Lignin, a complex aromatic polymer in terrestrial plants, contributes significantly to biomass recalcitrance to microbial and/or enzymatic deconstruction. To reduce biomass recalcitrance, substantial endeavors have been exerted on pretreatment and lignin engineering in the past few decades. Lignin removal and/or alteration of lignin structure have been shown to result in reduced biomass recalcitrance with improved cell wall digestibility. While high lignin content is usually a barrier to a cost-efficient application of bioresource to biofuels, the direct correlation of lignin structure and its concomitant properties with biomass remains unclear due to the complexity of cell wall and lignin structure. Advancement in application of biorefinery to production of biofuels, chemicals, and biomaterials necessitates a fundamental understanding of the relationship of lignin structure and biomass recalcitrance. In this mini-review, we focus on recent investigations on the influence of lignin chemical properties
The term "Lignin characterization" (or "Lignin analysis") refers to a group of activities within lignin research aiming at describing the characteristics of a lignin by determination of its most important properties. Most often, this term is used to describe the characterization of technical lignins by means of chemical or thermo-chemical analysis. Technical lignins are lignins isolated from various biomasses during various kinds of technical processes such as wood pulping. The most common technical lignins include lignosulphonates (isolated from sulfite pulping), kraft lignins (isolated from kraft pulping black liquor), organosolv lignins (isolated from organosolv pulping), soda lignins (isolated from soda pulping) and lignin residue after enzymatic treatment of biomass. Lignins can be characterized by determination of their purity, molecular structure and thermal properties. For certain applications, other properties such as electrical properties or color may be relevant to determine. The dry ...
One new trend in lignin research is to steer biosynthetic pathways toward the biosynthesis of molecules that, upon incorporation into the lignin polymer, will improve lignin degradation. This idea stems from the growing list of newly discovered lignin monomers, from the observation that lignin is able to readily copolymerize alternative units that derive from incomplete monolignol biosynthesis in plants with pathway perturbations, and from examples in which plants with altered lignin structures are shown to be viable and more easily processed (Pilate et al., 2002; Huntley et al., 2003; Ralph et al., 2006; Leplé et al., 2007). This concept of copolymerizing alternative lignin monomers into the polymer has already been demonstrated in a biomimetic system by polymerizing coniferyl ferulate together with normal monolignols into maize primary cell walls (Grabber et al., 2008). The resulting lignin, now strongly enriched in easily breakable ester bonds in the lignin backbone, degrades at lower ...
Bioreactor landfills have become a feasible alternative to the typical â dry tombâ landfill. By recirculating leachate and/or adding additional liquid wastes, bioreactor landfills operate to rapidly degrade and transform organic wastes. The reactions within a bioreactor landfill create elevated temperatures. The intent of this study was to determine the effect of elevated temperature on the degradation of lignocellulose compounds. In order to observe the effects of temperature on lignin, small bioreactors were created in the laboratory. Several experiments were performed by the authors. Solubility of lignin based on temperature and time of thermal exposure were conducted. In addition, degradation studies were conducted based on biological treatment of lignin as well as a combination of biological and thermal treatment. Samples were collected at specified intervals to determine the amount of water soluble lignin (WSL), volatile fatty acids (VFAs), lignin monomers, and/or methane present. Lignin ...
The conventional method for lignin quantitation in the pulp industry is the Klason lignin and acid-soluble lignin test, which is standardized according to TAPPI[37] or NREL[38] procedure. The cellulose is first decrystallized and partially depolymerized into oligomers by keeping the sample in 72% sulfuric acid at 30 °C for 1 h. Then, the acid is diluted to 4% by adding water, and the depolymerization is completed by either boiling (100 °C) for 4 h or pressure cooking at 2 bar (124 °C) for 1 h. The acid is washed out and the sample dried. The residue that remains is termed Klason lignin. A part of the lignin, acid-soluble lignin (ASL) dissolves in the acid. ASL is quantified by the intensity of its UV absorption peak at 280 nm. The method is suited for wood lignins, but not equally well for varied lignins from different sources. The carbohydrate composition may be also analyzed from the Klason liquors, although there may be sugar breakdown products (furfural and 5-hydroxymethylfurfural). A ...
The conventional method for lignin quantitation in the pulp industry is the Klason lignin and acid-soluble lignin test, which is standardized according to SCAN or NREL procedure. The cellulose is first decrystallized and partially depolymerized into oligomers by keeping the sample in 72% sulfuric acid at 30 C for 1 h. Then, the acid is diluted to 4% by adding water, and the depolymerization is completed by either boiling (100 C) for 4 h or pressure cooking at 2 bar (124 C) for 1 h. The acid is washed out and the sample dried. The residue that remains is termed Klason lignin. A part of the lignin, acid-soluble lignin (ASL) dissolves in the acid. ASL is quantified by the intensity of its UV absorption peak at 280 nm. The method is suited for wood lignins, but not equally well for varied lignins from different sources. The carbohydrate composition may be also analyzed from the Klason liquors, although there may be sugar breakdown products (furan and hydroxymethylfuran). A solution of hydrochloric ...
