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  • 1. Ahlgren, S.
    et al.
    Röös, E.
    Di Lucia, L.
    Sundberg, Cecilia
    Hansson, P. -A
    EU sustainability criteria for biofuels: Uncertainties in GHG emissions from cultivation2012In: Biofuels, ISSN 1759-7269, E-ISSN 1759-7277, Vol. 3, no 4, p. 399-411Article in journal (Refereed)
    Abstract [en]

    Background: Cultivation of raw material represents a large proportion of biofuelś GHG emissions. The EU renewable energy directive 2009/28/EC specifies a GHG emission default value for cultivation of biofuel raw material (23 g CO2-e/MJ ethanol for wheat). The aim of this study was to quantify the uncertainty in GHG emissions for wheat cultivation in Sweden, considering uncertainty and variability in data at farm level. Results: Two levels of data collection at farm level were analyzed; simple (only yield and amount of N) and advanced (also including amounts and types of energy). The 2.5-97.5 percentile uncertainty for Swedish winter wheat was 20-27 g CO 2-e/MJ, which can be considered large in the context of the Directives threshold of 23 g (to two significant figures). Conclusion: It is concluded that quantifying GHG emissions in order to regulate biofuels is a difficult task, especially emissions from cultivation, since these are biological systems with large variability.

  • 2.
    Ahmad, Arslan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Bhattacharya, Prosun
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Environmental arsenic in a changing world2019In: Groundwater for Sustainable Development, ISSN 2352-801X, Vol. 8, p. 169-171Article in journal (Refereed)
  • 3. Ahmed, Engy
    et al.
    Hugerth, Luisa W.
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Logue, Jürg Brendan
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Bruchert, Volker
    Andersson, Anders F.
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Holmström, Sara J. M.
    Mineral Type Structures Soil Microbial Communities2017In: Geomicrobiology Journal, ISSN 0149-0451, E-ISSN 1521-0529, Vol. 34, no 6, p. 538-545Article in journal (Refereed)
    Abstract [en]

    Soil microorganisms living in close contact with minerals play key roles in the biogeochemical cycling of elements, soil formation, and plant nutrition. Yet, the composition of microbial communities inhabiting the mineralosphere (i.e., the soil surrounding minerals) is poorly understood. Here, we explored the composition of soil microbial communities associated with different types of minerals in various soil horizons. To this effect, a field experiment was set up in which mineral specimens of apatite, biotite, and oligoclase were buried in the organic, eluvial, and upper illuvial horizons of a podzol soil. After an incubation period of two years, the soil attached to the mineral surfaces was collected, and microbial communities were analyzed by means of Illumina MiSeq sequencing of the 16S (prokaryotic) and 18S (eukaryotic) ribosomal RNA genes. We found that both composition and diversity of bacterial, archaeal, and fungal communities varied across the different mineral surfaces, and that mineral type had a greater influence on structuring microbial assemblages than soil horizon. Thus, our findings emphasize the importance of mineral surfaces as ecological niches in soils.

  • 4.
    Akin, Danny E.
    et al.
    Richard B. Russell Agricultural Research Center, Agricultural Research Service, US Department of Agriculture, Athens.
    Henriksson, Gunnar
    KTH, Superseded Departments, Fibre and Polymer Technology.
    Evans, J. D.
    South Central Poultry Research Laboratory, Agricultural Research Service, US Department of Agriculture, USA.
    Adamsen, A. S. P.
    Agro Business Par, Denmark.
    Foulk, J. A.
    Cotton Quality Research Station, Agricultural Research Service, US Department of Agriculture, USA.
    Dodd, R. B.
    Department of Agricultural and Biological Engineering, Clemson University.
    Progress in enzyme-retting of flax2004In: Journal of Natural Fibers, ISSN 1544-0478, Vol. 1, no 1, p. 21-47Article in journal (Refereed)
    Abstract [en]

    New methods for retting flax are sought to overcome problems in the current method of dew-retting of flax. Published data are reviewed and new data presented on the development and testing of a method to ret flax using pectinase-rich enzyme mixtures plus chelators based on cost and fiber yield and properties. In spray enzyme retting (SER), flax stems are crimped to physically disrupt the plant's protective barrier and then sprayed until soaked with, or briefly immersed in, an enzyme/ chelator formulation. Flax is then incubated at temperatures optimal for enzyme activity, washed, and dried. Pilot scale tests, conducted with 10 kg samples of flax retted with a series of formulations, showed that this method effectively retted flax stems from a variety of sources, including fiber flax, mature fiber flax, and linseed straw. Fiber yield, strength, and fineness were significantly influenced by variations in enzyme-chelator amounts. Cellulases in pectinase mixtures appeared to preferentially attack dislocations in fibers and fiber bundles resulting in loss of fiber strength. Polygalacturonases alone effectively separated fiber from non-fiber components. The SER method proved to be an effective framework for further tests on enzyme-chelator formulations that now must be integrated with physical processing to optimize the extraction of flax fibers based on cost and fiber yield and properties.

