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Hedenström, Mattias
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Publications (10 of 47) Show all publications
Laera, A., Yekta, S. S., Hedenström, M., Buzier, R., Guibaud, G., Dario, M., . . . van Hullebusch, E. D. (2019). A simultaneous assessment of organic matter and trace elements bio-accessibility in substrate and digestate from an anaerobic digestion plant. Bioresource Technology, 288, Article ID 121587.
Open this publication in new window or tab >>A simultaneous assessment of organic matter and trace elements bio-accessibility in substrate and digestate from an anaerobic digestion plant
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2019 (English)In: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 288, article id 121587Article in journal (Refereed) Published
Abstract [en]

This study evaluates a simultaneous assessment of organic matter (OM) and trace elements (TE) bio-accessibility in substrate and digestate from a full-scale anaerobic digester by a sequential OM extraction method. Simultaneous release of TE was determined along with the extraction of different OM fractions and the effects of extracting reagents on characteristics of OM were evaluated by nuclear magnetic resonance (NMR) spectroscopy. The reagents used for sequential extraction of OM were not enough selective. However, proteins were particularly removed by 0.1 M NaOH, while 72% H2SO4 mainly extracted hemicellulose and cellulose. The OM fractionation allowed for simultaneous extraction of > 60% of total As, Cd, Co, Fe, Mn, Ni and Zn, while the extraction was limited for Al, Cr, Cu, Mo, and Pb. In substrate, > 50% of total As, Co, Mn and Ni and < 40% of total Fe, Zn and Mo were identified in bio-accessible fractions. In digestate, all elements demonstrated poor bio-accessibility except for As.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Sequential chemical extraction, Organic matter fractionation, Trace elements fractionation, NMR spectroscopy, Anaerobic co-digestion
National Category
Biochemistry and Molecular Biology
Identifiers
urn:nbn:se:umu:diva-161497 (URN)10.1016/j.biortech.2019.121587 (DOI)000472018100008 ()31200348 (PubMedID)
Available from: 2019-07-12 Created: 2019-07-12 Last updated: 2019-07-12Bibliographically approved
Michel, M., Visnes, T., Homan, E. J., Seashore-Ludlow, B., Hedenström, M., Wiita, E., . . . Helleday, T. (2019). Computational and Experimental Druggability Assessment of Human DNA Glycosylases. ACS OMEGA, 4(7), 11642-11656
Open this publication in new window or tab >>Computational and Experimental Druggability Assessment of Human DNA Glycosylases
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2019 (English)In: ACS OMEGA, ISSN 2470-1343, Vol. 4, no 7, p. 11642-11656Article in journal (Refereed) Published
Abstract [en]

Due to a polar or even charged binding interface, DNA-binding proteins are considered extraordinarily difficult targets for development of small-molecule ligands and only a handful of proteins have been targeted successfully to date. Recently, however, it has been shown that development of selective and efficient inhibitors of 8-oxoguanine DNA glycosylase is possible. Here, we describe the initial druggability assessment of DNA glycosylases in a computational setting and experimentally investigate several methods to target endonuclease VIII-like 1 (NEIL1) with small-molecule inhibitors. We find that DNA glycosylases exhibit good predicted druggability in both DNA-bound and -unbound states. Furthermore, we find catalytic sites to be highly flexible, allowing for a range of interactions and binding partners. One flexible catalytic site was rationalized for NEIL1 and further investigated experimentally using both a biochemical assay in the presence of DNA and a thermal shift assay in the absence of DNA.

National Category
Biochemistry and Molecular Biology
Identifiers
urn:nbn:se:umu:diva-164548 (URN)10.1021/acsomega.9b00162 (DOI)000482176800036 ()31460271 (PubMedID)
Available from: 2019-10-23 Created: 2019-10-23 Last updated: 2019-10-23Bibliographically approved
Yekta, S. S., Hedenström, M., Svensson, B. H., Sundgren, I., Dario, M., Enrich-Prast, A., . . . Bjorn, A. (2019). Molecular characterization of particulate organic matter in full scale anaerobic digesters: An NMR spectroscopy study. Science of the Total Environment, 685, 1107-1115
Open this publication in new window or tab >>Molecular characterization of particulate organic matter in full scale anaerobic digesters: An NMR spectroscopy study
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2019 (English)In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 685, p. 1107-1115Article in journal (Refereed) Published
Abstract [en]

