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  • 1.
    Baath, Jenny Arnling
    et al.
    Chalmers Univ Technol, Div Ind Biotechnol, Dept Biol & Biol Engn, S-41296 Gothenburg, Sweden.;Chalmers Univ Technol, Wallenberg Wood Sci Ctr, S-41296 Gothenburg, Sweden..
    Martinez-Abad, Antonio
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Berglund, Jennie
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Larsbrink, Johan
    Chalmers Univ Technol, Div Ind Biotechnol, Dept Biol & Biol Engn, S-41296 Gothenburg, Sweden.;Chalmers Univ Technol, Wallenberg Wood Sci Ctr, S-41296 Gothenburg, Sweden..
    Vilaplana, Francisco
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Olsson, Lisbeth
    Chalmers Univ Technol, Div Ind Biotechnol, Dept Biol & Biol Engn, S-41296 Gothenburg, Sweden.;Chalmers Univ Technol, Wallenberg Wood Sci Ctr, S-41296 Gothenburg, Sweden..
    Mannanase hydrolysis of spruce galactoglucomannan focusing on the influence of acetylation on enzymatic mannan degradation2018Ingår i: Biotechnology for Biofuels, ISSN 1754-6834, E-ISSN 1754-6834, Vol. 11, artikel-id 114Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Galactoglucomannan (GGM) is the most abundant hemicellulose in softwood, and consists of a backbone of mannose and glucose units, decorated with galactose and acetyl moieties. GGM can be hydrolyzed into fermentable sugars, or used as a polymer in films, gels, and food additives. Endo-beta-mannanases, which can be found in the glycoside hydrolase families 5 and 26, specifically cleave the mannan backbone of GGM into shorter oligosaccharides. Information on the activity and specificity of different mannanases on complex and acetylated substrates is still lacking. The aim of this work was to evaluate and compare the modes of action of two mannanases from Cellvibrio japonicus (CjMan5A and CjMan26A) on a variety of mannan substrates, naturally and chemically acetylated to varying degrees, including naturally acetylated spruce GGM. Both enzymes were evaluated in terms of cleavage patterns and their ability to accommodate acetyl substitutions. Results: CjMan5A and CjMan26A demonstrated different substrate preferences on mannan substrates with distinct backbone and decoration structures. CjMan5A action resulted in higher amounts of mannotriose and mannotetraose than that of CjMan26A, which mainly generated mannose and mannobiose as end products. Mass spectrometric analysis of products from the enzymatic hydrolysis of spruce GGM revealed that an acetylated hexotriose was the shortest acetylated oligosaccharide produced by CjMan5A, whereas CjMan26A generated acetylated hexobiose as well as diacetylated oligosaccharides. A low degree of native acetylation did not significantly inhibit the enzymatic action. However, a high degree of chemical acetylation resulted in decreased hydrolyzability of mannan substrates, where reduced substrate solubility seemed to reduce enzyme activity. Conclusions: Our findings demonstrate that the two mannanases from C. japonicus have different cleavage patterns on linear and decorated mannan polysaccharides, including the abundant and industrially important resource spruce GGM. CjMan26A released higher amounts of fermentable sugars suitable for biofuel production, while CjMan5A, producing higher amounts of oligosaccharides, could be a good candidate for the production of oligomeric platform chemicals and food additives. Furthermore, chemical acetylation of mannan polymers was found to be a potential strategy for limiting the biodegradation of mannan-containing materials.

  • 2. Badia, J. D.
    et al.
    Vilaplana, Domingo Francisco Javier
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Karlsson, Sigbritt
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Ribes-Greus, A.
    Thermal analysis as a quality tool for assessing the influence of thermo-mechanical degradation on recycled poly(ethylene terephthalate)2009Ingår i: Polymer testing, ISSN 0142-9418, E-ISSN 1873-2348, Vol. 28, nr 2, s. 169-175Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Mechanical recycling of poly(ethylene terephthalate) (PET) was simulated by multiple processing to assess the effects of thermo-mechanical degradation, and characterized using rheological and thermal analysis techniques. Thermo-mechanical degradation under repeated extrusion induces chain scission reactions in PET, which result in a dramatic loss in the deformation capabilities and an increase in the fluidity of the polymer under reprocessing, reducing its recycling possibilities after four extrusion cycles. Multiple reprocessing severely affects the storage modulus and the microstructure of recycled PET, both in the amorphous and crystalline regions. Multimodal melting behavior is observed for reprocessed PET, indicating heterogeneous and segregated crystalline regions. A deconvolution procedure has been applied to individually characterize each crystalline population in terms of lamellar thickness distribution and partial crystallinity. Thermal analysis techniques such as differential scanning calorimetry (DSC) and dynamic-mechanical analysis (DMA) have proved to be suitable techniques for the quality assessment of recycled PET, giving unequivocal information about its degree of degradation compared to the common technological measurements of melt-mass flow rate (MFR) or oxidative stability (T-OX).

  • 3.
    Berglund, Jennie
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Angles d’Ortoli, Thibault
    Vilaplana, Francisco
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Widmalm, Göran
    Bergenstråhle-Wohlert, Malin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Lawoko, Martin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Henriksson, Gunnar
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Lindström, Mikael
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Wohlert, Jakob
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    A molecular dynamics study of the effect of glycosidic linkage type in the hemicellulose backbone on the molecular chain flexibility2016Ingår i: The Plant Journal, ISSN 0960-7412, E-ISSN 1365-313XArtikel i tidskrift (Refereegranskat)
    Abstract [en]

    The macromolecular conformation of the constituent polysaccharides in lignocellulosic biomass influences their supramolecular interactions, and therefore their function in plants and their performance in technical products. The flexibility of glycosidic linkages from the backbone of hemicelluloses was studied by evaluating the conformational freedom of the φ and ψ dihedral angles using molecular dynamic simulations, additionally selected molecules were correlated with experimental data by nuclear magnetic resonance spectroscopy. Three types of β-(1→4) glycosidic linkages involving the monosaccharides (Glcp, Xylp and Manp) present in the backbone of hemicelluloses were defined. Different di- and tetrasaccharides with combinations of such sugar monomers from hemicelluloses were simulated, and free energy maps of the φ – ψ space and hydrogen-bonding patterns were obtained. The glycosidic linkage between Glc-Glc or Glc-Man (C-type) was the stiffest with mainly one probable conformation; the linkage from Man-Man or Man-Glc (M-type) was similar but with an increased probability for an alternative conformation making it more flexible, and the linkage between two Xyl-units (X-type) was the most flexible with two almost equally populated conformations. Glycosidic linkages of the same type showed essentially the same conformational space in both disaccharides and in the central region of tetrasaccharides. Different probabilities of glycosidic linkage conformations in the backbone of hemicelluloses can be directly estimated from the free energy maps, which to a large degree affect the overall macromolecular conformations of these polymers. The information gained contributes to an increased understanding of the function of hemicelluloses both in the cell wall and in technical products.

  • 4.
    Berglund, Jennie
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Azhar, Shoaib
    Lawoko, Martin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Lindström, Mikael
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Vilaplana, Francisco
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Wohlert, Jakob
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Henriksson, Gunnar
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    The structure of galactoglucomannan impacts the degradation under alkaline conditions2018Ingår i: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882XArtikel i tidskrift (Refereegranskat)
    Abstract [en]

    Galactoglucomannan (GGM) from sprucewas studied with respect to the degradation behavior inalkaline solution. Three reference systems includinggalactomannan from locust bean gum, glucomannanfrom konjac and the linear water-soluble carboxymethylcellulose were studied with focus onmolecular weight, sugar composition, degradationproducts, as well as formed oligomers, to identifyrelative structural changes in GGM. Initially allmannan polysaccharides showed a fast decrease inthe molecular weight, which became stable in the laterstage. The degradation of the mannan polysaccharidescould be described by a function corresponding to thesum of two first order reactions; one slow that wasascribed to peeling, and one fast that was connectedwith hydrolysis. The galactose side group wasstable under conditions used in this study (150 min,90 C, 0.5 M NaOH). This could suggest that, apartfrom the covalent connection to C6 in mannose, thegalactose substitutions also interact non-covalentlywith the backbone to stabilize the structure againstdegradation. Additionally, the combination of differentbackbone sugars seems to affect the stability of thepolysaccharides. For carboxymethyl cellulose thedegradation was linear over time which furthersuggests that the structure and sugar composition playan important role for the alkaline degradation. Moleculardynamics simulations gave details about theconformational behavior of GGM oligomers in watersolution, as well as interaction between the oligomersand hydroxide ions.

