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Sample records for gene enhances lignin

  1. Genetic Augmentation of Syringyl Lignin in Low-lignin Aspen Trees, Final Report

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    Chung-Jui Tsai; Mark F. Davis; Vincent L. Chiang

    2004-11-10

    As a polysaccharide-encrusting component, lignin is critical to cell wall integrity and plant growth but also hinders recovery of cellulose fibers during the wood pulping process. To improve pulping efficiency, it is highly desirable to genetically modify lignin content and/or structure in pulpwood species to maximize pulp yields with minimal energy consumption and environmental impact. This project aimed to genetically augment the syringyl-to-guaiacyl lignin ratio in low-lignin transgenic aspen in order to produce trees with reduced lignin content, more reactive lignin structures and increased cellulose content. Transgenic aspen trees with reduced lignin content have already been achieved, prior to the start of this project, by antisense downregulation of a 4-coumarate:coenzyme A ligase gene (Hu et al., 1999 Nature Biotechnol 17: 808- 812). The primary objective of this study was to genetically augment syringyl lignin biosynthesis in these low-lignin trees in order to enhance lignin reactivity during chemical pulping. To accomplish this, both aspen and sweetgum genes encoding coniferaldehyde 5-hydroxylase (Osakabe et al., 1999 PNAS 96: 8955-8960) were targeted for over-expression in wildtype or low-lignin aspen under control of either a constitutive or a xylem-specific promoter. A second objective for this project was to develop reliable and cost-effective methods, such as pyrolysis Molecular Beam Mass Spectrometry and NMR, for rapid evaluation of cell wall chemical components of transgenic wood samples. With these high-throughput techniques, we observed increased syringyl-to-guaiacyl lignin ratios in the transgenic wood samples, regardless of the promoter used or gene origin. Our results confirmed that the coniferaldehyde 5-hydroxylase gene is key to syringyl lignin biosynthesis. The outcomes of this research should be readily applicable to other pulpwood species, and promise to bring direct economic and environmental benefits to the pulp and paper industry.

  2. Genes encoding enzymes of the lignin biosynthesis pathway in Eucalyptus

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    Ricardo Harakava

    2005-01-01

    Full Text Available Eucalyptus ESTs libraries were screened for genes involved in lignin biosynthesis. This search was performed under the perspective of recent revisions on the monolignols biosynthetic pathway. Eucalyptus orthologues of all genes of the phenylpropanoid pathway leading to lignin biosynthesis reported in other plant species were identified. A library made with mRNAs extracted from wood was enriched for genes involved in lignin biosynthesis and allowed to infer the isoforms of each gene family that play a major role in wood lignin formation. Analysis of the wood library suggests that, besides the enzymes of the phenylpropanoids pathway, chitinases, laccases, and dirigent proteins are also important for lignification. Colocalization of several enzymes on the endoplasmic reticulum membrane, as predicted by amino acid sequence analysis, supports the existence of metabolic channeling in the phenylpropanoid pathway. This study establishes a framework for future investigations on gene expression level, protein expression and enzymatic assays, sequence polymorphisms, and genetic engineering.

  3. Effect of hypergravity on lignin formation and expression of lignin-related genes in inflorescence stems of an ethylene-insensitive Arabidopsis mutant ein3-1

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    Karahara, Ichirou; Kobayashi, Mai; Tamaoki, Daisuke; Kamisaka, Seiichiro

    Our previous studies have shown that hypergravity inhibits growth and promotes lignin forma-tion in inflorescence stems of Arabidopsis thaliana by up-regulation of genes involved in lignin biosynthesis (Tamaoki et al. 2006, 2009). In the present study, we have examined whether ethylene is involved in these responses using an ethylene-insensitive Arabidopsis mutant ein3-1. Our results revealed that hypergravity treatment at 300 G for 24 h significantly inhibited growth of inflorescence stems, promoted both deposition of acetyl bromide extractable lignin and gene expression involved in lignin formation in inflorescence stems of wild type plants. Growth inhibition of inflorescence stems was also observed in ein3-1. However, the effects of hypergravity on the promotion of the deposition of acetyl bromide lignin and the expression of genes involved in lignin formation were not observed in ein3-1, indicating that ethylene sig-naling is involved in the up-regulation of the expression of lignin-related genes as well as the promotion of deposition of lignin by hypergravity in Arabidopsis inflorescence stems.

  4. Gene expression in the lignin biosynthesis pathway during soybean seed development.

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    Baldoni, A; Von Pinho, E V R; Fernandes, J S; Abreu, V M; Carvalho, M L M

    2013-02-28

    The study of gene expression in plants is fundamental, and understanding the molecular mechanisms involved in important biological processes, such as biochemical pathways or signaling that are used or manipulated in improvement programs, are key for the production of high-quality soybean seeds. Reports related to gene expression of lignin in seeds are scarce in the literature. We studied the expression of the phenylalanine ammonia-lyase (PAL), cinnamate 4-hydroxylase, 4-hydroxycinnamate 3-hydroxylase, and cinnamyl alcohol dehydrogenase genes involved in lignin biosynthesis during the development of soybean (Glycine max L. Merrill) seeds. As the endogenous control, the eukaryotic elongation factor 1-beta gene was used in two biological replicates performed in triplicate. Relative quantitative expression of these genes during the R4, R5, R6, and R7 development stages was analyzed. Real-time polymerase chain reaction was used for the gene expression study. The analyses were carried out in an ABI PRISM 7500 thermocycler using the comparative Ct method and SYBR Green to detect amplification. The seed samples at the R4 stage were chosen as calibrators. Increased expression of the cinnamate-4-hydroxylase and PAL genes occurred in soybean seeds at the R5 and R6 development stages. The cinnamyl alcohol dehydrogenase gene was expressed during the final development phases of soybean seeds. In low-lignin soybean cultivars, the higher expression of the PAL gene occurs at development stages R6 and R7. Activation of the genes involved in the lignin biosynthesis pathway occurs at the beginning of soybean seed development.

  5. Biosynthesis and incorporation of side-chain-truncated lignin monomers to reduce lignin polymerization and enhance saccharification.

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    Eudes, Aymerick; George, Anthe; Mukerjee, Purba; Kim, Jin S; Pollet, Brigitte; Benke, Peter I; Yang, Fan; Mitra, Prajakta; Sun, Lan; Cetinkol, Ozgül P; Chabout, Salem; Mouille, Grégory; Soubigou-Taconnat, Ludivine; Balzergue, Sandrine; Singh, Seema; Holmes, Bradley M; Mukhopadhyay, Aindrila; Keasling, Jay D; Simmons, Blake A; Lapierre, Catherine; Ralph, John; Loqué, Dominique

    2012-06-01

    Lignocellulosic biomass is utilized as a renewable feedstock in various agro-industrial activities. Lignin is an aromatic, hydrophobic and mildly branched polymer integrally associated with polysaccharides within the biomass, which negatively affects their extraction and hydrolysis during industrial processing. Engineering the monomer composition of lignins offers an attractive option towards new lignins with reduced recalcitrance. The presented work describes a new strategy developed in Arabidopsis for the overproduction of rare lignin monomers to reduce lignin polymerization degree (DP). Biosynthesis of these 'DP reducers' is achieved by expressing a bacterial hydroxycinnamoyl-CoA hydratase-lyase (HCHL) in lignifying tissues of Arabidopsis inflorescence stems. HCHL cleaves the propanoid side-chain of hydroxycinnamoyl-CoA lignin precursors to produce the corresponding hydroxybenzaldehydes so that plant stems expressing HCHL accumulate in their cell wall higher amounts of hydroxybenzaldehyde and hydroxybenzoate derivatives. Engineered plants with intermediate HCHL activity levels show no reduction in total lignin, sugar content or biomass yield compared with wild-type plants. However, cell wall characterization of extract-free stems by thioacidolysis and by 2D-NMR revealed an increased amount of unusual C₆C₁ lignin monomers most likely linked with lignin as end-groups. Moreover the analysis of lignin isolated from these plants using size-exclusion chromatography revealed a reduced molecular weight. Furthermore, these engineered lines show saccharification improvement of pretreated stem cell walls. Therefore, we conclude that enhancing the biosynthesis and incorporation of C₆C₁ monomers ('DP reducers') into lignin polymers represents a promising strategy to reduce lignin DP and to decrease cell wall recalcitrance to enzymatic hydrolysis. © 2012 The Authors. Plant Biotechnology Journal © 2012 Society for Experimental Biology, Association of Applied

  6. Improved Wood Properties Through Genetic Manipulation: Engineering of Syringyl Lignin in Softwood Species Through Xylem-Specific Expression of Hardwood Syringyl Monolignol Pathway Genes

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    Chandrashekhar P. Joshi; Vincent L. Chiang

    2009-01-29

    Project Objective: Our long-term goal is to genetically engineer higher value raw materials with desirable wood properties to promote energy efficiency, international competitiveness, and environmental responsiveness of the U.S. forest products industry. The immediate goal of this project was to produce the first higher value softwood raw materials engineered with a wide range of syringyl lignin quantities. Summary: The most important wood property affecting directly the levels of energy, chemical and bleaching requirements for kraft pulp production is lignin. Softwoods contain almost exclusively chemically resistant guaiacyl (G) lignin, whereas hardwoods have more reactive or easily degradable lignins of the guaiacyl (G)-syringyl (S) type. It is also well established that the reactive S lignin component is the key factor that permits much lower effective alkali and temperature, shorter pulping time and less bleaching stages for processing hardwoods than for softwoods. Furthermore, our pulping kinetic study explicitly demonstrated that every increase in one unit of the lignin S/G ratio would roughly double the rate of lignin removal. These are clear evidence that softwoods genetically engineered with S lignin are keys to revolutionizing the energy efficiency and enhancing the environmental performance of this industry. Softwoods and hardwoods share the same genetic mechanisms for the biosynthesis of G lignin. However, in hardwoods, three additional genes branch out from the G-lignin pathway and become specifically engaged in regulating S lignin biosynthesis. In this research, we simultaneously transferred aspen S-specific genes into a model softwood, black spruce, to engineer S lignin.

  7. Lignin depletion enhances the digestibility of cellulose in cultured xylem cells.

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    Catherine I Lacayo

    Full Text Available Plant lignocellulose constitutes an abundant and sustainable source of polysaccharides that can be converted into biofuels. However, the enzymatic digestion of native plant cell walls is inefficient, presenting a considerable barrier to cost-effective biofuel production. In addition to the insolubility of cellulose and hemicellulose, the tight association of lignin with these polysaccharides intensifies the problem of cell wall recalcitrance. To determine the extent to which lignin influences the enzymatic digestion of cellulose, specifically in secondary walls that contain the majority of cellulose and lignin in plants, we used a model system consisting of cultured xylem cells from Zinniaelegans. Rather than using purified cell wall substrates or plant tissue, we have applied this system to study cell wall degradation because it predominantly consists of homogeneous populations of single cells exhibiting large deposits of lignocellulose. We depleted lignin in these cells by treating with an oxidative chemical or by inhibiting lignin biosynthesis, and then examined the resulting cellulose digestibility and accessibility using a fluorescent cellulose-binding probe. Following cellulase digestion, we measured a significant decrease in relative cellulose content in lignin-depleted cells, whereas cells with intact lignin remained essentially unaltered. We also observed a significant increase in probe binding after lignin depletion, indicating that decreased lignin levels improve cellulose accessibility. These results indicate that lignin depletion considerably enhances the digestibility of cellulose in the cell wall by increasing the susceptibility of cellulose to enzymatic attack. Although other wall components are likely to contribute, our quantitative study exploits cultured Zinnia xylem cells to demonstrate the dominant influence of lignin on the enzymatic digestion of the cell wall. This system is simple enough for quantitative image analysis

  8. Cell wall composition and lignin biosynthetic gene expression along a developmental gradient in an Australian sugarcane cultivar

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    William P. Bewg

    2017-12-01

    Full Text Available Sugarcane bagasse is an abundant source of lignocellulosic material for bioethanol production. Utilisation of bagasse for biofuel production would be environmentally and economically beneficial, but the recalcitrance of lignin continues to provide a challenge. Further understanding of lignin production in specific cultivars will provide a basis for modification of genomes for the production of phenotypes with improved processing characteristics. Here we evaluated the expression profile of lignin biosynthetic genes and the cell wall composition along a developmental gradient in KQ228 sugarcane. The expression levels of nine lignin biosynthesis genes were quantified in five stem sections of increasing maturity and in root tissue. Two distinct expression patterns were seen. The first saw highest gene expression in the youngest tissue, with expression decreasing as tissue matured. The second pattern saw little to no change in transcription levels across the developmental gradient. Cell wall compositional analysis of the stem sections showed total lignin content to be significantly higher in more mature tissue than in the youngest section assessed. There were no changes in structural carbohydrates across developmental sections. These gene expression and cell wall compositional patterns can be used, along with other work in grasses, to inform biotechnological approaches to crop improvement for lignocellulosic biofuel production.

  9. Lignin-based polyoxyethylene ether enhanced enzymatic hydrolysis of lignocelluloses by dispersing cellulase aggregates.

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    Lin, Xuliang; Qiu, Xueqing; Yuan, Long; Li, Zihao; Lou, Hongming; Zhou, Mingsong; Yang, Dongjie

    2015-06-01

    Water-soluble lignin-based polyoxyethylene ether (EHL-PEG), prepared from enzymatic hydrolysis lignin (EHL) and polyethylene glycol (PEG1000), was used to improve enzymatic hydrolysis efficiency of corn stover. The glucose yield of corn stover at 72h was increased from 16.7% to 70.1% by EHL-PEG, while increase in yield with PEG4600 alone was 52.3%. With the increase of lignin content, EHL-PEG improved enzymatic hydrolysis of microcrystalline cellulose more obvious than PEG4600. EHL-PEG could reduce at least 88% of the adsorption of cellulase on the lignin film measured by quartz crystal microbalance with dissipation monitoring (QCM-D), while reduction with PEG4600 was 43%. Cellulase aggregated at 1220nm in acetate buffer analyzed by dynamic light scattering. EHL-PEG dispersed cellulase aggregates and formed smaller aggregates with cellulase, thereby, reduced significantly nonproductive adsorption of cellulase on lignin and enhanced enzymatic hydrolysis of lignocelluloses. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Reprogramming of gene expression during compression wood formation in pine: Coordinated modulation of S-adenosylmethionine, lignin and lignan related genes

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    2012-01-01

    Background Transcript profiling of differentiating secondary xylem has allowed us to draw a general picture of the genes involved in wood formation. However, our knowledge is still limited about the regulatory mechanisms that coordinate and modulate the different pathways providing substrates during xylogenesis. The development of compression wood in conifers constitutes an exceptional model for these studies. Although differential expression of a few genes in differentiating compression wood compared to normal or opposite wood has been reported, the broad range of features that distinguish this reaction wood suggest that the expression of a larger set of genes would be modified. Results By combining the construction of different cDNA libraries with microarray analyses we have identified a total of 496 genes in maritime pine (Pinus pinaster, Ait.) that change in expression during differentiation of compression wood (331 up-regulated and 165 down-regulated compared to opposite wood). Samples from different provenances collected in different years and geographic locations were integrated into the analyses to mitigate the effects of multiple sources of variability. This strategy allowed us to define a group of genes that are consistently associated with compression wood formation. Correlating with the deposition of a thicker secondary cell wall that characterizes compression wood development, the expression of a number of genes involved in synthesis of cellulose, hemicellulose, lignin and lignans was up-regulated. Further analysis of a set of these genes involved in S-adenosylmethionine metabolism, ammonium recycling, and lignin and lignans biosynthesis showed changes in expression levels in parallel to the levels of lignin accumulation in cells undergoing xylogenesis in vivo and in vitro. Conclusions The comparative transcriptomic analysis reported here have revealed a broad spectrum of coordinated transcriptional modulation of genes involved in biosynthesis of

  11. Reprogramming of gene expression during compression wood formation in pine: Coordinated modulation of S-adenosylmethionine, lignin and lignan related genes

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    Villalobos David P

    2012-06-01

    Full Text Available Abstract Background Transcript profiling of differentiating secondary xylem has allowed us to draw a general picture of the genes involved in wood formation. However, our knowledge is still limited about the regulatory mechanisms that coordinate and modulate the different pathways providing substrates during xylogenesis. The development of compression wood in conifers constitutes an exceptional model for these studies. Although differential expression of a few genes in differentiating compression wood compared to normal or opposite wood has been reported, the broad range of features that distinguish this reaction wood suggest that the expression of a larger set of genes would be modified. Results By combining the construction of different cDNA libraries with microarray analyses we have identified a total of 496 genes in maritime pine (Pinus pinaster, Ait. that change in expression during differentiation of compression wood (331 up-regulated and 165 down-regulated compared to opposite wood. Samples from different provenances collected in different years and geographic locations were integrated into the analyses to mitigate the effects of multiple sources of variability. This strategy allowed us to define a group of genes that are consistently associated with compression wood formation. Correlating with the deposition of a thicker secondary cell wall that characterizes compression wood development, the expression of a number of genes involved in synthesis of cellulose, hemicellulose, lignin and lignans was up-regulated. Further analysis of a set of these genes involved in S-adenosylmethionine metabolism, ammonium recycling, and lignin and lignans biosynthesis showed changes in expression levels in parallel to the levels of lignin accumulation in cells undergoing xylogenesis in vivo and in vitro. Conclusions The comparative transcriptomic analysis reported here have revealed a broad spectrum of coordinated transcriptional modulation of genes

  12. Delignification and Enhanced Gas Release from Soil Containing Lignocellulose by Treatment with Bacterial Lignin Degraders.

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    Rashid, Goran M M; Duran-Pena, Maria Jesus; Rahmanpour, Rahman; Sapsford, Devin; Bugg, Timothy D H

    2017-04-10

    The aim of the study was to isolate bacterial lignin-degrading bacteria from municipal solid waste soil, and to investigate whether they could be used to delignify lignocellulose-containing soil, and enhance methane release. A set of 20 bacterial lignin degraders, including 11 new isolates from municipal solid waste soil, were tested for delignification and phenol release in soil containing 1% pine lignocellulose. A group of 7 strains were then tested for enhancement of gas release from soil containing 1% lignocellulose in small-scale column tests. Using an aerobic pre-treatment, aerobic strains such as Pseudomonas putida showed enhanced gas release from the treated sample, but four bacterial isolates showed 5-10 fold enhancement in gas release in an in situ experiment under microanaerobic conditions: Agrobacterium sp., Lysinibacillus sphaericus, Comamonas testosteroni, and Enterobacter sp.. The results show that facultative anaerobic bacterial lignin degraders found in landfill soil can be used for in situ delignification and enhanced gas release in soil containing lignocellulose. The study demonstrates the feasibility of using an in situ bacterial treatment to enhance gas release and resource recovery from landfill soil containing lignocellulosic waste. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  13. Influence of EARLI1-like genes on flowering time and lignin synthesis of Arabidopsis thaliana.

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    Shi, Y; Zhang, X; Xu, Z-Y; Li, L; Zhang, C; Schläppi, M; Xu, Z-Q

    2011-09-01

    EARLI1 encodes a 14.7 kDa protein in the cell wall, is a member of the PRP (proline-rich protein) family and has multiple functions, including resistance to low temperature and fungal infection. RNA gel blot analyses in the present work indicated that expression of EARLI1-like genes, EARLI1, At4G12470 and At4G12490, was down-regulated in Col-FRI-Sf2 RNAi plants derived from transformation with Agrobacterium strain ABI, which contains a construct encoding a double-strand RNA targeting 8CM of EARLI1. Phenotype analyses revealed that Col-FRI-Sf2 RNAi plants of EARLI1 flowered earlier than Col-FRI-Sf2 wild-type plants. The average bolting time of Col-FRI-Sf2 and Col-FRI-Sf2 RNAi plants was 39.7 and 19.4 days, respectively, under a long-day photoperiod. In addition, there were significant differences in main stem length, internode number and rosette leaf number between Col-FRI-Sf2 and Col-FRI-Sf2 RNAi plants. RT-PCR showed that EARLI1-like genes might delay flowering time through the autonomous and long-day photoperiod pathways by maintaining the abundance of FLC transcripts. In Col-FRI-Sf2 RNAi plants, transcription of FLC was repressed, while expression of SOC1 and FT was activated. Microscopy observations showed that EARLI1-like genes were also associated with morphogenesis of leaf cells in Arabidopsis. Using histochemical staining, EARLI1-like genes were found to be involved in regulation of lignin synthesis in inflorescence stems, and Col-FRI-Sf2 and Col-FRI-Sf2 RNAi plants had 9.67% and 8.76% dry weight lignin, respectively. Expression analysis revealed that cinnamoyl-CoA reductase, a key enzyme in lignin synthesis, was influenced by EARLI1-like genes. These data all suggest that EARLI1-like genes could control the flowering process and lignin synthesis in Arabidopsis. © 2011 German Botanical Society and The Royal Botanical Society of the Netherlands.

  14. Lignin blockers and uses thereof

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    Yang, Bin [West Lebanon, NH; Wyman, Charles E [Norwich, VT

    2011-01-25

    Disclosed is a method for converting cellulose in a lignocellulosic biomass. The method provides for a lignin-blocking polypeptide and/or protein treatment of high lignin solids. The treatment enhances cellulase availability in cellulose conversion and allows for the determination of optimized pretreatment conditions. Additionally, ethanol yields from a Simultaneous Saccharification and Fermentation process are improved 5-25% by treatment with a lignin-blocking polypeptide and/or protein. Thus, a more efficient and economical method of processing lignin containing biomass materials utilizes a polypeptide/protein treatment step that effectively blocks lignin binding of cellulase.

  15. Biosynthesis and incorporation of side-chain-truncated lignin monomers to reduce lignin polymerization and enhance saccharification

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    Eudes, Aymerick; George, Anthe; Mukerjee, Purba; Kim, J.S.; Pollet, B.; Bnke, P.I.; Persil Çetinkol, Özgül

    2012-01-01

    Lignocellulosic biomass is utilized as a renewable feedstock in various agro-industrial activities. Lignin is an aromatic, hydrophobic and mildly branched polymer integrally associated with polysaccharides within the biomass, which negatively affects their extraction and hydrolysis during industrial processing. Engineering the monomer composition of lignins offers an attractive option towards new lignins with reduced recalcitrance. The presented work describes a new strategy developed in Arab...

  16. Lignin biosynthesis in wheat (Triticum aestivum L.): its response to waterlogging and association with hormonal levels.

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    Nguyen, Tran-Nguyen; Son, SeungHyun; Jordan, Mark C; Levin, David B; Ayele, Belay T

    2016-01-25

    Lignin is an important structural component of plant cell wall that confers mechanical strength and tolerance against biotic and abiotic stressors; however it affects the use of biomass such as wheat straw for some industrial applications such as biofuel production. Genetic alteration of lignin quantity and quality has been considered as a viable option to overcome this problem. However, the molecular mechanisms underlying lignin formation in wheat biomass has not been studied. Combining molecular and biochemical approaches, the present study investigated the transcriptional regulation of lignin biosynthesis in two wheat cultivars with varying lodging characteristics and also in response to waterlogging. It also examined the association of lignin level in tissues with that of plant hormones implicated in the control of lignin biosynthesis. Analysis of lignin biosynthesis in the two wheat cultivars revealed a close association of lodging resistance with internode lignin content and expression of 4-coumarate:CoA ligase1 (4CL1), p-coumarate 3-hydroxylase1 (C3H1), cinnamoyl-CoA reductase2 (CCR2), ferulate 5-hydroxylase2 (F5H2) and caffeic acid O-methyltransferase2 (COMT2), which are among the genes highly expressed in wheat tissues, implying the importance of these genes in mediating lignin deposition in wheat stem. Waterlogging of wheat plants reduced internode lignin content, and this effect is accompanied by transcriptional repression of three of the genes characterized as highly expressed in wheat internode including phenylalanine ammonia-lyase6 (PAL6), CCR2 and F5H2, and decreased activity of PAL. Expression of the other genes was, however, induced by waterlogging, suggesting their role in the synthesis of other phenylpropanoid-derived molecules with roles in stress responses. Moreover, difference in internode lignin content between cultivars or change in its level due to waterlogging is associated with the level of cytokinin. Lodging resistance, tolerance against

  17. Lignin-blocking treatment of biomass and uses thereof

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    Yang, Bin [Hanover, NH; Wyman, Charles E [Norwich, VT

    2009-10-20

    Disclosed is a method for converting cellulose in a lignocellulosic biomass. The method provides for a lignin-blocking polypeptide and/or protein treatment of high lignin solids. The treatment enhances cellulase availability in cellulose conversion. Cellulase efficiencies are improved by the protein or polypeptide treatment. The treatment may be used in combination with steam explosion and acid prehydrolysis techniques. Hydrolysis yields from lignin containing biomass are enhanced 5-20%, and enzyme utilization is increased from 10% to 50%. Thus, a more efficient and economical method of processing lignin containing biomass materials utilizes a polypeptide/protein treatment step that effectively blocks lignin binding of cellulase.

  18. Transcriptional profiles of hybrid Eucalyptus genotypes with contrasting lignin content reveal that monolignol biosynthesis-related genes regulate wood composition

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    Tomotaka eShinya

    2016-04-01

    Full Text Available Eucalyptus species constitutes the most widely planted hardwood trees in temperate and subtropical regions. In this study, we compared the transcript levels of genes involved in lignocellulose formation such as cellulose, hemicellulose and lignin biosynthesis in two selected three-year old hybrid Eucalyptus (Eucalyptus urophylla x E. grandis genotypes (AM063 and AM380 that have different lignin content. AM063 and AM380 had 20.2 and 35.5% of Klason lignin content and 59.0% and 48.2%, -cellulose contents, respectively. We investigated the correlation between wood properties and transcript levels of wood formation-related genes using RNA-seq with total RNAs extracted from developing xylem tissues at a breast height. Transcript levels of cell wall construction genes such as cellulose synthase (CesA and sucrose synthase (SUSY were almost the same in both genotypes. However, AM063 exhibited higher transcript levels of UDP-glucose pyrophosphorylase (UGP and xyloglucan endotransglucoxylase (XTH than those in AM380. Most monolignol biosynthesis- related isozyme genes showed higher transcript levels in AM380. These results indicate monolignol biosynthesis-related genes may regulate wood composition in Eucalyptus. Flavonoids contents were also observed at much higher levels in AM380 as a result of the elevated transcript levels of common phenylpropanoid pathway genes, phenylalanine ammonium lyase (PAL, cinnamate-4-hydroxylase (C4H and 4-coumarate-CoA ligase (4CL. Secondary plant cell wall formation is regulated by many transcription factors. We analyzed genes encoding NAC, WRKY, AP2/ERF and KNOX transcription factors and found higher transcript levels of these genes in AM380. We also observed increased transcription of some MYB and LIM domain transcription factors in AM380 compared to AM063. All these results show that genes related to monolignol biosynthesis may regulate the wood composition and help maintain the ratio of cellulose and lignin contents

  19. AP2/ERF Transcription Factor, Ii049, Positively Regulates Lignan Biosynthesis in Isatis indigotica through Activating Salicylic Acid Signaling and Lignan/Lignin Pathway Genes

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    Ruifang Ma

    2017-08-01

    Full Text Available Lignans, such as lariciresinol and its derivatives, have been identified as effective antiviral ingredients in Isatis indigotica. Evidence suggests that the APETALA2/ethylene response factor (AP2/ERF family might be related to the biosynthesis of lignans in I. indigotica. However, the special role played by the AP2/ERF family in the metabolism and its underlying putative mechanism still need to be elucidated. One novel AP2/ERF gene, named Ii049, was isolated and characterized from I. indigotica in this study. The quantitative real-time PCR analysis revealed that Ii049 was expressed highest in the root and responded to methyl jasmonate, salicylic acid (SA and abscisic acid treatments to various degrees. Subcellular localization analysis indicated that Ii049 protein was localized in the nucleus. Knocking-down the expression of Ii049 caused a remarkable reduction of lignan/lignin contents and transcript levels of genes involved in the lignan/lignin biosynthetic pathway. Ii049 bound to the coupled element 1, RAV1AAT and CRTAREHVCBF2 motifs of genes IiPAL and IiCCR, the key structural genes in the lignan/lignin pathway. Furthermore, Ii049 was also essential for SA biosynthesis, and SA induced lignan accumulation in I. indigotica. Notably, the transgenic I. indigotica hairy roots overexpressing Ii049 showed high expression levels of lignan/lignin biosynthetic genes and SA content, resulting in significant accumulation of lignan/lignin. The best-engineered line (OVX049-10 produced 425.60 μg·g−1 lariciresinol, an 8.3-fold increase compared with the wild type production. This study revealed the function of Ii049 in regulating lignan/lignin biosynthesis, which had the potential to increase the content of valuable lignan/lignin in economically significant medicinal plants.

  20. Structural Redesigning Arabidopsis Lignins into Alkali-Soluble Lignins through the Expression of p-Coumaroyl-CoA:Monolignol Transferase PMT1

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    Sibout, Richard; Le Bris, Philippe; Cézard, Laurent

    2016-01-01

    Grass lignins can contain up to 10% to 15% by weight of p-coumaric esters. This acylation is performed on monolignols under the catalysis of p-coumaroyl-coenzyme A monolignol transferase (PMT). To study the impact of p-coumaroylation on lignification, we first introduced the Brachypodium distachyon Bradi2g36910 (BdPMT1) gene into Arabidopsis (Arabidopsis thaliana) under the control of the constitutive maize (Zea mays) ubiquitin promoter. The resulting p-coumaroylation was far lower than that of lignins from mature grass stems and had no impact on stem lignin content. By contrast, introducing either the BdPMT1 or the Bradi1g36980 (BdPMT2) gene into Arabidopsis under the control of the Arabidopsis cinnamate-4-hydroxylase promoter boosted the p-coumaroylation of mature stems up to the grass lignin level (8% to 9% by weight), without any impact on plant development. The analysis of purified lignin fractions and the identification of diagnostic products confirmed that p-coumaric acid was associated with lignins. BdPMT1-driven p-coumaroylation was also obtained in the fah1 (deficient for ferulate 5-hydroxylase) and ccr1g (deficient for cinnamoyl-coenzyme A reductase) lines, albeit to a lower extent. Lignins from BdPMT1-expressing ccr1g lines were also found to be feruloylated. In Arabidopsis mature stems, substantial p-coumaroylation of lignins was achieved at the expense of lignin content and induced lignin structural alterations, with an unexpected increase of lignin units with free phenolic groups. This higher frequency of free phenolic groups in Arabidopsis lignins doubled their solubility in alkali at room temperature. These findings suggest that the formation of alkali-leachable lignin domains rich in free phenolic groups is favored when p-coumaroylated monolignols participate in lignification in a grass in a similar manner. PMID:26826222

  1. Enhancement of protocatechuate decarboxylase activity for the effective production of muconate from lignin-related aromatic compounds.

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    Sonoki, Tomonori; Morooka, Miyuki; Sakamoto, Kimitoshi; Otsuka, Yuichiro; Nakamura, Masaya; Jellison, Jody; Goodell, Barry

    2014-12-20

    The decarboxylation reaction of protocatechuate has been described as a bottleneck and a rate-limiting step in cis,cis-muconate (ccMA) bioproduction from renewable feedstocks such as sugar. Because sugars are already in high demand in the development of many bio-based products, our work focuses on improving protocatechuate decarboxylase (Pdc) activity and ccMA production in particular, from lignin-related aromatic compounds. We previously had transformed an Escherichia coli strain using aroY, which had been used as a protocatechuate decarboxylase encoding gene from Klebsiella pneumoniae subsp. pneumoniae A170-40, and inserted other required genes from Pseudomonas putida KT2440, to allow the production of ccMA from vanillin. This recombinant strain produced ccMA from vanillin, however the Pdc reaction step remained a bottleneck during incubation. In the current study, we identify a way to increase protocatechuate decarboxylase activity in E. coli through enzyme production involving both aroY and kpdB; the latter which encodes for the B subunit of 4-hydroxybenzoate decarboxylase. This permits expression of Pdc activity at a level approximately 14-fold greater than the strain with aroY only. The expression level of AroY increased, apparently as a function of the co-expression of AroY and KpdB. Our results also imply that ccMA may inhibit vanillate demethylation, a reaction step that is rate limiting for efficient ccMA production from lignin-related aromatic compounds, so even though ccMA production may be enhanced, other challenges to overcome vanilate demethylation inhibition still remain.

  2. Epigallocatechin gallate incorporation into lignin enhances the alkaline delignification and enzymatic saccharification of cell walls

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    Elumalai Sasikumar

    2012-08-01

    Full Text Available Abstract Background Lignin is an integral component of the plant cell wall matrix but impedes the conversion of biomass into biofuels. The plasticity of lignin biosynthesis should permit the inclusion of new compatible phenolic monomers such as flavonoids into cell wall lignins that are consequently less recalcitrant to biomass processing. In the present study, epigallocatechin gallate (EGCG was evaluated as a potential lignin bioengineering target for rendering biomass more amenable to processing for biofuel production. Results In vitro peroxidase-catalyzed polymerization experiments revealed that both gallate and pyrogallyl (B-ring moieties in EGCG underwent radical cross-coupling with monolignols mainly by β–O–4-type cross-coupling, producing benzodioxane units following rearomatization reactions. Biomimetic lignification of maize cell walls with a 3:1 molar ratio of monolignols and EGCG permitted extensive alkaline delignification of cell walls (72 to 92% that far exceeded that for lignified controls (44 to 62%. Alkali-insoluble residues from EGCG-lignified walls yielded up to 34% more glucose and total sugars following enzymatic saccharification than lignified controls. Conclusions It was found that EGCG readily copolymerized with monolignols to become integrally cross-coupled into cell wall lignins, where it greatly enhanced alkaline delignification and subsequent enzymatic saccharification. Improved delignification may be attributed to internal trapping of quinone-methide intermediates to prevent benzyl ether cross-linking of lignin to structural polysaccharides during lignification, and to the cleavage of ester intra-unit linkages within EGCG during pretreatment. Overall, our results suggest that apoplastic deposition of EGCG for incorporation into lignin would be a promising plant genetic engineering target for improving the delignification and saccharification of biomass crops.

  3. Evidence for lignin oxidation by the giant panda fecal microbiome.

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    Wei Fang

    Full Text Available The digestion of lignin and lignin-related phenolic compounds from bamboo by giant pandas has puzzled scientists because of the lack of lignin-degrading genes in the genome of the bamboo-feeding animals. We constructed a 16S rRNA gene library from the microorganisms derived from the giant panda feces to identify the possibility for the presence of potential lignin-degrading bacteria. Phylogenetic analysis showed that the phylotypes of the intestinal bacteria were affiliated with the phyla Proteobacteria (53% and Firmicutes (47%. Two phylotypes were affiliated with the known lignin-degrading bacterium Pseudomonas putida and the mangrove forest bacteria. To test the hypothesis that microbes in the giant panda gut help degrade lignin, a metagenomic library of the intestinal bacteria was constructed and screened for clones that contained genes encoding laccase, a lignin-degrading related enzyme. A multicopper oxidase gene, designated as lac51, was identified from a metagenomic clone. Sequence analysis and copper content determination indicated that Lac51 is a laccase rather than a metallo-oxidase and may work outside its original host cell because it has a TAT-type signal peptide and a transmembrane segment at its N-terminus. Lac51 oxidizes a variety of lignin-related phenolic compounds, including syringaldazine, 2,6-dimethoxyphenol, ferulic acid, veratryl alcohol, guaiacol, and sinapinic acid at conditions that simulate the physiologic environment in giant panda intestines. Furthermore, in the presence of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS, syringic acid, or ferulic acid as mediators, the oxidative ability of Lac51 on lignin was promoted. The absorbance of lignin at 445 nm decreased to 36% for ABTS, 51% for syringic acid, and 51% for ferulic acid after incubation for 10 h. Our findings demonstrate that the intestinal bacteria of giant pandas may facilitate the oxidation of lignin moieties, thereby clarifying the digestion

  4. Lignin nanotubes as vehicles for gene delivery into human cells.

    Science.gov (United States)

    Ten, Elena; Ling, Chen; Wang, Yuan; Srivastava, Arun; Dempere, Luisa Amelia; Vermerris, Wilfred

    2014-01-13

    Lignin nanotubes (LNTs) synthesized from the aromatic plant cell wall polymer lignin in a sacrificial alumina membrane template have as useful features their flexibility, ease of functionalization due to the availability of many functional groups, label-free detection by autofluorescence, and customizable optical properties. In this report we show that the physicochemical properties of LNTs can be varied over a wide range to match requirements for specific applications by using lignin with different subunit composition, a function of plant species and genotype, and by choosing the lignin isolation method (thioglycolic acid, phosphoric acid, sulfuric acid (Klason), sodium hydroxide lignin), which influences the size and reactivity of the lignin fragments. Cytotoxicity studies with human HeLa cells showed that concentrations of up to 90 mg/mL are tolerated, which is a 10-fold higher concentration than observed for single- or multiwalled carbon nanotubes (CNTs). Confocal microscopy imaging revealed that all LNT formulations enter HeLa cells without auxiliary agents and that LNTs made from NaOH-lignin penetrate the cell nucleus. We further show that DNA can adsorb to LNTs. Consequently, exposure of HeLa cells to LNTs coated with DNA encoding the green fluorescent protein (GFP) leads to transfection and expression of GFP. The highest transfection efficiency was obtained with LNTs made from NaOH-lignin due to a combination of high DNA binding capacity and DNA delivery directly into the nucleus. These combined features of LNTs make LNTs attractive as smart delivery vehicles of DNA without the cytotoxicity associated with CNTs or the immunogenicity of viral vectors.

  5. Morphological and transcript changes in the biosynthesis of lignin in oil palm (Elaeis guineensis) during Ganoderma boninense infections in vitro.

    Science.gov (United States)

    Goh, Kar Mun; Dickinson, Matthew; Supramaniam, Christina V

    2018-03-01

    Lignification of the plant cell wall could serve as the first line of defense against pathogen attack, but the molecular mechanisms of virulence and disease between oil palm and Ganoderma boninense are poorly understood. This study presents the biochemical, histochemical, enzymology and gene expression evidences of enhanced lignin biosynthesis in young oil palm as a response to G. boninense (GBLS strain). Comparative studies with control (T1), wounded (T2) and infected (T3) oil palm plantlets showed significant accumulation of total lignin content and monolignol derivatives (syringaldehyde and vanillin). These derivatives were deposited on the epidermal cell wall of infected plants. Moreover, substantial differences were detected in the activities of enzyme and relative expressions of genes encoding phenylalanine ammonia lyase (EC 4.3.1.24), cinnamate 4-hydroxylase (EC 1.14.13.11), caffeic acid O-methyltransferase (EC 2.1.1.68) and cinnamyl alcohol dehydrogenase (CAD, EC 1.1.1.195). These enzymes are key intermediates dedicated to the biosynthesis of lignin monomers, the guaicyl (G), syringyl (S) and ρ-hydroxyphenyl (H) subunits. Results confirmed an early, biphasic and transient positive induction of all gene intermediates, except for CAD enzyme activities. These differences were visualized by anatomical and metabolic changes in the profile of lignin in the oil palm plantlets such as low G lignin, indicating a potential mechanism for enhanced susceptibility toward G. boninense infection. © 2017 Scandinavian Plant Physiology Society.

  6. Genetic engineering of syringyl-enriched lignin in plants

    Science.gov (United States)

    Chiang, Vincent Lee; Li, Laigeng

    2004-11-02

    The present invention relates to a novel DNA sequence, which encodes a previously unidentified lignin biosynthetic pathway enzyme, sinapyl alcohol dehydrogenase (SAD) that regulates the biosynthesis of syringyl lignin in plants. Also provided are methods for incorporating this novel SAD gene sequence or substantially similar sequences into a plant genome for genetic engineering of syringyl-enriched lignin in plants.

  7. Enhancement of Environmental Hazard Degradation in the Presence of Lignin: a Proteomics Study

    OpenAIRE

    Sun, Su; Xie, Shangxian; Cheng, Yanbing; Yu, Hongbo; Zhao, Honglu; Li, Muzi; Li, Xiaotong; Zhang, Xiaoyu; Yuan, Joshua S.; Dai, Susie Y.

    2017-01-01

    Proteomics studies of fungal systems have progressed dramatically based on the availability of more fungal genome sequences in recent years. Different proteomics strategies have been applied toward characterization of fungal proteome and revealed important gene functions and proteome dynamics. Presented here is the application of shot-gun proteomic technology to study the bio-remediation of environmental hazards by white-rot fungus. Lignin, a naturally abundant component of the plant biomass,...

  8. Optimization of RT-PCR reactions in studies with genes of lignin biosynthetic route in Saccharum spontaneum

    Directory of Open Access Journals (Sweden)

    JUAN P.P. LLERENA

    Full Text Available ABSTRACT Saccharum spontaneum has been used for the development of energy cane a crop aimed to be used for the production of second-generation ethanol, or lignocellulosic ethanol. Lignin is a main challenge in the conversion of cell wall sugars into ethanol. In our studies to isolate the genes the lignin biosynthesis in S. spontaneum we have had great difficulty in RT-PCR reactions. Thus, we evaluated the effectiveness of different additives in the amplification of these genes. While COMT and CCoAOMT genes did not need any additives for other genes there was no amplification (HCT, F5H, 4CL and CCR or the yield was very low (CAD and C4H. The application of supplementary cDNA was enough to overcome the non-specificity and low yield for C4H and C3H, while the addition of 0.04% BSA + 2% formamide was effective to amplify 4CL, CCR, F5H and CCR. HCT was amplified only by addition of 0.04% BSA + 2% formamide + 0.1 M trehalose and amplification of PAL was possible with addition of 2% of DMSO. Besides optimization of expression assays, the results show that additives can act independently or synergistically.

  9. Development of a genetically programed vanillin-sensing bacterium for high-throughput screening of lignin-degrading enzyme libraries.

    Science.gov (United States)

    Sana, Barindra; Chia, Kuan Hui Burton; Raghavan, Sarada S; Ramalingam, Balamurugan; Nagarajan, Niranjan; Seayad, Jayasree; Ghadessy, Farid J

    2017-01-01

    Lignin is a potential biorefinery feedstock for the production of value-added chemicals including vanillin. A huge amount of lignin is produced as a by-product of the paper industry, while cellulosic components of plant biomass are utilized for the production of paper pulp. In spite of vast potential, lignin remains the least exploited component of plant biomass due to its extremely complex and heterogenous structure. Several enzymes have been reported to have lignin-degrading properties and could be potentially used in lignin biorefining if their catalytic properties could be improved by enzyme engineering. The much needed improvement of lignin-degrading enzymes by high-throughput selection techniques such as directed evolution is currently limited, as robust methods for detecting the conversion of lignin to desired small molecules are not available. We identified a vanillin-inducible promoter by RNAseq analysis of Escherichia coli cells treated with a sublethal dose of vanillin and developed a genetically programmed vanillin-sensing cell by placing the 'very green fluorescent protein' gene under the control of this promoter. Fluorescence of the biosensing cell is enhanced significantly when grown in the presence of vanillin and is readily visualized by fluorescence microscopy. The use of fluorescence-activated cell sorting analysis further enhances the sensitivity, enabling dose-dependent detection of as low as 200 µM vanillin. The biosensor is highly specific to vanillin and no major response is elicited by the presence of lignin, lignin model compound, DMSO, vanillin analogues or non-specific toxic chemicals. We developed an engineered E. coli cell that can detect vanillin at a concentration as low as 200 µM. The vanillin-sensing cell did not show cross-reactivity towards lignin or major lignin degradation products including vanillin analogues. This engineered E. coli cell could potentially be used as a host cell for screening lignin-degrading enzymes that

  10. Enhancement of Lignin Biopolymer Isolation from Hybrid Poplar by Organosolv Pretreatments

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    Miao Wu

    2014-01-01

    Full Text Available Lignocellulosic biomass is an abundant renewable resource that has the potential to displace petroleum in the production of biomaterials and biofuels. In the present study, the fractionation of different lignin biopolymers from hybrid poplar based on organosolv pretreatments using 80% aqueous methanol, ethanol, 1-propanol, and 1-butanol at 220°C for 30 min was investigated. The isolated lignin fractions were characterized by Fourier transform infrared spectroscopy (FT-IR, high-performance anion exchange chromatography (HPAEC, 2D nuclear magnetic resonance (2D NMR, and thermogravimetric analysis (TGA. The results showed that the lignin fraction obtained with aqueous ethanol (EOL possessed the highest yield and the strongest thermal stability compared with other lignin fractions. In addition, other lignin fractions were almost absent of neutral sugars (1.16–1.46% though lignin preparation extracted with 1-butanol (BOL was incongruent (7.53%. 2D HSQC spectra analysis revealed that the four lignin fractions mainly consisted of β-O-4′ linkages combined with small amounts of β-β′ and β-5′ linkages. Furthermore, substitution of Cα in β-O-4′ substructures had occurred due to the effects of dissolvent during the autocatalyzed alcohol organosolv pretreatments. Therefore, aqueous ethanol was found to be the most promising alcoholic organic solvent compared with other alcohols to be used in noncatalyzed processes for the pretreatment of lignocellulosic biomass in biorefinery.

  11. NMR analysis of lignins in CAD-deficient plants. Part 1. Incorporation of hydroxycinnamaldehydes and hydroxybenzaldehydes into lignins.

    Science.gov (United States)

    Kim, Hoon; Ralph, John; Lu, Fachuang; Ralph, Sally A; Boudet, Alain M; MacKay, John J; Sederoff, Ronald R; Ito, Takashi; Kawai, Shingo; Ohashi, Hideo; Higuchi, Takayoshi

    2003-01-21

    Peroxidase/H2O2-mediated radical coupling of 4-hydroxycinnamaldehydes produces 8-O-4-, 8-5-, and 8-8-coupled dehydrodimers as has been documented earlier, as well as the 5-5-coupled dehydrodimer. The 8-5-dehydrodimer is however produced kinetically in its cyclic phenylcoumaran form at neutral pH. Synthetic polymers produced from mixtures of hydroxycinnamaldehydes and normal monolignols provide the next level of complexity. Spectral data from dimers, oligomers, and synthetic polymers have allowed a more substantive assignment of aldehyde components in lignins isolated from a CAD-deficient pine mutant and an antisense-CAD-downregulated transgenic tobacco. CAD-deficient pine lignin shows enhanced levels of the typical benzaldehyde and cinnamaldehyde end-groups, along with evidence for two types of 8-O-4-coupled coniferaldehyde units. The CAD-downregulated tobacco also has higher levels of hydroxycinnamaldehyde and hydroxybenzaldehyde (mainly syringaldehyde) incorporation, but the analogous two types of 8-O-4-coupled products are the dominant features. 8-8-Coupled units are also clearly evident. There is clear evidence for coupling of hydroxycinnamaldehydes to each other and then incorporation into the lignin, as well as for the incorporation of hydroxycinnamaldehyde monomers into the growing lignin polymer. Coniferaldehyde and sinapaldehyde (as well as vanillin and syringaldehyde) co-polymerize with the traditional monolignols into lignins and do so at enhanced levels when CAD-deficiency has an impact on the normal monolignol production. The implication is that, particularly in angiosperms, the aldehydes behave like the traditional monolignols and should probably be regarded as authentic lignin monomers in normal and CAD-deficient plants.

  12. Effect of alkali lignins with different molecular weights from alkali pretreated rice straw hydrolyzate on enzymatic hydrolysis.

    Science.gov (United States)

    Li, Yun; Qi, Benkun; Luo, Jianquan; Wan, Yinhua

    2016-01-01

    This study investigated the effect of alkali lignins with different molecular weights on enzymatic hydrolysis of lignocellulose. Different alkali lignins fractions, which were obtained from cascade ultrafiltration, were added into the dilute acid pretreated (DAP) and alkali pretreated (AP) rice straws respectively during enzymatic hydrolysis. The results showed that the addition of alkali lignins enhanced the hydrolysis and the enhancement for hydrolysis increased with increasing molecular weights of alkali lignins, with maximum enhancement being 28.69% for DAP and 20.05% for AP, respectively. The enhancement was partly attributed to the improved cellulase activity, and filter paper activity increased by 18.03% when adding lignin with highest molecular weight. It was found that the enhancement of enzymatic hydrolysis was correlated with the adsorption affinity of cellulase on alkali lignins, and the difference in surface charge and hydrophobicity of alkali lignins were responsible for the difference in affinity between cellulase and lignins. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Enzymatic synthesis of lignin-siloxane hybrid functional polymers.

    Science.gov (United States)

    Prasetyo, Endry Nugroho; Kudanga, Tukayi; Fischer, Roman; Eichinger, Reinhard; Nyanhongo, Gibson S; Guebitz, Georg M

    2012-02-01

    This study combines the properties of siloxanes and lignin polymers to produce hybrid functional polymers that can be used as adhesives, coating materials, and/or multifunctionalized thin-coating films. Lignin-silica hybrid copolymers were synthesized by using a sol-gel process. Laccases from Trametes hirsuta were used to oxidize lignosulphonates to enhance their reactivity towards siloxanes and then were incorporated into siloxane precursors undergoing a sol-gel process. In vitro copolymerization studies using pure lignin monomers with aminosilanes or ethoxytrimethylsilane and analysis by ²⁹Si NMR spectroscopy revealed hybrid products. Except for kraft lignin, an increase in lignin concentration positively affected the tensile strength in all samples. Similarly, the viscosity generally increased in all samples with increasing lignin concentration and also affected the curing time. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. BSA treatment to enhance enzymatic hydrolysis of cellulose in lignin containing substrates.

    Science.gov (United States)

    Yang, Bin; Wyman, Charles E

    2006-07-05

    Cellulase and bovine serum albumin (BSA) were added to Avicel cellulose and solids containing 56% cellulose and 28% lignin from dilute sulfuric acid pretreatment of corn stover. Little BSA was adsorbed on Avicel cellulose, while pretreated corn stover solids adsorbed considerable amounts of this protein. On the other hand, cellulase was highly adsorbed on both substrates. Adding a 1% concentration of BSA to dilute acid pretreated corn stover prior to enzyme addition at 15 FPU/g cellulose enhanced filter paper activity in solution by about a factor of 2 and beta-glucosidase activity in solution by about a factor of 14. Overall, these results suggested that BSA treatment reduced adsorption of cellulase and particularly beta-glucosidase on lignin. Of particular note, BSA treatment of pretreated corn stover solids prior to enzymatic hydrolysis increased 72 h glucose yields from about 82% to about 92% at a cellulase loading of 15 FPU/g cellulose or achieved about the same yield at a loading of 7.5 FPU/g cellulose. Similar improvements were also observed for enzymatic hydrolysis of ammonia fiber explosion (AFEX) pretreated corn stover and Douglas fir treated by SO(2) steam explosion and for simultaneous saccharification and fermentation (SSF) of BSA pretreated corn stover. In addition, BSA treatment prior to hydrolysis reduced the need for beta-glucosidase supplementation of SSF. The results are consistent with non-specific competitive, irreversible adsorption of BSA on lignin and identify promising strategies to reduce enzyme requirements for cellulose hydrolysis. (c) 2006 Wiley Periodicals, Inc.

  15. Comparison studies on soda lignin and soda-anthraquinone lignin

    International Nuclear Information System (INIS)

    Ibrahim, M.N.M; Yusof, N.N.M.; Hashim, A.

    2007-01-01

    Soda lignin and soda anthraquinone lignin were compared in this study. The physico-chemical properties and structural features of the isolated lignin were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Ultraviolet (UV), ash test, Carbon-Hydrogen-Nitrogen (CHN) analyzer, Nuclear Magnetic Resonance ( 13 C-NMR) and High Performance Liquid Chromatography (HPLC). Nitrobenzene oxidation was performed on these two types of lignin especially for the HPLC analysis. Based on the CHN, 13 C-NMR and UV results there were no significant differences between soda lignin and soda anthraquinone lignin. The FTIR results also showed that there were no significant differences in terms of functional groups that exist in both lignins. (author)

  16. From gene to biorefinery: microbial β-etherases as promising biocatalysts for lignin valorization

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    Pere ePicart

    2015-09-01

    Full Text Available The set-up of biorefineries for the valorization of lignocellulosic biomass will be core in the future to reach sustainability targets. In this area, biomass-degrading enzymes are attracting significant research interest for their potential in the production of chemicals and biofuels from renewable feedstock. Gluthatione-dependent β-etherases are emerging enzymes for the biocatalytic depolymerization of lignin, a heterogeneous aromatic polymer abundant in Nature. They selectively catalyze the reductive cleavage of β-O-4 aryl-ether bonds which account for 45-60% of linkages present in lignin. Hence, application of β-etherases in lignin depolymerization would enable a specific lignin breakdown, selectively yielding (valuable low-molecular-mass aromatics. Albeit β-etherases have been biochemically known for decades, only very recently novel β-etherases have been identified and thoroughly characterized for lignin valorization, expanding the enzyme toolbox for efficient β-O-4 aryl-ether bond cleavage. Given their emerging importance and potential, this mini-review discusses recent developments in the field of β-etherase biocatalysis covering all aspects from enzyme identification to biocatalytic applications with real lignin samples.

  17. From gene to biorefinery: microbial β-etherases as promising biocatalysts for lignin valorization.

    Science.gov (United States)

    Picart, Pere; de María, Pablo Domínguez; Schallmey, Anett

    2015-01-01

    The set-up of biorefineries for the valorization of lignocellulosic biomass will be core in the future to reach sustainability targets. In this area, biomass-degrading enzymes are attracting significant research interest for their potential in the production of chemicals and biofuels from renewable feedstock. Glutathione-dependent β-etherases are emerging enzymes for the biocatalytic depolymerization of lignin, a heterogeneous aromatic polymer abundant in nature. They selectively catalyze the reductive cleavage of β-O-4 aryl-ether bonds which account for 45-60% of linkages present in lignin. Hence, application of β-etherases in lignin depolymerization would enable a specific lignin breakdown, selectively yielding (valuable) low-molecular-mass aromatics. Albeit β-etherases have been biochemically known for decades, only very recently novel β-etherases have been identified and thoroughly characterized for lignin valorization, expanding the enzyme toolbox for efficient β-O-4 aryl-ether bond cleavage. Given their emerging importance and potential, this mini-review discusses recent developments in the field of β-etherase biocatalysis covering all aspects from enzyme identification to biocatalytic applications with real lignin samples.

  18. Downregulation of the UDP-arabinomutase gene in switchgrass (Panicum virgatum L. results in increased cell wall lignin while reducing arabinose-glycans

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    Jonathan Duran Willis

    2016-10-01

    Full Text Available Switchgrass (Panicum virgatum L. is a C4 perennial prairie grass and a lignocellulosic biofuels feedstock. Saccharification and biofuel yields are inhibited by the plant cell wall’s natural recalcitrance against enzymatic degradation. Plant hemicellulose polysaccharides such as arabinoxylans structurally support and crosslink other cell wall polymers. Grasses have predominately Type II cell walls that are abundant in arabinoxylan, which comprise nearly 25% of aboveground biomass. A primary component of arabinoxylan synthesis is uridine diphosphate (UDP linked to arabinofuranose (Araf. A family of UDP-arabinopyranose mutase/reversible glycosylated polypeptides (UAM/RGPs catalyze the interconversion between UDP-arabinopyranose (UDP-Arap and UDP-Araf. In switchgrass we knocked down expression of the endogenous PvUAM1 gene via RNAi to investigate its role in cell wall recalcitrance in the feedstock. PvUAM1 encodes a switchgrass homolog of UDP-arabinose mutase, which converts UDP-Arap to UDP-Araf. Each transgenic line contained between one to at least seven T-DNA insertions, resulting in some cases, a 95% reduction of native PvUAM1 transcript in stem internodes. Transgenic plants had increased pigmentation in vascular tissues at nodes, but were otherwise morphologically similar to non-transgenics. There was decreased cell wall-associated arabinose in leaves and stems by over 50%, but there was an increase in cellulose in these organs. In addition, there was a commensurate change in arabinose side chain extension. Cell wall lignin composition was altered with a concurrent increase in lignin content and transcript abundance of lignin biosynthetic genes in mature tillers. Enzymatic saccharification efficiency was unchanged in the transgenic plants relative to the control, but had increased glucose in cell walls. The increased glucose detected in stems and leaves indicates that attenuation of PvUAM1 expression might have downstream effects on starch

  19. NMR of lignins

    Science.gov (United States)

    John Ralph; Larry L. Landucci

    2010-01-01

    This chapter will consider the basic aspects and findings of several forms of NMR spectroscopy, including separate discussions of proton, carbon, heteronuclear, and multidimensional NMR. Enhanced focus will be on 13C NMR, because of its qualitative and quantitative importance, followed by NMR’s contributions to our understanding of lignin...

  20. Nitroxyl-mediated oxidation of lignin and polycarboxylated products

    Energy Technology Data Exchange (ETDEWEB)

    Stahl, Shannon S.; Rafiee, Mohammad

    2018-02-27

    Methods of selectively modifying lignin, polycarboxylated products thereof, and methods of deriving aromatic compounds therefrom. The methods comprise electrochemically oxidizing lignin using stable nitroxyl radicals to selectively oxidize primary hydroxyls on .beta.-O-4 phenylpropanoid units to corresponding carboxylic acids while leaving the secondary hydroxyls unchanged. The oxidation results in polycarboxylated lignin in the form of a polymeric .beta.-hydroxy acid. The polymeric .beta.-hydroxy acid has a high loading of carboxylic acid and can be isolated in acid form, deprotonated, and/or converted to a salt. The .beta.-hydroxy acid, anion, or salt can also be subjected to acidolysis to generate various aromatic monomers or oligomers. The initial oxidation of lignin to the polycarboxylated form renders the lignin more susceptible to acidolysis and thereby enhances the yield of aromatic monomers and oligomers obtained through acidolysis.

  1. Lignin nanoparticle synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Dirk, Shawn M.; Cicotte, Kirsten Nicole; Wheeler, David R.; Benko, David A.

    2015-08-11

    A method including reducing a particle size of lignin particles to an average particle size less than 40 nanometers; after reducing the particle size, combining the lignin particles with a polymeric material; and forming a structure of the combination. A method including exposing lignin to a diazonium precursor including a functional group; modifying the lignin by introducing the functional group to the lignin; and combining the modified lignin with a polymeric material to form a composite. An apparatus including a composite of a polymer and lignin wherein the lignin has an average particle size less than 100 micrometers.

  2. Coordinated transcriptional regulation of two key genes in the lignin branch pathway--CAD and CCR--is mediated through MYB- binding sites.

    Science.gov (United States)

    Rahantamalala, Anjanirina; Rech, Philippe; Martinez, Yves; Chaubet-Gigot, Nicole; Grima-Pettenati, Jacqueline; Pacquit, Valérie

    2010-06-28

    Cinnamoyl CoA reductase (CCR) and cinnamyl alcohol dehydrogenase (CAD) catalyze the final steps in the biosynthesis of monolignols, the monomeric units of the phenolic lignin polymers which confer rigidity, imperviousness and resistance to biodegradation to cell walls. We have previously shown that the Eucalyptus gunnii CCR and CAD2 promoters direct similar expression patterns in vascular tissues suggesting that monolignol production is controlled, at least in part, by the coordinated transcriptional regulation of these two genes. Although consensus motifs for MYB transcription factors occur in most gene promoters of the whole phenylpropanoid pathway, functional evidence for their contribution to promoter activity has only been demonstrated for a few of them. Here, in the lignin-specific branch, we studied the functional role of MYB elements as well as other cis-elements identified in the regulatory regions of EgCAD2 and EgCCR promoters, in the transcriptional activity of these gene promoters. By using promoter deletion analysis and in vivo footprinting, we identified an 80 bp regulatory region in the Eucalyptus gunnii EgCAD2 promoter that contains two MYB elements, each arranged in a distinct module with newly identified cis-elements. A directed mutagenesis approach was used to introduce block mutations in all putative cis-elements of the EgCAD2 promoter and in those of the 50 bp regulatory region previously delineated in the EgCCR promoter. We showed that the conserved MYB elements in EgCAD2 and EgCCR promoters are crucial both for the formation of DNA-protein complexes in EMSA experiments and for the transcriptional activation of EgCAD2 and EgCCR promoters in vascular tissues in planta. In addition, a new regulatory cis-element that modulates the balance between two DNA-protein complexes in vitro was found to be important for EgCAD2 expression in the cambial zone. Our assignment of functional roles to the identified cis-elements clearly demonstrates the

  3. Chapter 16: Lignin Visualization: Advanced Microscopy Techniques for Lignin Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Yining [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Donohoe, Bryon S [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2018-04-03

    Visualization of lignin in plant cell walls, with both spatial and chemical resolution, is emerging as an important tool to understand lignin's role in the plant cell wall's nanoscale architecture and to understand and design processes intended to modify the lignin. As such, this chapter reviews recent advances in advanced imaging methods with respect to lignin in plant cell walls. This review focuses on the importance of lignin detection and localization for studies in both plant biology and biotechnology. Challenges going forward to identify and delineate lignin from other plant cell wall components and to quantitatively analyze lignin in whole cell walls from native plant tissue and treated biomass are also discussed.

  4. Reinforcing styrene butadiene rubber with lignin-novolac epoxy resin networks

    Directory of Open Access Journals (Sweden)

    P. Yu

    2015-01-01

    Full Text Available In this study, lignin-novolac epoxy resin networks were fabricated in the styrene butadiene rubber (SBR matrix by combination of latex compounding and melt mixing. Firstly, SBR/lignin compounds were co-coagulated by SBR latex and lignin aqueous solution. Then the novolac epoxy resin (F51 was added in the SBR/lignin compounds by melt compounding method. F51 was directly cured by lignin via the ring-opening reaction of epoxy groups of F51 and OH groups (or COOH groups of lignin during the curing process of rubber compounds, as was particularly evident from Fourier transform infrared spectroscopy (FTIR studies and maximum torque of the curing analysis. The existence of lignin-F51 networks were also detected by scanning electron microscope (SEM and dynamic mechanical analysis (DMA. The structure of the SBR/lignin/F51 was also characterized by rubber process analyzer (RPA, thermogravimetric analysis (TGA and determination of crosslinking density. Due to rigid lignin-F51 networks achieved in SBR/lignin/F51 composites, it was found that the hardness, modulus, tear strength, crosslinking density, the temperature of 5 and 10% weight-loss were significantly enhanced with the loading of F51.

  5. Isolation and characterization of lignin from the oak wood bioethanol production residue for adhesives.

    Science.gov (United States)

    Lee, Soo Jung; Kim, Hyun Joo; Cho, Eun Jin; Song, Younho; Bae, Hyeun-Jong

    2015-01-01

    Lignin was isolated from the residue of bioethanol production with oak wood via alkaline and catalyzed organosolv treatments at ambient temperature to improve the purity of lignin for the materials application. The isolated lignins were analyzed for their chemical composition by nitrobenzene oxidation method and their functionality was characterized via wet chemistry method, element analysis, (1)H NMR, GPC and FTIR-ATR. The isolated lignin by acid catalyzed organosolv treatment (Acid-OSL) contained a higher lignin content, aromatic proton, phenolic hydroxyl group and a lower nitrogen content that is more reactive towards chemical modification. The lignin-based adhesives were prepared and the bond strength was measured to evaluate the enhanced reactivity of lignin by the isolation. Two steps of phenolation and methylolation were applied for the modification of the isolated lignins and their tensile strengths were evaluated for the use as an adhesive. The acid catalyzed organosolv lignin-based adhesives had comparable bond strength to phenol-formaldehyde adhesives. The analysis of lignin-based adhesives by FTIR-ATR and TGA showed structural similarity to phenol adhesive. The results demonstrate that the reactivity of lignin was enhanced by isolation from hardwood bioethanol production residues at ambient temperature and it could be used in a value-added application to produce lignin-based adhesives. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Large-Scale Transcriptome Analysis of Two Sugarcane Genotypes Contrasting for Lignin Content.

    Directory of Open Access Journals (Sweden)

    Renato Vicentini

    Full Text Available Sugarcane is an important crop worldwide for sugar and first generation ethanol production. Recently, the residue of sugarcane mills, named bagasse, has been considered a promising lignocellulosic biomass to produce the second-generation ethanol. Lignin is a major factor limiting the use of bagasse and other plant lignocellulosic materials to produce second-generation ethanol. Lignin biosynthesis pathway is a complex network and changes in the expression of genes of this pathway have in general led to diverse and undesirable impacts on plant structure and physiology. Despite its economic importance, sugarcane genome was still not sequenced. In this study a high-throughput transcriptome evaluation of two sugarcane genotypes contrasting for lignin content was carried out. We generated a set of 85,151 transcripts of sugarcane using RNA-seq and de novo assembling. More than 2,000 transcripts showed differential expression between the genotypes, including several genes involved in the lignin biosynthetic pathway. This information can give valuable knowledge on the lignin biosynthesis and its interactions with other metabolic pathways in the complex sugarcane genome.

  7. pH-Induced Lignin Surface Modification to Reduce Nonspecific Cellulase Binding and Enhance Enzymatic Saccharification of Lignocelluloses

    Science.gov (United States)

    Hongming Lou; J.Y. Zhu; Tian Qing Lan; Huranran Lai; Xueqing Qiu

    2013-01-01

    We studied the mechanism of the significant enhancement in the enzymatic saccharification of lignocelluloses at an elevated pH of 5.5–6.0. Four lignin residues with different sulfonic acid contents were isolated from enzymatic hydrolysis of lodgepole pine pretreated by either dilute acid (DA) or sulfite pretreatment to overcome recalcitrance of lignocelluloses (SPORL...

  8. Lignin depolymerization by fungal secretomes and a microbial sink

    Energy Technology Data Exchange (ETDEWEB)

    Salvachúa, Davinia; Katahira, Rui; Cleveland, Nicholas S.; Khanna, Payal; Resch, Michael G.; Black, Brenna A.; Purvine, Samuel O.; Zink, Erika M.; Prieto, Alicia; Martínez, María J.; Martínez, Angel T.; Simmons, Blake A.; Gladden, John M.; Beckham, Gregg T.

    2016-08-25

    In Nature, powerful oxidative enzymes secreted by white rot fungi and some bacteria catalyze lignin depolymerization and some microbes are able to catabolize the resulting aromatic compounds as carbon and energy sources. Taken together, these two processes offer a potential route for microbial valorization of lignin. However, many challenges remain in realizing this concept, including that oxidative enzymes responsible for lignin depolymerization also catalyze polymerization of low molecular weight (LMW) lignin. Here, multiple basidiomycete secretomes were screened for ligninolytic enzyme activities in the presence of a residual lignin solid stream from a corn stover biorefinery, dubbed DMR-EH (Deacetylation, Mechanical Refining, and Enzymatic Hydrolysis) lignin. Two selected fungal secretomes, with high levels of laccases and peroxidases, were utilized for DMR-EH lignin depolymerization assays. The secretome from Pleurotus eryngii, which exhibited the highest laccase activity, reduced the lignin average molecular weight by 63% and 75% at pH 7 compared to the Mw of the control treated at the same conditions and the initial DMR-EH lignin, respectively, and was applied in further depolymerization assays as a function of time. As repolymerization was observed after 3 days of incubation, an aromatic-catabolic microbe (Pseudomonas putida KT2440) was incubated with the fungal secretome and DMR-EH lignin. These experiments demonstrated that the presence of the bacterium enhances lignin depolymerization, likely due to bacterial catabolism of LMW lignin, which may partially prevent repolymerization. In addition, proteomics was also applied to the P. eryngii secretome to identify the enzymes present in the fungal cocktail utilized for the depolymerization assays, which highlighted a significant number of glucose/ methanol/choline (GMC) oxidoreductases and laccases. Overall, this study demonstrates that ligninolytic enzymes can be used to partially depolymerize a solid, high

  9. Using The Corngrass1 Gene To Enhance The Biofuel Properties Of Crop Plants

    Energy Technology Data Exchange (ETDEWEB)

    Hake, Sarah [USDA Agricultural Research Service, Washington DC (United States); Chuck, George [USDA Agricultural Research Service, Washington DC (United States)

    2015-10-29

    The development of novel plant germplasm is vital to addressing our increasing bioenergy demands. The major hurdle to digesting plant biomass is the complex structure of the cell walls, the substrate of fermentation. Plant cell walls are inaccessible matrices of macromolecules that are polymerized with lignin, making fermentation difficult. Overcoming this hurdle is a major goal toward developing usable bioenergy crop plants. Our project seeks to enhance the biofuel properties of perennial grass species using the Corngrass1 (Cg1) gene and its targets. Dominant maize Cg1 mutants produce increased biomass by continuously initiating extra axillary meristems and leaves. We cloned Cg1 and showed that its phenotype is caused by over expression of a unique miR156 microRNA gene that negatively regulates SPL transcription factors. We transferred the Cg1 phenotype to other plants by expressing the gene behind constitutive promoters in four different species, including the monocots, Brachypodium and switchgrass, and dicots, Arabidopsis and poplar. All transformants displayed a similar range of phenotypes, including increased biomass from extended leaf production, and increased vegetative branching. Field grown switchgrass transformants showed that overall lignin content was reduced, the ratio of glucans to xylans was increased, and surprisingly, that starch levels were greatly increased. The goals of this project are to control the tissue and temporal expression of Cg1 by using different promoters to drive its expression, elucidate the function of the SPL targets of Cg1 by generating gain and loss of function alleles, and isolate downstream targets of select SPL genes using deep sequencing and chromatin immunoprecipitation. We believe it is possible to control biomass accumulation, cell wall properties, and sugar levels through manipulation of either the Cg1 gene and/or its SPL targets.

  10. Fast Curing Bio-Based Phenolic Resins via Lignin Demethylated under Mild Reaction Condition

    OpenAIRE

    Jiongjiong Li; Jizhi Zhang; Shifeng Zhang; Qiang Gao; Jianzhang Li; Wei Zhang

    2017-01-01

    Demethylation technique has been used to enhance lignin reactivity for preparation of phenolic resins. However, the demethylation efficiency and the demethylated lignin (DL) reactivity were still unsatisfactory. To improve the demethylation efficiency, alkali lignin was demethylated under different mild conditions using sodium sulfite as a catalyst. Lignin and DL were characterized by 1H-NMR (nuclear magnetic resonance) and Fourier transform infrared (FT-IR) spectroscopy to determine the deme...

  11. Formic-acid-induced depolymerization of oxidized lignin to aromatics

    Science.gov (United States)

    Rahimi, Alireza; Ulbrich, Arne; Coon, Joshua J.; Stahl, Shannon S.

    2014-11-01

    Lignin is a heterogeneous aromatic biopolymer that accounts for nearly 30% of the organic carbon on Earth and is one of the few renewable sources of aromatic chemicals. As the most recalcitrant of the three components of lignocellulosic biomass (cellulose, hemicellulose and lignin), lignin has been treated as a waste product in the pulp and paper industry, where it is burned to supply energy and recover pulping chemicals in the operation of paper mills. Extraction of higher value from lignin is increasingly recognized as being crucial to the economic viability of integrated biorefineries. Depolymerization is an important starting point for many lignin valorization strategies, because it could generate valuable aromatic chemicals and/or provide a source of low-molecular-mass feedstocks suitable for downstream processing. Commercial precedents show that certain types of lignin (lignosulphonates) may be converted into vanillin and other marketable products, but new technologies are needed to enhance the lignin value chain. The complex, irregular structure of lignin complicates chemical conversion efforts, and known depolymerization methods typically afford ill-defined products in low yields (that is, less than 10-20wt%). Here we describe a method for the depolymerization of oxidized lignin under mild conditions in aqueous formic acid that results in more than 60wt% yield of low-molecular-mass aromatics. We present the discovery of this facile C-O cleavage method, its application to aspen lignin depolymerization, and mechanistic insights into the reaction. The broader implications of these results for lignin conversion and biomass refining are also considered.

  12. Characterization of Trapped Lignin-Degrading Microbes in Tropical Forest Soil

    Energy Technology Data Exchange (ETDEWEB)

    DeAngelis, Kristen; Allgaier, Martin; Chavarria, Yaucin; Fortney, Julian; Hugenholtz, Phillip; Simmons, Blake; Sublette, Kerry; Silver, Whendee; Hazen, Terry

    2011-07-14

    Lignin is often the most difficult portion of plant biomass to degrade, with fungi generally thought to dominate during late stage decomposition. Lignin in feedstock plant material represents a barrier to more efficient plant biomass conversion and can also hinder enzymatic access to cellulose, which is critical for biofuels production. Tropical rain forest soils in Puerto Rico are characterized by frequent anoxic conditions and fluctuating redox, suggesting the presence of lignin-degrading organisms and mechanisms that are different from known fungal decomposers and oxygen-dependent enzyme activities. We explored microbial lignin-degraders by burying bio-traps containing lignin-amended and unamended biosep beads in the soil for 1, 4, 13 and 30 weeks. At each time point, phenol oxidase and peroxidase enzyme activity was found to be elevated in the lignin-amended versus the unamended beads, while cellulolytic enzyme activities were significantly depressed in lignin-amended beads. Quantitative PCR of bacterial communities showed more bacterial colonization in the lignin-amended compared to the unamended beads after one and four weeks, suggesting that the lignin supported increased bacterial abundance. The microbial community was analyzed by small subunit 16S ribosomal RNA genes using microarray (PhyloChip) and by high-throughput amplicon pyrosequencing based on universal primers targeting bacterial, archaeal, and eukaryotic communities. Community trends were significantly affected by time and the presence of lignin on the beads. Lignin-amended beads have higher relative abundances of representatives from the phyla Actinobacteria, Firmicutes, Acidobacteria and Proteobacteria compared to unamended beads. This study suggests that in low and fluctuating redox soils, bacteria could play a role in anaerobic lignin decomposition.

  13. Characterization of trapped lignin-degrading microbes in tropical forest soil

    Energy Technology Data Exchange (ETDEWEB)

    DeAngelis, K.M.; Allgaier, M.; Chavarria, Y.; Fortney, J.L.; Hugenholz, P.; Simmons, B.; Sublette, K.; Silver, W.L.; Hazen, T.C.

    2011-03-01

    Lignin is often the most difficult portion of plant biomass to degrade, with fungi generally thought to dominate during late stage decomposition. Lignin in feedstock plant material represents a barrier to more efficient plant biomass conversion and can also hinder enzymatic access to cellulose, which is critical for biofuels production. Tropical rain forest soils in Puerto Rico are characterized by frequent anoxic conditions and fluctuating redox, suggesting the presence of lignin-degrading organisms and mechanisms that are different from known fungal decomposers and oxygen-dependent enzyme activities. We explored microbial lignin-degraders by burying bio-traps containing lignin-amended and unamended biosep beads in the soil for 1, 4, 13 and 30 weeks. At each time point, phenol oxidase and peroxidase enzyme activity was found to be elevated in the lignin-amended versus the unamended beads, while cellulolytic enzyme activities were significantly depressed in lignin-amended beads. Quantitative PCR of bacterial communities showed more bacterial colonization in the lignin-amended compared to the unamended beads after one and four weeks, suggesting that the lignin supported increased bacterial abundance. The microbial community was analyzed by small subunit 16S ribosomal RNA genes using microarray (PhyloChip) and by high-throughput amplicon pyrosequencing based on universal primers targeting bacterial, archaeal, and eukaryotic communities. Community trends were significantly affected by time and the presence of lignin on the beads. Lignin-amended beads have higher relative abundances of representatives from the phyla Actinobacteria, Firmicutes, Acidobacteria and Proteobacteria compared to unamended beads. This study suggests that in low and fluctuating redox soils, bacteria could play a role in anaerobic lignin decomposition.