This study assesses the molecular characteristics of particulate organic matter (POM) in agricultural and food waste digesters and elucidates the molecular properties of the recalcitrant POM fraction, which remains in the digestate after AD process. Molecular properties of POM in influent (substrate) and effluent (digestate) of seven full-scale AD plants (three agricultural waste and four food waste digesters) were characterized and compared using solid-state (13)C( )cross-polarization magic angle spinning (CP-MAS) and solution-state H-1,C-13 heteronuclear single-quantum coherence (HSQC) nuclear magnetic resonance (NMR) spectroscopy. Comparison of the POM structural compositions of substrate and digestate from each AD plant revealed an enrichment of protein structures relative to the carbohydrates in most cases, implying a preferential degradation of the carbohydrates over proteins and/or increase of microbial biomass upon AD of agricultural and food wastes. Distinctive molecular structures of labile and recalcitrant fractions of POM, subjected to AD, were identified by comparing the NMR spectra of all substrate and digestate POM. Accordingly, the labile POM fraction in food and agricultural solid wastes is characterized by structural entities of lipids and starch-like carbohydrates, whereas recalcitrant POM structures resemble alkyl and aromatic subunits of amino acids, lignin, and polysaccharides with beta-glycosidic linkages. This information serves as a basis to further explore optimization approaches for improving AD of the underutilized POM and the fate of organic matter in digestate-amended arable lands. (C) 2018 The Authors. Published by Elsevier B.V.

Place, publisher, year, edition, pages
ELSEVIER, 2019
Keywords
Anaerobic digestion, Food waste, Agricultural waste, Organic matter, NMR, Digestate
National Category
Organic Chemistry
Identifiers
urn:nbn:se:umu:diva-162296 (URN)10.1016/j.scitotenv.2019.06.264 (DOI)000477951900102 ()31390701 (PubMedID)
Available from: 2019-08-27 Created: 2019-08-27 Last updated: 2019-08-27Bibliographically approved
Yekta, S. S., Hedenström, M., Stehr, J. E., Dario, M., Hertkorn, N. & Björn, A. (2018). Pretreatment of anaerobic digester samples by hydrochloric acid for solution-state H-1 and C-13 NMR spectroscopic characterization of organic matter. Chemosphere, 199, 201-209
Open this publication in new window or tab >>Pretreatment of anaerobic digester samples by hydrochloric acid for solution-state H-1 and C-13 NMR spectroscopic characterization of organic matter
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2018 (English)In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 199, p. 201-209Article in journal (Refereed) Published
Abstract [en]

Pretreatment of anaerobic digester samples by hydrochloric acid (HCl) resulted in removal of Fe-based mineral and coordination compounds, attenuating their interferences with solution-state nuclear magnetic resonance (NMR) spectroscopic characterization of the solid phase organic matter. Substrate (influent) and digestate (effluent) samples from two full-scale anaerobic digesters, designated CD (co-digester) and SSD (sewage sludge digester), were investigated. Pretreatment of CD samples with 0.2-2.0 mol l(-1) HCl and pretreatment of SSD samples with 1.0-3.0 mol l(-1) HCl removed 96-100% and 76-80% of total Fe, respectively. Pretreatment declined overall paramagnetic characteristics of digestate samples, manifested by 50% (CD) and 70% (SSD) decrease in electron paramagnetic resonance signal intensities. As a result, meaningful solution-state H-1,C-13 heteronuclear single quantum coherence and H-1 NMR spectra of DMSO-d(6) soluble organic matter could be acquired. Sample pretreatment with the lowest concentration of HCl resulted in alteration of C:N ratios in solid phase, likely due to removal of labile organic and inorganic C- and N-containing compounds, while elevating the HCl concentration did not further change the C:N ratios. Furthermore, sample pretreatment increased the solubility of carbohydrates and proteins in DMSO-d(6), enabling the detection of NMR resonances from certain structural units of carbohydrates (e.g. anomeric O2CH) and proteins (e.g. CH alpha in amino acids). Both attenuation of the paramagnetic matrix as well as art enhanced solubility of carbohydrate and protein fractions of the samples in DMSO-d(6) solvent contributed to an improved molecular characterization of anaerobic digester samples by solution-state NMR analysis. 