  • 5.
    Berglund, Jennie
    et al.
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Bergenstråhle, Malin
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Vilaplana, Francisco
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för bioteknologi (BIO), Centra, Albanova VinnExcellence Center for Protein Technology, ProNova. KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    d'Ortoli, Thibault Angles
    Stockholm Univ, Dept Organ Chem, Stockholm, Sweden..
    Widmalm, Goran
    Stockholm Univ, Dept Organ Chem, Stockholm, Sweden..
    Lawoko, Martin
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Henriksson, Gunnar
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Lindström, Mikael
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Wohlert, Jakob
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    How the flexibility properties of hemicelluloses are affected by the glycosidic bonds between different backbone sugars - A molecular dynamics study2016Ingår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 251Artikel i tidskrift (Övrigt vetenskapligt)
  • 6.
    Berglund, Jennie
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Chen, Pan
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Vilaplana, Francisco
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Wohlert, Jakob
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Computer modeling of the structure and dynamics of hemicelluloses2019Ingår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 257Artikel i tidskrift (Övrigt vetenskapligt)
  • 7.
    Berglund, Jennie
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Farahani, Saina Kishani
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    de Carvalho, Danila Morais
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Lawoko, Martin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Wohlert, Jakob
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Henriksson, Gunnar
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Lindström, Mikael
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Wågberg, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Vilaplana, Francisco
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap. AlbaNova University Centre.
    The influence of acetylation and sugar composition on the (in)solubility of mannans, their interaction with cellulose surfaces and thermal propertiesManuskript (preprint) (Övrigt vetenskapligt)
  • 8.
    Berglund, Jennie
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Kishani, Saina
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    de Carvalho, Danila Morais
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Lawoko, Martin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Wohlert, Jakob
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Henriksson, Gunnar
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Lindström, Mikael
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Wågberg, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Vilaplana, Francisco
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    The influence of acetylation and sugar composition on the (in)solubility of mannans, their interaction with cellulose surfaces and thermal properties.Manuskript (preprint) (Övrigt vetenskapligt)
  • 9.
    Berglund, Jennie
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Mikkelsen, Deirdre
    Univ Queensland, Queensland Alliance Agr & Food Innovat, Ctr Nutr & Food Sci, ARC Ctr Excellence Plant Cell Walls, Brisbane, Qld, Australia..
    Flanagan, Bernadine
    Univ Queensland, Queensland Alliance Agr & Food Innovat, Ctr Nutr & Food Sci, ARC Ctr Excellence Plant Cell Walls, Brisbane, Qld, Australia..
    Dhital, Sushil
    Univ Queensland, Queensland Alliance Agr & Food Innovat, Ctr Nutr & Food Sci, ARC Ctr Excellence Plant Cell Walls, Brisbane, Qld, Australia..
    Henriksson, Gunnar
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Lindström, Mikael
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Yakubov, Gleb
    Univ Queensland, Sch Chem Engn, ARC Ctr Excellence Plant Cell Walls, Brisbane, Qld, Australia..
    Gidley, Michael
    Univ Queensland, Queensland Alliance Agr & Food Innovat, Ctr Nutr & Food Sci, ARC Ctr Excellence Plant Cell Walls, Brisbane, Qld, Australia..
    Vilaplana, Francisco
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Hydrogels of bacterial cellulose and wood hemicelluloses as a model of plant secondary cell walls2019Ingår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 257Artikel i tidskrift (Övrigt vetenskapligt)
  • 10.
    Berglund, Jennie
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Mikkelsen, Deirdre
    University of Queensland, Australia.
    Flanagan, Bernadine M.
    University of Queensland, Australia.
    Dhital, Sushil
    University of Queensland, Australia.
    Henriksson, Gunnar
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Lindström, Mikael
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Yakubov, Gleb E.
    University of Queensland, Australia.
    Gidley, Michael J.
    University of Queensland, Australia.
    Vilaplana, Francisco
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Wood Hemicelluloses Exert Distinct Biomechanical Contributions in Bacterial Cellulose HydrogelsManuskript (preprint) (Övrigt vetenskapligt)
  • 11.
    Bi, Ran
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Träkemi och massateknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Berglund, Jennie
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Träkemi och massateknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Vilaplana, Francisco
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    McKee, Lauren
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Henriksson, Gunnar
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Träkemi och massateknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    The Degree Of Acetylation Affects The Microbial Degradability Of HemicellulosesManuskript (preprint) (Övrigt vetenskapligt)
  • 12.
    Bi, Ran
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Berglund, Jennie
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Vilaplana, Francisco
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    McKee, Lauren S.
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Henriksson, Gunnar
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    The degree of acetylation affects the microbial degradability of mannans2016Ingår i: Polymer degradation and stability, ISSN 0141-3910, E-ISSN 1873-2321, Vol. 133, s. 36-46Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Hemicelluloses as major components of plant cell walls are acetylated to different extents. The biologicalfunctions of acetylation are not completely understood but suggested that one reason is to decrease themicrobial degradability of cell walls. Model seed galactomannan and glucomannan, which are structurallysimilar to an abundant class of wood hemicelluloses, were acetylated to various degrees and usedas sole carbon source on agar plates for microbial growth. When soil samples were inoculated on theplates, significantly fewer strains grew on the agar plates with highly acetylated mannans than withslightly acetylated or non-acetylated mannans. One filamentous fungus isolated and identified as aPenicillium species was shown to grow faster and stronger on non-acetylated than on highly acetylatedmannan. The data therefore support the hypothesis that a high degree of acetylation (DSac) can decreasethe microbial degradability of hemicelluloses. Possible mechanisms and the technological significance ofthis are discussed.

  • 13. Castro, A.
    et al.
    Vilaplana, Francisco
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Nilsson, L.
    Characterization of a water soluble, hyperbranched arabinogalactan from yacon (Smallanthus sonchifolius) roots2017Ingår i: Food Chemistry, ISSN 0308-8146, E-ISSN 1873-7072, Vol. 223, s. 76-81Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Yacon (Smallanthus sonchifolius Poepp. & Endl.) roots are largely grown in Andean countries and have attracted recent interest due to their antioxidant and prebiotic effects. Yacon is typically consumed as a fruit due to its sweet taste and juiciness. The macromolecular properties of an aqueous extract of yacon are investigated using asymmetric flow field-flow fractionation (AF4) coupled to UV, multiangle light scattering (MALS) and differential refractive index (dRI) detection. The method allows for determination of molar mass and size over the size distribution. Three major populations were found of which one strongly dominates in concentration. Through collection of fractions from AF4, carbohydrate composition and glycosidic linkage analysis for the dominating population was performed. The results show that the dominating population consists of a highly branched arabinogalactan (type 2) with a molar mass of approximately 1–2 · 105 g/mol, a hydrodynamic radius of approximately 6–10 nm and a relatively high apparent density (approx. 70–150 kg/m3).