  14. Characterization of anaerobic consortia coupled lignin depolymerization with biomethane generation.

    Science.gov (United States)

    Wu, Yi-Rui; He, Jianzhong

    2013-07-01

    Two sediment-free microbial consortia (LI3 and LP3) were established to depolymerize lignin under anaerobic conditions. During depolymerizing high molecular weight lignin to low molecular weight molecules, the two cultures produced biomethane up to 151.7 and 113.0 mL g(-1) total lignin. Furthermore, LI3 and LP3 could also utilize the biomass - oil palm empty fruit bunch fiber (OPEFB) to produce 190.6 and 195.6 mL methaneg(-1) total lignin in OPEFB, and at the same time improve the bioavailability of lignocellulosic matters for further enzymatic hydrolysis. The microbial community analysis by denature gradient gel electrophoresis (DGGE) and the high-density 16S rDNA gene microarray (PhyloChip) exhibited that Methanomethylovorans sp. (LI3) and Methanoculleus sp. (LP3) were the main methanogens present, and phylum Firmicutes and Bacteroidetes were mainly involved in the lignin depolymerization. The established microbial consortia with both lignin depolymerization and biomethane production provide profound application on the environmental friendly pretreatment of lignocellulosic materials. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Lignin Valorization: Emerging Approaches

    Energy Technology Data Exchange (ETDEWEB)

    Beckham, Gregg T [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2018-04-03

    Lignin, an aromatic biopolymer found in plant cell walls, is a key component of lignocellulosic biomass and generally utilized for heat and power. However, lignin's chemical composition makes it an attractive source for biological and catalytic conversion to fuels and chemicals. Bringing together experts from biology, catalysis, engineering, analytical chemistry, and techno-economic/life-cycle analysis, Lignin Valorization presents a comprehensive, interdisciplinary picture of how lignocellulosic biorefineries could potentially employ lignin valorization technologies. Chapters will specifically focus on the production of fuels and chemicals from lignin and topics covered include (i) methods for isolating lignin in the context of the lignocellulosic biorefinery, (ii) thermal, chemo-catalytic, and biological methods for lignin depolymerization, (iii) chemo-catalytic and biological methods for upgrading lignin, (iv) characterization of lignin, and (v) techno-economic and life-cycle analysis of integrated processes to utilize lignin in an integrated biorefinery. The book provides the latest breakthroughs and challenges in upgrading lignin to fuels and chemicals for graduate students and researchers in academia, governmental laboratories, and industry interested in biomass conversion.

  16. Lignin Modification for Biopolymer/Conjugated Polymer Hybrids as Renewable Energy Storage Materials.

    Science.gov (United States)

    Nilsson, Ting Yang; Wagner, Michal; Inganäs, Olle

    2015-12-07

    Lignin derivatives, which arise as waste products from the pulp and paper industry and are mainly used for heating, can be used as charge storage materials. The charge storage function is a result of the quinone groups formed in the lignin derivative. Herein, we modified lignins to enhance the density of such quinone groups by covalently linking monolignols and quinones through phenolation. The extra guaiacyl, syringyl, and hydroquinone groups introduced by phenolation of kraft lignin derivatives were monitored by (31) P nuclear magnetic resonance and size exclusion chromatography. Electropolymerization in ethylene glycol/tetraethylammonium tosylate electrolyte was used to synthesize the kraft lignin/polypyrrole hybrid films. These modifications changed the phenolic content of the kraft lignin with attachment of hydroquinone units yielding the highest specific capacity (around 70 mA h g(-1) ). The modification of softwood and hardwood lignin derivatives yielded 50 % and 23 % higher charge capacity than the original lignin, respectively. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Enhanced lignin monomer production caused by cinnamic Acid and its hydroxylated derivatives inhibits soybean root growth.

    Directory of Open Access Journals (Sweden)

    Rogério Barbosa Lima

    Full Text Available Cinnamic acid and its hydroxylated derivatives (p-coumaric, caffeic, ferulic and sinapic acids are known allelochemicals that affect the seed germination and root growth of many plant species. Recent studies have indicated that the reduction of root growth by these allelochemicals is associated with premature cell wall lignification. We hypothesized that an influx of these compounds into the phenylpropanoid pathway increases the lignin monomer content and reduces the root growth. To confirm this hypothesis, we evaluated the effects of cinnamic, p-coumaric, caffeic, ferulic and sinapic acids on soybean root growth, lignin and the composition of p-hydroxyphenyl (H, guaiacyl (G and syringyl (S monomers. To this end, three-day-old seedlings were cultivated in nutrient solution with or without allelochemical (or selective enzymatic inhibitors of the phenylpropanoid pathway in a growth chamber for 24 h. In general, the results showed that 1 cinnamic, p-coumaric, caffeic and ferulic acids reduced root growth and increased lignin content; 2 cinnamic and p-coumaric acids increased p-hydroxyphenyl (H monomer content, whereas p-coumaric, caffeic and ferulic acids increased guaiacyl (G content, and sinapic acid increased sinapyl (S content; 3 when applied in conjunction with piperonylic acid (PIP, an inhibitor of the cinnamate 4-hydroxylase, C4H, cinnamic acid reduced H, G and S contents; and 4 when applied in conjunction with 3,4-(methylenedioxycinnamic acid (MDCA, an inhibitor of the 4-coumarate:CoA ligase, 4CL, p-coumaric acid reduced H, G and S contents, whereas caffeic, ferulic and sinapic acids reduced G and S contents. These results confirm our hypothesis that exogenously applied allelochemicals are channeled into the phenylpropanoid pathway causing excessive production of lignin and its main monomers. By consequence, an enhanced stiffening of the cell wall restricts soybean root growth.

  18. Enrichment of Bacteria From Eastern Mediterranean Sea Involved in Lignin Degradation via the Phenylacetyl-CoA Pathway

    Directory of Open Access Journals (Sweden)

    Hannah L. Woo

    2018-05-01

    Full Text Available The degradation of allochthonous terrestrial organic matter, such as recalcitrant lignin and hemicellulose from plants, occurs in the ocean. We hypothesize that bacteria instead of white-rot fungi, the model organisms of aerobic lignin degradation within terrestrial environments, are responsible for lignin degradation in the ocean due to the ocean’s oligotrophy and hypersalinity. Warm oxic seawater from the Eastern Mediterranean Sea was enriched on lignin in laboratory microcosms. Lignin mineralization rates by the lignin-adapted consortia improved after two sequential incubations. Shotgun metagenomic sequencing detected a higher abundance of aromatic compound degradation genes in response to lignin, particularly phenylacetyl-CoA, which may be an effective strategy for marine microbes in fluctuating oxygen concentrations. 16S rRNA gene amplicon sequencing detected a higher abundance of Gammaproteobacteria and Alphaproteobacteria bacteria such as taxonomic families Idiomarinaceae, Alcanivoraceae, and Alteromonadaceae in response to lignin. Meanwhile, fungal Ascomycetes and Basidiomycetes remained at very low abundance. Our findings demonstrate the significant potential of bacteria and microbes utilizing the phenylacetyl-CoA pathway to contribute to lignin degradation in the Eastern Mediterranean where environmental conditions are unfavorable for fungi. Exploring the diversity of bacterial lignin degraders may provide important enzymes for lignin conversion in industry. Enzymes may be key in breaking down high molecular weight lignin and enabling industry to use it as a low-cost and sustainable feedstock for biofuels or other higher-value products.

  19. Over-expression of histone H3K4 demethylase gene JMJ15 enhances salt tolerance in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Yuan eShen

    2014-06-01

    Full Text Available Histone H3 lysine 4 trimethylation (H3K4me3 has been shown to be involved in stress-responsive gene expression and gene priming in plants. However, the role of H3K4me3 resetting in the processes is not clear. In this work we studied the expression and function of Arabidopsis H3K4 demethylase gene JMJ15. We show that the expression of JMJ15 was relatively low and was limited to a number of tissues during vegetative growth but was higher in young floral organs. Over-expression of the gene in gain-of-function mutants reduced the plant height with accumulation of lignin in stems, while the loss-of-function mutation did not produce any visible phenotype. The gain-of-function mutants showed enhanced salt tolerance, whereas the loss-of-function mutant was more sensitive to salt compared to the wild type. Transcriptomic analysis revealed that over-expression of JMJ15 down-regulated many genes which are preferentially marked by H3K4me3 and H3K4me2. Many of the down-regulated genes encode transcription regulators involved in stress responses. The data suggest that increased JMJ15 levels may regulate the gene expression program that enhances stress tolerance.

  20. Influence of near-ultraviolet light enhancement and photosynthetic photon flux density during photoperiod extension on the morphology and lignin content of black spruce seedlings

    International Nuclear Information System (INIS)

    Margolis, H.; Vezina, L.P.; Bellefleur, P.

    1991-01-01

    When containerized black spruce seedlings (Picea mariana (Mill.) B.S.P.) are grown rapidly in greenhouse culture, they sometimes bend over, grow horizontally and become deformed. This phenomenon has been known to affect between 5% and 10% of a winter greenhouse crop. In this study, near-ultraviolet lamps were used to supplement the artificial light received from high-pressure sodium lamps and the effects on seedling morphology and lignin contents were examined. Neither height to diameter ratios nor lignin concentrations were significantly affected by UV radiation flux density. However, seedling biomass, height, root collar diameter, lignin content, and lignin to cellulose ratios of stems were significantly correlated with total photosynthetic photon flux density (PPFD) received during photoperiod extension. Height to diameter ratios were negatively correlated with PPFD during photoperiod enhancement because of a greater relative increase in diameter growth compared with height growth. Neither UV nor PAR flux density affected the percentage of black spruce seedlings having stem deformations greater than 30 ° from the vertical [fr

  1. 14C-labeled lignins as substrates for the study of lignin biodegradation and transformation

    International Nuclear Information System (INIS)

    Crawford, R.L.; Robinson, L.E.; Chen, A.M.

    1980-01-01

    Methods, both classical and isotopic, for quantifying lignin degradation are reviewed. Preparation and chemical characterization of 14 C-labeled lignins (both synthetic and plant-synthesized) are reviewed, with emphasis on the utilization of these 14 C-labeled substrates in biodegradation and biotransformation experiments. The scientific literature is reviewed concerning the use of 14 C-lignins to examine the following: microbial groups that are able to degrade lignins; lignin degradation in natural environments; biochemistry and microbial physiology of lignin degradation; biodegradability of industrial lignins and their by-products; and screening for industrially valuable, lignin-modifying microorganisms. Recent results obtained in our laboratory concerning lignin degradation by eubacteria are presented. Future directions for 14 C-methodology are examined

  2. Identifying new lignin bioengineering targets: 1. Monolignol-substitute impacts on lignin formation and cell wall fermentability

    Directory of Open Access Journals (Sweden)

    Lu Fachuang

    2010-06-01

    Full Text Available Abstract Background Recent discoveries highlighting the metabolic malleability of plant lignification indicate that lignin can be engineered to dramatically alter its composition and properties. Current plant biotechnology efforts are primarily aimed at manipulating the biosynthesis of normal monolignols, but in the future apoplastic targeting of phenolics from other metabolic pathways may provide new approaches for designing lignins that are less inhibitory toward the enzymatic hydrolysis of structural polysaccharides, both with and without biomass pretreatment. To identify promising new avenues for lignin bioengineering, we artificially lignified cell walls from maize cell suspensions with various combinations of normal monolignols (coniferyl and sinapyl alcohols plus a variety of phenolic monolignol substitutes. Cell walls were then incubated in vitro with anaerobic rumen microflora to assess the potential impact of lignin modifications on the enzymatic degradability of fibrous crops used for ruminant livestock or biofuel production. Results In the absence of anatomical constraints to digestion, lignification with normal monolignols hindered both the rate and extent of cell wall hydrolysis by rumen microflora. Inclusion of methyl caffeate, caffeoylquinic acid, or feruloylquinic acid with monolignols considerably depressed lignin formation and strikingly improved the degradability of cell walls. In contrast, dihydroconiferyl alcohol, guaiacyl glycerol, epicatechin, epigallocatechin, and epigallocatechin gallate readily formed copolymer-lignins with normal monolignols; cell wall degradability was moderately enhanced by greater hydroxylation or 1,2,3-triol functionality. Mono- or diferuloyl esters with various aliphatic or polyol groups readily copolymerized with monolignols, but in some cases they accelerated inactivation of wall-bound peroxidase and reduced lignification; cell wall degradability was influenced by lignin content and the degree

  3. Sugarcane expressed sequences tags (ESTs encoding enzymes involved in lignin biosynthesis pathways

    Directory of Open Access Journals (Sweden)

    Ramos Rose Lucia Braz

    2001-01-01

    Full Text Available Lignins are phenolic polymers found in the secondary wall of plant conductive systems where they play an important role by reducing the permeability of the cell wall to water. Lignins are also responsible for the rigidity of the cell wall and are involved in mechanisms of resistance to pathogens. The metabolic routes and enzymes involved in synthesis of lignins have been largely characterized and representative genes that encode enzymes involved in these processes have been cloned from several plant species. The synthesis of lignins is liked to the general metabolism of the phenylpropanoids in plants, having enzymes (e.g. phenylalanine ammonia-lyase (PAL, cinnamate 4-hydroxylase (C4H and caffeic acid O-methyltransferase (COMT common to other processes as well as specific enzymes such as cinnamoyl-CoA reductase (CCR and cinnamyl alcohol dehydrogenase (CAD. Some maize and sorghum mutants, shown to have defective in CAD and/or COMT activity, are easier to digest because they have a reduced lignin content, something which has motivated different research groups to alter the lignin content and composition of model plants by genetic engineering try to improve, for example, the efficiency of paper pulping and digestibility. In the work reported in this paper, we have made an inventory of the sugarcane expressed sequence tag (EST coding for enzymes involved in lignin metabolism which are present in the sugarcane EST genome project (SUCEST database. Our analysis focused on the key enzymes ferulate-5-hydroxylase (F5H, caffeic acid O-methyltransferase (COMT, caffeoyl CoA O-methyltransferase (CCoAOMT, hydroxycinnamate CoA ligase (4CL, cinnamoyl-CoA reductase (CCR and cinnamyl alcohol dehydrogenase (CAD. The comparative analysis of these genes with those described in other species could be used as molecular markers for breeding as well as for the manipulation of lignin metabolism in sugarcane.

  4. Enzymatic Transesterification of Kraft Lignin with Long Acyl Chains in Ionic Liquids

    OpenAIRE

    Hulin, Lise; Husson, Eric; Bonnet, Jean-Pierre; Stevanovic, Tatjana; Sarazin, Catherine

    2015-01-01

    Valorization of lignin is essential for the economic viability of the biorefinery concept. For example, the enhancement of lignin hydrophobicity by chemical esterification is known to improve its miscibility in apolar polyolefin matrices, thereby helping the production of bio-based composites. To this end and due to its many reactive hydroxyl groups, lignin is a challenging macromolecular substrate for biocatalyzed esterification in non-conventional media. The present work describes for the f...

  5. Chemical reactivity of alkali lignin modified with laccase

    International Nuclear Information System (INIS)

    Sun, Yong; Qiu, Xueqing; Liu, Yunquan

    2013-01-01

    The modification of alkali lignin with laccase was investigated. The structural change of lignin was analyzed. The sulfonation reactivity was measured by the content of sulfonic group. The results showed the sulfonation reactivity increased to some extent under the condition of atmosphere pressure, but decreased under the condition of 0.3 MPa oxygen pressure. The analysis of Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC) showed the cleavage of various ether linkages and demethylation took place in the structure of lignin to certain extent during modification with laccase, which contributed to the improvement of sulfonation reactivity. Under the condition of 0.3 MPa oxygen pressure, the ratio of s/g (guaiacyl/syringyl) increased after modification, which reduced the sulfonation reactivity of lignin. Simultaneously partial polymerization reaction, such as 4-O-5′, β-5, 5-5 and other reaction in the aromatic ring decreased the activity sites of C 2 , C 5 and C 6 . Abundant polymerization reaction of α-O increased steric hindrance of C 2 and C 6 in aromatic ring, resulting in low sulfonation reactivity of lignin. -- Highlights: ► The modification of alkali lignin with laccase was investigated. ► The sulfonation reactivity increased under the condition of atmosphere pressure. ► More content of guaiacyl and hydroxy, the less content of methoxyl, syringyl can enhance the sulfonation reactivity of lignin. ► Partial moieties polymerized each other with α-O linkgages during treatment with laccase under oxygen pressure. ► The steric hindrance on C 2 and C 6 in aromatic ring resulted in low sulfonation reaction reactivity of lignin

  6. Biodegradation of alkaline lignin by Bacillus ligniniphilus L1

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Daochen; Zhang, Peipei; Xie, Changxiao; Zhang, Weimin; Sun, Jianzhong; Qian, Wei-Jun; Yang, Bin

    2017-02-21

    Background: Lignin is the most abundant aromatic biopolymer in the biosphere and it comprises up to 30% of plant biomass. Although lignin is the most recalcitrant component of the plant cell wall, still there are microorganisms able to decompose it or degrade it. Fungi are recognized as the most widely used microbes for lignin degradation. However, bacteria have also been known to be able to utilize lignin as a carbon or energy source. Bacillus ligniniphilus L1 was selected in this study due to its capability to utilize alkaline lignin as a single carbon or energy source and its excellent ability to survive in extreme environments. Results: To investigate the aromatic metabolites of strain L1 decomposing alkaline lignin, GC-MS analyze was performed and fifteen single phenol ring aromatic compounds were identified. The dominant absorption peak included phenylacetic acid, 4-hydroxy-benzoicacid, and vanillic acid with the highest proportion of metabolites resulting in 42%. Comparison proteomic analysis were carried out for further study showed that approximately 1447 kinds of proteins were produced, 141 of which were at least 2-fold up-regulated with alkaline lignin as the single carbon source. The up-regulated proteins contents different categories in the biological functions of protein including lignin degradation, ABC transport system, environmental response factors, protein synthesis and assembly, etc. Conclusions: GC-MS analysis showed that alkaline lignin degradation of strain L1 produced 15 kinds of aromatic compounds. Comparison proteomic data and metabolic analysis showed that to ensure the degradation of lignin and growth of strain L1, multiple aspects of cells metabolism including transporter, environmental response factors, and protein synthesis were enhanced. Based on genome and proteomic analysis, at least four kinds of lignin degradation pathway might be present in strain L1, including a Gentisate pathway, the benzoic acid pathway and the

  7. Interconnection of Key Microbial Functional Genes for Enhanced Benzo[a]pyrene Biodegradation in Sediments by Microbial Electrochemistry.

    Science.gov (United States)

    Yan, Zaisheng; He, Yuhong; Cai, Haiyuan; Van Nostrand, Joy D; He, Zhili; Zhou, Jizhong; Krumholz, Lee R; Jiang, He-Long

    2017-08-01

    Sediment microbial fuel cells (SMFCs) can stimulate the degradation of polycyclic aromatic hydrocarbons in sediments, but the mechanism of this process is poorly understood at the microbial functional gene level. Here, the use of SMFC resulted in 92% benzo[a]pyrene (BaP) removal over 970 days relative to 54% in the controls. Sediment functions, microbial community structure, and network interactions were dramatically altered by the SMFC employment. Functional gene analysis showed that c-type cytochrome genes for electron transfer, aromatic degradation genes, and extracellular ligninolytic enzymes involved in lignin degradation were significantly enriched in bulk sediments during SMFC operation. Correspondingly, chemical analysis of the system showed that these genetic changes resulted in increases in the levels of easily oxidizable organic carbon and humic acids which may have resulted in increased BaP bioavailability and increased degradation rates. Tracking microbial functional genes and corresponding organic matter responses should aid mechanistic understanding of BaP enhanced biodegradation by microbial electrochemistry and development of sustainable bioremediation strategies.

  8. Cinnamic acid 4-hydroxylase of sorghum [Sorghum biocolor (L.) Moench] gene SbC4H1 restricts lignin synthesis in Arabidopsis

    Science.gov (United States)

    Cinnamic acid 4-hydroxylase (C4H) is the first hydroxylase enzyme of the phenylpropanoid pathway, and its content and activity affects the lignin synthesis. In this study, we isolated a C4H gene SbC4H1 from the suppression subtractive hybridization library of brown midrib (bmr) mutants of Sorghum b...

  9. Nano-lignin filled natural rubber composites: Preparation and characterization

    Directory of Open Access Journals (Sweden)

    C. Jiang

    2013-05-01

    Full Text Available This paper presents a novel strategy to prepare nano-lignin and its composites with natural rubber. The nanolignin was ontained by fabricating colloidal lignin-Poly (diallyldimethylammonium chloride (PDADMAC complexes (LPCs via self-assembly technology. The characteristics of LPCs were investigated by zeta potential, dynamic light scattering (DLS, transmission electron microscopy (TEM, Fourier transform infrared spectroscopy (FTIR and ultraviolet – visible (UV-vis absorption measurements. The results indicated that PDADMAC intensively interacted with lignin by cation-π and π-π interactions, and lignin particles were stable in aqueous solution with an average particle size less than 100 nm. LPCs accelerated the vulcanization of NR/LPCs nanocomposites. Morphological studies and Dynamic mechanical analysis (DMA showed the homogeneous dispersion of LPCs in the NR matrix and the strong interfacial adhesion between them. The nanoscale dispersion of LPCs significantly enhanced the thermal stability and mechanical properties of NR/LPCs nanocomposites.

  10. Characterization and analysis of CCR and CAD gene families at the whole-genome level for lignin synthesis of stone cells in pear (Pyrus bretschneideri fruit

    Directory of Open Access Journals (Sweden)

    Xi Cheng

    2017-11-01

    Full Text Available The content of stone cells has significant effects on the flavour and quality of pear fruit. Previous research suggested that lignin deposition is closely related to stone cell formation. In the lignin biosynthetic pathway, cinnamoyl-CoA reductase (CCR and cinnamyl alcohol dehydrogenase (CAD, dehydrogenase/reductase family members, catalyse the last two steps in monolignol synthesis. However, there is little knowledge of the characteristics of the CCR and CAD families in pear and their involvement in lignin synthesis of stone cells. In this study, 31 CCRs and 26 CADs were identified in the pear genome. Phylogenetic trees for CCRs and CADs were constructed; key amino acid residues were analysed, and three-dimensional structures were predicted. Using quantitative real-time polymerase chain reaction (qRT-PCR, PbCAD2, PbCCR1, -2 and -3 were identified as participating in lignin synthesis of stone cells in pear fruit. Subcellular localization analysis showed that the expressed proteins (PbCAD2, PbCCR1, -2 and -3 are found in the cytoplasm or at the cell membrane. These results reveal the evolutionary features of the CCR and CAD families in pear as well as the genes responsible for regulation of lignin synthesis and stone cell development in pear fruit.

  11. Flocculation of wheat straw soda lignin by hemoglobin and chicken blood: Effects of cationic polymer or calcium chloride

    Science.gov (United States)

    Flocculation can be used to separate non-sulfonated lignin from base hydrolyzed biomass. In the industrial process, the lignin is isolated by filtration and washed with water. Some of the lignin is lost in the wash water, and flocculation can be used to recover this lignin. Several ways of enhanc...

  12. Conversion of kraft lignin over hierarchical MFI zeolite.

    Science.gov (United States)

    Kim, Seong-Soo; Lee, Hyung Won; Ryoo, Ryong; Kim, Wookdong; Park, Sung Hoon; Jeon, Jong-Ki; Park, Young-Kwon

    2014-03-01

    Catalytic pyrolysis of kraft lignin was carried out using pyrolysis gas chromatography/mass spectrometry. Hierarchical mesoporous MFI was used as the catalyst and another mesoporous material Al-SBA-15 was also used for comparison. The characteristics of mesoporous MFI were analyzed by X-ray diffraction patterns, N2 adsorption-desorption isotherms, and temperature programmed desorption of NH3. Two catalyst/lignin mass ratios were tested: 5/1 and 10/1. Aromatics and alkyl phenolics were the main products of the catalytic pyrolysis of lignin over mesoporous MFI. In particular, the yields of mono-aromatics such as benzene, toluene, ethylbenzene, and xylene were increased substantially by catalytic upgrading. Increase in the catalyst dose enhanced the production of aromatics further, which is attributed to decarboxylation, decarbonlyation, and aromatization reactions occurring over the acid sites of mesoporous MFI.

  13. Disruption of Mediator rescues the stunted growth of a lignin-deficient Arabidopsis mutant.

    Science.gov (United States)

    Bonawitz, Nicholas D; Kim, Jeong Im; Tobimatsu, Yuki; Ciesielski, Peter N; Anderson, Nickolas A; Ximenes, Eduardo; Maeda, Junko; Ralph, John; Donohoe, Bryon S; Ladisch, Michael; Chapple, Clint

    2014-05-15

    Lignin is a phenylpropanoid-derived heteropolymer important for the strength and rigidity of the plant secondary cell wall. Genetic disruption of lignin biosynthesis has been proposed as a means to improve forage and bioenergy crops, but frequently results in stunted growth and developmental abnormalities, the mechanisms of which are poorly understood. Here we show that the phenotype of a lignin-deficient Arabidopsis mutant is dependent on the transcriptional co-regulatory complex, Mediator. Disruption of the Mediator complex subunits MED5a (also known as REF4) and MED5b (also known as RFR1) rescues the stunted growth, lignin deficiency and widespread changes in gene expression seen in the phenylpropanoid pathway mutant ref8, without restoring the synthesis of guaiacyl and syringyl lignin subunits. Cell walls of rescued med5a/5b ref8 plants instead contain a novel lignin consisting almost exclusively of p-hydroxyphenyl lignin subunits, and moreover exhibit substantially facilitated polysaccharide saccharification. These results demonstrate that guaiacyl and syringyl lignin subunits are largely dispensable for normal growth and development, implicate Mediator in an active transcriptional process responsible for dwarfing and inhibition of lignin biosynthesis, and suggest that the transcription machinery and signalling pathways responding to cell wall defects may be important targets to include in efforts to reduce biomass recalcitrance.

  14. Use of Agave tequilana-lignin and zinc oxide nanoparticles for skin photoprotection.

    Science.gov (United States)

    Gutiérrez-Hernández, José Manuel; Escalante, Alfredo; Murillo-Vázquez, Raquel Nalleli; Delgado, Ezequiel; González, Francisco Javier; Toríz, Guillermo

    2016-10-01

    The use of sunscreens is essential for preventing skin damage and the potential appearance of skin cancer in humans. Inorganic active components such as zinc oxide (ZnO) have been used commonly in sunscreens due to their ability to block UVA radiation. This ultraviolet (UV) protection might be enhanced to cover the UVB and UVC bands when combined with other components such as titanium dioxide (TiO2). In this work we evaluate the photoprotection properties of organic nanoparticles made from lignin in combination with ZnO nanoparticles as active ingredients for sunscreens. Lignin nanoparticles were synthesized from Agave tequilana lignin. Two different pulping methods were used for dissolving lignin from agave bagasse. ZnO nanoparticles were synthesized by the precipitation method. All nanoparticles were characterized by SEM, UV-Vis and FT-IR spectroscopy. Nanoparticles were mixed with a neutral vehicle in different concentrations and in-vitro sun protection factor (SPF) values were calculated. Different sizes of spherical lignin nanoparticles were obtained from the spent liquors of two different pulping methods. ZnO nanoparticles resulted with a flake shape. The mixture of all components gave SPF values in a range between 4 and 13. Lignin nanoparticles showed absorption in the UVB and UVC regions which can enhance the SPF value of sunscreens composed only of zinc oxide nanoparticles. Lignin nanoparticles have the added advantage of being of organic nature and its brown color can be used to match the skin tone of the person using it. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Analytical methodology for sulfonated lignins

    NARCIS (Netherlands)

    Brudin, S.; Schoenmakers, P.

    2010-01-01

    There is a significant need to characterize and classify lignins and sulfonated lignins. Lignins have so far received a good deal of attention, whereas this is not true for sulfonated lignins. There is a clear demand for a better understanding of sulfonated lignins on a chemical as well as physical

  16. Effect of mechanical activation on structure changes and reactivity in further chemical modification of lignin.

    Science.gov (United States)

    Zhao, Xiaohong; Zhang, Yanjuan; Hu, Huayu; Huang, Zuqiang; Yang, Mei; Chen, Dong; Huang, Kai; Huang, Aimin; Qin, Xingzhen; Feng, Zhenfei

    2016-10-01

    Lignin was treated by mechanical activation (MA) in a customized stirring ball mill, and the structure and reactivity in further esterification were studied. The chemical structure and morphology of MA-treated lignin and the esterified products were analyzed by chemical analysis combined with UV/vis spectrometer, FTIR,NMR, SEM and particle size analyzer. The results showed that MA contributed to the increase of aliphatic hydroxyl, phenolic hydroxyl, carbonyl and carboxyl groups but the decrease of methoxyl groups. Moreover, MA led to the decrease of particle size and the increase of specific surface area and roughness of surface in lignin. The reactivity of lignin was enhanced significantly for the increase of hydroxyl content and the improvement of mass transfer in chemical reaction caused by the changes of molecular structure and morphological structure. The process of MA is green and simple, and is an effective method for enhancing the reactivity of lignin. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. The synthesis and analysis of lignin-bound Hibbert ketone structures in technical lignins.

    Science.gov (United States)

    Miles-Barrett, Daniel M; Neal, Andrew R; Hand, Calum; Montgomery, James R D; Panovic, Isabella; Ojo, O Stephen; Lancefield, Christopher S; Cordes, David B; Slawin, Alexandra M Z; Lebl, Tomas; Westwood, Nicholas J

    2016-10-25

    Understanding the structure of technical lignins resulting from acid-catalysed treatment of lignocellulosic biomass is important for their future applications. Here we report an investigation into the fate of lignin under acidic aqueous organosolv conditions. In particular we examine in detail the formation and reactivity of non-native Hibbert ketone structures found in isolated organosolv lignins from both Douglas fir and beech woods. Through the use of model compounds combined with HSQC, HMBC and HSQC-TOCSY NMR experiments we demonstrate that, depending on the lignin source, both S and G lignin-bound Hibbert ketone units can be present. We also show that these units can serve as a source of novel mono-aromatic compounds following an additional lignin depolymerisation reaction.

  18. Influence of lignin on morphology, structure and thermal behavior of polylactic acid-based biocomposites

    Science.gov (United States)

    Canetti, Maurizio; Cacciamani, Adriana; Bertini, Fabio

    2016-05-01

    Polylactic acid (PLA) is a thermoplastic biodegradable polymer that can be made from annually renewable resources. Lignin is a natural amorphous polyphenolic macromolecule inexpensive and easily available. In the present study PLA and acetylated lignin biocomposites were prepared by casting from chloroform solution. PLA can crystallize from the melt in the α and α' forms, depending on the adopted crystallization conditions. The presence of the lignin in the biocomposites can interfere with the crystal formation process. Isothermal crystallizations were performed at different temperatures, the presence of lignin causes an increase of the time of crystallization, while the overall crystallization rate and the spherulite radial growth rate decrease with enhancing the lignin content in the biocomposites.

  19. Characterization and analysis of CCR and CAD gene families at the whole-genome level for lignin synthesis of stone cells in pear (Pyrus bretschneideri) fruit.

    Science.gov (United States)

    Cheng, Xi; Li, Manli; Li, Dahui; Zhang, Jinyun; Jin, Qing; Sheng, Lingling; Cai, Yongping; Lin, Yi

    2017-11-15

    The content of stone cells has significant effects on the flavour and quality of pear fruit. Previous research suggested that lignin deposition is closely related to stone cell formation. In the lignin biosynthetic pathway, cinnamoyl-CoA reductase (CCR) and cinnamyl alcohol dehydrogenase (CAD), dehydrogenase/reductase family members, catalyse the last two steps in monolignol synthesis. However, there is little knowledge of the characteristics of the CCR and CAD families in pear and their involvement in lignin synthesis of stone cells. In this study, 31 CCR s and 26 CAD s were identified in the pear genome. Phylogenetic trees for CCR s and CAD s were constructed; key amino acid residues were analysed, and three-dimensional structures were predicted. Using quantitative real-time polymerase chain reaction (qRT-PCR), PbCAD2 , PbCCR1 , -2 and - 3 were identified as participating in lignin synthesis of stone cells in pear fruit. Subcellular localization analysis showed that the expressed proteins (PbCAD2, PbCCR1, -2 and -3) are found in the cytoplasm or at the cell membrane. These results reveal the evolutionary features of the CCR and CAD families in pear as well as the genes responsible for regulation of lignin synthesis and stone cell development in pear fruit. © 2017. Published by The Company of Biologists Ltd.

  20. Expression of a bacterial 3-dehydroshikimate dehydratase reduces lignin content and improves biomass saccharification efficiency.

    Science.gov (United States)

    Eudes, Aymerick; Sathitsuksanoh, Noppadon; Baidoo, Edward E K; George, Anthe; Liang, Yan; Yang, Fan; Singh, Seema; Keasling, Jay D; Simmons, Blake A; Loqué, Dominique

    2015-12-01

    Lignin confers recalcitrance to plant biomass used as feedstocks in agro-processing industries or as source of renewable sugars for the production of bioproducts. The metabolic steps for the synthesis of lignin building blocks belong to the shikimate and phenylpropanoid pathways. Genetic engineering efforts to reduce lignin content typically employ gene knockout or gene silencing techniques to constitutively repress one of these metabolic pathways. Recently, new strategies have emerged offering better spatiotemporal control of lignin deposition, including the expression of enzymes that interfere with the normal process for cell wall lignification. In this study, we report that expression of a 3-dehydroshikimate dehydratase (QsuB from Corynebacterium glutamicum) reduces lignin deposition in Arabidopsis cell walls. QsuB was targeted to the plastids to convert 3-dehydroshikimate - an intermediate of the shikimate pathway - into protocatechuate. Compared to wild-type plants, lines expressing QsuB contain higher amounts of protocatechuate, p-coumarate, p-coumaraldehyde and p-coumaryl alcohol, and lower amounts of coniferaldehyde, coniferyl alcohol, sinapaldehyde and sinapyl alcohol. 2D-NMR spectroscopy and pyrolysis-gas chromatography/mass spectrometry (pyro-GC/MS) reveal an increase of p-hydroxyphenyl units and a reduction of guaiacyl units in the lignin of QsuB lines. Size-exclusion chromatography indicates a lower degree of lignin polymerization in the transgenic lines. Therefore, our data show that the expression of QsuB primarily affects the lignin biosynthetic pathway. Finally, biomass from these lines exhibits more than a twofold improvement in saccharification efficiency. We conclude that the expression of QsuB in plants, in combination with specific promoters, is a promising gain-of-function strategy for spatiotemporal reduction of lignin in plant biomass. © 2015 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The

  1. Coconut coir pith lignin: A physicochemical and thermal characterization.

    Science.gov (United States)

    Asoka Panamgama, L; Peramune, P R U S K

    2018-07-01

    The structural and thermal features of coconut coir pith lignin, isolated by three different extraction protocols incorporating two different energy supply sources, were characterized by different analytical tools. The three different chemical extraction protocols were alkaline - 7.5% (w/v) NaOH, organosolv - 85% (v/v) formic and acetic acids at 7:3 (v/v) ratio and polyethylene glycol (PEG): water ratio at 80:20wt%. The two sources of energy were thermal or microwave. Raw lignins were modified by epichlorohydrin to enhance reactivity, and the characteristics of raw and modified lignins were comparatively analysed. Using the thermal energy source, the alkaline and organosolv processes obtained the highest and lowest lignin yields of 26.4±1.5wt% and 3.4±0.2wt%, respectively, as shown by wet chemical analysis. Specific functional group analysis by Fourier transform infrared spectra (FTIR) revealed that significantly different amounts of hydroxyl and carbonyl groups exist in alkaline, organosolv and PEG lignins. Thermogravimetric analysis (TGA) illustrated that the lowest degradation onset temperature was recorded for organosolv lignin, and the overall order was organosolvlignin extraction from coir pith can be performed efficiently with several protocols and that those methods offer practical value to industry. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Lignin-Furfural Based Adhesives

    OpenAIRE

    Dongre, Prajakta; Driscoll, Mark; Amidon, Thomas; Bujanovic, Biljana

    2015-01-01

    Lignin recovered from the hot-water extract of sugar maple ( Acer saccharum ) is used in this study to synthesize adhesive blends to replace phenol-formaldehyde (PF) resin. Untreated lignin is characterized by lignin content and nuclear magnetic resonance (NMR) analysis. The molecular weight distribution of the lignin and the blends are characterized by size exclusion chromatography (SEC). The effect of pH (0.3, 0.65 and 1), ex situ furfural, and curing conditions on the tensile properties of...

  3. Cellobiose Dehydrogenase Inhibition of Polymerization of Phenolic Compounds and Enhancing Lignin Degradation by Lignina.

    Science.gov (United States)

    Fang, Jing; Liu, Wen; Gao, Pei-Ji

    1999-01-01

    The kinetic behavior of cellobiose dehydrogenase (CDH) was investigated by steady-state initial velocity studies. Variation in the concentration of one substrate led to changes in K(m) and V(max) of the other substrate. The results were consistent with a ping-pong mechanism. In the presence of cellobiose, CDH could reduce many oxidized products catalyzed by soybean hull peroxidase (SHP). The oxidation product of 1-hydroxybenzotriazole (HBT) catalyzed by SHP inactivated the enzyme itself however, CDH could prevent SHP from inactivation by reducing the oxidation product of HBT. CDH could also inhibit the polymerization of phenolic compounds catalyzed by SHP. It was found that the addition of CDH could enhance kraft pulp lignin degradation by ligninases.

  4. H2O2 recycling during oxidation of the arylglycerol beta-aryl ether lignin structure by lignin peroxidase and glyoxal oxidase.

    Science.gov (United States)

    Hammel, K E; Mozuch, M D; Jensen, K A; Kersten, P J

    1994-11-15

    Oxidative C alpha-C beta cleavage of the arylglycerol beta-aryl ether lignin model 1-(3,4-dimethoxy-phenyl)-2-phenoxypropane-1,3-diol (I) by Phanerochaete chrysosporium lignin peroxidase in the presence of limiting H2O2 was enhanced 4-5-fold by glyoxal oxidase from the same fungus. Further investigation showed that each C alpha-C beta cleavage reaction released 0.8-0.9 equiv of glycolaldehyde, a glyoxal oxidase substrate. The identification of glycolaldehyde was based on 13C NMR spectrometry of reaction product obtained from beta-, gamma-, and beta,gamma-13C-substituted I, and quantitation was based on an enzymatic NADH-linked assay. The oxidation of glycolaldehyde by glyoxal oxidase yielded 0.9 oxalate and 2.8 H2O2 per reaction, as shown by quantitation of oxalate as 2,3-dihydroxyquinoxaline after derivatization with 1,2-diaminobenzene and by quantitation of H2O2 in coupled spectrophotometric assays with veratryl alcohol and lignin peroxidase. These results suggest that the C alpha-C beta cleavage of I by lignin peroxidase in the presence of glyoxal oxidase should regenerate as many as 3 H2O2. Calculations based on the observed enhancement of LiP-catalyzed C alpha-C beta cleavage by glyoxal oxidase showed that approximately 2 H2O2 were actually regenerated per cleavage of I when both enzymes were present. The cleavage of arylglycerol beta-aryl ether structures by ligninolytic enzymes thus recycles H2O2 to support subsequent cleavage reactions.

  5. Modulating lignin in plants

    Science.gov (United States)

    Apuya, Nestor; Bobzin, Steven Craig; Okamuro, Jack; Zhang, Ke

    2013-01-29

    Materials and methods for modulating (e.g., increasing or decreasing) lignin content in plants are disclosed. For example, nucleic acids encoding lignin-modulating polypeptides are disclosed as well as methods for using such nucleic acids to generate transgenic plants having a modulated lignin content.

  6. Effect of temperature during wood torrefaction on the formation of lignin liquid intermediates

    Science.gov (United States)

    Manuel Raul Pelaez-Samaniego; Vikram Yadama; Manuel Garcia-Perez; Eini Lowell; Armando G. McDonald

    2014-01-01

    Torrefaction enhances physical properties of lignocellulosic biomass and improves its grindability. Energy densification, via fuel pellets production, is one of the most promising uses of torrefaction. Lignin contributes to self-bonding of wood particles during pelletization. In biomass thermal pretreatment, part oflignin (in the form of lignin liquid intermediates –...

  7. Effect of lignin on water vapor barrier, mechanical, and structural properties of agar/lignin composite films.

    Science.gov (United States)

    Shankar, Shiv; Reddy, Jeevan Prasad; Rhim, Jong-Whan

    2015-11-01

    Biodegradable composite films were prepared using two renewable resources based biopolymers, agar and lignin alkali. The lignin was used as a reinforcing material and agar as a biopolymer matrix. The effect of lignin concentration (1, 3, 5, and 10wt%) on the performance of the composite films was studied. In addition, the mechanical, water vapor barrier, UV light barrier properties, FE-SEM, and TGA of the films were analyzed. The agar/lignin films exhibited higher mechanical and UV barrier properties along with lower water vapor permeability compared to the neat agar film. The FTIR and SEM results showed the compatibility of lignin with agar polymer. The swelling ratio and moisture content of agar/lignin composite films were decreased with increase in lignin content. The thermostability and char content of agar/lignin composite films increased with increased lignin content. The results suggested that agar/lignin films have a potential to be used as a UV barrier food packaging material for maintaining food safety and extending the shelf-life of the packaged food. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Ultra violet resonance Raman spectroscopy in lignin analysis: determination of characteristic vibrations of p-hydroxyphenyl, guaiacyl, and syringyl lignin structures.

    Science.gov (United States)

    Saariaho, Anna-Maija; Jääskeläinen, Anna-Stiina; Nuopponen, Mari; Vuorinen, Tapani

    2003-01-01

    Raman spectroscopy of wood and lignin samples is preferably carried out in the near-infrared region because lignin produces an intense laser-induced fluorescence background at visible excitation wavelengths. However, excitation of aromatic and conjugated lignin structures with deep ultra violet (UV) light gives resonance-enhanced Raman signals while the overlapping fluorescence is eliminated. In this study, ultra violet resonance Raman (UVRR) spectroscopy was used to define characteristic vibration bands of model compounds of p-hydroxyphenyl, guaiacyl, and syringyl lignin structures at three excitation wavelengths (229, 244, and 257 nm). The intensities of each band, relative to the intensity of the aromatic vibration band at 1600 cm-1, were defined and the most suitable excitation wavelength was suggested for each structure. p-Hydroxyphenyl structures showed intensive characteristic bands at 1217-1214 and 1179-1167 cm-1 with excitation at 244 nm, whereas the bands of guaiacyl structures were more intensive with 257 nm excitation. Most intensive characteristic bands of guaiacyl structures were found at 1289-1279, 1187-1185, 1158-1155, and 791-704 cm-1. Syringyl structures had almost identical spectra with 244 and 257 nm excitations with characteristic bands at 1514-1506, 1333-1330, and 981-962 cm-1. The characteristic bands of the three structural units were also found from the compression wood, softwood, and hardwood samples, indicating that UVRR spectroscopy can be applied for the determination of chemical structures of lignin.

  9. Lignin Macromolecule

    Indian Academy of Sciences (India)

    plant or a structural component of a mature plant which is detected by certain colour reactions. An enzymologist has termed lignin as the ... a phenyl-propanoid structure. A soil chemist considers lignin to be the residue of .... refer to the hardness of wood, but to the botanical classifications. They are aptly called gymnosperms ...

  10. The Ve-mediated resistance response of the tomato to Verticillium dahliae involves H2O2, peroxidase and lignins and drives PAL gene expression

    Directory of Open Access Journals (Sweden)

    Merino Fuencisla

    2010-10-01

    Full Text Available Abstract Background Verticillium dahliae is a fungal pathogen that infects a wide range of hosts. The only known genes for resistance to Verticillium in the Solanaceae are found in the tomato (Solanum lycopersicum Ve locus, formed by two linked genes, Ve1 and Ve2. To characterize the resistance response mediated by the tomato Ve gene, we inoculated two nearly isogenic tomato lines, LA3030 (ve/ve and LA3038 (Ve/Ve, with V. dahliae. Results We found induction of H2O2 production in roots of inoculated plants, followed by an increase in peroxidase activity only in roots of inoculated resistant plants. Phenylalanine-ammonia lyase (PAL activity was also increased in resistant roots 2 hours after inoculation, while induction of PAL activity in susceptible roots was not seen until 48 hours after inoculation. Phenylpropanoid metabolism was also affected, with increases in ferulic acid, p-coumaric acid, vanillin and p-hydroxybenzaldehyde contents in resistant roots after inoculation. Six tomato PAL cDNA sequences (PAL1 - PAL6 were found in the SolGenes tomato EST database. RT-PCR analysis showed that these genes were expressed in all organs of the plant, albeit at different levels. Real-time RT-PCR indicated distinct patterns of expression of the different PAL genes in V. dahliae-inoculated roots. Phylogenetic analysis of 48 partial PAL cDNAs corresponding to 19 plant species grouped angiosperm PAL sequences into four clusters, suggesting functional differences among the six tomato genes, with PAL2 and PAL6 presumably involved in lignification, and the remaining PAL genes implicated in other biological processes. An increase in the synthesis of lignins was found 16 and 28 days after inoculation in both lines; this increase was greater and faster to develop in the resistant line. In both resistant and susceptible inoculated plants, an increase in the ratio of guaiacyl/syringyl units was detected 16 days after inoculation, resulting from the lowered amount

  11. Enhancement of fermentable sugar yield by competitive adsorption of non-enzymatic substances from yeast and cellulase on lignin.

    Science.gov (United States)

    Tang, Yong; Lei, Fuhou; Cristhian, Carrasco; Liu, Zuguang; Yu, Hailong; Jiang, Jianxin

    2014-03-20

    Enhancement of enzymatic digestibility by some supplementations could reduce enzyme loading and cost, which is still too high to realize economical production of lignocellulosic biofuels. A recent study indicates that yeast hydrolysates (YH) have improved the efficiency of cellulases on digestibility of furfural residues (FR). In the current work, the components of YH were separated by centrifugation and size exclusion chromatography and finally characterized in order to better understand this positive effect. A 60.8% of nitrogen of yeast cells was remained in the slurry (YHS) after hydrothermal treatment. In the supernatant of YH (YHL), substances of high molecular weight were identified as proteins and other UV-absorbing compounds, which showed close molecular weight to components of cellulases. Those substances attributed to a synergetic positive effect on enzymatic hydrolysis of FR. The fraction of YHL ranged from 1.19 to 2.19 mL (elution volume) contained over 50% of proteins in YHL and had the best performance in stimulating the release of glucose. Experiment results proved the adsorption of proteins in YHL on lignin. Supplementation of cellulases with YH enhances enzymatic digestibility of FR mainly by a competitive adsorption of non-enzymatic substances on lignin. The molecular weight of these substances has a significant impact on their performance. Different strategies can be used for a good utilization of yeast cells in terms of biorefinery concept.

  12. Chemicals from lignin: an interplay of lignocellulose fractionation, depolymerisation, and upgrading.

    Science.gov (United States)

    Schutyser, W; Renders, T; Van den Bosch, S; Koelewijn, S-F; Beckham, G T; Sels, B F

    2018-02-05

    In pursuit of more sustainable and competitive biorefineries, the effective valorisation of lignin is key. An alluring opportunity is the exploitation of lignin as a resource for chemicals. Three technological biorefinery aspects will determine the realisation of a successful lignin-to-chemicals valorisation chain, namely (i) lignocellulose fractionation, (ii) lignin depolymerisation, and (iii) upgrading towards targeted chemicals. This review provides a summary and perspective of the extensive research that has been devoted to each of these three interconnected biorefinery aspects, ranging from industrially well-established techniques to the latest cutting edge innovations. To navigate the reader through the overwhelming collection of literature on each topic, distinct strategies/topics were delineated and summarised in comprehensive overview figures. Upon closer inspection, conceptual principles arise that rationalise the success of certain methodologies, and more importantly, can guide future research to further expand the portfolio of promising technologies. When targeting chemicals, a key objective during the fractionation and depolymerisation stage is to minimise lignin condensation (i.e. formation of resistive carbon-carbon linkages). During fractionation, this can be achieved by either (i) preserving the (native) lignin structure or (ii) by tolerating depolymerisation of the lignin polymer but preventing condensation through chemical quenching or physical removal of reactive intermediates. The latter strategy is also commonly applied in the lignin depolymerisation stage, while an alternative approach is to augment the relative rate of depolymerisation vs. condensation by enhancing the reactivity of the lignin structure towards depolymerisation. Finally, because depolymerised lignins often consist of a complex mixture of various compounds, upgrading of the raw product mixture through convergent transformations embodies a promising approach to decrease the

  13. Chemicals from Lignin: An Interplay of Lignocellulose Fractionation, Depolymerisation, and Upgrading

    Energy Technology Data Exchange (ETDEWEB)

    Beckham, Gregg T [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Schutyser, Wouter [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Renders, Tom [KU Leuven; Van den Bosch, Sander [KU Leuven; Koelewijn, Steven-Friso [KU Leuven; Sels, Bert F. [KU Leuven

    2018-01-01

    In pursuit of more sustainable and competitive biorefineries, the effective valorisation of lignin is key. An alluring opportunity is the exploitation of lignin as a resource for chemicals. Three technological biorefinery aspects will determine the realisation of a successful lignin-to-chemicals valorisation chain, namely (i) lignocellulose fractionation, (ii) lignin depolymerisation, and (iii) upgrading towards targeted chemicals. This review provides a summary and perspective of the extensive research that has been devoted to each of these three interconnected biorefinery aspects, ranging from industrially well-established techniques to the latest cutting edge innovations. To navigate the reader through the overwhelming collection of literature on each topic, distinct strategies/topics were delineated and summarised in comprehensive overview figures. Upon closer inspection, conceptual principles arise that rationalise the success of certain methodologies, and more importantly, can guide future research to further expand the portfolio of promising technologies. When targeting chemicals, a key objective during the fractionation and depolymerisation stage is to minimise lignin condensation (i.e. formation of resistive carbon-carbon linkages). During fractionation, this can be achieved by either (i) preserving the (native) lignin structure or (ii) by tolerating depolymerisation of the lignin polymer but preventing condensation through chemical quenching or physical removal of reactive intermediates. The latter strategy is also commonly applied in the lignin depolymerisation stage, while an alternative approach is to augment the relative rate of depolymerisation vs. condensation by enhancing the reactivity of the lignin structure towards depolymerisation. Finally, because depolymerised lignins often consist of a complex mixture of various compounds, upgrading of the raw product mixture through convergent transformations embodies a promising approach to decrease the

  14. The chemistry of subcritical water reactions of a hardwood derived lignin and lignin model compounds with nitrogen, hydrogen, carbon monoxide and carbon dioxide

    Science.gov (United States)

    Hill Bembenic, Meredith A.

    added pressure is: 1) cleavage of ethers (via hydrolysis) to form smaller methoxy-substituted phenolic monomers with aldehyde- or ketone-substituents representative of lignin monomers; 2) cleavage of the methoxy-, aldehyde- and/or ketone-substituents to form primarily methoxy-substituted phenolic monomers; 3) rearrangement of these phenolic monomers due to the enhanced pressure at reaction temperature; 4) formation of oligomers due to interaction amongst the methoxy-substituted phenolic monomers, which is also due to the enhanced pressure at reaction temperature; and 5) repolymerization of the monomers and oligomers to form high molecular weight compounds (i.e., longer reactions times or different pressures seemed to enhance these reactions). Under these conditions, depolymerization seems to be the dominant reaction pathway versus repolymerization. Reactions with lignin and H2O at 365°C have not been previously reported nor has the reaction chemistry for lignin depolymerization at these conditions been established. The results with lignin (or lignin model compounds), subcritical H2O and CO also show that the desired product slate can be modified with different pressure and time conditions. In particular, increasing reaction time (from 15 to 60 min.) caused lignin conversion to decrease, and the products appeared to be reacting with each other. However, the longer reaction time also showed that more methanol is generated (along with more solids).

  15. Ferricyanide-based analysis of aqueous lignin suspension revealed sequestration of water-soluble lignin moieties

    OpenAIRE

    Joshua, CJ; Simmons, BA; Singer, SW

    2016-01-01

    © 2016 The Royal Society of Chemistry. This study describes the application of a ferricyanide-based assay as a simple and inexpensive assay for rapid analysis of aqueous lignin samples. The assay measures the formation of Prussian blue from the redox reaction between a mixture of potassium ferricyanide and ferric chloride, and phenolic hydroxyl groups of lignin or lignin-derived phenolic moieties. This study revealed that soluble lignin moieties exhibited stronger ferricyanide reactivity than...

  16. Reactivity of lignin and lignin models towards UV-assisted peroxide

    International Nuclear Information System (INIS)

    Sun, Y.P.; Wallis, A.F.A.; Nguyen, K.L.

    1997-01-01

    The comparative reactivities of a series of guaiacyl and syringyl lignin model compounds and their methylated analogues towards alkaline peroxide and UV-alkaline peroxide were investigated. The overall reaction was followed by monitoring the reduction of the substrate as a function of time, and in every case, the reaction showed pseudo-first-order kinetics. The reaction rates of most lignin models having identical sidechains with alkaline peroxide and with UV-alkaline peroxide were in the order syringyl guaiacyl 3,4,5-trimethoxyphenyl veratryl. Thus phenols react faster than their methyl ethers, and an extra ortho methoxyl group promotes the reaction. Lignin models possessing electron-donating sidechains had generally higher reaction rates than those with electron-withdrawing sidechains. The reaction rates of the series of benzoic acids were 2-4 times higher at pH 11 than at pH 5. UV-peroxide degradation of a eucalypt kraft lignin was faster than that of a pine kraft lignin, and degradation was 1.4-1.6 times faster at pH 11 than at pH 5. The data are consistent with the formation of higher amounts of reactive radicals under alkaline conditions, and aromatic rings with greater electronegativities promoting reactions with the radicals

  17. Exploring bacterial lignin degradation.

    Science.gov (United States)

    Brown, Margaret E; Chang, Michelle C Y

    2014-04-01

    Plant biomass represents a renewable carbon feedstock that could potentially be used to replace a significant level of petroleum-derived chemicals. One major challenge in its utilization is that the majority of this carbon is trapped in the recalcitrant structural polymers of the plant cell wall. Deconstruction of lignin is a key step in the processing of biomass to useful monomers but remains challenging. Microbial systems can provide molecular information on lignin depolymerization as they have evolved to break lignin down using metalloenzyme-dependent radical pathways. Both fungi and bacteria have been observed to metabolize lignin; however, their differential reactivity with this substrate indicates that they may utilize different chemical strategies for its breakdown. This review will discuss recent advances in studying bacterial lignin degradation as an approach to exploring greater diversity in the environment. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Characterization of novel Brown midrib 6 mutations affecting lignin biosynthesis in sorghum

    Science.gov (United States)

    The presence of lignin reduces the quality of lignocellulosic biomass for forage materials and feedstock for biofuels. In C4 grasses, the brown midrib phenotype has been linked to mutations to genes in the monolignol biosynthesis pathway. For example, the Bmr6 gene in sorghum (Sorghum bicolor) has b...

  19. Stone formation in peach fruit exhibits spatial coordination of the lignin and flavonoid pathways and similarity to Arabidopsis dehiscence

    Directory of Open Access Journals (Sweden)

    Piagnani M Claudia

    2010-02-01

    Full Text Available Abstract Background Lignification of the fruit endocarp layer occurs in many angiosperms and plays a critical role in seed protection and dispersal. This process has been extensively studied with relationship to pod shatter or dehiscence in Arabidopsis. Dehiscence is controlled by a set of transcription factors that define the fruit tissue layers and whether or not they lignify. In contrast, relatively little is known about similar processes in other plants such as stone fruits which contain an extremely hard lignified endocarp or stone surrounding a single seed. Results Here we show that lignin deposition in peach initiates near the blossom end within the endocarp layer and proceeds in a distinct spatial-temporal pattern. Microarray studies using a developmental series from young fruits identified a sharp and transient induction of phenylpropanoid, lignin and flavonoid pathway genes concurrent with lignification and subsequent stone hardening. Quantitative polymerase chain reaction studies revealed that specific phenylpropanoid (phenylalanine ammonia-lyase and cinnamate 4-hydroxylase and lignin (caffeoyl-CoA O-methyltransferase, peroxidase and laccase pathway genes were induced in the endocarp layer over a 10 day time period, while two lignin genes (p-coumarate 3-hydroxylase and cinnamoyl CoA reductase were co-regulated with flavonoid pathway genes (chalcone synthase, dihydroflavanol 4-reductase, leucoanthocyanidin dioxygen-ase and flavanone-3-hydrosylase which were mesocarp and exocarp specific. Analysis of other fruit development expression studies revealed that flavonoid pathway induction is conserved in the related Rosaceae species apple while lignin pathway induction is not. The transcription factor expression of peach genes homologous to known endocarp determinant genes in Arabidopsis including SHATTERPROOF, SEEDSTCK and NAC SECONDARY WALL THICENING PROMOTING FACTOR 1 were found to be specifically expressed in the endocarp while the

  20. Lignin-degrading enzyme activities.

    Science.gov (United States)

    Chen, Yi-ru; Sarkanen, Simo; Wang, Yun-Yan

    2012-01-01

    Over the past three decades, the activities of four kinds of enzyme have been purported to furnish the mechanistic foundations for macromolecular lignin depolymerization in decaying plant cell walls. The pertinent fungal enzymes comprise lignin peroxidase (with a relatively high redox potential), manganese peroxidase, an alkyl aryl etherase, and laccase. The peroxidases and laccase, but not the etherase, are expressed extracellularly by white-rot fungi. A number of these microorganisms exhibit a marked preference toward lignin in their degradation of lignocellulose. Interestingly, some white-rot fungi secrete both kinds of peroxidase but no laccase, while others that are equally effective express extracellular laccase activity but no peroxidases. Actually, none of these enzymes has been reported to possess significant depolymerase activity toward macromolecular lignin substrates that are derived with little chemical modification from the native biopolymer. Here, the assays commonly employed for monitoring the traditional fungal peroxidases, alkyl aryl etherase, and laccase are described in their respective contexts. A soluble native polymeric substrate that can be isolated directly from a conventional milled-wood lignin preparation is characterized in relation to its utility in next-generation lignin-depolymerase assays.

  1. Recovering hydrocarbons with surfactants from lignin

    Energy Technology Data Exchange (ETDEWEB)

    Naae, D.G.; Whittington, L.E.; Ledoux, W.A.; Debons, F.E.

    1988-11-29

    This patent describes a method of recovering hydrocarbons from an underground hydrocarbon formation penetrated by at least one injection well and at least one production well, which comprises: injecting into the formation through an injection well a surfactant slug comprising about 0.1% to about 10% by weight of surfactants produced from lignin, the surfactants produced by placing lignin in contact with water, converting the lignin into low molecular weight lignin phenols by reducing the lignin in the presence of a reducing agent of carbon monoxide or hydrogen creating a reduction reaction mixture comprising oil soluble lignin phenols, the reduction occurring at a temperature greater than about 200/sup 0/C and a pressure greater than about 100 psi, recovering the oil soluble lignin phenols from the reduction mixture, and converting the lignin phenols into lignin surfactants by a reaction selected from the group consisting of alkoxylation, sulfonation, sulfation, aklylation, sulfomethylation, and alkoxysulfation; injecting into the formation through the injection well a drive fluid to push the surfactant slug towards a production well; and recovering hydrocarbons at the production well.

  2. Polymerization of different lignins by laccase

    NARCIS (Netherlands)

    Mattinen, M.L.; Suortti, T.; Gosselink, R.J.A.; Argyropoulos, D.S.; Evtuguin, D.; Suurnäkki, A.; Jong, de E.; Tamminen, T.

    2008-01-01

    In this study the oxidative polymerization of different lignins, i.e. Flax Soda lignin, Spruce EMAL, and Eucalyptus Dioxane lignin by Trametes hirsuta laccase was compared. Initially the structures of the different lignins were compared by Fourier transform infrared spectroscopy. The reactivity of

  3. Lignin biodegradation and industrial implications

    Directory of Open Access Journals (Sweden)

    Adam B Fisher

    2014-12-01

    Full Text Available Lignocellulose, which comprises the cell walls of plants, is the Earth’s most abundant renewable source of convertible biomass. However, in order to access the fermentable sugars of the cellulose and hemicellulose fraction, the extremely recalcitrant lignin heteropolymer must be hydrolyzed and removed—usually by harsh, costly thermochemical pretreatments. Biological processes for depolymerizing and metabolizing lignin present an opportunity to improve the overall economics of the lignocellulosic biorefinery by facilitating pretreatment, improving downstream cellulosic fermentations or even producing a valuable effluent stream of aromatic compounds for creating value-added products. In the following review we discuss background on lignin, the enzymology of lignin degradation, and characterized catabolic pathways for metabolizing the by-products of lignin degradation. To conclude we survey advances in approaches to identify novel lignin degrading phenotypes and applications of these phenotypes in the lignocellulosic bioprocess.

  4. Fast Curing Bio-Based Phenolic Resins via Lignin Demethylated under Mild Reaction Condition

    Directory of Open Access Journals (Sweden)

    Jiongjiong Li

    2017-09-01

    Full Text Available Demethylation technique has been used to enhance lignin reactivity for preparation of phenolic resins. However, the demethylation efficiency and the demethylated lignin (DL reactivity were still unsatisfactory. To improve the demethylation efficiency, alkali lignin was demethylated under different mild conditions using sodium sulfite as a catalyst. Lignin and DL were characterized by 1H-NMR (nuclear magnetic resonance and Fourier transform infrared (FT-IR spectroscopy to determine the demethylation mechanism. With the demethylation of lignin, the methoxyl group content decreased from 1.93 m mol/g to 1.09 m mol/g, and the phenolic hydroxyl group content increased from 0.56 m mol/g to 0.82 m mol/g. These results revealed that methoxyl groups were attacked by SO32−, and some methoxyl groups were converted to phenolic hydroxyl groups by a nucleophilic substitution reaction, generating DL with high reactivity. The chemical properties of lignin-based phenolic resins were studied by 13C-NMR and FT-IR spectroscopy, and their physical properties were also investigated. The results indicated that lignin-based phenolic resins exhibited faster curing rate and shorter gel time. In addition, the bonding strength increased from 0.92 MPa to 1.07 MPa, and the formaldehyde emission decreased from 0.58 mg/L to 0.22 mg/L after lignin demethylated at the optimum condition.

  5. Comparison of the acetyl bromide spectrophotometric method with other analytical lignin methods for determining lignin concentration in forage samples.

    Science.gov (United States)

    Fukushima, Romualdo S; Hatfield, Ronald D

    2004-06-16

    Present analytical methods to quantify lignin in herbaceous plants are not totally satisfactory. A spectrophotometric method, acetyl bromide soluble lignin (ABSL), has been employed to determine lignin concentration in a range of plant materials. In this work, lignin extracted with acidic dioxane was used to develop standard curves and to calculate the derived linear regression equation (slope equals absorptivity value or extinction coefficient) for determining the lignin concentration of respective cell wall samples. This procedure yielded lignin values that were different from those obtained with Klason lignin, acid detergent acid insoluble lignin, or permanganate lignin procedures. Correlations with in vitro dry matter or cell wall digestibility of samples were highest with data from the spectrophotometric technique. The ABSL method employing as standard lignin extracted with acidic dioxane has the potential to be employed as an analytical method to determine lignin concentration in a range of forage materials. It may be useful in developing a quick and easy method to predict in vitro digestibility on the basis of the total lignin content of a sample.

  6. Cytocompatible cellulose hydrogels containing trace lignin

    International Nuclear Information System (INIS)

    Nakasone, Kazuki; Kobayashi, Takaomi

    2016-01-01

    Sugarcane bagasse was used as a cellulose resource to prepare transparent and flexible cellulose hydrogel films. On the purification process from bagasse to cellulose, the effect of lignin residues in the cellulose was examined for the properties and cytocompatibility of the resultant hydrogel films. The cellulose was dissolved in lithium chloride/N,N-dimethylacetamide solution and converted to hydrogel films by phase inversion. In the purification process, sodium hydroxide (NaOH) treatment time was changed from 1 to 12 h. This resulted in cellulose hydrogel films having small amounts of lignin from 1.62 to 0.68%. The remaining lignin greatly affected hydrogel properties. Water content of the hydrogel films was increased from 1153 to 1525% with a decrease of lignin content. Moreover, lower lignin content caused weakening of tensile strength from 0.80 to 0.43 N/mm"2 and elongation from 45.2 to 26.5%. Also, similar tendency was observed in viscoelastic behavior of the cellulose hydrogel films. Evidence was shown that the lignin residue was effective for the high strength of the hydrogel films. In addition, scanning probe microscopy in the morphological observation was suggested that the trace lignin in the cellulose hydrogel affected the cellulose fiber aggregation in the hydrogel network. The trace of lignin in the hydrogels also influenced fibroblast cell culture on the hydrogel films. The hydrogel film containing 1.68% lignin showed better fibroblast compatibility as compared to cell culture polystyrene dish used as reference. - Highlights: • Cellulose hydrogel films with trace lignin were obtained from sugarcane bagasse. • Lignin content was found to be in the range of 1.62 − 0.68% by UV–Vis spectroscopy. • Higher lignin content strengthened mechanical properties of the hydrogel films. • Trace lignin affected the hydrogel morphology such as roughness and porosity. • High cell proliferation was observed in the hydrogel containing 1.68% lignin.

  7. Cytocompatible cellulose hydrogels containing trace lignin

    Energy Technology Data Exchange (ETDEWEB)

    Nakasone, Kazuki; Kobayashi, Takaomi, E-mail: takaomi@nagaoakut.ac.jp

    2016-07-01

    Sugarcane bagasse was used as a cellulose resource to prepare transparent and flexible cellulose hydrogel films. On the purification process from bagasse to cellulose, the effect of lignin residues in the cellulose was examined for the properties and cytocompatibility of the resultant hydrogel films. The cellulose was dissolved in lithium chloride/N,N-dimethylacetamide solution and converted to hydrogel films by phase inversion. In the purification process, sodium hydroxide (NaOH) treatment time was changed from 1 to 12 h. This resulted in cellulose hydrogel films having small amounts of lignin from 1.62 to 0.68%. The remaining lignin greatly affected hydrogel properties. Water content of the hydrogel films was increased from 1153 to 1525% with a decrease of lignin content. Moreover, lower lignin content caused weakening of tensile strength from 0.80 to 0.43 N/mm{sup 2} and elongation from 45.2 to 26.5%. Also, similar tendency was observed in viscoelastic behavior of the cellulose hydrogel films. Evidence was shown that the lignin residue was effective for the high strength of the hydrogel films. In addition, scanning probe microscopy in the morphological observation was suggested that the trace lignin in the cellulose hydrogel affected the cellulose fiber aggregation in the hydrogel network. The trace of lignin in the hydrogels also influenced fibroblast cell culture on the hydrogel films. The hydrogel film containing 1.68% lignin showed better fibroblast compatibility as compared to cell culture polystyrene dish used as reference. - Highlights: • Cellulose hydrogel films with trace lignin were obtained from sugarcane bagasse. • Lignin content was found to be in the range of 1.62 − 0.68% by UV–Vis spectroscopy. • Higher lignin content strengthened mechanical properties of the hydrogel films. • Trace lignin affected the hydrogel morphology such as roughness and porosity. • High cell proliferation was observed in the hydrogel containing 1.68% lignin.

  8. Biotechnological modification of lignin

    Energy Technology Data Exchange (ETDEWEB)

    1989-01-01

    A literature search of organisms capable of degrading lignin was conducted. Four fungi were selected for study and these were Phanerochaete chrysosporium, Chrysosporium pruinosum, Phlebia tremellosus and Trametes versicolor. Other organisms, Pleurotus ostreatus, Pleurotus florida and Lentinus edodes were also tested in preliminary experiments. All cultures were screened for their ability to degrade the lignin component of aspen sawdust and also lignin extracted from steam-exploded wood. This type of screen was followed by analysis of culture filtrates for the presence of ligninase, the marker enzyme for lignin degradation. Phanerochaete chrysosporium and consequently chosen for further studies in fermentors. Considerable efforts were directed to production of ligninase in fermentors. Only when Chrysosporium pruinosum was pre-cultured in a shake flask for 4 days and then transferred to a fermentor could ligninase activity be detected. The enzyme from shake flasks has been concentrated ready for use in bench-scale studies on cell-free depolymerization of lignin. 13 refs., 8 tabs.

  9. PIROLISIS LIGNIN DARI LIMBAH INDUSTRI KELAPA SAWIT UNTUK PENGEMBANGAN SURFAKTAN DALAM PROSES ENHANCE OIL RECOVERY (EOR (Pyrolysis of Lignin From Waste of Palm Oil Industries for The Development of Surfactants for Enhance Oil Recovery (EOR

    Directory of Open Access Journals (Sweden)

    Suryo Purwono

    2001-12-01

    Full Text Available ABSTRAK Pirolisis dari lignin yang berasal dari limbah industri kelapa sawit dapat menghasilkan alkohol dan derivatif lainnyd yang dapat digunakan sehagai surfaktan. Prosedur penelitian proses pirolisis ini odalah sebagai berikut: I serabut atau tandan sisa pengolahon kelapa sawit yang sudah dikeringkan dimasukkan kedalam reaktor dengan berat tertentu dan dipanaskan sampai suhu yang diinginkan, 2 produk pirolisis yang keluar dari reoktor kemudian didinginkan sampoi mencapai suhu kamor, 3 hasil cair ditampung didalam gelas ukur dan hasil gasnya ditampung di suatu botol tertentu. Suhu paling baik yang dicapai adalah 4A0 "C untuk lignin yong berasal dari serabut dan 350'C untuk lignin yang berasal dari tandan kelapa sawit. Surfaktan yang dihasilkan sekitar j4 sampai 38% dari produk pirolisis. Pada penelitian ini kecepatan reaksi dianggap order satu. Hasil penelitian menunjukkan bahwa surfakton yang dihasilkan dapat membentuk emulsi dengan minyak menta.h. Hal ini menunjukkon bahwa surfaktan yang dihasilkan dapat digunakan sebagai bahan untuk proses EOR.   ABSTRACT Pyrolysis of lignin from waste of palm oil industries produces alcohol and its derivatives which can be sulfonated to become surfactant. The experimental procedures for the pyrolysis process were as follows: 1 dried palm oil husks at a certain weight were put into the pyrolysis reactor and heated up to a certain temperafure; 2 the product leaving the reactor was cooled down to room temperature; and 3 the liquid product was collected in a flask while the gas product was put into a big bottle. The best temperature obtained for producing liquid product was 400 oC for lignin from palm oil fruit fibers and 350 oC for lignin from palm oil fruit stems. The surfactant developed was in the range between 34 and 38% from the pyrolysis product. In this experiment, the reaction rate was assumed to be in first order. The result showed that the surfactant obtained from the experiment could form emulsion

  10. Structural elucidation and antioxidant activity of lignin isolated from rice straw and alkali‑oxygen black liquor.

    Science.gov (United States)

    Jiang, Bo; Zhang, Yu; Gu, Lihui; Wu, Wenjuan; Zhao, Huifang; Jin, Yongcan

    2018-05-17

    Alkali‑oxygen cooking of lignocellulose offers lignin many structural properties and bioactivities for biorefinery. In this work, milled wood lignin (MWL) and alkali‑oxygen lignin (AOL) were isolated from rice straw and alkali‑oxygen black liquor, respectively. The lignin structure was characterized by spectroscopy and wet chemistry. Antioxidant activity of lignins was assessed by DPPH·and ABTS scavenging ability assay. Results showed the oxidization and condensation of lignin occurred during alkali‑oxygen cooking. The p-hydroxyphenyl was more easily removed from rice straw than guaiacyl and syringyl units. The ester or ether linkages derived from hydroxycynnamic acids, and the main interunit linkages, i.e. β-O-4' bonds, were mostly cleaved. Lignin-xylan complex had high reactivity under alkali‑oxygen condition. Tricin, incorporated into lignin, was detected in MWL but was absent in AOL. Nitrobenzene oxidation showed MWL can well represent the protolignin of rice straw, and the products yield decreased dramatically after alkali‑oxygen cooking. AOL had higher radical scavenging ability than MWL indicating alkali‑oxygen cooking was an effective pathway for the enhancement of antioxidant activity of lignin. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Novel seed coat lignins in the Cactaceae: structure, distribution and implications for the evolution of lignin diversity.

    Science.gov (United States)

    Chen, Fang; Tobimatsu, Yuki; Jackson, Lisa; Nakashima, Jin; Ralph, John; Dixon, Richard A

    2013-01-01

    We have recently described a hitherto unsuspected catechyl lignin polymer (C-lignin) in the seed coats of Vanilla orchid and in cacti of one genus, Melocactus (Chen et al., Proc. Natl. Acad. Sci. USA. 2012, 109, 1772-1777.). We have now determined the lignin types in the seed coats of 130 different cactus species. Lignin in the vegetative tissues of cacti is of the normal guaiacyl/syringyl (G/S) type, but members of most genera within the subfamily Cactoidae possess seed coat lignin of the novel C-type only, which we show is a homopolymer formed by endwise β-O-4-coupling of caffeyl alcohol monomers onto the growing polymer resulting in benzodioxane units. However, the species examined within the genera Coryphantha, Cumarinia, Escobaria and Mammillaria (Cactoideae) mostly had normal G/S lignin in their seeds, as did all six species in the subfamily Opuntioidae that were examined. Seed coat lignin composition is still evolving in the Cactaceae, as seeds of one Mammillaria species (M. lasiacantha) possess only C-lignin, three Escobaria species (E. dasyacantha, E. lloydii and E. zilziana) contain an unusual lignin composed of 5-hydroxyguaiacyl units, the first report of such a polymer that occurs naturally in plants, and seeds of some species contain no lignin at all. We discuss the implications of these findings for the mechanisms that underlie the biosynthesis of these newly discovered lignin types. © 2012 The Authors The Plant Journal © 2012 Blackwell Publishing Ltd.

  12. Bacteria and lignin degradation

    Institute of Scientific and Technical Information of China (English)

    Jing LI; Hongli YUAN; Jinshui YANG

    2009-01-01

    Lignin is both the most abundant aromatic (phenolic) polymer and the second most abundant raw material.It is degraded and modified by bacteria in the natural world,and bacteria seem to play a leading role in decomposing lignin in aquatic ecosystems.Lignin-degrading bacteria approach the polymer by mechanisms such as tunneling,erosion,and cavitation.With the advantages of immense environmental adaptability and biochemical versatility,bacteria deserve to be studied for their ligninolytic potential.

  13. The Phenylpropanoid Pathway and Lignin in Defense against Ganoderma boninense Colonized Root Tissues in Oil Palm (Elaeis guineensis Jacq.).

