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  • An improved TCF sequence for biobleaching kenaf pulp: influence of the hexenuronic acid content and the use of xylanase

     Andreu Terren, Maria Gloria; Vidal Llucia, Teresa
    Bioresource technology
    Vol. 152, p. 253-258
    DOI: 10.1016/j.biortech.2013.11.014
    Date of publication: 2014-01-01
    Journal article

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    Enzymatic delignification with laccase from Trametes villosa used in combination with chemical mediators (acetosyringone, acetovanillone and 1-hydroxybenzotriazole) to improve the totally chlorine-free (TCF) bleaching of kenaf pulp was studied. The best final pulp properties were obtained by using an L-HBT-QPo sequence developed by incorporating a laccase-mediator stage into an industrial bleaching sequence involving chelation and peroxide stages. The new sequence resulted in increased kenaf pulp delignification (90.4%) and brightness (77.2%ISO) relative to a conventional TCF chemical sequence (74.5% delignification and 74.5% brightness). Also, the sequence provided bleached kenaf fibers with high cellulose content (pulp viscosity of 890 g . mL (1) vs 660 g . mL (1)). Scanning electron micrographs revealed that xylanase altered fiber surfaces and facilitated reagent access as a result. However, the LHBTX (xylanase) stage removed 21% of hexenuronic acids in kenaf pulp. These recalcitrant compounds spent additional bleaching reagents and affected pulp properties after peroxide stage. (C) 2013 Elsevier Ltd. All rights reserved.

    Enzymatic delignification with laccase from Trametes villosa used in combination with chemical mediators (acetosyringone, acetovanillone and 1-hydroxybenzotriazole) to improve the totally chlorine-free (TCF) bleaching of kenaf pulp was studied. The best final pulp properties were obtained by using an L-HBT-QPo sequence developed by incorporating a laccase-mediator stage into an industrial bleaching sequence involving chelation and peroxide stages. The new sequence resulted in increased kenaf pulp delignification (90.4%) and brightness (77.2%ISO) relative to a conventional TCF chemical sequence (74.5% delignification and 74.5% brightness). Also, the sequence provided bleached kenaf fibers with high cellulose content (pulp viscosity of 890 g . mL (1) vs 660 g . mL (1)). Scanning electron micrographs revealed that xylanase altered fiber surfaces and facilitated reagent access as a result. However, the LHBTX (xylanase) stage removed 21% of hexenuronic acids in kenaf pulp. These recalcitrant compounds spent additional bleaching reagents and affected pulp properties after peroxide stage. (C) 2013 Elsevier Ltd. All rights reserved.

  • Enzymatic strategies to improve removal of hexenuronic acids and lignin from cellulosic fibers

     Valls Vidal, Cristina; Vidal Llucia, Teresa; Roncero Vivero, Maria Blanca
    Holzforschung
    Vol. 68, num. 2, p. 229-237
    DOI: 10.1515/hf-2013-0033
    Date of publication: 2014
    Journal article

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    Different enzymatic strategies were applied to improve lignin and hexenuronic acid (HexA) removal. Three laccases (L) with different redox potentials were applied in combination with 1-hydroxybenzotriazole or methyl syringate to softwood sulfite and hardwood kraft fibers. The enzymes with a high-redox potential from Pycnoporus cinnabarinus and Trametes villosa were found to be the most efficient. The bleaching efficiency was not significantly influenced by the presence or absence of HexA in the different types of lignocellulosic fibers. Subsequently, the lignin or HexA removal in the presence of different mediators was evaluated in eucalyptus fibers with the T. villosa laccase (TvL). Natural mediators removed only lignin, whereas the combinations of TvL with synthetic mediators removed both HexA and lignin. The mediator violuric acid (VA) was the most efficient as judged by the properties of fiber and effluent. A xylanase pretreatment stage was found to boost the access of the LVA system to HexA without affecting lignin in the pulp

    Different enzymatic strategies were applied to improve lignin and hexenuronic acid (HexA) removal. Three laccases (L) with different redox potentials were applied in combination with 1-hydroxybenzotriazole or methyl syringate to softwood sulfite and hardwood kraft fibers. The enzymes with a high-redox potential from Pycnoporus cinnabarinus and Trametes villosa were found to be the most efficient. The bleaching efficiency was not significantly influenced by the presence or absence of HexA in the different types of lignocellulosic fibers.Subsequently, the lignin or HexA removal in the presence of different mediators was evaluated in eucalyptus fibers with the T. villosa laccase (TvL). Natural mediators removed only lignin, whereas the combinations of TvL with synthetic mediators removed both HexA and lignin. The mediator violuric acid (VA) was the most efficient as judged by the properties of fiber and effluent. A xylanase pretreatment stage was found to boost the access of the LVA system to HexA without affecting lignin in the pulp

  • Structural insights on laccase biografting of ferulic acid onto lignocellulosic fibers

     Rencoret, Jorge; Aracri, Elisabetta; Gutíerrez, Ana; Del Rio, Jose C.; Torres Lopez, Antonio Luis; Vidal Llucia, Teresa; Martínez, Ángel T.
    Biochemical engineering journal
    Vol. 86, p. 16-23
    DOI: 10.1016/j.bej.2014.02.013
    Date of publication: 2014-05-15
    Journal article

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    Treatment of high-kappa sisal pulp with Trametes villosa laccase and ferulic acid resulted in strong increases of kappa-number and acid-group content due to biografting of this phenolic acid, as shown by pyrolysis in the presence of tetramethylammonium hydroxide. The coupling linkages were investigated by 2D NMR of the lignin isolated from pulps. The aromatic region of the spectra showed incorporation of the cinnamic molecule, representing similar to 4% of the lignin content, that according to the displacement of its olefinic C-13(beta)-H-1(beta) signal to 117.0/6.40 ppm would be C-4-etherified. The aliphatic region of the spectra showed that ferulic acid also incorporates as the corresponding beta-beta' dilactone (another similar to 4% of the total lignin) with characteristic C-13(beta)-H-1(alpha) and C-13(beta)-H-1(beta) correlations at 81.8/5.69 and 47.9/4.19 ppm, respectively. The sisal lignin in the treated pulps was only slightly modified (including a small increase of C-alpha-oxidized units) revealing that the main effect of the treatment was ferulic acid biografting. (C) 2014 Elsevier B.V. All rights reserved

    Treatment of high-kappa sisal pulp with Trametes villosa laccase and ferulic acid resulted in strong increases of kappa-number and acid-group content due to biografting of this phenolic acid, as shown by pyrolysis in the presence of tetramethylammonium hydroxide. The coupling linkages were investigated by 2D NMR of the lignin isolated from pulps. The aromatic region of the spectra showed incorporation of the cinnamic molecule, representing similar to 4% of the lignin content, that according to the displacement of its olefinic C-13(beta)-H-1(beta) signal to 117.0/6.40 ppm would be C-4-etherified. The aliphatic region of the spectra showed that ferulic acid also incorporates as the corresponding beta-beta' dilactone (another similar to 4% of the total lignin) with characteristic C-13(beta)-H-1(alpha) and C-13(beta)-H-1(beta) correlations at 81.8/5.69 and 47.9/4.19 ppm, respectively. The sisal lignin in the treated pulps was only slightly modified (including a small increase of C-alpha-oxidized units) revealing that the main effect of the treatment was ferulic acid biografting. (C) 2014 Elsevier B.V. All rights reserved

  • Valortec

     Cusola Aumedes, Oriol; Valls Vidal, Cristina; Vidal Llucia, Teresa; Roncero Vivero, Maria Blanca
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  • EWLP 2014 - 13th European Workshop on Lignocellulosics and Pulp

     Cusola Aumedes, Oriol; Valls Vidal, Cristina; Vidal Llucia, Teresa; Roncero Vivero, Maria Blanca
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  • Biomodificación de papeles para la construcción de dispositivos microfluidicos

     Torres Lopez, Antonio Luis; Casals Terre, Jasmina; Vidal Llucia, Teresa
    Competitive project

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  • Effectiveness of novel xylanases belonging to different GH families on lignin and hexenuronic acids removal from specialty sisal fibres

     Valenzuela Mayorga, Susana Valeria; Valls Vidal, Cristina; Roncero Vivero, Maria Blanca; Vidal Llucia, Teresa; Díaz Lucea, Pilar; Pastor Blasco, Francisco Ignacio Javier
    Journal of chemical technology & biotechnology
    Vol. 89, num. 3, p. 401-406
    DOI: 10.1002/jctb.4132
    Date of publication: 2014-03-01
    Journal article

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    BACKGROUNDThe effectiveness of xylanases on lignin removal from pulps differs widely depending on the enzyme family, the type of pulp and the bleaching sequence among other factors. Xylanases can also reduce the presence of undesirable hexenuronic acids in the papermaking fibers. The performance of non-commercial xylanases belonging to families GH10, GH30, GH30-CBM35 and GH11, and of the multicomponent xylanase from Paenibacillus barcinonensis for lignin and hexenuronic acids removal from sisal (Agave sisalana) has been evaluated.; RESULTSSisal pulps were bleached by an XP sequence, where X denotes the enzyme treatment and P a hydrogen peroxide extraction stage. Kappa number, brightness, viscosity and hexenuronic acid content of samples were determined. Sugars released from sisal pulps, other non-wood fibres and also eucalyptus fibres, by the treatment with xylanases were also analysed. The best results were obtained with the GH10 xylanase and with crude supernatants of P. barcinonensis, which produced a lignin removal of 23% and a reduction of 25% in the hexenuronic acid content of sisal pulps without a significant loss of viscosity.; CONCLUSIONThe release of sugars in the effluents from the X stage applied to sisal correlated with the effectiveness of the xylanases tested. The xylan content of wood and non-wood fibres, the type of xylan and its accessibility also had an influence on the xylanase activity on pulps. (c) 2013 Society of Chemical Industry

  • Exploring biobleaching possibilities of dissolving pulps by means of enzymatic treatments

     Quintana Vilajuana, Elisabet; Valls Vidal, Cristina; Vidal Llucia, Teresa; Roncero Vivero, Maria Blanca
    European Workshop on Lignocellulosics and Pulp
    p. 695-698
    Presentation's date: 2014-06-27
    Presentation of work at congresses

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    Unbleached sulphite cellulose was subjected to an LQPo biobleaching sequence with the intention to elucidate the potential of LMS as an alternative to conventional bleaching processes. The enzymatic stage (L) was performed with the presence of Trametes villosa laccase and violuric acid. This enzymatic stage was followed by a chelating stage (Q) and then by a hydrogen peroxide stage reinforced with pressurized oxygen (Po). The outstanding results obtained with laccase-violuric acid system fulfil the characteristics of commercial dissolving-grade pulp (high reactivity, high ISO brightness, preserved cellulose integrity and low content of hemicellulose). Additionally, the enzymatic treatment saved 2h of reaction time and about 70% of hydrogen peroxide consumption, relative to a conventional hydrogen peroxide sequence (Po).

