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Sample records for acid insoluble lignin

  1. Comparison of acid-detergent lignin, alkaline-peroxide lignin, and acid-detergent insoluble ash as internal markers for predicting fecal output and digestibility by cattle offered bermudagrass hays of varying nutrient composition

    PubMed Central

    2014-01-01

    Background The potential for acid-detergent insoluble ash (ADIA), alkaline-peroxide lignin (APL), and acid-detergent lignin (ADL) to predict fecal output (FO) and dry matter digestibility (DMD) by cattle offered bermudagrass [Cynodon dactylon (L.) Pers.] hays of different qualities was evaluated. Eight ruminally cannulated cows (594 ± 35.5 kg) were allocated randomly to 4 hay diets: low (L), medium low (ML), medium high (MH), and high (H) crude protein (CP) concentration (79, 111, 131, and 164 g CP/kg on a DM basis, respectively). Diets were offered in 3 periods with 2 diet replicates per period and were rotated across cows between periods. Cows were individually fed 20 g DM/kg of body weight in equal feedings at 08:00 and 16:00 h for a 10-d adaptation followed by a 5-d total fecal collection. Actual DM intake (DMI), DMD, and FO were determined based on hay offered, ort, and feces excreted. These components were then analyzed for ADL, APL, and ADIA concentration to determine marker recovery and marker-based estimates of FO and DMD. Results Forage DMI was affected by diet (P = 0.02), and DMI from MH and H was greater (P < 0.05) than from L. Apparent DMD tended (P = 0.08) to differ among diets while FO (P = 0.20) was not affected by diet treatments. Average ADL recovery (1.16) was greater (P < 0.05) than that of ADIA (1.03) and APL (1.06), but ADIA and APL did not differ (P = 0.42). Estimates of FO and DMD derived using APL and ADIA were not different (P ≥ 0.05) from total fecal collection while those using ADL differed (P < 0.05). There was no diet by marker interaction (P ≥ 0.22) for either FO or DMD. Conclusion Acid-detergent insoluble ash and APL accurately predicted FO and DMD of cattle fed bermudagrass hay of varying nutrient composition. These internal markers may facilitate studies involving large numbers of animals and forages. Results from such studies may be used to develop improved equations to predict energy values of

  2. Biologically produced acid precipitable polymeric lignin

    DOEpatents

    Crawford, Don L.; Pometto, III, Anthony L.

    1984-01-01

    A water soluble, acid precipitable polymeric degraded lignin (APPL), having a molecular weight of at least 12,000 daltons, and comprising, by percentage of total weight, at least three times the number of phenolic hydroxyl groups and carboxylic acid groups present in native lignin. The APPL may be modified by chemical oxidation and reduction to increase its phenolic hydroxyl content and reduce the number of its antioxidant inhibitory side chains, thereby improving antioxidant properties.

  3. NMR CHARACTERIZATION OF LIGNINS ISOLATED FROM FRUIT AND VEGETABLE INSOLUBLE DIETARY FIBER

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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, including as antioxidants and carcinogen adsorbants, and may be partially converted to mammalian lignans, the confu...

  4. Selective Conversion of Biorefinery Lignin into Dicarboxylic Acids

    SciTech Connect

    Ma, Ruoshui; Guo, Mond; Zhang, Xiao

    2014-02-01

    The emerging biomass-to-biofuel conversion industry has created an urgent need for identifying new applications for biorefinery lignin. This paper demonstrates a new route to producing dicarboxylic acids from biorefinery lignin through chalcopyrite-catalyzed oxidation in a highly selective process. Up to 95 % selectivity towards stable dicarboxylic acids was obtained for several types of biorefinery lignin and model compounds under mild, environmentally friendly reaction conditions. The findings from this study paved a new avenue to biorefinery lignin conversions and applications.

  5. Characterization of lignin derived from water-only and dilute acid flowthrough pretreatment of poplar wood at elevated temperatures

    SciTech Connect

    Zhang, Libing; Yan, Lishi; Wang, Zheming; Laskar, Dhrubojyoti D.; Swita, Marie S.; Cort, John R.; Yang, Bin

    2015-12-01

    In this study, flowthrough pretreatment of biomass has high potential to valorize lignin derivatives to high-value products, which is vital to enhance the economy of biorefinery plants. Comprehensive understanding of lignin behaviors and solubilization chemistry in aqueous pretreatment such as water-only and dilute acid flowthrough pretreatment is of fundamental importance to achieve the goal of providing flexible platform for lignin utilization. In this study, the effects of flowthrough pretreatment conditions on lignin separation from poplar wood were reported as well as the characteristics of three sub-sets of lignin produced from the pretreatment, including residual lignin in pretreated solid residues (ReL), recovered insoluble lignin in pretreated liquid (RISL), and recovered soluble lignin in pretreatment liquid (RSL). Both the water-only and 0.05% (w/w) sulfuric acid pretreatments were performed at temperatures from 160 to 270°C on poplar wood in a flowthrough reactor system for 2-10 min. Results showed that water-only flowthrough pretreatment primarily removed syringyl (S units). Increased temperature and/or the addition of sulfuric acid enhanced the removal of guaiacyl (G units) compared to water-only pretreatments at lower temperatures, resulting in nearly complete removal of lignin from the biomass. Results also suggested that more RISL was recovered than ReL and RSL in both dilute acid and water-only flowthrough pretreatment at elevated temperatures. NMR spectra of the RISL revealed significant β-O-4 cleavage, α-β deoxygenation to form cinnamyl-like end groups, and slight β-5 repolymerization in both water-only and dilute acid flowthrough pretreatments. In conclusion, elevated temperature and/or dilute acid greatly enhanced lignin removal to almost 100% by improving G unit removal besides S unit removal in flowthrough system. A new lignin chemistry transformation pathway was proposed and revealed the complexity of lignin structural change during

  6. Selective conversion of biorefinery lignin into dicarboxylic acids.

    PubMed

    Ma, Ruoshui; Guo, Mond; Zhang, Xiao

    2014-02-01

    The emerging biomass-to-biofuel conversion industry has created an urgent need for identifying new applications for biorefinery lignin. This paper demonstrates a new route to producing dicarboxylic acids from biorefinery lignin through chalcopyrite-catalyzed oxidation in a highly selective process. Up to 95 % selectivity towards stable dicarboxylic acids was obtained for several types of biorefinery lignin and model compounds under mild, environmentally friendly reaction conditions. The findings from this study paved a new avenue to biorefinery lignin conversions and applications. PMID:24464928

  7. Experimental Study of Mechanistic Acid Deconstruction of Lignin

    SciTech Connect

    Sturgeon, M.; Kim, S.; Chmely, S. C.; Katahira, R.; Foust, T. D.; Beckham, G. T.

    2012-01-01

    Lignin is a major component of biomass, which remains highly underutilized in selective biomass conversion strategies to renewable fuels and chemicals. Here we are interested in studying the mechanisms related to the acid deconstruction of lignin with a combined theoretical and experimental approach. Quantum mechanical calculations were employed to elucidate possible deconstruction mechanisms with transition state theory. Model dimers, imitating H, S, and G lignins, were synthesized with the most abundant {beta} - O - 4 linkage in lignin. These compounds were then depolymerized using various acids and at different operating conditions. The deconstruction products were analyzed to complement the QM studies and investigate proposed mechanisms.

  8. Computational Mechanistic Studies of Acid-Catalyzed Lignin Model Dimers for Lignin Depolymerization

    SciTech Connect

    Kim, S.; Sturgeon, M. R.; Chmely, S. C.; Paton, R. S.; Beckham, G. T.

    2013-01-01

    Lignin is a heterogeneous alkyl-aromatic polymer that constitutes up to 30% of plant cell walls, and is used for water transport, structure, and defense. The highly irregular and heterogeneous structure of lignin presents a major obstacle in the development of strategies for its deconstruction and upgrading. Here we present mechanistic studies of the acid-catalyzed cleavage of lignin aryl-ether linkages, combining both experimental studies and quantum chemical calculations. Quantum mechanical calculations provide a detailed interpretation of reaction mechanisms including possible intermediates and transition states. Solvent effects on the hydrolysis reactions were incorporated through the use of a conductor-like polarizable continuum model (CPCM) and with cluster models including explicit water molecules in the first solvation shell. Reaction pathways were computed for four lignin model dimers including 2-phenoxy-phenylethanol (PPE), 1-(para-hydroxyphenyl)-2-phenoxy-ethanol (HPPE), 2-phenoxy-phenyl-1,3-propanediol (PPPD), and 1-(para-hydroxyphenyl)-2-phenoxy-1,3-propanediol (HPPPD). Lignin model dimers with a para-hydroxyphenyl ether (HPPE and HPPPD) show substantial differences in reactivity relative to the phenyl ether compound (PPE and PPPD) which have been clarified theoretically and experimentally. The significance of these results for acid deconstruction of lignin in plant cell walls will be discussed.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

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

    2014-11-13

    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. PMID:25363781

  11. Characterization of lignin derived from water-only and dilute acid flowthrough pretreatment of poplar wood at elevated temperatures

    DOE PAGESBeta

    Zhang, Libing; Yan, Lishi; Wang, Zheming; Laskar, Dhrubojyoti D.; Swita, Marie S.; Cort, John R.; Yang, Bin

    2015-12-01

    In this study, flowthrough pretreatment of biomass has high potential to valorize lignin derivatives to high-value products, which is vital to enhance the economy of biorefinery plants. Comprehensive understanding of lignin behaviors and solubilization chemistry in aqueous pretreatment such as water-only and dilute acid flowthrough pretreatment is of fundamental importance to achieve the goal of providing flexible platform for lignin utilization. In this study, the effects of flowthrough pretreatment conditions on lignin separation from poplar wood were reported as well as the characteristics of three sub-sets of lignin produced from the pretreatment, including residual lignin in pretreated solid residues (ReL),more » recovered insoluble lignin in pretreated liquid (RISL), and recovered soluble lignin in pretreatment liquid (RSL). Both the water-only and 0.05% (w/w) sulfuric acid pretreatments were performed at temperatures from 160 to 270°C on poplar wood in a flowthrough reactor system for 2-10 min. Results showed that water-only flowthrough pretreatment primarily removed syringyl (S units). Increased temperature and/or the addition of sulfuric acid enhanced the removal of guaiacyl (G units) compared to water-only pretreatments at lower temperatures, resulting in nearly complete removal of lignin from the biomass. Results also suggested that more RISL was recovered than ReL and RSL in both dilute acid and water-only flowthrough pretreatment at elevated temperatures. NMR spectra of the RISL revealed significant β-O-4 cleavage, α-β deoxygenation to form cinnamyl-like end groups, and slight β-5 repolymerization in both water-only and dilute acid flowthrough pretreatments. In conclusion, elevated temperature and/or dilute acid greatly enhanced lignin removal to almost 100% by improving G unit removal besides S unit removal in flowthrough system. A new lignin chemistry transformation pathway was proposed and revealed the complexity of lignin structural change

  12. Cinnamic acid increases lignin production and inhibits soybean root growth.

    PubMed

    Salvador, Victor Hugo; Lima, Rogério Barbosa; dos Santos, Wanderley Dantas; Soares, Anderson Ricardo; Böhm, Paulo Alfredo Feitoza; Marchiosi, Rogério; Ferrarese, Maria de Lourdes Lucio; Ferrarese-Filho, Osvaldo

    2013-01-01

    Cinnamic acid is a known allelochemical that affects seed germination and plant root growth and therefore influences several metabolic processes. In the present work, we evaluated its effects on growth, indole-3-acetic acid (IAA) oxidase and cinnamate 4-hydroxylase (C4H) activities and lignin monomer composition in soybean (Glycine max) roots. The results revealed that exogenously applied cinnamic acid inhibited root growth and increased IAA oxidase and C4H activities. The allelochemical increased the total lignin content, thus altering the sum and ratios of the p-hydroxyphenyl (H), guaiacyl (G), and syringyl (S) lignin monomers. When applied alone or with cinnamic acid, piperonylic acid (PIP, a quasi-irreversible inhibitor of C4H) reduced C4H activity, lignin and the H, G, S monomer content compared to the cinnamic acid treatment. Taken together, these results indicate that exogenously applied cinnamic acid can be channeled into the phenylpropanoid pathway via the C4H reaction, resulting in an increase in H lignin. In conjunction with enhanced IAA oxidase activity, these metabolic responses lead to the stiffening of the cell wall and are followed by a reduction in soybean root growth. PMID:23922685

  13. Oxidation in Acidic Medium of Lignins from Agricultural Residues

    NASA Astrophysics Data System (ADS)

    Labat, Gisele Aparecida Amaral; Gonçalves, Adilson Roberto

    Agricultural residues as sugarcane straw and bagasse are burned in boilers for generation of energy in sugar and alcohol industries. However, excess of those by-products could be used to obtain products with higher value. Pulping process generates cellulosic pulps and lignin. The lignin could be oxidized and applied in effluent treatments for heavy metal removal. Oxidized lignin presents very strong chelating properties. Lignins from sugarcane straw and bagasse were obtained by ethanol-water pulping. Oxidation of lignins was carried out using acetic acid and Co/Mn/Br catalytical system at 50, 80, and 115 °C for 5 h. Kinetics of the reaction was accomplished by measuring the UV-visible region. Activation energy was calculated for lignins from sugarcane straw and bagasse (34.2 and 23.4 kJ mol-1, respectively). The first value indicates higher cross-linked formation. Fourier-transformed infrared spectroscopy data of samples collected during oxidation are very similar. Principal component analysis applied to spectra shows only slight structure modifications in lignins after oxidation reaction.

  14. LIGNINS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lignins are complex and irregular polymers occurring in the cell walls of vascular plants. An understanding of their nature is evolving as a result of detailed structural investigations aided by recent improvements in analytical methodology and the availability of lignin-biosynthetic-pathway mutants...

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

    PubMed

    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. PMID:27310182

  16. Lignin analysis by FT-Raman spectroscopy

    SciTech Connect

    Agarwal, U.P.; Obst, J.R.; Cannon, A.B.

    1996-10-01

    Traditional methods of lignin analysis, such as Klason (acid insoluble) lignin determinations, give satisfactory results, are widely accepted, and often are considered as standard analyses. However, the Klason lignin method is laborious and time consuming; it also requires a fairly large-amount of isolated analyte. FT-Raman spectroscopy offers an opportunity to simplify and speed up lignin analyses. FT-Raman data for a number of hardwoods (angiosperms) and softwoods (gymnosperms) are compared with data obtained using other analytical methods, including Klason lignin (with corrections for acid soluble lignin), acetyl bromide, and FT-IR determinations. In addition, 10 different specimens of Nothofagus dombeyii (chosen because of the widely varying syringyl:guaiacyl monomer compositions of their lignins) were also analyzed. Lignin monomer compositions were determined by thioacidolysis of by nitrobenzene oxidation.

  17. [Consumption of water-insoluble phenolic products of lignin pyrolysis by the strain Penicillium tardum H-2].

    PubMed

    Karetnikova, E A

    2006-01-01

    Abstract-Physiological and biochemical properties of the strain Penicillium tardum H-2, a degrader of phenolic compounds formed during lignin pyrolysis, have been characterized. The micromycete P. tardum H-2 can consume phenol, pyrocatechol, p-cresol, vanillin, and guaiacum resin. When grown in a medium containing the water-soluble fraction of lignin pyrolysis waste at concentrations from 0.5 to 2%, it consumes 62-72% of the phenolic components of the waste. According to gas-liquid chromatography, cultivation of P. tardum H-2 in a medium with liquid pyrolysis products results in a complete consumption of the phenol-cresol fraction. PMID:16521577

  18. Hydroxylamine hydrochloride-acetic acid-soluble and -insoluble fractions of pelagic sediment: Readsorption revisited

    USGS Publications Warehouse

    Piper, D.Z.; Wandless, G.A.

    1992-01-01

    The extraction of the rare earth elements (REE) from deep-ocean pelagic sediment, using hydroxylamine hydrochloride-acetic acid, leads to the separation of approximately 70% of the bulk REE content into the soluble fraction and 30% into the insoluble fraction. The REE pattern of the soluble fraction, i.e., the content of REE normalized to average shale on an element-by-element basis and plotted against atomic number, resembles the pattern for seawater, whereas the pattern, as well as the absolute concentrations, in the insoluble fraction resembles the North American shale composite. These results preclude significant readsorption of the REE by the insoluble phases during the leaching procedure.

  19. DIRECT VERSES SEQUENTIAL ANALYSIS OF ACID-DETERGENT INSOLUBLE NITROGEN IN FORAGE LEGUME HAYS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Acid-detergent insoluble nitrogen (ADIN) is thought to represent nitrogen that is not degraded during ruminal and post-ruminal digestion of forages by cattle. Forage ADIN can be determined following direct acid detergent extraction or following sequential extraction with neutral and acid detergents....

  20. STRUCTURAL IDENTIFICATION OF DEHYDROTRIFERULIC AND DEHYDROTETRAFERULIC ACIDS ISOLATED FROM INSOLUBLE MAIZE FIBER

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two new dehydrotriferulic acids and two dehydrotetraferulic acids were isolated from saponified maize bran insoluble fiber using size exclusion chromatography on BioBeads S-X3 followed by Sephadex LH-20 chromatography and semi-preparative Phenyl-Hexyl-RP-HPLC. Based on UV-spectroscopy, mass spectros...

  1. XPS and STEM studies of Allende acid insoluble residues

    NASA Technical Reports Server (NTRS)

    Housley, R. M.; Clarke, D. R.

    1980-01-01

    Data on Allende acid residues obtained both before and after etching with hot HNO3 are presented. X-ray photoelectron spectra show predominantly carbonaceous material plus Fe-deficient chromite in both cases. The HNO3 oxidizes the carbonaceous material to some extent. The small chromites in these residues have a wide range of compositions somewhat paralleling those observed in larger Allende chromites and in Murchison chromites, especially in the high Al contents; however, they are deficient in divalent cations, which makes them metastable and indicates that they must have formed at relatively low temperatures. It is suggested that they formed by precipitation of Cr(3+) and Fe(3+) from olivine at low temperature or during rapid cooling.

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

    PubMed

    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. PMID:27373451

  3. Non-extractable procyanidins and lignin are important factors in the bile acid binding and radical scavenging properties of cell wall material in some fruits.

    PubMed

    Hamauzu, Yasunori; Mizuno, Yukari

    2011-03-01

    The cell wall components and the food functions of alcohol-insoluble solids (AIS) of Chinese quince, quince, hawthorn, apple, pear and blueberry fruits were analyzed. Chinese quince contained characteristically high contents of cellulose, lignin, and non-extractable procyanidins (NEPCs). On the other hand, the quince AIS contained the highest proportion of NEPCs, the highest mean degree of polymerization (mDP), the strongest radical scavenging activity, and strong bile acid binding activity. In fruit AIS, the lignin and NEPC contents both showed positive correlations with the bile acid binding and radical scavenging activities. The value for mDP × NEPC content was a good index for the radical scavenging activity. The results suggest that highly polymerized NEPCs and lignin are important factors of cell wall components of fruits to having a high functionality, and Chinese quince and quince are interesting fruits from this view point. PMID:21243435

  4. Mechanistic Study of the Acid Degradation of Lignin Model Compounds

    SciTech Connect

    Sturgeon, M.; Kim, S.; Chmely, S. C.; Foust, T. D.; Beckham, G. T.

    2012-01-01

    Lignin is a major constituent of biomass, which remains underutilized in selective biomass conversion strategies to renewable fuels and chemicals. Here we are interested in understanding the mechanisms related to the acid deconstruction of lignin with a combined theoretical and experimental approach. Two model dimers with a b-O-4 aryl ether linkage (2-phenoxy-1-phenethanol and 2-phenoxy-1-phenyl-1,3 propanediol) and model dimmers with an a-O-4 aryl ether linkage were synthesized and deconstructed in H2SO4. The major products of the acidolysis of the b-O-4 compounds consisted of phenol and two aldehydes, phenylacetaldehyde and benzaldehyde. Quantum mechanical calculations were employed to elucidate possible deconstruction mechanisms with transition state theory. To confirm proposed mechanisms several possible intermediates were studied under similar acidolysis conditions. Although the resonance time for cleavage was on the order several hours, we have shown that the cleavage of the aryl ether linkage affords phenol and aldehydes. We would next like to utilize our mechanism of aryl ether cleavage in actual lignin.

  5. Changes in Lignin and Polysaccharide Components in 13 Cultivars of Rice Straw following Dilute Acid Pretreatment as Studied by Solution-State 2D 1H-13C NMR

    PubMed Central

    Teramura, Hiroshi; Sasaki, Kengo; Oshima, Tomoko; Aikawa, Shimpei; Matsuda, Fumio; Okamoto, Mami; Shirai, Tomokazu; Kawaguchi, Hideo; Ogino, Chiaki; Yamasaki, Masanori; Kikuchi, Jun; Kondo, Akihiko

    2015-01-01

    A renewable raw material, rice straw is pretreated for biorefinery usage. Solution-state two-dimensional (2D) 1H-13 C hetero-nuclear single quantum coherence (HSQC) nuclear magnetic resonance (NMR) spectroscopy, was used to analyze 13 cultivars of rice straw before and after dilute acid pretreatment, to characterize general changes in the lignin and polysaccharide components. Intensities of most (15 of 16) peaks related to lignin aromatic regions, such as p-coumarate, guaiacyl, syringyl, p-hydroxyphenyl, and cinnamyl alcohol, and methoxyl, increased or remained unchanged after pretreatment. In contrast, intensities of most (11 of 13) peaks related to lignin aliphatic linkages or ferulate decreased. Decreased heterogeneity in the intensities of three peaks related to cellulose components in acid-insoluble residues resulted in similar glucose yield (0.45–0.59 g/g-dry biomass). Starch-derived components showed positive correlations (r = 0.71 to 0.96) with glucose, 5-hydroxymethylfurfural (5-HMF), and formate concentrations in the liquid hydrolysates, and negative correlations (r = –0.95 to –0.97) with xylose concentration and acid-insoluble residue yield. These results showed the fate of lignin and polysaccharide components by pretreatment, suggesting that lignin aromatic regions and cellulose components were retained in the acid insoluble residues and starch-derived components were transformed into glucose, 5-HMF, and formate in the liquid hydrolysate. PMID:26083431

  6. Structure-property characteristics of pyrolytic lignins derived from fast pyrolysis of a lignin rich biomass extract

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this study, various fractions of pyrolytic lignin were isolated from the fast pyrolysis oil of Etek lignin, a residue of acidic processing of wood. Based on the solubility differences in selected solvents, the water insolubles of the pyrolysis oil were separated into various fractions (methanol-i...

  7. Tandem Catalytic Depolymerization of Lignin by Water-Tolerant Lewis Acids and Rhodium Complexes.

    PubMed

    Jastrzebski, Robin; Constant, Sandra; Lancefield, Christopher S; Westwood, Nicholas J; Weckhuysen, Bert M; Bruijnincx, Pieter C A

    2016-08-23

    Lignin is an attractive renewable feedstock for aromatic bulk and fine chemicals production, provided that suitable depolymerization procedures are developed. Here, we describe a tandem catalysis strategy for ether linkage cleavage within lignin, involving ether hydrolysis by water-tolerant Lewis acids followed by aldehyde decarbonylation by a Rh complex. In situ decarbonylation of the reactive aldehydes limits loss of monomers by recondensation, a major issue in acid-catalyzed lignin depolymerization. Rate of hydrolysis and decarbonylation were matched using lignin model compounds, allowing the method to be successfully applied to softwood, hardwood, and herbaceous dioxasolv lignins, as well as poplar sawdust, to give the anticipated decarbonylation products and, rather surprisingly, 4-(1-propenyl)phenols. Promisingly, product selectivity can be tuned by variation of the Lewis-acid strength and lignin source. PMID:27440544

  8. Organic acids as cloud condensation nuclei: Laboratory studies of highly soluble and insoluble species

    NASA Astrophysics Data System (ADS)

    Pradeep Kumar, P.; Broekhuizen, K.; Abbatt, J. P. D.

    2003-05-01

    The ability of sub-micron-sized organic acid particles to act as cloud condensation nuclei (CCN) has been examined at room temperature using a newly constructed continuous-flow, thermal-gradient diffusion chamber (TGDC). The organic acids studied were: oxalic, malonic, glutaric, oleic and stearic. The CCN properties of the highly soluble acids - oxalic, malonic and glutaric - match very closely Köhler theory predictions which assume full dissolution of the dry particle and a surface tension of the growing droplet equal to that of water. In particular, for supersaturations between 0.3 and 0.6, agreement between the dry particle diameter which gives 50% activation and that calculated from Köhler theory is to within 3nm on average. In the course of the experiments, considerable instability of glutaric acid particles was observed as a function of time and there is evidence that they fragment to some degree to smaller particles. Stearic acid and oleic acid, which are both highly insoluble in water, did not activate at supersaturations of 0.6% with dry diameters up to 140nm. Finally, to validate the performance of the TGDC, we present results for the activation of ammonium sulfate particles that demonstrate good agreement with Köhler theory if solution non-ideality is considered. Our findings support earlier studies in the literature that showed highly soluble organics to be CCN active but insoluble species to be largely inactive.

  9. Structural Transformation of Isolated Poplar and Switchgrass Lignins from Dilute Acid Pretreatment

    SciTech Connect

    Sun, Qining; Pu, Yunqiao; Meng, Xianzhi; Wells, Tyrone; Ragauskas, Arthur J.

    2015-08-27

    A key step in conversion of cellulosic biomass into sustainable fuels and chemicals is thermochemical pretreatment to reduce plant cell wall recalcitrance. Obtaining an improved understanding of the fundamental chemistry of lignin, the most recalcitrant component of biomass, during pretreatment is critical to the continued development of renewable biofuel production. To examine the intrinsic chemistry of lignin during dilute acid pretreatment (DAP), lignin was isolated from poplar and switchgrass using a cellulolytic enzyme system and then treated under DAP conditions. These results highlight that lignin is subjected to depolymerization reactions within the first 2 min of dilute acid pretreatment and these changes are accompanied by increased generation of aliphatic and phenolic hydroxyl groups of lignin. This is followed by a competing set of depolymerization and repolymerization reactions that lead to a decrease in the content of guaiacyl lignin units and an increase in condensed lignin units as the reaction residence time is extended beyond 5 min. Finally, we showed that a detailed comparison of changes in functional groups and molecular weights of cellulolytic enzyme lignins with different structural parameters, related to the recalcitrant properties of lignin, could be successfully altered during DAP conditions.

  10. Structural Transformation of Isolated Poplar and Switchgrass Lignins from Dilute Acid Pretreatment

    DOE PAGESBeta

    Sun, Qining; Pu, Yunqiao; Meng, Xianzhi; Wells, Tyrone; Ragauskas, Arthur J.

    2015-08-27

    A key step in conversion of cellulosic biomass into sustainable fuels and chemicals is thermochemical pretreatment to reduce plant cell wall recalcitrance. Obtaining an improved understanding of the fundamental chemistry of lignin, the most recalcitrant component of biomass, during pretreatment is critical to the continued development of renewable biofuel production. To examine the intrinsic chemistry of lignin during dilute acid pretreatment (DAP), lignin was isolated from poplar and switchgrass using a cellulolytic enzyme system and then treated under DAP conditions. These results highlight that lignin is subjected to depolymerization reactions within the first 2 min of dilute acid pretreatment andmore » these changes are accompanied by increased generation of aliphatic and phenolic hydroxyl groups of lignin. This is followed by a competing set of depolymerization and repolymerization reactions that lead to a decrease in the content of guaiacyl lignin units and an increase in condensed lignin units as the reaction residence time is extended beyond 5 min. Finally, we showed that a detailed comparison of changes in functional groups and molecular weights of cellulolytic enzyme lignins with different structural parameters, related to the recalcitrant properties of lignin, could be successfully altered during DAP conditions.« less

  11. Redistribution of Lignin Caused by Dilute Acid Pretreatment of Biomass

    SciTech Connect

    Johnson, D. K.; Donohoe, B. S.; Katahira, R.; Tucker, M. P.; Vinzant, T. B.; Himmel, M. E.

    2012-01-01

    Research conducted at NREL has shown that lignin undergoes a phase transition during thermochemical pretreatments conducted above its glass transition temperature. The lignin coalesces within the plant cell wall and appears as microscopic droplets on cell surfaces. It is clear that pretreatment causes significant changes in lignin distribution in pretreatments at all scales from small laboratory reactors to pilot scale reactors. A method for selectively extracting lignin droplets from the surfaces of pretreated cell walls has allowed us to characterize the chemical nature and molecular weight distribution of this fraction. The effect of lignin redistribution on the digestibility of pretreated solids has also been tested. It is clear that removal of the droplets increases the digestibility of pretreated corn stover. The improved digestibility could be due to decreased non-specific binding of enzymes to lignin in the droplets, or because the droplets no longer block access to cellulose.

  12. Mechanistic Investigation of Acid-Catalyzed Cleavage of Aryl-Ether Linkages: Implications for Lignin Depolymerization

    SciTech Connect

    Sturgeon, M. R.; Kim, S.; Chmely, S. C.; Foust, T. D.; Beckham, G. T.

    2013-01-01

    Carbon-oxygen bonds are the primary inter-monomer linkages lignin polymers in plant cell walls, and as such, catalyst development to cleave these linkages is of paramount importance to deconstruct biomass to its constituent monomers for the production of renewable fuels and chemicals. For many decades, acid catalysis has been used to depolymerize lignin. Lignin is a primary component of plant cell walls, which is connected primarily by aryl-ether linkages, and the mechanism of its deconstruction by acid is not well understood, likely due to its heterogeneous and complex nature compared to cellulose. For effective biomass conversion strategies, utilization of lignin is of significant relevance and as such understanding the mechanisms of catalytic lignin deconstruction to constituent monomers and oligomers is of keen interest. Here, we present a comprehensive experimental and theoretical study of the acid catalysis of a range of dimeric species exhibiting the b-O-4 linkage, the most common inter-monomer linkage in lignin. We demonstrate that the presence of a phenolic species dramatically increases the rate of cleavage in acid at 150 degrees C. Quantum mechanical calculations on dimers with the para-hydroxyl group demonstrate that this acid-catalyzed pathway differs from the nonphenolic dimmers. Importantly, this result implies that depolymerization of native lignin in the plant cell wall will proceed via an unzipping mechanism wherein b-O-4 linkages will be cleaved from the ends of the branched, polymer chains inwards toward the center of the polymer. To test this hypothesis further, we synthesized a homopolymer of b-O-4 with a phenolic hydroxyl group, and demonstrate that it is cleaved in acid from the end containing the phenolic hydroxyl group. This result suggests that genetic modifications to lignin biosynthesis pathways in plants that will enable lower severity processes to fractionate lignin for upgrading and for easier access to the carbohydrate fraction of

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

    NASA Astrophysics Data System (ADS)

    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.

  14. Determination of surface-accessible acidic hydroxyls and surface area of lignin by cationic dye adsorption.

    PubMed

    Sipponen, Mika Henrikki; Pihlajaniemi, Ville; Littunen, Kuisma; Pastinen, Ossi; Laakso, Simo

    2014-10-01

    A new colorimetric method for determining the surface-accessible acidic lignin hydroxyl groups in lignocellulose solid fractions was developed. The method is based on selective adsorption of Azure B, a basic dye, onto acidic hydroxyl groups of lignin. Selectivity of adsorption of Azure B on lignin was demonstrated using lignin and cellulose materials as adsorbents. Adsorption isotherms of Azure B on wheat straw (WS), sugarcane bagasse (SGB), oat husk, and isolated lignin materials were determined. The maximum adsorption capacities predicted by the Langmuir isotherms were used to calculate the amounts of surface-accessible acidic hydroxyl groups. WS contained 1.7-times more acidic hydroxyls (0.21 mmol/g) and higher surface area of lignin (84 m(2)/g) than SGB or oat husk materials. Equations for determining the amount of surface-accessible acidic hydroxyls in solid fractions of the three plant materials by a single point measurement were developed. A method for high-throughput characterization of lignocellulosic materials is now available. PMID:25033327

  15. Degradation of carbohydrates during dilute sulfuric acid pretreatment can interfere with lignin measurements in solid residues.

    PubMed

    Katahira, Rui; Sluiter, Justin B; Schell, Daniel J; Davis, Mark F

    2013-04-01

    The lignin content measured after dilute sulfuric acid pretreatment of corn stover indicates more lignin than could be accounted for on the basis of the untreated corn stover lignin content. This phenomenon was investigated using a combination of (13)C cross-polarization/magic-angle spinning (CP/MAS) solid-state nuclear magnetic resonance (NMR) spectroscopy and lignin removal using acid chlorite bleaching. Only minimal contamination with carbohydrates and proteins was observed in the pretreated corn stover. Incorporating degradation products from sugars was also investigated using (13)C-labeled sugars. The results indicate that sugar degradation products are present in the pretreatment residue and may be intimately associated with the lignin. Studies comparing whole corn stover (CS) to extractives-free corn stover [CS(Ext)] clearly demonstrated that extractives are a key contributor to the high-lignin mass balance closure (MBC). Sugars and other low molecular weight compounds present in plant extractives polymerize and form solids during pretreatment, resulting in apparent Klason lignin measurements that are biased high. PMID:23428141

  16. Structure of Brewer's Spent Grain Lignin and Its Interactions with Gut Microbiota in Vitro.

    PubMed

    Ohra-aho, Taina; Niemi, Piritta; Aura, Anna-Marja; Orlandi, Marco; Poutanen, Kaisa; Buchert, Johanna; Tamminen, Tarja

    2016-02-01

    Lignin is part of dietary fiber, but its conversion in the gastrointestinal tract is not well understood. The aim of this work was to obtain structural information on brewer's spent grain (BSG) lignin and to understand the behavior of the polymeric part of lignin exposed to fecal microbiota. The original BSG and different lignin fractions were characterized by pyrolysis-GC/MS with and without methylation. Methylation pyrolysis proved that the ratio between guaiacyl and syringyl units was similar in all lignin samples, but the ratio between p-coumaric and ferulic acids varied by the isolation method. Combined pyrolysis results indicated higher acylation of γ-OH groups in syringyl than in guaiacyl lignin units. The polymeric lignin structure in the alkali-soluble fraction after enzymatic hydrolysis was slightly altered in the in vitro colon fermentation, whereas lignin in the insoluble residue after enzymatic treatments remained intact. PMID:26751846

  17. Effect of Penicillium chrysogenum on Lignin Transformation

    PubMed Central

    Rodríguez, A.; Carnicero, A.; Perestelo, F.; de la Fuente, G.; Milstein, O.; Falcón, M. A.

    1994-01-01

    A strain of Penicillium chrysogenum has been isolated from pine forest soils in Tenerife (Canary Islands). This strain was capable of utilizing hydroxylated and nonhydroxylated aromatic compounds, in particular cinnamic acid, as its sole carbon source. In an optimum medium with high levels of nitrogen (25.6 mM) and low levels of glucose (5.5 mM), it was able to decolorize Poly B-411 and to transform kraft, organosolv, and synthetic dehydrogenative polymerisate lignins. After 30 days of incubation, the amount of recovered kraft lignin was reduced to 83.5 and 91.3% of that estimated for uninoculated controls by spectrophotometry and klason lignin, respectively. At the same time, the pattern of molecular mass distribution of the lignin remaining in cultures was changed. The amount of organosolv lignin recovered from cultures was reduced to 90.1 and 94.6% of the initial amount as evaluated by spectrophotometry and klason lignin, respectively. About 6% of total applied radioactivity of O14CH3-organosolv lignin was recovered as 14CO2 after 30 days of incubation, and 18.5% of radioactivity from insoluble O14CH3-organosolv lignin was solubilized. After 26 days of incubation, 2.9% of 14C-β-dehydrogenative polymerisate and 4.1% of 14C-ring-dehydrogenative polymerisate evolved as 14CO2. PMID:16349361

  18. Ozonolysis mechanism of lignin model compounds and microbial treatment of organic acids produced.

    PubMed

    Nakamura, Y; Daidai, M; Kobayashi, F

    2004-01-01

    Treatment methods comprising ozonolysis and microbial treatment of lignin discharged from the pulp manufacture industries were investigated by using a sulfite pulp wastewater and a lignin model compound, i.e. sodium lignosulfonate. Dynamic behaviors for the formations of intermediate derivatives such as muconic acid, maleic acid, and oxalic acid produced from the ozonolysis of sulfite pulp wastewater were observed from data of UV absorption at 280 nm by a spectrophotometer and at 210 nm by high performance liquid chromatography. The microorganisms that were isolated by the enrichment culture method were used to degrade the organic acids such as oxalic acid and acetic acid. Time courses of biological degradation of these organic acids indicated diauxic growth, which was found in a culture with mixed substrates. In the treatment of sodium lignosulfonate, the ozonolysis and microbial treatment using activated sludge converted sodium lignosulfonate into carbon dioxide and water almost completely. PMID:15461411

  19. Gas-Phase Partial Oxidation of Lignin to Carboxylic Acids over Vanadium Pyrophosphate and Aluminum-Vanadium-Molybdenum.

    PubMed

    Lotfi, Samira; Boffito, Daria C; Patience, Gregory S

    2015-10-26

    Lignin is a complex polymer that is a potential feedstock for aromatic compounds and carboxylic acids by cleaving the β-O-4 and 5-5' linkages. In this work, a syringe pump atomizes an alkaline solution of lignin into a catalytic fluidized bed operating above 600 K. The vanadium heterogeneous catalysts convert all the lignin into carboxylic acids (up to 25 % selectivity), coke, carbon oxides, and hydrogen. Aluminum-vanadium-molybdenum mostly produced lactic acid (together with formic acid, acrylic acid, and maleic anhydride), whereas the vanadium pyrophosphate catalyst produced more maleic anhydride. PMID:26361086

  20. Unraveling the Structural Modifications in Lignin of Arundo donax Linn. during Acid-Enhanced Ionic Liquid Pretreatment.

    PubMed

    You, Tingting; Zhang, Liming; Guo, Siqin; Shao, Lupeng; Xu, Feng

    2015-12-23

    Solid acid-enhanced ionic liquid (IL) pretreatment is of paramount importance for boosting the yield of sugars from biomass cost-effectively and environmentally friendly. To unravel the chemical and supramolecular structural changes of lignin after pretreatment, IL-acid lignin (ILAL) and subsequent residual cellulolytic enzyme lignin (RCEL) were isolated from Arundo donax Linn. The structural features were compared with those of the corresponding milled wood lignin (MWL). Results indicated that the pretreatment caused loss of β-O-4', β-β', β-1' linkages and formation of condensed structures in lignin. A preferential breakdown of G-type lignin may have occurred, evidenced by an increased S/G ratio revealed by 2D HSQC NMR analysis. It was determined that the depolymerization of β-O-4' linkage, lignin recondensation, and cleavage of ferulate-lignin ether linkages took place. Moreover, a simulation module was first developed to define morphological changes in lignin based on AFM and TEM analyses. Briefly, tree branch like aggregates was destroyed to monodisperse particles. PMID:26621450

  1. Self-sufficient redox biotransformation of lignin-related benzoic acids with Aspergillus flavus.

    PubMed

    Palazzolo, Martín A; Mascotti, María L; Lewkowicz, Elizabeth S; Kurina-Sanz, Marcela

    2015-12-01

    Aromatic carboxylic acids are readily obtained from lignin in biomass processing facilities. However, efficient technologies for lignin valorization are missing. In this work, a microbial screening was conducted to find versatile biocatalysts capable of transforming several benzoic acids structurally related to lignin, employing vanillic acid as model substrate. The wild-type Aspergillus flavus growing cells exhibited exquisite selectivity towards the oxidative decarboxylation product, 2-methoxybenzene-1,4-diol. Interestingly, when assaying a set of structurally related substrates, the biocatalyst displayed the oxidative removal of the carboxyl moiety or its reduction to the primary alcohol whether electron withdrawing or donating groups were present in the aromatic ring, respectively. Additionally, A. flavus proved to be highly tolerant to vanillic acid increasing concentrations (up to 8 g/L), demonstrating its potential application in chemical synthesis. A. flavus growing cells were found to be efficient biotechnological tools to perform self-sufficient, structure-dependent redox reactions. To the best of our knowledge, this is the first report of a biocatalyst exhibiting opposite redox transformations of the carboxylic acid moiety in benzoic acid derivatives, namely oxidative decarboxylation and carboxyl reduction, in a structure-dependent fashion. PMID:26445878

  2. Preparation and evaluation of lignosulfonates as a dispersant for gypsum paste from acid hydrolysis lignin.

    PubMed

    Matsushita, Yasuyuki; Yasuda, Seiichi

    2005-03-01

    In order to effectively utilize a by-product of the acid saccharification process of woody materials, the chemical conversion of guaiacyl sulfuric acid lignin (SAL), one of the acid hydrolysis lignins, into water-soluble sulfonated products with high dispersibitity was investigated. At first, SAL was phenolated (P-SAL) to enhance the solubility and reactivity. Lignosulfonates were prepared from P-SAL by three methods of hydroxymethylation followed by neutral sulfonation (two-step method), sulfomethylation (one-step method) and arylsulfonation. Surprisingly, all prepared lignosulfonates possessed 30 to 70% higher dispersibility for gypsum paste than the commercial lignosulfonate. Evaluation of the preparations for gypsum paste suggested that the higher molecular weights and sulfur contents of the preparations increased their dispersibility. PMID:15491828

  3. Using acid insoluble ash marker ratios (diet:digesta) to predict digestibility of wheat and barley metabolizable energy and nitrogen retention in broiler chicks.

    PubMed

    Scott, T A; Hall, J W

    1998-05-01

    Routine bioassay measurements of AME or N retention of broiler diets require measurements of gross energy (GE) or N and an acid insoluble ash marker in diet, excreta, or ileal digesta. These measurements of GE and N are time-consuming and expensive in comparison to measurements of added or natural occurring levels of acid insoluble ash. Data from bioassay measurements of AME and N retention of 138 wheat and 97 barley samples (with or without enzyme) were used to develop prediction equations relying on measurements of one that uses acid insoluble ash of diet, excreta or ileal digesta and GE and N of diet only; and a second equation using only acid insoluble ash of diet, excreta, or ileal digesta. The prediction equations demonstrate that part of or all of routine bomb calorimetry measurements for GE used to determine AME of wheat- or barley-based diets could be eliminated if a prediction error of 80 kcal/kg ME or less were acceptable. The prediction of N retention as compared to AME, based in part or totally on acid insoluble ash measurements, was less accurate; the prediction errors were equal to 2.3 and 6.5% for wheat- and barley-based diets, respectively. Ongoing research to improve the determination (speed, ease, and accuracy) of acid insoluble ash could provide a useful method to assess feeding value of ingredients and commercial poultry diets. PMID:9603354

  4. Lignin preparation from oil palm empty fruit bunches by sequential acid/alkaline treatment--A biorefinery approach.

    PubMed

    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. PMID:26188560

  5. Technical note: improved methodology for analyses of acid detergent fiber and acid detergent lignin.

    PubMed

    Raffrenato, E; Van Amburgh, M E

    2011-07-01

    The objective of this study was to evaluate the methodology of the acid detergent lignin (ADL) assay in an effort to evaluate particle loss, improve repeatability, and decrease variation within and among samples. The original ADL method relied on asbestos as a filtering aid, but that was removed in 1989 with the mandate from the Environmental Protection Agency to eliminate asbestos in the environment. Furthermore, recent work on fiber methodology indicated that pore size in the Gooch sintered glass crucible (40-60 μm) was too large to trap all of the small particles associated with neutral detergent fiber (NDF) and acid detergent fiber (ADF). Thus, any loss of ADF could potentially result in a loss of ADL. Sixty forages including conventional and brown midrib corn silages, alfalfa silages and hays, mature grasses, early vegetative grasses, and 9 feces samples, were analyzed sequentially for ADF and ADL as outlined in the 1973 procedure of Van Soest except for the use of the asbestos fiber. A glass microfiber filter with a 1.5-μm pore size was chosen as a filtering aid because it met the criteria required by the assay: glass, heat resistant, acid resistant, chemically inert, and hydrophobic. To compare with the current ADF and ADL assays, the assays were conducted with either no filter or the glass filter inserted into crucibles, rinsed with acetone, and then according to the 1973 procedure of Van Soest. The samples analyzed covered a range from 18.11 to 55.79% ADF and from 0.96 to 9.94% ADL on a dry matter (DM) basis. With the use of the filter, the mean ADF values increased 4.2% and mean ADL values increased 18.9%. Overall, both ADF and ADL values were greater with the use of the glass microfiber filter than without, indicating that as the type of sample analyzed changed, use of the Gooch crucible without the filtering aid results in particle loss. The adoption of the use of a small pore size (1.5 μm) glass microfiber filter to improve filtration and recovery

  6. A clinical pilot study of lignin--ascorbic acid combination treatment of herpes simplex virus.

    PubMed

    Lopez, Blanca Silvia Gonzalez; Yamamoto, Masaji; Utsumi, Katsuaki; Aratsu, Chiaki; Sakagami, Hiroshi

    2009-01-01

    Antiviral drugs as well as natural remedies have been used to reduce symptoms and the rate of recurrences of herpes simplex virus type 1 (HSV-1) infection, a common disease. To evaluate anti-HSV-1 activity of a pine cone lignin and ascorbic acid treatment, a clinical pilot study was carried out. Forty-eight healthy patients of both genders between 4 and 61 years old (mean: 31+/-16 years), with active lesions of HSV-1, took part in the study. According to the HSV-1 stage at the presentation, the patients were classified into the prodromic (16 patients), erythema (11 patients), papule edema (1 patient), vesicle/pustule (13 patients) and ulcer stages (7 patients). One mg of lignin-ascorbic acid tablet or solution was orally administered three times daily for a month. Clinical evaluations were made daily the first week and at least three times a week during the second week after the onset and every six months during the subsequent year to identify recurrence episodes. The patients who began the lignin-ascorbic acid treatment within the first 48 hours of symptom onset did not develop HSV-1 characteristic lesions, whereas those patients who began the treatment later experienced a shorter duration of cold sore lesions and a decrease in the symptoms compared with previous episodes. The majority of the patients reported the reduction in the severity of symptoms and the reduction in the recurrence episodes after the lignin-ascorbic acid treatment compared with previous episodes, suggesting its possible applicability for the prevention and treatment of HSV-1 infection. PMID:20023248

  7. Modulating lignin in plants

    DOEpatents

    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.

  8. Aromatic and volatile acid intermediates observed during anaerobic metabolism of lignin-derived oligomers

    SciTech Connect

    Colberg, P.J.; Young, L.Y.

    1985-02-01

    Anaerobic enrichment cultures acclimated for 2 years to use a /sup 14/C-labeled, lignin-derived substrate with a molecular weight of 600 as a sole source of carbon were characterized by capillary and packed column gas chromatography. After acclimation, several of the active methanogenic organisms were inhibited with 2-bromoethanesulfonic acid, which suppressed methane formation and enhanced accumulation of a series of metabolic intermediates. Volatile fatty acids levels in 2-bromoethansulfonic acid-amended cultures were 10 times greater than those in the uninhibited, methane-forming organisms with acetate as the predominant component. Furthermore, in the 2-bromoethanesulfonic acid-amended organisms, almost half of the original substrate carbon was metabolized to 10 monaromatic compounds, with the most appreciable quantities accumulated as cinnamic, benzoic, caffeic, vanillic, and ferulic acids. 2-Bromoethanesulfonic acid seemed to effectively block CH/sub 4/ formation in the anaerobic food chain, resulting in the observed buildup of volatile fatty acids and monoaromatic intermediates. Neither fatty acids nor aromatic compounds were detected in the oligolignol substrate before its metabolism, suggesting that these anaerobic organisms have the ability to mediate the cleavage of the ..beta..-aryl-ether bond, the most common intermonomeric linkage in lignin, with the subsequent release of the observed constituent aromatic monomers.

  9. Effect of lignin content on changes occurring in poplar cellulose ultrastructure during dilute acid pretreatment

    DOE PAGESBeta

    Sun, Qining; Foston, Marcus; Meng, Xianzhi; Sawada, Daisuke; Pingali, Sai Venkatesh; O’Neill, Hugh M.; Li, Hongjia; Wyman, Charles E.; Langan, Paul; Ragauskas, Art J.; et al

    2014-10-14

    Obtaining a better understanding of the complex mechanisms occurring during lignocellulosic deconstruction is critical to the continued growth of renewable biofuel production. A key step in bioethanol production is thermochemical pretreatment to reduce plant cell wall recalcitrance for downstream processes. Previous studies of dilute acid pretreatment (DAP) have shown significant changes in cellulose ultrastructure that occur during pretreatment, but there is still a substantial knowledge gap with respect to the influence of lignin on these cellulose ultrastructural changes. This study was designed to assess how the presence of lignin influences DAP-induced changes in cellulose ultrastructure, which might ultimately have largemore » implications with respect to enzymatic deconstruction efforts. Native, untreated hybrid poplar (Populus trichocarpa x Populus deltoids) samples and a partially delignified poplar sample (facilitated by acidic sodium chlorite pulping) were separately pretreated with dilute sulfuric acid (0.10 M) at 160°C for 15 minutes and 35 minutes, respectively . Following extensive characterization, the partially delignified biomass displayed more significant changes in cellulose ultrastructure following DAP than the native untreated biomass. With respect to the native untreated poplar, delignified poplar after DAP (in which approximately 40% lignin removal occurred) experienced: increased cellulose accessibility indicated by increased Simons’ stain (orange dye) adsorption from 21.8 to 72.5 mg/g, decreased cellulose weight-average degree of polymerization (DPw) from 3087 to 294 units, and increased cellulose crystallite size from 2.9 to 4.2 nm. These changes following DAP ultimately increased enzymatic sugar yield from 10 to 80%. We conclude that, overall, the results indicate a strong influence of lignin content on cellulose ultrastructural changes occurring during DAP. With the reduction of lignin content during DAP, the enlargement of

  10. Effect of lignin content on changes occurring in poplar cellulose ultrastructure during dilute acid pretreatment

    SciTech Connect

    Sun, Qining; Foston, Marcus; Meng, Xianzhi; Sawada, Daisuke; Pingali, Sai Venkatesh; O’Neill, Hugh M.; Li, Hongjia; Wyman, Charles E.; Langan, Paul; Ragauskas, Art J.; Kumar, Rajeev

    2014-10-14

    Obtaining a better understanding of the complex mechanisms occurring during lignocellulosic deconstruction is critical to the continued growth of renewable biofuel production. A key step in bioethanol production is thermochemical pretreatment to reduce plant cell wall recalcitrance for downstream processes. Previous studies of dilute acid pretreatment (DAP) have shown significant changes in cellulose ultrastructure that occur during pretreatment, but there is still a substantial knowledge gap with respect to the influence of lignin on these cellulose ultrastructural changes. This study was designed to assess how the presence of lignin influences DAP-induced changes in cellulose ultrastructure, which might ultimately have large implications with respect to enzymatic deconstruction efforts. Native, untreated hybrid poplar (Populus trichocarpa x Populus deltoids) samples and a partially delignified poplar sample (facilitated by acidic sodium chlorite pulping) were separately pretreated with dilute sulfuric acid (0.10 M) at 160°C for 15 minutes and 35 minutes, respectively . Following extensive characterization, the partially delignified biomass displayed more significant changes in cellulose ultrastructure following DAP than the native untreated biomass. With respect to the native untreated poplar, delignified poplar after DAP (in which approximately 40% lignin removal occurred) experienced: increased cellulose accessibility indicated by increased Simons’ stain (orange dye) adsorption from 21.8 to 72.5 mg/g, decreased cellulose weight-average degree of polymerization (DPw) from 3087 to 294 units, and increased cellulose crystallite size from 2.9 to 4.2 nm. These changes following DAP ultimately increased enzymatic sugar yield from 10 to 80%. We conclude that, overall, the results indicate a strong influence of lignin content on cellulose ultrastructural changes occurring during DAP. With the reduction of lignin content during DAP, the enlargement of

  11. Mechanism on microwave-assisted acidic solvolysis of black-liquor lignin.

    PubMed

    Dong, Chengjian; Feng, Chunguang; Liu, Qian; Shen, Dekui; Xiao, Rui

    2014-06-01

    Microwave-assisted degradation of black-liquor lignin with formic acid was studied, concerning the product yield and distribution of phenolic compounds against reaction temperature (110-180°C) and reaction time (5-90 min). The liquid product consisting of bio-oil 1 and bio-oil 2, achieved the maxima yield of 64.08% at 160°C and 30 min (bio-oil 1: 9.69% and bio-oil 2: 54.39%). The chemical information of bio-oil 1 and bio-oil 2 were respectively identified by means of Gas Chromatography-Mass Spectrometer (GC-MS) and Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), while the solid residue was analyzed by Gel Permeation Chromatography (GPC) and Fourier Transform Infrared Spectroscopy (FTIR). A possible mechanism was proposed for the microwave-assisted acidic solvolysis of lignin, specifying the kinetic relationship among the primary cracking of lignin, repolymerization of the oligomers and formation of solid residue. PMID:24747392

  12. Highly efficient organosolv fractionation of cornstalk into cellulose and lignin in organic acids.

    PubMed

    Shui, Tao; Feng, Shanghuan; Yuan, Zhongshun; Kuboki, Takashi; Xu, Chunbao Charles

    2016-10-01

    In this study, effects of fractionation solvents, catalysts, temperatures and residence time on yields, purity and chemical composition of the products were investigated at the solid/solvent ratio of 1:5 (g/g). It was revealed that mixture of acetic acid/formic acid/water at the ratio of 3:6:1 (v/v/v) resulted in crude cellulose and lignin products of relatively high purity. The use of HCl catalyst contributed to a high crude cellulose yield, while H2SO4 showed an adverse effect on cellulose yield. However, both of these acidic catalysts contributed to much lower hemicellulose contents in the resulted crude cellulose products compared with those obtained without a catalyst. Fractionation at 90°C for 180min in mixed solvents of acetic acid/formic acid/water (3:6:1, v/v/v) with or without catalyst produced crude cellulose with very low residual lignin contents (<4%). PMID:27450125

  13. Trace metal occurrences in acid-insoluble residues of the Ordovician Galena Group, southeastern Minnesota

    SciTech Connect

    Lively, R.S.; Mossler, J.H.; Morey, G.B. ); Hauck, S.A. . Natural Resources Research Inst.)

    1993-03-01

    Regional geochemical, studies on insoluble residues from Paleozoic carbonate rocks have become an integral part of the search for new Upper Mississippi Valley-type mineral deposits in the northern Midcontinent. The authors have extended these studies to southeastern Minnesota, an area well to the north of known lead-zinc deposits of commercial size and grade. In this region, a thin sequence of Upper Cambrian to Middle Ordovician strata unconformably overlies a complex Precambrian basement. More than 500 samples of limestone and dolomite from 40 drill holes and outcrops were analyzed for 29 related trace elements. Preliminary interpretations are based on the analysis of 380 samples of the Ordovician Galena Group from 37 localities. Results indicate that anomalous concentrations of Pb, Cu, zn, As, Cd, and Ni are confined to the southern half of the Galena subgroup area and extend less than 30 miles north of the Iowa border. The anomalous areas, as well as saddles between the, have a distinct northwest trend, coincident with structural features previously recognized in the Precambrian basement. The spatial relationships of the anomalies and the lack of direct correlation imply deposition from fluids moving north out of the main lead-zinc district along structural pathways. The lack of significant anomalies in the northern part of the subcrop area implies northwest weakening of the forces driving the metal-bearing fluids, as well as a decrease over distance in the absolute metal content of the migrating fluids.

  14. Pyrolytic characteristics of biomass acid hydrolysis residue rich in lignin.

    PubMed

    Huang, Yanqin; Wei, Zhiguo; Yin, Xiuli; Wu, Chuangzhi

    2012-01-01

    Pyrolytic characteristics of acid hydrolysis residue (AHR) of corncob and pinewood (CAHR, WAHR) were investigated using a thermo-gravimetric analyzer (TGA) and a self-designed pyrolysis apparatus. Gasification reactivity of CAHR char was then examined using TGA and X-ray diffractometer. Result of TGA showed that thermal degradation curves of AHR descended smoothly along with temperature increasing from 150 °C to 850 °C, while a "sharp mass loss stage" for original biomass feedstock (OBF) was observed. Char yield from AHR (42.64-30.35 wt.%) was found to be much greater than that from OBF (26.4-19.15 wt.%). In addition, gasification reactivity of CAHR char was lower than that of corncob char, and there was big difference in micro-crystallite structure. It was also found that CAHR char reactivity decreased with pyrolysis temperature, but increased with pyrolysis heating rate and gasification temperature at 850-950 °C. Furthermore, CAHR char reactivity performed better under steam atmosphere than under CO2 atmosphere. PMID:22055106

  15. Degradation of Methoxylated Benzoic Acids by a Nocardia from a Lignin-Rich Environment: Significance to Lignin Degradation and Effect of Chloro Substituents

    PubMed Central

    Crawford, R. L.; McCoy, Elizabeth; Harkin, J. M.; Kirk, T. K.; Obst, J. R.

    1973-01-01

    Strain A81 of Nocardia corallina hydroxylates or demethylates p-anisic acid to p-hydroxybenzoic acid and isovanillic acid. It demethylates veratric acid to a mixture of vanillic and isovanillic acids. These are both demethylated to protocatechuic acid, which undergoes ring cleavage to afford β-carboxy-cis-cis-muconic acid. The intermediacy of protocatechuic acid in the catabolic pathway of veratric acid was confirmed by blocking ring cleavage with an additional substituent in the ring: 5-chlorovanillic acid was demethylated to 5-chloro-protocatechuic acid, which accumulated. Chloro substituents in the ring of other methoxylated benzoic acids also arrested their normal metabolism by the Nocardia: an ortho-chloro substituent thwarted both demethylation and ring-opening. ortho-Hydroxylation of p-methoxybenzoic acid to isovanillic acid was unaffected by a chlorine ortho to the methoxyl group. Washed whole cells of veratric acid-grown N. corallina A81 produced no detected structural changes in an isolated lignin. The implications of this observation are discussed. PMID:4743871

  16. Glucansucrases from lactic acid bacteria which produce water-insoluble polysaccharides from sucrose

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dextrans and related glucans produced from sucrose by lactic acid bacteria have been studied for many years and are used in numerous commercial applications and products. Most of these glucans are water-soluble, except for a few notable exceptions from cariogenic Streptococcus spp. and a very small ...

  17. Sequencing around 5-Hydroxyconiferyl Alcohol-Derived Units in Caffeic Acid O-Methyltransferase-Deficient Poplar Lignins1[OA

    PubMed Central

    Lu, Fachuang; Marita, Jane M.; Lapierre, Catherine; Jouanin, Lise; Morreel, Kris; Boerjan, Wout; Ralph, John

    2010-01-01

    Caffeic acid O-methyltransferase (COMT) is a bifunctional enzyme that methylates the 5- and 3-hydroxyl positions on the aromatic ring of monolignol precursors, with a preference for 5-hydroxyconiferaldehyde, on the way to producing sinapyl alcohol. Lignins in COMT-deficient plants contain benzodioxane substructures due to the incorporation of 5-hydroxyconiferyl alcohol (5-OH-CA), as a monomer, into the lignin polymer. The derivatization followed by reductive cleavage method can be used to detect and determine benzodioxane structures because of their total survival under this degradation method. Moreover, partial sequencing information for 5-OH-CA incorporation into lignin can be derived from detection or isolation and structural analysis of the resulting benzodioxane products. Results from a modified derivatization followed by reductive cleavage analysis of COMT-deficient lignins provide evidence that 5-OH-CA cross couples (at its β-position) with syringyl and guaiacyl units (at their O-4-positions) in the growing lignin polymer and then either coniferyl or sinapyl alcohol, or another 5-hydroxyconiferyl monomer, adds to the resulting 5-hydroxyguaiacyl terminus, producing the benzodioxane. This new terminus may also become etherified by coupling with further monolignols, incorporating the 5-OH-CA integrally into the lignin structure. PMID:20427467

  18. Sequencing around 5-hydroxyconiferyl alcohol-derived units in caffeic acid O-methyltransferase-deficient poplar lignins.

    PubMed

    Lu, Fachuang; Marita, Jane M; Lapierre, Catherine; Jouanin, Lise; Morreel, Kris; Boerjan, Wout; Ralph, John

    2010-06-01

    Caffeic acid O-methyltransferase (COMT) is a bifunctional enzyme that methylates the 5- and 3-hydroxyl positions on the aromatic ring of monolignol precursors, with a preference for 5-hydroxyconiferaldehyde, on the way to producing sinapyl alcohol. Lignins in COMT-deficient plants contain benzodioxane substructures due to the incorporation of 5-hydroxyconiferyl alcohol (5-OH-CA), as a monomer, into the lignin polymer. The derivatization followed by reductive cleavage method can be used to detect and determine benzodioxane structures because of their total survival under this degradation method. Moreover, partial sequencing information for 5-OH-CA incorporation into lignin can be derived from detection or isolation and structural analysis of the resulting benzodioxane products. Results from a modified derivatization followed by reductive cleavage analysis of COMT-deficient lignins provide evidence that 5-OH-CA cross couples (at its beta-position) with syringyl and guaiacyl units (at their O-4-positions) in the growing lignin polymer and then either coniferyl or sinapyl alcohol, or another 5-hydroxyconiferyl monomer, adds to the resulting 5-hydroxyguaiacyl terminus, producing the benzodioxane. This new terminus may also become etherified by coupling with further monolignols, incorporating the 5-OH-CA integrally into the lignin structure. PMID:20427467

  19. Long-Chain Fatty Acids Elicit a Bitterness-Masking Effect on Quinine and Other Nitrogenous Bitter Substances by Formation of Insoluble Binary Complexes.

    PubMed

    Ogi, Kayako; Yamashita, Haruyuki; Terada, Tohru; Homma, Ryousuke; Shimizu-Ibuka, Akiko; Yoshimura, Etsuro; Ishimaru, Yoshiro; Abe, Keiko; Asakura, Tomiko

    2015-09-30

    We have previously found that fatty acids can mask the bitterness of certain nitrogenous substances through direct molecular interactions. Using isothermal titration calorimetry, we investigated the interactions between sodium oleate and 22 bitter substances. The hydrochloride salts of quinine, promethazine, and propranolol interacted strongly with fatty acids containing 12 or more carbon atoms. The (1)H NMR spectra of these substances, obtained in the presence of the sodium salts of the fatty acids in dimethyl sulfoxide, revealed the formation of hydrogen bonds between the nitrogen atoms of the bitter substances and the carboxyl groups of the fatty acids. When sodium laurate and the hydrochloride salt of quinine were mixed in water, an equimolar complex formed as insoluble heterogeneous needlelike crystals. These results suggested that fatty acids interact directly with bitter substances through hydrogen bonds and hydrophobic interactions to form insoluble binary complexes that mask bitterness. PMID:26365517

  20. In situ micro-spectroscopic investigation of lignin in poplar cell walls pretreated by maleic acid

    DOE PAGESBeta

    Zeng, Yining; Zhao, Shuai; Wei, Hui; Tucker, Melvin P.; Himmel, Michael E.; Mosier, Nathan S.; Meilan, Richard; Ding, Shi -You

    2015-08-27

    In higher plant cells, lignin provides necessary physical support for plant growth and resistance to attack by microorganisms. For the same reason, lignin is considered to be a major impediment to the process of deconstructing biomass to simple sugars by hydrolytic enzymes. Furthermore, the in situ variation of lignin in plant cell walls is important for better understanding of the roles lignin play in biomass recalcitrance.

  1. Kinetic Study of the Acid Degradation of Lignin Model Compound Intermediates

    SciTech Connect

    Sturgeon, M.; Kim, S.; Chmely, S. C.; Foust, T. D.; Beckham, G. T.

    2012-01-01

    Lignin is a major constituent of biomass, which remains underutilized in selective biomass conversion strategies to renewable fuels and chemicals. Here we are interested in understanding the mechanisms related to the acid deconstruction of lignin with a combined theoretical and experimental approach. Two model dimers with a b-O-4 aryl ether linkage (2-phenoxy-1-phenethanol and 2-phenoxy-1-phenyl-1,3 propanediol) were synthesized and deconstructed in H2SO4. The major products of the acidolysis of the b-O-4 compounds consisted of phenol and two aldehydes, phenylacetaldehyde and benzaldehyde. Quantum mechanical calculations were employed to elucidate possible deconstruction mechanisms with transition state theory. To confirm the proposed mechanisms a kentic study of several possible intermediates was done under similar acidolysis conditions. Epoxystyrene and 1-phenyl-1,2-ethandiol were used as intermediates. 2-phenoxyvinylbenzene was synthesized and subsequently deconstructed in H2SO4. The kinetics and product distribution of these intermediates were then used in confirming our proposed mechanisms.