    Science.gov (United States)

    Govender, Nisha T; Mahmood, Maziah; Seman, Idris A; Wong, Mui-Yun

    2017-01-01

    Basal stem rot, caused by the basidiomycete fungus, Ganoderma boninense , is an economically devastating disease in Malaysia. Our study investigated the changes in lignin content and composition along with activity and expression of the phenylpropanoid pathway enzymes and genes in oil palm root tissues during G. boninense infection. We sampled control (non-inoculated) and infected (inoculated) seedlings at seven time points [1, 2, 3, 4, 8, and 12 weeks post-inoculation (wpi)] in a randomized design. The expression profiles of phenylalanine ammonia lyase (PAL), cinnamyl alcohol dehydrogenase (CAD), and peroxidase (POD) genes were monitored at 1, 2, and 3 wpi using real-time quantitative polymerase chain reaction. Seedlings at 4, 8, and 12 wpi were screened for lignin content, lignin composition, enzyme activities (PAL, CAD, and POD), growth (weight and height), and disease severity (DS). Gene expression analysis demonstrated up-regulation of PAL, CAD, and POD genes in the infected seedlings, relative to the control seedlings at 1, 2, and 3 wpi. At 2 and 3 wpi, CAD showed highest transcript levels compared to PAL and POD. DS increased progressively throughout sampling, with 5, 34, and 69% at 4, 8, and 12 wpi, respectively. Fresh weight and height of the infected seedlings were significantly lower compared to the control seedlings at 8 and 12 wpi. Lignin content of the infected seedlings at 4 wpi was significantly higher than the control seedlings, remained elicited with no change at 8 wpi, and then collapsed with a significant reduction at 12 wpi. The nitrobenzene oxidation products of oil palm root lignin yielded both syringyl and guaiacyl monomers. Accumulation of lignin in the infected seedlings was in parallel to increased syringyl monomers, at 4 and 8 wpi. The activities of PAL and CAD enzymes in the infected seedlings at DS = 5-34% were significantly higher than the control seedlings and thereafter collapsed at DS = 69%.

  14. Characterization of the effects of lignin and lignin complex particles as filler on a polystyrene film

    Energy Technology Data Exchange (ETDEWEB)

    El-Zawawy, Waleed K., E-mail: wkzawawy@yahoo.com [Cellulose and Paper Department, National Research Center, El-Tahrir St., Giza (Egypt); Ibrahim, Maha M. [Cellulose and Paper Department, National Research Center, El-Tahrir St., Giza (Egypt); Belgacem, Mohamed Naceur; Dufresne, Alain [Grenoble Institute of Technology (INP) - The International School of Paper, Print Media and Biomaterials (PAGORA), BP 65, 38402 Saint Martin d' Heres cedex, Grenoble (France)

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer We have studied the use of Co(II) to form a complex with the lignin. We use first vanillin as the lignin model and we observed a change in color for the produced complex depending on the light wavelength. The use of other transition metals does not give the same observation. Black-Right-Pointing-Pointer The use of the transition metal with the lignin precipitated from the black liquor after pulping of agricultural residues, gave a fluorescent color under fluorescent microscope. Black-Right-Pointing-Pointer We applied the resulted lignin complex to prepare polymer film that can be used as special polymer packaging which can be color changed under different wavelengths. - Abstract: The work in this research outlines the use of lignin precipitated from lignocellulosic substrate as fillers after modified with transition metal cations, Fe(III), Ni(II) and Co(II), in the production of a polystyrene based composite for polymer packaging applications. Virgin polystyrene was compared with lignin and lignin complex filled composites with loading of 5% by weight prepared using twin screw extrusion. The lignin complexes were first characterized by the UV spectra to identify the new absorption bands occurred due to the complex formation. Moreover, lignin model, namely vanillin, was used to notify the geometric structure of the resulting complexes applying the GC mass spectra. Scanning electron microscopy was used to indicate the change in the morphological structure of the filler particles. On the other hand, the mechanical and thermal analysis for the resulting polymer composites was studied and it was noticed that the type of lignin or lignin complex plays a roll in the results. The inclusion of the Co(II)-lignin complex was observed to increase the tensile strength of the resulting polymer composite and a decrease of the glass transition temperature. Furthermore, light wave lengths and UV fluorescent microscope were used to identify

  15. Characterization of the effects of lignin and lignin complex particles as filler on a polystyrene film

    International Nuclear Information System (INIS)

    El-Zawawy, Waleed K.; Ibrahim, Maha M.; Belgacem, Mohamed Naceur; Dufresne, Alain

    2011-01-01

    Highlights: ► We have studied the use of Co(II) to form a complex with the lignin. We use first vanillin as the lignin model and we observed a change in color for the produced complex depending on the light wavelength. The use of other transition metals does not give the same observation. ► The use of the transition metal with the lignin precipitated from the black liquor after pulping of agricultural residues, gave a fluorescent color under fluorescent microscope. ► We applied the resulted lignin complex to prepare polymer film that can be used as special polymer packaging which can be color changed under different wavelengths. - Abstract: The work in this research outlines the use of lignin precipitated from lignocellulosic substrate as fillers after modified with transition metal cations, Fe(III), Ni(II) and Co(II), in the production of a polystyrene based composite for polymer packaging applications. Virgin polystyrene was compared with lignin and lignin complex filled composites with loading of 5% by weight prepared using twin screw extrusion. The lignin complexes were first characterized by the UV spectra to identify the new absorption bands occurred due to the complex formation. Moreover, lignin model, namely vanillin, was used to notify the geometric structure of the resulting complexes applying the GC mass spectra. Scanning electron microscopy was used to indicate the change in the morphological structure of the filler particles. On the other hand, the mechanical and thermal analysis for the resulting polymer composites was studied and it was noticed that the type of lignin or lignin complex plays a roll in the results. The inclusion of the Co(II)–lignin complex was observed to increase the tensile strength of the resulting polymer composite and a decrease of the glass transition temperature. Furthermore, light wave lengths and UV fluorescent microscope were used to identify the change of color for the resulting polymer film.

  16. Lignin monomer composition affects Arabidopsis cell-wall degradability after liquid hot water pretreatment

    Directory of Open Access Journals (Sweden)

    Ladisch Michael

    2010-12-01

    Full Text Available Abstract Background Lignin is embedded in the plant cell wall matrix, and impedes the enzymatic saccharification of lignocellulosic feedstocks. To investigate whether enzymatic digestibility of cell wall materials can be improved by altering the relative abundance of the two major lignin monomers, guaiacyl (G and syringyl (S subunits, we compared the degradability of cell wall material from wild-type Arabidopsis thaliana with a mutant line and a genetically modified line, the lignins of which are enriched in G and S subunits, respectively. Results Arabidopsis tissue containing G- and S-rich lignins had the same saccharification performance as the wild type when subjected to enzyme hydrolysis without pretreatment. After a 24-hour incubation period, less than 30% of the total glucan was hydrolyzed. By contrast, when liquid hot water (LHW pretreatment was included before enzyme hydrolysis, the S-lignin-rich tissue gave a much higher glucose yield than either the wild-type or G-lignin-rich tissue. Applying a hot-water washing step after the pretreatment did not lead to a further increase in final glucose yield, but the initial hydrolytic rate was doubled. Conclusions Our analyses using the model plant A. thaliana revealed that lignin composition affects the enzymatic digestibility of LHW pretreated plant material. Pretreatment is more effective in enhancing the saccharification of A. thaliana cell walls that contain S-rich lignin. Increasing lignin S monomer content through genetic engineering may be a promising approach to increase the efficiency and reduce the cost of biomass to biofuel conversion.

  17. Lignin-Furfural Based Adhesives

    Directory of Open Access Journals (Sweden)

    Prajakta Dongre

    2015-07-01

    Full Text Available Lignin recovered from the hot-water extract of sugar maple (Acer saccharum is used in this study to synthesize adhesive blends to replace phenol-formaldehyde (PF resin. Untreated lignin is characterized by lignin content and nuclear magnetic resonance (NMR analysis. The molecular weight distribution of the lignin and the blends are characterized by size exclusion chromatography (SEC. The effect of pH (0.3, 0.65 and 1, ex situ furfural, and curing conditions on the tensile properties of adhesive reinforced glass fibers is determined and compared to the reinforcement level of commercially available PF resin. The adhesive blend prepared at pH = 0.65 with no added furfural exhibits the highest tensile properties and meets 90% of the PF tensile strength.

  18. Raman spectra of lignin model compounds

    Science.gov (United States)

    Umesh P. Agarwal; Richard S. Reiner; Ashok K. Pandey; Sally A. Ralph; Kolby C. Hirth; Rajai H. Atalla

    2005-01-01

    To fully exploit the value of Raman spectroscopy for analyzing lignins and lignin containing materials, a detailed understanding of lignins’ Raman spectra needs to be achieved. Although advances made thus far have led to significant growth in application of Raman techniques, further developments are needed to improve upon the existing knowledge. Considering that lignin...

  19. Lignin from Micro- to Nanosize: Applications

    Directory of Open Access Journals (Sweden)

    Stefan Beisl

    2017-11-01

    Full Text Available Micro- and nanosize lignin has recently gained interest due to improved properties compared to standard lignin available today. As the second most abundant biopolymer after cellulose, lignin is readily available but used for rather low-value applications. This review focuses on the application of micro- and nanostructured lignin in final products or processes that all show potential for high added value. The fields of application are ranging from improvement of mechanical properties of polymer nanocomposites, bactericidal and antioxidant properties and impregnations to hollow lignin drug carriers for hydrophobic and hydrophilic substances. Also, a carbonization of lignin nanostructures can lead to high-value applications such as use in supercapacitors for energy storage. The properties of the final product depend on the surface properties of the nanomaterial and, therefore, on factors like the lignin source, extraction method, and production/precipitation methods, as discussed in this review.

  20. Fabrication of environmentally biodegradable lignin nanoparticles.

    Science.gov (United States)

    Frangville, Camille; Rutkevičius, Marius; Richter, Alexander P; Velev, Orlin D; Stoyanov, Simeon D; Paunov, Vesselin N

    2012-12-21

    We developed a method for the fabrication of novel biodegradable nanoparticles (NPs) from lignin which are apparently non-toxic for microalgae and yeast. We compare two alternative methods for the synthesis of lignin NPs which result in particles of very different stability upon change of pH. The first method is based on precipitation of low-sulfonated lignin from an ethylene glycol solution by using diluted acidic aqueous solutions, which yields lignin NPs that are stable over a wide range of pH. The second approach is based on the acidic precipitation of lignin from a high-pH aqueous solution which produces NPs stable only at low pH. Our study reveals that lignin NPs from the ethylene glycol-based precipitation contain densely packed lignin domains which explain the stability of the NPs even at high pH. We characterised the properties of the produced lignin NPs and determined their loading capacities with hydrophilic actives. The results suggest that these NPs are highly porous and consist of smaller lignin domains. Tests with microalgae like Chlamydomonas reinhardtii and yeast incubated in lignin NP dispersions indicated that these NPs lack measurable effect on the viability of these microorganisms. Such biodegradable and environmentally compatible NPs can find applications as drug delivery vehicles, stabilisers of cosmetic and pharmaceutical formulations, or in other areas where they may replace more expensive and potentially toxic nanomaterials. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Manipulation Of Lignin Biosynthesis To Maximize Ethanol Production From Populus Feedstocks

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Clint Chapple; Dr. Rick Lindroth; Dr. Burce Dien; Dr. Glen Stanosz; Dr. Alex Wiedenhoeft; Dr. Fu Zhao; Dr. Duane Wegener; Dr. Janice Kelly; Dr. Leigh Raymond; Dr. Wallace Tyner

    2012-05-15

    Our research focuses on transgenic strategies for modifying lignification to improve biomass quality, without leading to deleterious effects on plant performance. In order to accomplish this objective, we designed molecular strategies and selected appropriate transgenes for manipulating the expression of lignification-associated genes; we generated poplar engineered for altered lignin content and/or monomer composition, and field-tested them for fitness; we analyzed the impact of these transgenic strategies on metabolism in general and lignin biosynthesis in particular; and evaluated the ease with which cell wall deconstruction can be accomplished using both chemical and enzymatic means using wild-type and high syringyl poplar.

  2. Study of lignin biotransformation by Aspergillus fumigatus and white-rot fungi using 14C-labeled and unlabeled kraft lignins

    International Nuclear Information System (INIS)

    Kadam, K.K.; Drew, S.W.

    1986-01-01

    The biodegradation of lignin by fungi was studied in shake flasks using 14 C-labeled kraft lignin and in a deep-tank fermentor using unlabeled kraft lignin. Among the fungi screened, A. fumigatus - isolated in our laboratories - was most potent in lignin biotransformation. Dialysis-type fermentation, designed to study possible accumulation of low MW lignin-derived products, showed no such accumulation. Recalcitrant carbohydrates like microcrystalline cellulose supported higher lignolytic activity than easily metabolized carbohydrates like cellobiose. An assay developed to distinguish between CO 2 evolved from lignin and carbohydrate substrates demonstrated no stoichiometric correlation between the metabolism of the two cosubstrates. The submerged fermentations with unlabeled liqnin are difficult to monitor since chemical assays do not give accurate and true results. Lignolytic efficiencies that allowed monitoring of such fermentations were defined. Degraded lignins were clearly superior to C. versicolor in all aspects of lignin degradation; A fumigatus brought about substantial demethoxylation and dehydroxylation, whereas C. versicolor degraded lignins closely resembled undegraded kraft lignin. There was a good agreement among the different indices of lignin degradation, namely, 14 CO evolution, OCH 3 loss, OH loss, and monomer and dimer yield after permanganate oxidation

  3. Degradation of lignin β-aryl ether units in Arabidopsis thaliana expressing LigD, LigF and LigG from Sphingomonas paucimobilis SYK-6

    DEFF Research Database (Denmark)

    Mnich, Ewelina; Vanholme, Ruben; Oyarce, Paula

    2017-01-01

    Lignin is a major polymer in the secondary plant cell wall and composed of hydrophobic interlinked hydroxyphenylpropanoid units. The presence of lignin hampers conversion of plant biomass into biofuels; plants with modified lignin are therefore being investigated for increased digestibility....... The bacterium Sphingomonas paucimobilis produces lignin-degrading enzymes including LigD, LigF and LigG involved in cleaving the most abundant lignin inter-unit linkage, the β-aryl ether bond. In this study, we expressed the LigD, LigF and LigG (LigDFG) genes in Arabidopsis thaliana to introduce post...

  4. Anaerobic biodegradation of the lignin and polysaccharide components of lignocellulose and synthetic lignin by sediment microflora

    Energy Technology Data Exchange (ETDEWEB)

    Benner, R.; Maccubbin, A.E.; Hodson, R.E.

    1984-05-01

    Specifically radiolabeled (/sup 14/C-lignin)lignocelluloses and (/sup 14/C-polysaccharide)lignocelluloses were prepared from a variety of marine and freshwater wetland plants including a grass, a sedge, a rush, and a hardwood. These (/sup 14/C)lignocellulose preparations and synthetic (/sup 14/C)lignin were incubated anaerobically with anoxic sediments collected from a salt marsh, a freshwater marsh, and a mangrove swamp. During long-term incubations lasting up to 300 days, the lignin and polysaccharide components of the lignocelluloses were slowly degraded anaerobically to /sup 14/CO/sub 2/ and /sup 14/CH/sub 4/. Lignocelluloses derived from herbaceous plants were degraded more rapidly than lignocellulose derived from the hardwood. After 294 days, 16.9% of the lignin component and 30.0% of the polysaccharide component of lignocellulose derived from the grass used (Spartina alterniflora) were degraded to gaseous end products. In contrast, after 246 days, only 1.5% of the lignin component and 4.1% of the polysaccharide component of lignocellulose derived from the hardwood used (Rhizophora mangle) were degraded to gaseous end products. Synthetic (/sup 14/C) lignin was degraded anaerobically faster than the lignin component of the hardwood lignocellulose; after 276 days 3.7% of the synthetic lignin was degraded to gaseous end products. Contrary to previous reports, these results demonstrate that lignin and lignified plant tissues are biodegradable in the absence of oxygen. Although lignocelluloses are recalcitrant to anaerobic biodegradation, rates of degradation measured in aquatic sediments are significant and have important implications for the biospheric cycling of carbon from these abundant biopolymers. 31 references.

  5. Effect of lignin content on a GH11 endoxylanase acting on glucuronoarabinoxylan-lignin nanocomposites.

    Science.gov (United States)

    Boukari, Imen; Rémond, Caroline; O'Donohue, Michael; Chabbert, Brigitte

    2012-06-20

    The effects of lignin content on the activity and action pattern of GH11 endoxylanase from Thermobacillus xylanilyticus were investigated using in vitro reconstituted non-covalent glucuronoarabinoxylan-model lignin (GAX-DHP) nanocomposites. Four types of nanocomposites were prepared, each displaying different lignin contents. Variations in the DHP (model lignin) polymerization process were induced by increasing the coniferyl alcohol concentration. Examination of the morphology of the nanocomposites revealed globular particles enrobed in a matrix. The size of these particles increased in line with the lignin concentration. Physicochemical characterization of the in vitro reconstituted GAX-DHPs strongly suggested that increased particle size is directly related to the solubility and reactivity of coniferyl alcohol, as reflected by changes in the amount of β-O-4 linkages. Evaluation of the impact of the GH11 endoxylanase on the GAX-DHP nanocomposites revealed a negative correlation between the proportion and organization patterns of DHP in the nanocomposites and enzyme activity. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Structural changes in lignin during organosolv pretreatment of Liriodendron tulipifera and the effect on enzymatic hydrolysis

    International Nuclear Information System (INIS)

    Koo, Bon-Wook; Min, Byeong-Cheol; Gwak, Ki-Seob; Lee, Soo-Min; Choi, Joon-Weon; Yeo, Hwanmyeong; Choi, In-Gyu

    2012-01-01

    Although organosolv pretreatment removed substantial amounts of lignin and xylan, the yield of glucan which is a major sugar source for fermentation to ethanol is more than 90% in most conditions of the organosolv pretreatment. Relative lignin contents of all pretreated biomass were more than 200 g kg −1 , however enzymatic conversions were increased dramatically comparing to untreated biomass. Therefore the correlation between lignin and enzymatic hydrolysis could not be explained just by lignin content, and other changes resulting from lignin removal affected enzymatic hydrolysis. Results on enzymatic conversion and sugar recovery suggested that the critical temperature improving enzymatic hydrolysis significantly was between 120 °C and 130 °C. Microscopic analysis using Field emission scanning electron microscopy (FE-SEM) showed that structural lignin changes happened through organosolv pretreatment. Lignins were isolated from lignin carbohydrate complex (LCC) at the initial stage and then migrated to the surface of biomass. The isolated and migrated lignins were finally redistributed onto surface. These structural changes formed droplets on surface and increased pore volume in pretreated biomass. The increase in pore volume also increased available surface area and enzyme adsorption at initial stage, and thus enzymatic conversion increased significantly through organosolv pretreatment. It was verified that the droplets were mainly composed of lignin and the lignin droplets inhibited enzymatic hydrolysis through adsorption with cellulase. -- Highlights: ► Just lignin contents cannot explain a correlation with enzymatic hydrolysis. ► Several changes resulted from lignin removal must affect enzymatic hydrolysis. ► Droplets are formed by structural changes in lignin during organosolv pretreatment. ► Formation of the lignin droplet increases the pore volume in biomass. ► The increase in pore volume enhances the enzymatic hydrolysis.

  7. Advanced Model Compounds for Understanding Acid-Catalyzed Lignin Depolymerization: Identification of Renewable Aromatics and a Lignin-Derived Solvent.

    Science.gov (United States)

    Lahive, Ciaran W; Deuss, Peter J; Lancefield, Christopher S; Sun, Zhuohua; Cordes, David B; Young, Claire M; Tran, Fanny; Slawin, Alexandra M Z; de Vries, Johannes G; Kamer, Paul C J; Westwood, Nicholas J; Barta, Katalin

    2016-07-20

    The development of fundamentally new approaches for lignin depolymerization is challenged by the complexity of this aromatic biopolymer. While overly simplified model compounds often lack relevance to the chemistry of lignin, the direct use of lignin streams poses significant analytical challenges to methodology development. Ideally, new methods should be tested on model compounds that are complex enough to mirror the structural diversity in lignin but still of sufficiently low molecular weight to enable facile analysis. In this contribution, we present a new class of advanced (β-O-4)-(β-5) dilinkage models that are highly realistic representations of a lignin fragment. Together with selected β-O-4, β-5, and β-β structures, these compounds provide a detailed understanding of the reactivity of various types of lignin linkages in acid catalysis in conjunction with stabilization of reactive intermediates using ethylene glycol. The use of these new models has allowed for identification of novel reaction pathways and intermediates and led to the characterization of new dimeric products in subsequent lignin depolymerization studies. The excellent correlation between model and lignin experiments highlights the relevance of this new class of model compounds for broader use in catalysis studies. Only by understanding the reactivity of the linkages in lignin at this level of detail can fully optimized lignin depolymerization strategies be developed.

  8. Selective lignin downregulation leads to constitutive defense response expression in alfalfa (Medicago sativa L.).

    Science.gov (United States)

    Gallego-Giraldo, Lina; Jikumaru, Yusuke; Kamiya, Yuji; Tang, Yuhong; Dixon, Richard A

    2011-05-01

    • Downregulation of hydroxycinnamoyl CoA: shikimate hydroxycinnamoyl transferase (HCT) in alfalfa (Medicago sativa) reduces lignin levels and improves forage quality and saccharification efficiency for bioethanol production. However, the plants have reduced stature. It was previously reported that HCT-down-regulated Arabidopsis have impaired auxin transport, but this has recently been disproved. • To address the basis for the phenotypes of lignin-modified alfalfa, we measured auxin transport, profiled a range of metabolites including flavonoids and hormones, and performed in depth transcriptome analyses. • Auxin transport is unaffected in HCT antisense alfalfa despite increased flavonoid biosynthesis. The plants show increased cytokinin and reduced auxin levels, and gibberellin levels and sensitivity are both reduced. Levels of salicylic, jasmonic and abscisic acids are elevated, associated with massive upregulation of pathogenesis and abiotic stress-related genes and enhanced tolerance to fungal infection and drought. • We suggest that HCT downregulated alfalfa plants exhibit constitutive activation of defense responses, triggered by release of bioactive cell wall fragments and production of hydrogen peroxide as a result of impaired secondary cell wall integrity. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  9. Lignin biodegradation by the ascomycete Chrysonilia sitophila.

    Science.gov (United States)

    Rodríguez, J; Ferraz, A; Nogueira, R F; Ferrer, I; Esposito, E; Durán, N

    1997-01-01

    The lignin biodegradation process has an important role in the carbon cycle of the biosphere. The study of this natural process has developed mainly with the use of basidiomycetes in laboratory investigations. This has been a logical approach since most of the microorganisms involved in lignocellulosic degradation belong to this class of fungi. However, other microorganisms such as ascomycetes and also some bacteria, are involved in the lignin decaying process. This work focuses on lignin biodegradation by a microorganism belonging to the ascomycete class, Chrysonilia sitophila. Lignin peroxidase production and characterization, mechanisms of lignin degradation (lignin model compounds and lignin in wood matrix) and biosynthesis of veratryl alcohol are outstanding. Applications of C. sitophila for effluent treatment, wood biodegradation and single-cell protein production are also discussed.

  10. Lignin recovery. A resource to value

    International Nuclear Information System (INIS)

    Zimbardi, P.; Cardinale, G.; Demichele, M.; Nanna, F.; Viggiano, D.; Bonini, C.; D'Alessio, L.; D'Auria, M.; Teghil, R.; Tofani, D.

    1999-01-01

    In the present paper, the effects of the steam explosion (ES) pretreatment conditions on recovery and chemical structure of wheat straw lignin are reported. The experimental data of lignin recovery by caustic extraction, followed by acid precipitation, have been interpolated to obtain the dependence on the time and temperature of SE. The lignin has been characterised by using several methods. Preliminary results on the synthesis of copolymers lignin-styrene are also reported [it

  11. Advances in the chemical utilization of alkali lignin

    International Nuclear Information System (INIS)

    Van der Klashorst, G.H.

    1985-06-01

    Large quantities of alkali lignin are produced as by-products by the South African pulping industry. The potential utilization of industrial soda/anthraquinone (soda/AQ) eucalyptus, kraft pine and soda bagasse lignin was subsequently investigated. The molecular mass distributions of the three lignins were similar when determined by high pressure gel permeation chromatography (HP-GPC). The quantitative and quanlitative occurrence of various low molecular mass lignin fragments in the different spent liquors, on the other hand, indicated that the three lignins have substantial chemical differences. Analysis of the purified degraded lignins by NMR, methoxyl content determinations, elemental analysis, carbohydrate content determinations etc., quantified various of the chemical properties of the lignin. The properties of the three lignins were ultimately used to make recommendations regarding the potential use of each lignin. One such application was investigated and it was shown that soda bagasse lignin can be used successfully in phenol formaldehyde resin applications. The reaction of formaldehyde with lignin model compounds in acidic medium was also investigated. This reaction was shown to give fast crosslinking of alkyl substituted phenolic and etherified phenolic lignin model compounds at positions meta to the aromatic hydroxy groups

  12. Lignin pyrolysis for profitable lignocellulosic biorefineries

    NARCIS (Netherlands)

    Wild, de P.J.; Gosselink, R.J.A.; Huijgen, W.J.J.

    2014-01-01

    Bio-based industries (pulp and paper and biorefineries) produce > 50 Mt/yr of lignin that results from fractionation of lignocellulosic biomass. Lignin is world's second biopolymer and a major potential source for production of performance materials and aromatic chemicals. Lignin valorization is

  13. The Phenylpropanoid Pathway and Lignin in Defense against Ganoderma boninense Colonized Root Tissues in Oil Palm (Elaeis guineensis Jacq.

    Directory of Open Access Journals (Sweden)

    Nisha T. Govender

    2017-08-01

    Full Text Available Basal stem rot, caused by the basidiomycete fungus, Ganoderma boninense, is an economically devastating disease in Malaysia. Our study investigated the changes in lignin content and composition along with activity and expression of the phenylpropanoid pathway enzymes and genes in oil palm root tissues during G. boninense infection. We sampled control (non-inoculated and infected (inoculated seedlings at seven time points [1, 2, 3, 4, 8, and 12 weeks post-inoculation (wpi] in a randomized design. The expression profiles of phenylalanine ammonia lyase (PAL, cinnamyl alcohol dehydrogenase (CAD, and peroxidase (POD genes were monitored at 1, 2, and 3 wpi using real-time quantitative polymerase chain reaction. Seedlings at 4, 8, and 12 wpi were screened for lignin content, lignin composition, enzyme activities (PAL, CAD, and POD, growth (weight and height, and disease severity (DS. Gene expression analysis demonstrated up-regulation of PAL, CAD, and POD genes in the infected seedlings, relative to the control seedlings at 1, 2, and 3 wpi. At 2 and 3 wpi, CAD showed highest transcript levels compared to PAL and POD. DS increased progressively throughout sampling, with 5, 34, and 69% at 4, 8, and 12 wpi, respectively. Fresh weight and height of the infected seedlings were significantly lower compared to the control seedlings at 8 and 12 wpi. Lignin content of the infected seedlings at 4 wpi was significantly higher than the control seedlings, remained elicited with no change at 8 wpi, and then collapsed with a significant reduction at 12 wpi. The nitrobenzene oxidation products of oil palm root lignin yielded both syringyl and guaiacyl monomers. Accumulation of lignin in the infected seedlings was in parallel to increased syringyl monomers, at 4 and 8 wpi. The activities of PAL and CAD enzymes in the infected seedlings at DS = 5–34% were significantly higher than the control seedlings and thereafter collapsed at DS = 69%.

  14. Studies on Lignin-Based Adhesives for Particleboard Panels

    OpenAIRE

    ÇETİN, Nihat Sami; ÖZMEN, Nilgül

    2003-01-01

    The ultimate aim of this work was to develop a phenolic resin for partially replacing phenol with modified organosolv lignin in phenol-formaldehyde (PF) resin production. The lignin-formaldehyde relationship was determined in a reactivity test. Organosolv lignin-phenol-formaldehyde (LPF) resins were produced in a two-step preparation with different additions of lignin. The method selected for the manufacture of lignin resins dealt with modification of the lignin by the methylolation route. Th...

  15. Effective Release of Lignin Fragments from Lignocellulose by Lewis Acid Metal Triflates in the Lignin-First Approach.

    Science.gov (United States)

    Huang, Xiaoming; Zhu, Jiadong; Korányi, Tamás I; Boot, Michael D; Hensen, Emiel J M

    2016-12-08

    Adding value to lignin, the most complex and recalcitrant fraction in lignocellulosic biomass, is highly relevant to costefficient operation of biorefineries. We report the use of homogeneous metal triflates to rapidly release lignin from biomass. Combined with metal-catalyzed hydrogenolysis, the process separates woody biomass into few lignin-derived alkylmethoxyphenols and cellulose under mild conditions. Model compound studies show the unique catalytic properties of metal triflates in cleaving lignin-carbohydrate interlinkages. The lignin fragments can then be disassembled by hydrogenolysis. The tandem process is flexible and allows obtaining good aromatic monomer yields from different woods (36-48 wt %, lignin base). The cellulose-rich residue is an ideal feedstock for established biorefining processes. The highly productive strategy is characterized by short reaction times, low metal triflate catalyst requirement, and leaving cellulose largely untouched. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. The impact of alterations in lignin deposition on cellulose organization of the plant cell wall

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jiliang; Kim, Jeong Im; Cusumano, Joanne C.; Chapple, Clint; Venugopalan, Nagarajan; Fischetti, Robert F.; Makowski, Lee

    2016-06-17

    Background: Coordination of synthesis and assembly of the polymeric components of cell walls is essential for plant growth and development. Given the degree of co-mingling and cross-linking among cell wall components, cellulose organization must be dependent on the organization of other polymers such as lignin. Here we seek to identify aspects of that codependency by studying the structural organization of cellulose fibrils in stems from Arabidopsis plants harboring mutations in genes encoding enzymes involved in lignin biosynthesis. Plants containing high levels of G-lignin, S-lignin, H-lignin, aldehyde-rich lignin, and ferulic acid-containing lignin, along with plants with very low lignin content were grown and harvested and longitudinal sections of stem were prepared and dried. Scanning X-ray microdiffraction was carried out using a 5-micron beam that moved across the sections in 5-micron steps and complete diffraction patterns were collected at each raster point. Approximately, 16,000 diffraction patterns were analyzed to determine cellulose fibril orientation and order within the tissues making up the stems. Results: Several mutations-most notably those exhibiting (1) down-regulation of cinnamoyl CoA reductase which leads to cell walls deficient in lignin and (2) defect of cinnamic acid 4-hydroxylase which greatly reduces lignin content-exhibited significant decrease in the proportion of oriented cellulose fibrils in the cell wall. Distinctions between tissues were maintained in all variants and even in plants exhibiting dramatic changes in cellulosic order the trends between tissues (where apparent) were generally maintained. The resilience of cellulose to degradative processes was investigated by carrying out the same analysis on samples stored in water for 30 days prior to data collection. This treatment led to significant loss of cellulosic order in plants rich in aldehyde or H-lignin, less change in wild type, and essentially no change in samples with

  17. Recent advances in the molecular genetics of the lignin degrading fungus, phanerochaete chrysosporium

    International Nuclear Information System (INIS)

    Covert, S.F.

    1991-01-01

    During the past several years, molecular genetics research on phanerochaete chrysosporium, a white-rot basidiomycete, has increased dramatically. It is known that families of highly homologous, clustered genes encode the lignin peroxidases. The same appears to be true with the exocellobiohydrolase genes. Functional domains and active sites have been tentatively identified from the deduced amino acid sequences of these genes. Current investigations focus on elucidating the genomic organization of gene families, the mechanism(s) of gene regulation, and the role and interaction of specific gene products in lignocellulose degradation. (author)

  18. Chapter 1: A Brief Introduction to Lignin Structure

    Energy Technology Data Exchange (ETDEWEB)

    Katahira, Rui [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Beckham, Gregg T [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Elder, Thomas J. [USDA-Forest Service

    2018-04-03

    Lignin is an alkyl-aromatic polymer found in the cell walls of terrestrial plants. Lignin provides structure and rigidity to plants, is a natural, highly effective barrier against microbial attack, and enables water and nutrient transport through plant tissues. Depending on the plant species, the constituents of lignin can vary considerably, leading to substantial diversity in lignin chemistry and structure. Despite nearly a century of research and development attempting to convert lignin into valuable products, lignin in most current and planned biorefinery contexts remains underutilized, most often being burned to generate heat and power. However, the drive towards effective lignin valorization processes has witnessed a significant resurgence in the past decade, catalyzed by advances in improved understanding of lignin chemistry, structure, and plasticity in parallel with new catalytic and biological approaches to valorize this important, prevalent biopolymer. As a preface to the subsequent chapters in this book, this chapter briefly highlights the known aspects of lignin structure.

  19. Lignin-Modified Carbon Nanotube/Graphene Hybrid Coating as Efficient Flame Retardant

    Directory of Open Access Journals (Sweden)

    Kunlin Song

    2017-11-01

    Full Text Available To reduce fire hazards and expand high-value applications of lignocellulosic materials, thin films comprising graphene nanoplatelets (GnPs and multi-wall carbon nanotubes (CNTs pre-adsorbed with alkali lignin were deposited by a Meyer rod process. Lightweight and highly flexible papers with increased gas impermeability were obtained by coating a protective layer of carbon nanomaterials in a randomly oriented and overlapped network structure. Assessment of the thermal and flammability properties of papers containing as low as 4 wt % carbon nanomaterials exhibited self-extinguishing behavior and yielded up to 83.5% and 87.7% reduction in weight loss and burning area, respectively, compared to the blank papers. The maximum burning temperature as measured by infrared pyrometry also decreased from 834 °C to 705 °C with the presence of flame retardants. Furthermore, papers coated with composites of GnPs and CNTs pre-adsorbed with lignin showed enhanced thermal stability and superior fire resistance than samples treated with either component alone. These outstanding flame-retardant properties can be attributed to the synergistic effects between GnPs, CNTs and lignin, enhancing physical barrier characteristics, formation of char and thermal management of the material. These results provide great opportunities for the development of efficient, cost-effective and environmentally sustainable flame retardants.

  20. Identification of Manganese Superoxide Dismutase from Sphingobacterium sp. T2 as a Novel Bacterial Enzyme for Lignin Oxidation.

    Science.gov (United States)

    Rashid, Goran M M; Taylor, Charles R; Liu, Yangqingxue; Zhang, Xiaoyang; Rea, Dean; Fülöp, Vilmos; Bugg, Timothy D H

    2015-10-16

    The valorization of aromatic heteropolymer lignin is an important unsolved problem in the development of a biomass-based biorefinery, for which novel high-activity biocatalysts are needed. Sequencing of the genomic DNA of lignin-degrading bacterial strain Sphingobacterium sp. T2 revealed no matches to known lignin-degrading genes. Proteomic matches for two manganese superoxide dismutase proteins were found in partially purified extracellular fractions. Recombinant MnSOD1 and MnSOD2 were both found to show high activity for oxidation of Organosolv and Kraft lignin, and lignin model compounds, generating multiple oxidation products. Structure determination revealed that the products result from aryl-Cα and Cα-Cβ bond oxidative cleavage and O-demethylation. The crystal structure of MnSOD1 was determined to 1.35 Å resolution, revealing a typical MnSOD homodimer harboring a five-coordinate trigonal bipyramidal Mn(II) center ligated by three His, one Asp, and a water/hydroxide in each active site. We propose that the lignin oxidation reactivity of these enzymes is due to the production of a hydroxyl radical, a highly reactive oxidant. This is the first demonstration that MnSOD is a microbial lignin-oxidizing enzyme.

  1. Cationic electrodepositable coating composition comprising lignin

    Science.gov (United States)

    Fenn, David; Bowman, Mark P; Zawacky, Steven R; Van Buskirk, Ellor J; Kamarchik, Peter

    2013-07-30

    A cationic electrodepositable coating composition is disclosed. The present invention in directed to a cationic electrodepositable coating composition comprising a lignin-containing cationic salt resin, that comprises (A) the reaction product of: lignin, an amine, and a carbonyl compound; (B) the reaction product of lignin, epichlorohydrin, and an amine; or (C) combinations thereof.

  2. Systematic Parameterization of Lignin for the CHARMM Force Field

    Energy Technology Data Exchange (ETDEWEB)

    Vermaas, Joshua; Petridis, Loukas; Beckham, Gregg; Crowley, Michael

    2017-07-06

    Plant cell walls have three primary components, cellulose, hemicellulose, and lignin, the latter of which is a recalcitrant, aromatic heteropolymer that provides structure to plants, water and nutrient transport through plant tissues, and a highly effective defense against pathogens. Overcoming the recalcitrance of lignin is key to effective biomass deconstruction, which would in turn enable the use of biomass as a feedstock for industrial processes. Our understanding of lignin structure in the plant cell wall is hampered by the limitations of the available lignin forcefields, which currently only account for a single linkage between lignins and lack explicit parameterization for emerging lignin structures both from natural variants and engineered lignin structures. Since polymerization of lignin occurs via radical intermediates, multiple C-O and C-C linkages have been isolated , and the current force field only represents a small subset of lignin the diverse lignin structures found in plants. In order to take into account the wide range of lignin polymerization chemistries, monomers and dimer combinations of C-, H-, G-, and S-lignins as well as with hydroxycinnamic acid linkages were subjected to extensive quantum mechanical calculations to establish target data from which to build a complete molecular mechanics force field tuned specifically for diverse lignins. This was carried out in a GPU-accelerated global optimization process, whereby all molecules were parameterized simultaneously using the same internal parameter set. By parameterizing lignin specifically, we are able to more accurately represent the interactions and conformations of lignin monomers and dimers relative to a general force field. This new force field will enables computational researchers to study the effects of different linkages on the structure of lignin, as well as construct more accurate plant cell wall models based on observed statistical distributions of lignin that differ between

  3. Lignin Biodegradation with Laccase-Mediator Systems

    International Nuclear Information System (INIS)

    Christopher, Lew Paul; Yao, Bin; Ji, Yun

    2014-01-01

    Lignin has a significant and largely unrealized potential as a source for the sustainable production of fuels and bulk high-value chemicals. It can replace fossil-based oil as a renewable feedstock that would bring about socio-economic and environmental benefits in our transition to a biobased economy. The efficient utilization of lignin however requires its depolymerization to low-molecular weight phenolics and aromatics that can then serve as the building blocks for chemical syntheses of high-value products. The ability of laccase to attack and degrade lignin in conjunction with laccase mediators is currently viewed as one of the potential “breakthrough” applications for lignin valorization. Here, we review the recent progress in lignin biodegradation with laccase-mediator systems, and research needs that need to be addressed in this field.

  4. Lignin Biodegradation with Laccase-Mediator Systems

    Energy Technology Data Exchange (ETDEWEB)

    Christopher, Lew Paul, E-mail: lew.christopher@sdsmt.edu [Center for Bioprocessing Research and Development, South Dakota School of Mines & Technology, Rapid City, SD (United States); Department of Civil and Environmental Engineering, South Dakota School of Mines & Technology, Rapid City, SD (United States); Yao, Bin [Center for Bioprocessing Research and Development, South Dakota School of Mines & Technology, Rapid City, SD (United States); Ji, Yun [Department of Chemical Engineering, University of North Dakota, Grand Forks, ND (United States)

    2014-03-31

    Lignin has a significant and largely unrealized potential as a source for the sustainable production of fuels and bulk high-value chemicals. It can replace fossil-based oil as a renewable feedstock that would bring about socio-economic and environmental benefits in our transition to a biobased economy. The efficient utilization of lignin however requires its depolymerization to low-molecular weight phenolics and aromatics that can then serve as the building blocks for chemical syntheses of high-value products. The ability of laccase to attack and degrade lignin in conjunction with laccase mediators is currently viewed as one of the potential “breakthrough” applications for lignin valorization. Here, we review the recent progress in lignin biodegradation with laccase-mediator systems, and research needs that need to be addressed in this field.

  5. Advanced Model Compounds for Understanding Acid-Catalyzed Lignin Depolymerization : Identification of Renewable Aromatics and a Lignin-Derived Solvent

    NARCIS (Netherlands)

    Lahive, Ciaran W; Deuss, Peter J; Lancefield, Christopher S; Sun, Zhuohua; Cordes, David B; Young, Claire; Tran, Fanny; Slawin, Alexandra M Z; de Vries, Johannes G; Kamer, Paul C J; Westwood, Nicholas J; Barta, Katalin

    2016-01-01

    The development of fundamentally new approaches for lignin depolymerization is challenged by the complexity of this aromatic biopolymer. While overly simplified model compounds often lack relevance to the chemistry of lignin, the direct use of lignin streams poses significant analytical challenges

  6. Liquid Fuels from Lignins: Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Chum, H. L.; Johnson, D. K.

    1986-01-01

    This task was initiated to assess the conversion of lignins into liquid fuels, primarily of lignins relevant to biomass-to-ethanol conversion processes. The task was composed of a literature review of this area and an experimental part to obtain pertinent data on the conversion of lignins germane to biomass-to-ethanol conversion processes.

  7. Radical nature of C- lignin

    Science.gov (United States)

    Laura Berstis; Thomas Elder; Michael Crowley; Gregg T. Beckham

    2016-01-01

    The recently discovered lignin composed of caffeoyl alcohol monolignols or C-lignin is particularly intriguing given its homogeneous, linear polymeric structure and exclusive benzodioxane linkage between monomers. By virtue of this simplified chemistry, the potential emerges for improved valorization strategies with C-lignin relative to other natural heterogeneous...

  8. Dissolution of lignin in green urea aqueous solution

    Science.gov (United States)

    Wang, Jingyu; Li, Ying; Qiu, Xueqing; Liu, Di; Yang, Dongjie; Liu, Weifeng; Qian, Yong

    2017-12-01

    The dissolution problem is the main obstacle for the value-added modification and depolymerization of industrial lignin. Here, a green urea aqueous solution for complete dissolution of various lignin is presented and the dissolution mechanism is analyzed by AFM, DLS and NMR. The results show that the molecular interaction of lignin decreases from 32.3 mN/m in pure water to 11.3 mN/m in urea aqueous solution. The immobility of 1H NMR spectra and the shift of 17O NMR spectra of urea in different lignin/urea solutions indicate that the oxygen of carbonyl in urea and the hydrogen of hydroxyl in lignin form new hydrogen bonds and break the original hydrogen bonds among lignin molecules. The shift of 1H NMR spectra of lignin and the decrease of interactions in model compound polystyrene indicate that urea also breaks the π-π interactions between aromatic rings of lignin. Lignin dissolved in urea aqueous has good antioxidant activity and it can scavenge at least 63% free radicals in 16 min.

  9. Lignin derivatives from desilicated rice straw soda black liquor

    Energy Technology Data Exchange (ETDEWEB)

    El-Taraboulsi, M A; Nasser, M M

    1979-01-01

    Carboxymethyl lignin, cyanoethyl lignin, carboxyethyl lignin, and aminopropyl lignin were prepared from alkali lignin of rice straw black liquor (after disilication by storage for 1 wk to 1 yr) and used as sizes for paper, drilling fluid additives and flocculants.

  10. Lignin poly(lactic acid) copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Olsson, Johan Vilhelm; Chung, Yi-Lin; Li, Russell Jingxian; Waymouth, Robert; Sattely, Elizabeth; Billington, Sarah; Frank, Curtis W.

    2017-02-14

    Provided herein are graft co-polymers of lignin and poly(lactic acid) (lignin-g-PLA copolymer), thermoset and thermoplastic polymers including them, methods of preparing these polymers, and articles of manufacture including such polymers.

  11. Abiotic stress induces change in Cinnamoyl CoA Reductase (CCR) protein abundance and lignin deposition in developing seedlings of Leucaena leucocephala.

    Science.gov (United States)

    Srivastava, Sameer; Vishwakarma, Rishi K; Arafat, Yasir Ali; Gupta, Sushim K; Khan, Bashir M

    2015-04-01

    Aboitic stress such as drought and salinity are class of major threats, which plants undergo through their lifetime. Lignin deposition is one of the responses to such abiotic stresses. The gene encoding Cinnamoyl CoA Reductase (CCR) is a key gene for lignin biosynthesis, which has been shown to be over-expressed under stress conditions. In the present study, developing seedlings of Leucaena leucocephala (Vernacular name: Subabul, White popinac) were treated with 1 % mannitol and 200 mM NaCl to mimic drought and salinity stress conditions, respectively. Enzyme linked immunosorbant assay (ELISA) based expression pattern of CCR protein was monitored coupled with Phlorogucinol/HCl activity staining of lignin in transverse sections of developing L. leucocephala seedlings under stress. Our result suggests a differential lignification pattern in developing root and stem under stress conditions. Increase in lignification was observed in mannitol treated stems and corresponding CCR protein accumulation was also higher than control and salt stress treated samples. On the contrary CCR protein was lower in NaCl treated stems and corresponding lignin deposition was also low. Developing root tissue showed a high level of CCR content and lignin deposition than stem samples under all conditions tested. Overall result suggested that lignin accumulation was not affected much in case of developing root however developing stems were significantly affected under drought and salinity stress condition.

  12. Lignin solubilisation and gentle fractionation in liquid ammonia

    NARCIS (Netherlands)

    Strassberger, Z.; Prinsen, P.; Klis, van der F.; Es, van D.S.; Tanase, S.; Rothenberg, G.

    2015-01-01

    We present a simple method for solubilising lignin using liquid ammonia. Unlike water, which requires harsh conditions, ammonia can solubilise technical lignins, in particular kraft lignin. A commercial pine wood Kraft lignin (Indulin AT) was solubilized instantaneously at room temperature and 7–11

  13. Identification of lignin genes and regulatory sequences involved in secondary cell wall formation in Acacia auriculiformis and Acacia mangium via de novo transcriptome sequencing

    Directory of Open Access Journals (Sweden)

    Cannon Charles H

    2011-07-01

    Full Text Available Abstract Background Acacia auriculiformis × Acacia mangium hybrids are commercially important trees for the timber and pulp industry in Southeast Asia. Increasing pulp yield while reducing pulping costs are major objectives of tree breeding programs. The general monolignol biosynthesis and secondary cell wall formation pathways are well-characterized but genes in these pathways are poorly characterized in Acacia hybrids. RNA-seq on short-read platforms is a rapid approach for obtaining comprehensive transcriptomic data and to discover informative sequence variants. Results We sequenced transcriptomes of A. auriculiformis and A. mangium from non-normalized cDNA libraries synthesized from pooled young stem and inner bark tissues using paired-end libraries and a single lane of an Illumina GAII machine. De novo assembly produced a total of 42,217 and 35,759 contigs with an average length of 496 bp and 498 bp for A. auriculiformis and A. mangium respectively. The assemblies of A. auriculiformis and A. mangium had a total length of 21,022,649 bp and 17,838,260 bp, respectively, with the largest contig 15,262 bp long. We detected all ten monolignol biosynthetic genes using Blastx and further analysis revealed 18 lignin isoforms for each species. We also identified five contigs homologous to R2R3-MYB proteins in other plant species that are involved in transcriptional regulation of secondary cell wall formation and lignin deposition. We searched the contigs against public microRNA database and predicted the stem-loop structures of six highly conserved microRNA families (miR319, miR396, miR160, miR172, miR162 and miR168 and one legume-specific family (miR2086. Three microRNA target genes were predicted to be involved in wood formation and flavonoid biosynthesis. By using the assemblies as a reference, we discovered 16,648 and 9,335 high quality putative Single Nucleotide Polymorphisms (SNPs in the transcriptomes of A. auriculiformis and A. mangium

  14. Effect of xylan and lignin removal by batch and flowthrough pretreatment on the enzymatic digestibility of corn stover cellulose.

    Science.gov (United States)

    Yang, Bin; Wyman, Charles E

    2004-04-05

    Compared with batch systems, flowthrough and countercurrent reactors have important potential advantages for pretreating cellulosic biomass, including higher hemicellulose sugar yields, enhanced cellulose digestibility, and reduced chemical additions. Unfortunately, they suffer from high water and energy use. To better understand these trade-offs, comparative data are reported on xylan and lignin removal and enzymatic digestibility of cellulose for corn stover pretreated in batch and flowthrough reactors over a range of flow rates between 160 degrees and 220 degrees C, with water only and also with 0.1 wt% sulfuric acid. Increasing flow with just water enhanced the xylan dissolution rate, more than doubled total lignin removal, and increased cellulose digestibility. Furthermore, adding dilute sulfuric acid increased the rate of xylan removal for both batch and flowthrough systems. Interestingly, adding acid also increased the lignin removal rate with flow, but less lignin was left in solution when acid was added in batch. Although the enzymatic hydrolysis of pretreated cellulose was related to xylan removal, as others have shown, the digestibility was much better for flowthrough compared with batch systems, for the same degree of xylan removal. Cellulose digestibility for flowthrough reactors was related to lignin removal as well. These results suggest that altering lignin also affects the enzymatic digestibility of corn stover. Copyright 2004 Wiley Periodicals, Inc.

  15. Hydroxide catalysts for lignin depolymerization

    Science.gov (United States)

    Beckham, Gregg T; Biddy, Mary J.; Kruger, Jacob S.; Chmely, Stephen C.; Sturgeon, Matthew

    2017-10-17

    Solid base catalysts and their use for the base-catalyzed depolymerization (BCD) of lignin to compounds such as aromatics are presented herein. Exemplary catalysts include layered double hydroxides (LDHs) as recyclable, heterogeneous catalysts for BCD of lignin.

  16. Hydroxide catalysts for lignin depolymerization

    Energy Technology Data Exchange (ETDEWEB)

    Beckham, Gregg T.; Biddy, Mary J.; Chmely, Stephen C.; Sturgeon, Matthew

    2017-04-25

    Solid base catalysts and their use for the base-catalyzed depolymerization (BCD) of lignin to compounds such as aromatics are presented herein. Exemplary catalysts include layered double hydroxides (LDHs) as recyclable, heterogeneous catalysts for BCD of lignin.

  17. The effect of epoxidized soybean oil on mechanical and rheological properties of poly(butylene succinate)/lignin via vane extruder

    Science.gov (United States)

    Liu, Huanyu; Huang, Zhaoxia; Qu, Jinping; Meng, Cong

    2016-03-01

    Epoxidized Soybean Oil (ESO) have been used as the compatilizer in the Poly (butylene succinate)/lignin (PBS/lignin) composites. Compatibilized composites were fabricated by a novel vane extruder (VE) which can generate global and dynamic elongational flow. The effects of ESO on the mechanical, rheological properties and morphology of PBS/lignin were studied. The results indicated that the use of ESO had plasticizing effect on the matrix PBS while the addition reduced tensile strength. From SEM micrographs it could be clearly observed that there was a better interfacial adhesion between lignin and matrix. Meanwhile, rheological tests showed the incorporation of ESO improved its Newtonian behavior and can enhance PBS's flexibility.

  18. Reactions of Lignin Model Compounds in Ionic Liquids

    Energy Technology Data Exchange (ETDEWEB)

    Holladay, John E.; Binder, Joseph B.; Gray, Michel J.; White, James F.; Zhang, Z. Conrad

    2009-09-15

    Lignin, a readily available form of biomass, awaits novel chemistry for converting it to valuable aromatic chemicals. Recent work has demonstrated that ionic liquids are excellent solvents for processing woody biomass and lignin. Seeking to exploit ionic liquids as media for depolymerization of lignin, we investigated reactions of lignin model compounds in these solvents. Using Brønsted acid catalysts in 1-ethyl-3-methylimidazolium triflate at moderate temperatures, we obtained up to 11.6% yield of the dealkylation product guaiacol from the model compound eugenol and cleaved phenethyl phenyl ether, a model for lignin ethers. Despite these successes, acid catalysis failed in dealkylation of the unsaturated model compound 4-ethylguaiacol and did not produce monomeric products from organosolv lignin, demonstrating that further work is required to understand the complex chemistry of lignin depolymerization.

  19. Improved lignin polyurethane properties with Lewis acid treatment.

    Science.gov (United States)

    Chung, Hoyong; Washburn, Newell R

    2012-06-27

    Chemical modification strategies to improve the mechanical properties of lignin-based polyurethanes are presented. We hypothesized that treatment of lignin with Lewis acids would increase the concentration of hydroxyl groups available to react with diisocyanate monomers. Under the conditions used, hydrogen bromide-catalyzed modification resulted in a 28% increase in hydroxyl group content. Associated increases in hydrophilicity of solvent-cast thin films were also recorded as evidenced by decreases in water contact angle. Polyurethanes were then prepared by first preparing a prepolymer based on mixtures of toluene-2,4-diisocyanate (TDI) and unmodified or modified lignin, then polymerization was completed through addition of polyethylene glycol (PEG), resulting in mass ratios of TDI:lignin:PEG of 43:17:40 in the compositions investigated here. The mixture of TDI and unmodified lignin resulted in a lignin powder at the bottom of the liquid, suggesting it did not react directly with TDI. However, a homogeneous solution resulted when TDI and the hydrogen bromide-treated lignin were mixed, suggesting demethylation indeed increased reactivity and resulted in better integration of lignin into the urethane network. Significant improvements in mechanical properties of modified lignin polyurethanes were observed, with a 6.5-fold increase in modulus, which were attributed to better integration of the modified lignin into the covalent polymer network due to the higher concentration of hydroxyl groups. This research indicates that chemical modification strategies can lead to significant improvements in the properties of lignin-based polymeric materials using a higher fraction of an inexpensive lignin monomer from renewable resources and a lower fraction an expensive, petroleum-derived isocyanate monomer to achieve the required material properties.

  20. Lignin-based cement fluid loss control additive

    Energy Technology Data Exchange (ETDEWEB)

    Schilling, P.

    1990-05-22

    This patent describes a hydraulic cement slurry composition. It comprises: a hydraulic cement, and the following expressed as parts by weight per 100 parts of the hydraulic cement, water from about 25 to 105 parts, and from abut 0.5 to 2.5 parts of a compound selected from the group consisting of a sulfonated lignin and a sulfomethylated lignin, wherein the lignin has been sequentially crosslinked by reacting the lignin with a member of the group consisting of formaldehyde and epichlorohydrin and alkoxylated with between about 2 to about 6 moles of a compound selected from the group consisting of ethylene oxide, propylene oxide, butylene oxide and a combination thereof per 1000 g of the lignin.

  1. Acid detergent lignin, lodging resistance index, and expression of the caffeic acid O-methyltransferase gene in brown midrib-12 sudangrass.

    Science.gov (United States)

    Li, Yuan; Liu, Guibo; Li, Jun; You, Yongliang; Zhao, Haiming; Liang, Huan; Mao, Peisheng

    2015-09-01

    Understanding the relationship between acid detergent lignin (ADL) and lodging resistance index (LRI) is essential for breeding new varieties of brown midrib (bmr) sudangrass (Sorghum sudanense (Piper) Stapf.). In this study, bmr-12 near isogenic lines and their wild-types obtained by back cross breeding were used to compare relevant forage yield and quality traits, and to analyze expression of the caffeic acid O-methyltransferase (COMT) gene using quantitative real time-PCR. The research showed that the mean ADL content of bmr-12 mutants (20.94 g kg(-1)) was significantly (P bmr-12 mutants (0.29) was significantly (P bmr-12 materials (r = -0.44, P > 0.05). Sequence comparison of the COMT gene revealed two point mutations present in bmr-12 but not in the wild-type, the second mutation changed amino acid 129 of the protein from Gln (CAG) to a stop codon (UAG). The relative expression level of COMT gene was significantly reduced, which likely led to the decreased ADL content observed in the bmr-12 mutant.

  2. Enzymatic Synthesis of Lignin-Based Concrete Dispersing Agents.

    Science.gov (United States)

    Jankowska, Dagmara; Heck, Tobias; Schubert, Mark; Yerlikaya, Alpaslan; Weymuth, Christophe; Rentsch, Daniel; Schober, Irene; Richter, Michael

    2018-03-15

    Lignin is the most abundant aromatic biopolymer, functioning as an integral component of woody materials. In its unmodified form it shows limited water solubility and is relatively unreactive, so biotechnological lignin valorisation for high-performance applications is greatly underexploited. Lignin can be obtained from the pulp and paper industry as a by-product. To expand its application, a new synthesis route to new dispersing agents for use as concrete additives was developed. The route is based on lignin functionalisation by enzymatic transformation. Screening of lignin-modifying systems resulted in functionalised lignin polymers with improved solubility in aqueous systems. Through grafting of sulfanilic acid or p-aminobenzoic acid by fungal laccases, lignin became soluble in water at pH≤4 or pH≤7, respectively. Products were analysed and evaluated in miniaturised application tests in cement paste and mortar. Their dispersing properties match the performance criteria of commercially available lignosulfonates. The study provides examples of new perspectives for the use of lignin. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Lignin Contribution to the Global Carbon Pool: Investigating the Abiotic Modification of Lignin by Reactive Oxygen Species

    Science.gov (United States)

    Waggoner, Derek Charles

    Evidence suggests that reactive oxygen species (ROS), largely generated through photochemical processes, are important in transforming the chemical composition of the large pool of terrestrially-derived dissolved organic matter (DOM) exported from land to water annually. However, due to the challenges inherent in isolating the effects of individual ROS on DOM composition, the role of ROS in the photochemical alteration of DOM remains poorly characterized. The main focus of the studies within this dissertation aim to more thoroughly characterize the alterations to lignin, used as an analog for terrestrial DOM, resulting from reactions with ROS. To investigate the possibility that the alteration of lignin, through reactions involving ROS, could lead to the production of compounds not recognized as having terrestrial origin, lignin-derived DOM was prepared from a sample of Atlantic white cedar (Chamaecyparis thyoides) and used for a number of studies. Lignin-derived DOM was independently exposed to hydroxyl radical (•OH) generated by Fenton reaction, singlet oxygen (1O2) produced using the photosensitizer Rose Bengal, and superoxide (O2-•) via stable potassium superoxide solution, under controlled laboratory conditions to accentuate how each ROS is responsible for the alteration of lignin. Advanced analytical techniques including high performance liquid chromatography (HPLC), nuclear magnetic resonance (NMR), and Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS), were employed to characterize alteration to lignin taking place following various ROS treatments. Results of these studies have shown distinct differences in the types of new compounds observed from exposure to each ROS as well as ROS reactivity. The alteration of lignin to compounds not typically associated with terrestrial DOM has been demonstrated upon exposure to ROS. It is also suggested that ROS could selectively react with different fractions of lignin like compounds based

  4. Quantification of Lignin and Its Structural Features in Plant Biomass Using 13C Lignin as Internal Standard for Pyrolysis-GC-SIM-MS.

    Science.gov (United States)

    van Erven, Gijs; de Visser, Ries; Merkx, Donny W H; Strolenberg, Willem; de Gijsel, Peter; Gruppen, Harry; Kabel, Mirjam A

    2017-10-17

    Understanding the mechanisms underlying plant biomass recalcitrance at the molecular level can only be achieved by accurate analyses of both the content and structural features of the molecules involved. Current quantification of lignin is, however, majorly based on unspecific gravimetric analysis after sulfuric acid hydrolysis. Hence, our research aimed at specific lignin quantification with concurrent characterization of its structural features. Hereto, for the first time, a polymeric 13 C lignin was used as internal standard (IS) for lignin quantification via analytical pyrolysis coupled to gas chromatography with mass-spectrometric detection in selected ion monitoring mode (py-GC-SIM-MS). In addition, relative response factors (RRFs) for the various pyrolysis products obtained were determined and applied. First, 12 C and 13 C lignin were isolated from nonlabeled and uniformly 13 C labeled wheat straw, respectively, and characterized by heteronuclear single quantum coherence (HSQC), nuclear magnetic resonance (NMR), and py-GC/MS. The two lignin isolates were found to have identical structures. Second, 13 C-IS based lignin quantification by py-GC-SIM-MS was validated in reconstituted biomass model systems with known contents of the 12 C lignin analogue and was shown to be extremely accurate (>99.9%, R 2 > 0.999) and precise (RSD corn stover, and sugar cane bagasse), and lignin contents were in good agreement with the total gravimetrically determined lignin contents. Our robust method proves to be a promising alternative for the high-throughput quantification of lignin in milled biomass samples directly and simultaneously provides a direct insight into the structural features of lignin.

  5. Converting lignin to aromatics: step by step

    NARCIS (Netherlands)

    Strassberger, Z.I.

    2014-01-01

    Lignin, the glue that holds trees together, is the most abundant natural resource of aromatics. In that respect, it is a far more advanced resource than crude oil. This is because lignin already contains the aromatic functional groups. Thus, catalytic conversion of lignin to high-value aromatics is

  6. Iron addition to soil specifically stabilized lignin

    Science.gov (United States)

    Steven J. Hall; Whendee L. Silver; Vitaliy I. Timokhin; Kenneth E. Hammel

    2016-01-01

    The importance of lignin as a recalcitrant constituent of soil organic matter (SOM) remains contested. Associations with iron (Fe) oxides have been proposed to specifically protect lignin from decomposition, but impacts of Fe-lignin interactions on mineralization rates remain unclear. Oxygen (O2) fluctuations characteristic of humid tropical...

  7. Hydrothermal Liquefaction of Enzymatic Hydrolysis Lignin: Biomass Pretreatment Severity Affects Lignin Valorization

    DEFF Research Database (Denmark)

    Jensen, Mads M.; Djajadi, Demi T.; Torri, Cristian

    2018-01-01

    Alkalinehydrothermal liquefaction (HTL) of lignin-rich enzymatichydrolysis residues (EnzHR) from wheat straw and Miscanthusx giganteus was performed at 255, 300, and 345 °C to investigate valorization of this side-stream from second-generation bioethanol production. The EnzHR were from biomass...... contributed with additional chemical information as well as confirming trends seen from quantified monomers. This work is relevant for future lignin valorization in biorefineries based on current second-generation bioethanol production....

  8. Noncatalytic Direct Liquefaction of Biorefinery Lignin by Ethanol

    DEFF Research Database (Denmark)

    Nielsen, Joachim Bachmann; Jensen, Anders; Madsen, Line Riis

    2017-01-01

    There is a growing interest in lignin valorization to biofuels and chemicals. Here, we propose a novel and simple noncatalytic process to directly liquefy lignin rich solid residual from second generation bioethanol production by solvolysis with ethanol. Through an extensive parameter study...... in batch autoclaves assessing the effects of varying reaction temperature, reaction time, and solvent:lignin ratio, it is shown that hydrothermally pretreated enzymatic hydrolysis lignin solvolysis in supercritical ethanol can produce a heptane soluble bio-oil without the need for exhaustive deoxygenation....... The process does not require addition of catalyst or a reducing agent such as hydrogen. The process is advantageously carried out with a low reaction period ((ethanol:lignin (w/w) ratio of 2:1) which is a previously unexplored domain for lignin...

  9. Solvothermal conversion of technical lignins over NiMo catalysts

    DEFF Research Database (Denmark)

    Ghafarnejad Parto, Soheila; Christensen, Jakob Munkholt; Pedersen, Lars Saaby

    Scope: Lignin, cellulose and hemicellulose are the main constituents of plants cell walls. Lignin is an aromatic rich compound, composed of phenolic building blocks. Depending on the method used for isolation of lignin from cellulose and hemicellulose, several types of technical lignin are availa......Scope: Lignin, cellulose and hemicellulose are the main constituents of plants cell walls. Lignin is an aromatic rich compound, composed of phenolic building blocks. Depending on the method used for isolation of lignin from cellulose and hemicellulose, several types of technical lignin...... of the range of available technical lignins. In this work, catalytic conversion of different types of lignin using an alumina supported NiMo catalyst (provided by Haldor Topsøe A/S) is conducted in ethanol at 310 ˚C with initial hydrogen pressure of 25 barg. The reaction time was set to 3 hours. Proton......, attributed as ‘bio-oil’. GC-MS-FID analysis was used for identification and quantification of the bio-oil and ethanol rich light fraction. The molecular weight of the oil fraction was determined by size exclusion chromatography (SEC). Elemental analysis (Eurovector EuroEA3000) was conducted for measuring...

  10. Syringyl-Rich Lignin Renders Poplars More Resistant to Degradation by Wood Decay Fungi

    Science.gov (United States)

    Skyba, Oleksandr; Douglas, Carl J.

    2013-01-01

    In order to elucidate the effects of lignin composition on the resistance of wood to degradation by decay fungi, wood specimens from two transgenic poplar lines expressing an Arabidopsis gene encoding ferulate 5-hydroxylase (F5H) driven by the cinnimate-4-hydroxylase promoter (C4H::F5H) that increased syringyl/guaiacyl (S/G) monolignol ratios relative to those in the untransformed control wood were incubated with six different wood decay fungi. Alterations in wood weight and chemical composition were monitored over the incubation period. The results showed that transgenic poplar lines extremely rich in syringyl lignin exhibited a drastically improved resistance to degradation by all decay fungi evaluated. Lignin monomer composition and its distribution among cell types and within different cell layers were the sole wood chemistry parameters determining wood durability. Since transgenic poplars with exceedingly high syringyl contents were recalcitrant to degradation, where wood durability is a critical factor, these genotypes may offer improved performance. PMID:23396333

  11. Diesel-soluble lignin oils and methods of their production

    DEFF Research Database (Denmark)

    2016-01-01

    Solvent consumption in supercritical ethanol, propanol or butanol treatment of either refined pre-extracted lignin or comparatively impure lignin-rich solid residual from hydrothermally pretreated lignocellulosic biomass can be minimized by conducting the reaction at very high loading of lignin...... to solvent. Comparatively impure, crude lignin- rich solid residual can be directly converted by supercritical alcohol treatment to significantly diesel-soluble lignin oil without requirement for pre-extraction or pre- solubilisation of lignin or for added reaction promoters such as catalysts, hydrogen donor...... co-solvents, acids, based or H2 gas. O:C ratio of product oil can readily be obtained using crude lignin residual in such a process at levels 0.20 or lower....

  12. Heterogenous expression of Pyrus pyrifolia PpCAD2 and PpEXP2 in tobacco impacts lignin accumulation in transgenic plants.

    Science.gov (United States)

    Wang, Yuling; Zhang, Xinfu; Yang, Shaolan; Wang, Caihong; Lu, Guilong; Wang, Ran; Yang, Yingjie; Li, Dingli

    2017-12-30

    Lignin, a natural macromolecular compound, plays an important role in the texture and taste of fruit. Hard end is a physiological disorder of pear fruit, in which the level of lignification in fruit tissues is dramatically elevated. Cinnamyl alcohol dehydrogenase and expansin genes (PpCAD2 and PpEXP2, respectively) exhibit higher levels of expression in 'Whangkeumbae' (Pyrus pyrifolia) pear fruit exhibiting this physiological disorder, relative to control fruit without symptoms. These genes were isolated from pear fruit and subsequently expressed in tobacco (Nicotiana tabacum) to investigate their function. Histochemical staining for lignin revealed that the degree of lignification in leaf veins and stem tissues increased in plants transformed with sense constructs and decreased in plants transformed with antisense constructs of PpCAD2. The expression of native NtCADs was also inhibited in the antisense PpCAD2 transgenic tobacco. Sense and antisense PpCAD2 transgenic tobacco exhibited an 86.7% increase and a 60% decrease in CAD activity, respectively, accompanied by a complementary response in lignin content in root tissues. The basal portion of the stem in PpEXP2 transgenic tobacco was bent and highly lignified. Additionally, the level of cellulose also increased in the stem of PpEXP2 transgenic tobacco. Collectively, these results suggested that PpCAD2 and PpEXP2 genes play a significant role in lignin accumulation in transgenic tobacco plants, and it is inferred that these two genes may also participate in the increased lignification observed in hard end pear fruit. Copyright © 2017. Published by Elsevier B.V.

  13. Oxidative polymerization of lignins by laccase in water-acetone mixture.

    Science.gov (United States)

    Fiţigău, Ionița Firuța; Peter, Francisc; Boeriu, Carmen Gabriela

    2013-01-01

    The enzymatic oxidative polymerization of five technical lignins with different molecular properties, i.e. Soda Grass/Wheat straw Lignin, Organosolv Hardwood Lignin, Soda Wheat straw Lignin, Alkali pretreated Wheat straw Lignin, and Kraft Softwood was studied. All lignins were previously fractionated by acetone/water 50:50 (v/v) and the laccase-catalyzed polymerization of the low molecular weight fractions (Mw Reactivity of lignin substrates in laccase-catalyzed reactions was determined by monitoring the oxygen consumption. The oxidation reactions in 50% acetone in water mixture proceed with high rate for all tested lignins. Polymerization products were analyzed by size exclusion chromatography, FT-IR, and (31)P-NMR and evidence of important lignin modifications after incubation with laccase. Lignin polymers with higher molecular weight (Mw up to 17500 g/mol) were obtained. The obtained polymers have potential for applications in bioplastics, adhesives and as polymeric dispersants.

  14. Electrochemical synthesis and characterization of bilayers of poly(O-aminophenol/ polypyrrole/lignin composites for enhanced charge storage in supercapacitors

    Directory of Open Access Journals (Sweden)

    S. Admassie

    2016-02-01

    Full Text Available Using simple electrosynthesis methods a single and bilayer of conducting polymers, polypyrrole and poly(o-aminophenol with biopolymer lignin hybrid composites were formed on gold electrodes. The specific capacitance of the single polymer-lignin composite value of 400 F/g obtained from galvanostatic charge-discharge experiment at 1 A/g is improved to a value of 514 F/g in the bilayer polymer-lignin composite systems. The charge capacity is also improved from 61 mAh/g to 121 mAh/g by forming a bilayer of conducting polymers. Moreover, the charge retention during self-discharge is improved in the bilayer system. DOI: http://dx.doi.org/10.4314/bcse.v30i1.15

  15. Theoretical Approaches to Lignin Chemistry

    OpenAIRE

    Shevchenko, Sergey M.

    1994-01-01

    A critical review is presented of the applications of theoretical methods to the studies of the structure and chemical reactivity of lignin, including simulation of macromolecular properties, conformational calculations, quantum chemical analyses of electronic structure, spectra and chemical reactivity. Modern concepts of spatial organization and chemical reactivity of lignins are discussed.

  16. Reactivity of bacterial and fungal laccases with lignin under alkaline conditions.

    Science.gov (United States)

    Moya, Raquel; Saastamoinen, Päivi; Hernández, Manuel; Suurnäkki, Anna; Arias, Enriqueta; Mattinen, Maija-Liisa

    2011-11-01

    The ability of Streptomyces ipomoea laccase to polymerize secoisolariciresinol lignan and technical lignins was assessed. The reactivity of S. ipomoea laccase was also compared to that of low redox fungal laccase from Melanocarpus albomyces using low molecular mass p-coumaric, ferulic and sinapic acid as well as natural (acetosyringone) and synthetic 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) mediators as substrates. Oxygen consumption measurement, MALDI-TOF MS and SEC were used to follow the enzymatic reactions at pH 7, 8, 9 and 10 at 30°C and 50°C. Polymerization of lignins and lignan by S. ipomoea laccase under alkaline reaction conditions was observed, and was enhanced in the presence of acetosyringone almost to the level obtained with M. albomyces laccase without mediator. Reactivities of the enzymes towards acetosyringone and TEMPO were similar, suggesting exploitation of the compounds and low redox laccase in lignin valorization under alkaline conditions. The results have scientific impact on basic research of laccases. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Exploring the potential of high resolution mass spectrometry for the investigation of lignin-derived phenol substitutes in phenolic resin syntheses.

    Science.gov (United States)

    Dier, Tobias K F; Fleckenstein, Marco; Militz, Holger; Volmer, Dietrich A

    2017-05-01

    Chemical degradation is an efficient method to obtain bio-oils and other compounds from lignin. Lignin bio-oils are potential substitutes for the phenol component of phenol formaldehyde (PF) resins. Here, we developed an analytical method based on high resolution mass spectrometry that provided structural information for the synthesized lignin-derived resins and supported the prediction of their properties. Different model resins based on typical lignin degradation products were analyzed by electrospray ionization in negative ionization mode. Utilizing enhanced mass defect filter techniques provided detailed structural information of the lignin-based model resins and readily complemented the analytical data from differential scanning calorimetry and thermogravimetric analysis. Relative reactivity and chemical diversity of the phenol substitutes were significant determinants of the outcome of the PF resin synthesis and thus controlled the areas of application of the resulting polymers. Graphical abstract ᅟ.

  18. Preparation of lignin-based carbon aerogels as biomaterials for nano-supercapacitor

    Science.gov (United States)

    Yang, Bong Suk; Kang, Kyu-Young; Jeong, Myung-Joon

    2017-10-01

    Kraft and organosolv lignins, generally produced in chemical pulping and bio-refinery processes of lignocellulosic biomass, were used to prepare lignin-based carbon aerogels for supercapacitors as raw materials. The difference between lignins and lignin-based aerogels were compared by analyzing physical and chemical properties, including molecular weight, polydispersity, and reactivity with formaldehyde. Also, density, shrinkage, Brunauer-Emmett-Teller (BET) surface area and scanning electron microscope (SEM) images of the lignin-based aerogel were investigated. Kraft lignin consisting of coniferyl alcohol (G) and p-coumaryl alcohol (H) increased the reactivity of formaldehyde, formed a hydrogel well (porosity > 0.45), and specific surface area higher than organosolv lignin. In the case of kraft lignin, there were irregular changes such as oxidation and condensation in the pulping process. However, reaction sites with aromatic rings in lignin impacted the production of aerogel and required a long gelation period. The molecular weight of lignin influences the gelation time in producing lignin-based aerogel, and lignin composition affects the BET surface area and pore structures of the lignin-based carbon aerogels.

  19. Loss of function of cinnamyl alcohol dehydrogenase 1 leads to unconventional lignin and a temperature-sensitive growth defect in Medicago truncatula.

    Science.gov (United States)

    Zhao, Qiao; Tobimatsu, Yuki; Zhou, Rui; Pattathil, Sivakumar; Gallego-Giraldo, Lina; Fu, Chunxiang; Jackson, Lisa A; Hahn, Michael G; Kim, Hoon; Chen, Fang; Ralph, John; Dixon, Richard A

    2013-08-13

    There is considerable debate over the capacity of the cell wall polymer lignin to incorporate unnatural monomer units. We have identified Tnt1 retrotransposon insertion mutants of barrel medic (Medicago truncatula) that show reduced lignin autofluorescence under UV microscopy and red coloration in interfascicular fibers. The phenotype is caused by insertion of retrotransposons into a gene annotated as encoding cinnamyl alcohol dehydrogenase, here designated M. truncatula CAD1. NMR analysis indicated that the lignin is derived almost exclusively from coniferaldehyde and sinapaldehyde and is therefore strikingly different from classical lignins, which are derived mainly from coniferyl and sinapyl alcohols. Despite such a major alteration in lignin structure, the plants appear normal under standard conditions in the greenhouse or growth chamber. However, the plants are dwarfed when grown at 30 °C. Glycome profiling revealed an increased extractability of some xylan and pectin epitopes from the cell walls of the cad1-1 mutant but decreased extractability of others, suggesting that aldehyde-dominant lignin significantly alters cell wall structure.