  • 14.
    de Carvalho, Danila Morais
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Träkemi och massateknologi. KTH, Stockholm, Sweden.;Univ Fed Vicosa, Vicosa, MG, Brazil..
    Martinez-Abad, Antonio
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Stockholm, Sweden..
    Colodette, Jorge Luiz
    Univ Fed Vicosa, Vicosa, MG, Brazil..
    Lindström, Mikael
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Stockholm, Sweden..
    Vilaplana, Francisco
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Stockholm, Sweden..
    Sevastyanova, Olena
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. Fibre Wood Tech Wood Chem Pulp Tech, Stockholm, Sweden..
    Chemical and structural characterization of xylans from sugarcane bagasse and sugarcane straw2016Ingår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 251Artikel i tidskrift (Övrigt vetenskapligt)
  • 15.
    de Jesus, Liana Inara
    et al.
    Univ Fed Parana, Dept Biochem & Mol Biol, CP 19046, Curitiba, PR, Brazil..
    Smiderle, Fhernanda R.
    Univ Fed Parana, Dept Biochem & Mol Biol, CP 19046, Curitiba, PR, Brazil..
    Ruthes, Andrea C.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Vilaplana, Francisco
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Dal'Lin, Fernando Tonholi
    Univ Fed Parana, Dept Pharmacol, CP 19046, Curitiba, PR, Brazil..
    Maria-Ferreira, Daniele
    Univ Fed Parana, Dept Biochem & Mol Biol, CP 19046, Curitiba, PR, Brazil.;Univ Fed Parana, Dept Pharmacol, CP 19046, Curitiba, PR, Brazil..
    Werner, Maria Fernanda
    Univ Fed Parana, Dept Pharmacol, CP 19046, Curitiba, PR, Brazil..
    Van Griensven, Leo J. L. D.
    Wageningen Univ & Res, Plant Res Int, Bomsesteeg 1, NL-6708 PD Wageningen, Netherlands..
    Iacomini, Marcello
    Univ Fed Parana, Dept Biochem & Mol Biol, CP 19046, Curitiba, PR, Brazil..
    Chemical characterization and wound healing property of a beta-D-glucan from edible mushroom Piptoporus betulinus2018Ingår i: International Journal of Biological Macromolecules, ISSN 0141-8130, E-ISSN 1879-0003, Vol. 117, s. 1361-1366Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A water-soluble beta-D-glucan was obtained from fruiting bodies of Piptoporus betulinus, by hot aqueous extraction followed by freeze-thawing procedure and dialysis. Its molar mass distribution and conformational behavior in solution was assessed by size-exclusion chromatography coupled with multiangle laser light scattering, showing a polysaccharide with an average molecular weight of 2.5 x 10(5) Da with a random coil conformation for molecular weights below 1 x 10(6) Da. Typical signals of beta-(1 -> 3)-linkages were observed in NMR spectrum (delta 102.7/4.76; 102.8/4.74; 102.9/4.52; and delta 85.1/3.78; 85.0/3.77) and also signals of O-6 substitution at delta 69.2/4.22 and 69.2/3.87. The analysis of partially O-methylated alditol acetates corroborates the NMR results, indicating the presence of a beta-D-glucan with a main chain (1 -> 3)-linked, substituted at O-6 by single-units of glucose. The beta-D-glucan showed no toxicity on human colon carcinoma cell line (Caco-2) up to 1000 mu g mL(-1) and promoted cell migration on in vitro scratch assay, demonstrating a potential wound healing capacity.

  • 16.
    Duval, Antoine
    et al.
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Vilaplana, Francisco
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Crestini, Claudia
    Lawoko, Martin
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Solvent screening for the fractionation of industrial kraft lignin2016Ingår i: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, Vol. 70, nr 1, s. 11-20Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The polydispersity of commercially available kraft lignins (KLs) is one of the factors limiting their applications in polymer-based materials. A prerequisite is thus to develop lignin fractionation strategies compatible with industrial requirements and restrictions. For this purpose, a solvent-based lignin fractionation technique has been addressed. The partial solubility of KL in common industrial solvents compliant with the requirements of sustainable chemistry was studied, and the results were discussed in relation to Hansen solubility parameters. Based on this screening, a solvent sequence is proposed, which is able to separate well-defined KL fractions with low polydispersity.

  • 17.
    Espert, Ana
    et al.
    KTH, Tidigare Institutioner, Fiber- och polymerteknologi.
    Vilaplana, Francisco
    KTH, Tidigare Institutioner, Fiber- och polymerteknologi.
    Karlsson, Sigbritt
    KTH, Tidigare Institutioner, Fiber- och polymerteknologi.
    Comparison of water absorption in natural cellulosic fibres from wood and one-year crops in polypropylene composites and its influence on their mechanical properties2004Ingår i: Composites. Part A, Applied science and manufacturing, ISSN 1359-835X, E-ISSN 1878-5840, Vol. 35, nr 11, s. 1267-1276Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Environmentally beneficial composites can be made by replacing glass fibres with various types of cellulose fibres. Fibres from pine or eucalyptus wood and also one-year crops such as coir, sisal, etc. are all good candidates. The poor resistance towards water absorption is one of the drawbacks of natural fibres/polypropylene composites. New natural fibres/polypropylene composites were made and the water absorption in them was studied by immersion of the composites in water at three different temperatures, 23, 50 and 70 degreesC. The process of absorption of water was found to follow the kinetics and mechanisms described by Fick's theory. In addition, the diffusivity coefficient was dependent on the temperature as estimated by means of Arrhenius law. A decrease in tensile properties of the composites was demonstrated, showing a great loss in mechanical properties of the water-saturated samples compared to the dry samples. The morphology change was monitored by scanning electron microscopy studies of the samples before and after exposure to water and the devastating effect of water on the fibre structure was shown.

  • 18.
    Farahani, Saina Kishani
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Escalante, Alfredo
    Toriz, Guillermo
    Vilaplana, Francisco
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Gatenholm, Paul
    Hansson, Per
    Wågberg, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Experimental and Theoretical Evaluation of the Solubility/Insolubility Spruce Xylan (Arabino Glucuronoxylan)2019Ingår i: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 20, nr 3, s. 1263-1270Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The molecular solubility of softwood arabinoglucuronoxylan (AGX) has been thoroughly investigated, and it has been shown that the chemical and physical structures of the extracted hemicellulose are not significantly influenced by different purification steps, but a transient molecular solubility of AGX was observed in aqueous media at low concentrations (1 g/L) when the dissolved macromolecules had a hydrodynamic diameter of up to 10 nm. A phase separation was detected when the concentration was increased to 15 g/L leading to an association of the smaller molecules into fractal structures with a considerably larger diameter, even though the dispersions were still transparent to ocular inspection. Dynamic Light Scattering and Cryo-Transmission Electron Microscopy showed dimensions in the range of 1000 nm. The phase separation of the sample was further characterized by estimating the χ-interaction parameter of AGX in water using the Flory-Huggins theory, and the results supported that water is a poor solvent for AGX. This behavior is crucial when films and hydrogels based on these biopolymers are made, since the association will dramatically affect barrier and mechanical properties of films made from these materials.

  • 19.
    Farahani, Saina Kishani
    et al.
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Vilaplana, Francisco
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Gatenholm, Paul
    Chalmers Univ Technol, Chem Biol Engn Biopolymer, Gothenburg, Sweden..
    Wågberg, Lars
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Solubility and adsorption of wood biopolymers at model surfaces2016Ingår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 251Artikel i tidskrift (Övrigt vetenskapligt)
  • 20.
    Farahani, Saina Kishani
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Vilaplana, Francisco
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Hansson, Per
    Uppsala Univ, Uppsala, Sweden..
    Wågberg, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Influence of solubility on the adsorption of different Xyloglucan fractions to cellulose model surfaces2019Ingår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 257Artikel i tidskrift (Övrigt vetenskapligt)
  • 21.
    Farahani, Saina Kishani
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Vilaplana, Francisco
    KTH, Tidigare Institutioner (före 2005), Fiber- och polymerteknologi.
    Ruda, Marcus
    Hansson, Per
    Wågberg, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    The influence of solubility on the adsorption of different Xyloglucan fractions at Cellulose Water InterfacesManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Xylogucan (XG) fractions with different molar masses were prepared while preserving the natural structure of the XG. The solubility of the fractions was investigated using light- scattering, chromatography and microscopy techniques. The conformational changes of the XG molecules and their association and phase separation were investigated together with concentration and molar mass changes. The knowledge gained was then applied to investigate the interaction of different XG fractions at cellulose model surfaces using a quartz crystal microbalance with dissipation. The results indicate that there is a cluster formation and phase separation of the XG molecules at the cellulose/water interface induced by the increase in XG concentration close to the surface. Concomitantly, the adsorption regimes are altered for the XG fractions depending on the solubility properties, indicating that the insolubility, association and phase separation of XGs in aqueous media affect their interaction with cellulose. The study is of vital importance for improving the functionality of sustainable materials made from xyloglucan/cellulose natural composites.