    Unbleached sulphite cellulose was subjected to an LQPo biobleaching sequence with the intention to elucidate the potential of LMS as an alternative to conventional bleaching processes. The enzymatic stage (L) was performed with the presence of Trametes villosa laccase and violuric acid. This enzymatic stage was followed by a chelating stage (Q) and then by a hydrogen peroxide stage reinforced with pressurized oxygen (Po). The outstanding results obtained with laccase-violuric acid system fulfil the characteristics of commercial dissolving-grade pulp (high reactivity, high ISO brightness, preserved cellulose integrity and low content of hemicellulose). Additionally, the enzymatic treatment saved 2h of reaction time and about 70% of hydrogen peroxide consumption, relative to a conventional hydrogen peroxide sequence (Po)

  • Xylanase treatment of eucalyptus pulps in different chemical bleaching stages

     Ariza, María; Barneto, A. G.; Vidal Llucia, Teresa; Ariza, J.
    European Workshop on Lignocellulosics and Pulp
    p. 175-178
    Presentation's date: 2014-06-25
    Presentation of work at congresses

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    Xylanase significantly reduces the kappa number but almost not modifies brightness and viscosity in studied pulps. On average, xylanase decreases the kappa number of chemical pulps 25 %. This intense effect on the kappa number can be explained by enzymatic hydrolysis of hemicellulose. We proved that xylanase treatment on P0 pulp (first chlorine dioxide step) yield a kappa number reduction higher than obtained by chemical PO and D1 steps together. On the other hand, thermogravimetric analysis shows that xylanase treatment has influence on the thermal degradation path of pulps. As general rule, control treatment (with TrisHCl buffer but without enzyme) leads broads cellulose degradation peak, shown that chlorhydrate of tris(hydroxymethyl) aminoethane adsorb on cellulose surface increasing paracrystalline cellulose content, that is, not-ordered surface crystalline cellulose. When TrisHCl and xylanase are used together, adsorption is less important. In any case, in xylanase-treated pulps cellulose thermally degrades in broader temperature interval than in initial pulps

    Xylanase significantly reduces the kappa number but almost not modifies brightness and viscosity in studied pulps. On average, xylanase decreases the kappa number of chemical pulps 25 %. This intense effect on the kappa number can be explained by enzymatic hydrolysis of hemicellulose. We proved that xylanase treatment on P0 pulp (first chlorine dioxide step) yield a kappa number reduction higher than obtained by chemical PO and D1 steps together. On the other hand, thermogravimetric analysis shows that xylanase treatment has influence on the thermal degradation path of pulps. As general rule, control treatment (with TrisHCl buffer but without enzyme) leads broads cellulose degradation peak, shown that chlorhydrate of tris(hydroxymethyl) aminoethane adsorb on cellulose surface increasing paracrystalline cellulose content, that is, not-ordered surface crystalline cellulose. When TrisHCl and xylanase are used together, adsorption is less important. In any case, in xylanase-treated pulps cellulose thermally degrades in broader temperature interval than in initial pulps

  • Monitoring oxidation-reduction potential of laccase-mediator system: can the efficiency of a redox mediator for deslignifying kenaf pulp be predicted?

     Andreu Terren, Maria Gloria; Vidal Llucia, Teresa
    European Workshop on Lignocellulosics and Pulp
    p. 171-174
    Presentation's date: 2014-06-24
    Presentation of work at congresses

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    The oxidative ability of five phenolic compounds (acetosyringone, syringaldehyde, p-coumaric acid, vanillin and actovanillone) and the laccase¿mediator systems was determined by monitoring the oxidation¿reduction potential (ORP) during solution oxidation and kenaf lignin oxidation process. The results confirmed the production of phenoxy radicals of variable reactivity and stressed the significant role of lignin structure in the enzymatic process. Although changes in ORP were correlated with the oxidative ability of the mediators, pulp properties determined after the bleaching stage were also influenced by condensation and grafting reactions.

    The oxidative ability of five phenolic compounds (acetosyringone, syringaldehyde, p-coumaric acid, vanillin and actovanillone) and the laccase–mediator systems was determined by monitoring the oxidation–reduction potential (ORP) during solution oxidation and kenaf lignin oxidation process. The results confirmed the production of phenoxy radicals of variable reactivity and stressed the significant role of lignin structure in the enzymatic process. Although changes in ORP were correlated with the oxidative ability of the mediators, pulp properties determined after the bleaching stage were also influenced by condensation and grafting reactions.

  • Functionalization of cellulosic model substrates via laccase-mediated coupling of non-polar particles

     Cusola Aumedes, Oriol; Valls Vidal, Cristina; Vidal Llucia, Teresa; Roncero Vivero, Maria Blanca; Rojas, Orlando J.
    European Workshop on Lignocellulosics and Pulp
    p. 119-122
    Presentation's date: 2014-06-27
    Presentation of work at congresses

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    In the present work we investigate the physicochemical interactions between silica and nanofibrillar cellulose (CNF) with a multi component system (MCS) obtained from an enzymatic reaction of a laccase enzyme and a short-chain organic molecule, dodecyl 3,4,5-trihydroxybenzoate (commonly known as lauryl gallate, LG) as well as sulphonated lignin (SL). Hydrophobic chains of enzyme-modified LG were coupled onto CNF and silica surfaces by direct adsorption of the MCS. Quartz crystal microgravimetry (QCM-D), Atomic Force Microscopy (AFM) and water contact angle (WCA) were used to monitor in situ and characterize the hydrophobization process. Efficient adsorption of the MCS onto CNF and silica surfaces increased their WCA by 88° and 78°, respectively. Dynamic Light Scattering (DLS) measurements revealed an effect of the enzyme on LG: reducing particle size from several microns down to 300 nm. The laccase (Lacc) treatment in the presence of SL reduced even more the LG particle size to 80 nm through a dispersive effect of SL

    In the present work we investigate the physicochemical interactions between silica and nanofibrillar cellulose (CNF) with a multi component system (MCS) obtained from an enzymatic reaction of a laccase enzyme and a short-chain organic molecule, dodecyl 3,4,5-trihydroxybenzoate (commonly known as lauryl gallate, LG) as well as sulphonated lignin (SL). Hydrophobic chains of enzyme-modified LG were coupled onto CNF and silica surfaces by direct adsorption of the MCS. Quartz crystal microgravimetry (QCM-D), Atomic Force Microscopy (AFM) and water contact angle (WCA) were used to monitor in situ and characterize the hydrophobization process. Efficient adsorption of the MCS onto CNF and silica surfaces increased their WCA by 88° and 78°, respectively. Dynamic Light Scattering (DLS) measurements revealed an effect of the enzyme on LG: reducing particle size from several microns down to 300 nm. The laccase (Lacc) treatment in the presence of SL reduced even more the LG particle size to 80 nm through a dispersive effect of SL

  • Evaluating changes on cellulosic biobleached fibers by means of thermogravimetric analysis

     Quintana Vilajuana, Elisabet; Garcia Barneto, Agustín; Valls Vidal, Cristina; Vidal Llucia, Teresa; Ariza, J.; Roncero Vivero, Maria Blanca
    European Workshop on Lignocellulosics and Pulp
    p. 691-694
    Presentation's date: 2014-06-27
    Presentation of work at congresses

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    The effects on fibre surface produced by the laccase-mediator system on softwood sulphite fibres were analysed in terms of surface crystallinity using thermogravimetric analysis. The starting pulp presented low content of lignin and hemicelluloses and these characteristics were clearly reflected on TGA graphs, indicating a clean and crystalline surface. Unbleached sulphite pulps were subjected to a biobleaching process using the well-know laccase-mediator system (LMS). From all studied mediators, violuric acid, VA, was the most efficient biobleaching compound. By contrast, HBT also provided a good delignification but affected negatively the fibre ¿surface¿. The natural mediators, SA and PCA were not grafted on sulphite pulp unlike what have been observed with other raw materials. These observations led to the development of an extended biobleaching sequence named LVAQPo, using a laccase from Trametes villosa in combination with VA as a mediator. The characterization of treated pulp in terms of dissolving pulp characteristics showed that this enzymatic sequence could satisfy the market-like requirements. In addition, TGA results showed that the introduction of an enzymatic stage let to reduce the adverse effect caused by a hydrogen peroxide treatment in terms of pulp crystallinity

  • Coating of laccase-activated phenols for the industrially-feasible functionalization of cellulose-based substrates

     Cusola Aumedes, Oriol; Valls Vidal, Cristina; Vidal Llucia, Teresa; Roncero Vivero, Maria Blanca
    European Workshop on Lignocellulosics and Pulp
    p. 295-298
    Presentation's date: 2014-06-25
    Presentation of work at congresses

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    The present work describes an innovative method for the hydrophobization of cellulosic material by impregnation with an enzymatically obtained functionalization solution (FS). Application of FS to the surface of previously formed cellulose sheets was found to confer them hydrophobic properties. The absorbance of functionalized sheets was assessed with the water-drop test (WDT), and their hydrophobicity from their contact angle (WCA) and the surface free energy (SFE) as determined with a goniophotometer. The proposed method is an effective choice for the hydrophobization of paper sheets, with absorption times of up to 4000 s and WCA values around 130°. Treating eucalyptus paper sheets dramatically decreased SFE (from 55 to 10 mJ/m2), and evidences on the grafting of the FS onto the cellulosic sheets were assessed by using ATR-FTIR. The stability of FS and the control solutions was characterized in terms of Z potential and light scattering measurements

