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  • 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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  • 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

  • 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

  • A facile and green method to hydrophobize films of cellulose nanofibrils and silica by laccase-mediated coupling of nonpolar colloidal particles

     Cusola Aumedes, Oriol; Roncero Vivero, Maria Blanca; Vidal Llucia, Teresa; Rojas, Orlando J.
    ChemSusChem (Weinheim. Print)
    Vol. 7, num. 10, p. 2868-2878
    DOI: 10.1002/cssc.201402432
    Date of publication: 2014-10-01
    Journal article

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    Hydrophobic particles based on dodecyl 3,4,5-trihydroxybenzoate (LG) were coupled onto the surface of cellulose nanofibrils (CNFs) and silica by treatment with a multicomponent colloidal system (MCS) derived from the laccase-mediated reaction of LG in the presence of a sulfonated lignin (SL). Surface modification upon treatment with MCS was monitored insitu and in real time by quartz crystal microgravimetry. The colloidal stability of MCS and its components in water was followed by measuring space- and time-resolved light transmission and back scattering. The sulfonated lignin increased dispersion stability and reduced the characteristic MCS particle size [from approximate to 4 to approximate to 80nm, according to AFM and dynamic light scattering (DLS)]. It also facilitated the surface enzymatic reaction that led to adsorption and coupling of MCS onto CNFs and silica surfaces. The combined effect of reduced surface energy and surface roughness by MCS treatment produced an increase in water contact angle on CNFs and silica of about 90 and 80 degrees, respectively. Surface pretreatment with chitosan further increased the extent of MCS adsorption on the surfaces. This method represents a sustainable alternative to traditional approaches for cellulose hydrophobization and a step forward in implementing green routes for surface modification.

  • Inter-laboratory comparisons of hexenuronic acid measurements in kraft eucalyptus pulps using a UV-Vis spectroscopic method

     Zhu, Yufan; Zhou, H.F; Chai, X.S; Johannes, Donna; Pope, Richard; Valls Vidal, Cristina; Roncero Vivero, Maria Blanca
    TAPPI journal
    Vol. 13, num. 1, p. 57-61
    Date of publication: 2014-01-01
    Journal article

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    An inter-laboratory comparison of a UV-Vis spectroscopic method (TAPPI T 282 om-13 "Hexeneuronic acid content of chemical pulp") for hexeneuronic acid measurements was conducted using three eucalyptus kraft pulps. The pulp samples were produced in a laboratory at kappa numbers of approximately 14, 20, and 35. The hexeneuronic acid contents of the three pulps were approximately 55-65 mu mol/g, or with a variation of approximately 15%. Five laboratories from four different countries participated in this round-robin study as part of the evaluation of the TAPPI provisional method for upgrading to a TAPPI standard method. The comparative study showed that the orders of hexeneuronic acid content from low to high among the three pulp samples produced by four laboratories were in agreement. Replicate measurements were not conducted at the laboratory that produced an inconsistent order of hexeneuronic acid among the three pulp samples compared with the other four laboratories. The differences in hexeneuronic acid contents from different laboratories were systematic and consistent; that is, some laboratories consistently produced high values of hexeneuronic acid for all three samples. The comparative data of three pulp samples concluded that the measurement repeatability (within a laboratory) was less than 3% and reproducibility (among laboratories) was less than 16%.

    An inter-laboratory comparison of a UV-Vis spectroscopic method (TAPPI T 282 om-13 “Hexeneuronic acid content of chemical pulp”) for hexeneuronic acid measurements was conducted using three eucalyptus kraft pulps. The pulp samples were produced in a laboratory at kappa numbers of approximately 14, 20, and 35. The hexeneuronic acid contents of the three pulps were approximately 55–65 μmol/g, or with a variation of approximately 15%. Five laboratories from four different countries participated in this round-robin study as part of the evaluation of the TAPPI provisional method for upgrading to a TAPPI standard method. The comparative study showed that the orders of hexeneuronic acid content from low to high among the three pulp samples produced by four laboratories were in agreement. Replicate measurements were not conducted at the laboratory that produced an inconsistent order of hexeneuronic acid among the three pulp samples compared with the other four laboratories. The differences in hexeneuronic acid contents from different laboratories were systematic and consistent; that is, some laboratories consistently produced high values of hexeneuronic acid for all three samples. The comparative data of three pulp samples concluded that the measurement repeatability (within a laboratory) was less than 3% and reproducibility (among laboratories) was less than 16%. Application: Analytical test laboratories, pulp mills, and research organizations can use the information in this paper for chemical pulp analysis

  • 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

  • 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

  • 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

  • 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)

  • 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

  • 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

  • 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

  • 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)

  • 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

  • Surface functionalization of cellulosic substrates by using chemical and biotechnological methods.

