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Publications (10 of 11) Show all publications
Berglund, J., Chen, P., Vilaplana, F. & $$$Wohlert, J. (2019). Computer modeling of the structure and dynamics of hemicelluloses. Paper presented at National Meeting of the American-Chemical-Society (ACS), MAR 31-APR 04, 2019, Orlando, FL. Abstracts of Papers of the American Chemical Society, 257
Open this publication in new window or tab >>Computer modeling of the structure and dynamics of hemicelluloses
2019 (English)In: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 257Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2019
National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:kth:diva-257594 (URN)000478860502443 ()
Conference
National Meeting of the American-Chemical-Society (ACS), MAR 31-APR 04, 2019, Orlando, FL
Note

QC 20190919

Available from: 2019-09-19 Created: 2019-09-19 Last updated: 2019-09-19Bibliographically approved
Berglund, J., Mikkelsen, D., Flanagan, B., Dhital, S., Henriksson, G., Lindström, M., . . . Vilaplana, F. (2019). Hydrogels of bacterial cellulose and wood hemicelluloses as a model of plant secondary cell walls. Paper presented at National Meeting of the American-Chemical-Society (ACS), MAR 31-APR 04, 2019, Orlando, FL. Abstracts of Papers of the American Chemical Society, 257
Open this publication in new window or tab >>Hydrogels of bacterial cellulose and wood hemicelluloses as a model of plant secondary cell walls
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2019 (English)In: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 257Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2019
National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:kth:diva-257620 (URN)000478860502446 ()
Conference
National Meeting of the American-Chemical-Society (ACS), MAR 31-APR 04, 2019, Orlando, FL
Note

QC 20190918

Available from: 2019-09-18 Created: 2019-09-18 Last updated: 2019-09-18Bibliographically approved
Martinez-Abad, A., Quero, A. J., Berglund, J., Giummarella, N., Henriksson, G., Lindström, M., . . . Vilaplana, F. (2018). Influence of the molecular structure of wood hemicelluloses on the recalcitrance of lignocellulosic biomass. Paper presented at 255th National Meeting and Exposition of the American-Chemical-Society (ACS) - Nexus of Food, Energy, and Water, MAR 18-22, 2018, New Orleans, LA. Abstract of Papers of the American Chemical Society, 255
Open this publication in new window or tab >>Influence of the molecular structure of wood hemicelluloses on the recalcitrance of lignocellulosic biomass
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2018 (English)In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 255Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
American Chemical Society (ACS), 2018
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-240163 (URN)000435537702769 ()
Conference
255th National Meeting and Exposition of the American-Chemical-Society (ACS) - Nexus of Food, Energy, and Water, MAR 18-22, 2018, New Orleans, LA
Note

QC 20190111

Available from: 2019-01-11 Created: 2019-01-11 Last updated: 2019-01-11Bibliographically approved
Henriksson, G., Berglund, J., Wohlert, J., Lawoko, M., Aminzadeh, S., Lindström, M. & Vilaplana, F. (2018). Non-cellulose wood polysaccharides - a need for a stricter structural and functional classification?. Paper presented at 255th National Meeting and Exposition of the American-Chemical-Society (ACS) - Nexus of Food, Energy, and Water, MAR 18-22, 2018, New Orleans, LA. Abstract of Papers of the American Chemical Society, 255
Open this publication in new window or tab >>Non-cellulose wood polysaccharides - a need for a stricter structural and functional classification?
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2018 (English)In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 255Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
American Chemical Society (ACS), 2018
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-240158 (URN)000435537702766 ()
Conference
255th National Meeting and Exposition of the American-Chemical-Society (ACS) - Nexus of Food, Energy, and Water, MAR 18-22, 2018, New Orleans, LA
Note

QC 20190108

Available from: 2019-01-08 Created: 2019-01-08 Last updated: 2019-01-08Bibliographically approved
Berglund, J. (2018). Wood Hemicelluloses - Fundamental Insights on Biological and Technical Properties. (Doctoral dissertation). Stockholm, Sweden: KTH Royal Institute of Technology
Open this publication in new window or tab >>Wood Hemicelluloses - Fundamental Insights on Biological and Technical Properties
2018 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Hemicelluloses are a group of heterogeneous polysaccharides representing around 30 % of wood where the dominating types are xylans, glucomannans and xyloglucans. Hemicelluloses complex molecular structure makes it difficult to understand the relationship between structure and properties entirely, and their biological role is not yet fully verified. Additionally, hemicelluloses are sensitive to chemical processing and are not utilized to their full potentials for production of value-added products such as materials, additives to food and pharmaceutical products, etc. Increased knowledge regarding their functions is important for the development of both processes and products. The aim with this work has therefore been to increase the fundamental understanding about how the structure and properties of wood hemicelluloses are correlated, and properties such as flexibility, interaction with cellulose, solubility, resistance to chemical-, thermal-, and enzymatic degradation have been explored.