  20. Thermal Decomposition Mechanisms of Lignin Model Compounds: From Phenol to Vanillin

    Science.gov (United States)

    Scheer, Adam Michael

    Lignin is a complex, aromatic polymer abundant in cellulosic biomass (trees, switchgrass etc.). Thermochemical breakdown of lignin for liquid fuel production results in undesirable polycyclic aromatic hydrocarbons that lead to tar and soot byproducts. The fundamental chemistry governing these processes is not well understood. We have studied the unimolecular thermal decomposition mechanisms of aromatic lignin model compounds using a miniature SiC tubular reactor. Products are detected and characterized using time-of-flight mass spectrometry with both single photon (118.2 nm; 10.487 eV) and 1 + 1 resonance-enhanced multiphoton ionization (REMPI) as well as matrix isolation infrared spectroscopy. Gas exiting the heated reactor (300 K--1600 K) is subject to a free expansion after a residence time of approximately 100 micros. The expansion into vacuum rapidly cools the gas mixture and allows the detection of radicals and other highly reactive intermediates. By understanding the unimolecular fragmentation patterns of phenol (C6H5OH), anisole (C6H 5OCH3) and benzaldehyde (C6H5CHO), the more complicated thermocracking processes of the catechols (HO-C 6H4-OH), methoxyphenols (HO-C6H4-OCH 3) and hydroxybenzaldehydes (HO-C6H4-CHO) can be interpreted. These studies have resulted in a predictive model that allows the interpretation of vanillin, a complex phenolic ether containing methoxy, hydroxy and aldehyde functional groups. This model will serve as a guide for the pyrolyses of larger systems including lignin monomers such as coniferyl alcohol. The pyrolysis mechanisms of the dimethoxybenzenes (H3C-C 6H4-OCH3) and syringol, a hydroxydimethoxybenzene have also been studied. These results will aid in the understanding of the thermal fragmentation of sinapyl alcohol, the most complex lignin monomer. In addition to the model compound work, pyrolyisis of biomass has been studied via the pulsed laser ablation of poplar wood. With the REMPI scheme, aromatic lignin decomposition

  1. Mineralisation of 14C-labelled synthetic lignin and ligninolytic enzyme activities of litter-decomposing basidiomycetous fungi.

    Science.gov (United States)

    Steffen, K T; Hofrichter, M; Hatakka, A

    2000-12-01

    Within a screening program, 27 soil litter-decomposing basidiomycetes were tested for ligninolytic enzyme activities using agar-media containing 2,2'-azinobis(3-ethylbenzthiazoline-6-sulphonate), a humic acid or Mn2+ ions as indicator substrates. Most active species were found within the family Strophariaceae (Agrocybe praecox, Stropharia coronilla, S. rugosoannulata) and used for mineralisation experiments with a 14C-ring-labelled synthetic lignin (14C-DHP). The fungi mineralised around 25% of the lignin to 14CO2 within 12 weeks of incubation in a straw environment; about 20% of the lignin was converted to water-soluble fragments. Mn-peroxidase was found to be the predominant ligninolytic enzyme of all three fungi in liquid culture and its production was strongly enhanced in the presence of Mn2+ ions. The results of this study demonstrate that certain ubiquitous litter-decomposing basidiomycetes possess ligninolytic activities similar to the wood-decaying white-rot fungi, the most efficient lignin degraders in nature.

  2. Chemical factors that control lignin polymerization.

    Science.gov (United States)

    Sangha, Amandeep K; Davison, Brian H; Standaert, Robert F; Davis, Mark F; Smith, Jeremy C; Parks, Jerry M

    2014-01-09

    Lignin is a complex, branched polymer that reinforces plant tissue. Understanding the factors that govern lignin structure is of central importance to the development of technologies for converting lignocellulosic biomass into fuels because lignin imparts resistance to chemical, enzymatic, and mechanical deconstruction. Lignin is formed by enzymatic oxidation of phenolic monomers (monolignols) of three main types, guaiacyl (G), syringyl (S), and p-hydroxyphenyl (H) subunits. It is known that increasing the relative abundance of H subunits results in lower molecular weight lignin polymers and hence more easily deconstructed biomass, but it is not known why. Here, we report an analysis of frontier molecular orbitals in mono-, di-, and trilignols, calculated using density functional theory, which points to a requirement of strong p-electron density on the reacting phenolic oxygen atom of the neutral precursor for enzymatic oxidation to occur. This model is consistent with a proton-coupled electron transfer (PCET) mechanism and for the first time explains why H subunits in certain linkages (β-β or β-5) react poorly and tend to "cap" the polymer. In general, β-5 linkages with either a G or H terminus are predicted to inhibit elongation. More broadly, the model correctly accounts for the reactivity of the phenolic groups in a diverse set of dilignols comprising H and G subunits. Thus, we provide a coherent framework for understanding the propensity toward growth or termination of different terminal subunits in lignin.

  3. Understanding the fast pyrolysis of lignin.

    Science.gov (United States)

    Patwardhan, Pushkaraj R; Brown, Robert C; Shanks, Brent H

    2011-11-18

    In the present study, pyrolysis of corn stover lignin was investigated by using a micro-pyrolyzer coupled with a GC-MS/FID (FID=flame ionization detector). The system has pyrolysis-vapor residence times of 15-20 ms, thus providing a regime of minimal secondary reactions. The primary pyrolysis product distribution obtained from lignin is reported. Over 84 % mass balance and almost complete closure on carbon balance is achieved. In another set of experiments, the pyrolysis vapors emerging from the micro-pyrolyzer are condensed to obtain lignin-derived bio-oil. The chemical composition of the bio-oil is analyzed by using GC-MS and gel permeation chromatography techniques. The comparison between results of two sets of experiments indicates that monomeric compounds are the primary pyrolysis products of lignin, which recombine after primary pyrolysis to produce oligomeric compounds. Further, the effect of minerals (NaCl, KCl, MgCl(2), and CaCl(2)) and temperature on the primary pyrolysis product distribution is investigated. The study provides insights into the fundamental mechanisms of lignin pyrolysis and a basis for developing more descriptive models of biomass pyrolysis. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Mn(II) regulation of lignin peroxidases and manganese-dependent peroxidases from lignin-degrading white rot fungi

    International Nuclear Information System (INIS)

    Bonnarme, P.; Jeffries, T.W.

    1990-01-01

    Two families of peroxidases-lignin peroxidase (LiP) and manganese-dependent lignin peroxidase (MnP)-are formed by the lignin-degrading white rot basidiomycete Phanerochaete chrysosporium and other white rot fungi. Isoenzymes of these enzyme families carry out reactions important to the biodegradation of lignin. This research investigated the regulation of LiP and MnP production by Mn(II). In liquid culture, LiP titers varied as an inverse function of and MnP titers varied as a direct function of the Mn(II) concentration. The extracellular isoenzyme profiles differed radically at low and high Mn(II) levels, whereas other fermentation parameters, including extracellular protein concentrations, the glucose consumption rate, and the accumulation of cell dry weight, did not change significantly with the Mn(II) concentration. In the absence of Mn(II), extracellular LiP isoenzymes predominated, whereas in the presence of Mn(II), MnP isoenzymes were dominant. The release of 14 CO 2 from 14 C-labeled dehydrogenative polymerizate lignin was likewise affected by Mn(II). The rate of 14 CO 2 release increased at low Mn(II) and decreased at high Mn(II) concentrations. This regulatory effect of Mn(II) occurred with five strains of P. chrysosporium, two other species of Phanerochaete, three species of Phlebia, Lentinula edodes, and Phellinus pini

  5. Structure, organization, and transcriptional regulation of a family of copper radical oxidase genes in the lignin-degrading basidiomycete Phanerochaete chrysosporium

    Science.gov (United States)

    Amber Vanden Wymelenberg; Grzegorz Sabat; Michael Mozuch; Philip J. Kersten; Dan Cullen; Robert A. Blanchette

    2006-01-01

    The white rot basidiomycete Phanerochaete chrysosporium produces an array of nonspecific extracellular enzymes thought to be involved in lignin degradation, including lignin peroxidases, manganese peroxidases, and the H2O2-generating copper radical oxidase, glyoxal oxidase (GLX). Preliminary analysis of the P. chrysosporium draft genome had identified six sequences...

  6. Effect of lignin chemistry on the enzymatic hydrolysis of woody biomass.

    Science.gov (United States)

    Yu, Zhiying; Gwak, Ki-Seob; Treasure, Trevor; Jameel, Hasan; Chang, Hou-min; Park, Sunkyu

    2014-07-01

    The impact of lignin-derived inhibition on enzymatic hydrolysis is investigated by using lignins isolated from untreated woods and pretreated wood pulps. A new method, biomass reconstruction, for which isolated lignins are precipitated onto bleached pulps to mimic lignocellulosic biomass, is introduced, for the first time, to decouple the lignin distribution issue from lignin chemistry. Isolated lignins are physically mixed and reconstructed with bleached pulps. Lignins obtained from pretreated woods adsorb two to six times more cellulase than lignins obtained from untreated woods. The higher adsorption of enzymes on lignin correlates with decreased carbohydrate conversion in enzymatic hydrolysis. In addition, the reconstructed softwood substrate has a lower carbohydrate conversion than the reconstructed hardwood substrate. The degree of condensation of lignin increases significantly after pretreatment, especially with softwood lignins. In this study, the degree of condensation of lignin (0.02 to 0.64) and total OH groups in lignin (1.7 to 1.1) have a critical impact on cellulase adsorption (9 to 70%) and enzymatic hydrolysis (83.2 to 58.2%); this may provide insights into the more recalcitrant nature of softwood substrates. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Preparation and Characterization of Modified Soda Lignin with Polyethylene Glycol

    Directory of Open Access Journals (Sweden)

    Fangda Zhang

    2016-10-01

    Full Text Available Soda lignin does not have thermal flowing characteristics and it is impossible for it to be further thermally molded. To achieve the fusibility of soda lignin for fiber preparation by melt-spinning, an effective method for soda lignin modification was conducted by cooking it with polyethylene glycol (PEG 400 at various ratios. The higher the ratio of PEG that was used, the more PEG molecular chains were grafted at the alpha carbon of the soda lignin through ether bonds, resulting in lower thermal transition temperatures and more excellent fusibility. The modified soda lignin with a weight ratio of lignin to PEG of 1:4 exhibited a relative thermal stability of molten viscosity at selected temperatures. Thereafter, the resultant fusible soda lignin was successfully melt-spun into filaments with an average diameter of 33 ± 5 μm, which is smaller than that of some industrial lignins. Accordingly, it is possible to utilize soda lignin to produce fibrous carbonaceous materials.

  8. New techniques for the characterization of lignins

    International Nuclear Information System (INIS)

    Javor, T.

    2001-09-01

    In the present work new techniques for the characterization of lignins, ligninsulfonates as well as lignin degradation products with capillary electrophoresis (CE), size exclusion chromatography (SEC) and mass spectrometry (ESI-MS, APCI-MS and MALDI-MS) are described. After an overview on wood and wood pulping the development of microemulsion electrokinetic chromatography (MEEKC) for the investigation of low-molecular-mass lignin degradation compounds is described. This method is suited for the analysis of phenolic compounds as well as for non-phenolic compounds in this kind of samples. Using a carrier electrolyte system consisting of 1-butanol/n-heptane/sodiumdodeylsulfate (SDS)/20 mM borate (6.61/0.81/1.66/90,29 % (w/w)) pH 9.2 it was possible to separate 14 lignin degradation compounds (2-methoxyphenol, 3,4,5-trimethoxyphenol, 2,6-dimethoxyphenol, 3,4-dimethoxybenzaldehyde, 3,4-dimethoxyacetophenone, 3,4,5-trimethoxybenzaldehyde, 3,4,5-trimethoxyacetophenone, 3-(3,4-dimethoxyphenyl)-2-propen-1-ol, 4-methoxyacetophenone, 3,5-Dimethoxy-4-hydroxyacetophenone, acetovanillone, syringaldehyde, vanillin, 4-hydroxybenzaldehyde and 1-(3-methoxy-4-hydroxyphenyl)-2-(2-methoxyphenoxy)-ethanol). In addition the advantages and disadvantages of microemulsions are discussed in comparison with carrier electrolytes containing micelles. Subsequently, the results from size exclusion chromatographic measurements are presented. SEC using modern high-performance poly(styrene-divinylbenzene) gels as stationary phase and 0.1 M NaOH as mobile phase allows efficient separations and good characterization of lignins and ligninsulfonates. Adsorption effects are practical negligible. SEC yields results which are independent of the charge of lignins or ligninsulfonates, so that this technique looks complementary to capillary electrophoresis. For the characterization of intact lignins and ligninsulfonates by capillary zone electrophoretic techniques, carrier electrolytes in the the pH range 10

  9. Analytical methods for lignin characterization - Differential scanning calorimetry

    NARCIS (Netherlands)

    Koullas, D.P.; Koukios, E.G.; Avgerinos, E.; Abaecherli, A.; Gosselink, R.; Vasile, C.; Lehnen, R.; Saake, B.; Suren, J.

    2006-01-01

    Results of a round robin on lignin thermal analyses are reported. Six laboratories have conducted thermal analyses of four lignin types to determine their cp values and softening points, and to study the thermal behaviour, materials endo- and exotherms included. The lignin types examined were wood

  10. Catalytic Oxidation and Depolymerization of Lignin in Aqueous Ionic Liquid

    Energy Technology Data Exchange (ETDEWEB)

    Das, Lalitendu [Biosystems and Agricultural Engineering, University of Kentucky, Lexington, KY (United States); Xu, Siquan [Biosystems and Agricultural Engineering, University of Kentucky, Lexington, KY (United States); College of Chemical Engineering, Nanjing Forestry University, Nanjing (China); Shi, Jian, E-mail: j.shi@uky.edu [Biosystems and Agricultural Engineering, University of Kentucky, Lexington, KY (United States)

    2017-08-10

    Lignin is an integral part of the plant cell wall, which provides rigidity to plants, also contributes to the recalcitrance of the lignocellulosic biomass to biochemical and biological deconstruction. Lignin is a promising renewable feedstock for aromatic chemicals; however, an efficient and economic lignin depolymerization method needs to be developed to enable the conversion. In this study, we investigated the depolymerization of alkaline lignin in aqueous 1-ethyl-3-methylimidazolium acetate [C{sub 2}C{sub 1}Im][OAc] under oxidizing conditions. Seven different transition metal catalysts were screened in presence of H{sub 2}O{sub 2} as oxidizing agent in a batch reactor. CoCl{sub 2} and Nb{sub 2}O{sub 5} proved to be the most effective catalysts in degrading lignin to aromatic compounds. A central composite design was used to optimize the catalyst loading, H{sub 2}O{sub 2} concentration, and temperature for product formation. Results show that lignin was depolymerized, and the major degradation products found in the extracted oil were guaiacol, syringol, vanillin, acetovanillone, and homovanillic acid. Lignin streams were characterized by Fourier transform infrared spectroscopy and gel permeation chromatography to determine effects of the experimental parameters on lignin depolymerization. The weight-average molecular weight (M{sub w}) of liquid stream lignin after oxidation, for CoCl{sub 2} and Nb{sub 2}O{sub 5} catalysts were 1,202 and 1,520 g mol{sup −1}, respectively, lower than that of Kraft lignin. Polydispersity index of the liquid stream lignin increased as compared with Kraft lignin, indicating wide span of the molecular weight distribution as a result of lignin depolymerization. Results from this study provide insights into the role of oxidant and transition metal catalysts and the oxidative degradation reaction sequence of lignin toward product formation in presence of aqueous ionic liquid.

  11. Catalytic Oxidation and Depolymerization of Lignin in Aqueous Ionic Liquid

    International Nuclear Information System (INIS)

    Das, Lalitendu; Xu, Siquan; Shi, Jian

    2017-01-01

    Lignin is an integral part of the plant cell wall, which provides rigidity to plants, also contributes to the recalcitrance of the lignocellulosic biomass to biochemical and biological deconstruction. Lignin is a promising renewable feedstock for aromatic chemicals; however, an efficient and economic lignin depolymerization method needs to be developed to enable the conversion. In this study, we investigated the depolymerization of alkaline lignin in aqueous 1-ethyl-3-methylimidazolium acetate [C 2 C 1 Im][OAc] under oxidizing conditions. Seven different transition metal catalysts were screened in presence of H 2 O 2 as oxidizing agent in a batch reactor. CoCl 2 and Nb 2 O 5 proved to be the most effective catalysts in degrading lignin to aromatic compounds. A central composite design was used to optimize the catalyst loading, H 2 O 2 concentration, and temperature for product formation. Results show that lignin was depolymerized, and the major degradation products found in the extracted oil were guaiacol, syringol, vanillin, acetovanillone, and homovanillic acid. Lignin streams were characterized by Fourier transform infrared spectroscopy and gel permeation chromatography to determine effects of the experimental parameters on lignin depolymerization. The weight-average molecular weight (M w ) of liquid stream lignin after oxidation, for CoCl 2 and Nb 2 O 5 catalysts were 1,202 and 1,520 g mol −1 , respectively, lower than that of Kraft lignin. Polydispersity index of the liquid stream lignin increased as compared with Kraft lignin, indicating wide span of the molecular weight distribution as a result of lignin depolymerization. Results from this study provide insights into the role of oxidant and transition metal catalysts and the oxidative degradation reaction sequence of lignin toward product formation in presence of aqueous ionic liquid.

  12. Characteristics of Lignin from Flax Shives as Affected by Extraction Conditions

    Science.gov (United States)

    Ross, Kelly; Mazza, Giuseppe

    2010-01-01

    Lignin, a polyphenolic molecule, is a major constituent of flax shives. This polyphenolic molecular structure renders lignin a potential source of a variety of commercially viable products such as fine chemicals. This work compares the performance of different lignin isolation methods. Lignin from flax shive was isolated using both conventional alkaline extraction method and a novel experimental pressurized low polarity water (PLPW) extraction process. The lignin yields and chemical composition of the lignin fractions were determined. The conventional alkali treatment with 1.25 M NaOH, heated at 80 °C for 5 h, extracted 92 g lignin per kg flax shives, while lignin yields from the PLPW extracts ranged from 27 to 241 g lignin per kg flax shives. The purity and monomeric composition of the lignins obtained from the different extraction conditions was assessed via UV spectroscopy and alkaline nitrobenzene oxidation. Lignin obtained from conventional alkali treatment with 1.25 M NaOH, heated at 80 °C for 5 h was of low purity and exhibited the lowest yields of nitrobenzene oxidation products. With respect to alkali assisted PLPW extractions, temperature created an opposing effect on lignin yield and nitrobenzene oxidation products. More lignin was extracted as temperature increased, yet the yield of nitrobenzene oxidation products decreased. The low yield of nitrobenzene oxidation products may be attributed to either the formation of condensed structures or the selective dissolution of condensed structures of lignin during the pressurized alkaline high temperature treatment. Analytical pyrolysis, using pyroprobe GC-MS, was used to investigate the molecular composition of the lignin samples. The total yield of pyrolysis lignin products was 13.3, 64.7, and 30.5% for the 1.25 M NaOH extracted lignin, alkaline assisted PLPW extracted lignin, and the unprocessed flax shives, respectively. Key lignin derived compounds such as guaiacol, 4-vinyl guaiacol, 4-methyl guaiacol

  13. Environmental economics of lignin derived transport fuels

    OpenAIRE

    Obydenkova, SV; Kouris, P Panagiotis; Hensen, EJM Emiel; Heeres, Hero J; Boot, MD Michael

    2017-01-01

    This paper explores the environmental and economic aspects of fast pyrolytic conversion of lignin, obtained from 2G ethanol plants, to transport fuels for both the marine and automotive markets. Various scenarios are explored, pertaining to aggregation of lignin from several sites, alternative energy carries to replace lignin, transport modalities, and allocation methodology. The results highlight two critical factors that ultimately determine the economic and/or environmental fuel viability....

  14. Characterization of the lignin polymer in Brassicaceae family

    Directory of Open Access Journals (Sweden)

    S. Hemmati

    2017-04-01

    Full Text Available Background and objectives: Residues of medicinal plants after extraction and weeds are suitable candidates for bioethanol production. Significant barriers exist to make the conversion of lignocellulosic feedstock to biofuel cost effective and environmentally friendly; one of which is the lignin polymer. Brassicaceae family is one of the potential targets for biofuel production. The structural characteristics of lignin from Hirschfeldia incana, Sisymbrium altissimum and Cardaria draba were studied in comparison to that of Brassica napus. Methods: Lignin deposition was observed by phloroglucinol and Mäule staining. The total lignin content was determined by Klason method. Maximum UV absorbance and FT-IR spectra were compared. Ratio of syringyl to guaiacyl lignin (S/G ratio as a metric of lignin digestibility was determined by DFRC followed by GC-MS analysis. 1H-NMR spectra of the total lignin was compared with other spectroscopic methods. Results: Staining of thestem cross sections of C. draba showed higher G units in contrast to the higher S units in S. altissimum which was in agreement with 1H-NMR analysis. Total lignin content for H. incana, C. draba and S. altissimum was 27.10%, 23.8% and 24.5%, respectively. The specific maximum UV absorbance appeared between 230-260 nm. FT-IR analysis confirmed the presence of more aromatic structures in the seed maturation stage than the flowering stage. S/G ratio was 0.26, 0.10 and 0.22 for H. incana, C. draba and S. altissimum, respectively.  Conclusion: Except Cardaria draba with the predominance of G subunits in lignin polymer, Hirschfeldia incana and Sisymbrium altissimum are suitable candidates for bioethanol production.

  15. Alkali-treated kraft lignin as a component in flakeboard eesins

    Science.gov (United States)

    Mon-Lin Kuo; Chung-Yun Hse; Dee-Hua Huang

    1991-01-01

    Southern pine kraft lignin was reacted with NaOH (15 and 20% based on dry lignin) at 170, 200, and 250°C for 30 and 60 min. Sweetgum flake boards bonded with phenolic resins containing 50% hydroxymethylated lignin prepared from some of the alkali treated lignins were compared with boards bonded with a neat PF resin. Results indicate that boards bonded with lignin-...

  16. Bacterial enzymes involved in lignin degradation

    NARCIS (Netherlands)

    de Gonzalo, Gonzalo; Colpa, Dana I; Habib, Mohamed H M; Fraaije, Marco W

    2016-01-01

    Lignin forms a large part of plant biomass. It is a highly heterogeneous polymer of 4-hydroxyphenylpropanoid units and is embedded within polysaccharide polymers forming lignocellulose. Lignin provides strength and rigidity to plants and is rather resilient towards degradation. To improve the

  17. Effective release of lignin fragments from lignocellulose by lewis acid metal triflates in the lignin-first approach

    NARCIS (Netherlands)

    Huang, X.; Zhu, J.; Koranyi, T.I.; Boot, M.D.; Hensen, E.J.M.

    2016-01-01

    Adding value to lignin, the most complex and recalcitrant fraction in lignocellulosic biomass, is highly relevant to costefficient operation of biorefineries. We report the use of homogeneous metal triflates to rapidly release lignin from biomass. Combined with metal-catalyzed hydrogenolysis, the

  18. Transgenic poplars with reduced lignin show impaired xylem conductivity, growth efficiency and survival

    Science.gov (United States)

    Steven L. Voelker; Barbara Lachenbruch; Frederick C. Meinzer; Peter Kitin; Steven H. Strauss

    2011-01-01

    We studied xylem anatomy and hydraulic architecture in 14 transgenic insertion events and a control line of hybrid poplar (Populus spp.) that varied in lignin content. Transgenic events had different levels of down-regulation of two genes encoding 4-coumarate:coenzyme A ligase (4CL). Two-year-old trees were characterized after...

  19. Pyrolysis-gas chromatography-mass spectrometry of isolated, synthetic and degraded lignins

    Energy Technology Data Exchange (ETDEWEB)

    Saiz-Jimenez, C.; De Leeuw, J.W.

    1984-01-01

    Curie-point pyrolysis-gas chromatography-mass spectrometry was applied to study the chemical structure of sound and fungus degraded, industrial and synthetic lignins. Pyrolysis products reflected in some detail the structural units present in the lignin polymer. Thus, sound spruce lignin yielded trans-isoeugenol coniferaldehyde and trans-coniferyl alcohol as major pyrolysis products. Biodegraded lignin yielded oxidized units, including vanillin, acetoguaiacone, methyl vanillate, propioguaiacone, vanilloyl methyl ketone and vanillic acid as major products. Kraft lignin also showed evidence of oxidation, although not as much as the biodegraded lignin. Major products from this industrial lignin were guaiacol, methylguaiacol, vinylguaiacol and homovanillic acid. Results indicated that synthetic lignin duplicates fairly well the structure of natural lignin. However, coniferylaldehyde and trans-coniferyl alcohol were the dominant products only from the synthetic lignin, indicating the presence of large amounts of coniferyl alcohol and coniferylaldehyde end groups. 21 references.

  20. Isolation and Characterization of Gramineae and Fabaceae Soda Lignins.

    Science.gov (United States)

    Domínguez-Robles, Juan; Sánchez, Rafael; Espinosa, Eduardo; Savy, Davide; Mazzei, Pierluigi; Piccolo, Alessandro; Rodríguez, Alejandro

    2017-02-04

    Some agricultural residues such as wheat or barley straw, as well as certain fast-growing plants like Leucaena leucocephala and Chamaecytisus proliferus , could be used as raw materials for the paper industry as an alternative to traditional plants (eucalyptus, pine, etc.). In the present study, four types of lignin obtained from the spent liquors produced by the pulping processes using the abovementioned feedstocks were isolated and characterized. Lignin samples were acquired through an acid precipitation from these spent liquors. The characterization of the precipitated lignin samples were performed using a Fourier transform infrared spectroscopy (FT-IR) and both liquid- and solid-state nuclear magnetic resonance spectroscopy (NMR) to analyse the chemical structure, and thermogravimetric analysis (TGA) for determining the thermal properties. Additionally, chemical composition of lignin fractions was also measured. Even though they were of different botanical origin, all the studied samples except for wheat straw lignin had a similar chemical composition and thermal behaviour, and identical chemical structure. Wheat straw lignin showed a greater amount of Klason lignin and lower carbohydrate content. Furthermore, this lignin sample showed a higher thermal stability and significantly different cross-peak patterns in the 2D-NMR experiments. The molecular structures corresponding to p -coumarate (PCA), ferulate (FA) and cinnamyl aldehyde end-groups (J) were only detected in wheat isolated lignin.

  1. Isolation and Characterization of Gramineae and Fabaceae Soda Lignins

    Science.gov (United States)

    Domínguez-Robles, Juan; Sánchez, Rafael; Espinosa, Eduardo; Savy, Davide; Mazzei, Pierluigi; Piccolo, Alessandro; Rodríguez, Alejandro

    2017-01-01

    Some agricultural residues such as wheat or barley straw, as well as certain fast-growing plants like Leucaena leucocephala and Chamaecytisus proliferus, could be used as raw materials for the paper industry as an alternative to traditional plants (eucalyptus, pine, etc.). In the present study, four types of lignin obtained from the spent liquors produced by the pulping processes using the abovementioned feedstocks were isolated and characterized. Lignin samples were acquired through an acid precipitation from these spent liquors. The characterization of the precipitated lignin samples were performed using a Fourier transform infrared spectroscopy (FT-IR) and both liquid- and solid-state nuclear magnetic resonance spectroscopy (NMR) to analyse the chemical structure, and thermogravimetric analysis (TGA) for determining the thermal properties. Additionally, chemical composition of lignin fractions was also measured. Even though they were of different botanical origin, all the studied samples except for wheat straw lignin had a similar chemical composition and thermal behaviour, and identical chemical structure. Wheat straw lignin showed a greater amount of Klason lignin and lower carbohydrate content. Furthermore, this lignin sample showed a higher thermal stability and significantly different cross-peak patterns in the 2D-NMR experiments. The molecular structures corresponding to p-coumarate (PCA), ferulate (FA) and cinnamyl aldehyde end-groups (J) were only detected in wheat isolated lignin. PMID:28165411

  2. Isolation and Characterization of Gramineae and Fabaceae Soda Lignins

    Directory of Open Access Journals (Sweden)

    Juan Domínguez-Robles

    2017-02-01

    Full Text Available Some agricultural residues such as wheat or barley straw, as well as certain fast-growing plants like Leucaena leucocephala and Chamaecytisus proliferus, could be used as raw materials for the paper industry as an alternative to traditional plants (eucalyptus, pine, etc.. In the present study, four types of lignin obtained from the spent liquors produced by the pulping processes using the abovementioned feedstocks were isolated and characterized. Lignin samples were acquired through an acid precipitation from these spent liquors. The characterization of the precipitated lignin samples were performed using a Fourier transform infrared spectroscopy (FT-IR and both liquid- and solid-state nuclear magnetic resonance spectroscopy (NMR to analyse the chemical structure, and thermogravimetric analysis (TGA for determining the thermal properties. Additionally, chemical composition of lignin fractions was also measured. Even though they were of different botanical origin, all the studied samples except for wheat straw lignin had a similar chemical composition and thermal behaviour, and identical chemical structure. Wheat straw lignin showed a greater amount of Klason lignin and lower carbohydrate content. Furthermore, this lignin sample showed a higher thermal stability and significantly different cross-peak patterns in the 2D-NMR experiments. The molecular structures corresponding to p-coumarate (PCA, ferulate (FA and cinnamyl aldehyde end-groups (J were only detected in wheat isolated lignin.

  3. Lignosulfonate To Enhance Enzymatic Saccharification of Lignocelluloses: Role of Molecular Weight and Substrate Lignin

    Science.gov (United States)

    Haifeng Zhou; Hongming Lou; Dongjie Yang; J.Y. Zhu; Xueqing Qiu

    2013-01-01

    This study conducted an investigation of the effect of lignosulfonate (LS) on enzymatic saccharification of lignocelluloses. Two commercial LSs and one laboratory sulfonated kraft lignin were applied to Whatman paper, dilute acid and SPORL (sulfite pretreatment to overcome recalcitrance of lignocelluloses) pretreated aspen, and kraft alkaline and SPORL pretreated...

  4. Characterization of electrospun lignin based carbon fibers

    International Nuclear Information System (INIS)

    Poursorkhabi, Vida; Mohanty, Amar; Misra, Manjusri

    2015-01-01

    The production of lignin fibers has been studied in order to replace the need for petroleum based precursors for carbon fiber production. In addition to its positive environmental effects, it also benefits the economics of the industries which cannot take advantage of carbon fiber properties because of their high price. A large amount of lignin is annually produced as the byproduct of paper and growing cellulosic ethanol industry. Therefore, finding high value applications for this low cost, highly available material is getting more attention. Lignin is a biopolymer making about 15 – 30 % of the plant cell walls and has a high carbon yield upon carbonization. However, its processing is challenging due to its low molecular weight and also variations based on its origin and the method of separation from cellulose. In this study, alkali solutions of organosolv lignin with less than 1 wt/v% of poly (ethylene oxide) and two types of lignin (hardwood and softwood) were electrospun followed by carbonization. Different heating programs for carbonization were tested. The carbonized fibers had a smooth surface with an average diameter of less than 5 µm and the diameter could be controlled by the carbonization process and lignin type. Scanning electron microscopy (SEM) was used to study morphology of the fibers before and after carbonization. Thermal conductivity of a sample with amorphous carbon was 2.31 W/m.K. The electrospun lignin carbon fibers potentially have a large range of application such as in energy storage devices and water or gas purification systems

  5. Characterization of electrospun lignin based carbon fibers

    Energy Technology Data Exchange (ETDEWEB)

    Poursorkhabi, Vida; Mohanty, Amar; Misra, Manjusri [School of Engineering, Thornbrough Building, University of Guelph, Guelph, N1G 2W1, Ontario (Canada); Bioproducts Discovery and Development Centre, Department of Plant Agriculture, Crop Science Building, University of Guelph, Guelph, N1G 2W1, Ontario (Canada)

    2015-05-22

    The production of lignin fibers has been studied in order to replace the need for petroleum based precursors for carbon fiber production. In addition to its positive environmental effects, it also benefits the economics of the industries which cannot take advantage of carbon fiber properties because of their high price. A large amount of lignin is annually produced as the byproduct of paper and growing cellulosic ethanol industry. Therefore, finding high value applications for this low cost, highly available material is getting more attention. Lignin is a biopolymer making about 15 – 30 % of the plant cell walls and has a high carbon yield upon carbonization. However, its processing is challenging due to its low molecular weight and also variations based on its origin and the method of separation from cellulose. In this study, alkali solutions of organosolv lignin with less than 1 wt/v% of poly (ethylene oxide) and two types of lignin (hardwood and softwood) were electrospun followed by carbonization. Different heating programs for carbonization were tested. The carbonized fibers had a smooth surface with an average diameter of less than 5 µm and the diameter could be controlled by the carbonization process and lignin type. Scanning electron microscopy (SEM) was used to study morphology of the fibers before and after carbonization. Thermal conductivity of a sample with amorphous carbon was 2.31 W/m.K. The electrospun lignin carbon fibers potentially have a large range of application such as in energy storage devices and water or gas purification systems.

  6. Native lignin for bonding fiber boards - evaluation of bonding mechanisms in boards made from laccase-treated fibers of beech (Fagus sylvatica)

    DEFF Research Database (Denmark)

    Felby, Claus; Thygesen, Lisbeth Garbrecht; Sanadi, Anand

    2004-01-01

    indicate that lignin extractives are precipitated on the fiber surfaces. The improved bonding may be related to several factors, linked to a more lignin rich fiber surface, such as surface molecular entanglements and covalent bonding between fibers through cross-linking of radicals. (C) 2004 Published......The auto-adhesion of beech wood (Fagus sylvatica) fibers can be enhanced by a pretreatment of the fibers with a phenol oxidase enzyme. The mechanism of enzymatic catalyzed bonding is linked to the generation of stable radicals in lignin by oxidation. Fiberboards made from laccase-treated fibers...

  7. Manipulation of Guaiacyl and Syringyl Monomer Biosynthesis in an Arabidopsis Cinnamyl Alcohol Dehydrogenase Mutant Results in Atypical Lignin Biosynthesis and Modified Cell Wall Structure

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Nickolas A.; Tobimatsu, Yuki; Ciesielski, Peter N.; Ximenes, Eduardo; Ralph, John; Donohoe, Bryon S.; Ladisch, Michael; Chapple, Clint

    2015-08-01

    Modifying lignin composition and structure is a key strategy to increase plant cell wall digestibility for biofuel production. Disruption of the genes encoding both cinnamyl alcohol dehydrogenases (CADs), including CADC and CADD, in Arabidopsis thaliana results in the atypical incorporation of hydroxycinnamaldehydes into lignin. Another strategy to change lignin composition is downregulation or overexpression of ferulate 5-hydroxylase (F5H), which results in lignins enriched in guaiacyl or syringyl units, respectively. Here, we combined these approaches to generate plants enriched in coniferaldehyde-derived lignin units or lignins derived primarily from sinapaldehyde. The cadc cadd and ferulic acid hydroxylase1 (fah1) cadc cadd plants are similar in growth to wild-type plants even though their lignin compositions are drastically altered. In contrast, disruption of CAD in the F5H-overexpressing background results in dwarfism. The dwarfed phenotype observed in these plants does not appear to be related to collapsed xylem, a hallmark of many other lignin-deficient dwarf mutants. cadc cadd, fah1 cadc cadd, and cadd F5H-overexpressing plants have increased enzyme-catalyzed cell wall digestibility. Given that these CAD-deficient plants have similar total lignin contents and only differ in the amounts of hydroxycinnamaldehyde monomer incorporation, these results suggest that hydroxycinnamaldehyde content is a more important determinant of digestibility than lignin content.

  8. Manipulation of Guaiacyl and Syringyl Monomer Biosynthesis in an Arabidopsis Cinnamyl Alcohol Dehydrogenase Mutant Results in Atypical Lignin Biosynthesis and Modified Cell Wall Structure.

    Science.gov (United States)

    Anderson, Nickolas A; Tobimatsu, Yuki; Ciesielski, Peter N; Ximenes, Eduardo; Ralph, John; Donohoe, Bryon S; Ladisch, Michael; Chapple, Clint

    2015-08-01

    Modifying lignin composition and structure is a key strategy to increase plant cell wall digestibility for biofuel production. Disruption of the genes encoding both cinnamyl alcohol dehydrogenases (CADs), including CADC and CADD, in Arabidopsis thaliana results in the atypical incorporation of hydroxycinnamaldehydes into lignin. Another strategy to change lignin composition is downregulation or overexpression of ferulate 5-hydroxylase (F5H), which results in lignins enriched in guaiacyl or syringyl units, respectively. Here, we combined these approaches to generate plants enriched in coniferaldehyde-derived lignin units or lignins derived primarily from sinapaldehyde. The cadc cadd and ferulic acid hydroxylase1 (fah1) cadc cadd plants are similar in growth to wild-type plants even though their lignin compositions are drastically altered. In contrast, disruption of CAD in the F5H-overexpressing background results in dwarfism. The dwarfed phenotype observed in these plants does not appear to be related to collapsed xylem, a hallmark of many other lignin-deficient dwarf mutants. cadc cadd, fah1 cadc cadd, and cadd F5H-overexpressing plants have increased enzyme-catalyzed cell wall digestibility. Given that these CAD-deficient plants have similar total lignin contents and only differ in the amounts of hydroxycinnamaldehyde monomer incorporation, these results suggest that hydroxycinnamaldehyde content is a more important determinant of digestibility than lignin content. © 2015 American Society of Plant Biologists. All rights reserved.

  9. Structural characterization of lignin from grape stalks (Vitis vinifera L.).

    Science.gov (United States)

    Prozil, Sónia O; Evtuguin, Dmitry V; Silva, Artur M S; Lopes, Luísa P C

    2014-06-18

    The chemical structure of lignin from grape stalks, an abundant waste of winemaking, has been studied. The dioxane lignin was isolated from extractive- and protein-free grape stalks (Vitis vinifera L.) by modified acidolytic procedure and submitted to a structural analysis by wet chemistry (nitrobenzene and permanganate oxidation (PO)) and spectroscopic techniques. The results obtained suggest that grape stalk lignin is an HGS type with molar proportions of p-hydroxyphenyl (H), guaiacyl (G) and syringyl (S) units of 3:71:26. Structural analysis by (1)H and (13)C NMR spectroscopy and PO indicates the predominance of β-O-4' structures (39% mol) in grape stalk lignin together with moderate amounts of β-5', β-β, β-1', 5-5', and 4-O-5' structures. NMR studies also revealed that grape lignin should be structurally associated with tannins. The condensation degree of grape stalks lignin is higher than that of conventional wood lignins and lignins from other agricultural residues.

  10. Reductive Catalytic Fractionation of Corn Stover Lignin

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Eric M.; Katahira, Rui; Reed, Michelle; Resch, Michael G.; Karp, Eric M.; Beckham, Gregg T.; Román-Leshkov, Yuriy

    2016-12-05

    Reductive catalytic fractionation (RCF) has emerged as an effective biomass pretreatment strategy to depolymerize lignin into tractable fragments in high yields. We investigate the RCF of corn stover, a highly abundant herbaceous feedstock, using carbon-supported Ru and Ni catalysts at 200 and 250 degrees C in methanol and, in the presence or absence of an acid cocatalyst (H3PO4 or an acidified carbon support). Three key performance variables were studied: (1) the effectiveness of lignin extraction as measured by the yield of lignin oil, (2) the yield of monomers in the lignin oil, and (3) the carbohydrate retention in the residual solids after RCF. The monomers included methyl coumarate/ferulate, propyl guaiacol/syringol, and ethyl guaiacol/syringol. The Ru and Ni catalysts performed similarly in terms of product distribution and monomer yields. The monomer yields increased monotonically as a function of time for both temperatures. At 6 h, monomer yields of 27.2 and 28.3% were obtained at 250 and 200 degrees C, respectively, with Ni/C. The addition of an acid cocatalysts to the Ni/C system increased monomer yields to 32% for acidified carbon and 38% for phosphoric acid at 200 degrees C. The monomer product distribution was dominated by methyl coumarate regardless of the use of the acid cocatalysts. The use of phosphoric acid at 200 degrees C or the high temperature condition without acid resulted in complete lignin extraction and partial sugar solubilization (up to 50%) thereby generating lignin oil yields that exceeded the theoretical limit. In contrast, using either Ni/C or Ni on acidified carbon at 200 degrees C resulted in moderate lignin oil yields of ca. 55%, with sugar retention values >90%. Notably, these sugars were amenable to enzymatic digestion, reaching conversions >90% at 96 h. Characterization studies on the lignin oils using two-dimensional heteronuclear single quantum coherence nuclear magnetic resonance and gel permeation chromatrography revealed

  11. Selective Oxidation of Lignin Model Compounds.

    Science.gov (United States)

    Gao, Ruili; Li, Yanding; Kim, Hoon; Mobley, Justin K; Ralph, John

    2018-05-02

    Lignin, the planet's most abundant renewable source of aromatic compounds, is difficult to degrade efficiently to welldefined aromatics. We developed a microwave-assisted catalytic Swern oxidation system using an easily prepared catalyst, MoO 2 Cl 2 (DMSO) 2 , and DMSO as the solvent and oxidant. It demonstrated high efficiency in transforming lignin model compounds containing the units and functional groups found in native lignins. The aromatic ring substituents strongly influenced the selectivity of β-ether phenolic dimer cleavage to generate sinapaldehyde and coniferaldehyde, monomers not usually produced by oxidative methods. Time-course studies on two key intermediates provided insight into the reaction pathway. Owing to the broad scope of this oxidation system and the insight gleaned with regard to its mechanism, this strategy could be adapted and applied in a general sense to the production of useful aromatic chemicals from phenolics and lignin. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Loss of function of cinnamyl alcohol dehydrogenase 1 leads to unconventional lignin and a temperature-sensitive growth defect in Medicago truncatula

    OpenAIRE

    Zhao, Qiao; Tobimatsu, Yuki; Zhou, Rui; Pattathil, Sivakumar; Gallego-Giraldo, Lina; Fu, Chunxiang; Jackson, Lisa A.; Hahn, Michael G.; Kim, Hoon; Chen, Fang; Ralph, John; Dixon, Richard A.

    2013-01-01

    There is considerable debate over the capacity of the cell wall polymer lignin to incorporate unnatural monomer units. We have identified Tnt1 retrotransposon insertion mutants of barrel medic (Medicago truncatula) that show reduced lignin autofluorescence under UV microscopy and red coloration in interfascicular fibers. The phenotype is caused by insertion of retrotransposons into a gene annotated as encoding cinnamyl alcohol dehydrogenase, here designated M. truncatula CAD1. NMR analysis in...

  13. Formation of aromatic products at radiation-thermal destruction of lignin

    International Nuclear Information System (INIS)

    Metreveli, P.K.; Bludenko, A.V.; Ponomarev, A.V.

    2012-01-01

    Influence of electron irradiation on lignin destruction is studied. Hydrolyzed lignin and mixture of fatty acid triglycerides (FATG) have been irradiated by 8.5 MeV electrons. Comparative study of four variants of lignin destruction is carried out, they are pyrogenic distillation, post-radiation dry distillation, electron-beam distillation (EBD) and EBD at combined heating. The mechanism of lignin radiation-thermal transformation with guaiacol and creosol formation is considered. Lignin EBD is investigated depending on dose rate, absorbed dose, electroheating power and addition (FATG and chitin) content. It is pointed out, that lignin stimulates radiation-thermal conversion of FATG into low-viscosity diesel fuel. The conclusion is made, that lignin EBD at radiation and combined heating can be perspective effective method of vegetal polyphenols conversion into liquid phenols [ru

  14. Kraft Lignin Depolymerization in an Ionic Liquid without a Catalyst

    Directory of Open Access Journals (Sweden)

    Amadou Diop

    2015-06-01

    Full Text Available In this paper, the depolymerization of lignin was successfully achieved by the thermal treatment of kraft lignin in butyl-1,8-diazabicyclo[5.4.0]undec-7-enium chloride ([DBUC4+][Cl-] without a catalyst. The thermal treatment experiments were performed in an oven at 150, 200, and 250 °C for 1 h. The changes in kraft lignin structure over the course of depolymerization were characterized by gel permeation chromatography (GPC, Fourier transform infrared (FTIR spectroscopy, and 1H / 31P NMR analyses. GPC chromatograms indicated that the retention time of the original kraft lignin had shifted toward higher values after the thermal treatment, which indicated lignin depolymerization. The average molecular weight of the lignin obtained after 1 h reaction time decreased by 23, 70, and 58 wt% for the treatment at 150, 200, and 250 °C, respectively. FTIR spectra indicated the cleavage of β-O-4 bonds of kraft lignin. The 1H NMR spectra showed demethylation of all treated kraft lignins. Moreover, the 31P NMR analysis demonstrated that the demethylation phenomenon of the treated kraft lignin contributed to the formation of catechol groups.

  15. Fabrication of Environmentally Biodegradable Lignin Nanoparticles

    NARCIS (Netherlands)

    Frangville, C.; Rutkevicius, M.; Richter, A.P.; Velev, O.D.; Stoyanov, S.D.; Paunov, V.N.

    2012-01-01

    We developed a method for the fabrication of novel biodegradable nanoparticles (NPs) from lignin which are apparently non-toxic for microalgae and yeast. We compare two alternative methods for the synthesis of lignin NPs which result in particles of very different stability upon change of pH. The

  16. Biological and Catalytic Conversion of Sugars and Lignin Publications |

    Science.gov (United States)

    biorefinery lignins, ACS Sust. Chem. Eng. Lignin depolymerization with nitrate-intercalated hydrotalcite catalysts, ACS Catalysis Pyrolysis reaction networks for lignin model compounds: Unraveling thermal Free Energy, J. Amer. Chem. Soc. Process Design and Economics for the Conversion of Lignocellulosic

  17. Production of Flocculants, Adsorbents, and Dispersants from Lignin.

    Science.gov (United States)

    Chen, Jiachuan; Eraghi Kazzaz, Armin; AlipoorMazandarani, Niloofar; Hosseinpour Feizi, Zahra; Fatehi, Pedram

    2018-04-10

    Currently, lignin is mainly produced in pulping processes, but it is considered as an under-utilized chemical since it is being mainly used as a fuel source. Lignin contains many hydroxyl groups that can participate in chemical reactions to produce value-added products. Flocculants, adsorbents, and dispersants have a wide range of applications in industry, but they are mainly oil-based chemicals and expensive. This paper reviews the pathways to produce water soluble lignin-based flocculants, adsorbents, and dispersants. It provides information on the recent progress in the possible use of these lignin-based flocculants, adsorbents, and dispersants. It also critically discusses the advantages and disadvantages of various approaches to produce such products. The challenges present in the production of lignin-based flocculants, adsorbents, and dispersants and possible scenarios to overcome these challenges for commercial use of these products in industry are discussed.

  18. Impact of lignins isolated from pretreated lignocelluloses on enzymatic cellulose saccharification.

    Science.gov (United States)

    Barsberg, Søren; Selig, Michael Joseph; Felby, Claus

    2013-02-01

    Lignins were enzymatically isolated from corn stover and wheat straw samples and subjected to hydrothermal or wet oxidation pretreatments for enzyme adsorption experimentations. Lignin contents of the isolates ranged from 26 to 71 % (w/w); cellulose ranged from 3 to 22 % (w/w); xylan from 0.7 to 6 % (w/w) and ash was from 5.8 to 30 % (w/w). ATR-IR analyses indicated significant and similar levels of calcium in all lignin isolates. Commercial cellulase adsorption studies showed that the presence of these lignins had no significant impact on the total amount of adsorbed enzyme in cellulose and cellulose-lignin systems. Consequently, the presence of the lignins had minimal effect, if any, on enzymatic cellulose conversion. Furthermore, this result, coupled with significant calcium levels in the isolated lignins, supports previous work suggesting lignin-calcium complexes reduce enzyme-lignin interactions.

  19. Revealing the fate of the phenylcoumaran linkage during lignin oxidation reactions.

    Science.gov (United States)

    Lahive, Ciaran W; Lancefield, Christopher S; Codina, Anna; Kamer, Paul C J; Westwood, Nicholas J

    2018-03-14

    The fate of most lignin linkages, other than the β-O-4, under selective oxidation conditions is largely unknown. In this work we use advanced β-5 lignin model compounds to identify the fate of phenylcoumaran units in a softwood lignin during oxidation with DDQ. By using model compounds combined with detailed characterisation of the oxidised lignin polymer using HSQC and HMBC NMR we show that phenylcoumarones are a major product, and therefore constitute a novel non-native β-5 linkage in oxidised lignins. Additionally, the reactivity of these units in lignin led us to further investigate their connectivity in lignin, showing that they are found as both phenolic and etherified units. The findings and approach developed here will help improve the efficiency of selective oxidative lignin depolymerisation processes, particularly those aimed at the upgrading of softwood lignin in which phenylcoumarans are a major linkage.

  20. Unique low-molecular-weight lignin with high purity extracted from wood by deep eutectic solvents (DES): a source of lignin for valorization

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez-Vasco, Carlos; Ma, Ruoshui; Quintero, Melissa; Guo, Mond; Geleynse, Scott; Ramasamy, Karthikeyan K.; Wolcott, Michael; Zhang, Xiao

    2016-01-01

    This paper reports a new method of applying Deep Eutectic Solvents (DES) for extracting lignin from woody biomass with high yield and high purity. DES mixtures prepared from Choline Chloride (ChCl) and four hydrogen-bond donors–acetic acid, lactic acid, levulinic acid and glycerol–were evaluated for treatment of hardwood (poplar) and softwood (D. fir). It was found that these DES treatments can selectively extract a significant amount of lignin from wood with high yields: 78% from poplar and 58% from D. fir. The extracted lignin has high purity (95%) with unique structural properties. We discover that DES can selectively cleave ether linkages in wood lignin and facilitate lignin removal from wood. The mechanism of DES cleavage of ether bonds between phenylpropane units was investigated. The results from this study demonstrate that DES is a promising solvent for wood delignification and the production of a new source of lignin with promising potential applications.

  1. Pyrolysis - gas chromatography - mass spectrometry of lignins

    Energy Technology Data Exchange (ETDEWEB)

    Martin, F; Saiz-Jimenez, C; Gonzalez-Vila, F J

    1979-01-01

    Milled wood lignins from spruce, beech and bamboo were pyrolysed. The high-boiling products of pyrolysis were studied by GLC and mass spectrometry. The forty-three products identified provide information on the structural units of lignin.

  2. The Use of Esterified Lignin for Synthesis of Durable Composites

    Science.gov (United States)

    S. Olsson; E. Ostmark; R.E. Ibach; C.M. Clemons; K.B. Segerholm; F. Englund

    2011-01-01

    Lignin is a natural polymer and one of the most abundant materials on earth. Despite this fact, lignin is often viewed as a by-product in chemical pulp processing and the use of lignin as a sustainable material is low. However, research and public awareness of sustainability have opened up new possibilities for using lignin as a material.

  3. Production of Flocculants, Adsorbents, and Dispersants from Lignin

    Directory of Open Access Journals (Sweden)

    Jiachuan Chen

    2018-04-01

    Full Text Available Currently, lignin is mainly produced in pulping processes, but it is considered as an under-utilized chemical since it is being mainly used as a fuel source. Lignin contains many hydroxyl groups that can participate in chemical reactions to produce value-added products. Flocculants, adsorbents, and dispersants have a wide range of applications in industry, but they are mainly oil-based chemicals and expensive. This paper reviews the pathways to produce water soluble lignin-based flocculants, adsorbents, and dispersants. It provides information on the recent progress in the possible use of these lignin-based flocculants, adsorbents, and dispersants. It also critically discusses the advantages and disadvantages of various approaches to produce such products. The challenges present in the production of lignin-based flocculants, adsorbents, and dispersants and possible scenarios to overcome these challenges for commercial use of these products in industry are discussed.

  4. Influence of Reaction Conditions on Lignin Hydrothermal Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Erdocia, Xabier; Prado, Raquel; Corcuera, M. Ángeles; Labidi, Jalel, E-mail: jalel.labidi@ehu.es [Chemical and Environmental Engineering Department, University of the Basque Country, San Seabastian (Spain)

    2014-04-01

    Organosolv lignin, obtained from olive tree pruning under optimized conditions, was subjected to a hydrothermal depolymerization process catalyzed by sodium hydroxide. The depolymerization of lignin was carried out at 300°C using different reaction times (20, 40, 60, 70, 80, 90, and 100 min) in order to study the influence of this parameter on lignin depolymerization. The resulting products (oil and residual lignin) were measured and analyzed by different techniques (GC/MS, high-performance size-exclusion chromatography, and pyrolysis–GC/MS) in order to determine their nature and composition. Coke was also formed, at a lower quantity, uncompetitive repolymerization reactions during the lignin hydrothermal treatment. The maximum oil yield and concentration of monomeric phenolic compounds was obtained after 80 min of reaction time. The highest reaction time studied (100 min) had the worst results with the lowest oil yield and highest coke production.

  5. Engineering Plant Biomass Lignin Content and Composition for Biofuels and Bioproducts

    Directory of Open Access Journals (Sweden)

    Cassie Marie Welker

    2015-07-01

    Full Text Available Lignin is an aromatic biopolymer involved in providing structural support to plant cell walls. Compared to the other cell wall polymers, i.e., cellulose and hemicelluloses, lignin has been considered a hindrance in cellulosic bioethanol production due to the complexity involved in its separation from other polymers of various biomass feedstocks. Nevertheless, lignin is a potential source of valuable aromatic chemical compounds and upgradable building blocks. Though the biosynthetic pathway of lignin has been elucidated in great detail, the random nature of the polymerization (free radical coupling process poses challenges for its depolymerization into valuable bioproducts. The absence of specific methodologies for lignin degradation represents an important opportunity for research and development. This review highlights research development in lignin biosynthesis, lignin genetic engineering and different biological and chemical means of depolymerization used to convert lignin into biofuels and bioproducts.

  6. Impact of lignins isolated from pretreated lignocelluloses on enzymatic cellulose saccharification

    DEFF Research Database (Denmark)

    Barsberg, Søren Talbro; Selig, Michael Joseph; Felby, Claus

    2013-01-01

    and cellulose-lignin systems. Consequently, the presence of the lignins had minimal effect, if any, on enzymatic cellulose conversion. Furthermore, this result, coupled with significant calcium levels in the isolated lignins, supports previous work suggesting lignin-calcium complexes reduce enzyme......Lignins were enzymatically isolated from corn stover and wheat straw samples and subjected to hydrothermal or wet oxidation pretreatments for enzyme adsorption experimentations. Lignin contents of the isolates ranged from 26 to 71 % (w/w); cellulose ranged from 3 to 22 % (w/w); xylan from 0.7 to 6...

  7. Directional synthesis of ethylbenzene through catalytic transformation of lignin.

    Science.gov (United States)

    Fan, Minghui; Jiang, Peiwen; Bi, Peiyan; Deng, Shumei; Yan, Lifeng; Zhai, Qi; Wang, Tiejun; Li, Quanxin

    2013-09-01

    Transformation of lignin to ethylbenzene can provide an important bulk raw material for the petrochemical industry. This work explored the production of ethylbenzene from lignin through the directional catalytic depolymerization of lignin into the aromatic monomers followed by the selective alkylation of the aromatic monomers. For the first step, the aromatics selectivity of benzene derived from the catalytic depolymerization of lignin reached about 90.2 C-mol% over the composite catalyst of Re-Y/HZSM-5 (25). For the alkylation of the aromatic monomers in the second step, the highest selectivity of ethylbenzene was about 72.3 C-mol% over the HZSM-5 (25) catalyst. The reaction pathway for the transformation of lignin to ethylbenzene was also addressed. Present transformation potentially provides a useful approach for the production of the basic petrochemical material and development of high-end chemicals utilizing lignin as the abundant natural aromatic resource. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Biodegradation of lignin by Shiitake Lentinus edodes (berk. ) sing

    Energy Technology Data Exchange (ETDEWEB)

    Oki, T.; Watanabe, H.; Ishikawa, H.

    1981-01-01

    Each strain of L. edodes destroyed all of the structural components of wood (Fagus crenata) at almost the same rate during the loss of approximately 30% of the total weight of wood. The activities of the extracellular enzymes, i.e. peroxidase, laccase, and polyphenol oxidase, in the wood powder and lignin-containing cultures increased during the early period of mycelial growth, and then declined rapidly, while the activity of Beta-glucosidase increased gradually throughout the growth period. Functional group analysis, nitrobenzene oxidation, and spectroscopic characterization showed that dioxane lignin from F. crenata degraded by L. edodes or in crude enzyme solution isolated from wood-containing culture had a higher content of carboxyl groups than the sound dioxane lignin, whereas the content of methoxyl group was lower in the degraded dioxane lignin than in sound dioxane lignin. The building units of dioxane lignin, which yield aromatic aldehydes on nitrobenzene oxidation, were attacked preferentially by L. edodes under the above conditions.

  9. Lignin biomass conversion into chemicals and fuels

    DEFF Research Database (Denmark)

    Melián Rodríguez, Mayra

    Second-generation biomass or lignocellulosic biomass, which is mainly composed of cellulose, hemicellulose and lignin, is a very important and promising feedstock for the renewable production of fuels and chemicals of the future. Lignin is the second most abundant natural polymer, representing 30...... and show similar, although simplified, characteristics to the natural biopolymer. Among them, the most abundant structural unit is the β-O-4, representing approximately 60% of the bonds in hardwood and 45-50% of those in softwood. Oxidative depolymerization is one of the most viable methods for lignin...... valorization. It involves the cleavage of ether bonds, such as β-O-4 and other linkages present in lignin and its model compounds, giving aldehydes or carboxylic acids as products, depending on the reaction conditions used. In Chapter 2 of this thesis, the preparation, characterization and catalytic...

  10. The Effect of Plant Source on the Properties of Lignin-Based Polyurethanes

    Directory of Open Access Journals (Sweden)

    Jason M. Lang

    2018-02-01

    Full Text Available This work increases our understanding of the effect of plant source on the mechanical and morphological properties of lignin-based polyurethanes (PUs. Lignin is a polymer that is synthesized inside the plant cell wall and can be used as a polyol to synthesize PUs. The specific aromatic structure of the lignin is heavily reliant on the plant source from which it is extracted. These results show that the mechanical properties of lignin-based PUs differ based on lignin’s plant source. The morphology of lignin-based PUs was examined using atomic force microscopy and scanning electron microscopy and the mechanical properties of lignin-based PU samples were measured using dynamic mechanical analysis and shore hardness (Type A. The thermal analysis and morphology studies demonstrate that all PUs prepared form a multiphase morphology. In these PUs, better mixing was observed in the wheat straw lignin PU samples leading to higher moduli than in the hardwood lignin and softwood lignin PUs whose morphology was dominated by larger aggregates. Independent of the type of the lignin used, increasing the fraction of lignin increased the rigidity of PU. Among the different types of lignin studied, PU with wheat straw soda lignin exhibited storage moduli ~2-fold higher than those of PUs incorporating other lignins. This study also showed that during synthesis all hydroxyl groups in the lignin are not available to react with isocyanates, which alters the number of cross-links formed within the PU and impacts the mechanical properties of the material.

  11. Can laccases catalyze bond cleavage in lignin?

    DEFF Research Database (Denmark)

    Munk, Line; Sitarz, Anna Katarzyna; Kalyani, Dayanand

    2015-01-01

    illustrations of the putative laccase catalyzed reactions, including the possible reactions of the reactive radical intermediates taking place after the initial oxidation of the phenol-hydroxyl groups, we show that i) Laccase activity is able to catalyze bond cleavage in low molecular weight phenolic lignin......-substituted phenols, benzenethiols, polyphenols, and polyamines, which may be oxidized. In addition, the currently available analytical methods that can be used to detect enzyme catalyzed changes in lignin are summarized, and an improved nomenclature for unequivocal interpretation of the action of laccases on lignin...

  12. Producing a True Lignin Depolymerase for Biobleaching Softwood Kraft Pulp

    Energy Technology Data Exchange (ETDEWEB)

    Simo Sarkanen

    2002-02-04

    This project constituted an intensive effort devoted to producing, from the white-rot fungus Tramets Cingulata, a lignin degrading enzyme (lignin depolymerase) that is directly able to biobleach or delignify softwood kraft pulp brownstock. To this end, the solutions in which T. cingulata was grown contained dissolved kraft lignin which fulfilled two functions; it behaved as a lignin deploymerase substrate and it also appeared to act as an inducer of enzyme expression. However, the lignin depolymerase isoenzymes (and other extracellular T. cingulata enzymes) interacted very strongly with both the kraft lignin components and the fungal hypae, so the isolating these proteins from the culture solutions proved to be unexpectedly difficult. Even after extensive experimentation with a variety of protein purification techniques, only one approach appeared to be capable of purifying lignin depolymerases to homogeneity. Unfortunately the procedure was extremely laborious; it involved the iso electric focusing of concentrated buffer-exchanged culture solutions followed by electro-elution of the desired protein bands from the appropriate polyacrylamide gel segments

  13. Progress in lignin hydrogels and nanocomposites for water purification

    DEFF Research Database (Denmark)

    Tamulevicius, Sigitas; Thakur, Sourbh; Govender, Penny P.

    2017-01-01

    -based hydrogels have shown excellent performance for removal of various pollutants from water. The adsorption properties of lignin based hydrogels can further be improved by using a combination of nanomaterials and lignin that results in promising hydrogel nanocomposites. In nature, the most abundant structures...... are formed by the combination of lignin, cellulose and hemicelluloses. In this article, we have attempted to comprehensively review the research work carried out in the direction of usage of lignin-based hydrogel for removal of toxic pollutants including metal ions and dyes....

  14. The effect of amphipilic lignin derivatives addition on enzymatic hydrolysis performance of kraft pulp from sorghum bagasse

    Science.gov (United States)

    Fatriasari, Widya; Nugroho Adi, D. T.; Laksana, R. P. B.; Fajriutami, T.; Raniya, R.; Ghozali, M.; Hermiati, E.

    2018-03-01

    Previously, the chemical characteristics of isolated lignin from Acacia mangium black liquor of kraft pulping was characterized. This lignin was blended with natural rubber latex (NR-L) as adhesive in laminated wood. In addition, lignin has potency for biosurfactant materials by modification of the hydrophobic into hydrophilic properties. Therefore, this study was intended to develop lignin as material for amphipilic lignin derivatives (A-LD) biosurfactant by reacting lignin with epoxilated polyethylene glicol (PEG). A-LD addition in slurries was used to improve the enzymatic hydrolysis (EH) of kraft pulp sweet bagasse sorghum (SSB). The main observation in EH performance was to investigate the effect of lignin isolation method (one and two step) in A-LD and A-LD loading addition on reducing sugar yield (RSY) of SSB kraft pulp. The pulp was hydrolyzed at 50°C and 150 rpm for 72 h with 10 FPU cellulase loading in the shaking incubator. A-LD from one (L1S) and two step (L2S) lignin was added with A-LD loading of 0, 1, 2, 5, and 10% (b/v). The RSY of hydrolyzate has been observed after EH. A-LDs addition in EH of SSB kraft pulp enhanced RSY. L1S worked better in reaction performance with PEDGE compared to L2S and LS. A better performance was showed by PEDGE 500 than that of PEDGE 6000. Generally, the higher A-LDs loading resulted higher RSY. The highest RSY (81.33%) was resulted in addition of 10% A-LD L1S using PEDGE 500. A 5% A-LD loading was more considered to be added in EH because the RSY was comparable with 10% A-LD loading.

  15. Solid-state 29Si NMR and FTIR analyses of lignin-silica coprecipitates

    DEFF Research Database (Denmark)

    Cabrera Orozco, Yohanna; Cabrera, Andrés; Larsen, Flemming Hofmann

    2016-01-01

    When agricultural residues are processed to ethanol, lignin and silica are some of the main byproducts. Separation of these two products is difficult and the chemical interactions between lignin and silica are not well described. In the present study, the effect of lignin-silica complexing has been...... investigated by characterizing lignin and silica coprecipitates by FTIR and solid state NMR. Silica particles were coprecipitated with three different lignins, three lignin model compounds, and two silanes representing silica-in-lignin model compounds. Comparison of 29Si SP/MAS NMR spectra revealed differences...

  16. Insights into lignin degradation and its potential industrial applications.

    Science.gov (United States)

    Abdel-Hamid, Ahmed M; Solbiati, Jose O; Cann, Isaac K O

    2013-01-01

    Lignocellulose is an abundant biomass that provides an alternative source for the production of renewable fuels and chemicals. The depolymerization of the carbohydrate polymers in lignocellulosic biomass is hindered by lignin, which is recalcitrant to chemical and biological degradation due to its complex chemical structure and linkage heterogeneity. The role of fungi in delignification due to the production of extracellular oxidative enzymes has been studied more extensively than that of bacteria. The two major groups of enzymes that are involved in lignin degradation are heme peroxidases and laccases. Lignin-degrading peroxidases include lignin peroxidase (LiP), manganese peroxidase (MnP), versatile peroxidase (VP), and dye-decolorizing peroxidase (DyP). LiP, MnP, and VP are class II extracellular fungal peroxidases that belong to the plant and microbial peroxidases superfamily. LiPs are strong oxidants with high-redox potential that oxidize the major non-phenolic structures of lignin. MnP is an Mn-dependent enzyme that catalyzes the oxidation of various phenolic substrates but is not capable of oxidizing the more recalcitrant non-phenolic lignin. VP enzymes combine the catalytic activities of both MnP and LiP and are able to oxidize Mn(2+) like MnP, and non-phenolic compounds like LiP. DyPs occur in both fungi and bacteria and are members of a new superfamily of heme peroxidases called DyPs. DyP enzymes oxidize high-redox potential anthraquinone dyes and were recently reported to oxidize lignin model compounds. The second major group of lignin-degrading enzymes, laccases, are found in plants, fungi, and bacteria and belong to the multicopper oxidase superfamily. They catalyze a one-electron oxidation with the concomitant four-electron reduction of molecular oxygen to water. Fungal laccases can oxidize phenolic lignin model compounds and have higher redox potential than bacterial laccases. In the presence of redox mediators, fungal laccases can oxidize non

  17. Redox Fluctuations Increase the Contribution of Lignin to Soil Respiration

    Science.gov (United States)

    Hall, S. J.; Silver, W. L.; Timokhin, V.; Hammel, K.

    2014-12-01

    Lignin mineralization represents a critical flux in the terrestrial carbon (C) cycle, yet little is known about mechanisms and environmental factors controlling lignin breakdown in mineral soils. Hypoxia has long been thought to suppress lignin decomposition, yet variation in oxygen (O2) availability in surface soils accompanying moisture fluctuations could potentially stimulate this process by generating reactive oxygen species via coupled biotic and abiotic iron (Fe) redox cycling. Here, we tested the impact of redox fluctuations on lignin breakdown in humid tropical forest soils during ten-week laboratory incubations. We used synthetic lignins labeled with 13C in either of two positions (aromatic methoxyl and propyl Cβ) to provide highly sensitive and specific measures of lignin mineralization not previously employed in soils. Four-day redox fluctuations increased the percent contribution of methoxyl C to soil respiration, and cumulative methoxyl C mineralization was equivalent under static aerobic and fluctuating redox conditions despite lower total C mineralization in the latter treatment. Contributions of the highly stable Cβ to mineralization were also equivalent in static aerobic and fluctuating redox treatments during periods of O2 exposure, and nearly doubled in the fluctuating treatment after normalizing to cumulative O2 exposure. Oxygen fluctuations drove substantial net Fe reduction and oxidation, implying that reactive oxygen species generated during abiotic Fe oxidation likely contributed to the elevated contribution of lignin to C mineralization. Iron redox cycling provides a mechanism for lignin breakdown in soils that experience conditions unfavorable for canonical lignin-degrading organisms, and provides a potential mechanism for lignin depletion in soil organic matter during late-stage decomposition. Thus, close couplings between soil moisture, redox fluctuations, and lignin breakdown provide potential a link between climate variability and

  18. Enhancing the laccase production and laccase gene expression in the white-rot fungus Trametes velutina 5930 with great potential for biotechnological applications by different metal ions and aromatic compounds.

    Directory of Open Access Journals (Sweden)

    Yang Yang

    Full Text Available Laccase is useful for various biotechnological and industrial applications. The white-rot fungus Trametes velutina 5930 and its laccase, isolated from the Shennongjia Nature Reserve in China by our laboratory, has great potential for practical application in environmental biotechnology. However, the original level of laccase produced by Trametes velutina 5930 was relatively low in the absence of any inducer. Therefore, in order to enhance the laccase production by Trametes velutina 5930 and make better use of this fungus in the field of environmental biotechnology, the regulation of laccase production and laccase gene expression in Trametes velutina 5930 were investigated in this study. Different metal ions such as Cu(2+ and Fe(2+ could stimulate the laccase synthesis and laccase gene transcription in Trametes velutina 5930. Some aromatic compounds structurally related to lignin, such as tannic acid, syringic acid, cinnamic acid, gallic acid and guaiacol, could also enhance the level of laccase activity and laccase gene transcription. We also found that there existed a positive synergistic effect of aromatic compound and metal ion on the laccase production and laccase gene transcription in Trametes velutina 5930. Taken together, our study may contribute to the improvement of laccase productivity by Trametes velutina 5930.

  19. Enhancing the laccase production and laccase gene expression in the white-rot fungus Trametes velutina 5930 with great potential for biotechnological applications by different metal ions and aromatic compounds.

    Science.gov (United States)

    Yang, Yang; Wei, Fuxiang; Zhuo, Rui; Fan, Fangfang; Liu, Huahua; Zhang, Chen; Ma, Li; Jiang, Mulan; Zhang, Xiaoyu

    2013-01-01

    Laccase is useful for various biotechnological and industrial applications. The white-rot fungus Trametes velutina 5930 and its laccase, isolated from the Shennongjia Nature Reserve in China by our laboratory, has great potential for practical application in environmental biotechnology. However, the original level of laccase produced by Trametes velutina 5930 was relatively low in the absence of any inducer. Therefore, in order to enhance the laccase production by Trametes velutina 5930 and make better use of this fungus in the field of environmental biotechnology, the regulation of laccase production and laccase gene expression in Trametes velutina 5930 were investigated in this study. Different metal ions such as Cu(2+) and Fe(2+) could stimulate the laccase synthesis and laccase gene transcription in Trametes velutina 5930. Some aromatic compounds structurally related to lignin, such as tannic acid, syringic acid, cinnamic acid, gallic acid and guaiacol, could also enhance the level of laccase activity and laccase gene transcription. We also found that there existed a positive synergistic effect of aromatic compound and metal ion on the laccase production and laccase gene transcription in Trametes velutina 5930. Taken together, our study may contribute to the improvement of laccase productivity by Trametes velutina 5930.

  20. Isolation, identification and characterization of lignin-degrading bacteria from Qinling, China.

    Science.gov (United States)

    Yang, C-X; Wang, T; Gao, L-N; Yin, H-J; Lü, X

    2017-12-01

    Lignin is an aromatic heteropolymer forming a physical barrier and it is a big challenge in biomass utilization. This paper first investigated lignin-degradation bacteria from rotten wood in Qinling Mountain. Nineteen potential strains were selected and ligninolytic enzyme activities were determined over 84 h. Strains that had higher enzyme activities were selected. Further, the biodegradation of wheat straw lignin and alkali lignin was evaluated indicating that Burkholderia sp. H1 had the highest capability. It was confirmed by gel permeation chromatography and field emission scanning electron microscope that alkali lignin was depolymerized into small fragments. The degraded products were analysed using gas chromatography-mass spectrometry. The total ion chromatograph of products treated for 7 days showed the formation of aromatic compounds, an important intermediate from lignin degradation. Interestingly, they disappeared in 15 days while the aldehyde and ester compounds increased. The results suggest that the lignin-degrading bacteria are abundant in rotten wood and strain H1 has high potential to break down lignin. The diversity of lignin-degrading bacteria in Qinling Mountain is revealed. The study of Burkholderia sp. H1 expands the range of bacteria for lignin degradation and provides novel bacteria for application to lignocellulosic biomass. © 2017 The Society for Applied Microbiology.

  1. Valorization of lignin from biorefineries for fuels and chemicals

    DEFF Research Database (Denmark)

    Nielsen, Joachim Bachmann

    Direct lignin liquefaction is a promising process for lignin valorization in which ligninis treated in a solvent at elevated temperature and pressure. Liquefaction of sulfur freelignin obtained as a waste product from 2nd generation bio-ethanol production canprovide a sulfur free bio-oil which may...... substitute fossil fuel.In this Ph.D. study the direct liquefaction of a biorefinery lignin (hydrothermallypretreated enzymatic hydrolysis lignin) is explored. The goal is to provide a bio-crude which can substitute marine diesel as the engines found aboard large ships are adapted to more crude fuels. A novel...

  2. Environmental economics of lignin derived transport fuels

    NARCIS (Netherlands)

    Obydenkova, Svetlana V.; Kouris, Panos D.; Hensen, Emiel J. M.; Heeres, Hero J.; Boot, Michael D.

    2017-01-01

    This paper explores the environmental and economic aspects of fast pyrolytic conversion of lignin, obtained from 2G ethanol plants, to transport fuels for both the marine and automotive markets. Various scenarios are explored, pertaining to aggregation of lignin from several sites, alternative

  3. Brown Midrib (Low Lignin) Sorghum Mutations Result in Restricted Growth of Fusarium and Alternaria spp

    Science.gov (United States)

    To increase usability of sorghum for bioenergy and forages, two different brown midrib (bmr) genes, bmr6 and bmr12, were backcrossed into five elite backgrounds, resulting in reduced lignin near-isogenic genotypes. When compared with wild-type, field-grown grain from bmr6 and bmr12 plants had signif...

  4. CHARACTERIZATION OF ALKALINE LIGNINS FOR USE IN PHENOL-FORMALDEHYDE AND EPOXY RESINS

    Directory of Open Access Journals (Sweden)

    Nour Eddine El Mansouri

    2011-05-01

    Full Text Available Besides polyurethanes and polyesters, phenolic and epoxy resins are the most prominent applications for technical lignins in thermosetting materials. To evaluate the potential application of lignin raw materials in phenol formaldehyde and epoxy resins, three types of alkaline lignins were characterized in terms of their structures and thermal properties. The lignin samples analyzed were kraft lignin (LIG-1, soda–rice straw lignin (LIG-2, and soda-wheat straw lignin (LIG-3. FTIR and 1H-NMR methods were used to determine their structure. Gel permeation chromatography (GPC was used to determine the molecular weight distribution (MWD. Differential scanning calorimetry (DSC was used to measure the glass transition temperature (Tg, and thermogravimetric analysis (TGA to determine the thermal stability of lignin samples. Results showed that kraft lignin (LIG-1 has moderate hydroxyl-group content, is rich in G-type units, and has good thermal stability. These properties make it more suitable for direct use in phenol formaldehyde resins, and it is therefore a good raw material for this purpose. The alkaline soda-rice straw lignin (LIG-2 with a high hydroxyl-group content and excellent thermal stability is most suited to preparing lignin-based epoxy resins.

  5. Gene doping: a review of performance-enhancing genetics.

    Science.gov (United States)

    Gaffney, Gary R; Parisotto, Robin

    2007-08-01

    Unethical athletes and their mentors have long arrogated scientific and medical advances to enhance athletic performance, thus gaining a dishonest competitive advantage. Building on advances in genetics, a new threat arises from athletes using gene therapy techniques in the same manner that some abused performance-enhancing drugs were used. Gene doping, as this is known, may produce spectacular physiologic alterations to dramatically enhance athletic abilities or physical appearance. Furthermore, gene doping may present pernicious problems for the regulatory agencies and investigatory laboratories that are entrusted to keep sporting events fair and ethical. Performance-enhanced genetics will likewise present unique challenges to physicians in many spheres of their practice.

  6. NMR characterization of lignins isolated from fruit and vegetable insoluble dietary fiber.

    Science.gov (United States)

    Bunzel, Mirko; Ralph, John

    2006-10-18

    Compositional information for lignins in food is rare and concentrated on cereal grains and brans. As lignins are suspected to have important health roles in the dietary fiber complex, the confusing current information derived from nonspecific lignin determination methods needs to be augmented by diagnostic structural studies. For this study, lignin fractions were isolated from kiwi, pear, rhubarb, and, for comparison, wheat bran insoluble dietary fiber. Clean pear and kiwi lignin isolates allowed for substantive structural profiling, but it is suggested that the significance of lignin in wheat has been overestimated by reliance on nonspecific analytical methods. Volume integration of NMR contours in two-dimensional (13)C-(1)H correlation spectra shows that pear and wheat lignins have comparable guaiacyl and syringyl contributions and that kiwi lignins are particularly guaiacyl-rich (approximately 94% guaiacyl) and suggest that rhubarb lignins, which could not be isolated from contaminating materials, are as syringyl-rich (approximately 96% syringyl) as lignins from any known natural or transgenic fiber source. Typical lignin structures, including those newly NMR-validated (glycerols, spirodienones, and dibenzodioxocins), and resinols implicated as possible mammalian lignan precursors in the gut are demonstrated via their NMR correlation spectra in the fruit and vegetable samples. A novel putative benzodioxane structure appears to be associated with the kiwi lignin. It is concluded that the fruits and vegetables examined contain authentic lignins and that the detailed structural analysis exposes limitations of currently accepted analytical methods.