     Cusola Aumedes, Oriol
    Universitat Politècnica de Catalunya
    Theses

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    La present tesi tracta sobre la modificació superficial de substrats cel·lulòsics utilitzant mètodes químics i enzimàtics. Lafuncionalització de la cel¿lulosa consisteix en ajustar-ne les seves propietats, per a poder-la utilitzar en gran varietatd'aplicacions. Habitualment aquesta modificació s'aconsegueix tractant les fibres en suspensió aquosa i abans de laformació del substrat. No obstant, en la present tesi els tractaments s'apliquen utilitzant substrats cel¿lulòsics ja formats(FCS), obtenint una sèrie d'avantatges en termes de formació, consum de químics, i velocitat de fabricació. S¿han estudiatdos enfocaments diferents per a la funcionalització: tècniques no-enzimàtiques i enzimàtiques. Els esforços s¿han centrat enl'enfoc enzimàtic.Aquest treball es va dur a terme en el grup de recerca CELBIOTECH (UPC-BarcelonTech), en el marc dels projectesFUNCICEL (CTQ2009-12904) , BIOSURFACEL (CTQ2012-34109) , BIOFIBRECELL (CTQ2010-20238-CO3-01), del MICINNEspanyol i el Projecte integrat BIORENEW (NMP2-CT-2006-026456) del sisè Programa Marc.Pel que fa a la funcionalització no-enzimàtica, s¿han utilitzat -ciclodextrines (-CD) per a la modificació superficial de tresFCS comercials. L'empelt s¿ha avaluat mitjançant microscòpia electrònica de rastreig i anàlisi FTIR. Els substrats empeltatsamb -CDs s¿han carregat amb digluconat de clorhexidina (digCHX), i s¿ha analitzat l¿alliberament d¿aquest principi actiuutilitzant espectroscòpia UV. Diversos substrats han estat capaços de retenir quantitats significatives de digCHX, i demantenir-ne l¿alliberament durant períodes de temps de fins a 20 dies.La funcionalització enzimàtica per al desenvolupament de derivats de la cel·lulosa ha guanyat interès en la comunitatcientífica i industrial darrerament. No obstant, l'ús de sistemes enzimàtics superficials encara es troba en una fase moltprematura; la present tesi fa èmfasi en aquest aspecte. En un primer estudi s¿analitza la hidrofobització superficial de FCScomercials, mitjançant una lacasa en combinació amb compostos hidròfobs. L'eficiència s¿ha vist augmentada amb l'ús delignosulfonats (SL), els quals milloren la distribució superficial, augmenten els nivells d¿hidrofobicitat, i ajuden a preservarl'activitat enzimàtica. La dosi de LG i el temps de tractament s¿han optimitzat resultant en una major hidrofobicitat.Seguidament, els tractaments han evolucionat cap a un nou mètode basat en l¿obtenció d'una solució funcionalitzadora (FS),consistent en un producte derivat d¿una reacció enzimàtica, el qual és aplicat posteriorment a la superfície dels FCS. Aquestmètode també s¿ha mostrat efectiu, i proporciona avantatges importants respecte a la possible aplicació industrial; de fet, elnou mètode ha permès realitzar una sol·licitud internacional de patent. L¿aplicació de la FS a la superfície de FCS elsconfereix propietats hidrofòbica i antioxidant gràcies a les interaccions fisicoquímiques que es produeixen. S¿han utilitzatsuperfícies model de cel·lulosa per tal d¿avaluar l'adsorció de la FS, i s¿han emprat les tècniques de WDT, WCA, SEM, AFM iSFE per caracteritzar-les. La força de l¿enllaç s¿avalua mitjançant rentats agressius i extraccions Soxhlet. Es demostra perprimer cop el potencial dels tractaments enzimàtics superficials per a conferir propietats avançades als substrats cel·lulòsics. La tècnica també s¿ha assajat emprant diverses lacases.S¿han utilitzat diverses tècniques d¿anàlisi per estudiar els mecanismes de reacció, i les interaccions FS-substrat. Lestècniques han estat: DLS, QCM, FTIR, espectroscopia UV-VIS, potencial-Z, Turbiscan® i Voltametria Cíclica. S¿ha proposatl¿estructura química de les molècules resultants de l¿oxidació del LG, els possibles mecanismes d'oxidació, i possiblesmecanismes d'empelt entre els compostos modificats i la cel·lulosa. També s¿ha analitzat l'efecte de la longitud de lacadena alquílica i dels tractaments tèrmics en les propietats antioxidant i hidrofòbica