    The present work describes an innovative method for the hydrophobization of cellulosic material by impregnation with an enzymatically obtained functionalization solution (FS). Application of FS to the surface of previously formed cellulose sheets was found to confer them hydrophobic properties. The absorbance of functionalized sheets was assessed with the water-drop test (WDT), and their hydrophobicity from their contact angle (WCA) and the surface free energy (SFE) as determined with a goniophotometer. The proposed method is an effective choice for the hydrophobization of paper sheets, with absorption times of up to 4000 s and WCA values around 130°. Treating eucalyptus paper sheets dramatically decreased SFE (from 55 to 10 mJ/m2), and evidences on the grafting of the FS onto the cellulosic sheets were assessed by using ATR-FTIR. The stability of FS and the control solutions was characterized in terms of Z potential and light scattering measurements

  • Evaluating the impact of combining mediators in the LMS for biobleaching or functionalization

     Valls Vidal, Cristina; Vidal Llucia, Teresa; Roncero Vivero, Maria Blanca
    European Workshop on Lignocellulosics and Pulp
    p. 843-846
    Presentation's date: 2014-06-27
    Presentation of work at congresses

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    In this work, a laccase from Cerrena Unicolor (CuL) supplied by Fungal Bioproducts® was firstly applied in combination with VA in Eucalyptus globulus in order to compare its biobleaching effect with the well-known laccase from Trametes villosa supplied by Novozymes®. However, the main purpose of this work was to apply the CuL in presence of two different mediators like VA (as synthetic compound) or p-coumaric acid (PCA), acetosyringone (AS) or syringaldehide (SA) (as natural compounds). Each compound was applied alone or in combination with another one in order to find a possible biobleaching or functionalising boosting effect between them. Concerning the biobleaching effects, the highest delignification and brightness increase was produced with the VA applied alone. The natural mediators failed to increase delignification and contrary, they hindered the effect of VA due to possible interactions with the natural phenols and fibres. Concerning the grafting effects, the highest increase in kappa number and in colour properties was produced with the combination of PCA and AS. Finally, the best way of applying these mediators, together in one step (LAS+PCA), or in two steps with (LASwashing-LPCA) or without (LAS-LPCA) washing was evaluated

    In this work, a laccase from Cerrena Unicolor (CuL) supplied by Fungal Bioproducts® was firstly applied in combination with VA in Eucalyptus globulus in order to compare its biobleaching effect with the well-known laccase from Trametes villosa supplied by Novozymes®. However, the main purpose of this work was to apply the CuL in presence of two different mediators like VA (as synthetic compound) or p-coumaric acid (PCA), acetosyringone (AS) or syringaldehide (SA) (as natural compounds). Each compound was applied alone or in combination with another one in order to find a possible biobleaching or functionalising boosting effect between them. Concerning the biobleaching effects, the highest delignification and brightness increase was produced with the VA applied alone. The natural mediators failed to increase delignification and contrary, they hindered the effect of VA due to possible interactions with the natural phenols and fibres. Concerning the grafting effects, the highest increase in kappa number and in colour properties was produced with the combination of PCA and AS. Finally, the best way of applying these mediators, together in one step (LAS+PCA), or in two steps with (LASwashing-LPCA) or without (LAS-LPCA) washing was evaluated

  • Biografting of ferulic acid onto lignocellulosic fibers by the use of laccases

     Rencoret, Jorge; Aracri, Elisabetta; Gutíerrez, Ana; del Rio Andrade, José Carlos; Torres Lopez, Antonio Luis; Vidal Llucia, Teresa; Martínez, Ángel T.
    European Workshop on Lignocellulosics and Pulp
    p. 703-706
    Presentation's date: 2014-06-26
    Presentation of work at congresses

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    Laccases can functionalize paper pulps with phenolic compounds but little is known about the formed linkages. Treatment of a high-kappa sisal pulp with Trametes villosa laccase and ferulic acid resulted in strong increases of kappa-number and acid-group content. This suggested extensive incorporation of ferulic acid, as confirmed by pyrolysis in the presence of tetramethylammonium hydroxide. The coupling linkages were investigated by 2DNMR of the lignin isolated from pulps. The aromatic region of the spectra showed incorporation of the cinnamic molecule, representing ~4% of the lignin content. Interestingly, the spectra revealed that ferulic acid is C4- etherified. The aliphatic region of the spectra showed that ferulic acid also incorporates as the corresponding _-_' dilactone (another ~4% of the total lignin) with characteristic 13C_-1H_ and 13C_-1H_ correlations. The lignin composition and interunit linkages in the treated pulps were only slightly modified revealing that the main effect of the treatment was ferulic acid biografting

    Laccases can functionalize paper pulps with phenolic compounds but little is known about the formed linkages. Treatment of a high-kappa sisal pulp with Trametes villosa laccase and ferulic acid resulted in strong increases of kappa-number and acid-group content. This suggested extensive incorporation of ferulic acid, as confirmed by pyrolysis in the presence of tetramethylammonium hydroxide. The coupling linkages were investigated by 2DNMR of the lignin isolated from pulps. The aromatic region of the spectra showed incorporation of the cinnamic molecule, representing ~4% of the lignin content. Interestingly, the spectra revealed that ferulic acid is C4- etherified. The aliphatic region of the spectra showed that ferulic acid also incorporates as the corresponding _-_' dilactone (another ~4% of the total lignin) with characteristic 13C_-1H_ and 13C_-1H_ correlations. The lignin composition and interunit linkages in the treated pulps were only slightly modified revealing that the main effect of the treatment was ferulic acid biografting

  • Removal of lignin and hexenuronic acids from sisal fibers with novel xylanases belonging to different GH families

     Valenzuela, Susana V.; Valls Vidal, Cristina; Roncero Vivero, Maria Blanca; Vidal Llucia, Teresa; Diaz, Pilar; Pastor Blasco, Francisco Ignacio Javier
    European Workshop on Lignocellulosics and Pulp
    p. 839-842
    Presentation's date: 2014-06-27
    Presentation of work at congresses

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    The aim of this study was to evaluate five different preparations of xylanases from Paenibacillus barcinonensis, a highly xylanolytic species, who is able to grow on xylan as a sole carbon source. As raw material to assess, fibers from sisal (Agave sisalana) were chosen. Sisal pulps were bleached by an XP sequence, where X denotes the enzyme treatment and P a hydrogen peroxide extraction stage. Kappa number, brightness, viscosity and hexenuronic acid content of samples were determined. Sugars released from sisal pulps, other non-wood fibres and also eucalyptus fibres, by the treatment with the xylanases were also analysed. The best results were obtained with the GH10 xylanase and with crude supernatants of P. barcinonensis, which produced a lignin removal of 23% and a reduction of 25% in the hexenuronic acid content of sisal pulps without a significant loss of viscosity. The xylanases of family GH30 showed good performance, being more efficient when applied as a single catalytic domain. On the contrary, Xyn11E did not show any significant effect on pulp properties. The release of sugars in the effluents from the X stage applied to sisal correlated with the effectiveness of the xylanases tested. The xylan content of wood and non-wood fibres, the type of xylan and its accessibility also had an influence on the xylanase activity on pulps

    The aim of this study was to evaluate five different preparations of xylanases from Paenibacillus barcinonensis, a highly xylanolytic species, who is able to grow on xylan as a sole carbon source. As raw material to assess, fibers from sisal (Agave sisalana) were chosen. Sisal pulps were bleached by an XP sequence, where X denotes the enzyme treatment and P a hydrogen peroxide extraction stage. Kappa number, brightness, viscosity and hexenuronic acid content of samples were determined. Sugars released from sisal pulps, other non-wood fibres and also eucalyptus fibres, by the treatment with the xylanases were also analysed. The best results were obtained with the GH10 xylanase and with crude supernatants of P. barcinonensis, which produced a lignin removal of 23% and a reduction of 25% in the hexenuronic acid content of sisal pulps without a significant loss of viscosity. The xylanases of family GH30 showed good performance, being more efficient when applied as a single catalytic domain. On the contrary, Xyn11E did not show any significant effect on pulp properties. The release of sugars in the effluents from the X stage applied to sisal correlated with the effectiveness of the xylanases tested. The xylan content of wood and non-wood fibres, the type of xylan and its accessibility also had an influence on the xylanase activity on pulps

  • Photobleaching of eucalyptus kraft pulps. Thermogravimetric monitoring

     Barneto, A. G.; Ariza, María; Vidal Llucia, Teresa; Ariza, J.
    European Workshop on Lignocellulosics and Pulp
    p. 195-198
    Presentation's date: 2014-06-25
    Presentation of work at congresses

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    This study assesses the potential of UV light as method to bleach eucalyptus pulps in different steps of their chemical bleaching process in a pulp mill. Higher brightness increasing were obtained on dirtier pulps, that is, alkaline washed and oxygen delignified pulps. In any case, photobleaching shows first-order kinetics. Rate of chromophores removal is proportional to the chromophores content in fiber surface. Complementarily, thermogravimetric analysis proved that UV light (400 nm wavelength) do not damages fiber integrity

    This study assesses the potential of UV light as method to bleach eucalyptus pulps in different steps of their chemical bleaching process in a pulp mill. Higher brightness increasing were obtained on dirtier pulps, that is, alkaline washed and oxygen delignified pulps. In any case, photobleaching shows first-order kinetics. Rate of chromophores removal is proportional to the chromophores content in fiber surface. Complementarily, thermogravimetric analysis proved that UV light (400 nm wavelength) do not damages fiber integrity

  • Using glycosidases to modify TCF bleached specialty sisal fibers

     Beltramino Heffes, Facundo; Valls Vidal, Cristina; Vidal Llucia, Teresa; Roncero Vivero, Maria Blanca
    European Workshop on Lignocellulosics and Pulp
    p. 211-214
    Presentation's date: 2014-06-25
    Presentation of work at congresses

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    Modifying fibers in order to upgrade them to dissolving grade involves several changes. Paper grade pulps can be used to yield this kind of raw materials, if the necessary modifications are carried out. Classic processes are capable of producing these changes. However, these classic processes present many drawbacks. In this direction biotechnology, and particularly enzymes, are attracting an increasing interest due to the special features they present. Enzymes (glycosidases) are applied in this work on an alkaline TCF bleached sisal pulp. A xylanase and a cellulase preparation, both commercial, are applied on this pulp in order to evaluate their potential as catalysts for carrying out the previously stated upgrade. The main objective is to remove hemicelluloses present in starting pulp, which are an undesirable impurity in final product. Other modifications are as well profitable, such as increases in cellulose reactivity, a key parameter in dissolving pulps quality. After application, it is observed that final pulps present a lower content in hemicelluloses, a higher reactivity as well as other positive modifications