  2. Insoluble Fe-humic acid complex as a solid-phase electron mediator for microbial reductive dechlorination.

    PubMed

    Zhang, Chunfang; Zhang, Dongdong; Li, Zhiling; Akatsuka, Tetsuji; Yang, Suyin; Suzuki, Daisuke; Katayama, Arata

    2014-06-01

    We report that the insoluble Fe-HA complex, which was synthesized with both commercial Aldrich humic acid (HA) and natural HA, functions as a solid-phase electron mediator (EM) for the anaerobic microbial dechlorination of pentachlorophenol. Spectroscopic characterizations and sequential Fe extraction demonstrated that the Fe-HA complex was predominated with Na4P2O7-labile Fe (represented as the organically bound Fe fraction) and poorly ordered Fe fraction (the fraction left in the residue after the sequential extraction), which were associated with different possible binding processes with carboxylate and phenolic groups. The change in the electron-mediating activity caused by Fe extraction indicated that the electron-mediating function of the Fe-HA complex is attributable to the Na4P2O7-labile Fe fraction. The Fe-HA complex also accelerated the microbial reduction of Fe(III) oxide, which suggested the presence of multiple electron-mediating functions in the complex. The electron shuttle assay showed that the Fe-HA complex had an electron-accepting capacity of 0.82 mequiv g(-1) dry Fe-HA complex. The presence of redox-active moieties in the Fe-HA complex was verified by cyclic voltammetry analysis of the sample after electrical reduction, with a redox potential estimated at 0.02 V (vs a standard hydrogen electrode). PMID:24758743

  3. Evaluation of the effect of hot-compressed water treatment on enzymatic hydrolysis of lignocellulosic nanofibrils with different lignin content using a quartz crystal microbalance.

    PubMed

    Kumagai, Akio; Lee, Seung-Hwan; Endo, Takashi

    2016-07-01

    Hot-compressed water (HCW) treatment is known to not only improve enzymatic hydrolysis efficiency of lignocellulosic biomass but to also generate insoluble lignin droplets, which retard enzymatic hydrolysis. In this study, the inhibitory effect of the lignin droplets was evaluated by monitoring the initial enzyme adsorption and degradation of lignocellulosic nanofibrils (LCNFs) using a quartz crystal microbalance (QCM). Lignin content was adjusted by the sodium chlorite-acetic acid method and divided into samples with high (24.9 wt%) and low (5.6 wt%) lignin content, which were then subjected to HCW treatment at various temperatures. The changes in lignin content were small with increasing HCW temperature, whereas hemicellulose content decreased, regardless of the initial lignin content. The formation of lignin droplets and pseudo-lignin-like products was confirmed in both LCNFs by atomic force microscopy (AFM) and was predominant in LCNFs with high lignin content treated at 200°C. QCM data showed that the enzyme adsorption amount in both LCNFs after HCW treatment was increased and was greater in LCNFs with low lignin content. Initial enzymatic degradation was substantially slowed in LCNFs with high lignin content, particularly after HCW treatment at temperatures higher than 180°C. These QCM results suggest that the steric hindrance of the deposited lignin is the primary mechanism by which the initial enzymatic hydrolysis is delayed. Biotechnol. Bioeng. 2016;113: 1441-1447. © 2015 Wiley Periodicals, Inc. PMID:26694223

  4. Thioacidolysis Marker Compound for Ferulic Acid Incorporation into Angiosperm Lignins (and an Indicator for Cinnamoyl-coenzyme-A Reductase Deficiency

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A molecular marker compound, derived from lignin by the thioacidolysis degradative method, for structures produced when ferulic acid is incorporated into lignification in angiosperms (poplar, Arabidopsis, tobacco) has been structurally identified as 1,2,2-trithioethyl ethylguaiacol [1-(4-hydroxy-3-m...

  5. Variation of S/G Ratio and Lignin Content in a Populus Family Influences the Release of Xylose by Dilute Acid Hydrolysis.

    SciTech Connect

    Davison, Brian H; Drescher, Sadie R; Tuskan, Gerald A; Davis, Dr. Mark F.; Nghiem, Nhuan Phu

    2006-01-01

    Wood samples from second generation Populus cross were shown to have different lignin contents and S/G ratios (S: syringyl-like lignin structures; G: guaiacyl-like lignin structures). The lignin contents varied from 22.7% to 25.8% and the S/G ratio from 1.8 to 2.3. Selected samples spanning these ranges were hydrolyzed with dilute (1%) sulfuric acid to release fermentable sugars. The conditions were chosen for partial hydrolysis of the hemicellulosic fraction to maximize the expression of variation among samples. The results indicated that both lignin contents and S/G ratio significantly affected the yield of xylose. For example, the xylose yield of the 25.8% lignin and 2.3 S/G (hihg lignin, high S/G) sample produced 30% of the theoretical yield, whereas the xylose yield of the 22.7% lignin and 1.8 S/G (low lignin, low S/G) was 55% of the theoretical value. These results indicate that lignin content and composition among genetic variants within a single species can influence the hydrolyzability of the biomass.

  6. Potent inhibitory effects of D-tagatose on the acid production and water-insoluble glucan synthesis of Streptococcus mutans GS5 in the presence of sucrose.

    PubMed

    Sawada, Daijo; Ogawa, Takaaki; Miyake, Minoru; Hasui, Yoshinori; Yamaguchi, Fuminori; Izumori, Ken; Tokuda, Masaaki

    2015-01-01

    We examined and compared the inhibitory effects of D-tagatose on the growth, acid production, and water-insoluble glucan synthesis of GS5, a bacterial strain of Streptococcus mutans, with those of xylitol, D-psicose, L-psicose and L-tagatose. GS5 was cultured for 12h in a medium containing 10% (w/v) of xylitol, D-psicose, L-psicose, D-tagatose or L-tagatose, and the inhibitory effect of GS5 growth was assessed. Each sugar showed different inhibitory effects on GS5. Both D-tagatose and xylitol significantly inhibited the acid production and water-insoluble glucan synthesis of GS5 in the presence of 1% (w/v) sucrose. However, the inhibitory effect of acid production by D-tagatose was significantly stronger than that of xylitol in presence of sucrose. PMID:25899632

  7. Direct production of biodiesel from high-acid value Jatropha oil with solid acid catalyst derived from lignin

    PubMed Central

    2011-01-01

    Background Solid acid catalyst was prepared from Kraft lignin by chemical activation with phosphoric acid, pyrolysis and sulfuric acid. This catalyst had high acid density as characterized by scanning electron microscope (SEM), energy-dispersive x-ray spectrometry (EDX) and Brunauer, Emmett, and Teller (BET) method analyses. It was further used to catalyze the esterification of oleic acid and one-step conversion of non-pretreated Jatropha oil to biodiesel. The effects of catalyst loading, reaction temperature and oil-to-methanol molar ratio, on the catalytic activity of the esterification were investigated. Results The highest catalytic activity was achieved with a 96.1% esterification rate, and the catalyst can be reused three times with little deactivation under optimized conditions. Biodiesel production from Jatropha oil was studied under such conditions. It was found that 96.3% biodiesel yield from non-pretreated Jatropha oil with high-acid value (12.7 mg KOH/g) could be achieved. Conclusions The catalyst can be easily separated for reuse. This single-step process could be a potential route for biodiesel production from high-acid value oil by simplifying the procedure and reducing costs. PMID:22145867

  8. Catalytic Fast Pyrolysis of Lignin over High-Surface-Area Mesoporous Aluminosilicates: Effect of Porosity and Acidity.

    PubMed

    Custodis, Victoria B F; Karakoulia, Stamatia A; Triantafyllidis, Kostas S; van Bokhoven, Jeroen A

    2016-05-23

    Catalytic fast pyrolysis (CFP) of lignin with amorphous mesoporous aluminosilicates catalysts yields a high fraction of aromatics and a relatively low amount of char/coke. The relationship between the acidity and porosity of Al-MCM-41, Al-SBA-15, and Al-MSU-J with product selectivity during lignin CFP is determined. The acid sites (mild Brønsted and stronger Lewis) are able to catalyze pyrolysis intermediates towards fewer oxygenated phenols and aromatic hydrocarbons. A generalized correlation of the product selectivity and yield with the aluminum content and acidity of the mesoporous aluminosilicates is hard to establish. Zeolitic strong acid sites are not required to achieve high conversion and selectivity to aromatic hydrocarbon because nanosized MCM-41 produces a high liquid yield and selectivity. The two most essential parameters are diffusion, which is influenced by pore and grain size, and the active site, which may be mildly acidic, but is dominated by Lewis acid sites. Nanosized grains and mild acidity are essential ingredients for a good lignin CFP catalyst. PMID:27079742

  9. The Acetyl Bromide Method Is Faster, Simpler and Presents Best Recovery of Lignin in Different Herbaceous Tissues than Klason and Thioglycolic Acid Methods

    PubMed Central

    Moreira-Vilar, Flavia Carolina; Siqueira-Soares, Rita de Cássia; Finger-Teixeira, Aline; de Oliveira, Dyoni Matias; Ferro, Ana Paula; da Rocha, George Jackson; Ferrarese, Maria de Lourdes L.; dos Santos, Wanderley Dantas; Ferrarese-Filho, Osvaldo

    2014-01-01

    We compared the amount of lignin as determined by the three most traditional methods for lignin measurement in three tissues (sugarcane bagasse, soybean roots and soybean seed coat) contrasting for lignin amount and composition. Although all methods presented high reproducibility, major inconsistencies among them were found. The amount of lignin determined by thioglycolic acid method was severely lower than that provided by the other methods (up to 95%) in all tissues analyzed. Klason method was quite similar to acetyl bromide in tissues containing higher amounts of lignin, but presented lower recovery of lignin in the less lignified tissue. To investigate the causes of the inconsistencies observed, we determined the monomer composition of all plant materials, but found no correlation. We found that the low recovery of lignin presented by the thioglycolic acid method were due losses of lignin in the residues disposed throughout the procedures. The production of furfurals by acetyl bromide method does not explain the differences observed. The acetyl bromide method is the simplest and fastest among the methods evaluated presenting similar or best recovery of lignin in all the tissues assessed. PMID:25330077

  10. Incorporation of glycine-2-C-14 in acid-insoluble proteins of rat bones and teeth during hypokinesia and administration of thyrocalcitonine

    NASA Technical Reports Server (NTRS)

    Volozhin, A. I.; Stekolnikov, L. I.; Uglova, N. N.; Potkin, V. Y.

    1979-01-01

    A forced limitation of the motor activity in rats (from 5 to 60 days) results in reduced incorporation of glycine 2-C14 in the total acid insoluble proteins of limb bones and its increase in the teeth and mandibular-maxillary bones. Daily administration of five micrograms of thyrocalcitonine together with polyvinylpyrrolidone normalizes the protein metabolism in the bone tissues during the 40 days of experimentation.

  11. Extracting lignins from mill wastes

    NASA Technical Reports Server (NTRS)

    Humphrey, M. F.

    1977-01-01

    Addition of quaternary ammonium compound and activated charcoal to pulp and mill wastes precipitates lignins in sludge mixture. Methanol dissolves lignins for separation from resulting slurry. Mineral acid reprecipitates lignins in filtered solution. Quaternary ammonium compound, activated charcoal, as well as water may be recovered and recycled from this process.

  12. Isolation and structural characterization of sugarcane bagasse lignin after dilute phosphoric acid plus steam explosion pretreatment and its effect on cellulose hydrolysis.

    PubMed

    Zeng, Jijiao; Tong, Zhaohui; Wang, Letian; Zhu, J Y; Ingram, Lonnie

    2014-02-01

    The structure of lignin after dilute phosphoric acid plus steam explosion pretreatment process of sugarcane bagasse in a pilot scale and the effect of the lignin extracted by ethanol on subsequent cellulose hydrolysis were investigated. The lignin structural changes caused by pretreatment were identified using advanced nondestructive techniques such as gel permeation chromatography (GPC), quantitative (13)C, and 2-D nuclear magnetic resonance (NMR). The structural analysis revealed that ethanol extractable lignin preserved basic lignin structure, but had relatively lower amount of β-O-4 linkages, syringyl/guaiacyl units ratio (S/G), p-coumarate/ferulate ratio, and other ending structures. The results also indicated that approximately 8% of mass weight was extracted by pure ethanol. The bagasse after ethanol extraction had an approximate 22% higher glucose yield after enzyme hydrolysis compared to pretreated bagasse without extraction. PMID:24412855

  13. Structural and functional characterization of solute binding proteins for aromatic compounds derived from lignin: p-coumaric acid and related aromatic acids

    PubMed Central

    Tan, Kemin; Chang, Changsoo; Cuff, Marianne; Osipiuk, Jerzy; Landorf, Elizabeth; Mack, Jamey C.; Zerbs, Sarah; Joachimiak, Andrzej; Collart, Frank R.

    2013-01-01

    Lignin comprises 15.25% of plant biomass and represents a major environmental carbon source for utilization by soil microorganisms. Access to this energy resource requires the action of fungal and bacterial enzymes to break down the lignin polymer into a complex assortment of aromatic compounds that can be transported into the cells. To improve our understanding of the utilization of lignin by microorganisms, we characterized the molecular properties of solute binding proteins of ATP.binding cassette transporter proteins that interact with these compounds. A combination of functional screens and structural studies characterized the binding specificity of the solute binding proteins for aromatic compounds derived from lignin such as p-coumarate, 3-phenylpropionic acid and compounds with more complex ring substitutions. A ligand screen based on thermal stabilization identified several binding protein clusters that exhibit preferences based on the size or number of aromatic ring substituents. Multiple X-ray crystal structures of protein-ligand complexes for these clusters identified the molecular basis of the binding specificity for the lignin-derived aromatic compounds. The screens and structural data provide new functional assignments for these solute.binding proteins which can be used to infer their transport specificity. This knowledge of the functional roles and molecular binding specificity of these proteins will support the identification of the specific enzymes and regulatory proteins of peripheral pathways that funnel these compounds to central metabolic pathways and will improve the predictive power of sequence-based functional annotation methods for this family of proteins. PMID:23606130

  14. Structural and functional characterization of solute binding proteins for aromatic compounds derived from lignin: p-coumaric acid and related aromatic acids.

    PubMed

    Tan, Kemin; Chang, Changsoo; Cuff, Marianne; Osipiuk, Jerzy; Landorf, Elizabeth; Mack, Jamey C; Zerbs, Sarah; Joachimiak, Andrzej; Collart, Frank R

    2013-10-01

    Lignin comprises 15-25% of plant biomass and represents a major environmental carbon source for utilization by soil microorganisms. Access to this energy resource requires the action of fungal and bacterial enzymes to break down the lignin polymer into a complex assortment of aromatic compounds that can be transported into the cells. To improve our understanding of the utilization of lignin by microorganisms, we characterized the molecular properties of solute binding proteins of ATP-binding cassette transporter proteins that interact with these compounds. A combination of functional screens and structural studies characterized the binding specificity of the solute binding proteins for aromatic compounds derived from lignin such as p-coumarate, 3-phenylpropionic acid and compounds with more complex ring substitutions. A ligand screen based on thermal stabilization identified several binding protein clusters that exhibit preferences based on the size or number of aromatic ring substituents. Multiple X-ray crystal structures of protein-ligand complexes for these clusters identified the molecular basis of the binding specificity for the lignin-derived aromatic compounds. The screens and structural data provide new functional assignments for these solute-binding proteins which can be used to infer their transport specificity. This knowledge of the functional roles and molecular binding specificity of these proteins will support the identification of the specific enzymes and regulatory proteins of peripheral pathways that funnel these compounds to central metabolic pathways and will improve the predictive power of sequence-based functional annotation methods for this family of proteins. PMID:23606130

  15. Catalyst of a metal heteropoly acid salt that is insoluble in a polar solvent on a non-metallic porous support and method of making

    DOEpatents

    Wang, Yong [Richland, WA; Peden, Charles H. F. [West Richland, WA; Choi, Saemin [Richland, WA

    2002-10-29

    The present invention includes a catalyst having (a) a non-metallic support having a plurality of pores; (b) a metal heteropoly acid salt that is insoluble in a polar solvent on the non-metallic support; wherein at least a portion of the metal heteropoly acid salt is dispersed within said plurality of pores. The present invention also includes a method of depositing a metal heteropoly acid salt that is insoluble in a polar solvent onto a non-metallic support having a plurality of pores. The method has the steps of: (a) obtaining a first solution containing a first precursor of a metal salt cation; (b) obtaining a second solution containing a second precursor of a heteropoly acid anion in a solvent having a limited dissolution potential for said first precursor; (c) impregnating the non-metallic support with the first precursor forming a first precursor deposit within the plurality of pores, forming a first precursor impregnated support; (d) heating said first precursor impregnated support forming a bonded first precursor impregnated support; (e) impregnating the second precursor that reacts with the precursor deposit and forms the metal heteropoly acid salt.

  16. Catalyst Of A Metal Heteropoly Acid Salt That Is Insoluble In A Polar Solvent On A Non-Metallic Porous Support And Method Of Making

    DOEpatents

    Wang. Yong; Peden. Charles H. F.; Choi. Saemin

    2004-11-09

    The present invention includes a catalyst having (a) a non-metallic support having a plurality of pores; (b) a metal heteropoly acid salt that is insoluble in a polar solvent on the non-metallic support; wherein at least a portion of the metal heteropoly acid salt is dispersed within said plurality of pores. The present invention also includes a method of depositing a metal heteropoly acid salt that is insoluble in a polar solvent onto a non-metallic support having a plurality of pores. The method has the steps of: (a) obtaining a first solution containing a first precursor of a metal salt cation; (b) obtaining a second solution containing a second precursor of a heteropoly acid anion in a solvent having a limited dissolution potential for said first precursor; (c) impregnating the non-metallic support with the first precursor forming a first precursor deposit within the plurality of pores, forming a first precursor impregnated support; (d) heating said first precursor impregnated support forming a bonded first precursor impregnated support; (e) impregnating the second precursor that reacts with the precursor deposit and forms the metal heteropoly acid salt.

  17. Acidic pretreatment of wheat straw in decanol for the production of surfactant, lignin and glucose.

    PubMed

    Marinkovic, Sinisa; Le Bras, Jean; Nardello-Rataj, Véronique; Agach, Mickaël; Estrine, Boris

    2012-01-01

    Wheat straw is an abundant residue of agriculture which is increasingly being considered as feedstock for the production of fuels, energy and chemicals. The acidic decanol-based pre-treatment of wheat straw has been investigated in this work. Wheat straw hemicellulose has been efficiently converted during a single step operation into decyl pentoside surfactants and the remaining material has been preserved keeping all its promises as potential feedstock for fuels or value added platform chemicals such as hydroxymethylfurfural (HMF). The enzymatic digestibility of the cellulose contained in the straw residue has been evaluated and the lignin prepared from the material characterized. Wheat-based surfactants thus obtained have exhibited superior surface properties compared to fossil-based polyethoxylates decyl alcohol or alkyl oligoglucosides, some of which are largely used surfactants. In view of the growing importance of renewable resource-based molecules in the chemical industry, this approach may open a new avenue for the conversion of wheat straw into various chemicals. PMID:22312256

  18. Acidic Pretreatment of Wheat Straw in Decanol for the Production of Surfactant, Lignin and Glucose

    PubMed Central

    Marinkovic, Sinisa; Le Bras, Jean; Nardello-Rataj, Véronique; Agach, Mickaël; Estrine, Boris

    2012-01-01

    Wheat straw is an abundant residue of agriculture which is increasingly being considered as feedstock for the production of fuels, energy and chemicals. The acidic decanol-based pre-treatment of wheat straw has been investigated in this work. Wheat straw hemicellulose has been efficiently converted during a single step operation into decyl pentoside surfactants and the remaining material has been preserved keeping all its promises as potential feedstock for fuels or value added platform chemicals such as hydroxymethylfurfural (HMF). The enzymatic digestibility of the cellulose contained in the straw residue has been evaluated and the lignin prepared from the material characterized. Wheat-based surfactants thus obtained have exhibited superior surface properties compared to fossil-based polyethoxylates decyl alcohol or alkyl oligoglucosides, some of which are largely used surfactants. In view of the growing importance of renewable resource-based molecules in the chemical industry, this approach may open a new avenue for the conversion of wheat straw into various chemicals. PMID:22312256

  19. Deposition of Lignin Droplets Produced During Dilute Acid Pretreatment of Maize Stems Retards Enzymatic Hydrolysis of Cellulose

    SciTech Connect

    Selig, M. J.; Viamajala, S.; Decker, S. R.; Tucker, M. P.; Himmel, M. E.; Vinzant, T. B.

    2007-01-01

    Electron microscopy of lignocellulosic biomass following high-temperature pretreatment revealed the presence of spherical formations on the surface of the residual biomass. The hypothesis that these droplet formations are composed of lignins and possible lignin carbohydrate complexes is being explored. Experiments were conducted to better understand the formation of these lignin droplets and the possible implications they might have on the enzymatic saccharification of pretreated biomass. It was demonstrated that these droplets are produced from corn stover during pretreatment under neutral and acidic pH at and above 130C, and that they can deposit back onto the surface of residual biomass. The deposition of droplets produced under certain pretreatment conditions (acidic pH; T > 150C) and captured onto pure cellulose was shown to have a negative effect (5-20%) on the enzymatic saccharification of this substrate. It was noted that droplet density (per unit area) was greater and droplet size more variable under conditions where the greatest impact on enzymatic cellulose conversion was observed. These results indicate that this phenomenon has the potential to adversely affect the efficiency of enzymatic conversion in a lignocellulosic biorefinery.

  20. Effects of Soluble Lignin on the Formic Acid-Catalyzed Formation of Furfural: A Case Study for the Upgrading of Hemicellulose.

    PubMed

    Dussan, Karla; Girisuta, Buana; Lopes, Marystela; Leahy, James J; Hayes, Michael H B

    2016-03-01

    A comprehensive study is presented on the conversion of hemicellulose sugars in liquors obtained from the fractionation of Miscanthus, spruce bark, sawdust, and hemp by using formic acid. Experimental tests with varying temperature (130-170 °C), formic acid concentration (10-80 wt%), carbohydrate concentrations, and lignin separation were carried out, and experimental data were compared with predictions obtained by reaction kinetics developed in a previous study. The conversions of xylose and arabinose into furfural were inherently affected by the presence of polymeric soluble lignin, decreasing the maximum furfural yields observed experimentally by up to 24%. These results were also confirmed in synthetic mixtures of pentoses with Miscanthus and commercial alkali lignin. This observation was attributed to side reactions involving intermediate stable sugar species reacting with solubilized lignin during the conversion of xylose into furfural. PMID:26805656

  1. Evolution of insoluble eutectic Si particles in anodic oxidation films during adipic-sulfuric acid anodizing processes of ZL114A aluminum alloys

    NASA Astrophysics Data System (ADS)

    Hua, Lei; Liu, Jian-hua; Li, Song-mei; Yu, Mei; Wang, Lei; Cui, Yong-xin

    2015-03-01

    The effects of insoluble eutectic Si particles on the growth of anodic oxide films on ZL114A aluminum alloy substrates were investigated by optical microscopy (OM) and scanning electron microscopy (SEM). The anodic oxidation was performed at 25°C and a constant voltage of 15 V in a solution containing 50 g/L sulfuric acid and 10 g/L adipic acid. The thickness of the formed anodic oxidation film was approximately 7.13 μm. The interpore distance and the diameters of the major pores in the porous layer of the film were within the approximate ranges of 10-20 nm and 5-10 nm, respectively. Insoluble eutectic Si particles strongly influenced the morphology of the anodic oxidation films. The anodic oxidation films exhibited minimal defects and a uniform thickness on the ZL114A substrates; in contrast, when the front of the oxide oxidation films encountered eutectic Si particles, defects such as pits and non-uniform thickness were observed, and pits were observed in the films.

  2. Improving the enzymatic hydrolysis of dilute acid pretreated wheat straw by metal ion blocking of non-productive cellulase adsorption on lignin.

    PubMed

    Akimkulova, Ardak; Zhou, Yan; Zhao, Xuebing; Liu, Dehua

    2016-05-01

    Eleven salts were selected to screen the possible metal ions for blocking the non-productive adsorption of cellulase onto the lignin of dilute acid pretreated wheat straw. Mg(2+) was screened finally as the promising candidate. The optimal concentration of MgCl2 was 1mM, but the beneficial action was also dependent on pH, hydrolysis time and cellulase loading. Significant improvement of glucan conversion (19.3%) was observed at low cellulase loading (5FPU/g solid). Addition of isolated lignins, tannic acid and lignin model compounds to pure cellulose hydrolysis demonstrated that phenolic hydroxyl group (Ph-OH) was the main active site blocked by Mg(2+). The interaction between Mg(2+) and Ph-OH of lignin monomeric moieties followed an order of p-hydroxyphenyl (H)>guaiacyl (G)>syringyl (S). Mg(2+) blocking made the lignin surface less negatively charged, which might weaken the hydrogen bonding and electrostatically attractive interaction between lignin and cellulase enzymes. PMID:26930032

  3. Through Lignin Biodegradation to Lignin-based Plastics

    NASA Astrophysics Data System (ADS)

    Wang, Yun-Yan

    The consequences of strong noncovalent intermolecular interactions between oligomeric and/or polymeric lignin components are encountered during enzyme-catalyzed lignin degradation and in the properties of lignin-based plastics. A new chapter in the 30-year quest for functional lignin-depolymerizing enzymes has been opened. The lignin-degrading capacity of the flavin-dependent monooxygenase, salicylate hydroxylase acting as a putative lignin depolymerase, has been characterized using a water-soluble native softwood lignin substrate under mildly acidic aqueous conditions. When macromolecular lignins undergo lignin-depolymerase catalyzed degradation, the cleaved components tend to associate with one another, or with nearby associated lignin complexes, through processes mediated by the enzyme acting in a non-catalytic capacity. As a result, the radius of gyration (Rg) falls rapidly to approximately constant values, while the weight-average molecular weight (Mw) of the substrate rises more slowly to an extent dependent on enzyme concentration. Xylanase, when employed in an auxiliary capacity, is able to facilitate dissociation of the foregoing complexes through its interactions with the lignin depolymerase. The flavin-dependent lignin depolymerase must be reduced before reaction with oxygen can occur to form the hydroperoxy intermediate that hydroxylates the lignin substrate prior to cleavage. In the absence of the cofactor, NADH, the necessary reducing power can be provided (albeit more slowly) by the lignin substrate itself. Under such conditions, a simultaneous decrease in R g and Mw is initially observed during the enzymatic process through which the lignin is cleaved. The partially degraded product-lignins arising from lignin depolymerase activity can be readily converted into polymeric materials with mechanical properties that supersede those of polystyrene. Methylation and blending of ball-milled softwood lignins with miscible low-Tg polymers, or simple low

  4. Molecular-Level Transformations of Lignin During Photo-Oxidation and Biodegradation

    NASA Astrophysics Data System (ADS)

    Feng, X.; Hills, K.; Simpson, A. J.; Simpson, M. J.

    2009-05-01

    As the second most abundant component of terrestrial plant residues, lignin plays a key role in regulating plant litter decomposition, humic substance formation, and dissolved organic matter (OM) production from terrestrial sources. Biodegradation is the primary decomposition process of lignin on land. However, photo- oxidation of lignin-derived compounds has been reported in aquatic systems and is considered to play a vital role in arid and semiarid regions. With increasing ultraviolet (UV) radiation due to ozone depletion, it is important to understand the biogeochemical fate of lignin exposed to photo-oxidation in terrestrial environments. This study examines and compares the transformation of lignin in a three-month laboratory simulation of biodegradation and photo-oxidation using molecular-level techniques. Lignin-derived monomers extracted by copper oxidation were analyzed by gas chromatography/mass spectrometry (GC/MS) from the water-soluble and insoluble OM of 13C-labeled corn leaves. Biodegradation increased the solubility of lignin monomers in comparison to the control samples, and the acid-to-aldehyde (Ad/Al) ratios increased in both the water-soluble and insoluble OM, indicating a higher degree of side-chain lignin oxidation. Photo-oxidation did not produce a significant change on the solubility or Ad/Al ratios of lignin from corn leaves. However, the ratios of trans-to-cis isomers of both cinnamyl units (p-coumaric acid and ferulic acid) increased with photo-oxidation and decreased with biodegradation in the insoluble OM. We also investigated the role of photo-oxidation in lignin transformation in soils cropped with 13C-labeled corn. Interestingly, the organic carbon content increased significantly with time in the water-soluble OM from soil/corn residues under UV radiation. An increase in the concentration of lignin monomers and dimers and the Ad/Al ratios was also observed with photo-oxidation. Iso-branched fatty acids of microbial origin remained in

  5. Molecular-level transformations of lignin during photo-oxidation and biodegradation

    NASA Astrophysics Data System (ADS)

    Feng, X.; Hills, K.; Simpson, A. J.; Simpson, M. J.

    2009-04-01

    As the second most abundant component of terrestrial plant residues, lignin plays a key role in regulating plant litter decomposition, humic substance formation, and dissolved organic matter (OM) production from terrestrial sources. Biodegradation is the primary decomposition process of lignin on land. However, photo-oxidation of lignin-derived compounds has been reported in aquatic systems and is considered to play a vital role in arid and semiarid regions. With increasing ultraviolet (UV) radiation due to ozone depletion, it is important to understand the biogeochemical fate of lignin exposed to photo-oxidation in terrestrial environments. This study examines and compares the transformation of lignin in a three-month laboratory simulation of biodegradation and photo-oxidation using molecular-level techniques. Lignin-derived monomers extracted by copper oxidation were analyzed by gas chromatography/mass spectrometry (GC/MS) from the water-soluble and insoluble OM of 13C-labeled corn leaves. Biodegradation increased the solubility of lignin monomers in comparison to the control samples, and the acid-to-aldehyde (Ad/Al) ratios increased in both the water-soluble and insoluble OM, indicating a higher degree of side-chain lignin oxidation. Photo-oxidation did not produce a significant change on the solubility or Ad/Al ratios of lignin from corn leaves. However, the ratios of trans-to-cis isomers of both cinnamyl units (p-coumaric acid and ferulic acid) increased with photo-oxidation and decreased with biodegradation in the insoluble OM. We also investigated the role of photo-oxidation in lignin transformation in soils cropped with 13C-labeled corn. Interestingly, the organic carbon content increased significantly with time in the water-soluble OM from soil/corn residues under UV radiation. An increase in the concentration of lignin monomers and dimers and the Ad/Al ratios was also observed with photo-oxidation. Iso-branched fatty acids of microbial origin remained in

  6. Cell wall, lignin and fatty acid-related transcriptome in soybean: Achieving gene expression patterns for bioenergy legume

    PubMed Central

    Pestana-Calsa, Maria Clara; Pacheco, Cinthya Mirella; de Castro, Renata Cruz; de Almeida, Renata Rodrigues; de Lira, Nayara Patrícia Vieira; Junior, Tercilio Calsa

    2012-01-01

    Increasing efforts to preserve environmental resources have included the development of more efficient technologies to produce energy from renewable sources such as plant biomass, notably through biofuels and cellulosic residues. The relevance of the soybean industry is due mostly to oil and protein production which, although interdependent, results from coordinated gene expression in primary metabolism. Concerning biomass and biodiesel, a comprehensive analysis of gene regulation associated with cell wall components (as polysaccharides and lignin) and fatty acid metabolism may be very useful for finding new strategies in soybean breeding for the expanding bioenergy industry. Searching the Genosoja transcriptional database for enzymes and proteins directly involved in cell wall, lignin and fatty acid metabolism provides gene expression datasets with frequency distribution and specific regulation that is shared among several cultivars and organs, and also in response to different biotic/abiotic stress treatments. These results may be useful as a starting point to depict the Genosoja database regarding gene expression directly associated with potential applications of soybean biomass and/or residues for bioenergy-producing technologies. PMID:22802717

  7. Production of furfural from xylose, water-insoluble hemicelluloses and water-soluble fraction of corncob via a tin-loaded montmorillonite solid acid catalyst.

    PubMed

    Li, Huiling; Ren, Junli; Zhong, Linjie; Sun, Runcang; Liang, Lei

    2015-01-01

    The conversion of xylose, water-insoluble hemicelluloses (WIH) and water-soluble fraction (WSF) of corncob to furfural was performed using montmorillonite with tin ions (Sn-MMT) containing double acid sites as a solid acid catalyst. The co-existence of Lewis acids and Brønsted acids in Sn-MMT was shown to improve the furfural yield and selectivity. 76.79% furfural yield and 82.45% furfural selectivity were obtained from xylose using Sn-MMT as a catalyst in a biphasic system with 2-s-butylphenol (SBP) as the organic extracting layer and dimethyl sulfoxide (DMSO) as the co-solvent in contact with an aqueous phase saturated with NaCl (SBP/NaCl-DMSO) at 180°C for 30min. Furthermore, Sn-MMT also demonstrated the excellent catalytic performance in the conversion of pentose-rich materials of corncob and 39.56% and 54.15% furfural yields can be directly obtained from WIH and WSF in the SBP/NaCl-DMSO system, respectively. PMID:25461009

  8. Properties of lignin, cellulose, and hemicelluloses isolated from olive cake and olive stones: binding of water, oil, bile acids, and glucose.

    PubMed

    Rodríguez-Gutiérrez, Guillermo; Rubio-Senent, Fátima; Lama-Muñoz, Antonio; García, Aránzazu; Fernández-Bolaños, Juan

    2014-09-10

    A process based on a steam explosion pretreatment and alkali solution post-treatment was applied to fractionate olive stones (whole and fragmented, without seeds) and olive cake into their main constitutive polymers of cellulose (C), hemicelluloses (H), and lignin (L) under optimal conditions for each fraction according to earlier works. The chemical characterization (chromatographic method and UV and IR spectroscopy) and the functional properties (water- and oil-holding capacities, bile acid binding, and glucose retardation index) of each fraction were analyzed. The in vitro studies showed a substantial bile acid binding activity in the fraction containing lignin from olive stones (L) and the alkaline extractable fraction from olive cake (Lp). Lignin bound significantly more bile acid than any other fraction and an amount similar to that bound by cholestyramine (a cholesterol-lowering, bile acid-binding drug), especially when cholic acid (CA) was tested. These results highlight the health-promoting potential of lignin from olive stones and olive cake extracted from olive byproducts. PMID:25140731

  9. Enhancing muconic acid production from glucose and lignin-derived aromatic compounds via increased protocatechuate decarboxylase activity

    DOE PAGESBeta

    Johnson, Christopher W.; Salvachua, Davinia; Khanna, Payal; Smith, Holly; Peterson, Darren J.; Beckham, Gregg T.

    2016-04-22

    The conversion of biomass-derived sugars and aromatic molecules to cis,cis-muconic acid (referred to hereafter as muconic acid or muconate) has been of recent interest owing to its facile conversion to adipic acid, an important commodity chemical. Metabolic routes to produce muconate from both sugars and many lignin-derived aromatic compounds require the use of a decarboxylase to convert protocatechuate (PCA, 3,4-dihydroxybenzoate) to catechol (1,2-dihydroxybenzene), two central aromatic intermediates in this pathway. Several studies have identified the PCA decarboxylase as a metabolic bottleneck, causing an accumulation of PCA that subsequently reduces muconate production. A recent study showed that activity of the PCAmore » decarboxylase is enhanced by co-expression of two genetically associated proteins, one of which likely produces a flavin-derived cofactor utilized by the decarboxylase. Using entirely genome-integrated gene expression, we have engineered Pseudomonas putida KT2440-derived strains to produce muconate from either aromatic molecules or sugars and demonstrate in both cases that co-expression of these decarboxylase associated proteins reduces PCA accumulation and enhances muconate production relative to strains expressing the PCA decarboxylase alone. In bioreactor experiments, co-expression increased the specific productivity (mg/g cells/h) of muconate from the aromatic lignin monomer p-coumarate by 50% and resulted in a titer of >15 g/L. In strains engineered to produce muconate from glucose, co-expression more than tripled the titer, yield, productivity, and specific productivity, with the best strain producing 4.92+/-0.48 g/L muconate. Furthermore, this study demonstrates that overcoming the PCA decarboxylase bottleneck can increase muconate yields from biomass-derived sugars and aromatic molecules in industrially relevant strains and cultivation conditions.« less

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  11. IDENTIFICATION OF THE STRUCTURE AND ORIGIN OF A THIOACIDOLYSIS MARKER COMPOUND FOR FERULIC ACID INCORPORATION INTO ANGIOSPERM LIGNINS (AND AN INDICATOR FOR CINNAMOYL-CoA REDUCTASE DEFICIENCY)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A molecular marker compound, derived from lignin by the thioacidolysis degradative method, for structures produced when ferulic acid is incorporated into lignification in angiosperms (poplar, Arabidopsis, tobacco), has been structurally identified as 1,2,2-trithioethyl ethylguaiacol [1-(4-hydroxy-3-...

  12. Soluble vs. insoluble fiber

    MedlinePlus

    ... soluble and insoluble. Both are important for health, digestion, and preventing diseases. Soluble fiber attracts water and turns to gel during digestion. This slows digestion. Soluble fiber is found in ...

  13. Mutation in Brachypodium caffeic acid O-methyltransferase 6 alters stem and grain lignins and improves straw saccharification without deteriorating grain quality

    PubMed Central

    Ho-Yue-Kuang, Séverine; Alvarado, Camille; Antelme, Sébastien; Bouchet, Brigitte; Cézard, Laurent; Le Bris, Philippe; Legée, Frédéric; Maia-Grondard, Alessandra; Yoshinaga, Arata; Saulnier, Luc; Guillon, Fabienne; Sibout, Richard; Lapierre, Catherine; Chateigner-Boutin, Anne-Laure

    2016-01-01

    Cereal crop by-products are a promising source of renewable raw material for the production of biofuel from lignocellulose. However, their enzymatic conversion to fermentable sugars is detrimentally affected by lignins. Here the characterization of the Brachypodium Bd5139 mutant provided with a single nucleotide mutation in the caffeic acid O-methyltransferase BdCOMT6 gene is reported. This BdCOMT6-deficient mutant displayed a moderately altered lignification in mature stems. The lignin-related BdCOMT6 gene was also found to be expressed in grains, and the alterations of Bd5139 grain lignins were found to mirror nicely those evidenced in stem lignins. The Bd5139 grains displayed similar size and composition to the control. Complementation experiments carried out by introducing the mutated gene into the AtCOMT1-deficient Arabidopsis mutant demonstrated that the mutated BdCOMT6 protein was still functional. Such a moderate down-regulation of lignin-related COMT enzyme reduced the straw recalcitrance to saccharification, without compromising the vegetative or reproductive development of the plant. PMID:26433202

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

    PubMed Central

    2011-01-01

    Background Lignin and hemicelluloses are the major components limiting enzyme infiltration into cell walls. Determination of the topochemical distribution of lignin and aromatics in sugar cane might provide important data on the recalcitrance of specific cells. We used cellular ultraviolet (UV) microspectrophotometry (UMSP) to topochemically detect lignin and hydroxycinnamic acids in individual fiber, vessel and parenchyma cell walls of untreated and chlorite-treated sugar cane. Internodes, presenting typical vascular bundles and sucrose-storing parenchyma cells, were divided into rind and pith fractions. Results Vascular bundles were more abundant in the rind, whereas parenchyma cells predominated in the pith region. UV measurements of untreated fiber cell walls gave absorbance spectra typical of grass lignin, with a band at 278 nm and a pronounced shoulder at 315 nm, assigned to the presence of hydroxycinnamic acids linked to lignin and/or to arabino-methylglucurono-xylans. The cell walls of vessels had the highest level of lignification, followed by those of fibers and parenchyma. Pith parenchyma cell walls were characterized by very low absorbance values at 278 nm; however, a distinct peak at 315 nm indicated that pith parenchyma cells are not extensively lignified, but contain significant amounts of hydroxycinnamic acids. Cellular UV image profiles scanned with an absorbance intensity maximum of 278 nm identified the pattern of lignin distribution in the individual cell walls, with the highest concentration occurring in the middle lamella and cell corners. Chlorite treatment caused a rapid removal of hydroxycinnamic acids from parenchyma cell walls, whereas the thicker fiber cell walls were delignified only after a long treatment duration (4 hours). Untreated pith samples were promptly hydrolyzed by cellulases, reaching 63% of cellulose conversion after 72 hours of hydrolysis, whereas untreated rind samples achieved only 20% hydrolyzation. Conclusion The low

  15. THE PROPERTIES OF SYRINGYL, GUAIACYL AND P-HYDROXYPHENYL ARTIFICIAL LIGNINS.

    PubMed

    BLAND, D E; LOGAN, A F

    1965-05-01

    1. Artificial lignins have been produced on potato parenchyma. 2. The methoxyl-free lignin and 4-hydroxy-3-methoxy (guaiacyl) lignins could be estimated by the sulphuric acid method but the 4-hydroxy-3,5-dimethoxy (syringyl) lignins could not. 3. Permanganate oxidation of isolated p-coumaric lignin gave 4-hydroxybenzoic acid, 4-hydroxyisophthalic acid and small amounts of hydroxytrimesic acid and 4-hydroxyphthalic acid. Ferulic lignin gave vanillic acid and 5-carboxyvanillic acid and also small amounts of 4-hydroxybenzoic acid and dehydrodivanillic acid. The sinapic lignin gave traces of syringic acid and of 4-hydroxybenzoic acid. 4. The p-coumaric lignin is a highly condensed polymer. The ferulic lignin is partly uncondensed and partly condensed through the 5-position like gymnosperm lignin. The sinapic lignin shows no evidence of condensation and is probably an ether-linked polymer. PMID:14340102

  16. The properties of syringyl, guaiacyl and p-hydroxyphenyl artificial lignins

    PubMed Central

    Bland, D. E.; Logan, A. F.

    1965-01-01

    1. Artificial lignins have been produced on potato parenchyma. 2. The methoxyl-free lignin and 4-hydroxy-3-methoxy (guaiacyl) lignins could be estimated by the sulphuric acid method but the 4-hydroxy-3,5-dimethoxy (syringyl) lignins could not. 3. Permanganate oxidation of isolated p-coumaric lignin gave 4-hydroxybenzoic acid, 4-hydroxyisophthalic acid and small amounts of hydroxytrimesic acid and 4-hydroxyphthalic acid. Ferulic lignin gave vanillic acid and 5-carboxyvanillic acid and also small amounts of 4-hydroxybenzoic acid and dehydrodivanillic acid. The sinapic lignin gave traces of syringic acid and of 4-hydroxybenzoic acid. 4. The p-coumaric lignin is a highly condensed polymer. The ferulic lignin is partly uncondensed and partly condensed through the 5-position like gymnosperm lignin. The sinapic lignin shows no evidence of condensation and is probably an ether-linked polymer. PMID:14340102

  17. Estimating pasture intake and nutrient digestibility of growing pigs fed a concentrate-forage diet by n-alkane and acid-insoluble ash markers.

    PubMed

    Kanga, Jean Serge; Kanengoni, Arnold Tapera; Makgothi, Onkabetswe Gogakgamatsamang; Baloyi, Joseph Jimu

    2012-10-01

    A study was carried out to determine voluntary forage intake and nutrient digestibility in growing pigs fed a mixed forage and concentrate diet. Twenty-five 8-week-old Large White × Landrace crossbred male pigs (27 ± 3.8 kg) were blocked by weight into five groups, and each was randomly allocated to four indoor treatments (A, B, C, and D), which received 100, 90, 80, and 70 % of ad lib concentrated intake and an outdoor treatment (E) that received 80 % of ad lib concentrate. Indoor treatments were either fed the concentrate only (A) or also received freshly cut Kikuyu grass (Pennissetum clandestinum) ad libitum (B, C, and D), while pigs on treatment E were reared outdoors in Kikuyu grass paddocks. There was a significant correlation between the amount of concentrate offered and its intake (P < 0.01). The intake of Kikuyu was similar among treatments (P > 0.05). Mean acid-insoluble ash digestibility estimates of organic and dry matter were superior to C(32) estimates (P < 0.05). Kikuyu intake was higher (P < 0.05) than the estimated intake by 0.076 ± 0.03 kg. It was concluded that Kikuyu intake was not affected by the reduction of the concentrate allowance, and this should be taken into consideration when feeding pigs on pasture. PMID:22467043

  18. The relationship between surface tension and the industrial performance of water-soluble polymers prepared from acid hydrolysis lignin, a saccharification by-product from woody materials.

    PubMed

    Matsushita, Yasuyuki; Imai, Masanori; Iwatsuki, Ayuko; Fukushima, Kazuhiko

    2008-05-01

    In this study, water-soluble anionic and cationic polymers were prepared from sulfuric acid lignin (SAL), an acid hydrolysis lignin, and the relationship between the surface tension of these polymers and industrial performance was examined. The SAL was phenolized (P-SAL) to enhance its solubility and reactivity. Sulfonation and the Mannich reaction with aminocarboxylic acids produced water-soluble anionic polymers and high-dispersibility gypsum paste. The dispersing efficiency increased as the surface tension decreased, suggesting that the fluidity of the gypsum paste increased with the polymer adsorption on the gypsum particle surface. Water-soluble cationic polymers were prepared using the Mannich reaction with dimethylamine. The cationic polymers showed high sizing efficiency under neutral papermaking conditions; the sizing efficiency increased with the surface tension. This suggests that the polymer with high hydrophilicity spread in the water and readily adhered to the pulp surface and the rosin, showing good retention. PMID:17664066

  19. Does elevated N make lignin more recalcitrant?

    NASA Astrophysics Data System (ADS)

    Weintraub, M. N.; Rinkes, Z. L.; Grandy, S.; Wickings, K.; Bertrand, I.

    2014-12-01

    Increases in nitrogen (N) availability are often found to reduce decomposition rates of lignin-rich plant litter. However, the biological and chemical mechanisms that cause this inhibitory effect are still unclear. Our goal was to determine why increased N availability inhibits lignin decomposition. We tested two competing hypotheses: 1) decomposers degrade lignin to obtain protected N compounds and stop producing lignin-degrading enzymes if mineral N is available; or 2) chemical reactions between lignin and mineral N make lignin more recalcitrant, thereby limiting the ability of decomposers to break it down. To test these hypotheses, we followed changes in carbon (C) mineralization, microbial biomass and enzyme activities, litter chemistry, and lignin monomer concentrations over a 478-day laboratory incubation of three genotypes of maize stem internodes varying in litter quality. They were factorially combined with either an acidic or neutral pH sandy soil, with and without added N. Adding N reduced C mineralization, microbial biomass, and lignin-degrading enzyme activities in all treatments. Furthermore, our data on litter chemistry and lignin monomers indicate that N addition did not significantly alter the quantity or quality of lignin in any treatment. These results suggest that abiotic interactions between N and lignin compounds did not alter the ability of decomposers to breakdown lignin. Thus, we conclude that mineral N alters microbial enzyme and biomass dynamics, but not lignin chemistry during maize decomposition.

  20. Production of short-chain fatty acids from the biodegradation of wheat straw lignin by Aspergillus fumigatus.

    PubMed

    Baltierra-Trejo, Eduardo; Sánchez-Yáñez, Juan Manuel; Buenrostro-Delgado, Otoniel; Márquez-Benavides, Liliana

    2015-11-01

    The wheat straw lignin-rich fraction (WSLig-RF) can be used as a raw material for the production of metabolites for industrial use if ligninolytic mitosporic fungi are used for its biodegradation into aromatics and short-chain fatty acids (SCFAs, i.e., SCFA2-6). Although methods for the production of SCFA2-6 have been described previously, quantitative data of SCFA2-6 production have not been reported. The objectives of this study were to investigate the biodegradation of different concentrations of WSLig-RF by Aspergillus fumigatus and to identify whether SCFA2-6 production was dependent on the concentration of aromatics. A. fumigatus generated 2805mgL(-1) acetic acid when mixed with WSLig-RF at a concentration of 20gL(-1). Thus, aromatics are a substrate for the biosynthesis of SCFA2-6, and their production depends on the concentration of WSLig-RF aromatics. PMID:26263005

  1. Isolation of Bacillus sp. strains capable of decomposing alkali lignin and their application in combination with lactic acid bacteria for enhancing cellulase performance.

    PubMed

    Chang, Young-Cheol; Choi, Dubok; Takamizawa, Kazuhiro; Kikuchi, Shintaro

    2014-01-01

    Effective biological pretreatment method for enhancing cellulase performance was investigated. Two alkali lignin-degrading bacteria were isolated from forest soils in Japan and named CS-1 and CS-2. 16S rDNA sequence analysis indicated that CS-1 and CS-2 were Bacillus sp. Strains CS-1 and CS-2 displayed alkali lignin degradation capability. With initial concentrations of 0.05-2.0 g L(-1), at least 61% alkali lignin could be degraded within 48 h. High laccase activities were observed in crude enzyme extracts from the isolated strains. This result indicated that alkali lignin degradation was correlated with laccase activities. Judging from the net yields of sugars after enzymatic hydrolysis, the most effective pretreatment method for enhancing cellulase performance was a two-step processing procedure (pretreatment using Bacillus sp. CS-1 followed by lactic acid bacteria) at 68.6%. These results suggest that the two-step pretreatment procedure is effective at accelerating cellulase performance. PMID:24316485

  2. IDENTIFICATION OF THE STRUCTURE AND ORIGIN OF A THIOACIDOLYSIS MARKER COMPOUND FOR FERULIC ACID INCORPORATION INTO ANGIOSPERM LIGNINS AND A PSEUDO-MARKER COMPOUND FOR CINNAMOYL-COA REDUCTASE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A molecular marker compound, derived from lignin by the thioacidolysis degradative method, for structures produced during lignification when ferulic acid is incorporated into lignification in angiosperms (poplar, Arabidopsis, tobacco) has been structurally identified as 1,2,2-trithioethyl ethylguaia...

  3. Elicitor-Induced Spruce Stress Lignin (Structural Similarity to Early Developmental Lignins).

    PubMed Central

    Lange, B. M.; Lapierre, C.; Sandermann, H.

    1995-01-01

    Suspension cultures of Picea abies (L.) Karst released polymeric material into the culture medium when treated with an elicitor preparation from the spruce needle pathogen Rhizosphaera kalkhoffii. The presence of lignin (about 35%, w/w) was demonstrated by phloroglucinol/HCI reactivity and quantitation with thioglycolic acid. Carbohydrate (about 14%, w/w) and protein (about 32%, w/w) were also detected. Amino acid analysis revealed that hydroxyproline and proline predominated. Thioacidolysis and subsequent Raney nickel desulfurization allowed the analysis of lignin-building units and interunit bonds. Compared with spruce wood lignin, an approximately 20-fold higher relative amount of p-hydroxyphenyl units was determined. A high content of p-hydroxyphenyl units is typical for certain developmental lignins, such as conifer compression wood and middle lamella lignins, as well as all induced cell culture lignins so far analyzed. Cross-linkages of the pinoresinol type ([beta]-[beta]) in the excreted cell culture lignin were markedly increased, whereas [beta]-1 interunit linkages were decreased relative to spruce wood lignin. The amount and nature of cross-linkages were shown to be intermediate between those in wood lignin and in enzymatically prepared lignins. In summary, the elicitor-induced stress lignin was excreted as a lignin-extensin complex that closely resembled early developmental lignins. PMID:12228544

  4. Insights into lignin primary structure and deconstruction from Arabidopsis thaliana COMT (caffeic acid O-methyl transferase) mutant Atomt1.

    PubMed

    Moinuddin, Syed G A; Jourdes, Michaël; Laskar, Dhrubojyoti D; Ki, Chanyoung; Cardenas, Claudia L; Kim, Kye-Won; Zhang, Dianzhong; Davin, Laurence B; Lewis, Norman G

    2010-09-01

    The Arabidopsis mutant Atomt1 lignin differs from native lignin in wild type plants, in terms of sinapyl (S) alcohol-derived substructures in fiber cell walls being substituted by 5-hydroxyconiferyl alcohol (5OHG)-derived moieties. During programmed lignin assembly, these engender formation of benzodioxane substructures due to intramolecular cyclization of their quinone methides that are transiently formed following 8-O-4' radical-radical coupling. Thioacidolytic cleavage of the 8-O-4' inter-unit linkages in the Atomt1 mutant, relative to the wild type, indicated that cleavable sinapyl (S) and coniferyl (G) alcohol-derived monomeric moieties were stoichiometrically reduced by a circa 2 : 1 ratio. Additionally, lignin degradative analysis resulted in release of a 5OHG-5OHG-G trimer from the Atomt1 mutant, which then underwent further cleavage. Significantly, the trimeric moiety released provides new insight into lignin primary structure: during polymer assembly, the first 5OHG moiety is linked via a C8-O-X inter-unit linkage, whereas subsequent addition of monomers apparently involves sequential addition of 5OHG and G moieties to the growing chain in a 2 : 1 overall stoichiometry. This quantification data thus provides further insight into how inter-unit linkage frequencies in native lignins are apparently conserved (or near conserved) during assembly in both instances, as well as providing additional impetus to resolve how the overall question of lignin macromolecular assembly is controlled in terms of both type of monomer addition and primary sequence. PMID:20652169

  5. Genome-Wide Analysis of Seed Acid Detergent Lignin (ADL) and Hull Content in Rapeseed (Brassica napus L.).

    PubMed

    Wang, Jia; Jian, Hongju; Wei, Lijuan; Qu, Cunmin; Xu, Xinfu; Lu, Kun; Qian, Wei; Li, Jiana; Li, Maoteng; Liu, Liezhao

    2015-01-01

    A stable yellow-seeded variety is the breeding goal for obtaining the ideal rapeseed (Brassica napus L.) plant, and the amount of acid detergent lignin (ADL) in the seeds and the hull content (HC) are often used as yellow-seeded rapeseed screening indices. In this study, a genome-wide association analysis of 520 accessions was performed using the Q + K model with a total of 31,839 single-nucleotide polymorphism (SNP) sites. As a result, three significant associations on the B. napus chromosomes A05, A09, and C05 were detected for seed ADL content. The peak SNPs were within 9.27, 14.22, and 20.86 kb of the key genes BnaA.PAL4, BnaA.CAD2/BnaA.CAD3, and BnaC.CCR1, respectively. Further analyses were performed on the major locus of A05, which was also detected in the seed HC examination. A comparison of our genome-wide association study (GWAS) results and previous linkage mappings revealed a common chromosomal region on A09, which indicates that GWAS can be used as a powerful complementary strategy for dissecting complex traits in B. napus. Genomic selection (GS) utilizing the significant SNP markers based on the GWAS results exhibited increased predictive ability, indicating that the predictive ability of a given model can be substantially improved by using GWAS and GS. PMID:26673885

  6. Genome-Wide Analysis of Seed Acid Detergent Lignin (ADL) and Hull Content in Rapeseed (Brassica napus L.)

    PubMed Central

    Wei, Lijuan; Qu, Cunmin; Xu, Xinfu; Lu, Kun; Qian, Wei; Li, Jiana; Li, Maoteng; Liu, Liezhao

    2015-01-01

    A stable yellow-seeded variety is the breeding goal for obtaining the ideal rapeseed (Brassica napus L.) plant, and the amount of acid detergent lignin (ADL) in the seeds and the hull content (HC) are often used as yellow-seeded rapeseed screening indices. In this study, a genome-wide association analysis of 520 accessions was performed using the Q + K model with a total of 31,839 single-nucleotide polymorphism (SNP) sites. As a result, three significant associations on the B. napus chromosomes A05, A09, and C05 were detected for seed ADL content. The peak SNPs were within 9.27, 14.22, and 20.86 kb of the key genes BnaA.PAL4, BnaA.CAD2/BnaA.CAD3, and BnaC.CCR1, respectively. Further analyses were performed on the major locus of A05, which was also detected in the seed HC examination. A comparison of our genome-wide association study (GWAS) results and previous linkage mappings revealed a common chromosomal region on A09, which indicates that GWAS can be used as a powerful complementary strategy for dissecting complex traits in B. napus. Genomic selection (GS) utilizing the significant SNP markers based on the GWAS results exhibited increased predictive ability, indicating that the predictive ability of a given model can be substantially improved by using GWAS and GS. PMID:26673885

  7. Lignin Formation in Wheat Coleoptile Cell Walls

    PubMed Central

    Whitmore, F. W.

    1971-01-01

    Four growth-influencing compounds—hydroxyproline, 2,2′-dipyridyl, 2-chloroethylphosphonic acid, and indoleacetic acid—were used to examine the relationship between lignin formation and growth of wheat coleoptile sections. Hydroxyproline and 2-chloroethylphosphonic acid, at low concentrations, inhibited growth and increased lignin content. Dipyridyl, which promoted coleoptile elongation, decreased lignin content. Indoleacetic acid caused a 300% increase in growth at 0.1 mm but resulted in lignin content no different from controls with no auxin. Chemical and anatomical evidence is given which indicates that lignin is present in the epidermal cell walls of the wheat coleoptile. It is thus possible that bonding between lignin and hemicellulose may have some influence on coleoptile growth. Images PMID:16657843

  8. Organic geochemistry of sediments from the continental margin off southern New England, U.S.A.--Part I. Amino acids, carbohydrates and lignin

    NASA Technical Reports Server (NTRS)

    Steinberg, S. M.; Venkatesan, M. I.; Kaplan, I. R.

    1987-01-01

    Total organic carbon (TOC), lignin, amino acids, sugars and amino sugars were measured in recent sediments for the continental margin off southern New England. The various organic carbon fractions decreased in concentration with increasing distance from shore. The fraction of the TOC that was accounted for by these major components also decreased with increasing distance from shore. The concentration of lignin indicated that only about 3-5% of the organic carbon in the nearshore sediment was of terrestrial origin. The various fractions were highly correlated, which was consistent with a simple linear mixing model of shelf organic matter with material form the slope and rise and indicated a significant transport of sediment from the continental shelf to the continental slope and rise.

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

    PubMed Central

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

    2015-01-01

    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 < 0.05) lower than measured in N-12 lines (43.45 g kg−1), whereas the LRI of bmr-12 mutants (0.29) was significantly (P < 0.05) higher than in N-12 lines (0.22). There was no significant correlation between the two indexes in 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. PMID:26366111

  10. Effect of insoluble-low fermentable fiber from corn on energy, fiber, and amino acid digestibility, and on hindgut degradability of fiber and growth performance of pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extensive use of corn co-products in swine diets increases the concentration of dietary fiber, raising concerns about energy and nutrient digestibility, and ultimately on pig performance. A metabolism trial was conducted to determine the effect of increasing levels of insoluble-low fermentable fiber...

  11. Short communication: Evaluation of acid-insoluble ash and indigestible neutral detergent fiber as total-tract digestibility markers in dairy cows fed corn silage-based diets.

    PubMed

    Lee, C; Hristov, A N

    2013-08-01

    The objective of this experiment was to evaluate acid-insoluble ash (AIA) and indigestible NDF (iNDF) as intrinsic digestibility markers in comparison with total fecal collection (TC) in dairy cows fed corn silage- and alfalfa haylage-based diets. The experiment was part of a larger experiment, which involved 8 Holstein cows [102±28.4 d in milk, 26.4±0.27 kg/d of dry matter (DM) intake, and 43±5.3 kg/d milk yield]. The experimental design was a replicated 4×4 Latin square with the following treatments: metabolizable protein (MP)-adequate diet [15.6% crude protein (CP); high-CP], MP-deficient diet (14.0% CP; low-CP), and 2 other low-CP diets supplemented (top-dressed) with ruminally protected Lys or Lys and Met. Data for the 3 low-CP diets were combined for this analysis. Total feces were collected for 5 consecutive days during each period to estimate total-tract apparent digestibility. Digestibility was also estimated using AIA (digestion with 2 N HCl) and iNDF (12-d ruminal incubation in 25-μm-pore-size bags). Significant diet × digestibility method interactions were observed for fecal output of nutrients and digestibility. Fecal output of nutrients estimated using AIA or iNDF was lower compared with TC and fecal output of DM, organic matter, and CP tended to be higher for iNDF compared with AIA for the high-CP diet. For the low-CP diet, however, fecal output of all nutrients was lower for AIA compared with TC and was higher for iNDF compared with TC. Data from this experiment showed that, compared with TC, AIA underestimated fecal output and overestimated digestibility, particularly evident with the fiber fractions and the protein-deficient diet. Compared with TC, fecal output was overestimated and digestibility of the low-CP diet was underestimated when iNDF was used as a marker, although the magnitude of the difference was smaller compared with that for AIA. In the conditions of the current study, iNDF appeared to be a more reliable digestibility marker

  12. Bacterial extracellular lignin peroxidase

    DOEpatents

    Crawford, Donald L.; Ramachandra, Muralidhara

    1993-01-01

    A newly discovered lignin peroxidase enzyme is provided. The enzyme is obtained from a bacterial source and is capable of degrading the lignin portion of lignocellulose in the presence of hydrogen peroxide. The enzyme is extracellular, oxidative, inducible by lignin, larch wood xylan, or related substrates and capable of attacking certain lignin substructure chemical bonds that are not degradable by fungal lignin peroxidases.

  13. In-depth proteomic analysis of a mollusc shell: acid-soluble and acid-insoluble matrix of the limpet Lottia gigantea

    PubMed Central

    2012-01-01

    Background Invertebrate biominerals are characterized by their extraordinary functionality and physical properties, such as strength, stiffness and toughness that by far exceed those of the pure mineral component of such composites. This is attributed to the organic matrix, secreted by specialized cells, which pervades and envelops the mineral crystals. Despite the obvious importance of the protein fraction of the organic matrix, only few in-depth proteomic studies have been performed due to the lack of comprehensive protein sequence databases. The recent public release of the gastropod Lottia gigantea genome sequence and the associated protein sequence database provides for the first time the opportunity to do a state-of-the-art proteomic in-depth analysis of the organic matrix of a mollusc shell. Results Using three different sodium hypochlorite washing protocols before shell demineralization, a total of 569 proteins were identified in Lottia gigantea shell matrix. Of these, 311 were assembled in a consensus proteome comprising identifications contained in all proteomes irrespective of shell cleaning procedure. Some of these proteins were similar in amino acid sequence, amino acid composition, or domain structure to proteins identified previously in different bivalve or gastropod shells, such as BMSP, dermatopontin, nacrein, perlustrin, perlucin, or Pif. In addition there were dozens of previously uncharacterized proteins, many containing repeated short linear motifs or homorepeats. Such proteins may play a role in shell matrix construction or control of mineralization processes. Conclusions The organic matrix of Lottia gigantea shells is a complex mixture of proteins comprising possible homologs of some previously characterized mollusc shell proteins, but also many novel proteins with a possible function in biomineralization as framework building blocks or as regulatory components. We hope that this data set, the most comprehensive available at present, will

  14. Lignin nanoparticle synthesis

    DOEpatents

    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.

  15. Lignin-degrading peroxidases of Phanerochaete chrysosporium.

    PubMed

    Cai, D; Tien, M

    1993-07-01

    Lignin and manganese peroxidases are secreted by the basidiomycete Phanerochaete chrysosporium during secondary metabolism. These enzymes play major roles in lignin degradation. The active site amino acid sequence of these lignin-degrading peroxidases is similar to that of horseradish peroxidase (HRP) and cytochrome c peroxidase (CcP). The mechanism by which they oxidize substrates also appears to be the similar. pH has a similar effect on lignin peroxidase compound I formation as on HRP or CcP; however, the pKa controlling compound I formation for lignin peroxidase appears to be much lower. Lignin-degrading peroxidases are able to catalyze the oxidation of substrates with high redox potential. This unique ability is consistent with a heme active site of low electron density, which is indicated by high redox potential. PMID:7763834

  16. Structure and radical scavenging activity relationships of pyrolytic lignins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This work deals with antioxidant properties of pyrolytic lignins against two free radicals, the 1,1-diphenyl-2-picrylhydrazyl and the 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid). Pyrolytic lignins produced by the thermal pyrolysis of the Etek lignin were extracted from the liquid pyrolysi...

  17. Solubilization of lignin by the ruminal anaerobic fungus Neocallimastix patriciarum.

    PubMed Central

    McSweeney, C S; Dulieu, A; Katayama, Y; Lowry, J B

    1994-01-01

    The ability of the ruminal anaerobic phycomycete Neocallimastix patriciarum to digest model lignin compounds and lignified structures in plant material was studied in batch culture. The fungus did not degrade or transform model lignin compounds that were representative of the predominant intermonomer linkages in lignin, nor did it solubilize acid detergent lignin that had been isolated from spear grass. In a stem fraction of sorghum, 33.6% of lignin was apparently solubilized by the fungus. Solubilization of ester- and either-linked phenolics accounted for 9.2% of the lignin released. The amounts of free phenolic acids detected in culture fluid were equivalent to the apparent loss of ester-linked phenolics from the sorghum substrate. However, the fungus was unable to cleave the ether bond in hydroxycinnamic acid bridges that cross-link lignin and polysaccharide. It is suggested that the majority of the solubilized lignin fraction was a lignin carbohydrate complex containing ether-linked hydroxycinnamic acids. The lignin carbohydrate complex was probably solubilized through dissolution of xylan in the lignin-xylan matrix rather than by lignin depolymerization. PMID:8085834

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

    DOEpatents

    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.