  • Antioxidant property of TCF pulp with a high hexenuronic acid (HexA) content

     Valls Vidal, Cristina; Roncero Vivero, Maria Blanca
    Holzforschung
    Vol. 67, num. 3, p. 257-263
    DOI: 10.1515/hf-2012-0114
    Date of publication: 2013-04
    Journal article

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    Totally chlorine free (TCF) pulp with a high content of hexenuronic acids (HexAs) was found to possess a high antioxidant power. The contribution of HexA to kappa number in unbleached Eucalyptus globulus kraft pulp was estimated to be 1.05 units per 10 mu mol of HexA. The variation of HexA and lignin contents in enzymatic elemental chlorine free (ECF) and TCF sequences was monitored, and interesting effects were observed during the TCF XLE sequence, where X denotes an enzyme pretreatment with xylanase, L a laccase-mediator stage, and E an alkaline extraction stage. Thus, HexA removal during L stage was strongly enhanced after the X stage; also, the HexA content was decreased by the alkaline stage. None of these effects was observed in the ECF sequence with chlorine dioxide. The antioxidant power detected in HexA makes TCF pulp an excellent raw material for manufacturing packaging for easily oxidized products.

  • Obtaining biobleached eucalyptus cellulose fibres by using various enzyme combinations

     Valls Vidal, Cristina; Cadena Chamorro, Edith Marleny; Roncero Vivero, Maria Blanca
    Carbohydrate polymers
    Vol. 92, p. 276-282
    DOI: 10.1016/j.carbpol.2012.08.083
    Date of publication: 2013
    Journal article

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    Various combinations of laccases, xylanase and cellulase were used to biobleach cellulose fibres from eucalyptus. The Trametes villosa and Myceliophthora thermophila laccases were used in combination with violuric acid (VATvL system) and methyl syringate (MeSMtL system), respectively, as mediator. A dissimilar mode of action of the two systems was found: the VATvL treatment released both hexenuronic acids and lignin, whereas the MeSMtL released lignin alone. Pulp properties were further improved by applying the mediator before the enzyme during treatment. Pulp properties comparable to those provided by industrial TCF sequences were obtained by inserting a xylanase pretreatment before VATvL, but no significant effect was observed after the cellulase pretreatment. As an added value, the resulting enzymatically bleached fibres possess a reduced hexenuronic acid content. The chemical oxygen demand of the effluents from each stage was also assessed

  • Influence of enzyme and chemical adsorption on the thermal degradation path for eucalyptus pulp

     Barneto, A. G.; Valls Vidal, Cristina; Ariza Carmona, José; Roncero Vivero, Maria Blanca
    Thermochimica acta
    Vol. 551, p. 62-69
    DOI: 10.1016/j.tca.2012.10.019
    Date of publication: 2013
    Journal article

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    Changes in thermal degradation path of eucalyptus pulp support enzymes (laccase from Trametes villosa) and chemicals (Tris–HCl or tartrate–tartaric buffer) adsorption on cellulose during biobleaching, thereby increasing cellulose amount that degrades at low temperature and decreasing the apparent crystallinity (ApC) of cellulose crystallites. Changes in ApC, which can be assessed by thermogravimetric analysis—but not X-ray diffraction spectroscopy—affect cellulose volatilization; thus, the higher ApC is, the lower is char production and the higher the volatilization temperature. A linear relationship between ApC and the volatilization/charring ratio (V/C) was observed in this work