  7. Metal Triflates for the Production of Aromatics from Lignin.

    Science.gov (United States)

    Deuss, Peter J; Lahive, Ciaran W; Lancefield, Christopher S; Westwood, Nicholas J; Kamer, Paul C J; Barta, Katalin; de Vries, Johannes G

    2016-10-20

    The depolymerization of lignin into valuable aromatic chemicals is one of the key goals towards establishing economically viable biorefineries. In this contribution we present a simple approach for converting lignin to aromatic monomers in high yields under mild reaction conditions. The methodology relies on the use of catalytic amounts of easy-to-handle metal triflates (M(OTf) x ). Initially, we evaluated the reactivity of a broad range of metal triflates using simple lignin model compounds. More advanced lignin model compounds were also used to study the reactivity of different lignin linkages. The product aromatic monomers were either phenolic C2-acetals obtained by stabilization of the aldehyde cleavage products by reaction with ethylene glycol or methyl aromatics obtained by catalytic decarbonylation. Notably, when the method was ultimately tested on lignin, especially Fe(OTf) 3 proved very effective and the phenolic C2-acetal products were obtained in an excellent, 19.3±3.2 wt % yield. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Role of paramagnetic polyconjugated clusters in lignin antioxidant activity (in vitro)

    International Nuclear Information System (INIS)

    Dizhbite, T; Ponomarenko, J; Andersone, A; Dobele, G; Lauberts, M; Krasilnikova, J; Telysheva, G; Mironova-Ulmane, N

    2012-01-01

    Using physico-chemical methods (EPR, SEC, Py-GC/MS and UV/VIS spectroscopy) and wet chemical analysis, the characteristics of 6 hardwood lignins in terms of functionality, molecular weight and composition of lignin substructures were determined and considered together with the results of DPPH., ABTS. + and O 2 . − antioxidant assays with the aim to understand the relationships governing antioxidant properties of lignin. The strong positive linear correlation between lignin antioxidant capacity in the three assays used and the extent of conjugation of paramagnetic polyconjugated clusters in lignin macromolecules was found. The biological activity of the most active alkaline lignins was assessed by in vitro experiment with human blood.

  9. Animal bioavailability of defined xenobiotic lignin metabolites

    International Nuclear Information System (INIS)

    Sandermann, H. Jr.; Arjmand, M.; Gennity, I.; Winkler, R.; Struble, C.B.; Aschbacher, P.W.

    1990-01-01

    Lignin has been recognized as a major component of bound pesticide residues in plants and is thought to be undigestible in animals. Two defined ring-U- 14 C-labeled chloroaniline/lignin metabolites have now been fed to rats, where a release of ∼66% of the bound xenobiotic occurred in the form of simple chloroaniline derivatives. The observed high degree of bioavailability indicates that bound pesticidal residues may possess ecotoxicological significance. In parallel studies, the white-rot fungus Phanerochaete chrysosporium was more efficient, and a soil system was much less efficient, in the degradation of the [ring-U- 14 C]chloroaniline/lignin metabolites

  10. Lignin-Retaining Transparent Wood.

    Science.gov (United States)

    Li, Yuanyuan; Fu, Qiliang; Rojas, Ramiro; Yan, Min; Lawoko, Martin; Berglund, Lars

    2017-09-11

    Optically transparent wood, combining optical and mechanical performance, is an emerging new material for light-transmitting structures in buildings with the aim of reducing energy consumption. One of the main obstacles for transparent wood fabrication is delignification, where around 30 wt % of wood tissue is removed to reduce light absorption and refractive index mismatch. This step is time consuming and not environmentally benign. Moreover, lignin removal weakens the wood structure, limiting the fabrication of large structures. A green and industrially feasible method has now been developed to prepare transparent wood. Up to 80 wt % of lignin is preserved, leading to a stronger wood template compared to the delignified alternative. After polymer infiltration, a high-lignin-content transparent wood with transmittance of 83 %, haze of 75 %, thermal conductivity of 0.23 W mK -1 , and work-tofracture of 1.2 MJ m -3 (a magnitude higher than glass) was obtained. This transparent wood preparation method is efficient and applicable to various wood species. The transparent wood obtained shows potential for application in energy-saving buildings. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  11. Effects of laccase on lignin depolymerization and enzymatic hydrolysis of ensiled corn stover.

    Science.gov (United States)

    Chen, Qin; Marshall, Megan N; Geib, Scott M; Tien, Ming; Richard, Tom L

    2012-08-01

    The aim of this study was to explore the synergies of laccase, a ligninolytic enzyme, with cellulose and hemicellulase amendments on ensiled corn stover. Molecular signals of lignin decomposition were observed by tetramethylammonium hydroxide thermochemolysis and gas chromatography-mass spectroscopy (TMAH-GC-MS) analysis. The significant findings suggest that ensilage might provide a platform for biological pretreatment. By partially hydrolyzing cellulose and hemicellulose into soluble sugars, ensilage facilitates laccase penetration into the lignocellulose complex to enhance lignin degradation. Downstream cellulose hydrolysis was improved 7% with increasing laccase loading rate. These results demonstrate the potential of enzymes, either directly amended or expressed by microbes during ensilage, to maximize utilization of corn stover for cellulosic biofuels and other downstream fermentations. Copyright © 2012. Published by Elsevier Ltd.

  12. Expression of brown-midrib in a spontaneous sorghum mutant is linked to a 5'-UTR deletion in lignin biosynthesis gene SbCAD2

    Science.gov (United States)

    Brown midrib (bmr) mutants in sorghum (Sorghum bicolor (L.) Moench) and several other C4 grasses are associated with reduced lignin concentration, altered lignin composition and improved cell wall digestibility, which are desirable properties in biomass development for the emerging lignocellulosic b...

  13. Characterisation and application of NovaFiber lignin

    NARCIS (Netherlands)

    Gosselink, R.J.A.; Snijder, M.H.B.; Kranenbarg, A.; Keijsers, E.R.P.; Jong, de E.; Stigsson, L.L.

    2004-01-01

    Sulphur-free lignin coming from a novel alkaline-pulping process called NovaFiber, which has been developed by KIRAM AB, has been characterised and evaluated for potential applications. A Kraft lignin has been used for comparison. Considering the characterisation results of a NovaFiber softwood and

  14. Characterisation of Authentic Lignin Biorefinery Samples by Fourier Transform Infrared Spectroscopy and Determination of the Chemical Formula for Lignin

    DEFF Research Database (Denmark)

    Le, Duy Michael; Damgaard Nielsen, Anders; Sørensen, Hanne

    2017-01-01

    samples in situ with no prior purification and minimal sample preparation. Lignin chemical formulas and lignin Fourier transform infrared (FTIR) spectra were extracted from mixed spectra by filtering out signals from residual carbohydrates and minerals. From estimations of C, H and O and adjustment...

  15. Alkaline and Organosolv Lignins from Furfural Residue: Structural Features and Antioxidant Activity

    Directory of Open Access Journals (Sweden)

    Xue-Fei Cao

    2013-12-01

    Full Text Available Furfural residue (FR, composed mainly of cellulose and lignin, is an industrial waste produced during furfural manufacture. In this study, dioxane, alkali, ethanol, alkali-ethanol, and alkaline hydrogen peroxide (AHP were used to extract lignins from FR. The structural features of these lignins obtained were characterized by sugar analysis, GPC, UV, FT-IR, and HSQC spectra. As compared to dioxane lignin (DL, other lignins showed lower molecular weights (Mw owing to the partial cleavage of the linkages between lignin units. Results from HSQC spectra revealed that β-O-4' and β-5' were still the major linkages of the FR lignin. Moreover, p-coumaric and ferulic acids were released and co-precipitated in the lignin preparations extracted with alkali and AHP, whereas part of the esters in DL were preserved during the dioxane extraction. Antioxidant activity investigation indicated that the antioxidant property of the alkali and alkali-ethanol lignins was higher than that of the commercial antioxidant, butylated hydroxytoluene.

  16. Environmental economics of lignin derived transport fuels.

    Science.gov (United States)

    Obydenkova, Svetlana V; Kouris, Panos D; Hensen, Emiel J M; Heeres, Hero J; Boot, Michael D

    2017-11-01

    This paper explores the environmental and economic aspects of fast pyrolytic conversion of lignin, obtained from 2G ethanol plants, to transport fuels for both the marine and automotive markets. Various scenarios are explored, pertaining to aggregation of lignin from several sites, alternative energy carries to replace lignin, transport modalities, and allocation methodology. The results highlight two critical factors that ultimately determine the economic and/or environmental fuel viability. The first factor, the logistics scheme, exhibited the disadvantage of the centralized approach, owing to prohibitively expensive transportation costs of the low energy-dense lignin. Life cycle analysis (LCA) displayed the second critical factor related to alternative energy carrier selection. Natural gas (NG) chosen over additional biomass boosts well-to-wheel greenhouse gas emissions (WTW GHG) to a level incompatible with the reduction targets set by the U.S. renewable fuel standard (RFS). Adversely, the process' economics revealed higher profits vs. fossil energy carrier. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  17. Selective aerobic alcohol oxidation method for conversion of lignin into simple aromatic compounds

    Science.gov (United States)

    Stahl, Shannon S; Rahimi, Alireza

    2015-03-03

    Described is a method to oxidize lignin or lignin sub-units. The method includes oxidation of secondary benzylic alcohol in the lignin or lignin sub-unit to a corresponding ketone in the presence of unprotected primarily aliphatic alcohol in the lignin or lignin sub-unit. The optimal catalyst system consists of HNO.sub.3 in combination with another Bronsted acid, in the absence of a metal-containing catalyst, thereby yielding a selectively oxidized lignin or lignin sub-unit. The method may be carried out in the presence or absence of additional reagents including TEMPO and TEMPO derivatives.

  18. Advancing Eucalyptus genomics: identification and sequencing of lignin biosynthesis genes from deep-coverage BAC libraries

    Directory of Open Access Journals (Sweden)

    Kudrna David

    2011-03-01

    Full Text Available Abstract Background Eucalyptus species are among the most planted hardwoods in the world because of their rapid growth, adaptability and valuable wood properties. The development and integration of genomic resources into breeding practice will be increasingly important in the decades to come. Bacterial artificial chromosome (BAC libraries are key genomic tools that enable positional cloning of important traits, synteny evaluation, and the development of genome framework physical maps for genetic linkage and genome sequencing. Results We describe the construction and characterization of two deep-coverage BAC libraries EG_Ba and EG_Bb obtained from nuclear DNA fragments of E. grandis (clone BRASUZ1 digested with HindIII and BstYI, respectively. Genome coverages of 17 and 15 haploid genome equivalents were estimated for EG_Ba and EG_Bb, respectively. Both libraries contained large inserts, with average sizes ranging from 135 Kb (Eg_Bb to 157 Kb (Eg_Ba, very low extra-nuclear genome contamination providing a probability of finding a single copy gene ≥ 99.99%. Libraries were screened for the presence of several genes of interest via hybridizations to high-density BAC filters followed by PCR validation. Five selected BAC clones were sequenced and assembled using the Roche GS FLX technology providing the whole sequence of the E. grandis chloroplast genome, and complete genomic sequences of important lignin biosynthesis genes. Conclusions The two E. grandis BAC libraries described in this study represent an important milestone for the advancement of Eucalyptus genomics and forest tree research. These BAC resources have a highly redundant genome coverage (> 15×, contain large average inserts and have a very low percentage of clones with organellar DNA or empty vectors. These publicly available BAC libraries are thus suitable for a broad range of applications in genetic and genomic research in Eucalyptus and possibly in related species of Myrtaceae

  19. A radioimmunoassay for lignin in plant cell walls

    International Nuclear Information System (INIS)

    Dawley, R.M.

    1989-01-01

    Lignin detection and determination in herbaceous tissue requires selective, specific assays which are not currently available. A radioimmunoassay (RIA) was developed to study lignin metabolism in these tissues. A β-aryl ether lignin model compound was synthesized, linked to keyhole limpet hemocyanin using a water-soluble carbodiimide, and injected into rabbits. The highest titer of the antiserum obtained was 34 ηg/mL of model derivatized BSA. An in vitro system was developed to characterize the RIA. The model compound was linked to amino activated polyacrylamide beads to mimic lignin in the cell walls. 125 I Radiolabelled protein A was used to detect IgG antibody binding. The RIA was shown in the in vitro system to exhibit saturable binding. The amount of antibody bound decreased when the serum was diluted. Immunoelectrophoresis and competitive binding experiments confirmed that both aromatic rings of the lignin model compound had been antigenic. Chlorogenic acid, a phenolic known to be present in plant cells, did not compete for antibody binding. The RIA was used to measure lignin in milled plant samples and barley seedlings. Antiserum binding to wheat cell walls and stressed barley segments was higher than preimmune serum binding. Antibody binding to stressed barley tissue decreased following NaClO 2 delignification. The RIA was found to be less sensitive than expected, so several avenues for improving the method are discussed

  20. Reactivity of lignin with different composition of aromatic syringyl/guaiacyl structures and erythro/threo side chain structures in β-O-4 type during alkaline delignification: as a basis for the different degradability of hardwood and softwood lignin.

    Science.gov (United States)

    Shimizu, Satoko; Yokoyama, Tomoya; Akiyama, Takuya; Matsumoto, Yuji

    2012-07-04

    The reactivity of lignin during alkaline delignification was quantitatively investigated focusing on the effect of the structural differences between syringyl and guaiacyl aromatic nuclei and between erythro and threo in the side chain of β-O-4 type lignin substructure on the β-O-4 bond cleavage rate. It was known that the ratio of this reaction rate of the erythro to threo isomers of the dimeric β-O-4 type lignin model compound with two guaiacyl aromatic nuclei was ca. 4. However, the presence of a syringyl nucleus strongly influenced the rate, and the ratio of the syringyl type analogue was in the range between 2.7 and 8.0 depending on the reaction temperature. The effect of syringyl nucleus on the enhancement of the reaction rate appeared to be greater when the syringyl nucleus consists of the cleaving ether bond rather than being a member of the carbon framework.

  1. Nano Transition Metal Sulfide Catalyst for Solvolysis Liquefaction of Soda Lignin

    International Nuclear Information System (INIS)

    Fei-Ling, P.; Chin-Hua, C.; Sarani Zakaria; Soon-Keong, N.; Tze-Khong, L.

    2011-01-01

    Solvolysis liquefaction of soda lignin in the presence of various transition metal sulfide catalysts was studied to investigate the catalyst effects on the oil and gas yields, conversion rate and higher heating value (HHV) of oil. Nano sized copper sulfide, iron sulfide and molybdenum sulfide were successfully synthesized via a simple hydrothermal method under reaction temperature 200 degree Celsius for 90 min. The addition of transition metal sulfide based catalysts (CuS, MoS 2 and FeS 2 ) enhanced both production of the oils and gas and the higher heating value (HHV) of oil products. A high oil and gas yields of 82.1 % and 2890 cm 3 was obtained with MoS 2 at 250 degree Celsius for 60 min. Elemental analyses for the oils revealed that the liquid products have much higher heating values than the crude soda lignin powder. (author)

  2. Signatures of cinnamyl alcohol dehydrogenase deficiency in poplar lignins.

    Science.gov (United States)

    Lapierre, Catherine; Pilate, Gilles; Pollet, Brigitte; Mila, Isabelle; Leplé, Jean-Charles; Jouanin, Lise; Kim, Hoon; Ralph, John

    2004-02-01

    A series of transgenic poplars down-regulated for cinnamyl alcohol dehydrogenase (CAD) was analyzed by thioacidolysis. Among the lignin-derived monomers, the indene compounds that were recently shown to originate from sinapaldehyde incorporated into lignins through 8-O-4-cross-coupling, were found to increase as a function of CAD deficiency level. While these syringyl markers were recovered in substantial amounts in the most severely depressed lines, the markers for coniferaldehyde incorporation were recovered in only low amounts. In conjunction with these additional sinapaldehyde units and relative to the control samples, lignins in CAD-deficient poplar lines had less conventional syringyl-units and beta-O-4-bonds and more free phenolic groups. We found that almost half of the polymers in the most deficient lines could be solubilized in alkali and at room temperature. This unusual behavior suggests that lignins in CAD-deficient poplars occur as small, alkali-leachable lignin domains. That mainly sinapaldehyde incorporates into the lignins of CAD-deficient poplars suggests that the recently identified sinapyl alcohol dehydrogenase (SAD), which is structurally distinct from the CAD enzyme targeted herein, does not play any substantial role in constitutive lignification in poplar.

  3. Development of C-lignin with G/S-lignin and lipids in orchid seed coats – an unexpected diversity exposed by ATR-FT-IR spectroscopy

    DEFF Research Database (Denmark)

    Barsberg, Søren Talbro; Lee, Y.-I.; Rasmussen, Hanne Nina

    2018-01-01

    Cite this article: Barsberg ST, Lee Y-I, Rasmussen HN. Development of C-lignin with G/S-lignin and lipids in orchid seed coats – an unexpected diversity exposed by ATR-FT-IR spectroscopy. Seed Science Research https:// doi.org/10.1017/S0960258517000344......Cite this article: Barsberg ST, Lee Y-I, Rasmussen HN. Development of C-lignin with G/S-lignin and lipids in orchid seed coats – an unexpected diversity exposed by ATR-FT-IR spectroscopy. Seed Science Research https:// doi.org/10.1017/S0960258517000344...

  4. Adsorption of cellulase on cellulolytic enzyme lignin from lodgepole pine.

    Science.gov (United States)

    Tu, Maobing; Pan, Xuejun; Saddler, Jack N

    2009-09-09

    Enzymatic hydrolysis of lignocellulosic materials is significantly affected by cellulase adsorption onto the lignocellulosic substrates and lignin. The presence of lignin plays an important role in lignocellulosic hydrolysis and enzyme recycling. Three cellulase preparations (Celluclast, Spezyme CP, and MSUBC) were evaluated to determine their adsorption onto cellulolytic enzyme lignin (CEL) from steam-exploded Lodgepole pine (SELP) and ethanol (organosolv)-pretreated Lodgepole pine (EPLP). The adsorption affinity of cellulase (Celluclast) onto isolated lignin (CEL-EPLP and CEL-SELP) was slightly higher than that from corresponding EPLP and SELP substrates on the basis of the Langmuir constants. Effects of temperature, ionic strength, and surfactant on cellulase adsorption onto isolated lignin were also explored in this study. Thermodynamic analysis of enzyme adsorption onto isolated lignin (Gibbs free energy change DeltaG(0) approximately -30 kJ/mol) indicated this adsorption was a spontaneous process. The addition of surfactant (0.2% w/v) could reduce the adsorption of cellulase onto CEL-SELP by 60%. Two types of adsorption isotherm were compared for cellulase adsorption onto isolated lignin. A Langmuir adsorption isotherm showed better fit for the experimental data than a Freundlich adsorption isotherm.

  5. Process for conversion of lignin to reformulated hydrocarbon gasoline

    Science.gov (United States)

    Shabtai, Joseph S.; Zmierczak, Wlodzimierz W.; Chornet, Esteban

    1999-09-28

    A process for converting lignin into high-quality reformulated hydrocarbon gasoline compositions in high yields is disclosed. The process is a two-stage, catalytic reaction process that produces a reformulated hydrocarbon gasoline product with a controlled amount of aromatics. In the first stage, a lignin material is subjected to a base-catalyzed depolymerization reaction in the presence of a supercritical alcohol as a reaction medium, to thereby produce a depolymerized lignin product. In the second stage, the depolymerized lignin product is subjected to a sequential two-step hydroprocessing reaction to produce a reformulated hydrocarbon gasoline product. In the first hydroprocessing step, the depolymerized lignin is contacted with a hydrodeoxygenation catalyst to produce a hydrodeoxygenated intermediate product. In the second hydroprocessing step, the hydrodeoxygenated intermediate product is contacted with a hydrocracking/ring hydrogenation catalyst to produce the reformulated hydrocarbon gasoline product which includes various desirable naphthenic and paraffinic compounds.

  6. Production of Jet Fuel-Range Hydrocarbons from Hydrodeoxygenation of Lignin over Super Lewis Acid Combined with Metal Catalysts

    International Nuclear Information System (INIS)

    Wang, Hongliang; Wang, Huamin; Kuhn, Eric; Tucker, Melvin P.; Yang, Bin

    2017-01-01

    Super Lewis acids containing the triflate anion [e.g., Hf(OTf) 4 , Ln(OTf) 3 , In(OTf) 3 , Al(OTf) 3 ] and noble metal catalysts (e.g., Ru/C, Ru/Al2O 3 ) formed efficient catalytic systems to generate saturated hydrocarbons from lignin in high yields. In such catalytic systems, the metal triflates mediated rapid ether bond cleavage through selective bonding to etheric oxygens while the noble metal catalyzed subsequent hydrodeoxygenation (HDO) reactions. Near theoretical yields of hydrocarbons were produced from lignin model compounds by the combined catalysis of Hf(OTf)4 and ruthenium-based catalysts. When a technical lignin derived from a pilot-scale biorefinery was used, more than 30 wt % of the hydrocarbons produced with this catalytic system were cyclohexane and alkylcyclohexanes in the jet fuel range. Super Lewis acids are postulated to strongly interact with lignin substrates by protonating hydroxyl groups and ether linkages, forming intermediate species that enhance hydrogenation catalysis by supported noble metal catalysts. Meanwhile, the hydrogenation of aromatic rings by the noble metal catalysts can promote oxygenation reactions catalyzed by super Lewis acids.

  7. Production of Jet Fuel-Range Hydrocarbons from Hydrodeoxygenation of Lignin over Super Lewis Acid Combined with Metal Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hongliang [Department of Biological Systems Engineering, Washington State University, Richland WA 99354 USA; Current address: Center of Biomass Engineering/College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193 PR China; Wang, Huamin [Pacific Northwest National Laboratory, 902 Battelle Boulevard Richland WA 99354 USA; Kuhn, Eric [National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway Golden CO 80401 USA; Tucker, Melvin P. [National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway Golden CO 80401 USA; Yang, Bin [Department of Biological Systems Engineering, Washington State University, Richland WA 99354 USA

    2017-11-14

    Super Lewis acids containing the triflate anion (e.g. Hf(OTf)4, Ln(OTf)3, Al(OTf)3) and noble metal catalysts (e.g. Ru/C, Ru/Al2O3) formed efficient catalytic systems to generate saturated hydrocarbons from lignin in high yields. In such catalytic systems, the metal triflates mediated rapid ether bond cleavage via selective bonding to etheric oxygens while the noble metal catalysed subsequent hydrodeoxygenation (HDO) reactions. Near theoretical yields of hydrocarbons were produced from lignin model compounds by the combined catalysis of Hf(OTf)4 and ruthenium-based catalysts. When a technical lignin derived from a pilot-scale biorefinery was used, more than 30 wt% of the hydrocarbons produced with this catalytic system were cyclohexane and alkylcyclohexanes in the jet fuel range. Super Lewis acids are postulated to strongly interact with lignin substrates via protonating hydroxyls and ether linkages, forming intermediate species that enhance hydrogenation catalysis by supported noble metal catalysts. Meanwhile, the hydrogenation of aromatic rings by the noble metal catalysts can promote oxygenation reactions catalysed by super Lewis acids.

  8. Isolation and characterization of new lignin streams derived from extractive-ammonia (EA) pretreatment

    Energy Technology Data Exchange (ETDEWEB)

    da Costa Sousa, Leonardo [Michigan State Univ., East Lansing, MI (United States); Foston, Marcus [Washington Univ., St. Louis, MO (United States); Bokade, Vijay [National Chemical Lab., Pune (India); Azarpira, Ali [Univ. of Wisconsin, Madison, WI (United States); Lu, Fachuang [Univ. of Wisconsin, Madison, WI (United States); Ragauskas, Arthur J. [Univ. of Tennessee, Knoxville, TN (United States); Ralph, John [Univ. of Wisconsin, Madison, WI (United States); Dale, Bruce [Michigan State Univ., East Lansing, MI (United States); Balan, Venkatesh [Michigan State Univ., East Lansing, MI (United States)

    2016-05-05

    One of the key challenges facing lignin conversion to fuels and chemicals is related to the level of carbohydrate and ash impurities found in extracted lignin. Structural modifications of lignin may also occur as a result of biomass pretreatment and harsh lignin extraction protocols. Extractive-Ammonia (EA) is a new pretreatment technology that uses liquid ammonia to cleave lignin–carbohydrate complexes, decrystallize cellulose, solubilize lignin, and selectively extract lignin from lignocellulosic biomass, enabling better utilization of both lignin and carbohydrate components in a biorefinery. The EA-based biorefinery produces two different lignin-rich streams, with different properties, that could potentially be upgraded to fuels and chemicals using green processes. Here, a water/ethanol-based fractionation method was developed to enrich the ammonia-soluble extractives, resulting in a major product stream containing 92% lignin. Detailed characterization of the various streams resulting from EA treatment, including compositional analysis, structural characterization by nuclear magnetic resonance (NMR) spectrometry, elemental analysis, molecular weight analysis, and thermo-gravimetric analysis provides a broad evaluation of the EA-derived lignin product stream structures and properties, assessing their potential for commercial applications. In conclusion, EA-derived lignins preserve much of lignin's functionality, including the sensitive β-aryl ether units. Furthermore, we observed nitrogen incorporation in the lignin-rich streams, notably due to the presence of hydroxycinnamoyl amides formed during ammonia pretreatment.

  9. Lignin Formation and the Effects of Gravity: A New Approach

    Science.gov (United States)

    Lewis, Norman G.

    1997-01-01

    Two aspects of considerable importance in the enigmatic processes associated with lignification have made excellent progress. The first is that, even in a microgravity environment, compression wood formation, and hence altered lignin deposition, can be induced upon mechanically bending the stems of woody gymnosperms. It now needs to be established if an organism reorientating its woody stem tissue will generate this tissue in microgravity, in the absence of externally applied pressure. If it does not, then gravity has no effect on its formation, and instead it results from alterations in the stress gradient experienced by the organism impacted. The second area of progress involves establishing how the biochemical pathway to lignin is regulated, particularly with respect to selective monolignol biosynthesis. This is an important question since individual monomer deposition occurs in a temporally and spatially specific manner. In this regard, the elusive metabolic switch between E-p-coumaryl alcohol and E-coniferyl alcohol synthesis has been detected, the significance of which now needs to be defined at the enzyme and gene level. Switching between monolignol synthesis is important, since it is viewed to be a consequence of different perceptions by plants in the gravitational load experienced, and thus in the control of the type of lignification response. Additional experiments also revealed the rate-limiting processes involved in monolignol synthesis, and suggest that a biological system (involving metabolite concentrations, as well as enzymatic and gene (in)activation processes) is involved, rather than a single rate-limiting step.

  10. Formation of a tyrosine adduct involved in lignin degradation by Trametopsis cervina lignin peroxidase: a novel peroxidase activation mechanism

    Science.gov (United States)

    Yuta Miki; Rebecca Pogni; Sandra Acebes; Fatima Lucas; Elena Fernandez-Fueyo; Maria Camilla Baratto; Maria I. Fernandez; Vivian De Los Rios; Francisco J. Ruiz-duenas; Adalgisa Sinicropi; Riccardo Basosi; Kenneth E. Hammel; Victor Guallar; Angel T. Martinez

    2013-01-01

    LiP (lignin peroxidase) from Trametopsis cervina has an exposed catalytic tyrosine residue (Tyr181) instead of the tryptophan conserved in other lignin-degrading peroxidases. Pristine LiP showed a lag period in VA (veratryl alcohol) oxidation. However, VA-LiP (LiP after treatment with H2O2...

  11. Esterification and characterization of lignin aiming the synthesis of polymeric composite

    International Nuclear Information System (INIS)

    Victor, Priscilla A.; Machado, Fabricio

    2015-01-01

    Lignin is a natural polymer derived from lignocellulosic materials with high availability, presenting a huge potential for production of new materials. Due to its complex macromolecular structure, and its low compatibility with styrene, eucalyptus wood-extracted lignin method was esterified with methacrylic anhydride - exhibiting a yield of 64% - in order to ensure homogeneity in the organic phase into the reaction medium. The evaluation of both the natural and esterified lignin through infrared (IR) spectroscopy showed a decrease of the hydroxyl band, characteristic of natural lignin (3200-3400 cm"-"1) and an increase of the characteristic ester band (1720 to 1740 cm"-"1). According to nuclear magnetic resonance ("1H NMR) analysis on esterified lignin, intense peaks were observed in the range from 1.7 to 2.05 ppm (-CH_3) and 5.4 ppm to 6.2 ppm (=CH_2), related to methacrylic anhydride. According to the thermogravimetric analysis (TGA), the esterified lignin showed a decrease in its thermal stability when compared to natural lignin, exhibiting two main weight losses between 200 °C and 300 °C and in the interval from 550 °C to 800 °C. Comparatively, the esterified lignin also displayed an increase in its glass transition temperature (Tg = 98 °C) for, when compared to natural lignin, whose Tg value was determined to be equal to 91 °C. (author)

  12. Genetic loci simultaneously controlling lignin monomers and biomass digestibility of rice straw.

    Science.gov (United States)

    Hu, Zhen; Zhang, Guifen; Muhammad, Ali; Samad, Rana Abdul; Wang, Youmei; Walton, Jonathan D; He, Yuqing; Peng, Liangcai; Wang, Lingqiang

    2018-02-26

    Lignin content and composition are crucial factors affecting biomass digestibility. Exploring the genetic loci simultaneously affecting lignin-relevant traits and biomass digestibility is a precondition for lignin genetic manipulation towards energy crop breeding. In this study, a high-throughput platform was employed to assay the lignin content, lignin composition and biomass enzymatic digestibility of a rice recombinant inbred line population. Correlation analysis indicated that the absolute content of lignin monomers rather than lignin content had negative effects on biomass saccharification, whereas the relative content of p-hydroxyphenyl unit and the molar ratio of p-hydroxyphenyl unit to guaiacyl unit exhibited positive roles. Eight QTL clusters were identified and four of them affecting both lignin composition and biomass digestibility. The additive effects of clustered QTL revealed consistent relationships between lignin-relevant traits and biomass digestibility. Pyramiding rice lines containing the above four positive alleles for increasing biomass digestibility were selected and showed comparable lignin content, decreased syringyl or guaiacyl unit and increased molar percentage of p-hydroxyphenyl unit, the molar ratio of p-hydroxyphenyl unit to guaiacyl unit and sugar releases. More importantly, the lodging resistance and eating/cooking quality of pyramiding lines were not sacrificed, indicating the QTL information could be applied to select desirable energy rice lines.

  13. Dissolved Vanillin as Tracer for Estuarine Lignin Conversion

    Science.gov (United States)

    Edelkraut, F.

    1996-12-01

    Lignin is produced only by vascular plants and therefore can be used as a tracer for terrestrial organic carbon input to the estuarine and marine environments. Lignin measurements have been done by analyses of the oxidation products such as vanillin or 4-hydroxybenzaldehyde. In the Elbe Estuary, free dissolved vanillin was analysed in order to test whether such measurements yield information on terrestrial carbon inputs into the Estuary and on the vanillin derived from lignin oxidation. In the period 1990-1992, concentrations of dissolved vanillin in the Elbe ranged from 0 to 60 μ g l -1(mean: 8 μg l -1). Higher values were found in areas of increased microbial activity such as the turbidity zone and the river mouth where the water chemistry is influenced by large tidal flats. No correlation was found between dissolved vanillin and suspended matter concentrations, although lignin is normally associated with suspended particulate matter, nor was a covariance seen between dissolved vanillin and the terrestrial carbon inputs into the Estuary. Apparently, biological conversion of lignin was faster than the transport processes, and local sources were more dominant for the vanillin concentration than riverine sources. The dissolved vanillin turnover was fast and, consequently, a significant amount of lignin may be converted within an estuary. In sediments from the Estuary, the concentrations of dissolved vanillin were similar to those found in the water phase and showed no clear vertical profile. The sediment is unlikely to be the source for vanillin.

  14. Abundance and reactivity of dibenzodioxocins in softwood lignin.

    Science.gov (United States)

    Argyropoulos, Dimitris S; Jurasek, Lubo; Kristofová, Lívia; Xia, Zhicheng; Sun, Yujun; Palus, Ernest

    2002-02-13

    To define the abundance and comprehend the reactivity of dibenzodioxocins in lignin, model compound studies, specific degradation experiments on milled wood lignin, and molecular modeling calculations have been performed. Quantitative (31)P NMR measurements of the increase of biphenolic hydroxyl groups formed after a series of alkaline degradations in the presence of hydrosulfide anions (kraft conditions) showed the presence of 3.7 dibenzodioxocin rings/100 C9 units in milled wood lignin. The DFRC degradation protocol (Derivatization Followed by Reductive Cleavage) was chosen as an independent means to estimate their abundance. Initial experiments with a dibenzodioxocin model compound, trans-6,7-dihydro-7-(4-hydroxy-3-methoxyphenyl)-4,9-dimethoxy-2,11-dipropyldibenzo[e,g][1,4]dioxocin-6-ylmethanol, showed that it is not cleaved under DFRC conditions, but rather it isomerizes into a cyclic oxepine structure. Steric effects precluded this isomerization from occurring when DFRC was applied to milled wood lignin. Instead, monoacetylated biphenolic moieties were released and quantified by (31)P NMR, at 4.3 dibenzodioxocin rings/100 C9 units. The dibenzodioxocin content in residual lignins isolated from kraft pulps delignified to various degrees showed that during pulp delignification, the initial rate of dibenzodioxocin removal was considerably greater than the cleavage rate of arylglycerol-beta-aryl ether bonds. The activation energy for the degradation of dibenzodioxocins under kraft conditions in milled wood lignin was 96 +/- 9 kJ/mol, similar to that of arylglycerol-beta-aryl ether bond cleavage.

  15. Fast Pyrolysis of Four Lignins from Different Isolation Processes Using Py-GC/MS

    OpenAIRE

    Lin, Xiaona; Sui, Shujuan; Tan, Shun; Pittman, Charles; Sun, Jianping; Zhang, Zhijun

    2015-01-01

    Pyrolysis is a promising approach that is being investigated to convert lignin into higher value products including biofuels and phenolic chemicals. In this study, fast pyrolysis of four types of lignin, including milled Amur linden wood lignin (MWL), enzymatic hydrolysis corn stover lignin (EHL), wheat straw alkali lignin (AL) and wheat straw sulfonate lignin (SL), were performed using pyrolysis gas-chromatography/mass spectrometry (Py-GC/MS). Thermogravimetric analysis (TGA) showed that the...

  16. Fractionation of bamboo culms by autohydrolysis, organosolv delignification and extended delignification: understanding the fundamental chemistry of the lignin during the integrated process.

    Science.gov (United States)

    Wen, Jia-Long; Sun, Shao-Ni; Yuan, Tong-Qi; Xu, Feng; Sun, Run-Cang

    2013-12-01

    Bamboo (Phyllostachys pubescens) was successfully fractionated using a three-step integrated process: (1) autohydrolysis pretreatment facilitating xylooligosaccharide (XOS) production (2) organosolv delignification with organic acids to obtain high-purity lignin, and (3) extended delignification with alkaline hydrogen peroxide (AHP) to produce purified pulp. The integrated process was comprehensively evaluated by component analysis, SEM, XRD, and CP-MAS NMR techniques. Emphatically, the fundamental chemistry of the lignin fragments obtained from the integrated process was thoroughly investigated by gel permeation chromatography and solution-state NMR techniques (quantitative (13)C, 2D-HSQC, and (31)P-NMR spectroscopies). It is believed that the integrated process facilitate the production of XOS, high-purity lignin, and purified pulp. Moreover, the enhanced understanding of structural features and chemical reactivity of lignin polymers will maximize their utilizations in a future biorefinery industry. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Lignins : natural polymers from oxidative coupling of 4-hydroxyphenyl-propanoids

    Science.gov (United States)

    John Ralph; Knut Lundquist; Gosta Brunow; Fachuang Lu; Hoon Kim; Paul F. Schatz; Jane M. Marita; Ronald D. Hatfield; Sally A. Ralph; Jorgen Holst Christensen; Wout Boerjan

    2004-01-01

    Lignins are complex natural polymers resulting from oxidative coupling of, primarily, 4-hydroxyphenylpropanoids. An understanding of their nature is evolving as a result of detailed structural studies, recently aided by the availability of lignin-biosynthetic-pathway mutants and transgenics. The currently accepted theory is that the lignin polymer is formed by...

  18. Lignin-solubilizing ability of actinomycetes isolated from termite (Termitidae) gut

    International Nuclear Information System (INIS)

    Pasti, M.B.; Crawford, D.L.; Pometto, A.L. III; Nuti, M.P.

    1990-01-01

    The lignocellulose-degrading abilities of 11 novel actinomycete strains isolated from termite gut were determined and compared with that of the well-characterized actinomycete, Streptomyces viridosporus T7A. Lignocellulose bioconversion was followed by (i) monitoring the degradation of [ 14 C]lignin- and [ 14 C]cellulose-labeled phloem of Abies concolor to 14 CO 2 and 14 C-labeled water-soluble products, (ii) determining lignocellulose, lignin, and carbohydrate losses resulting from growth on a lignocellulose substrate prepared from corn stalks (Zea mays), and (iii) quantifying production of a water-soluble lignin degradation intermediate (acid-precipitable polymeric lignin). Of the assays used, total lignocellulose weight loss was most useful in determining overall bioconversion ability but not in identifying the best lignin-solubilizing strains. A screening procedure based on 14 CO 2 evolution from [ 14 C-lignin]lignocellulose combined with measurement of acid-precipitable polymeric lignin yield was the most effective in identifying lignin-solubilizing strains. For the termite gut strains, the pH of the medium showed no increase after 3 weeks of growth on lignocellulose. This is markedly different from the pattern observed with S. viridosporus T7A, which raises the medium pH considerably. Production of extracellular peroxidases by the 11 strains and S. viridosporus T7A was followed for 5 days in liquid cultures. On the basis of an increase of specific peroxidase activity in the presence of lignocellulose in the medium, the actinomycetes could be placed into the same three groups

  19. Genome Sequence of Streptomyces viridosporus Strain T7A ATCC 39115, a Lignin-Degrading Actinomycete

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Jennifer R. [Brown University; Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Teshima, Hazuki [Los Alamos National Laboratory (LANL); Detter, J. Chris [U.S. Department of Energy, Joint Genome Institute; Tapia, Roxanne [Los Alamos National Laboratory (LANL); Han, Cliff [Los Alamos National Laboratory (LANL); Huntemann, Marcel [U.S. Department of Energy, Joint Genome Institute; Wei, Chia-Lin [Los Alamos National Laboratory (LANL); Han, James [U.S. Department of Energy, Joint Genome Institute; Chen, Amy [U.S. Department of Energy, Joint Genome Institute; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Mavromatis, K [U.S. Department of Energy, Joint Genome Institute; Szeto, Ernest [U.S. Department of Energy, Joint Genome Institute; Markowitz, Victor [U.S. Department of Energy, Joint Genome Institute; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Mikhailova, Natalia [U.S. Department of Energy, Joint Genome Institute; Ovchinnikova, Galina [U.S. Department of Energy, Joint Genome Institute; Pagani, Ioanna [U.S. Department of Energy, Joint Genome Institute; Pati, Amrita [U.S. Department of Energy, Joint Genome Institute; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute; Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Peters, Lin [U.S. Department of Energy, Joint Genome Institute; Nolan, Matt [U.S. Department of Energy, Joint Genome Institute; Land, Miriam L [ORNL; Sello, Jason K. [Brown University

    2013-01-01

    We announce the availability of the genome sequence of Streptomyces viridosporus strain T7A ATCC 39115, a plant biomass- degrading actinomycete. This bacterium is of special interest because of its capacity to degrade lignin, an underutilized compo- nent of plants in the context of bioenergy. It has a full complement of genes for plant biomass catabolism.

  20. Lignin transformations and reactivity upon ozonation in aqueous media

    Science.gov (United States)

    Khudoshin, A. G.; Mitrofanova, A. N.; Lunin, V. V.

    2012-03-01

    The reaction of ozone with lignin in aqueous acidic solutions is investigated. The Danckwerst model is used to describe the kinetics of gas/liquid processes occurring in a bubble reactor. The efficient ozonation rate of a soluble lignin analog, sodium lignosulfate, is determined. The main lines of the reaction between ozone and lignin are revealed on the basis of kinetic analysis results and IR and UV spectroscopy data.

  1. Towards development of lignin reinforced elastomeric compounds with reduced energy dissipation

    Science.gov (United States)

    Bahl, Kushal

    This research deals with development of lignin as reinforcing filler for elastomeric compounds. Lignins are naturally abundant and cost competitive wood derivatives possessing strong mechanical properties and offering reactive functional groups on their surfaces. The presence of the functional groups imparts polarity to the lignin molecules and makes them incompatible with non-polar elastomers. Also, the large particle size of lignin does not produce desired mechanical reinforcement. The present study deals with solving the outstanding issues associated with the use of lignin as fillers for polymeric compounds. In addition, the work specifically focuses on producing rubber compounds with reduced energy dissipation via partial replacement of carbon black with lignin. The first part of this study is devoted to suppression of the polarity of lignin and achievement of compatibility with rubber matrix via modification of lignosulfonates (LS) with cyclohexylamine (CA). CA reduces the polarity of lignin via interactions originating from proton transfer and hydrogen bonding. X-ray Photoelectron Spectroscopy (XPS) confirms the attachment of CA on the surfaces of lignin. The mechanical properties of rubber compounds increase substantially along with improvement in cure properties and increase in crosslink density in the presence of LS particles modified with CA. The tensile strength and storage modulus show an increase by 45% and 41% respectively. The values of the 100% modulus and elongation at break also improve by 35% and 60% respectively. The second part of this study exploits the non-covalent interactions between lignin and carbon black (CB) for the design of novel hybrid filler particles exhibiting lower energy loss in rubber compounds. The hybrid fillers offer unique morphology consisting of coating layers of lignin on carbon black particle aggregates. It is found that such coating layers are formed due to pi-pi interactions between lignin and carbon black. Raman

  2. Electron-beam mediated dry distillation of lignin

    International Nuclear Information System (INIS)

    Chulkov, V.N.; Bludenko, A.V.; Ponomarev, A.V.

    2007-01-01

    Radiation heating was studied for its application in dry distillation of lignin under high absorbed-dose irradiation with no supplementary heating device used. Commercial preparation Polyphepan containing lignin (90 wt.%) and cellulose (10 wt.%), dried at 102 deg C, was used. The test samples were exposed to 8 MeV electron beams on U-003 linear accelerator under atmospheric pressure, with dose rates of 3.6 and 4.8 kGy/s. It is demonstrated that an increased yield of liquid products of dry lignin distillation is observed under conditions studied with a two-fold decrease in energy consumption due to more favorable heating conditions and intensification of free-radical reactions [ru

  3. Membrane Technology for the Recovery of Lignin: A Review

    Directory of Open Access Journals (Sweden)

    Daniel Humpert

    2016-09-01

    Full Text Available Utilization of renewable resources is becoming increasingly important, and only sustainable processes that convert such resources into useful products can achieve environmentally beneficial economic growth. Wastewater from the pulp and paper industry is an unutilized resource offering the potential to recover valuable products such as lignin, pigments, and water [1]. The recovery of lignin is particularly important because it has many applications, and membrane technology has been investigated as the basis of innovative recovery solutions. The concentration of lignin can be increased from 62 to 285 g∙L−1 using membranes and the recovered lignin is extremely pure. Membrane technology is also scalable and adaptable to different waste liquors from the pulp and paper industry.

  4. Membrane Technology for the Recovery of Lignin: A Review

    Science.gov (United States)

    Humpert, Daniel; Ebrahimi, Mehrdad; Czermak, Peter

    2016-01-01

    Utilization of renewable resources is becoming increasingly important, and only sustainable processes that convert such resources into useful products can achieve environmentally beneficial economic growth. Wastewater from the pulp and paper industry is an unutilized resource offering the potential to recover valuable products such as lignin, pigments, and water [1]. The recovery of lignin is particularly important because it has many applications, and membrane technology has been investigated as the basis of innovative recovery solutions. The concentration of lignin can be increased from 62 to 285 g∙L−1 using membranes and the recovered lignin is extremely pure. Membrane technology is also scalable and adaptable to different waste liquors from the pulp and paper industry. PMID:27608047

  5. Structural Changes of Lignin from Wheat Straw by Steam Explosion and Ethanol Pretreatments

    Directory of Open Access Journals (Sweden)

    Cheng Pan

    2016-06-01

    Full Text Available Effects of the pretreatment of wheat straw by steam explosion and ethanol were evaluated relative to the structural changes of lignin from the pretreated pulp. The lignin from steam explosion pulp (LS, lignin from steam blasting residual liquid (LL, lignin from ethanol pretreatment pulp (LE, lignin from black liquor (LB, and lignin from wheat straw (LW were separated, and the structural characteristics of the lignin fractions were compared based on analyses of Fourier transform-infrared, ultraviolet, thermogravimetric, and 1H and 13C nuclear magnetic resonance spectra. The proportions of the three structural units in all lignin fractions clearly changed during the pretreatment process because of inter-conversion reactions. The conjugated structure of lignin was destroyed in the pretreatment process and was also affected by the alkali extraction process. The alcoholic hydroxyl links on the aliphatic side chain were partly transformed into carbonyl groups during ethanol pretreatment. Demethoxylation occurred in all lignin fractions during the ethanol pretreatment and steam explosion process. The thermal stability of the LB fraction was relatively high because of the condensation reaction.

  6. Comparison of the degradation of 14C-labeled DHP and corn stalk lignins by micro- and macrofungi and bacteria

    International Nuclear Information System (INIS)

    Haider, K.; Trojanowski, J.

    1980-01-01

    To what extent and by which mode microfungi and bacteria from soil are able to degrade lignin have been investigated and their activity compared with those of white and brown rot Basidiomycetes. The experiments were made by means of specifically 14C-labeled DHPs prepared by polymerization of correspondingly labeled coniferyl alcohol. Also, a corn stalk material was used which was specifically labeled in the lignin part. This material was prepared by infusion of specifically labeled cinnamic acid compounds into growing maize plants. The potential of the organisms to degrade several specifically labeled phenols was determined and compared. White and brown rot fungi, as well as several microscopic fungi, were able to degrade phenolcarboxylic and cinnamic acids and even some phenolic compounds with completely alkylated phenolic hydroxl groups. They could also introduce hydroxl groups into benzoic and pi-hydroxybenzoic acids before ring cleavage. As compared to brown rot, the white rot fungi released higher amounts of CO2 from the aromatic and side chain carbons of DHP and plant lignins. Some brown rot fungi, however, had similar capacities in degrading DHP lignin as white rot fungi. They especially released more CO2 from methoxyl groups. This release was dependent upon the added carbohydrate source and could be either repressed or enhanced. Several bacteria, especially Nocardia spp. and Pseudomonas spp., were tested for their potential to degrade the labeled lignins or phenols. Most of these bacteria did not appreciably degrade lignins, although they were highly active in the metabolization of phenols. Some Nocardia spp., however, were found to have a noteworthy capacity in the degradation of lignins and phenols. Preliminary studies of the potentials of the organisms to attack labeled lignin sulfonates either in liquid or soil cultures are presented. (Refs. 100)

  7. Accumulation of proanthocyanidins and/or lignin deposition in buff-pigmented soybean seed coats may lead to frequent defective cracking.

    Science.gov (United States)

    Senda, Mineo; Yamaguchi, Naoya; Hiraoka, Miho; Kawada, So; Iiyoshi, Ryota; Yamashita, Kazuki; Sonoki, Tomonori; Maeda, Hayato; Kawasaki, Michio

    2017-03-01

    Defective cracking frequently occurs in buff-pigmented soybean seed coats, where proanthocyanidins accumulate and lignin is deposited, suggesting that proanthocyanidins and/or lignin may change physical properties and lead to defective cracking. In the seed production of many yellow soybean (Glycine max) cultivars, very low percentages of self-pigmented seeds are commonly found. This phenomenon is derived from a recessive mutation of the I gene inhibiting seed coat pigmentation. In Japan, most of these self-pigmented seeds are buff-colored, and frequently show multiple defective cracks in the seed coat. However, it is not known why cracking occurs specifically in buff seed coats. In this study, quantitative analysis was performed between yellow and buff soybean seed coats. Compared with yellow soybeans, in which defective cracking rarely occurs, contents of proanthocyanidins (PAs) and lignin were significantly higher in buff seed coats. Histochemical data of PAs and lignin in the seed coats strongly supported this result. Measurements of the physical properties of seed coats using a texture analyzer showed that a hardness value was significantly decreased in the buff seed coats. These results suggest that PA accumulation and/or lignin deposition may affect the physical properties of buff seed coats and lead to the defective cracking. This work contributes to understanding of the mechanism of defective cracking, which decreases the seed quality of soybean and related legumes.

  8. Identification of the primary mechanism for fungal lignin degradation. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-06-01

    Many lignin-degrading fungi appear to lack lignin peroxidase (LiP), an enzyme generally thought important for fungal ligninolysis. The authors are working with one of these fungi, Ceriporiopsis subvermispora, an aggressive white-rotter that selectively removes lignin from wood. During this project period, they have obtained the following principal results: new polymeric lignin model compounds were developed to assist in the elucidation of fungal ligninolytic mechanisms; experiments with one of the polymeric lignin models showed that C. subvermispora cultures which express no detectable LiP activity are nevertheless able to degrade nonphenolic lignin structures, this result is significant because LiPs were previously considered essential for fungal attack on these recalcitrant structures, which constitute about 90% of lignin; manganese peroxidases (MnPs), which C. subvermispora does produce, catalyze the peroxidation of unsaturated fatty acids to give fatty acid hydroperoxides, fatty acid hydroperoxides are also used by MnP as oxidants (in place of H{sub 2}O{sub 2}) that support the MnP catalytic cycle, these results indicate that MnP turnover in the presence of unsaturated lipids generates reactive lipid oxyradicals that could act as oxidant of other molecules; MnP-mediated lipid peroxidation results in the co-oxidative cleavage of nonphenolic lignin structures, the MnP/lipid peroxidation system may therefore provide C. subvermispora and other LiP-negative fungi with a mechanism to degrade the principal structures of lignin.

  9. Recent Progress in Producing Lignin-Based Carbon Fibers for Functional Applications

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Ryan [GrafTech International Holdings Inc.; Burwell, Deanna [GrafTech International Holdings Inc.; Dai, Xuliang [GrafTech International Holdings Inc.; Naskar, Amit [Oak Ridge National Laboratory; Gallego, Nidia [Oak Ridge National Laboratory; Akato, Kokouvi [Oak Ridge National Laboratory

    2015-10-29

    Lignin, a biopolymer, has been investigated as a renewable and low-cost carbon fiber precursor since the 1960s. Although successful lab-scale production of lignin-based carbon fibers has been reported, there are currently not any commercial producers. This paper will highlight some of the known challenges with converting lignin-based precursors into carbon fiber, and the reported methods for purifying and modifying lignin to improve it as a precursor. Several of the challenges with lignin are related to its diversity in chemical structure and purity, depending on its biomass source (e.g. hardwood, softwood, grasses) and extraction method (e.g. organosolv, kraft). In order to make progress in this field, GrafTech and Oak Ridge National Laboratory are collaborating to develop lignin-based carbon fiber technology and to demonstrate it in functional applications, as part of a cooperative agreement with the DOE Advanced Manufacturing Office. The progress made to date with producing lignin-based carbon fiber for functional applications, as well as developing and qualifying a supply chain and value proposition, are also highlighted.

  10. Effect of alkaline pretreatment on mesophilic and thermophilic anaerobic digestion of a submerged macrophyte: Inhibition and recovery against dissolved lignin during semi-continuous operation.

    Science.gov (United States)

    Koyama, Mitsuhiko; Watanabe, Keiko; Kurosawa, Norio; Ishikawa, Kanako; Ban, Syuhei; Toda, Tatsuki

    2017-08-01

    The long-term effect of alkaline pretreatment on semi-continuous anaerobic digestion (AD) of the lignin-rich submerged macrophyte Potamogeton maackianus was investigated using mesophilic and thermophilic conditions. In pretreated reactors, dissolved lignin accumulated to high levels. CH 4 production under the pretreated condition was higher than that of the untreated condition, but decreased from Days 22 (mesophilic) and 42 (thermophilic). However, CH 4 production subsequently recovered, although dissolved lignin accumulated. Further, the change in the microbial community was observed between conditions. These results suggest that dissolved lignin temporarily inhibited AD, although acclimatization to dissolved lignin occurred during long-term operation. During the steady state period, mesophilic conditions achieved a 42% increase in the CH 4 yield using pretreatment, while thermophilic conditions yielded an 8% increment. Because volatile fatty acids accumulated even after acclimatization during the thermophilic pretreated condition and was discharged with the effluent, improvement of the methanogenic step would enable enhanced CH 4 recovery. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Lignin biopolymer based triboelectric nanogenerators

    Science.gov (United States)

    Bao, Yukai; Wang, Ruoxing; Lu, Yunmei; Wu, Wenzhuo

    2017-07-01

    Ongoing research in triboelectric nanogenerators (TENGs) focuses on increasing power generation, but obstacles concerning economical and eco-friendly utilization of TENGs continue to prevail. Being the second most abundant biopolymer on earth, lignin offers a valuable opportunity for low-cost TENG applications in biomedical devices, benefitting from its biodegradability and biocompatibility. Here, we develop for the first time a lignin biopolymer based TENGs for harvesting mechanical energy in the environment, which shows great potential for self-powered biomedical devices among other applications and opens doors to new technologies that utilize otherwise wasted materials for economically feasible and ecologically friendly production of energy devices.

  12. Synthesis and characterization of biodegradable lignin nanoparticles with tunable surface properties

    NARCIS (Netherlands)

    Richter, Alexander P.; Bharti, Bhuvnesh; Armstrong, Hinton B.; Brown, Joseph S.; Plemmons, Dayne; Paunov, Vesselin N.; Stoyanov, Simeon D.; Velev, Orlin D.

    2016-01-01

    Lignin nanoparticles can serve as biodegradable carriers of biocidal actives with minimal environmental footprint. Here we describe the colloidal synthesis and interfacial design of nanoparticles with tunable surface properties using two different lignin precursors, Kraft (Indulin AT) lignin and

  13. Structural characterization of alkaline hydrogen peroxide pretreated grasses exhibiting diverse lignin phenotypes

    Science.gov (United States)

    2012-01-01

    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 p-hydroxycinnamates. 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 the susceptibility to alkaline hydrogen peroxide (AHP) pretreatment and subsequent enzymatic deconstruction. Results We were able to determine that the enzymatic hydrolysis of cellulose to to glucose (i.e. digestibility) of four grasses with relatively diverse lignin phenotypes could be correlated to total lignin content and the content of p-hydroxycinnamates, while S/G ratios did not appear to contribute to the enzymatic digestibility or delignification. The lignins of the brown midrib corn stovers tested were significantly more condensed than a typical commercial corn stover and a significant finding was that pretreatment with alkaline hydrogen peroxide increases the fraction of lignins involved in condensed linkages from 88–95% to ~99% for all the corn stovers tested, which is much more than has been reported in the literature for other pretreatments. This indicates significant scission of β-O-4 bonds by pretreatment and/or induction of lignin condensation reactions. The S/G ratios in grasses determined by analytical pyrolysis are significantly lower than values obtained using either thioacidolysis or 2DHSQC NMR due to presumed interference by ferulates. Conclusions It was found that grass cell wall polysaccharide hydrolysis by cellulolytic enzymes for grasses exhibiting a diversity of

  14. Structural characterization of alkaline hydrogen peroxide pretreated grasses exhibiting diverse lignin phenotypes

    Directory of Open Access Journals (Sweden)

    Li Muyang

    2012-06-01

    Full Text Available Abstract 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 p-hydroxycinnamates. 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 the susceptibility to alkaline hydrogen peroxide (AHP pretreatment and subsequent enzymatic deconstruction. Results We were able to determine that the enzymatic hydrolysis of cellulose to to glucose (i.e. digestibility of four grasses with relatively diverse lignin phenotypes could be correlated to total lignin content and the content of p-hydroxycinnamates, while S/G ratios did not appear to contribute to the enzymatic digestibility or delignification. The lignins of the brown midrib corn stovers tested were significantly more condensed than a typical commercial corn stover and a significant finding was that pretreatment with alkaline hydrogen peroxide increases the fraction of lignins involved in condensed linkages from 88–95% to ~99% for all the corn stovers tested, which is much more than has been reported in the literature for other pretreatments. This indicates significant scission of β-O-4 bonds by pretreatment and/or induction of lignin condensation reactions. The S/G ratios in grasses determined by analytical pyrolysis are significantly lower than values obtained using either thioacidolysis or 2DHSQC NMR due to presumed interference by ferulates. Conclusions It was found that grass cell wall polysaccharide hydrolysis by cellulolytic enzymes for grasses

  15. Combinatorial pretreatment and fermentation optimization enabled a record yield on lignin bioconversion.

    Science.gov (United States)

    Liu, Zhi-Hua; Xie, Shangxian; Lin, Furong; Jin, Mingjie; Yuan, Joshua S

    2018-01-01

    Lignin valorization has recently been considered to be an essential process for sustainable and cost-effective biorefineries. Lignin represents a potential new feedstock for value-added products. Oleaginous bacteria such as Rhodococcus opacus can produce intracellular lipids from biodegradation of aromatic substrates. These lipids can be used for biofuel production, which can potentially replace petroleum-derived chemicals. However, the low reactivity of lignin produced from pretreatment and the underdeveloped fermentation technology hindered lignin bioconversion to lipids. In this study, combinatorial pretreatment with an optimized fermentation strategy was evaluated to improve lignin valorization into lipids using R. opacus PD630. As opposed to single pretreatment, combinatorial pretreatment produced a 12.8-75.6% higher lipid concentration in fermentation using lignin as the carbon source. Gas chromatography-mass spectrometry analysis showed that combinatorial pretreatment released more aromatic monomers, which could be more readily utilized by lignin-degrading strains. Three detoxification strategies were used to remove potential inhibitors produced from pretreatment. After heating detoxification of the lignin stream, the lipid concentration further increased by 2.9-9.7%. Different fermentation strategies were evaluated in scale-up lipid fermentation using a 2.0-l fermenter. With laccase treatment of the lignin stream produced from combinatorial pretreatment, the highest cell dry weight and lipid concentration were 10.1 and 1.83 g/l, respectively, in fed-batch fermentation, with a total soluble substrate concentration of 40 g/l. The improvement of the lipid fermentation performance may have resulted from lignin depolymerization by the combinatorial pretreatment and laccase treatment, reduced inhibition effects by fed-batch fermentation, adequate oxygen supply, and an accurate pH control in the fermenter. Overall, these results demonstrate that combinatorial

  16. Peracetic Acid Depolymerization of Biorefinery Lignin for Production of Selective Monomeric Phenolic Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Ruoshui [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA; Guo, Mond [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA; Lin, Kuan-ting [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA; Hebert, Vincent R. [Food and Environmental Laboratory, Washington State, University-TriCities, 2710 Crimson Way Richland WA 99354 USA; Zhang, Jinwen [Wood Materials and Engineering Laboratory, Washington State University, Pullman WA 99164 USA; Wolcott, Michael P. [Wood Materials and Engineering Laboratory, Washington State University, Pullman WA 99164 USA; Quintero, Melissa [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA; Ramasamy, Karthikeyan K. [Chemical and Biological Process Development Group, Pacific Northwest National Laboratory, Richland WA 99354 USA; Chen, Xiaowen [National Bioenergy Center, National Renewable Energy Lab, 1617 Cole Blvd Golden CO 80127 USA; Zhang, Xiao [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA

    2016-07-04

    Lignin is the largest source of renewable material with an aromatic skeleton. However, due to the recalcitrant and heterogeneous nature of the lignin polymer, it has been a challenge to effectively depolymerize lignin and produce high-value chemicals with high selectivity. In this study, a highly efficient lignin-to-monomeric phenolic compounds (MPC) conversion method based on peracetic acid (PAA) treatment was reported. PAA treatment of two biorefinery lignin samples, diluted acid pretreated corn stover lignin (DACSL) and steam exploded spruce lignin (SESPL), led to complete solubilization and production of selective hydroxylated monomeric phenolic compounds (MPC-H) and monomeric phenolic acid compounds (MPC-A) including 4-hydroxy-2-methoxyphenol, p-hydroxybenzoic acid, vanillic acid, syringic acid, and 3,4-dihydroxybenzoic acid. The maximized MPC yields obtained were 18 and 22 % based on the initial weight of the lignin in SESPL and DACSL, respectively. However, we found that the addition of niobium pentoxide catalyst to PAA treatment of lignin can significantly improve the MPC yields up to 47 %. The key reaction steps and main mechanisms involved in this new lignin-to-MPC valorization pathway were investigated and elucidated.

  17. Peracetic Acid Depolymerization of Biorefinery Lignin for Production of Selective Monomeric Phenolic Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Ruoshui [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA; Guo, Mond [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA; Lin, Kuan-ting [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA; Hebert, Vincent R. [Food and Environmental Laboratory, Washington State, University-TriCities, 2710 Crimson Way Richland WA 99354 USA; Zhang, Jinwen [Wood Materials and Engineering Laboratory, Washington State University, Pullman WA 99164 USA; Wolcott, Michael P. [Wood Materials and Engineering Laboratory, Washington State University, Pullman WA 99164 USA; Quintero, Melissa [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA; Ramasamy, Karthikeyan K. [Chemical and Biological Process Development Group, Pacific Northwest National Laboratory, Richland WA 99354 USA; Chen, Xiaowen [National Bioenergy Center, National Renewable Energy Lab, 1617 Cole Blvd Golden CO 80127 USA; Zhang, Xiao [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA

    2016-07-04

    Lignin is the largest source of renewable material with an aromatic skeleton. However, due to the recalcitrant and heterogeneous nature of the lignin polymer as well as its complex side chain structures, it has been a challenge to effectively depolymerize lignin and produce high value chemicals with high selectivity. In this study, a highly efficient lignin-to-monomeric phenolic compounds (MPC) conversion method based on peracetic acid (PAA) treatment was reported. PAA treatment of two biorefinery lignin samples, diluted acid pretreated corn stover lignin (DACSL) and steam exploded spruce lignin (SESPL), led to complete solubilization and production of selective hydroxylated monomeric phenolic compounds (MPC-H) and monomeric phenolic acid compounds (MPC-A) inclduing 4-hydroxy-2-methoxyphenol, p-hydroxybenzoic acid, vanillic acid, syringic acid, and 3,4-dihydroxybenzoic acid. The maximized MPCs yields obtained were 18% and 22% based on the initial weight of the lignin in SESPL and DACSL respectively. However, we found that the addition of niobium pentoxide catalyst to PAA treatment of lignin can significantly improve the MPC yields up to 47%. The key reaction steps and main mechanisms involved in this new lignin-to-MPC valorization pathway were investigated and elucidated.

  18. Dual role of lignin in plant litter decomposition in terrestrial ecosystems.

    Science.gov (United States)

    Austin, Amy T; Ballaré, Carlos L

    2010-03-09

    Plant litter decomposition is a critical step in the formation of soil organic matter, the mineralization of organic nutrients, and the carbon balance in terrestrial ecosystems. Biotic decomposition in mesic ecosystems is generally negatively correlated with the concentration of lignin, a group of complex aromatic polymers present in plant cell walls that is recalcitrant to enzymatic degradation and serves as a structural barrier impeding microbial access to labile carbon compounds. Although photochemical mineralization of carbon has recently been shown to be important in semiarid ecosystems, litter chemistry controls on photodegradative losses are not understood. We evaluated the importance of litter chemistry on photodegradation of grass litter and cellulose substrates with varying levels of lignin [cellulose-lignin (CL) substrates] under field conditions. Using wavelength-specific light attenuation filters, we found that light-driven mass loss was promoted by both UV and visible radiation. The spectral dependence of photodegradation correlated with the absorption spectrum of lignin but not of cellulose. Field incubations demonstrated that increasing lignin concentration reduced biotic decomposition, as expected, but linearly increased photodegradation. In addition, lignin content in CL substrates consistently decreased in photodegradative incubations. We conclude that lignin has a dual role affecting litter decomposition, depending on the dominant driver (biotic or abiotic) controlling carbon turnover. Under photodegradative conditions, lignin is preferentially degraded because it acts as an effective light-absorbing compound over a wide range of wavelengths. This mechanistic understanding of the role of lignin in plant litter decomposition will allow for more accurate predictions of carbon dynamics in terrestrial ecosystems.

  19. Cellulase-lignin interactions in the enzymatic hydrolysis of lignocellulose

    Energy Technology Data Exchange (ETDEWEB)

    Rahikainen, J.

    2013-11-01

    Today, the production of transportation fuels and chemicals is heavily dependent on fossil carbon sources, such as oil and natural gas. Their limited availability and the environmental concerns arising from their use have driven the search for renewable alternatives. Lignocellulosic plant biomass is the most abundant, but currently underutilised, renewable carbon-rich resource for fuel and chemical production. Enzymatic degradation of structural polysaccharides in lignocellulose produces soluble carbohydrates that serve as ideal precursors for the production of a vast amount of different chemical compounds. The difficulty in full exploitation of lignocellulose for fuel and chemical production lies in the complex and recalcitrant structure of the raw material. Lignocellulose is mainly composed of structural polysaccharides, cellulose and hemicellulose, but also of lignin, which is an aromatic polymer. Enzymatic degradation of cellulose and hemicellulose is restricted by several substrate- and enzyme-related factors, among which lignin is considered as one of the most problematic issues. Lignin restricts the action of hydrolytic enzymes and enzyme binding onto lignin has been identified as a major inhibitory mechanism preventing efficient hydrolysis of lignocellulosic feedstocks. In this thesis, the interactions between cellulase enzymes and lignin-rich compounds were studied in detail and the findings reported in this work have the potential to help in controlling the harmful cellulase-lignin interactions, and thus improve the biochemical processing route from lignocellulose to fuels and chemicals.

  20. Thermochemical Conversion of Lignin for Fuels and Chemicals: A Review Conversion thermochimique de la lignine en carburants et produits chimiques : une revue

    Directory of Open Access Journals (Sweden)

    Joffres B.

    2013-10-01

    Full Text Available Lignin is one of the biomass components potentially usable as renewable resource to produce fuels or chemicals. After separation from the lignocellulosic matrix, this macromolecule is nowadays essentially valorized by combustion in paper mills. If second generation ethanol is produced in the future from lignocellulosic biomass, some increasing reserves of lignin will be available in addition to the ones coming from the paper industry. The main thermochemical ways such as pyrolysis, solvolysis, hydrothermal conversion and hydroconversion considered for the valorization of the lignin are reviewed in this article. La lignine est une des composantes de la biomasse lignocellulosique potentiellement valorisable comme ressource renouvelable pour la production de carburants ou de produits chimiques. Après séparation de la matrice lignocellulosique, cette macromolécule est de nos jours essentiellement utilisée comme combustible dans l’industrie papetière. Outre cette filière papetière, la production d’éthanol de seconde génération à partir de la cellulose aura comme conséquence la mise à disponibilité d’encore plus grandes quantités de lignine. De nouvelles applications pourront donc être proposées pour l’utilisation de cette bio-ressource. Les différentes voies thermochimiques : pyrolyse, solvolyse, conversion hydrothermale et hydroconversion envisagées pour la valorisation de la lignine sont décrites dans cet article.

  1. Production of Jet Fuel-Range Hydrocarbons from Hydrodeoxygenation of Lignin over Super Lewis Acid Combined with Metal Catalysts.

    Science.gov (United States)

    Wang, Hongliang; Wang, Huamin; Kuhn, Eric; Tucker, Melvin P; Yang, Bin

    2018-01-10

    Super Lewis acids containing the triflate anion [e.g., Hf(OTf) 4 , Ln(OTf) 3 , In(OTf) 3 , Al(OTf) 3 ] and noble metal catalysts (e.g., Ru/C, Ru/Al 2 O 3 ) formed efficient catalytic systems to generate saturated hydrocarbons from lignin in high yields. In such catalytic systems, the metal triflates mediated rapid ether bond cleavage through selective bonding to etheric oxygens while the noble metal catalyzed subsequent hydrodeoxygenation (HDO) reactions. Near theoretical yields of hydrocarbons were produced from lignin model compounds by the combined catalysis of Hf(OTf) 4 and ruthenium-based catalysts. When a technical lignin derived from a pilot-scale biorefinery was used, more than 30 wt % of the hydrocarbons produced with this catalytic system were cyclohexane and alkylcyclohexanes in the jet fuel range. Super Lewis acids are postulated to strongly interact with lignin substrates by protonating hydroxyl groups and ether linkages, forming intermediate species that enhance hydrogenation catalysis by supported noble metal catalysts. Meanwhile, the hydrogenation of aromatic rings by the noble metal catalysts can promote deoxygenation reactions catalyzed by super Lewis acids. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Modified lignin: Preparation and use in reversible gel via Diels-Alder reaction.

    Science.gov (United States)

    Zhou, Wanpeng; Zhang, Hui; Chen, Fangeng

    2018-02-01

    In this study, popular soda lignin was modified with either furan or maleimide ring, and the modified lignins were subjected to reversible Diels-Alder reaction. A new process was proposed to prepare the functionalized lignin. A long chain was introduced to the hydroxyl groups of lignin, and then either the furan or maleimide ring was added to the other end of the chain. The test results confirmed that either the furan ring or the maleimide ring was bound to lignin. Furan- and maleimide-functionalized lignins were also combined to generate crosslinking via Diels-Alder [4+2] cycloaddition reaction. Under appropriate conditions, the formation of a gel was identified, which reverted to liquid state after retro Diels-Alder reaction upon heating at 120°C. This study reveals the significant versatility and potential of the developed strategy for the utilization of lignin-based recyclable networks. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. EFFECT OF LIGNIN CONTENT ON ENZYMATIC HYDROLYSIS OF FURFURAL RESIDUES

    Directory of Open Access Journals (Sweden)

    Jianxin Jiang

    2011-02-01

    Full Text Available The enzymatic saccharification of pretreated furfural residues with different lignin content was studied to verify the effect of lignin removal in the hydrolysis process. The results showed that the glucose yield was improved by increasing the lignin removal. A maximum glucose yield of 96.8% was obtained when the residue with a lignin removal of 51.4% was hydrolyzed for 108 h at an enzyme loading of 25 FPU/g cellulose. However, further lignin removal did not increase the hydrolysis. The effect of enzyme loading on the enzymatic hydrolysis was also explored in this work. It was concluded that a high glucose yield of 90% was achieved when the enzyme dosage was reduced from 25 to 15 FPU/g cellulose, which was cost-effective for the sugar and ethanol production. The structures of raw material and delignified samples were further characterized by XRD and scanning electron microscopy (SEM.

  4. Tunable Thermosetting Epoxies Based on Fractionated and Well-Characterized Lignins.

    Science.gov (United States)

    Gioia, Claudio; Lo Re, Giada; Lawoko, Martin; Berglund, Lars

    2018-03-21

    Here we report the synthesis of thermosetting resins from low molar mass Kraft lignin fractions of high functionality, refined by solvent extraction. Such fractions were fully characterized by 31 P NMR, 2D-HSQC NMR, SEC, and DSC in order to obtain a detailed description of the structures. Reactive oxirane moieties were introduced on the lignin backbone under mild reaction conditions and quantified by simple 1 H NMR analysis. The modified fractions were chemically cross-linked with a flexible polyether diamine ( M n ≈ 2000), in order to obtain epoxy thermosets. Epoxies from different lignin fractions, studied by DSC, DMA, tensile tests, and SEM, demonstrated substantial differences in terms of thermo-mechanical properties. For the first time, strong relationships between lignin structures and epoxy properties could be demonstrated. The suggested approach provides unprecedented possibilities to tune network structure and properties of thermosets based on real lignin fractions, rather than model compounds.

  5. Fast Pyrolysis of Lignin Using a Pyrolysis Centrifuge Reactor

    DEFF Research Database (Denmark)

    Trinh, Ngoc Trung; Jensen, Peter Arendt; Sárossy, Zsuzsa

    2013-01-01

    Fast pyrolysis of lignin from an ethanol plant was investigated on a lab scale pyrolysis centrifuge reactor (PCR) with respect to pyrolysis temperature, reactor gas residence time, and feed rate. A maximal organic oil yield of 34 wt % dry basis (db) (bio-oil yield of 43 wt % db) is obtained...... at temperatures of 500−550 °C, reactor gas residence time of 0.8 s, and feed rate of 5.6 g/min. Gas chromatography mass spectrometry and size-exclusion chromatography were used to characterize the Chemical properties of the lignin oils. Acetic acid, levoglucosan, guaiacol, syringols, and p-vinylguaiacol are found...... components and molecular mass distribution of the lignin oils. The obtained lignin oil has a very different components composition when compared to a beech wood oil....

  6. Peracetic Acid Depolymerization of Biorefinery Lignin for Production of Selective Monomeric Phenolic Compounds.

    Science.gov (United States)

    Ma, Ruoshui; Guo, Mond; Lin, Kuan-Ting; Hebert, Vincent R; Zhang, Jinwen; Wolcott, Michael P; Quintero, Melissa; Ramasamy, Karthikeyan K; Chen, Xiaowen; Zhang, Xiao

    2016-07-25

    Lignin is the largest source of renewable material with an aromatic skeleton. However, due to the recalcitrant and heterogeneous nature of the lignin polymer, it has been a challenge to effectively depolymerize lignin and produce high-value chemicals with high selectivity. In this study, a highly efficient lignin-to-monomeric phenolic compounds (MPC) conversion method based on peracetic acid (PAA) treatment was reported. PAA treatment of two biorefinery lignin samples, diluted acid pretreated corn stover lignin (DACSL) and steam exploded spruce lignin (SESPL), led to complete solubilization and production of selective hydroxylated monomeric phenolic compounds (MPC-H) and monomeric phenolic acid compounds (MPC-A) including 4-hydroxy-2-methoxyphenol, p-hydroxybenzoic acid, vanillic acid, syringic acid, and 3,4-dihydroxybenzoic acid. The maximized MPC yields obtained were 18 and 22 % based on the initial weight of the lignin in SESPL and DACSL, respectively. However, we found that the addition of niobium pentoxide catalyst to PAA treatment of lignin can significantly improve the MPC yields up to 47 %. The key reaction steps and main mechanisms involved in this new lignin-to-MPC valorization pathway were investigated and elucidated. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Fast Pyrolysis of Four Lignins from Different Isolation Processes Using Py-GC/MS

    Directory of Open Access Journals (Sweden)

    Xiaona Lin

    2015-06-01

    Full Text Available Pyrolysis is a promising approach that is being investigated to convert lignin into higher value products including biofuels and phenolic chemicals. In this study, fast pyrolysis of four types of lignin, including milled Amur linden wood lignin (MWL, enzymatic hydrolysis corn stover lignin (EHL, wheat straw alkali lignin (AL and wheat straw sulfonate lignin (SL, were performed using pyrolysis gas-chromatography/mass spectrometry (Py-GC/MS. Thermogravimetric analysis (TGA showed that the four lignins exhibited widely different thermolysis behaviors. The four lignins had similar functional groups according to the FTIR analysis. Syringyl, guaiacyl and p-hydroxyphenylpropane structural units were broken down during pyrolysis. Fast pyrolysis product distributions from the four lignins depended strongly on the lignin origin and isolation process. Phenols were the most abundant pyrolysis products from MWL, EHL and AL. However, SL produced a large number of furan compounds and sulfur compounds originating from kraft pulping. The effects of pyrolysis temperature and time on the product distributions from corn stover EHL were also studied. At 350 °C, EHL pyrolysis mainly produced acids and alcohols, while phenols became the main products at higher temperature. No obvious influence of pyrolysis time was observed on EHL pyrolysis product distributions.