Sugarcane is a subtropical crop that produces large amounts of biomass annually. It is a key agricultural crop in many countries for the production of sugar and other products. Residual bagasse following sucrose extraction is currently underutilized and it has potential as a carbohydrate source for the production of biofuels. As with all lignocellulosic crops, lignin acts as a barrier to accessing the polysaccharides, and as such, is the focus of transgenic efforts. In this study, we used RNAi to individually reduce the expression of three key genes in the lignin biosynthetic pathway in sugarcane. Furthermore, these genes, caffeoyl-CoA O-methyltransferase ( CCoAOMT), ferulate 5-hydroxylase ( F5H) and caffeic acid O-methyltransferase ( COMT), impact lignin content and/or composition. ...
Several analytical methods have been developed to measure the lignin content corresponding to different plant species and different regions. The sulphuric acid method is commonly used for objective determinations of lignin content using near-infrared spectroscopy. Lignin is a complex polymer of lignin units. The types and ratios of lignin units vary among taxonomic classes of plants. To compare the lignin content as determined by different methods of chemical analysis, fallen leaves of different species were analysed using both the acid detergent and acetyl bromide procedures. Near-infrared reflectance spectra were obtained for each sample of dried ground leaves, and stepwise multiple linear regression analyses were performed to compare the amounts of lignin determined using acid detergent and acetyl bromide. In monocotyledonous herbaceous plants, the lignin content determined by acetyl bromide was more than twice that determined by acid detergent. Despite the difference in the values, ...
Lignin, as highly cross-linked and three-dimensional organic polymer, is the second most abundant in nature following cellulose.1 Due to its complex and rigid structure, lignin is hard to decompose.2 Over 50-60 million tons of lignin are produced annually in the world, most of which come from the black liquor of the paper industry.3 Lignin waste is usually burned resulting in low heat and power energy generation efficiency. Therefore, new approaches for lignin utilization,4 for example production of high value-added products from lignin, are required.5 Microbes are known to naturally decompose lignin.6 Among them, white rot fungi is known as the most efficient microbe for lignin degradation that produces three peroxidases7 and laccase enzymes.8 The copper-containing laccase (p-diphenol oxygen oxidoreductase, EC 1.10.3.2) is able to catalyze the one-electron oxidation of phenolic substrates9 that supply electrons to the laccase molecule for the four electron reduction of oxygen to water.10 This ...
The antiradical and antimicrobial activity of lignin and lignin-based films are both of great interest for applications such as food packaging additives. The polyphenolic structure of lignin in addition to the presence of O-containing functional groups is potentially responsible for these activities. This study used DPPH assays to discuss the antiradical activity of HPMC/lignin and HPMC/lignin/chitosan films. The scavenging activity (SA) of both binary (HPMC/lignin) and ternary (HPMC/lignin/chitosan) systems was affected by the percentage of the added lignin: the 5% addition showed the highest activity and the 30% addition had the lowest. Both scavenging activity and antimicrobial activity are dependent on the biomass source showing the following trend: organosolv of softwood | kraft of softwood | organosolv of grass. Testing the antimicrobial activities of lignins and lignin-containing films showed high antimicrobial activities against Gram-positive and Gram-negative bacteria at 35 °C and at low
TY - GEN. T1 - Lignin recovery from alkaline hydrolysis and glycerolysis of oil palm fiber. AU - Hassan, Nur Syakilla. AU - Badri, Khairiah. PY - 2014/1/1. Y1 - 2014/1/1. N2 - In the present work, two types of treatment namely alkaline hydrolysis and glycerolysis have been conducted for lignin extraction from oil palm empty fruit bunch (EFB) fiber. Lignin has been retrieved from two sequential methods, which was the klason lignin from residue and lignin from precipitation of the filtrate. Alkaline hydrolysis was performed using 10% NaOH solution at room condition. This has extracted 13.0 % lignin. On the other hand, glycerolysis was carried out using 70% glycerol catalyzed with 5% of 1 M NaOH at 60-70 °C. This has successfully extracted 16.0% lignin. The SEM micrographs exhibited some physical changes on the surface where the impurities and waxes have been removed, exposing the,lumen. Besides that, FTIR analysis was conducted on untreated EFB, treated EFB and extracted lignin. Delignification ...
Read "Methylenetetrahydrofolate reductase modulates methyl metabolism and lignin monomer methylation in maize, Journal of Experimental Botany" on DeepDyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips.