  19. Solvent Fractionation of Lignin

    SciTech Connect

    Chatterjee, Sabornie; Saito, Tomonori

    2014-01-01

    Lignin is a highly abundant source of renewable carbon that can be considered as a valuable sustainable source of biobased materials. The major issues for the commercial production of value added high performance lignin products are lignin s physical and chemical heterogenities. To overcome these problems, a variety of procedures have been developed to produce pure lignin suitable for high performace applications such as lignin-derived carbon materials. However, most of the isolation procedures affect lignin s properties and structure. In this chapter, a short review of the effect of solvent fractionation on lignin s properties and structure is presented.

  20. Characterization of water insoluble solids isolated from various biomass fast pyrolysis oils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A solid water insoluble material, commonly called pyrolytic lignin, can be isolated from biomass fast pyrolysis oils. Such material was isolated from the bio-oils produced from barley straw, barley hulls, switchgrass, soystraw and oak and then fully characterized. Analytical techniques employed in...

  1. Biochemical distributions (amino acids, neutral sugars, and lignin phenols) among size-classes of modern marine sediments from the Washington coast

    NASA Astrophysics Data System (ADS)

    Keil, Richard G.; Tsamakis, Elizabeth; Giddings, J. Calvin; Hedges, John I.

    1998-04-01

    In order to examine relationships of organic matter source, composition, and diagenesis with particle size and mineralogy in modern marine depositional regimes, sediments from the continental shelf and slope along the Northwest Pacific rim (Washington coast, USA) were sorted into hydrodynamic size fractions (sand: >250, 63-250 μm; silt: 35-63, 17-35, 8-17, 3-8 μm; and clay-sized: 1-3, 0.5-1, <0.5 μm). The size fractions were then density fractionated to separate distinct organic debris from mineral-associated organic matter, and the various separates were analyzed for their amino acid, aldose, and lignin compositions. The composition of organic matter in the separates changes markedly as a function of particle size and density. Large compositional differences were observed between the clay-sized fractions (dominated mineralogically by smectites), the sand-sized mineral-associated isolates (quartz-rich), and floated coarse organic matter (dominated by vascular plant debris). Organic matter intimately associated with the clay-sized fractions shows the most extensive diagenetic alteration, as reflected in high abundances of nonprotein amino acids (especially β-alanine), elevated lignin phenol acid/aldehyde ratios, and high relative concentrations of the deoxyhexoses fucose and rhamnose. Organic matter in the silt fractions, though degraded, is not as diagenetically altered as in the clay fractions. Enrichment of pollen grains in the silt-size material is reflected by high cinnamic acid to ferulic acid lignin phenol ratios. The highest pollen biochemical signal is observed in the silt fractions of the deepest station (1835 m), where pollen abundances are also highest. Organic matter tightly bound in the silt and sand-sized fractions are enriched in aldoses and show indications of enhanced microbial biomass as reflected by high weight percentages of ribose. Distinct organic debris was composed of relatively unaltered vascular plant remains as reflected by high

  2. Soluble and insoluble fiber (image)

    MedlinePlus

    Dietary fiber is the part of food that is not affected by the digestive process in the body. ... of the stool. There are two types of dietary fiber, soluble and insoluble. Soluble fiber retains water and ...

  3. Beta-ketoadipic acid and muconolactone production from a lignin-related aromatic compound through the protocatechuate 3,4-metabolic pathway.

    PubMed

    Okamura-Abe, Yuriko; Abe, Tomokuni; Nishimura, Kei; Kawata, Yasutaka; Sato-Izawa, Kanna; Otsuka, Yuichiro; Nakamura, Masaya; Kajita, Shinya; Masai, Eiji; Sonoki, Tomonori; Katayama, Yoshihiro

    2016-06-01

    In this work, the effects of PcaJ (beta-ketoadipate:succinyl-coenzyme A transferase)- and PcaD (beta-ketoadipate enol-lactone hydrolase)-inactivation on protocatechuic acid metabolism in Pseudomonas putida KT2440 were evaluated. Beta-ketoadipic acid was produced from protocatechuic acid by the inactivation of PcaJ as expected; however, a portion of the produced beta-ketoadipic acid was converted to levulinic acid through a purification step consisting of extraction from the culture and recrystallization. On the other hand, muconolactone was purified from the culture of the PcaD-inactivated mutant of KT2440, although beta-ketoadipate enol-lactone was supposed to be produced because it is the substrate of PcaD. Under aerobic conditions, it has been reported that lignin-related aromatics are metabolized through PCA 2,3- or 3,4- or 4,5-ring cleavage pathways, and muconolactone is an intermediate observed in the metabolism of catechol, not protocatechuic acid. Our results will provide a prospective route to produce muconolactone with a high yield through the protocatechuate-3,4-metabolic pathway. PMID:26723258

  4. Artificial miRNA-mediated down-regulation of two monolignoid biosynthetic genes (C3H and F5H) cause reduction in lignin content in jute.

    PubMed

    Shafrin, Farhana; Das, Sudhanshu Sekhar; Sanan-Mishra, Neeti; Khan, Haseena

    2015-11-01

    Artificial microRNAs (amiRNA) provide a new feature in the gene silencing era. Concomitantly, reducing the amount of lignin in fiber-yielding plants such as jute holds significant commercial and environmental potential, since this amount is inversely proportional to the quality of the fiber. The present study aimed at reducing the lignin content in jute, by introducing amiRNA based vectors for down-regulation of two monolignoid biosynthetic genes of jute, coumarate 3-hydroxylase (C3H) and ferulate 5-hydroxylase (F5H). The transgenic lines of F5H-amiRNA and C3H-amiRNA showed a reduced level of gene expression, which resulted in about 25% reduction in acid insoluble lignin content for whole stem and 12-15% reduction in fiber lignin as compared to the non-transgenic plants. The results indicate successful F5H-amiRNA and C3H-amiRNA transgenesis for lignin reduction in jute. This is likely to have far-reaching commercial implications and economic acceleration for jute producing countries. PMID:26453352

  5. Measurement of xylanase activity with insoluble xylan substrate.

    PubMed Central

    Nummi, M; Perrin, J M; Niku-Paavola, M L; Enari, T M

    1985-01-01

    Insoluble xylan was prepared from ground birch (Betula pubescens) pulp by alkali extraction and precipitation with ethanol. The only sugar detected after acid hydrolysis of the preparation was xylose. The insoluble xylan was used as substrate in a nephelometric assay to determine the xylanase (EC 3.2.1.8, 1,4-beta-D-xylan xylanohydrolase and EC 3.2.1.37, 1,4-beta-D-xylan xylohydrolase) activities of Aspergillus and Trichoderma enzymes. The nephelometric method is reliable in evaluating xylanase hydrolysis of insoluble xylan. PMID:3922355

  6. Recovering ultraclean lignins of controlled molecular weight from Kraft black-liquor lignins.

    PubMed

    Klett, A S; Chappell, P V; Thies, M C

    2015-08-18

    By operating in a region of liquid-liquid equilibrium, hot acetic acid-water mixtures can be used to simultaneously clean, fractionate, and solvate Kraft black-liquor lignins. Lignin-rich liquid phases of controlled molecular weight with key metals contents reduced to <50 ppm are obtained without a washing step. PMID:26169767

  7. Enzymatic conversion of lignin into renewable chemicals.

    PubMed

    Bugg, Timothy D H; Rahmanpour, Rahman

    2015-12-01

    The aromatic heteropolymer lignin is a major component of plant cell walls, and is produced industrially from paper/pulp manufacture and cellulosic bioethanol production. Conversion of lignin into renewable chemicals is a major unsolved problem in the development of a biomass-based biorefinery. The review describes recent developments in the understanding of bacterial enzymes for lignin breakdown, such as DyP peroxidases, bacterial laccases, and beta-etherase enzymes. The use of pathway engineering methods to construct genetically modified microbes to convert lignin to renewable chemicals (e.g. vanillin, adipic acid) via fermentation is discussed, and the search for novel applications for lignin (e.g. carbon fibre). PMID:26121945

  8. Reactions of Lignin Model Compounds in Ionic Liquids

    SciTech Connect

    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.

  9. Lignin-blocking treatment of biomass and uses thereof

    DOEpatents

    Yang, Bin; Wyman, Charles E.

    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.

  10. Direct interaction of lignin and lignin peroxidase from Phanerochaete chrysosporium.

    PubMed

    Johjima, T; Itoh, N; Kabuto, M; Tokimura, F; Nakagawa, T; Wariishi, H; Tanaka, H

    1999-03-01

    Binding properties of lignin peroxidase (LiP) from the basidiomycete Phanerochaete chrysosporium against a synthetic lignin (dehydrogenated polymerizate, DHP) were studied with a resonant mirror biosensor. Among several ligninolytic enzymes, only LiP specifically binds to DHP. Kinetic analysis revealed that the binding was reversible, and that the dissociation equilibrium constant was 330 microM. The LiP-DHP interaction was controlled by the ionization group with a pKa of 5.3, strongly suggesting that a specific amino acid residue plays a role in lignin binding. A one-electron transfer from DHP to oxidized intermediates LiP compounds I and II (LiPI and LiPII) was characterized by using a stopped-flow technique, showing that binding interactions of DHP with LiPI and LiPII led to saturation kinetics. The dissociation equilibrium constants for LiPI-DHP and LiPII-DHP interactions were calculated to be 350 and 250 microM, and the first-order rate constants for electron transfer from DHP to LiPI and to LiPII were calculated to be 46 and 16 s-1, respectively. These kinetic and spectral studies strongly suggest that LiP is capable of oxidizing lignin directly at the protein surface by a long-range electron transfer process. A close look at the crystal structure suggested that LiP possesses His-239 as a possible lignin-binding site on the surface, which is linked to Asp-238. This Asp residue is hydrogen-bonded to the proximal His-176. This His-Asp...proximal-His motif would be a possible electron transfer route to oxidize polymeric lignin. PMID:10051582

  11. LIGNIN ACYLATION IN GRASSES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Acylation of lignin during growth and development is a commonly found among some plant species. Grasses form unique acylated lignins involving p-coumarate (pCA). In corn rind tissue, it is exclusively attached to the gamma-carbon of lignin monomers, with a strong preference (over 90%) for attachment...

  12. Lignin pyrolysis products, lignans, and resin acids as specific tracers of plant classes in emissions from biomass combustion

    SciTech Connect

    Simoneit, B.R.T. ); Rogge, W.F.; Cass, G.R. ); Mazurek, M.A. ); Standley, L.J. ); Hildemann, L.M. )

    1993-11-01

    Biomass smoke aerosols contain thermally unaltered and partially altered biomarker compounds from major vegetation taxa. These compounds range from C[sub 8] to C[sub 31] and include phytosterols, lignans, phenolic products from lignin, and diterpenoids from resins. Certain of the higher molecular weight biomarkers are vaporized from the parent plant material and subsequently condense unaltered into the particle phase. Other compounds undergo pyrolytic alteration and possibly dimerization. In both cases it is possible to assign many of these compounds to the plant taxa of the unburned fuel. The diterpenoids are good indicators for smoke from burning of gymnosperm wood. The relative distribution of the OH/OCH[sub 3] substituent patterns on the phenolic products indicates the plant class of the biomass that was burned. Application of these relationships to the interpretation of ambient smoke aerosols may permit further evaluation of the sources that contribute to regional biomass burning. 80 refs., 5 figs., 1 tab.

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

    PubMed

    Fang, Wei; Fang, Zemin; Zhou, Peng; Chang, Fei; Hong, Yuzhi; Zhang, Xuecheng; Peng, Hui; Xiao, Yazhong

    2012-01-01

    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 of bamboo lignin

  14. Evidence for Lignin Oxidation by the Giant Panda Fecal Microbiome

    PubMed Central

    Zhou, Peng; Chang, Fei; Hong, Yuzhi; Zhang, Xuecheng; Peng, Hui; Xiao, Yazhong

    2012-01-01

    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 of bamboo

  15. Chromium(III), insoluble salts

    Integrated Risk Information System (IRIS)

    Chromium ( III ) , insoluble salts ; CASRN 16065 - 83 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments

  16. The effect of dietary psyllium hydrocolloid and lignin on bile.

    PubMed

    Brydon, W G; Borup-Christensen, S; Van der Linden, W; Eastwood, M A

    1979-07-01

    Animal experiments suggest that supplementing the diet with either psyllium seed husk or lignin alters the ratio of deoxycholic acid to chenodeoxycholic in bile. In this study dosages of psyllium seed husk or lignin acceptable to patients with gallstones do not appear to alter the relative amounts of cholesterol, or individual bile acids in the bile. PMID:524929

  17. Discovery of 12-mer peptides that bind to wood lignin

    PubMed Central

    Yamaguchi, Asako; Isozaki, Katsuhiro; Nakamura, Masaharu; Takaya, Hikaru; Watanabe, Takashi

    2016-01-01

    Lignin, an abundant terrestrial polymer, is the only large-volume renewable feedstock composed of an aromatic skeleton. Lignin has been used mostly as an energy source during paper production; however, recent interest in replacing fossil fuels with renewable resources has highlighted its potential value in providing aromatic chemicals. Highly selective degradation of lignin is pivotal for industrial production of paper, biofuels, chemicals, and materials. However, few studies have examined natural and synthetic molecular components recognizing the heterogeneous aromatic polymer. Here, we report the first identification of lignin-binding peptides possessing characteristic sequences using a phage display technique. The consensus sequence HFPSP was found in several lignin-binding peptides, and the outer amino acid sequence affected the binding affinity of the peptides. Substitution of phenylalanine7 with Ile in the lignin-binding peptide C416 (HFPSPIFQRHSH) decreased the affinity of the peptide for softwood lignin without changing its affinity for hardwood lignin, indicating that C416 recognised structural differences between the lignins. Circular dichroism spectroscopy demonstrated that this peptide adopted a highly flexible random coil structure, allowing key residues to be appropriately arranged in relation to the binding site in lignin. These results provide a useful platform for designing synthetic and biological catalysts selectively bind to lignin. PMID:26903196

  18. Discovery of 12-mer peptides that bind to wood lignin.

    PubMed

    Yamaguchi, Asako; Isozaki, Katsuhiro; Nakamura, Masaharu; Takaya, Hikaru; Watanabe, Takashi

    2016-01-01

    Lignin, an abundant terrestrial polymer, is the only large-volume renewable feedstock composed of an aromatic skeleton. Lignin has been used mostly as an energy source during paper production; however, recent interest in replacing fossil fuels with renewable resources has highlighted its potential value in providing aromatic chemicals. Highly selective degradation of lignin is pivotal for industrial production of paper, biofuels, chemicals, and materials. However, few studies have examined natural and synthetic molecular components recognizing the heterogeneous aromatic polymer. Here, we report the first identification of lignin-binding peptides possessing characteristic sequences using a phage display technique. The consensus sequence HFPSP was found in several lignin-binding peptides, and the outer amino acid sequence affected the binding affinity of the peptides. Substitution of phenylalanine7 with Ile in the lignin-binding peptide C416 (HFPSPIFQRHSH) decreased the affinity of the peptide for softwood lignin without changing its affinity for hardwood lignin, indicating that C416 recognised structural differences between the lignins. Circular dichroism spectroscopy demonstrated that this peptide adopted a highly flexible random coil structure, allowing key residues to be appropriately arranged in relation to the binding site in lignin. These results provide a useful platform for designing synthetic and biological catalysts selectively bind to lignin. PMID:26903196

  19. Direct Image-Based Enumeration of Clostridium phytofermentans Cells on Insoluble Plant Biomass Growth Substrates

    PubMed Central

    Alvelo-Maurosa, Jesús G.; Lee, Scott J.; Hazen, Samuel P.

    2015-01-01

    A dual-fluorescent-dye protocol to visualize and quantify Clostridium phytofermentans ISDg (ATCC 700394) cells growing on insoluble cellulosic substrates was developed by combining calcofluor white staining of the growth substrate with cell staining using the nucleic acid dye Syto 9. Cell growth, cell substrate attachment, and fermentation product formation were investigated in cultures containing either Whatman no. 1 filter paper, wild-type Sorghum bicolor, or a reduced-lignin S. bicolor double mutant (bmr-6 bmr-12 double mutant) as the growth substrate. After 3 days of growth, cell numbers in cultures grown on filter paper as the substrate were 6.0- and 2.2-fold higher than cell numbers in cultures with wild-type sorghum and double mutant sorghum, respectively. However, cells produced more ethanol per cell when grown with either sorghum substrate than with filter paper as the substrate. Ethanol yields of cultures were significantly higher with double mutant sorghum than with wild-type sorghum or filter paper as the substrate. Moreover, ethanol production correlated with cell attachment in sorghum cultures: 90% of cells were directly attached to the double mutant sorghum substrate, while only 76% of cells were attached to wild-type sorghum substrate. With filter paper as the growth substrate, ethanol production was correlated with cell number; however, with either wild-type or mutant sorghum, ethanol production did not correlate with cell number, suggesting that only a portion of the microbial cell population was active during growth on sorghum. The dual-staining procedure described here may be used to visualize and enumerate cells directly on insoluble cellulosic substrates, enabling in-depth studies of interactions of microbes with plant biomass. PMID:26637592

  20. Direct Image-Based Enumeration of Clostridium phytofermentans Cells on Insoluble Plant Biomass Growth Substrates.

    PubMed

    Alvelo-Maurosa, Jesús G; Lee, Scott J; Hazen, Samuel P; Leschine, Susan B

    2016-02-01

    A dual-fluorescent-dye protocol to visualize and quantify Clostridium phytofermentans ISDg (ATCC 700394) cells growing on insoluble cellulosic substrates was developed by combining calcofluor white staining of the growth substrate with cell staining using the nucleic acid dye Syto 9. Cell growth, cell substrate attachment, and fermentation product formation were investigated in cultures containing either Whatman no. 1 filter paper, wild-type Sorghum bicolor, or a reduced-lignin S. bicolor double mutant (bmr-6 bmr-12 double mutant) as the growth substrate. After 3 days of growth, cell numbers in cultures grown on filter paper as the substrate were 6.0- and 2.2-fold higher than cell numbers in cultures with wild-type sorghum and double mutant sorghum, respectively. However, cells produced more ethanol per cell when grown with either sorghum substrate than with filter paper as the substrate. Ethanol yields of cultures were significantly higher with double mutant sorghum than with wild-type sorghum or filter paper as the substrate. Moreover, ethanol production correlated with cell attachment in sorghum cultures: 90% of cells were directly attached to the double mutant sorghum substrate, while only 76% of cells were attached to wild-type sorghum substrate. With filter paper as the growth substrate, ethanol production was correlated with cell number; however, with either wild-type or mutant sorghum, ethanol production did not correlate with cell number, suggesting that only a portion of the microbial cell population was active during growth on sorghum. The dual-staining procedure described here may be used to visualize and enumerate cells directly on insoluble cellulosic substrates, enabling in-depth studies of interactions of microbes with plant biomass. PMID:26637592

  1. Lignin transformations and reactivity upon ozonation in aqueous media

    NASA Astrophysics Data System (ADS)

    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.

  2. Influence of molasses lignin-hemicellulose fractions in rat nutrition.

    PubMed

    Fahey, G C; Williams, J E; McLaren, G A

    1976-10-01

    Previous reports have shown that fractionation of the non-sugar, non-dialyzable components of cane molasses yielded a fraction designated as a black phenolic-carbohydrate complex. Incorporation of 0.03% of this complex into diets fed weanling male rats significantly increased the growth rate above that of rats fed the basal diet alone. This study was conducted to determine the chemical nature and growth stimulating action of the black phenol-carbohydrate complex. Alkaline cleavage under nitrogen yielded a mixture of phenols and a carbohydrate fraction which was recovered by precipitation at pH 6 in four volumes of ethanol. The alkaline cleaved, free hemicellulose was non-diayzable and stimulated growth when incorporated into rat diets at the 0.03% levels. Acid hydrolysis of the complex yielded an insoluble product identified as lignin and found to represent 18% to 20% of the entire complex. The chemical nature of this ligninhemicellulose fraction and the previously reported growth-enhancing acid resistant hemicellulose fraction isolated from various plant sources were found to be similar. PMID:9493

  3. Modulation of mutagenicity of various mutagens by lignin derivatives.

    PubMed

    Mikulásová, Mária; Kosíková, Bozena

    2003-03-01

    The effect of lignin on cytotoxicity, mutagenicity and SOS response induced by 4-nitroquinoline-N-oxide (4NQO), 3-(5-nitro-2-furyl)acrylic acid (5NFAA), 2-nitrofluorene (2NF) as well as hydrogen peroxide was investigated in bacterial assay systems, i.e. the Ames test with Salmonella typhimurium TA98, TA100, TA102 and the SOS chromotest with Escherichia coli PQ37. Lignin preparations obtained from beech wood significantly decreased the mutagenicity induced by 4NQO, 2NF and H(2)O(2). In the case of mutagenicity induced by 5NFAA the effect was lower. Antimutagenic properties of lignin samples tested were shown also by SOS chromotest where lignin inhibited the ability of both 4NQO and H(2)O(2) to induce the SOS response. Derivatives of lignin including those from soft and hard wood, as well as from annual plants differ in their efficiency to inhibit the induction of the SOS response. The modified lignins isolated from beech and spruce wood exhibit a high level of protection. Lignins from annual plants-corn cobs and straw-only marginally evoked an antimutagenic response, but their effect was increased by hydrothermic treatment of both annual plants. The results obtained indicate the prospective utilization of lignin preparations as additive in chemo-prevention. The antimutagenic effect of lignin samples varies with the method of isolation and modification, as well as with the genetic origin of the lignin. PMID:12581535

  4. Comparison of lignin extraction processes: Economic and environmental assessment.

    PubMed

    Carvajal, Juan C; Gómez, Álvaro; Cardona, Carlos A

    2016-08-01

    This paper presents the technical-economic and environmental assessment of four lignin extraction processes from two different raw materials (sugarcane bagasse and rice husks). The processes are divided into two categories, the first processes evaluates lignin extraction with prior acid hydrolysis step, while in the second case the extraction processes are evaluated standalone for a total analysis of 16 scenarios. Profitability indicators as the net present value (NPV) and environmental indicators as the potential environmental impact (PEI) are used through a process engineering approach to understand and select the best lignin extraction process. The results show that both economically and environmentally process with sulfites and soda from rice husk presents the best results; however the quality of lignin obtained with sulfites is not suitable for high value-added products. Then, the soda is an interesting option for the extraction of lignin if high quality lignin is required for high value-added products at low costs. PMID:27174614

  5. Green Diesel from Kraft Lignin in Three Steps.

    PubMed

    Löfstedt, Joakim; Dahlstrand, Christian; Orebom, Alexander; Meuzelaar, Gerrit; Sawadjoon, Supaporn; Galkin, Maxim V; Agback, Peter; Wimby, Martin; Corresa, Elena; Mathieu, Yannick; Sauvanaud, Laurent; Eriksson, Sören; Corma, Avelino; Samec, Joseph S M

    2016-06-22

    Precipitated kraft lignin from black liquor was converted into green diesel in three steps. A mild Ni-catalyzed transfer hydrogenation/hydrogenolysis using 2-propanol generated a lignin residue in which the ethers, carbonyls, and olefins were reduced. An organocatalyzed esterification of the lignin residue with an in situ prepared tall oil fatty acid anhydride gave an esterified lignin residue that was soluble in light gas oil. The esterified lignin residue was coprocessed with light gas oil in a continous hydrotreater to produce a green diesel. This approach will enable the development of new techniques to process commercial lignin in existing oil refinery infrastructures to standardized transportation fuels in the future. PMID:27246391

  6. Exploring bacterial lignin degradation.

    PubMed

    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. PMID:24780273

  7. Modification of lignin content and composition in plants

    DOEpatents

    Ye, Zheng-Hua

    2002-01-01

    Plants and methods of preparing plants having reduced lignin content and/or altered lignin composition are provided. The activities of caffeoyl-CoA O-methyltransferase and/or caffeic acid O-methyltransferase enzymes in the modified plants are reduced.

  8. Genome Sequence of Halomonas sp. Strain KO116, an Ionic Liquid-Tolerant Marine Bacterium Isolated from a Lignin-Enriched Seawater Microcosm.

    PubMed

    O'Dell, Kaela B; Woo, Hannah L; Utturkar, Sagar; Klingeman, Dawn; Brown, Steven D; Hazen, Terry C

    2015-01-01

    Halomonas sp. strain KO116 was isolated from Nile Delta Mediterranean Sea surface water enriched with insoluble organosolv lignin. It was further screened for growth on alkali lignin minimal salts medium agar. The strain tolerates the ionic liquid 1-ethyl-3-methylimidazolium acetate. Its complete genome sequence is presented in this report. PMID:25953187

  9. Genome Sequence of Halomonas sp. Strain KO116, an Ionic Liquid-Tolerant Marine Bacterium Isolated from a Lignin-Enriched Seawater Microcosm

    PubMed Central

    O’Dell, Kaela B.; Woo, Hannah L.; Utturkar, Sagar; Klingeman, Dawn; Brown, Steven D.

    2015-01-01

    Halomonas sp. strain KO116 was isolated from Nile Delta Mediterranean Sea surface water enriched with insoluble organosolv lignin. It was further screened for growth on alkali lignin minimal salts medium agar. The strain tolerates the ionic liquid 1-ethyl-3-methylimidazolium acetate. Its complete genome sequence is presented in this report. PMID:25953187

  10. Genome Sequence of Halomonas sp. Strain KO116, an Ionic Liquid- Tolerant Marine Bacterium Isolated from a Lignin-Enriched Seawater Microcosm

    DOE PAGESBeta

    O'Dell, Kaela; Woo, Hannah L.; Utturkar, Sagar M.; Klingeman, Dawn Marie; Brown, Steven D.; Hazen, Terry C.

    2015-05-07

    Halomonas sp. strain KO116 was isolated from Nile Delta Mediterranean Sea surface water enriched with insoluble organosolv lignin. It was further screened for growth on alkali lignin minimal salts medium agar. The strain tolerates the ionic liquid 1-ethyl-3-methylimidazolium acetate. Its complete genome sequence is presented in this report.

  11. Lignin phenols derivatives in lichens.

    PubMed

    Zavarzina, A G; Romankevich, E A; Peresypkin, V I; Ulyantzev, A S; Belyaev, N A; Zavarzin, A A

    2015-01-01

    Lignin monophenols have been measured in the cupric oxide oxidation products from lichens of different systematic groups. It is shown for the first time that syringyl structures in most lichens strongly dominate over vanillyl and p-hydroxyl ones (S/V 7-583, S/P 3-30). This distinguishes lichens from algae and mosses (p-hydroxyl phenols are dominant) and from higher plants (S/V ratios are from 0 in gymnosperms to 1.1-5.2 in angiosperms). Molecular ratios of phenols as well as the ratios of acids to aldehydes in lichens were different from lignin of higher plants, suggesting contribution of non-lignin phenols in CuO oxidation products. The contents of syringyl and vanillyl phenols in some lichen species were comparable to non-woody tissues of higher plants. Results of the study suggest that lichens can be important source of aromatic structures in soils and hydrosphere, particularly in the regions were lichens are abundant. PMID:26728733

  12. A 2000-yr record of the extent of decomposition and vegetation change in peats from the Western Siberian Lowland as revealed from carbohydrate, lignin and amino acid analyses

    NASA Astrophysics Data System (ADS)

    Benner, R. H.; Kaiser, K.; Philben, M. J.; Beilman, D.; MacDonald, G. M.

    2011-12-01

    The Western Siberian Lowland is among the largest wetlands in the world, and it is estimated to store ~70 Pg C as peat. Based on radiocarbon dating, peat accumulation rates at sites south of 60°N are higher than those at more northerly sites during the past 2000 yr. The biochemical composition of peat from high-resolution sampling in four cores was analyzed to investigate the influence of current and past climatic events on the decomposition and diagenetic alteration of the accumulated peat. The analyzed cores were collected from 56.8°N (SIB04), 58.4°N (SIB06), 63.8°N (G137) and 66.5°N (E113). Molecular analyses of hydrolysable neutral sugars, amino acids and lignin phenols accounted for about 36% of the C and 50% of the N in the peat samples, indicating the observed compositional trends are generally representative of bulk C and N dynamics. Prominent compositional anomalies were observed in the upper 6-43 cm of SIB04, the most southern core. An 8-fold decline in Sphagnum-derived p-hydroxy phenols was accompanied by a 5-fold increase in gymnosperm-derived vanillyl phenols in the upper SIB04 core, indicating a shift in vegetation that was also observed at 5 other depths in the core. The yield of neutral sugars decreased from 27% to 10% of total C in peat deposited over a span of about 230 yr. The C/N ratio declined from 68 to 45, and the yield of amino acids increased two-fold. These changes indicate extensive decomposition of the surface (6-9 cm) peat occurred during the last few decades, a period of significant warming in the region. We estimate a 50-65% mass loss in surface peat at the SIB04 site. No apparent indication of extensive decomposition was observed in surface peat at the SIB06 site located 2° further north. About 33% of total C was accounted for in neutral sugars, the C/N ratio was above 100 and amino acid yields were relatively low. A 2-fold increase in vanillyl and syringyl phenols indicates the input of angiosperm vegetation in the upper SIB06

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

    PubMed

    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. PMID:25453284

  14. Selective electrochemical detection of 2,4,6-trinitrotoluene (TNT) in water based on poly(styrene-co-acrylic acid) PSA/SiO2/Fe3O4/AuNPs/lignin-modified glassy carbon electrode.

    PubMed

    Mahmoud, Khaled A; Abdel-Wahab, Ahmed; Zourob, Mohammed

    2015-01-01

    A new versatile electrochemical sensor based on poly(styrene-co-acrylic acid) PSA/SiO2/Fe3O4/AuNPs/lignin (L-MMS) modified glassy carbon electrode (GCE) was developed for the selective detection of trace trinitrotoluene (TNT) from aqueous media with high sensitivity. The fabricated magnetic microspheres were characterized by transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). L-MMS films were cast on the GCE surface to fabricate the TNT sensing electrode. The limit of detection (LOD) of TNT determined by the amperometric i-t curve reached 35 pM. The lignin film and well packed Fe3O4/AuNPs facilitated the pre-concentration of trace TNT on the electrode surface resulting in a fast amperometric response of 3 seconds near the detection limit. The high sensitivity and excellent catalytic activity of the modified electrode could be attributed to the lignin layer and highly packed Fe3O4/AuNPs on the electrode surface. The total recovery of TNT from tapwater and seawater matrices was 98% and 96%, respectively. The electrode film was highly stable after five repeated adsorption/desorption cycles. The new electrochemical sensing scheme provides a highly selective, sensitive and versatile assay for the in-situ detection of TNT in complex water media. PMID:26540539

  15. Isolation and characterization of lignins from Eucalyptus tereticornis (12ABL).

    PubMed

    Zhang, Aiping; Lu, Fachuang; Liu, Chuanfu; Sun, Run-Cang

    2010-11-10

    A three-step sequential extraction-precipitation method was used to isolate lignin from Eucalyptus tereticornis. The ball-milled eucalyptus was extracted with 96% dioxane, 50% dioxane, and 80% dioxane containing 1% NaOH at boiling temperature, consecutively resulting in solubilization of lignin and hemicelluloses. By precipitating such solutions into 70% aqueous ethanol, the hemicelluloses were removed substantially although there were still some carbohydrates left over, especially for lignin fraction extracted by 50% dioxane. Lignins dissolved in the 70% ethanol solutions were recovered via concentration and precipitation into acidified water. About 37% of the original lignin was released following such procedure whereas only 13.5% can be isolated by traditional milled wood lignin (MWL) method. The obtained lignin fractions were analyzed by high performance anion exchange chromatography (HPAEC) following acid hydrolysis for sugar composition of the contaminating carbohydrates and characterized by quantitative (31)P NMR as well as two-dimensional heteronuclear single-quantum coherence ((13)C-(1)H) NMR. The results showed that 96% aqueous dioxane extraction of ball-milled wood under conditions used in this study resulted in lignin preparation with very similar structures and sugar composition as traditional MWL. Therefore extracting ball-milled wood with 96% aqueous dioxane produced lignin in 33.6% yield, which makes it very attractive as an alternative to the traditional MWL method. However further extraction with 50% aqueous dioxane or 80% aqueous dioxane containing 1% NaOH gave just a little more lignins with different carbohydrate compositions from those in MWL. The eucalyptus lignins obtained were syringyl and guaiacyl type units. Lignin fraction obtained from 96% dioxane extraction was found to have more phenolic hydroxyl and less aliphatic hydroxyl than the other two preparations. PMID:20954709

  16. Both caffeoyl Coenzyme A 3-O-methyltransferase 1 and caffeic acid O-methyltransferase 1 are involved in redundant functions for lignin, flavonoids and sinapoyl malate biosynthesis in Arabidopsis.

    PubMed

    Do, Cao-Trung; Pollet, Brigitte; Thévenin, Johanne; Sibout, Richard; Denoue, Dominique; Barrière, Yves; Lapierre, Catherine; Jouanin, Lise

    2007-10-01

    Two methylation steps are necessary for the biosynthesis of monolignols, the lignin precursors. Caffeic acid O-methyltransferase (COMT) O-methylates at the C5 position of the phenolic ring. COMT is responsible for the biosynthesis of sinapyl alcohol, the precursor of syringyl lignin units. The O-methylation at the C3 position of the phenolic ring involves the Caffeoyl CoA 3-O-methyltransferase (CCoAOMT). The CCoAOMT 1 gene (At4g34050) is believed to encode the enzyme responsible for the first O-methylation in Arabidopsis thaliana. A CCoAOMT1 promoter-GUS fusion and immunolocalization experiments revealed that this gene is strongly and exclusively expressed in the vascular tissues of stems and roots. An Arabidopsis T-DNA null mutant named ccomt 1 was identified and characterised. The mutant stems are slightly smaller than wild-type stems in short-day growth conditions and has collapsed xylem elements. The lignin content of the stem is low and the S/G ratio is high mainly due to fewer G units. These results suggest that this O-methyltransferase is involved in G-unit biosynthesis but does not act alone to perform this step in monolignol biosynthesis. To determine which O-methyltransferase assists CCoAOMT 1, a comt 1 ccomt1 double mutant was generated and studied. The development of comt 1 ccomt1 is arrested at the plantlet stage in our growth conditions. Lignins of these plantlets are mainly composed of p-hydroxyphenyl units. Moreover, the double mutant does not synthesize sinapoyl malate, a soluble phenolic. These results suggest that CCoAOMT 1 and COMT 1 act together to methylate the C3 position of the phenolic ring of monolignols in Arabidopsis. In addition, they are both involved in the formation of sinapoyl malate and isorhamnetin. PMID:17594112

  17. Improved lignin pyrolysis for phenolics production in a bubbling bed reactor--Effect of bed materials.

    PubMed

    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. PMID:25863324

  18. Fungal biodegradation and enzymatic modification of lignin

    PubMed Central

    Dashtban, Mehdi; Schraft, Heidi; Syed, Tarannum A.; Qin, Wensheng

    2010-01-01

    Lignin, the most abundant aromatic biopolymer on Earth, is extremely recalcitrant to degradation. By linking to both hemicellulose and cellulose, it creates a barrier to any solutions or enzymes and prevents the penetration of lignocellulolytic enzymes into the interior lignocellulosic structure. Some basidiomycetes white-rot fungi are able to degrade lignin efficiently using a combination of extracellular ligninolytic enzymes, organic acids, mediators and accessory enzymes. This review describes ligninolytic enzyme families produced by these fungi that are involved in wood decay processes, their molecular structures, biochemical properties and the mechanisms of action which render them attractive candidates in biotechnological applications. These enzymes include phenol oxidase (laccase) and heme peroxidases [lignin peroxidase (LiP), manganese peroxidase (MnP) and versatile peroxidase (VP)]. Accessory enzymes such as H2O2-generating oxidases and degradation mechanisms of plant cell-wall components in a non-enzymatic manner by production of free hydroxyl radicals (·OH) are also discussed. PMID:21968746

  19. 40 CFR 227.12 - Insoluble wastes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 25 2014-07-01 2014-07-01 false Insoluble wastes. 227.12 Section 227.12 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING CRITERIA FOR... Insoluble wastes. (a) Solid wastes consisting of inert natural minerals or materials compatible with...

  20. 40 CFR 227.12 - Insoluble wastes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Insoluble wastes. 227.12 Section 227.12 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING CRITERIA FOR... Insoluble wastes. (a) Solid wastes consisting of inert natural minerals or materials compatible with...

  1. Plant and soil intake by organic broilers reared in tree- or grass-covered plots as determined by means of n-alkanes and of acid-insoluble ash.

    PubMed

    Jurjanz, S; Germain, K; Juin, H; Jondreville, C

    2015-05-01

    Free-range birds such as organic broilers may ingest soil and plants during exploration. The estimation of such intakes is of great interest to quantify possible nutritional supplies and also to evaluate the risk of exposure to parasites or to environmental contaminants. Marker-based techniques are now available and would allow to quantify plant and, especially, soil intake in free-range birds, and this quantification was the aim of this study. Methodologically, the proportion of plants in diet intake was determined first using a method based on n-alkanes. Subsequently, the fraction of soil in the total intake was estimated with a second marker, acid-insoluble ash. This approach was carried out to estimate ingested amounts of plants and soil for five successive flocks of organic broilers, exploring grass-covered yards or those under trees, at two time points for each yard: 51 and 64 days of age. Each factor combination (yard type×period=flock number×age) was repeated on two different yards of 750 broilers each. The birds' plant intake varied widely, especially on grass-covered yards. The proportion of plant intake was significantly higher on grass-covered plots than under trees and was also affected, but to a lesser extent, by age or flock number. The ingestion of plants would generally not exceed 11 g of DM daily, except two extreme outliers of nearly 30 g. The daily plant intake under trees tended to be lower and never exceeded 7 g of DM. The amount of ingested plants increased significantly for spring flocks. It increased slightly but significantly with age. The proportion of ingested soil was significantly higher under trees than on grass-covered yards. Dry soil intake was generally low with not more than 3 g per day. Only in adverse conditions - that is, older birds exploring yards under trees in winter - soil intake reached the extreme value of nearly 5 g. Broilers on yards under trees ingested significantly more soil than on grass-covered yards with least

  2. Changes to Lignin Phenol and Hydroxy Alkanoic Acid yStable Carbon Isotope Composition and Concentration in ySoil Fractions from a Grassland/Woodland Conversion in ya Subtropical Savannay

    NASA Astrophysics Data System (ADS)

    Filley, T.; Gamblin, D.; Boutton, T.; Liao, J.; Jastrow, J.

    2005-12-01

    The response of soil organic carbon (SOC) pools to changes in land cover during woody yplant encroachment is an issue of great importance to soil carbon modeling as grassland ysoils represent a major Earth C stock. Bulk assessments of carbon turn over in soils can ybe obtained in systems where C4 plants are being replaced by C3 trees using stable yisotope modeling along a chronosequence. Few SOC studies, however, approach the yquestion of carbon storage and turn over at the compound specific level even though ybiopolymers turnover at vastly different rates and have selective affinities for long term ypreservation. Defining what compound classes represent relatively recalcitrant or labile ypools can be made in such systems where intrinsic differences in stable isotope ycomposition and molecular chemistry are very large. We quantified changes in lignin yphenol and hydroxyl alkanoic acid chemistry and stable carbon isotope composition of ysize and density fractionated soil from the Rio Grande Plains of Texas where C4 ygrasslands (δ13C = -14%) have undergone succession to subtropical thorn woodland ydominated by C3 trees/shrubs (δ13C = -27%) over an 80 year chronosequence. yComparison of the extant of conversion of the grassland SOM to C3 carbon by bulk SOC yisotope modeling to that obtained using compound specific isotope analysis of lignin yphenols in the microaggreagate (53-250 microns), macroaggregates (>250 microns), and ythe microaggregated particulate organic matter (<1.8 g/cc) demonstrates faster turn over yfor the average bulk pool than for lignin. Additionally, p-hyroxy lignin converts to C3 at yabout twice the rate as does vanillyl and syringyl lignin phenol pools reflecting both ydifferences in input rate and ease by which the different pools can be degraded by ymicrobes. The relative extent of turn over between the physical fractions remained the ysame in the two analyses with macroaggrgates>microaggregated pom>microaggregates. yThis work adds to a

  3. Lignin-rich Enzyme Lignin (LREL), a Cellulase-treated Lignin-Carbohydrate Derived from Plants, Activates Myeloid Dendritic Cells via Toll-like Receptor 4 (TLR4)

    PubMed Central

    Tsuji, Ryohei; Koizumi, Hideki; Aoki, Dan; Watanabe, Yuta; Sugihara, Yoshihiko; Matsushita, Yasuyuki; Fukushima, Kazuhiko; Fujiwara, Daisuke

    2015-01-01

    Lignin-carbohydrates, one of the major cell wall components, are believed to be the structures that form chemical linkage between lignin and cell wall polysaccharides. Due to the molecular complexity of lignin-containing substances, their isolation and the assignment of their biological activities have so far remained a difficult task. Here, we extracted two lignin-containing carbohydrates, lignin-rich enzyme lignin (LREL) and pure enzyme lignin (PEL), from barley husk and demonstrated that they act as immune stimulators of dendritic cells (DCs), which are particularly important in linking innate and adaptive immunity. Thioacidolysis, acid hydrolysis, and mild alkali hydrolysis of both LREL and PEL revealed that their immunostimulatory activities depended on the lignin structure and/or content, neutral sugar content (especially the characteristic distribution of galactose and mannose), and presence of an ester bond. Furthermore, we showed that the immunostimulatory potency of the lignin-carbohydrate depended on its molecular weight and degree of polymerization. We also demonstrated that the LREL-induced activation of DCs was mediated via TLR4. Thus, LREL-induced increases in the expression levels of several cell surface marker proteins, production of inflammatory cytokines IL-12p40 and TNF-α, and activation and nuclear translocation of transcription factors, as was observed in the WT DCs, were completely abrogated in DCs derived from the TLR4−/− mice but not in DCs derived from the TLR2−/−, TLR7−/−, and TLR9−/− mice. We further demonstrated that LRELs isolated from other plant tissues also activated DCs. These immunostimulatory activities of lignin-carbohydrates, extracted from edible plant tissues, could have potential relevance in anti-infectious immunity and vaccine adjuvants. PMID:25548274

  4. Characterization of insoluble fractions of TNT transformed by composting

    SciTech Connect

    Caton, J.E.; Ho, C.H.; Williams, R.T.; Griest, W.H. )

    1994-05-01

    Soil contaminated with explosives was supplemented with carbon-14 labelled 2,4,6-trinitrotoluene ([sup 14]C-TNT) and was composted in a field static pile composting experiment. After 90 d of composting, the distribution of carbon-14 ([sup 14]C) activity in fractions from acetonitrile extraction ([open quotes]free[close quotes] fraction, 1.2% of the initial [sup 14]C-activity) and filtration ([open quotes]insoluble-particle[close quotes] fraction, 17.9%), alkaline hydrolysis ([open quotes]insoluble-hydrolyzable[close quotes] fraction, 56.8%), and combustion of the residue ([open quotes]insoluble-nonhydrolyzable[close quotes] fraction, 4.7%) showed that the bulk of the [sup 14]C-activity, and presumably transformed product(s) of the [sup 14]C-TNT, accumulated in a nonextractable, but hydrolyzable fraction. Repetitive aqueous leaching of the compost and also ultraviolet light irradiation followed by leaching suggest that the insoluble fraction of transformed TNT should not be released appreciably by the action of acid rain or sunlight. 16 refs., 11 figs., 2 tabs.

  5. Chromium adsorption by lignin

    SciTech Connect

    Lalvani, S.B.; Huebner, A.; Wiltowski, T.S.

    2000-01-01

    Hexavalent chromium is a known carcinogen, and its maximum contamination level in drinking water is determined by the US Environmental Protection Agency (EPA). Chromium in the wastewaters from plating and metal finishing, tanning, and photographic industries poses environmental problems. A commercially available lignin was used for the removal of hexavalent as well as trivalent chromium from aqueous solution. It is known that hexavalent chromium is present as an anionic species in the solution. It was found that lignin can remove up to 63% hexavalent and 100% trivalent chromium from aqueous solutions. The removal of chromium ions was also investigated using a commercially available activated carbon. This absorbent facilitated very little hexavalent and almost complete trivalent chromium removal. Adsorption isotherms and kinetics data on the metal removal by lignin and activated carbon are presented and discussed.

  6. Microbial degradation of lignin-derived compounds under anaerobic conditions

    SciTech Connect

    Colberg, P.J.

    1983-01-01

    Lignin is the second most abundant form of organic carbon in the biosphere. Recent laboratory studies indicate that a large fraction of polymeric lignin is incompletely degraded by aerobic lignolytic microorganisms and is subsequently released as lignin fragments of reduced molecular size. If such lignin-derived compounds become available in the anaerobic environment, they may serve as potential sources of organic carbon for organisms which release methane precursors. The methanogenic bacteria, in turn, serve as terminal members of the anaerobic food chain, and thus, limit the accumulation of organic carbon in anaerobic sinks. This thesis presents evidence to suggest that lignin-derived compounds which have molecular sizes greater than those of single-ring aromatic compounds (MW > 200) are anaerobically biodegradable to methane. This research involved development of selective enrichment cultures capable of utilizing oligolignols as sole carbon sources. Radiolabeled water-soluble catabolites, released during aerobic lignin degradation by the white rot fungus Phanerochaete chrysosporium, were subjected to anaerobic degradation. The second phase of work involved capillary gas chromatographic analyses of enrichment cultures fed a /sup 14/C-labeled, lignin-derived substrate of average molecular weight 600. 2-Bromoethanesulfonic acid was used to inhibit methane formation and enhance buildup of metabolic intermediates, resulting in the accumulation of volatile fatty acids, phenylacetate, benzoate, catechol, 3-phenyl-propionate, vanillin, syringic acid, vanillic acid, ferulic acid, and caffeic acid. A conceptual model for the anaerobic degradation of two- and three-ring lignin fragments is proposed which overlaps both the ferulate and benzoate degradation pathways at the level of single-ring aromatic compounds.

  7. Visualizing Lignin Coalescence and Migration Through Maize Cell Walls Following Thermochemical Pretreatment

    SciTech Connect

    Donohoe, B. S.; Decker, S. R.; Tucker, M. P.; Himmel, M. E.; Vinzant, T. B.

    2008-12-01

    Plant cell walls are composed primarily of cellulose, hemicelluloses, lignins, and pectins. Of these components, lignins exhibit unique chemistry and physiological functions. Although lignins can be used as a product feedstock or as a fuel, lignins are also generally seen as a barrier to efficient enzymatic breakdown of biomass to sugars. Indeed, many pretreatment strategies focus on removing a significant fraction of lignin from biomass to better enable saccharification. In order to better understand the fate of biomass lignins that remain with the solids following dilute acid pretreatment, we undertook a structural investigation to track lignins on and in biomass cell walls. SEM and TEM imaging revealed a range of droplet morphologies that appear on and within cell walls of pretreated biomass; as well as the specific ultrastructural regions that accumulate the droplets. These droplets were shown to contain lignin by FTIR, NMR, antibody labeling, and cytochemical staining. We provide evidence supporting the idea that thermochemical pretreatments reaching temperatures above the range for lignin phase transition cause lignins to coalesce into larger molten bodies that migrate within and out of the cell wall, and can redeposit on the surface of plant cell walls. This decompartmentalization and relocalization of lignins is likely to be at least as important as lignin removal in the quest to improve the digestibility of biomass for sugars and fuels production.

  8. Starch-Lignin Baked Foams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Starch-kraft lignin foams were prepared by a baking process. Replacing up to 20% of the starch with lignin has no effect on foam density or overall morphology. At 10% replacement, lignin marginally increases water resistance and modulus of elasticity but decreases strain at maximum stress. At 20% re...

  9. Fluorescence analyzer for lignin

    DOEpatents

    Berthold, John W.; Malito, Michael L.; Jeffers, Larry

    1993-01-01

    A method and apparatus for measuring lignin concentration in a sample of wood pulp or black liquor comprises a light emitting arrangement for emitting an excitation light through optical fiber bundles into a probe which has an undiluted sensing end facing the sample. The excitation light causes the lignin concentration to produce fluorescent emission light which is then conveyed through the probe to analyzing equipment which measures the intensity of the emission light. Measures a This invention was made with Government support under Contract Number DOE: DE-FC05-90CE40905 awarded by the Department of Energy (DOE). The Government has certain rights in this invention.

  10. Lignin blockers and uses thereof

    DOEpatents

    Yang, Bin; Wyman, Charles E.

    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.

  11. Biosynthsis of Lignin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In order to understand the effects of up- and down-regulating genes on the lignin biosynthetic pathway, the intracacies of the pathway should be known. Many of the genes are long-known, although the actual substrates of some have been clarified in planta. Others are surprisingly new. All of the majo...

  12. Enzymatic cellulose oxidation is linked to lignin by long-range electron transfer

    PubMed Central

    Westereng, Bjørge; Cannella, David; Wittrup Agger, Jane; Jørgensen, Henning; Larsen Andersen, Mogens; Eijsink, Vincent G.H.; Felby, Claus

    2015-01-01

    Enzymatic oxidation of cell wall polysaccharides by lytic polysaccharide monooxygenases (LPMOs) plays a pivotal role in the degradation of plant biomass. While experiments have shown that LPMOs are copper dependent enzymes requiring an electron donor, the mechanism and origin of the electron supply 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 new light on how oxidative enzymes present in plant degraders may act in concert. PMID:26686263

  13. Lignin-Based Thermoplastic Materials.

    PubMed

    Wang, Chao; Kelley, Stephen S; Venditti, Richard A

    2016-04-21

    Lignin-based thermoplastic materials have attracted increasing interest as sustainable, cost-effective, and biodegradable alternatives for petroleum-based thermoplastics. As an amorphous thermoplastic material, lignin has a relatively high glass-transition temperature and also undergoes radical-induced self-condensation at high temperatures, which limits its thermal processability. Additionally, lignin-based materials are usually brittle and exhibit poor mechanical properties. To improve the thermoplasticity and mechanical properties of technical lignin, polymers or plasticizers are usually integrated with lignin by blending or chemical modification. This Review attempts to cover the reported approaches towards the development of lignin-based thermoplastic materials on the basis of published information. Approaches reviewed include plasticization, blending with miscible polymers, and chemical modifications by esterification, etherification, polymer grafting, and copolymerization. Those lignin-based thermoplastic materials are expected to show applications as engineering plastics, polymeric foams, thermoplastic elastomers, and carbon-fiber precursors. PMID:27059111

  14. Plants with modified lignin content and methods for production thereof

    SciTech Connect

    Zhao, Qiao; Chen, Fang; Dixon, Richard A.

    2014-08-05

    The invention provides methods for decreasing lignin content and for increasing the level of fermentable carbohydrates in plants by down-regulation of the NST transcription factor. Nucleic acid constructs for down-regulation of NST are described. Transgenic plants are provided that comprise reduced lignin content. Plants described herein may be used, for example, as improved biofuel feedstock and as highly digestible forage crops. Methods for processing plant tissue and for producing ethanol by utilizing such plants are also provided.

  15. Transcription factors for modification of lignin content in plants

    SciTech Connect

    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.

  16. Efficiency of single stage- and two stage pretreatment in biomass with different lignin content.

    PubMed

    Kärcher, M A; Iqbal, Y; Lewandowski, I; Senn, T

    2016-07-01

    In current study the enzymatic glucose yields of miscanthus and wheat straw were compared after single stage- and two stage pretreatment with dilute sulfuric acid at different pretreatment severities. Glucose yields after two stage pretreatment were higher than after single stage pretreatment in miscanthus. Whereas wheat straw had higher glucose yields after single stage pretreatment. The study shows that two stage pretreatment has a negative effect on glucose yield in biomass with low not-acid-degradable lignin content and a positive one in biomass with high not-acid-degradable lignin content. The not-acid-degradable lignin fraction offers a higher degree of protection of the whole lignin structure against chemical attacks by mineral acids. More severe pretreatment conditions were needed to achieve a sufficient breakup of the lignin structure. But more severe conditions enhance resin formation, leading to lower enzyme activity and reduced carbohydrate yields. PMID:27067673

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

    PubMed

    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. PMID:24308459

  18. Lignin cross-links with cysteine- and tyrosine-containing peptides under biomimetic conditions.

    PubMed

    Diehl, Brett G; Brown, Nicole R

    2014-10-22

    The work presented here investigates the cross-linking of various nucleophilic amino acids with lignin under aqueous conditions, thus providing insight as to which amino acids might cross-link with lignin in planta. Lignin dehydrogenation polymer (DHP) was prepared in aqueous solutions that contained tripeptides with the general structure XGG, where X represents an amino acid with a nucleophilic side chain. Fourier-transform infrared spectroscopy and energy dispersive X-ray spectroscopy showed that peptides containing cysteine and tyrosine were incorporated into the DHP to form DHP-CGG and DHP-YGG adducts, whereas peptides containing other nucleophilic amino acids were not incorporated. Scanning electron microscopy showed that the physical morphology of DHP was altered by the presence of peptides in the aqueous solution, regardless of peptide incorporation into the DHP. Nuclear magnetic resonance (NMR) spectroscopy showed that cysteine-containing peptide cross-linked with lignin at the lignin α-position, whereas in the case of the lignin-tyrosine adduct the exact cross-linking pathway could not be determined. This is the first study to use NMR to confirm cross-linking between lignin and peptides under biomimetic conditions. The results of this study may indicate the potential for lignin-protein linkage formation in planta, particularly between lignin and cysteine- and/or tyrosine-rich proteins. PMID:25275918

  19. Independent Recruitment of an O-Methyltransferase for Syringyl Lignin Biosynthesis in Selaginella moellendorffii[W

    PubMed Central

    Weng, Jing-Ke; Akiyama, Takuya; Ralph, John; Chapple, Clint

    2011-01-01

    Syringyl lignin, an important component of the secondary cell wall, has traditionally been considered to be a hallmark of angiosperms because ferns and gymnosperms in general lack lignin of this type. Interestingly, syringyl lignin was also detected in Selaginella, a genus that represents an extant lineage of the most basal of the vascular plants, the lycophytes. In angiosperms, syringyl lignin biosynthesis requires the activity of ferulate 5-hydroxylase (F5H), a cytochrome P450-dependent monooxygenase, and caffeic acid/5-hydroxyferulic acid O-methyltransferase (COMT). Together, these two enzymes divert metabolic flux from the biosynthesis of guaiacyl lignin, a lignin type common to all vascular plants, toward syringyl lignin. Selaginella has independently evolved an alternative lignin biosynthetic pathway in which syringyl subunits are directly derived from the precursors of p-hydroxyphenyl lignin, through the action of a dual specificity phenylpropanoid meta-hydroxylase, Sm F5H. Here, we report the characterization of an O-methyltransferase from Selaginella moellendorffii, COMT, the coding sequence of which is clustered together with F5H at the adjacent genomic locus. COMT is a bifunctional phenylpropanoid O-methyltransferase that can methylate phenylpropanoid meta-hydroxyls at both the 3- and 5-position and function in concert with F5H in syringyl lignin biosynthesis in S. moellendorffii. Phylogenetic analysis reveals that Sm COMT, like F5H, evolved independently from its angiosperm counterparts. PMID:21742988

  20. Epoxy resin synthesis using low molecular weight lignin separated from various lignocellulosic materials.

    PubMed

    Asada, Chikako; Basnet, Sunita; Otsuka, Masaya; Sasaki, Chizuru; Nakamura, Yoshitoshi

    2015-03-01

    A low molecular weight lignin from various lignocellulosic materials was used for the synthesis of bio-based epoxy resins. The lignin extracted with methanol from steam-exploded samples (steaming time of 5 min at steam pressure of 3.5 MPa) from different biomasses (i.e., cedar, eucalyptus, and bamboo) were functionalized by the reaction with epichlorohydrin, catalyzed by a water-soluble phase transfer catalyst tetramethylammonium chloride, which was further reacted with 30 wt% aqueous NaOH for ring closure using methyl ethyl ketone as a solvent. The glycidylated products of the lignin with good yields were cured to epoxy polymer networks with bio-based curing agents i.e., lignin itself and a commercial curing agent TD2131. Relatively good thermal properties of the bio-based epoxy network was obtained and thermal decomposition temperature at 5% weight loss (Td5) of cedar-derived epoxy resin was higher than that derived from eucalyptus and bamboo. The bio-based resin satisfies the stability requirement of epoxy resin applicable for electric circuit boards. The methanol-insoluble residues were enzymatically hydrolyzed to produce glucose. This study indicated that the biomass-derived methanol-soluble lignin may be a promising candidate to be used as a substitute for petroleum-based epoxy resin derived from bisphenol A, while insoluble residues may be processed to give a bioethanol precursor i.e., glucose. PMID:25572718

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

    PubMed

    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. PMID:26496216

  2. Lignin Peroxidase Activity Is Not Important in Biological Bleaching and Delignification of Unbleached Kraft Pulp by Trametes versicolor

    PubMed Central

    Archibald, Frederick S.

    1992-01-01

    The discovery in 1983 of fungal lignin peroxidases able to catalyze the oxidation of nonphenolic aromatic lignin model compounds and release some CO2 from lignin has been seen as a major advance in understanding how fungi degrade lignin. Recently, the fungus Trametes versicolor was shown to be capable of substantial decolorization and delignification of unbleached industrial kraft pulps over 2 to 5 days. The role, if any, of lignin peroxidase in this biobleaching was therefore examined. Several different assays indicated that T. versicolor can produce and secrete peroxidase proteins, but only under certain culture conditions. However, work employing a new lignin peroxidase inhibitor (metavanadate ions) and a new lignin peroxidase assay using the dye azure B indicated that secreted lignin peroxidases do not play a role in the T. versicolor pulp-bleaching system. Oxidative activity capable of degrading 2-keto-4-methiolbutyric acid (KMB) appeared unique to ligninolytic fungi and always accompanied pulp biobleaching. PMID:16348775

  3. Lignin blockers and uses thereof

    SciTech Connect

    Yang, Bin; Wyman, Charles E

    2013-11-12

    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.

  4. INFLUENCE OF LIGNIN ON THE ADSORPTION OF HETERO-CYCLIC AROMATIC AMINES BY INSOLUBLE FIBER

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The prevention of colon cancer by dietary fiber is widely discussed. One possible mechanism is by adsorbing carcinogens and transporting them out of the body. It was shown that several model dietary fibers are able to adsorb heterocyclic aromatic amines (HAAs), a group of carcinogens mostly found in...

  5. Mild acetosolv process to fractionate bamboo for the biorefinery: structural and antioxidant properties of the dissolved lignin.

    PubMed

    Li, Ming-Fei; Sun, Shao-Ni; Xu, Feng; Sun, Run-Cang

    2012-02-22

    Fractionation of lignocellulosic material into its constitutive components is of vital importance for the production of biofuels as well as other value-added chemicals. The conventional acetosolv processes are mainly focused on the production of pulp from woody lignocelluloses. In this study, a mild acetosolv process was developed to fractionate bamboo under atmospheric pressure to obtain cellulosic pulp, water-soluble fraction, and acetic acid lignin. The structural features of the lignins obtained under various conditions were characterized with elemental analysis, sugar analysis, alkaline nitrobenzene oxidation, gel permeation chromatography (GPC), (1)H nuclear magnetic resonance ((1)H NMR), and heteronuclear single-quantum coherence (HSQC) spectroscopy. As compared to milled wood lignin (MWL) of bamboo, acetic acid lignins had low impurities (carbohydrates 2.48-4.56%) mainly due to the cleavage of linkages between lignin and carbohydrates. In addition, acetic acid lignins showed a low proportion of syringyl (S) units. Due to the cleavage of linkages between lignin units, acetic acid lignins had weight-average molecular weights ranging from 4870 to 5210 g/mol, less than half that of MWL (13000 g/mol). In addition, acetic acid lignins showed stronger antioxidant activity mainly due to the significant increase of free phenolic hydroxyls. The lignins obtained with such low impurities, high free phenolic hydroxyls, and medium molecular weights are promising feedstocks to replace petroleum chemicals. PMID:22283627

  6. Lignin valorization: improving lignin processing in the biorefinery.

    PubMed

    Ragauskas, Arthur J; Beckham, Gregg T; Biddy, Mary J; Chandra, Richard; Chen, Fang; Davis, Mark F; Davison, Brian H; Dixon, Richard A; Gilna, Paul; Keller, Martin; Langan, Paul; Naskar, Amit K; Saddler, Jack N; Tschaplinski, Timothy J; Tuskan, Gerald A; Wyman, Charles E

    2014-05-16

    Research and development activities directed toward commercial production of cellulosic ethanol have created the opportunity to dramatically increase the transformation of lignin to value-added products. Here, we highlight recent advances in this lignin valorization effort. Discovery of genetic variants in native populations of bioenergy crops and direct manipulation of biosynthesis pathways have produced lignin feedstocks with favorable properties for recovery and downstream conversion. Advances in analytical chemistry and computational modeling detail the structure of the modified lignin and direct bioengineering strategies for future targeted properties. Refinement of biomass pretreatment technologies has further facilitated lignin recovery, and this coupled with genetic engineering will enable new uses for this biopolymer, including low-cost carbon fibers, engineered plastics and thermoplastic elastomers, polymeric foams, fungible fuels, and commodity chemicals. PMID:24833396

  7. Lignin Valorization: Improving Lignin Processing in the Biorefinery

    SciTech Connect

    Ragauskas, Arthur; Beckham, Gregg; Biddy, Mary J; Chandra, Richard; Chen, Fang; Davis, Dr. Mark F.; Davison, Brian H; Dixon, Richard; Gilna, Paul; Keller, Martin; Langan, Paul; Naskar, Amit K; Saddler, Jack N; Tschaplinski, Timothy J; Tuskan, Gerald A; Wyman, Charles E,; Harber, Karen S

    2014-01-01

    Research and development activities directed toward commercial production of cellulosic ethanol have created the opportunity to dramatically increase the transformation of lignin to value-added products. Here we highlight recent advances in this lignin valorization effort. Discovery of genetic variants in native populations of bioenergy crops and direct manipulation of biosynthesis pathways have produced lignin feedstocks with favorable properties for recovery and downstream conversion. Advances in analytical chemistry and computational modeling detail the structure of the modified lignin and direct bioengineering strategies for future targeted properties. Refinement of biomass pretreatment technologies has further facilitated lignin recovery, and this coupled with genetic engineering will enable new uses for this biopolymer, including low-cost carbon fibers, engineered plastics and thermoplastic elastomers, polymeric foams, fungible fuels, and commodity chemicals.

  8. CHALLENGES IN MEASURING INSOLUBLE DIETARY FIBER

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objectives of this review are to define the criteria needed to evaluate insoluble dietary fiber (IDF) methods, discuss their relevance in meeting nutritional needs, describe problems with empirical IDF methods, and assess their relative merits. The challenge for the researcher, nutritionist, and...

  9. Endoplasmic Reticulum Bodies: Solving the Insoluble

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant cells produce and accumulate insoluble triglycerides, proteins and rubber that are assembled into inert ER-derived organelles broadly termed ER-bodies. ER-bodies appear to originate from tubular ER domains that are maintained by cytoskeletal interactions and integral ER proteins. ER-bodies seq...

  10. 40 CFR 227.12 - Insoluble wastes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ....12 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING CRITERIA FOR THE EVALUATION OF PERMIT APPLICATIONS FOR OCEAN DUMPING OF MATERIALS Environmental Impact § 227.12... ocean environment may be generally approved for ocean dumping provided they are insoluble above...

  11. 40 CFR 227.12 - Insoluble wastes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Insoluble wastes. 227.12 Section 227.12 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING CRITERIA FOR THE... wastes. (a) Solid wastes consisting of inert natural minerals or materials compatible with the...

  12. CELL WALL HYDROXYCINNAMATES IN WILD RICE (ZIZANIA AQUATICA L.) INSOLUBLE DIETARY FIBER

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The contents of ester-linked phenolic acids in wild rice (Zizania aquatica L.) dietary fibre were quantified by HPLC analysis, and oligosaccharide hydroxycinnamates were isolated and identified to investigate the linkages of hydroxycinnamic acids to cell wall polymers. In wild rice insoluble dietary...