  • 5. Almström, Peter
    et al.
    Mårtensson, Pär
    KTH, Superseded Departments, Production Engineering.
    Functional coupling in manufacturing systems and its implications2002In: Proceedings of the Institution of mechanical engineers. Part B, journal of engineering manufacture, ISSN 0954-4054, E-ISSN 2041-2975, Vol. 216, no 4, p. 623-626Article in journal (Refereed)
    Abstract [en]

    The axiomatic design theory as stated by Suh has proven useful when designing products, and this success has led to an increasing interest in applying the theory to manufacturing systems development. The theory states that functional couplings should be avoided in general. However, manufacturing systems are potentially coupled in many ways, the most obvious being that manufacturing operations usually are performed in a sequence. Functional coupling is defined as a dependence between functional requirements. The subject of couplings in manufacturing systems is not extensively explored or described in the literature, and specifically not in relation to the axiomatic design theory. Five different categories of couplings in manufacturing systems are described and exemplified in this paper. Couplings can be designed into the manufacturing system for a diverse range of reasons, e.g. selection of manufacturing processes or materials, but they may also be irrational, e.g. decisions based on political opinions.

  • 6. Alsanius, B. W.
    et al.
    Löfkvist, K.
    Kritz, G.
    Ratkic, Adrian
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Skills and Technology.
    Reflection on reflection in action: A case study of growers conception of irrigation strategies in pot plant production2009In: AI & Society: The Journal of Human-Centred Systems and Machine Intelligence, ISSN 0951-5666, E-ISSN 1435-5655, Vol. 23, no 4, p. 545-558Article in journal (Refereed)
    Abstract [en]

    A case study of growers conception of irrigation strategies indicates that pot plant growers in Scandinavia base their management approaches on experientially based art. The study also indicates that there is a gap between experientially based art and available greenhouse technology. In order to standardize production and produce quality, both the grower's experience and available technology should be taken into account. In order to achieve this, the present study proposes to arrange reflection on reflection in action with a group of growers by means of the dialogue seminar method. The concept of reflection on reflection in action is novel to horticultural practice. Therefore, we suggest future inter- and multidisciplinary research within this domain.

  • 7. Alsanius, B. W.
    et al.
    Ratkic, Adrian
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Skills and Technology.
    Persson, E.
    Löfkvist, K.
    Prospects of dialogue-inspired methods as tools for knowledge transfer: Technology for sustainable horticulture meets experiential knowledge communities2009In: Acta Horticulturae, International Society for Horticultural Science , 2009, p. 27-32Chapter in book (Refereed)
    Abstract [en]

    Horticultural production systems have a large environmental impact. Legislation, ordinances and quality assurance systems provide guidelines for implementing sustainable production technologies in horticulture at a higher level. Horticultural research has compiled solutions to improve sustainable production. Despite of regulations, hands-on information, solid scientific data on sustainable strategies for horticulture and a general environmental awareness, there is reluctance in considering sustainable technology and reorganizing horticultural production lines. Knowledge within commercial horticulture is situated knowledge; this means experience consolidated within the branch is a precondition for application. However, knowledge on sustainable technology follows the tradition of natural sciences and technology. Another crucial aspect concerns the path from understanding sustainable technology to putting it into action. Reflection on reflection in action as an activity aims at producing a good verbal description of reflection in action, which can be shared with other people. While reflection in or on action is primarily private the notion of reflection on reflection in action is tied to the fact that learning and experience exchange are social activities that proceed in different communities of practice. Dialogue-inspired methods may act as a tool. In the present paper we discuss the dialogue seminar and Socratic dialog methods to bridge the gap between scientific and technological progress in horticulture and horticultural practice to be employed in horticultural extension.

  • 8.
    Arnling Bååth, Jenny
    et al.
    Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden.
    Giummarella, Nicola
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Klaubauf, Sylvia
    Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden.
    Lawoko, Martin
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Olsson, Lisbeth
    Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden.
    A glucuronoyl esterase from Acremonium alcalophilum cleaves native lignin-carbohydrate ester bonds2016In: FEBS Letters, ISSN 0014-5793, E-ISSN 1873-3468, Vol. 590, no 16, p. 2611-2618Article in journal (Refereed)
    Abstract [en]

    The Glucuronoyl esterases (GE) have been proposed to target lignin-carbohydrate (LC) ester bonds between lignin moieties and glucuronic acid side groups of xylan, but to date, no direct observations of enzymatic cleavage on native LC ester bonds have been demonstrated. In the present investigation, LCC fractions from spruce and birch were treated with a recombinantly produced GE originating from Acremonium alcalophilum (AaGE1). A combination of size exclusion chromatography and 31P NMR analyses of phosphitylated LCC samples, before and after AaGE1 treatment provided the first evidence for cleavage of the LC ester linkages existing in wood.

  • 9.
    Aspeborg, Henrik
    et al.
    KTH, School of Biotechnology (BIO), Glycoscience.
    Bhalerao, Rishikeshi
    Hertzberg, Magnus
    Johansson, Karin
    Johnsson, P.
    Karlsson, Ann
    Sandberg, Göran
    Schrader, Jarmo
    Sundberg, Björn
    Teeri, Tuula
    Trygg, Johan
    Wallbäcks, Lars
    Vegetabile material, plants and a method of producing a plant having altered lignin properties2008Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    The present invention is related to a set of genes, which when modified in plants gives altered lignin properties. The invention provides DNA construct such as a vector useful in the method of the invention. Further, the invention relates to a plant cell or plant progeny of the plants and wood produced by the plants according to the invention Lower lignin levels will result in improved saccharification for bio-refining and ethanol production and improved pulp and paper. Increased lignin levels will utilise lignin properties for energy production. The genes and DNA constructs may be used for the identification of plants having altered lignin characteristics as compared to the wild-type. According to the invention genes and DNA constructs may also be used as candidate genes in marker assisted breeding.