TY - JOUR. T1 - Optimised recovery of lignin-derived phenols in a Scottish fjord by the CuO oxidation method. AU - Loh, Pei Sun. AU - Miller, Axel E. J.. AU - Reeves, Alison D.. AU - Harvey, S. Martyn. AU - Overnell, Julian. PY - 2008. Y1 - 2008. N2 - Lignin is found only in vascular plant tissues, hence monitoring of lignin in aquatic environments is important in the determination of the sources and fate of terrestrial organic matter (OM). Concentrations of lignin-derived phenols provide an estimate of the amount of terrestrial OM in a system. Other lignin parameters such as the ratios of syringyl to vanillyl (S/V) and cinnamyl to vanillyl (C/V) phenols provide information on vegetation sources; and the ratios of vanillic acid to vanillin, (Ad/Al)v, and syringic acid to syringaldehyde, (Ad/Al)s, indicate the degradation stage of lignin materials. Concentrations of lignin-derived phenols were determined for the surface and subsurface sediments of a Scottish sea loch, Loch Creran, using a CuO ...
TY - CHAP. T1 - Effect of transition metal catalyst on lignin oxidation during alkaline hydrogen peroxide pretreatment. AU - Li,Zhenglun. AU - Hodge,David. PY - 2011. Y1 - 2011. N2 - Biomass lignocellulose can be used as feedstock for bioethanol production, and a pretreatment is necessary for achieving high ethanol yield and economical feasibility. As a method to increase enzyme digestibility of biomass by selective delignification, alkaline hydrogen peroxide (AHP) pretreatment has been proposed and studied. The lignin recalcitrance in lignocellulose biomass can be removed by H 2O 2 oxidation and the enzymatic hydrolysis efficiency of the polysaccharides can be greatly improved. However, a big issue with AHP pretreatment is the high cost of hydrogen peroxide during the pretreatment, and the selectivity of the oxidant need to be improved, i.e. to achieve highest pretreatment efficiency with low level of H 2O 2 loading. In 1890s, Fenton discovered that iron ion can catalyze the oxidation of ...
Lignin is a class of complex organic polymers that form important structural materials in the support tissues of vascular plants and some algae. Lignins are particularly important in the formation of cell walls, especially in wood and bark, because they lend rigidity and do not rot easily. Chemically, lignins are cross-linked phenolic polymers. Lignin was first mentioned in 1813 by the Swiss botanist A. P. de Candolle, who described it as a fibrous, tasteless material, insoluble in water and alcohol but soluble in weak alkaline solutions, and which can be precipitated from solution using acid. He named the substance "lignine", which is derived from the Latin word lignum, meaning wood. It is one of the most abundant organic polymers on Earth, exceeded only by cellulose. Lignin constitutes 30% of non-fossil organic carbon and 20-35% of the dry mass of wood. The Carboniferous Period (geology) is in part defined by the evolution of lignin. The composition of lignin varies from species to species. An ...
Titanium dioxide (TiO2) is added in sunscreens due to its ability to absorb ultraviolet (UV) light. However, upon irradiation of UV light, reactive oxygen species particularly hydroxyl radical which can damage human skin will be generated. In this study, lignin/TiO2 composites were employed to quench the hydroxyl radicals generated by the TiO2. The lignin was extracted from oil palm empty fruit bunch (OPEFB) via kraft and soda pulping processes. The kraft lignin composite was labelled as KL/TiO2 whereas the soda lignin composite was labelled as SL/TiO2. The lignins and the composites were characterized by FTIR, UV spectroscopy, 13C NMR, SEM, EDX, and XRD. The relative hydroxyl radical production of composites and TiO2 were compared through photo-oxidation of coumarin to 7-hydroxycoumarin as a test medium. The effect of types and amounts of lignin used were studied. The KL/TiO2 composite showed the least radical production due to higher phenolic hydroxyl content of kraft lignin. The activity of the
This invention relates to a process for production of ethanol from lignocellulosic material. Lignocellulosic material treated with dicarboxylic acid, preferably with oxalic acid, separating hemicellulosic fraction to ferment pentose sugar. The lignin is dissolve in alkali, preferably with NaOH, separating cellulose fraction for further enzymatic treatment with one or more than one cellulytic enzymes capable of hydrolyzing cellulose. Enzyme hydrolyasate further subjected to fermentation in presence of ethanol producing yeast, preferably Saccharomyces cerevisiae. The fermented broth further subjected to distillation followed by dehydration to yield ethanol.
The interactions between lignin and cellulase play a major role in enzymatic hydrolysis of lignocelluloses for sugar and biofuel production from biomass [1]. These interactions can be described as (1) lignin physical blockage to limit cellulose accessibility to cellulase [2], and (2) nonspecific adsorption or binding of cellulase enzymes to lignin [3-7]. Reported studies indicate that these two mechanisms produced negative effects on enzymatic saccharification of lignocelluloses. Pretreatment of lignocelluloses such as Organosolv [8, 9] and SPORL [10] is able to partially remove lignin physical blockage by solubilizing a fraction of lignin into the hemicellulosic sugar stream (pretreatment spent liquor). However, further processing lignocelluloses to remove lignin blockage such as by delignification is not only expensive but also may not be necessary in terms of improving cellulose accessibility. It is probably more effective to address the issue of nonspecific binding of cellulase to lignin to ...