  13. Deconstruction of lignin linked p-coumarates, ferulates and xylan by NaOH enhances the enzymatic conversion of glucan.

    PubMed

    Murciano Martínez, Patricia; Punt, Arjen M; Kabel, Mirjam A; Gruppen, Harry

    2016-09-01

    Thermo-assisted NaOH pretreatment to deconstruct xylan and lignin in sugar cane bagasse (SCB) is poorly understood. Hence, in this research it is was aimed to study the effect of NaOH pretreatment on the insoluble remaining lignin structures. Hereto, SCB milled fibres were pretreated using different dosages of NaOH at different temperatures and residence times. Of untreated SCB about 63% of the lignin compounds were assigned as p-coumarates and ferulates, analysed by pyrolysis-GC/MS as 4-vinyl phenol and 4-vinyl guaiacol, and designated as non-core lignin (NCL) compounds. More severe NaOH pretreatments resulted in lower xylan and lower lignin recoveries in the insoluble residues. Especially, the relative abundance of NCL decreased and this decrease followed a linear trend with the decrease in xylan. Core lignin compounds, analysed as phenol, guaiacol and syringol, accumulated in the residues. The decrease in residual xylan and NCL correlated positively with the enzymatic hydrolysis of the residual glucan. PMID:27233096

  14. Lignin amine microemulsions

    SciTech Connect

    DaGue, M.G.

    1992-03-10

    This patent describes a method of recovering hydrocarbons from an underground hydrocarbon formation having at least one injection well and at least one production well. It comprises injecting into the formation through an injection well a microemulsion comprising an internal phase of a primary amine having from about 8 to about 22 carbon atoms, lignin, a water soluble anionic surfactant, a solubilizer and an oil; and an external phase of brine comprising greater than about 90% by weight of the microemulsion; driving the microemulsion through the formation; and producing hydrocarbons through a production well.

  15. Model pathways in lignin thermolysis

    SciTech Connect

    Klein, M.T.; Virk, P.S.

    1981-02-01

    A fundamental description of lignin thermolysis was attempted. Analysis of the chemical topology of lignin suggested likely reaction pathways of import to lignin pyrolysis. In turn, 20 model compound pyrolysis substrates were selected to mimic the important reactive functional groups present in whole-lignin thermolysis. The more salient models were: phenethyl phenyl ether (PPE), which depicts the most prevalent lignin interunit linkage, guaiacol, model of the predominant aromatic methoxyl, and saligenol and cinnamyl alcohol, models of important propanoid side chains. Detailed pathway and kinetic analyses and determination of reaction Arrhenius parameters provided mechanistic insights into the model compound pyrolyses. Several pericyclic reaction mechanisms, hitherto not mentioned in the lignin pyrolysis literature, were suggested. In particular, PPE likely pyrolyses via a concerted retro-ene mechanism, whereas guaiacol and saligenol may respectively eliminate methane and water by concerted group transfers. A statistical interpretation of the lignin substrate coupled with the experimental model compound pyrolyses allowed simulation of whole-lignin thermolysis. The simulations were in substantial agreement with experimental pyrolyses reported in the literature in regard to overall gas, methane, carbon monoxide, individual phenols, and carbonaceous residue yields. Weight loss kinetics deduced from the time dependency of the latter yield also accorded well with the experimental literature.

  16. Mechanism of the catalytic ozonization of lignin in the presence of Mn(II) ions

    NASA Astrophysics Data System (ADS)

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

    2013-07-01

    The reaction between ozone and lignin in aqueous solutions catalyzed by Mn(II) ions is studied. The rate of destruction for aromatic structures of lignin is found to increase in the presence of Mn(II) ions. However, the greatest catalytic effect is observed upon the transformation of aliphatic acids that are difficult to oxidize with ozone. The introduction of catalyst raises the total consumption of ozone from 3 to 7 mol per each structural unit of lignin. A scheme is proposed for the transformation of phenol fragments of lignin using ozone with the participation of Mn(II) ions: at the initial stage, we observe the ozone oxidation of lignin and Mn(II) to Mn(III) ions stabilized with products of lignin oxidation and accompanied by the formation of chelate complexes, and the Mn(III) chelate complexes act as low-molecular mediators, attacking phenol structures and initiating radical processes.

  17. Biomass pretreatments capable of enabling lignin valorization in a biorefinery process.

    PubMed

    Narron, Robert H; Kim, Hoyong; Chang, Hou-Min; Jameel, Hasan; Park, Sunkyu

    2016-04-01

    Recent techno-economic studies of proposed lignocellulosic biorefineries have concluded that creating value from lignin will assist realization of biomass utilization into valuable fuels, chemicals, and materials due to co-valorization and the new revenues beyond carbohydrates. The pretreatment step within a biorefinery process is essential for recovering carbohydrates, but different techniques and intensities have a variety of effects on lignin. Acidic and alkaline pretreatments have been shown to produce diverse lignins based on delignification chemistry. The valorization potential of pretreated lignin is affected by its chemical structure, which is known to degrade, including inter-lignin condensation under high-severity pretreatment. Co-valorization of lignin and carbohydrates will require dampening of pretreatment intensities to avoid such effects, in spite of tradeoffs in carbohydrate production. PMID:26780496

  18. Lignin structural alterations in thermochemical pretreatments with limited delignification

    SciTech Connect

    Pu, Yunqiao; Hu, Fan; Huang, Fang; Ragauskas, Arthur J.

    2015-08-02

    Lignocellulosic biomass has a complex and rigid cell wall structure that makes biomass recalcitrant to biological and chemical degradation. Among the three major structural biopolymers (i.e., cellulose, hemicellulose and lignin) in plant cell walls, lignin is considered the most recalcitrant component and generally plays a negative role in the biochemical conversion of biomass to biofuels. The conversion of biomass to biofuels through a biochemical platform usually requires a pretreatment stage to reduce the recalcitrance. Pretreatment renders compositional and structural changes of biomass with these changes ultimately govern the efficiency of the subsequent enzymatic hydrolysis. Dilute acid, hot water, steam explosion, and ammonia fiber expansion pretreatments are among the leading thermochemical pretreatments with a limited delignification that can reduce biomass recalcitrance. Practical applications of these pretreatment are rapidly developing as illustrated by recent commercial scale cellulosic ethanol plants. While these thermochemical pretreatments generally lead to only a limited delignification and no significant change of lignin content in the pretreated biomass, the lignin transformations that occur during these pretreatments and the roles they play in recalcitrance reduction is an important research aspect. This review highlights recent advances in our understanding of lignin alterations during these limited delignification thermochemical pretreatments, with emphasis on lignin chemical structures, molecular weights, and redistributions in the pretreated biomass.

  19. Lignin structural alterations in thermochemical pretreatments with limited delignification

    DOE PAGESBeta

    Pu, Yunqiao; Hu, Fan; Huang, Fang; Ragauskas, Arthur J.

    2015-08-02

    Lignocellulosic biomass has a complex and rigid cell wall structure that makes biomass recalcitrant to biological and chemical degradation. Among the three major structural biopolymers (i.e., cellulose, hemicellulose and lignin) in plant cell walls, lignin is considered the most recalcitrant component and generally plays a negative role in the biochemical conversion of biomass to biofuels. The conversion of biomass to biofuels through a biochemical platform usually requires a pretreatment stage to reduce the recalcitrance. Pretreatment renders compositional and structural changes of biomass with these changes ultimately govern the efficiency of the subsequent enzymatic hydrolysis. Dilute acid, hot water, steam explosion,more » and ammonia fiber expansion pretreatments are among the leading thermochemical pretreatments with a limited delignification that can reduce biomass recalcitrance. Practical applications of these pretreatment are rapidly developing as illustrated by recent commercial scale cellulosic ethanol plants. While these thermochemical pretreatments generally lead to only a limited delignification and no significant change of lignin content in the pretreated biomass, the lignin transformations that occur during these pretreatments and the roles they play in recalcitrance reduction is an important research aspect. This review highlights recent advances in our understanding of lignin alterations during these limited delignification thermochemical pretreatments, with emphasis on lignin chemical structures, molecular weights, and redistributions in the pretreated biomass.« less

  20. A radioimmunoassay for lignin in plant cell walls

    SciTech Connect

    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 {beta}-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 {eta}g/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. {sup 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{sub 2} delignification. The RIA was found to be less sensitive than expected, so several avenues for improving the method are discussed.

  1. Biomass-derived Lignin to Jet Fuel Range Hydrocarbons via Aqueous Phase Hydrodeoxygenation

    SciTech Connect

    Wang, Hongliang; Ruan, Hao; Pei, Haisheng; Wang, Huamin; Chen, Xiaowen; Tucker, Melvin P.; Cort, John R.; Yang, Bin

    2015-09-14

    A catalytic process, involving the hydrodeoxygenation (HDO) of the dilute alkali extracted corn stover lignin catalysed by noble metal catalyst (Ru/Al2O3) and acidic zeolite (H+-Y), to produce lignin-substructure-based hydrocarbons (C7-C18), primarily C12-C18 cyclic structure hydrocarbons in the jet fuel range, was demonstrated.

  2. Transformation of lignin in surface and buried soils of mountainous landscapes

    NASA Astrophysics Data System (ADS)

    Kovaleva, N. O.; Kovalev, I. V.

    2009-11-01

    The content and composition of the lignin phenols in plants and soils of vertical natural zones were studied in the Northern Caucasus region and Northwestern Tien Shan. Three types of lignin transformation were revealed: steppe, forest, and meadow ones. It was shown that the degree of oxidation of the biopolymer during the transformation of organic matter increased when going from the living plant tissues to humic acids in surface and buried soils. The portion of lignin fragments remained unchanged during the biopolymer transformation in the following series: plant tissues-falloff-litter-soil-humic acids-buried humic acids. It was also shown that the biochemical composition of the plants had a decisive effect on the structure of the humic acids in the soils. The quantitative analysis of the lignin phenols and the 13C NMR spectroscopy proved that the lignin in higher plants was involved in the formation of specific compounds of soil humus, including aliphatic and aromatic molecular fragments. The first analysis of the lignin content and composition in buried soils of different ages was performed, and an increase in the degree of oxidation of the lignin structures was revealed in the soil chronoseries. It was proposed to use the proportions of lignin phenols in surface and buried soils as diagnostic criteria of the vegetation types in different epochs.

  3. Contribution of plant lignin to the soil organic matter formation and stabilization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lignin is the third most abundant plant constituent after cellulose and hemicellulose and thought to be one of the building blocks for soil organic matter formation. Lignin can be used as a predictor for long-term soil organic matter stabilization and C sequestration. Soils and humic acids from fo...

  4. Red Xylem and Higher Lignin Extractability by Down-Regulating a Cinnamyl Alcohol Dehydrogenase in Poplar.

    PubMed Central

    Baucher, M.; Chabbert, B.; Pilate, G.; Van Doorsselaere, J.; Tollier, M. T.; Petit-Conil, M.; Cornu, D.; Monties, B.; Van Montagu, M.; Inze, D.; Jouanin, L.; Boerjan, W.

    1996-01-01

    Cinnamyl alcohol dehydrogenase (CAD) catalyzes the last step in the biosynthesis of the lignin precursors, the monolignols. We have down-regulated CAD in transgenic poplar (Populus tremula X Populus alba) by both antisense and co-suppression strategies. Several antisense and sense CAD transgenic poplars had an approximately 70% reduced CAD activity that was associated with a red coloration of the xylem tissue. Neither the lignin amount nor the lignin monomeric composition (syringyl/guaiacyl) were significantly modified. However, phloroglucinol-HCl staining was different in the down-regulated CAD plants, suggesting changes in the number of aldehyde units in the lignin. Furthermore, the reactivity of the cell wall toward alkali treatment was altered: a lower amount of lignin was found in the insoluble, saponified residue and more lignin could be precipitated from the soluble alkali fraction. Moreover, large amounts of phenolic compounds, vanillin and especially syringaldehyde, were detected in the soluble alkali fraction of the CAD down-regulated poplars. Alkaline pulping experiments on 3-month-old trees showed a reduction of the kappa number without affecting the degree of cellulose degradation. These results indicate that reducing the CAD activity in trees might be a valuable strategy to optimize certain processes of the wood industry, especially those of the pulp and paper industry. PMID:12226459

  5. Potential origin and formation for molecular components of humic acids in soils

    NASA Astrophysics Data System (ADS)

    DiDonato, Nicole; Chen, Hongmei; Waggoner, Derek; Hatcher, Patrick G.

    2016-04-01

    Soil humic acids are the base soluble/acid insoluble organic components of soil organic matter. Most of what we know about humic acids comes from studies of their bulk molecular properties or analysis of individual fractions after extraction from soils. This work attempts to better define humic acids and explain similarities and differences for several soils varying in degrees of humification using advanced molecular level techniques. Our investigation using electrospray ionization coupled to Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS) and nuclear magnetic resonance spectroscopy (NMR) has given new insight into the distinctive molecular characteristics of humic acids which suggest a possible pathway for their formation. Humic acids from various ecosystems, climate regions and soil textural classes are distinguished by the presence of three predominant molecular components: lignin-like molecules, carboxyl-containing aliphatic molecules and condensed aromatic molecules that bear similarity to black carbon. Results show that humification may be linked to the relative abundance of these three types of molecules as well as the relative abundance of carboxyl groups in each molecular type. This work also demonstrates evidence for lignin as the primary source of soil organic matter, particularly condensed aromatic molecules often categorized as black carbon and is the first report of the non-pyrogenic source for these compounds in soils. We also suggest that much of the carboxyl-containing aliphatic molecules are sourced from lignin.

  6. Intermediates and products of synthetic lignin (dehydrogenative polymerizate) degradation by Phlebia tremellosa.

    PubMed Central

    Reid, I D

    1991-01-01

    Agitated, nitrogen-limited cultures of Phlebia tremellosa caused substantial changes in the distribution of 14C-labelled synthetic lignin (dehydrogenative polymerizate [DHP]) between water-soluble, dioxane-soluble, alkali-soluble, and insoluble fractions before much lignin carbon was metabolized to CO2. First, the insoluble form increased at the expense of the dioxane-soluble form. Later, the amounts of alkali-soluble and water-soluble 14C increased, and release of 14CO2 began. The molecular weight distribution of the dioxane-soluble lignin remained constant during degradation, but that of the water-soluble fraction changed to higher molecular weights. Culture agitation accelerated the attachment of suspended DHP to the mycelia and stimulated production of water-soluble 14C and 14CO2. The nonionic detergent Tween 80 also hastened release of 14CO2 and increased the early conversion of dioxane-soluble DHP to the alkali-soluble and insoluble forms. Oxidative polymerization is suggested as the first step in degradation of DHP by P. tremellosa. PMID:1746943

  7. 21 CFR 573.600 - Lignin sulfonates.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Lignin sulfonates. 573.600 Section 573.600 Food... Additive Listing § 573.600 Lignin sulfonates. Lignin sulfonates may be safely used in animal feeds in... feeds, as liquid lignin sulfonate, in an amount not to exceed 11 percent of the molasses. (4) As...

  8. 21 CFR 573.600 - Lignin sulfonates.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Lignin sulfonates. 573.600 Section 573.600 Food... Additive Listing § 573.600 Lignin sulfonates. Lignin sulfonates may be safely used in animal feeds in... feeds, as liquid lignin sulfonate, in an amount not to exceed 11 percent of the molasses. (4) As...

  9. 21 CFR 573.600 - Lignin sulfonates.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Lignin sulfonates. 573.600 Section 573.600 Food... Additive Listing § 573.600 Lignin sulfonates. Lignin sulfonates may be safely used in animal feeds in... feeds, as liquid lignin sulfonate, in an amount not to exceed 11 percent of the molasses. (4) As...

  10. 21 CFR 573.600 - Lignin sulfonates.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Lignin sulfonates. 573.600 Section 573.600 Food... Additive Listing § 573.600 Lignin sulfonates. Lignin sulfonates may be safely used in animal feeds in... feeds, as liquid lignin sulfonate, in an amount not to exceed 11 percent of the molasses. (4) As...

  11. 21 CFR 573.600 - Lignin sulfonates.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Lignin sulfonates. 573.600 Section 573.600 Food... Additive Listing § 573.600 Lignin sulfonates. Lignin sulfonates may be safely used in animal feeds in... feeds, as liquid lignin sulfonate, in an amount not to exceed 11 percent of the molasses. (4) As...

  12. Antimicrobial characteristic of insoluble alkylpyridinium iodide.

    PubMed Central

    Nakagawa, Y; Yamano, Y; Tawaratani, T; Kourai, H; Horie, T; Shibasaki, I

    1982-01-01

    Insoluble and soluble alkylpyridinium iodides (C8 to C18) were synthesized. The insoluble agents were quaternized 4-vinylpyridine-divinylbenzene copolymers. The insoluble agent [C12(50)] that contained 50% divinylbenzene and had a C12 alkyl chain was selected as the most suitable insoluble agent. C12(50) showed poor durability of the antibacterial activity, but C12(50), which had lost the activity, was refreshed by washing with ethanol. This washing became ineffective after a few cycles of antibacterial treatment and refreshment. Such C12(50) recovered the activity upon 1.0 N NaOH treatment. The antibacterial activity of C12(50) depended on its surface area. It showed high antimicrobial activity against gram-positive bacteria and also showed activity against gram-negative bacteria and yeasts. But the activities of C12(50) and laurylpyridinium iodide solution were different against some microbes. The antibacterial activities of the agents were investigated against Escherichia coli and Micrococcus luteus under various conditions. The activity of C12(50) was higher at a higher temperature or at a lower cell concentration. The activity of C12(50) decreased on addition of NaCl, glucose, or bovine albumin to the cell suspension or in 0.01 M sodium-potassium phosphate buffer. C12(50) showed less activity when cells were mixed with dead cells or the supernatant of dead cells killed in an autoclave. The mode of action of the laurylpyridinium iodide solution against E. coli and M. luteus was similar to that of C12(50) except for the influence of E. coli cell concentration. PMID:6808918

  13. Structural features and antioxidant activities of lignins from steam-exploded bamboo (Phyllostachys pubescens).

    PubMed

    Sun, Shao-Ni; Cao, Xue-Fei; Xu, Feng; Sun, Run-Cang; Jones, Gwynn Lloyd

    2014-06-25

    An environmentally friendly steam explosion process of bamboo, followed by alkali and alkaline ethanol delignification, was developed to fractionate lignins. Results showed that after steam explosion the lignins isolated showed relatively low carbohydrate contents (0.55-1.76%) and molecular weights (780-1050 g/mol). For each steam-exploded sample, alkali-extracted lignins presented higher phenolic OH values (1.41-1.82 mmol/g), p-coumaric acid to ferulic acid ratios (pCA/FA ratios 4.5-14.1), and syringyl to guaiacyl ratios (S/G ratios 5.0-8.5) than those from alkaline ethanol-extracted lignins (phenolic OH 0.85-1.35 mmol/g, pCA/FA ratios 1.6-5.2, and S/G ratios 3.5-4.8). The lignins obtained consisted mainly of β-O-4' linkages combined with small amounts of β-β', β-5', and α-O-4/β-O-4 linkages. Antioxidant activities of the lignins obtained were tested by the 2,2-diphenyl-1-picrylhydrazyl, 2,2'-azobis(3-ethylbenzothiazoline-6-sulfonic acid), and ferric reducing activity power methods. It was found that alkali-extracted lignins obtained during the initial extraction process had higher antioxidant activities than alkaline ethanol-extracted lignins obtained during the second extraction process. PMID:24927101

  14. Manganese-dependent cleavage of nonphenolic lignin structures by Ceriporiopsis subvermispora in the absence of lignin peroxidase

    SciTech Connect

    Jensen, K.A. Jr.; Bao, W.; Kawai, S.

    1996-10-01

    Many ligninolytic fungi appear to lack lignin peroxidase (LiP), the enzyme generally thought to cleave nonphenolic structures in lignin. However, the fungus, Ceriporiopsis subvermispora, is able to degrade these nonphenolic structures. Experiments showed wood block cultures and defined liquid medium cultures of C. subvermispora rapidly deploymerized and mineralized a {sup 14}C-labeled, polyethylene glycol-linked, high-molecular-weight {beta}-O-4 lignin model compound (model I) that represents the major nonphenolic structure of lignin. The fungus cleaved model I between C{sub {alpha}} and C{sub {beta}} to release benzylic fragments, which were shown in isotope trapping experiments to be major products of model I metabolism. The C{sub {alpha}}-C{sub {beta}} cleavage of {beta}-O-4 lignin structures to release benzylic fragments is characteristic of LiP catalysis, but no detectable LiP activity. Three results pointed, instead, to the participation of a different enzyme, manganese peroxidase (MnP), in the degradation of nonphenolic lignin structures by C. subvermispora. (1) The degradation of model I and of exhaustively methylated (nonphenolic), {sup 14}C-labeled, synthetic lignin by the fungus in liquid cultures was almost completely inhibited when the Mn concentration of the medium was decreased from 35 {mu}M to approximately 5 {mu}M. (2) The fungus degraded model I and methylated lignin significantly faster in the presence of Tween 80, a source of unsaturated fatty acids, than it did in the presence of Tween 20, which contains only saturated fatty acids. Previous work has shown that nonphenolic lignin structures are degraded during the MnP-mediated peroxidation of unsaturated lipids. (3) In experiments with MnP, Mn(II), and unsaturated lipid in vitro, this system mimicked intact C. subvermispora cultures in that it cleaved nonphenolic {beta}-O-4 lignin model compounds between C{sub {alpha}} and C{sub {beta}} to release a benzylic fragment. 41 refs., 7 figs., 2 tabs.

  15. 21 CFR 184.1372 - Insoluble glucose isomerase enzyme preparations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Insoluble glucose isomerase enzyme preparations... Substances Affirmed as GRAS § 184.1372 Insoluble glucose isomerase enzyme preparations. (a) Insoluble glucose isomerase enzyme preparations are used in the production of high fructose corn syrup described in §...

  16. 21 CFR 184.1372 - Insoluble glucose isomerase enzyme preparations.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Insoluble glucose isomerase enzyme preparations... RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS § 184.1372 Insoluble glucose isomerase enzyme preparations. (a) Insoluble glucose isomerase enzyme preparations are used in the production...

  17. 21 CFR 184.1372 - Insoluble glucose isomerase enzyme preparations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Insoluble glucose isomerase enzyme preparations... RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS § 184.1372 Insoluble glucose isomerase enzyme preparations. (a) Insoluble glucose isomerase enzyme preparations are used in the production...

  18. Catalytic pyrolysis-GC/MS of lignin from several sources

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lignin from four different sources extracted by various methods were pyrolyzed at 650 degree C using analytical pyrolysis methods, py-GC/MS. Pyrolysis was carried out in the absence and presence of two heterogeneous catalysts , an acidic zeolite (HZSM-5) catalyst and a mixed metal oxide catalyst (Co...

  19. Effects of Kraft lignin on hydrolysis/dehydration of sugars, cellulosic and lignocellulosic biomass under hot compressed water.

    PubMed

    Daorattanachai, Pornlada; Viriya-empikul, Nawin; Laosiripojana, Navadol; Faungnawakij, Kajornsak

    2013-09-01

    The effect of Kraft lignin presenting on the hydrolysis and dehydration of C5 and C6 sugars, cellulose, hemicelluloses and biomass under hot compressed water (HCW) in the presence of H3PO4 catalyst was intensively studied. The lignin strongly inhibited the acid hydrolysis of cellulose and hemicellulose to glucose and xylose, respectively. Interestingly, the admixed lignin markedly promoted the isomerization of glucose to fructose, and dehydration of fructose (except at the low catalyst loading), resulting in high 5-hydroxymethylfurfural yields. Nonetheless, lignin inhibited the hydrolysis of xylan to xylose and dehydration of xylose to furfural. Moreover, the acidity of the system significantly affects the hydrolysis/dehydration of biomass. It was revealed that the presence of lignin strongly interfered the yields of sugars and furans produced from raw corncob, while the delignified corncob provided significant improvement of product yields, confirming the observed role of lignin in the biomass conversion system via sugar platforms. PMID:23907066

  20. Nanoparticles Containing Insoluble Drug for Cancer Therapy

    PubMed Central

    Guo, Shutao; Huang, Leaf

    2014-01-01

    Nanoparticle drug formulations have been extensively researched and developed in the field of drug delivery as a means to efficiently deliver insoluble drugs to tumor cells. By mechanisms of the enhanced permeability and retention effect, nanoparticle drug formulations are capable of greatly enhancing the safety, pharmacokinetic profiles and bioavailability of the administered treatment. Here, the progress of various nanoparticle formulations in both research and clinical applications is detailed with a focus on the development of drug/gene delivery systems. Specifically, the unique advantages and disadvanges of polymeric nanoparticles, liposomes, solid lipid nanoparticles, nanocrystals and lipid-coated nanoparticles for targeted drug delivery will be investigated in detail. PMID:24113214

  1. Effects of mutations on the insoluble glucan synthesized by Leuconostoc mesenteroides NRRL B-1118 glucansucrase

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Twelve different amino acids were each substituted for Threonine-654 in a cloned glucansucrase from Leuconostoc mesenteroides NRRL B-1118 (DSR-I). The native enzyme produces a water-insoluble glucan containing approximately 44 mol% 1,3-disubstituted a-D-glucopyranosyl units and 29 mol% 1,6-disubstit...

  2. Differences in the adsorption of enzymes onto lignins from diverse types of lignocellulosic biomass and the underlying mechanism

    PubMed Central

    2014-01-01

    Background Non-productive cellulase adsorption onto lignin has always been deemed to negatively affect the enzymatic hydrolysis of lignocellulosic feedstocks. Therefore, understanding enzyme-lignin interactions is essential for the development of enzyme mixtures, the processes of lignocellulose hydrolysis, and the genetic modification of lignocellulosic biomass and enzymes. In this work, we examined the properties of six lignins from diverse types of lignocellulosic biomass (aspen, pine, corn stover, kenaf, and two Arabidopsis lines, wild-type and SALK mutant of fah1) to determine the mechanism of differences in their adsorption of enzymes. Results We found that lignin sources affected enzyme adsorption using structural features, such as functional groups and lignin composition. Guaiacyl (G) lignin had a higher adsorption capacity on enzymes than syringyl (S) lignin. The low S/G ratio and high uniform lignin fragment size had good correlations with high adsorption capacity. A higher content of phenolic hydroxyl groups and a lower content of carboxylic acid groups resulted in stronger adsorption affinity for corn stover lignin (CL) than for kenaf lignin (KL) and aspen lignin (AL). The lower amount of aliphatic hydroxyls that reduced hydrophobic interactions could explain the higher adsorption capacity of pine lignin (PL) than CL. Enzyme activity assays, as well as the hydrolysis of Avicel, phosphoric acid-swollen cellulose (PASC), and holocellulose, were performed to study the behaviors of mono-component enzymes that resulted in adsorption. We found that cellobiohydrolase (CBH) and xylanase were adsorbed the most by all lignins, endoglucanase (EG) showed less inhibition, and β-glucosidase (BG) was the least affected by lignins, indicating the important role of carbohydrate-binding module (CBM) in protein adsorption. Conclusion Lignin sources affect enzyme adsorption using structural features and lignin composition, such as S/G ratio, carboxylic acid, aliphatic

  3. Interference of condensed tannin in lignin analyses of dry bean and forage crops.

    PubMed

    Marles, M A Susan; Coulman, Bruce E; Bett, Kirstin E

    2008-11-12

    Legumes with high concentrations of condensed tannin (pinto bean [Phaseolus vulgaris L.], sainfoin [Onobrychis viciifolia Scop.], and big trefoil [Lotus uliginosus Hoff.]), were compared to a selection of forages, with low or zero condensed tannin (smooth bromegrass [ Bromus inermis Leyss], Lotus japonicus [Regel] K. Larsen, and alfalfa [Medicago sativa L.]), using four methods to estimate fiber or lignin. Protocols were validated by using semipurified condensed tannin polymers in adulteration assays that tested low-lignin tissue with polyphenolic-enriched samples. The effect on lignin assay methods by condensed tannin concentration was interpreted using a multivariate analysis. There was an overestimation of fiber or lignin in the presence of condensed tannin in the acid detergent fiber (ADF) and Klason lignin (KL) assays compared to that in the thioglycolic acid (TGA) and acid detergent lignin (ADL) methods. Sulfite reagents (present in TGA lignin method) or sequential acidic digests at high temperatures (ADF followed by ADL) were required to eliminate condensed tannin. The ADF (alone) and KL protocols are not recommended to screen nonwoody plants, such as forages, where condensed tannin has accumulated in the tissue. PMID:18841900

  4. On the surface interactions of proteins with lignin.

    PubMed

    Salas, Carlos; Rojas, Orlando J; Lucia, Lucian A; Hubbe, Martin A; Genzer, Jan

    2013-01-01

    Lignins are used often in formulations involving proteins but little is known about the surface interactions between these important biomacromolecules. In this work, we investigate the interactions at the solid-liquid interface of lignin with the two main proteins in soy, glycinin (11S) and β-conglycinin (7S). The extent of adsorption of 11S and 7S onto lignin films and the degree of hydration of the interfacial layers is quantified via Quartz crystal microgravimetry (QCM) and surface plasmon resonance (SPR). Solution ionic strength and protein denaturation (2-mercaptoethanol and urea) critically affect the adsorption process as protein molecules undergo conformational changes and their hydrophobic or hydrophilic amino acid residues interact with the surrounding medium. In general, the adsorption of the undenatured proteins onto lignin is more extensive compared to that of the denatured biomolecules and a large amount of water is coupled to the adsorbed molecules. The reduction in water contact angle after protein adsorption (by ~40° and 35° for undenatured 11S and 7S, respectively) is explained by strong nonspecific interactions between soy proteins and lignin. PMID:23234476

  5. From waste to functional additive: toughening epoxy resin with lignin.

    PubMed

    Liu, Wanshuang; Zhou, Rui; Goh, Hwee Li Sally; Huang, Shu; Lu, Xuehong

    2014-04-23

    A novel approach to toughen epoxy resin with lignin, a common waste material from the pulp and paper industry, is presented in this article. First, carboxylic acid-functionalized alkali lignin (AL-COOH) was prepared and subsequently incorporated into anhydride-cured epoxy networks via a one-pot method. The results of mechanical tests show that covalent incorporation of rigid AL-COOH into epoxy networks can significantly toughen the epoxy matrix without deteriorating its tensile strength and modulus. The addition of 1.0 wt % AL-COOH gives increases of 68 and 164% in the critical stress intensity factor (K(IC)) and critical strain energy release rate (G(IC)), respectively, relative to that of neat epoxy. This article opens up the possibility of utilizing low-cost and renewable lignin feedstocks as effective toughening agents for thermoset polymers. PMID:24660855

  6. Mechanochemical modification of lignin and application of the modified lignin for thermoplastics and thermosets

    NASA Astrophysics Data System (ADS)

    Guo, Xiaojie; Zhang, Jinwen; Xin, Junna

    In this work, mechanochemical modification of lignin and use of the modified lignin in thermoplastics and thermosets were studied. Oleated lignin was successfully prepared by transesterification between lignin and methyl, and the oleation reaction was performed in a solvent-free and room temperature ball milling process with a relatively short time. PLA/lignin blends were prepared through melt extrusion. Compared with the PLA/lignin blends, the PLA/oleated lignin blends exhibited finer dispersion of lignin in the blends, increased glass transition temperature and higher tensile properties, suggesting improved compatibility between lignin and PLA. Carboxylic and anhydride groups were also introduced into the structure of lignin via mechanochemical modification, and the resulting lignin derivatives were used as curing agents for epoxies. The dynamic mechanical properties and thermal stability of the cured epoxy resins were studied using dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA).

  7. Lignin-Derived Advanced Carbon Materials

    SciTech Connect

    Chatterjee, Sabornie; Saito, Tomonori

    2015-01-01

    Lignin is a highly abundant source of renewable carbon that can be considered as a valuable sustainable source of biobased materials. By application specific pretreatments and manufacturing method, lignin can be converted to a variety of value added carbon materials. However, the physical and chemical heterogenitites in lignin complicate its use as a feedstock. In this review, lignin manufacturing process, effects of pretreatments and manufacturing methods on the properties of lignin, properties and applications of various lignin derived carbon materials such as carbon fibers, carbon mats, activated carbons, carbon films; are discussed.

  8. Abnormal lignin in a loblolly pine mutant

    SciTech Connect

    Ralph, J.; MacKay, J.J.; Hatfield, R.D.

    1997-07-11

    Novel lignin is formed in a mutant loblolly pine (Pinus taeda L.) severely depleted in cinnamyl alcohol dehydrogenase (E.C. 1.1.1.195), which converts coniferaldehyde to coniferyl alcohol, the primary lignin precursor in pines. Dihydroconiferyl alcohol, a monomer not normally associated with the lignin biosynthetic pathway, is the major component of the mutant`s lignin, accounting for {approximately}30 percent (versus {approximately}3 percent in normal pine) of the units. The level of aldehydes, including new 2-methoxybenzaldehydes, is also increased. The mutant pines grew normally indicating that, even within a species, extensive variations in lignin composition need not disrupt the essential functions of lignin.

  9. Lignin-Derived Advanced Carbon Materials.

    PubMed

    Chatterjee, Sabornie; Saito, Tomonori

    2015-12-01

    Lignin is a highly abundant source of renewable carbon that can be considered as a valuable sustainable source of biobased materials. By applying specific pretreatments and manufacturing methods, lignin can be converted into a variety of value-added carbon materials. However, the physical and chemical heterogeneities of lignin complicate its use as a feedstock. Herein lignin manufacturing process, the effects of pretreatments and manufacturing methods on the properties of product lignin, and structure-property relationships in various applications of lignin-derived carbon materials, such as carbon fibers, carbon mats, activated carbons, carbon films, and templated carbon, are discussed. PMID:26568373

  10. Lignin-Derived Advanced Carbon Materials

    SciTech Connect

    Chatterjee, Sabornie; Saito, Tomonori

    2015-11-16

    Lignin is a highly abundant source of renewable carbon that can be considered as a valuable sustainable source of biobased materials. By applying specific pretreatments and manufacturing methods, it has been found that lignin can be converted into a variety of value-added carbon materials. However, the physical and chemical heterogeneities of lignin complicate its use as a feedstock. Herein, we discuss the lignin manufacturing process, the effects of pretreatments and manufacturing methods on the properties of product lignin, and structure–property relationships in various applications of lignin-derived carbon materials, such as carbon fibers, carbon mats, activated carbons, carbon films, and templated carbon.

  11. Comparative geochemistries of lignins and carbohydrates in an anoxic fjord

    SciTech Connect

    Hamilton, S.E.; Hedges, J.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. 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. 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 and plankton components and must have additional sources.

  12. Recent Development in Chemical Depolymerization of Lignin: A Review

    DOE PAGESBeta

    Wang, Hai; Tucker, Melvin; Ji, Yun

    2013-01-01

    This article reviewed recent development of chemical depolymerization of lignins. There were five types of treatment discussed, including base-catalyzed, acid-catalyzed, metallic catalyzed, ionic liquids-assisted, and supercritical fluids-assisted lignin depolymerizations. The methods employed in this research were described, and the important results were marked. Generally, base-catalyzed and acid-catalyzed methods were straightforward, but the selectivity was low. The severe reaction conditions (high pressure, high temperature, and extreme pH) resulted in requirement of specially designed reactors, which led to high costs of facility and handling. Ionic liquids, and supercritical fluids-assisted lignin depolymerizations had high selectivity, but the high costs of ionic liquids recyclingmore » and supercritical fluid facility limited their applications on commercial scale biomass treatment. Metallic catalyzed depolymerization had great advantages because of its high selectivity to certain monomeric compounds and much milder reaction condition than base-catalyzed or acid-catalyzed depolymerizations. It would be a great contribution to lignin conversion if appropriate catalysts were synthesized.« less

  13. Early diagenesis of lignin-associated phenolics in the salt marsh grass Spartina alterniflora

    SciTech Connect

    Haddad, R.I.; Martens, C.S. ); Newell, S.Y. ); Fallon, R.D. )

    1992-10-01

    The predepositional stability of lignin in the salt marsh cordgrass Spartina alterniflora was examined in two different degradation studies: one was a traditional litterbag study carried out using post-senescent brown leaves in a North Carolina marsh creek, and the other was a study in which senescing, standing plants were tagged and allowed to undergo in situ degradation in a Sapelo Island, Georgia, salt marsh. Based on results from lignin oxidation product (LOP) analysis of leaves, lignin in the S. alterniflora was shown to be significantly degraded in both studies, with 13 [plus minus] 2% and 25 [plus minus] 12% of the total lignin mass loss occurring over the 496-day litterbag and 146-day tagged studies, respectively. A comparison of the results from both studies suggests that most of the calculated lignin loss (> 90%) occurs early in the degradation history of the plant, with a significant portion occurring while the plant is still standing in the salt marsh. Further detailed evaluation of this loss demonstrates that selective lignin degradation occurs in S. alterniflora, deriving from the preferential loss of labile lignin moieties. Based on measured changes in both the lignin mass loss and the LOP acid/aldehyde ratio, as well as evidence suggesting that degradation occurred under oxic conditions, it is proposed that aromatic ring cleavage was the predominant mechanism of lignin degradation in both studies. In light of these results and those from other recent lignin degradation studies, the authors discuss the geochemical consequences regarding the usefulness of lignin oxidation products as quantitative tracers of vascular plant-derived organic matter being transported, deposited, and buried in aquatic environments.

  14. Engineering Cel7A carbohydrate binding module and linker for reduced lignin inhibition.

    PubMed

    Strobel, Kathryn L; Pfeiffer, Katherine A; Blanch, Harvey W; Clark, Douglas S

    2016-06-01

    Non-productive binding of cellulases to lignin inhibits enzymatic hydrolysis of biomass, increasing enzyme requirements and the cost of biofuels. This study used site-directed mutagenesis of the Trichoderma Cel7A carbohydrate binding module (CBM) and linker to investigate the mechanisms of adsorption to lignin and engineer a cellulase with increased binding specificity for cellulose. CBM mutations that added hydrophobic or positively charged residues decreased the specificity for cellulose, while mutations that added negatively charged residues increased the specificity. Linker mutations that altered predicted glycosylation patterns selectively impacted lignin affinity. Beneficial mutations were combined to generate a mutant with 2.5-fold less lignin affinity while fully retaining cellulose affinity. This mutant was uninhibited by added lignin during hydrolysis of Avicel and generated 40% more glucose than the wild-type enzyme from dilute acid-pretreated Miscanthus. Biotechnol. Bioeng. 2016;113: 1369-1374. © 2015 Wiley Periodicals, Inc. PMID:26616493

  15. Depolymerization of lignin by microwave-assisted methylation of benzylic alcohols.

    PubMed

    Zhu, Guodian; Qiu, Xueqing; Zhao, Ying; Qian, Yong; Pang, Yuxia; Ouyang, Xinping

    2016-10-01

    A new two-step lignin depolymerization strategy was developed, in which the benzylic alcohols in lignin was methylated under microwave irradiation, followed by a hydrogenolysis for the cleavage of βO4 bond with Pd/C as the catalyst. The results showed that an efficient and selective catalytic methylation of benzylic alcohols was achieved with various lignin model compounds, and the acidic environment promoted the methylation of benzylic alcohol. Methylation of benzylic alcohol increased the βO4 bond cleavage rate by 55.9%, and improved products selectivity. Preliminary study of lignin depolymerization illustrated that methylation pretreatment of benzylic alcohols facilitated lignin depolymerization to produce aromatic monomers and reduced the oxygen content of aromatic monomers. PMID:27420159

  16. The effect of non-structural components and lignin on hemicellulose extraction.

    PubMed

    Liu, Kai-Xuan; Li, Hong-Qiang; Zhang, Jie; Zhang, Zhi-Guo; Xu, Jian

    2016-08-01

    As the important structural component of corn stover, hemicellulose could be converted into a variety of high value-added products. However, high quality hemicellulose extraction is not an easy issue. The present study aims to investigate the effects of non-structural components (NSCs) and lignin removal on alkaline extraction of hemicellulose. Although NSCs were found to have a minimal effect on hemicellulose dissolution, they affected the color values of the hemicellulose extracts. The lignin limited the hemicellulose dissolution and increased the color value by binding to hemicellulose molecules and forming lignin-carbohydrate complexes. Sodium chlorite method can remove about 90% lignin from corn stover, especially the lignin connected to hemicellulose through p-coumaric and ferulic acids. Which increased the hemicellulose dissolution ratio to 93% and reduced the color value 14-28%, but the cost is about 20% carbohydrates lost. PMID:27213576

  17. Preparation and Analysis of Biomass Lignins

    SciTech Connect

    Compere, A L; Griffith, William {Bill} L

    2009-01-01

    Lignin, comprised primarily of three randomly polymerized phenylpropenyl monomers, is, arguably, the second most common organic molecule on earth. In current biorefinery applications, lignin is burned, usually in concentrated pulping or hydrolysis liquor, as a source of process steam and both internal and exported electricity. The aromatic content of lignin makes it a potentially attractive feedstock for highly-valued aromatic chemicals, polymers, and carbon products (graphite, activated carbon, and carbon fiber). Revenue from production of lignin-based chemicals could play a major role in biorefinery profitability if cost-effective methods for lignin separation and purification can be developed. This article presents descriptions of methods for assessing and purifying biorefinery lignins so that they can be evaluated for use as feedstocks for production of chemical products. Areas covered are: 1) initial evaluations of as-received lignin samples (visual, microscopic, separable organics), 2) analysis of common contaminants (bulk and filterable ash and particulate contaminants in liquid and dry lignin samples), 3) preparation of lignins for experimental use as chemical feedstocks (prefiltration, filtration using bench-scale chemical apparatus and larger scale bag filters, one-step lignin precipitation, two-step carbohydrate and lignin precipitation, desalting of dry powdered or precipitated lignin, and lyophilization). These methods have been used successfully at bench-scale to produce the 1 50 kg amounts of wood and grass lignins typically required for bench-scale assessment as chemical feedstocks

  18. The fate of lignin during hydrothermal pretreatment

    PubMed Central

    2013-01-01

    Background Effective enzymatic hydrolysis of lignocellulosic biomass benefits from lignin removal, relocation, and/or modification during hydrothermal pretreatment. Phase transition, depolymerization/repolymerization, and solubility effects may all influence these lignin changes. To better understand how lignin is altered, Populus trichocarpa x P. deltoides wood samples and cellulolytic enzyme lignin (CEL) isolated from P. trichocarpa x P. deltoides were subjected to batch and flowthrough pretreatments. The residual solids and liquid hydrolysate were characterized by gel permeation chromatography, heteronuclear single quantum coherence NMR, compositional analysis, and gas chromatography–mass spectrometry. Results Changes in the structure of the solids recovered after the pretreatment of CEL and the production of aromatic monomers point strongly to depolymerization and condensation being primary mechanisms for lignin extraction and redeposition. The differences in lignin removal and phenolic compound production from native P. trichocarpa x P. deltoides and CEL suggested that lignin-carbohydrate interactions increased lignin extraction and the extractability of syringyl groups relative to guaiacyl groups. Conclusions These insights into delignification during hydrothermal pretreatment point to desirable pretreatment strategies and plant modifications. Because depolymerization followed by repolymerization appears to be the dominant mode of lignin modification, limiting the residence time of depolymerized lignin moieties in the bulk liquid phase should reduce lignin content in pretreated biomass. In addition, the increase in lignin removal in the presence of polysaccharides suggests that increasing lignin-carbohydrate cross-links in biomass would increase delignification during pretreatment. PMID:23902789

  19. Preparation and Analysis of Biomass Lignins

    NASA Astrophysics Data System (ADS)

    Compere, Alicia L.; Griffith, William L.

    Lignin, comprised primarily of three randomly polymerized phenylpropenyl monomers, is, arguably, the second most common organic molecule on earth. In current biorefinery applications, lignin is burned, usually in concentrated pulping or hydrolysis liquor, as a source of process steam and both internal and exported electricity. The aromatic content of lignin makes it a potentially attractive feedstock for high-value aromatic chemicals, polymers, and carbon products (graphite, activated carbon, and carbon fiber). Revenue from production of lignin-based chemicals could play a major role in biorefinery profitability if cost-effective methods for lignin separation and purification can be developed. This chapter presents descriptions of methods for assessing and purifying biorefinery lignins so that they can be evaluated for use as feedstock for production of chemical products. Areas covered are: (1) initial evaluations of as-received lignin samples (visual, microscopic, separable organics); (2) analysis of common contaminants (bulk and filterable ash and particulate contaminants in liquid and dry lignin samples); (3) preparation of lignins for experimental use as chemical feedstock (prefiltration, filtration using bench-scale chemical apparatus and larger scale bag filters, one-step lignin precipitation, two-step carbohydrate and lignin precipitation, desalting of dry powdered or precipitated lignin, and lyophilization). These methods have been used successfully at the bench scale to produce the 1-50 kg amounts of wood and grass lignins typically required for bench-scale assessment as chemical feedstocks.

  20. Novel surface-based methodologies for investigating GH11 xylanase-lignin derivative interactions.

    PubMed

    Zeder-Lutz, G; Renau-Ferrer, S; Aguié-Béghin, V; Rakotoarivonina, H; Chabbert, B; Altschuh, D; Rémond, C

    2013-11-21

    The recalcitrance of lignocellulose to bioprocessing represents the core problem and remains the limiting factor in creating an economy based on lignocellulosic ethanol production. Lignin is responsible for unproductive interactions with enzymes, and understanding how lignin impairs the susceptibility of biomass to enzymatic hydrolysis represents a significant aim in optimising the biological deconstruction of lignocellulose. The objective of this study was to develop methodologies based on surface plasmon resonance (SPR), which provide novel insights into the interactions between xylanase (Tx-xyn11) and phenolic compounds or lignin oligomers. In a first approach, Tx-xyn11 was fixed onto sensor surfaces, and phenolic molecules were applied in the liquid phase. The results demonstrated weak affinity and over-stoichiometric binding, as several phenolic molecules bound to each xylanase molecule. This approach, requiring the use of soluble molecules in the liquid phase, is not applicable to insoluble lignin oligomers, such as the dehydrogenation polymer (DHP). An alternative approach was developed in which a lignin oligomer was fixed onto a sensor surface. Due to their hydrophobic properties, the preparation of stable lignin layers on the sensor surfaces represented a considerable challenge. Among the various chemical and physico-chemical approaches assayed, two approaches (physisorption via the Langmuir-Blodgett technique onto self-assembled monolayer (SAM)-modified gold and covalent coupling to a carboxylated dextran matrix) led to stable lignin layers, which allowed the study of its interactions with Tx-xyn11 in the liquid phase. Our results indicated the presence of weak and non-specific interactions between Tx-xyn11 and DHP. PMID:24071685

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

    PubMed Central

    2012-01-01

    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. PMID:22889353

  2. ''The control of lignin synthesis''

    SciTech Connect

    Carlson, John E.

    2005-04-07

    In this project we tested the hypothesis that regulation of the synthesis of lignin in secondary xylem cells in conifer trees involves the transport of glucosylated lignin monomers to the wall of xylem cells, followed by de-glucosylation in the cell wall by monolignol-specific glucosidase enzymes, which activates the monomers for lignin polymerization. The information we gathered is relevant to the fundamental understanding of how trees make wood, and to the applied goal of more environmentally friendly pulp and paper production. We characterized the complete genomic structure of the Coniferin-specific Beta-glucosidase (CBG) gene family in the conifers loblolly pine (Pinus taeda) and lodgepole pine (Pinus contorta), and partial genomic sequences were obtained in several other tree species. Both pine species contain multiple CBG genes which raises the possibility of differential regulation, perhaps related to the multiple roles of lignin in development and defense. Subsequent projects will need to include detailed gene expression studies of each gene family member during tree growth and development, and testing the role of each monolignol-specific glucosidase gene in controlling lignin content.

  3. Lignin-assisted coal depolymerization

    SciTech Connect

    Lalvani, S.B.

    1991-01-01

    Previous research has shown that addition of lignin-derived liquids to coal stirred in tetralin under mild reaction conditions (375{degree}C and 300--500 psig) results in a marked enhancement in the rate of coal depolymerization. A mathematical model was developed to study the kinetics of coal depolymerization in the presence of liquid-derived liquids. In the present study, a reaction pathway was formulated to explain the enhancement in coal depolymerization due to lignin (solid) addition. The model postulated assumes that the products of lignin obtained during thermolysis interact with the reactive moieties present in coal while simultaneous depolymerization of coal occurs. A good fit between the experimental data and the kinetic model was found. The results show that in addition to the enhancement in the rate of coal depolymerization, lignin also reacts (and enhances the extent of depolymerization of coal) with those reaction sites in coal that are not susceptible to depolymerization when coal alone is reacted in tetralin under identical reaction conditions. Additional work is being carried out to determine a thorough materials balance on the lignin-assisted coal depolymerization process. A number of liquid samples have been obtained which are being studied for their stability in various environments. 5 refs., 4 figs., 1 tab.

  4. Unravelling lignin formation and structure

    SciTech Connect

    Lewis, N.G. . Inst. of Biological Chemistry)

    1991-01-01

    During this study, we established that the Fagaceae exclusively accumulate Z-monolignois/glucosides, and not the E-isomers. Evidence for the presence of a novel E{yields}Z isomerse has been obtained. Our pioneering work in lignin biosynthesis and structure in situ has also progressed smoothly. We established the bonding environments of a woody angiosperm, Leucanea leucocephala, as well as wheat (T. aestivum) and tobacco (N. tabacum). A cell culture system from Pinus taeda was developed which seems ideal for investigating the early stages of lignification. These cultures excrete peroxidase isozymes, considered to be specifically involved in lignin deposition. We also studied the effect of the putative lignin-degrading enzyme, lignin peroxidase, on monolignols and dehydropolymerisates therefrom. In all cases, polymerization was observed, and not degradation; these polymers are identical to that obtained with horseradish peroxidases/H{sub 2}O{sub 2}. It seems inconceivable that these enzymes can be considered as being primarily responsible for lignin biodegradation.

  5. Pulsed corona discharge oxidation of aqueous lignin: decomposition and aldehydes formation.

    PubMed

    Panorel, Iris; Kaijanen, Laura; Kornev, Iakov; Preis, Sergei; Louhi-Kultanen, Marjatta; Sirén, Heli

    2014-01-01

    Lignin is the mass waste product of pulp and paper industry mostly incinerated for energy recovery. Lignin is, however, a substantial source of raw material for derivatives currently produced in costly wet oxidation processes. The pulsed corona discharge (PCD) for the first time was applied to lignin oxidation aiming a cost-effective environmentally friendly lignin removal and transformation to aldehydes. The experimental research into treatment of coniferous kraft lignin aqueous solutions was undertaken to establish the dependence of lignin oxidation and aldehyde formation on the discharge parameters, initial concentration of lignin and gas phase composition. The rate and the energy efficiency of lignin oxidation increased with increasing oxygen concentration reaching up to 82 g kW-1 h-1 in 89% vol. oxygen. Oxidation energy efficiency in PCD treatment exceeds the one for conventional ozonation by the factor of two under the experimental conditions. Oxidation at low oxygen concentrations showed a tendency of the increasing aldehydes and glyoxylic acid formation yield. PMID:24600854

  6. Identification and thermochemical analysis of high-lignin feedstocks for biofuel and biochemical production

    PubMed Central

    2011-01-01

    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. PMID:22018114

  7. ISSUES IN LIGNIN CHEMISTRY. "THE HELSINKI CONNECTION"

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This presentation covers advances in lignin chemistry (and our Helsinki connection) on dibenzodioxocins, spirodienones, and reduced structures in lignins. It also explores the various roles in defending lignification theory (based on Freudenberg's original hypothesis) against a supposed new contende...

  8. Using NMR chemical shift imaging to monitor swelling and molecular transport in drug-loaded tablets of hydrophobically modified poly(acrylic acid): methodology and effects of polymer (in)solubility.

    PubMed

    Knöös, Patrik; Topgaard, Daniel; Wahlgren, Marie; Ulvenlund, Stefan; Piculell, Lennart

    2013-11-12

    A new technique has been developed using NMR chemical shift imaging (CSI) to monitor water penetration and molecular transport in initially dry polymer tablets that also contain small low-molecular weight compounds to be released from the tablets. Concentration profiles of components contained in the swelling tablets could be extracted via the intensities and chemical shift changes of peaks corresponding to protons of the components. The studied tablets contained hydrophobically modified poly(acrylic acid) (HMPAA) as the polymer component and griseofulvin and ethanol as hydrophobic and hydrophilic, respectively, low-molecular weight model compounds. The water solubility of HMPAA could be altered by titration with NaOH. In the pure acid form, HMPAA tablets only underwent a finite swelling until the maximum water content of the polymer-rich phase, as confirmed by independent phase studies, had been reached. By contrast, after partial neutralization with NaOH, the polyacid became fully miscible with water. The solubility of the polymer affected the water penetration, the polymer release, and the releases of both ethanol and griseofulvin. The detailed NMR CSI concentration profiles obtained highlighted the clear differences in the disintegration/dissolution/release behavior for the two types of tablet and provided insights into their molecular origin. The study illustrates the potential of the NMR CSI technique to give information of importance for the development of pharmaceutical tablets and, more broadly, for the general understanding of any operation that involves the immersion and ultimate disintegration of a dry polymer matrix in a solvent. PMID:24106807

  9. Lignin degradation during plant litter photodegradation

    NASA Astrophysics Data System (ADS)

    Lin, Y.; King, J. Y.

    2014-12-01

    Lignin is the second most abundant compound, after cellulose, synthesized by plants. Numerous studies have demonstrated that initial lignin concentration is negatively correlated with litter decomposition rate under both laboratory and field conditions. Thus lignin is commonly considered to be a "recalcitrant" compound during litter decomposition. However, lignin can also serve as a radiation-absorbing compound during photodegradation, the process through which solar radiation breaks down organic matter. Here, we synthesize recent studies concerning lignin degradation during litter photodegradation and report results from our study on how photodegradation changes lignin chemistry at a molecular scale. Recent field studies have found that litter with high initial lignin concentration does not necessarily exhibit high mass loss during photodegradation. A meta-analysis (King et al. 2012) even found a weak negative correlation between initial lignin concentration and photodegradation rate. Contradicting results have been reported with regard to the change in lignin concentration during photodegradation. Some studies have found significant loss of lignin during photodegradation, while others have not. In most studies, loss of lignin only accounts for a small proportion of the overall mass loss. Using NMR spectroscopy, we found significant loss of lignin structural units containing beta-aryl ether linkages during photodegradation of a common grass litter, Bromus diandrus, even though conventional forage fiber analysis did not reveal changes in lignin concentration. Both our NMR and fiber analyses supported the idea that photodegradation induced loss of hemicellulose, which was mainly responsible for the litter mass loss during photodegradation. Our results suggest that photodegradation induces degradation, but not necessarily complete breakdown, of lignin structures and consequently exposes hemicellulose and cellulose to microbial decomposition. We conclude that lignin

  10. Development of novel assays for lignin degradation: comparative analysis of bacterial and fungal lignin degraders.

    PubMed

    Ahmad, Mark; Taylor, Charles R; Pink, David; Burton, Kerry; Eastwood, Daniel; Bending, Gary D; Bugg, Timothy D H

    2010-05-01

    Two spectrophotometric assays have been developed to monitor breakdown of the lignin component of plant lignocellulose: a continuous fluorescent assay involving fluorescently modified lignin, and a UV-vis assay involving chemically nitrated lignin. These assays have been used to analyse lignin degradation activity in bacterial and fungal lignin degraders, and to identify additional soil bacteria that show activity for lignin degradation. Two soil bacteria known to act as aromatic degraders, Pseudomonas putida and Rhodococcus sp. RHA1, consistently showed activity in these assays, and these strains were shown in a small scale experiment to breakdown lignocellulose, producing a number of monocyclic phenolic products. Using milled wood lignin prepared from wheat straw, pine, and miscanthus, some bacterial lignin degraders were found to show specificity for lignin type. These assays could be used to identify novel lignin degraders for breakdown of plant lignocellulose. PMID:20567767

  11. EDTA-insoluble, calcium-binding proteoglycan in bovine bone

    NASA Technical Reports Server (NTRS)

    Hashimoto, Y.; Lester, G. E.; Caterson, B.; Yamauchi, M.

    1995-01-01

    A calcium ion precipitable, trypsin-generated proteoglycan fragment has been isolated from the demineralized, EDTA-insoluble matrices of bone. The demineralized matrix was completely digested with trypsin, increasing concentrations of CaCl2 were added to the supernatant, and the resulting precipitates were analyzed. The amount of precipitate gradually increased with higher concentrations of calcium and was reversibly solubilized by EDTA. After molecular sieve and anion exchange chromatography, a proteoglycan-containing peak was obtained. Immunochemical analysis showed that this peak contained chondroitin 4-sulfate and possibly keratan sulfate. Amino acid analysis showed that this proteoglycan contained high amounts of aspartic acid/asparagine (Asx), serine (Ser), glutamic acid/glutamine (Glx), proline (Pro), and glycine (Gly); however, it contained little leucine (Leu) which suggests that it is not a member of the leucine-rich small proteoglycan family. In addition, significant amounts of phosphoserine (P-Ser) and hydroxyproline (Hyp) were identified in hydrolysates of this fraction. A single band (M(r) 59 kDa) was obtained on SDS-PAGE that stained with Stains-all but not with Coomassie Brilliant Blue R-250. If bone powder was trypsinized prior to demineralization, this proteoglycan-containing fraction was not liberated. Collectively, these results indicate that a proteoglycan occurs in the demineralized matrix that is precipitated with CaCl2 and is closely associated with both mineral and collagen matrices. Such a molecule might facilitate the structural network for the induction of mineralization in bone.

  12. Liquid Fuels from Lignins: Annual Report

    SciTech Connect

    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.

  13. 40 CFR 721.5460 - Organosolv lignin.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Organosolv lignin. 721.5460 Section... Substances § 721.5460 Organosolv lignin. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as an organosolv lignin (PMN P-95-1584; CAS No. 8068-03-9)...

  14. 40 CFR 721.5460 - Organosolv lignin.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Organosolv lignin. 721.5460 Section... Substances § 721.5460 Organosolv lignin. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as an organosolv lignin (PMN P-95-1584; CAS No. 8068-03-9)...

  15. 40 CFR 721.5460 - Organosolv lignin.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Organosolv lignin. 721.5460 Section... Substances § 721.5460 Organosolv lignin. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as an organosolv lignin (PMN P-95-1584; CAS No. 8068-03-9)...

  16. 40 CFR 721.5460 - Organosolv lignin.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Organosolv lignin. 721.5460 Section... Substances § 721.5460 Organosolv lignin. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as an organosolv lignin (PMN P-95-1584; CAS No. 8068-03-9)...

  17. 40 CFR 721.5460 - Organosolv lignin.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Organosolv lignin. 721.5460 Section... Substances § 721.5460 Organosolv lignin. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as an organosolv lignin (PMN P-95-1584; CAS No. 8068-03-9)...

  18. Cationic electrodepositable coating composition comprising lignin

    DOEpatents

    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.

  19. Mapping the lignin distribution in pretreated sugarcane bagasse by confocal and fluorescence lifetime imaging microscopy

    PubMed Central

    2013-01-01

    Background Delignification pretreatments of biomass and methods to assess their efficacy are crucial for biomass-to-biofuels research and technology. Here, we applied confocal and fluorescence lifetime imaging microscopy (FLIM) using one- and two-photon excitation to map the lignin distribution within bagasse fibers pretreated with acid and alkali. The evaluated spectra and decay times are correlated with previously calculated lignin fractions. We have also investigated the influence of the pretreatment on the lignin distribution in the cell wall by analyzing the changes in the fluorescence characteristics using two-photon excitation. Eucalyptus fibers were also analyzed for comparison. Results Fluorescence spectra and variations of the decay time correlate well with the delignification yield and the lignin distribution. The decay dependences are considered two-exponential, one with a rapid (τ1) and the other with a slow (τ2) decay time. The fastest decay is associated to concentrated lignin in the bagasse and has a low sensitivity to the treatment. The fluorescence decay time became longer with the increase of the alkali concentration used in the treatment, which corresponds to lignin emission in a less concentrated environment. In addition, the two-photon fluorescence spectrum is very sensitive to lignin content and accumulation in the cell wall, broadening with the acid pretreatment and narrowing with the alkali one. Heterogeneity of the pretreated cell wall was observed. Conclusions Our results reveal lignin domains with different concentration levels. The acid pretreatment caused a disorder in the arrangement of lignin and its accumulation in the external border of the cell wall. The alkali pretreatment efficiently removed lignin from the middle of the bagasse fibers, but was less effective in its removal from their surfaces. Our results evidenced a strong correlation between the decay times of the lignin fluorescence and its distribution within the cell

  20. Cytotoxic factor induced in murine serum after intravenous administration of a dehydrogenation polymer of p-coumaric acid (a synthetic lignin).

    PubMed

    Kohara, A; Shimizu, N; Kawazoe, Y

    1998-10-01

    A cytotoxic factor (CF) toward cultured murine leukemia L1210 cells was induced in mouse serum by intravenous injection of a dehydrogenation polymer of p-coumaric acid (DHP-pCA). When the serum from the treated mice was diluted with ethanol, CF was preserved in its supernatant (EtOH-sup). An EtOH-sup prepared from untreated control mice also showed cytotoxicity, although at much higher concentrations. The CF activity of EtOH-sups from both treated and untreated mice was completely eliminated by acid treatment at pH 2 at 90 degrees C for 30 min but kept intact by alkali treatment. In addition, the CF activity of both EtOH-sups was not affected by digestion with chymotrypsin. CF was recovered in a neutral MeOH-eluate from a DEAE-cellulofine column but not in HCI-MeOH eluate, in which lignified materials including DHP-pCA should have been recovered. These findings strongly suggest that CF is not a metabolite of DHP-pCA but an endogenous component of the normal serum which is augmented by DHP-pCA administration. PMID:9821818

  1. Enzymatic monitoring of lignin and lignin derivatives biooxidation.

    PubMed

    Ibrahim, Victor; Mamo, Gashaw

    2016-01-01

    Lignin oxidation was enzymatically monitored by measuring methanol released during the reaction. The methanol was oxidized to formaldehyde and hydrogen peroxide, and the latter used to oxidize ABTS to a product measured spectrophotometrically. The efficiency was comparable to the commonly used gas chromatography method. The assay was fast and inexpensive. PMID:26632344

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

    PubMed Central

    2010-01-01

    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 of ester group hydroxylation

  3. Phenols and lignin: Key players in reducing enzymatic hydrolysis yields of steam-pretreated biomass in presence of laccase.

    PubMed

    Oliva-Taravilla, Alfredo; Tomás-Pejó, Elia; Demuez, Marie; González-Fernández, Cristina; Ballesteros, Mercedes

    2016-01-20

    Phenols are known as inhibitors for cellulases and fermentative microorganisms in bioethanol production processes. The addition of laccases removes the phenolic compounds and subsequently reduces the lag phase of the fermentative microorganism. However, the application of laccases diminishes glucose release during the enzymatic hydrolysis. In this study a model cellulosic substrate (Sigmacell) together with lignin extract, whole steam-pretreated wheat straw (slurry) and its water insoluble solid fraction (WIS) were subjected to enzymatic hydrolysis to evaluate the effects of laccase treatment in presence of lignin and phenols. The presence of laccase in enzymatic hydrolysis of Sigmacell with lignin extract reduced glucose yield by 37% compared with assays without laccase. Furthermore, this reduction was even more marked in presence of phenols (55% reduction). Interestingly, when hydrolyzing WIS, the addition of phenols coupled with laccase treatment did not show a reduction when compared with only laccase addition. This fact suggests the key role of lignin in the hydrolysis inhibition since in WIS the ratio cellulase per gram of lignin was much lower than in Sigmacell experiments. Finally, the lower cellobiose and xylose recoveries point out that phenolic oligomers formed by laccase oxidation play important roles in the inhibition of endoglucanases, cellobiohydrolases and xylanases. To conclude, the proportion of lignin and the composition of phenols are key players in the inhibition of cellulases when the enzymatic hydrolysis is combined with laccases detoxification. PMID:26684987

  4. Separation and characterization of lignins from the black liquor of oil palm trunk fiber pulping

    SciTech Connect

    Sun, R.; Tomkinson, J.; Bolton, J.