  • 10.
    Aspeborg, Henrik
    et al.
    KTH, School of Biotechnology (BIO).
    Schrader, J.
    Coutinho, P. M.
    Stam, M.
    Kallas, A.
    Djerbi, S.
    Nilsson, Peter
    KTH, School of Biotechnology (BIO), Proteomics (closed 20130101).
    Denman, S.
    Amini, B.
    Sterky, Fredrik
    KTH, School of Biotechnology (BIO), Proteomics (closed 20130101).
    Master, E.
    Sandberg, G.
    Mellerowicz, E.
    Sundberg, B.
    Henrissat, B.
    Teeri, Tuula T.
    KTH, School of Biotechnology (BIO), Glycoscience.
    Carbohydrate-active enzymes involved in the secondary cell wall biogenesis in hybrid aspen2005In: Plant Physiology, ISSN 0032-0889, E-ISSN 1532-2548, Vol. 137, no 3, p. 983-997Article in journal (Refereed)
    Abstract [en]

    Wood formation is a fundamental biological process with significant economic interest. While lignin biosynthesis is currently relatively well understood, the pathways leading to the synthesis of the key structural carbohydrates in wood fibers remain obscure. We have used a functional genomics approach to identify enzymes involved in carbohydrate biosynthesis and remodeling during xylem development in the hybrid aspen Populus tremula x tremuloides. Microarrays containing cDNA clones from different tissue-specific libraries were hybridized with probes obtained from narrow tissue sections prepared by cryosectioning of the developing xylem. Bioinformatic analyses using the sensitive tools developed for carbohydrate-active enzymes allowed the identification of 25 xylem-specific glycosyltransferases belonging to the Carbohydrate-Active EnZYme families GT2, GT8, GT14, GT31, GT43, GT47, and GT61 and nine glycosidases (or transglycosidases) belonging to the Carbohydrate-Active EnZYme families GH9, GH10, GH16, GH17, GH19, GH28, GH35, and GH51. While no genes encoding either polysaccharide lyases or carbohydrate esterases were found among the secondary wall-specific genes, one putative O-acetyltransferase was identified. These wood-specific enzyme genes constitute a valuable resource for future development of engineered fibers with improved performance in different applications.

  • 11.
    Asperö Lind, Mikael
    KTH, School of Industrial Engineering and Management (ITM), Industrial Ecology.
    Biologisk behandling av matavfall med avfallskvarn: En systemanalys2009Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The municipal sewage treatment plant Käppalaverket and municipally owned waste handling company SÖRAB, both located in the northern part of Stockholm Sweden, have together started the BOA project. BOA means “Biologisk behandling av Organiskt matavfall medhjälp av Avfallskvarnar” which is translated to biological treatment of organic food waste using food waste macerators. The initiative stems from one of Sweden’s national environmental goals: Saying that at least 35 percent of all the organic waste produced byhouseholds and companies shall be treated biologically by the year 2010 and that the nutrients from this waste should be used as fertilizer.

    In the first phase of the project, seven different scenarios on how to transport the food waste from the households to the digestion chamber were described. To be able to evaluate these scenarios from a societal and sustainability perspective, seven criteria were chosen:technology, environment, work environment, economy, quality, law, and acceptance. The first part of the thesis consisted of formulating indicators from these criteria, through meetings and discussions with different working groups, all consisting of people in the waste and wastewater field. After that, a review of available tools was done to find the ones that were best suited for each chosen indicator.

    For the indicators that required calculations, Substance Flow Analysis, Life Cycle Analysis, Energy Analysis and Life Cycle Costing were chosen. After the tools had been used the results were given grades depending on how big impact they would have on society. For some of the indicators calculations were not possible and instead a qualitative grading system was used, in which the different working groups graded each scenario depending on the indicator and the grades were weighted and summed together.

    Finally, a multi criteria analysis was made together with the project managers from Käppalaverket and SÖRAB, in which the different indicators were discussed and weighted depending on how important they were considered to be. The final result of the multi criteria analysis was that one scenario could be chosen as the most suited for transport of food waste, from the perspective of the chosen indicators and their given weight.

    The scenario in which food waste is collected in bins and then transported by car to a centralprocessing plant, and finally transported by car to Käppalaverkets digestion chambers, got the highest score in the multi criteria analysis and is therefore the best scenario from the perspective of the chosen indicators and given weight. But from the multi criteria analysis onecould also see that none of the scenarios were given a particularly low score. This opens upfor the possibility of combined scenarios were all the residents of the SÖRAB region are given the possibility to recycle their food waste with a bin collecting system, but were there isa will to use systems with a kitchen food waste disposer instead it can be accepted as long as they do not become too popular.