  • 22.
    Henriksson, Gunnar
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Berglund, Jennie
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Wohlert, Jakob
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Lawoko, Martin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Aminzadeh, Selda
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Lindström, Mikael
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Vilaplana, Francisco
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Non-cellulose wood polysaccharides - a need for a stricter structural and functional classification?2018Ingår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 255Artikel i tidskrift (Övrigt vetenskapligt)
  • 23.
    Imre, Balázs
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Lidia, García
    AITIIP.
    Puglia, Debora
    University of Perugia.
    Vilaplana, Francisco
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Reactive Compatibilization of Plant Polysaccharidesand Biobased Polymers: Review on Current Strategies,Expectations and Reality2018Ingår i: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Our society is amidst a technological revolution towards a sustainable economy, focused on the development of biobased products in virtually all sectors. In this context, plant polysaccharides, as the most abundant macromoleculespresent in biomass represent a fundamental renewable resource for the replacement of fossil-based polymeric materials in commodity and engineering applications. However, native polysaccharides have several disadvantages compared to their synthetic counterparts, including reduced thermal stability, moisture absorption and limited mechanical performance, which hinder their direct application in native form in advanced material systems. Thus, polysaccharides are generally used in a derivatized form and/or in combination with other biobased polymers, requiring the compatibilization of such blends and composites. In this review we critically explore the current status and the future outlook of reactive compatibilization strategies of the most common plant polysaccharides in blends with biobased polymers. The chemical processes for the modification and compatibilization of starch and lignocellulosic based materialsare discussed, together with the practical implementation of these reactive compatibilization strategies with special emphasis on reactive extrusion. The efficiency of these strategies is critically discussed in the context on the definition of blending and compatibilization from a polymer physics standpoint; this relies on the detailed evaluation of the chemical structure of the constituent plant polysaccharides and biobased polymers, the morphology of the heterogeneous polymeric blends, and their macroscopic behavior, in terms of rheological and mechanical properties.

  • 24. Jamshidian, H.
    et al.
    Shojaosadati, S. A.
    Vilaplana, Francisco
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Mousavi, S. M.
    Soudi, M. R.
    Characterization and optimization of schizophyllan production from date syrup2016Ingår i: International Journal of Biological Macromolecules, ISSN 0141-8130, E-ISSN 1879-0003, Vol. 92, s. 484-493Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study demonstrates the efficient utilization of low-cost agricultural substrates, particularly date syrup, by Schizophyllum commune ATCC 38548 for schizophyllan production. Initially, one factor-at-a-time method was used to find the best carbon and nitrogen sources for schizophyllan production. Subsequently, response surface methodology was employed to optimize the level of culture medium components to maximize substrate conversion yield and schizophyllan production in submerged culture. Maximum product yield (0.12 g schizophyllan/g date syrup) and schizophyllan production (8.5 g/l) were obtained at concentrations of date syrup and corn steep liquor, inoculum size and agitation rate at 7.02 %w/v, 0.10 %w/v, 7.68 %v/v and 181 rpm, respectively. Sugar composition analysis, FTIR, NMR and molar mass determination revealed the purity and molecular properties of recovered schizophyllan produced from date syrup as glycosidic linkage analysis showed three main schizophyllan characteristic peaks arising from the 3-linked, 3,6-linked and terminal glucose residues. Finally, process economic analysis suggested that use of date syrup and corn steep liquor as nutrients would result in approximately 6-fold reduction in cost of raw materials for schizophyllan production as compared to conventional carbon and nitrogen sources such as sucrose and malt extract.

  • 25. Jamshidian, Hajar
    et al.
    Shojaosadati, Seyed Abbas
    Mousavi, Seyed Mohammad
    Soudi, Mohammad Reza
    Vilaplana, Francisco
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Implications of recovery procedures on structural and rheological properties of schizophyllan produced from date syrup2017Ingår i: International Journal of Biological Macromolecules, ISSN 0141-8130, E-ISSN 1879-0003, Vol. 105, s. 36-44Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study investigates the effects of different recovery procedures on high molar mass schizophyl-Ian produced by Schizophyllum commune using low value agricultural residues. Recovered extracellular polysaccharides (EPSs) were compared in terms of purity, sugar composition, degree of branching, molecular weight, and rheological properties. Performing different recovery methods, such as re-dissolving in water and re-precipitation with ethanol on produced EPS, provided schizophyllan with purity similar to the commercial grade. Besides, Freeze-thawing cycles allowed the fractionation of schizophyllan based on branching degree and solubility. The EPSs with higher purity and lower degree of branching (less conformational flexibility) showed higher viscosity. This study evidences the possibility of producing EPSs with excellent rheological properties using low value agricultural side products. Furthermore, our results demonstrate the importance of recovery methods for tailoring the purity, molecular structure and macroscopic properties of the produced polysaccharides for specific applications.

  • 26.
    Johansson, Jan
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Luttropp, Conrad
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Strömberg, Emma
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Vilaplana, Francisco
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Polymer recycling of sorted WEEE at a refrigerator recycling plantManuskript (Övrigt vetenskapligt)
  • 27.
    Kishani, Saina
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Vilaplana, Francisco
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Xu, Wenyang
    Abo Akad Univ, Lab Wood & Paper Chem, Johan Gadolin Proc Chem Ctr, FI-20500 Turku, Finland..
    Xu, Chunlin
    Abo Akad Univ, Lab Wood & Paper Chem, Johan Gadolin Proc Chem Ctr, FI-20500 Turku, Finland..
    Wågberg, Lars
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Solubility of Softwood Hemicelluloses2018Ingår i: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 19, nr 4, s. 1245-1255Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    It is demonstrated that the molecular solubility of softwood hemicelluloses is significantly influenced by pretreatment of the fibers, extraction, and downstream processing. To quantify these effects, four hemicellulose samples were extracted from different thermomechanical pulps of Norway spruce. The molecular solubility of the samples was characterized by size and molar mass distributions, and the morphology of the molecules was studied using high resolution microscopy techniques. All extracted samples were well dispersed in aqueous media creating transparent dispersions, but dynamic light scattering measurements showed that molecular solubility can only be achieved using specific pretreatments and extractions. The procedure yields acetylated galactoglucomannan (AcGGM)-rich hemicelluloses with an average molar mass of 21-35 kDa and a diameter up to 10 nm but also shows that water is a poor solvent for this sample since an association is detected as soon as the concentration is about 20 g/L. These associated hemicellulose dispersions are still absolutely dear on visual inspection, underlining the need for careful measurement when assessing the solubility of wood hemicelluloses.

  • 28.
    Kishani, Saina
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Wohlert, Jakob
    KTH.
    Vilaplana, Francisco
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Wågberg, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Solubility and adsorption of different xyloglucan fractions to model surfaces2018Ingår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 255Artikel i tidskrift (Övrigt vetenskapligt)
  • 29. Kisonen, Victor
    et al.
    Xu, Chunlin
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Eklund, Patrik
    Lindqvist, Hanna
    Sundberg, Anna
    Pranovich, Andrey
    Sinkkonen, Jari
    Vilaplana, Francisco
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Willför, Stefan
    Cationised O-acetyl galactoglucomannans: Synthesis and characterisation2014Ingår i: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 99, s. 755-764Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Water-soluble O-acetyl-galactoglucomannans (GGMs) can be obtained from Norway spruce by hot-water-extraction of the wood or as a side product by ultrafiltration of mechanical pulping waters. Cationic and amphiphilic polysaccharides and their derivatives are of interest for a number of applications and thus quaternary nitrogen moieties with cationic charge were grafted onto GGMs in the heterogeneous reaction to render a cationic polyelectrolyte. The degree of substitution was measured by elemental analysis of nitrogen, by quantitative C-13 NMR and interestingly also by polyelectrolyte titration and the results were congruent. NMR, matrix-assisted laser desorption/ionisation mass spectroscopy (MALDI-TOF-MS), and FT-IR analysis were used to characterise the product. THF or DMSO with water enhanced the reaction efficiency and decreased M-w reduction in comparison to plain water as a reaction media. Cationised GGM was also successfully acetylated. The cationic derivatives of hemicelluloses can potentially be utilised as polyelectrolyte layers in packaging and pharmaceutical applications.