  • 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

  • A new use for TCF pulp with a high hexenuronic acid content

     Valls Vidal, Cristina; 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 importance of HexA groups lies on their influence on the bleaching process and the properties of the resulting pulp. In this work, various aspects of HexA were examined in order to elucidate their role in eucalyptus fibres. Thus, the contribution of HexA to kappa number in eucalyptus pulp was estimated to be 1.05 units per 10 µmol of HexA. Also, HexA changes during an ECF and a TCF sequence were examined in relation to lignin. Interesting results were found by comparing the boosting effect of xylanase and the impact of the alkaline stage in both sequences. The antioxidant activity of eucalyptus pulp with a variable HexA content was also measured. Although the presence of HexA in pulp has so far been deemed detrimental, HexA can have a favourable effect derived from their antioxidant ability. This property of HexA can be useful to obtain TCF paper for use in food packaging for easily oxidized products

    The importance of HexA groups lies on their influence on the bleaching process and the properties of the resulting pulp. In this work, various aspects of HexA were examined in order to elucidate their role in eucalyptus fibres. Thus, the contribution of HexA to kappa number in eucalyptus pulp was estimated to be 1.05 units per 10 μmol of HexA. Also, HexA changes during an ECF and a TCF sequence were examined in relation to lignin. Interesting results were found by comparing the boosting effect of xylanase and the impact of the alkaline stage in both sequences. The antioxidant activity of eucalyptus pulp with a variable HexA content was also measured. Although the presence of HexA in pulp has so far been deemed detrimental, HexA can have a favourable effect derived from their antioxidant ability. This property of HexA can be useful to obtain TCF paper for use in food packaging for easily oxidized products

  • 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

  • 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)

  • 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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  • Integrating a xylanase treatment into an industrial-type sequence for eucalyptus kraft pulp bleaching

     Fillat Latorre, Úrsula; Roncero Vivero, Maria Blanca; Sacón, Vera Maria; Bassa, Alexandre
    Industrial & engineering chemistry research
    Vol. 51, num. 7, p. 2830-2837
    DOI: 10.1021/ie202863d
    Date of publication: 2012-01-23
    Journal article

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    The influence of a treatment with two commercial xylanases on pulp and effluents obtained after the bleaching stages in the OXAZDP (O, oxygen stage; X, xylanase treatment; A, acid stage; Z, ozone stage; D, chlorine dioxide stage; P, hydrogen peroxide stage) sequence was studied. Also, the potential saving in chlorine dioxide was assessed. The enzyme treatment was performed on pulp containing some black liquor since the operating conditions were close to the conditions used in the storage tower in Fibria, identified as the most suitable point for application. The greatest differences in kappa number and hexenuronic acid content were observed after the X stage. Whereas, in brightness were observed after the Z stage. The effluent properties from the X stage were higher with the enzyme treatments. Also, the enzymes allowed chlorine dioxide consumption in the bleaching stage to be reduced. The control pulp contained twice as much adsorbable organic halides (AOX) and exhibited twice more brightness reversion than did the enzyme-treated samples. However, the tensile index and drainability at an identical degree of refining were lower in the enzyme-treated samples

  • 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

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    Simulation of bleaching of soda pulp from Hesperaloe funifera by polynomial and neural fuzzy models  Open access

     Rosal Raya, Antonio; Valls Vidal, Cristina; Roncero Vivero, Maria Blanca; Rodríguez Pascual, Alejandro
    Scientific research and essays
    Vol. 7, num. 40, p. 3357-3367
    DOI: 10.5897/SRE11.1749
    Date of publication: 2012
    Journal article

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    Influence of variables [soda, (0.5 to 3.0%), hydrogen peroxide (1.0 to 10.0%) and time (1 to 5 h)] in the bleaching of soda pulp of Hesperaloe funifera, on the properties of bleached pulps, was studied. Polynomial and neural fuzzy models had reproduced the results of Kappa number, brightness and viscosity of the pulps with errors less than 10 and 15%, respectively. By simulating the bleaching process of pulp H. funifera, with the polynomial and neural fuzzy models, the optimal values of operating variables can be found, so that the properties of bleached pulps differ little from their best values and instead will save chemical reagents, energy and plant size, operating with lower values of operating variables. Thus, by application of polynomial models, it was found that operating with a soda concentration of 0.5%, a hydrogen peroxide concentration of 5.5% and for a processing time of 3 h, it was possible to get a pulp with a brightness of 65.9% and a viscosity of 587 ml/g.