  8. Demonstration of Lignin-to-Peroxidase Direct Electron Transfer

    Science.gov (United States)

    Sáez-Jiménez, Verónica; Baratto, Maria Camilla; Pogni, Rebecca; Rencoret, Jorge; Gutiérrez, Ana; Santos, José Ignacio; Martínez, Angel T.; Ruiz-Dueñas, Francisco Javier

    2015-01-01

    Versatile peroxidase (VP) is a high redox-potential peroxidase of biotechnological interest that is able to oxidize phenolic and non-phenolic aromatics, Mn2+, and different dyes. The ability of VP from Pleurotus eryngii to oxidize water-soluble lignins (softwood and hardwood lignosulfonates) is demonstrated here by a combination of directed mutagenesis and spectroscopic techniques, among others. In addition, direct electron transfer between the peroxidase and the lignin macromolecule was kinetically characterized using stopped-flow spectrophotometry. VP variants were used to show that this reaction strongly depends on the presence of a solvent-exposed tryptophan residue (Trp-164). Moreover, the tryptophanyl radical detected by EPR spectroscopy of H2O2-activated VP (being absent from the W164S variant) was identified as catalytically active because it was reduced during lignosulfonate oxidation, resulting in the appearance of a lignin radical. The decrease of lignin fluorescence (excitation at 355 nm/emission at 400 nm) during VP treatment under steady-state conditions was accompanied by a decrease of the lignin (aromatic nuclei and side chains) signals in one-dimensional and two-dimensional NMR spectra, confirming the ligninolytic capabilities of the enzyme. Simultaneously, size-exclusion chromatography showed an increase of the molecular mass of the modified residual lignin, especially for the (low molecular mass) hardwood lignosulfonate, revealing that the oxidation products tend to recondense during the VP treatment. Finally, mutagenesis of selected residues neighboring Trp-164 resulted in improved apparent second-order rate constants for lignosulfonate reactions, revealing that changes in its protein environment (modifying the net negative charge and/or substrate accessibility/binding) can modulate the reactivity of the catalytic tryptophan. PMID:26240145

  9. Structure variations of carbonizing lignin

    International Nuclear Information System (INIS)

    Otani, C.; Polidoro, H.A.; Otani, S.; Craievich, A.F.

    1984-01-01

    The studied lignin is a by-product of the process of ethanol production from eucaliptus. It was heat-treated under inert atmosphere conditions at increasing temperatures from 300C up to 2400C. The structural variations were studied by wide-angle X-ray diffraction, small-angle X-ray scattering and infrared absorption spectroscopy. The bulk and 'real' density of the compacted materials have also been determined as functions of the final temperature. These experimental results enabled us to establish a mechanism of structure variation based on the formation of a turbostratic graphite-like and porous structure within the initially amorphous lignin matrix. (Author) [pt

  10. Effects of lignin and surfactant on adsorption and hydrolysis of cellulases on cellulose

    OpenAIRE

    Li, Yanfei; Sun, Zongping; Ge, Xiaoyan; Zhang, Junhua

    2016-01-01

    Background Considerable works have been reported concerning the obstruction of enzymatic hydrolysis efficiency by lignin. However, there is a lack of information about the influence of lignin on the adsorption of cellulases on cellulose, along with the hydrolytic activity of the cellulases adsorbed on lignin. In addition, limited discovery has been reported about the influence of additives on cellulase desorption from lignin and lignocellulosic materials. In this work, the effects of lignin o...

  11. Unravelling Some of the Key Transformations in the Hydrothermal Liquefaction of Lignin.

    Science.gov (United States)

    Lui, Matthew Y; Chan, Bun; Yuen, Alexander K L; Masters, Anthony F; Montoya, Alejandro; Maschmeyer, Thomas

    2017-05-22

    Using both experimental and computational methods, focusing on intermediates and model compounds, some of the main features of the reaction mechanisms that operate during the hydrothermal processing of lignin were elucidated. Key reaction pathways and their connection to different structural features of lignin were proposed. Under neutral conditions, subcritical water was demonstrated to act as a bifunctional acid/base catalyst for the dissection of lignin structures. In a complex web of mutually dependent interactions, guaiacyl units within lignin were shown to significantly affect overall lignin reactivity. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Modification of lignin for the production of new compounded materials.

    Science.gov (United States)

    Hüttermann, A; Mai, C; Kharazipour, A

    2001-05-01

    The cell walls of woody plants are compounded materials made by in situ polymerization of a polyphenolic matrix (lignin) into a web of fibers (cellulose), a process that is catalysed by polyphenoloxidases (laccases) or peroxidases. The first attempt to transform the basic strategy of this natural process for use in human craftsmanship was the ancient lacquer method. The sap of the lacquer tree (Rhus verniciflua) contains large amounts of a phenol (urushiol), a polysaccharide and the enzyme laccase. This oil-in-water emulsion solidifies in the presence of oxygen. The Chinese began using this phenomenon for the production of highly creative artwork more than 6,000 years ago. It was the first example of an isolated enzyme being used as a catalyst to create an artificial plastic compound. In order to apply this process to the production of products on an industrial scale, an inexpensive phenol must be used, which is transferred by an enzyme to active radicals that react with different components to form a compounded material. At present, the following approaches have been studied: (1) In situ polymerization of lignin for the production of particle boards. Adhesive cure is based on the oxidative polymerization of lignin using phenoloxidases (laccase) as radical donors. This lignin-based bio-adhesive can be applied under conventional pressing conditions. The resulting particle boards meet German performance standards. By this process, 80% of the petrochemical binders in the wood-composite industry can be replaced by materials from renewable resources. (2) Enzymatic copolymerization of lignin and alkenes. In the presence of organic hydroperoxides, laccase catalyses the reaction between lignin and olefins. Detailed studies on the reaction between lignin and acrylate monomers showed that chemo-enzymatic copolymerization offers the possibility to produce defined lignin-acrylate copolymers. The system allows control of the molecular weights of the products in a way that has

  13. Aktivitas Ligninolitik Beberapa Jamur Aphyllophorales dan Kemampuannya Mendegradasi Lignin pada Lindi Hitam

    Directory of Open Access Journals (Sweden)

    Atria Martina

    2016-03-01

    Full Text Available Fourteen local isolate Aphyllophorales fungi were screened their ligninolytic activity. The isolate with highest ligninolytic activity was tested it capability to degrade kraft blackliquor lignin. The biodegradability of black liquor is low because the presence of lignin and lignin derivative in the wastewater. These fungal were screened for ligninolytic activity by decolorization on solid mediacontaining RBBR dye. The ability of the fungal strains to biodegrade kraft black liquor lignin was performed by submerged fermentation condition with agitation and incubation time as treatment. The solid culture result in 3 isolates had ligninolytic activity and Ganoderma sp.BTA1 gave the highest ligninolytic. Agitation and incubation time influenced ligninbiodegradation of blackliquor significantly. Optimum condition for lignin biodegradation was at 200 rpm during 25 days with lignin reduction was 45,786%.

  14. Characterisation of lignins isolated from sugarcane bagasse pretreated with acidified ethylene glycol and ionic liquids

    International Nuclear Information System (INIS)

    Moghaddam, Lalehvash; Zhang, Zhanying; Wellard, R. Mark; Bartley, John P.; O'Hara, Ian M.; Doherty, William O.S.

    2014-01-01

    Sugarcane bagasse pretreatment processes using acidified aqueous ethylene glycol (EG) and ionic liquids (ILs) have been reported recently. In this study, recovery of lignins from these processes was conducted, as well as determination of their physico-chemical properties. The amount of lignins recovered from 1-butyl-3-methylimidazolium chloride ([bmim]Cl) with HCl as a catalyst and [bmim][CH 3 SO 3 ] was ∼42%, and ∼35%–36% by EG with HCl or H 2 SO 4 as a catalyst, respectively. The isolated lignins were characterised using wet chemistry, spectroscopy and thermogravimetry analysis (TGA), and the results compared to soda lignin from NaOH pretreatment of bagasse. The IL and EG lignins contained no or trace amounts of carbohydrates, slightly lower hydrogen content but slightly higher oxygen contents than soda lignin. The IL and EG lignins contained more C-3 and C-5 reactive sites for Mannich reaction and had more p-hydroxypheny propane unit structures than soda lignin. Two-dimensional heteronuclear single quantum coherence (2D HSQC) nuclear magnetic resonance (NMR) identified the major substructural units in the lignins, and allowed differences among them to be studied. As EG lignins were extracted in very reactive environment, intermediate enol ethers were formed and led to cleavage reactions which were not apparent in the other lignins. 31 P NMR and infra-red spectroscopy results showed that IL and EG lignins had lower total hydroxyl content than soda lignin, probably indicating that a higher degree of self-polymerisation occurred during bagasse pretreatment, despite the use of lower temperature and shorter reaction time. On the basis of the salient features of these lignins, potential applications were proposed. - Highlights: • Lignins were recovered from ethylene glycol (EG) and ionic liquid (IL) processes. • IL and EG lignins contained no or trace amounts of carbohydrates. • IL and EG lignin had more C-3 and C-5 sites for Mannich reaction than soda

  15. Imbalanced lignin biosynthesis promotes the sexual reproduction of homothallic oomycete pathogens.

    Directory of Open Access Journals (Sweden)

    Michaël Quentin

    2009-01-01

    Full Text Available Lignin is incorporated into plant cell walls to maintain plant architecture and to ensure long-distance water transport. Lignin composition affects the industrial value of plant material for forage, wood and paper production, and biofuel technologies. Industrial demands have resulted in an increase in the use of genetic engineering to modify lignified plant cell wall composition. However, the interaction of the resulting plants with the environment must be analyzed carefully to ensure that there are no undesirable side effects of lignin modification. We show here that Arabidopsis thaliana mutants with impaired 5-hydroxyguaiacyl O-methyltransferase (known as caffeate O-methyltransferase; COMT function were more susceptible to various bacterial and fungal pathogens. Unexpectedly, asexual sporulation of the downy mildew pathogen, Hyaloperonospora arabidopsidis, was impaired on these mutants. Enhanced resistance to downy mildew was not correlated with increased plant defense responses in comt1 mutants but coincided with a higher frequency of oomycete sexual reproduction within mutant tissues. Comt1 mutants but not wild-type Arabidopsis accumulated soluble 2-O-5-hydroxyferuloyl-L-malate. The compound weakened mycelium vigor and promoted sexual oomycete reproduction when applied to a homothallic oomycete in vitro. These findings suggested that the accumulation of 2-O-5-hydroxyferuloyl-L-malate accounted for the observed comt1 mutant phenotypes during the interaction with H. arabidopsidis. Taken together, our study shows that an artificial downregulation of COMT can drastically alter the interaction of a plant with the biotic environment.

  16. Imbalanced lignin biosynthesis promotes the sexual reproduction of homothallic oomycete pathogens.

    Science.gov (United States)

    Quentin, Michaël; Allasia, Valérie; Pegard, Anthony; Allais, Florent; Ducrot, Paul-Henri; Favery, Bruno; Levis, Caroline; Martinet, Sophie; Masur, Clarissa; Ponchet, Michel; Roby, Dominique; Schlaich, Nikolaus L; Jouanin, Lise; Keller, Harald

    2009-01-01

    Lignin is incorporated into plant cell walls to maintain plant architecture and to ensure long-distance water transport. Lignin composition affects the industrial value of plant material for forage, wood and paper production, and biofuel technologies. Industrial demands have resulted in an increase in the use of genetic engineering to modify lignified plant cell wall composition. However, the interaction of the resulting plants with the environment must be analyzed carefully to ensure that there are no undesirable side effects of lignin modification. We show here that Arabidopsis thaliana mutants with impaired 5-hydroxyguaiacyl O-methyltransferase (known as caffeate O-methyltransferase; COMT) function were more susceptible to various bacterial and fungal pathogens. Unexpectedly, asexual sporulation of the downy mildew pathogen, Hyaloperonospora arabidopsidis, was impaired on these mutants. Enhanced resistance to downy mildew was not correlated with increased plant defense responses in comt1 mutants but coincided with a higher frequency of oomycete sexual reproduction within mutant tissues. Comt1 mutants but not wild-type Arabidopsis accumulated soluble 2-O-5-hydroxyferuloyl-L-malate. The compound weakened mycelium vigor and promoted sexual oomycete reproduction when applied to a homothallic oomycete in vitro. These findings suggested that the accumulation of 2-O-5-hydroxyferuloyl-L-malate accounted for the observed comt1 mutant phenotypes during the interaction with H. arabidopsidis. Taken together, our study shows that an artificial downregulation of COMT can drastically alter the interaction of a plant with the biotic environment.

  17. Novel Bioactive Antimicrobial Lignin Containing Coatings on Titanium Obtained by Electrophoretic Deposition

    Directory of Open Access Journals (Sweden)

    Sanja Erakovic

    2014-07-01

    Full Text Available Hydroxyapatite (HAP is the most suitable biocompatible material for bone implant coatings; its brittleness, however, is a major obstacle, and the reason why research focuses on creating composites with biopolymers. Organosolv lignin (Lig is used for the production of composite coatings, and these composites were examined in this study. Titanium substrate is a key biomedical material due to its well-known properties, but infections of the implantation site still impose a serious threat. One approach to prevent infection is to improve antimicrobial properties of the coating material. Silver doped hydroxyapatite (Ag/HAP and HAP coatings on titanium were obtained by an electrophoretic deposition method in order to control deposited coating mass and morphology by varying applied voltage and deposition time. The effect of lignin on microstructure, morphology and thermal behavior of biocomposite coatings was investigated. The results showed that higher lignin concentrations protect the HAP lattice during sintering, improving coating stability. The corrosion stability was evaluated in simulated body fluid (SBF at 37 °C. Newly formed plate-shaped carbonate-HAP was detected, indicating enhanced bioactive performance. The antimicrobial efficiency of Ag/HAP/Lig was confirmed by its higher reduction of bacteria Staphylococcus aureus TL (S. aureus TL than of HAP/Lig coating. Cytotoxicity assay revealed that both coatings can be classified as non-toxic against healthy immunocompetent peripheral blood mononuclear cells (PBMC.

  18. Topochemical distribution of lignin and hydroxycinnamic acids in sugar-cane cell walls and its correlation with the enzymatic hydrolysis of polysaccharides

    Directory of Open Access Journals (Sweden)

    Koch Gerald

    2011-03-01

    % hydrolyzation. Conclusion The low recalcitrance of pith cells correlated with the low UV-absorbance values seen in parenchyma cells. Chlorite treatment of pith cells did not enhance cellulose conversion. By contrast, application of the same treatment to rind cells led to significant removal of hydroxycinnamic acids and lignin, resulting in marked enhancement of cellulose conversion by cellulases.

  19. Lignin engineering in field-grown poplar trees affects the endosphere bacterial microbiome.

    Science.gov (United States)

    Beckers, Bram; Op De Beeck, Michiel; Weyens, Nele; Van Acker, Rebecca; Van Montagu, Marc; Boerjan, Wout; Vangronsveld, Jaco

    2016-02-23

    Cinnamoyl-CoA reductase (CCR), an enzyme central to the lignin biosynthetic pathway, represents a promising biotechnological target to reduce lignin levels and to improve the commercial viability of lignocellulosic biomass. However, silencing of the CCR gene results in considerable flux changes of the general and monolignol-specific lignin pathways, ultimately leading to the accumulation of various extractable phenolic compounds in the xylem. Here, we evaluated host genotype-dependent effects of field-grown, CCR-down-regulated poplar trees (Populus tremula × Populus alba) on the bacterial rhizosphere microbiome and the endosphere microbiome, namely the microbiota present in roots, stems, and leaves. Plant-associated bacteria were isolated from all plant compartments by selective isolation and enrichment techniques with specific phenolic carbon sources (such as ferulic acid) that are up-regulated in CCR-deficient poplar trees. The bacterial microbiomes present in the endosphere were highly responsive to the CCR-deficient poplar genotype with remarkably different metabolic capacities and associated community structures compared with the WT trees. In contrast, the rhizosphere microbiome of CCR-deficient and WT poplar trees featured highly overlapping bacterial community structures and metabolic capacities. We demonstrate the host genotype modulation of the plant microbiome by minute genetic variations in the plant genome. Hence, these interactions need to be taken into consideration to understand the full consequences of plant metabolic pathway engineering and its relation with the environment and the intended genetic improvement.

  20. Fiber and lignin analysis in concentrate, forage, and feces

    DEFF Research Database (Denmark)

    Hindrichsen, I.K.; Kreuzer, M.; Madsen, Jørgen

    2006-01-01

    Hemicelluloses, cellulose, and lignin contents of contrasting feeds, with emphasis on concentrate ingredients and complete concentrates, were analyzed using the Van Soest detergent procedure (analyzing neutral detergent fiber, acid detergent fiber, and acid detergent lignin) and the enzymatic...

  1. Lignin-solubilizing ability of actinomycetes isolated from termite (Termitidae) gut.

    Science.gov (United States)

    Pasti, M B; Pometto, A L; Nuti, M P; Crawford, D L

    1990-01-01

    The lignocellulose-degrading abilities of 11 novel actinomycete strains isolated from termite gut were determined and compared with that of the well-characterized actinomycete, Streptomyces viridosporus T7A. Lignocellulose bioconversion was followed by (i) monitoring the degradation of [14C]lignin- and [14C]cellulose-labeled phloem of Abies concolor to 14CO2 and 14C-labeled water-soluble products, (ii) determining lignocellulose, lignin, and carbohydrate losses resulting from growth on a lignocellulose substrate prepared from corn stalks (Zea mays), and (iii) quantifying production of a water-soluble lignin degradation intermediate (acid-precipitable polymeric lignin). The actinomycetes were all Streptomyces strains and could be placed into three groups, including a group of five strains that appear superior to S. viridosporus T7A in lignocellulose-degrading ability, three strains of approximately equal ability, and three strains of lesser ability. Strain A2 was clearly the superior and most effective lignocellulose decomposer of those tested. Of the assays used, total lignocellulose weight loss was most useful in determining overall bioconversion ability but not in identifying the best lignin-solubilizing strains. A screening procedure based on 14CO2 evolution from [14C-lignin]lignocellulose combined with measurement of acid-precipitable polymeric lignin yield was the most effective in identifying lignin-solubilizing strains. For the termite gut strains, the pH of the medium showed no increase after 3 weeks of growth on lignocellulose. This is markedly different from the pattern observed with S. viridosporus T7A, which raises the medium pH considerably. Production of extracellular peroxidases by the 11 strains and S. viridosporus T7A was followed for 5 days in liquid cultures.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2167628

  2. Global transcriptomic profiling of aspen trees under elevated [CO2] to identify potential molecular mechanisms responsible for enhanced radial growth.

    Science.gov (United States)

    Wei, Hairong; Gou, Jiqing; Yordanov, Yordan; Zhang, Huaxin; Thakur, Ramesh; Jones, Wendy; Burton, Andrew

    2013-03-01

    Aspen (Populus tremuloides) trees growing under elevated [CO(2)] at a free-air CO(2) enrichment (FACE) site produced significantly more biomass than control trees. We investigated the molecular mechanisms underlying the observed increase in biomass by producing transcriptomic profiles of the vascular cambium zone (VCZ) and leaves, and then performed a comparative study to identify significantly changed genes and pathways after 12 years exposure to elevated [CO(2)]. In leaves, elevated [CO(2)] enhanced expression of genes related to Calvin cycle activity and linked pathways. In the VCZ, the pathways involved in cell growth, cell division, hormone metabolism, and secondary cell wall formation were altered while auxin conjugation, ABA synthesis, and cytokinin glucosylation and degradation were inhibited. Similarly, the genes involved in hemicellulose and pectin biosynthesis were enhanced, but some genes that catalyze important steps in lignin biosynthesis pathway were inhibited. Evidence from systemic analysis supported the functioning of multiple molecular mechanisms that underpin the enhanced radial growth in response to elevated [CO(2)].

  3. Treatment of Lignin Precursors to Improve their Suitability for Carbon Fibers: A Literature Review

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Ryan [GrafTech International Holdings Inc.; Naskar, Amit [Oak Ridge National Laboratory; Gallego, Nidia [Oak Ridge National Laboratory; Dai, Xuliang [GrafTech International Holdings Inc.; Hausner, Andrew [GrafTech International Holdings Inc.

    2015-04-17

    Lignin has been investigated as a carbon fiber precursor since the 1960s. Although there have been a number of reports of successful lignin-based carbon fiber production at the lab scale, lignin-based carbon fibers are not currently commercially available. This review will highlight some of the known challenges, and also the reported methods for purifying and modifying lignin to improve it as a precursor. Lignin can come from different sources (e.g. hardwood, softwood, grasses) and extraction methods (e.g. organosolv, kraft), meaning that lignin can be found with a diversity of purity and structure. The implication of these conditions on lignin as carbon fiber precursor is not comprehensively known, especially as the lignin landscape is evolving. The work presented in this review will help guide the direction of a project between GrafTech and ORNL to develop lignin carbon fiber technology, as part of a cooperative agreement with the DOE Advanced Manufacturing Office.

  4. Sulfur-free lignins from alkaline pulping tested in mortar for use as mortar additives.

    Science.gov (United States)

    Nadif, A; Hunkeler, D; Käuper, P

    2002-08-01

    Sulfur-free lignin, obtained through the acid precipitation of black liquor from the soda pulping process, has been tested as water reducer in mortar. It has also been compared to existing commercial additives such as naphthalene sulfonates and lignosulfonates. The ash content and sugar content of these lignins are low in comparison to lignosulfonates, conferring on them higher purity. A procedure for small scale testing derived from the industrial norms SN-EN196 and ASTM (Designation C230-90) is presented. Specifically, all the sulfur-free lignins tested improved the flow of the mortar. Selected flax lignins performed better than lignosulfonates though still less than naphthalene sulfonates. Furthermore, certain hemp lignins gave comparable results to the lignosulfonates. Overall, the straw lignin prepared herein is comparable in performance to commercially available lignins, such as Organocell, Alcell and Curan 100. The plant from which the lignin was isolated, and the process of the pulp mill are the primary influences on the performance of the lignin.

  5. Coupling and reactions of 5- hydroxyconiferyl alcohol in lignin formation

    Science.gov (United States)

    Thomas Elder; Laura Berstis; Gregg T. Beckham; Michael F. Crowley

    2016-01-01

    The catechol alcohols, caffeyl and 5-hydroxyconiferyl alcohol, may be incorporated into lignin either naturally or through genetic manipulation. Due to the presence of o-OH groups, these compounds form benzodioxanes, a departure from the interunit connections found in lignins derived from the cinnamyl alcohols. In nature, lignins composed of caffeyl and 5-...

  6. Survey of Lignin-Structure Changes and Depolymerization during Ionic Liquid Pretreatment

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, Tanmoy; Isern, Nancy G.; Sun, Jian; Wang, Eileen; Hull, Sarah; Cort, John R.; Simmons, Blake A.; Singh, Seema

    2017-09-26

    A detailed study of chemical changes in lignin structure during the ionic liquid (IL) pretreatment process is not only pivotal for understanding and overcoming biomass recalcitrance during IL pretreatment, but also is necessary for designing new routes for lignin valorization. Chemical changes in lignin were systematically studied as a function of pretreatment temperature, time and type of IL used. Kraft lignin was used as the lignin source and common pretreatment conditions were employed using three different ILs of varying chemical structure in terms of acidic or basic character. The chemical changes in the lignin structure due to IL pretreatment processes were monitored using 1H-13C HSQC NMR, 31P NMR, elemental analysis, GPC, FT-IR, and the depolymerized products were analyzed using GC-MS. Although pretreatment in acidic IL, triethylammonium hydrogensulfate ([TEA][HSO4]) results in maximum decrease in β-aryl ether bond, maximum dehydration and recondensation pathways were also evident, with the net process showing a minimum decrease in the molecular weight of regenerated lignin. However, 1-ethyl-3-methylimidazolium acetate ([C2C1Im][OAc]) pretreatment yields a smaller decrease in the β-aryl ether content along with minimum evidence of recondensation, resulting in the maximum decrease in the molecular weight. Cholinium lysinate ([Ch][Lys]) pretreatment shows an intermediate result, with moderate depolymerization, dehydration and recondensation observed. The depolymerization products after IL pretreatment are found to be a function of the pretreatment temperature and the specific chemical nature of the IL used. At higher pretreatment temperature, [Ch][Lys] pretreatment yields guaiacol, [TEA][HSO4] yields guaiacylacetone, and [C2C1Im][OAc] yields both guaiacol and guaiacylacetone as major products. These results clearly indicate that the changes in lignin structure as well as the depolymerized product profile depend on the pretreatment conditions and the nature

  7. Fabrication of high-performance poly(l-lactic acid)/lignin-graft-poly(d-lactic acid) stereocomplex films.

    Science.gov (United States)

    Liu, Rui; Dai, Lin; Hu, Li-Qiu; Zhou, Wen-Qin; Si, Chuan-Ling

    2017-11-01

    The need for green renewable alternatives such as lignin to traditional fillers has driven recent interest in polylactic acid blend materials. Herein, lignin-graft-polylactic acid copolymers (LG-g-PDLA, LG-g-PDLLA, and LG-g-PLLA) have been synthesized via ring-opening polymerization of d-, dl-, and l-lactic acid. Then poly(l-lactic acid)/lignin-graft-polylactic acid (PLLA/LG-g-PDLA, /LG-g-PDLLA, and /LG-g-PLLA) complex films have been prepared. The results showed that, compared with LG-g-PDLA and LG-g-PLLA, a small amount of LG-g-PDLA addition could improve the crystallization rate, reduce the glass transition temperature and cold crystallization temperature of PLLA due to the stereocomplex crystallites. The thermal stability, tensile strength and strain of the stereocomplex films were also enhanced. Moreover, the PLLA/LG-g-PDLA films have good ultraviolet resistance and excellent biocompatibility. This study provides a green approach to design advanced polylactic acid-based blends with renewable natural resources. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Synthesis of novel ionic liquids from lignin-derived compounds

    Science.gov (United States)

    Socha, Aaron; Singh, Seema; Simmons, Blake A.; Bergeron, Maxime

    2017-09-19

    Methods and compositions are provided for synthesizing ionic liquids from lignin derived compounds comprising: contacting a starting material comprising lignin with a depolymerization agent to depolymerize the lignin and form a mixture of aldehyde containing compounds; contacting the mixture of aldehyde containing compounds with an amine under conditions suitable to convert the mixture of aldehyde containing compounds to a mixture of amine containing compounds; and contacting the mixture of amine containing compounds with an acid under conditions suitable to form an ammonium salt, thereby preparing the ionic liquid.

  9. Syringyl lignin is unaltered by severe sinapyl alcohol dehydrogenase suppression in tobacco.

    Science.gov (United States)

    Barakate, Abdellah; Stephens, Jennifer; Goldie, Alison; Hunter, William N; Marshall, David; Hancock, Robert D; Lapierre, Catherine; Morreel, Kris; Boerjan, Wout; Halpin, Claire

    2011-12-01

    The manipulation of lignin could, in principle, facilitate efficient biofuel production from plant biomass. Despite intensive study of the lignin pathway, uncertainty exists about the enzyme catalyzing the last step in syringyl (S) monolignol biosynthesis, the reduction of sinapaldehyde to sinapyl alcohol. Traditional schemes of the pathway suggested that both guaiacyl (G) and S monolignols are produced by a single substrate-versatile enzyme, cinnamyl alcohol dehydrogenase (CAD). This was challenged by the discovery of a novel sinapyl alcohol dehydrogenase (SAD) that preferentially uses sinapaldehyde as a substrate and that was claimed to regulate S lignin biosynthesis in angiosperms. Consequently, most pathway schemes now show SAD (or SAD and CAD) at the sinapaldehyde reduction step, although functional evidence is lacking. We cloned SAD from tobacco (Nicotiana tabacum) and suppressed it in transgenic plants using RNA interference-inducing vectors. Characterization of lignin in the woody stems shows no change to content, composition, or structure, and S lignin is normal. By contrast, plants additionally suppressed in CAD have changes to lignin structure and S:G ratio and have increased sinapaldehyde in lignin, similar to plants suppressed in CAD alone. These data demonstrate that CAD, not SAD, is the enzyme responsible for S lignin biosynthesis in woody angiosperm xylem.

  10. Understanding the chemical and structural transformations of lignin macromolecule during torrefaction

    International Nuclear Information System (INIS)

    Wen, Jia-Long; Sun, Shao-Long; Yuan, Tong-Qi; Xu, Feng; Sun, Run-Cang

    2014-01-01

    Highlights: • The terrified bamboo has a high energy yield of 85.7% and a HHV of 20.13 MJ/kg. • The structural changes of hemicelluloses, cellulose, and lignin were investigated. • First study on the structural transformations of lignin during torrefaction. • The mechanism of structural changes of lignin has been proposed. - Abstract: Torrefaction is an efficient method to recover energy from biomass. Herein, the characteristics (mass yield, energy yield, physical, and chemical characteristics) of torrefied bamboo at diverse temperatures (200–300 °C) were firstly evaluated by elemental analysis, XRD, and CP–MAS 13 C NMR methodologies. Under an optimal condition the terrified bamboo has a relative high energy yield of 85.7% and a HHV of 20.13 MJ/kg. The chemical and structural transformations of lignin induced by thermal treatment were thoroughly investigated by FT-IR and solution-state NMR techniques (quantitative 13 C NMR, 2D-HSQC, and 31 P-NMR methodologies). The results highlighted the chemical reactions of the native bamboo lignins towards severe torrefaction treatments occurred, such as depolymerization, demethoxylation, bond cleavage, and condensation reactions. NMR results indicated that aryl-ether bonds (β-O-4) and p-coumaric ester in lignin were cleaved during the torrefaction process at mild conditions. The severe treatments of bamboo (275 °C and 300 °C) induced a dramatic enrichment in lignin content together with the almost complete disappearance of β-O-4, β-β, and β-5 linkages. Further analysis of the molecular weight of milled wood lignin (MWL) indicated that the average molecular weights of “torrefied MWL” were lower than those of control MWL. It is believed that understanding of the reactivity and chemical transformations of lignin during torrefaction will contribute to the integrated torrefaction mechanism

  11. Lignin conversion to high-octane fuel additives

    Energy Technology Data Exchange (ETDEWEB)

    Shabtai, J.; Zmierczak, W.; Kadangode, S. [University of Utah, Salt Lake City (United States); Chornet, E.; Johnson, D.K. [National Renewable Energy Laboratory, Golden, CO (United States)

    1999-07-01

    Continuing previous studies on the conversion of lignin to reformulated gasoline compositions, new lignin upgrading processes were developed that allow preferential production of specific high-octane fuel additives of two distinct types: (1) C{sub 7}-C{sub 10} alkylbenzenes; and (2) aryl methyl ethers, where aryl mostly = phenyl, 2-methylphenyl, 4-methylphenyl, and dimethylphenyl. Process (1) comprises base-catalyzed depolymerization (BCD) and simultaneous partial ({approx} 50%) deoxygenation of lignin at 270 - 290{sup o}C, in the presence of supercritical methanol as reaction medium, followed by exhaustive hydrodeoxygenation and attendant mild hydrocracking of the BCD product with sulfided catalysts to yield C{sub 8}-C{sub 10} alkylbenzenes as main products. Process (2) involves mild BCD at 250 - 270{sup o}C with preservation of the lignin oxygen, followed by selective C-C hydrocracking with solid superacid catalysts. This method preferentially yields a mixture of alkylated phenols, which upon acid-catalyzed etherification with methanol are converted into corresponding aryl methyl ethers (see above) possessing blending octane numbers in the range of 142-166. In a recent extension of this work, a greatly advantageous procedure for performing the BCD stage of processes (1) and (2) in water as reaction medium was developed. (author)

  12. Influence of lignin on biochemical methane potential of biomass for biogas production

    DEFF Research Database (Denmark)

    Triolo, Jin Mi; Sommer, Sven G.; Møller, Henrik Bjarne

    2011-01-01

    model for these two biomass groups. Validation of the combined model was carried out using datasets from the literature. This study showed that lignin was not degraded during anaerobic digestion. Furthermore, lignin concentration in organic materials was the strongest predictor of BMP for all...... the biomass groups. The square of the sample correlation coefficient (R2) from the BMP versus lignin was 0.908 (P lignin concentration could be used to predict...

  13. Bio-based polyurethane prepared from Kraft lignin and modified castor oil

    Directory of Open Access Journals (Sweden)

    L. B. Tavares

    2016-11-01

    Full Text Available Current challenges highlight the need for polymer research using renewable natural sources as a substitute for petroleum-based polymers. The use of polyols obtained from renewable sources combined with the reuse of industrial residues such as lignin is an important agent in this process. Different compositions of polyurethane-type materials were prepared by combining technical Kraft lignin (TKL with castor oil (CO or modified castor oil (MCO1 and MCO2 to increase their reactivity towards diphenylmethane diisocyanate (MDI. The results indicate that lignin increases the glass transition temperature, the crosslinking density and improves the ultimate stress especially for those prepared from MCO2 and 30% lignin content from 8.2 MPa (lignin free to 23.5 MPa. Scanning electron microscopy (SEM micrographs of rupture surface after uniaxial tensile tests show ductile-to-brittle transition. The results show the possibility to develop polyurethane-type materials, varying technical grade Kraft lignin content, which cover a wide range of mechanical properties (from large elastic/low Young modulus to brittle/high Young modulus polyurethanes.

  14. Structural characterization of lignin isolated from coconut (Cocos nucifera) coir fibers.

    Science.gov (United States)

    Rencoret, Jorge; Ralph, John; Marques, Gisela; Gutiérrez, Ana; Martínez, Ángel T; del Río, José C

    2013-03-13

    The structure of the isolated milled "wood" lignin from coconut coir has been characterized using different analytical methods, including Py-GC/MS, 2D NMR, DFRC, and thioacidolysis. The analyses demonstrated that it is a p-hydroxyphenyl-guaiacyl-syringyl (H-G-S) lignin, with a predominance of G units (S/G ratio 0.23) and considerable amounts of associated p-hydroxybenzoates. Two-dimensional NMR indicated that the main substructures present in this lignin include β-O-4' alkyl aryl ethers followed by phenylcoumarans and resinols. Two-dimensional NMR spectra also indicated that coir lignin is partially acylated at the γ-carbon of the side chain with p-hydroxybenzoates and acetates. DFRC analysis showed that acetates preferentially acylate the γ-OH in S rather than in G units. Despite coir lignin's being highly enriched in G-units, thioacidolysis indicated that β-β' resinol structures are mostly derived from sinapyl alcohol. Finally, we find evidence that the flavone tricin is incorporated into the coconut coir lignin, as has been recently noted for various grasses.

  15. Lignin: an adhesive raw material of the future or waste of research energy?

    OpenAIRE

    Hemmilä, Venla; Trischler, Johann; Sandberg, Dick

    2013-01-01

    Lignin has been studied as an adhesive for more than 100 years, but there are only a few industrial applications. The reason for the current interest is the high availability and low price of lignin. Lignin is the main by-product of paper pulping processes and is typically burned as fuel. Being the natural glue in plants and having a phenolic nature makes lignins an attractive replacement for wood adhesives.An adhesive system for wood composites consisting mainly of lignin has yet to be devel...

  16. Metal Triflates for the Production of Aromatics from Lignin

    NARCIS (Netherlands)

    Deuss, Peter J.; Lahive, Ciaran W.; Lancefield, Christopher S.; Westwood, Nicholas J.; Kamer, Paul C. J.; Barta, Katalin; de Vries, Johannes G.

    2016-01-01

    The depolymerization of lignin into valuable aromatic chemicals is one of the key goals towards establishing economically viable biorefineries. In this contribution we present a simple approach for converting lignin to aromatic monomers in high yields under mild reaction conditions. The methodology

  17. Efficient, environmentally-friendly and specific valorization of lignin: promising role of non-radical lignolytic enzymes.

    Science.gov (United States)

    Wang, Wenya; Zhang, Chao; Sun, Xinxiao; Su, Sisi; Li, Qiang; Linhardt, Robert J

    2017-06-01

    Lignin is the second most abundant bio-resource in nature. It is increasingly important to convert lignin into high value-added chemicals to accelerate the development of the lignocellulose biorefinery. Over the past several decades, physical and chemical methods have been widely explored to degrade lignin and convert it into valuable chemicals. Unfortunately, these developments have lagged because of several difficulties, of which high energy consumption and non-specific cleavage of chemical bonds in lignin remain the greatest challenges. A large number of enzymes have been discovered for lignin degradation and these are classified as radical lignolytic enzymes and non-radical lignolytic enzymes. Radical lignolytic enzymes, including laccases, lignin peroxidases, manganese peroxidases and versatile peroxidases, are radical-based bio-catalysts, which degrade lignins through non-specific cleavage of chemical bonds but can also catalyze the radical-based re-polymerization of lignin fragments. In contrast, non-radical lignolytic enzymes selectively cleave chemical bonds in lignin and lignin model compounds and, thus, show promise for use in the preparation of high value-added chemicals. In this mini-review, recent developments on non-radical lignolytic enzymes are discussed. These include recently discovered non-radical lignolytic enzymes, their metabolic pathways for lignin conversion, their recent application in the lignin biorefinery, and the combination of bio-catalysts with physical/chemical methods for industrial development of the lignin refinery.

  18. [Phenolic foam prepared by lignin from a steam-explosion derived biorefinery of corn stalk].

    Science.gov (United States)

    Wang, Guanhua; Chen, Hongzhang

    2014-06-01

    To increase the integral economic effectiveness, biorefineries of lignocellulosic materials should not only utilize carbohydrates hydrolyzed from cellulose and hemicellulose but also use lignin. We used steam-exploded corn stalk as raw materials and optimized the temperature and alkali concentration in the lignin extraction process to obtain lignin liquor with higher yield and purity. Then the concentrated lignin liquor was used directly to substitute phenol for phenolic foam preparation and the performances of phenolic foam were characterized by microscopic structure analysis, FTIR, compression strength and thermal conductivity detection. The results indicated that, when steam-exploded corn stalk was extracted at 120 degrees C for 2 h by 1% NaOH with a solid to liquid ratio of 1:10, the extraction yield of lignin was 79.67%. The phenolic foam prepared from the concentrated lignin liquor showed higher apparent density and compression strength with the increasing substitution rate of lignin liquor. However, there were not significant differences of thermal conductivity and flame retardant properties by the addition of lignin, which meant that the phenolic foam substituted by lignin liquor was approved for commercial application. This study, which uses alkali-extracted lignin liquor directly for phenolic foam preparation, provides a relatively simple way for utilization of lignin and finally increases the overall commercial operability ofa lignocellulosic biorefinery derived by steam explosion.

  19. System analyse cellulose ethanol in combines - Combustion characterisation of lignin from cellulose based ethanol production; Systemanalys foer cellulosabaserad etanol i kombinat - Foerbraenningskarakterisering av lignin fraan cellulosabaserad etanolproduktion

    Energy Technology Data Exchange (ETDEWEB)

    Lindstedt, Jan; Wingren, Anders; Magnusson, Staffan; Wiinikka, Henrik; Westbom, Urban; Lidman, Marcus; Groenberg, Carola

    2012-02-15

    In this work 3 different hydrolysed lignin fractions produced from Sugarcane Bagasse, Spruce and Wheat Straw were burned in a 150 kW horizontal furnace equipped with a powder burner to assess the combustion behaviour of hydrolysed lignin fuels. The combustion experiments showed that the feeding properties of all three lignin fractions were better compared to ordinary wood powder

  20. Lignin as a Binder Material for Eco-Friendly Li-Ion Batteries

    Science.gov (United States)

    Lu, Huiran; Cornell, Ann; Alvarado, Fernando; Behm, Mårten; Leijonmarck, Simon; Li, Jiebing; Tomani, Per; Lindbergh, Göran

    2016-01-01

    The industrial lignin used here is a byproduct from Kraft pulp mills, extracted from black liquor. Since lignin is inexpensive, abundant and renewable, its utilization has attracted more and more attention. In this work, lignin was used for the first time as binder material for LiFePO4 positive and graphite negative electrodes in Li-ion batteries. A procedure for pretreatment of lignin, where low-molecular fractions were removed by leaching, was necessary to obtain good battery performance. The lignin was analyzed for molecular mass distribution and thermal behavior prior to and after the pretreatment. Electrodes containing active material, conductive particles and lignin were cast on metal foils, acting as current collectors and characterized using scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and galvanostatic charge-discharge cycles. Good reversible capacities were obtained, 148 mAh·g−1 for the positive electrode and 305 mAh·g−1 for the negative electrode. Fairly good rate capabilities were found for both the positive electrode with 117 mAh·g−1 and the negative electrode with 160 mAh·g−1 at 1C. Low ohmic resistance also indicated good binder functionality. The results show that lignin is a promising candidate as binder material for electrodes in eco-friendly Li-ion batteries. PMID:28773252

  1. A structured understanding of cellobiohydrolase I binding to poplar lignin fractions after dilute acid pretreatment.

    Science.gov (United States)

    Yao, Lan; Yoo, Chang Geun; Meng, Xianzhi; Li, Mi; Pu, Yunqiao; Ragauskas, Arthur J; Yang, Haitao

    2018-01-01

    Cellulase adsorption to lignin is considered a cost barrier for bioethanol production; however, its detailed association mechanism is still not fully understood. In this study, two natural poplar variants with high and low sugar release performance were selected as the low and high recalcitrant raw materials (named L and H , respectively). Three different lignin fractions were extracted using ethanol, followed by p -dioxane and then cellulase treatment from the dilute acid pretreated poplar solids (fraction 1, 2, and 3, respectively). Each lignin fraction had different physicochemical properties. Ethanol-extracted lignin had the lowest weight average molecular weight, while the molecular weights for the other two lignin fractions were similar. 31 P NMR analysis revealed that lignin fraction with higher molecular weight contained more aliphatic hydroxyl groups and less phenolic hydroxyl groups. Semi-quantitative analysis by 2D HSQC NMR indicated that the lignin fractions isolated from the natural variants had different contents of syringyl (S), guaiacyl (G) and interunit linkages. Lignin extracted by ethanol contained the largest amount of S units, the smallest amounts of G and p -hydroxybenzoate (PB) subunits, while the contents of these lignin subunits in the other two lignin fractions were similar. The lignin fraction obtained after cellulase treatment was primarily comprised of β- O -4 linkages with small amounts of β-5 and β-β linkages. The binding strength of these three lignin fractions obtained by Langmuir equations were in the order of L 1  >  L 3  >  L 2 for the low recalcitrance poplar and H 1  >  H 2  >  H 3 for the high recalcitrance poplar. Overall, adsorption ability of lignin was correlated with the sugar release of poplar. Structural features of lignin were associated with its binding to CBH. For natural poplar variants, lignin fractions with lower molecular weight and polydispersity index (PDI) exhibited more CBH adsorption

  2. Bio-oil from fast pyrolysis of lignin: Effects of process and upgrading parameters.

    Science.gov (United States)

    Fan, Liangliang; Zhang, Yaning; Liu, Shiyu; Zhou, Nan; Chen, Paul; Cheng, Yanling; Addy, Min; Lu, Qian; Omar, Muhammad Mubashar; Liu, Yuhuan; Wang, Yunpu; Dai, Leilei; Anderson, Erik; Peng, Peng; Lei, Hanwu; Ruan, Roger

    2017-10-01

    Effects of process parameters on the yield and chemical profile of bio-oil from fast pyrolysis of lignin and the processes for lignin-derived bio-oil upgrading were reviewed. Various process parameters including pyrolysis temperature, reactor types, lignin characteristics, residence time, and feeding rate were discussed and the optimal parameter conditions for improved bio-oil yield and quality were concluded. In terms of lignin-derived bio-oil upgrading, three routes including pretreatment of lignin, catalytic upgrading, and co-pyrolysis of hydrogen-rich materials have been investigated. Zeolite cracking and hydrodeoxygenation (HDO) treatment are two main methods for catalytic upgrading of lignin-derived bio-oil. Factors affecting zeolite activity and the main zeolite catalytic mechanisms for lignin conversion were analyzed. Noble metal-based catalysts and metal sulfide catalysts are normally used as the HDO catalysts and the conversion mechanisms associated with a series of reactions have been proposed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Structure of Thermobifida fusca DyP-type peroxidase and activity towards Kraft lignin and lignin model compounds.

    Science.gov (United States)

    Rahmanpour, Rahman; Rea, Dean; Jamshidi, Shirin; Fülöp, Vilmos; Bugg, Timothy D H

    2016-03-15

    A Dyp-type peroxidase enzyme from thermophilic cellulose degrader Thermobifida fusca (TfuDyP) was investigated for catalytic ability towards lignin oxidation. TfuDyP was characterised kinetically against a range of phenolic substrates, and a compound I reaction intermediate was observed via pre-steady state kinetic analysis at λmax 404 nm. TfuDyP showed reactivity towards Kraft lignin, and was found to oxidise a β-aryl ether lignin model compound, forming an oxidised dimer. A crystal structure of TfuDyP was determined, to 1.8 Å resolution, which was found to contain a diatomic oxygen ligand bound to the heme centre, positioned close to active site residues Asp-203 and Arg-315. The structure contains two channels providing access to the heme cofactor for organic substrates and hydrogen peroxide. Site-directed mutant D203A showed no activity towards phenolic substrates, but reduced activity towards ABTS, while mutant R315Q showed no activity towards phenolic substrates, nor ABTS. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. A novel lignin-based surfactant system for the Salem Unit

    International Nuclear Information System (INIS)

    DeBons, F.E.; Whittington, L.E.

    1991-01-01

    Texaco conducted a successful surfactant/polymer flood in a 60-acre [24 ha] portion of the Salem Benoist reservoir in Salem, Illinois, in 1981. This pilot used a brine-tolerant petroleum sulfonate surfactant system blended in injection brine followed by a xanthan mobility control polymer in fresher water. The oil recovery over the seven year life of the flood was 487,050 bbl [77 435 m 3 ]. This represents 45% of the oil remaining in the total thickness of 73% of that from the more permeable lower interval where most of the surfactant flowed. Since this successful project, Texaco has continued to improve enhanced oil recovery surfactant systems. We have developed novel, brine tolerant surfactants based on the renewable resources lignin and tallow amine. This paper describes the laboratory work leading to a surfactant system which has been recommended for field testing. The laboratory work includes blending, interfacial tension measurements, and core floods in Berea and reservoir cores. The type of lignin based surfactant system described in this report has applicability in all fields where conventional petroleum-based surfactants have been used. Their much lower cost means that they can be used economically at lower crude oil prices

  5. Identification and thermochemical analysis of high-lignin feedstocks for biofuel and biochemical production

    Directory of Open Access Journals (Sweden)

    Mendu Venugopal

    2011-10-01

    Full Text Available Abstract Background Lignin is a highly abundant biopolymer synthesized by plants as a complex component of plant secondary cell walls. Efforts to utilize lignin-based bioproducts are needed. Results Herein we identify and characterize the composition and pyrolytic deconstruction characteristics of high-lignin feedstocks. Feedstocks displaying the highest levels of lignin were identified as drupe endocarp biomass arising as agricultural waste from horticultural crops. By performing pyrolysis coupled to gas chromatography-mass spectrometry, we characterized lignin-derived deconstruction products from endocarp biomass and compared these with switchgrass. By comparing individual pyrolytic products, we document higher amounts of acetic acid, 1-hydroxy-2-propanone, acetone and furfural in switchgrass compared to endocarp tissue, which is consistent with high holocellulose relative to lignin. By contrast, greater yields of lignin-based pyrolytic products such as phenol, 2-methoxyphenol, 2-methylphenol, 2-methoxy-4-methylphenol and 4-ethyl-2-methoxyphenol arising from drupe endocarp tissue are documented. Conclusions Differences in product yield, thermal decomposition rates and molecular species distribution among the feedstocks illustrate the potential of high-lignin endocarp feedstocks to generate valuable chemicals by thermochemical deconstruction.

  6. Bio-inspired MOF-based Catalysts for Lignin Valorization.

    Energy Technology Data Exchange (ETDEWEB)

    Allendorf, Mark D.; Stavila, Vitalie; Ramakrishnan, Parthasarathi; Davis, Ryan Wesley

    2014-09-01

    Lignin is a potentially plentiful source of renewable organics, with %7E50Mtons/yr produced by the pulp/paper industry and 200-300 Mtons/yr projected production by a US biofuels industry. This industry must process approximately 1 billion tons of biomass to meet the US Renewable Fuel goals. However, there are currently no efficient processes for converting lignin to value-added chemicals and drop-in fuels. Lignin is therefore an opportunity for production of valuable renewable chemicals, but presents staggering technical and economic challenges due to the quantities of material involved and the strong chemical bonds comprising this polymer. Aggressive chemistries and high temperatures are required to degrade lignin without catalysts. Moreover, chemical non-uniformity among lignins leads to complex product mixtures that tend to repolymerize. Conventional petrochemical approaches (pyrolysis, catalytic cracking, gasification) are energy intensive (400-800 degC), require complicated separations, and remove valuable chemical functionality. Low-temperature (25-200 degC) alternatives are clearly desirable, but enzymes are thermally fragile and incompatible with liquid organic compounds, making them impractical for large-scale biorefining. Alternatively, homogeneous catalysts, such as recently developed vanadium complexes, must be separated from product mixtures, while many heterogenous catalysts involve costly noble metals. The objective of this project is to demonstrate proof of concept that an entirely new class of biomimetic, efficient, and industrially robust synthetic catalysts based on nanoporous Metal- Organic Frameworks (MOFs) can be developed. Although catalytic MOFs are known, catalysis of bond cleavage reactions needed for lignin degradation is completely unexplored. Thus, fundamental research is required that industry and most sponsoring agencies are currently unwilling to undertake. We introduce MOFs infiltrated with titanium and nickel species as catalysts

  7. Effect of Lignin-Containing Media on Growth of Medicinal Mushroom Lentinula Edodes

    Directory of Open Access Journals (Sweden)

    Matjuškova Nataļja

    2017-04-01

    Full Text Available The effect of lignocellulose and lignin on growth of mycelium of mushroom Lentinula edodes and laccase activity in cultivation medium was studied. It was shown that cultivation of L. edodes mycelium in liquid nutrient medium with addition of 0.25-0.5% of kraft lignin increased mycelium biomass yield approximately two times compared with reference conditions without addition of lignin. Similar results were obtained in experiments in which 0.5% lignocellulose that remained after obtaining furfural, and 0.5% lignin that remained after obtaining furfural and glucose from wheat straw, were added to the nutrient medium. This effect was greater in the conditions of cultivation with good aeration, compared with static culture. Laccase activity in medium increased after addition of wheat straw lignocellulose or lignin only in the case of mycelium cultivation with aeration. In the case of mushroom cultivation on solid nutrient medium, addition of wheat straw lignocellulose and lignin promoted growth of mycelium only during the first 7 days of cultivation.

  8. A cell wall-bound anionic peroxidase, PtrPO21, is involved in lignin polymerization in Populus trichocarpa

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Chien-Yuan; Li, Quanzi; Tunlaya-Anukit, Sermsawat; Shi, Rui; Sun, Ying-Hsuan; Wang, Jack P.; Liu, Jie; Loziuk, Philip; Edmunds, Charles W.; Miller, Zachary D.; Peszlen, Ilona; Muddiman, David C.; Sederoff, Ronald R.; Chiang, Vincent L.

    2016-03-11

    Class III peroxidases are members of a large plant-specific sequence-heterogeneous protein family. Several sequence-conserved homologs have been associated with lignin polymerization in Arabidopsis thaliana, Oryza sativa, Nicotiana tabacum, Zinnia elegans, Picea abies, and Pinus sylvestris. In Populus trichocarpa, a model species for studies of wood formation, the peroxidases involved in lignin biosynthesis have not yet been identified. To do this, we retrieved sequences of all PtrPOs from Peroxibase and conducted RNA-seq to identify candidates. Transcripts from 42 PtrPOs were detected in stem differentiating xylem (SDX) and four of them are the most xylem-abundant (PtrPO12, PtrPO21, PtrPO42, and PtrPO64). PtrPO21 shows xylem-specific expression similar to that of genes encoding the monolignol biosynthetic enzymes. Using protein cleavage-isotope dilution mass spectrometry, PtrPO21 is detected only in the cell wall fraction and not in the soluble fraction. Downregulated transgenics of PtrPO21 have a lignin reduction of ~20% with subunit composition (S/G ratio) similar to wild type. The transgenics show a growth reduction and reddish color of stem wood. The modulus of elasticity (MOE) of the stems of the downregulated PtrPO21-line 8 can be reduced to ~60% of wild type. Differentially expressed gene (DEG) analysis of PtrPO21 downregulated transgenics identified a significant overexpression of PtPrx35, suggesting a compensatory effect within the peroxidase family. No significant changes in the expression of the 49 P. trichocarpa laccases (PtrLACs) were observed.

  9. Final Report: Investigation of Catalytic Pathways for Lignin Breakdown into Monomers and Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Gluckstein, Jeffrey A [ORNL; Hu, Michael Z. [ORNL; Kidder, Michelle [ORNL; McFarlane, Joanna [ORNL; Narula, Chaitanya Kumar [ORNL; Sturgeon, Matthew R [ORNL

    2010-12-01

    Lignin is a biopolymer that comprises up to 35% of woody biomass by dry weight. It is currently underutilized compared to cellulose and hemicellulose, the other two primary components of woody biomass. Lignin has an irregular structure of methoxylated aromatic groups linked by a suite of ether and alkyl bonds which makes it difficult to degrade selectively. However, the aromatic components of lignin also make it promising as a base material for the production of aromatic fuel additives and cyclic chemical feed stocks such as styrene, benzene, and cyclohexanol. Our laboratory research focused on three methods to selectively cleave and deoxygenate purified lignin under mild conditions: acidolysis, hydrogenation and electrocatalysis. (1) Acidolysis was undertaken in CH2Cl2 at room temperature. (2) Hydrogenation was carried out by dissolving lignin and a rhodium catalyst in 1:1 water:methoxyethanol under a 1 atm H2 environment. (3) Electrocatalysis of lignin involved reacting electrically generated hydrogen atoms at a catalytic palladium cathode with lignin dissolved in a solution of aqueous methanol. In all of the experiments, the lignin degradation products were identified and quantified by gas chromatography mass spectroscopy and flame ionization detection. Yields were low, but this may have reflected the difficulty in recovering the various fractions after conversion. The homogeneous hydrogenation of lignin showed fragmentation into monomers, while the electrocatalytic hydrogenation showed production of polyaromatic hydrocarbons and substituted benzenes. In addition to the experiments, promising pathways for the conversion of lignin were assessed. Three conversion methods were compared based on their material and energy inputs and proposed improvements using better catalyst and process technology. A variety of areas were noted as needing further experimental and theoretical effort to increase the feasibility of lignin conversion to fuels.

  10. Developing lignin-based bio-nanofibers by centrifugal spinning technique.

    Science.gov (United States)

    Stojanovska, Elena; Kurtulus, Mustafa; Abdelgawad, Abdelrahman; Candan, Zeki; Kilic, Ali

    2018-07-01

    Lignin-based nanofibers were produced via centrifugal spinning from lignin-thermoplastic polyurethane polymer blends. The most suitable process parameters were chosen by optimization of the rotational speed, nozzle diameter and spinneret-to-collector distance using different blend ratios of the two polymers at different total polymer concentrations. The basic characteristics of polymer solutions were enlightened by their viscosity and surface tension. The morphology of the fibers produced was characterized by SEM, while their thermal properties by DSC and TG analysis. Multiply regression was used to determine the parameters that have higher impact on the fiber diameter. It was possible to obtain thermally stable lignin/polyurethane nanofibers with diameters below 500nm. From the aspect of spinnability, 1:1 lignin/TPU contents were shown to be more feasible. On the other side, the most suitable processing parameters were found to be angular velocity of 8500rpm for nozzles of 0.5mm diameter and working distance of 30cm. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Depolymerization and hydrodeoxygenation of switchgrass lignin with formic acid.

    Science.gov (United States)

    Xu, Weiyin; Miller, Stephen J; Agrawal, Pradeep K; Jones, Christopher W

    2012-04-01

    Organosolv switchgrass lignin is depolymerized and hydrodeoxygenated with a formic acid hydrogen source, 20 wt % Pt/C catalyst, and ethanol solvent. The combination of formic acid and Pt/C is found to promote production of higher fractions of lower molecular weight compounds in the liquid products. After 4 h of reaction, all of the switchgrass lignin is solubilized and 21 wt % of the biomass is shown to be converted into seven prominent molecular species that are identified and quantified. Reaction time is shown to be an important variable in affecting changes in product distributions and bulk liquid product properties. At 20 h of reaction, the lignin is significantly depolymerized to form liquid products with a 76 % reduction in the weighted average molecular weight. Elemental analysis also shows that the resultant liquid products have a 50 % reduction in O/C and 10 % increase in H/C molar ratios compared to the switchgrass lignin after 20 h. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Low Lignin (Brown Mid-rib) Sorghum Genotypes Restrict Growth of Fusarium Spp. as Compared with Near-Isogenic Wild-Type Sorghum

    Science.gov (United States)

    To increase usability of sorghum for bioenergy and forages, two different brown midrib (bmr) genes, bmr-6 and bmr-12, were backcrossed into five elite backgrounds, resulting in reduced lignin near-isogenic genotypes. Field-grown grain from bmr-6 and bmr-12 plants had significantly reduced colonizati...

  13. Analysis of syringyl and guaiacyl (S/G) ratio in lignin

    CSIR Research Space (South Africa)

    Spark, A

    2006-12-01

    Full Text Available the acidolysis products – Validate the new S/G ratio method Why are S/G ratios important? Gives a good indication of the reactivity of the lignin Experimental design Literature Review Establishing Acidolysis conditions Permanganate oxidation Lignin...-method is quick • Permanganate oxidation-method is slow but it is the standard method used at present • Nitrobenzene Oxidation, Pyrolysis, Cupric Oxidation and Thioacidolysis Lignin can be broken down to syringyl and guaiacyl subunits: OCH3 OH OCH3 OH...

  14. Laccase catalyzed grafting of-N-OH type mediators to lignin via radical-radical coupling

    DEFF Research Database (Denmark)

    Munk, Line; Punt, A. M.; Kabel, M. A.

    2017-01-01

    Lignin is an underexploited resource in biomass refining. Laccases (EC 1.10.3.2) catalyze oxidation of phenolic hydroxyls using O2 as electron acceptor and may facilitate lignin modification in the presence of mediators. This study assessed the reactivity of four different synthetic mediators...... better than HBT (1-hydroxybenzotriazole). Three different mechanisms are suggested to explain the grafting of HPI and HBT, all involving radical-radical coupling to produce covalent bonding to lignin. Lignin from exhaustive cellulase treatment of wheat straw was more susceptible to grafting than beech...... organosolv lignin with the relative abundance of grafting being 35% vs. 11% for HPI and 5% vs. 1% for HBT on these lignin substrates. The data imply that lignin can be functionalized via laccase catalysis with-N-OH type mediators....

  15. Methylene blue as a lignin surrogate in manganese peroxidase reaction systems.

    Science.gov (United States)

    Goby, Jeffrey D; Penner, Michael H; Lajoie, Curtis A; Kelly, Christine J

    2017-11-15

    Manganese peroxidase (MnP) is associated with lignin degradation and is thus relevant to lignocellulosic-utilization technologies. Technological applications require reaction mixture optimization. A surrogate substrate can facilitate this if its susceptibility to degradation is easily monitored and mirrors that of lignin. The dye methylene blue (MB) was evaluated in these respects as a surrogate substrate by testing its reactivity in reaction mixtures containing relevant redox mediators (dicarboxylic acids, fatty acids). Relative rates of MB degradation were compared to available literature reports of lignin degradation under similar conditions, and suggest that MB can be a useful lignin surrogate in MnP systems. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Thermoplastic Starch with Improved Properties by Blending with Lignins and Radiation Processing

    International Nuclear Information System (INIS)

    Zheng, D.; Baumberger, S.; Mikus, P.-Y.; Dole, P.; Soulestin, J.; Lacrampe, M.F.; Bliard, C.; Coqueret, X.

    2010-01-01

    The biorefinery of lignocellulosics generates lignin-rich fractions, which are potential source of phenolic molecules for chemistry and polymeric materials. The LignoStarch project aims at using such fractions to functionalize a renewable material, starch, by a clean physical grafting process, without any synthetic chemical additive and without any by-products generation. Previous works suggested that the low-molar-mass phenolic compounds in technical lignin could be responsible for the reactivity of starch-lignin system under electron-beam irradiation and improvement of starch water resistance. A particular aspect of the current studies is focused on the role of lignin phenolic extractables and to investigate the different chemical and physical parameters likely to impact the surface properties of starch-lignin materials. (author)

  17. Impact of Different Lignin Fractions on Saccharification Efficiency in Diverse Species of the Bioenergy Crop Miscanthus

    NARCIS (Netherlands)

    Weijde, van der Tim; Torres Salvador, Andres Francisco; Dolstra, Oene; Dechesne, Annemarie; Visser, Richard G.F.; Trindade, Luisa M.

    2016-01-01

    Lignin is a key factor limiting saccharification of lignocellulosic feedstocks. In this comparative study, various lignin methods—including acetyl bromide lignin (ABL), acid detergent lignin (ADL), Klason lignin (KL), and modified ADL and KL determination methods—were evaluated for their

  18. Base-catalyzed depolymerization of lignin : separation of monomers

    Energy Technology Data Exchange (ETDEWEB)

    Vigneault, A. [Sherbrooke Univ., PQ (Canada). Dept. of Chemical Engineering; Johnson, D.K. [National Renewable Energy Laboratory, Golden, CO (United States); Chornet, E. [Sherbrooke Univ., PQ (Canada). Dept. of Chemical Engineering; National Renewable Energy Laboratory, Golden, CO (United States)

    2007-12-15

    Biofuels produced from residual lignocellulosic biomass range from ethanol to biodiesel. The use of lignin for the production of alternate biofuels and green chemicals has been studied with particular emphasis on the structure of lignin and its oxyaromatic nature. In an effort to fractionate lignocellulosic biomass and valorize specific constitutive fractions, the authors developed a strategy for the separation of 12 added value monomers produced during the hydrolytic base catalyzed depolymerization (BCD) of a Steam Exploded Aspen Lignin. The separation strategy was similar to vanillin purification to obtain pure monomers, but combining more steps after the lignin depolymerization such as acidification, batch liquid-liquid-extraction (LLE), followed by vacuum distillation, liquid chromatography (LC) and crystallization. The purpose was to develop basic data for an industrial size process flow diagram, and to evaluate both the monomer losses during the separation and the energy requirements. Experimentally testing of LLE, vacuum distillation and flash LC in the laboratory showed that batch vacuum distillation produced up to 4 fractions. Process simulation revealed that a series of 4 vacuum distillation columns could produce 5 distinct monomer streams, of which 3 require further chromatography and crystallization operations for purification. 22 refs., 4 tabs., 8 figs.

  19. Production of lignin peroxidase by Ganoderma leucidum using solid ...

    African Journals Online (AJOL)

    The main objectives of this study were to optimize the culture conditions for the production of lignin peroxidase by Ganoderma leucidum, economic utilization of waste corn cobs as inducers substrate by pollution free fermentation technology and to optimize the solid state fermentation (SSF) process for lignin peroxidase ...

  20. Effect of periodate on lignin for wood adhesive application

    NARCIS (Netherlands)

    Gosselink, R.J.A.; Dam, van J.E.G.; Jong, de E.; Gellerstedt, G.; Scott, E.L.; Sanders, J.P.M.

    2011-01-01

    Development of eco-friendly binders with no harmful emission during its complete life cycle is of high interest for the wood-based industry. In this paper, a fully renewable binder based on activated lignin and poly-furfuryl alcohol and a partly renewable lignin based phenol-formaldehyde (PF) binder

  1. Lewis acid-catalyzed depolymerization of soda lignin in supercritical ethanol/water mixtures

    NARCIS (Netherlands)

    Güvenatam, Burcu; Heeres, Erik H.J.; Pidko, Evgeny A.; Hensen, Emiel J M

    2016-01-01

    The depolymerization of lignin model compounds and soda lignin by super Lewis acidic metal triflates has been investigated in a mixture of ethanol and water at 400 °C. The strong Lewis acids convert representative model compounds for the structure-forming linkages in lignin, namely α-O-4, 5-O-4

  2. Lignin-enriched Fermentation Residues from Bioethanol Production of Fast-growing Poplar and Forage Sorghum

    Directory of Open Access Journals (Sweden)

    José I Santos

    2015-07-01

    Full Text Available The current challenges in developing a cost-effective bioethanol industry include the production of not only high-volume, low cost biofuels but also high-value products with minimal downstream waste. The up-grading of side-stream lignins from bioethanol production plants to novel high-value products will improve the profitability of the bioethanol industry; to do that, a precise understanding of lignin is required. In the present study, lignin-enriched fermentation residues from bioethanol production (steam explosion pretreatment, saccharification, and fermentation of fast-growing poplar and forage sorghum were characterized. In addition to the purity and composition, lignin structure (syringyl/guaiacyl (S/G ratio, inter-unit linkages was also analyzed with spectroscopy techniques such as Fourier transform infrared and two-dimensional nuclear magnetic resonance. Bioethanol processing and feedstock origins seemed to be the main factors determining the purity, composition, and structure of lignins. Residual lignins from poplar and forage sorghum contained significant amounts of sugar and protein impurities. Poplar lignin showed a very high S/G ratio associated with p-hydroxybenzoate. A lower S/G ratio together with H lignin units and p-hydroxycinnamates (p-coumarate and ferulate was observed for forage sorghum lignin. The main inter-unit linkages present in both lignins were β-O-4´ aryl ether followed by resinols and phenylcoumarans.

  3. Enzymatic cellulose oxidation is linked to lignin by long-range electron transfer

    DEFF Research Database (Denmark)

    Westereng, Bjorge; Cannella, David; Wittrup Agger, Jane

    2015-01-01

    in biological systems are only partly understood. We show here that insoluble high molecular weight lignin functions as a reservoir of electrons facilitating LPMO activity. The electrons are donated to the enzyme by long-range electron transfer involving soluble low molecular weight lignins present in plant...... cell walls. Electron transfer was confirmed by electron paramagnetic resonance spectroscopy showing that LPMO activity on cellulose changes the level of unpaired electrons in the lignin. The discovery of a long-range electron transfer mechanism links the biodegradation of cellulose and lignin and sheds...

  4. Catalytic hydrotreating of lignin with water-soluble molybdenum catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Osmaa, A.; Johansson, A. (Technical Research Centre of Finland, Espoo (Finland). Lab. of Fuel and Process Technology)

    High yields (61% of the original lignin) of low molecular weight oil (84% of the oil eluted through GC) have been obtained by hydrotreating kraft pine lignin with a water-soluble molybdenum catalyst at 430[degree]C for 60 min. The main compounds in the product oil were phenols (8.7% of the original lignin), cyclohexanes (5.0%), benzenes (3.8%), naphthalenes (4.0%), and phenanthrenes (1.2%). The degree of hydrodeoxygenation was 98%. The quality (measured by GPC and GC) of the product was as good as when using more expensive solid NiMo-CR[sub 2]O[sub 3] catalysts. 30 refs., 6 tabs.

  5. Radiolysis of lignin: Prospective mechanism of high-temperature decomposition

    Science.gov (United States)

    Ponomarev, A. V.

    2017-12-01

    The range of the radiation-thermal processes resulting in conversion of lignin into monomeric phenols is considered. Statistically the most probable places of macromolecule ionization are aromatic units. Release of phenolic products from a lignin macromolecule is the multistage process beginning via fragmentation of primary cation-radicals. Reactions of electrons and small radicals with macromolecules, also as degradation of cation-radicals, result in formation of phenoxyl radicals. Macroradicals possess lower heat stability in comparison with macromolecules. Thermal decomposition of macroradicals leads to release of monohydric and dihydric phenols. The probability of benzenediols formation increases in the presence of alkanes. As noted, partial transformation of lignin into charcoal is inevitable.

  6. Structural Changes of Lignin after Liquid Hot Water Pretreatment and Its Effect on the Enzymatic Hydrolysis

    Directory of Open Access Journals (Sweden)

    Wen Wang

    2016-01-01

    Full Text Available During liquid hot water (LHW pretreatment, lignin is mostly retained in the pretreated biomass, and the changes in the chemical and structural characteristics of lignin should probably refer to re-/depolymerization, solubilization, or glass transition. The residual lignin could influence the effective enzymatic hydrolysis of cellulose. The pure lignin was used to evaluate the effect of LHW process on its structural and chemical features. The surface morphology of LHW-treated lignin observed with the scanning electron microscopy (SEM was more porous and irregular than that of untreated lignin. Compared to the untreated lignin, the surface area, total pore volume, and average pore size of LHW-treated lignin tested with the Brunner-Emmet-Teller (BET measurement were increased. FTIR analysis showed that the chemical structure of lignin was broken down in the LHW process. Additionally, the impact of untreated and treated lignin on the enzymatic hydrolysis of cellulose was also explored. The LHW-treated lignin had little impact on the cellulase adsorption and enzyme activities and somehow could improve the enzymatic hydrolysis of cellulose.

  7. Biobased alkylphenols from lignins via a two-step pyrolysis - Hydrodeoxygenation approach.

    Science.gov (United States)

    de Wild, P J; Huijgen, W J J; Kloekhorst, A; Chowdari, R K; Heeres, H J

    2017-04-01

    Five technical lignins (three organosolv, Kraft and soda lignin) were depolymerised to produce monomeric biobased aromatics, particularly alkylphenols, by a new two-stage thermochemical approach consisting of dedicated pyrolysis followed by catalytic hydrodeoxygenation (HDO) of the resulting pyrolysis oils. Pyrolysis yielded a mixture of guaiacols, catechols and, optionally, syringols in addition to alkylphenols. HDO with heterogeneous catalysts (Ru/C, CoMo/alumina, phosphided NiMO/C) effectively directed the product mixture towards alkylphenols by, among others, demethoxylation. Up to 15wt% monomeric aromatics of which 11wt% alkylphenols was obtained (on the lignin intake) with limited solid formation (<3wt% on lignin oil intake). For comparison, solid Kraft lignin was also directly hydrotreated for simultaneous depolymerisation and deoxygenation resulting in two times more alkylphenols. However, the alkylphenols concentration in the product oil is higher for the two-stage approach. Future research should compare direct hydrotreatment and the two-stage approach in more detail by techno-economic assessments. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Comparison of common lignin methods and modifications on forage and lignocellulosic biomass materials.

    Science.gov (United States)

    Goff, Ben M; Murphy, Patrick T; Moore, Kenneth J

    2012-03-15

    A variety of methods have been developed for estimating lignin concentration within plant materials. The objective of this study was to compare the lignin concentrations produced by six methods on a diverse population of forage and biomass materials and to examine the relationship between these concentrations and the portions of these materials that are available for utilisation by livestock or for ethanol conversion. Several methods produced lignin concentrations that were highly correlated with the digestibility of the forages, but there were few relationships between these methods and the available carbohydrate of the biomass materials. The use of Na₂SO₃ during preparation of residues for hydrolysis resulted in reduced lignin concentrations and decreased correlation with digestibility of forage materials, particularly the warm-season grasses. There were several methods that were well suited for predicting the digestible portion of forage materials, with the acid detergent lignin and Klason lignin method giving the highest correlation across the three types of forage. The continued use of Na₂SO₃ during preparation of Van Soest fibres needs to be evaluated owing to its ability to reduce lignin concentrations and effectiveness in predicting the utilisation of feedstuffs and feedstocks. Because there was little correlation between the lignin concentration and the biomass materials, there is a need to examine alternative or develop new methods to estimate lignin concentrations that may be used to predict the availability of carbohydrates for ethanol conversion. Copyright © 2011 Society of Chemical Industry.

  9. Syringyl Lignin Is Unaltered by Severe Sinapyl Alcohol Dehydrogenase Suppression in Tobacco[W

    Science.gov (United States)

    Barakate, Abdellah; Stephens, Jennifer; Goldie, Alison; Hunter, William N.; Marshall, David; Hancock, Robert D.; Lapierre, Catherine; Morreel, Kris; Boerjan, Wout; Halpin, Claire

    2011-01-01

    The manipulation of lignin could, in principle, facilitate efficient biofuel production from plant biomass. Despite intensive study of the lignin pathway, uncertainty exists about the enzyme catalyzing the last step in syringyl (S) monolignol biosynthesis, the reduction of sinapaldehyde to sinapyl alcohol. Traditional schemes of the pathway suggested that both guaiacyl (G) and S monolignols are produced by a single substrate-versatile enzyme, cinnamyl alcohol dehydrogenase (CAD). This was challenged by the discovery of a novel sinapyl alcohol dehydrogenase (SAD) that preferentially uses sinapaldehyde as a substrate and that was claimed to regulate S lignin biosynthesis in angiosperms. Consequently, most pathway schemes now show SAD (or SAD and CAD) at the sinapaldehyde reduction step, although functional evidence is lacking. We cloned SAD from tobacco (Nicotiana tabacum) and suppressed it in transgenic plants using RNA interference–inducing vectors. Characterization of lignin in the woody stems shows no change to content, composition, or structure, and S lignin is normal. By contrast, plants additionally suppressed in CAD have changes to lignin structure and S:G ratio and have increased sinapaldehyde in lignin, similar to plants suppressed in CAD alone. These data demonstrate that CAD, not SAD, is the enzyme responsible for S lignin biosynthesis in woody angiosperm xylem. PMID:22158465

  10. Microwave-assisted acid pretreatment of alkali lignin: Effect on characteristics and pyrolysis behavior.

    Science.gov (United States)

    Duan, Dengle; Ruan, Roger; Wang, Yunpu; Liu, Yuhuan; Dai, Leilei; Zhao, Yunfeng; Zhou, Yue; Wu, Qiuhao

    2018-03-01

    This study performed microwave-assisted acid pretreatment on pure lignin. The effects of microwave temperature, microwave time, and hydrochloric acid concentration on characteristics and pyrolysis behavior of lignin were examined. Results of ultimate analysis revealed better properties of all pretreated samples than those of raw lignin. Fourier transform infrared spectroscopy analysis showed breakage of βO4 bond and aliphatic side chain, decrease in OH groups, and formation of CO groups in pretreatment. Microwave temperature exerted more significant influence on lignin structure. Thermal stability of treated lignin was improved and insensitive to short microwave time and acid concentration under mild conditions. Resulting from improved alkyl-phenols and decreased alkoxy-phenols, microwave-assisted acid pretreatment of lignin yielded bio-oil with excellent quality. Total yield of phenols in pyrolysis vapors (200 °C) improved to 14.15%, whereas that of guaiacols decreased to 22.36%. This study shows that microwave-assisted acid pretreatment is a promising technology for lignin conversion. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Production of Micro- and Nanoscale Lignin from Wheat Straw Using Different Precipitation Setups.