    Modifying fibers in order to upgrade them to dissolving grade involves several changes. Paper grade pulps can be used to yield this kind of raw materials, if the necessary modifications are carried out. Classic processes are capable of producing these changes. However, these classic processes present many drawbacks. In this direction biotechnology, and particularly enzymes, are attracting an increasing interest due to the special features they present. Enzymes (glycosidases) are applied in this work on an alkaline TCF bleached sisal pulp. A xylanase and a cellulase preparation, both commercial, are applied on this pulp in order to evaluate their potential as catalysts for carrying out the previously stated upgrade. The main objective is to remove hemicelluloses present in starting pulp, which are an undesirable impurity in final product. Other modifications are as well profitable, such as increases in cellulose reactivity, a key parameter in dissolving pulps quality. After application, it is observed that final pulps present a lower content in hemicelluloses, a higher reactivity as well as other positive modifications

  • Application of surface enzyme treatments using laccase and a hydrophobic compound to paper-based media

     Cusola Aumedes, Oriol; Valls Vidal, Cristina; Vidal Llucia, Teresa; Roncero Vivero, Maria Blanca
    Bioresource technology
    Vol. 131, p. 521-526
    DOI: 10.1016/j.biortech.2012.12.186
    Date of publication: 2013-01-11
    Journal article

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    A new approach for the hydrophobization of finished cellulosic substrates based on a previously reported enzymatic technique is proposed. Commercial finished paper was hydrophobized by using laccase from Trametes villosa in combination with lauryl gallate (LG) as hydrophobic compound. The efficiency of the method was increased by the use of a lignosulfonate as a natural dispersant to improve the surface distribution of LG on the paper, raise its hydrophobicity and help preserve the enzyme activity. No similar threefold effect from a single compound for the improvement of enzymatic treatments was previously reported. The influence of processing conditions including the LG dose, treatment time and temperature was also examined, resulting in further increased hydrophobicity. Efficient fiber bonding and chemical functionalization were confirmed by thorough washing and Soxhlet extraction of the paper. As shown here for the first time, enzyme treatments have the potential to improve the surface hydrophobicity of paper-based media.

    A new approach for the hydrophobization of finished cellulosic substrates based on a previously reported enzymatic technique is proposed. Commercial finished paper was hydrophobized by using laccase from Trametes villosa in combination with lauryl gallate (LG) as hydrophobic compound. The efficiency of the method was increased by the use of a lignosulfonate as a natural dispersant to improve the surface distribution of LG on the paper, raise its hydrophobicity and help preserve the enzyme activity. No similar threefold effect from a single compound for the improvement of enzymatic treatments was previously reported. The influence of processing conditions including the LG dose, treatment time and temperature was also examined, resulting in further increased hydrophobicity. Efficient fiber bonding and chemical functionalization were confirmed by thorough washing and Soxhlet extraction of the paper. As shown here for the first time, enzyme treatments have the potential to improve the surface hydrophobicity of paper-based media

  • Blanqueig enzimàtic de pasta de kenaf emprant sistemes lacasa-mediador  Open access

     Andreu Terren, Maria Gloria
    Department of Textile and Paper Engineering, Universitat Politècnica de Catalunya
    Theses

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    La present tesi s¿emmarca dins d¿una de les línies del Grup de Recerca Paperer i Gràfic (CIPAGRAF), del Departament d¿Enginyeria Tèxtil i Paperera de l¿Escola Tècnica Superior d¿Enginyeries Industrial i Aeronàutica de Terrassa, encaminada a l¿aplicació de la Biotecnologia per desenvolupar nous sistemes enzimàtics per al blanqueig de pastes i modificació de fibres cel¿lulòsiques. La implantació d¿etapes enzimàtiques en les seqüències de blanqueig de pasta de paper a nivell industrial continua essent, avui en dia, un dels principals reptes en el camp de la investigació paperera. La reducció de l¿impacte ambiental, l¿optimització de costos, així com el desenvolupament de productes paperers amb propietats noves i millorades, justifiquen l¿estudi de noves seqüències enzimàtiques basades en l¿aplicació de sistemes lacasa-mediador. La utilització d¿una matèria prima renovable, el kenaf, està en sintonia amb el creixent interès de l¿ús de fibres no fusteres per a l¿obtenció de nous productes lignocel¿lulòsics d¿alt valor afegit. Així doncs, aquesta tesi es fonamenta en l¿ús d¿enzims per a blanquejar pasta de kenaf. Les seqüències de blanqueig enzimàtic estudiades consten de diferents tractaments amb el sistema lacasa-mediador (Etapa L). Les lacases utilitzades en aquesta etapa provenen dels fongs Pycnoporus cinnabarinus i Trametes villosa, les quals s¿apliquen amb diferents mediadors naturals (compostos fenòlics derivats de la lignina) i amb un mediador sintètic. L¿etapa enzimàtica es completa amb diferents etapes de blanqueig químic (quelant, peròxid d¿hidrogen i peròxid d¿hidrogen pressuritzat).Al final de les seqüències s¿obtenen, en funció del mediador utilitzat en l¿etapa enzimàtica, fibres de kenaf amb un alt contingut de cel¿lulosa i altes blancors. En aquest sentit, en el transcurs de l¿experimentació s¿ha constatat la importància de la naturalesa química del mediador, ja que els diferents radicals fenoxi formats en l¿etapa enzimàtica determinen la capacitat oxidativa del sistema lacasa-mediador.Per altra banda, els resultats obtinguts remarquen el paper de la composició química de la lignina de kenaf en el procés enzimàtic. La capacitat oxidativa de la lacasa augmenta en presència de pasta de kenaf i la quantitat d¿àcids hexenurònics presents en la mateixa limita el grau de blancor assolit en els diferents tractaments, encara que el resultat final es semblant o superior a una pasta TCF convencional. L¿aplicació de xilanases després de l¿etapa enzimàtica lacasa-mediador es mostra efectiva en l¿eliminació d¿aquests àcids, essent una possible via de millora als tractaments proposats en la present tesi.

    La present tesi s’emmarca dins d’una de les línies del Grup de Recerca Paperer i Gràfic (CIPAGRAF), del Departament d’Enginyeria Tèxtil i Paperera de l’Escola Tècnica Superior d’Enginyeries Industrial i Aeronàutica de Terrassa, encaminada a l’aplicacióde la Biotecnologia per desenvolupar nous sistemes enzimàtics per al blanqueig depastes i modificació de fibres cel·lulòsiques. La implantació d’etapes enzimàtiques en les seqüències de blanqueig de pasta de paper a nivell industrial continua essent, avui en dia, un dels principals reptes en el camp de la investigació paperera. La reducció de l’impacte ambiental, l’optimització de costos, així com el desenvolupament de productes paperers amb propietats noves i millorades, justifiquen l’estudi de noves seqüències enzimàtiques basades en l’aplicació de sistemes lacasa-mediador. La utilització d’una matèria prima renovable, el kenaf, està en sintonia amb el creixent interès de l’ús de fibres no fusteres per a l’obtenció de nous productes lignocel·lulòsics d’alt valor afegit. Així doncs, aquesta tesi es fonamenta en l’ús d’enzims per a blanquejar pasta de kenaf. Les seqüències de blanqueig enzimàtic estudiades consten de diferents tractaments amb el sistema lacasa-mediador (Etapa L). Les lacases utilitzades en aquesta etapa provenen dels fongs Pycnoporus cinnabarinus i Trametes villosa, les quals s’apliquen amb diferents mediadors naturals (compostos fenòlics derivats de la lignina) i amb un mediador sintètic. L’etapa enzimàtica es completa amb diferents etapes de blanqueig químic (quelant, peròxid d’hidrogen i peròxid d’hidrogen pressuritzat). Al final de les seqüències s’obtenen, en funció del mediador utilitzat en l’etapa enzimàtica, fibres de kenaf amb un alt contingut de cel·lulosa i altes blancors. En aquest sentit, en el transcurs de l’experimentació s’ha constatat la importància de la naturalesa química del mediador, ja que els diferents radicals fenoxi formats en l’etapa enzimàtica determinen la capacitat oxidativa del sistema lacasa-mediador. Per altra banda, els resultats obtinguts remarquen el paper de la composició química de la lignina de kenaf en el procés enzimàtic. La capacitat oxidativa de la lacasa augmenta en presència de pasta de kenaf i la quantitat d’àcids hexenurònics presents en la mateixa limita el grau de blancor assolit en els diferents tractaments, encara que el resultat final es semblant o superior a una pasta TCF convencional. L’aplicació de xilanases després de l’etapa enzimàtica lacasa-mediador es mostra efectiva en l’eliminació d’aquests àcids, essent una possible via de millora als tractaments proposats en la present tesi.

    The present thesis has been performed in the research group CIPAGRAF (Grup de Recerca Paperer i Gràfic) of the Departament d'Enginyeria Tèxtil i Paperera at the Escola Tècnica Superior d'Enginyeries Industrial i Aeronàutica de Terrassa. One of the research topics of the group is the application of enzymes in pulp biobleaching processes and in the modification of cellulosic fibers. The implementation of enzymatic stages in paper pulp bleaching sequences is, at present, one of the main challenges of the research in the paper industry. The application of laccase-mediator systems can lead to a reduction of environmental impact and to cost optimization, as well as to the development of paper-derived products with novel and improved properties. The use of a renewable raw material -kenaf- is in accordance with the growing interest in the utilization of non-wood fibers for the production of new high-added value lignocellulosic products. Consequently, the present thesis is based on the use of enzymes for kenaf pulp bleaching. The enzymatic bleaching sequences studied involve different treatments with the laccase-mediator system (Stage L). The two fungal enzymes used in this stage- Pycnoporus cinnabarinus and Trametes villosa laccases-have been assisted by different natural mediators (lignin-derived phenolic compounds) and a synthetic one. The enzymatic stage has been completed with different chemical bleaching stages (chelating, hydrogen peroxide and pressurized hydrogen peroxide). At the end of the sequences, kenaf fibers with high cellulose levels and brightness were obtained. The significance of the chemical nature of the mediator has been emphasized because the different phenoxy radicals formed in the enzymatic stage determine the oxidative capacity of the laccase-mediator system. In addition, the results obtained also show the role of the chemical composition of kenaf lignin in the enzymatic process. The laccase oxidative capacity increases in the presence of kenaf pulp, and the amount of hexenuronic acids present limits the degree of brightness. Nevertheless, for the enzymatic treatments, the final results are similar to or better than for a conventional chlorine-free treatment. The application of xilanases after the laccase-mediator stage has been shown to be efficient in hexenuronic acids removal, opening possible new improvements to the treatments reported in this work.