  • Assessing the environmental impact of biobleaching: effects of the operational conditions

     Valls Vidal, Cristina; Quintana Vilajuana, Elisabet; Roncero Vivero, Maria Blanca
    Bioresource technology
    Vol. 104, p. 557-564
    DOI: 10.1016/j.biortech.2011.10.044
    Date of publication: 2012-01
    Journal article

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    The environmental impact of enzyme bleaching stages applied to oxygen-delignified eucalypt kraft pulp was assessed via the chemical oxygen demand (COD), color, absorbance spectrum, residual enzyme activity and Microtox toxicity of the effluents from a laccase–HBT (1-hydoxybenzotriazole) treatment. The influence of the laccase and HBT doses, and reaction time, on these effluent properties was also examined. The laccase dose was found to be the individual variable most strongly affecting COD, whereas the oxidized form of HBT was the main source of increased color and toxicity in the effluents. Moreover, it inactivated the enzyme. Oxidation of the mediator was very fast and essentially dependent on the laccase dose. Using the laccase–mediator treatment after a xylanase stage improved pulp properties without affecting effluent properties. This result holds great promise with a view to the industrial implementation of biobleaching sequences involving the two enzymes in the future.

  • 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

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

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

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  • Effect of commercial xylanases applied at extreme conditions in a eucalyptus pulp mill

     Fillat Latorre, Úrsula; Roncero Vivero, Maria Blanca; Bassa, Alexandre; Sacón, Vera Maria
    TAPPI journal
    Vol. 11, num. 10, p. 53-59
    Date of publication: 2012-10
    Journal article

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    In this study, we examined the effect of treating eucalyptus pulp with various commercial xylanases to identify the most effective enzyme for use under the industrial bleaching conditions used at the Jacareí mill of the Brazilian firm Fibria, which include a high pH and temperature. Based on the results, the use of two of the nine enzymes studied reduced the kappa number by 1.5 units, increased brightness by 2.5% ISO, and decreased hexenuronic acids (HexA) content by more than 10 µmol/g relative to a control treatment in the absence of enzyme. The most marked changes in brightness were observed on application of an oxidative D stage to enzyme-treated pulp samples. Finally, the chemical oxygen demand (COD), total organic carbon (TOC), color, and turbidity of the effluents obtained at the end of the processes involving the enzymes were all higher than in the control process. Application: The use of xylanases can raise productivity in mills with limited ability to produce chlorine dioxide, can potentially reduce bleaching reagents cost, and can increase the flexibility of the bleaching sequence

    In this study, we examined the effect of treating eucalyptus pulp with various commercial xylanases to identify the most effective enzyme for use under the industrial bleaching conditions used at the Jacareí mill of the Brazilian firm Fibria, which include a high pH and temperature. Based on the results, the use of two of the nine enzymes studied reduced the kappa number by 1.5 units, increased brightness by 2.5% ISO, and decreased hexenuronic acids (HexA) content by more than 10 μmol/g relative to a control treatment in the absence of enzyme. The most marked changes in brightness were observed on application of an oxidative D stage to enzyme-treated pulp samples. Finally, the chemical oxygen demand (COD), total organic carbon (TOC), color, and turbidity of the effluents obtained at the end of the processes involving the enzymes were all higher than in the control process. Application: The use of xylanases can raise productivity in mills with limited ability to produce chlorine dioxide, can potentially reduce bleaching reagents cost, and can increase the flexibility of the bleaching sequence

  • 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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  • 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)

  • 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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  • Bleached dissolving pulps applying laccase treatments

     Quintana Vilajuana, Elisabet; Valls Vidal, Cristina; Roncero Vivero, Maria Blanca
    European Workshop on Lignocellulosics and Pulp
    p. 464-467
    Presentation's date: 2012-08-27
    Presentation of work at congresses

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    A biobleaching sequence, using a laccase enzyme (Trametes Villosa) in combination with different mediators, was applied to softwood dissolving cellulose in order to study its bleaching efficiency and its potential in terms of kappa number, ISO brightness and viscosity. The tested mediators were classified as synthetic compounds such as HBT (1-hydroxybenzotriazole) and VA (violuric acid), and as natural compounds such as SA (syringaldehyde) and pCA (p-coumaric acid). The influence of the enzymatic stage in the bleaching sequence was compared with a control treatment and also with a conventional alkaline hydrogen peroxide stage. The contribution of L (laccasemediator) stage on the effluent properties is important for evaluating and minimizing its environmental impact. Therefore, effluent properties (COD, colour, residual enzyme activity and toxicity) were determined. Laccase-VA system showed the most promising results in reducing kappa number and increasing brightness without detriment to viscosity

  • 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.