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Anaerobic digestion, Organic matter characterization, Solution-state NMR, Sample pretreatment, HCI
National Category
Analytical Chemistry
Identifiers
urn:nbn:se:umu:diva-148628 (URN)10.1016/j.chemosphere.2018.02.015 (DOI)000428973200025 ()29438947 (PubMedID)
Available from: 2018-06-26 Created: 2018-06-26 Last updated: 2018-06-26Bibliographically approved
Talyzin, A., Mercier, G., Klechikov, A., Hedenström, M., Johnels, D., Wei, D., . . . Moons, E. (2017). Brodie vs Hummers graphite oxides for preparation of multi-layered materials. Carbon, 115, 430-440
Open this publication in new window or tab >>Brodie vs Hummers graphite oxides for preparation of multi-layered materials
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2017 (English)In: Carbon, ISSN 0008-6223, E-ISSN 1873-3891, Vol. 115, p. 430-440Article in journal (Refereed) Published
Abstract [en]

Graphite oxides synthesized by one and two step Brodie oxidation (BGO) and Hummers (HGO) methods were analyzed by a variety of characterization methods in order to evaluate the reasons behind the difference in their properties. It is found that the Brodie method results in a higher relative amount of hydroxyl groups and a more homogeneous overall distribution of functional groups over the planar surface of the graphene oxide flakes. The higher number of carbonyl and carboxyl groups in HGO, detected by several methods, including XPS, NMR and FTIR, unavoidably results in defects of the graphene "skeleton", holes and overall disruption of the carbon-carbon bond network, stronger deviation from planar flake shape and poor ordering of the graphene oxide layers. It is also suggested that functional groups in HGO are less homogeneously distributed over the flake surface, forming some nanometer-sized graphene areas. The presence of differently oxidized areas on the GO surface results in inhomogeneous solvation and hydration of HGO and effects of inter- and intra-stratification. The proposed interpretation of the data explains the higher mechanical strength of multi-layered BGO membranes/papers, which are also less affected by humidity changes, thus providing an example of a membrane property superior to that of HGO.

Place, publisher, year, edition, pages
Elsevier, 2017
Keywords
graphite, oxide
National Category
Condensed Matter Physics
Research subject
Physics
Identifiers
urn:nbn:se:umu:diva-130949 (URN)10.1016/j.carbon.2016.12.097 (DOI)000395601300045 ()
Available from: 2017-02-01 Created: 2017-02-01 Last updated: 2018-06-09Bibliographically approved
Gillgren, T., Hedenström, M. & Jönsson, L. J. (2017). Comparison of laccase-catalyzed cross-linking of organosolv lignin and lignosulfonates. International Journal of Biological Macromolecules, 105(1), 438-446
Open this publication in new window or tab >>Comparison of laccase-catalyzed cross-linking of organosolv lignin and lignosulfonates
2017 (English)In: International Journal of Biological Macromolecules, ISSN 0141-8130, E-ISSN 1879-0003, Vol. 105, no 1, p. 438-446Article in journal (Refereed) Published
Abstract [en]

Lignin, an underutilized by-product from chemical pulping of wood, can be modified enzymatically through oxidation by laccase. However, little is known about the molecular details surrounding the cross linking which is a result of the oxidation. To reduce this lack of knowledge, we used oxygen consumption rate data, phenolic content data and molecular weight data together with data from NMR and FTIR spectroscopy to.characterize laccase-catalyzed cross-linking of the industrial lignin preparations organosolv lignin and lignosulfonate. The organosolv lignin preparation had a M-n of 780 g/mol, a M-w of 5200 g/mol, and a phenolic content of 1.8 mmol/g. The lignosulfonate preparation had a M-n of 6000 g/mol, a M-w of 19800 g/mol, and a phenolic content of 1.1 mmol/g. Laccase-catalyzed oxidation of organosolv lignin was characterized by a relatively slow increase in molecular weight, decreased intensities for aromatic signals and p-hydroxycinnamyl groups, and increased intensity for beta-O-4' signals, whereas oxidation of lignosulfonates resulted in a very rapid increase in molecular weight, and strongly decreased intensities for aromatic signals. The data suggest that lignosulfonates cross-linked by couplings to the aromatic ring (e.g. 5-5' and 4-O-5'), whereas beta-O-4' coupling characterized cross-linking of organosolv lignin, probably involving cinnamyl alcohol end-groups. (C) 2017 Published by Elsevier B.V.

Place, publisher, year, edition, pages
ELSEVIER SCIENCE BV, 2017
Keywords
Lignin, Lignosulfonate, Organosolv, Laccase, Polymerization, Cross-link
National Category
Polymer Chemistry
Identifiers
urn:nbn:se:umu:diva-143011 (URN)10.1016/j.ijbiomac.2017.07.061 (DOI)000414882900049 ()28711620 (PubMedID)
Projects
Bio4Energy
Available from: 2017-12-14 Created: 2017-12-14 Last updated: 2019-08-30Bibliographically approved
Pawar, P.-A. M., Ratke, C., Balasubramanian, V. K., Chong, S.-L., Gandla, M. L., Adriasola, M., . . . Mellerowicz, E. J. (2017). Downregulation of RWA genes in hybrid aspen affects xylan acetylation and wood saccharification. New Phytologist, 214, 1491-1505
Open this publication in new window or tab >>Downregulation of RWA genes in hybrid aspen affects xylan acetylation and wood saccharification
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2017 (English)In: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 214, p. 1491-1505Article in journal (Refereed) Published
Abstract [en]