    Science.gov (United States)

    Beisl, Stefan; Loidolt, Petra; Miltner, Angela; Harasek, Michael; Friedl, Anton

    2018-03-11

    Micro- and nanosize lignin has recently gained interest due to its improved properties compared to standard lignin available today. As the second most abundant biopolymer after cellulose, lignin is readily available but used for rather low-value applications. Applications for lignin in micro- to nanoscale however, ranging from improvement of mechanical properties of polymer nanocomposites, have bactericidal and antioxidant properties and impregnations to hollow lignin drug carriers for hydrophobic and hydrophilic substances. This research represents a whole biorefinery process chain and compares different precipitation setups to produce submicron lignin particles from lignin containing an organosolv pretreatment extract from wheat straw. A batch precipitation in a stirred vessel was compared with continuous mixing of extract and antisolvent in a T-fitting and mixing in a T-fitting followed by a static mixer. The precipitation in the combination of T-fitting and static mixer with improved precipitation parameters yields the smallest particle size of around 100 nm. Furthermore, drying of particles did not influence the particle sizes negatively by showing decreased particle diameters after the separation process.

  12. Enzymes in Commercial Cellulase Preparations Bind Differently to Dioxane Extracted Lignins

    Energy Technology Data Exchange (ETDEWEB)

    Yarbrough, John M.; Mittal, Ashutosh; Katahira, Rui; Mansfield, Elisabeth; Taylor, Larry E.; Decker, Stephen R.; Himmel, Michael E.; Vinzant, Todd

    2017-04-24

    Commercial fungal cellulases used in biomass-to-biofuels processes can be grouped into three general classes: native, augmented, and engineered. To evaluate lignin binding affinities of different enzyme activities in various commercial cellulase formulations in order to determine if enzyme losses due to lignin binding can be modulated by using different enzymes of the same activity We used water:dioxane (1:9) to extract lignin from pretreated corn stover. Commercial cellulases were incubated with lignin and the unbound supernatants were evaluated for individual enzyme loss by SDS=PAGE and these were correlated with activity loss using various pNP-sugar substrates. Colorimetric assays for general glycosyl hydrolase activities showed distinct differences in enzyme binding to lignin for each enzyme activity. Native systems demonstrated low binding of endo- and exo-cellulases, high binding of xylanase, and moderate ..beta..-glucosidase binding. Engineered cellulase mixtures exhibited low binding of exo-cellulases, very strong binding of endocellulases and ..beta..- glucosidase, and mixed binding of xylanase activity. The augmented cellulase had low binding of exocellulase, high binding of endocellulase and xylanase, and moderate binding of ..beta..-glucosidase activities. Bound and unbound activities were correlated with general molecular weight ranges of proteins as measured by loss of proteins bands in bound fractions on SDS-PAGE gels. Lignin-bound high molecular weight bands correlated with binding of ..beta..-glucosidase activity. While ..beta..-glucosidases demonstrated high binding in many cases, they have been shown to remain active. Bound low molecular weight bands correlated with xylanase activity binding. Contrary to other literature, exocellulase activity did not show strong lignin binding. The variation in enzyme activity binding between the three classes of cellulases preparations indicate that it is certainly possible to alter the binding of specific

  13. The influence of lignin on steam pretreatment and mechanical pulping of poplar to achieve high sugar recovery and ease of enzymatic hydrolysis.

    Science.gov (United States)

    Chandra, Richard P; Chu, QiuLu; Hu, Jinguang; Zhong, Na; Lin, Mandy; Lee, Jin-Suk; Saddler, Jack

    2016-01-01

    With the goal of enhancing overall carbohydrate recovery and reducing enzyme loading refiner mechanical pulping and steam pretreatment (210°C, 5 min) were used to pretreat poplar wood chips. Neutral sulphonation post-treatment indicated that, although the lignin present in the steam pretreated substrate was less reactive, the cellulose-rich, water insoluble component was more accessible to cellulases and Simons stain. This was likely due to lignin relocation as the relative surface lignin measured by X-ray photoelectron spectroscopy increased from 0.4 to 0.8. The integration of sulphite directly into steam pretreatment resulted in the solubilisation of 60% of the lignin while more than 80% of the carbohydrate present in the original substrate was recovered in the water insoluble fraction after Na2CO3 addition. More than 80% of the sugars present in the original cellulose and xylan could be recovered after 48 h using an enzyme loading of 20 mg protein/g cellulose at a 10% substrate concentration. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Exploring the antioxidant potential of lignin isolated from black liquor of oil palm waste.

    Science.gov (United States)

    Bhat, Rajeev; Khalil, H P S A; Karim, A A

    2009-09-01

    This study was conducted to evaluate the potential antioxidant activity of lignin obtained from black liquor, a hazardous waste product generated during the extraction of palm oil. Antioxidant potential of the extracted lignin was evaluated by dissolving the extracted samples in 2 different solvent systems, namely, 2-methoxy ethanol and DMSO. Results revealed high percent inhibition of the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical in the lignin sample dissolved in 2-methoxy ethanol over DMSO (concentration range of 1-100 microg/ml). Lignin extracted in 2-methoxy ethanol exhibited higher inhibition percentage (at 50 microg/ml, 84.2%), whereas a concentration of 100 microg/ml was found to be effective in the case of the DMSO solvent (69.8%). Fourier transform infrared (FTIR) spectrometry revealed that the functional groups from the extracted lignin and commercial lignin were highly similar, indicating the purity of the lignin extracted from black liquor. These results provide a strong basis for further applications of lignin in the food industry and also illustrate an eco-friendly approach to utilize oil palm black liquor.

  15. Properties and Possible Applications for Lignin Streams Obtained from Rice Straw Processing

    DEFF Research Database (Denmark)

    Mussatto, Solange I.

    This study aimed to evaluate the chemical and physical properties of lignin streams recovered from rice straw processing and to study the extraction of antioxidant phenolic compounds from these materials. The evaluated samples included two different cellulignin fermentation residues (FR’s) and an......This study aimed to evaluate the chemical and physical properties of lignin streams recovered from rice straw processing and to study the extraction of antioxidant phenolic compounds from these materials. The evaluated samples included two different cellulignin fermentation residues (FR......’s) and an acid-precipitated lignin from alkaline-deacetylated black liquor (DBLL). For comparison, a standard lignin sample (Kraft lignin, from Sigma-Aldrich) was also assayed. Besides providing a better understanding about such materials, the obtained results made also possible to propose some potential...

  16. Structural changes of corn stover lignin during acid pretreatment.

    Science.gov (United States)

    Moxley, Geoffrey; Gaspar, Armindo Ribeiro; Higgins, Don; Xu, Hui

    2012-09-01

    In this study, raw corn stover was subjected to dilute acid pretreatments over a range of severities under conditions similar to those identified by the National Renewable Energy Laboratory (NREL) in their techno-economic analysis of biochemical conversion of corn stover to ethanol. The pretreated corn stover then underwent enzymatic hydrolysis with yields above 70 % at moderate enzyme loading conditions. The enzyme exhausted lignin residues were characterized by ³¹P NMR spectroscopy and functional moieties quantified and correlated to enzymatic hydrolysis yields. Results from this study indicated that both xylan solubilization and lignin degradation are important for improving the enzyme accessibility and digestibility of dilute acid pretreated corn stover. At lower pretreatment temperatures, there is a good correlation between xylan solubilization and cellulose accessibility. At higher pretreatment temperatures, lignin degradation correlated better with cellulose accessibility, represented by the increase in phenolic groups. During acid pretreatment, the ratio of syringyl/guaiacyl functional groups also gradually changed from less than 1 to greater than 1 with the increase in pretreatment temperature. This implies that more syringyl units are released from lignin depolymerization of aryl ether linkages than guaiacyl units. The condensed phenolic units are also correlated with the increase in pretreatment temperature up to 180 °C, beyond which point condensation reactions may overtake the hydrolysis of aryl ether linkages as the dominant reactions of lignin, thus leading to decreased cellulose accessibility.

  17. Enzymatically and chemically oxidized lignin nanoparticles for biomaterial applications.

    Science.gov (United States)

    Mattinen, Maija-Liisa; Valle-Delgado, Juan José; Leskinen, Timo; Anttila, Tuomas; Riviere, Guillaume; Sipponen, Mika; Paananen, Arja; Lintinen, Kalle; Kostiainen, Mauri; Österberg, Monika

    2018-04-01

    Cross-linked and decolorized lignin nanoparticles (LNPs) were prepared enzymatically and chemically from softwood Kraft lignin. Colloidal lignin particles (CLPs, ca. 200 nm) in a non-malodorous aqueous dispersion could be dried and redispersed in tetrahydrofuran (THF) or in water retaining their stability i.e. spherical shape and size. Two fungal laccases, Trametes hirsuta (ThL) and Melanocarpus albomyces (MaL) were used in the cross-linking reactions. Reactivity of ThL and MaL on Lignoboost™ lignin and LNPs was confirmed by high performance size exclusion chromatography (HPSEC) and oxygen consumption measurements with simultaneous detection of red-brown color due to the formation of quinones. Zeta potential measurements verified oxidation of LNPs via formation of surface-oriented carboxylic acid groups. Dynamic light scattering (DLS) revealed minor changes in the particle size distributions of LNPs after laccase catalyzed radicalization, indicating preferably covalent intraparticular cross-linking over polymerization. Changes in the surface morphology of laccase treated LNPs were imaged by atomic force (AFM) and transmission emission (TEM) microscopy. Furthermore, decolorization of LNPs without degradation was obtained using ultrasonication with H 2 O 2 in alkaline reaction conditions. The research results have high impact for the utilization of Kraft lignin as nanosized colloidal particles in advanced bionanomaterial applications in medicine, foods and cosmetics including different sectors from chemical industry. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  18. Aromatic chemicals by iron-catalyzed hydrotreatment of lignin pyrolysis vapor.

    Science.gov (United States)

    Olcese, Roberto Nicolas; Lardier, George; Bettahar, Mohammed; Ghanbaja, Jaafar; Fontana, Sébastien; Carré, Vincent; Aubriet, Frédéric; Petitjean, Dominique; Dufour, Anthony

    2013-08-01

    Lignin is a potential renewable material for the production of bio-sourced aromatic chemicals. We present the first hydrotreatment of lignin pyrolysis vapors, before any condensation, using inexpensive and sustainable iron-silica (Fe/SiO2 ) and iron-activated carbon (Fe/AC) catalysts. Lignin pyrolysis was conducted in a tubular reactor and vapors were injected in a fixed bed of catalysts (673 K, 1 bar) with stacks to investigate the profile of coke deposit. More than 170 GC-analyzable compounds were identified by GCxGC (heart cutting)/flame ionization detector mass spectrometry. Lignin oligomers were analyzed by very high resolution mass spectrometry, called the "petroleomic" method. They are trapped by the catalytic fixed bed and, in particular, by the AC. The catalysts showed a good selectivity for the hydrodeoxygenation of real lignin vapors to benzene, toluene, xylenes, phenol, cresols, and alkyl phenols. The spent catalysts were characterized by temperature-programmed oxidation, transmission electron microscopy (TEM), and N2 sorption. Micropores in the Fe/AC catalyst are completely plugged by coke deposits, whereas the mesoporous structure of Fe/SiO2 is unaffected. TEM images reveal two different types of coke deposit: 1) catalytic coke deposited in the vicinity of iron particles and 2) thermal coke (carbonaceous particles ≈1 μm in diameter) formed from the gas-phase growth of lignin oligomers. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Catalytic Reforming of Lignin-Derived Bio-Oil Over a Nanoporous Molecular Sieve Silicoaluminophosphate-11.

    Science.gov (United States)

    Park, Y K; Kang, Hyeon Koo; Jang, Hansaem; Suh, Dong Jin; Park, Sung Hoon

    2016-05-01

    Catalytic pyrolysis of lignin, a major constituent of biomass, was performed. A nanoporous molecular sieve silicoaluminophosphate-11 (SAPO-11) was selected as catalyst. Thermogravimetric analysis showed that 500 degrees C was the optimal pyrolysis temperature. Pyrolyzer-gas chromatography/mass spectroscopy was used to investigate the pyrolysis product distribution. Production of phenolics, the dominant product from the pyrolysis of lignin, was promoted by the increase in the catalyst dose. In particular, low-molecular-mass phenolics were produced more over SAPO-11, while high-molecular-mass phenolics and double-bond-containing phenolics were produced less. The fraction of aromatic compounds, including benzene, toluene, xylene, and ethylbenzene, was also increased by catalytic reforming. The catalytic effects were more pronounced when the catalyst/biomass ratio was increased. The enhanced production of aromatic compounds by an acidic catalyst obtained in this study is in good agreement with the results of previous studies.

  20. Deciphering the function and regulation of SbCAD2: A key lignin gene to improve sorghum biomass degradability

    Science.gov (United States)

    Genetic modification of lignin biosynthesis in the cell wall of biofuel feedstocks is likely one of the most effective ways to improve the conversion efficiency of cellulosic biomass to biofuel for the bioenergy industry. As a key enzyme that catalyzes the last step of monolignol synthesis, cinnamy...

  1. Oxidative degradation of lignin by photochemical and chemical radical generating systems

    International Nuclear Information System (INIS)

    Gold, M.H.; Kutsuki, H.; Morgan, M.A.

    1983-01-01

    Oxidation of specifically radiolabeled 14 C-lignins by UV/H 2 O 2 , Fenton's reagent, photosensitizing riboflavin, UV- and γ-irradiation was examined. In the presence of UV/H 2 O 2 , a hydroxyl radical (radicalOH) generating system, 14 C-methoxy, 2-[ 14 C-sidechain] and 14 C-ring labeled lignin were rapidly and extensively degraded as measured by gel filtration of the reaction products on Sephadex LH-20. This suggested that exposure to radicalOH leads to rapid, nonspecific lignin degradation. Rapid degradation of 14 C-methoxy, 2-[ 14 C-sidechain] and 14 C-ring labeled lignin also occurred in the presence of the radicalOH generating system, Fenton's reagent, confirming the primary role of radicalOH in these reactions. Photosensitizing riboflavin, also capable of effecting transformation of organic compounds via Type I hydrogen radical abstractions, caused extensive oxidative degradation of 14 C-methoxy labeled lignin and significant degradation of 2-[ 14 C-sidechain] and 14 C-ring labeled lignin. In addition, UV- and γ-irradiation caused slower but extensive degradation of the polymers, probably via radical type mechanisms. All of these results indicate that radicalOH as well as organic radical generating systems are effective agents for the purpose of degrading this heterogeneous, optically inactive and random biopolymer. (author)

  2. Improved Lignin Polyurethane Properties with Lewis Acid Treatment

    OpenAIRE

    Chung, Hoyong; Washburn, Newell R.

    2012-01-01

    Chemical modification strategies to improve the mechanical properties of lignin-based polyurethanes are presented. We hypothesized that treatment of lignin with Lewis acids would increase the concentration of hydroxyl groups available to react with diisocyanate monomers. Under the conditions used, hydrogen bromide-catalyzed modification resulted in a 28% increase in hydroxyl group content. Associated increases in hydrophilicity of solvent-cast thin films were also recorded as evidenced by ...

  3. Valorisation of lignin – Achievements of the LignoValue project

    NARCIS (Netherlands)

    Gosselink, R.J.A.; Dam, van J.E.G.; Wild, de P.; Huijgen, W.; Bridgwater, T.; Heeres, H.J.; Kloekhorst, A.; Scott, E.L.; Sanders, J.P.M.

    2011-01-01

    Lignocellulosic biorefinery for production of biofuels, materials and chemicals requires valorization of all fractions including lignin. As a consequence of its poly-aromatic structure, lignin potentially serves as a source for aromatic chemicals. The developed biorefinery concept of the LignoValue

  4. A NEW PROCESS DEVELOPED FOR SEPARATION OF LIGNIN FROM AMMONIUM HYDROXIDE PRETREATMENT SOLUTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Sherman, S.; Gorensek, M.; Milliken, C.

    2010-12-14

    A method is described for separating lignin from liquid solutions resulting from the pretreatment of lignocellulosic materials such as switchgrass with ammonium hydroxide. The method involves a sequence of steps including acidification, evaporation, and precipitation or centrifugation that are performed under defined conditions, and results in a relatively pure, solid lignin product. The method is tested on ammonium hydroxide solutions containing lignin extracted from switchgrass. Experimental results show that the method is capable of recovering between 66-95% of dissolved lignin as a precipitated solid. Cost estimates of pilot-scale and industrial-scale expressions of the process indicate that breakeven lignin prices of $2.36/kg and $0.78/kg, respectively, may be obtainable with this recovery method.

  5. Paving the Way for Lignin Valorisation : Recent Advances in Bioengineering, Biorefining and Catalysis

    NARCIS (Netherlands)

    Rinaldi, Roberto; Jastrzebski, Robin|info:eu-repo/dai/nl/338017747; Clough, Matthew T; Ralph, John; Kennema, Marco; Bruijnincx, Pieter C A|info:eu-repo/dai/nl/33799529X; Weckhuysen, Bert M|info:eu-repo/dai/nl/285484397

    2016-01-01

    Lignin is an abundant biopolymer with a high carbon content and high aromaticity. Despite its potential as a raw material for the fuel and chemical industries, lignin remains the most poorly utilised of the lignocellulosic biopolymers. Effective valorisation of lignin requires careful fine-tuning of

  6. Probing the interactions between lignin and inorganic oxides using atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jingyu; Qian, Yong, E-mail: qianyong86@163.com; Deng, Yonghong; Liu, Di; Li, Hao; Qiu, Xueqing, E-mail: xueqingqiu66@163.com

    2016-12-30

    Graphical abstract: The interactions between lignin and inorganic oxides are quantitatively probed by atomic force microscopy, which is fundamental but beneficial for understanding and optimizing the absorption-dispersion and catalytic degradation processes of lignin. - Highlights: • The interactions between lignin and inorganic oxides are measured using AFM. • The adhesion forces between lignin and metal oxides are larger than that in nonmetal systems. • Hydrogen bond plays an important role in lignin-inorganic oxides system. - Abstract: Understanding the interactions between lignin and inorganic oxides has both fundamental and practical importance in industrial and energy fields. In this work, the specific interactions between alkali lignin (AL) and three inorganic oxide substrates in aqueous environment are quantitatively measured using atomic force microscopy (AFM). The results show that the average adhesion force between AL and metal oxide such as Al{sub 2}O{sub 3} or MgO is nearly two times bigger than that between AL and nonmetal oxide such as SiO{sub 2} due to the electrostatic difference and cation-π interaction. When 83% hydroxyl groups of AL is blocked by acetylation, the adhesion forces between AL and Al{sub 2}O{sub 3}, MgO and SiO{sub 2} decrease 43, 35 and 75% respectively, which indicate hydrogen bonds play an important role between AL and inorganic oxides, especially in AL-silica system.

  7. Improved lignin pyrolysis for phenolics production in a bubbling bed reactor--Effect of bed materials.

    Science.gov (United States)

    Li, Dongbing; Briens, Cedric; Berruti, Franco

    2015-01-01

    Lignin pyrolysis was studied in a bubbling fluidized bed reactor equipped with a fractional condensation train, using nitrogen as the fluidization gas. The effect of different bed materials (silica sand, lignin char, activated lignin char, birch bark char, and foamed glass beads) on bio-oil yield and quality was investigated for a pyrolysis temperature of 550 °C. Results how that a bed of activated lignin char is preferable to the commonly used silica sand: pyrolysis of Kraft lignin with a bed of activated lignin char not only provides a pure char product, but also a higher dry bio-oil yield (with a relative increase of 43%), lower pyrolytic water production, and better bio-oil quality. The bio-oil obtained from Kraft lignin pyrolysis with a bed of activated lignin char has a lower average molecular weight, less tar, more phenolics, and less acidity than when sand is used as bed material. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Connecting tropical river DOM and POM to the landscape with lignin

    Science.gov (United States)

    Hernes, Peter J.; Dyda, Rachael Y.; McDowell, William H.

    2017-12-01

    Tropical rivers account for two thirds of global fluxes of terrigenous organic matter to the oceans, yet because of their remote locations relative to most industrialized countries, they are poorly studied compared to temperate and even Arctic rivers. Further, most tropical river research has focused on large rivers like the Amazon or Congo, yet more than half of organic matter fluxes from tropical rivers comes from much smaller rivers. This study focuses on two such rivers in the Luquillo Experimental Forest of Puerto Rico, namely the Rio Mameyes and Rio Icacos, and uses time-series measurements of lignin biomarkers to put them in context with much bigger tropical rivers in the literature. Although lignin concentrations and carbon-normalized yields offer some distinction between mountainous vs. floodplain tropical river reaches, compositional differences appear to offer greater potential, including S:V vs. C:V plots that may capture the poorly-studied influence of palm trees, and (Ad:Al)s vs. (Ad:Al)v plots that may reflect differences in underlying mineralogy and degradation in soils. Even though dissolved and particulate lignin ultimately come from the same vegetation sources, comparison of dissolved and particulate lignin parameters within the two Puerto Rican rivers indicate that the pathways by which they end up in the same parcel of river water are largely decoupled. Across several particulate lignin studies in tropical rivers, mineral composition and concentration appears to exert a strong control on particulate lignin compositions and concentrations. Finally, the time-series nature of this study allows for new ways of analyzing dissolved lignin endmember compositions and degradation within the catchment. Plots of dissolved lignin parameters vs. lignin concentration reveal both the composition of "fresh" DOM that is likely mobilized from organic-rich soil surface layers along with the extent and trajectory of degradation of that signature that is possible

  9. Analysis of Structural Units and Their Influence on Thermal Degradation of Alkali Lignins

    Directory of Open Access Journals (Sweden)

    Wen Hua

    2016-01-01

    Full Text Available The chemical structures of four alkali lignins isolated from poplar, fir, straw, and bagasse were investigated. To explore the relationship between the structural units and the thermal decomposition behavior, the system was tested by elemental analysis, Fourier transform infrared spectrometry, thermogravimetric analysis (TGA, and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS. The results indicated that the carbon content of poplar lignin (PL was higher than that of others. Fir lignin (FL exhibited the highest guaiacol units, while the other three lignins were abundant in syringol units. The thermal decomposition characteristics and pyrolysis products of the four lignins were influenced by the material structural and composition. The DTG curves showed that the initial temperatures and major degradation temperatures of woody lignins(FL and PL) with complex inherent structures were shifted to the high temperature zoom compared with that of non-woody (BL and SL)lignins. Py-GC/MS analysis showed that guaiacol-type phenolic compounds were predominant pyrolysis products derived from the four lignins. The yield of guaiacol-type phenols could reach 82.87%. Moreover, the BL had selectively on phenol-type compounds with yield of 27.89%.

  10. Removal of oil palm trunk lignin in ammonium hydroxide pretreatment

    Science.gov (United States)

    Az-Zahraa, Balqis; Zakaria, Sarani; Daud, Muhammad F. B.; Jaafar, Sharifah Nabihah Syed

    2018-04-01

    Alkaline pretreatment using ammonium hydroxide, NH4OH serves as one of a process to remove lignin from lignocellulosic biomass such as oil palm trunk fiber. In this study, the effect of NH4OH pretreatment on removal of oil palm trunk lignin was investigated. The oil palm trunk fiber was dissolved in NH4OH with different concentrations (6, 8 and 10 %), different duration (3, 5 and 7 h) and temperatures (60, 80 and 100 °C). The samples were analyzed by using UV-Vis to estimate the concentration of extracted lignin. The result indicates that the optimum conditions to gain maximum extracted lignin were 8% NH4OH, 100 °C and 5 h with concentration of 64 mgL-1 while the lowest was at 6% NH4OH, 100 °C and 5 h with concentration of 62.5 mgL-1.

  11. Structural variations and physical properties of lignin coke

    International Nuclear Information System (INIS)

    Otani, C.

    1986-01-01

    The studied lignin is a by-product of the process of ethanol production from eucaliptus. It was heat-treated under inert atmosphere conditions at increasing temperatures from 300 0 C up to 2600 0 C. This material has about 35 weight % of carbon yield and low ash content (0.70 w %). The structural variations were studied by wide-angle X-ray diffraction, small-angle X-ray scattering and infra-red spectroscopy. The bulk and the ''real'' density of the samples have also been determined as a function of the heat treatment temperatures. These experimental results enabled us to establish a mechanism of structure variation based on the formation of a graphite-like and porous structure within the initially amorphous lignin matrix. It has been possible to specify the adequate heat treatment temperature based upon the lignin coke applications. (author) [pt

  12. Effective depolymerization of concentrated acid hydrolysis lignin using a carbon-supported ruthenium catalyst in ethanol/formic acid media.

    Science.gov (United States)

    Kristianto, Ivan; Limarta, Susan Olivia; Lee, Hyunjoo; Ha, Jeong-Myeong; Suh, Dong Jin; Jae, Jungho

    2017-06-01

    Lignin isolated by two-step concentrated acid hydrolysis of empty fruit bunch (EFB) was effectively depolymerized into a high-quality bio-oil using formic acid (FA) as an in-situ hydrogen source and Ru/C as a catalyst in supercritical ethanol. A bio-oil yield of 66.3wt% with an average molecular weight of 822g/mol and an aromatic monomer content of 6.1wt% was achieved at 350°C and a FA-to-lignin mass ratio of 3 after a reaction time of 60min. The combination of Ru/C and FA also resulted in a significant reduction in the oxygen content of the bio-oil by ∼60% and a corresponding increase in the higher heating value (HHV) to 32.7MJ/kg due to the enhanced hydrodeoxygenation activity. An examination of the FA decomposition characteristics revealed that Ru/C provides a greater increase in the rate of hydrogen production from FA, explaining the efficient depolymerization of lignin in a combined system. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Reactivity of lignin and problems of its oxidative destruction with peroxy reagents

    International Nuclear Information System (INIS)

    Demin, Valerii A; Shereshovets, Valerii V; Monakov, Yurii B

    1999-01-01

    Published data on reactivity and oxidation of lignin and model compounds with hydrogen peroxide, ozone and chlorine dioxide as well as on oxidative destruction of the sulfate pulp lignin with various reagents during bleaching are systematised and generalised. Concepts of lignin activation towards its selective oxidation and kinetic features of sulfate pulp oxidative delignification are considered. The bibliography includes 157 references.

  14. The Paleozoic Origin of Enzymatic Lignin Decomposition Reconstructed from 31 Fungal Genomes

    Science.gov (United States)

    Dimitrios Floudas; Manfred Binder; Robert Riely; Kerrie Barry; Robert A. Blanchette; Bernard Henrissat; Angel T. Martínez; Robert Otillar; Joseph W. Spatafora; Jagjit S. Yadav; Andrea Aerts; Isabelle Benoit; Alex Boyd; Alexis Carlson; Alex Copeland; Pedro M. Coutinho; Ronald P. deVries; Patricia Ferreira; Keisha Findley; Brian Foster; Jill Gaskell; Dylan Glotzer; Pawe³ Górecki; Joseph Heitman; Cedar Hesse; Chiaki Hori; Kiyohiko Igarashi; Joel A. Jurgens; Nathan Kallen; Phil Kersten; Annegret Kohler; Ursula Kües; T. K. ArunKumar; Alan Kuo; Kurt LaButti; Luis F. Larrondo; Erika Lindquist; Albee Ling; Vincent Lombard; Susan Lucas; Taina Lundell; Rachael Martin; David J. McLaughlin; Ingo Morgenstern; Emanuelle Morin; Claude Murat; Laszlo G. Nagy; Matt Nolan; Robin A. Ohm; Aleksandrina Patyshakuliyeva; Antonis Rokas; Francisco J. Ruiz-Dueñas; Grzegorz Sabat; Asaf Salamov; Masahiro Samejima; Jeremy Schmutz; Jason C. Slot; Franz St. John; Jan Stenlid; Hui Sun; Sheng Sun; Khajamohiddin Syed; Adrian Tsang; Ad Wiebenga; Darcy Young; Antonio Pisabarro; Daniel C. Eastwood; Francis Martin; Dan Cullen; Igor V. Grigoriev; David S. Hibbett

    2012-01-01

    Wood is a major pool of organic carbon that is highly resistant to decay, owing largely to the presence of lignin. The only organisms capable of substantial lignin decay are white rot fungi in the Agaricomycetes, which also contains non–lignin-degrading brown rot and ectomycorrhizal species. Comparative analyses of 31 fungal genomes (12 generated for this study)...

  15. Lignin properties in topsoils of a beech/oak forest after 8 years of manipulated litter fall: relevance of altered input and oxidation of lignin

    NARCIS (Netherlands)

    Klotzbücher, T.; Strohmeier, S.; Kaiser, K.; Bowden, R.D.; Lajtha, K.; Ohm, H.; Kalbitz, K.

    2013-01-01

    Background and aims We studied the response of lignin oxidation in soils of a beech/oak forest to changes in litter fall. Additionally we considered possible factors in lignin oxidation, including altered (i) input of fresh organic matter and (ii) fungi-to-bacteria ratios. Methods The field-based

  16. Influence of alkaline hydrothermal pretreatment on shrub wood Tamarix ramosissima: Characteristics of degraded lignin

    International Nuclear Information System (INIS)

    Xiao, Ling-Ping; Bai, Yuan-Yuan; Shi, Zheng-Jun; Lu, Qiang; Sun, Run-Cang

    2014-01-01

    The objective of this work was to evaluate the influence of alkaline hydrothermal (AH) pretreatment on the physicochemical properties of the degraded lignins, attempt to upgrade the potential of lignin for value-added chemicals and fuel production. For this purpose, shrub wood Tamarix ramosissima lignin was fractionated using a two-stage process based on an AH pretreatment followed by an alkaline ethanol post-treatment. The recovered lignin fractions were investigated by comparison with milled wood lignin (MWL) in terms of fractionation yield, carbohydrate composition, gel permeation chromatography, Fourier transform infrared spectroscopy, 13 C and 2D heteronuclear single quantum correlation nuclear magnetic resonance, as well as pyrolysis-gas chromatography/mass spectrometry. The result showed that AH pretreatment led to the degradation of β-O-4 linkages and consequently the increased severity caused a release of more S-units lignin fractions with molecular weights between 1300 and 2500 g/mol in the liquid but higher molecular weights (3000–4400 g/mol) in the residues. Moreover, it was found that the lignin syringyl-to-guaiacyl (S/G) ratios from analytical pyrolysis slightly changed after AH pretreatment (S/G, 1.8–2.3) but higher than those of MWL (S/G, 1.7). Overall, the present study demonstrates that these lignins dissolved during AH pretreatment and those recovered from the solid residues isolated with alkaline ethanol post-treatment could be profitably exploited as feedstock in integrated forest biorefineries, rather than traditional use as low-value energy sources.- Highlights: • Alkaline hydrothermal pretreatment and alkaline ethanol post-treatment were proposed. • The influence of AH pretreatment on the lignin structural changes was characterized. • Aryl-O-ether linkages of lignin were extensively cleaved. • Lignin recovered from solid residue is a potential resource for the production of value-added chemicals

  17. Selective production of arenes via direct lignin upgrading over a niobium-based catalyst

    Science.gov (United States)

    Shao, Yi; Xia, Qineng; Dong, Lin; Liu, Xiaohui; Han, Xue; Parker, Stewart F.; Cheng, Yongqiang; Daemen, Luke L.; Ramirez-Cuesta, Anibal J.; Yang, Sihai; Wang, Yanqin

    2017-07-01

    Lignin is the only large-volume renewable source of aromatic chemicals. Efficient depolymerization and deoxygenation of lignin while retaining the aromatic functionality are attractive but extremely challenging. Here we report the selective production of arenes via direct hydrodeoxygenation of organosolv lignin over a porous Ru/Nb2O5 catalyst that enabled the complete removal of the oxygen content from lignin. The conversion of birch lignin to monomer C7-C9 hydrocarbons is nearly quantitative based on its monomer content, with a total mass yield of 35.5 wt% and an exceptional arene selectivity of 71 wt%. Inelastic neutron scattering and DFT calculations confirm that the Nb2O5 support is catalytically unique compared with other traditional oxide supports, and the disassociation energy of Caromatic-OH bonds in phenolics is significantly reduced upon adsorption on Nb2O5, resulting in its distinct selectivity to arenes. This one-pot process provides a promising approach for improved lignin valorization with general applicability.

  18. A process for producing lignin and volatile compounds from hydrolysis liquor.

    Science.gov (United States)

    Khazraie, Tooran; Zhang, Yiqian; Tarasov, Dmitry; Gao, Weijue; Price, Jacquelyn; DeMartini, Nikolai; Hupa, Leena; Fatehi, Pedram

    2017-01-01

    Hot water hydrolysis process is commercially applied for treating wood chips prior to pulping or wood pellet production, while it produces hydrolysis liquor as a by-product. Since the hydrolysis liquor is dilute, the production of value-added materials from it would be challenging. In this study, acidification was proposed as a viable method to extract (1) furfural and acetic acid from hot water hydrolysis liquor and (2) lignin compounds from the liquor. The thermal properties of the precipitates made from the acidification of hydrolysis liquor confirmed the volatile characteristics of precipitates. Membrane dialysis was effective in removing inorganic salts associated with lignin compounds. The purified lignin compounds had a glass transition temperature (Tg) of 180-190 °C, and were thermally stable. The results confirmed that lignin compounds present in hot water hydrolysis liquor had different characteristics. The acidification of hydrolysis liquor primarily removed the volatile compounds from hydrolysis liquor. Based on these results, a process for producing purified lignin and precipitates of volatile compounds was proposed.

  19. Reactivity improvement of cellulolytic enzyme lignin via mild hydrothermal modification.

    Science.gov (United States)

    Ma, Zhuoming; Tang, Jiafa; Li, Shujun; Suo, Enxiang

    2017-12-01

    Isolated by the cellulolytic enzyme lignin (CEL) process, water-alcohol (1:1, v/v) was introduced as co-solvent in the process of the hydrothermal treatment. The modification parameters such as reaction temperature and time, solid-to-liquid ratio, and catalysts (NaOH and NaOAlO 2 ) have been investigated in terms of the specific lignin properties, such as the phenolic hydroxyl content (OH phen ), DPPH free radical scavenging rate, and formaldehyde value. The CELs were also characterized by GPC, FT-IR and 1 H NMR spectroscopy, and Py-GC/MS. The key data are under optimal lignin modification conditions (solid-to-liquid ratio of 1:10 (w/v) and a temperature of 250°C for 60min) are: OH phen content: 2.50mmol/g; half maximal inhibitory concentration (IC 50 ) towards DPPH free radicals: 88.2mg/L; formaldehyde value: 446.9g/kg). Both base catalysts decrease the residue rate, but phenol reactivities of the products were also detracted. Py-GC/MS results revealed that modified lignin had a higher phenolic composition than the CEL did, especially the modified lignin without catalyst (ML), which represented 74.51% phenolic content. Copyright © 2017. Published by Elsevier Inc.

  20. Purification and characterization of lignin peroxidases from Penicillium decumbens P6

    Energy Technology Data Exchange (ETDEWEB)

    Yang, J.S.; Yuan, H.L.; Wang, H.X.; Chen, W.X. [China Agricultural University, Beijing (China). College of Biological Science

    2005-06-01

    Peroxidases are essential enzymes in biodegradation of lignin and lignite which have been investigated intensively in the white-rot fungi. This is the first report of purification and characterization of lignin peroxidase from Penicillium sp. P6 as lignite degradation fungus. The results indicated that the lignin peroxidase of Penicillium decumbens P6 had physical and chemical properties and a N-terminal amino acid sequence different from the lignin peroxidases of white-rot fungi. The lignin peroxidase was isolated from a liquid culture of P. decumbens P6. This enzyme had a molecular weight of 46.3 KDa in SDS-PAGE and exhibited greater activity, temperature stability and wider pH range than those previously reported. The isolation procedure involved (NH{sub 4}){sub 2}SO{sub 4} precipitation, ion-exchange chromatography on DEAE-cellulose and CM-cellulose, gel filtration on Sephadex G-100, and non-denaturing, discontinuous polyacrylamide gel electrophoresis. The K{sub m} and V{sub max} values of this enzyme using veratryl alcohol as substrate were 0.565 mmol L{sup -1} and 0.088 mmol (mg protein){sup -1} min{sup -1} respectively. The optimum pH of P6 lignin peroxidase was 4.0, and 70.6% of the relative activity was remained at pH 9.0. The optimum temperature of the enzyme was 45{sup o}C.

  1. Kraft lignin chain extension chemistry via propargylation, oxidative coupling, and Claisen rearrangement.

    Science.gov (United States)

    Sen, Sanghamitra; Sadeghifar, Hasan; Argyropoulos, Dimitris S

    2013-10-14

    Despite its aromatic and polymeric nature, the heterogeneous, stochastic, and reactive characteristics of softwood kraft lignin seriously limit its potential for thermoplastic applications. Our continuing efforts toward creating thermoplastic lignin polymers are now focused at exploring propargylation derivatization chemistry and its potential as a versatile novel route for the eventual utilization of technical lignins with a significant amount of molecular control. To do this, we initially report the systematic propargylation of softwood kraft lignin. The synthesized derivatives were extensively characterized with thermal methods (DSC, TGA), (1)H, (13)C, and quantitative (31)P NMR and IR spectroscopies. Further on, we explore the versatile nature of the lignin pendant propargyl groups by demonstrating two distinct chain extension chemistries; the solution-based, copper-mediated, oxidative coupling and the thermally induced, solid-state, Claissen rearrangement polymerization chemistries. Overall, we show that it is possible to modulate the reactivity of softwood kraft lignin via a combination of methylation and chain extension providing a rational means for the creation of higher molecular weight polymers with the potential for thermoplastic materials and carbon fibers with the desired control of structure-property relations.

  2. Optimizing Noncovalent Interactions Between Lignin and Synthetic Polymers to Develop Effective Compatibilizers

    Energy Technology Data Exchange (ETDEWEB)

    Henry, Nathan [University of Tennessee, Knoxville (UTK); Harper, David [University of Tennessee, Knoxville (UTK), Center for Renewable Carbon; Dadmun, Mark D [ORNL

    2012-01-01

    Experiments are designed and completed to identify an effective polymeric compatibilizer for lignin polystyrene blends. Copolymers of styrene and vinylphenol are chosen as the structure of the compatibilizer as the VPh unit can readily form intermolecular hydrogen bonds with the lignin molecule. Electron microscopy, thermal analysis, and neutron refl ectivity results demonstrate that among these compatibilizers, a copolymer of styrene and VPh with 20% 30% VPh most readily forms intermolecular interactions with the lignin molecule and results in the most well-dispersed blends with lignin. This behavior is explained by invoking the competition of intra- and intermolecular hydrogen bonding and functional group accessibility in forming intermolecular interactions.

  3. The investigation of wood hydrolysis lignin ability for uranium sorption

    International Nuclear Information System (INIS)

    Rachkova, N.G.; Shuktomova, I.I.; Taskaev, A.I.

    2001-01-01

    The uranium are sorbed in wood hydrolysis lignin efficacious and very strong both in uranyl nitrate solutions and in podsolic soil. It may well be that formation of complexes are possible mechanism of irreversible sorption. The static capacity of lignin are 2.7 mg/g. (author)

  4. The phosphatidylinositol synthase gene (GhPIS) contributes to longer, stronger, and finer fibers in cotton.

    Science.gov (United States)

    Long, Qin; Yue, Fang; Liu, Ruochen; Song, Shuiqing; Li, Xianbi; Ding, Bo; Yan, Xingying; Pei, Yan

    2018-05-11

    Cotton fibers are the most important natural raw material used in textile industries world-wide. Fiber length, strength, and fineness are the three major traits which determine the quality and economic value of cotton. It is known that exogenous application of phosphatidylinositols (PtdIns), important structural phospholipids, can promote cotton fiber elongation. Here, we sought to increase the in planta production of PtdIns to improve fiber traits. Transgenic cotton plants were generated in which the expression of a cotton phosphatidylinositol synthase gene (i.e., GhPIS) was controlled by the fiber-specific SCFP promoter element, resulting in the specific up-regulation of GhPIS during cotton fiber development. We demonstrate that PtdIns content was significantly enhanced in transgenic cotton fibers and the elevated level of PtdIns stimulated the expression of genes involved in PtdIns phosphorylation as well as promoting lignin/lignin-like phenolic biosynthesis. Fiber length, strength and fineness were also improved in the transgenic plants as compared to the wild-type cotton, with no loss in overall fiber yield. Our data indicate that fiber-specific up-regulation of PtdIns synthesis is a promising strategy for cotton fiber quality improvement.

  5. Lignin decomposition is sustained under fluctuating redox conditions in humid tropical forest soils

    Science.gov (United States)

    Steven J. Hall; Whendee L. Silver; Vitaliy I. Timokhin; Kenneth E. Hammel

    2015-01-01

    Lignin mineralization represents a critical flux in the terrestrial carbon (C) cycle, yet little is known about mechanisms and environmental factors controlling lignin breakdown in mineral soils. Hypoxia is thought to suppress lignin decomposition, yet potential effects of oxygen (O2) variability in surface soils have not been explored. Here, we...

  6. Porous core-shell carbon fibers derived from lignin and cellulose nanofibrils

    KAUST Repository

    Xu, Xuezhu

    2013-10-01

    This letter reports a method to produce lignin and cellulose nanofibrils (CNFs) based porous core-shell carbon fibers via co-electrospinning followed by controlled carbonization. Lignin formed the shell of the fiber while CNF network formed the porous core. Polyacrylonitrile (PAN) was added to the lignin solution to increase its electrospinability. CNFs were surface acetylated and dispersed in silicon oil to obtain a homogenous dispersion for electrospinning the porous core. Hollow lignin fibers were also electrospun using glycerin as the core material. FT-IR measurements confirmed the CNF acetylation. SEM micrographs showed the core-shell and hollow fiber nanostructures before and after carbonization. The novel carbon fibers synthesized in this study exhibited increased surface area and porosity that are promising for many advanced applications. © 2013 Elsevier B.V.

  7. Porous core-shell carbon fibers derived from lignin and cellulose nanofibrils

    KAUST Repository

    Xu, Xuezhu; Zhou, Jian; Jiang, Long; Lubineau, Gilles; Chen, Ye; Wu, Xiangfa; Piere, Robert

    2013-01-01

    This letter reports a method to produce lignin and cellulose nanofibrils (CNFs) based porous core-shell carbon fibers via co-electrospinning followed by controlled carbonization. Lignin formed the shell of the fiber while CNF network formed the porous core. Polyacrylonitrile (PAN) was added to the lignin solution to increase its electrospinability. CNFs were surface acetylated and dispersed in silicon oil to obtain a homogenous dispersion for electrospinning the porous core. Hollow lignin fibers were also electrospun using glycerin as the core material. FT-IR measurements confirmed the CNF acetylation. SEM micrographs showed the core-shell and hollow fiber nanostructures before and after carbonization. The novel carbon fibers synthesized in this study exhibited increased surface area and porosity that are promising for many advanced applications. © 2013 Elsevier B.V.

  8. Evidence supporting dissimilatory and assimilatory lignin degradation in Enterobacter lignolyticus SCF1

    Energy Technology Data Exchange (ETDEWEB)

    DeAngelis, Kristen M.; Sharma, Deepak; Varney, Rebecca; Simmons, Blake A.; Isern, Nancy G.; Markillie, Lye Meng; Nicora, Carrie D.; Norbeck, Angela D.; Taylor, Ronald C.; Aldrich, Joshua T.; Robinson, Errol W.

    2013-08-29

    The anaerobic isolate Enterobacter lignolyticus SCF1 was initially cultivated based on anaerobic growth on lignin as sole carbon source. The source of the isolated bacteria was from tropical forest soils that decompose litter rapidly with low and fluctuating redox potentials, making it likely that bacteria using oxygen-independent enzymes play an important role in decomposition. We have examined differential expression of the anaerobic isolate Enterobacter lignolyticus SCF1 during growth on lignin. After 48 hours of growth, we used transcriptomics and proteomics to define the enzymes and other regulatory machinery that these organisms use to degrade lignin, as well as metabolomics to measure lignin degradation and monitor the use of lignin and iron as terminal electron acceptors that facilitate more efficient use of carbon. Proteomics revealed accelerated xylose uptake and metabolism under lignin-amended growth, and lignin degradation via the 4-hydroxyphenylacetate degradation pathway, catalase/peroxidase enzymes, and the glutathione biosynthesis and glutathione S-transferase proteins. We also observed increased production of NADH-quinone oxidoreductase, other electron transport chain proteins, and ATP synthase and ATP-binding cassette (ABC) transporters. Our data shows the advantages of a multi-omics approach, where incomplete pathways identified by genomics were completed, and new observations made on coping with poor carbon availability. The fast growth, high efficiency and specificity of enzymes employed in bacterial anaerobic litter deconstruction makes these soils useful templates for improving biofuel production.

  9. Preparation of Silk Sericin/Lignin Blend Beads for the Removal of Hexavalent Chromium Ions

    Science.gov (United States)

    Kwak, Hyo Won; Shin, Munju; Yun, Haesung; Lee, Ki Hoon

    2016-01-01

    In the present study, novel adsorbents having high adsorption capability and reusability were prepared using agricultural by-products: silk sericin and lignin. Silk sericin and lignin blend beads were successfully prepared using simple coagulation methods for the removal of hexavalent chromium (Cr(VI)) from aqueous solution. A 1 M lithium chloride (LiCl)/dimethyl sulfoxide (DMSO) solvent system successfully dissolved both sericin and lignin and had sufficient viscosity for bead preparation. Compared to the conventional sericin bead adsorbent, sericin/lignin blend beads showed higher Cr(VI) adsorption capacity. The amount of lignin added to the adsorbent greatly affected the adsorption capacity of the beads, and a 50:50 sericin/lignin blend ratio was optimal. Adsorption behavior followed the Freundlich isotherm, which means the adsorption of Cr(VI) occurred on the heterogeneous surface. Cr(VI) adsorption capability increased with temperature because of thermodynamic-kinetic effects. In addition, over 90% of Cr(VI) ions were recovered from the Cr(VI) adsorbed sericin/lignin beads in a 1 M NaOH solution. The adsorption-desorption recycling process was stable for more than seven cycles, and the recycling efficiency was 82%. It is expected that the sericin/lignin beads could be successfully applied in wastewater remediation especially for hazardous Cr(VI) ions in industrial wastewater. PMID:27598142

  10. Preparation of Silk Sericin/Lignin Blend Beads for the Removal of Hexavalent Chromium Ions

    Directory of Open Access Journals (Sweden)

    Hyo Won Kwak

    2016-09-01

    Full Text Available In the present study, novel adsorbents having high adsorption capability and reusability were prepared using agricultural by-products: silk sericin and lignin. Silk sericin and lignin blend beads were successfully prepared using simple coagulation methods for the removal of hexavalent chromium (Cr(VI from aqueous solution. A 1 M lithium chloride (LiCl/dimethyl sulfoxide (DMSO solvent system successfully dissolved both sericin and lignin and had sufficient viscosity for bead preparation. Compared to the conventional sericin bead adsorbent, sericin/lignin blend beads showed higher Cr(VI adsorption capacity. The amount of lignin added to the adsorbent greatly affected the adsorption capacity of the beads, and a 50:50 sericin/lignin blend ratio was optimal. Adsorption behavior followed the Freundlich isotherm, which means the adsorption of Cr(VI occurred on the heterogeneous surface. Cr(VI adsorption capability increased with temperature because of thermodynamic-kinetic effects. In addition, over 90% of Cr(VI ions were recovered from the Cr(VI adsorbed sericin/lignin beads in a 1 M NaOH solution. The adsorption-desorption recycling process was stable for more than seven cycles, and the recycling efficiency was 82%. It is expected that the sericin/lignin beads could be successfully applied in wastewater remediation especially for hazardous Cr(VI ions in industrial wastewater.

  11. Comparative studies on anthraquinone retention following the soda/anthraquinone process using 14C-labelled anthraquinone, and mode of action of anthraquinone on lignins and lignin model components

    International Nuclear Information System (INIS)

    Pfuetze, E.

    1982-01-01

    This dissertation contributes to the clarification of the following questions: how much of the additive is retained in cellulose following soda/anthraquinone-wood pulping; how much anthraquinone can be detected after extraction studies and after a conventional CEHD-bleaching treatment; can differences be detected between soda lignins and soda/anthraquinone lignins with respect to analytical data, spectroscopie characteristics and macromolecular properties; and how do dimeric lignin models with #betta#-arylether structure behave in decomposition studies using the soda/anthraquinone process. (orig./MG) [de

  12. Anti-HCV effect of Lentinula edodes mycelia solid culture extracts and low-molecular-weight lignin.

    Science.gov (United States)

    Matsuhisa, Koji; Yamane, Seiji; Okamoto, Toru; Watari, Akihiro; Kondoh, Masuo; Matsuura, Yoshiharu; Yagi, Kiyohito

    2015-06-19

    Lentinula edodes mycelia solid culture extract (MSCE) contains several bioactive molecules, including some polyphenolic compounds, which exert immunomodulatory, antitumor, and hepatoprotective effects. In this study, we examined the anti-hepatitis C virus (HCV) activity of MSCE and low-molecular-weight lignin (LM-lignin), which is the active component responsible for the hepatoprotective effect of MSCE. Both MSCE and LM-lignin inhibited the entry of two HCV pseudovirus (HCVpv) types into Huh7.5.1 cells. LM-lignin inhibited HCVpv entry at a lower concentration than MSCE and inhibited the entry of HCV particles in cell culture (HCVcc). MSCE also inhibited HCV subgenome replication. LM-lignin had no effect on HCV replication, suggesting that MSCE contains additional active substances. We demonstrate here for the first time the anti-HCV effects of plant-derived LM-lignin and MSCE. The hepatoprotective effect of LM-lignin suggests that lignin derivatives, which can be produced in abundance from existing plant resources, may be effective in the treatment of HCV-related diseases. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Thermochemical properties of cellulose acetate blends with acetosolv and sawdust lignin: A comparative study.

    Science.gov (United States)

    Peredo, Karol; Escobar, Danilo; Vega-Lara, Johana; Berg, Alex; Pereira, Miguel

    2016-02-01

    Sawdust (SD) and cotton-lignin blends (CLB) were acetylated and the effect of lignin type and content on thermoplastic properties of the acetate produced was studied. The lignin in samples did not significantly affect the degree of acetylation. An increase in acetyl groups of 1-3% was observed in acetylated SD (ASD) unlike acetylated CLB (ACLB). Thermogravimetric analysis showed two thermal degradation zones; one at 190-200°C and the other at 330-370°C. The early degradation in ASD corresponds to galactoglucomannans while that in ACLB corresponds to the low-molecular-weight lignin. The second degradation is due to decomposition of cellulose acetate and high-molecular-weight lignin. DSC analysis showed homogeneous behaviour in ASD with only one glass transition temperature (Tg) at 170-180°C, unlike ACLB that showed two Tgs at 170-180°C. Sawdust acetylation, taking advantage of its residual lignin, showed higher reactivity and miscibility as compared to the same material produced by adding previously extracted lignin on cotton. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Inhibition of lignin-derived phenolic compounds to cellulase.

    Science.gov (United States)

    Qin, Lei; Li, Wen-Chao; Liu, Li; Zhu, Jia-Qing; Li, Xia; Li, Bing-Zhi; Yuan, Ying-Jin

    2016-01-01

    Lignin-derived phenolic compounds are universal in the hydrolysate of pretreated lignocellulosic biomass. The phenolics reduce the efficiency of enzymatic hydrolysis and increase the cost of ethanol production. We investigated inhibition of phenolics on cellulase during enzymatic hydrolysis using vanillin as one of the typical lignin-derived phenolics and Avicel as cellulose substrate. As vanillin concentration increased from 0 to 10 mg/mL, cellulose conversion after 72-h enzymatic hydrolysis decreased from 53 to 26 %. Enzyme deactivation and precipitation were detected with the vanillin addition. The enzyme concentration and activity consecutively decreased during hydrolysis, but the inhibition degree, expressed as the ratio of the cellulose conversion without vanillin to the conversion with vanillin (A 0 /A), was almost independent on hydrolysis time. Inhibition can be mitigated by increasing cellulose loading or cellulase concentration. The inhibition degree showed linear relationship with the vanillin concentration and exponential relationship with the cellulose loading and the cellulase concentration. The addition of calcium chloride, BSA, and Tween 80 did not release the inhibition of vanillin significantly. pH and temperature for hydrolysis also showed no significant impact on inhibition degree. The presence of hydroxyl group, carbonyl group, and methoxy group in phenolics affected the inhibition degree. Besides phenolics concentration, other factors such as cellulose loading, enzyme concentration, and phenolic structure also affect the inhibition of cellulose conversion. Lignin-blocking agents have little effect on the inhibition effect of soluble phenolics, indicating that the inhibition mechanism of phenolics to enzyme is likely different from insoluble lignin. The inhibition of soluble phenolics can hardly be entirely removed by increasing enzyme concentration or adding blocking proteins due to the dispersity and multiple binding sites of phenolics

  15. One-Pot Process for Hydrodeoxygenation of Lignin to Alkanes Using Ru-Based Bimetallic and Bifunctional Catalysts Supported on Zeolite Y

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hongliang [Department of Biological Systems Engineering, Washington State University, Richland WA 99354 USA; Ruan, Hao [Department of Biological Systems Engineering, Washington State University, Richland WA 99354 USA; Feng, Maoqi [Chemistry & Chemical Engineering Division, Southwest Research Institute, San Antonio TX 78238 USA; Qin, Yuling [Department of Biological Systems Engineering, Washington State University, Richland WA 99354 USA; Job, Heather [Pacific Northwest National Laboratory, 902 Battelle Blvd Richland WA 99354 USA; Luo, Langli [Environmental Molecular Sciences Laboratory, 3335 Q Ave Richland WA 99354 USA; Wang, Chongmin [Environmental Molecular Sciences Laboratory, 3335 Q Ave Richland WA 99354 USA; Engelhard, Mark H. [Environmental Molecular Sciences Laboratory, 3335 Q Ave Richland WA 99354 USA; Kuhn, Erik [National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway Golden CO. 80401 USA; Chen, Xiaowen [National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway Golden CO. 80401 USA; Tucker, Melvin P. [National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway Golden CO. 80401 USA; Yang, Bin [Department of Biological Systems Engineering, Washington State University, Richland WA 99354 USA

    2017-03-16

    The synthesis of high-efficiency and low-cost multifunctional catalysts for hydrodeoxygenation (HDO) of waste lignin into advanced biofuels is crucial for enhancing current biorefinery processes. Inexpensive transition metals, including Fe, Ni, Cu, Zn, were severally co-loaded with Ru on HY zeolite to form bimetallic and bifunctional catalysts. These catalysts were subsequently tested for HDO conversion of softwood lignin and several lignin model compounds. Results indicated that the inexpensive earth abundant metals could modulate the hydrogenolysis activity of Ru and decrease the yield of low molecular weight gaseous side-products. Among all the prepared catalysts, Ru-Cu/HY showed the best HDO performance, giving the highest selectivity to hydrocarbon products. The improved catalytic performance of Ru-Cu/HY was probably due to the following three factors: (1) high total and strong acid sites, (2) good dispersion of metal species and limited segregation, (3) high adsorption capacity for polar fractions, including hydroxyl groups and ether bonds. Moreover, all the bifunctional catalysts were proven to be superior over the combination catalysts of Ru/Al2O3 and HY zeolite, and this could be attributed to the “intimacy criterion”. The practical use of the designed catalysts would be promising in lignin valorization.

  16. Acid-catalysed xylose dehydration into furfural in the presence of kraft lignin.

    Science.gov (United States)

    Lamminpää, Kaisa; Ahola, Juha; Tanskanen, Juha

    2015-02-01

    In this study, the effects of kraft lignin (Indulin AT) on acid-catalysed xylose dehydration into furfural were studied in formic and sulphuric acids. The study was done using D-optimal design. Three variables in both acids were included in the design: time (20-80 min), temperature (160-180°C) and initial lignin concentration (0-20 g/l). The dependent variables were xylose conversion, furfural yield, furfural selectivity and pH change. The results showed that the xylose conversion and furfural yield decreased in sulphuric acid, while in formic acid the changes were minor. Additionally, it was showed that lignin has an acid-neutralising capacity, and the added lignin increased the pH of reactant solutions in both acids. The pH rise was considerably lower in formic acid than in sulphuric acid. However, the higher pH did not explain all the changes in conversion and yield, and thus lignin evidently inhibits the formation of furfural. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Modification of chemical reactivity of enzymatic hydrolysis lignin by ultrasound treatment in dilute alkaline solutions.

    Science.gov (United States)

    Ma, Zhuoming; Li, Shujun; Fang, Guizhen; Patil, Nikhil; Yan, Ning

    2016-12-01

    In this study, we have explored various ultrasound treatment conditions for structural modification of enzymatic hydrolysis lignin (EHL) for enhanced chemical reactivity. The key structural modifications were characterized by using a combination of analytical methods, including, Fourier Transform-Infrared spectroscopy (FTIR), Proton Nuclear Magnetic Resonance ( 1 H NMR), Gel permeation chromatography (GPC), X-ray photoelectron spectroscopy (XPS), and Folin-Ciocalteu (F-C) method. Chemical reactivity of the modified EHL samples was determined by both 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity and their reactivity towards formaldehyde. It was observed that the modified EHL had a higher phenolic hydroxyl group content, a lower molecular weight, a higher reactivity towards formaldehyde, and a greater antioxidant property. The higher reactivity demonstrated by the samples after treatment suggesting that ultrasound is a promising method for modifying enzymatic hydrolysis lignin for value-added applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. New insights into the structure and composition of technical lignins : A comparative characterisation study

    NARCIS (Netherlands)

    Constant, Sandra|info:eu-repo/dai/nl/374650519; Wienk, Hans L J|info:eu-repo/dai/nl/203884884; Frissen, Augustinus E.; Peinder, Peter De|info:eu-repo/dai/nl/325810818; Boelens, Rolf|info:eu-repo/dai/nl/070151407; Van Es, Daan S.; Grisel, Ruud J H; Weckhuysen, Bert M.|info:eu-repo/dai/nl/285484397; Huijgen, Wouter J J; Gosselink, Richard J A; Bruijnincx, Pieter C A|info:eu-repo/dai/nl/33799529X

    2016-01-01

    Detailed insight into the structure and composition of industrial (technical) lignins is needed to devise efficient thermal, bio- or chemocatalytic valorisation strategies. Six such technical lignins covering three main industrial pulping methods (Indulin AT Kraft, Protobind 1000 soda lignin and

  19. New insights into the structure and composition of technical lignins: a comparative characterisation study

    NARCIS (Netherlands)

    Constant, Sandra; Wienk, Hans L.J.; Frissen, A.E.; Peinder, de Peter; Boelens, Rolf; Es, van D.S.; Grisel, Ruud J.H.; Weckhuysen, Bert M.; Huijgen, W.J.J.; Gosselink, R.J.A.; Bruijnincx, Pieter C.A.

    2016-01-01

    Detailed insight into the structure and composition of industrial (technical) lignins is needed to devise efficient thermal, bio- or chemocatalytic valorisation strategies. Six such technical lignins covering three main industrial pulping methods (Indulin AT Kraft, Protobind 1000 soda lignin and

  20. Imidazolium-Based Ionic Liquids as Efficient Reagents for the C-O Bond Cleavage of Lignin.

    Science.gov (United States)

    Thierry, Marina; Majira, Amel; Pégot, Bruce; Cezard, Laurent; Bourdreux, Flavien; Clément, Gilles; Perreau, François; Boutet-Mercey, Stéphanie; Diter, Patrick; Vo-Thanh, Giang; Lapierre, Catherine; Ducrot, Paul-Henri; Magnier, Emmanuel; Baumberger, Stéphanie; Cottyn, Betty

    2018-01-23

    The demethylation of lignin in ionic liquids (ILs) was investigated by using pure lignin model monomers and dimers together with dioxane-isolated lignins from poplar, miscanthus, and maize. Different methylimidazolium ILs were compared and the samples were treated with two different heating processes: microwave irradiation and conventional heating in a sealed tube. The conversion yield and influence of the treatment on the lignin structure were assessed by 31 P NMR spectroscopy, size-exclusion chromatography, and thioacidolysis. The acidic methylimidazolium IL [HMIM]Br was shown to be an effective combination of solvent and reagent for the demethylation and depolymerization of lignin. The relatively mild reaction conditions, the clean work-up, and the ability to reuse the IL makes the described procedure an attractive and new green method for the conversion of lignin to produce phenol-rich lignin oligomers. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Lignin phenols used to infer organic matter sources to Sepetiba Bay - RJ, Brasil

    Science.gov (United States)

    Rezende, C. E.; Pfeiffer, W. C.; Martinelli, L. A.; Tsamakis, E.; Hedges, J. I.; Keil, R. G.

    2010-04-01

    Lignin phenols were measured in the sediments of Sepitiba Bay, Rio de Janeiro, Brazil and in bedload sediments and suspended sediments of the four major fluvial inputs to the bay; São Francisco and Guandu Channels and the Guarda and Cação Rivers. Fluvial suspended lignin yields (Σ8 3.5-14.6 mgC 10 g dw -1) vary little between the wet and dry seasons and are poorly correlated with fluvial chlorophyll concentrations (0.8-50.2 μgC L -1). Despite current land use practices that favor grassland agriculture or industrial uses, fluvial lignin compositions are dominated by a degraded leaf-sourced material. The exception is the Guarda River, which has a slight influence from grasses. The Lignin Phenol Vegetation Index, coupled with acid/aldehyde and 3.5 Db/V ratios, indicate that degraded leaf-derived phenols are also the primary preserved lignin component in the bay. The presence of fringe Typha sp. and Spartina sp. grass beds surrounding portions of the Bay are not reflected in the lignin signature. Instead, lignin entering the bay appears to reflect the erosion of soils containing a degraded signature from the former Atlantic rain forest that once dominated the watershed, instead of containing a significant signature derived from current agricultural uses. A three-component mixing model using the LPVI, atomic N:C ratios, and stable carbon isotopes (which range between -26.8 and -21.8‰) supports the hypothesis that fluvial inputs to the bay are dominated by planktonic matter (78% of the input), with lignin dominated by leaf (14% of the input) over grass (6%). Sediments are composed of a roughly 50-50 mixture of autochthonous material and terrigenous material, with lignin being primarily sourced from leaf.

  2. Drivers of lignin composition in boreal forest organic soils across a climate gradient

    Science.gov (United States)

    Myers-Pigg, A.; Kaiser, K.; Benner, R. H.; Ziegler, S. E.

    2017-12-01

    Lignin diagenesis in soils, including the cumulative effects of degradation and leaching, increases with experimental warming, signifying a potentially important change relevant to soil organic matter accumulation and fate. However, decadal to centennial climatic effects including changes in precipitation, litterfall inputs, and understory sources, on lignin composition are poorly constrained. We examined the lignin content and composition, via cupric oxide oxidation (CuO), within the organic layers of podzolic soils under similar balsam fir forests across a latitudinal climate gradient in Atlantic Canada. By exploring variation in lignin by both soil depth and climate region, this study informs on the climate drivers of lignin stability within boreal forest soil. A two-way analysis of variance (ANOVA) revealed significant variations in common signatures of CuO by-products with depth and/or site, indicating source and/or diagenetic controllers. Importantly, none of these signatures, with the exception of p-hydroxyphenols, exhibited a site by depth interaction indicating a similar degree of diagenetic alternation with depth across climates. The site by depth interaction for p-hydroxyphenols is a result of greater moss input in the northernmost site. To better elucidate this climate-induced source variation on our interpretation of lignin diagenesis, a principle component (PCA) model was built using signatures varying by site (pforest soils. A lignin diagenesis PCA model was built using (1) all non-moss related signatures identified in the first PCA model, and (2) scores for additional sites within each region, calculated from modeled lignin composition based on 13C-NMR spectra. The combined results indicate that the lignin diagenetic states among soils is similar, despite the large increase in soil C turnover with climate warming across this transect. Thus our results indicate that shifts in moss contribution, and not increased diagenesis, controls CuO by

  3. Lignin-Based Materials Through Thiol-Maleimide "Click" Polymerization.

    Science.gov (United States)

    Buono, Pietro; Duval, Antoine; Averous, Luc; Habibi, Youssef

    2017-03-09

    In the present report an environmentally friendly approach to transforming renewable feedstocks into value-added materials is proposed. This transformation pathway was conducted under green conditions, without the use of solvents or catalyst. First, controlled modification of lignin, a major biopolymer present in wood and plants, was achieved by esterification with 11-maleimidoundecylenic acid (11-MUA), a derivative from castor oil that contains maleimide groups, following its transformation into 11-maleimidoundecanoyl chloride (11-MUC). Different degrees of substitution were achieved by using various amounts of the 11-MUC, leading to an efficient conversion of lignin hydroxy groups, as demonstrated by 1 H and 31 P NMR analyses. These fully biobased maleimide-lignin derivatives were subjected to an extremely fast (ca. 1 min) thiol-ene "click" polymerization with thiol-containing linkers. Aliphatic and aromatic thiol linkers bearing two to four thiol groups were used to tune the reactivity and crosslink density. The properties of the resulting materials were evaluated by swelling tests and thermal and mechanical analyses, which showed that varying the degree of functionality of the linker and the linker structure allowed accurate tailoring of the thermal and mechanical properties of the final materials, thus providing interesting perspectives for lignin in functional aromatic polymers. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Biobased alkylphenols from lignins via a two-step pyrolysis - Hydrodeoxygenation approach

    NARCIS (Netherlands)

    de Wild, P. J.; Huijgen, W.J.J.; Kloekhorst, A.; Chowdari, R. K.; Heeres, H. J.

    Five technical lignins (three organosolv, Kraft and soda lignin) were depolymerised to produce monomeric biobased aromatics, particularly alkylphenols, by a new two-stage thermochemical approach consisting of dedicated pyrolysis followed by catalytic hydrodeoxygenation (HDO) of the resulting

  5. Structural characterization of guaiacyl-rich lignins in flax (Linum usitatissimum) fibers and shives.

    Science.gov (United States)

    del Río, José C; Rencoret, Jorge; Gutiérrez, Ana; Nieto, Lidia; Jiménez-Barbero, Jesús; Martínez, Ángel T

    2011-10-26

    The structural characteristics of the lignins from flax (Linum usitatissimum) fibers and shives were studied. Significant differences in the content and composition of the lignin from both parts were observed. The lignin contents were 3.8% in the fibers and 29.0% in the shives. Analysis by Py-GC/MS indicated a H:G:S molar ratio of 13:72:15 in the milled wood lignin (MWL) isolated from flax fibers and a molar ratio of 5:87:8 in the MWL isolated from flax shives. In addition, 2D-NMR showed a predominance of β-O-4' aryl ether linkages, followed by β-5' phenylcoumaran and β-β' resinol-type linkages in both MWLs, with a higher content of condensed linkages in flax shives. Thioacidolysis (followed by Raney nickel desulfurization) gave further information on the lignin units involved in the different linkages and confirmed the enrichment of G units. The thioacidolysis dimers released were similar from both lignins, with a predominance of the β-5' followed by β-1' and 5-5' structures.

  6. Lignin valorization through integrated biological funneling and chemical catalysis

    Science.gov (United States)

    Linger, Jeffrey G.; Vardon, Derek R.; Guarnieri, Michael T.; Karp, Eric M.; Hunsinger, Glendon B.; Franden, Mary Ann; Johnson, Christopher W.; Chupka, Gina; Strathmann, Timothy J.; Pienkos, Philip T.; Beckham, Gregg T.

    2014-01-01

    Lignin is an energy-dense, heterogeneous polymer comprised of phenylpropanoid monomers used by plants for structure, water transport, and defense, and it is the second most abundant biopolymer on Earth after cellulose. In production of fuels and chemicals from biomass, lignin is typically underused as a feedstock and burned for process heat because its inherent heterogeneity and recalcitrance make it difficult to selectively valorize. In nature, however, some organisms have evolved metabolic pathways that enable the utilization of lignin-derived aromatic molecules as carbon sources. Aromatic catabolism typically occurs via upper pathways that act as a “biological funnel” to convert heterogeneous substrates to central intermediates, such as protocatechuate or catechol. These intermediates undergo ring cleavage and are further converted via the β-ketoadipate pathway to central carbon metabolism. Here, we use a natural aromatic-catabolizing organism, Pseudomonas putida KT2440, to demonstrate that these aromatic metabolic pathways can be used to convert both aromatic model compounds and heterogeneous, lignin-enriched streams derived from pilot-scale biomass pretreatment into medium chain-length polyhydroxyalkanoates (mcl-PHAs). mcl-PHAs were then isolated from the cells and demonstrated to be similar in physicochemical properties to conventional carbohydrate-derived mcl-PHAs, which have applications as bioplastics. In a further demonstration of their utility, mcl-PHAs were catalytically converted to both chemical precursors and fuel-range hydrocarbons. Overall, this work demonstrates that the use of aromatic catabolic pathways enables an approach to valorize lignin by overcoming its inherent heterogeneity to produce fuels, chemicals, and materials. PMID:25092344

  7. The chemical oxidation of lignin found in Sappi Saiccor dissolving ...

    African Journals Online (AJOL)

    Sappi Saiccor (situated in Durban, South Africa) dissolving pulp mill effluent, produced from an acid bisulphite pulping process, uses acacia and eucalyptus hardwoods to produce a unique and different blend of lignin that has not been previously studied. The chemical oxidation of lignin found in Sappi Saiccor's effluent has ...

  8. The Paleozoic origin of enzymatic mechanisms for lignin degradation reconstructed using 31 fungal genomes

    OpenAIRE

    Floudas, Dimitrios; Binder, Manfred; Riley, Robert; Barry, Kerrie; Blanchette, Robert A; Henrissat, Bernard; Martinez, Angel T.; Otillar, Robert; Spatafora, Joseph W.; Yadav, Jagit S.; Aerts, Andrea; Benoit, Isabelle; Boyd, Alex; Carlson, Alexis; Copeland, Alex

    2012-01-01

    Wood is a major pool of organic carbon that is highly resistant to decay, owing largely to the presence of lignin. The only organisms capable of substantial lignin decay are white rot fungi in the Agaricomycetes, which also contains non?lignin-degrading brown rot and ectomycorrhizal species. Comparative analyses of 31 fungal genomes (12 generated for this study) suggest that lignin-degrading peroxidases expanded in the lineage leading to the ancestor of the Agaricomycetes, which is reconstruc...

  9. Conditions for selective degradation of lignin by the fungus Ganoderma australis

    Energy Technology Data Exchange (ETDEWEB)

    Rios, S.; Eyzaguirre, J. (Universidad Catolica de Chile, Santiago (Chile). Lab. de Bioquimica)

    1992-08-01

    The white-rot fungus Ganoderma australis selectively degrades lignin in the ecosystem 'palo podrido'. Using conditions that simulate those of 'palo podrido' in the laboratory, it was found that low nitrogen content and low O{sub 2} tension stimulate the production of manganese peroxidase and lignin degradation, and depress cellulose degradation and cellulase production. The inverse is found at high nitrogen concentration and high O{sub 2} tension. This agrees with previous results indicating that low O{sub 2} tension and low nitrogen stimulate selective lignin degradation by this fungus. (orig.).

  10. Temperature and pH influence adsorption of cellobiohydrolase onto lignin by changing the protein properties.

    Science.gov (United States)

    Lu, Xianqin; Wang, Can; Li, Xuezhi; Zhao, Jian

    2017-12-01

    Non-productive adsorption of cellulase onto lignin restricted the movement of cellulase and also hindered the cellulase recycling in bioconversion of lignocellulose. In this study, effect of temperature and pH on adsorption and desorption of cellobiohydrolase (CBH) on lignin and its possible mechanism were discussed. It found that pH value and temperature influenced the adsorption and desorption behaviors of CBH on lignin. Different thermodynamic models suggested that the action between lignin and CBH was physical action. More CBH was adsorbed onto lignin, but lower initial adsorption velocity was detected at 50°C comparing with 4°C. Elevating pH value could improve desorption of cellulase from lignin. The changes of hydrophobicity and electric potential on protein surface may partially explain the impact of environmental conditions on the adsorption and desorption behaviors of CBH on lignin, and comparing to electrical interaction, the hydrophobicity may be the dominating factor influencing the behaviors. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Interactive forces between lignin and cellulase as determined by atomic force microscopy

    OpenAIRE

    Qin, Chengrong; Clarke, Kimberley; Li, Kecheng

    2014-01-01

    Background Lignin is a complex polymer which inhibits the enzymatic conversion of cellulose to glucose in lignocellulose biomass for biofuel production. Cellulase enzymes irreversibly bind to lignin, deactivating the enzyme and lowering the overall activity of the hydrolyzing reaction solution. Within this study, atomic force microscopy (AFM) is used to compare the adhesion forces between cellulase and lignin with the forces between cellulase and cellulose, and to study the moiety groups invo...

  12. Mixture Design Approach on the Physical Properties of Lignin-Resorcinol-Formaldehyde Xerogels

    Directory of Open Access Journals (Sweden)

    Chris D. Castro

    2015-01-01

    Full Text Available Organic xerogels were functionalized by incorporating sugarcane bagasse lignin from soda pulping black liquor, not used so far in this materials, with the aim of introducing new functional groups on traditional gels that could improve its adsorptive capacity. Two mixing designs were applied to identify the reactive combinations that allow a well gel formation and to adjust models that predict physical properties. The designs study five components: resorcinol (R, 0.04–0.3, lignin (L, 0.004–0.14, formaldehyde (F, 0.08–0.17, water (W, 0.45–0.8, and NaOH (C, 0.0003–0.0035. The first experimental design was an extreme vertices design and its results showed shrinkage between 4.3 and 59.7 and a bulk density from 0.54 to 1.3; a mass ratio LR/F near 1.5 was required for gel formation. In the second design a D-Optimal was used to achieve better adjusted coefficients and incorporate the largest possible amount of lignin in the gels. Bulk density varies from 0.42 to 0.9, shrinkage varies from 3.42 to 25.35, and specific surface area reaches values of 451.86 m2/g with 13% lignin and 270 m2/g with 27% lignin. High catalyst content improves lignin dissolution and increase shrinkage and bulk density of xerogels and bulk density. Lignin contributes to reducing shrinkage and specific surface area due to his compact and rigid structure.

  13. Application of bioethanol derived lignin for improving physico-mechanical properties of thermoset biocomposites.

    Science.gov (United States)

    Bajwa, Dilpreet S; Wang, Xinnan; Sitz, Evan; Loll, Tyler; Bhattacharjee, Sujal

    2016-08-01

    Lignin is the most abundant of renewable polymers next to cellulose with a global annual production of 70million tons, largely produced from pulping and second generation biofuel industries. Low value of industrial lignin makes it an attractive biomaterial for wide range of applications. The study investigated the application of wheat straw and corn stover based lignin derived from ethanol production for use in thermoset biocomposites. The biocomposite matrix constituted a two component low viscosity Araldite(®)LY 8601/Aradur(®) 8602 epoxy resin system and the lignin content varied from 0 to 25% by weight fraction. The analysis of the physical and mechanical properties of the biocomposites show bioethanol derived lignin can improve selective properties such as impact strength, and thermal stability without compromising the modulus and strength attributes. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Characterisation of structure-dependent functional properties of lignin with infrared spectroscopy

    NARCIS (Netherlands)

    Boeriu, C.G.; Bravo, D.; Gosselink, R.J.A.; Dam, van J.E.G.