  • Assessing the use of xylanase and laccases in biobleaching stages of a TCF sequence for flax pulp

     Fillat Latorre, Amanda; Roncero Vivero, Maria Blanca; Vidal Llucia, Teresa
    Journal of chemical technology & biotechnology
    Vol. 86, num. 12, p. 1501-1507
    DOI: 10.1002/jctb.2662
    Date of publication: 2011-12
    Journal article

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  • Enzymatic treatments of pulp using laccase and hydrophobic compounds

     Garcia Ubasart, Jordi; Esteban Barbero, Alberto; Vila Babarro, Carlos; Roncero Vivero, Maria Blanca; Vidal Llucia, Teresa; Colom Pastor, Josep Francesc
    Paper technology and industry
    Vol. 52, num. 4, p. 7-9
    Date of publication: 2011-09-01
    Journal article

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  • Studying the effects of laccase-catalysed grafting of ferulic acid on sisal pulp fibers

     Aracri, Elisabetta; Roncero Vivero, Maria Blanca; Vidal Llucia, Teresa
    Bioresource technology
    Vol. 102, num. 16, p. 7555-7560
    DOI: 10.1016/j.biortech.2011.05.046
    Date of publication: 2011-05-26
    Journal article

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  • Performance of new and commercial xylanases for ECF and TCF bleaching of eucalyptus kraft pulp

     Valls Vidal, Cristina; Gallardo Román, Óscar; Vidal Llucia, Teresa; Pastor Blasco, F.I. Javier; Díaz Lucea, Pilar; Roncero Vivero, Maria Blanca
    Wood science and technology
    Vol. 45, num. 3, p. 433-448
    DOI: 10.1007/s00226-010-0340-8
    Date of publication: 2011-08
    Journal article

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    Since xylanases can differ widely in their bleaching efficiency, the performance of one new and two commercial xylanases was evaluated in an eucalyptus kraft pulp following XD (X: xylanase; D: chlorine dioxide) and XP (P: hydrogen peroxide) sequences. The new xylanase did not show a significant bleach boosting effect but increased the hexenuronic acid (HexA) removal by 10% after the D stage. The two commercial xylanases behaved in a different way, being one of them (XC) the most effective in increasing delignification (9%) and brightness (3%ISO). Its effectiveness was related to its greater action on releasing the xylan polymer, thus producing also a strong decrease in the HexA contents during the enzymatic stage (15%). All xylanases produced morphological changes in the fibre surfaces, but only with XC cracks and holes that improved the diffusion of reactives were observed. Finally, the best bleaching results were obtained with the XD sequence and therefore, a complete bleaching sequence XDEopD1 (Eop: alkaline extraction with oxygen and peroxide) was carried out with the best enzyme

  • Thermogravimetry study of xylanase- and laccase/mediator-treated eucalyptus pulp fibres

     Barneto, A. G.; Valls Vidal, Cristina; Ariza, J.; Roncero Vivero, Maria Blanca
    Bioresource technology
    Vol. 102, num. 19, p. 9033-9039
    DOI: 10.1016/j.biortech.2011.07.061
    Date of publication: 2011-10
    Journal article

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  • Enzymatic treatments of pulp using laccase and hydrophobic compounds

     Garcia Ubasart, Jordi; Esteban, Alberto; Vila Babarro, Carlos; Roncero Vivero, Maria Blanca; Vidal Llucia, Teresa
    Bioresource technology
    Vol. 102, num. 3, p. 2799-2803
    DOI: 10.1016/j.biortech.2010.10.020
    Date of publication: 2011-02
    Journal article

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    The aim of this work was to develop an innovative method for the internal sizing of paper by use of laccase and hydrophobic compounds. Nine different products containing hydrophobic moieties were tested in combination with laccase derived from Trametes villosa on Eucalyptus globulus kraft pulp in order to assess their internal sizing capability. The strongest internal sizing effect was obtained with lauryl gallate (LG). Heat treatment of the handsheets was found to increase the resistance to water absorption of internally sized samples significantly. Tests were conducted under variable operating conditions, including enzyme and reactant doses and treatment time. In addition to altering the water absorption rate, internal sizing with the laccase–LG treatments was found to affect the mechanical and optical properties of the handsheets. As shown in this work, treatments based on laccase and a hydrophobic compound (particularly lauryl gallate), can provide a new, effective biotechnological method for the internal sizing of paper.