    During the work of this thesis several questions have been raised that needs further investigation. One is what happens with the food waste when it is transported in the sewagesystem and another is how it will change during storage longer than four days. Also, the final results have shown that the impact on climate change from the scenarios could besignificantly decreased if a leakage free methane production could be assured and the possibility to use renewable fuels for the collecting cars was investigated.

  • 12. Baken, S.
    et al.
    Larsson, M. A.
    Gustafsson, Jon Petter
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering (moved 20130630).
    Cubadda, F.
    Smolders, E.
    Ageing of vanadium in soils and consequences for bioavailability2012In: European Journal of Soil Science, ISSN 1351-0754, E-ISSN 1365-2389, Vol. 63, no 6, p. 839-847Article in journal (Refereed)
    Abstract [en]

    Total vanadium (V) concentrations in soils commonly range from 20 to 120 mg kg-1. Vanadium added directly to soils is more soluble than geogenic V and can be phytotoxic at doses within this range of background concentrations. However, it is unknown how slow sorption reactions change the fate and effect of added V in soils. This study addresses the changes in V solubility, toxicity and bioavailability in soils over time. Four soils were amended with pentavalent V in the form of a soluble vanadate salt, and extractable V concentrations were monitored over 100 days. The toxicity to barley and tomato plants was evaluated in freshly spiked soils and in the corresponding aged soils that were equilibrated for up to 330 days after spiking. The V concentrations in 0.01 m CaCl2 soil extracts decreased approximately two-fold between 14 and 100 days after soil spiking, and the reaction kinetics were similar for all soils. The phytotoxicity of added V decreased on average two-fold between freshly spiked and aged soils. The reduced toxicity was associated with a corresponding decrease in V concentrations in the isolated soil solutions and in the shoots. The V speciation in the soil solution of the aged soils was dominated by V(V); less than 8% was present as V(IV). Oxalate extractions suggest that the V(V) added to soils is predominantly sorbed onto poorly crystalline oxyhydroxides. It is concluded that the toxicity of V measured in freshly spiked soils may not be representative of soils subject to a long-term V contamination in the field.

  • 13.
    Bautista, Rocí­o
    et al.
    University of Malaga.
    Villalobos, David, P.
    University of Malaga.
    Diaz-Moreno, Sara M
    University of Malaga.
    Cantón, Francisco, R.
    University of Malaga.
    Cánovas, Francisco, M.
    University of Malaga.
    Gonzalo Claros, M.
    University of Malaga.
    Toward a Pinus pinaster bacterial artificial chromosome library2007In: Annals of Forest Science, ISSN 1286-4560, E-ISSN 1297-966X, Vol. 64, no 8, p. 855-864Article in journal (Refereed)
    Abstract [en]

    Conifers are of great economic and ecological importance, but little is known concerning their genomic organization. This study is an attempt to obtain high-quality high-molecular-weight DNA from Pinus pinaster cotyledons and the construction of a pine BAC library. The preparation incorporates modifications like low centrifugation speeds, increase of EDTA concentration for plug maintenance, use of DNase inhibitors to reduce DNA degradation, use of polyvinylpyrrolidone and ascorbate to avoid secondary metabolites, and a brief electrophoresis of the plugs prior to their use. A total of 72 192 clones with an average insert size of 107 kb, which represents an equivalent of 11X pine haploid genomes, were obtained. The proportions of clones lacking inserts or containing chloroplast DNA are both approximately 1.6%. The library was screened with cDNA probes for seven genes, and two clones containing Fd-GOGAT sequences were found, one of them seemingly functional. Ongoing projects aimed at constructing a pinebacterial artificial chromosome library may benefit from the methods described here.

  • 14. Bazilian, Morgan
    et al.
    Rogner, Holger
    Howells, Mark
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Energy Systems Analysis.
    Hermann, Sebastian
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Energy Systems Analysis.
    Arent, Douglas
    Gielen, Dolf
    Steduto, Pasquale
    Mueller, Alexander
    Komor, Paul
    Tol, Richard S.J.
    Yumkella, Kandeh K.
    Considering the energy, water and food nexus: Towards an integrated modelling approach2011In: Energy Policy, ISSN 0301-4215, E-ISSN 1873-6777, Vol. 39, no 12, p. 7896-7906Article in journal (Refereed)
    Abstract [en]

    The areas of energy, water and food policy have numerous interwoven concerns ranging from ensuring access to services, to environmental impacts to price volatility. These issues manifest in very different ways in each of the three "spheres", but often the impacts are closely related. Identifying these interrelationships a priori is of great importance to help target synergies and avoid potential tensions. Systems thinking is required to address such a wide swath of possible topics. This paper briefly describes some of the linkages at a high-level of aggregation - primarily from a developing country perspective - and via case studies, to arrive at some promising directions for addressing the nexus. To that end, we also present the attributes of a modelling framework that specifically addresses the nexus, and can thus serve to inform more effective national policies and regulations. While environmental issues are normally the 'cohesive principle' from which the three areas are considered jointly, the enormous inequalities arising from a lack of access suggest that economic and security-related issues may be stronger motivators of change. Finally, consideration of the complex interactions will require new institutional capacity both in industrialised and developing countries.