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MOESM1 of Oxidation of a non-phenolic lignin model compound by two Irpex lacteus manganese peroxidases: evidence for implication of carboxylate and radicals
TY - JOUR. T1 - Structural characterization of alkaline hydrogen peroxide pretreated grasses exhibiting diverse lignin phenotypes. AU - Li,Muyang. AU - Foster,Cliff. AU - Kelkar,Shantanu. AU - Pu,Yunqiao. AU - Holmes,Daniel. AU - Ragauskas,Arthur. AU - Saffron,Christopher M.. AU - Hodge,David B.. PY - 2012. Y1 - 2012. N2 - Background: For cellulosic biofuels processes, suitable characterization of the lignin remaining within the cell wall and correlation of quantified properties of lignin to cell wall polysaccharide enzymatic deconstruction is underrepresented in the literature. This is particularly true for grasses which represent a number of promising bioenergy feedstocks where quantification of grass lignins is particularly problematic due to the high fraction of phydroxycinnamates. The main focus of this work is to use grasses with a diverse range of lignin properties, and applying multiple lignin characterization platforms, attempt to correlate the differences in these lignin properties to ...
TY - JOUR. T1 - Analytical Py-GC/MS of Genetically Modified Poplar for the Increased Production of Bio-aromatics. AU - SriBala, Gorugantu. AU - Toraman, Hilal Ezgi. AU - Symoens, Steffen. AU - Déjardin, Annabelle. AU - Pilate, Gilles. AU - Boerjan, Wout. AU - Ronsse, Frederik. AU - Van Geem, Kevin M.. AU - Marin, Guy B.. PY - 2019. Y1 - 2019. N2 - Genetic engineering is a powerful tool to steer bio-oil composition towards the production of speciality chemicals such as guaiacols, syringols, phenols, and vanillin through well-defined biomass feedstocks. Our previous work demonstrated the effects of lignin biosynthesis gene modification on the pyrolysis vapour compositions obtained from wood derived from greenhouse-grown poplars. In this study, field-grown poplars downregulated in the genes encoding CINNAMYL ALCOHOL DEHYDROGENASE (CAD), CAFFEIC ACID O-METHYLTRANSFERASE (COMT) and CAFFEOYL-CoA O-METHYLTRANSFERASE (CCoAOMT), and their corresponding wild type were pyrolysed in a Py-GC/MS. This work ...
Lignocellulosic biomass (LB) is nowadays an important raw material due to its cellulose, hemicellulose and lignin content. These materials can be used to obtain high value-added products. The annual production of these materials is of approximately 200 million tonnes. The main lignin producer is the paper industry. For 2010 this industry produced 50 millions of tonnes of lignin represented as black liquor that is obtained in pulping paper. Only the 5% was used to produce adhesives, dispersants, surfactants, antioxidants and rubbers, while the remaining 95% was used to produce energy in cogeneration systems. Lignin is an organic polymer which alike the cellulose has an important production in the vegetable world. Some high value-added compounds that can be derived from lignin correspond to the binders and cosmetic, among others. These compounds have important uses in the cosmetic, pharmaceutical and chemical industries. Lignin is commonly used to produce bioenergy in cogeneration system. However, ...
The forest is alarge and important natural resourcein Sweden, and approximately 70% of the countrys land area is woodland. Wood is an excellent raw material for the replacement of oil-based products because it is renewable, biodegradable and carbon neutral. Furthermore, the forest industry is searching for new processes and methods to utilise by-product streams in a so-called integrated biorefinery. A key to the success of producing new products from wood could be pure and homogenous raw materials. Because wood contains a large variety of components with different characteristics and sizes, cross-flow filtration (CFF) will be a key separation technique to obtain homogenous and pure raw materials in the biorefinery concept.. Different wood material components have been studied in this thesis. The first part of this work focuses on kraft lignin. Kraft lignin is interesting because approximately 3.5-4 million metric tonnes are produced in Sweden annually (~7million tonnes of kraft pulp/year in ...
Lignin is like any other polymer in that the molecular weight (MW) can have a dramatic impact on its suitability for a given application. Furthermore, polymer purity can be an equally important factor if the desired materials properties are to be achieved. Two large and growing markets have been identified for lignin use, where both MW and purity can play an important role: (1) high-performance carbon fibers for automotive applications and (2) rigid polyurethane foams for spray insulation for buildings. In both cases, we hypothesize that todayâ s commercial lignins have too broad a molecular weight (MW) distribution and are too low in purity to give acceptable performance. Preliminary results with lignins of controlled MW and high purity are encouraging. For example, very clean, high-MW lignins isolated via ALPHA were converted into carbon fibers almost 40% stronger than any previously reported from lignin. For rigid polyurethane foams, preliminary data suggest that very clean lignins of low ...