  • Use of cyclic voltammetry as an effective tool for selecting efficient enhancers for oxidative bioprocesses: Importance of pH

     Aracri, Elisabetta; Tzanov, Tzanko; Vidal Llucia, Teresa
    Industrial & engineering chemistry research
    Vol. 52, num. 4, p. 1455-1463
    DOI: 10.1021/ie3027586
    Date of publication: 2013-01-04
    Journal article

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    Seven natural phenols and two synthetic compounds were evaluated by means of cyclic voltammetry as enhancers for the oxidation of the lignin model compound veratryl alcohol (VAl) and a sulfonated lignin (SL). Their electrochemical behaviors and catalytic efficiencies (CEs) against both substrates were assessed as a function of pH. A general increase in CE of the phenols was for the first time observed in the oxidation of VAl at pH 7 and 8. Methyl syringate (MS), syringic acid (SRC), and syringaldehyde (SRD) exhibited the highest CEs against VAl among the studied phenolic compounds despite the reduced stabilities of their phenoxy radicals. This was a result of favorable stability−reactivity balances, which were apparently influenced by both the chemical structures of the enhancers and the experimental conditions. Violuric acid (VAc) proved the most efficient compound in oxidizing lignin, followed by SRD and MS, which showed regeneration in the interval of pHs studied

  • Laccase-mediated coupling of nonpolar chains for the hydrophobization of lignocellulose

     Garcia Ubasart, Jordi; Vidal Llucia, Teresa; Torres Lopez, Antonio Luis; Rojas, Orlando J.
    Biomacromolecules
    Vol. 14, num. 5, p. 1637-1644
    DOI: 10.1021/bm400291s
    Date of publication: 2013-04-09
    Journal article

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    We investigate the use of laccase enzymes to couple short nonpolar chains containing aromatic groups onto flax fibers and nanofibrillated cellulose (NFC) with different lignin contents. Trametes villosa, Pycnoporus cinnabarinus, and Myceliophthora thermophila were used to facilitate surface coupling and to produce materials with different levels of hydrophobicity. Heat treatment of fiber webs after lacccase-mediated coupling markedly increased the resistance to water absorption. The highest hydrophobization levels of flax fibers was achieved by coupling dodecyl 3,4,5-trihydroxybenzoate (HB-C12), which yielded water contact angles (WCAs) of 80-96 degrees and water absorption times (drop tests) of ca. 73 min. The results from apparent aromatic content and FTIR analyses confirmed the laccase-mediated coupling of HB-C12 onto the cellulose fibers. Ultrathin films of NFC were also used as substrates for enzyme-mediated hydrophobization with HB-C12. In these cases, WCAs in the range of 87-104 degrees were achieved, depending on the conditions. Quartz crystal microgravimetry (QCM) was used to study the dynamics and the extent of the coupling process onto cellulose. The results help to better understand the mechanisms involved in laccase-mediated hydrophobization and provide a proof of a biotechnological platform for the development of value-added fiber products.

    We investigate the use of laccase enzymes to couple short nonpolar chains containing aromatic groups onto flax fibers and nanofibrillated cellulose (NFC) with different lignin contents. Trametes villosa, Pycnoporus cinnabarinus, and Myceliophthora thermophila were used to facilitate surface coupling and to produce materials with different levels of hydrophobicity. Heat treatment of fiber webs after lacccase-mediated coupling markedly increased the resistance to water absorption. The highest hydrophobization levels of flax fibers was achieved by coupling dodecyl 3,4,5-trihydroxybenzoate (HB-C12), which yielded water contact angles (WCAs) of 80−96 degrees and water absorption times (drop tests) of ca. 73 min. The results from apparent aromatic content and FTIR analyses confirmed the laccase-mediated coupling of HB-C12 onto the cellulose fibers. Ultrathin films of NFC were also used as substrates for enzyme-mediated hydrophobization with HBC12. In these cases, WCAs in the range of 87−104 degrees were achieved, depending on the conditions. Quartz crystal microgravimetry (QCM) was used to study the dynamics and the extent of the coupling process onto cellulose. The results help to better understand the mechanisms involved in laccase-mediated hydrophobization and provide a proof of a biotechnological platform for the development of value-added fiber products

  • An enzyme-catalysed bleaching treatment to meet dissolving pulp characteristics for cellulose derivatives applications

     Quintana Vilajuana, Elisabet; Valls Vidal, Cristina; Vidal Llucia, Teresa; Roncero Vivero, Maria Blanca
    Bioresource technology
    Vol. 148, p. 1-8
    DOI: 10.1016/j.biortech.2013.08.104
    Date of publication: 2013-11
    Journal article

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    Bleached cellulose with good end-properties (~90% ISO brightness and 62% cellulose preservation) was obtained by using a totally chlorine-free biobleaching process (TCF). Unbleached sulphite cellulose was treated with Trametes villosa laccase in combination with violuric acid. This enzymatic stage (L) was followed by a chelating stage (Q) and then by a hydrogen peroxide stage reinforced with pressurized oxygen (Po), resulting to an overall LQPo sequence. The use of violuric acid was dictated by the results of a preliminary study, where the bleaching efficiency of various natural (syringaldehyde and p-coumaric acid) and synthetic mediators (violuric acid and 1-hydroxybenzotriazole) were assessed. The outstanding results obtained with laccase-violuric acid system fulfil most of the characteristics of commercial dissolving pulp, totally acceptable for viscose manufacturing or CMC derivatives, with the added advantage that the enzymatic treatment saved 2. h of reaction time and about 70% of hydrogen peroxide consumption, relative to a conventional sequence (Po)

    Bleached cellulose with good end-properties (_90% ISO brightness and 62% cellulose preservation) was obtained by using a totally chlorine-free biobleaching process (TCF). Unbleached sulphite cellulose was treated with Trametes villosa laccase in combination with violuric acid. This enzymatic stage (L) was followed by a chelating stage (Q) and then by a hydrogen peroxide stage reinforced with pressurized oxygen (Po), resulting to an overall LQPo sequence. The use of violuric acid was dictated by the results of a preliminary study, where the bleaching efficiency of various natural (syringaldehyde and p-coumaric acid) and synthetic mediators (violuric acid and 1-hydroxybenzotriazole) were assessed. The outstanding results obtained with laccase-violuric acid system fulfil most of the characteristics of commercial dissolving pulp, totally acceptable for viscose manufacturing or CMC derivatives, with the added advantage that the enzymatic treatment saved 2 h of reaction time and about 70% of hydrogen peroxide consumption, relative to a conventional sequence (Po)

  • A new biobleaching sequence for kenaf pulp: influence of the chemical nature of the mediator and thermogravimetric analysis of the pulp

     Andreu Terren, Maria Gloria; Barneto, A. G.; Vidal Llucia, Teresa
    Bioresource technology
    Vol. 130, p. 431-438
    DOI: 10.1016/j.biortech.2012.12.014
    Date of publication: 2013-02
    Journal article

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    This paper evaluates five phenolic compounds as mediators for kenaf pulp biobleaching by laccase. The results have been compared with the treatment using a non-phenolic mediator, 1-hydroxybenzotriole and laccase alone. The influence of the nature of the chemical mediators used on various pulp properties is discussed. In addition to oxidizing lignin, the phenolic radicals formed in the process take part in condensation and grafting reactions in enzymatic stage. After biobleaching sequence (LP), syringaldehyde was shown to be the best phenolic mediator, allowing a delignification of 43% and 72% ISO brightness. These results were similar to the use of laccase alone due to the role as mediators of syringyl units resulting from oxidative lignin degradation. As a novelty, the study was supplemented with thermogravimetric analysis, with emphasis on the crystallinity degree of the cellulose surface and the aim of elucidating the action mechanisms of laccase-mediator systems on fiber.

  • Biomodification of cellulose flax fibers by a new cellulase

     Garcia Ubasart, Jordi; Torres Lopez, Antonio Luis; Vila, Carlos; Pastor, Francisco J.; Vidal Llucia, Teresa
    Industrial crops and products
    Vol. 44, p. 71-76
    DOI: 10.1016/j.indcrop.2012.10.019
    Date of publication: 2013-01
    Journal article

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    The potential of the new cellulase Cel9B from Paenibacillus barcinonensis for the modification of cellulose flax fibers was for the first time assessed in this work. Cel9B treatments were found to enhance the development of properties during the refining of fibers, the precise effects depending on the enzyme dose used. Scanning electron micrographs showed the treatments to alter flax fiber surface and cause defibrillation, peeling and fiber wall removal. Zero-span tensile strength was determined to elucidate the changes in intrinsic resistance of cellulose fibers and solubilization of carbohydrates evaluated by HPLC. Low Cel9B doses resulted in improved tensile strength in handsheets and can thus be used to save energy in the refining process. Also, on equal tear resistance, handsheets had a higher tensile index. High doses of Cel9B raised the collapsibility and bonding potential of cellulose flax fibers and produced heavier handsheets. Cel9B also improved air permeance at low refining intensities. The results obtained in this work are useful in understanding the effects brought by cellulase Cel9B on flax fibers and provide a proof of a biotechnological platform for the development of added-value fiber products

    The potential of the new cellulase Cel9B from Paenibacillus barcinonensis for the modification of cellulose flax fibers was for the first time assessed in this work. Cel9B treatments were found to enhance the development of properties during the refining of fibers, the precise effects depending on the enzyme dose used. Scanning electron micrographs showed the treatments to alter flax fiber surface and cause defibrillation, peeling and fiber wall removal. Zero-span tensile strength was determined to elucidate the changes in intrinsic resistance of cellulose fibers and solubilization of carbohydrates evaluated by HPLC. Low Cel9B doses resulted in improved tensile strength in handsheets and can thus be used to save energy in the refining process. Also, on equal tear resistance, handsheets had a higher tensile index. High doses of Cel9B raised the collapsibility and bonding potential of cellulose flax fibers and produced heavier handsheets. Cel9B also improved air permeance at low refining intensities. The results obtained in this work are useful in understanding the effects brought by cellulase Cel9B on flax fibers and provide a proof of a biotechnological platform for the development of added-value fiber products

  • Laccase from Pycnoporus cinnabarinus and phenolic compounds: can the efficiency of an enzyme mediator for delignifying kenaf pulp be predicted?