  • 15. Berggren Kleja, Dan
    et al.
    Svensson, Magnus
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering.
    Majdi, Hooshang
    Jansson, Per-Erik
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering.
    Langvall, Ola
    Bergkvist, Bo
    Johansson, Maj-Britt
    Weslien, Per
    Lindroth, Anders
    Pools and fluxes of carbon in three Norway spruce ecosystems along a climatic gradient in Sweden.2008In: Biogeochemistry, ISSN 0168-2563, E-ISSN 1573-515X, Vol. 89, no 1, p. 7-25Article in journal (Refereed)
    Abstract [en]

    This paper presents an integrated analysis of organic carbon (C) pools in soils and vegetation, within-ecosystem fluxes and net ecosystem exchange (NEE) in three 40-year old Norway spruce stands along a north-south climatic gradient in Sweden, measured 2001-2004. A process-orientated ecosystem model (CoupModel), previously parameterised on a regional dataset, was used for the analysis. Pools of soil organic carbon (SOC) and tree growth rates were highest at the southernmost site (1.6 and 2.0-fold, respectively). Tree litter production (litterfall and root litter) was also highest in the south, with about half coming from fine roots (< 1 mm) at all sites. However, when the litter input from the forest floor vegetation was included, the difference in total litter input rate between the sites almost disappeared (190-233 g C m(-2) year(-1)). We propose that a higher N deposition and N availability in the south result in a slower turnover of soil organic matter than in the north. This effect seems to overshadow the effect of temperature. At the southern site, 19% of the total litter input to the O horizon was leached to the mineral soil as dissolved organic carbon, while at the two northern sites the corresponding figure was approx. 9%. The CoupModel accurately described general C cycling behaviour in these ecosystems, reproducing the differences between north and south. The simulated changes in SOC pools during the measurement period were small, ranging from -8 g C m(-2) year(-1) in the north to +9 g C m(-2) year(-1) in the south. In contrast, NEE and tree growth measurements at the northernmost site suggest that the soil lost about 90 g C m(-2) year(-1).

  • 16.
    Berglund, Jennie
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Wood Chemistry and Pulp Technology. Wallenberg Wood Science Center.
    Wood Hemicelluloses - Fundamental Insights on Biological and Technical Properties2018Doctoral 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.

  • 17.
    Berglund, Jennie
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Angles d’Ortoli, Thibault
    Vilaplana, Francisco
    KTH, School of Biotechnology (BIO), Glycoscience. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center. KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Widmalm, Göran
    Bergenstråhle-Wohlert, Malin
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Lawoko, Martin
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Henriksson, Gunnar
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Lindström, Mikael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Wohlert, Jakob
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    A molecular dynamics study of the effect of glycosidic linkage type in the hemicellulose backbone on the molecular chain flexibility2016In: The Plant Journal, ISSN 0960-7412, E-ISSN 1365-313XArticle in journal (Refereed)
    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.

  • 18.
    Berglund, Jennie
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Azhar, Shoaib
    Lawoko, Martin
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Lindström, Mikael
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Vilaplana, Francisco
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Wohlert, Jakob
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Henriksson, Gunnar
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    The structure of galactoglucomannan impacts the degradation under alkaline conditions2018In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882XArticle in journal (Refereed)
    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.

  • 19.
    Berglund, Torkel
    et al.
    KTH, School of Biotechnology (BIO), Industrial Biotechnology.
    Lindström, Anders
    Aghelpasand, Hooman
    KTH, School of Biotechnology (BIO), Industrial Biotechnology.
    Stattin, Eva
    Ohlsson, Anna B.
    KTH, School of Biotechnology (BIO), Industrial Biotechnology.
    Protection of spruce seedlings against pine weevil attacks by treatment of seeds or seedlings with nicotinamide, nicotinic acid and jasmonic acid2016In: Forestry (London), ISSN 0015-752X, E-ISSN 1464-3626, Vol. 89, no 2, p. 127-135Article in journal (Refereed)
    Abstract [en]

    Sustainable methods are required to protect newly planted tree seedlings from insect herbivore attack. To this end, here Norway spruce (Picea abies (L.) Karst.) seeds were treated with 2.5 mM nicotinamide (NIC), 2.5 mM nicotinic acid (NIA), 3 mM jasmonic acid (JA) or 0.2 mM 5-azacytidine (5-Aza), and 6-month-old seedlings grown from these seeds were planted at a reforestation area in central Sweden. Attack by pine weevils (Hylobius abietis) was reduced by 50 per cent by NIC treatment, 62.5 per cent by JA treatment and 25 per cent by 5-Aza treatment, when compared with seedlings grown from untreated seeds. Watering 18-month-old spruce seedlings with 2 mM NIC or 2 mM NIA did reduce attack during the first season in the field by 40 and 53 per cent, respectively, compared with untreated plants. Girdling was also reduced by the different treatments. Analysis of conifer seedlings treated with 5-Aza points at a possible involvement of epigenetic mechanisms in this defensive capacity. This is supported by a reduced level of DNA methylation in the needles of young spruce seedlings grown in a greenhouse from NIC-treated seeds. Seed treatment for seedling defense potentiation is simple, inexpensive and also a new approach for forestry with many potential applications.