Lignin, a major component of lignocellulosic biomass, is crucial to plant growth and development but is a major impediment to efficient biomass utilization in various processes. Valorizing lignin is increasingly realized as being essential. However, rapid condensation of lignin during acidic extraction leads to the formation of recalcitrant condensed units that, along with similar units and structural heterogeneity in native lignin, drastically limits product yield and selectivity. Catechyl lignin (C-lignin), which is essentially a benzodioxane homopolymer without condensed units, might represent an ideal lignin for valorization, as it circumvents these issues. We discovered that C-lignin is highly acid-resistant. Hydrogenolysis of C-lignin resulted in the cleavage of all benzodioxane structures to produce catechyl-type monomers in near-quantitative yield with a selectivity of 90% to a single monomer. ...
An accurate assessment of forage quality is required to allow prediction of animal performance. One of the most commonly used methods of forage evaluation is to measure lignin content, with more heavily lignified materials being considered less digestible. Two measures of lignin, acid detergent lignin (ADL) and acetyl bromide lignin (ABL), were assessed with regard to their ability to predict forage digestibility. Big bluestem forage samples were collected from three ungrazed, annually burned pastures at 38, 58, and 97 days postburn. These times were selected to represent a broad range of forage quality. Cell wall material was treated chemically by: 1) partial delignification (chlorite), 2) isolation o f "- cellulose, or 3) NaOH extraction. Control and treated cell-w all material was analyzed for ABL and ADL and 24 and 72 hr in vitro dry matter disappearance (IVDMD). ABL increased with advancing maturity for intact fibers, whereas ADL was highest in the most mature forage but lowest for the ...
Structural Changes to Aspen Wood Lignin during Autohydrolysis Pretreatment. Peng Wang,a Yingjuan Fu,a,* Zhiyong Shao,a Fengshan Zhang,b and Menghua Qin a,b,c,*. Aspen wood was subjected to autohydrolysis as a pre-treatment to characterize the structural changes occurring in lignin fractions during the pre-treatment process. Milled wood lignin (MWL) was isolated from both the native aspen wood and hydrolyzed wood chips, and its structural features were characterized by Fourier transform infrared (FT-IR), quantitative 13C, two-dimensional heteronuclear single quantum coherence (2D HSQC), and 31P nuclear magnetic resonance (NMR) spectroscopies, gel permeation chromatography/multi-angle laser light scattering (GPC-MALLS), and thermal analysis. The lignin remaining in the hydrolyzed wood chips revealed more phenolic OH groups, fewer aliphatic OH groups, higher syringyl/guaiacyl ratios (S/G), higher molecular weights, and narrower polydispersities than the native lignin of aspen wood. The inter-unit ...
Dissolved lignin phenols and optical properties of dissolved organic matter (DOM) were measured to investigate the sources and transformations of terrigenous DOM (tDOM) in Otsuchi Bay, Japan. Three rivers discharge into the bay, and relatively high values of syringyl:vanillyl phenols (0.73 ± 0.07) and cinnamyl:vanillyl phenols (0.33 ± 0.10) indicated large contributions of non-woody angiosperm tissues to lignin and tDOM. The physical mixing of river and seawater played an important role in controlling the concentrations and distributions of lignin phenols and chromophoric DOM (CDOM) optical properties in the bay. Lignin phenol concentrations and the CDOM absorption coefficient at 350 nm, a(350), were strongly correlated in river and bay waters. Measurements of lignin phenols and CDOM in bay waters indicated a variety of photochemical and biological transformations of tDOM, including oxidation reactions, photobleaching and a decrease in molecular weight. Photodegradation and biodegradation of lignin
cinnamyl alcohol dehydrogenase: NADP-dependent enzyme that catalyzes the reversible conversion of p-hydroxycinnamaldehydes to their corresponding alcohols, leading to the biosynthesis of lignin in plants
Figure 2. A, The observed NADP+ in the binding pocket of SbCCR1. NADP+ and all interacting residues are represented as stick models. The backbone of SbCCR1 is represented as a ribbon diagram, and dashed lines represent hydrogen bonds or ionic interactions. All residues that contribute to NADP+ binding are labeled according to their single-letter abbreviations and numbered according to sequence positions. The catalytic triad, composed of Ser-149, Tyr-183, and Lys-187, is in close proximity to the nicotinamide ring and serves to promote hydride transfer to hydroxycinnamoyl-CoA substrates. B, Coniferaldehyde docked into the putative phenylpropanoid-binding region of SbCCR1. The backbone of SbCCR1 is represented by a ribbon diagram, with protruding side chains that contribute to coniferaldehyde binding modeled as sticks. Coniferaldehyde, which is the product of the reaction with the preferred substrate feruloyl-CoA, is shown in gray. Kinetics experiments with T154A and Y310F mutants revealed that ...