    2004-01-01

    Fourier-transformed infrared spectroscopy (FT-IR) was evaluated as an analytical technique for the estimation of the chemical composition and functional properties of lignin. A sample set containing various non-wood, hardwood and softwood lignins isolated by different processing technologies was

  15. Properties of Lignin from Oil Palm Empty Fruit Bunch and Its Application for Plywood Adhesive

    Directory of Open Access Journals (Sweden)

    Lucky Risanto

    2014-10-01

    Full Text Available Lignin from lignocellulosic biomass is a potential biopolymer for wood adhesive. The aims of this study were to characterize lignin isolated from the black liquor of oil palm empty fruit bunch fiber pretreated with steam explosion in alkaline conditions and to examine the bond quality of aqueous polymer isocyanate (API adhesive prepared from lignin, natural rubber latex (NRL, and polyvinyl alcohol (PVA as base polymers with isocyanate crosslinkers. Lignin was precipitated from the black liquor by adding hydrochloric acid; then the precipitate was separated by filtration, thoroughly washed with water up to pH 2 and pH 5, and dried. The isolated lignin was characterized by ultimate analysis, UV spectroscopy, FT-IR spectroscopy, and thermal analysis. Three-layer plywood samples were prepared, and the bond strengths of the plywood samples were determined in dry conditions and after cyclic boiling. The lignin isolates with different pH values did not have significantly different chemical and thermal properties. Both lignin isolates had similar C, H, and O contents, identical functional groups in the FTIR spectra, similar absorption in the UV spectra, and high decomposition temperatures. The base polymers composition that could produce API adhesive for exterior applications was NRL/PVA/lignin (4/4/2. The use of more lignin in the adhesive formulation decreased the bond strength of the plywood.

  16. Preparation of Lignin/Sodium Dodecyl Sulfate Composite Nanoparticles and Their Application in Pickering Emulsion Template-Based Microencapsulation.

    Science.gov (United States)

    Pang, Yuxia; Wang, Shengwen; Qiu, Xueqing; Luo, Yanling; Lou, Hongming; Huang, Jinhao

    2017-12-20

    Lignin is a vastly underutilized biomass resource. The preparation of water-dispersed lignin nanoparticles is an effective way to realize the high-value utilization of lignin. However, the currently reported preparation methods of lignin nanoparticles still have some drawbacks, such as the requirement for toxic organic solvent or chemical modification, complicated operation process, and poor dispersibility. Here, lignin/sodium dodecyl sulfate (SDS) composite nanoparticles (LSNPs) with outstanding water dispersibility and a size range of 70-200 nm were facilely prepared via acidifying the mixed basic solution of alkaline lignin and SDS. No harsh chemical was needed. The formation mechanism was systematically studied. Results indicated that the LSNPs were obtained by acid precipitation of the mixed micelles formed by the self-assembly of lignin and SDS. In addition, on the basis of the LSNP-stabilized Pickering emulsions, lignin/polyurea composite microcapsules combining the excellent chemical stability of a synthetic polyurea shell with the fantastic antiphotolysis and antioxidant properties of lignin were successfully prepared.

  17. Characteristics of Lignin Fractions from Dilute Acid Pretreated Switchgrass and Their Effect on Cellobiohydrolase from Trichoderma longibrachiatum

    Directory of Open Access Journals (Sweden)

    Lan Yao

    2018-02-01

    Full Text Available To investigate the interactions between acid pretreated switchgrass lignin and cellobiohydrolase (CBH, three different lignin fractions were isolated from dilute acid pretreated switchgrass by (i ethanol extraction, followed by (ii dioxane/H2O extraction, and (iii cellulase treatment, respectively. Structural properties of each lignin fraction were elucidated by GPC, 13C-NMR, and 2D-HSQC NMR analyses. The adsorptions of CBH to the isolated lignin fractions were also studied by Langmuir adsorption isotherms. Ethanol-extractable lignin fraction, mainly composed of syringyl (S and guaiacyl (G units, had the lowest molecular weight, while dioxane/H2O-extracted lignin fraction had the lowest S/G ratio with higher content of p-coumaric acid (pCA unit. The residual lignin fraction after enzymatic treatment had the highest S/G ratio without hydroxyphenyl (H unit. Strong associations were found between lignin properties such as lignin composition and S/G ratio and its non-productive enzyme adsorption factors including the maximum adsorption capacity and binding strength.

  18. Chemical composition and enzymatic digestibility of sugarcane clones selected for varied lignin content

    Directory of Open Access Journals (Sweden)

    Masarin Fernando

    2011-12-01

    Full Text Available Abstract Background The recalcitrance of lignocellulosic materials is a major limitation for their conversion into fermentable sugars. Lignin depletion in new cultivars or transgenic plants has been identified as a way to diminish this recalcitrance. In this study, we assessed the success of a sugarcane breeding program in selecting sugarcane plants with low lignin content, and report the chemical composition and agronomic characteristics of eleven experimental hybrids and two reference samples. The enzymatic digestion of untreated and chemically delignified samples was evaluated to advance the performance of the sugarcane residue (bagasse in cellulosic-ethanol production processes. Results The ranges for the percentages of glucan, hemicellulose, lignin, and extractive (based on oven-dry biomass of the experimental hybrids and reference samples were 38% to 43%, 25% to 32%, 17% to 24%, and 1.6% to 7.5%, respectively. The samples with the smallest amounts of lignin did not produce the largest amounts of total polysaccharides. Instead, a variable increase in the mass of a number of components, including extractives, seemed to compensate for the reduction in lignin content. Hydroxycinnamic acids accounted for a significant part of the aromatic compounds in the samples, with p-coumaric acid predominating, whereas ferulic acid was present only in low amounts. Hydroxycinnamic acids with ester linkage to the hemicelluloses varied from 2.3% to 3.6%. The percentage of total hydroxycinnamic acids (including the fraction linked to lignin through ether linkages varied from 5.0% to 9.2%, and correlated to some extent with the lignin content. These clones released up to 31% of glucose after 72 hours of digestion with commercial cellulases, whereas chemically delignified samples led to cellulose conversion values of more than 80%. However, plants with lower lignin content required less delignification to reach higher efficiencies of cellulose conversion during

  19. SbCOMT (Bmr12) is involved in the biosynthesis of tricin-lignin in sorghum

    Science.gov (United States)

    Lignin in plant biomass represents a target for engineering strategies towards the development of a sustainable bioeconomy. In addition to the conventional lignin monomers, namely p-coumaryl, coniferyl and sinapyl alcohols, tricin has been shown to be part of the native lignin polymer in certain mon...

  20. Chemoselective Methylation of Phenolic Hydroxyl Group Prevents Quinone Methide Formation and Repolymerization During Lignin Depolymerization

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kwang Ho; Dutta, Tanmoy; Walter, Eric D.; Isern, Nancy G.; Cort, John R.; Simmons, Blake A.; Singh, Seema

    2017-03-30

    Chemoselective blocking of the phenolic hydroxyl (Ar-OH) group by methylation was found to suppress secondary repolymerization and charring during lignin depolymerization. Methylation of Ar-OH prevents formation of reactive quinone methide intermediates, which are partly responsible for undesirable secondary repolymerization reactions. Instead, this structurally modified lignin produces more relatively low molecular weight products from lignin depolymerization compared to unmodified lignin. This result demonstrates that structural modification of lignin is desirable for production of low molecular weight phenolic products. This approach could be directed toward alteration of natural lignification processes to produce biomass more amenable to chemical depolymerization.

  1. New Insights Toward Quantitative Relationships between Lignin Reactivity to Monomers and Their Structural Characteristics.

    Science.gov (United States)

    Ma, Ruoshui; Zhang, Xiumei; Wang, Yi; Zhang, Xiao

    2018-04-27

    The heterogeneous and complex structural characteristics of lignin present a significant challenge to predict its processability (e.g. depolymerization, modifications etc) to valuable products. This study provides a detailed characterization and comparison of structural properties of seven representative biorefinery lignin samples derived from forest and agricultural residues, which were subjected to representative pretreatment methods. A range of wet chemistry and spectroscopy methods were applied to determine specific lignin structural characteristics such as functional groups, inter-unit linkages and peak molecular weight. In parallel, oxidative depolymerization of these lignin samples to either monomeric phenolic compounds or dicarboxylic acids were conducted, and the product yields were quantified. Based on these results (lignin structural characteristics and monomer yields), we demonstrated for the first time to apply multiple-variable linear estimations (MVLE) approach using R statistics to gain insight toward a quantitative correlation between lignin structural properties and their conversion reactivity toward oxidative depolymerization to monomers. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Relationship between lignin structure and delignification degree in Pinus pinaster kraft pulps.

    Science.gov (United States)

    Baptista, C; Robert, D; Duarte, A P

    2008-05-01

    This study examines the structure of residual and dissolved lignins from Pinus pinaster pulps obtained at different degrees of delignification by laboratory conventional kraft pulping. The cooking H factor was varied from 85 to 8049. The residual and dissolved lignin samples were characterised by elemental analysis, residual carbohydrate content, permanganate oxidation and 13C NMR spectroscopy. The reflectance factor of the pulps was also determined in order to tentatively correlate the delignification degree and residual lignin structure with the pulp colour. The obtained results confirmed that the delignification degree increases the condensation of the lignin structure, which might have an influence upon the observed increased pulp colour. The lack of selectivity of kraft pulping process in the case of more delignified pulps was also shown.

  3. EFFECT OF LIGNIN CONTENT OF Eucalyptus globulus WOOD IN KRAFT PULPING PERFORMANCE

    Directory of Open Access Journals (Sweden)

    Gabriel Valim Cardoso

    2011-03-01

    Full Text Available In this research, it was analyzed the lignin content effect of Eucalyptus globulus wood in kraft pulping optimization. Seventy-two laboratory cooking were made with wood chips obtained from six Eucalyptus globulus trees selected from a group of 50 trees. The wood chips from three trees with the lowest lignin content, with average 20,53%, were mixed proportionally based on the tree weights, obtaining the sample of low lignin content wood. The same was made to obtain the sample for wood chips with the highest lignin content, with average 23,02%. The two lignin levels were statistically different. The two wood samples had basic densities statistically not different. Using three maximum temperatures levels (160, 165 and 170ºC, and three active alkali charged (17, 18,5 and 20%, the wood chips were converted to kraft pulps. The pulps were then characterized to analyze the influence of the distinct treatments employed in the cooking on their properties. The effect of the cooking conditions was expressed by mathematical models in order to determine the optimum points for each of the evaluated properties. The optimization process indicated maximum temperature of 168ºC, and active alkali of 19%, for maximum kraft pulping yield to achieve kappa number 18; this result was for woods with low lignin content. For woods containing the high lignin content, the optimization showed maximum cooking temperature of 169ºC and active alkali of 19% for kappa number of 18. The average reduction of 2,49% in wood lignin content resulted a correspondent gain of 2,2% in the kraft yield (o.d. basis and a reduction on the active alkali charge of 1,2% (o.d. basis to achieve kappa numbers from 16 to 19, preserving pulp properties. If the option is to work with kappa number 19 instead of 16, the gain in kraft yield is approximately 2%. Therefore, when working with low lignin content wood and kappa number 19 instead of 16, a substantial gain of approximately 4,2% is obtained

  4. Density functional theory study of spirodienone stereoisomers in lignin

    Science.gov (United States)

    Thomas Elder; Laura Berstis; Gregg T. Beckham; Michael F. Crowley

    2017-01-01

    The spirodienone structure in lignin is a relatively recent discovery, and it has been found to occur in lignin of various plant species at concentrations of ∼3%, which is sufficiently high to be important for better understanding of its properties and reactivity. The cyclic structure, with a β-1 bond, has been proposed to be a precursor for acyclic β-1 linkages in...

  5. Retention of lignin in seagrasses: angiosperms that returned to the sea

    NARCIS (Netherlands)

    Klap, V.A.; Hemminga, M.A.; Boon, J.J.

    2000-01-01

    Using Curie-point Pyrolysis Gas Chromatography Mass Spectrometry (Py-GCMS) and Direct Temperature-resolved Mass Spectrometry (DT-MS), lignin was detected in highly purified preparations (Milled Wood Lignin = MWL) of various tissues of the seagrasses Zostera marina and Posidonia oceanica. The results

  6. Polymorphisms in O-methyltransferase genes are associated with stover cell wall digestibility in European maize (Zea mays L.)

    DEFF Research Database (Denmark)

    Brenner, Everton A; Zein, Imad; Chen, Yongsheng

    2010-01-01

    Background OMT (O-methyltransferase) genes are involved in lignin biosynthesis, which relates to stover cell wall digestibility. Reduced lignin content is an important determinant of both forage quality and ethanol conversion efficiency of maize stover. Results Variation in genomic sequences codi...

  7. Lignin solubilization and aqueous phase reforming for the production of aromatic chemicals and hydrogen

    NARCIS (Netherlands)

    Zakzeski, J.|info:eu-repo/dai/nl/326160256; Weckhuysen, B.M.|info:eu-repo/dai/nl/285484397

    2011-01-01

    The solubilization and aqueous phase reforming of lignin, including kraft, soda, and alcell lignin along with sugarcane bagasse, at low temperatures (T≤498 K) and pressures (P≤29 bar) is reported for the first time for the production of aromatic chemicals and hydrogen. Analysis of lignin model

  8. Control of lignin solubility and particle formation modulates its antioxidant efficiency in lipid medium

    DEFF Research Database (Denmark)

    Barsberg, Søren Talbro; Thygesen, Lisbeth Garbrecht; Sanadi, Anand Ramesh

    2014-01-01

    Lignin is an abundant plant polymer usually regarded as waste material. In the present work, antioxidant properties of lignin preparations with differing lipid solubility were studied using biodiesel as a convenient lipid test substrate. In place of formerly used assays, we used attenuated total...... reflectance (ATR) FT-IR spectroscopy to follow in situ biodiesel autoxidation on a heated ATR crystal as a function of time. The study demonstrates that a complex balance between intrinsic (chemical) efficiency, solubility, and particle formation controls the antioxidant efficiency of differently prepared...... lignin fractions. It was found that solubility and particle formation of lignin preparations strongly modulate its antioxidant efficiency and that these properties might depend on the presence of lipid components within the original lignin source....

  9. The Paleozoic origin of enzymatic mechanisms for lignin degradation reconstructed using 31 fungal genomes

    Energy Technology Data Exchange (ETDEWEB)

    Floudas, Dimitrios; Binder, Manfred; Riley, Robert; Barry, Kerrie; Blanchette, Robert A; Henrissat, Bernard; Martinez, Angel T.; Otillar, Robert; Spatafora, Joseph W.; Yadav, Jagit S.; Aerts, Andrea; Benoit, Isabelle; Boyd, Alex; Carlson, Alexis; Copeland, Alex; Coutinho, Pedro M.; de Vries, Ronald P.; Ferreira, Patricia; Findley, Keisha; Foster, Brian; Gaskell, Jill; Glotzer, Dylan; Gorecki, Pawel; Heitman, Joseph; Hesse, Cedar; Hori, Chiaki; Igarashi, Kiyohiko; Jurgens, Joel A.; Kallen, Nathan; Kersten, Phil; Kohler, Annegret; Kues, Ursula; Kumar, T. K. Arun; Kuo, Alan; LaButti, Kurt; Larrondo, Luis F.; Lindquist, Erika; Ling, Albee; Lombard, Vincent; Lucas, Susan; Lundell, Taina; Martin, Rachael; McLaughlin, David J.; Morgenstern, Ingo; Morin, Emanuelle; Murat, Claude; Nagy, Laszlo G.; Nolan, Matt; Ohm, Robin A.; Patyshakuliyeva, Aleksandrina; Rokas, Antonis; Ruiz-Duenas, Francisco J.; Sabat, Grzegorz; Salamov, Asaf; Samejima, Masahiro; Schmutz, Jeremy; Slot, Jason C.; John, Franz; Stenlid, Jan; Sun, Hui; Sun, Sheng; Syed, Khajamohiddin; Tsang, Adrian; Wiebenga, Ad; Young, Darcy; Pisabarro, Antonio; Eastwood, Daniel C.; Martin, Francis; Cullen, Dan; Grigoriev, Igor V.; Hibbett, David S.

    2012-03-12

    Wood is a major pool of organic carbon that is highly resistant to decay, owing largely to the presence of lignin. The only organisms capable of substantial lignin decay are white rot fungi in the Agaricomycetes, which also contains non?lignin-degrading brown rot and ectomycorrhizal species. Comparative analyses of 31 fungal genomes (12 generated for this study) suggest that lignin-degrading peroxidases expanded in the lineage leading to the ancestor of the Agaricomycetes, which is reconstructed as a white rot species, and then contracted in parallel lineages leading to brown rot and mycorrhizal species. Molecular clock analyses suggest that the origin of lignin degradation might have coincided with the sharp decrease in the rate of organic carbon burial around the end of the Carboniferous period.

  10. Catalytic biorefining of plant biomass to non-pyrolytic lignin bio-oil and carbohydrates through hydrogen transfer reactions.

    Science.gov (United States)

    Ferrini, Paola; Rinaldi, Roberto

    2014-08-11

    Through catalytic hydrogen transfer reactions, a new biorefining method results in the isolation of depolymerized lignin--a non-pyrolytic lignin bio-oil--in addition to pulps that are amenable to enzymatic hydrolysis. Compared with organosolv lignin, the lignin bio-oil is highly susceptible to further hydrodeoxygenation under low-severity conditions and therefore establishes a unique platform for lignin valorization by heterogeneous catalysis. Overall, the potential of a catalytic biorefining method designed from the perspective of lignin utilization is reported. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Involvement of alternative oxidase (AOX) in adventitious rooting of Olea europaea L. microshoots is linked to adaptive phenylpropanoid and lignin metabolism.

    Science.gov (United States)

    Santos Macedo, E; Sircar, D; Cardoso, H G; Peixe, A; Arnholdt-Schmitt, B

    2012-09-01

    Alternative oxidase (AOX) has been proposed as a functional marker candidate in a number of events involving cell differentiation, including rooting efficiency in semi-hardwood shoot cuttings of olive (Olea europaea L.). To ascertain the general importance of AOX in olive rooting, the auxin-induced rooting process was studied in an in vitro system for microshoot propagation. Inhibition of AOX by salicylhydroxamic acid (SHAM) significantly reduced rooting efficiency. However, the inhibitor failed to exhibit any effect on the preceding calli stage. This makes the system appropriate for distinguishing dedifferentiation and de novo differentiation during root induction. Metabolite analyses of microshoots showed that total phenolics, total flavonoids and lignin contents were significantly reduced upon SHAM treatment. It was concluded that the influence of alternative respiration on root formation was associated to adaptive phenylpropanoid and lignin metabolism. Transcript profiles of two olive AOX genes (OeAOX1a and OeAOX2) were examined during the process of auxin-induced root induction. Both genes displayed stable transcript accumulation in semi-quantitative RT-PCR analysis during all experimental stages. In contrary, when the reverse primer for OeAOX2 was designed from the 3'-UTR instead of the ORF, differential transcript accumulation was observed suggesting posttranscriptional regulation of OeAOX2 during metabolic acclimation. This result confirms former observations in olive semi-hardwood shoot cuttings on differential OeAOX2 expression during root induction. It further points to the importance of future studies on the functional role of sequence and length polymorphisms in the 3'-UTR of this gene. The manuscript reports the general importance of AOX in olive adventitious rooting and the association of alternative respiration to adaptive phenylpropanoid and lignin metabolism.

  12. The effect of altered lignin composition on mechanical properties of CINNAMYL ALCOHOL DEHYDROGENASE (CAD) deficient poplars.

    Science.gov (United States)

    Özparpucu, Merve; Gierlinger, Notburga; Burgert, Ingo; Van Acker, Rebecca; Vanholme, Ruben; Boerjan, Wout; Pilate, Gilles; Déjardin, Annabelle; Rüggeberg, Markus

    2018-04-01

    CAD-deficient poplars enabled studying the influence of altered lignin composition on mechanical properties. Severe alterations in lignin composition did not influence the mechanical properties. Wood represents a hierarchical fiber-composite material with excellent mechanical properties. Despite its wide use and versatility, its mechanical behavior has not been entirely understood. It has especially been challenging to unravel the mechanical function of the cell wall matrix. Lignin engineering has been a useful tool to increase the knowledge on the mechanical function of lignin as it allows for modifications of lignin content and composition and the subsequent studying of the mechanical properties of these transgenics. Hereby, in most cases, both lignin composition and content are altered and the specific influence of lignin composition has hardly been revealed. Here, we have performed a comprehensive micromechanical, structural, and spectroscopic analysis on xylem strips of transgenic poplar plants, which are downregulated for cinnamyl alcohol dehydrogenase (CAD) by a hairpin-RNA-mediated silencing approach. All parameters were evaluated on the same samples. Raman microscopy revealed that the lignin of the hpCAD poplars was significantly enriched in aldehydes and reduced in the (relative) amount of G-units. FTIR spectra indicated pronounced changes in lignin composition, whereas lignin content was not significantly changed between WT and the hpCAD poplars. Microfibril angles were in the range of 18°-24° and were not significantly different between WT and transgenics. No significant changes were observed in mechanical properties, such as tensile stiffness, ultimate stress, and yield stress. The specific findings on hpCAD poplar allowed studying the specific influence of lignin composition on mechanics. It can be concluded that the changes in lignin composition in hpCAD poplars did not affect the micromechanical tensile properties.

  13. Laccase/Mediator Systems: Their Reactivity toward Phenolic Lignin Structures.

    Science.gov (United States)

    Hilgers, Roelant; Vincken, Jean-Paul; Gruppen, Harry; Kabel, Mirjam A

    2018-02-05

    Laccase-mediator systems (LMS) have been widely studied for their capacity to oxidize the nonphenolic subunits of lignin (70-90% of the polymer). The phenolic subunits (10-30% of the polymer), which can also be oxidized without mediators, have received considerably less attention. Consequently, it remains unclear to what extent the presence of a mediator influences the reactions of the phenolic subunits of lignin. To get more insight in this, UHPLC-MS was used to study the reactions of a phenolic lignin dimer (GBG), initiated by a laccase from Trametes versicolor , alone or in combination with the mediators HBT and ABTS. The role of HBT was negligible, as its oxidation by laccase occurred slowly in comparison to that of GBG. Laccase and laccase/HBT oxidized GBG at a comparable rate, resulting in extensive polymerization of GBG. In contrast, laccase/ABTS converted GBG at a higher rate, as GBG was oxidized both directly by laccase but also by ABTS radical cations, which were rapidly formed by laccase. The laccase/ABTS system resulted in Cα oxidation of GBG and coupling of ABTS to GBG, rather than polymerization of GBG. Based on these results, we propose reaction pathways of phenolic lignin model compounds with laccase/HBT and laccase/ABTS.

  14. Evidence supporting dissimilatory and assimilatory lignin degradation in Enterobacter lignolyticus SCF1

    Directory of Open Access Journals (Sweden)

    Kristen M DeAngelis

    2013-09-01

    Full Text Available The anaerobic isolate Enterobacter lignolyticus SCF1 was initially cultivated based on anaerobic growth on lignin as sole carbon source. The source of the isolated bacteria was from tropical forest soils that decompose litter rapidly with low and fluctuating redox potentials, making it likely that bacteria using oxygen-independent enzymes play an important role in decomposition. We have used transcriptomics and proteomics to examine the increased growth of the anaerobic isolate Enterobacter lignolyticus SCF1 when grown on media amended with lignin compared to unamended growth. Proteomics revealed accelerated xylose uptake and metabolism under lignin-amended growth, and lignin degradation via the 4-hydroxyphenylacetate degradation pathway, catalase/peroxidase enzymes, and the glutathione biosynthesis and glutathione S-transferase proteins. We also observed increased production of NADH-quinone oxidoreductase, other electron transport chain proteins, and ATP synthase and ATP-binding cassette (ABC transporters. We detected significant lignin degradation over time by absorbance, and also used metabolomics to demonstrate increased xylose utilization in lignin-amended compared to unamended growth. Our data shows the advantages of a multi-omics approach, where incomplete pathways identified by genomics were completed, and new observations made on coping with poor carbon availability. The fast growth, high efficiency and specificity of enzymes employed in bacterial anaerobic litter deconstruction makes these soils useful templates for improving biofuel production.

  15. Lignin preparation from oil palm empty fruit bunches by sequential acid/alkaline treatment--A biorefinery approach.

    Science.gov (United States)

    Medina, Jesus David Coral; Woiciechowski, Adenise; Zandona Filho, Arion; Noseda, Miguel D; Kaur, Brar Satinder; Soccol, Carlos Ricardo

    2015-10-01

    Lignin is an important raw material for the sustainable biorefineries and also the forerunner of high-value added products, such as biocomposite for chemical, pharmaceutical and cement industries. Oil palm empty fruit bunches (OPEFB) were used for lignin preparation by successive treatment with 1% (w/w) H2SO4 at 121°C for 60 min and 2.5% NaOH at 121°C for 80 min resulting in the high lignin yield of 28.89%, corresponding to 68.82% of the original lignin. The lignin obtained was characterized by gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). The results indicated a lignin with molecular masses ramping from 4500 kDa to 12,580 kDa. FTIR and NMR of these lignins showed more syringyl and p-hydroxyphenyl than guaiacyl units. Moderate acid/alkaline treatment provided lignin with high industrial potential and acid hydrolyzates rich in fermentable sugars and highly porous cellulosic fibers. Copyright © 2015. Published by Elsevier Ltd.

  16. Lignin Sulfonation - A different Approach

    DEFF Research Database (Denmark)

    Bjørkmann, Anders

    2001-01-01

    The research on sulfite pulping has been characterized by the attempts to explain its chemistry. The. different approach presented is incited by perceptions about the (still) unsolved problem of the ultrastructural features of lignin in wood. A simple kinetic model has been chosen to describe the...

  17. Ligninolytic peroxidase genes in the oyster mushroom genome: heterologous expression, molecular structure, catalytic and stability properties, and lignin-degrading ability

    Science.gov (United States)

    Elena Fernández-Fueyo; Francisco J Ruiz-Dueñas; María Jesús Martinez; Antonio Romero; Kenneth E Hammel; Francisco Javier Medrano; Angel T. Martínez

    2014-01-01

    Background: The genome of Pleurotus ostreatus, an important edible mushroom and a model ligninolytic organism of interest in lignocellulose biorefineries due to its ability to delignify agricultural wastes, was sequenced with the purpose of identifying and characterizing the enzymes responsible for lignin degradation. ...

  18. Lignin as a facilitator, not a barrier, during saccharification by brown rot fungi

    Energy Technology Data Exchange (ETDEWEB)

    Schilling, Jonathan S. [Univ. of Minnesota, Minneapolis, MN (United States); Tschirner, Ulrike [Univ. of Minnesota, Minneapolis, MN (United States); Blanchette, Robert A [Univ. of Minnesota, Minneapolis, MN (United States); Filley, Timothy [Purdue Univ., West Lafayette, IN (United States)

    2012-11-28

    This research focused on the biology of a group of wood-degrading fungi that cause brown rot in wood, with particular attention to the potential to mimic this biological approach ex situ for bioprocessing lignocellulosic biomass. Supported by the long-standing theory that these fungi use a two-step oxidative/enzymatic approach during brown rot, our team’s objectives were as follows: 1) to determine the discrete timing of lignin modifications, 2) to correlate these alterations with biocatalyst efficiency and ingress into plant cell walls, and 3) to reproduce modifications prior to saccharification for efficient bioprocessing. The core findings of our research were that 1) lignin modifications occur nearly coincident with enzyme secretion during brown rot and 2) there is no specificity to the benefit that a brown rot pretreatment has on the efficacy of cellulases – it is a general enhancement best predicted by chemical changes to lignin and side-chain hemicellulose sugars. In our work, this meant we could attain and predict broad improvements in saccharification using commercial cellulase cocktails, in some cases more than three-fold of that in untreated biomass. This project was completed with minimal variance from the original project management plan (PMP), resulting in fourteen presentations and posters, four peer-reviewed publications, and one additional publication now in review. The publications have been valuable to other scientists working toward similar goals and have been cited in thirteen peer-reviewed publications written by others since 2010. We are working with ADM to advance application options for industry, building on the lessons learned during this DOE award period.

  19. Lignin- and Hemicellulose-derived Biomass Recalcitrance

    DEFF Research Database (Denmark)

    Deralia, Parveen Kumar

    technology bringing the multitude of chemical and physical changes, which govern the level of biomass recalcitrance. The lignocellulosic biomasses in question are wheat straw and poplar and the hydrothermal pretreatment is used as pretreatment technology. The 2D HSQC NMR and wet chemistry chemical...... degree to the biomass surface, giving a proportional increase in the specific surface area opposite to wheat straw, which has a marked increase in the specific surface area. The distinctly different chemistry of lignin and hemicellulose and different lignin migration and reorganization appear...... to be correlative, helping explain differences in enzymatic saccharification performance across the pretreatment severities and between two biomasses. The main contribution of this work to the current state-of-the-art in the field is the revelation of distinct behaviors of generation of different repolymerized...

  20. Trends in lignin modification: a comprehensive analysis of the effects of genetic manipulations/mutations on lignification and vascular integrity

    Science.gov (United States)

    Anterola, Aldwin M.; Lewis, Norman G.

    2002-01-01

    activities. Such enzymes thus fulfill subsidiary processing roles, with all (except CCOMT) apparently being bifunctional for both H and G substrates. Their severe downregulation does, however, predictably result in impaired monolignol biosynthesis, reduced lignin deposition/vascular integrity, (upstream) metabolite build-up and/or shunt pathway metabolism. There was no evidence for an alternative acid/ester O-methyltransferase (AEOMT) being involved in lignin biosynthesis.The G/S lignin pathway networks are operative in specific cell types in angiosperms and employ two additional biosynthetic steps to afford the corresponding S components, i.e. through introduction of an hydroxyl group at C-5 and its subsequent O-methylation. [These enzymes were originally classified as ferulate-5-hydroxylase (F5H) and caffeate O-methyltransferase (COMT), respectively.] As before, neither step has apparently any role in carbon allocation to the pathway; hence their individual downregulation/manipulation, respectively, gives either a G enriched lignin or formation of the well-known S-deficient bm3 "lignin" mutant, with cell walls of impaired vascular integrity. In the latter case, COMT downregulation/mutation apparently results in utilization of the isoelectronic 5-hydroxyconiferyl alcohol species albeit in an unsuccessful attempt to form G-S lignin proper. However, there is apparently no effect on overall G content, thereby indicating that deposition of both G and S moieties in the G/S lignin forming cells are kept spatially, and presumably temporally, fully separate. Downregulation/mutation of further downstream steps in the G/S network [i.e. utilizing 4CL, CCR and CAD isoforms] gives predictable effects in terms of their subsidiary processing roles: while severe downregulation of 4CL gave phenotypes with impaired vascular integrity due to reduced monolignol supply, there was no evidence in support of increased growth and/or enhanced cellulose biosynthesis. CCR and CAD downregulation

  1. Animated sulfonated or sulformethylated lignins as cement fluid loss control additives

    Energy Technology Data Exchange (ETDEWEB)

    Schilling, P.

    1991-05-07

    This patent describes a method of cementing a zone in a well penetrating a subterranean formation comprising injecting down the well and positioning in the zone to be cemented a hydraulic aqueous cement slurry composition. It comprises: a hydraulic cement, and the following expressed as parts by weight per 100 parts of the hydraulic cement, water from about 25 to 105 parts, and a fluid loss control additive comprising from about 0.5 to 2.5 parts of a compound selected from the group consisting of a sulfonated lignin and a sulfomethylated lignin, wherein the lignin has been aminated by reacting it with between about 2-5 moles of a polyamine and 2-5 moles of an aldehyde per 1,000g of the lignin, and 0.1 to 1.5 parts of a compound selected from the group consisting of sodium carbonate, sodium metasilicate, sodium phosphate, sodium sulfite and sodium naphthalene sulfonate and a combination thereof.

  2. Towards Environmentally-benign Nanoengineering: Antimicrobial Nanoparticles Based on Silver-infused Lignin Cores

    Science.gov (United States)

    Richter, Alexander Philipp

    quaternary ammonium resistant Ralstonia bacteria. The enhanced antimicrobial action is due to highly-biocidal silver ions released from the EbNP matrix at the cell. High-throughput bioactivity screening using mammalian cell and zebrafish embryo assays performed in collaboration with the U.S. Environmental Protection Agency did not reveal increased safety concerns of the EbNPs, when compared to equivalent amount of AgNPs or AgNO3 solution. The silver ion functionalized EbNPs exhibit broad spectrum microbicide action and are capable of neutralizing common gram-negative human pathogens as well as quaternary amineresistant bacteria, while using ten times less silver when compared with conventional AgNPs and AgNO3 aqueous solution. We envisage that the overall environmental impact of silver ion functionalized EbNPs is likely to be significantly smaller when compared to AgNPs. As more general impact, the approach of engineering environmentally-benign lignin-core nanoparticles with matching functionality to persistent nanoparticles illustrates how green chemistry principles including atom economy, use of renewable feedstocks, and design for degradation can be applied to design more sustainable nanomaterials with increased functionality and decreased environmental footprint.

  3. Polymorphisms in monolignol biosynthetic genes are associated with biomass yield and agronomic traits in European maize (Zea mays L.)

    DEFF Research Database (Denmark)

    Chen, Yongsheng; Zein, Imad; Brenner, Everton A

    2010-01-01

    Background Reduced lignin content leads to higher cell wall digestibility and, therefore, better forage quality and increased conversion of lignocellulosic biomass into ethanol. However, reduced lignin content might lead to weaker stalks, lodging, and reduced biomass yield. Genes encoding enzymes...

  4. Lignin based controlled release coatings

    NARCIS (Netherlands)

    Mulder, W.J.; Gosselink, R.J.A.; Vingerhoeds, M.H.; Harmsen, P.F.H.; Eastham, D.

    2011-01-01

    Urea is a commonly used fertilizer. Due to its high water-solubility, misuse easily leads to excess nitrogen levels in the soil. The aim of this research was to develop an economically feasible and biodegradable slow-release coating for urea. For this purpose, lignin was selected as coating

  5. Solar radiation uncorks the lignin bottleneck on plant litter decomposition in terrestrial ecosystems

    Science.gov (United States)

    Austin, A.; Ballare, C. L.; Méndez, M. S.

    2015-12-01

    Plant litter decomposition is an essential process in the first stages of carbon and nutrient turnover in terrestrial ecosystems, and together with soil microbial biomass, provide the principal inputs of carbon for the formation of soil organic matter. Photodegradation, the photochemical mineralization of organic matter, has been recently identified as a mechanism for previously unexplained high rates of litter mass loss in low rainfall ecosystems; however, the generality of this process as a control on carbon cycling in terrestrial ecosystems is not known, and the indirect effects of photodegradation on biotic stimulation of carbon turnover have been debated in recent studies. We demonstrate that in a wide range of plant species, previous exposure to solar radiation, and visible light in particular, enhanced subsequent biotic degradation of leaf litter. Moreover, we demonstrate that the mechanism for this enhancement involves increased accessibility for microbial enzymes to plant litter carbohydrates due to a reduction in lignin content. Photodegradation of plant litter reduces the structural and chemical bottleneck imposed by lignin in secondary cell walls. In litter from woody plant species, specific interactions with ultraviolet radiation obscured facilitative effects of solar radiation on biotic decomposition. The generalized positive effect of solar radiation exposure on subsequent microbial activity is mediated by increased accessibility to cell wall polysaccharides, which suggests that photodegradation is quantitatively important in determining rates of mass loss, nutrient release and the carbon balance in a broad range of terrestrial ecosystems.

  6. Chalcone Synthase (CHS) Gene Suppression in Flax Leads to Changes in Wall Synthesis and Sensing Genes, Cell Wall Chemistry and Stem Morphology Parameters

    Science.gov (United States)

    Zuk, Magdalena; Działo, Magdalena; Richter, Dorota; Dymińska, Lucyna; Matuła, Jan; Kotecki, Andrzej; Hanuza, Jerzy; Szopa, Jan

    2016-01-01

    The chalcone synthase (CHS) gene controls the first step in the flavonoid biosynthesis. In flax, CHS down-regulation resulted in tannin accumulation and reduction in lignin synthesis, but plant growth was not affected. This suggests that lignin content and thus cell wall characteristics might be modulated through CHS activity. This study investigated the possibility that CHS affects cell wall sensing as well as polymer content and arrangement. CHS-suppressed and thus lignin-reduced plants showed significant changes in expression of genes involved in both synthesis of components and cell wall sensing. This was accompanied by increased levels of cellulose and hemicellulose. CHS-reduced flax also showed significant changes in morphology and arrangement of the cell wall. The stem tissue layers were enlarged averagely twofold compared to the control, and the number of fiber cells more than doubled. The stem morphology changes were accompanied by reduction of the crystallinity index of the cell wall. CHS silencing induces a signal transduction cascade that leads to modification of plant metabolism in a wide range and thus cell wall structure. PMID:27446124

  7. Multi-time series RNA-seq analysis of Enterobacter lignolyticus SCF1 during growth in lignin-amended medium

    Energy Technology Data Exchange (ETDEWEB)

    Orellana, Roberto; Chaput, Gina; Markillie, Lye Meng; Mitchell, Hugh; Gaffrey, Matt; Orr, Galya; DeAngelis, Kristen M.; Yang, Shihui

    2017-10-19

    The production of lignocellulosic-derived biofuels is a highly promising source of alternative energy, but it has been constrained by the lack of a microbial platform capable to efficiently degrade this recalcitrant material and cope with by-products that can be toxic to cells. Species that naturally grow in environments where carbon is mainly available as lignin are promising for finding new ways of removing the lignin that protects cellulose for improved conversion of lignin to fuel precursors. Enterobacter lignolyticus SCF1 is a facultative anaerobic Gammaproteobacteria isolated from tropical rain forest soil collected in El Yunque forest, Puerto Rico under anoxic growth conditions with lignin as sole carbon source. Whole transcriptome analysis of SCF1 during E.lignolyticus SCF1 lignin degradation was conducted on cells grown in the presence (0.1%, w/w) and the absence of lignin, where samples were taken at three different times during growth, beginning of exponential phase, midexponential phase and beginning of stationary phase. Lignin-amended cultures achieved twice the cell biomass as unamended cultures over three days, and in this time degraded 60% of lignin. Transcripts in early exponential phase reflected this accelerated growth. A complement of laccases, aryl-alcohol dehydrogenases, and peroxidases were most up-regulated in lignin amended conditions in mid-exponential and early stationary phases compared to unamended growth. The association of hydrogen production by way of the formate hydrogenlyase complex with lignin degradation suggests a possible value added to lignin degradation in the future.

  8. Multi-time series RNA-seq analysis of Enterobacter lignolyticus SCF1 during growth in lignin-amended medium.

    Science.gov (United States)

    Orellana, Roberto; Chaput, Gina; Markillie, Lye Meng; Mitchell, Hugh; Gaffrey, Matt; Orr, Galya; DeAngelis, Kristen M

    2017-01-01

    The production of lignocellulosic-derived biofuels is a highly promising source of alternative energy, but it has been constrained by the lack of a microbial platform capable to efficiently degrade this recalcitrant material and cope with by-products that can be toxic to cells. Species that naturally grow in environments where carbon is mainly available as lignin are promising for finding new ways of removing the lignin that protects cellulose for improved conversion of lignin to fuel precursors. Enterobacter lignolyticus SCF1 is a facultative anaerobic Gammaproteobacteria isolated from tropical rain forest soil collected in El Yunque forest, Puerto Rico under anoxic growth conditions with lignin as sole carbon source. Whole transcriptome analysis of SCF1 during E.lignolyticus SCF1 lignin degradation was conducted on cells grown in the presence (0.1%, w/w) and the absence of lignin, where samples were taken at three different times during growth, beginning of exponential phase, mid-exponential phase and beginning of stationary phase. Lignin-amended cultures achieved twice the cell biomass as unamended cultures over three days, and in this time degraded 60% of lignin. Transcripts in early exponential phase reflected this accelerated growth. A complement of laccases, aryl-alcohol dehydrogenases, and peroxidases were most up-regulated in lignin amended conditions in mid-exponential and early stationary phases compared to unamended growth. The association of hydrogen production by way of the formate hydrogenlyase complex with lignin degradation suggests a possible value added to lignin degradation in the future.

  9. Adsorption of Pb(II) ions from aqueous solution using lignin from ...

    African Journals Online (AJOL)

    The adsorption of lead(II) ions from aqueous solution onto alkali lignin extracted from Hagenia abyssinica was investigated by electrochemical methods. The effect of solution pH, lignin dosage and contact time were investigated at room temperature in a batch system. Adsorption equilibrium was approached within 80 min.

  10. Toward engineering E. coli with an autoregulatory system for lignin valorization.

    Science.gov (United States)

    Wu, Weihua; Liu, Fang; Singh, Seema

    2018-03-20

    Efficient lignin valorization could add more than 10-fold the value gained from burning it for energy and is critical for economic viability of future biorefineries. However, lignin-derived aromatics from biomass pretreatment are known to be potent fermentation inhibitors in microbial production of fuels and other value-added chemicals. In addition, isopropyl-β-d-1-thiogalactopyranoside and other inducers are routinely added into fermentation broth to induce the expression of pathway enzymes, which further adds to the overall process cost. An autoregulatory system that can diminish the aromatics' toxicity as well as be substrate-inducible can be the key for successful integration of lignin valorization into future lignocellulosic biorefineries. Toward that goal, in this study an autoregulatory system is demonstrated that alleviates the toxicity issue and eliminates the cost of an external inducer. Specifically, this system is composed of a catechol biosynthesis pathway coexpressed with an active aromatic transporter CouP under induction by a vanillin self-inducible promoter, ADH7, to effectively convert the lignin-derived aromatics into value-added chemicals using Escherichia coli as a host. The constructed autoregulatory system can efficiently transport vanillin across the cell membrane and convert it to catechol. Compared with the system without CouP expression, the expression of catechol biosynthesis pathway with transporter CouP significantly improved the catechol yields about 30% and 40% under promoter pTrc and ADH7, respectively. This study demonstrated an aromatic-induced autoregulatory system that enabled conversion of lignin-derived aromatics into catechol without the addition of any costly, external inducers, providing a promising and economically viable route for lignin valorization. Copyright © 2018 the Author(s). Published by PNAS.

  11. Isolation of Thermophilic Lignin Degrading Bacteria from Oil-Palm Empty Fruit Bunch (EFB) Compost

    Science.gov (United States)

    Lai, C. M. T.; Chua, H. B.; Danquah, M. K.; Saptoro, A.

    2017-06-01

    Empty Fruit Bunch (EFB) is a potential and sustainable feedstock for bioethanol production due to its high cellulosic content and availability in Malaysia. Due to high lignin content of EFB and the lack of effective delignification process, commercial bioethanol production from EFB is presently not viable. Enzymatic delignification has been identified as one of the key steps in utilising EFB as a feedstock for bioethanol conversion. To date, limited work has been reported on the isolation of lignin degrading bacteria. Hence, there is a growing interest to search for new lignin degrading bacteria with greater tolerance to temperature and high level of ligninolytic enzymes for more effective lignin degradation. This study aimed to isolate and screen thermophilic ligninolytic microorganisms from EFB compost. Ten isolates were successfully isolated from EFB compost. Although they are not capable of decolorizing Methylene Blue (MB) dye under agar plate assay method, they are able to utilize lignin mimicked compound - guaiacol as a sole carbon on the agar plate assay. This infers that there is no correlation of ligninolytic enzymes with dye decolourization for all the isolates that have been isolated. However, they are able to produce ligninolytic enzymes (Lignin peroxidase, Manganese peroxidase, Laccase) in Minimal Salt Medium with Kraft Lignin (MSM-KL) with Lignin Peroxidase (LiP) as the predominant enzyme followed by Manganese Peroxidase (MnP) and Laccase (Lac). Among all the tested isolates, CLMT 29 has the highest LiP production up to 8.7673 U/mL following 24 h of growth.

  12. Quantitative analysis of detailed lignin monomer composition by pyrolysis-gas chromatography combined with preliminary acetylation of the samples.

    Science.gov (United States)

    Sonoda, T; Ona, T; Yokoi, H; Ishida, Y; Ohtani, H; Tsuge, S

    2001-11-15

    Detailed quantitative analysis of lignin monomer composition comprising p-coumaryl, coniferyl, and sinapyl alcohol and p-coumaraldehyde, coniferaldehyde, and sinapaldehyde in plant has not been studied from every point mainly because of artifact formation during the lignin isolation procedure, partial loss of the lignin components inherent in the chemical degradative methods, and difficulty in the explanation of the complex spectra generally observed for the lignin components. Here we propose a new method to quantify lignin monomer composition in detail by pyrolysis-gas chromatography (Py-GC) using acetylated lignin samples. The lignin acetylation procedure would contribute to prevent secondary formation of cinnamaldehydes from the corresponding alcohol forms during pyrolysis, which are otherwise unavoidable in conventional Py-GC process to some extent. On the basis of the characteristic peaks on the pyrograms of the acetylated sample, lignin monomer compositions in various dehydrogenative polymers (DHP) as lignin model compounds were determined, taking even minor components such as cinnamaldehydes into consideration. The observed compositions by Py-GC were in good agreement with the supplied lignin monomer contents on DHP synthesis. The new Py-GC method combined with sample preacetylation allowed us an accurate quantitative analysis of detailed lignin monomer composition using a microgram order of extractive-free plant samples.

  13. Biobleaching chemistry of laccase-mediator systems on high-lignin-content kraft pulps

    International Nuclear Information System (INIS)

    Chakar, F.S.; Ragauskas, A.J.

    2004-01-01

    A high-lignin-content softwood kraft pulp was reacted with laccase in the presence of 1-hydroxybenzotriazole (HBT), N-acetyl-N-phenylhydroxylamine (NHA), and violuric acid (VA). The biodelignification response with violuric acid was superior to both 1-hydroxybenzotriazole and N-acetyl-N-phenylhydroxylamine. NMR analysis of residual lignins isolated before and after the biobleaching treatments revealed that the latter material was highly oxidized and that the magnitude of structural changes was most pronounced with the laccase - violuric acid biobleaching system. An increase in the content of carboxylic acid groups and a decrease in methoxyl groups were noted with all three laccase-mediator systems. The oxidation biobleaching pathway is directed primarily towards noncondensed C5 phenolic lignin functional structures for all three laccase-mediated systems. The laccase - violuric acid system was also reactive towards C5-condensed phenolic lignin structures. (author)

  14. Effect of an electron beam on the subsequent pyrogenic distillation of lignin and cellulose

    International Nuclear Information System (INIS)

    Metreveli, P.K.; Metreveli, A.K.; Kholodkova, E.M.; Ponomarev, A.V.

    2014-01-01

    The irradiation notably influences responsiveness of cellulose and lignin to the subsequent pyrogenic distillation though both weight and the form of samples do not change almost at doses up to 3 MGy. Decreases in overpoint of lignin and cellulose irradiated at 2.2 MGy are ∼80°and ∼100°, respectively. Third of condensate from cellulose and almost half from lignin are distilled-off at lower temperatures. The thermally instable compounds convertible mainly to furans via subsequent heating are forming in cellulose. Distillation of the irradiated lignin gives less tar which, however, is richer by methoxy-phenols. In distilled-off water–organic fraction the content of soluble organic compounds is increased. - Highlights: • Irradiation facilitates subsequent dry distillation of cellulose and lignin. • Overpoints of irradiated samples are decreasing. • Furans and methoxy-phenols formation improves

  15. Chapter 17: Adding Value to the Biorefinery with Lignin: An Engineer's Perspective

    Energy Technology Data Exchange (ETDEWEB)

    Biddy, Mary J [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2018-04-03

    There is a long-standing belief that 'you can make anything out of lignin...except money.' This chapter serves to highlight that opportunities for making money from biomass-derived lignin exist both with current technology in the production of steam and power to new emerging areas of R&D focused on value-added chemical and material coproducts from lignin. To understand and quantify the economic potential for lignin valorization, the techno-economic analysis methodology is first described in detail. As demonstrated in the provided case study, these types of economic evaluations serve not only to estimate the economic impacts that lignin conversion could have for an integrated biorefinery and outline drivers for further cost reduction but also identify data gaps and R&D needs for improving the design basis and reducing the risk for process scale-up.

  16. Enhancing gene delivery of adeno-associated viruses by cell-permeable peptides

    Directory of Open Access Journals (Sweden)

    Yarong Liu

    2014-01-01

    Full Text Available Adeno-associated virus type 2 (AAV2 is considered a promising gene delivery vector and has been extensively applied in several disease models; however, inefficient transduction in various cells and tissues has limited its widespread application in many areas of gene therapy. In this study, we have developed a general, but efficient, strategy to enhance viral transduction, both in vitro and in vivo, by incubating viral particles with cell-permeable peptides (CPPs. We show that CPPs increase internalization of viral particles into cells by facilitating both energy-independent and energy-dependent endocytosis. Moreover, CPPs can significantly enhance the endosomal escape process of viral particles, thus enhancing viral transduction to those cells that have exhibited very low permissiveness to AAV2 infection as a result of impaired intracellular viral processing. We also demonstrated that this approach could be applicable to other AAV serotypes. Thus, the membrane-penetrating ability of CPPs enables us to generate an efficient method for enhanced gene delivery of AAV vectors, potentially facilitating its applicability to human gene therapy.

  17. Rice Snl6, a cinnamoyl-CoA reductase-like gene family member, is required for NH1-mediated immunity to Xanthomonas oryzae pv. oryzae.

    Directory of Open Access Journals (Sweden)

    Rebecca S Bart

    2010-09-01

    Full Text Available Rice NH1 (NPR1 homolog 1 is a key mediator of innate immunity. In both plants and animals, the innate immune response is often accompanied by rapid cell death at the site of pathogen infection. Over-expression of NH1 in rice results in resistance to the bacterial pathogen, Xanthomonas oryzae pv. oryzae (Xoo, constitutive expression of defense related genes and enhanced benzothiadiazole (BTH- mediated cell death. Here we describe a forward genetic screen that identified a suppressor of NH1-mediated lesion formation and resistance, snl6. Comparative genome hybridization and fine mapping rapidly identified the genomic location of the Snl6 gene. Snl6 is a member of the cinnamoyl-CoA reductase (CCR-like gene family. We show that Snl6 is required for NH1-mediated resistance to Xoo. Further, we show that Snl6 is required for pathogenesis-related gene expression. In contrast to previously described CCR family members, disruption of Snl6 does not result in an obvious morphologic phenotype. Snl6 mutants have reduced lignin content and increased sugar extractability, an important trait for the production of cellulosic biofuels. These results suggest the existence of a conserved group of CCR-like genes involved in the defense response, and with the potential to alter lignin content without affecting development.

  18. Evaluation of lignins from side-streams generated in an olive tree pruning-based biorefinery: Bioethanol production and alkaline pulping.

    Science.gov (United States)

    Santos, José I; Fillat, Úrsula; Martín-Sampedro, Raquel; Eugenio, María E; Negro, María J; Ballesteros, Ignacio; Rodríguez, Alejandro; Ibarra, David

    2017-12-01

    In modern lignocellulosic-based biorefineries, carbohydrates can be transformed into biofuels and pulp and paper, whereas lignin is burned to obtain energy. However, a part of lignin could be converted into value-added products including bio-based aromatic chemicals, as well as building blocks for materials. Then, a good knowledge of lignin is necessary to define its valorisation procedure. This study characterized different lignins from side-streams produced from olive tree pruning bioethanol production (lignins collected from steam explosion pretreatment with water or phosphoric acid as catalysts, followed by simultaneous saccharification and fermentation process) and alkaline pulping (lignins recovered from kraft and soda-AQ black liquors). Together with the chemical composition, the structure of lignins was investigated by FTIR, 13 C NMR, and 2D NMR. Bioethanol lignins had clearly distinct characteristics compared to pulping lignins; a certain number of side-chain linkages (mostly alkyl-aryl ether and resinol) accompanied with lower phenolic hydroxyls content. Bioethanol lignins also showed a significant amount of carbohydrates, mainly glucose and protein impurities. By contrast, pulping lignins revealed xylose together with a dramatical reduction of side-chains (some resinol linkages survive) and thereby higher phenol content, indicating rather severe lignin degradation during alkaline pulping processes. All lignins showed a predominance of syringyl units. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Depolymerization of organosolv lignin using doped porous metal oxides in supercritical methanol

    DEFF Research Database (Denmark)

    Warner, Genoa; Hansen, Thomas Søndergaard; Riisager, Anders

    2014-01-01

    conversion to methanol-soluble products, without char formation, were based on copper in combination with other dopants based on relatively earth-abundant metals. Nearly complete conversion of lignin to bio-oil composed of monomers and low-mass oligomers with high aromatic content was obtained in 6. h at 310......An isolated, solvent-extracted lignin from candlenut (Aleurites moluccana) biomass was subjected to catalytic depolymerization in the presence of supercritical methanol, using a range of porous metal oxides derived from hydrotalcite-like precursors. The most effective catalysts in terms of lignin...

  20. Radiotracer experiments on lignin reactions, 2

    International Nuclear Information System (INIS)

    Terashima, Noritsugu; Araki, Hiroshi; Suganuma, Nobuo.

    1977-01-01

    The behavior of the specific carbon atoms of lignin during the cooking process was studied. Pine wood meal containing the protolignin labelled with 14-C was prepared, and treated under sulfate cooking conditions. The incorporation and distribution of radioactivity were traced in three fractions separated from the black liquor according to their solubilities and molecular weights. The gamma position carbon at the end of side chain of phenylpropane unit in lignin was eliminated easily from the high molecular weight portion in considerable extent during the cooking process, and a part of the eliminated carbon condenses again with the aromatic ring. However, a large portion of the eliminated gamma-carbon was found in the low molecular fraction of water soluble part of the black liquor. The radioactivity of alpha-carbons in the side chains adjacent to aromatic rings was found to be distributed in three fractions similarly to that of beta-carbons, except that the incorporation of radioactivity of alpha-carbons was slightly low in high molecular fraction, and slightly high in low molecular water soluble fraction as compared with that of beta-carbons and aromatic ring carbons. The number of residual carbon atoms per one monomer unit in high molecular kraft lignin was calculated from the specific incorporation ratio of radioactivity. The carbon skelton was estimated and the molecular formula was given by the elementary analysis and molecular weight determination. (Iwakiri, K.)

  1. Chemical groups and structural characterization of lignin via thiol-mediated demethylation

    Science.gov (United States)

    Lihong Hu; Hui Pan; Yonghong Zhou; Chung-Yun Hse; Chengguo Liu; Baofang Zhang; Bin Xu

    2014-01-01

    A new approach to increase the reactivity of lignin by thiol-mediated demethylation was investigated in this study. Demethylated lignin was characterized by the changes in its hydroxyl and methoxyl groups, molecular weight, and other properties using titration and spectroscopy methods including FT-IR, 1H NMR, UV,and GPC. The total...

  2. Transcription factors for modification of lignin content in plants

    Science.gov (United States)

    Wang, Huanzhong; Chen, Fang; Dixon, Richard A.

    2015-06-02

    The invention provides methods for modifying lignin, cellulose, xylan, and hemicellulose content in plants, and for achieving ectopic lignification and, for instance, secondary cell wall synthesis in pith cells, by altered regulation of a WRKY transcription factor. Nucleic acid constructs for altered WRKY-TF expression are described. Transgenic plants are provided that comprise modified pith cell walls, and lignin, cellulose, and hemicellulose content. Plants described herein may be used, for example, as improved biofuel feedstock and as highly digestible forage crops.

  3. Lignin plays a negative role in the biochemical process for producing lignocellulosic biofuels.

    Science.gov (United States)

    Zeng, Yining; Zhao, Shuai; Yang, Shihui; Ding, Shi-You

    2014-06-01

    A biochemical platform holds the most promising route toward lignocellulosic biofuels, in which polysaccharides are hydrolyzed by cellulase enzymes into simple sugars and fermented to ethanol by microbes. However, these polysaccharides are cross-linked in the plant cell walls with the hydrophobic network of lignin that physically impedes enzymatic deconstruction. A thermochemical pretreatment process is often required to remove or delocalize lignin, which may also generate inhibitors that hamper enzymatic hydrolysis and fermentation. Here we review recent advances in understanding lignin structure in the plant cell walls and the negative roles of lignin in the processes of converting biomass to biofuels. Perspectives and future directions to improve the biomass conversion process are also discussed. Copyright © 2013. Published by Elsevier Ltd.

  4. Effect of biotic lignin decomposition on the fate of radiocesium-contaminated plant litter

    Energy Technology Data Exchange (ETDEWEB)

    Hashida, Shin-nosuke; Yoshihara, Toshihiro [Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry, Abiko 1646, Abiko-shi, Chiba (Japan)

    2014-07-01

    Fungi are the most important components in the fate of radionuclides deposited in forests following the Fukushima nuclear accident. Pruned woody parts and litter contain a considerable amount of radiocesium. Studies that focused on the migration of radiocesium have demonstrated that its ecological half-life is lower in the humus layer than in the deeper soil zone, suggesting a substantial contribution of litter decomposition on the mobilization of radiocesium. Furthermore, white-rot fungi appear to play a key role in the mobilization of radiocesium because they are the primary source of enzymes necessary to degrade the litter organic matter. Cell walls are the primary component of plant litter; they are composed of cellulose, hemi-cellulose, and lignin. Although cellulose is the most abundant organic compound in litter, the strength of the cell wall is limited by rigid hemi-cellulose complexes that protect the surrounding cellulose microfibrils. In the cell wall, lignin fills the spaces between cellulose and hemi-cellulose; thus, the biotic degradation of lignin could be considered a primary step in litter decomposition. The contribution of the amount of lignin on the fate of radiocesium has not been identified, which limits the possibility of predicting the effect of the bacterial community structure that determines the biodegradation activity of lignin on the vertical migration of radiocesium. Here, we directly addressed the role of lignin as controller of the distribution of radiocesium in soil-ecosystems. Radiocesium-contaminated litter samples were collected with traps set under the target stands, i.e., Japanese flowering cherry trees (Prunus x yedoensis cv. Somei-Yoshino) and Japanese cedars (Cryptomeria japonica) at Abiko (Laboratory of Environmental Science, CRIEPI) located approximately 200 km SSW from the Fukushima Daiichi Nuclear Power Plant in 2011. The litter samples were inoculated with white-rot fungi having ligno-celluloses-degrading activity, i

  5. Inhibition and kinetic studies of lignin degrading enzymes of Ganoderma boninense by naturally occurring phenolic compounds.

    Science.gov (United States)

    Surendran, Arthy; Siddiqui, Yasmeen; Saud, Halimi Mohd; Ali, Nusaibah Syd; Manickam, Sivakumar

    2018-05-22

    Lignolytic (Lignin degrading) enzyme, from oil palm pathogen Ganoderma boninense Pat. (Syn G. orbiforme (Ryvarden), is involved in the detoxification and the degradation of lignin in the oil palm and is the rate-limiting step in the infection process of this fungus. Active inhibition of lignin degrading enzymes secreted by G. boninense by various naturally occurring phenolic compounds and estimation of efficiency on pathogen suppression was aimed at. In our work, ten naturally occurring phenolic compounds were evaluated for their inhibitory potential towards the lignolytic enzymes of G.boninense. Additionally, the lignin degrading enzymes were characterised. Most of the peholic compounds exhibited an uncompetitive inhibition towards the lignin degrading enzymes. Benzoic acid was the superior inhibitor to the production of lignin degrading enzymes, when compared between the ten phenolic compounds. The inhibitory potential of the phenolic compounds toward the lignin degrading enzymes are higher than that of the conventional metal ion inhibitor. The lignin degrading enzymes were stable in a wide range of pH but were sensitive to higher to temperature. The study demonstrated the inhibitor potential of ten naturally occurring phenolic compounds toward the lignin degrading enzymes of G. boninense with different efficacies. The study has shed a light towards a new management strategy to control BSR in oil palm. It serves as replacement for the existing chemical control. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  6. Improvement of linerboard compressive strength by hot-pressing and addition of recovered lignin from spent pulping liquor

    Directory of Open Access Journals (Sweden)

    Saidan Motasem N.

    2015-01-01

    Full Text Available This paper evaluates the effect of addition of precipitated lignin, from spent pulping black liquor, to a wet single-ply linerboard handsheet followed by hot-pressing at different temperatures, on the improvement of its compressive strength. Linerboard handsheets for testing the effect of lignin addition were prepared so that the lignin-modified sheets would have the same basis weights as the control handsheets. Both the commercial and the black liquor lignin were added as a powder to wet handsheets after couching from the handsheet mold. The experiments and testing of the physical and strength properties of dried handsheets were conducted according to TAPPI test methods. The results revealed that the addition of the recovered lignin (at pH of 2 to the wet handsheet followed by hot-pressing at 150°C increased the compressive strength of linerboard handsheets by 10% to 20% above that for handsheets made without the addition of lignin. The same results were achieved using purchased lignin. However, with a 16% addition to linerboard, purchased lignin would be too expensive. These results indicate that inclusion of kraft lignin in linerboard sheets could be proved as an attractive option to reduce linerboard basis weight.

  7. The comparative geochemistries of lignins and carbohydrates in an anoxic fjord

    Science.gov (United States)

    Hamilton, Susan E.; Hedges, John I.

    1988-01-01

    A reducing, varved sediment core and monthly (May-September) plankton and sediment trap samples from Saanich Inlet, B.C., Canada, were analyzed for their elemental, lignin and neutral sugar compositions. Total yields of lignin-derived phenols from both the sediment trap and core samples indicated less than 15% and 30%, respectively, of chemically recognizable vascular plant remains, derived predominantly from gymnosperm wood and nonwoody angiosperm tissues. The elevated vanillyl and syringyl acid/aldehyde ratios of this material compared to fresh plant material indicated that it suffered mild aerobic decomposition prior to introduction to the Inlet. Most of the remaining particular organic material was nitrogen-rich, carbohydrate-poor and apparently plankton-derived. Organic carbon, total nitrogen, and total neutral sugars and lignin phenols all exhibited decreasing concentrations with depth in a region of uniform varving (upper 15 cm) in the sediment core. All profiles exhibited particularly steep concentration decreases within the top 2 cm of sediment. First-order decay constants for all four chemical categories within the upper 14 cm of the core ranged between 0.1-0.2 yr -1. Neutral sugars were consistently the most reactive chemical class, accounting for roughly 15% of the total organic carbon turnover. Although lignin appeared to be degraded within the sediment core, this degradation was nonselective for different lignin types and did not lead to increased acid/aldehyde ratios as occur during aerobic lignin decomposition. Comparisons of the yields of individual neutral sugars from the sediment and sediment trap samples to those expected from the vascular plant component alone indicated that the vascular plant debris in the upper portion of the sediment core had lost a portion of its initial glucose, lyxose, and mannose. In contrast, rhamnose and fucose were produced by all samples in large excess of total yields expected for chemically intact vascular plant

  8. Studies of lignin transformation in polyoxometalate (POM) bleaching of kraft pulp

    Science.gov (United States)

    Biljana Bujanovic; Richard S. Reiner; Kolby C. Hirth; Sally A. Ralph; Rajai H. Atalla

    2005-01-01

    In order to elucidate changes occurring in lignin during polyoxometalate delignification of kraft pulp, residual lignins of a series of POM- delignified kraft pulps of decreasing kappa number were isolated and characterized. Oxidative treatment of commercial unbleached kraft pulp was performed using complex POM solutions containing the active [SiVW11O40]anion. For...

  9. Method to separate lignin-rich solid phase from acidic biomass suspension at an acidic pH

    Science.gov (United States)

    Yasarla, Kumar Lakshmi Rakesh; Ramarao, Bandaru V; Amidon, Thomas

    2017-09-05

    A method of separating a lignin-rich solid phase from a solution suspension, by pretreating a lignocellulosic biomass with a pretreatment fluid having remove soluble components, colloidal material and primarily lignin containing particles; separating the pretreated lignocellulosic biomass from the pretreatment fluid with soluble components, colloidal material and primarily lignin containing particles; flocculating the separated pretreatment fluid with soluble components, colloidal material and primarily lignin containing particles using polyethylene oxide (i.e., PEO) or cationic Poly acrylamide (i.e., CPAM) as a flocculating agent; and filtering the flocculated separated pretreatment fluid with soluble components, colloidal material and primarily lignin containing particles to remove agglomerates.

  10. Preoxidation and Activation of the Lignin Char: Carbonization and Oxidation Procedures

    Directory of Open Access Journals (Sweden)

    Saloua Sebbahi

    2014-01-01

    Full Text Available A comprehensive process of pretreatment and oxidation of lignin char was developed to optimize the production of activated carbon. The lignin char was obtained by carbonization of lignin under nitrogen at 600°C for 2 hours. The optimum time and temperature used to oxidize the char without destruction were, respectively, 6 hours and 245°C. The oxygen improves the reactivity of the sample in CO2 and evolved the sample of a thermoplastic behaviour to a thermosetting behaviour. The oxygenation in air of the lignin char does not change the mode of deformation acquired by the material during the carbonization. The preoxidized coal reacts more than the nonoxidized coal during the CO2 activation, whereas the reduction in volume in the first case is smaller than in the second. The preoxidized and then activated carbon shows the formation and the development of microporosity at the expense of macroporosity. This microstructure is one of the main characteristics of activated carbon, which can be used as adsorbent for different pollutants.

  11. Lewis-acid catalyzed depolymerization of Protobind lignin in supercritical water and ethanol

    NARCIS (Netherlands)

    Guvenatam, Burcu; Heeres, Erik H.J.; Pidko, Evgeny A.; Hensen, Ernie J. M.

    2016-01-01

    The use of metal acetates, metal chlorides and metal triflates as Lewis acid catalysts for the depolymerization of soda lignin under supercritical conditions was investigated. The reactions were carried out at 400 degrees C in water and ethanol. Lignin conversion in supercritical water led to

  12. Enzymatic cellulose oxidation is linked to lignin by long-range electron transfer

    DEFF Research Database (Denmark)

    Westereng, Bjorge; Cannella, David; Wittrup Agger, Jane

    2015-01-01

    cell walls. Electron transfer was confirmed by electron paramagnetic resonance spectroscopy showing that LPMO activity on cellulose changes the level of unpaired electrons in the lignin. The discovery of a long-range electron transfer mechanism links the biodegradation of cellulose and lignin and sheds...

  13. Experimental Studies on the Hydrotreatment of Kraft Lignin to Aromatics and Alkylphenolics Using Economically Viable Fe-Based Catalysts

    Science.gov (United States)

    2017-01-01

    Limonite, a low-cost iron ore, was investigated as a potential hydrotreatment catalyst for kraft lignin without the use of an external solvent (batch reactor, initial H2 pressure of 100 bar, 4 h). The best results were obtained at 450 °C resulting in 34 wt % of liquefied kraft lignin (lignin oil) on lignin intake. The composition of the lignin oil was determined in detail (elemental composition, GC-MS, GC×GC-FID, and GPC). The total GC-detectable monomeric species amounts up to 31 wt % on lignin intake, indicating that 92 wt % of the products in the lignin oil are volatile and thus of low molecular weight. The lignin oil was rich in low-molecular-weight alkylphenolics (17 wt % on lignin) and aromatics (8 wt % on lignin). Performance of the limonite catalyst was compared to other Fe-based catalysts (goethite and iron disulfide) and limonite was shown to give the highest yields of alkylphenolics and aromatics. The limonite catalyst before and after reaction was characterized using XRD, TEM, and nitrogen physisorption to determine changes in structure during reaction. Catalyst recycling tests were performed and show that the catalyst is active after reuse, despite the fact that the morphology changed and that the surface area of the catalyst particles was decreased. Our results clearly reveal that cheap limonite catalysts have the potential to be used for the depolymerization/hydrodeoxygenation of kraft lignin for the production of valuable biobased phenolics and aromatics. PMID:28413733

  14. Mechanochemical production of lignin-containing powder fuels from biotechnical industry waste: A review

    Directory of Open Access Journals (Sweden)

    Lomovsky Oleg

    2015-01-01

    Full Text Available In biotechnological processing of plant raw materials, carbohydrates that are soluble and accessible for microorganisms are the only usable components. The lignin-rich part of the plant raw materials usually ends up in the waste. Lignin transferred into water suspensions cannot be used efficiently as a fuel. In this review, a new processing scheme of plant raw materials is presented, which includes mechanochemical treatment of the plant raw materials and separation of the powder product into particles of lignified and non-lignified tissues rich in lignin and cellulose, respectively. The cellulose-rich powders can then be used in biotechnological processes. Lignin-rich powder aerodynamically separated using cyclone-type apparatus can be used as a powder fuel to satisfy the needs of the main biotechnological plant in heat and steam.

  15. Expression atlas and comparative coexpression network analyses reveal important genes involved in the formation of lignified cell wall in Brachypodium distachyon.

    Science.gov (United States)

    Sibout, Richard; Proost, Sebastian; Hansen, Bjoern Oest; Vaid, Neha; Giorgi, Federico M; Ho-Yue-Kuang, Severine; Legée, Frédéric; Cézart, Laurent; Bouchabké-Coussa, Oumaya; Soulhat, Camille; Provart, Nicholas; Pasha, Asher; Le Bris, Philippe; Roujol, David; Hofte, Herman; Jamet, Elisabeth; Lapierre, Catherine; Persson, Staffan; Mutwil, Marek

    2017-08-01

    While Brachypodium distachyon (Brachypodium) is an emerging model for grasses, no expression atlas or gene coexpression network is available. Such tools are of high importance to provide insights into the function of Brachypodium genes. We present a detailed Brachypodium expression atlas, capturing gene expression in its major organs at different developmental stages. The data were integrated into a large-scale coexpression database ( www.gene2function.de), enabling identification of duplicated pathways and conserved processes across 10 plant species, thus allowing genome-wide inference of gene function. We highlight the importance of the atlas and the platform through the identification of duplicated cell wall modules, and show that a lignin biosynthesis module is conserved across angiosperms. We identified and functionally characterised a putative ferulate 5-hydroxylase gene through overexpression of it in Brachypodium, which resulted in an increase in lignin syringyl units and reduced lignin content of mature stems, and led to improved saccharification of the stem biomass. Our Brachypodium expression atlas thus provides a powerful resource to reveal functionally related genes, which may advance our understanding of important biological processes in grasses. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  16. Antioxidant Activity of the Lignins Derived from Fluidized-Bed Fast Pyrolysis

    Directory of Open Access Journals (Sweden)

    Sohail S. Qazi

    2017-03-01

    Full Text Available A challenge in recent years has been the rational use of forest and agriculture residues for the production of bio-fuel, biochemical, and other bioproducts. In this study, potentially useful compounds from pyrolytic lignins were identified by HPLC-MS/MS and untargeted metabolomics. The metabolites identified were 2-(4-allyl-2-methoxyphenoxy-1-(4-hydroxy-3-methoxyphenyl-1-propanol, benzyl benzoate, fisetinidol, phenyllactic acid, 2-phenylpropionic acid, 6,3′-dimethoxyflavone, and vanillin. The 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (DPPH, trolox equivalent antioxidant capacity (TEAC, and total phenolics content (TPC per gram of pyrolytic lignin ranged from 14 to 503 mg ascorbic acid equivalents, 35 to 277 mg trolox equivalents, and 0.42 to 50 mg gallic acid equivalents, respectively. A very significant correlation was observed between the DPPH and TPC (r = 0.8663, p ≤ 0.0001, TEAC and TPC (r = 0.8044, p ≤ 0.0001, and DPPH and TEAC (r = 0.8851, p ≤ 0.0001. The polyphenolic compounds in the pyrolytic lignins which are responsible for radical scavenging activity and antioxidant properties can be readily profiled with HPLC-MS/MS combined with untargeted metabolomics. The results also suggest that DPPH, TEAC, and TPC assays are suitable methods for the measurement of antioxidant activity in a variety of pyrolytic lignins. These data show that the pyrolytic lignins can be considered as promising sources of natural antioxidants and value-added chemicals.

  17. Influence of RANEY Nickel on the Formation of Intermediates in the Degradation of Lignin

    Directory of Open Access Journals (Sweden)

    Daniel Forchheim

    2012-01-01

    Full Text Available Lignin forms an important part of lignocellulosic biomass and is an abundantly available residue. It is a potential renewable source of phenol. Liquefaction of enzymatic hydrolysis lignin as well as catalytical hydrodeoxygenation of the main intermediates in the degradation of lignin, that is, catechol and guaiacol, was studied. The cleavage of the ether bonds, which are abundant in the molecular structure of lignin, can be realised in near-critical water (573 to 673 K, 20 to 30 MPa. Hydrothermal treatment in this context provides high selectivity in respect to hydroxybenzenes, especially catechol. RANEY Nickel was found to be an adequate catalyst for hydrodeoxygenation. Although it does not influence the cleavage of ether bonds, RANEY Nickel favours the production of phenol from both lignin and catechol. The main product from hydrodeoxygenation of guaiacol with RANEY Nickel was cyclohexanol. Reaction mechanism and kinetics of the degradation of guaiacol were explored.

  18. Solvent consumption in non-catalytic alcohol solvolysis of biorefinery lignin

    DEFF Research Database (Denmark)

    Nielsen, J. B.; Jensen, A.; Schandel, Christian Bækhøj

    2017-01-01

    Lignin solvolysis in supercritical alcohols provides a method for producing a deoxygenated liquid bio-oil. Solvent consumption is however inevitable and due to the high cost of alcohols, relative to a bio-oil product, it can hinder commercial viability. In order to investigate the reactions...... of solvent consumption we studied solvolysis of biorefinery lignin in several primary alcohols. Lignin solvolysis in methanol, ethanol, 1-propanol and 1-butanol performed similarly with respect to bio-oil composition; however, methanol gave much lower bio-oil yield. Solvent consumption increases...... with reaction temperature for all alcohols and from 10 wt% at 300 °C to 35 wt% at 400 °C when using ethanol. The mechanism for solvent consumption was found mainly to take place through three different reactions: direct decomposition to gas through decarbonylation, formation of light condensation products...

  19. Lewis-acid catalyzed depolymerization of Protobind lignin in supercritical water and ethanol

    NARCIS (Netherlands)

    Güvenatam, B.; Heeres, E.H.J.; Pidko, E.A.; Hensen, E.J.M.

    2014-01-01

    The use of metal acetates, metal chlorides and metal triflates as Lewis acid catalysts for the depolymerization of soda lignin under supercritical conditions was investigated. The reactions were carried out at 400°C in water and ethanol. Lignin conversion in supercritical water led to formation of

  20. UV-Vis as quantification tool for solubilized lignin following a single-shot steam process.

    Science.gov (United States)

    Lee, Roland A; Bédard, Charles; Berberi, Véronique; Beauchet, Romain; Lavoie, Jean-Michel

    2013-09-01

    In this short communication, UV/Vis was used as an analytical tool for the quantification of lignin concentrations in aqueous mediums. A significant correlation was determined between absorbance and concentration of lignin in solution. For this study, lignin was produced from different types of biomasses (willow, aspen, softwood, canary grass and hemp) using steam processes. Quantification was performed at 212, 225, 237, 270, 280 and 287 nm. UV-Vis quantification of lignin was found suitable for different types of biomass making this a timesaving analytical system that could lead to uses as Process Analytical Tool (PAT) in biorefineries utilizing steam processes or comparable approaches. Copyright © 2013 Elsevier Ltd. All rights reserved.