  • 20.
    Berríos-Negrón, Luis
    KTH / Konstfack.
    Earthscore Specularium2018In: On Curating, no 36, p. 94-105Article in journal (Other academic)
    Abstract [en]

    Through an artistic contribution, Luis Berríos-Negrón introduces his project “Earthscore Specularium,” developed at Färg fabriken in Stockholm in 2015. The work of Berríos-Negrón departs from a practice that deals with complexity to reflect upon notions that bring together ecology, art, architecture, science, and social practice. In recent years, he has been developing a set of conceptual devices he ultimately refers to as “social pedestals.” The latter consist of a series of architectonical installations that facilitate social encounters by resolving spatial practicalities, and at the same time reflect conceptually upon the dematerialization of sculpture. The “social pedestal” is conceived as a site for networked agency for social transformation, where the roles of the agents involved can permute, and different configurations can be organized depending of the needs of every specific situation. The “greenhouse”—which Luis treats as a social pedestal itself as well—is a long-term research site of the artist on the possibility of emancipating this type of technology in order to obtain anticipatory spatial, artistic, and social media.

  • 21.
    Berríos-Negrón, Luis
    KTH / Konstfack.
    Greenhouse Doppelgänger Deposed: An Indexical Prototype about Parastructures, Anarchives, and the Social (Hyperobjective) Pedestal2018In: Architecture in Effect: Volume 1: Rethinking the Social in Architecture / [ed] Gromark, et al, Barcelona: ACTAR, 2018, , p. 480Chapter in book (Other academic)
    Abstract [en]

    Greenhouse is an opaque manifold of meanings. The opacity is not just the result of a layering that occurs when considering its many definitions. It is more so the result of the suppressed colonial violence that is implicit in its technological instrumentalization. This mythical violence, of willfully transplanting the exotic, is at the heart of allother compound terms and subsets of ‘greenhouse’. I have been working on how this opacity obscures a range of forces that shape the environment. More specifically, I amexploring how these opaque forces affect, and may be perceived through, the forms and languages of sculptural and spatial production beyond prescribed visual or imagined outcomes. The work you will encounter here is then a probe to test how the violent opacity of greenhouse may be demystified by shaping an index as potential format for dematerialized display.

  • 22.
    Berríos-Negrón, Luis
    KTH / Konstfack.
    Greenhouse Superstructures as Social Pedestals: displaying site-specific non-locality as a possible form of resilience2015In: Architecture and Resilience on the Human Scale: Cross-Disciplinary Conference, 10-12 September 2015 / [ed] University of Sheffield, UK, Sheffield, UK: University of Sheffield , 2015, p. 70-71Conference paper (Other academic)
    Abstract [en]

    In this paper I will propose that greenhouse superstructures are not just the surface envelop of an industrial typology: they are more so a spatial archetype. As such, they are historiographical boundary objects that at times display the spatiotemporal dimensions and geopolitical flows of environmental form in accelerated climate change. This abovementioned hypothesis is reflected through the manifold of “resilience” as defined by Prof. Lawrence Vale - of resilience being “a window into conflicting human values”. The aim of this effort is to ultimately centre the manifold notion of “greenhouse” as an index that points away from itself towards the impact of anthropological and technocratic ideologies on agricultural and spatial production. It is these binary ideologies that arguably create what we sense to be a crisis of scale, now further articulated as the hyperobject of climate change as a disjuncture that we nostalgically entertain as a chasm between the human condition and the living environment. Parsed by augmenting the notion of 'greenhouse superstructure' – as technology, gas, and effect – the hypothesis looks to articulate the greenhouse as a 'site-specific non-local' sensation on the expanding sculptural field. What this expanding sculptural netherworld implies needs to be rigorously addressed for it may very well become what tautologically heightens the greenhouse to the providence of becoming our future atmosphere and landscape. To elaborate this potentiality, I will first present the schematics and precedents of the dissertation, including four installations of my authorship in Germany, Brazil, and Sweden. These sections then lead to an argument instantiated by thinking of the greenhouse as 'social pedestal'. The objective is therefore to embody the notion of non-local site-specific resilience as modes of pedagogy and production that aspire to destabilise the anthropological machine, as resilient modes not limited to historic, scientific, artistic, correlational, nor speculative conventions.

  • 23.
    Bhale, Vilas
    et al.
    Department of Agronomy, Dr. PDKV, Akola-444 101 (MS), India.
    Tupe, Arvind
    Department of Agronomy, Dr. PDKV, Akola-444 101 (MS), India.
    Karmore, Jayashri
    Department of Agronomy, Dr. PDKV, Akola-444 101 (MS), India.
    Kale, Manoj
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering.
    Crop planning in relation to climate change in rain fed regions2012In: Journal of Agricultural Technology, ISSN 1686-9141, Vol. 8, no 2, p. 443-452Article in journal (Refereed)
    Abstract [en]

    Uncertainty and variability of rains both space and time is the major constraints affecting agricultural production in rain fed farming. Scientific study on the quantum and distribution of rainfall would enable to farming community and researcher to adjust or modify the cropping pattern as well as the cultural operation to utilize the actual moisture available in the field for profitable crop production. The daily rainfall data for last 39 year were analyzed to study its variability and probability. In rain fed farming rainfall is the primary and most important factor affecting productivity and it is mostly uncertain and erratic. Thus, the change in the rainfall pattern and amount suggests adjusting or modifying the cropping pattern and cultural practices of agricultural crops in the region for achieving the sustainable productivity. Under short break of monsoon, repeated hoeing to prevent soil moisture loss and under long dry spell, agronomic management like mulching, relay cropping or re-sowing are advocated.