Simultaneous saccharification and fermentation (SSF) and simultaneous saccharification and cofermentation (SSCF) are two process options for production of ethanol from lignocellulosic substrates that are superior to separate hydrolysis and fermentation (SHF). The principal benefits of performing the enzymatic hydrolysis together with the fermentation, instead of in a separate step after the hydrolysis as SHF does, are the reduced end-product inhibition of the enzymatic hydrolysis, and the reduced investment costs. The principal drawbacks, on the other hand, are the need to find favorable conditions (e.g. temperature and pH) for both the enzymatic hydrolysis and the fermentation and the difficulty to recycle the fermenting organism and the enzymes. In order to enhance the efficiency of the lignocellulose-to-ethanol conversion, optimization of the hydrolysis (also called saccharification) process step to achieve an optimal conversion of crystalline domains of cellulose is crucial. Towards this ...
Lignin model surfaces were prepared from aqueous alkaline solutions by spin-coating on silica wafers. Films of thicknesses between 20 and 140 nm were easily made by variations in the spinning rate or in the lignin concentration. The roughnesses of the lignin surfaces were relatively low, approximately 1.1 nm (rms) on an area of 25 μm2, as determined by atomic force microscopy imaging. The stability of the lignin films in aqueous solutions was found to be excellent. No changes in the thickness of model surfaces immersed in slightly alkaline solutions (pH 9.2) could be detected even after 5 h soaking. A 10 percent reduction in the thickness of the lignin film was observed after 5 h of exposure to a solution containing 0. M NaCl. This novel preparation method opens great possibilities for further fundamental studies, where interactions between lignin and other substances are of interest to investigate.. ...
China Wood Pulp Powder Sodium Lignin for Concrete Admixure (lignolphonate), Find details about China Sodium Lignin Price, Sodium Lignin MSDS from Wood Pulp Powder Sodium Lignin for Concrete Admixure (lignolphonate) - Shandong Jufu Chemical Technology Co., Ltd.
The woody cell wall is the most developed biological composite material existing today. Its components, phenols and carbohydrates, in combination with phenoloxidase were already used in the antique to produce lacquerwork. To allow the use at an industrial scale of these processes today, there must be a cheap phenol, as for example technical lignins produced in the paper industry that can be transformed into active radicals by using the enzyme laccase. This study used activated lignins that had a high density of phenoxy radicals. They were used because they proved to be more active than non-activated lignin and could even react with nucleophiles as cellulose and starch. The chemical properties leading towards this reaction allows for innovative use of lignin in biotechnology. The thesis analysed the reaction of activated lignin, water-soluble lignin and water insoluble indulin with maize starch to allow an improvement of the water solubility. Furthermore, the influence of an addition of mediators ...
Profitable biomass conversion processes are highly dependent on the use of efficient enzymes for lignocellulose degradation. Among the cellulose degrading enzymes, beta-glucosidases are essential for efficient hydrolysis of cellulosic biomass as they relieve the inhibition of the cellobiohydrolases and endoglucanases by reducing cellobiose accumulation. In this review, we discuss the important role beta-glucosidases play in complex biomass hydrolysis and how they create a bottleneck in industrial use of lignocellulosic materials. An efficient beta-glucosidase facilitates hydrolysis at specified process conditions, and key points to consider in this respect are hydrolysis rate, inhibitors, and stability. Product inhibition impairing yields, thermal inactivation of enzymes, and the high cost of enzyme production are the main obstacles to commercial cellulose hydrolysis. Therefore, this sets the stage in the search for better alternatives to the currently available enzyme preparations either by improving
Lignocellulosic substrates are increasingly gaining attention as raw materials for biofuels and chemicals although numerous challenges on fermentability confront their usage as production platforms [1, 2]. Lignocellulosic substrates are primarily composed of cellulose, hemicellulose and lignin [3]. To disintegrate and make lignocellulosic biomass structurally accessible to enzymatic hydrolysis before fermentation, it is first subjected to a pre-treatment process [4, 5].. Also, the concept of chemical and fuel production in an integrated biorefinery is driving the interest in pulping process streams which are often rich in derivatives of lignin and hemicellulose [6, 7].. Pulping is a well-established technology for biomass disintegration and fractionation to make wood pulps [8]. Chemical pulping is a widespread process, the four classical methods principally used in chemical pulping are the kraft, sulfite, soda, and neutral sulfite semi-chemical pulping (NSSC) processes [9]. Pulping involves ...
Lignocellulosic biomass has a complex and rigid cell wall structure that makes biomass recalcitrant to biological and chemical degradation. Among the three major structural biopolymers (i.e., cellulose, hemicellulose and lignin) in plant cell walls, lignin is considered the most recalcitrant component and generally plays a negative role in the biochemical conversion of biomass to biofuels. The conversion of biomass to biofuels through a biochemical platform usually requires a pretreatment stage to reduce the recalcitrance. Pretreatment renders compositional and structural changes of biomass with these changes ultimately govern the efficiency of the subsequent enzymatic hydrolysis. Dilute acid, hot water, steam explosion, and ammonia fiber expansion pretreatments are among the leading thermochemical pretreatments with a limited delignification that can reduce biomass recalcitrance. Practical applications of these pretreatment are rapidly developing as illustrated by recent commercial scale ...
