that these responses are also affected by polysaccharide composition. Given these observations, it seems probable that plant environmental responses include measures to regulate cell wall water content or mitigate the consequences of changes in wall hydration and that it may be possible to exploit such mechanisms to improve crop resilience.

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