  • 24.
    Bi, Ran
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Berglund, Jennie
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Vilaplana, Francisco
    KTH, School of Biotechnology (BIO), Glycoscience. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center. KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    McKee, Lauren S.
    KTH, School of Biotechnology (BIO), Glycoscience. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center. KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Henriksson, Gunnar
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    The degree of acetylation affects the microbial degradability of mannans2016In: Polymer degradation and stability, ISSN 0141-3910, E-ISSN 1873-2321, Vol. 133, p. 36-46Article in journal (Refereed)
    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.

  • 25.
    Bjurhager, Ingela
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Mechanical behaviour of hardwoods: effects from cellular and cell wall structures2008Licentiate thesis, comprehensive summary (Other scientific)
    Abstract [en]

    The aim of this work was to investigate the mechanical properties of different hardwood species and relate the properties to the structure at the cellular and cell wall level. The species examined were European aspen (Populus tremula), hybrid aspen (Populus tremula x Populus tremuloides) and European oak (Quercus robur). The Populus species, including the fast-growing hybrid aspen, are used in a large number of projects using transgene technology, which also has raised the demand for a more extensive determination of mechanical properties of the species. Oak have been a popular construction material for thousands of years, esulting in a vast number of archaeological findings. Preservation of these often includes dimensional stabilization by polyethylene glycol (PEG), an impregnation agent which affects the mechanical properties. To which extent is not properly investigated, however. The study on European and hybrid aspen included development of a method for tensile testing of small, juvenile specimens in the green condition, where strain was measured using the digital speckle photography (DSP) technique. Mechanical performance of the species in terms of longitudinal tensile stiffness and strength were of special interest. Inferior mechanical properties of hybrid aspen corresponded well to mean values of density, which were lower for the hybrid aspen compared to European aspen.

    Oak was examined in the swollen state, where swelling was induced by PEG with molecular weight 600. Longitudinal tensile stiffness and strength as well as radial stiffness and yield strength in compression were compared. Longitudinal and radial strain was measured using video extensiometry and DSP, respectively. Additional characterization of the material included imaging from scanning electron microscopy (SEM), X-ray microtomography and determination of microfibril angle using wide angle X-ray scattering (WAXS). Tensile stiffness and strength in the axial direction were only slightly affected by PEG-impregnation. WAXS measurements showed that microfibril angles were close to zero which implicates that cell wall properties are strongly dependent on the microfibrils, and only marginally influenced by the plasticization effects from PEG on the lignin/hemicellulose matrix. In the radial direction, on the other hand, mechanical performance was strongly decreased by PEG-impregnation. This was believed to originate from softening of rays.

  • 26.
    Bjurhager, Ingela
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Berglund, Lars A.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Bardage, Stig
    Sundberg, Björn
    Mechanical characterization of juvenile European aspen (Populus tremula) and hybrid aspen (Populus tremula × Populus tremuloides) using full-field strain measurements2008In: Journal of Wood Science, ISSN 1435-0211, E-ISSN 1611-4663, Vol. 54, no 5, p. 349-355Article in journal (Refereed)
    Abstract [en]

    Functional analysis of genes and proteins involved in wood formation and fiber properties often involves phenotyping saplings of transgenic trees. The objective of the present study was to develop a tensile test method for small green samples from saplings, and to compare mechanical properties of juvenile European aspen (Populus tremula) and hybrid aspen (Populus tremula × tremuloides). Small microtomed sections were manufactured and successfully tested in tension parallel to fiber orientation. Strain was determined by digital speckle photography. Results showed significantly lower values for juvenile hybrid aspen in both Young's modulus and tensile strength parallel to the grain. Average Young's moduli spanned the ranges of 5.9-6.6 and 4.8-6.0 GPa for European aspen and hybrid aspen, respectively. Tensile strength was in the range of 45-49 MPa for European aspen and 32-45 MPa for hybrid aspen. The average density (oven-dry) was 284 kg/m3 for European aspen and 221 kg/m3 for hybrid aspen. Differences in mechanical properties correlated with differences in density.

  • 27.
    Bjurhager, Ingela
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Halonen, Helena
    KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Lindfors, E. -L
    Iversen, Tommy
    KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Almkvist, G.
    Gamstedt, E. Kristofer
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Berglund, Lars A.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    State of degradation in archeological oak from the 17th century vasa ship: Substantial strength loss correlates with reduction in (holo)cellulose molecular weight2012In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 13, no 8, p. 2521-2527Article in journal (Refereed)
    Abstract [en]

    In 1628, the Swedish warship Vasa capsized on her maiden voyage and sank in the Stockholm harbor. The ship was recovered in 1961 and, after polyethylene glycol (PEG) impregnation, it was displayed in the Vasa museum. Chemical investigations of the Vasa were undertaken in 2000, and extensive holocellulose degradation was reported at numerous locations in the hull. We have now studied the longitudinal tensile strength of Vasa oak as a function of distance from the surface. The PEG-content, wood density, and cellulose microfibril angle were determined. The molar mass distribution of holocellulose was determined as well as the acid and iron content. A good correlation was found between the tensile strength of the Vasa oak and the average molecular weight of the holocellulose, where the load-bearing cellulose microfibril is the critical constituent. The mean tensile strength is reduced by approximately 40%, and the most affected areas show a reduction of up to 80%. A methodology is developed where variations in density, cellulose microfibril angle, and PEG content are taken into account, so that cell wall effects can be evaluated in wood samples with different rate of impregnation and morphologies.