High acetylation of angiosperm wood hinders its conversion to sugars by glycoside hydrolases, subsequent ethanol fermentation and (hence) its use for biofuel production. We studied the REDUCED WALL ACETYLATION (RWA) gene family of the hardwood model Populus to evaluate its potential for improving saccharification. The family has two clades, AB and CD, containing two genes each. All four genes are expressed in developing wood but only RWA-A and -B are activated by master switches of the secondary cell wall PtNST1 and PtMYB21. Histochemical analysis of promoter:: GUS lines in hybrid aspen (Populus tremula x tremuloides) showed activation of RWA-A and -B promoters in the secondary wall formation zone, while RWA-C and -D promoter activity was diffuse. Ectopic downregulation of either clade reduced wood xylan and xyloglucan acetylation. Suppressing both clades simultaneously using the wood-specific promoter reduced wood acetylation by 25% and decreased acetylation at position 2 of Xylp in the dimethyl sulfoxide-extracted xylan. This did not affect plant growth but decreased xylose and increased glucose contents in the noncellulosic monosaccharide fraction, and increased glucose and xylose yields of wood enzymatic hydrolysis without pretreatment. Both RWA clades regulate wood xylan acetylation in aspen and are promising targets to improve wood saccharification.

Keywords
Cas1p, Populus, REDUCED CELL WALL ACETYLATION, saccharification, wood acetylation, xylan, xylan etylation, xylem
National Category
Organic Chemistry
Identifiers
urn:nbn:se:umu:diva-137061 (URN)10.1111/nph.14489 (DOI)000402412500011 ()
Projects
Bio4Energy
Available from: 2017-06-26 Created: 2017-06-26 Last updated: 2019-08-30Bibliographically approved
Pawar, P.-A. M., Derba-Maceluch, M., Chong, S.-L., Gandla, M. L., Bashar, S. S., Sparrman, T., . . . Mellerowicz, E. J. (2017). In muro deacetylation of xylan affects lignin properties and improves saccharification of aspen wood. Biotechnology for Biofuels, 10, Article ID 98.
Open this publication in new window or tab >>In muro deacetylation of xylan affects lignin properties and improves saccharification of aspen wood
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2017 (English)In: Biotechnology for Biofuels, ISSN 1754-6834, E-ISSN 1754-6834, Vol. 10, article id 98Article in journal (Refereed) Published
Abstract [en]

Background: Lignocellulose from fast growing hardwood species is a preferred source of polysaccharides for advanced biofuels and “green” chemicals. However, the extensive acetylation of hardwood xylan hinders lignocellulose saccharification by obstructing enzymatic xylan hydrolysis and causing inhibitory acetic acid concentrations during microbial sugar fermentation. To optimize lignocellulose for cost-effective saccharification and biofuel production, an acetyl xylan esterase AnAXE1 from Aspergillus niger was introduced into aspen and targeted to cell walls.

Results: AnAXE1-expressing plants exhibited reduced xylan acetylation and grew normally. Without pretreatment, their lignocellulose yielded over 25% more glucose per unit mass of wood (dry weight) than wild-type plants. Glucose yields were less improved (+7%) after acid pretreatment, which hydrolyses xylan. The results indicate that AnAXE1 expression also reduced the molecular weight of xylan, and xylan–lignin complexes and/or lignin co-extracted with xylan, increased cellulose crystallinity, altered the lignin composition, reducing its syringyl to guaiacyl ratio, and increased lignin solubility in dioxane and hot water. Lignin-associated carbohydrates became enriched in xylose residues, indicating a higher content of xylo-oligosaccharides.

Conclusions: This work revealed several changes in plant cell walls caused by deacetylation of xylan. We propose that deacetylated xylan is partially hydrolyzed in the cell walls, liberating xylo-oligosaccharides and their associated lignin oligomers from the cell wall network. Deacetylating xylan thus not only increases its susceptibility to hydrolytic enzymes during saccharification but also changes the cell wall architecture, increasing the extractability of lignin and xylan and facilitating saccharification.