    1999-11-01

    Six lignin preparations, isolated by a novel two-step precipitation method instead of the traditional one-step precipitation method from the oil palm trunk fiber pulping (OPTFP) black liquor, were found to be relatively free of nonlignin materials such as polysaccharide degradation products, ash, and salts. A lignin fraction with a purity of 99.5% was obtained at an optimum precipitation pH 1.5 after isolation of the nonlignin materials in ethanol. About 94% of the total lignin was recovered by this novel method at this condition, and the value of COD in the treated black liquor reduced significantly to lower 250. The isolated lignin fractions contained syringyl, guaiacyl, and p-hydroxyphenyl units in an approximate molar ratio of 16--20:5:1 on the basis of chemical and spectroscopic analysis. Small amounts of p-hydroxybenzoic acids were found to be esterified to lignin, while ferulic acids were associated to lignin by ether linkage. {sup 13}C-NMR indicated the presence of {beta}-O-4 ether bonds, and {beta}-5 and 5-5{prime} carbon-carbon linkages between the lignin molecules.

  5. Lysosomal glycosidases in mouse peritoneal macrophages stimulated in vitro with soluble and insoluble glycans.

    PubMed

    Bøgwald, J; Johnson, E; Hoffman, J; Seljelid, R

    1984-04-01

    Mouse peritoneal macrophages stimulated with insoluble glycans in vitro release high amounts of acid hydrolases, N-acetyl-beta-D-glucosaminidase, beta-D-glucuronidase, and beta-D-galactosidase. The most potent of the stimulatory glycans is a beta-1,3-D-glucan isolated from yeast cell walls. Up to 50% of total enzyme activity was found in the medium after stimulation with this glycan for three days. Agarose, another insoluble glycan containing an alternating sequence of the disaccharide beta-1,3-D-galactose-alpha-1,4-3,6-anhydro-L-galactose units was less potent. The soluble beta-1,3-D-glucan laminaran, which also contains small amounts of mannitol, was not able to induce release of acid glycosidases from macrophages. The release was independent of serum since macrophages cultured under serum-free conditions showed nearly the same pattern of enzyme activities, both in the cells and media. There was no increased release of the acid hydrolase alpha-D-mannosidase after stimulation with the insoluble beta-1,3-D-glucan for three days. The release of the lysosomal glycosidases was not due to cell death, since only small amounts of the cytoplasmic enzyme lactate dehydrogenase were found in the culture media. Insoluble polystyrene latex particles were not able to stimulate mouse macrophages to release lysosomal glycosidases. Tritiated glycans (amylose, dextran, laminaran, the insoluble beta-1,3-D-glucan, and agarose) and the p-nitrophenyl-glycopyranoside derivatives were used as substrates to investigate whether the macrophages contained or released glucanases capable of degrading alpha-1,4-D-glucans, alpha-1-6-D-glucans, beta-1,3-D-glucans, and agarose respectively. We conclude that the glycans were not degraded in macrophage cultures during the time period tested nor were the enzymes induced in macrophages by the glycans during in vitro culture for seven days. PMID:6584526

  6. Hydrotreating Pyrolytic Lignin to Produce a Refinery Feedstock (Poster)

    SciTech Connect

    French, R. J.

    2013-09-01

    Fast pyrolysis of biomass followed by water separation to produce pyrolytic lignin and hydrotreating of the lignin could be used to produce a stable volatile low-oxygen intermediate liquid. Such a liquid could be converted into a finished motor-fuel in a refinery, taking advantage of the existing infrastructure and economies of scale of refineries. Hydrotreating just the lignin would consume less hydrogen while preserving about half of the energy of the original oil. The aqueous by-products could be reformed to produce the needed hydrogen and would contain much of the unwanted acids and unstable oxygenates. To assess such intermediate liquids, several pyrolytic lignins were prepared by mixing pyrolysis oil with water at 1:1 and 3:1 ratios. The carboxylic acidity in the pyrolytic lignin was reduced to 24 and 10 mg-KOH/g-lignin compared to 81 in the whole oil. These lignins were hydrotreated using Ni-Mo(S)/alumina, Pt/char, or Pd/C(activated) in a semi-batch 1 L stirred autoclave. The oil was stabilized under hydrogen at 150-280 degrees C, then water and light organics were removed by partial depressurization. Hydrodeoxygenation was then performed at 340-400 degrees C. Total pressure was controlled at 70 or 170 bar with hydrogen gas. Organic liquid yields of 39-56% were obtained. For many experiments the organic oxygen content was <7%, acidity was < 7 mg-KOH/g-oil, the volatility was greater than or equal to 94% and, on a carbon basis, the total yield of organic products miscible in hydrocarbons at a 1:10 ratio was over 50%. These properties are probably acceptable to a refinery.The residual liquids left in the reactor at the end of the experiment comprised 60-85% of the organic-phase product while the rest was condensate. 13C-NMR of the residual liquids showed that they were 50-80% aliphatic. 13C-NMR coupled with GC-MS identified phenolic compounds as the main oxygenates in most residual liquids.

  7. VARIABILITY OF GRASS LIGNIN ACYLATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grasses are being championed as biomass sources for bioenergy production. Their ultimate use would be as a source of carbohydrate for fermentation to ethanol, conversion to oils via pyrolysis, or direct conversion to energy through combustion. In the latter case, increasing lignin content would enha...

  8. Adsorption of Ions at Uncharged Insoluble Monolayers.

    PubMed

    Peshkova, Tatyana V; Minkov, Ivan L; Tsekov, Roumen; Slavchov, Radomir I

    2016-09-01

    A method is proposed for the experimental determination of the adsorption of inorganic electrolytes at a surface covered with insoluble surfactant monolayer. This task is complicated by the fact that the change of the salt concentration alters both chemical potentials of the electrolyte and the surfactant. Our method resolves the question by combining data for the surface pressure versus area of the monolayer at several salt concentrations with data for the equilibrium spreading pressure of crystals of the surfactant (used to fix a standard state). We applied the method to alcohols spread at the surface of concentrated halide solutions. The measured salt adsorption is positive and has nonmonotonic dependence on the area per surfactant molecule. For the liquid expanded film, depending on the concentration, there is one couple of ions adsorbed per each 3-30 surfactant molecules. We analyzed which ion, the positive or the negative, stands closer to the surface, by measuring the effect of NaCl on the Volta potential of the monolayer. The potentiometric data suggest that Na(+) is specifically adsorbed, while Cl(-) remains in the diffuse layer, i.e., the surface is positively charged. The observed reverse Hofmeister series of the adsorptions of NaF, NaCl, and NaBr suggests the same conclusion holds for all these salts. The force that causes the adsorption of Na(+) seems to be the interaction of the ion with the dipole moment of the monolayer. PMID:27529571

  9. The cellulase-mediated saccharification on wood derived from transgenic low-lignin lines of black cottonwood (Populus trichocarpa).

    PubMed

    Min, Douyong; Li, Quanzi; Jameel, Hasan; Chiang, Vincent; Chang, Hou-min

    2012-10-01

    Downregulated lignin transgenic black cottonwood (Populus trichocarpa) was used to elucidate the effect of lignin and xylan content on enzymatic saccharification. The lignin contents of three transgenic samples (4CL1-1, 4CL1-4, and CH8-1-4) were 19.3, 16.7, and 15.0 %, respectively, as compared with the wild type (21.3 %). The four pretreatments were dilute acid (0.1 % sulfuric acid, 185 °C, 30 min), green liquor (6 % total titratable alkali, 25 % sulfidity based on TTA, 185 °C, and 15 min.), autohydrolysis (185 °C, 30 min), and ozone delignification (25 °C, 30 min). Following the pretreatment, enzymatic saccharification was carried out using an enzyme charge of 5 FPU/g of substrates. The removal of lignin and hemicellulose varies with both the types of pretreatments and the lignin content of the transgenic trees. Due to the greatest removal of lignin, green liquor induced the highest sugar production and saccharification efficiency, followed by acid, ozone, and autohydrolysis in descending order. The results indicated that lignin is the main recalcitrance of biomass degradation. At a given lignin content, pretreatment with ozone delignification had lower saccharification efficiency than the other pretreatment methods due to higher xylan content. PMID:22903324

  10. Engineering Monolignol 4-O-Methyltransferases to Modulate Lignin Biosynthesis

    SciTech Connect

    Bhuiya, M.W.; Liu, C.

    2010-01-01

    Lignin is a complex polymer derived from the oxidative coupling of three classical monolignols. Lignin precursors are methylated exclusively at the meta-positions (i.e. 3/5-OH) of their phenyl rings by native O-methyltransferases, and are precluded from substitution of the para-hydroxyl (4-OH) position. Ostensibly, the para-hydroxyls of phenolics are critically important for oxidative coupling of phenoxy radicals to form polymers. Therefore, creating a 4-O-methyltransferase to substitute the para-hydroxyl of monolignols might well interfere with the synthesis of lignin. The phylogeny of plant phenolic O-methyltransferases points to the existence of a batch of evolutionarily 'plastic' amino acid residues. Following one amino acid at a time path of directed evolution, and using the strategy of structure-based iterative site-saturation mutagenesis, we created a novel monolignol 4-O-methyltransferase from the enzyme responsible for methylating phenylpropenes. We show that two plastic residues in the active site of the parental enzyme are vital in dominating substrate discrimination. Mutations at either one of these separate the evolutionarily tightly linked properties of substrate specificity and regioselective methylation of native O-methyltransferase, thereby conferring the ability for para-methylation of the lignin monomeric precursors, primarily monolignols. Beneficial mutations at both sites have an additive effect. By further optimizing enzyme activity, we generated a triple mutant variant that may structurally constitute a novel phenolic substrate binding pocket, leading to its high binding affinity and catalytic efficiency on monolignols. The 4-O-methoxylation of monolignol efficiently impairs oxidative radical coupling in vitro, highlighting the potential for applying this novel enzyme in managing lignin polymerization in planta.

  11. 21 CFR 184.1372 - Insoluble glucose isomerase enzyme preparations.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Insoluble glucose isomerase enzyme preparations... enzyme preparations. (a) Insoluble glucose isomerase enzyme preparations are used in the production of... additional requirements for enzyme preparations in the Food Chemicals Codex, 3d Ed. (1981), p. 107, which...

  12. 21 CFR 184.1372 - Insoluble glucose isomerase enzyme preparations.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Insoluble glucose isomerase enzyme preparations... enzyme preparations. (a) Insoluble glucose isomerase enzyme preparations are used in the production of... additional requirements for enzyme preparations in the Food Chemicals Codex, 3d Ed. (1981), p. 107, which...

  13. Isolation and structural characterization of the milled wood lignin, dioxane lignin, and cellulolytic lignin preparations from brewer's spent grain.

    PubMed

    Rencoret, Jorge; Prinsen, Pepijn; Gutiérrez, Ana; Martínez, Ángel T; Del Río, José C

    2015-01-21

    The structure of the lignin from brewer's spent grain (BSG) has been studied in detail. Three different lignin preparations, the so-called "milled-wood" lignin (MWL), dioxane lignin (DL), and cellulolytic lignin (CEL), were isolated from BSG and then thoroughly characterized by pyrolysis GC/MS, 2D-NMR, and derivatization followed by reductive cleavage (DFRC). The data indicated that BSG lignin presents a predominance of guaiacyl units (syringyl/guaiacyl ratio of 0.4-0.5) with significant amounts of associated p-coumarates and ferulates. The flavone tricin was also present in the lignin from BSG, as also occurred in other grasses. 2D-NMR (HSQC) revealed that the main substructures present are β-O-4' alkyl-aryl ethers (77-79%) followed by β-5' phenylcoumarans (11-13%) and lower amounts of β-β' resinols (5-6%) and 5-5' dibenzodioxocins (3-5%). The results from 2D-NMR (HMBC) and DFRC indicated that p-coumarates are acylating the γ-carbon of lignin side chains and are mostly involved in condensed structures. DFRC analyses also indicated a minor degree of γ-acylation with acetate groups, which takes place preferentially on S lignin (6% of S units are acetylated) over G lignin (only 1% of G units are acetylated). PMID:25520237

  14. Chemical composition and enzymatic digestibility of sugarcane clones selected for varied lignin content

    PubMed Central

    2011-01-01

    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 the enzymatic treatment

  15. The Influence of Zeolites on Radical Formation During Lignin Pyrolysis.

    PubMed

    Bährle, Christian; Custodis, Victoria; Jeschke, Gunnar; van Bokhoven, Jeroen A; Vogel, Frédéric

    2016-09-01

    Lignin from lignocellulosic biomass is a promising source of energy, fuels, and chemicals. The conversion of the polymeric lignin to fuels and chemicals can be achieved by catalytic and noncatalytic pyrolysis. The influence of nonporous silica and zeolite catalysts, such as silicalite, HZSM5, and HUSY, on the radical and volatile product formation during lignin pyrolysis was studied by in situ high-temperature electron paramagnetic resonance spectroscopy (HTEPR) as well as GC-MS. Higher radical concentrations were observed in the samples containing zeolite compared to the sample containing only lignin, which suggests that there is a stabilizing effect by the inorganic surfaces on the formed radical fragments. This effect was observed for nonporous silica as well as for HUSY, HZSM5, and silicalite zeolite catalysts. However, the effect is far larger for the zeolites owing to their higher specific surface area. The zeolites also showed an effect on the volatile product yield and the product distribution within the volatile phase. Although silicalite showed no effect on the product selectivity, the acidic zeolites such as HZSM5 or HUSY increased the formation of deoxygenated products such as benzene, toluene, xylene (BTX), and naphthalene. PMID:27486717

  16. Organic matter transformation in the environment investigated by quantitative electron paramagnetic resonance (EPR) spectroscopy: studies on lignins

    NASA Astrophysics Data System (ADS)

    Czechowski, Franciszek; Golonka, Iwona; Jezierski, Adam

    2004-05-01

    The lignins separated from angiosperm and gymnosperm trees, peat and xylitic brown coal were investigated by quantitative EPR. Observed free radicals in lignins are sensitive to alkaline environment. Gaseous ammonia interacting with solid lignins in resonance cavity shifts quinone-hydroquinone equilibria towards formation of semiquinone anions. Complexation of copper(II) by lignins causes drastic decrease of the semiquinones in the matrices. Formation of lignin-Pb(II) complexes yielded radicals characterised by unusually low g-value (1.9999-2.0003). Monomeric structural units of the investigated lignins were recognised by pyrolysis with in situ methylation by tetramethylammonium hydroxide. Although for the natural lignins the mixture of normal semiquinone signals at g about 2.0034 and signals at g 1.9999 were observed, some monomeric components of lignins (e.g., caffeic acid, pyrogallol) gave pure lines at g=1.9999. The bacterial oxidative biodegradation of lignin monomeric components and their Pb(II) complexes resulted in increase of the radical signals.

  17. Bacterial degradation of synthetic and kraft lignin by axenic and mixed culture and their metabolic products.

    PubMed

    Chandra, Ram; Bharagava, Ram Naresh

    2013-11-01

    Pulp paper mill effluent has high pollution load due to presence of lignin and its derivatives as major colouring and polluting constituents. In this study, two lignin degrading bacteria IITRL1 and IITRSU7 were isolated and identified as Citrobacter freundii (FJ581026) and Citrobacter sp. (FJ581023), respectively. In degradation study by axenic and mixed culture, mixed bacterial culture was found more effective compared to axenic culture as it decolourized 85 and 62% of synthetic and kraft lignin whereas in axenic conditions, bacterium IITRL1 and IITRSU7 decolourized 61 and 64% synthetic and 49 and 54% kraft lignin, respectively. Further, the mixed bacterial culture also showed the removal of 71, 58% TOC; 78, 53% AOX; 70, 58% COD and 74, 58% lignin from synthetic and kraft lignin, respectively. The ligninolytic enzyme was characterized as manganese peroxidase by SDS-PAGE yielding a single band of 43 KDa. The HPLC analysis of degraded samples showed reduction as well as shifting of peaks compared to control indicating the degradation as well as transformation of compounds. Further, in GC-MS analysis of synthetic and kraft lignin degraded samples, hexadecanoic acid was found as recalcitrant compounds while 2,4,6-trichloro-phenol, 2,3,4,5-tetrachloro-phenol and pentachloro-phenol were detected as new metabolites. PMID:24555327

  18. Solubilization of insoluble inorganic phosphate by Burkholderia cepacia DA23 isolated from cultivated soil

    PubMed Central

    Song, Ok-Ryul; Lee, Seung-Jin; Lee, Yong-Seok; Lee, Sang-Cheol; Kim, Keun-Ki; Choi, Yong-Lark

    2008-01-01

    A mineral phosphate solubilizing bacterium, Burkholderia cepacia DA23 has been isolated from cultivated soils. Phosphate-solubilizing activities of the strain against three types of insoluble phosphate were quantitatively determined. When 3% of glucose concentration was used for carbon source, the strain had a marked mineral phosphate-solubilizing activity. Mineral phosphate solubilization was directly related to the pH drop by the strain. Analysis of the culture medium by high pressure liquid chromatography identified gluconic acid as the main organic acid released by Burkholderia cepacia DA23. Gluconic acid production was apparently the result of the glucose dehydrogenase activity and glucose dehydrogenase was affected by phosphate regulation. PMID:24031195

  19. Combination of different methods to assess the fate of lignin in decomposing needle and leave litter

    NASA Astrophysics Data System (ADS)

    Klotzbücher, Thimo; Filley, Timothy; Kaiser, Klaus; Kalbitz, Karsten

    2010-05-01

    Lignin is a major component of plant litter. However, its fate during litter decay is still poorly understood. One reason is the difficult analysis. Commonly used methods utilize different methodological approaches and focus on different aspects, e.g., content of lignin and/or of lignin-derived phenols and the degree of oxidation. The comparability and feasibility of the methods has not been tested so far. Our aims were: (1) to compare different methods with respect to track lignin degradation during plant litter decay and (2) to evaluate possible advantages of combining the different results. We assessed lignin degradation in decaying litter by 13C-TMAH thermochemolysis and CuO oxidation (each combined with GC/MS) and by determination of acid-detergent lignin (ADL) combined with near infrared spectroscopy. Furthermore, water-extractable organic matter produced during litter decay was examined for indicators of lignin-derived compounds by UV absorbance at 280 nm, fluorescence spectroscopy, and 13C-TMAH GC/MS. The study included litter samples from 5 different tree species (acer, ash, beech, pine, spruce), exposed in litterbags to degradation in a spruce stand for 27 months. First results suggested stronger lignin degradation in coniferous than in deciduous litter. This was indicated by complementary results from various methods: Conifer litter showed a more pronounced decrease in ADL content and a stronger increase in oxidation degree of side chains (Ac/Al ratios of CuO oxidation and 13C-TMAH products). Furthermore water extracted organic matter from needles showed a higher aromaticity and molecule complexity. Thus properties of water extractable organic matter seemed to reflect the extents of lignin degradation in solid litter samples. Contents of lignin-derived phenols determined with the CuO method (VSC content) hardly changed during decay of needles and leaves. These results thus not matched the trends found with the ADL method. Our results suggested that water

  20. Purification, structural characterization, and modification of organosolv wheat straw lignin.

    PubMed

    Mbotchak, Laurie; Le Morvan, Clara; Duong, Khanh Linh; Rousseau, Brigitte; Tessier, Martine; Fradet, Alain

    2015-06-01

    Biolignin, a wheat straw lignin produced by acetic acid/formic acid/water hydrolysis, was characterized by (31)P and (13)C-(1)H 2D NMR spectroscopy and by size-exclusion chromatography. Biolignin is a mixture of low molar mass compounds (Mn = 1660 g/mol) made up of S, G, and H units and of coumaric and ferulic acid units. β-5 and β-O-4 interunit linkages are partially acylated in the γ-position by acetate and p-coumarate groups. Deacylated samples with a low content of contaminants were obtained by combining alkaline hydrolysis and solvent extraction. The high phenolic OH content found by (31)P NMR reflects the presence of condensed aromatic units, such as 5-5 units. Reaction of purified lignin with ethanol and ethane-1,2-diol yielded esterified lignins much more soluble than Biolignin in common organic solvents. During this reaction, the secondary OH of β-O-4 linkages was simultaneously etherified. Phenol hydroxyethylation by 2-chloroethanol yielded samples containing only aliphatic hydroxyl groups. PMID:25961961

  1. Heterogeneous Ozonolysis of Surface Adsorbed Lignin Pyrolysis Products

    NASA Astrophysics Data System (ADS)

    Hinrichs, R. Z.

    2012-12-01

    Biomass combustion releases semi-volatile organic compounds into the troposphere, including many phenols and methoxyphenols as the result of lignin pyrolysis. Given their relatively low vapor pressures, these compounds readily adsorb on inorganic and organic aerosol substrates where they may alter aerosol properties and undergo heterogeneous chemistry. We use infrared spectroscopy (DRIFTS and ATR-FTIR) to monitor the adsorption and subsequent heterogeneous ozonolysis of model lignin pyrolysis products, including catechol, eugenol, and 4-propylguaiacol. Ozonolysis reaction kinetics were compared on various inorganic substrates - such as Al2O3 and NaCl, which serve as mineral and sea salt aerosol substrates, respectively - and as a function of ozone concentration and relative humidity. Following in situ FTIR analysis, the adsorbed organics were extracted and analyzed using gas chromatography-mass spectroscopy to identify reaction products and quantify product branching ratios. Ozonolysis of catechol and 4-propylguaiacol readily resulted in ring cleavage forming dicarboxylic acids (e.g., muconic acid). Eugenol ozonolysis proceeded rapidly at the alkene side chain producing homovanillic acid and homovanillin in an approximate 2:1 branching ratio at 0% RH; ring cleavage was also observed. For all lignin pyrolysis products, heterogeneous ozonolysis was faster on NaCl versus Al2O3. Implications for the atmospheric chemistry of semi-volatile methoxylphenols adsorbed on aerosol substrates will be discussed.

  2. Lignin phenols used to infer organic matter sources to Sepetiba Bay - RJ, Brasil

    NASA Astrophysics Data System (ADS)

    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.

  3. Lignins of bioenergy crops: a review?

    PubMed

    Guragain, Yadhu N; Herrera, Alvaro I; Vadlani, Praveen V; Prakash, Om

    2015-01-01

    Lignin provides structural support, a mechanical barrier against microbial infestation and facilitates movement of water inside plant systems. It is the second most abundant natural polymer in the terrestrial environments and possesses unique routes for the production of bulk and specialty chemicals with aromatic/phenolic skeletons. The commercial applications of lignin are limited and it is often recognized for its negative impact on the biochemical conversion of lignocellulosic biomass to fuels and chemicals. Understanding of the structure of lignin monomers and their interactions among themselves, as well as with carbohydrate polymers in biomass, is vital for the development of innovative biomass deconstruction processes and thereby valorization of all biopolymers of lignocellulosic residues, including lignin. In this paper, we review the major energy crops and their lignin structure, as well as the recent developments in biomass lignin characterization, with special focus on 1D and 2D Nuclear Magnetic Resonance (NMR) techniques. PMID:25920245

  4. Designer lignins: harnessing the plasticity of lignification.

    PubMed

    Mottiar, Yaseen; Vanholme, Ruben; Boerjan, Wout; Ralph, John; Mansfield, Shawn D

    2016-02-01

    Lignin is a complex polyphenolic constituent of plant secondary cell walls. Inspired largely by the recalcitrance of lignin to biomass processing, plant engineering efforts have routinely sought to alter lignin quantity, composition, and structure by exploiting the inherent plasticity of lignin biosynthesis. More recently, researchers are attempting to strategically design plants for increased degradability by incorporating monomers that lead to a lower degree of polymerisation, reduced hydrophobicity, fewer bonds to other cell wall constituents, or novel chemically labile linkages in the polymer backbone. In addition, the incorporation of value-added structures could help valorise lignin. Designer lignins may satisfy the biological requirement for lignification in plants while improving the overall efficiency of biomass utilisation. PMID:26775114

  5. Lignin-Derived Advanced Carbon Materials

    DOE PAGESBeta

    Chatterjee, Sabornie; Saito, Tomonori

    2015-11-16

    Lignin is a highly abundant source of renewable carbon that can be considered as a valuable sustainable source of biobased materials. By applying specific pretreatments and manufacturing methods, it has been found that lignin can be converted into a variety of value-added carbon materials. However, the physical and chemical heterogeneities of lignin complicate its use as a feedstock. Herein, we discuss the lignin manufacturing process, the effects of pretreatments and manufacturing methods on the properties of product lignin, and structure–property relationships in various applications of lignin-derived carbon materials, such as carbon fibers, carbon mats, activated carbons, carbon films, and templatedmore » carbon.« less

  6. Conversion and Extraction of Insoluble Organic Materials in Meteorites

    NASA Technical Reports Server (NTRS)

    Locke, Darren R.; Burton, Aaron S.; Niles, Paul B.

    2016-01-01

    We endeavor to develop and implement methods in our laboratory to convert and extract insoluble organic materials (IOM) from low car-bon bearing meteorites (such as ordinary chondrites) and Precambrian terrestrial rocks for the purpose of determining IOM structure and prebiotic chemistries preserved in these types of samples. The general scheme of converting and extracting IOM in samples is summarized in Figure 1. First, powdered samples are solvent extracted in a micro-Soxhlet apparatus multiple times using solvents ranging from non-polar to polar (hexane - non-polar, dichloromethane - non-polar to polar, methanol - polar protic, and acetonitrile - polar aprotic). Second, solid residue from solvent extractions is processed using strong acids, hydrochloric and hydrofluoric, to dissolve minerals and isolate IOM. Third, the isolated IOM is subjected to both thermal (pyrolysis) and chemical (oxidation) degradation to release compounds from the macromolecular material. Finally, products from oxidation and pyrolysis are analyzed by gas chromatography - mass spectrometry (GCMS). We are working toward an integrated method and analysis scheme that will allow us to determine prebiotic chemistries in ordinary chondrites and Precambrian terrestrial rocks. Powerful techniques that we are including are stepwise, flash, and gradual pyrolysis and ruthenium tetroxide oxidation. More details of the integrated scheme will be presented.

  7. Isotopic composition of hydrogen in insoluble organic matter from cherts

    NASA Technical Reports Server (NTRS)

    Krishnamurthy, R. V.; Epstein, S.

    1991-01-01

    Robert (1989) reported the presence of unusually enriched hydrogen in the insoluble HF-HCl residue extracted from two chert samples of Eocene and Pliocene ages. Since the presence of heavy hydrogen might be due to the incorporation of extraterrestrial materials, we desired to reexamine the same samples to isolate the D-rich components. Our experiments did not reveal any D-rich components, but the hydrogen isotope composition of the insoluble residue of the two chert samples was well within the range expected for terrestrial organic matter. We also describe a protocol that needs to be followed in the hydrogen isotope analysis of any insoluble organic matter.

  8. Biochemical Composition and Assembly of Biosilica-associated Insoluble Organic Matrices from the Diatom Thalassiosira pseudonana.

    PubMed

    Kotzsch, Alexander; Pawolski, Damian; Milentyev, Alexander; Shevchenko, Anna; Scheffel, André; Poulsen, Nicole; Shevchenko, Andrej; Kröger, Nils

    2016-03-01

    The nano- and micropatterned biosilica cell walls of diatoms are remarkable examples of biological morphogenesis and possess highly interesting material properties. Only recently has it been demonstrated that biosilica-associated organic structures with specific nanopatterns (termed insoluble organic matrices) are general components of diatom biosilica. The model diatom Thalassiosira pseudonana contains three types of insoluble organic matrices: chitin meshworks, organic microrings, and organic microplates, the latter being described in the present study for the first time. To date, little is known about the molecular composition, intracellular assembly, and biological functions of organic matrices. Here we have performed structural and functional analyses of the organic microrings and organic microplates from T. pseudonana. Proteomics analysis yielded seven proteins of unknown function (termed SiMat proteins) together with five known silica biomineralization proteins (four cingulins and one silaffin). The location of SiMat1-GFP in the insoluble organic microrings and the similarity of tyrosine- and lysine-rich functional domains identifies this protein as a new member of the cingulin protein family. Mass spectrometric analysis indicates that most of the lysine residues of cingulins and the other insoluble organic matrix proteins are post-translationally modified by short polyamine groups, which are known to enhance the silica formation activity of proteins. Studies with recombinant cingulins (rCinY2 and rCinW2) demonstrate that acidic conditions (pH 5.5) trigger the assembly of mixed cingulin aggregates that have silica formation activity. Our results suggest an important role for cingulins in the biogenesis of organic microrings and support the hypothesis that this type of insoluble organic matrix functions in biosilica morphogenesis. PMID:26710847

  9. Insoluble layer deposition and dilatational rheology at a microscale spherical cap interface.

    PubMed

    Kotula, Anthony P; Anna, Shelley L

    2016-08-17

    The dilatational properties of insoluble monolayers are important for understanding the mechanics of biological systems and consumer products, but isolating the dilatational response of an interface is challenging due to the difficulties in separating dilatation from shear and other deformation modes. Oscillations of a microscale bubble radius are useful for generating purely dilatational flows, but the current deposition methods for insoluble layers onto fluid interfaces are not easily scaled down. In this paper, we describe a miscible solvent exchange procedure for generating insoluble layers at an air-water interface pinned at the tip of a capillary tens of micrometers in diameter. We show that the amount of surfactant adsorbed at the interface can be controlled by the initial concentration dissolved in isopropanol (the starting solvent) and the volumetric flow rate of solvent exchange. Surface pressure-area isotherms and dilatational moduli are measured concurrently for three insoluble surfactants: palmitic acid (PA), dimyristoylphosphatidylcholine (DMPC) and dipalmitoylphosphatidylcholine (DPPC). The isotherms measured on the microscale interface compare well with previous experiments performed on a Langmuir trough. However, the magnitudes of the dilatational moduli differ from those measured on either Langmuir trough or pendant drop apparatuses. Several possible reasons for the observed differences are discussed. A comparison of the dilatational modulus with the Gibbs elasticity is used to determine the presence of dilatational extra stresses at the interface. The isotherm and dilatational modulus of the insoluble component of the industrial surfactant Tween 80 are measured using this approach. The methods developed here also open the possibility for future study of the important role of finite size effects on microstructure formation and the resulting interfacial mechanics. PMID:27478885

  10. G-lignin and hemicellulosic monosaccharides distinctively affect biomass digestibility in rapeseed.

    PubMed

    Pei, Yanjie; Li, Yuyang; Zhang, Youbing; Yu, Changbing; Fu, Tingdong; Zou, Jun; Tu, Yuanyuan; Peng, Liangcai; Chen, Peng

    2016-03-01

    In this study, total 19 straw samples from four Brassica species were determined with a diverse cell wall composition and varied biomass enzymatic digestibility under sulfuric acid or lime pretreatment. Correlation analysis was then performed to detect effects of cell wall compositions and wall polymer features (cellulose crystallinity, hemicellulosic monosaccharides and lignin monomers) on rapeseeds biomass digestibility. As a result, coniferyl alcohol (G-lignin) showed a strongly negative effect on biomass saccharification, whereas hemicellulosic monosaccharides (fucose, galactose, arabinose and rhamnose) were positive factors on lignocellulose digestions. Notably, chemical analyses of four typical pairs of samples indicated that hemicellulosic monosaccharides and G-lignin may coordinately influence biomass digestibility in rapeseeds. In addition, Brassica napus with lower lignin content exhibited more efficiency on both biomass enzymatic saccharification and ethanol production, compared with Brassica junjea. Hence, this study has at first time provided a genetic strategy on cell wall modification towards bioenergy rapeseed breeding. PMID:26748046

  11. Use of food and packaging model matrices to investigate the antioxidant properties of biorefinery grass lignins.

    PubMed

    Aguié-Béghin, Véronique; Foulon, Laurence; Soto, Paola; Crônier, David; Corti, Elena; Legée, Frédéric; Cézard, Laurent; Chabbert, Brigitte; Maillard, Marie-Noëlle; Huijgen, Wouter J J; Baumberger, Stéphanie

    2015-11-18

    The antioxidant properties of grass lignins recovered from an alkaline industrial process and from different ethanol organosolv pretreatment processes were compared using two types of tests: (i) classical radical 2,2'-diphenyl-1-picrylhydrazyl (DPPH(•)) scavenging tests in dioxane/water or ethanol and (ii) tests involving multiphasic systems (lipid dispersion in water or cellulose film suspended in ethanol). These multiphasic systems were representative of food and packaging matrices in view of high-value applications. All lignins, in solution or in the film, effectively scavenged radicals. Moreover, they were competitive with a food commercial rosemary extract to protect linoleic acid against oxidation. Whereas the DPPH(•) test in dioxane was not discriminant, differences appeared between lignins when the test was performed in ethanol or with the multiphasic systems. Moreover, radical scavenging activity was preserved in the film even after its immersion in ethanol. Structural analysis of lignins revealed that low-molar-mass phenolics, namely p-hydroxycinnamic acids and lignin depolymerization products, governed lignin antioxidant properties in the multiphasic systems. PMID:26477864

  12. Cytocompatible cellulose hydrogels containing trace lignin.

    PubMed

    Nakasone, Kazuki; Kobayashi, Takaomi

    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 12h. 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 0.43N/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. PMID:27127053

  13. Structural characterization of lignin: a potential source of antioxidants guaiacol and 4-vinylguaiacol.

    PubMed

    Azadfar, Mohammadali; Gao, Allan Haiming; Bule, Mahesh V; Chen, Shulin

    2015-04-01

    The structure of lignin obtained from the ozone and soaking aqueous ammonia pretreatment of wheat straw has been characterized utilizing chemical analytical methods in order to reveal its antioxidant characteristics, including attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), pyrolysis/tetramethylammonium hydroxide-gas chromatography/mass spectrometry (Py/TMAH-GC/MS), gel permeation chromatography (GPC), ultra violet-visible spectroscopy (UV-vis), and 1,1-diphenyl-2-picrylhydrazyl (DPPH) antioxidant evaluation assay. The results demonstrated that the isolated lignin is a ρ-hydroxyphenyl- guaiacyl-syringyl (H-G-S) lignin, with S/G ratio of 0.35 and significant amounts of phenol 2-methoxy (guaiacol) and phenol 2-methoxy-4-vinyl (4-vinylguaiacol). The Py-GC/MS and Py/TMAH-GC/MS pyrograms indicated that the major units in this lignin are derived from hydroxycinnamic acids. The GPC results revealed the molecular weight of the lignin was considerably low and also the FTIR analysis showed that the lignin possessed hydroxyl and methoxy functional groups; the factors led to the extracted lignin having a comparable antioxidant activity to that of currently used commercial antioxidants. The UV-vis and DPPH antioxidant assay results suggested a percentage of inhibition of the DPPH radicals in the following order: guaiacol (103.6 ± 1.36)>butylated hydroxytoluene (103.3 ± 1)>ferulic acid (102.6 ± 0.79)>pretreated lignin (86.9 ± 0.34). PMID:25603142

  14. Lignin-solubilizing ability of actinomycetes isolated from termite (Termitidae) gut. [Streptomyces viridosporus

    SciTech Connect

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

    1990-07-01

    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 ({sup 14}C)lignin- and ({sup 14}C)cellulose-labeled phloem of Abies concolor to {sup 14}CO{sub 2} and {sup 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 {sup 14}CO{sub 2} evolution from ({sup 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.

  15. Dissolving mechanism of strain P17 on insoluble phosphorus of yellow-brown soil

    PubMed Central

    Chuan-qing, Zhong; Guang-xiang, Cao; Wei-yi, Huang; Xing-she, Luan; Yi-fei, Yang

    2014-01-01

    Strain P17 was a bacterial strain identified as Bacillus megaterium isolated from ground accumulating phosphate rock powder. The fermentation broth of strain P17 and the yellow-brown soil from Nanjing Agricultural University garden were collected to conduct this study. The simulation of fixed insoluble phosphorous forms after applying calcium superphosphate into yellow-brown soil was performed in pots, while available P and total P of soil were extremely positive correlative with those of groundwater. Then the dissolving effect of strain P17 on insoluble P of yellow-brown soil was studied. Results showed that Bacillus megaterium strain P17 had notable solubilizing effect on insoluble phosphates formed when too much water-soluble phosphorous fertilizer used. During 100 days after inoculation, strain P17 was dominant. Until the 120th day, compared with water addition, available P of strain P17 inoculation treated soil increased by 3 times with calcium superphosphate addition. Besides available P, pH, activity of acid and alkaline phosphatase and population of P-solubilizing microbes were detected respectively. P-solubilizing mechanism of P-solubilizing bacteria strain P17 seems to be a synergetic effect of pH decrease, organic acids, phosphatase, etc. PMID:25477929

  16. Dissolving mechanism of strain P17 on insoluble phosphorus of yellow-brown soil.

    PubMed

    Zhong, Chuan-qing; Cao, Guang-xiang; Huang, Wei-yi; Luan, Xing-she; Yang, Yi-fei

    2014-01-01

    Strain P17 was a bacterial strain identified as Bacillus megaterium isolated from ground accumulating phosphate rock powder. The fermentation broth of strain P17 and the yellow-brown soil from Nanjing Agricultural University garden were collected to conduct this study. The simulation of fixed insoluble phosphorous forms after applying calcium superphosphate into yellow-brown soil was performed in pots, while available P and total P of soil were extremely positive correlative with those of groundwater. Then the dissolving effect of strain P17 on insoluble P of yellow-brown soil was studied. Results showed that Bacillus megaterium strain P17 had notable solubilizing effect on insoluble phosphates formed when too much water-soluble phosphorous fertilizer used. During 100 days after inoculation, strain P17 was dominant. Until the 120th day, compared with water addition, available P of strain P17 inoculation treated soil increased by 3 times with calcium superphosphate addition. Besides available P, pH, activity of acid and alkaline phosphatase and population of P-solubilizing microbes were detected respectively. P-solubilizing mechanism of P-solubilizing bacteria strain P17 seems to be a synergetic effect of pH decrease, organic acids, phosphatase, etc. PMID:25477929

  17. Structural and physico-chemical properties of insoluble rice bran fiber: effect of acid–base induced modifications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The structural modifications of insoluble rice bran fiber (IRBF) by sequential regimes of sulphuric acid (H2SO4) and their effects on the physicochemical attributes were studied. The increment of H2SO4 concentration resulted in decreased water holding capacity that ultimately enhanced the oil bindin...

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

    PubMed

    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. PMID:26265762

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

    PubMed Central

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

    2015-01-01

    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. PMID:26265762

  20. Phenolic compounds as enhancers in enzymatic and electrochemical oxidation of veratryl alcohol and lignins.

    PubMed

    Díaz-González, María; Vidal, Teresa; Tzanov, Tzanko

    2011-03-01

    Sixteen phenolic compounds, 14 of which naturally occurring, were compared to the synthetic 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) and violuric acid (VA) in terms of their ability to act as mediators/enhancers in: (1) laccase oxidation of veratryl alcohol as a lignin model compound, and (2) electrochemical oxidation of kraft and flax lignins. HPLC analysis revealed that the syringyl-type phenols methyl syringate and acetosyringone were the most efficient natural enhancers in the laccase oxidation of veratryl alcohol. Both compounds, though far from the performance of ABTS were able to generate veratraldehyde in amount similar to that obtained with VA. By contrast, the best performing phenolic enhancers for the electrochemical oxidation of lignins were sinapinaldehyde, vanillin, acetovanillone, and syringic acid. Catalytic efficiencies close to those achieved with ABTS and VA were calculated for these phenolic compounds. PMID:21110019

  1. Method for recovering and using lignin in adhesive resins by extracting demethylated lignin

    DOEpatents

    Schroeder, Herbert A.

    1991-01-01

    Lignin, or a lignin derived material, which has been significantly demethylated (e.g., the demethylated lignin found in the raffinate produced as a by-product of dimethyl sulfide production which can be carried out using the spent liquor from wood pulping operations) can be isolated by a process wherein an organic solvent is added to a lignin-containing aqueous solution. The organic solvent is typically a polar, and at least a partially water-immiscible substance such as, for example, ethyl acetate. The resulting lignin-containing aqueous solution/organic solvent mixture is acidified to produce a water layer which is discarded and an organic solvent layer which contains the demethylated lignin. Upon its recovery, the demethylated lignin is preferably dried and stored until it is used (along with an alkali, an aldehyde and an adhesive filler) in compounding an adhesive of the type generally used in the manufacture of plywood.

  2. Identification of 4-O-5-Units in Softwood Lignins via Definitive Lignin Models and NMR.

    PubMed

    Yue, Fengxia; Lu, Fachuang; Ralph, Sally; Ralph, John

    2016-06-13

    Lignins are complex and heterogeneous natural polymers in which the major units are characterized by certain prominent interunit linkages. Previous attempts to identify and quantify 4-O-5-linked units in softwood lignins by NMR were not successful. In this work, various lignin model compounds, including the tetramers formed by the 4-O-5-coupling of β-O-4-, β-β-, and β-5-model dimers, were synthesized. Such compounds are better able to model the corresponding structures in lignins than those used previously. 4-O-5-Linked structures could be clearly observed and identified in real softwood lignin samples by comparison of their 2D HSQC NMR spectra with those from the model compounds. When comparing NMR data of phenol-acetylated versus phenol-etherified model compounds with those of acetylated lignins, it was apparent that most of the 4-O-5-linked structures in softwood lignins are present as free-phenolic end units. PMID:27078826

  3. Method for recovering and using lignin in adhesive resins by extracting demethylated lignin

    DOEpatents

    Schroeder, Herbert A.

    1991-01-01

    Lignin, or a lignin derived material, which has been significantly demethylated (e.g., the demethylated lignin found in the raffinate produced as a by-product of dimethyl sulfide production which can be carried out using the spent liquor from wood pulping operations) can be isolated by a process wherein an organic solvent is added to a lignin-containing aqueous solution. The organic solvent is typically a polar, and at least a partially water-immiscible substance such as, for example, ethyl acetate. The resulting lignin-containing aqueous solution/organic solvent mixture is acidified to produce a water layer which is discarded and an organic solvent layer which contains the demethylated lignin. Upon its recovery, the demethylated lignin is dissolved in an alkaline solution to which an aldehyde source is added to produce a resol-type resin. The aldehyde source may be formaldehyde in solution, paraformaldehyde, hexamethylenetetramine, or other aldehydes including acetaldehyde, furfural, and their derivatives.

  4. Development of Lignin-Based Polyurethane Thermoplastics

    SciTech Connect

    Saito, Tomonori; Perkins, Joshua H; Jackson, Daniel C; Trammell, Neil E; Hunt, Marcus A; Naskar, Amit K

    2013-01-01

    In our continued effort to develop value-added thermoplastics from lignin, here we report utilizing a tailored feedstock to synthesize mechanically robust thermoplastic polyurethanes at very high lignin contents (75 65 wt %). The molecular weight and glass transition temperature (Tg) of lignin were altered through cross-linking with formaldehyde. The cross-linked lignin was coupled with diisocyanate-based telechelic polybutadiene as a network-forming soft segment. The appearance of two Tg s, around 35 and 154 C, for the polyurethanes indicates the existence of two-phase morphology, a characteristic of thermoplastic copolymers. A calculated Flory-Huggins interaction parameter of 7.71 also suggests phase immiscibility in the synthesized lignin polyurethanes. An increase in lignin loading increased the modulus, and an increase in crosslink-density increased the modulus in the rubbery plateau region of the thermoplastic. This path for synthesis of novel lignin-based polyurethane thermoplastics provides a design tool for high performance lignin-based biopolymers.

  5. Lignin: Characterization of a Multifaceted Crop Component

    PubMed Central

    2013-01-01

    Lignin is a plant component with important implications for various agricultural disciplines. It confers rigidity to cell walls, and is therefore associated with tolerance to abiotic and biotic stresses and the mechanical stability of plants. In animal nutrition, lignin is considered an antinutritive component of forages as it cannot be readily fermented by rumen microbes. In terms of energy yield from biomass, the role of lignin depends on the conversion process. It contains more gross energy than other cell wall components and therefore confers enhanced heat value in thermochemical processes such as direct combustion. Conversely, it negatively affects biological energy conversion processes such as bioethanol or biogas production, as it inhibits microbial fermentation of the cell wall. Lignin from crop residues plays an important role in the soil organic carbon cycling, as it constitutes a recalcitrant carbon pool affecting nutrient mineralization and carbon sequestration. Due to the significance of lignin in several agricultural disciplines, the modification of lignin content and composition by breeding is becoming increasingly important. Both mapping of quantitative trait loci and transgenic approaches have been adopted to modify lignin in crops. However, breeding goals must be defined considering the conflicting role of lignin in different agricultural disciplines. PMID:24348159

  6. (Characterization of lignin peroxidases from Phanerochaete)

    SciTech Connect

    Not Available

    1990-11-14

    Work has continued on characterizing the kinetics of lignin peroxidases and has now expanded to include the chemistry of Mn peroxidases. Progress in these two area in addition to the authors work on the molecular biology of lignin biodegradation is briefly described below. Copies of two reprints and one preprint which have resulted from the work are attached.

  7. Method for regulation of plant lignin composition

    DOEpatents

    Chapple, Clint

    1999-01-01

    A method is disclosed for the regulation of lignin composition in plant tissue. Plants are transformed with a gene encoding an active F5H gene. The expression of the F5H gene results in increased levels of syringyl monomer providing a lignin composition more easily degraded with chemicals and enzymes.

  8. Biodegradation of lignin by Agaricus Bisporus

    SciTech Connect

    Vane, C.H.; Abbott, G.D.; Head, I.M.

    1996-12-31

    The lignolytic activity of Agaricus bisporus will be addressed in this paper. Sound and fungally degraded lignins were characterized by Pyrolysis-Gas Chromatography-Mass Spectrometry (Py-GC-MS), Fourier Transform Infrared Spectroscopy (FnR) and elemental analysis. Fungally degraded lignins displayed increased wt%N, wt%H and wt%O content and decreased wt%C content The FTIR spectrum of decayed lignin showed an increase in the relative intensity of absorption bands assigned to carbonyl and carboxyl functional groups located on the aliphatic side chain and a decrease in absorption bands assigned to aromatic skeletal vibration modes. Semiquantitative Py-GC-MS revealed an 82% decrease in lignin derived pyrolysis products upon biodegradation. No significant increase in pyrolysis products with an oxygenated aliphatic side chain were detected in the fungally degraded lignin however shortening of the aliphatic side chain via cleavage at the {alpha}, {beta} and {gamma} positions was observed.

  9. Genome sequence and description of the anaerobic lignin-degrading bacterium Tolumonas lignolytica sp. nov.

    DOE PAGESBeta

    Billings, Andrew F.; Fortney, Julian L.; Hazen, Terry C.; Simmons, Blake; Davenport, Karen W.; Goodwin, Lynne; Ivanova, Natalia; Kyrpides, Nikos C.; Mavromatis, Konstantinos; Woyke, Tanja; et al

    2015-11-19

    Tolumonas lignolytica BRL6-1T sp. nov. is the type strain of T. lignolytica sp. nov., a proposed novel species of the Tolumonas genus. This strain was isolated from tropical rainforest soils based on its ability to utilize lignin as a sole carbon source. Cells of Tolumonas lignolytica BRL6-1T are mesophilic, non-spore forming, Gram-negative rods that are oxidase and catalase negative. The genome for this isolate was sequenced and returned in seven unique contigs totaling 3.6Mbp, enabling the characterization of several putative pathways for lignin breakdown. Particularly, we found an extracellular peroxidase involved in lignin depolymerization, as well as several enzymes involvedmore » in β-aryl ether bond cleavage, which is the most abundant linkage between lignin monomers. We also found genes for enzymes involved in ferulic acid metabolism, which is a common product of lignin breakdown. Finally, by characterizing pathways and enzymes employed in the bacterial breakdown of lignin in anaerobic environments, this work should assist in the efficient engineering of biofuel production from lignocellulosic material.« less

  10. Catalytic oxidation of biorefinery lignin to value-added chemicals to support sustainable biofuel production.

    PubMed

    Ma, Ruoshui; Xu, Yan; Zhang, Xiao

    2015-01-01

    Transforming plant biomass to biofuel is one of the few solutions that can truly sustain mankind's long-term needs for liquid transportation fuel with minimized environmental impact. However, despite decades of effort, commercial development of biomass-to-biofuel conversion processes is still not an economically viable proposition. Identifying value-added co-products along with the production of biofuel provides a key solution to overcoming this economic barrier. Lignin is the second most abundant component next to cellulose in almost all plant biomass; the emerging biomass refinery industry will inevitably generate an enormous amount of lignin. Development of selective biorefinery lignin-to-bioproducts conversion processes will play a pivotal role in significantly improving the economic feasibility and sustainability of biofuel production from renewable biomass. The urgency and importance of this endeavor has been increasingly recognized in the last few years. This paper reviews state-of-the-art oxidative lignin depolymerization chemistries employed in the papermaking process and oxidative catalysts that can be applied to biorefinery lignin to produce platform chemicals including phenolic compounds, dicarboxylic acids, and quinones in high selectivity and yield. The potential synergies of integrating new catalysts with commercial delignification chemistries are discussed. We hope the information will build on the existing body of knowledge to provide new insights towards developing practical and commercially viable lignin conversion technologies, enabling sustainable biofuel production from lignocellulosic biomass to be competitive with fossil fuel. PMID:25272962

  11. Syringyl lignin production in conifers: Proof of concept in a Pine tracheary element system

    PubMed Central

    Wagner, Armin; Tobimatsu, Yuki; Phillips, Lorelle; Flint, Heather; Geddes, Barbara; Lu, Fachuang; Ralph, John

    2015-01-01

    Conifers (softwoods) naturally lack syringyl units in their lignins, rendering lignocellulosic materials from such species more difficult to process than syringyl-rich hardwood species. Using a transformable Pinus radiata tracheary element (TE) system as an experimental platform, we investigated whether metabolic engineering can be used to create syringyl lignin in conifers. Pyrolysis-GC/MS and 2D-NMR analysis of P. radiata TE cultures transformed to express ferulate 5-hydroxylase (F5H) and caffeic acid O-methyltransferase (COMT) from Liquidambar styraciflua confirmed the production and incorporation of sinapyl alcohol into the lignin polymer. Transformation with F5H was sufficient for the production of syringyl lignin in TEs, but cotransformation with COMT improved its formation. In addition, lower levels of the pathway intermediate 5-hydroxyconiferyl alcohol were evidenced in cotransformation experiments, indicating that the introduction of the COMT overcame the inefficiency of the native pine methyltransferases for supporting sinapyl alcohol production.Our results provide the proof of concept that it is possible to generate a lignin polymer that contains syringyl units in softwood species such as P. radiata, suggesting that it might be possible to retain the outstanding fiber properties of softwoods while imbuing them with the lignin characteristics of hardwoods that are more favorable for industrial processing. PMID:25902506

  12. In vitro evaluation of antioxidant and cytotoxic activities of lignin fractions extracted from Acacia nilotica.

    PubMed

    Barapatre, Anand; Meena, Avtar Singh; Mekala, Sowmya; Das, Amitava; Jha, Harit

    2016-05-01

    Lignin is one of the most important phytomacromolecule with diverse therapeutic properties such as anticancer, antimicrobial, anti-inflammatory and immune-stimulatory. The present study was carried out to evaluate the in vitro antioxidant, free radical scavenging and anti-proliferative/cytotoxic activities of eleven different lignin fractions, extracted from the wood of Acacia nilotica by pressurized solvent extraction (PSE) and successive solvent extraction (SSE) methods. Results indicate that the PSE fractions have high polyphenolic content and reducing power. However, the antioxidant efficiency examined by DPPH and ABTS radical scavenging assay was higher in SSE fractions. All lignin fractions revealed a significant ability to scavenge nitric oxide, hydroxyl and superoxide radicals. The extracted lignin fractions display high ferric ion reducing capacity and also possess excellent antioxidant potential in the hydrophobic (linoleic acid) system. Fractions extracted by polar solvent has the highest iron (Fe(2+)) chelating activity as compared to other factions, indicating their effect on the redox cycling of iron. Four lignin fractions depicted higher cytotoxic potential (IC50: 2-15 μg/mL) towards breast cancer cell line (MCF-7) but were ineffective (IC50: ≥ 100 μg/mL) against normal primary human hepatic stellate cells (HHSteCs). These findings suggest that the lignin extracts of A. nilotica wood has a remarkable potential to prevent disease caused by the overproduction of radicals and also seem to be a promising candidate as natural antioxidant and anti-cancer agents. PMID:26836619

  13. Genome sequence and description of the anaerobic lignin-degrading bacterium Tolumonas lignolytica sp. nov.

    PubMed

    Billings, Andrew F; Fortney, Julian L; Hazen, Terry C; Simmons, Blake; Davenport, Karen W; Goodwin, Lynne; Ivanova, Natalia; Kyrpides, Nikos C; Mavromatis, Konstantinos; Woyke, Tanja; DeAngelis, Kristen M

    2015-01-01

    Tolumonas lignolytica BRL6-1(T) sp. nov. is the type strain of T. lignolytica sp. nov., a proposed novel species of the Tolumonas genus. This strain was isolated from tropical rainforest soils based on its ability to utilize lignin as a sole carbon source. Cells of Tolumonas lignolytica BRL6-1(T) are mesophilic, non-spore forming, Gram-negative rods that are oxidase and catalase negative. The genome for this isolate was sequenced and returned in seven unique contigs totaling 3.6Mbp, enabling the characterization of several putative pathways for lignin breakdown. Particularly, we found an extracellular peroxidase involved in lignin depolymerization, as well as several enzymes involved in β-aryl ether bond cleavage, which is the most abundant linkage between lignin monomers. We also found genes for enzymes involved in ferulic acid metabolism, which is a common product of lignin breakdown. By characterizing pathways and enzymes employed in the bacterial breakdown of lignin in anaerobic environments, this work should assist in the efficient engineering of biofuel production from lignocellulosic material. PMID:26594307

  14. Isolation and characterization of a fungus Aspergillus sp. strain F-3 capable of degrading alkali lignin.

    PubMed

    Yang, Y S; Zhou, J T; Lu, H; Yuan, Y L; Zhao, L H

    2011-09-01

    A fungus strain F-3 was selected from fungal strains isolated from forest soil in Dalian of China. It was identified as one Aspergillus sp. stain F-3 with its morphologic, cultural characteristics and high homology to the genus of rDNA sequence. The budges or thickened node-like structures are peculiar structures of hyphae of the strain. The fungus degraded 65% of alkali lignin (2,000 mg l(-1)) after day 8 of incubation at 30°C at pH 7. The removal of colority was up to 100% at 8 days. The biodegradation of lignin by Aspergillus sp. F-3 favored initial pH 7.0. Excess acid or alkali conditions were not propitious to lignin decomposing. Addition of ammonium L: -tartrate or glucose delayed or repressed biodegradation activities. During lignin degradation, manganese peroxidase (28.2 U l(-1)) and laccase (3.5 U l(-1))activities were detected after day 7 of incubation. GC-MS analysis of biodegraded products showed strain F-3 could convert alkali lignin into small molecules or other utilizable products. Strain F-3 may co-culture with white rot fungus and decompose alkali lignin effectively. PMID:21350882

  15. Syringyl lignin production in conifers: Proof of concept in a Pine tracheary element system.

    PubMed

    Wagner, Armin; Tobimatsu, Yuki; Phillips, Lorelle; Flint, Heather; Geddes, Barbara; Lu, Fachuang; Ralph, John

    2015-05-12

    Conifers (softwoods) naturally lack syringyl units in their lignins, rendering lignocellulosic materials from such species more difficult to process than syringyl-rich hardwood species. Using a transformable Pinus radiata tracheary element (TE) system as an experimental platform, we investigated whether metabolic engineering can be used to create syringyl lignin in conifers. Pyrolysis-GC/MS and 2D-NMR analysis of P. radiata TE cultures transformed to express ferulate 5-hydroxylase (F5H) and caffeic acid O-methyltransferase (COMT) from Liquidambar styraciflua confirmed the production and incorporation of sinapyl alcohol into the lignin polymer. Transformation with F5H was sufficient for the production of syringyl lignin in TEs, but cotransformation with COMT improved its formation. In addition, lower levels of the pathway intermediate 5-hydroxyconiferyl alcohol were evidenced in cotransformation experiments, indicating that the introduction of the COMT overcame the inefficiency of the native pine methyltransferases for supporting sinapyl alcohol production.Our results provide the proof of concept that it is possible to generate a lignin polymer that contains syringyl units in softwood species such as P. radiata, suggesting that it might be possible to retain the outstanding fiber properties of softwoods while imbuing them with the lignin characteristics of hardwoods that are more favorable for industrial processing. PMID:25902506

  16. Genome sequence and description of the anaerobic lignin-degrading bacterium Tolumonas lignolytica sp. nov.

    SciTech Connect

    Billings, Andrew F.; Fortney, Julian L.; Hazen, Terry C.; Simmons, Blake; Davenport, Karen W.; Goodwin, Lynne; Ivanova, Natalia; Kyrpides, Nikos C.; Mavromatis, Konstantinos; Woyke, Tanja; DeAngelis, Kristen M.

    2015-11-19

    Tolumonas lignolytica BRL6-1T sp. nov. is the type strain of T. lignolytica sp. nov., a proposed novel species of the Tolumonas genus. This strain was isolated from tropical rainforest soils based on its ability to utilize lignin as a sole carbon source. Cells of Tolumonas lignolytica BRL6-1T are mesophilic, non-spore forming, Gram-negative rods that are oxidase and catalase negative. The genome for this isolate was sequenced and returned in seven unique contigs totaling 3.6Mbp, enabling the characterization of several putative pathways for lignin breakdown. Particularly, we found an extracellular peroxidase involved in lignin depolymerization, as well as several enzymes involved in β-aryl ether bond cleavage, which is the most abundant linkage between lignin monomers. We also found genes for enzymes involved in ferulic acid metabolism, which is a common product of lignin breakdown. Finally, by characterizing pathways and enzymes employed in the bacterial breakdown of lignin in anaerobic environments, this work should assist in the efficient engineering of biofuel production from lignocellulosic material.

  17. Knocking on wood: base metal complexes as catalysts for selective oxidation of lignin models and extracts.

    PubMed

    Hanson, Susan K; Baker, R Tom

    2015-07-21

    This work began as part of a biomass conversion catalysis project with UC Santa Barbara funded by the first NSF Chemical Bonding Center, CATSB. Recognizing that catalytic aerobic oxidation of diol C-C bonds could potentially be used to break down lignocellulose, we began to synthesize oxovanadium complexes and explore their fundamental reactivity. Of course there were theories regarding the oxidation mechanism, but our mechanistic studies soon revealed a number of surprises of the type that keep all chemists coming back to the bench! We realized that these reactions were also exciting in that they actually used the oxygen-on-every-carbon property of biomass-derived molecules to control the selectivity of the oxidation. When we found that these oxovanadium complexes tended to convert sugars predominantly to formic acid and carbon dioxide, we replaced one of the OH groups with an ether and entered the dark world of lignin chemistry. In this Account, we summarize results from our collaboration and from our individual labs. In particular, we show that oxidation selectivity (C-C vs C-O bond cleavage) of lignin models using air and vanadium complexes depends on the ancillary ligands, the reaction solvent, and the substrate structure (i.e., phenolic vs non-phenolic). Selected vanadium complexes in the presence of added base serve as effective alcohol oxidation catalysts via a novel base-assisted dehydrogenation pathway. In contrast, copper catalysts effect direct C-C bond cleavage of these lignin models, presumably through a radical pathway. The most active vanadium catalyst exhibits unique activity for the depolymerization of organosolv lignin. After Weckhuysen's excellent 2010 review on lignin valorization, the number of catalysis studies and approaches on both lignin models and extracts has expanded rapidly. Today we are seeing new start-ups and lignin production facilities sprouting up across the globe as we all work to prove wrong the old pulp and paper chemist

  18. In vitro mineral binding capacity of five fiber sources and their insoluble components for copper and zinc.

    PubMed

    Claye, S S; Idouraine, A; Weber, C W

    1996-06-01

    Five fiber-rich food sources, wheat bran (WB), rice bran (RB), oat fiber (OF), apple fiber (AF), and tomato fiber (TF) and their isolated insoluble fiber fractions were evaluated in vitro for their binding capacity for zinc (Zn) and copper (Cu). Endogenous Zn concentrations of the fibers varied from 11.0 micrograms/g for OF to 136.0 micrograms/g for WB, whereas Cu concentrations ranged from 1.0 microgram/g for OF to 14.0 micrograms/g for WB. In all the fibers, total Cu bound was significantly higher than Zn. Total Cu bound ranged from 3687 micrograms/g for OF to 8019 micrograms/g and 8073 micrograms/g for WB and AF, whereas, bound Zn levels varied from 1213 micrograms/g for OF to 7121 micrograms/g and 7166 micrograms/g for WB and RB, respectively. Significantly more Zn and Cu were bound by the fiber fractions than the whole fibers, probably due to the exposure of more binding sites on the polymers during the fractionation process. Generally, the fiber components of all five fibers showed Cu and Zn binding capacities decreasing in the order; hemicellulose A > lignocellulose > lignin > cellulose. A strong correlation was seen between the combined effects of protein, hemicellulose, and lignin contents of the fibers versus total Zn binding capacity and a lesser correlation with Cu. PMID:8983052

  19. EFFECT OF ANATOMICAL FRACTIONATION ON THE ENZYMATIC HYDROLYSIS OF ACID AND ALKALINE PRETREATED CORN STOVER

    SciTech Connect

    K. B. Duguid; M. D. Montross; C. W. Radtke; C. L. Crofcheck; L. M. Wendt; S. A. Shearer

    2009-11-01

    Due to concerns with biomass collection systems and soil sustainability there are opportunities to investigate the optimal plant fractions to collect for conversion. An ideal feedstock would require low severity pretreatment to release a maximum amount of sugar during enzymatic hydrolysis. Corn stover fractions were separated by hand and analyzed for glucan, xylan, acid soluble lignin, acid insoluble lignin, and ash composition. The stover fractions were also pretreated with either 0, 0.4, or 0.8% NaOH for 2 hours at room temperature, washed, autoclaved and saccharified. In addition, acid pretreated samples underwent simultaneous saccharification and fermentation (SSF) to ethanol. In general, the two pretreatments produced similar trends with cobs, husks, and leaves responding best to the pretreatments, the tops of stalks responding slightly less, and the bottom of the stalks responding the least. For example, corn husks pretreated with 0.8% NaOH released over 90% (standard error of 3.8%) of the available glucan, while only 45% (standard error of 1.1%) of the glucan was produced from identically treated stalk bottoms. Estimates of the theoretical ethanol yield using acid pretreatment followed by SSF were 65% (standard error of 15.9%) for husks and 29% (standard error of 1.8%) for stalk bottoms. This suggests that integration of biomass collection systems to remove sustainable feedstocks could be integrated with the processes within a biorefinery to minimize overall ethanol production costs.

  20. Methanol Fractionation of Softwood Kraft Lignin: Impact on the Lignin Properties

    SciTech Connect

    Saito, Tomonori; Perkins, Joshua H; Vautard, Frederic; Meyer III, Harry M; Messman, Jamie M; Tolnai, Balazs; Naskar, Amit K

    2014-01-01

    The development of technologies to tune lignin properties for high-performance lignin-based materials is crucial for the utilization of lignin in various applications. Here, the effect of methanol (MeOH) fractionation on the molecular weight, molecular weight distribution, glass transition temperature (Tg), thermal decomposition, and chemical structure of lignin were investigated. Repeated MeOH fractionation of softwood Kraft lignin successfully removed the low-molecular-weight fraction. The separated high-molecular-weight lignin showed a Tg of 211 C and a char yield of 47%, much higher than those of asreceived lignin (Tg 153 C, char yield 41%). The MeOH-soluble fraction of lignin showed an increased low-molecular-weight fraction and a lower Tg (117 C) and char yield (32%). The amount of low-molecular-weight fraction showed a quantitative correlation with both 1/Tg and char yield in a linear regression. This study demonstrated the efficient purification or fractionation technology for lignin; it also established a theoretical and empirical correlation between the physical characteristics of fractionated lignins.

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

    SciTech Connect

    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. The potency-insolubility conundrum in pharmaceuticals: Mechanism and solution for hepatitis C protease inhibitors.