PDF version. Investigators. John Ralph, Xuejun Pan, and Sara Patterson, University of Wisconsin, Madison. Objective. To delineate a set of approaches for successfully altering lignin structure, in a way that allows plant cell wall breakdown to produce biofuels in more energy-efficient manner, by providing alternative plant-compatible monomers to the lignification process.. Background. Over the past decade it has become apparent that the metabolic malleability of lignification, the process of polymerization of phenolic monomers to produce lignin polymers, provides enormous potential for engineering the resistant polymer to be more amenable to processing. Massive compositional changes can be realized by perturbing single genes in the monolignol pathway, particularly the hydroxylases. More strikingly, monomer substitution in the process of lignification, particularly in cases where a plants ability to biosynthesize the usual complement of monolignols is compromised, has been observed. These ...
Plant biomass conversion for green chemistry and bio-energy is a current challenge for a modern sustainable bioeconomy. The complex polyaromatic lignin polymers in raw biomass feedstocks (i.e., agriculture and forestry by-products) are major obstacles for biomass conversions. White-rot fungi are wood decayers able to degrade all polymers from lignocellulosic biomass including cellulose, hemicelluloses, and lignin. The white-rot fungus Polyporus brumalis efficiently breaks down lignin and is regarded as having a high potential for the initial treatment of plant biomass in its conversion to bio-energy. Here, we describe the extraordinary ability of P. brumalis for lignin degradation using its enzymatic arsenal to break down wheat straw, a lignocellulosic substrate that is considered as a biomass feedstock worldwide.We performed integrative multi-omics analyses by combining data from the fungal genome, transcriptomes, and secretomes. We found that the fungus possessed an unexpectedly large set of ...
Citation: N/A Interpretive Summary: Fiber makes up 15 to 80% of the dry weight of plants. Fiber is composed primarily of polysaccharides and lignin. Polysaccharides can be degraded by some types of fungi and bacteria to simple sugars. These sugars are an important source of energy for humans and for livestock. These sugars may also be converted into ethanol for use in automobile fuels or other purposes. Polysaccharides in fiber are poorly degraded into simple sugars because of their association with lignin. Lignin is normally made up of three different kinds of building blocks--p-coumaryl, coniferyl, and sinapyl alcohols. In some genetically modified plants, coniferaldehyde and other aldehydes become major components of lignin. We ran experiments to determine how lignins formed with coniferaldehyde affect the degradability of polysaccharides in fiber. To do this, we isolated fiber from plant cells that were composed of just polysaccharides. We then formed an artificial lignin within this fiber ...
in reducing the lignin amount in plants cell walls or in altering its composition such that the lignin polymer becomes easier to process during biomass pretreatments Composition of the plant cell wall Both approaches require a deep understanding of the biosynthesis pathway of the monolignols and how this pathway is integrated in and interacts with plant metabolism To this end we have identified all Arabidopsis genes that share homology with known genes in monolignol biosynthesis Raes et al 2003 and characterized the corresponding mutants by combined microarray analyses metabolomics LC MS GC MS and FTMS and computational analyses Vanholme et al 2012 Subsequently we have identified genes that are closely co expressed with known genes of the monolignol biosynthesis pathway The function of a selection of these genes is now studied by reverse genetics in Arabidopsis For example we recently identified a new gene encoding caffeoyl shikimate esterase CSE an enzyme central to the lignin biosynthetic ...
Date: Tuesday the 26th of January 2016, 9:00 - 15:30.. Venue: Odense Adelige Jomfru Kloster, Albani Torv 6, 5000 Odense. Objective of the workshop The objective of this workshop is to exchange ideas and experience regarding the characterization, processing of lignocellulosic biomass, and of lignin. Lignin in natural lignocellulosic biomass plays multiple roles in the biorefinery industry. It is a barrier to biochemical conversion, an important material in the thermal biorefinery process, and also a high value product. The workshop will provide a forum for transfer of knowledge and methods among researchers working from these differing perspectives, and will contribute to a better understanding of the role of lignin in the biorefinery field. Additionally, the workshop will provide the participants with an opportunity to network and thereby develop ideas for joint research proposals to relevant funding bodies. Susanne Kjelstrup from TEK Innovation at the Faculty of Engineering will present ...
A collaboration between the National Renewable Energy Laboratory (NREL) and three other national laboratories has yielded new insight into the ability of bacteria to break down the hardy part of a plant known as lignin. The additional understanding of the process could open a path to industrial applications.. Plants are protected by a complex cell wall made up of polymers of cellulose, hemicellulose, and lignin. The first two components can be broken down into sugars by various methods, and then turned into valuable biofuels and bioproducts. But lignin has proven recalcitrant, and its use largely limited. "For more than a century, researchers have been trying to figure out what to do with lignin," said Gregg Beckham, a researcher at NREL and senior author of a new paper published in the Proceedings of the National Academy of Sciences of the United States of America. "Theres a famous phrase about this polymer: You can make anything out of lignin except money." But knowing exactly how bacteria ...