Keywords
Acetylation, Xylan, Saccharification, Wood, Populus
National Category
Plant Biotechnology
Identifiers
urn:nbn:se:umu:diva-135281 (URN)10.1186/s13068-017-0782-4 (DOI)000399714200002 ()28428822 (PubMedID)
Projects
Bio4Energy
Available from: 2017-05-24 Created: 2017-05-24 Last updated: 2019-08-30Bibliographically approved
Mojica, S. A., Salin, O., Bastidas, R. J., Sunduru, N., Hedenström, M., Andersson, C. D., . . . Gylfe, Å. (2017). N-acylated derivatives of sulfamethoxazole block Chlamydia fatty acid synthesis and interact with FabF. Antimicrobial Agents and Chemotherapy, 61(10), Article ID e00716-17.
Open this publication in new window or tab >>N-acylated derivatives of sulfamethoxazole block Chlamydia fatty acid synthesis and interact with FabF
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2017 (English)In: Antimicrobial Agents and Chemotherapy, ISSN 0066-4804, E-ISSN 1098-6596, Vol. 61, no 10, article id e00716-17Article in journal (Refereed) Published
Abstract [en]

The type II fatty acid synthesis (FASII) pathway is essential for bacterial lipid biosynthesis and continues to be a promising target for novel antibacterial compounds. Recently, it has been demonstrated that Chlamydia is capable of FASII and this pathway is indispensable for Chlamydia growth. Previously, a high-content screen with Chlamydia trachomatis-infected cells was performed, and acylated sulfonamides were identified to be potent growth inhibitors of the bacteria. C. trachomatis strains resistant to acylated sulfonamides were isolated by serial passage of a wild-type strain in the presence of low compound concentrations. Results from whole-genome sequencing of 10 isolates from two independent drug-resistant populations revealed that mutations that accumulated in fabF were predominant. Studies of the interaction between the FabF protein and small molecules showed that acylated sulfonamides directly bind to recombinant FabF in vitro and treatment of C. trachomatis-infected HeLa cells with the compounds leads to a decrease in the synthesis of Chlamydia fatty acids. This work demonstrates the importance of FASII for Chlamydia development and may lead to the development of new antimicrobials.

Place, publisher, year, edition, pages
American society for microbiology, 2017
Keywords
Chlamydia trachomatis, FAS, antimicrobial agents, drug targets
National Category
Microbiology Pharmaceutical Sciences
Identifiers
urn:nbn:se:umu:diva-140637 (URN)10.1128/AAC.00716-17 (DOI)000411481800016 ()
Available from: 2017-10-18 Created: 2017-10-18 Last updated: 2018-06-09Bibliographically approved
Berglund, L., Anugwom, I., Hedenström, M., Aitomäki, Y., Mikkola, J.-P. & Oksman, K. (2017). Switchable ionic liquids enable efficient nanofibrillation of wood pulp. Cellulose (London), 24(8), 3265-3279
Open this publication in new window or tab >>Switchable ionic liquids enable efficient nanofibrillation of wood pulp
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2017 (English)In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 24, no 8, p. 3265-3279Article in journal (Refereed) Published
Abstract [en]

Use of switchable ionic liquid (SIL) pulp offers an efficient and greener technology to produce nanofibers via ultrafine grinding. In this study, we demonstrate that SIL pulp opens up a mechanically efficient route to the nanofibrillation of wood pulp, thus providing both a low cost and chemically benign route to the production of cellulose nanofibers. The degree of fibrillation during the process was evaluated by viscosity and optical microscopy of SIL treated, bleached SIL treated and a reference pulp. Furthermore, films were prepared from the fibrillated material for characterization and tensile testing. It was observed that substantially improved mechanical properties were attained as a result of the grinding process, thus signifying nanofibrillation. Both SIL treated and bleached SIL treated pulps were fibrillated into nanofibers with fiber diameters below 15 nm thus forming networks of hydrophilic nature with an intact crystalline structure. Notably, it was found that the SIL pulp could be fibrillated more efficiently than traditional pulp since nanofibers could be produced with more than 30% less energy when compared to the reference pulp. Additionally, bleaching reduced the energy demand by further 16%. The study demonstrated that this switchable ionic liquid treatment has considerable potential in the commercial production of nanofibers due to the increased efficiency in fibrillation.

Keywords
Switchable ionic liquids (SIL), Efficient fibrillation, Wood pulp, Cellulose nanofiber, Ultrafine grinding
National Category
Paper, Pulp and Fiber Technology Chemical Process Engineering
Identifiers
urn:nbn:se:umu:diva-137721 (URN)10.1007/s10570-017-1354-2 (DOI)000405612000013 ()
Projects
Bio4Energy
Available from: 2017-07-07 Created: 2017-07-07 Last updated: 2019-08-30Bibliographically approved
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