    PubMed

    Connelly, Patrick R; Snyder, Phillip W; Zhang, Yuegang; McClain, Brian; Quinn, Brian P; Johnston, Steve; Medek, Ales; Tanoury, Jerry; Griffith, James; Patrick Walters, W; Dokou, Eleni; Knezic, Dragutin; Bransford, Philip

    2015-01-01

    As compounds are optimized for greater potency during pharmaceutical discovery, their aqueous solubility often decreases, making them less viable as orally-administered drugs. To investigate whether potency and insolubility share a common origin, we examined the structural and thermodynamic properties of telaprevir, a sparingly soluble inhibitor of hepatitis C virus protease. Comparison of the hydrogen bond motifs in crystalline telaprevir with those present in the protease-telaprevir complex revealed striking similarities. Additionally, the thermodynamics of telaprevir dissolution closely resembles those of protein-ligand dissociation. Together, these findings point to a common origin of potency and insolubility rooted in particular amide-amide hydrogen bond patterns. The insolubility of telaprevir is shown by computational analysis to be caused by interactions in the crystal, not unfavorable hydrophobic hydration. Accordingly, competing out the particular amide-amide hydrogen bond motifs in crystalline telaprevir with 4-hydroxybenzoic acid yielded a co-crystalline solid with excellent aqueous dissolution and oral absorption. The analysis suggests a generalizable approach for identifying drug candidate compounds that either can or cannot be rendered orally bioavailable by alteration of their crystalline solid phases, in an approach that provides a pragmatic way to attain substantial enhancements in the success rate of drug discovery and development. PMID:25451684

  3. Improvement of thermostability and activity of Trichoderma reesei endo-xylanase Xyn III on insoluble substrates.

    PubMed

    Matsuzawa, Tomohiko; Kaneko, Satoshi; Yaoi, Katsuro

    2016-09-01

    Trichoderma reesei Xyn III, an endo-β-1,4-xylanase belonging to glycoside hydrolase family 10 (GH10), is vital for the saccharification of xylans in plant biomass. However, its enzymatic thermostability and hydrolytic activity on insoluble substrates are low. To overcome these difficulties, the thermostability of Xyn III was improved using random mutagenesis and directed evolution, and its hydrolytic activity on insoluble substrates was improved by creating a chimeric protein. In the screening of thermostable Xyn III mutants from a random mutagenesis library, we identified two amino acid residues, Gln286 and Asn340, which are important for the thermostability of Xyn III. The Xyn III Gln286Ala/Asn340Tyr mutant showed xylanase activity even after heat treatment at 60 °C for 30 min or 50 °C for 96 h, indicating a dramatic enhancement in thermostability. In addition, we found that the addition of a xylan-binding domain (XBD) to the C-terminal of Xyn III improved its hydrolytic activity on insoluble xylan. PMID:27138202

  4. Phenolic compounds in ectomycorrhizal interaction of lignin modified silver birch

    PubMed Central

    Sutela, Suvi; Niemi, Karoliina; Edesi, Jaanika; Laakso, Tapio; Saranpää, Pekka; Vuosku, Jaana; Mäkelä, Riina; Tiimonen, Heidi; Chiang, Vincent L; Koskimäki, Janne; Suorsa, Marja; Julkunen-Tiitto, Riitta; Häggman, Hely

    2009-01-01

    Background The monolignol biosynthetic pathway interconnects with the biosynthesis of other secondary phenolic metabolites, such as cinnamic acid derivatives, flavonoids and condensed tannins. The objective of this study is to evaluate whether genetic modification of the monolignol pathway in silver birch (Betula pendula Roth.) would alter the metabolism of these phenolic compounds and how such alterations, if exist, would affect the ectomycorrhizal symbiosis. Results Silver birch lines expressing quaking aspen (Populus tremuloides L.) caffeate/5-hydroxyferulate O-methyltransferase (PtCOMT) under the 35S cauliflower mosaic virus (CaMV) promoter showed a reduction in the relative expression of a putative silver birch COMT (BpCOMT) gene and, consequently, a decrease in the lignin syringyl/guaiacyl composition ratio. Alterations were also detected in concentrations of certain phenolic compounds. All PtCOMT silver birch lines produced normal ectomycorrhizas with the ectomycorrhizal fungus Paxillus involutus (Batsch: Fr.), and the formation of symbiosis enhanced the growth of the transgenic plants. Conclusion The down-regulation of BpCOMT in the 35S-PtCOMT lines caused a reduction in the syringyl/guaiacyl ratio of lignin, but no significant effect was seen in the composition or quantity of phenolic compounds that would have been caused by the expression of PtCOMT under the 35S or UbB1 promoter. Moreover, the detected alterations in the composition of lignin and secondary phenolic compounds had no effect on the interaction between silver birch and P. involutus. PMID:19788757

  5. Lignin oxidation by laccase isozymes from Trametes versicolor and role of the mediator 2,2'-azinobis(3-ethylbenzthiazoline-6-sulfonate) in kraft lignin depolymerization.

    PubMed Central

    Bourbonnais, R; Paice, M G; Reid, I D; Lanthier, P; Yaguchi, M

    1995-01-01

    Two laccase isozymes (I and II) produced by the white-rot fungus Trametes versicolor were purified, and their reactivities towards various substrates and lignins were studied. The N-terminal amino acid sequences of these enzymes were determined and compared to other known laccase sequences. Laccase II showed a very high sequence similarity to a laccase which was previously reported to depolymerize lignin. The reactivities of the two isozymes on most of the substrates tested were similar, but there were some differences in the oxidation rate of polymeric substrates. We found that the two laccases produced similar qualitative effects on kraft lignin and residual lignin in kraft pulp, with no evidence of a marked preference for depolymerization by either enzyme. However, the presence of the mediator 2,2'-azinobis(3-ethylbenzthiazoline-6-sulfonate) prevented and reversed the polymerization of kraft lignin by either laccase. The delignification of hardwood and softwood kraft pulps with the two isozymes and the mediator was compared; either laccase was able to reduce the kappa number of pulp, but only in the presence of 2,2'-azinobis(3-ethylbenzthiazoline-6-sulfonate). PMID:7646025

  6. Proteins of insoluble matrix of avian (gallus gallus) eggshell.

    PubMed

    Miksík, Ivan; Eckhardt, Adam; Sedláková, Pavla; Mikulikova, Katerina

    2007-01-01

    The protein composition of the insoluble avian eggshell matrix was studied. The determination of these proteins insoluble in water (EDTA-insoluble) was carried out using enzymatic cleavage followed by a high-performance liquid chromatography-mass spectrometry method. The influence of various enzymes on the protein splitting also was studied. The distribution of proteins depends on the type of layer (localization within the eggshell): ovocalyxin-32 was found mainly in the outer layer (the cuticle); ovocleidin-116 and 17 and ovocalyxin-36 were found throughout the whole eggshell, whereas ovalbumin was only found in the inner layer, the mammillary. The pigment (protoporphyrin IX) was mainly found in the cuticle and is incorporated into the protein network. PMID:17364661

  7. Lignin degradation in a compost environment by the deuteromycete Paecilomyces inflatus.

    PubMed

    Kluczek-Turpeinen, B; Tuomela, M; Hatakka, A; Hofrichter, M

    2003-05-01

    Two strains of the deuteromycete Paecilomyces inflatus were isolated from compost samples consisting of municipal wastes, paper and wood chips. Lignin degradation by P. inflatus was studied following the mineralization of a synthetic (14)C(beta)-labeled lignin (side-chain labeled dehydrogenation polymer, DHP). Approximately 6.5% of the synthetic lignin was mineralized during solid-state cultivation of the fungus in autoclaved compost; and 15.5% was converted into water-soluble fragments. Laccase was the only ligninolytic enzyme detectable when the isolates were grown in autoclaved compost. Production of the enzyme was growth-associated and dependent on the culture conditions. The optimal pH for laccase production was between 4.5 and 5.5 and the optimal temperature was around 30 degrees C. Activity levels of laccase increased in the presence of low-molecular-mass aromatic compounds, such as veratryl alcohol, veratric acid, vanillin and vanillic acid. PMID:12743768

  8. Microwave-Assisted γ-Valerolactone Production for Biomass Lignin Extraction: A Cascade Protocol.

    PubMed

    Tabasso, Silvia; Grillo, Giorgio; Carnaroglio, Diego; Calcio Gaudino, Emanuela; Cravotto, Giancarlo

    2016-01-01

    The general need to slow the depletion of fossil resources and reduce carbon footprints has led to tremendous effort being invested in creating "greener" industrial processes and developing alternative means to produce fuels and synthesize platform chemicals. This work aims to design a microwave-assisted cascade process for a full biomass valorisation cycle. GVL (γ-valerolactone), a renewable green solvent, has been used in aqueous acidic solution to achieve complete biomass lignin extraction. After lignin precipitation, the levulinic acid (LA)-rich organic fraction was hydrogenated, which regenerated the starting solvent for further biomass delignification. This process does not requires a purification step because GVL plays the dual role of solvent and product, while the reagent (LA) is a product of biomass delignification. In summary, this bio-refinery approach to lignin extraction is a cascade protocol in which the solvent loss is integrated into the conversion cycle, leading to simplified methods for biomass valorisation. PMID:27023511

  9. Characterization of electrospun lignin based carbon fibers

    NASA Astrophysics Data System (ADS)

    Poursorkhabi, Vida; Mohanty, Amar; Misra, Manjusri

    2015-05-01

    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.

  10. Characterization of asparagus lignin by HPLC.

    PubMed

    Jaramillo-Carmona, S; Fuentes-Alventosa, J M; Rodríguez-Gutiérrez, G; Waldron, K W; Smith, A C; Guillén-Bejarano, R; Fernández-Bolaños, J; Jiménez-Araujo, A; Rodríguez-Arcos, R

    2008-09-01

    Lignin is the cell wall component most frequently associated with hardening. Its characterization and quantification are very important to understand the biochemical modifications related to the changes in texture of vegetables such as asparagus (Asparagus officinalis), in which this organoleptic attribute is a very important quality factor. In this study, asparagus lignin from the basal sections of fresh and stored spears was analyzed using 2 methods, the traditional (Klason lignin) and the recently developed derivatization, followed by reductive cleavage (DFRC) method. The latter is a simple and reproducible technique for lignin characterization based on a degradation procedure that produces analyzable monomers and dimers by cleaving alpha- and beta-aryl ethers in lignins. The primary monomers derived from DFRC degradation of lignins are essentially p-coumaryl peracetate, coniferyl peracetate, and sinapyl peracetate. To evaluate the efficiency of the DFRC method, our investigations have been carried on distinct sample types, including wood (data not shown), straw, and asparagus samples. The results have confirmed that lignin composition is affected by plant nature. It has been found that whereas wood samples mostly contain coniferyl units, plant foods, such as straw and asparagus, contain both coniferyl and guaiacyl units. PMID:18803697

  11. A molecular mechanics force field for lignin

    SciTech Connect

    Petridis, Loukas; Smith, Jeremy C

    2009-02-01

    A CHARMM molecular mechanics force field for lignin is derived. Parameterization is based on reproducing quantum mechanical data of model compounds. Partial atomic charges are derived using the RESP electrostatic potential fitting method supplemented by the examination of methoxybenzene:water interactions. Dihedral parameters are optimized by fitting to critical rotational potentials and bonded parameters are obtained by optimizing vibrational frequencies and normal modes. Finally, the force field is validated by performing a molecular dynamics simulation of a crystal of a lignin fragment molecule and comparing simulation-derived structural features with experimental results. Together with the existing force field for polysaccharides, this lignin force field will enable full simulations of lignocellulose.

  12. Lignin Sensor Based On Flash-Pyrolysis Mass Spectrometry

    NASA Technical Reports Server (NTRS)

    Kwack, Eug Y.; Lawson, Daniel D.; Shakkottai, Parthasarathy

    1990-01-01

    New lignin sensor takes only few minutes to measure lignin content of specimen of wood, pulp, paper, or similar material. Includes flash pyrolizer and ion-trap detector that acts as mass spectrometer. Apparatus measures amount of molecular fragments of lignin in pyrolysis products of samples. Helpful in controlling digestors in paper mills to maintain required lignin content, and also in bleaching plants, where good control of bleaching becomes possible if quick determination of lignin content made.

  13. Structural basis of stereospecificity in the bacterial enzymatic cleavage of β-aryl ether bonds in lignin

    DOE PAGESBeta

    Helmich, Kate E.; Pereira, Jose Henrique; Gall, Daniel L.; Heins, Richard A.; McAndrew, Ryan P.; Bingman, Craig; Deng, Kai; Holland, Keefe C.; Noguera, Daniel R.; Simmons, Blake A.; et al

    2015-12-04

    Here, lignin is a combinatorial polymer comprising monoaromatic units that are linked via covalent bonds. Although lignin is a potential source of valuable aromatic chemicals, its recalcitrance to chemical or biological digestion presents major obstacles to both the production of second-generation biofuels and the generation of valuable coproducts from lignin's monoaromatic units. Degradation of lignin has been relatively well characterized in fungi, but it is less well understood in bacteria. A catabolic pathway for the enzymatic breakdown of aromatic oligomers linked via β-aryl ether bonds typically found in lignin has been reported in the bacterium Sphingobium sp. SYK-6. Here, wemore » present x-ray crystal structures and biochemical characterization of the glutathione-dependent β-etherases, LigE and LigF, from this pathway. The crystal structures show that both enzymes belong to the canonical two-domain fold and glutathione binding site architecture of the glutathione S-transferase family. Mutagenesis of the conserved active site serine in both LigE and LigF shows that, whereas the enzymatic activity is reduced, this amino acid side chain is not absolutely essential for catalysis. The results include descriptions of cofactor binding sites, substrate binding sites, and catalytic mechanisms. Because β-aryl ether bonds account for 50–70% of all interunit linkages in lignin, understanding the mechanism of enzymatic β-aryl ether cleavage has significant potential for informing ongoing studies on the valorization of lignin.« less

  14. Structural Basis of Stereospecificity in the Bacterial Enzymatic Cleavage of β-Aryl Ether Bonds in Lignin*

    PubMed Central

    Helmich, Kate E.; Pereira, Jose Henrique; Gall, Daniel L.; Heins, Richard A.; McAndrew, Ryan P.; Bingman, Craig; Deng, Kai; Holland, Keefe C.; Noguera, Daniel R.; Simmons, Blake A.; Sale, Kenneth L.; Ralph, John; Donohue, Timothy J.; Adams, Paul D.; Phillips, George N.

    2016-01-01

    Lignin is a combinatorial polymer comprising monoaromatic units that are linked via covalent bonds. Although lignin is a potential source of valuable aromatic chemicals, its recalcitrance to chemical or biological digestion presents major obstacles to both the production of second-generation biofuels and the generation of valuable coproducts from lignin's monoaromatic units. Degradation of lignin has been relatively well characterized in fungi, but it is less well understood in bacteria. A catabolic pathway for the enzymatic breakdown of aromatic oligomers linked via β-aryl ether bonds typically found in lignin has been reported in the bacterium Sphingobium sp. SYK-6. Here, we present x-ray crystal structures and biochemical characterization of the glutathione-dependent β-etherases, LigE and LigF, from this pathway. The crystal structures show that both enzymes belong to the canonical two-domain fold and glutathione binding site architecture of the glutathione S-transferase family. Mutagenesis of the conserved active site serine in both LigE and LigF shows that, whereas the enzymatic activity is reduced, this amino acid side chain is not absolutely essential for catalysis. The results include descriptions of cofactor binding sites, substrate binding sites, and catalytic mechanisms. Because β-aryl ether bonds account for 50–70% of all interunit linkages in lignin, understanding the mechanism of enzymatic β-aryl ether cleavage has significant potential for informing ongoing studies on the valorization of lignin. PMID:26637355

  15. Structural Basis of Stereospecificity in the Bacterial Enzymatic Cleavage of β-Aryl Ether Bonds in Lignin.

    PubMed

    Helmich, Kate E; Pereira, Jose Henrique; Gall, Daniel L; Heins, Richard A; McAndrew, Ryan P; Bingman, Craig; Deng, Kai; Holland, Keefe C; Noguera, Daniel R; Simmons, Blake A; Sale, Kenneth L; Ralph, John; Donohue, Timothy J; Adams, Paul D; Phillips, George N

    2016-03-01

    Lignin is a combinatorial polymer comprising monoaromatic units that are linked via covalent bonds. Although lignin is a potential source of valuable aromatic chemicals, its recalcitrance to chemical or biological digestion presents major obstacles to both the production of second-generation biofuels and the generation of valuable coproducts from lignin's monoaromatic units. Degradation of lignin has been relatively well characterized in fungi, but it is less well understood in bacteria. A catabolic pathway for the enzymatic breakdown of aromatic oligomers linked via β-aryl ether bonds typically found in lignin has been reported in the bacterium Sphingobium sp. SYK-6. Here, we present x-ray crystal structures and biochemical characterization of the glutathione-dependent β-etherases, LigE and LigF, from this pathway. The crystal structures show that both enzymes belong to the canonical two-domain fold and glutathione binding site architecture of the glutathione S-transferase family. Mutagenesis of the conserved active site serine in both LigE and LigF shows that, whereas the enzymatic activity is reduced, this amino acid side chain is not absolutely essential for catalysis. The results include descriptions of cofactor binding sites, substrate binding sites, and catalytic mechanisms. Because β-aryl ether bonds account for 50-70% of all interunit linkages in lignin, understanding the mechanism of enzymatic β-aryl ether cleavage has significant potential for informing ongoing studies on the valorization of lignin. PMID:26637355

  16. Structural basis of stereospecificity in the bacterial enzymatic cleavage of β-aryl ether bonds in lignin

    SciTech Connect

    Helmich, Kate E.; Pereira, Jose Henrique; Gall, Daniel L.; Heins, Richard A.; McAndrew, Ryan P.; Bingman, Craig; Deng, Kai; Holland, Keefe C.; Noguera, Daniel R.; Simmons, Blake A.; Sale, Kenneth L.; Ralph, John; Donohue, Timothy J.; Adams, Paul D.; Phillips, George N.

    2015-12-04

    Here, lignin is a combinatorial polymer comprising monoaromatic units that are linked via covalent bonds. Although lignin is a potential source of valuable aromatic chemicals, its recalcitrance to chemical or biological digestion presents major obstacles to both the production of second-generation biofuels and the generation of valuable coproducts from lignin's monoaromatic units. Degradation of lignin has been relatively well characterized in fungi, but it is less well understood in bacteria. A catabolic pathway for the enzymatic breakdown of aromatic oligomers linked via β-aryl ether bonds typically found in lignin has been reported in the bacterium Sphingobium sp. SYK-6. Here, we present x-ray crystal structures and biochemical characterization of the glutathione-dependent β-etherases, LigE and LigF, from this pathway. The crystal structures show that both enzymes belong to the canonical two-domain fold and glutathione binding site architecture of the glutathione S-transferase family. Mutagenesis of the conserved active site serine in both LigE and LigF shows that, whereas the enzymatic activity is reduced, this amino acid side chain is not absolutely essential for catalysis. The results include descriptions of cofactor binding sites, substrate binding sites, and catalytic mechanisms. Because β-aryl ether bonds account for 50–70% of all interunit linkages in lignin, understanding the mechanism of enzymatic β-aryl ether cleavage has significant potential for informing ongoing studies on the valorization of lignin.

  17. Sequestration and transport of lignin monomeric precursors.

    PubMed

    Liu, Chang-Jun; Miao, Yu-Chen; Zhang, Ke-Wei

    2011-01-01

    Lignin is the second most abundant terrestrial biopolymer after cellulose. It is essential for the viability of vascular plants. Lignin precursors, the monolignols, are synthesized within the cytosol of the cell. Thereafter, these monomeric precursors are exported into the cell wall, where they are polymerized and integrated into the wall matrix. Accordingly, transport of monolignols across cell membranes is a critical step affecting deposition of lignin in the secondarily thickened cell wall. While the biosynthesis of monolignols is relatively well understood, our knowledge of sequestration and transport of these monomers is sketchy. In this article, we review different hypotheses on monolignol transport and summarize the recent progresses toward the understanding of the molecular mechanisms underlying monolignol sequestration and transport across membranes. Deciphering molecular mechanisms for lignin precursor transport will support a better biotechnological solution to manipulate plant lignification for more efficient agricultural and industrial applications of cell wall biomass. PMID:21245806

  18. Computational Design of Lignin Depolymerization Catalysts

    SciTech Connect

    Kim, S.; Chmely, S. C.; Sturgeon, M.; Katahira, R.; Paton, R. S.; Beckham, G. T.

    2012-01-01

    Lignin is a major component of plant cell walls that is typically underutilized in selective conversion strategies for renewable fuels and chemicals. The mechanisms by which thermal and catalytic treatments deconstruct lignin remain elusive, for which quantum mechanical calculations can offer fundamental insights. In this work, a computational approach has been used to elucidate the reductive deconstruction pathway of a ruthenium-catalyzed system. Transition states have been computed to determine the rate-limiting steps for a catalyst that cleaves arylether linkages. Our calculations are supported by experimental synthesis and kinetic and thermodynamic measurements of the deconstruction of model lignin dimers by a ruthenium catalyst with the ultimate objective of designing new catalysts to eventually utilize lignin in biorefineries.

  19. Sequestration and Transport of Lignin Monomeric Precursors

    SciTech Connect

    Liu, C.J.; Miao, Y.-C.; Zhang, K.-W.

    2011-01-18

    Lignin is the second most abundant terrestrial biopolymer after cellulose. It is essential for the viability of vascular plants. Lignin precursors, the monolignols, are synthesized within the cytosol of the cell. Thereafter, these monomeric precursors are exported into the cell wall, where they are polymerized and integrated into the wall matrix. Accordingly, transport of monolignols across cell membranes is a critical step affecting deposition of lignin in the secondarily thickened cell wall. While the biosynthesis of monolignols is relatively well understood, our knowledge of sequestration and transport of these monomers is sketchy. In this article, we review different hypotheses on monolignol transport and summarize the recent progresses toward the understanding of the molecular mechanisms underlying monolignol sequestration and transport across membranes. Deciphering molecular mechanisms for lignin precursor transport will support a better biotechnological solution to manipulate plant lignification for more efficient agricultural and industrial applications of cell wall biomass.

  20. Insoluble distillers' dried grain (DDG) fraction in chemically leavened bread

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to evaluate the addition of thermo-mechanically treated corn Distillers’ Dried Grain (DDG) on batter and bread quality characteristics. DDG was processed by jet-cooking homogenized slurry of DDG and water followed by centrifugation and drum drying the insoluble fract...

  1. Battle of the starches: Insoluble versus soluble at the refinery

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study using the USDA starch research method has been conducted to evaluate the effects of total, insoluble, and soluble starch on raw sugar filterability and viscosity in international carbonatation refineries. Raw sugar qualities, i.e., pol, color, % invert, ash, and dextran, were also studied in...

  2. Investigation of insoluble endogenous fractions of gastrointestinal tract by SRXRF

    NASA Astrophysics Data System (ADS)

    Trunova, V. A.; Zvereva, V. V.

    2005-05-01

    For the determination of the elemental composition of insoluble endogenous fractions from gastrointestinal tract by SRXRF (XRF experimental beam line, VEPP-3, INP SU RAS, Novosibirsk), an analytical method was developed for producing epithelial tissue in vivo. The metrological characteristics were determined using a number of international biological standards.

  3. Aqueous alkali metal hydroxide insoluble cellulose ether membrane

    NASA Technical Reports Server (NTRS)

    Hoyt, H. E.; Pfluger, H. L. (Inventor)

    1969-01-01

    A membrane that is insoluble in an aqueous alkali metal hydroxide medium is described. The membrane is a resin which is a water-soluble C2-C4 hydroxyalkyl cellulose ether polymer and an insolubilizing agent for controlled water sorption, a dialytic and electrodialytic membrane. It is particularly useful as a separator between electrodes or plates in an alkaline storage battery.

  4. Transportation and Distribution of Particulate Lignin in Changjiang (Yangtze River) Drainage Basin

    NASA Astrophysics Data System (ADS)

    Yu, H.; Wu, Y.; Zhang, J.

    2006-12-01

    Plant, soil and surface sediment and surface suspended particulate matter (SPM) samples from Yangtze River basin were analyzed for elements, stable isotopes and lignin phenols to investigate the transport and early diagenesis characteristics of terrestrial organic matter (OM). There was relatively large amount of less degraded lignin in soils of middle/down reaches, compared to that of upper reaches. OC%, ¦Ä13C and λ8 (yields of lignin phenols) also discriminated soils of northern tributaries from soils of southern tributaries. Lignin characteristics of sediments and SPM in main stream were similar to soils. C/V, S/V (molar ratio of syringyl phenols to vanillyl phenols) and (Ad/Al)v (ratio of vanillic acid to vanillin) suggested a non- woody angiosperm tissues origin in sediments of down reaches and a soil origin in upper reaches. The change of lignin contents in SPM along the main stream from upper reaches to down reaches was reversed to that of sediments and lignin was much fresher, which indicated more plant detritus contribution to SPM. A simple three-end-member model with ¦Ä13C and λ8 was applied to evaluate the contribution of sources (plant detritus, soils of northern tributaries and southern tributaries) to OM in SPM and sediments. Results of calculation indicated soils of northern tributaries account for nearly \\70% of the OM in sediments of upper reaches and \\30% of that of down reaches. The contribution of plant detritus was very low to sediments of upper reaches and gradually increased to around \\50% to that of down reaches. As to SPM, plant detritus and northern soils contributed nearly \\50% and \\40% respectively to upper reaches and about \\20% and \\10% to down reaches. A model was built up to explain the lignin transfer from land to river, from surface SPM to surface sediments and it proved that lignin was relative reserved in Changjiang. Physical processes such as hydrodynamic sorting, velocity of flow and sedimentation controlled the

  5. Chemical factors that control lignin polymerization.

    PubMed

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

    2014-01-01

    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. PMID:24341896

  6. Chemical factors that control lignin polymerization

    SciTech Connect

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

    2014-01-01

    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). 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 ( - or -5) react poorly and tend to cap the polymer. In general, -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.

  7. Metagenomic scaffolds enable combinatorial lignin transformation

    PubMed Central

    Strachan, Cameron R.; Singh, Rahul; VanInsberghe, David; Ievdokymenko, Kateryna; Budwill, Karen; Mohn, William W.; Eltis, Lindsay D.; Hallam, Steven J.

    2014-01-01

    Engineering the microbial transformation of lignocellulosic biomass is essential to developing modern biorefining processes that alleviate reliance on petroleum-derived energy and chemicals. Many current bioprocess streams depend on the genetic tractability of Escherichia coli with a primary emphasis on engineering cellulose/hemicellulose catabolism, small molecule production, and resistance to product inhibition. Conversely, bioprocess streams for lignin transformation remain embryonic, with relatively few environmental strains or enzymes implicated. Here we develop a biosensor responsive to monoaromatic lignin transformation products compatible with functional screening in E. coli. We use this biosensor to retrieve metagenomic scaffolds sourced from coal bed bacterial communities conferring an array of lignin transformation phenotypes that synergize in combination. Transposon mutagenesis and comparative sequence analysis of active clones identified genes encoding six functional classes mediating lignin transformation phenotypes that appear to be rearrayed in nature via horizontal gene transfer. Lignin transformation activity was then demonstrated for one of the predicted gene products encoding a multicopper oxidase to validate the screen. These results illuminate cellular and community-wide networks acting on aromatic polymers and expand the toolkit for engineering recombinant lignin transformation based on ecological design principles. PMID:24982175

  8. Antioxidant activity of lignin phenolic compounds as by-product of pretreatment process of bioethanol production from empty fruits palm bunch

    NASA Astrophysics Data System (ADS)

    Meliana, Y.; Setiawan, A. H.

    2016-02-01

    As by-product of pretreatment bioethanol production, ligno-cellulosic biomass creates an abundance of bioresidue. This work is devoted to studies the antioxidant activity of lignin that obtained from recovery process of bioethanol by-product. This by-product comes from pretreatment process of empty fruit palm bunch in acid (pH 2) and alkaline (pH 12) conditions. The samples of purified lignin were characterized by Fourier Transform Infrared (FTIR) and Particle Size Analyzer (PSA). Radical scavenging efficiency of lignin was examined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method using quercetin as a standard. The value of IC50 showed that the lignin that was purified in acid condition (pH 2) gave the activity value in antioxidant active range (IC50 sample Lignin pH 2 = 69.41), on the other hand the lignin that was purified in alkaline condition (Lignin pH 12) did not have the activity value as an antioxidant (IC50 sample Lignin pH 12 = NA).

  9. A glucuronoyl esterase from Acremonium alcalophilum cleaves native lignin-carbohydrate ester bonds.

    PubMed

    Arnling Bååth, Jenny; Giummarella, Nicola; Klaubauf, Sylvia; Lawoko, Martin; Olsson, Lisbeth

    2016-08-01

    The Glucuronoyl esterases (GE) have been proposed to target lignin-carbohydrate (LC) ester bonds between lignin moieties and glucuronic acid side groups of xylan, but to date, no direct observations of enzymatic cleavage on native LC ester bonds have been demonstrated. In the present investigation, LCC fractions from spruce and birch were treated with a recombinantly produced GE originating from Acremonium alcalophilum (AaGE1). A combination of size exclusion chromatography and (31) P NMR analyses of phosphitylated LCC samples, before and after AaGE1 treatment provided the first evidence for cleavage of the LC ester linkages existing in wood. PMID:27397104

  10. Encapsulated Laccases for the Room-Temperature Oxidation of Aromatics: Towards Synthetic Low-Molecular-Weight Lignins.

    PubMed

    Pistone, Lucia; Ottolina, Gianluca; De, Sudipta; Romero, Antonio A; Martins, Lígia O; Luque, Rafael

    2016-04-01

    A new approach for the encapsulation of laccases with enhanced activity and stability by biomimetic silica mineralisation is reported. A range of lignin model compounds, which includes syringol, syringyl acid, 4-vinylphenol, gallic acid, vanillic acid and guaiacol, was oxidised to lignin-type polymers by the silica-immobilised laccase systems at room temperature. The oxidation rate of the immobilised systems was lower than that of the free enzyme counterparts, but interesting products were observed with the new bio-catalytic materials, which showed reusability and good stability. PMID:26898517

  11. Carbon-13 nuclear magnetic resonance analysis, lignin content and carbohydrate composition of humic substances from salt marsh estuaries

    NASA Astrophysics Data System (ADS)

    Alberts, James J.; Hatcher, Patrick G.; Price, Mary T.; Filip, Zdenek

    13C nuclear magnetic resonance spectroscopy, CuO oxidation products of lignin and hydrolyzable carbohydrates were measured for fulvic and humic acids extracted from living and dead Spartina alterniflora and salt marsh sediments. With these methods, there was little evidence for early diagenetic alteration of the humic materials. No trends consistent for fulvic and humic acids were observed for either hydrolyzable carbohydrates or lignin derived phenols, and chemical measurements of these fractions did not agree with spectral estimates. Humic acids appear to contain secondary amide linkages typical of proteins and peptides.

  12. Copper- and Vanadium-Catalyzed Oxidative Cleavage of Lignin using Dioxygen.

    PubMed

    Mottweiler, Jakob; Puche, Marta; Räuber, Christoph; Schmidt, Thomas; Concepción, Patricia; Corma, Avelino; Bolm, Carsten

    2015-06-22

    Transition-metal-containing hydrotalcites (HTc) and V(acac)3 /Cu(NO3 )2 ⋅3 H2 O (acac=acetylacetonate) mixtures were tested for their catalytic activity in the cleavage of the lignin model compound erythro-1-(3,4-dimethoxyphenyl)-2-(2-methoxyphenoxy)-l,3-propanediol (1) with molecular oxygen as oxidant. Both catalytic systems displayed high activity and good selectivity and afforded veratric acid as the main product. The catalyst behavior was studied by EPR spectroscopy, XRD, and Raman spectroscopy. After the catalysts were established for the model system, lignin depolymerization studies were performed with various organsolv and kraft lignin sources. The oxidative depolymerization and lignin bond cleavage were monitored by gel permeation chromatography (GPC), MALDI MS, and 2D-NMR (HSQC). Irrespective of the lignin pretreatment, both HTc-Cu-V and V(acac)3 /Cu(NO3 )2 ⋅3 H2 O were able to cleave the β-O-4 linkages and the resinol structures to form dimeric and trimeric products. PMID:26013592

  13. Leucaena leucocephala (Lam.) de Wit., "subabul" stem lignin: Isolation, structural characterization and thermal properties.

    PubMed

    Yearla, Srinivasa Rao; Padmasree, Kollipara

    2016-06-01

    Lignin is the second most abundant renewable biopolymer on earth after cellulose. It is being used in many industrial applications due to its abundance. In the present study, lignin was isolated from the stems of Leucaena leucocephala (Lam.) de Wit., a high biomass yielding plant using acidic dioxane under N2 atmosphere. Structural characterization of isolated dioxane lignin (DL) was performed by analytical techniques: UV, FT-IR, ¹H NMR and ¹³C NMR. Their monolignol content was determined by nitrobenzene oxidation followed by HPLC-MS/MS analysis. The data was compared with commercial alkali lignin (AL). The results showed that DL is of hardwood guaiacyl-syringyl (GS) type, whereas AL is softwood type with more guaiacyl units and trace amounts of p-hydroxyphenyl units (H). Thermogravimetric analysis (TGA) of DL showed two stage thermal degradation profile similar to AL. The DTGmax for DL and AL were found in the second major loss event of second stage of TGA at 424°C and 404°C, respectively. Differential scanning calorimetry (DSC) study exhibited the glass transition temperatures (Tg) at 132°C and 122°C for DL and AL, respectively. The results from thermal stability studies suggest that dioxane lignin isolated from the "miracle tree" (subabul) can be exploited in various thermoplastic industrial applications. PMID:27468468

  14. Enzymatic aryl-O-methyl-/sup 14/C labeling of model lignin monomers

    SciTech Connect

    Frazer, A.C.; Bossert, I.; Young, L.Y.

    1986-01-01

    Aryl-O-methyl ethers are abundant in aerobic and anaerobic environments. In particular, lignin is composed of units of this type. Lignin monomers specifically radiolabeled in methoxy, side chain, and ring carbons have been synthesized by chemical procedures and are important in studies of lignin synthesis and degradation, humus formation, and microbial O-demethylation. In this paper attention is drawn to an enzymatic procedure for preparing O-methyl-/sup 14/C-labeled aromatic lignin monomers which has not previously been exploited in microbial ecology and physiology studies and which has several advantages compared with chemical synthesis procedures. O-(methyl-/sup 14/C)vanillic and O-(methyl-/sup 14/C)ferulic acids were prepared with S-(methyl-/sup 14/C)adenosyl-L-methionine as the methyl donor, using commercially obtained porcine liver catechol-O-methyltransferase (EC 2.1.1.6). The specific activity of the methylated products was the same as that of the methyl donor, a maximum of about 58 ..mu..Ci/..mu..mol, and the yields were 42% (vanillate) and 35% (ferulate). Thus lignin monomers are readily prepared as O-methylated products of the catechol-O-methyltransferase reaction and, with this enzyme method of preparation, would be more widely available than labeled compounds which require chemical synthesis.

  15. Lignin removal enhancement from prehydrolysis liquor of kraft-based dissolving pulp production by laccase-induced polymerization.

    PubMed

    Wang, Qiang; Jahan, M Sarwar; Liu, Shanshan; Miao, Qingxian; Ni, Yonghao

    2014-07-01

    Lignin removal is essential for value-added utilization of hemicelluloses and acetic acid present in the prehydrolysis liquor (PHL) of a kraft-based hardwood dissolving pulp production. In this paper, a novel process concept, consisting of laccase-induced lignin polymerization, followed by filtration/flocculation, was developed to enhance the lignin removal. The results showed that the lignin removal increased from 11% to 46-61% at laccase concentration of 1-4 U mL(-1). The GPC results showed that the molecular weight of the lignin from the laccase treated PHL was increased by 160% in comparison with the original one. The subsequent flocculation using singular Poly-DADMAC system or dual polymer system of Poly-DADMAC/CPAM can further remove 10-15% lignin. The concentrations of hemicelluloses and acetic acid were negligibly affected during the laccase treatment, while flocculation caused 12-15% of total sugar loss. Additionally, the process incorporates this new concept into the kraft-based dissolving pulp production process was proposed. PMID:24865327

  16. An In Situ Method for Sizing Insoluble Residues in Precipitation

    NASA Astrophysics Data System (ADS)

    Axson, J. L.; Creamean, J.; Bondy, A. L.; Warner, K. Y.; Ault, A. P.

    2014-12-01

    Aerosols acting as cloud condensation nuclei (CCN) and ice nuclei (IN) play an important role in the climate effects of clouds. Wet deposition of these particles via rainout, washout, or cloud seeding is an important removal mechanism for aerosols in the atmosphere. Many of these particles, especially those that serve as IN, are insoluble and remain suspended after uptake within precipitating droplets/crystals as insoluble residues. While studies have measured the dissolved ions or mass of species within collected precipitation, no studies to date have quantified the number and size of insoluble residues. Herein, we demonstrate for the first time an in situ method for determining the number concentration, number size distribution, and surface area distribution of insoluble residues < 1 μm in diameter in samples of melted snow and rain. This work evaluates the use of nanoparticle tracking analysis (NTA), a new and novel technique for determining particle size distributions in a liquid medium, to determine in situ size distributions of insoluble residue particles in precipitation and evaluate this technique versus other analytical methods, including dynamic light scattering (DLS) and transmission electron microscopy (TEM). Number size distribution modes ranged from 80-150 nm and were strongly sample dependent. Surface area distribution modes ranged from 150-400 nm. Differences were observed between concentrations and size distributions for snow collected at different locations and elevations and between rain and melted snow. These differences can indicate changes in the insoluble residues that vary with ambient aerosol concentration, cloud microphysics, and meteorological dynamics. This method has great potential for improving our understanding of the properties of the particles nucleating droplets and crystals, the surface area available for reactions to occur, and the number of particles removed by scavenging. Additionally, the snow samples were further evaluated

  17. Characterization of electrospun lignin based carbon fibers

    SciTech Connect

    Poursorkhabi, Vida; Mohanty, Amar; Misra, Manjusri

    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.

  18. The comparative geochemistries of lignins and carbohydrates in an anoxic fjord

    NASA Astrophysics Data System (ADS)

    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

  19. Connecting lignin-degradation pathway with pre-treatment inhibitor sensitivity of Cupriavidus necator.

    PubMed

    Wang, Wei; Yang, Shihui; Hunsinger, Glendon B; Pienkos, Philip T; Johnson, David K

    2014-01-01

    To produce lignocellulosic biofuels economically, the complete release of monomers from the plant cell wall components, cellulose, hemicellulose, and lignin, through pre-treatment and hydrolysis (both enzymatic and chemical), and the efficient utilization of these monomers as carbon sources, is crucial. In addition, the identification and development of robust microbial biofuel production strains that can tolerate the toxic compounds generated during pre-treatment and hydrolysis is also essential. In this work, Cupriavidus necator was selected due to its capabilities for utilizing lignin monomers and producing polyhydroxylbutyrate (PHB), a bioplastic as well as an advanced biofuel intermediate. We characterized the growth kinetics of C. necator in pre-treated corn stover slurry as well as individually in the pre-sence of 11 potentially toxic compounds in the saccharified slurry. We found that C. necator was sensitive to the saccharified slurry produced from dilute acid pre-treated corn stover. Five out of 11 compounds within the slurry were characterized as toxic to C. necator, namely ammonium acetate, furfural, hydroxymethylfurfural (HMF), benzoic acid, and p-coumaric acid. Aldehydes (e.g., furfural and HMF) were more toxic than the acetate and the lignin degradation products benzoic acid and p-coumaric acid; furfural was identified as the most toxic compound. Although toxic to C. necator at high concentration, ammonium acetate, benzoic acid, and p-coumaric acid could be utilized by C. necator with a stimulating effect on C. necator growth. Consequently, the lignin degradation pathway of C. necator was reconstructed based on genomic information and literature. The efficient conversion of intermediate catechol to downstream products of cis,cis-muconate or 2-hydroxymuconate-6-semialdehyde may help improve the robustness of C. necator to benzoic acid and p-coumaric acid as well as improve PHB productivity. PMID:24904560

  20. Connecting Lignin-Degradation Pathway with Pre-Treatment Inhibitor Sensitivity of Cupriavidus necator

    SciTech Connect

    Wang, W.; Yang, S.; Hunsinger, G. B.; Pienkos, P. T.; Johnson, D. K.

    2014-05-27

    In order to produce lignocellulosic biofuels economically, the complete release of monomers from the plant cell wall components, cellulose, hemicellulose, and lignin, through pre-treatment and hydrolysis (both enzymatic and chemical), and the efficient utilization of these monomers as carbon sources, is crucial. In addition, the identification and development of robust microbial biofuel production strains that can tolerate the toxic compounds generated during pre-treatment and hydrolysis is also essential. In this work, Cupriavidus necator was selected due to its capabilities for utilizing lignin monomers and producing polyhydroxylbutyrate (PHB), a bioplastic as well as an advanced biofuel intermediate. We characterized the growth kinetics of C. necator in pre-treated corn stover slurry as well as individually in the pre-sence of 11 potentially toxic compounds in the saccharified slurry. We found that C. necator was sensitive to the saccharified slurry produced from dilute acid pre-treated corn stover. Five out of 11 compounds within the slurry were characterized as toxic to C. necator, namely ammonium acetate, furfural, hydroxymethylfurfural (HMF), benzoic acid, and p-coumaric acid. Aldehydes (e.g., furfural and HMF) were more toxic than the acetate and the lignin degradation products benzoic acid and p-coumaric acid; furfural was identified as the most toxic compound. Although toxic to C. necator at high concentration, ammonium acetate, benzoic acid, and p-coumaric acid could be utilized by C. necator with a stimulating effect on C. necator growth. Consequently, the lignin degradation pathway of C. necator was reconstructed based on genomic information and literature. The efficient conversion of intermediate catechol to downstream products of cis,cis-muconate or 2-hydroxymuconate-6-semialdehyde may help improve the robustness of C. necator to benzoic acid and p-coumaric acid as well as improve PHB productivity.

  1. Connecting lignin-degradation pathway with pre-treatment inhibitor sensitivity of Cupriavidus necator

    PubMed Central

    Wang, Wei; Yang, Shihui; Hunsinger, Glendon B.; Pienkos, Philip T.; Johnson, David K.

    2014-01-01

    To produce lignocellulosic biofuels economically, the complete release of monomers from the plant cell wall components, cellulose, hemicellulose, and lignin, through pre-treatment and hydrolysis (both enzymatic and chemical), and the efficient utilization of these monomers as carbon sources, is crucial. In addition, the identification and development of robust microbial biofuel production strains that can tolerate the toxic compounds generated during pre-treatment and hydrolysis is also essential. In this work, Cupriavidus necator was selected due to its capabilities for utilizing lignin monomers and producing polyhydroxylbutyrate (PHB), a bioplastic as well as an advanced biofuel intermediate. We characterized the growth kinetics of C. necator in pre-treated corn stover slurry as well as individually in the pre-sence of 11 potentially toxic compounds in the saccharified slurry. We found that C. necator was sensitive to the saccharified slurry produced from dilute acid pre-treated corn stover. Five out of 11 compounds within the slurry were characterized as toxic to C. necator, namely ammonium acetate, furfural, hydroxymethylfurfural (HMF), benzoic acid, and p-coumaric acid. Aldehydes (e.g., furfural and HMF) were more toxic than the acetate and the lignin degradation products benzoic acid and p-coumaric acid; furfural was identified as the most toxic compound. Although toxic to C. necator at high concentration, ammonium acetate, benzoic acid, and p-coumaric acid could be utilized by C. necator with a stimulating effect on C. necator growth. Consequently, the lignin degradation pathway of C. necator was reconstructed based on genomic information and literature. The efficient conversion of intermediate catechol to downstream products of cis,cis-muconate or 2-hydroxymuconate-6-semialdehyde may help improve the robustness of C. necator to benzoic acid and p-coumaric acid as well as improve PHB productivity. PMID:24904560

  2. Physicochemical and structural characterization of alkali soluble lignins from oil palm trunk and empty fruit-bunch fibers.

    PubMed

    Sun, R; Fang, J M; Tomkinson, J; Bolton, J

    1999-07-01

    Six alkali soluble lignin fractions were extracted from the cell wall materials of oil palm trunk and empty fruit-bunch (EFB) fibers with 5% NaOH, 10% NaOH, and 24% KOH/2% H(3)BO(3). All of the lignin fractions contained rather low amounts of associated neutral sugars (0.8-1.2%) and uronic acids (1.1-2.0%). The lignin fractions isolated with 5% NaOH from the lignified palm trunk and EFB fibers gave a relatively higher degree of polymerization as shown by weight-average molecular weights ranging between 2620 and 2840, whereas the lignin fractions isolated with 10% NaOH and 24% KOH/2% H(3)BO(3) from the partially delignified palm trunk and EFB fibers showed a relatively lower degree of polymerization, as shown by weight-average molecular weights ranging between 1750 and 1980. The results obtained by alkaline nitrobenzene oxidation showed that all of the lignin preparations contained a high proportion of noncondensed syringyl units with small amounts of noncondensed guaiacyl and fewer p-hydroxyphenyl units. The lignin fraction extracted with 5% NaOH from the lignified EFB fiber was mainly composed of beta-O-4 ether-linked units. Small amounts of 5-5', beta-5, and beta-beta' carbon-carbon linkages were also found to be present between the lignin structural units. Further studies showed that uronic, p-hydroxybenzoic, and ferulic acids in the cell walls of palm fibers were esterified to lignin. PMID:10552589

  3. Biobutanediol-mediated liquefaction of empty fruit bunch saccharification residues to prepare lignin biopolyols.

    PubMed

    Lee, Jae Hoon; Lee, Eun Yeol

    2016-05-01

    Saccharification residue from empty fruit bunch (EFB) was liquefied with bio-butanediol to produce lignin biopolyols for the preparation of biopolyurethane. To substitute petroleum-derived polyhydric alcohols, butanediol isomers (1,4-butanediol, levo-2,3-bio-butanediol, and meso-2,3-bio-butanediol) or PEG#400-blended butanediol isomers were used as liquefaction solvents in the presence of sulfuric acid catalyst. Lignin biopolyols with a conversion of 63.3%, a hydroxyl number of 582.7 mg KOH/g and an acid number of 21.7 mg KOH/g were obtained under the optimal condition consisting of 25% biomass loading, 3% acid loading, and a temperature of 150°C for 120 min when liquefied with 1,4-butanediol/PEG#400 blended solvent (9/1, w/w). When the levo-2,3-bio-butanediol solvent was used in the absence of PEG#400, the highest conversion, 68.9%, was obtained. Lignin biopolyol-based biopolyurethanes were synthesized with toluene diisocyanate. FT-IR analysis revealed that EFB lignin biopolyols liquefied with bio-butanediols were suitable monomers for the preparation of biopolyurethane. PMID:26918835

  4. Characterization of insoluble nanoparticles in Antarctic ice cores

    NASA Astrophysics Data System (ADS)

    Ellis, A.; Edwards, R.; Van Riessen, A.; Saunders, M.; Smith, A. M.; Curran, M. A.; Goodwin, I. D.; Feiteng, W.

    2013-12-01

    Insoluble nanoparticles in the form of aerosols have significant effects on climate and biogeochemical cycles. Records of these aerosols are essential for understanding paleoclimate forcing and future climate change. These particles and their precursors are emitted to the atmosphere from a variety of primary and secondary sources including biomass burning as well as biogenic, anthropogenic, volcanic, extraterrestrial, and terrestrial mineral emissions. While a large body of research exists with respect to mineral dust particles (on the micrometer scale) derived from ice and sediment cores, very little is known with regards to the history of insoluble particles on the nano scale. Ice core records are the only reliable way to study the past history of these particles. Here, we will present new data regarding the physical and chemical properties of nanoparticles found in ice cores from East Antarctica.

  5. Synthesis and characterization of carbon cryogel microspheres from lignin-furfural mixtures for biodiesel production.

    PubMed

    Zainol, Muzakkir Mohammad; Amin, Nor Aishah Saidina; Asmadi, Mohd

    2015-08-01

    The aim of this work was to study the potential of biofuel and biomass processing industry side-products as acid catalyst. The synthesis of carbon cryogel from lignin-furfural mixture, prepared via sol-gel polycondensation at 90°C for 0.5h, has been investigated for biodiesel production. The effect of lignin to furfural (L/F) ratios, lignin to water (L/W) ratios and acid concentration on carbon cryogel synthesis was studied. The carbon cryogels were characterized and tested for oleic acid conversion. The thermally stable amorphous spherical carbon cryogel has a large total surface area with high acidity. Experimental results revealed the optimum FAME yield and oleic acid conversion of 91.3wt.% and 98.1wt.%, respectively were attained at 65°C for 5h with 5wt.% catalyst loading and 20:1 methanol to oleic acid molar ratio. Therefore, carbon cryogel is highly potential for heterogeneous esterification of free fatty acid to biodiesel. PMID:25919936

  6. Insoluble polyelectrolyte and ion-exchange hollow fiber impregnated therewith

    NASA Technical Reports Server (NTRS)

    Rembaum, A. (Inventor)

    1977-01-01

    The number of quaternary sites and ion exchange capacity of a polyquaternary, cross linked, insoluble copolymer of a vinyl pyridine and a dihalo organic compound is increased by about 15-35% by reaction of the polymer with an amine followed by quaternization, if required. The polymer forms spontaneously in the presence of a substrate such as within the pores of a hollow fiber. The improved resin impregnated fiber may be utilized to remove ions from waste or process steams.

  7. Water-insoluble Silk Films with Silk I Structure

    SciTech Connect

    Lu, Q.; Hu, X; Wang, X; Kluge, J; Lu, S; Cebe, P; Kaplan, D

    2010-01-01

    Water-insoluble regenerated silk materials are normally produced by increasing the {beta}-sheet content (silk II). In the present study water-insoluble silk films were prepared by controlling the very slow drying of Bombyx mori silk solutions, resulting in the formation of stable films with a predominant silk I instead of silk II structure. Wide angle X-ray scattering indicated that the silk films stabilized by slow drying were mainly composed of silk I rather than silk II, while water- and methanol-annealed silk films had a higher silk II content. The silk films prepared by slow drying had a globule-like structure at the core surrounded by nano-filaments. The core region was composed of silk I and silk II, surrounded by hydrophilic nano-filaments containing random turns and {alpha}-helix secondary structures. The insoluble silk films prepared by slow drying had unique thermal, mechanical and degradative properties. Differential scanning calorimetry results revealed that silk I crystals had stable thermal properties up to 250 C, without crystallization above the T{sub g}, but degraded at lower temperatures than silk II structure. Compared with water- and methanol-annealed films the films prepared by slow drying had better mechanical ductility and were more rapidly enzymatically degraded, reflecting the differences in secondary structure achieved via differences in post processing of the cast silk films. Importantly, the silk I structure, a key intermediate secondary structure for the formation of mechanically robust natural silk fibers, was successfully generated by the present approach of very slow drying, mimicking the natural process. The results also point to a new mode of generating new types of silk biomaterials with enhanced mechanical properties and increased degradation rates, while maintaining water insolubility, along with a low {beta}-sheet content.

  8. Water-Insoluble Silk Films with Silk I Structure

    PubMed Central

    Lu, Qiang; Hu, Xiao; Wang, Xiaoqin; Kluge, Jonathan A.; Lu, Shenzhou; Cebe, Peggy; Kaplan, David L.

    2009-01-01

    Water-insoluble regenerated silk materials are normally achieved by increasing β-sheet content (silk II). In the present study, water-insoluble silk films were prepared by controlling very slow drying of B. mori silk solutions, resulting in the formation of stable films with dominating silk I instead of silk II structure. Wide angle x-ray scattering (WAXS) indicated that the silk films stabilized by slow drying were mainly composed of silk I rather than silk II, while water- and methanol-annealed silk films had a higher silk II content. The silk films prepared through slow drying had a globule-like structure in the core with nano-filaments. The core region was composed of silk I and silk II, and these regions are surrounded by hydrophilic nano-filaments containing random, turns, and α-helix secondary structures. The insoluble silk films prepared by slow drying had unique thermal, mechanical and degradative properties. DSC results revealed that silk I crystals had stable thermal properties up to 250°C, without crystallization above the Tg, but degraded in lower temperature than silk II structure. Compared with water- and methanol-annealed films, the films prepared through slow drying achieved better mechanical ductility and more rapid enzymatic degradation, reflective of the differences in secondary structure achieved via differences in post processing of the cast silk films. Importantly, the silk I structure, a key intermediate secondary structure for the formation of mechanically robust natural silk fibers, was successfully generated in the present approach of very slow drying, mimicking the natural process. The results also point to a new mode to generate new types of silk biomaterials, where mechanical properties can be enhanced, and degradation rates increased, yet water insolubility is maintained along with low beta sheet content. PMID:19874919

  9. Transmission of Soluble and Insoluble α-Synuclein to Mice.

    PubMed

    Jones, Daryl Rhys; Delenclos, Marion; Baine, AnnMarie T; DeTure, Michael; Murray, Melissa E; Dickson, Dennis W; McLean, Pamela J

    2015-12-01

    The neurodegenerative synucleinopathies, which include Parkinson disease, multiple-system atrophy, and Lewy body disease, are characterized by the presence of abundant neuronal inclusions called Lewy bodies and Lewy neurites. These disorders remain incurable, and a greater understanding of the pathologic processes is needed for effective treatment strategies to be developed. Recent data suggest that pathogenic misfolding of the presynaptic protein, α-synuclein (α-syn), and subsequent aggregation and accumulation are fundamental to the disease process. It is hypothesized that the misfolded isoform is able to induce misfolding of normal endogenous α-syn, much like what occurs in the prion diseases. Recent work highlighting the seeding effect of pathogenic α-syn has largely focused on the detergent-insoluble species of the protein. In this study, we performed intracerebral inoculations of the sarkosyl-insoluble or sarkosyl-soluble fractions of human Lewy body disease brain homogenate and show that both fractions induce CNS pathology in mice at 4 months after injection. Disease-associated deposits accumulated both near and distal to the site of the injection, suggesting a cell-to-cell spread via recruitment of α-syn. These results provide further insight into the prion-like mechanisms of α-syn and suggest that disease-associated α-syn is not homogeneous within a single patient but might exist in both soluble and insoluble isoforms. PMID:26574670

  10. Modification of high-lignin kraft pulps with laccase. Part 2. Xylanase-enhanced strength benefits.

    PubMed

    Chandra, Richard P; Ragauskas, Arthur J

    2005-01-01

    The effects of xylanase pretreatment of high lignin content softwood (SW) kraft pulp on subsequent pulp treatment with laccase in combination with gallic acid were investigated. Although xylanase pretreatment was ineffective in enhancing the laccase-facilitated biografting of gallic acid to kraft fibers, it was beneficial for subsequent treatment with laccase exclusively. Treating pulp fibers with xylanase followed by laccase provided a collective 25% and 46% increase in dry and wet tensile strength properties, respectively. PMID:16080715

  11. Incorporation of Epicatechin Esters into Lignin Enhances Cell Wall Fermentability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Polyphenolic catechin esters are potentially attractive targets for lignin bioengineering because their copolymerization with monolignols could reduce lignin hydrophobicity and cross-linking to polysaccharides, or facilitate delignification by biomass pretreatments. To test this hypothesis, we biomi...

  12. Studies on the solubilization of the water-insoluble fraction from human lens and cataract.

    PubMed

    Ortwerth, B J; Olesen, P R

    1992-12-01

    Studies were carried out comparing the ability of urea extraction and sonication to solubilize the water-insoluble (WI) protein fraction from human lens tissue. Sonication and urea extraction were able to solubilize greater than 80% of the insoluble protein whether whole lenses or lens nuclei were used. This was true for normal lens and +1 cataracts; however, only 60% solubilization was obtained with the WI fraction from more advanced cataracts. Equal aliquots of a WI fraction from both pooled normal and pooled cataract lens nuclei were solubilized with and without reducing agents. The addition of dithiothreitol (DTT) had no significant effect on solubilization of the normal lens WI fraction. DTT did increase the protein solubilized from the cataract WI fraction by 30% with urea extraction; however, no increase was seen with sonication. When sodium borohydride was used as the reducing agent, essentially the same results were obtained. The solubilized protein populations were identical by SDS-PAGE and amino acid analysis. The addition of reducing agents had no effect on the amino acid content of the solubilized proteins with the single exception of lysine. This amino acid was markedly decreased in the proteins extracted in the presence of 40 mM sodium borohydride, but not with DTT. These data suggest that the borohydride not only increased the amount of protein solubilized, but likely also stabilized glycated lysine residues during the acid hydrolysis. Therefore, sonication readily provides a soluble preparation of the WI proteins from normal and cataract lens nuclei without the need for denaturing agents, however, disulfide-linked and lysine modified crystallins were best solubilized with urea. PMID:1486936

  13. Deconstruction of Lignin Model Compounds and Biomass-Derived Lignin using Layered Double Hydroxide Catalysts

    SciTech Connect

    Chmely, S. C.; McKinney, K. A.; Lawrence, K. R.; Sturgeon, M.; Katahira, R.; Beckham, G. T.

    2013-01-01

    Lignin is an underutilized value stream in current biomass conversion technologies because there exist no economic and technically feasible routes for lignin depolymerization and upgrading. Base-catalyzed deconstruction (BCD) has been applied for lignin depolymerization (e.g., the Kraft process) in the pulp and paper industry for more than a century using aqueous-phase media. However, these efforts require treatment to neutralize the resulting streams, which adds significantly to the cost of lignin deconstruction. To circumvent the need for downstream treatment, here we report recent advances in the synthesis of layered double hydroxide and metal oxide catalysts to be applied to the BCD of lignin. These catalysts may prove more cost-effective than liquid-phase, non-recyclable base, and their use obviates downstream processing steps such as neutralization. Synthetic procedures for various transition-metal containing catalysts, detailed kinetics measurements using lignin model compounds, and results of the application of these catalysts to biomass-derived lignin will be presented.

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

    SciTech Connect

    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.

  15. CCoAOMT suppression modifies lignin composition in Pinus radiata.

    PubMed

    Wagner, Armin; Tobimatsu, Yuki; Phillips, Lorelle; Flint, Heather; Torr, Kirk; Donaldson, Lloyd; Pears, Lana; Ralph, John

    2011-07-01

    A cDNA clone encoding the lignin-related enzyme caffeoyl CoA 3-O-methyltransferase (CCoAOMT) was isolated from a Pinus radiata cDNA library derived from differentiating xylem. Suppression of PrCCoAOMT expression in P. radiata tracheary element cultures affected lignin content and composition, resulting in a lignin polymer containing p-hydroxyphenyl (H), catechyl (C) and guaiacyl (G) units. Acetyl bromide-soluble lignin assays revealed reductions in lignin content of up to 20% in PrCCoAOMT-deficient transgenic lines. Pyrolysis-GC/MS and 2D-NMR studies demonstrated that these reductions were due to depletion of G-type lignin. Correspondingly, the proportion of H-type lignin in PrCCoAOMT-deficient transgenic lines increased, resulting in up to a 10-fold increase in the H/G ratio relative to untransformed controls. 2D-NMR spectra revealed that PrCCoAOMT suppression resulted in formation of benzodioxanes in the lignin polymer. This suggested that phenylpropanoids with an ortho-diphenyl structure such as caffeyl alcohol are involved in lignin polymerization. To test this hypothesis, synthetic lignins containing methyl caffeate or caffeyl alcohol were generated and analyzed by 2D-NMR. Comparison of the 2D-NMR spectra from PrCCoAOMT-RNAi lines and synthetic lignins identified caffeyl alcohol as the new lignin constituent in PrCCoAOMT-deficient lines. The incorporation of caffeyl alcohol into lignin created a polymer containing catechyl units, a lignin type that has not been previously identified in recombinant lignin studies. This finding is consistent with the theory that lignin polymerization is based on a radical coupling process that is determined solely by chemical processes. PMID:21426426

  16. 21 CFR 177.1400 - Hydroxyethyl cellulose film, water-insoluble.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Hydroxyethyl cellulose film, water-insoluble. 177... SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances... cellulose film, water-insoluble. Water-insoluble hydroxyethyl cellulose film may be safely used...

  17. 21 CFR 177.1400 - Hydroxyethyl cellulose film, water-insoluble.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Hydroxyethyl cellulose film, water-insoluble. 177... SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances... cellulose film, water-insoluble. Water-insoluble hydroxyethyl cellulose film may be safely used...

  18. 21 CFR 177.1400 - Hydroxyethyl cellulose film, water-insoluble.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Hydroxyethyl cellulose film, water-insoluble. 177... cellulose film, water-insoluble. Water-insoluble hydroxyethyl cellulose film may be safely used for... cellulose film consists of a base sheet manufactured by the ethoxylation of cellulose under...

  19. 21 CFR 177.1400 - Hydroxyethyl cellulose film, water-insoluble.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Hydroxyethyl cellulose film, water-insoluble. 177... cellulose film, water-insoluble. Water-insoluble hydroxyethyl cellulose film may be safely used for... cellulose film consists of a base sheet manufactured by the ethoxylation of cellulose under...

  20. 21 CFR 177.1400 - Hydroxyethyl cellulose film, water-insoluble.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Hydroxyethyl cellulose film, water-insoluble. 177... Repeated Use Food Contact Surfaces § 177.1400 Hydroxyethyl cellulose film, water-insoluble. Water-insoluble hydroxyethyl cellulose film may be safely used for packaging food in accordance with the following...

  1. Genetics and chemistry of lignin degradation by Streptomyces

    SciTech Connect

    Crawford, D.L.

    1992-01-01

    Our research goal was to define the involvement of lignin peroxidases and other extracellular enzymes in lignin degradation by Streptomyces. We examined the biochemistry and genetics of lignin degrading enzyme production by several strains of Streptomyces. The lignin peroxidase ALiP-P3 of S. viridosporus was characterized kinetically and its activity optimized for oxidation of 2,4-dichlorophenol and vanillyl-acetone. Sensitive spectrophotometric assays were developed for monitoring oxidation of these substrates. ALiP-P3 reaction chemistry was examined using both spectrophotometric assays and gas chromatography/mass spectroscopy. Results showed that the enzyme oxidizes phenolic lignin substructure models in strong preference to nonphenolic ones. The peroxidase was also shown to depolymerize native lignin. We also cloned the ALip-P3 gene S. lividans in plasmid vector pIJ702. The cloned gene was partially sequenced, We also immunologically characterized the lignin peroxidase of S. viridosporus T7A and showed it to be structurally related to peroxidases produced by other lignin-solubilizing Streptomyces, but not the the H8 lignin peroxidase of P. chrysosporium. Studies with peroxidase deficient mutants of strain T7A showed that lignin peroxidases of S. viridosporus are directly involved in the solubilization of lignin. Additional research showed that other enzymes are also probably involved in lignin solubilization, possibly including extracellular esterases.

  2. Genetic engineering of syringyl-enriched lignin in plants

    DOEpatents

    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.

  3. Direct production of naphthenes and paraffins from lignin.

    PubMed

    Kong, Jiechen; He, Mingyuan; Lercher, Johannes A; Zhao, Chen

    2015-12-25

    The utilization of lignin as a fuel precursor has attracted attention, and a novel and facile process has been developed for one-pot conversion of lignin into cycloalkanes and alkanes with Ni catalysts under moderate conditions. This cascade hydrodeoxygenation approach may open the route to a new promising technique for direct liquefaction of lignin to hydrocarbons. PMID:26478925

  4. Caterpillar feeding responses to sorghum leaves with altered lignin levels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Production of liquid fuels from biomass is impeded by the presence of lignin. Plants with lower or altered lignin are more amenable to lignocellulosic conversion to ethanol and other biofuels, but may be more susceptible to insect damage where lignin is an important resistance factor. Sorghum, Sorg...

  5. Synthesis and characterization of aminated lignin.

    PubMed

    Pan, Hong; Sun, Gang; Zhao, Tao

    2013-08-01

    Amination of lignin can bring reactive amino groups onto the natural polymer and enable it to be employed in engineering materials. The amination reaction was successfully implemented after some of the hydroxyl groups on lignin were epoxidized. The resulted products showed a great quantity of primary amine group and secondary amine group which can be used as curing agents of epoxy resin. The results revealed that several factors including reaction temperature and time, as well as ratios of compounds, could influence the epoxidation and amination reactions. The resulted products were characterized by FT-IR spectra, (1)H NMR, (13)C NMR, element analysis, XPS and thermogravimetry analysis. PMID:23618954

  6. Process for producing phenolic compounds from lignins

    DOEpatents

    Agblevor, Foster A.

    1998-01-01

    A process for the production of low molecular weight phenolic compounds from lignins through the pyrolysis of the lignins in the presence of a strong base. In a preferred embodiment, potassium hydroxide is present in an amount of from about 0.1% to about 5% by weight, the pyrolysis temperature is from about 400.degree. C. to about 600.degree. C. at atmospheric pressure, and the time period for substantial completion of the reaction is from about 1-3 minutes. Examples of low molecular weight phenolic compounds produced include methoxyphenols, non-methoxylated phenols, and mixtures thereof.

  7. Process for producing phenolic compounds from lignins

    DOEpatents

    Agblevor, F.A.