     Andreu Terren, Maria Gloria; Vidal Llucia, Teresa
    Bioresource technology
    Vol. 131, p. 536-540
    DOI: 10.1016/j.biortech.2013.01.033
    Date of publication: 2013-03
    Journal article

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    In this work, kenaf pulp was delignified by using laccase in combination with various redox mediators and the efficiency of the different laccase-mediator systems assessed in terms of the changes in pulp properties after bleaching. The oxidative ability of the individual mediators used (acetosyringone, syringaldehyde, p-coumaric acid, vanillin and actovanillone) and the laccase-mediator systems was determined by monitoring the oxidation-reduction potential (ORP) during process. The results confirmed the production of phenoxy radicals of variable reactivity and stressed the significant role of lignin structure in the enzymatic process. Although changes in ORP were correlated with the oxidative ability of the mediators, pulp properties as determined after the bleaching stage were also influenced by condensation and grafting reactions. As shown here, ORP measurements provide a first estimation of the delignification efficiency of a laccase-mediator system

    In this work, kenaf pulp was delignified by using laccase in combination with various redox mediators and the efficiency of the different laccase–mediator systems assessed in terms of the changes in pulp properties after bleaching. The oxidative ability of the individual mediators used (acetosyringone, syringaldehyde, p-coumaric acid, vanillin and actovanillone) and the laccase–mediator systems was determined by monitoring the oxidation–reduction potential (ORP) during process. The results confirmed the production of phenoxy radicals of variable reactivity and stressed the significant role of lignin structure in the enzymatic process. Although changes in ORP were correlated with the oxidative ability of the mediators, pulp properties as determined after the bleaching stage were also influenced by condensation and grafting reactions. As shown here, ORP measurements provide a first estimation of the delignification efficiency of a laccase–mediator system.

  • Enzymatically treated sulphite pulp to give dissolving-pulp characteristics

     Quintana Vilajuana, Elisabet; Valls Vidal, Cristina; Vidal Llucia, Teresa; Roncero Vivero, Maria Blanca
    International Symposium on Wood, Fiber and Pulping Chemistry
    Presentation's date: 2013
    Presentation of work at congresses

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    Bleached cellulose with good end-properties (~90% ISO brightness, < 0.5 kappa number and substantially preserved cellulose integrity) was obtained by using a totally chlorine-free (TCF) biobleaching sequence. The initial pulp was subjected to an overall LQPo sequence. Unbleached sulphite cellulose was treated with Trametes villosa laccase (L) in combination with violuric acid (VA). This enzymatic stage was followed by a chelating stage (Q) and then by a hydrogen peroxide stage reinforced with pressurized oxygen (Po). The use of violuric acid was dictated by the results of a preliminary study, where the bleaching efficiency of various natural (syringaldehyde and pcoumaric acid) and synthetic mediators (violuric acid and 1-hydroxybenzotriazole) were assessed. The outstanding results obtained with laccase-violuric acid system fulfil the characteristics of commercial dissolving-grade pulp with the added advantage that the enzymatic treatment saved 2h of reaction time and about 70% of hydrogen peroxide consumption, relative to a conventional hydrogen peroxide sequence (Po)

    Bleached cellulose with good end-properties (~90% ISO brightness, < 0.5 kappa number and substantially preserved cellulose integrity) was obtained by using a totally chlorine-free (TCF) biobleaching sequence. The initial pulp was subjected to an overall LQPo sequence. Unbleached sulphite cellulose was treated with Trametes villosa laccase (L) in combination with violuric acid (VA). This enzymatic stage was followed by a chelating stage (Q) and then by a hydrogen peroxide stage reinforced with pressurized oxygen (Po). The use of violuric acid was dictated by the results of a preliminary study, where the bleaching efficiency of various natural (syringaldehyde and pcoumaric acid) and synthetic mediators (violuric acid and 1-hydroxybenzotriazole) were assessed. The outstanding results obtained with laccase-violuric acid system fulfil the characteristics of commercial dissolving-grade pulp with the added advantage that the enzymatic treatment saved 2h of reaction time and about 70% of hydrogen peroxide consumption, relative to a conventional hydrogen peroxide sequence (Po)

  • High cellulose-content alkaline pulps obtained by enzyme-assisted hemicelluloses removal

     Beltramino Heffes, Facundo; Valls Vidal, Cristina; Vidal Llucia, Teresa; Roncero Vivero, Maria Blanca
    International Symposium on Wood, Fiber and Pulping Chemistry
    Presentation's date: 2013
    Presentation of work at congresses

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    Several procedures have been studied in order to carry out the necessary modifications to ¿upgrade¿ paper-grade pulps to dissolving grade including various chemical and biotechnological procedures. Among the last ones, enzymes, and particularly xylanases have a special interest due to their specificity characteristics. In the present work, xylanases are applied on a bleached alkaline pulp (lignin content close to 1%) in order to eliminate xylans. To achieve the highest purity grade, it is desirable to remove as much hemicelluloses as possible. Xylanases are applied on a TCF bleached nonwood NaOH-AQ pulp from Sisal (Agave Sisalana) at different conditions (xylanase dose, reaction time and procedure). The aim of this research is to find the best conditions for this application and establish an enzymatic procedure for obtaining pulps with low xylans content from bleached alkaline pulps. And as a consequence, obtain high cellulose-content fibers with longer durability and improved characteristics

  • Functionalization of cellulosic substrates using a product derived from an enzymatic reaction

     Cusola Aumedes, Oriol; Valls Vidal, Cristina; Vidal Llucia, Teresa; Roncero Vivero, Maria Blanca
    International Symposium on Wood, Fiber and Pulping Chemistry
    Presentation's date: 2013
    Presentation of work at congresses

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    The present work describes a new method for the surface functionalization of cellulosic sheets, overcoming the limitations of the traditional treatments, which are usually performed using fibrous suspensions. The method consists in obtaining a product (post-enzymatic) derived from an enzymatic reaction using Laccase and a compound showing a specific property. The obtained product, which has aqueous consistency, is then applied to the surface of a finished paper sheet (or cellulosic substrate) by means of impregnation, spray, size-press, or other available surface deposition technique used in the industry. The functionalization is produced by means of physicochemical interaction between the product and the substrate. In the present research, the methodology is developed to achieve the hydrophobization of finished paper sheets using Lauryl Gallate (LG) as hydrophobic compound, and a laccase derived from Trametes Villosa, reaching absorption times of up to 4000 s and CA values around 130° as assessed by the water drop test (WDT) and contact angle measurements (CA) respectively.

    The present work describes a new method for the surface functionalization of cellulosic sheets, overcoming the limitations of the traditional treatments, which are usually performed using fibrous suspensions. The method consists in obtaining a product (post-enzymatic) derived from an enzymatic reaction using Laccase and a compound showing a specific property. The obtained product, which has aqueous consistency, is then applied to the surface of a finished paper sheet (or cellulosic substrate) by means of impregnation, spray, size-press, or other available surface deposition technique used in the industry. The functionalization is produced by means of physicochemical interaction between the product and the substrate. In the present research, the methodology is developed to achieve the hydrophobization of finished paper sheets using Lauryl Gallate (LG) as hydrophobic compound, and a laccase derived from Trametes Villosa, reaching absorption times of up to 4000 s and CA values around 130° as assessed by the water drop test (WDT) and contact angle measurements (CA) respectively

  • Laccase for biobleaching of eucalypt kraft pulp by means of a modified industrial bleaching sequence

     Moldes, Diego; Vidal Llucia, Teresa
    Biotechnology progress
    Vol. 28, num. 5, p. 1225-1231
    DOI: 10.1002/btpr.1594
    Date of publication: 2012-09
    Journal article

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    Biobleaching of kraft pulp is a possible application of laccase, but it has not been described in detail for complete industrial bleaching sequences yet. Therefore, in this work, the biobleaching of Eucalyptus globulus kraft pulp was performed using a modified industrial totally chlorine-free sequence. The modification consisted in the substitution of an enzymatic delignification stage, based on the application of laccase from Trametes villosa, for the first alkaline extraction one. The enzymatic stage was performed with several synthetic and natural mediators, namely 1-hydroxybenzotriazole (HBT), violuric acid (VA), methyl syringate, and syringaldehyde. Several pulp properties were analyzed after each stage of the bleaching process¿kappa number, ISO brightness, viscosity, and optical properties of CIEL*a*b* system. The new biobleaching sequence improved the pulp properties, in comparison to the conventional bleaching sequence, if HBT or VA was used as mediators. VA was selected as the best mediator of those tested and the effect of its concentration in the enzymatic stage was subsequently studied. Reducing the initial concentration by 30%, the same pulp quality was obtained, but if the reduction attained 60%, an important decrease in pulp integrity was detected. The modified bleaching sequence could improve the bleached pulp properties (kappa number 10%, ISO brightness 1%, and viscosity 5%) in comparison to the mill sequence

    Biobleaching of kraft pulp is a possible application of laccase, but it has not been described in detail for complete industrial bleaching sequences yet. Therefore, in this work, the biobleaching of Eucalyptus globulus kraft pulp was performed using a modified industrial totally chlorine-free sequence. The modification consisted in the substitution of an enzymatic delignification stage, based on the application of laccase from Trametes villosa, for the first alkaline extraction one. The enzymatic stage was performed with several synthetic and natural mediators, namely 1-hydroxybenzotriazole (HBT), violuric acid (VA), methyl syringate, and syringaldehyde. Several pulp properties were analyzed after each stage of the bleaching process—kappa number, ISO brightness, viscosity, and optical properties of CIEL*a*b* system. The new biobleaching sequence improved the pulp properties, in comparison to the conventional bleaching sequence, if HBT or VA was used as mediators. VA was selected as the best mediator of those tested and the effect of its concentration in the enzymatic stage was subsequently studied. Reducing the initial concentration by 30%, the same pulp quality was obtained, but if the reduction attained 60%, an important decrease in pulp integrity was detected. The modified bleaching sequence could improve the bleached pulp properties (kappa number 10%, ISO brightness 1%, and viscosity 5%) in comparison to the mill sequence