  • 30. Liu, Jun
    et al.
    Kisonen, Victor
    Willfor, Stefan
    Xu, Chunlin
    Vilaplana, Francisco
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Profiling the substitution pattern of xyloglucan derivatives by integrated enzymatic hydrolysis, hydrophilic-interaction liquid chromatography and mass spectrometry2016Ingår i: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 1463, s. 110-120Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Plant polysaccharides constitute arguably the most complex family of biomacromolecules in terms of the stereochemistry and regiochemistry of their intramolecular linkages. The chemical modification of such polysaccharides introduces an additional level of complexity for structural determinations. We have developed an integrated analytical procedure combining selective enzymatic hydrolysis, hydrophilic interaction liquid chromatography (HILIC), and mass spectrometry (MS) to describe the substitution pattern of xyloglucan (XyG) and its chemo-enzymatic derivatives (cationic, anionic, and benzyl aminated). Enzymatic hydrolysis of XyG derivatives by a xyloglucan-specific endoglucanase (XEG) generates oligosaccharides amenable for mass spectrometric identification with distinct structures, based on enzymatic substrate recognition and hydrolytic pattern. Matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-ToF-MS) and electrospray ionisation mass spectrometry (ESI-MS) offer qualitative mass profiling of the chemical derivatives. Separation and identification of the complex oligosaccharide profiles released by enzymatic hydrolysis is achieved by hyphenation of hydrophilic interaction liquid chromatography with mass spectrometry (HILIC-ESI-MS). Further fragmentation by tandem mass spectrometry (ESI-MS/MS) in positive mode enables the structural sequencing of modified XyG oligosaccharides and the identification of the substituent position without further derivatisation. This integrated approach can be used to obtain semi-quantitative information of the substitution pattern of hemicellulose derivatives, with fundamental implications for their modification mechanisms and performance.

  • 31.
    Liu, Jun
    et al.
    Abo Akad Univ, Johan Gadolin Proc Chem Ctr, Lab Wood & Paper Chem, Porthansgatan 3-5, FI-20500 Turku, Finland.;Jiangsu Univ, Dept Environm & Safety, Biofuels Inst, Zhenjiang 212013, Peoples R China..
    Leppanen, Ann-Sofie
    Abo Akad Univ, Johan Gadolin Proc Chem Ctr, Lab Wood & Paper Chem, Porthansgatan 3-5, FI-20500 Turku, Finland..
    Kisonen, Victor
    Abo Akad Univ, Johan Gadolin Proc Chem Ctr, Lab Wood & Paper Chem, Porthansgatan 3-5, FI-20500 Turku, Finland..
    Willfor, Stefan
    Abo Akad Univ, Johan Gadolin Proc Chem Ctr, Lab Wood & Paper Chem, Porthansgatan 3-5, FI-20500 Turku, Finland..
    Xu, Chunlin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. Abo Akad Univ, Johan Gadolin Proc Chem Ctr, Lab Wood & Paper Chem, Porthansgatan 3-5, FI-20500 Turku, Finland..
    Vilaplana, Francisco
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för bioteknologi (BIO), Centra, Albanova VinnExcellence Center for Protein Technology, ProNova. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Insights on the distribution of substitutions in spruce galactoglucomannan and its derivatives using integrated chemo-enzymatic deconstruction, chromatography and mass spectrometry2018Ingår i: International Journal of Biological Macromolecules, ISSN 0141-8130, E-ISSN 1879-0003, Vol. 112, s. 616-625Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Accurate determination of the distribution of substitutions in the primary molecular structure of heteropolysaccharides and their derivatives is a prerequisite for their increasing application in the pharmaceutical and biomedical fields, which is unfortunately hindered due to the lack of effective analytical techniques. Acetylated galactoglucomannan (GGM) is an abundant plant polysaccharide as the main hemicellulose in softwoods, and therefore constitutes an important renewable resource from lignocellulosic biomass for the development of bioactive and functional materials. Here we present a methodology for profiling the intramolecular structure of spruce GGM and its chemical derivatives (cationic, anionic, and benzoylated) by combining chemo-enzymatic hydrolysis, liquid chromatography, and mass spectrometry. Fast identification and qualitative mass profiling of GGM and its derivatives was conducted using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF-MS) and electrospray ionization mass spectrometry (ESI-MS). Tandem mass fragmentation analysis and its hyphenation with hydrophilic interaction liquid chromatography (HILIC-ESI-MS/MS) provide further insights on the substitution placement of the GGM oligosaccharides and its derivatives. This method will be useful in understanding the structure-function relationships of native GGM and their derivatives, and therefore facilitate their potential application. 

  • 32.
    Luttropp, Conrad
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Johansson, Jan
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinelement.
    Vilaplana, Francisco
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymera material.
    Strömberg, Emma
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymera material.
    Karlsson, Sigbritt
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymera material.
    Design for material hygiene - An ecodesign strategy for improved recycling of polymers2010Ingår i: Proceedings of the 8th International Symposium on Tools and Methods of Competitive Engineering, TMCE 2010, 2010, s. 1223-1231Konferensbidrag (Refereegranskat)
    Abstract [en]

    Recycling of polymers has come into focus lately. Many polymers carry a backpack of energy from manufacturing, which is lost in present recycling of e.g. automotives and small house hold appliances. This calls for higher efficiency in recycling. To take a step in this direction a literature study is made and an experiment at a recycling plant for refrigerators and freezers. A batch of 30m3 of electronic waste was collected and processed in a so-called Hurricane machine. The experiment showed that recycling of polymers can be made on higher levels of efficiency with the used machine, if complemented with sorting and some initial processing before shredding. In order to improve polymer recycling a set of process steps must be designed in order to get secondary polymer fractions that can be used in products.

  • 33.
    Marti-Ferrer, F.
    et al.
    AIMPLAS.
    Vilaplana, Francisco
    Universidad Politecnica de Valencia.
    Ribes-Greus, A.
    Universidad Politecnica de Valencia.
    Benedito-Borras, A.
    AIMPLAS.
    Sanz-Box, C.
    AIMPLAS.
    Flour rice husk as filler in block copolymer polypropylene: Effect of different coupling agents2006Ingår i: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 99, nr 4, s. 1823-1831Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Flour rice husk (FRH) was employed as a filler in block copolymer polypropylene (PPB) in order to prepare polymer-based reinforced composites. Four coupling agents were selected to modify the surface of the rice husk in the composite materials, including two types of functionalized polymers [PP homopolymer grafted with maleic anhydride (MA-PP) and an elastomer styrene-ethylene-butadiene-styrene triblock copolymer grafted with MA (MA-SEBS)] and two bifunctional organometallic coupling agents (silane and titanate with linear low-density polyethylene as a carrier). The influence of each type of coupling agent on the interfacial bonding strength was studied by dynamic mechanical analysis, scanning electronic microscopy, and rheological tests. The results showed that strong interactions were formed between the coupling agents and the filler surface. The addition of a coupling agent with an elastomeric carrier (MA-SEBS) increased the loss tangent and reduced the storage modulus of the composite. A similar but less intense effect was observed for the titanate coupling agent. However, an antagonistic performance was obtained when MA-PP and silane were employed as coupling agents. In addition, when the percentage of MA-SEBS was increased, the impact properties of FRH/PPB blends were improved and the strength was reduced.

  • 34.
    Martinez-Abad, Antonio
    et al.
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Berglund, Jennie
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Träkemi och massateknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Toriz, Guillermo
    Gatenholm, Paul
    Henriksson, Gunnar
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Lindström, Mikael
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Wohlert, Jakob
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Vilaplana, Francisco
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Regular Motifs in Xylan Modulate Molecular Flexibility and Interactions with Cellulose Surfaces2017Ingår i: Plant Physiology, ISSN 0032-0889, E-ISSN 1532-2548, Vol. 175, nr 4, s. 1579-1592Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Xylan is tightly associated with cellulose and lignin in secondary plant cell walls, contributing to its rigidity and structural integrity in vascular plants. However, the molecular features and the nanoscale forces that control the interactions among cellulose microfibrils, hemicelluloses, and lignin are still not well understood. Here, we combine comprehensive mass spectrometric glycan sequencing and molecular dynamics simulations to elucidate the substitution pattern in softwood xylans and to investigate the effect of distinct intramolecular motifs on xylan conformation and on the interaction with cellulose surfaces in Norway spruce (Picea abies). We confirm the presence of motifs with evenly spaced glycosyl decorations on the xylan backbone, together with minor motifs with consecutive glucuronation. These domains are differently enriched in xylan fractions extracted by alkali and subcritical water, which indicates their preferential positioning in the secondary plant cell wall ultrastructure. The flexibility of the 3-fold screw conformation of xylan in solution is enhanced by the presence of arabinofuranosyl decorations. Additionally, molecular dynamic simulations suggest that the glycosyl substitutions in xylan are not only sterically tolerated by the cellulose surfaces but that they increase the affinity for cellulose and favor the stabilization of the 2-fold screw conformation. This effect is more significant for the hydrophobic surface compared with the hydrophilic ones, which demonstrates the importance of nonpolar driving forces on the structural integrity of secondary plant cell walls. These novel molecular insights contribute to an improved understanding of the supramolecular architecture of plant secondary cell walls and have fundamental implications for overcoming lignocellulose recalcitrance and for the design of advanced wood-based materials.