9.C.8 The ABC Lignin Precursor Transporters (ALPT) Family. Lignin is a complex biopolymer derived primarily from the condensation of three monomeric precursors, the monolignols. The synthesis of monolignols occurs in the cytoplasm. To reach the cell wall where they are oxidized and polymerized, they must be transported across the cell membrane. Using isolated plasma and vacuolar membrane vesicles prepared from Arabidopsis, together with applying different transporter inhibitors in the assays, Miao and Liu (2010) examined the uptake of monolignols and their derivatives by these native membrane vesicles. They demonstrated that the transport of lignin precursors across plasmalemma and their sequestration into vacuoles are ATP-dependent primary-transport processes, involving ATP-binding cassette-like transporters. Moreover, both plasma and vacuolar membrane vesicles selectively transported different forms of lignin precursors. In the presence of ATP, the inverted plasma membrane vesicles ...
Global Lignin Market: Lignin is a renewable raw material used in various applications and is available at an affordable price. It is naturally present in cells and cell walls of all vascular plants. The fiber in food, crunchiness in leafy vegetables and texture of wood comes from lignin. It is responsible for binding cellulose fiber in certain plants and protecting plants from collapsing and grow straight. Lignin is highly complex chemical in nature, only its physical and chemical properties are known and its structure is still unknown. Due to its organic properties and functions, its demand in diverse niche applications are consistently rising. Linin is mainly used as a byproduct of paper industry. Moreover, it is used in making of aromatic alcohol, dispersant in concrete additive, animal nutritional food, etc.. Increasing use of lignin in various applications such as agriculture sector, animal feed and concrete additive segment are fueling growth of the market. However, inclination towards ...
TY - JOUR. T1 - Steam gasification of a thermally pretreated high lignin corn stover simultaneous saccharification and fermentation digester residue. AU - Howe, Daniel T.. AU - Taasevigen, Danny. AU - Garcia-Perez, Manuel. AU - McDonald, Armando G.. AU - Li, Guosheng. AU - Wolcott, Michael. PY - 2017. Y1 - 2017. N2 - Efficient conversion of all components in lignocellulosic biomass is essential to realizing economic feasibility of biorefineries. However, lignin cannot be fermented using biochemical routes. Furthermore, high lignin and high ash residues from simultaneous saccharification and fermentation (SSF) is difficult to thermochemically process due to feed line plugging and bed agglomeration. In this study a corn stover SSF digester residue was thermally pretreated at 300 °C for 22.5 min and gasified in a fluidized bed gasifier to study the effect of thermal pretreatment on its processing behavior. Untreated, pelletized SSF residue was gasified at the same conditions to establish the ...
No molecule has been found to be effective against emphysema to date primarily because of its complex pathogenesis that involves elastolysis, oxidation and inflammation. We here describe novel unsulfated or sulfated low molecular weight lignins (LMWLs) chemo-enzymatically prepared from 4-hydroxycinnamic acids monomers, as the first potent triple-action inhibitors of neutrophil elastase, oxidation and inflammation. The inhibitory potencies of three different cinnamic acid-based LMWLs were determined in vitro using chromogenic substrate hydrolysis assays, radical scavenging and lung cellular oxidative biomarker reduced glutathione (rGSH) assays, and lung cellular inflammatory biomarker NFκB and IL-8 assays, respectively. Each LWML uniquely displayed triple-action inhibition, among which CDSO3, a sulfated caffeic acid-based LMWL, was most potent. The half-maximal anti-human neutrophil elastase (HNE) potency of CDSO3 was 0.43 μM. This high potency arose from lignin-like oligomerization, which was ...
This study reports the compound specific stable carbon isotope compositions (δ13C) of lignin tetramethylammonium hydroxide (TMAH) chemolysates obtained with gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). The possible sources of the errors associated are considered. Off-line (TMAH) thermochemolysis was performed on wood samples and the δ13C values of the chemolysates were compared with the bulk δ13C of the native woods and their Klason lignins. For the four woods investigated, the δ13C values, corrected for derivative carbons added, were spread over a wide range of values, ranging from −40 to −25‰ and were, on average, depleted in 13C by ca. 9‰ relative to the native woods and by ca. 7‰ relative to the Klason lignins. This large variability can be partially attributed to overlapping chromatographic peaks and to the low intensity of some of the peaks. However, isotopic fractionation cannot be ruled out, especially in compounds resulting from CC bond ...
An apparatus for enzymatic hydrolysis and fermentation of pretreated lignocellulosic material, in the form of a tower bioreactor, having mixers to achieve intermittent mixing of the material. Precise