  • BIO2011-15394-E. Biotecnología de Materiales Lignocelulósicos. Retos enzimáticos, químicos y moleculares para su aplicación industrial, energética y medioambiental

     Camarero, Susana; Vidal Llucia, Teresa; Roncero Vivero, Maria Blanca; Valls Vidal, Cristina; Cusola Aumedes, Oriol; Quintana Vilajuana, Elisabet; Beltramino Heffes, Facundo
    Competitive project

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  • Application of laccase-based systems for biobleaching and functionalization of sisal fibres  Open access  awarded activity

     Aracri, Elisabetta
    Department of Textile and Paper Engineering, Universitat Politècnica de Catalunya
    Theses

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    This research project originated from interest in assessing the potential of enzyme technology (particularly laccase-based systems) for the biomodification of sisal specialty fibres by using environmentally friendly processes. This doctoral work focused on two different research lines, namely: biobleaching and enzymatic functionalization of sisal pulp fibres. The study was started by assessing the use of natural, potentially cost-effective phenolic compounds as substitutes for expensive, potentially toxic laccase mediators. The tendency of natural phenols to either promote delignification or couple onto pulp was examined with a view to assessing their potential for either bleaching or functionalizing sisal fibres. In the biobleaching study, totally chlorine free (TCF) sequences were implemented in order to compare the efficiency of a selected natural mediator and a well-known synthetic mediator, both in the presence and absence of a xylanase pre-treatment. The effluents resulting from each stage in the sequence were analysed with a view to assessing the environmental impact of the laccase treatments ¿a scarcely explored aspect of biobleaching sequences. The xylanase stage proved highly efficient in reducing the HexA content of sisal fibres and in boosting the bleaching effect of the laccase treatments. The proposed TCF sequences provided high-cellulose sisal pulp with brightness above 80% ISO and a reduced HexA content; also, they exhibited improved performance and a reduced impact on effluent properties relative to the use of the synthetic mediator. Two different approaches to fibre functionalization were explored, namely: lignin modification (biografting) and cellulose modification (laccase¿TEMPO oxidation). Biografting of phenolic compounds was for the first time studied in sisal pulp. Covalent binding of the originally assayed phenolic compounds to sisal fibres during the laccase treatment was exposed by a novel analytical approach based on pyrolysis-GC/MS. The phenolic compound showing the highest tendency to couple to fibres was selected to investigate biografting under different reaction conditions and to evaluate the extent of phenol coupling via various pulp properties. Biografting efficiency was enhanced by refining the fibres prior to the enzyme treatment, which provided improved strength-related properties in the resulting paper. The use of the laccase-TEMPO system to oxidatively modify cellulose and improve strength-related properties in sisal pulp was for the first time evaluated as an environmentally friendly alternative to existing halide-based systems. The first part of this study revealed that the laccase¿TEMPO system considerably improved wet strength in sisal pulp by effect of the formation of a substantial amount of aldehyde groups in cellulose chains that facilitated inter-fibre bonding through hemiacetal linkages. The influence of process variables on various properties of the oxidized fibres and resulting paper was assessed by using a three-variable statistical plan. The conditions maximizing functionalization and the improvement in paper strength properties were used to design treatments of increased efficiency that exposed the potential of laccase¿TEMPO oxidation for biorefining pulp fibres. Analytical methods including pyrolysis-GC/MS, polyelectrolyte titration, conductimetric titration, carbohydrate determination by HPLC, fibre morphology analysis by SEM and thermogravimetry were used to both characterize the raw material and gain a better understanding of the reaction mechanisms behind the different laccase-based treatments. Some of the analyses were performed by collaborating research groups at IRNAS (Seville, Spain) and the Department of Chemical Engineering of the University of Huelva (Spain). Also, part of this doctoral work was conducted at the Institute of Paper Science and Technology of the Georgia Institute of Technology (Atlanta, USA).

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    Nanofibrillated cellulose (NFC) as a potential reinforcement for high performance cement mortar composites  Open access

     Ardanuy Raso, Monica; Claramunt Blanes, Josep; Arevalo Peces, Raquel; Pares Sabates, Ferran; Aracri, Elisabetta; Vidal Llucia, Teresa
    Bioresources
    Vol. 7, num. 3, p. 3883-3894
    Date of publication: 2012-07-09
    Journal article

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    In this work, nanofibrillated cellulose (NFC) has been evaluated as a potential reinforcement for cement mortar composites. Two types of vegetable fibres with different composition and properties (cellulose content and microfibrillar angle), sisal, and cotton linters pulps, were initially characterized in order to assess their reinforcement capability. Sisal pulp was found to be most suitable as reinforcement for their brittle cementitious matrix. Nanofibrillated cellulose was produced by the application of a high intensity refining process of the sisal pulp. It was found that 6 hours of refining time was required to obtain the desired nanofibrillation of the fibers. Cement mortar composites reinforced with both the sisal fibers and the nanofibrillated cellulose were prepared, and the mechanical properties were determined under flexural test. The cement mortar composites reinforced with the nanofibrillated cellulose exhibited enhanced flexural properties, but lower values of fracture energy, than the ones reinforced with the conventional sisal fibres.

  • A new procedure for the hydrophobization of cellulose fibre using laccase and a hydrophobic phenolic compound

     Garcia Ubasart, Jordi; Colom Pastor, Josep Francesc; Vila, Carlos; Gomez Hernandez, Núria; Roncero Vivero, Maria Blanca; Vidal Llucia, Teresa
    Bioresource technology
    Vol. 112, p. 341-344
    DOI: 10.1016/j.biortech.2012.02.075
    Date of publication: 2012-05
    Journal article

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    A new biotechnological procedure using laccase in combination with a hydrophobic phenolic compound (lauryl gallate) for the hydrophobization of cellulose fibres and internal sizing of paper was developed. Cellulose fibres from hardwood kraft pulp were incubated with laccase (Lac), in combination with lauryl gallate (LG). The Lac-LG treatment resulted in the internal sizing of paper, and also in significantly reduced water penetration in the handsheets and wettability of the paper surface. Paper was found not to be effectively rendered hydrophobic by LG alone. SEM images of the fibre network revealed the presence of the sizing agent: a product of the reaction between laccase and lauryl gallate. Binding of lauryl gallate to cellulose fibres was suggested by the increase in kappa number of the pulp and further confirmed by IR spectroscopy

  • Comparative Study of the Effects Induced by Different Laccase-Based Systems on Sisal Cellulose Fibers

     Aracri, Elisabetta; Barneto, A. G.; Vidal Llucia, Teresa
    Industrial & engineering chemistry research
    Vol. 51, num. 10, p. 3895-3902
    DOI: 10.1021/ie2028206
    Date of publication: 2012-03-14
    Journal article

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  • Enhancing the effectiveness of a laccase¿TEMPO treatment has a biorefining effect on sisal cellulose fibres

     Aracri, Elisabetta; Vidal Llucia, Teresa
    Cellulose
    Vol. 19, num. 3, p. 867-877
    DOI: 10.1007/s10570-012-9686-4
    Date of publication: 2012-03-09
    Journal article

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  • Investigating the structure-effect relationship of various natural phenols used as laccase mediators in the biobleaching of kenaf and sisal pulps

     Barneto, A. G.; Aracri, Elisabetta; Andreu Terren, Maria Gloria; Vidal Llucia, Teresa
    Bioresource technology
    Vol. 112, p. 327-335
    DOI: 10.1016/j.biortech.2012.02.136
    Date of publication: 2012-03
    Journal article

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  • Elucidating the effects of laccase-modifying compounds treatments on bast and core fibers in flax pulp

     Fillat Latorre, Amanda; Roncero Vivero, Maria Blanca; Vidal Llucia, Teresa
    Biotechnology and bioengineering
    Vol. 109, num. 1, p. 225-233
    DOI: 10.1002/bit.23278
    Date of publication: 2012-01
    Journal article

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  • Effect of residual lignin and heteropolysaccharides in nanofibrillar cellulose and nanopaper from wood fibers

     Ferrer Carrera, Ana; Quintana Vilajuana, Elisabet; Filpponen, Ilari; Solala, Iina; Vidal Llucia, Teresa; Rodríguez Pascual, Alejandro; Laine, Janne; Rojas, Orlando J.
    Cellulose
    Vol. 19, num. 6, p. 2179-2193
    DOI: 10.1007/s10570-012-9788-z
    Date of publication: 2012-12
    Journal article

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    Unbleached (UN), oxygen-delignified and fully-bleached (FB) birch fibers with a residual lignin content of ca. 3, 2 and\1 %, respectively, were used to produce nanofibrillated cellulose (NFC) and nanopaper by using an overpressure device. The tensile index, elongation and elastic modulus of nanopaper were compared and the effect of residual cellwall components accessed. Under similar manufacturing conditions, UN NFC produced nanopaper with a density of 0.99 g/cm3, higher than that from FB NFC (0.7 g/cm3). This translated in much lower air permeability in the case of UN nanopaper (1 and 11 mL/min for UN and FB samples, respectively). Fundamentally, these observations are ascribed to the finer fibrils produced during microfluidization of UN fibers compared to those from lower yield counterparts(AFMroughness of 8 and 17 nm and surface areas of 124 and 98 m2/g for NFC from UN and FBfibers, respectively).As a result, values of stress at break and energy absorption of nanopaper from high yield fibers are distinctively higher than those from fully bleached NFC. Interactions of water with the surface and bulk materialwere affected by the chemical composition and structure of the nanofibrils. While UN nanopaper presented higher water contact angles their sorption capacity (and rate of water absorption) was much higher than thosemeasured for nanopaper from FB NFC. These and other observations provided in this contribution are proposed to be related to the mechanoradical scavenging capacity of lignin in high shear microfluidization and the presence of residual heteropolysaccharides.