  • 35.
    Martinez-Abad, Antonio
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap. AlbaNova University Centre.
    Giummarella, Nicola
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Lawoko, Martin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Vilaplana, Francisco
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Differences in extractability under subcritical water reveal interconnected hemicellulose and lignin recalcitrance in birch hardwoods2018Ingår i: Green Chemistry, ISSN 1463-9262, E-ISSN 1463-9270Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Hardwoods constitute an essential renewable resource for the production of platform chemicals and bio-based materials. A method for the sequential extraction of hemicelluloses and lignin from hardwoods is proposed using subcritical water in buffered conditions without prior delignification. This allows the cascade isolation of mannan, xylan and lignin-carbohydrate complexes based on their extractability and recalcitrance in birch lignocellulose. The time evolution of the extraction was monitored in terms of composition, oligomeric mass profiling and sequencing of the hemicelluloses, and molecular structure of the lignin and lignin-carbohydrate complexes (LCCs) by heteronuclear single quantum coherence nuclear magnetic resonance (2D HSQC NMR). The minor mannan and pectin populations are easily extractable at short times (<5 min), whereas the major glucuronoxylan (GX) becomes enriched at moderate extraction times. Longer extraction times results in major hydrolysis exhibiting GX fractions with tighter glucuronation spacing and lignin enrichment. The pattern of acetylation and glucuronation in GX is correlated with extractability and with connectivity with lignin through LCCs. This interconnected molecular heterogeneity of hemicelluloses and lignin has important implications for their supramolecular assembly and therefore determines the recalcitrance of hardwood lignocellulosic biomass.

  • 36.
    Martinez-Abad, Antonio
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap. Univ Alicante, Analyt Chem Nutr & Food Sci, Alicante, Spain.
    Jimenez-Quero, Amparo
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Wohlert, Jakob
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Vilaplana, Francisco
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Spruce hemicelluloses (galactoglucomannan and arabinoglucuronoxylan): Interplay with cellulose and lignin in softwoods2019Ingår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 257Artikel i tidskrift (Övrigt vetenskapligt)
  • 37.
    Martinez-Abad, Antonio
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Quero, Amparo Jimenez
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Berglund, Jennie
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Giummarella, Nicola
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Henriksson, Gunnar
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Lindström, Mikael
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. Wallenberg Wood Sci Ctr, Stockholm, Sweden.;KTH Royal Inst Technol, Fibre & Polymer Technol, Stockholm, Sweden..
    Wohlert, Jakob
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Lawoko, Martin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Vilaplana, Francisco
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Influence of the molecular structure of wood hemicelluloses on the recalcitrance of lignocellulosic biomass2018Ingår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 255Artikel i tidskrift (Övrigt vetenskapligt)
  • 38.
    Martínez-Abad, Antonio
    et al.
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Ruthes, Andrea C.
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Vilaplana, Francisco
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Enzymatic-assisted extraction and modification of lignocellulosic plant polysaccharides for packaging applications2015Ingår i: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 133, nr 2, artikel-id 42523Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Plant polysaccharides comprise the main renewable resource available in the biosphere for biomaterial production. However, the recalcitrant and heterogeneous structure of lignocellulosic biomass hinders the effective fractionation and exploitation of the polysaccharide components for the design of carbohydrate-based materials. Carbohydrate-active enzymes constitute a selective and versatile biotechnological tool that can assist during the biomass pretreatment steps to extract and fractionate the polysaccharide macromolecular components. Moreover, this enzymatic toolbox can be as well exploited for the tailored modification of the molecular structure of relatively pure polysaccharide components to achieve customized macroscopic properties. This review critically discusses the potential and challenges of the use of plant lignocellulosic polysaccharides and enzymatic modifications to design and prepare suitable materials for packaging applications in terms of their structure-property relations. Structural factors such as the molar mass and crystallinity of the polysaccharide fractions and functional factors such as water sensitivity and processability of the derived films are critical for the material performance.

  • 39.
    McKee, Lauren S.
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Martinez-Abad, Antonio
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Ruthes, Andrea C.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap. AlbaNova Univ Ctr, KTH Royal Inst .
    Vilaplana, Francisco
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Brumer, Harry
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Focused Metabolism of beta-Glucans by the Soil Bacteroidetes Species Chitinophaga pinensis2019Ingår i: Applied and Environmental Microbiology, ISSN 0099-2240, E-ISSN 1098-5336, Vol. 85, nr 2, artikel-id UNSP e02231-18Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The genome and natural habitat of Chitinophaga pinensis suggest it has the ability to degrade a wide variety of carbohydrate-based biomass. Complementing our earlier investigations into the hydrolysis of some plant polysaccharides, we now show that C. pinensis can grow directly on spruce wood and on the fungal fruiting body. Growth was stronger on fungal material, although secreted enzyme activity was high in both cases, and all biomass-induced secretomes showed a predominance of beta-glucanase activities. We therefore conducted a screen for growth on and hydrolysis of beta-glucans isolated from different sources. Most noncrystalline beta-glucans supported good growth, with variable efficiencies of polysaccharide deconstruction and oligosaccharide uptake, depending on the polysaccharide backbone linkage. In all cases, beta-glucan was the only type of polysaccharide that was effectively hydrolyzed by secreted enzymes. This contrasts with the secretion of enzymes with a broad range of activities observed during growth on complex heteroglycans. Our findings imply a role for C. pinensis in the turnover of multiple types of biomass and suggest that the species may have two metabolic modes: a "scavenging mode," where multiple different types of glycan may be degraded, and a more "focused mode" of beta-glucan metabolism. The significant accumulation of some types of beta-gluco-oligosaccharides in growth media may be due to the lack of an appropriate transport mechanism, and we propose that this is due to the specificity of expressed polysaccharide utilization loci. We present a hypothetical model for beta-glucan metabolism by C. pinensis that suggests the potential for nutrient sharing among the microbial litter community. IMPORTANCE It is well known that the forest litter layer is inhabited by a complex microbial community of bacteria and fungi. However, while the importance of fungi in the turnover of natural biomass is well established, the role of their bacterial counterparts is less extensively studied. We show that Chitinophaga pinensis, a prominent member of an important bacterial genus, is capable of using both plant and fungal biomass as a nutrient source but is particularly effective at deconstructing dead fungal material. The turnover of dead fungus is key in natural elemental cycles in the forest. We show that C. pinensis can perform extensive degradation of this material to support its own growth while also releasing sugars that may serve as nutrients for other microbial species. Our work adds detail to an increasingly complex picture of life among the environmental microbiota.