Molecular dynamics (MD) simulations were used to, in detail, study the structures found in wood hemicelluloses. The flexibility was evaluated by comparing the impact of backbone sugars on the conformational space and also the impact of side groups was considered. Based on the conformational space of backbone glycosidic linkages the flexibility order of hemicelluloses in an aqueous environment was determined to be: xylan > glucomannan > xyloglucan. Additionally, the impact of xylan structure on cellulose interaction was evaluated by MD methods.

Hemicelluloses were extracted from birch and spruce, and were used to fabricate different composite hydrogels with bacterial cellulose. These materials were studied with regards to mechanical properties, and it was shown that galactoglucomannans mainly contributed to an increased modulus in compression, whereas the most significant effect from xylan was increased strain under uniaxial tensile testing. Besides, other polysaccharides of similar structure as galactoglucomannans were modified and used as pure, well defined, models. Acetyl groups are naturally occurring decorations of wood hemicelluloses and can also be chemically introduced. Here, mannans with different degrees of acetylation were prepared and the influence of structure on solubility in water and the organic solvent DMSO were evaluated. Furthermore, the structure and water solubility influenced the interaction with cellulose. Acetylation also showed to increase the thermal and biological stability of mannans.

With chemical pulping processes in mind, the degradability of spruce galactoglucomannans in alkaline solution were studied with regards to the structure, and the content of more or less stable structural regions were proposed.

Abstract [sv]

Hemicellulosor är en grupp av heterogena polysackarider som utgör ca 30 % av trä och där de vanligaste typerna är xylaner, glukomannaner och xyloglukaner. Den komplexa strukturen gör det svårt att fullständigt förstå förhållandet mellan struktur och egenskaper, och deras biologiska roll är ännu inte fullständigt kartlagd. Dessutom är hemicellulosor känsliga för kemiska processer och tas inte tillvara på bästa sätt för att tillverka förädlade produkter så som nya material eller användas som additiv till livsmedel och farmaceutiska produkter etc. En ökad kunskap om deras funktion är viktig för utvecklingen av både processer och material. Målet med detta arbete har därför varit att öka den fundamentala förståelsen för hur struktur och egenskaper hos hemicellulosor från trä hänger ihop. Egenskaper så som flexibilitet, interaktion med cellulosa, löslighet, samt kemisk-, termisk- och biologisk stabilitet har utvärderats.

Molekyldynamiska (MD) simuleringar användes för att studera strukturer som återfinns i hemicellulosor på detaljnivå. Flexibiliteten utvärderades med avseende på hur konformationsrymden påverkades av vilka monosackarider som ingick i huvudkedjan, samt påverkan från sidogrupper. Baserat på huvudkedjan bör flexibilitetsordningen för studerade hemicellulosor i vattenlösning vara: xylan > glukomannan > xyloglukan. Dessutom användes MD simuleringar för att analysera hur strukturen hos xylaner påverkar interaktionen med cellulosa.

Hemicellulosor extraherades från björk och gran, och användes för att producera flera olika komposithydrogeler med bakteriell cellulosa. Dessa material studerades bland annat med avseende på de mekaniska egenskaperna och de tydligaste observationerna var att galaktoglukomannan bidrog till en ökad kompressionsmodul, medan xylan framförallt ökade töjbarheten i dragprov. Dessutom modifierades modellpolysackarider med liknande struktur som galaktoglukomannan och användes som extra rena och väldefinierade modellsystem. Acetylgrupper förekommer naturligt som sidogrupper på hemicellulosor och de kan även introduceras via kemisk modifiering. I detta projekt tillverkades mannaner med olika acetyleringsgrad och hur strukturen påverkade lösligheten i vatten och det organiska lösningsmedlet DMSO utvärderades. Det visade sig även att strukturen och lösligheten i vatten påverkade interaktionen med cellulosa. Acetyleringen hade också en positiv effekt på den biologiska och termiska stabiliteten.

Med kemiska massaprocesser i åtanke studerades nedbrytbarheten hos galaktoglukomannaner från gran i alkalisk lösning med avseende på strukturen och förekomsten av mer eller mindre stabila strukturella regioner föreslogs.