    1998-09-15

    A process is described for the production of low molecular weight phenolic compounds from lignins through the pyrolysis of the lignins in the presence of a strong base. In a preferred embodiment, potassium hydroxide is present in an amount of from about 0.1% to about 5% by weight, the pyrolysis temperature is from about 400 C to about 600 C at atmospheric pressure, and the time period for substantial completion of the reaction is from about 1--3 minutes. Examples of low molecular weight phenolic compounds produced include methoxyphenols, non-methoxylated phenols, and mixtures thereof. 16 figs.

  8. Evaluation of Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry for Second-Generation Lignin Analysis

    PubMed Central

    Richel, Aurore; Vanderghem, Caroline; Simon, Mathilde; Wathelet, Bernard; Paquot, Michel

    2012-01-01

    Matrix-Assisted Laser Desorption/Ionization time-of-flight (MALDI-TOF) mass spectrometry is evaluated as an elucidation tool for structural features and molecular weights estimation of some extracted herbaceous lignins. Optimization of analysis conditions, using a typical organic matrix, namely α-cyano-4-hydroxycinnamic acid (CHCA), in combination with α-cyclodextrin, allows efficient ionization of poorly soluble lignin materials and suppression of matrix-related ions background. Analysis of low-mass fragments ions (m/z 100–600) in the positive ion mode offers a “fingerprint” of starting lignins that could be a fine strategy to qualitatively identify principal inter-unit linkages between phenylpropanoid units. The molecular weights of lignins are estimated using size exclusion chromatography and compared to MALDI-TOF-MS profiles. Miscanthus (Miscanthus x giganteus) and Switchgrass (Panicum Virgatum L.) lignins, recovered after a formic acid/acetic acid/water process or aqueous ammonia soaking, are selected as benchmarks for this study. PMID:23300342

  9. Insoluble calcium content and rheological properties of Colby cheese during ripening.

    PubMed

    Lee, M-R; Johnson, M E; Govindasamy-Lucey, S; Jaeggi, J J; Lucey, J A

    2010-05-01

    Colby cheese was made using different manufacturing conditions (i.e., varying the lactose content of milk and pH values at critical steps in the cheesemaking process) to alter the extent of acid development and the insoluble and total Ca contents of cheese. Milk was concentrated by reverse osmosis (RO) to increase the lactose content. Extent of acid development was modified by using high (HPM) and low (LPM) pH values at coagulant addition, whey drainage, and curd milling. Total Ca content was determined by atomic absorption spectroscopy, and the insoluble (INSOL) Ca content of cheese was measured by the cheese juice method. The rheological and melting properties of cheese were measured by small amplitude oscillatory rheometry and UW-Melt Profiler, respectively. There was very little change in pH during ripening even in cheese made from milk with high lactose content. The initial (d 1) cheese pH was in the range of 4.9 to 5.1. The INSOL Ca content of cheese decreased during the first 4 wk of ripening. Cheeses made with the LPM had lower INSOL Ca content during ripening compared with cheese made with HPM. There was an increase in melt and maximum loss tangent values during ripening except for LPM cheeses made with RO-concentrated milk, as this cheese had pH <4.9 and exhibited limited melt. Curd washing reduced the levels of lactic acid produced during ripening and resulted in significantly higher INSOL Ca content. The use of curd washing for cheeses made from high lactose milk prevented a large pH decrease during ripening; high rennet and draining pH values also retained more buffering constituents (i.e., INSOL Ca phosphate), which helped prevent a large pH decrease. PMID:20412897

  10. Lignin Degradation in a Coastal Groundwater Aquifer: a Useful Tracer?

    NASA Astrophysics Data System (ADS)

    Howley, E. M.; Jex, C.; Andersen, M. S.; Baker, A.; Zainuddin, N. S.; Meredith, K.; Wells, E.; McDonald, J.; Khan, S.; Blyth, A. J.; Spencer, R. G.

    2014-12-01

    Lignin as a biomarker in soils, peat, lakes and intertidal and marine sediment cores has been widely researched in the last four decades. The biogeochemical processes controlling their distribution and composition include fractionation due to phase changes, mineral binding, and abiotic and biotic decay. However, there appears to be no studies in the literature describing the concentration and composition of lignin in groundwater aquifers, despite lignin tracing having the potential to differentiate between types of vegetation and recharge source. In the latter case aquifers could potentially be a source of old, degradation resistant lignin. In this study, we characterise the lignin composition in groundwater samples from a coastal sand aquifer, in SE Australia. We compare these data with lignin composition of fresh vegetation samples from the study site, and with lignin data from other environments in the literature. Groundwater samples were also analysed for Dissolved Organic Carbon (DOC) and inorganic chemistry (major ions, Dissolved Inorganic Carbon (DIC) and redox sensitive species) to investigate lignin fractionation processes. To achieve this, the groundwater lignin composition was compared to the total DOC and DIC in the samples and the prevailing redox reactions. The lignin composition in groundwater was found to be unrelated to the surrounding surface vegetation, indicating significant alteration by biogeochemical processes along its flow paths. We identify potential lignin degradation zones, via determination of total OC consumed through redox reactions and microbial activity. In conclusion, this study, by closely examining the correlations of lignin phenols in groundwater with lignin in surface waters, as well as biogeochemical processes in the aquifer is shedding a new light on the ability of lignin as a biomarker in these subsurface systems. To our knowledge, this is the first attempt to assess the usefulness of lignin as a tracer in groundwater.

  11. Hydroxycinnamate conjugates as potential monolignol replacements: In vitro lignification and cell wall studies with rosmarinic acid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The plasticity of lignin biosynthesis should permit the inclusion of new compatible phenolic monomers such as rosmarinic acid (RA) and analogous catechol derivatives to create cell wall lignins that are less recalcitrant to biomass processing. In vitro lignin polymerization experiments revealed that...

  12. Development of Stable Solidification Method for Insoluble Ferrocyanides-13170

    SciTech Connect

    Ikarashi, Yuki; Masud, Rana Syed; Mimura, Hitoshi; Ishizaki, Eiji; Matsukura, Minoru

    2013-07-01

    The development of stable solidification method of insoluble ferrocyanides sludge is an important subject for the safety decontamination in Fukushima NPP-1. By using the excellent immobilizing properties of zeolites such as gas trapping ability and self-sintering properties, the stable solidification of insoluble ferrocyanides was accomplished. The immobilization ratio of Cs for K{sub 2}[CoFe(CN){sub 6}].nH{sub 2}O saturated with Cs{sup +} ions (Cs{sub 2}[CoFe(CN){sub 6}].nH{sub 2}O) was estimated to be less than 0.1% above 1,000 deg. C; the adsorbed Cs{sup +} ions are completely volatilized. In contrast, the novel stable solid form was produced by the press-sintering of the mixture of Cs{sub 2}[CoFe(CN){sub 6}].nH{sub 2}O and zeolites at higher temperature of 1,000 deg. C and 1,100 deg. C; Cs volatilization and cyanide release were completely depressed. The immobilization ratio of Cs, under the mixing conditions of Cs{sub 2}[CoFe(CN){sub 6}].nH{sub 2}O:CP= 1:1 and calcining temperature: 1,000 deg. C, was estimated to be nearly 100%. As for the kinds of zeolites, natural mordenite (NM), clinoptilolite (CP) and Chabazite tended to have higher immobilization ratio compared to zeolite A. This may be due to the difference in the phase transformation between natural zeolites and synthetic zeolite A. In the case of the composites (K{sub 2-X}Ni{sub X/2}[NiFe(CN){sub 6}].nH{sub 2}O loaded natural mordenite), relatively high immobilization ratio of Cs was also obtained. This method using zeolite matrices can be applied to the stable solidification of the solid wastes of insoluble ferrocyanides sludge. (authors)

  13. Identifying New Lignin Bioengineering Targets: Monolignol Substitute Impacts on Lignin Formation and Cell Wall Utilization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent discoveries highlighting the metabolic malleability of plant lignification indicate that lignin can be engineered to dramatically alter its composition and properties. Current plant engineering efforts are primarily aimed at manipulating the biosynthesis of normal monolignols, but in the futu...

  14. Identifying New Lignin Bioengineering Targets: 1. Monolignol Substitute Impacts on Lignin Formation and Cell Wall Fermentability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 engineering efforts are primarily aimed at manipulating the biosynthesis of normal monolignols but,...

  15. Effect of reduced ferulate-mediated lignin/arabinoxylan cross-linking in corn silage on feed intake, digestibility, and milk production.

    PubMed

    Jung, H G; Mertens, D R; Phillips, R L

    2011-10-01

    Cross-linking of lignin to arabinoxylan by ferulates limits in vitro rumen digestibility of grass cell walls. The effect of ferulate cross-linking on dry matter intake (DMI), milk production, and in vivo digestibility was investigated in ad libitum and restricted-intake digestion trials with lambs, and in a dairy cow performance trial using the low-ferulate sfe corn mutant. Silages of 5 inbred corn lines were fed: W23, 2 W23sfe lines (M04-4 and M04-21), B73, and B73bm3. As expected, the W23sfe silages contained fewer ferulate ether cross-links and B73bm3 silage had a lower lignin concentration than the respective genetic controls. Silages were fed as the sole ingredient to 4 lambs per silage treatment. Lambs were confined to metabolism crates and fed ad libitum for a 12-d adaptation period followed by a 5-d collection period of feed refusals and feces. Immediately following the ad libitum feeding trial, silage offered was limited to 2% of body weight. After a 2-d adaptation to restricted feeding, feed refusals and feces were collected for 5 d. Seventy Holstein cows were blocked by lactation, days in milk, body weight, and milk production and assigned to total mixed ration diets based on the 5 corn silages. Diets were fed for 28 d and data were collected on weekly DMI and milk production and composition. Fecal grab samples were collected during the last week of the lactation trial for estimation of feed digestibility using acid-insoluble ash as a marker. Silage, total mixed ration, feed refusals, and fecal samples were analyzed for crude protein, starch, neutral detergent fiber (NDF), cell wall polysaccharides, and lignin. The W23sfe silages resulted in lower DMI in the ad libitum trial than the W23 silage, but DMI did not differ in the restricted trial. No differences were observed for NDF or cell wall polysaccharide digestibility by lambs with restricted feeding, but the amount of NDF digested daily increased for lambs fed the M04-21 W23sfe silage ad libitum

  16. Nylon biodegradation by lignin-degrading fungi.

    PubMed Central

    Deguchi, T; Kakezawa, M; Nishida, T

    1997-01-01

    The biodegradation of nylon by lignin-degrading fungi was investigated. The fungus IZU-154 significantly degraded nylon-66 membrane under ligninolytic conditions. Nuclear magnetic resonance analysis showed that four end groups, CHO, NHCHO, CH3, and CONH2, were formed in the biodegraded nylon-66 membranes, suggesting that nylon-66 was degraded oxidatively. PMID:8979361

  17. Pyrolysis mechanisms of lignin model compounds

    SciTech Connect

    Britt, P.F.; Buchanan, A.C. III; Cooney, M.J.

    1997-06-01

    The flash vacuum pyrolysis of lignin model compounds was studied under conditions optimized for the production of liquid products to provide mechanistic insight into the reaction pathways that lead to product formation. The major reaction products can be explained by cleavage of the C-O either linkage by a free radial or concerted 1,2-elimination.

  18. Three-dimensional model of lignin structure

    SciTech Connect

    Jurasek, L.

    1995-12-01

    An attempt to build a three-dimensional model of lignin structure using a computer program is described. The program simulates the biosynthesis of spruce lignin by allowing coniferyl alcohol subunits to be added randomly by six different types of linkages, assumed to be most common. The simulated biosynthesis starts from a number of seed points within restricted space, corresponding to 50 mM initial concentration of coniferyl alcohol. Rules of three-dimensional packing of the subunits within the lignin macro-molecule are observed during the simulated biosynthetic process. Branched oligomeric structures thus generated form crosslinks at those positions where the chains grow close enough to form a link. Inter-chain crosslinking usually joins the oligomers into one macromolecule. Intra-chain crosslinks are also formed and result in closed loops. Typically, a macromolecule with molecular weight of approx. 2 x 105 is formed, with internal density of 1.35g/cm3. Various characteristics of the internal structure, such as branching, crosslinking, bond frequencies, and chain length distribution are described. Breakdown of the polymer was also simulated and the effect of closed loops on the weight average molecular weight is shown. The effect of the shape of the biosynthetic space on the degree of crosslinking is discussed and predictions of the overall molecular shape of lignin particles are made.

  19. Flash vacuum pyrolysis of lignin model compounds

    SciTech Connect

    Cooney, M.J.; Britt, P.F.; Buchanan, A.C. III

    1997-03-01

    Despite the extensive research into the pyrolysis of lignin, the underlying chemical reactions that lead to product formation are poorly understood. Detailed mechanistic studies on the pyrolysis of biomass and lignin under conditions relevant to current process conditions could provide insight into utilizing this renewable resource for the production of chemicals and fuel. Currently, flash or fast pyrolysis is the most promising process to maximize the yields of liquid products (up to 80 wt %) from biomass by rapidly heating the substrate to moderate temperatures, typically 500{degrees}C, for short residence times, typically less than two seconds. To provide mechanistic insight into the primary reaction pathways under process relevant conditions, we are investigating the flash vacuum pyrolysis (FVP) of lignin model compounds that contain a {beta}-ether. linkage and {alpha}- or {gamma}-alcohol, which are key structural elements in lignin. The dominant products from the FVP of PhCH{sub 2}CH{sub 2}OPh (PPE), PhC(OH)HCH{sub 2}OPh, and PhCH{sub 2}CH(CH{sub 2}OH)OPh at 500{degrees}C can be attributed to homolysis of the weakest bond in the molecule (C-O bond) or 1,2-elimination. Surprisingly, the hydroxy-substituent dramatically increases the decomposition of PPE. It is proposed that internal hydrogen bonding is accelerating the reaction.

  20. Kinetic Model Development for Lignin Pyrolysis

    SciTech Connect

    Clark, J.; Robichaud, D.; Nimlos, M.

    2012-01-01

    Lignin pyrolysis poses a significant barrier to the formation of liquid fuel products from biomass. Lignin pyrolyzes at higher temperatures than other biomass components (e.g. cellulose and hemi-cellulose) and tends to form radicals species that lead to cross-linking and ultimately char formation. A first step in the advancement of biomass-to-fuel technology is to discover the underlying mechanisms that lead to the breakdown of lignin at lower temperatures into more stable and usable products. We have investigated the thermochemistry of the various inter-linkage units found in lignin (B-O4, a-O4, B-B, B-O5, etc) using electronic structure calculations at the M06-2x/6-311++G(d,p) on a series of dimer model compounds. In addition to bond homolysis reactions, a variety of concerted elimination pathways are under investigation that tend to produce closed-shell stable products. Such a bottom-up approach could aid in the targeted development of catalysts that produce more desirable products under less severe reactor conditions.

  1. Phoma herbarum, a soil fungus able to grow on natural lignin and synthetic lignin (DHP) as sole carbon source and cause lignin degradation.

    PubMed

    Bi, Ran; Lawoko, Martin; Henriksson, Gunnar

    2016-08-01

    The fungus Phoma herbarum isolated from soil showed growth on highly pure lignin extracted from spruce wood and on synthetic lignin (DHP). The lignin remaining after cultivation was shown to have a lower molecular weight. The reduction in the numbers of ether linkages of the extracted lignins was also observed by derivatization followed by reductive cleavage (DFRC) in combination with (31)P NMR studies. The fungal strain showed an ability to degrade synthetic lignin by extracellular catalysts. GC-MS was applied to study the evolution of low molar mass adducts, e.g., monolignols and it was shown that a reduced coniferyl alcohol product was produced from DHP in a cell-free environment. The work has demonstrated the ability of soil microbes to grow on lignin as sole carbon source. The potential impact is in the production of low molar mass renewable phenols for material application. PMID:27260523

  2. Isolation of a bacterium capable of degrading peanut hull lignin

    SciTech Connect

    Kerr, T.A.; Kerr, R.D.; Benner, R.

    1983-11-01

    Thirty-seven bacterial strains capable of degrading peanut hull lignin were isolated by using four types of lignin preparations and hot-water-extracted peanut hulls. One of the isolates, tentatively identified as Arthrobacter species, was capable of utilizing all four lignin preparations as well as extracted peanut hulls as a sole source of carbon. The bacterium was also capable of degrading specifically labeled (/sup 14/C) lignin-labeled lignocellulose and (/sup 14/C)cellulose-labeled lignocellulose from the cordgrass Spartina alterniflora and could also degrade (/sup 14/C) Kraft lignin from slash pine. After 10 days of incubation with (/sup 14/C) cellulose-labeled lignocellulose or (/sup 14/C) lignin-labeled lignocellulose from S. alterniflora, the bacterium mineralized 6.5% of the polysaccharide component and 2.9% of the lignin component. (Refs. 24).

  3. Poplar lignin decomposition by gram-negative aerobic bacteria

    SciTech Connect

    Odier, E.; Janin, G.; Monties, B.

    1981-02-01

    Eleven gram-negative aerobic bacteria (Pseudomonadaceae and Neisseriaceae) out of 122 soil isolates were selected for their ability to assimilate poplar dioxane lignin without a cosubstrate. Dioxane lignin and milled wood lignin degradation rates ranged between 20 and 40% of initial content after 7 days in mineral medium, as determined by a loss of absorbance at 280 nm; 10 strains could degrade in situ lignin, as evidenced by the decrease of the acetyl bromide lignin content of microtome wood sections. No degradation of wood polysaccharides was detected. Lignin biodegradation by Pseudomonas 106 was confirmed by 14CO2 release from labeled poplar wood, although in lower yields compared with results obtained through chemical analysis based on acetyl bromide residual lignin determination. (Refs. 31).

  4. Method for recovering and using lignin in adhesive resins

    DOEpatents

    Schroeder, Herbert A.

    1993-01-01

    Lignin, or a lignin derived material, which has been significantly demethylated (e.g., the demethylated lignin found in the raffinate produced as a by-product of dimethyl sulfide production which can be carried out using the spent liquor from wood pulping operations) can be isolated by a process wherein an organic solvent is added to a lignin-containing aqueous solution. The organic solvent is typically a polar, and at least a partially water-immiscible substance such as, for example, ethyl acetate. The resulting lignin-containing aqueous solution/organic solvent mixture is acidified to produce a water layer which is discarded and an organic solvent layer which contains the demethylated lignin. Upon its recovery, the demethylated lignin is dissolved in an alkaline solution to which an aldehyde source is added to produce a resol-type resin. The aldehyde source may be formaldehyde in solution, paraformaldehyde, hexamethylenetetramine, or other aldehydes including acetaldehyde, furfural, and their derivatives.

  5. Analytical pyrolysis of hardwood and softwood lignins and its use in lignin-type determination of hardwood vessel elements

    SciTech Connect

    Obst, J.R.

    1983-01-01

    Pyrolysis, GC and mass spectrometry were performed on milled wood lignins and wood samples. Among the major pyrolysis products identified from loblolly pine lignin were: guaiacol, 4-methylguaiacol, 4-vinylguaiacol, vanillin, coniferaldehyde and coniferyl alcohol. White oak lignin pyrolysis products included: guaiacol, 4-methylguaiacol, vanillin, 2,6-dimethoxyphenol, 4-methyl-2,6-dimethoxyphenol, syringaldehyde and sinapaldehyde. By the identification of pyrolysis products it is thus possible to classify lignins as either guaiacyl-type or syringyl/guaiacyl-type. Pyrolysis of isolated vessel elements from white oak, white birch (Betula papyrifera) and American elm (Ulmus americana) indicated that vessel lignin is of the syringyl/guaiacyl type. 14 references.

  6. Insoluble and soluble roasted walnut proteins retain antibody reactivity.

    PubMed

    Downs, Melanie L; Simpson, Angela; Custovic, Adnan; Semic-Jusufagic, Aida; Bartra, Joan; Fernandez-Rivas, Montserrat; Taylor, Steve L; Baumert, Joseph L; Mills, E N Clare

    2016-03-01

    Thermal processing techniques commonly used during food production have the potential to impact food allergens by inducing physical and/or chemical changes to the proteins. English walnuts (Juglans regia) are among the most commonly allergenic tree nuts, but little information is available regarding how walnut allergens respond to thermal processing. This study evaluated the effects of dry roasting (132 or 180°C for 5, 10, or 20min) on the solubility and immunoreactivity of walnut proteins. A dramatic decrease in walnut protein solubility was observed following dry roasting at 180°C for 20min. However, both the soluble and insoluble protein fractions from roasted walnuts maintained substantial amounts of IgG immunoreactivity (using anti-raw and anti-roasted walnut antisera), with similar patterns of reactivity observed for human IgE from walnut-allergic individuals. Thus, walnut proteins are relatively stable under certain thermal processing conditions, and IgE reactivity remains present even when insoluble aggregates are formed. PMID:26471647

  7. Insoluble Coatings for Stirling Engine Heat Pipe Condenser Surfaces

    NASA Technical Reports Server (NTRS)

    Dussinger, Peter M.; Lindemuth, James E.

    1997-01-01

    The principal objective of this Phase 2 SBIR program was to develop and demonstrate a practically insoluble coating for nickel-based superalloys for Stirling engine heat pipe applications. Specific technical objectives of the program were: (1) Determine the solubility corrosion rates for Nickel 200, Inconel 718, and Udimet 72OLI in a simulated Stirling engine heat pipe environment, (2) Develop coating processes and techniques for capillary groove and screen wick structures, (3) Evaluate the durability and solubility corrosion rates for capillary groove and screen wick structures coated with an insoluble coating in cylindrical heat pipes operating under Stirling engine conditions, and (4) Design and fabricate a coated full-scale, partial segment of the current Stirling engine heat pipe for the Stirling Space Power Convertor program. The work effort successfully demonstrated a two-step nickel aluminide coating process for groove wick structures and interior wall surfaces in contact with liquid metals; demonstrated a one-step nickel aluminide coating process for nickel screen wick structures; and developed and demonstrated a two-step aluminum-to-nickel aluminide coating process for nickel screen wick structures. In addition, the full-scale, partial segment was fabricated and the interior surfaces and wick structures were coated. The heat pipe was charged with sodium, processed, and scheduled to be life tested for up to ten years as a Phase 3 effort.

  8. Comparative toxicity and carcinogenicity of soluble and insoluble cobalt compounds.

    PubMed

    Behl, Mamta; Stout, Matthew D; Herbert, Ronald A; Dill, Jeffrey A; Baker, Gregory L; Hayden, Barry K; Roycroft, Joseph H; Bucher, John R; Hooth, Michelle J

    2015-07-01

    Occupational exposure to cobalt is of widespread concern due to its use in a variety of industrial processes and the occurrence of occupational disease. Due to the lack of toxicity and carcinogenicity data following exposure to cobalt, and questions regarding bioavailability following exposure to different forms of cobalt, the NTP conducted two chronic inhalation exposure studies in rats and mice, one on soluble cobalt sulfate heptahydrate, and a more recent study on insoluble cobalt metal. Herein, we compare and contrast the toxicity profiles following whole-body inhalation exposures to these two forms of cobalt. In general, both forms were genotoxic in the Salmonella T98 strain in the absence of effects on micronuclei. The major sites of toxicity and carcinogenicity in both chronic inhalation studies were the respiratory tract in rats and mice, and the adrenal gland in rats. In addition, there were distinct sites of toxicity and carcinogenicity noted following exposure to cobalt metal. In rats, carcinogenicity was observed in the blood, and pancreas, and toxicity was observed in the testes of rats and mice. Taken together, these findings suggest that both forms of cobalt, soluble and insoluble, appear to be multi-site rodent carcinogens following inhalation exposure. PMID:25896363

  9. Reductive deconstruction of organosolv lignin catalyzed by zeolite supported nickel nanoparticles

    SciTech Connect

    Kasakov, Stanislav; Shi, Hui; Camaioni, Donald M.; Zhao, Chen; Barath, Eszter; Jentys, Andreas; Lercher, Johannes A.

    2015-11-01

    Mechanistic aspects of deconstruction and hydrodeoxygenation of organosolv lignin using supported Ni catalysts with (Ni/HZSM-5 and Ni/HBEA) and without Brønsted acid sites (Ni/SiO2) are reported. Lignin was deconstructed and converted to saturated cyclic hydrocarbons ranging from C5 to C14. In the one-stage reaction, full conversion with total yield of 70 ± 5 wt.% saturated hydrocarbons was achieved at 593 K and 20 bar H2. The organosolv lignin used consists of seven to eight monolignol subunits and has an average molecular weight of ca. 1200 g mol-1. The monolignols were mainly guaiacyl, syringyl and phenylcoumaran, randomly interconnected through β-O-4, 4-O-5, β-1, 5-5’ and β-β ether bonds. In situ IR spectroscopy was used to follow the changes in lignin constituents during reaction. The proposed reaction pathways for the catalytic transformation of this organosolv lignin to alkanes start with the hydrogenolysis of aryl alkyl ether bonds, followed by hydrogenation of the aromatic compounds on Ni to cyclic alcohols. Oxygen is removed from the alcohols via dehydration on Brønsted acid sites to yield cyclic alkenes that are further hydrogenated to alkanes. Formation of condensation products may occur via intermolecular recombination of aromatic monomers or alkylation of aromatic compounds by alkenes. The financial support from TUM-PNNL cooperation project “Development of new methods for in situ characterization in liquid phase reactions” (CN-177939) is highly appreciated. The work by S.K., H.S., and J.A.L was partially supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences.

  10. Evaluation of monitoring indicators for the post-closure care of a landfill for MSW characterized with low lignin content.

    PubMed

    Zheng, Wei; Lü, Fan; Bolyard, Stephanie C; Shao, Liming; Reinhart, Debra R; He, Pinjing

    2015-02-01

    To understand the applicability of the termination indicators for landfill municipal solid waste (MSW) with low initial lignin content, four different accelerated landfill stabilization techniques were applied to anaerobic landfilled waste, including anaerobic flushing with water, anaerobic flushing with Fenton-treated leachate, and aerobic flushing with Fenton-treated and UV/H2O2-treated leachate. Termination indicators, including total organic carbon (TOC), ammonia-N (NH4(+)-N), the ratio of UV absorbance at 254 nm to TOC concentration (SUVA254), fluorescence spectra of leachate, methane production, oxygen consumption, lignocellulose content, and humus-like content were evaluated. Results suggest that oxygen consumption related indicators used as a termination indicator for low-lignin-content MSW were more sensitive than methane consumption related indicators. Aeration increased humic acid (HA) and (HA+FA)/HyI content by 2.9 and 1.7 times compared to the anaerobically stabilized low-lignin-content MSW. On the other hand, both the fulvic acid (FA) and hydrophilic (HyI) fractions remained constant regardless of stabilization technique. The target value developed for low-lignin-content MSW was quite different than developed countries mainly due to low residual biodegradable organic carbon content in stabilized low-lignin-content MSW. PMID:25433407

  11. Ultra-high performance supercritical fluid chromatography of lignin-derived phenols from alkaline cupric oxide oxidation.

    PubMed

    Sun, Mingzhe; Lidén, Gunnar; Sandahl, Margareta; Turner, Charlotta

    2016-08-01

    Traditional chromatographic methods for the analysis of lignin-derived phenolic compounds in environmental samples are generally time consuming. In this work, an ultra-high performance supercritical fluid chromatography method with a diode array detector for the analysis of major lignin-derived phenolic compounds produced by alkaline cupric oxide oxidation was developed. In an analysis of a collection of 11 representative monomeric lignin phenolic compounds, all compounds were clearly separated within 6 min with excellent peak shapes, with a limit of detection of 0.5-2.5 μM, a limit of quantification of 2.5-5.0 μM, and a dynamic range of 5.0-2.0 mM (R(2) > 0.997). The new ultra-high performance supercritical fluid chromatography method was also applied for the qualitative and quantitative analysis of lignin-derived phenolic compounds obtained upon alkaline cupric oxide oxidation of a commercial humic acid. Ten out of the previous eleven model compounds could be quantified in the oxidized humic acid sample. The high separation power and short analysis time obtained demonstrate for the first time that supercritical fluid chromatography is a fast and reliable technique for the analysis of lignin-derived phenols in complex environmental samples. PMID:27452148

  12. Structure and expression of the lignin O-methyltransferase gene from Zea mays L.

    PubMed

    Collazo, P; Montoliu, L; Puigdomènech, P; Rigau, J

    1992-12-01

    The isolation and characterization of cDNA and homologous genomic clones encoding the lignin O-methyltransferase (OMT) from maize is reported. The cDNA clone has been isolated by differential screening of maize root cDNA library. Southern analysis indicates that a single gene codes for this protein. The genomic sequence contains a single 916 bp intron. The deduced protein sequence from DNA shares significant homology with the recently reported lignin-bispecific caffeic acid/5-hydroxyferulic OMTs from alfalfa and aspen. It also shares homology with OMTs from bovine pineal glands and a purple non-sulfur photosynthetic bacterium. The mRNA of this gene is present at different levels in distinct organs of the plant with the highest accumulation detected in the elongation zone of roots. Bacterial extracts from clones containing the maize OMT cDNA show an activity in methylation of caffeic acid to ferulic acid comparable to that existing in the plant extracts. These results indicate that the described gene encodes the caffeic acid 3-O-methyltransferase (COMT) involved in the lignin bio-synthesis of maize. PMID:1463825

  13. Lignin-degrading Peroxidases from Genome of Selective Ligninolytic Fungus Ceriporiopsis subvermispora*

    PubMed Central

    Fernández-Fueyo, Elena; Ruiz-Dueñas, Francisco J.; Miki, Yuta; Martínez, María Jesús; Hammel, Kenneth E.; Martínez, Angel T.

    2012-01-01

    The white-rot fungus Ceriporiopsis subvermispora delignifies lignocellulose with high selectivity, but until now it has appeared to lack the specialized peroxidases, termed lignin peroxidases (LiPs) and versatile peroxidases (VPs), that are generally thought important for ligninolysis. We screened the recently sequenced C. subvermispora genome for genes that encode peroxidases with a potential ligninolytic role. A total of 26 peroxidase genes was apparent after a structural-functional classification based on homology modeling and a search for diagnostic catalytic amino acid residues. In addition to revealing the presence of nine heme-thiolate peroxidase superfamily members and the unexpected absence of the dye-decolorizing peroxidase superfamily, the search showed that the C. subvermispora genome encodes 16 class II enzymes in the plant-fungal-bacterial peroxidase superfamily, where LiPs and VPs are classified. The 16 encoded enzymes include 13 putative manganese peroxidases and one generic peroxidase but most notably two peroxidases containing the catalytic tryptophan characteristic of LiPs and VPs. We expressed these two enzymes in Escherichia coli and determined their substrate specificities on typical LiP/VP substrates, including nonphenolic lignin model monomers and dimers, as well as synthetic lignin. The results show that the two newly discovered C. subvermispora peroxidases are functionally competent LiPs and also suggest that they are phylogenetically and catalytically intermediate between classical LiPs and VPs. These results offer new insight into selective lignin degradation by C. subvermispora. PMID:22437835

  14. Norway spruce (Picea abies) laccases: characterization of a laccase in a lignin-forming tissue culture.

    PubMed

    Koutaniemi, Sanna; Malmberg, Heli A; Simola, Liisa K; Teeri, Teemu H; Kärkönen, Anna

    2015-04-01

    Secondarily thickened cell walls of water-conducting vessels and tracheids and support-giving sclerenchyma cells contain lignin that makes the cell walls water impermeable and strong. To what extent laccases and peroxidases contribute to lignin biosynthesis in muro is under active evaluation. We performed an in silico study of Norway spruce (Picea abies (L.) Karst.) laccases utilizing available genomic data. As many as 292 laccase encoding sequences (genes, gene fragments, and pseudogenes) were detected in the spruce genome. Out of the 112 genes annotated as laccases, 79 are expressed at some level. We isolated five full-length laccase cDNAs from developing xylem and an extracellular lignin-forming cell culture of spruce. In addition, we purified and biochemically characterized one culture medium laccase from the lignin-forming cell culture. This laccase has an acidic pH optimum (pH 3.8-4.2) for coniferyl alcohol oxidation. It has a high affinity to coniferyl alcohol with an apparent Km value of 3.5 μM; however, the laccase has a lower catalytic efficiency (V(max)/K(m)) for coniferyl alcohol oxidation compared with some purified culture medium peroxidases. The properties are discussed in the context of the information already known about laccases/coniferyl alcohol oxidases of coniferous plants. PMID:25626739

  15. Kraft lignin biodegradation by Novosphingobium sp. B-7 and analysis of the degradation process.

    PubMed

    Chen, Yuehui; Chai, Liyuan; Tang, Chongjian; Yang, Zhihui; Zheng, Yu; Shi, Yan; Zhang, Huan

    2012-11-01

    This study focused on the biodegradation of kraft lignin (KL) by Novosphingobium sp. B-7 using KL as sole carbon source. Results revealed that Novosphingobium sp. B-7 reduced the chemical oxygen demand (COD) by 34.7% in KL mineral salt medium after 7days of incubation. Additionally, the maximum activities of manganese peroxidase (MnP) of 3229.8Ul(-1) and laccase (Lac) of 1275Ul(-1) were observed at 4th and 5th day, respectively. GC-MS analysis indicated that after incubated with Novosphingobium sp. B-7, low molecular weight alcohols and lignin-related monomer compounds such as ethanediol, p-hydroxy benzoic acid and vanillic acid were formed in the system, which strongly confirmed the degradation of KL by Novosphingobium sp. B-7. PMID:22921251

  16. Lignin biomarkers and pollen in the postglacial sediment of an Alaskan Lake

    NASA Astrophysics Data System (ADS)

    Hu, Feng Sheng; Hedges, John I.; Gordon, Elizabeth S.; Brubaker, Linda B.

    1999-05-01

    We analyzed a 12,000-yr sediment core from Wien Lake, central Alaska, for a suite of phenolic products from CuO oxidation of lignin polymers and compared their composition with pollen data from the same core to assess lignin phenols as sedimentary biomarkers. Inferences of the gross taxonomic origin of sediment organic matter from lignin-phenol composition agree with vegetational reconstructions based on pollen assemblages. In particular, the ratios of syringyl to vanillyl phenols are consistently higher before 6500 yr BP, when angiosperms dominated or codominated the regional vegetation, than after 6500 yr BP, when gymnosperms dominated. However, the ratios of cinnamyl ( p-coumaric and ferulic acids) to total vanillyl phenols (C/V) do not show patterns expected from the abundance of woody plants. C/V ratios are particularly high (0.7-0.85) after 6500 yr BP when pollen spectra suggest closed boreal forests dominated by Picea, and the stratigraphic patterns are strikingly similar between C/V and Picea pollen concentrations. CuO oxidation of modern pollen of P. glauca and P. mariana yields exceptionally high amounts of cinnamyl phenols (8.90 and 6.41 mg/100 mg OC for P. glauca and P. mariana, respectively). In particular, p-coumaric acid is obtained in large amounts (8.87 and 6.41 mg/100 mg OC for P. glauca and P. mariana, respectively) versus vanillyl phenols (0.25 and 0.49 mg/100 mg OC for P. glauca and P. mariana, respectively) and ferulic acid (0.03 and 0.00 mg/100 mg OC for P. glauca and P. mariana, respectively). Thus lignin phenols derived from fossil Picea pollen preserved in sediments likely drive the C/V profile of the Wien Lake core. These data imply that if Picea pollen concentrations are sufficiently high, the amount of nonwoody tissue in sediments may be grossly overestimated when the lignin composition of gymnosperm needles is used as the end member of nonwoody tissues. Given that pollen grains are among the most resistant components of sedimentary

  17. A modified enzyme-linked immunosorbent assay adapted for immunodetection of low amounts of water-insoluble proteins.

    PubMed

    Godfrin, Dominique; Sénéchal, Hélène; Sutra, Jean-Pierre; Busnel, Jean-Marc; Desvaux, François-Xavier; Peltre, Gabriel

    2007-09-30

    A mixture of thiourea, urea and CHAPS (TUC) is an excellent solvent compatible with isoelectrofocusing (IEF) separation of water-insoluble protein extracts, and their subsequent two-dimensional gel electrophoresis is an important step in proteomic studies. The main aim of this work was to quantify extremely low amounts of water-insoluble proteins contained, for instance, in samples collected in bio-aerosol samplers. High CHAPS concentrations solubilize many proteins. However, enzyme-linked immunosorbent assay (ELISA), which is the most popular immunodetection method of quantifying antigens, is unfortunately not compatible with these high CHAPS concentrations and with the low protein concentrations of TUC extracts. The most common mixture used to solubilize these proteins contains 2 mol l(-1) thiourea, 7 mol l(-1) urea and 5% w/v CHAPS. This paper shows that these components inhibit the adsorption and/or recognition of proteins on microtitration plates, preventing antigen quantification under classic ELISA conditions. We have tried several solvents (ethanol, isopropanol, acetonitrile and trichloroacetic acid) to make the TUC-soluble proteins stick to the ELISA plates, and ethanol was shown to be the most appropriate. In this study, we have defined a new ELISA protocol allowing rapid and sensitive detection of low concentrations (60-500 ng ml(-1)) of water-insoluble proteins extracted with high concentrations of TUC. PMID:17706662

  18. Lignin geochemistry of sediments from the Narragansett Bay Estuary

    NASA Astrophysics Data System (ADS)

    Requejo, A. G.; Brown, John S.; Boehm, Paul D.

    1986-12-01

    Cupric oxide oxidation has been employed to characterize the lignin geochemistry of Narragansett Bay sediments. Lignin concentrations throughout the estuary are low when expressed on a carbon-normalized basis, but can be characterized as enriched when expressed on a mass-normalized basis. This implies substantial dilution of the sedimentary lignin by inputs of lignin-poor carbon. Lignin concentrations do not correlate with the 13C isotopic composition of the sedimentary organic matter. These results are consistent with a sediment lignin component consisting of varying amounts of vascular plant debris and lignin-depleted organic matter, the latter originating from both marine (planktonic) and terrestrial (uncharacterized) sources. Compositional plots of lignin-derived phenols show that sediments in the upper estuary are influenced to a greater extent by gymnosperm lignin sources than those in the mid-and lower estuary. Given the extent to which the upper estuary is affected by pollution sources, inputs from anthropogenic discharges are the most likely cause of these compositional differences. However, an evaluation of processed paper products as an "anthropogenic" lignin source indicates that the lignin content of these materials is insufficient to account for the levels found in the sediments. Subsurface lignin compositions at an upper estuary site reveal that lignin originating from the inferred anthropogenic sources disappears at a depth shallower than that which would be expected based on the distribution of other trace organic pollutants (hydrocarbons and several synthetic organic compounds). We speculate that differences in either the depositional history or the degree of preservation of these two compound classes are responsible for the observed trends.

  19. Morphological Study of Insoluble Organic Matter Residues from Primitive

    NASA Technical Reports Server (NTRS)

    Changela, H. G.; Stroud, R. M.; Peeters, Z.; Nittler, L. R.; Alexander, C. M. O'D.; DeGregorio, B. T.; Cody, G. D.

    2012-01-01

    Insoluble organic matter (IOM) constitutes a major proportion, 70-99%, of the total organic carbon found in primitive chondrites [1, 2]. One characteristic morphological component of IOM is nanoglobules [3, 4]. Some nanoglobules exhibit large N-15 and D enrichments relative to solar values, indicating that they likely originated in the ISM or the outskirts of the protoplanetary disk [3]. A recent study of samples from the Tagish Lake meteorite with varying levels of hydrothermal alteration suggest that nanoglobule abundance decreases with increasing hydrothermal alteration [5]. The aim of this study is to further document the morphologies of IOM from a range of primitive chondrites in order to determine any correlation of morphology with petrographic grade and chondrite class that could constrain the formation and/or alteration mechanisms.

  20. CLAY MINERALOGY OF INSOLUBLE RESIDUES IN MARINE EVAPORITES.

    USGS Publications Warehouse

    Bodine, Marc W., Jr.

    1985-01-01

    Insoluble residues from three sequences of Paleozoic marine evaporites (Retsof salt bed in western New York, Salado Formation in south-eastern New Mexico, and Paradox Member of the Hermosa Formation in southeastern Utah) are rich in trioctahedral clays. Chlorite (clinochlore), corrensite (mixed-layer chlorite-trioctahedral smectite), talc, and illite (the only dioctahedral clay) are the dominant clay minerals; serpentine, discrete trioctahedral smectite (saponite), and interstratified talc-trioctahedral smectite are sporadically abundant. These clay-mineral assemblages differ chemically and mineralogically from those observed in most continental and normal marine rocks, which commonly contain kaolinite, dioctahedral smectite (beidellite-montmorillonite), illite, mixed-layer illite-dioctahedral smectite, and, in most cases, no more than minor quantities of trioctahedral clay minerals. The distinctive clay mineralogy in these evaporite sequences suggests a largely authigenic origin. These clay minerals are thought to have formed during deposition and early diagenesis through interaction between argillaceous detritus and Mg-rich marine evaporite brines.

  1. Insoluble starch composite foams produced through microwave expansion.

    PubMed

    Deng, Yuzhi; Catchmark, Jeffrey M

    2014-10-13

    An insoluble biocomposite composed of potato starch and chitosan was prepared by microwave treatment. The effect of pH on swelling (liquid absorption) behavior of the composites was investigated at pH 2, pH 6.8 and pH 12. Analysis revealed that the solution uptake ratio of composites depends both on the aqueous pH value and the content of the chitosan. Composites exhibited a relatively high swelling ratio at pH environments lower than the pK(a) of amine groups on chitosan (about 6.3). Glucose analysis by ion exchange chromatography showed that there was little hydrolysis of such composites at low pH. When immersed in the same pH solution, composites with higher chitosan content exhibited higher swelling ratios. The microstructure of composites produced was also investigated by FE-SEM. PMID:25037426

  2. New insights into the characterization of 'insoluble black HCN polymers'.

    PubMed

    Ruiz-Bermejo, Marta; de la Fuente, José L; Rogero, Celia; Menor-Salván, César; Osuna-Esteban, Susana; Martín-Gago, José A

    2012-01-01

    The data presented here provide a novel contribution to the understanding of the structural features of HCN polymers and could be useful in further development of models for prebiotic chemistry. The interpretation of spectroscopic and analytical data, along with previous results reported by other authors, allowed us to propose a mechanism for the aqueous polymerization of HCN from its primary and simplest isolated oligomer, the diaminomaleonitrile (DAMN) tetramer. We suggest that 'insoluble black HCN polymers' are formed by an unsaturated complex matrix, which retains a significant amount of H(2) O and important bioorganic compounds or their precursors. This polymeric matrix can be formed by various motifs of imidazoles and cyclic amides, among others. The robust formation of HCN polymers assayed under several conditions seems to explain the plausible ubiquity of these complex substances in space. PMID:22253100

  3. Dynamics and turnover of lignins in soils: a review

    NASA Astrophysics Data System (ADS)

    Thevenot, M.; Rumpel, C.; Dignac, M.-F.

    2009-04-01

    Lignins are amongst the most studied bio-macromolecules in natural environments, for their properties as biomarkers and their suggested influence on soil organic carbon dynamics. A large number of methods exists to characterize lignins, but the alkaline CuO oxidation is the most used for determining lignin fate in soils. The CuO oxidation products of lignins yield quantitative information (sum of V, S and C monomers) as well as qualitative information on the degradation of lignins (S/V, C/V, (Ad/Al)V,S…). The CuO-lignin products provide information on lignins but also on the environment and particularly on the present and past vegetation. Data from several studies were compiled in order to evaluate the relations between lignins in soils and various environmental parameters. The results of the multiple correspondence analysis (MCA) performed suggest that the lignin content in soils is directly related to the C and N contents, confirming its contribution to the pool of organic carbon. The lignin distribution appears also related to the climate and to the soil texture, which suggests the impact of these parameters on the lignin degradation and retention in soils, as observed for organic carbon (Burke et al., 1989). The total lignin content generally decreases with the soil depth and with the decreasing size of the granulometric fractions. Hence, the more lignins are degraded, the more they are associated with the finest fractions. In addition, it appears that lignin contents are linked to land-use. Thus, in accordance with the land cover, management type and amount of annual input, the forest soils are described by high contents of VSC, C and N, in contrast with the arable land. Lignins were often considered to greatly participate to the stock of slowly degradable and stable carbon in soils. However, several studies suggest that lignin turnover can be more rapid than that of the bulk soil organic carbon (SOC), suggesting that they are not stabilized in soil. On the

  4. Production of Monomeric Aromatic Compounds from Oil Palm Empty Fruit Bunch Fiber Lignin by Chemical and Enzymatic Methods.

    PubMed

    Tang, Pei-Ling; Hassan, Osman; Maskat, Mohamad Yusof; Badri, Khairiah

    2015-01-01

    In this study, oil palm empty fruit bunch (OPEFBF) was pretreated with alkali, and lignin was extracted for further degradation into lower molecular weight phenolic compounds using enzymes and chemical means. Efficiency of monomeric aromatic compounds production from OPEFBF lignin via chemical (nitrobenzene versus oxygen) and enzymatic [cutinase versus manganese peroxidase (MnP)] approaches was investigated. The effects of sodium hydroxide concentration (2, 5, and 10% wt.) and reaction time (30, 90, and 180 minutes) on the yield of aromatic compounds were studied. The results obtained indicated that nitrobenzene oxidation produced the highest yield (333.17 ± 49.44 ppm hydroxybenzoic acid, 5.67 ± 0.25 ppm p-hydroxybenzaldehyde, 25.57 ± 1.64 ppm vanillic acid, 168.68 ± 23.23 ppm vanillin, 75.44 ± 6.71 ppm syringic acid, 815.26 ± 41.77 ppm syringaldehyde, 15.21 ± 2.19 ppm p-coumaric acid, and 44.75 ± 3.40 ppm ferulic acid), among the tested methods. High sodium hydroxide concentration (10% wt.) was needed to promote efficient nitrobenzene oxidation. However, less severe oxidation condition was preferred to preserve the hydroxycinnamic acids (p-coumaric acid and ferulic acid). Cutinase-catalyzed hydrolysis was found to be more efficient than MnP-catalyzed oxidation in the production of aromatic compounds. By hydrolyzed 8% wt. of lignin with 0.625 mL cutinase g(-1) lignin at pH 8 and 55°C for 24 hours, about 642.83 ± 14.45 ppm hydroxybenzoic acid, 70.19 ± 3.31 ppm syringaldehyde, 22.80 ± 1.04 ppm vanillin, 27.06 ± 1.20 ppm p-coumaric acid, and 50.19 ± 2.23 ppm ferulic acid were produced. PMID:26798644

  5. Microencapsulation of human fibroblasts in a water-insoluble polyacrylate.

    PubMed

    Boag, A H; Sefton, M V

    1987-12-01

    Viable human diploid fibroblasts have been micro-encapsulated in EUDRAGIT RL, a commercially available water-insoluble polyacrylate, by an interfacial precipitation technique. Cells in medium and polymer solution (in diethyl phthalate) were coextruded and formed into droplets by a coaxial air stream. The droplets fell into a corn-oil/mineral-oil mixture to extract the solvent to precipitate the polymer around the cells. Capsules were ca. 500 mum in diameter depending on the air flowrate with a ca. 10-mum thick wall. When collagen (1 mg/mL) was added to the cell suspension prior to encapsulation and base-washed corn oil was used, cell growth occurred with one doubling achieved after five to six days as the collagen gel contracted inside the capsule. In the absence of collagen, cells spread on the inner wall of the capsule but did not grow, presumably because the surface charge on the capsule was inadequate. In similar fashion fibroblasts spread but did not grow on films of EUDRAGIT RL but did grow on blends of EUDRAGIT RL and EUDRAGIT E containing 10-30% of the latter more highly aminated polyacrylate. Although not suitable for anchorage-dependent cell growth by itself, EUDRAGIT RL has been suitable as a model polymer to demonstrate the feasibility of using water insoluble polyacrylates and organic solvents and nonsolvents for the micro-encapsulation of fibroblasts. Such microcapsules are of potential interest as a mode of large scale tissue culture for the production of novel therapeutic agents. PMID:18581534

  6. COPOLYMERIZATION OF CONIFERYL FERULATE WITH MONOLIGNOLS: IMPACT ON LIGNIN FORMATION AND ALKALINE DELIGNIFICATION OF MAIZE CELL WALLS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Incorporating alkali-labile (ester) interunit linkages into plant lignins could enhance fiber delignification during papermaking and improve the ruminal or industrial biofermentation of structural polysaccharides into organic acids, ethanol, or other products. In this model study, we examined how su...

  7. Soybean seed phenol, lignin, and isoflavones and sugars composition are altered by Foliar Boron application in soybean under water stress

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous research showed that foliar boron (B) fertilizer at flowering or seed-fill growth stages altered seed protein, oil, and fatty acids. The objective of this research was to investigate the effects of foliar B fertilizer on seed phenolics (phenol, lignin, and isoflavones) and sugars concentrat...

  8. 31P NMR characterization and efficiency of new types of water-insoluble phosphate fertilizers to supply plant-available phosphorus in diverse soil types.

    PubMed

    Erro, Javier; Baigorri, Roberto; Yvin, Jean-Claude; Garcia-Mina, Jose M

    2011-03-01

    Hydroponic plant experiments demonstrated the efficiency of a type of humic acid-based water-insoluble phosphate fertilizers, named rhizosphere controlled fertilizers (RCF), to supply available phosphorus (P) to different plant species. This effect was well correlated to the root release of specific organic acids. In this context, the aims of this study are (i) to study the chemical nature of RCF using solid-state (31)P NMR and (ii) to evaluate the real efficiency of RCF matrix as a source of P for wheat plants cultivated in an alkaline and acid soil in comparison with traditional water-soluble (simple superphosphate, SSP) and water-insoluble (dicalcium phosphate, DCP) P fertilizers. The (31)P NMR study revealed the formation of multimetal (double and triple, MgZn and/or MgZnCa) phosphates associated with chelating groups of the humic acid through the formation of metal bridges. With regard to P fertilizer efficiency, the results obtained show that the RCF matrix produced higher plant yields than SSP in both types of soil, with DCP and the water-insoluble fraction from the RCF matrix (WI) exhibiting the best results in the alkaline soil. By contrast, in the acid soil, DCP showed very low efficiency, WI performed on a par with SSP, and RCF exhibited the highest efficiency, thus suggesting a protector effect of humic acid from soil fixation. PMID:21254775

  9. De novo assembly, transcriptome characterization, lignin accumulation, and anatomic characteristics: novel insights into lignin biosynthesis during celery leaf development.

    PubMed

    Jia, Xiao-Ling; Wang, Guang-Long; Xiong, Fei; Yu, Xu-Run; Xu, Zhi-Sheng; Wang, Feng; Xiong, Ai-Sheng

    2015-01-01

    Celery of the family Apiaceae is a biennial herb that is cultivated and consumed worldwide. Lignin is essential for cell wall structural integrity, stem strength, water transport, mechanical support, and plant pathogen defense. This study discussed the mechanism of lignin formation at different stages of celery development. The transcriptome profile, lignin distribution, anatomical characteristics, and expression profile of leaves at three stages were analyzed. Regulating lignin synthesis in celery growth development has a significant economic value. Celery leaves at three stages were collected, and Illumina paired-end sequencing technology was used to analyze large-scale transcriptome sequences. From Stage 1 to 3, the collenchyma and vascular bundles in the petioles and leaf blades thickened and expanded, whereas the phloem and the xylem extensively developed. Spongy and palisade mesophyll tissues further developed and were tightly arranged. Lignin accumulation increased in the petioles and the mesophyll (palisade and spongy), and the xylem showed strong lignification. Lignin accumulation in different tissues and at different stages of celery development coincides with the anatomic characteristics and transcript levels of genes involved in lignin biosynthesis. Identifying the genes that encode lignin biosynthesis-related enzymes accompanied by lignin distribution may help elucidate the regulatory mechanisms of lignin biosynthesis in celery. PMID:25651889

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

    PubMed

    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. PMID:26271435

  11. p-Hydroxyphenyl (H) Units Lower the Degree of Polymerization in Lignin: Chemical Control in Lignin Biosynthesis

    SciTech Connect

    Sangha, A. K.; Parks, J. M.; Davis, M. F.; Smith, J. C.

    2013-01-01

    Lignin, composed predominantly of p-hydroxyphenyl (H), guaiacyl (G) and syringyl (S) subunits, is a major component of plant cell walls that imparts resistance toward chemical and microbial deconstruction of plant biomass, rendering its conversion inefficient and costly. Previous studies have shown that alterating lignin composition, i.e., the relative abundance of H, G and S subunits, promises more efficient extraction of sugars from plant biomass. Smaller and less branched lignin chains are more easily extracted during pretreatment, making cellulose more readily degradable. Here, using density functional theory calculations, we show that the incorporation of H subunits into lignin via b-b and b-5 interunit linkages reduces the degree of polymerization in lignin. Frontier molecular orbital analyses of lignin dimers and trimers show that H as a terminal subunit on a growing lignin polymer linked via b-b and b-5 linkage cannot undergo radical formation, preventing further chain growth by endwise polymerization resulting in lignin polymers with lower degree of polymerization. These results indicate that, for endwise polymerization in lignin synthesis, there exists a chemical control that may lay a significant role in determining the structure of lignin.

  12. De novo assembly, transcriptome characterization, lignin accumulation, and anatomic characteristics: novel insights into lignin biosynthesis during celery leaf development

    PubMed Central

    Jia, Xiao-Ling; Wang, Guang-Long; Xiong, Fei; Yu, Xu-Run; Xu, Zhi-Sheng; Wang, Feng; Xiong, Ai-Sheng

    2015-01-01

    Celery of the family Apiaceae is a biennial herb that is cultivated and consumed worldwide. Lignin is essential for cell wall structural integrity, stem strength, water transport, mechanical support, and plant pathogen defense. This study discussed the mechanism of lignin formation at different stages of celery development. The transcriptome profile, lignin distribution, anatomical characteristics, and expression profile of leaves at three stages were analyzed. Regulating lignin synthesis in celery growth development has a significant economic value. Celery leaves at three stages were collected, and Illumina paired-end sequencing technology was used to analyze large-scale transcriptome sequences. From Stage 1 to 3, the collenchyma and vascular bundles in the petioles and leaf blades thickened and expanded, whereas the phloem and the xylem extensively developed. Spongy and palisade mesophyll tissues further developed and were tightly arranged. Lignin accumulation increased in the petioles and the mesophyll (palisade and spongy), and the xylem showed strong lignification. Lignin accumulation in different tissues and at different stages of celery development coincides with the anatomic characteristics and transcript levels of genes involved in lignin biosynthesis. Identifying the genes that encode lignin biosynthesis-related enzymes accompanied by lignin distribution may help elucidate the regulatory mechanisms of lignin biosynthesis in celery. PMID:25651889

  13. A facile method for processing lignin reinforced chitosan biopolymer microfibres: optimising the fibre mechanical properties through lignin type and concentration

    NASA Astrophysics Data System (ADS)

    Wang, K.; Loo, L. S.; Goh, K. L.

    2016-03-01

    A chitosan biopolymer microfibre—reinforced by lignin—has been processed by a wet-spinning method. To optimise the fibre mechanical and structural properties two types of lignin, with molecular weights 28 000 g mol-1 and 60 000 g mol-1, were examined and the chitosan fibre was blended with the respective lignin type at 1, 3, 5, 7 and 8 wt% lignin concentrations. The main effects of lignin type and concentration, as well as the interaction between the two parameters, on the fibre tensile stiffness, extensibility, strength and toughness were evaluated using the two-factor analysis of variance. Significant variations in the respective mechanical properties were observed with varying lignin concentrations (P < 0.05). The magnitude of the respective mechanical properties is low at 1 wt% but peaks at 3 wt% before decreasing steadily with increasing lignin concentration. Except for extensibility, significant variations in the strength and toughness were observed with respect to lignin type (P < 0.05) variations in the stiffness were masked by interactions between lignin type and concentration. These results were related to the dispersion of lignin in the fibre and the nature of the bonds between lignin and chitosan, based on findings from scanning electron microscopy and Fourier transform infrared spectroscopy. This new method for the fabrication of chitosan biopolymer microfibre is inexpensive and versatile and could lend itself to the production of high performance biocomposite structures.

  14. Rates of dissolution and biodegradation of water-insoluble organic compounds.

    PubMed Central

    Thomas, J M; Yordy, J R; Amador, J A; Alexander, M

    1986-01-01

    We conducted a study of the relationship between the dissolution rates of organic compounds that are sparingly soluble in water and the biodegradation of these compounds by mixed cultures of bacteria. The rates of dissolution of naphthalene and 4-chlorobiphenyl were directly related to their surface areas. The bacteria caused a decline in the concentration of the soluble substrate. The rate of bacterial growth fell abruptly when 4-chlorobiphenyl or naphthalene was no longer detectable in solution. The population continued to increase in media with different surface areas of insoluble 4-chlorobiphenyl, but the final counts were higher in media in which the surface areas of the substrate were larger. The rates of dissolution of palmitic acid, octadecane, di(2-ethylhexyl) phthalate, and 1-naphthyl N-methylcarbamate were determined in the absence of microorganisms. A mixed culture of microorganisms mineralized palmitic acid, di(2-ethylhexyl) phthalate, and Sevin (1-naphthyl N-methylcarbamate) at a logarithmic rate, but octadecane mineralization was linear. The rates of mineralization at the end of the active phase of the biodegradation were lower than the rate of dissolution of palmitic acid but higher than the rate of dissolution of octadecane in the uninoculated medium. We suggest that spontaneous dissolution rates are only one of the factors that govern the rates of biodegradation. PMID:3092736

  15. Surface-functionalized diatom microcapsules for drug delivery of water-insoluble drugs.

    PubMed

    Aw, Moom Sinn; Bariana, Manpreet; Yu, Yang; Addai-Mensah, Jonas; Losic, Dusan

    2013-08-01

    Naturally available and biocompatible materials are potential substitutes for synthetic mesoporous materials as suitable drug carriers for the development of cost-effective drug delivery systems. This work investigates the application of a porous silica material derived from diatoms, also known as diatomaceous earth. The aim is to explore the surface functionalization of diatom microcapsules and their impact on the drug loading and release characteristics of water-insoluble drugs. Indomethacin was used as the model for poorly soluble drug. The surface modification on diatoms was performed with two organosilanes; 3-aminopropyltriethoxy silane and N-(3-(trimethoxysilyl) propyl) ethylene diamine and phosphonic acids (2-carboxyethyl-phosphonic acid and 16-phosphono-hexadecanoic acid) providing organic surface hydrophilic and hydrophobic properties. Extensive characterizations using scanning electron microscopy, X-ray photoelectron spectroscopy and differential scanning calorimetry was performed to confirm covalent grafting of monolayer aminosilane and phosphonic acid on the diatom surfaces. Differences in loading capacity of diatoms (15-24%) and release time (6-15 days) were observed which is due to the presence of different functional groups on the surface. It was found that 2-carboxyethyl-phosphonic acid, 3-aminopropyltriethoxy silane and N-(3-(trimethoxysilyl) propyl) ethylene diamine render diatom surfaces hydrophilic, due to polar carboxyl functional group (COOH) and active amine species (NH and NH2) that favor drug adsorption; better encapsulation efficiency and prolonged release of drugs, over the hydrophobic surface created by 16-phosphono-hexadecanoic acid. This work demonstrates diatom porous silica as a promising drug carrier, with possibility to further improve their performances by tailoring their surface functionalities to achieve the required drug loading and release characteristics for different therapeutic conditions. PMID:22457043

  16. Export of Dissolved Lignin from Coastal Wetlands to the Louisiana Shelf

    NASA Astrophysics Data System (ADS)

    Bianchi, T. S.; Dimarco, S. F.; Smith, R. W.; Schreiner, K. M.

    2008-12-01

    Here we report on spatial and temporal changes in the concentration and composition of dissolved lignin- phenols in surface and bottom waters off the Louisiana coast (USA). Samples were collected at 7 stations on 2 cruises (April, and July, 2008) along a transect that spanned from inside Terrebonne Bay, Louisiana (12 m water depth) to the outer-most station on the inner Louisiana shelf (21 m water depth). The highest average concentration of dissolved organic carbon (DOC) and dissolved lignin, during both cruises, occurred at the interface between Terrebonne Bay and the inner shelf. Average DOC and dissolved lignin concentrations were significantly higher in April than in July across most stations. Based on hydrologic data, these higher concentrations clearly reflect a combined mixing of DOM from plume waters to the west and local marsh inputs. The cinnamyl/vanillyl (C/V) and syringyl/vanillyl (S/V) ratios indicated that the predominant source of lignin was from non-woody angiosperms - likely the dominant species of wetland plants Spartina alterniflora and S. patens (Spartina spp.) that border the entire bay. The high vanillic acid to vanillin (Ad/Al)v ratios for all stations were typical of that found near estuarine boundaries, where biologically- and photochemically-mediated lignin decay processes are important. This preliminary data indicates that wetlands provide another source of dissolved organic matter (DOM) to the Louisiana shelf that likely contributes to microbial food resources and hence hypoxia, especially in the context of the instability and extensive erosion of these marshes over the past ca. 50 years. This has important implications for the current management plan to reduce hypoxia in the GOM, particularly in those regions that extend west of the nutrient-rich highly productive near-field zones of Atchafalaya-Mississippi river plumes.

  17. Developing energy efficient lignin biomass processing - towards understanding mediator behaviour in ionic liquids.

    PubMed

    Eshtaya, Majd; Ejigu, Andinet; Stephens, Gill; Walsh, Darren A; Chen, George Z; Croft, Anna K

    2016-08-15

    Environmental concerns have brought attention to the requirement for more efficient and renewable processes for chemicals production. Lignin is the second most abundant natural polymer, and might serve as a sustainable resource for manufacturing fuels and aromatic derivatives for the chemicals industry after being depolymerised. In this work, the mediator 2,2'-azino-bis(3-ethylbenthiazoline-6-sulfonic acid) diammonium salt (ABTS), commonly used with enzyme degradation systems, has been evaluated by means of cyclic voltammetry (CV) for enhancing the oxidation of the non-phenolic lignin model compound veratryl alcohol and three types of lignin (organosolv, Kraft and lignosulfonate) in the ionic liquid 1-ethyl-3-methylimidazolium ethyl sulfate, ([C2mim][C2SO4]). The presence of either veratryl alcohol or organosolv lignin increased the second oxidation peak of ABTS under select conditions, indicating the ABTS-mediated oxidation of these molecules at high potentials in [C2mim][C2SO4]. Furthermore, CV was applied as a quick and efficient way to explore the impact of water in the ABTS-mediated oxidation of both organosolv and lignosulfonate lignin. Higher catalytic efficiencies of ABTS were observed for lignosulfonate solutions either in sodium acetate buffer or when [C2mim][C2SO4] (15 v/v%) was present in the buffer solution, whilst there was no change found in the catalytic efficiency of ABTS in [C2mim][C2SO4]-lignosulfonate mixtures relative to ABTS alone. In contrast, organosolv showed an initial increase in oxidation, followed by a significant decrease on increasing the water content of a [C2mim][C2SO4] solution. PMID:27228384

  18. Degradation of 2,4-dichlorophenol by the lignin-degrading fungus Phanerochaete chrysosporium.

    PubMed Central

    Valli, K; Gold, M H

    1991-01-01

    Under secondary metabolic conditions the white rot basidiomycete Phanerochaete chrysosporium mineralizes 2,4-dichlorophenol (I). The pathway for the degradation of 2,4-dichlorophenol (I) was elucidated by the characterization of fungal metabolites and of oxidation products generated by purified lignin peroxidase and manganese peroxidase. The multistep pathway involves the oxidative dechlorination of 2,4-dichlorophenol (I) to yield 1,2,4,5-tetrahydroxybenzene (VIII). The intermediate 1,2,4,5-tetrahydroxybenzene (VIII) is ring cleaved to produce, after subsequent oxidation, malonic acid. In the first step of the pathway, 2,4-dichlorophenol (I) is oxidized to 2-chloro-1,4-benzoquinone (II) by either manganese peroxidase or lignin peroxidase. 2-Chloro-1,4-benzoquinone (II) is then reduced to 2-chloro-1,4-hydroquinone (III), and the latter is methylated to form the lignin peroxidase substrate 2-chloro-1,4-dimethoxybenzene (IV). 2-Chloro-1,4-dimethoxybenzene (IV) is oxidized by lignin peroxidase to generate 2,5-dimethoxy-1,4-benzoquinone (V), which is reduced to 2,5-dimethoxy-1,4-hydroquinone (VI). 2,5-Dimethoxy-1,4-hydroquinone (VI) is oxidized by either peroxidase to generate 2,5-dihydroxy-1,4-benzoquinone (VII) which is reduced to form the tetrahydroxy intermediate 1,2,4,5-tetrahydroxybenzene (VIII). In this pathway, the substrate is oxidatively dechlorinated by lignin peroxidase or manganese peroxidase in a reaction which produces a p-quinone. The p-quinone intermediate is then recycled by reduction and methylation reactions to regenerate an intermediate which is again a substrate for peroxidase-catalyzed oxidative dechlorination. This unique pathway apparently results in the removal of both chlorine atoms before ring cleavage occurs. PMID:1987125

  19. Lignin Fast Pyrolysis: Results from an International Collaboration

    SciTech Connect

    Nowakowski, Daniel J.; Bridgwater, Anthony V.; Elliott, Douglas C.; Meier, Dietrich; de Wild, Paul

    2010-05-01

    An international study of fast pyrolysis of lignin was undertaken. Fourteen laboratories in eight different countries contributed. Two lignin samples were distributed to the laboratories for analysis and bench-scale process testing in fast pyrolysis. Analyses included proximate and ultimate analysis, thermogravimetric analysis, and analytical pyrolysis. The bench-scale test included bubbling fluidized bed reactors and entrained flow systems. Based on the results of the various analyses and tests it was concluded that a concentrated lignin (estimated at about 50% lignin and 50% cellulose) behaved like a typical biomass, producing a slightly reduced amount of a fairly typical bio-oil, while a purified lignin material was difficult to process in the fast pyrolysis reactors and produced a much lower amount of a different kind of bio-oil. It was concluded that for highly concentrated lignin feedstocks new reactor designs will be required other than the typical fluidized bed fast pyrolysis systems.