  • 40.
    McKee, Lauren S.
    et al.
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Sunner, Hampus
    Anasontzis, George E.
    Toriz, Guillermo
    Gatenholm, Paul
    Bulone, Vincent
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. Univ Adelaide, Australia.
    Vilaplana, Francisco
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Olsson, Lisbeth
    A GH115 alpha-glucuronidase from Schizophyllum commune contributes to the synergistic enzymatic deconstruction of softwood glucuronoarabinoxylan2016Ingår i: Biotechnology for Biofuels, ISSN 1754-6834, E-ISSN 1754-6834, Vol. 9, artikel-id 2Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Lignocellulosic biomass from softwood represents a valuable resource for the production of biofuels and bio-based materials as alternatives to traditional pulp and paper products. Hemicelluloses constitute an extremely heterogeneous fraction of the plant cell wall, as their molecular structures involve multiple monosaccharide components, glycosidic linkages, and decoration patterns. The complete enzymatic hydrolysis of wood hemicelluloses into monosaccharides is therefore a complex biochemical process that requires the activities of multiple degradative enzymes with complementary activities tailored to the structural features of a particular substrate. Glucuronoarabinoxylan (GAX) is a major hemicellulose component in softwood, and its structural complexity requires more enzyme specificities to achieve complete hydrolysis compared to glucuronoxylans from hardwood and arabinoxylans from grasses. Results: We report the characterisation of a recombinant alpha-glucuronidase (Agu115) from Schizophyllum commune capable of removing (4-O-methyl)-glucuronic acid ((Me) GlcA) residues from polymeric and oligomeric xylan. The enzyme is required for the complete deconstruction of spruce glucuronoarabinoxylan (GAX) and acts synergistically with other xylan-degrading enzymes, specifically a xylanase (Xyn10C), an alpha-l-arabinofuranosidase (AbfA), and a beta-xylosidase (XynB). Each enzyme in this mixture showed varying degrees of potentiation by the other activities, likely due to increased physical access to their respective target monosaccharides. The exo-acting Agu115 and AbfA were unable to remove all of their respective target side chain decorations from GAX, but their specific activity was significantly boosted by the addition of the endo-Xyn10C xylanase. We demonstrate that the proposed enzymatic cocktail (Agu115 with AbfA, Xyn10C and XynB) achieved almost complete conversion of GAX to arabinofuranose (Araf), xylopyranose (Xylp), and MeGlcA monosaccharides. Addition of Agu115 to the enzymatic cocktail contributes specifically to 25 % of the conversion. However, traces of residual oligosaccharides resistant to this combination of enzymes were still present after deconstruction, due to steric hindrances to enzyme access to the substrate. Conclusions: Our GH115 alpha-glucuronidase is capable of finely tailoring the molecular structure of softwood GAX, and contributes to the almost complete saccharification of GAX in synergy with other exo- and endo-xylan-acting enzymes. This has great relevance for the cost-efficient production of biofuels from softwood lignocellulose.

  • 41. Mellroth, Peter
    et al.
    Sandalova, Tatyana
    Kikhney, Alexey
    Vilaplana, Francisco
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Hesek, Dusan
    Lee, Mijoon
    Mobashery, Shahriar
    Normark, Staffan
    Svergun, Dmitri
    Henriques-Normark, Birgitta
    Achour, Adnane
    Structural and Functional Insights into Peptidoglycan Access for the Lytic Amidase LytA of Streptococcus pneumoniae2014Ingår i: mBio, ISSN 2161-2129, E-ISSN 2150-7511, Vol. 5, nr 1, s. e01120-13-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The cytosolic N-acetylmuramoyl-L-alanine amidase LytA protein of Streptococcus pneumoniae, which is released by bacterial lysis, associates with the cell wall via its choline-binding motif. During exponential growth, LytA accesses its peptidoglycan substrate to cause lysis only when nascent peptidoglycan synthesis is stalled by nutrient starvation or beta-lactam antibiotics. Here we present three-dimensional structures of LytA and establish the requirements for substrate binding and catalytic activity. The solution structure of the full-length LytA dimer reveals a peculiar fold, with the choline-binding domains forming a rigid V-shaped scaffold and the relatively more flexible amidase domains attached in a trans position. The 1.05-angstrom crystal structure of the amidase domain reveals a prominent Y-shaped binding crevice composed of three contiguous subregions, with a zinc-containing active site localized at the bottom of the branch point. Site-directed mutagenesis was employed to identify catalytic residues and to investigate the relative impact of potential substrate-interacting residues lining the binding crevice for the lytic activity of LytA. In vitro activity assays using defined muropeptide substrates reveal that LytA utilizes a large substrate recognition interface and requires large muropeptide substrates with several connected saccharides that interact with all subregions of the binding crevice for catalysis. We hypothesize that the substrate requirements restrict LytA to the sites on the cell wall where nascent peptidoglycan synthesis occurs. IMPORTANCE Streptococcus pneumoniae is a human respiratory tract pathogen responsible for millions of deaths annually. Its major pneumococcal autolysin, LytA, is required for autolysis and fratricidal lysis and functions as a virulence factor that facilitates the spread of toxins and factors involved in immune evasion. LytA is also activated by penicillin and vancomycin and is responsible for the lysis induced by these antibiotics. The factors that regulate the lytic activity of LytA are unclear, but it was recently demonstrated that control is at the level of substrate recognition and that LytA required access to the nascent peptidoglycan. The present study was undertaken to structurally and functionally investigate LytA and its substrate-interacting interface and to determine the requirements for substrate recognition and catalysis. Our results reveal that the amidase domain comprises a complex substrate-binding crevice and needs to interact with a large-motif epitope of peptidoglycan for catalysis.

  • 42.
    Menzel, Carolin
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap. Univ Politecn Valencia, Inst Ingn Alimentos Desarrolla, Dept Tecnol Alimentos, Valencia, Spain..
    Gonzalez-Martinez, Chelo
    Univ Politecn Valencia, Inst Ingn Alimentos Desarrolla, Dept Tecnol Alimentos, Valencia, Spain..
    Chiralt, Amparo
    Univ Politecn Valencia, Inst Ingn Alimentos Desarrolla, Dept Tecnol Alimentos, Valencia, Spain..
    Vilaplana, Francisco
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Antioxidant starch films containing sunflower hull extracts2019Ingår i: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 214, s. 142-151Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study explores the preparation of antioxidant starch food packaging materials by the incorporation of valuable phenolic compounds extracted from sunflower hulls, which are an abundant by-product from food industry. The phenolic compounds were extracted with aqueous methanol and embedded into starch films. Their effect on starch films was investigated in terms of antioxidant activity, optical, thermal, mechanical, barrier properties and changes in starch molecular structure. The starch molecular structure was affected during thermal processing resulting in a decrease in molar mass, smaller amylopectin molecules and shorter amylose branches. Already 1-2% of extracts were sufficient to produce starch films with high antioxidant capacity. Higher amounts (4-6%) of extract showed the highest antioxidant activity, the lowest oxygen permeability and high stiffness and poor extensibility. The phenolic extracts affected predominantly the mechanical properties, whereas other changes could mainly be correlated to the lower glycerol content which was partially substituted by the extract.

  • 43.
    Morais de Carvalho, Danila
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Abad, Antonio Martinez
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Evtuguin, D. V.
    Colodette, J. L.
    Lindström, Mikael
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Vilaplana, Francisco
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Sevastyanova, Olena
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Isolation and characterization of acetylated glucuronoarabinoxylan from sugarcane bagasse and straw2017Ingår i: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 156, s. 223-234Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Sugarcane bagasse and straw are generated in large volumes as by-products of agro-industrial production. They are an emerging valuable resource for the generation of hemicellulose-based materials and products, since they contain significant quantities of xylans (often twice as much as in hardwoods). Heteroxylans (yields of ca 20% based on xylose content in sugarcane bagasse and straw) were successfully isolated and purified using mild delignification followed by dimethyl sulfoxide (DMSO) extraction. Delignification with peracetic acid (PAA) was more efficient than traditional sodium chlorite (NaClO2) delignification for xylan extraction from both biomasses, resulting in higher extraction yields and purity. We have shown that the heteroxylans isolated from sugarcane bagasse and straw are acetylated glucuronoarabinoxylans (GAX), with distinct molecular structures. Bagasse GAX had a slightly lower glycosyl substitution molar ratio of Araf to Xylp to (0.5:10) and (4-O-Me)GlpA to Xylp (0.1:10) than GAX from straw (0.8:10 and 0.1:10 respectively), but a higher degree of acetylation (0.33 and 0.10, respectively). A higher frequency of acetyl groups substitution at position α-(1 → 3) (Xyl-3Ac) than at position α-(1 → 2) (Xyl-2Ac) was confirmed for both bagasse and straw GAX, with a minor ratio of diacetylation (Xyl-2,3Ac). The size and molecular weight distributions for the acetylated GAX extracted from the sugarcane bagasse and straw were analyzed using multiple-detection size-exclusion chromatography (SEC-DRI-MALLS). Light scattering data provided absolute molar mass values for acetylated GAX with higher average values than did standard calibration. Moreover, the data highlighted differences in the molar mass distributions between the two isolation methods for both types of sugarcane GAX, which can be correlated with the different Araf and acetyl substitution patterns. We have developed an empirical model for the molecular structure of acetylated GAX extracted from sugarcane bagasse and straw with PAA/DMSO through the integration of results obtained from glycosidic linkage analysis, 1H NMR spectroscopy and acetyl quantification. This knowledge of the structure of xylans in sugarcane bagasse and straw will provide a better understanding of the isolation-structure-properties relationship of these biopolymers and, ultimately, create new possibilities for the use of sugarcane xylan in high-value applications, such as biochemicals and bio-based materials. © 2016 Elsevier Ltd