Place, publisher, year, edition, pages
Stockholm, Sweden: KTH Royal Institute of Technology, 2018. p. 82
Series
TRITA-CBH-FOU ; 2018:63
Keywords
hemicellulose, wood, glucomannan, xylan, structure, acetylation, flexibility, solubility, interaction with cellulose, stability., hemicellulosa, trä, glukomannan, xylan, struktur, acetylering, flexibilitet, löslighet, interaktion med cellulosa, stabilitet.
National Category
Wood Science Chemical Sciences Paper, Pulp and Fiber Technology Plant Biotechnology
Research subject
Fibre and Polymer Science
Identifiers
urn:nbn:se:kth:diva-240982 (URN)978-91-7873-068-1 (ISBN)
Public defence
2019-02-01, F3, Lindstedtsvägen 26, Stockholm, 10:00 (English)
Opponent
Supervisors
Funder
Knut and Alice Wallenberg Foundation
Note

QC 20190107

Available from: 2019-01-07 Created: 2019-01-07 Last updated: 2019-01-07Bibliographically approved
Martinez-Abad, A., Berglund, J., Toriz, G., Gatenholm, P., Henriksson, G., Lindström, M., . . . Vilaplana, F. (2017). Regular Motifs in Xylan Modulate Molecular Flexibility and Interactions with Cellulose Surfaces. Plant Physiology, 175(4), 1579-1592
Open this publication in new window or tab >>Regular Motifs in Xylan Modulate Molecular Flexibility and Interactions with Cellulose Surfaces
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2017 (English)In: Plant Physiology, ISSN 0032-0889, E-ISSN 1532-2548, Vol. 175, no 4, p. 1579-1592Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
American Society of Plant Biologists, 2017
National Category
Plant Biotechnology
Identifiers
urn:nbn:se:kth:diva-220477 (URN)10.1104/pp.17.01184 (DOI)000417083900007 ()2-s2.0-85037747688 (Scopus ID)
Note

QC 20171222

Available from: 2017-12-22 Created: 2017-12-22 Last updated: 2019-01-07Bibliographically approved
Berglund, J., Bergenstråhle, M., Vilaplana, F., d'Ortoli, T. A., Widmalm, G., Lawoko, M., . . . Wohlert, J. (2016). How the flexibility properties of hemicelluloses are affected by the glycosidic bonds between different backbone sugars - A molecular dynamics study. Abstracts of Papers of the American Chemical Society, 251
Open this publication in new window or tab >>How the flexibility properties of hemicelluloses are affected by the glycosidic bonds between different backbone sugars - A molecular dynamics study
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2016 (English)In: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 251Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2016
National Category
Organic Chemistry
Identifiers
urn:nbn:se:kth:diva-242668 (URN)000431903802406 ()
Note

QC 20190222

Available from: 2019-02-22 Created: 2019-02-22 Last updated: 2019-08-21Bibliographically approved
Bi, R., Berglund, J., Vilaplana, F., McKee, L. & Henriksson, G.The Degree Of Acetylation Affects The Microbial Degradability Of Hemicelluloses.
Open this publication in new window or tab >>The Degree Of Acetylation Affects The Microbial Degradability Of Hemicelluloses
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(English)Manuscript (preprint) (Other academic)
National Category
Polymer Technologies Microbiology
Identifiers
urn:nbn:se:kth:diva-182286 (URN)
Note

QS 2016

Available from: 2016-02-18 Created: 2016-02-18 Last updated: 2016-02-23Bibliographically approved
Berglund, J., Farahani, S. K., de Carvalho, D. M., Lawoko, M., Wohlert, J., Henriksson, G., . . . Vilaplana, F.The influence of acetylation and sugar composition on the (in)solubility of mannans, their interaction with cellulose surfaces and thermal properties.
Open this publication in new window or tab >>The influence of acetylation and sugar composition on the (in)solubility of mannans, their interaction with cellulose surfaces and thermal properties
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(English)Manuscript (preprint) (Other academic)
National Category
Natural Sciences
Identifiers
urn:nbn:se:kth:diva-251378 (URN)
Note

QC 20190514

Available from: 2019-05-13 Created: 2019-05-13 Last updated: 2019-05-14Bibliographically approved
Berglund, J., Kishani, S., de Carvalho, D. M., Lawoko, M., Wohlert, J., Henriksson, G., . . . Vilaplana, F.The influence of acetylation and sugar composition on the (in)solubility of mannans, their interaction with cellulose surfaces and thermal properties..
Open this publication in new window or tab >>The influence of acetylation and sugar composition on the (in)solubility of mannans, their interaction with cellulose surfaces and thermal properties.
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(English)Manuscript (preprint) (Other academic)
National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:kth:diva-240496 (URN)
Note

QC 20190108

Available from: 2018-12-19 Created: 2018-12-19 Last updated: 2019-05-09Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-0277-2269

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