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

    PubMed

    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. PMID:23777846

  1. Mechanism of lignin inhibition of enzymatic biomass deconstruction

    SciTech Connect

    Vermaas, Josh V.; Petridis, Loukas; Qi, Xianghong; Schulz, Roland; Lindner, Benjamin; Smith, Jeremy. C.

    2015-12-01

    The conversion of plant biomass to ethanol via enzymatic cellulose hydrolysis offers a potentially sustainable route to biofuel production. However, the inhibition of enzymatic activity in pretreated biomass by lignin severely limits the efficiency of this process. By performing atomic-detail molecular dynamics simulation of a biomass model containing cellulose, lignin, and cellulases (TrCel7A), we elucidate detailed lignin inhibition mechanisms. We find that lignin binds preferentially both to the elements of cellulose to which the cellulases also preferentially bind (the hydrophobic faces) and also to the specific residues on the cellulose-binding module of the cellulase that are critical for cellulose binding of TrCel7A (Y466, Y492, and Y493). In conclusion, lignin thus binds exactly where for industrial purposes it is least desired, providing a simple explanation of why hydrolysis yields increase with lignin removal.

  2. Mechanism of lignin inhibition of enzymatic biomass deconstruction

    DOE PAGESBeta

    Vermaas, Josh V.; Petridis, Loukas; Qi, Xianghong; Schulz, Roland; Lindner, Benjamin; Smith, Jeremy. C.

    2015-12-01

    The conversion of plant biomass to ethanol via enzymatic cellulose hydrolysis offers a potentially sustainable route to biofuel production. However, the inhibition of enzymatic activity in pretreated biomass by lignin severely limits the efficiency of this process. By performing atomic-detail molecular dynamics simulation of a biomass model containing cellulose, lignin, and cellulases (TrCel7A), we elucidate detailed lignin inhibition mechanisms. We find that lignin binds preferentially both to the elements of cellulose to which the cellulases also preferentially bind (the hydrophobic faces) and also to the specific residues on the cellulose-binding module of the cellulase that are critical for cellulose bindingmore » of TrCel7A (Y466, Y492, and Y493). In conclusion, lignin thus binds exactly where for industrial purposes it is least desired, providing a simple explanation of why hydrolysis yields increase with lignin removal.« less

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

    PubMed

    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. PMID:21751391

  4. Lignin profiling in extracted xylans by size-exclusion chromatography.

    PubMed

    Hutterer, Christian; Schild, Gabriele; Kliba, Gerhard; Potthast, Antje

    2016-10-20

    Utilization of the polymeric parts of lignocellulose is expected to gain increasing importance in future biorefinery scenarios. In that respect, a particular focus is placed on hemicelluloses from different wood species gained from an industrially feasible upgrading step in the production of dissolving pulps from paper pulps. During alkaline post-extractions for hemicellulose removal, residual lignins are extracted as well. They are either covalently linked to the extracted hardwood xylans or simply co-dissolved in the alkaline lye. In order to better describe the lignin in xylan containing lyes, a method for lignin profiling was set up by hyphenating size-exclusion chromatography of xylans with UV detection which facilitates visualization of the residual lignin distribution. Simultaneous lignin quantification was achieved with lignin standards prepared from Kraft cooking liquors. The setup presented may serve as advanced characterization for novel xylan products. PMID:27474629

  5. Structural Characterization of Modified Lignin in Transgenic Tobacco Plants in Which the Activity of 4-Coumarate:Coenzyme A Ligase Is Depressed.

    PubMed

    Kajita, S.; Hishiyama, S.; Tomimura, Y.; Katayama, Y.; Omori, S.

    1997-07-01

    Transgenic tobacco (Nicotiana tabacum L.) plants in which the activity of 4-coumarate:coenzyme A ligase is very low contain a novel lignin in their xylem. Details of changes in hydroxycinnamic acids bound to cell walls and in the structure of the novel lignin were identified by base hydrolysis, alkaline nitrobenzene oxidation, pyrolysis-gas chromatography, and 13C-nuclear magnetic resonance analysis. In the brownish tissue of the transgenic plants, the levels of three hydroxycinnamic acids, p-coumaric, ferulic, and sinapic, which were bound to cell walls, were apparently increased as a result of down-regulation of the expression of the gene for 4-coumarate:coenzyme A ligase. Some of these hydroxycinnamic acids were linked to cell walls via ester and ether linkages. The accumulation of hydroxycinnamic acids also induced an increase in the level of condensed units in the novel lignin of the brownish tissue. Our data indicate that the behavior of some of the incorporated hydroxycinnamic acids resembles lignin monomers in the brownish tissue, and their accumulation results in dramatic changes in the biosynthesis of lignin in transgenic plants. PMID:12223748

  6. Modeling lignin liquefaction: 1. Catalytic hydroprocessing of lignin-related methoxyphenols and interaromatic unit linkages

    SciTech Connect

    Petrocelli, F.P.; Klein, M.T.

    1987-01-01

    The reactions of two sets of lignin model compounds over a sulfided CoOMoO/sub 3//..gamma..-Al/sub 2/O/sub 3/ catalyst were studied. The first set mimicked lignin methoxyphenol residues and comprised 4-methyl-guaiacol, 4-methylcatechol, eugenol and vanillin. Deoxygenation and hydrogenation were facile and led to ultimate molar yields of single-ring products as high as 0.70. The selectivity to single-ring products increased with increases in temperature. o-hydroxydiphenylmethane, phenyl ether and o,o'-biphenol constituted the second set that mimicked thermally stable lignin bonds. Fragmentation of o-hydroxydiphenylmethane and phenyl ether occurred readily; o,o'-biphenol reacted to dibenzofuran.

  7. Recovery of organic acids

    DOEpatents

    Verser, Dan W.; Eggeman, Timothy J.

    2009-10-13

    A method is disclosed for the recovery of an organic acid from a dilute salt solution in which the cation of the salt forms an insoluble carbonate salt. A tertiary amine and CO.sub.2 are introduced to the solution to form the insoluble carbonate salt and a complex between the acid and an amine. A water immiscible solvent, such as an alcohol, is added to extract the acid/amine complex from the dilute salt solution to a reaction phase. The reaction phase is continuously dried and a product between the acid and the solvent, such as an ester, is formed.

  8. Recovery of organic acids

    SciTech Connect

    Verser, Dan W.; Eggeman, Timothy J.

    2011-11-01

    A method is disclosed for the recovery of an organic acid from a dilute salt solution in which the cation of the salt forms an insoluble carbonate salt. A tertiary amine and CO.sub.2 are introduced to the solution to form the insoluble carbonate salt and a complex between the acid and an amine. A water immiscible solvent, such as an alcohol, is added to extract the acid/amine complex from the dilute salt solution to a reaction phase. The reaction phase is continuously dried and a product between the acid and the solvent, such as an ester, is formed.

  9. The well-coordinated linkage between acidogenicity and aciduricity via insoluble glucans on the surface of Streptococcus mutans

    PubMed Central

    Guo, Lihong; McLean, Jeffrey S.; Lux, Renate; He, Xuesong; Shi, Wenyuan

    2015-01-01

    Streptococcus mutans is considered the principal cariogenic bacterium for dental caries. Despite the recognition of their importance for cariogenesis, the possible coordination among S. mutans’ main virulence factors, including glucan production, acidogenicity and aciduricity, has been less well studied. In the present study, using S. mutans strains with surface-displayed pH-sensitive pHluorin, we revealed sucrose availability- and Gtf functionality-dependent proton accumulation on S. mutans surface. Consistent with this, using a pH-sensitive dye, we demonstrated that both in vivo cell-produced and in vitro enzymatically synthesized insoluble glucans displayed proton-concentrating ability. Global transcriptomics revealed proton accumulation triggers the up-regulation of genes encoding functions involved in acid tolerance response in a glucan-dependent manner. Our data suggested that this proton enrichment around S. mutans could pre-condition the bacterium for acid-stress. Consistent with this hypothesis, we found S. mutans strains defective in glucan production were more acid sensitive. Our study revealed for the first time that insoluble glucans is likely an essential factor linking acidogenicity with aciduricity. The coordination of these key virulence factors could provide new insights on how S. mutans may have become a major cariogenic pathogen. PMID:26657939

  10. Water-Soluble Lignins from Different Bioenergy Crops Stimulate the Early Development of Maize (Zea mays, L.).

    PubMed

    Savy, Davide; Cozzolino, Vincenza; Vinci, Giovanni; Nebbioso, Antonio; Piccolo, Alessandro

    2015-01-01

    The molecular composition of water-soluble lignins isolated from four non-food bioenergy crops (cardoon CAR, eucalyptus EUC, and two black poplars RIP and LIM) was characterized in detail, and their potential bioactivity towards maize germination and early growth evaluated. Lignins were found to not affect seed germination rates, but stimulated the maize seedling development, though to a different extent. RIP promoted root elongation, while CAR only stimulated the length of lateral seminal roots and coleoptile, and LIM improved only the coleoptile development. The most significant bioactivity of CAR was related to its large content of aliphatic OH groups, C-O carbons and lowest hydrophobicity, as assessed by (31)P-NMR and (13)C-CPMAS-NMR spectroscopies. Less bioactive RIP and LIM lignins were similar in composition, but their stimulation of maize seedling was different. This was accounted to their diverse content of aliphatic OH groups and S- and G-type molecules. The poorest bioactivity of the EUC lignin was attributed to its smallest content of aliphatic OH groups and largest hydrophobicity. Both these features may be conducive of a EUC conformational structure tight enough to prevent its alteration by organic acids exuded from vegetal tissues. Conversely the more labile conformational arrangements of the other more hydrophilic lignin extracts promoted their bioactivity by releasing biologically active molecules upon the action of exuded organic acids. Our findings indicate that water-soluble lignins from non-food crops may be effectively used as plant biostimulants, thus contributing to increase the economic and ecological liability of bio-based industries. PMID:26556330

  11. Trends in lignin modification: a comprehensive analysis of the effects of genetic manipulations/mutations on lignification and vascular integrity

    NASA Technical Reports Server (NTRS)

    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

  12. Degradation of polysaccharides and lignin by ruminal bacteria and fungi.

    PubMed Central

    Akin, D E; Benner, R

    1988-01-01

    Bermudagrass (Cynodon dactylon) leaf blades and whole cordgrass (Spartina alterniflora) fiber were evaluated for degradation of cell walls by microbial groups in ruminal fluid. The groups were selected by the addition of antibiotics to the inoculum as follows: (i) whole ruminal fluid (WRF), no antibiotics; (ii) cycloheximide (C) to inhibit fungi, thus showing potential bacterial activity; (iii) streptomycin and penicillin (S,P) to inhibit fiber-degrading bacteria, showing potential fungal activity; (iv) streptomycin, penicillin, and chloramphenicol (S,P,CAM) to inhibit all bacteria including methanogens; (v) streptomycin, penicillin, and cycloheximide (S,P,C) to inhibit all microbial activity as a control; and (vi) autoclaved ruminal fluid (ARF) to inhibit all biological activity as a second control. Scanning electron microscopy of tissue degradation indicated that tissues not giving a positive histological reaction for lignin were more readily degraded. Cordgrass was more highly lignified, with more tissues resisting degradation than in bermudagrass. Patterns of degradation due to treatment resulted in three distinct groups of data based on the extent of fiber or component losses: WRF and C greater than S,P and S,P,CAM greater than S,P,C and ARF. Therefore, bacterial activity was responsible for most of the fiber loss. Fiber degradation by anaerobic fungi was significantly less (P = 0.05). Cupric oxide oxidation of undigested and digested bermudagrass fiber indicated that phenolic constituents differed in their order of resistance to removal or solubilization. Vanillyl and syringyl components of lignin were the most resistant to decomposition, whereas ferulic acid was readily solubilized from fiber in the absence of microbial activity.(ABSTRACT TRUNCATED AT 250 WORDS) Images PMID:3389808

  13. Pathways associated with lignin biosynthesis in lignomaniac jute fibres.

    PubMed

    Chakraborty, Avrajit; Sarkar, Debabrata; Satya, Pratik; Karmakar, Pran Gobinda; Singh, Nagendra Kumar

    2015-08-01

    We generated the bast transcriptomes of a deficient lignified phloem fibre mutant and its wild-type jute (Corchorus capsularis) using Illumina paired-end sequencing. A total of 34,163 wild-type and 29,463 mutant unigenes, with average lengths of 1442 and 1136 bp, respectively, were assembled de novo, ~77-79 % of which were functionally annotated. These annotated unigenes were assigned to COG (~37-40 %) and GO (~22-28 %) classifications and mapped to 189 KEGG pathways (~19-21 %). We discovered 38 and 43 isoforms of 16 and 10 genes of the upstream shikimate-aromatic amino acid and downstream monolignol biosynthetic pathways, respectively, rendered their sequence similarities, confirmed the identities of 22 of these candidate gene families by phylogenetic analyses and reconstructed the pathway leading to lignin biosynthesis in jute fibres. We also identified major genes and bast-related transcription factors involved in secondary cell wall (SCW) formation. The quantitative RT-PCRs revealed that phenylalanine ammonia-lyase 1 (CcPAL1) was co-down-regulated with several genes of the upstream shikimate pathway in mutant bast tissues at an early growth stage, although its expression relapsed to the normal level at the later growth stage. However, cinnamyl alcohol dehydrogenase 7 (CcCAD7) was strongly down-regulated in mutant bast tissues irrespective of growth stages. CcCAD7 disruption at an early growth stage was accompanied by co-up-regulation of SCW-specific genes cellulose synthase A7 (CcCesA7) and fasciclin-like arabinogalactan 6 (CcFLA6), which was predicted to be involved in coordinating the S-layers' deposition in the xylan-type jute fibres. Our results identified CAD as a promising target for developing low-lignin jute fibres using genomics-assisted molecular approaches. PMID:25724692

  14. Lignin decomposition and microbial community in paddy soils: effects of alternating redox conditions

    NASA Astrophysics Data System (ADS)

    Cerli, Chiara; Liu, Qin; Hanke, Alexander; Kaiser, Klaus; Kalbitz, Karsten

    2013-04-01

    Paddy soils are characterised by interchanging cycles of anaerobic and aerobic conditions. Such fluctuations cause continuous changes in soil solution chemistry as well as in the composition and physiological responses of the microbial community. Temporary deficiency in oxygen creates conditions favourable to facultative or obligates anaerobic bacteria, while aerobic communities can thrive in the period of water absence. These alterations can strongly affect soil processes, in particular organic matter (OM) accumulation and mineralization. In submerged soils, lignin generally constitutes a major portion of the total OM because of hampered degradation under anoxic conditions. The alternating redox cycles resulting from paddy soil management might promote both degradation and preservation of lignin, affecting the overall composition and reactivity of total and dissolved OM. We sampled soils subjected to cycles of anoxic (rice growing period) and oxic (harvest and growth of other crops) conditions since 700 and 2000 years. We incubated suspended Ap material, sampled from the two paddy plus two corresponding non-paddy control soils under oxic and anoxic condition, for 3 months, interrupted by a short period of three weeks (from day 21 to day 43) with reversed redox conditions. At each sampling time (day 2, 21, 42, 63, 84), we determined lignin-derived phenols (by CuO oxidation) as well as phospholipids fatty acids contents and composition. We aimed to highlight changes in lignin decomposition as related to the potential rapid changes in microbial community composition. Since the studied paddy soils had a long history of wet rice cultivation, the microbial community should be well adapted to interchanging oxic and anoxic cycles, therefore fully expressing its activity at both conditions. In non-paddy soil changes in redox conditions caused modification of quantity and composition of the microbial community. On the contrary, in well-established paddy soils the microbial

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

    PubMed

    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. PMID:22458713

  16. Insoluble coatings for Stirling engine heat pipe condenser surfaces

    NASA Astrophysics Data System (ADS)

    Dussinger, Peter M.

    1993-09-01

    The work done by Thermacore, Inc., Lancaster, Pennsylvania, for the Phase 1, 1992 SBIR National Aeronautics and Space Administration Contract, 'Insoluble Coatings for Stirling Engine Heat Pipe Condenser Surfaces' is described. The work was performed between January 1992 and July 1992. Stirling heat engines are being developed for electrical power generation use on manned and unmanned earth orbital and planetary missions. Dish Stirling solar systems and nuclear reactor Stirling systems are two of the most promising applications of the Stirling engine electrical power generation technology. The sources of thermal energy used to drive the Stirling engine typically are non-uniform in temperature and heat flux. Liquid metal heat pipe receivers are used as thermal transformers and isothermalizers to deliver the thermal energy at a uniform high temperature to the heat input section of the Stirling engine. The use of a heat pipe receiver greatly enhances system efficiency and potential life span. One issue that is raised during the design phase of heat pipe receivers is the potential solubility corrosion of the Stirling engine heat input section by the liquid metal working fluid. This Phase 1 effort initiated a program to evaluate and demonstrate coatings, applied to nickel based Stirling engine heater head materials, that are practically 'insoluble' in sodium, potassium, and NaK. This program initiated a study of nickel aluminide as a coating and developed and demonstrated a heat pipe test vehicle that can be used to test candidate materials and coatings. Nickel 200 and nickel aluminide coated Nickel 200 were tested for 1000 hours at 800 C at a condensation heat flux of 25 W/sq cm. Subsequent analyses of the samples showed no visible sign of solubility corrosion of either coated or uncoated samples. The analysis technique, photomicrographs at 200X, has a resolution of better than 2.5 microns (.0001 in). The results indicate that the heat pipe environment is not directly

  17. Soluble and insoluble signals sculpt osteogenesis in angiogenesis.

    PubMed

    Ripamonti, Ugo

    2010-05-26

    The basic tissue engineering paradigm is tissue induction and morphogenesis by combinatorial molecular protocols whereby soluble molecular signals are combined with insoluble signals or substrata. The insoluble signal acts as a three-dimensional scaffold for the initiation of de novo tissue induction and morphogenesis. The osteogenic soluble molecular signals of the transforming growth factor-β (TGF-β) supergene family, the bone morphogenetic/osteogenic proteins (BMPs/OPs) and, uniquely in the non-human primate Papio ursinus (P. ursinus), the three mammalian TGF-β isoforms induce bone formation as a recapitulation of embryonic development. In this paper, I discuss the pleiotropic activity of the BMPs/OPs in the non-human primate P. ursinus, the induction of bone by transitional uroepithelium, and the apparent redundancy of molecular signals initiating bone formation by induction including the three mammalian TGF-β isoforms. Amongst all mammals tested so far, the three mammalian TGF-β isoforms induce endochondral bone formation in the non-human primate P. ursinus only. Bone tissue engineering starts by erecting scaffolds of biomimetic biomaterial matrices that mimic the supramolecular assembly of the extracellular matrix of bone. The molecular scaffolding lies at the hearth of all tissue engineering strategies including the induction of bone formation. The novel concept of tissue engineering is the generation of newly formed bone by the implantation of "smart" intelligent biomimetic matrices that per se initiate the ripple-like cascade of bone differentiation by induction without exogenously applied BMPs/OPs of the TGF-β supergene family. A comprehensive digital iconographic material presents the modified tissue engineering paradigm whereby the induction of bone formation is initiated by intelligent smart biomimetic matrices that per se initiate the induction of bone formation without the exogenous application of the soluble osteogenic molecular signals. The

  18. Insoluble coatings for Stirling engine heat pipe condenser surfaces

    NASA Technical Reports Server (NTRS)

    Dussinger, Peter M.

    1993-01-01

    The work done by Thermacore, Inc., Lancaster, Pennsylvania, for the Phase 1, 1992 SBIR National Aeronautics and Space Administration Contract, 'Insoluble Coatings for Stirling Engine Heat Pipe Condenser Surfaces' is described. The work was performed between January 1992 and July 1992. Stirling heat engines are being developed for electrical power generation use on manned and unmanned earth orbital and planetary missions. Dish Stirling solar systems and nuclear reactor Stirling systems are two of the most promising applications of the Stirling engine electrical power generation technology. The sources of thermal energy used to drive the Stirling engine typically are non-uniform in temperature and heat flux. Liquid metal heat pipe receivers are used as thermal transformers and isothermalizers to deliver the thermal energy at a uniform high temperature to the heat input section of the Stirling engine. The use of a heat pipe receiver greatly enhances system efficiency and potential life span. One issue that is raised during the design phase of heat pipe receivers is the potential solubility corrosion of the Stirling engine heat input section by the liquid metal working fluid. This Phase 1 effort initiated a program to evaluate and demonstrate coatings, applied to nickel based Stirling engine heater head materials, that are practically 'insoluble' in sodium, potassium, and NaK. This program initiated a study of nickel aluminide as a coating and developed and demonstrated a heat pipe test vehicle that can be used to test candidate materials and coatings. Nickel 200 and nickel aluminide coated Nickel 200 were tested for 1000 hours at 800 C at a condensation heat flux of 25 W/sq cm. Subsequent analyses of the samples showed no visible sign of solubility corrosion of either coated or uncoated samples. The analysis technique, photomicrographs at 200X, has a resolution of better than 2.5 microns (.0001 in). The results indicate that the heat pipe environment is not directly

  19. Insoluble surface carbon on steel sheet annealed in hydrogen-nitrogen atmosphere

    NASA Astrophysics Data System (ADS)

    Biber, H. E.; Takacs, R. C.; Dickey, A. E.

    1983-09-01

    The way in which heating in hydrogen-nitrogen atmosphere affects the pyrolysis of the residual lubricant on cold-reduced steel sheet was studied to discover the factors responsible for the formation of carbonaceous films on the steel surface. These films, referred to as insoluble surface carbon, cannot be removed with the usual solvents or water-base cleaners and adversely affect the paintability of the steel. A surprising result was the observation that the full-hard steel surface has a significant amount of insoluble surface carbon; amounts in excess of 0.010 gm/m2 (1 mg/ft2) were observed. The origin of this “initial” insoluble carbon can be traced to the pickling operation after hot rolling. During annealing much of the residual rolling lubricant on the surface is driven off by evaporation, but concurrently insoluble pyrolysis products are formed. The amount of insoluble pyrolysis product formed is directly related to the amount of “initial” insoluble carbon on the surface before annealing. The results show that at some point during annealing the total amount of insoluble carbon on the surface is more than double the amount of “initial” insoluble carbon. These insoluble pyrolysis products can also be driven from the surface at higher temperatures than are required for evaporation of the oil. The results suggest that removal of the “initial” insoluble carbon prior to cold reduction might be very beneficial with respect to decreasing the amount of insoluble carbon on the surface of steel sheet after annealing.

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

    PubMed

    Scully, Erin D; Gries, Tammy; Funnell-Harris, Deanna L; Xin, Zhanguo; Kovacs, Frank A; Vermerris, Wilfred; Sattler, Scott E

    2016-02-01

    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 been previously shown to encode cinnamyl alcohol dehydrogenase (CAD), which catalyzes the final step of the monolignol biosynthesis pathway. Mutations in this gene have been shown to reduce the abundance of lignin, enhance digestibility, and improve saccharification efficiencies and ethanol yields. Nine sorghum lines harboring five different bmr6 alleles were identified in an EMS-mutagenized TILLING population. DNA sequencing of Bmr6 revealed that the majority of the mutations impacted evolutionarily conserved amino acids while three-dimensional structural modeling predicted that all of these alleles interfered with the enzyme's ability to bind with its NADPH cofactor. All of the new alleles reduced in vitro CAD activity levels and enhanced glucose yields following saccharification. Further, many of these lines were associated with higher reductions in acid detergent lignin compared to lines harboring the previously characterized bmr6-ref allele. These bmr6 lines represent new breeding tools for manipulating biomass composition to enhance forage and feedstock quality. PMID:26172142

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

    NASA Astrophysics Data System (ADS)

    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

  2. Pathways for Biomass-Derived Lignin to Hydrocarbon Fuels

    SciTech Connect

    Laskar, Dhrubojyoti; Yang, Bin; Wang, Huamin; Lee, Guo-Shuh J.

    2013-09-01

    Production of hydrocarbon fuel from biomass-derived lignin sources with current version of biorefinery infrastructure would significantly improve the total carbon use in biomass and make biomass conversion more economically viable. Thus, developing specialty and commodity products from biomass derived-lignin has been an important industrial and scientific endeavor for several decades. However, deconstruction of lignin’s complex polymeric framework into low molecular weight reactive moieties amenable for deoxygenation and subsequent processing into hydrocarbons has been proven challenging. This review offers a comprehensive outlook on the existing body of work that has been devoted to catalytic processing of lignin derivatives into hydrocarbon fuels, focusing on: (1) The intrinsic complexity and characteristic structural features of biomass-derived lignin; (2) Existing processing technologies for the isolation and depolymerization of bulk lignin (including detailed mechanistic considerations); (3) Approaches aimed at significantly improving the yields of depolymerized lignin species amenable to catalytic upgrading, and; (4) Catalytic upgrading, using aqueous phase processes for transforming depolymerized lignin to hydrocarbon derivatives. Technical barriers and challenges to the valorization of lignin are highlighted throughout. The central goal of this review is to present an array of strategies that have been reported to obtain lignin, deconstruct it to reactive intermediates, and reduce its substantial oxygen content to yield hydrocarbon liquids. In this regard, reaction networks with reference to studies of lignin model compounds are exclusively surveyed. Special attention is paid to catalytic hydrodeoxygenation, hydrogenolyis and hydrogenation. Finally, this review addresses important features of lignin that are vital to economic success of hydrocarbon production.

  3. Application of mesoporous Al-MCM-48 material to the conversion of lignin.

    PubMed

    Lee, Hyung Won; Lee, In-Gu; Park, Sung Hoon; Jeon, Jong-Ki; Suh, Dong Jin; Jung, Jinho; Park, Young-Kwon

    2014-04-01

    Al-MCM-48 was applied to the catalytic pyrolysis of lignin for the first time. The pyrolysis reaction and in-situ product were analyzed by pyrolysis gas chromatography/mass spectrometry. The main products of the non-catalytic pyrolysis of lignin were phenols. The use of Al-MCM-48 increased the production of light phenols considerably. The yields of high-value-added compounds, such as hydrocarbons and aromatics, were also increased by catalytic upgrading. Al-MCM-48 is believed to promote cracking, aromatization and deoxygenation, such as decarbonylation. On the other hand, Si-MCM-48, which has no acid sites, showed lower deoxygenation efficiency than Al-MCM-48. Al-MCM-48 could be regenerated by calcining in air. PMID:24734722

  4. Catalytic Reforming of Lignin-Derived Bio-Oil Over a Nanoporous Molecular Sieve Silicoaluminophosphate-11.

    PubMed

    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. PMID:27483769

  5. Toward an experimental synthesis of the chondritic insoluble organic matter

    NASA Astrophysics Data System (ADS)

    Biron, Kasia; Derenne, Sylvie; Robert, FrançOis; Rouzaud, Jean-NoëL.

    2015-08-01

    Based on the statistical model proposed for the molecular structure of the insoluble organic matter (IOM) isolated from the Murchison meteorite, it was recently proposed that, in the solar T-Tauri disk regions where (photo)dissociation of gaseous molecules takes place, aromatics result from the cyclization/aromatization of short aliphatics. This hypothesis is tested in this study, with n-alkanes being submitted to high-frequency discharge at low pressure. The contamination issue was eliminated using deuterated precursor. IOM was formed and studied using solid-state nuclear magnetic resonance, pyrolysis coupled to gas chromatography and mass spectrometry, RuO4 oxidation, and high-resolution transmission electron microscopy. It exhibits numerous similarities at the molecular level with the hydrocarbon backbone of the natural IOM, reinforcing the idea that the initial precursors of the IOM were originally chains in the gas. Moreover, a fine comparison between the chemical structure of several meteorite IOM suggests either that (i) the meteorite IOMs share a common precursor standing for the synthetic IOM or that (ii) the slight differences between the meteorite IOMs reflect differences in their environment at the time of their formation i.e., related to plasma temperature that, in turn, dictates the dissociation-recombination rates of organic fragments.

  6. Vibrational instabilities of a nonisothermal liquid layer with insoluble surfactant

    NASA Astrophysics Data System (ADS)

    Mikishev, Alexander; Nepomnyashchy, Alexander

    2015-11-01

    We consider an infinite horizontal layer of an incompressible liquid, the deformable upper free surface is covered by insoluble surfactant. The layer is subjected to vertical harmonic oscillations with fixed amplitude and frequency, as well as to a transverse gradient of temperature. We suppose that the surface tension of upper boundary linearly depends on temperature and surfactant concentration. Two types of waves on the surface are possible. The first one is capillary-gravity waves (transverse waves) excited by the usual Faraday instability mechanism, under the influence of the surfactant elasticity. The second type of waves is Marangoni waves (longitudinal waves) related to compressions - dilations of the surface. In this work we study the excitation of Marangoni waves by vibration and determine the existence conditions for each type of waves. The results are connected with our previous research on parametric excitation of Marangoni instability when the gradient of temperature is harmonically changed. The instability thresholds are calculated numerically using the Floquet method for disturbances with arbitrary wave numbers.

  7. Secreted expression of Leuconostoc mesenteroides glucansucrase in Lactococcus lactis for the production of insoluble glucans.

    PubMed

    Skory, Christopher D; Côté, Gregory L

    2015-12-01

    We expressed a glucansucrase, DsrI, from Leuconostoc mesenteroides that catalyzes formation of water-insoluble glucans from sucrose using a nisin-controlled gene expression system in Lactococcus lactis. These polymers have potential for production of biodegradable gels, fibers, and films. We optimized production of DsrI using several different background vectors, signal peptides, strains, induction conditions, and bioreactor parameters to increase extracellular accumulation. Optimal production of the enzyme utilized a high-copy plasmid, pMSP3535H3, which contains a nisin immunity gene, L. lactis LM0230, and bioreactors maintained at pH 6.0 to stabilize the enzyme. We were able to significantly improve growth using the lactic acid inhibitor heme and by continuous removal of lactic acid with anion exchange resins, but enzyme production was less than the controls. The recombinant enzyme under optimized conditions accumulated in the culture medium to approximately 380 mg/L, which was over 150-fold higher compared to the native L. mesenteroides strain. Methods are also included for purification of DsrI utilizing the glucan-binding domain of the enzyme. PMID:26239071

  8. Conquering the control of insoluble and soluble starch with novel applications of amylase

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The new knowledge that there is markedly more insoluble starch than previously considered in products across both the sugarcane factory and refinery has processing implications. This includes the application of a-amylases in the factory to control not only soluble but insoluble starch. Studies wer...

  9. A method for the determination of soluble arabinoxylan released from insoluble substrates by xylanases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The propensity for xylanase to convert insoluble arabinoxylan to soluble oligosaccharides is an important parameter in many applications. Current methods for determining xylanase activity on insoluble substrates are labor intensive, non-specific, or utilize artificial substrates which may provide mu...

  10. A Simple Method for the Determination of Xylanase Activity on Insoluble Substrates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The propensity for a xylanase to convert insoluble (arabino)xylan into soluble oligosaccharides is an important parameter in the baking, pulp and paper, prebiotics, and biofuel industries. Current methods for determining xylanase activity on insoluble substrates are labor intensive, non-specific, or...

  11. Production of ligninolytic enzymes and synthetic lignin mineralization by the bird's nest fungus Cyathus stercoreus.

    PubMed

    Sethuraman, A; Akin, D E; Eriksson, K E

    1999-11-01

    Production of ligninolytic enzymes and degradation of 14C-ring labeled synthetic lignin by the white-rot fungus Cyathus stercoreus ATCC 36910 were determined under a variety of conditions. The highest mineralization rate for 14C dehydrogenative polymerizates (DHP; 38% 14CO2 after 30 days) occurred with 1 mM ammonium tartrate as nitrogen source and 1% glucose as additional carbon source, but levels of extracellular laccase and manganese peroxidase (MnP) were low. In contrast, 10 mM ammonium tartrate with 1% glucose gave low mineralization rates (10% 14CO2 after 30 days) but higher levels of laccase and manganese peroxidase. Lignin peroxidase was not produced by C. stercoreus under any of the studied conditions. Mn(II) at 11 ppm gave a higher rate of 14C DHP mineralization than 0.3 or 40 ppm, but the highest manganese peroxidase level was obtained with Mn(II) at 40 ppm. Cultivation in aerated static flasks gave rise to higher levels of both laccase and manganese peroxidase compared to the levels in shake cultures. 3,4-Dimethoxycinnamic acid at 500 microM concentration was the most effective inducer of laccase of those tested. The purified laccase was a monomeric glycoprotein having an apparent molecular mass of 70 kDa, as determined by calibrated gel filtration chromatography. The pH optimum and isoelectric point of the purified laccase were 4.8 and 3.5, respectively. The N-terminal amino acid sequence of C. stercoreus laccase showed close homology to the N-terminal sequences determined from other basidiomycete laccases. Information on C. stercoreus, whose habitat and physiological requirements for lignin degradation differ from many other white-rot fungi, expands the possibilities for industrial application of biological systems for lignin degradation and removal in biopulping and biobleaching processes. PMID:10570816

  12. Lignin-modifying enzymes of the white rot basidiomycete Ganoderma lucidum

    SciTech Connect

    D Merritt, C.S.; Reddy, C.A.

    1999-12-01

    Ganoderma lucidum, a white rot basidiomycete widely distributed worldwide, was studied for the production of the lignin-modifying enzymes laccase, manganese-dependent peroxidase (MnP), and lignin peroxidase (LiP). Laccase levels observed in high-nitrogen shaken cultures were much greater than those seen in low-nitrogen, malt extract, or wool-grown cultures and those reported for most other white rot fungi to date. Laccase production was readily seen in cultures grown with pine or poplar as the sole carbon and energy source. Cultures containing both pine and poplar showed 5- to 10-fold-higher levels of laccase than cultures containing pine or poplar alone. Since syringyl units are structural components important in poplar lignin and other hardwoods but much less so in pine lignin and other softwoods, pine cultures were supplemented with syringic acid, and this resulted in laccase levels comparable to those seen in pine-plus-poplar cultures. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of concentrated extracellular culture fluid from HM cultures showed two laccase activity bands, where as isoelectric focusing revealed five major laccase activity bands with estimated pIs of 3.0, 4.25, 4.5, and 5.1. Low levels of MnP activity were detected in poplar-grown cultures but not in cultures grown with pine, with pine plus syringic acid, or in HN medium. No LiP activity was seen in any of the media tested; however, probing the genomic DNA with the LiP cDNA (CLG4) from the white rot fungus Phanerochaete chrysosporium showed distinct hybridization bands suggesting the presence of lip-like sequences in G. lucidum.

  13. Trends in lignin modification: a comprehensive analysis of the effects of genetic manipulations/mutations on lignification and vascular integrity

    NASA Technical Reports Server (NTRS)

    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

  14. Organic trace analysis of lignin phenols in speleothems using UHPLC-ESI-HRMS and their use as vegetation proxy

    NASA Astrophysics Data System (ADS)

    Hitzemann, Inken; Hoffmann, Thorsten

    2016-04-01

    To understand the climate of the past, it is necessary to get information not only about temperature and precipitation, but also about the vegetation. In contrast to the vegetation proxies used in speleothems so far, like δ13C, the analysis of lignin can provide information not only about the quantity, but also about the type of the regional vegetation. Lignin is widely used as vegetation proxy in sediment samples and natural waters,[1] but there are no methods to analyse lignin in speleothems yet. Lignin is one of the main constituents of wood and woody plants. It is a biopolymer that consists mainly of three monomers, p-coumaryl alcohol, coniferyl alcohol and sinapyl alcohol. The proportion of these three monomers varies with the type of vegetation, for example gymnosperms, angiosperms or herbaceous plants.[2] To analyse the composition of lignin particles in speleothems, it is necessary to extract the speleothem samples, to digest the lignin polymer in order to split it into its monomers, also called lignin phenols, and then to enrich and quantify these lignin phenols. In the method we are presenting here, stalagmite samples are acid digested and the acidic solution is extracted by solid phase extraction. The resulting organic fraction is submitted to an alkaline cupric oxide oxidation using a microwave digestion system.[3] The oxidation products are enriched by solid phase extraction and analysed by ultra high performance liquid chromatography coupled to electrospray high resolution mass spectrometry. We present the limits of detection and quantification, reproducibility and recovery rates as well as first proof-of-principle results from stalagmite samples from the Herbstlabyrinth-Adventshöhle in Germany. References: [1] S. M. Tareq, H. Kitagawa, K. Ohta, Holocene Lake Records: Patterns, Impacts, Causes And Societal Response Selected Papers from the 3rd LIMPACS Conference, Chandigarh, India 2011, 229, 47-56. [2] C. N. Jex, G. H. Pate, A. J. Blyth, R. G

  15. Biomass conversion: Lignin up for break-down

    NASA Astrophysics Data System (ADS)

    Bruijnincx, Pieter C. A.; Weckhuysen, Bert M.

    2014-12-01

    Lignin is an abundant renewable resource, but its intrinsic recalcitrant nature has so far hampered its conversion into higher value chemicals. Now, a two-step strategy, oxidation followed by bond cleavage, has been shown to deconstruct lignin into high yields of low-molecular-weight aromatics.

  16. Metabolic engineering of novel lignin in biomass crops.

    PubMed

    Vanholme, Ruben; Morreel, Kris; Darrah, Chiarina; Oyarce, Paula; Grabber, John H; Ralph, John; Boerjan, Wout

    2012-12-01

    Lignin, a phenolic polymer in the secondary wall, is the major cause of lignocellulosic biomass recalcitrance to efficient industrial processing. From an applications perspective, it is desirable that second-generation bioenergy crops have lignin that is readily degraded by chemical pretreatments but still fulfill its biological role in plants. Because plants can tolerate large variations in lignin composition, often without apparent adverse effects, substitution of some fraction of the traditional monolignols by alternative monomers through genetic engineering is a promising strategy to tailor lignin in bioenergy crops. However, successful engineering of lignin incorporating alternative monomers requires knowledge about phenolic metabolism in plants and about the coupling properties of these alternative monomers. Here, we review the current knowledge about lignin biosynthesis and the pathways towards the main phenolic classes. In addition, the minimal requirements are defined for molecules that, upon incorporation into the lignin polymer, make the latter more susceptible to biomass pretreatment. Numerous metabolites made by plants meet these requirements, and several have already been tested as monolignol substitutes in biomimetic systems. Finally, the status of detection and identification of compounds by phenolic profiling is discussed, as phenolic profiling serves in pathway elucidation and for the detection of incorporation of alternative lignin monomers. PMID:23035778

  17. Metabolic engineering of novel lignin in biomass crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lignin, a phenolic polymer in the secondary-thickened plant cell wall, is the major cause of lignocellulosic biomass recalcitrance toward efficient industrial processing. From an applications perspective, it is desirable that secondary cell walls of second generation bioenergy crops have lignin that...

  18. THERMOPLASTIC STARCH-KRAFT LIGNIN-GLYCEROL BLENDS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Starch-kraft lignin-glycerol blends were extruded in a twin-screw extruder to produce non-brittle films. One week after extrusion, films with a mid-range composition of 52% starch, 20% lignin, and 28% glycerol showed a tensile strength at break of 2.8 MPa, Young's modulus of 48 MPa, and elongation ...

  19. [Characterization of lignin and Mn peroxidases from Phanerochaete chrysosporium

    SciTech Connect

    Not Available

    1992-01-01

    Lignin peroxidases were investigated with respect to enzyme kinetics and NMR spectroscopy of the heme domain. MN peroxidases were studied with respect to the role of oxalate in enzyme activity, the NMR spectroscopy of the heme domain. Gene expression of both lignin and MN peroxidases were examined as well as expression of site-directed mutants aimed at scale up production of these enzymes.

  20. Lignin Degradation by Fusarium solani f. sp. glycines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sudden death syndrome (SDS), caused by the soilborne fungal pathogen Fusarium solani f. sp. glycines, is one of the most important diseases of soybean. Lignin degradation may play a role in the infection, colonization, and survival of the fungus in root tissue . Lignin degradation by F. solani f. sp...

  1. Roles of lignin biosynthesis and regulatory genes in plant development.

    PubMed

    Yoon, Jinmi; Choi, Heebak; An, Gynheung

    2015-11-01

    Lignin is an important factor affecting agricultural traits, biofuel production, and the pulping industry. Most lignin biosynthesis genes and their regulatory genes are expressed mainly in the vascular bundles of stems and leaves, preferentially in tissues undergoing lignification. Other genes are poorly expressed during normal stages of development, but are strongly induced by abiotic or biotic stresses. Some are expressed in non-lignifying tissues such as the shoot apical meristem. Alterations in lignin levels affect plant development. Suppression of lignin biosynthesis genes causes abnormal phenotypes such as collapsed xylem, bending stems, and growth retardation. The loss of expression by genes that function early in the lignin biosynthesis pathway results in more severe developmental phenotypes when compared with plants that have mutations in later genes. Defective lignin deposition is also associated with phenotypes of seed shattering or brittle culm. MYB and NAC transcriptional factors function as switches, and some homeobox proteins negatively control lignin biosynthesis genes. Ectopic deposition caused by overexpression of lignin biosynthesis genes or master switch genes induces curly leaf formation and dwarfism. PMID:26297385

  2. Paving the Way for Lignin Valorisation: Recent Advances in Bioengineering, Biorefining and Catalysis.

    PubMed

    Rinaldi, Roberto; Jastrzebski, Robin; Clough, Matthew T; Ralph, John; Kennema, Marco; Bruijnincx, Pieter C A; Weckhuysen, Bert M

    2016-07-11

    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 multiple "upstream" (i.e., lignin bioengineering, lignin isolation and "early-stage catalytic conversion of lignin") and "downstream" (i.e., lignin depolymerisation and upgrading) process stages, demanding input and understanding from a broad array of scientific disciplines. This review provides a "beginning-to-end" analysis of the recent advances reported in lignin valorisation. Particular emphasis is placed on the improved understanding of lignin's biosynthesis and structure, differences in structure and chemical bonding between native and technical lignins, emerging catalytic valorisation strategies, and the relationships between lignin structure and catalyst performance. PMID:27311348

  3. Proteomic characterization of a triton-insoluble fraction from chloroplasts defines a novel group of proteins associated with macromolecular structures.

    PubMed

    Phinney, Brett S; Thelen, Jay J

    2005-01-01

    Proteomic analysis of a Triton X-100 insoluble, 30,000 x g pellet from purified pea chloroplasts resulted in the identification of 179 nonredundant proteins. This chloroplast fraction was mostly depleted of chloroplast membranes since only 23% and 9% of the identified proteins were also observed in envelope and thylakoid membranes, respectively. One of the most abundant proteins in this fraction was sulfite reductase, a dual function protein previously shown to act as a plastid DNA condensing protein. Approximately 35 other proteins known (or predicted) to be associated with high-density protein-nucleic acid particles (nucleoids) were also identified including a family of DNA gyrases, as well as proteins involved in plastid transcription and translation. Although nucleoids appeared to be the predominant component of 30k x g Triton-insoluble chloroplast preparations, multi-enzyme protein complexes were also present including each subunit to the pyruvate dehydrogenase and acetyl-CoA carboxylase multi-enzyme complexes, as well as a proposed assembly of the first three enzymes of the Calvin cycle. Approximately 18% of the proteins identified were annonated as unknown or hypothetical proteins and another 20% contained "putative" or "like" in the identifier tag. This is the first proteomic characterization of a membrane-depleted, high-density fraction from plastids and demonstrates the utility of this simple procedure to isolate intact macromolecular structures from purified organelles for analysis of protein-protein and protein-nucleic acid interactions. PMID:15822927

  4. Lignin depolymerisation strategies: towards valuable chemicals and fuels.

    PubMed

    Xu, Chunping; Arancon, Rick Arneil D; Labidi, Jalel; Luque, Rafael

    2014-11-21

    Research on lignin deconstruction has recently become the center of interest for scientists and companies worldwide, racing towards harvesting fossil-fuel like aromatic compounds which are so durably put together by plants as products of millions of years of evolution. The natural complexity and high stability of lignin bonds (also as an evolutionary adaptation by plants) makes lignin depolymerization a highly challenging task. Several efforts have been directed towards a more profound understanding of the structure and composition of lignin in order to devise pathways to break down the biopolymer into useful compounds. The present contribution aims to provide an overview of key advances in the field of lignin depolymerisation. Protocols and technologies will be discussed as well as critically evaluated in terms of possibilities and potential for further industrial implementation. PMID:25287249

  5. Conformations of Low-Molecular-Weight Lignin Polymers in Water.

    PubMed

    Petridis, Loukas; Smith, Jeremy C

    2016-02-01

    Low-molecular-weight lignin binds to cellulose during the thermochemical pretreatment of biomass for biofuel production, which prevents the efficient hydrolysis of the cellulose to sugars. The binding properties of lignin are influenced strongly by the conformations it adopts. Here, we use molecular dynamics simulations in aqueous solution to investigate the dependence of the shape of lignin polymers on chain length and temperature. Lignin is found to adopt collapsed conformations in water at 300 and 500 K. However, at 300 K, a discontinuous transition is found in the shape of the polymer as a function of the chain length. Below a critical degree of polymerization, Nc =15, the polymer adopts less spherical conformations than above Nc. The transition disappears at high temperatures (500 K) at which only spherical shapes are adopted. An implication relevant to cellulosic biofuel production is that lignin will self-aggregate even at high pretreatment temperatures. PMID:26763657

  6. Catalytic Hydrolytic Cleavage and Oxy-Cleavage of Lignin Linkages

    SciTech Connect

    Xia, Guanguang; Chen, Baowei; Zhang, Rui; Zhang, Z. Conrad

    2014-07-26

    In this work, new strategies involving organic bases were evaluated to depolymerize lignin to reduced molecular fragments in aqueous medium. NaOH as an inorganic base was also investigated as a reference. Full nature lignin samples are used for the study. As research tools to unravel the complexity of the macro lignin structure and bulky molecular size under this study, size exclusion chromatography and high resolution mass spectrometric analysis, typically used for protein characterizations, were used to follow the progress of lignin depolymerisation by measuring the molecular weight distribution of the products and determining the key molecular fingerprints, respectively. The results show that sodium phenoxide and guanidine carbonate are effective catalysts for lignin depolymerization. It is observed that there exists a synergism between H2O2 and the organic base, which is strongest with guanidine carbonate.

  7. Process for conversion of lignin to reformulated hydrocarbon gasoline

    DOEpatents

    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.

  8. Over-expression of F5H in COMT-deficient Arabidopsis leads to enrichment of an unusual lignin and disruption of pollen wall formation.

    PubMed

    Weng, Jing-Ke; Mo, Huaping; Chapple, Clint

    2010-12-01

    The presence of the phenylpropanoid polymer lignin in plant cell walls impedes breakdown of polysaccharides to the fermentable sugars that are used in biofuel production. Genetically modified plants with altered lignin properties hold great promise to improve biomass degradability. Here, we describe the generation of a new type of lignin enriched in 5-hydroxy-guaiacyl units by over-expressing ferulate 5-hydroxylase in a line of Arabidopsis lacking caffeic acid O-methyltransferase. The lignin modification strategy had a profound impact on plant growth and development and cell-wall properties, and resulted in male sterility due to complete disruption of formation of the pollen wall. The modified plants showed significantly improved cell-wall enzymatic saccharification efficiency without a reduction in post-harvest biomass yield despite the alterations in the overall growth morphology. This study demonstrated the plasticity of lignin polymerization in terms of incorporation of unusual monomers that chemically resemble conventional monomers, and also revealed the link between the biosynthetic pathways of lignin and the pollen wall-forming sporopollenin. PMID:21143672

  9. Valorization of an industrial organosolv-sugarcane bagasse lignin: Characterization and use as a matrix in biobased composites reinforced with sisal fibers.

    PubMed

    Ramires, Elaine C; Megiatto, Jackson D; Gardrat, Christian; Castellan, Alain; Frollini, Elisabete

    2010-11-01

    In the present study, the main focus was the characterization and application of the by-product lignin isolated through an industrial organosolv acid hydrolysis process from sugarcane bagasse, aiming at the production of bioethanol. The sugarcane lignin was characterized and used to prepare phenolic-type resins. The analysis confirmed that the industrial sugarcane lignin is of HGS type, with a high proportion of the less substituted aromatic ring p-hydroxyphenyl units, which favors further reaction with formaldehyde. The lignin-formaldehyde resins were used to produce biobased composites reinforced with different proportions of randomly distributed sisal fibers. The presence of lignin moieties in both the fiber and matrix increases their mutual affinity, as confirmed by SEM images, which showed good adhesion at the biocomposite fiber/matrix interface. This in turn allowed good load transference from the matrix to the fiber, leading to biobased composites with good impact strength (near 500 J m(-1) for a 40 wt% sisal fiber-reinforced composite). The study demonstrates that sugarcane bagasse lignin obtained from a bioethanol plant can be used without excessive purification in the preparation of lignocellulosic fiber-reinforced biobased composites displaying high mechanical properties. PMID:20589841

  10. Chemical Composition of Hypodermal and Endodermal Cell Walls and Xylem Vessels Isolated from Clivia miniata (Identification of the Biopolymers Lignin and Suberin).

    PubMed Central

    Zeier, J.; Schreiber, L.

    1997-01-01

    The occurrence of the biopolymers lignin and suberin was investigated with hypodermal (HCW) and endodermal cell walls (ECW) and xylem vessels (XV) isolated from Clivia miniata Reg. roots. Both biopolymers were detected in HCW and ECW, whereas in XV, typical aliphatic suberin monomers were missing and only representative lignin monomers such as guaiacyl (G) and syringyl (S) units could be detected. The absolute amounts of lignin were about one order of magnitude higher compared with suberin in both HCW and ECW. The ratios of the two aromatic lignin units (G/S) decreased from 39 in XV and 10 in HCW to about 1 in ECW, indicating significant differences in lignin structure and function between the three investigated samples. Additionally, compared with the detectable lignin-derived aromatic units G and S, significantly higher amounts of esterified p-coumaric acid-derived aromatic monomers were obtained with HCW, but not with ECW. This is interpreted as a functional adaption of HCW toward pathogen defense at the root/soil interface. The final aim of this study was to provide a thorough chemical characterization of the composition of HCW, ECW, and XV, which in turn will form the basis for a better understanding of the relevant barriers toward the passive, radial, and apoplastic diffusion of solutes from the soil across the root cortex into the root cylinder. PMID:12223670

  11. Evaporation of Sessile Droplets Laden with Particles and Insoluble Surfactants.

    PubMed

    Karapetsas, George; Chandra Sahu, Kirti; Matar, Omar K

    2016-07-12

    We consider the flow dynamics of a thin evaporating droplet in the presence of an insoluble surfactant and noninteracting particles in the bulk. On the basis of lubrication theory, we derive a set of evolution equations for the film height, the interfacial surfactant, and bulk particle concentrations, taking into account the dependence of liquid viscosity on the local particle concentration. An important ingredient of our model is that it takes into account the fact that the surfactant adsorbed at the interface hinders evaporation. We perform a parametric study to investigate how the presence of surfactants affects the evaporation process as well as the flow dynamics with and without the presence of particles in the bulk. Our numerical calculations show that the droplet lifetime is affected significantly by the balance between the ability of the surfactant to enhance spreading, suppressing the effect of thermal Marangoni stresses-induced motion, and to hinder the evaporation flux through the reduction of the effective interfacial area of evaporation, which tend to accelerate and decelerate the evaporation process, respectively. For particle-laden droplets and in the case of dilute solutions, the droplet lifetime is found to be weakly dependent on the initial particle concentration. We also show that the particle deposition patterns are influenced strongly by the direct effect of the surfactant on the evaporative flux; in certain cases, the "coffee-stain" effect is enhanced significantly. A discussion of the delicate interplay between the effects of capillary pressure and solutal and thermal Marangoni stresses, which drive the liquid flow inside of the evaporating droplet giving rise to the observed results, is provided herein. PMID:27300638

  12. Physiochemical characterization of insoluble residues in California Sierra Nevada snow

    NASA Astrophysics Data System (ADS)

    Creamean, Jessie; Axson, Jessica; Bondy, Amy; Craig, Rebecca; May, Nathaniel; Shen, Hongru; Weber, Michael; Warner, Katy; Pratt, Kerri; Ault, Andrew

    2015-04-01

    The effects atmospheric aerosols have on cloud particle formation are dependent on both the aerosol physical and chemical characteristics. For instance, larger, irregular-shaped mineral dusts efficiently form cloud ice crystals, enhancing precipitation, whereas small, spherical pollution aerosols have the potential to form small cloud droplets that delay the autoconversion of cloudwater to precipitation. Thus, it is important to understand the physiochemical properties and sources of aerosols that influence cloud and precipitation formation. We present an in-depth analysis of the size, chemistry, and sources of soluble and insoluble residues found in snow collected at three locations in the California Sierra Nevada Mountains during the 2012/2013 winter season. For all sites, February snow samples contained high concentrations of regional pollutants such as ammonium nitrate and biomass burning species, while March snow samples were influenced by mineral dust. The snow at the lower elevation sites in closer proximity to the Central Valley of California were heavily influenced by agricultural and industrial emissions, whereas the highest elevation site was exposed to a mixture of Central Valley pollutants in addition to long-range transported dust from Asia and Africa. Further, air masses likely containing transported dust typically traveled over cloud top heights at the low elevation sites, but were incorporated into the cold (-28°C, on average) cloud tops more often at the highest elevation site, particularly in March, which we hypothesize led to enhanced ice crystal formation and thus the observation of dust in the snow collected at the ground. Overall, understanding the spatial and temporal dependence of aerosol sources is important for remote mountainous regions such as the Sierra Nevada where snowpack provides a steady, vital supply of water.

  13. Proteome analysis of the triton-insoluble erythrocyte membrane skeleton.

    PubMed

    Basu, Avik; Harper, Sandra; Pesciotta, Esther N; Speicher, Kaye D; Chakrabarti, Abhijit; Speicher, David W

    2015-10-14

    Erythrocyte shape and membrane integrity is imparted by the membrane skeleton, which can be isolated as a Triton X-100 insoluble structure that retains the biconcave shape of intact erythrocytes, indicating isolation of essentially intact membrane skeletons. These erythrocyte "Triton Skeletons" have been studied morphologically and biochemically, but unbiased proteome analysis of this substructure of the membrane has not been reported. In this study, different extraction buffers and in-depth proteome analyses were used to more fully define the protein composition of this functionally critical macromolecular complex. As expected, the major, well-characterized membrane skeleton proteins and their associated membrane anchors were recovered in good yield. But surprisingly, a substantial number of additional proteins that are not considered in erythrocyte membrane skeleton models were recovered in high yields, including myosin-9, lipid raft proteins (stomatin, flotillin1 and 2), multiple chaperone proteins (HSPs, protein disulfide isomerase and calnexin), and several other proteins. These results show that the membrane skeleton is substantially more complex than previous biochemical studies indicated, and it apparently has localized regions with unique protein compositions and functions. This comprehensive catalog of the membrane skeleton should lead to new insights into erythrocyte membrane biology and pathogenic mutations that perturb membrane stability. Biological significance Current models of erythrocyte membranes describe fairly simple homogenous structures that are incomplete. Proteome analysis of the erythrocyte membrane skeleton shows that it is quite complex and includes a substantial number of proteins whose roles and locations in the membrane are not well defined. Further elucidation of interactions involving these proteins and definition of microdomains in the membrane that contain these proteins should yield novel insights into how the membrane skeleton

  14. Insoluble nonstarch polysaccharides in diets for weaned piglets.

    PubMed

    Gerritsen, R; van der Aar, P; Molist, F

    2012-12-01

    To examine the effect of inclusion insoluble nonstarch polysaccharides (iNSP) in weaned diets on postweaning piglet performance, intestinal activity, and microbial composition 2 experiments were designed. In Exp. 1, 180 piglets were weaned at 28 d of age and divided over 3 treatments: positive control (PC; highly digestible protein), negative control (NC; standard cereal-based diet), and an experimental diet {iNSP; standard + 15% iNSP [wheat straw and oat (Avena sativa) hull]}. Diets were fed during 14 d after weaning. The ADFI, ADG, and G:F were determined. The inclusion of iNSP increased (P < 0.001) ADFI and G:F during days 0 to 14 after weaning and increased the ADG (P = 0.008) during days 0 to 7 after weaning compared with the NC diet. In Exp. 2, 36 piglets were fed the same diets as in Exp. 1. On days 5 and 14 after weaning, 18 piglets were euthanized to determine enzyme activity, intestinal morphology, and microbial population in the ileum and colon and organ weight. The iNSP diet reduced the concentration of Escherichia coli bacteria in the ileum (P = 0.021) and in the colon (P = 0.002) digesta and tended to increase (P = 0.060) the amylase activity. The iNSP diet stimulated the physical adaptation of the gastrointestinal tract because stomach weight as percentage of BW was heavier (P = 0.004) than for the NC diet. In conclusion, the consumption of diets with higher iNSP content in the early weaning period affects the microbial colonization without reducing enzyme activity or animal performance compared with a standard weaned pig diet. PMID:23365366

  15. Lignin biodegradation and the production of ethyl alcohol from cellulose

    SciTech Connect

    Rosenberg, S.L.; Wilke, C.R.

    1981-02-01

    During the last few years our group has been engaged in developing a biochemical process for the conversion of lignocellulosic materials to ethyl alcohol. Lignin is a barrier to complete cellulose saccharification in this process, but chemical and physical delignification steps are too expensive to be used at the present time. An enzymatic delignification process might be attractive for several reasons: little energy would be expected to be needed, enzymes could be recovered and reused, and useful chemicals might be produced from dissolved lignin. A number of thermophilic and thermotolerant fungi were examined for the ability to rapidly degrade lignocellulose in order to find an organism whcih produced an active lignin-degrading enzyme system. Chryosporium pruinosum and Sporotrichum pulverulentum were found to be active lignocellulose degraders, and C. pruinosum was chosen for further study. Lignin and carbohydrate were degraded when the substrate remained moistened by, but not submerged in, the liquid medium. Attempts were made to demonstrate a cell-free lignin degrading system by both extraction and pressing of cultures grown on moist lignocellulose. Carbohydrate-degrading activity was found but not lignin-degrading activity. This led us to ask whether diffusible lignin-degrading activity could be demonstrated in this organism. The data indicate that the lignin degradation system, or one or more of its components, produced by this organism is either unstable, non-diffusible, or inactive at small distances (about 1 mm) from growing hyphae. At present, studies are being conducted using diffusion cultures to select mutants of C. pruinosum that do produce a diffusible lignin degradation system. We are also examining a number of mesophilic lignin-degrading molds for this ability.

  16. Cell wall fermentation kinetics are impacted more by lignin content and ferulate cross-linking than by lignin composition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    BACKGROUND: We used a biomimetic model system to ascertain how reductions in ferulate-lignin cross-linking and shifts in lignin composition influence ruminal cell wall fermentation. Primary walls from maize cell suspensions with normal or reduced feruloylation were artificially lignified with variou...

  17. Computational inference of the structure and regulation of the lignin pathway in Panicum virgatum

    SciTech Connect

    Faraji, Mojdeh; Fonseca, Luis L.; Escamilla-Treviño, Luis; Dixon, Richard A.; Voit, Eberhard O.

    2015-09-17

    and that product inhibition and competition over cinnamoyl-CoA-reductase (CCR1) are essential for matching the model to observed increases in H-lignin levels in 4-coumarate:CoA-ligase (4CL) knockdowns. Moreover, competition for 4-coumarate:CoA-ligase (4CL) is essential for matching the model to observed increases in the pathway metabolites in caffeic acid O-methyltransferase (COMT) knockdowns. As far as possible, the model was validated with independent data.

  18. Computational inference of the structure and regulation of the lignin pathway in Panicum virgatum

    DOE PAGESBeta

    Faraji, Mojdeh; Fonseca, Luis L.; Escamilla-Treviño, Luis; Dixon, Richard A.; Voit, Eberhard O.

    2015-09-17

    necessary and that product inhibition and competition over cinnamoyl-CoA-reductase (CCR1) are essential for matching the model to observed increases in H-lignin levels in 4-coumarate:CoA-ligase (4CL) knockdowns. Moreover, competition for 4-coumarate:CoA-ligase (4CL) is essential for matching the model to observed increases in the pathway metabolites in caffeic acid O-methyltransferase (COMT) knockdowns. As far as possible, the model was validated with independent data.« less

  19. Proteomics analysis of the nacre soluble and insoluble proteins from the oyster Pinctada margaritifera.

    PubMed

    Bédouet, Laurent; Marie, Arul; Dubost, Lionel; Péduzzi, Jean; Duplat, Denis; Berland, Sophie; Puisségur, Marion; Boulzaguet, Hélène; Rousseau, Marthe; Milet, Christian; Lopez, Evelyne

    2007-01-01

    Shell nacre is laid upon an organic cell-free matrix, part of which, paradoxically, is water soluble and displays biological activities. Proteins in the native shell also constitute an insoluble network and offer a model for studying supramolecular organization as a means of self-ordering. Consequently, difficulties are encountered in extraction and purification strategies for protein characterization. In this work, water-soluble proteins and the insoluble conhiolin residue of the nacre of Pinctada margaritifera matrix were analyzed via a proteomics approach. Two sequences homologous to nacre matrix proteins of other Pinctada species were identified in the water-soluble extract. One of them is known as a fundamental component of the insoluble organic matrix of nacre. In the conchiolin, the insoluble residue, four homologs of Pinctada nacre matrix proteins were found. Two of them were the same as the molecules characterized in the water-soluble extract. Results established that soluble and insoluble proteins of the nacre organic matrix share constitutive material. Surprisingly, a peptide in the conchiolin residue was found homologous to a prismatic matrix protein of Pinctada fucata, suggesting that prismatic and nacre matrices may share common proteins. The insoluble properties of shell matrix proteins appear to arise from structural organization via multimerization. The oxidative activity, found in the water-soluble fraction of the nacre matrix, is proposed as a leading process in the transformation of transient soluble proteins into the insoluble network of conchiolin during nacre growth. PMID:17641930

  20. Characterization of Transport Proteins for Aromatic Compounds Derived from Lignin: Benzoate Derivative Binding Proteins

    PubMed Central

    Michalska, Karolina; Chang, Changsoo; Mack, Jamey C.; Zerbs, Sarah; Joachimiak, Andrzej; Collart, Frank R.

    2013-01-01

    In vitro growth experiments have demonstrated that aromatic compounds derived from lignin can be metabolized and represent a major carbon resource for many soil bacteria. However, the proteins that mediate the movement of these metabolites across the cell membrane have not been thoroughly characterized. To address this deficiency, we used a library representative of lignin degradation products and a thermal stability screen to determine ligand specificity for a set of solute-binding proteins (SBPs) from ATP-binding cassette (ABC) transporters. The ligand mapping process identified a set of proteins from Alphaproteobacteria that recognize various benzoate derivatives. Seven high-resolution crystal structures of these proteins in complex with four different aromatic compounds were obtained. The protein–ligand complexes provide details of molecular recognition that can be used to infer binding specificity. This structure–function characterization provides new insight for the biological roles of these ABC transporters and their SBPs, which had been previously annotated as branched-chain amino-acid-binding proteins. The knowledge derived from the crystal structures provides a foundation for development of sequencebased methods to predict the ligand specificity of other uncharacterized transporters. These results also demonstrate that Alphaproteobacteria possess a diverse set of transport capabilities for lignin-derived compounds. Characterization of this new class of transporters improves genomic annotation projects and provides insight into the metabolic potential of soil bacteria. PMID:22925578