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    Modeling hydrogen peroxide bleaching of soda pulp from oil-palm empty fruit bunches  Open access

     Ferrer Carrera, Ana; Rosal Raya, Antonio; Valls Vidal, Cristina; Roncero Vivero, Maria Blanca; Rodríguez Pascual, Alejandro
    Bioresources
    Vol. 6, num. 2, p. 1298-1307
    Date of publication: 2011
    Journal article

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  • La química i la societat

     Grau Vilalta, Maria Dolors; Font Soldevila, Jose; Sanz Balague, Joaquim; Guaus Guerrero, Ester; Calvet Tarragona, Aurelio; Salán Ballesteros, Mª Núria; Martínez Martínez, María R.; Farran Marsa, Adriana; Gorchs Altarriba, Roser; Alvarez Del Castillo, M. Dolores; Garrido Soriano, Nuria; Morillo Cazorla, Margarita; Almajano Pablos, Maria Pilar; Cardona Planes, Anna Maria; Macanás de Benito, Jorge; Bonsfills Pedros, Ana; Gamisans Noguera, Javier; Dorado Castaño, Antonio David; Lao Luque, Concepcion; Torrent Burgues, Juan; Molins Duran, Gemma; Colom Fajula, Xavier; Carrillo Navarrete, Fernando; Ramon Portés, Eva; Garriga Sole, Pere; Sole Sardans, M. Montserrat; Ardanuy Raso, Monica; Pares Sabates, Ferran; Roncero Vivero, Maria Blanca; Cusola Aumedes, Oriol
    Collaboration in exhibitions

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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.

  • Study of the effects on bast and core flax fibres of laccase + mediator/phenol treatments

     Fillat Latorre, Amanda; Roncero Vivero, Maria Blanca; Vidal Llucia, Teresa
    Italian Meeting on Lignocellulosic Chemistry
    p. 327-330
    Presentation's date: 2011-09-05
    Presentation of work at congresses

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  • A new approach to the internal sizing of paper via biotechnological processes

     Garcia Ubasart, Jordi; Roncero Vivero, Maria Blanca; Vidal Llucia, Teresa
    International Colloquium on Eucalyptus Pulp
    Presentation's date: 2011-05-10
    Presentation of work at congresses

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    This work deals with the study of a new biotechnological procedure, employing laccase in combination with hydrophobic compounds, for the biomodification of fibres and the internal sizing of paper. Cellulose fibres from eucalyptus kraft pulp, unbleached and TCF bleached, were incubated with laccase, in combination with a series of hydrophobes. Laccase treatments of cellulose fibres with lauryl gallate conferred the lowest level of water penetration in handsheets. It was observed that the hydrophobization of paper was not possible using the hidrophobe alone. The coupling of lauryl gallate onto cellulose fibres was firstly denoted by kappa number analysis, and further demonstrated by IR spectroscopy. The internal sizing of paper proved to be effective regardless the lignin content of eucalyptus fibres

  • Tratamientos enzimáticos superficiales utilizando lacasa, compuestos hidrófobos y surfactantes

     Cusola Aumedes, Oriol; Roncero Vivero, Maria Blanca; Garcia Ubasart, Jordi; Valls Vidal, Cristina
    Reunión de la Red Temática
    Presentation's date: 2011-09-06
    Presentation of work at congresses

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  • Enzymatic treatments of paper surface using laccase, hydrophobic compounds and lignin

     Cusola Aumedes, Oriol; Roncero Vivero, Maria Blanca; Garcia Ubasart, Jordi; Valls Vidal, Cristina
    International Colloquium on Eucalyptus Pulp
    Presentation's date: 2011-05-12
    Presentation of work at congresses

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