    Unbleached (UN), oxygen-delignified and fully-bleached (FB) birch fibers with a residual lignin content of ca. 3, 2 and\1 %, respectively, were used to produce nanofibrillated cellulose (NFC) and nanopaper by using an overpressure device. The tensile index, elongation and elastic modulus of nanopaper were compared and the effect of residual cellwall components accessed. Under similar manufacturing conditions, UN NFC produced nanopaper with a density of 0.99 g/cm3, higher than that from FB NFC (0.7 g/cm3). This translated in much lower air permeability in the case of UN nanopaper (1 and 11 mL/min for UN and FB samples, respectively). Fundamentally, these observations are ascribed to the finer fibrils produced during microfluidization of UN fibers compared to those from lower yield counterparts(AFMroughness of 8 and 17 nm and surface areas of 124 and 98 m2/g for NFC from UN and FBfibers, respectively).As a result, values of stress at break and energy absorption of nanopaper from high yield fibers are distinctively higher than those from fully bleached NFC. Interactions of water with the surface and bulk materialwere affected by the chemical composition and structure of the nanofibrils. While UN nanopaper presented higher water contact angles their sorption capacity (and rate of water absorption) was much higher than thosemeasured for nanopaper from FB NFC. These and other observations provided in this contribution are proposed to be related to the mechanoradical scavenging capacity of lignin in high shear microfluidization and the presence of residual heteropolysaccharides

  • Enzymatic grafting of natural phenols to flax fibres: development of antimicrobial properties

     Fillat Latorre, Amanda; Gallardo Román, Óscar; Vidal Llucia, Teresa; Pastor Blasco, F.I. Javier; Díaz Lucea, Pilar; Roncero Vivero, Maria Blanca
    Carbohydrate polymers
    Vol. 87, num. 1, p. 146-152
    DOI: 10.1016/j.carbpol.2011.07.030
    Date of publication: 2012-01-04
    Journal article

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    Unbleached flax fibres for paper production were treated with laccase from Pycnoporus cinnabarinus and low molecular weight phenols (syringaldehyde – SA, acetosyringone – AS and p-coumaric acid – PCA) to evaluate the potential of this treatment to biomodify high cellulose content fibres. After the enzymatic treatment with the phenols, an increase in kappa number was found, probably due to a covalent binding of the phenoxy radicals on fibres. Grafting was more evident in pulps treated with PCA (an increase of 4 kappa number points with respect to the laccase control was achieved). Paper handsheets from treated pulps showed antimicrobial activity against the bacteria tested: Staphylococcus aureus, Pseudomonas aeruginosa and Klebsiella pneumoniae. An important reduction on microbial count was obtained after incubation of liquid cultures of the bacteria with grafted handsheets. AS and PCA grafted fibres showed a high antibacterial activity on K. pneumoniae, getting a nearly total growth inhibition. AS fibres also caused a high reduction in bacterial population of P. aeruginosa (97% reduction). Optical properties of handsheets from treated pulps were also determined, showing a brightness decrease and increase in coloration, evaluated by CIE L*a*b* system, caused by the laccase induced grafting of the phenols. The results suggest that these low molecular weight phenols, covalently bound to the flax fibres by the laccase treatment, can act as antimicrobial agents and produce handsheets with antimicrobial activity

  • Paper strength improvement by oxidative modification of sisal cellulose fibres with laccase-TEMPO system: Influence of the process variables

     Aracri, Elisabetta; Valls Vidal, Cristina; Vidal Llucia, Teresa
    Carbohydrate polymers
    Vol. 88, num. 3, p. 830-837
    DOI: 10.1016/j.carbpol.2012.01.011
    Date of publication: 2012-01-04
    Journal article

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  • Biorefining of sisal pulp fibres by effect of a laccase-TEMPO treatment of enhanced effectiveness

     Aracri, Elisabetta; Vidal Llucia, Teresa
    International Symposium on Paradigms for the Pulp and Paper Industry in the XXI Century: Opportunities for a Sustainable Future
    Presentation's date: 2012-06-25
    Presentation of work at congresses

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  • Lignin and cellulose nanofibers and nanoparticles from pulping streams: developments and applications

     Ago, Mariko; Silveira, Joao; Taajamaa, Laura; Quintana Vilajuana, Elisabet; Ferrer Carrera, Ana; Filipponen, Ilari; Jakes, Joseph E.; Kontturi, Eero; Vidal Llucia, Teresa; Jiménez Alcaide, Luis; Rodríguez Pascual, Alejandro; Bittencourt, Edison; Laine, Janne; Rojas, Orlando J.
    International Symposium on Paradigms for the Pulp and Paper Industry in the XXI Century: Opportunities for a Sustainable Future
    Presentation's date: 2012-06-26
    Presentation of work at congresses

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  • Blanqueo de pastas al sulfito mediante tratamientos enzimáticos con lacasa

     Quintana Vilajuana, Elisabet; Valls Vidal, Cristina; Vidal Llucia, Teresa; Roncero Vivero, Maria Blanca
    Reunión de la Red Temática Española Lignocel
    Presentation's date: 2012-11
    Presentation of work at congresses

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  • Nanofibrillated cellulose as reinforcement for high performance cement mortar composites

     Ardanuy Raso, Monica; Claramunt Blanes, Josep; Pares Sabates, Ferran; Aracri, Elisabetta; Vidal Llucia, Teresa
    European Conference on Composite Materials
    p. 1-6
    Presentation's date: 2012-06-25
    Presentation of work at congresses

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  • Funcionalización de sustratos celulósicos mediante un producto derivado de una reacción enzimática

     Cusola Aumedes, Oriol; Valls Vidal, Cristina; Vidal Llucia, Teresa; Roncero Vivero, Maria Blanca
    Reunión de la Red Temática Española Lignocel
    DOI: BIO2011-15394-E
    Presentation's date: 2012-11-14
    Presentation of work at congresses

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  • Paper functionalization by means of enzymatic surface treatments using hydrophobic compounds and lignosulfonates

     Cusola Aumedes, Oriol; Garcia Ubasart, Jordi; Valls Vidal, Cristina; Vidal Llucia, Teresa; Roncero Vivero, Maria Blanca
    European Workshop on Lignocellulosics and Pulp
    p. 146-149
    Presentation's date: 2012-08-30
    Presentation of work at congresses

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    In the present work an innovative method for achieving enzymatic surface functionalization on finished paper sheets is presented. A commercial filter paper was surface sized with laccase derived from Trametes Villosa, Lauryl Gallate (LG) as hydrophobic compound, and soluble lignin. Moreover, this study shows the positive influence of sulfonated lignin (SL) acting as a dispersant improving the surface distribution of the LG along the paper sheet. The hydrophobic behavior of obtained sheets is comparable to the commercial ones. Hydrophobicity was measured by the water absorption test, and the variation in the contact angle through time was monitorized by a contact angle goniometer. Hydrophobized paper absorption was compared with Teflon® in order to determine the evaporated and absorbed water amounts from the paper surface. The treatment time, was also studied

    Postprint (author’s final draft)

  • Preparación enzimática acuosa aislada y su uso para la funcionalización de la superficie del papel o soportes celulósicos

     Cusola Aumedes, Oriol; Roncero Vivero, Maria Blanca; Valls Vidal, Cristina; Vidal Llucia, Teresa
    Date of request: 2012-06-04
    Invention patent

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    Preparación enzimática acuosa aislada y uso para la funcionalización de la superficie del papel o soportes celulósicos.

    En un primer aspecto, la presente invención se refiere a una preparación enzimática acuosa aislada obtenida a partir de la reacción de por lo menos una enzima oxidorreductasa, preferiblemente una lacasa, y por lo menos un producto natural o sintético, preferiblemente un compuesto natural, cuyo producto natural o sintético comprende en su estructura por lo menos un grupo fenol o alcohol, que opcionalmente tiene una o más cadenas hidrofóbicas, o por lo menos un grupo esterol.

    En un segundo aspecto, la presente invención se refiere a la utilización de dicha preparación enzimática acuosa aislada en la funcionalización de la superficie del papel o soportes celulósicos.

  • NUEVOS PROCESOS OBTENCION PRODUCTOS CELULOSICOS ALTO VALOR AÑADIDO

     Torres Lopez, Antonio Luis; Fillat Latorre, Amanda; Garcia Ubasart, Jordi; Cusola Aumedes, Oriol; Vidal Llucia, Teresa
    Competitive project

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  • Flax fibre modification using enzyme systems to obtain high-value cellulose products  Open access  awarded activity

     Fillat Latorre, Amanda
    Department of Textile and Paper Engineering, Universitat Politècnica de Catalunya
    Theses

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    The aim of this thesis is to modify flax pulp fibres (Linum usitatissimum) by more friendly environmental processes. Pulp and paper research is focussing through enzyme systems investigation for developing green chemistry technologies due to existing environmental concerns and to legal restrictions. Moreover, it exists also an increasing strategic interest in using flax fibres to obtain high-quality specialty papers. That is why we study the application of biotechnology as an efficient alternative to traditional industrial processes based on the use of chemical agents. This work is framed by two of the main research topics of the Paper and Graphic Specialty Laboratory in the Textile and Paper Engineering Department of the Universitat Politècnica de Catalunya. One research line is based on pulp bleaching and is focused basically on the study of enzymatic systems as biobleaching agents; the other research topic that has been recently introduced in our investigation group is the use of enzymes as functionalisation agents by promoting the grafting of several compounds. Laccase is the main enzyme used in this thesis; it is an oxidoreductase that can assist reactions in an eco-friendly way since laccase uses air and produces water as the only by-product. Moreover, laccase can work under mill conditions and has wide application potential. The first part of this thesis involved the use of enzymes to bleach flax pulp. The aim was to explore the potential of various natural mediators (lignin-derived compounds) for delignifying flax fibres in order to identify the most efficient and ecofriendly choice among them. Afterwards, we assessed the use of various enzyme delignification stages in an industrial bleaching sequence. The ensuing totally chlorine free (TCF) sequence comprised various laccase-mediator system treatments (L stage) followed by a by a chelating stage (Q stage) and a subsequent bleaching step with hydrogen peroxide (Po stage). A xylanase pretreatment was additionally carried out. Laccases used came from the fungi Pycnoporus cinnabarinus and Myceliophthora thermophila; the performance of several natural mediators was compared with the obtained with the application of various synthetic mediators. In addition, the lack of studies on the properties of effluents from the treatment of non-wood pulp with laccase and natural mediators led A-1 A-2 us to examine effluent properties upon biotreatments and after different bleaching stages. The results obtained warrant upscaling any of the biobleaching sequences for flax pulp as they provide sustainable flax fibre with a high cellulose content and brightness above 80% ISO. The use of xylanase pretreatment was found to efficiently remove HexA and enhance delignification by laccase.