  • 44.
    Moraisde Carvalho, Danila
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Träkemi och massateknologi. Univ Fed Vicosa, Dept Forestry Engn, Pulp & Paper Lab, BR-36570900 Vicosa, MG, Brazil.
    Martinez Abad, Antonio
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Colodette, Jorge Luiz
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Lindström, Mikael
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Vilaplana, Fransisco
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Sevastyanova, Olena
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Träkemi och massateknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Comparative characterization of acetylated heteroxylan from eucalyptus, sugarcane bagasse and sugarcane strawManuskript (preprint) (Övrigt vetenskapligt)
  • 45. Moreno, Roberta B.
    et al.
    Ruthes, Andrea Caroline
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap. Universidade Federal Do Paraná, Brazil.
    Baggio, Cristiane H.
    Vilaplana, Francisco
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Komura, Dirce L.
    Iacomini, Marcello
    Structure and antinociceptive effects of beta-D-glucans from Cookeina tricholoma2016Ingår i: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 141, s. 220-228Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Structurally different water-insoluble (1 -> 3),(1 -> 6) beta-D-glucans were isolated from aqueous and alkaline extracts of the mushroom-forming ascomycete Cookeina tricholoma, a wild edible mushroom found in Brazilian Amazon forest. The structures showed different substitution patterns, which may influence their extractability and consequently their conformation in solution, and different M-w (4.3 x 10(5) Da, 3.7 x 10(5) Da and 8.2 x 10(5) Da, for ICW-Ct, IHW-Ct and IK2-ct, respectively). The main-chains are composed of (1 -> 3) -linked beta-D-Glcp units 0-6 substituted by side chains with different lengths of (1 -> 6)-linked beta-D-Glcp units (ICW-Ct and IHW-Ct) or by a combination of (1 -> 6) -linked beta-D-Glcp units and single units of beta-D-Glcp (IK2-ct). beta-D-glucans with similar Mw and showing only (1 6) -linked beta-D-Glcp units as side chains (ICW-Ct and IHW-Ct) showed significant inhibition of neurogenic pain, 69 +/- 11 and 57 +/- 11% at the dose of 10 mg kg(-1), respectively, in the model of nociception induced by intraplantar injection of formalin.

  • 46.
    Moriana, Rosana
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Vilaplana, Francisco
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Ek, Monica
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Cellulose Nanocrystals from Forest Residues as Reinforcing Agents for Composites: A Study from Macro- to Nano-Dimensions2016Ingår i: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 139, s. 139-149Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study investigates for the first time the feasibility of extracting cellulose nanocrystals (CNCs) from softwood forestry logging residues (woody chips, branches and pine needles), with an obtained gravimetric yield of over 13%. Compared with the other residues, woody chips rendered a higher yield of bleached cellulosic fibers with higher hemicellulose, pectin and lignin content, longer diameter, and lower crystallinity and thermal stability. The isolation of CNCs from these bleached cellulosic fibers was verified by the removal of most of their amorphous components, the increase in the crystallinity index, and the nano-dimensions of the individual crystals. The differences in the physico-chemical properties of the fibers extracted from the three logging residues resulted in CNCs with specific physico-chemical properties. The potential of using the resulting CNCs as reinforcements in nanocomposites was discussed in terms of aspect ratio, crystallinity and thermal stability.

  • 47.
    Moriana, Rosana
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Träkemi och massateknologi. Instituto de Tecnología de Materiales (ITM), Escuela Técnica Superior de Ingeniería Del Diseño (ETSID), Universidad Politécnica, Spain.
    Vilaplana, Francisco
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Träkemi och massateknologi. KTH, Skolan för bioteknologi (BIO), Glykovetenskap. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Karlsson, Sigbritt
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Träkemi och massateknologi. University of Skövde, Sweden .
    Ribes, Amparo
    Correlation of chemical, structural and thermal properties of natural fibres for their sustainable exploitation2014Ingår i: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 112, s. 422-431Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The potential of lignocellulosic natural fibres as renewable resources for thermal conversion and material reinforcement is largely dependent on the correlation between their chemical composition, crystalline structure and thermal decomposition properties. Significant differences were observed in the chemical composition of cotton, flax, hemp, kenaf and jute natural fibres in terms of cellulose, hemicellulose and lignin content, which influence their morphology, thermal properties and pyrolysis product distribution. A suitable methodology to study the kinetics of the thermal decomposition process of lignocellulosic fibres is proposed combining different models (Friedman, Flynn-Wall-Ozawa, Criado and Coats-Redfern). Cellulose pyrolysis can be modelled with similar kinetic parameters for all the natural fibres whereas the kinetic parameters for hemicellulose pyrolysis show intrinsic differences that can be assigned to the heterogeneous hemicellulose sugar composition in each natural fibre. This study provides the ground to critically select the most promising fibres to be used either for biofuel or material applications.

  • 48. Moriana, Rosana
    et al.
    Vilaplana, Francisco
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Karlsson, Sigbritt
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Ribes-Greus, Amparo
    Improved thermo-mechanical properties by the addition of natural fibres in starch-based sustainable biocomposites2011Ingår i: Composites. Part A, Applied science and manufacturing, ISSN 1359-835X, E-ISSN 1878-5840, Vol. 42, nr 1, s. 30-40Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Sustainable biocomposites based on thermoplastic starch copolymers (Mater-Bi KE03B1) and biofibres (cotton, hemp and kenaf) were prepared and characterised in terms of their thermo-mechanical and morphological properties. Biocomposites exhibit improved thermal stability and mechanical properties in comparison with the Mater-Bi KE. Biofibres act as suitable thermal stabilizers for the Mater-Bi KE, by increasing the maximum decomposition temperature and the Ea associated to the thermal decomposition process. Biofibre addition into the Mater-Bi KE results in higher storage modulus and in a reduction of the free-volume-parameter associated to the Mater-Bi KE glass transition. The influence of different biofibres on the thermo-mechanical properties of the biocomposites has been discussed. Hemp and kenaf enhance the thermal stability and reduce the free volume-parameter of Mater-Bi KE more significantly than cotton fibres, although the latter exhibits the highest mechanical performance. These differences may be explained by the improved interaction of lignocellulosic fibres with the Mater-Bi KE, due to the presence of hemicellulose and lignin in their formulation.

  • 49.
    Moriana, Rosana
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Vilaplana, Francisco
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Zhang, Yujia
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Ek, Monica
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Using waste biomass to obtain a renewable nanocomposite based on cellulosic biofibre and cereal wall polymers2013Ingår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 245Artikel i tidskrift (Övrigt vetenskapligt)
  • 50. Nilsson, Johanna
    et al.
    Vilaplana, Francisco
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymera material.
    Karlsson, Sigbritt
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymera material.
    Bjurman, Jonny
    Iversen, Tommy
    The Validation of Artificial Ageing Methods for Silk Textiles Using Markers for Chemical and Physical Properties of Seventeenth-Century Silk2010Ingår i: Studies in Conservation, ISSN 0039-3630, E-ISSN 2047-0584, Vol. 55, nr 1, s. 55-65Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Royal Armoury in Stockholm has conducted a project to experimentally evaluate conservation methods used for historic costumes. As the historic value of authentic artefacts precludes their use in experimental work, artificially aged standard silk needs to be used as a substitute. This study aimed to find a suitable artificial ageing method for standard silk resulting in a degradation state that simulated that of silk from seventeenth-century costumes. Four artificial ageing methods were studied: (1) thermal oxidation it, dry air, (2) exposure to different relative humidity (RH), (3) immersion in solutions of varied pH, (4) accelerated ultraviolet (UV) exposure at 50 +/- 2 degrees C, 95% RH. Different chemical and physical properties for silk were evaluated using Fourier transform infrared spectroscopy, size exclusion chromatography and tensile tests, which were employed as analytical indicators for comparison between the artificially aged silk and samples front seventeenth-century costumes. Of the ageing methods tested in this study, thermo-oxidation at 125 degrees C in dry air for 28-56 days produced silk with properties most like those of-historic silk samples.

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