  • 28.
    Bjurhager, Ingela
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Ljungdahl, Jonas
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Wallstrom, Lennart
    Gamstedt, E. Kristofer
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Berglund, Lars A.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Biocomposites.
    Towards improved understanding of PEG-impregnated waterlogged archaeological wood: A model study on recent oak2010In: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, Vol. 64, no 2, p. 243-250Article in journal (Refereed)
    Abstract [en]

    To prevent deformation and cracking of waterlogged archaeological wood, polyethylene glycol (PEG) as a bulk impregnation agent is commonly applied. PEG maintains the wood in a swollen state during drying. However, swelling of wood can reduce its mechanical properties. In this study, the cellular structure of oak and cell wall swelling was characterized by scanning electron microscopy (SEM) of transverse cross-sections, and the microfibril angle of oak fibers was determined by wide angle X-ray scattering (WAXS). Samples of recent European oak (Quercus robur L) impregnated with PEG (molecular weight of 600) were tested in axial tension and radial compression. Mechanical tests showed that axial tensile modulus and strength were only slightly affected by PEG, whereas radial compressive modulus and yield strength were reduced by up to 50%. This behavior can be explained by the microstructure and deformation mechanisms of the material. Microfibril angles in tensile test samples were close to zero. This implies tensile loading of cellulose microfibrils within the fiber cell walls without almost any shear in the adjacent amorphous matrix. These results are important because they can help separate the impact of PEG on mechanical properties from that of chemical degradation in archaeological artifacts, which display only small to moderate biological degradation.

  • 29.
    Bjurhager, Ingela
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Ljungdahl, Jonas
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Wallström, Lennart
    Division of Polymer Engineering, Luleå University of Technology (LTU).
    Gamstedt, E. Kristofer
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Effects of polyethylene glycol treatment on the mechanical properties of oakManuscript (Other academic)
  • 30. Björklund, Johanna
    et al.
    Westberg, Lotten
    Geber, Ulrika
    Milestad, Rebecka
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Environmental Strategies.
    Ahnström, Johan
    Local selling as a driving force for increased on-farm biodiversity2009In: Journal of Sustainable Agriculture, ISSN 1044-0046, E-ISSN 1540-7578, Vol. 33, no 8, p. 885-902Article in journal (Refereed)
    Abstract [en]

    This paper addresses the question of whether local selling of farm products improves on-farm biodiversity in rural areas. In contrast to the main agricultural trend of farms specializing and increasing in size in response to national and global markets, increasing numbers of Swedish farmers are diverting their efforts towards selling at local markets. Based on case studies of six farms selling their products locally, this paper explores the nature of the diversity on these farms and identifies qualities in the interaction between the farmers and their consumers that are supporting this diversity. The study showed that farmers who interacted with consumers were encouraged to diversify their production. Marketing a large diversity of products at a local market led to better income for participating farmers. Animal farms maintained important biodiversity associated with their extensive way of rearing animals on semi-natural pastures. Access to local markets promoted this.

  • 31.
    Bladby, Hanna
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Industrial Ecology.
    Wersäll, Johanna
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Industrial Ecology.
    A meat free society: The different substitutes for meat, their future and their environmental and health impact compared to meat2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The worldwide consumption of meat continues to increase and in Sweden the annual consumption has gone from 24 kg/person in 1990 to about 78 kg/person in 2005. This contributes to large environmental impacts such as an increase of greenhouse gas emissions, unsustainable land and resource use and shortage of water. A solution to the problem is to change our diets to be more sustainable. The purpose with this research is therefore to study the positive environmental and health aspects of alternative protein rich products based on soya, grown meat, algae and insects in comparison with meat. The goal is then to compare the environmental impacts from these products by studying different LCA-studies. Furthermore, also to understand how the future will be developed by interviewing producers of meat substitutes in Sweden. Some difficulties of comparing different LCA-studies are the choice of system boundaries, functional units and environmental aspects in the studies. Nevertheless, after studying a large amount of reports and articles about the products conclusions could yet be drawn. The carbonfootprint from beef is up to 20 times larger than from the substitutes and the land use is up to 125 times larger for beef compared to substitutes. Pork and chicken have lower impact but the lowest impact seems to come from producing substitutes based on soya beans. Insects and algae also have a low impact, but the products are still in the stage of development in Sweden due to laws, regulations and lack of knowledge. Regarding the health aspects substitutes could possibly replace meat since both insects and soya are rich of protein. Insects are also rich oniron and other nutrition. Algae consist as well of good nutrition. The companies interviewed in this study were Kung Markatta, Ekko gourmet and Veggi. They had some different opinions on future products, but they could all agree on that we need to eat less meat and more substitutes. The conclusions of this research are that the environmental aspects considered in the analysed LCA-studies are mostly carbon footprint and land use. They show that beef have a larger environmental impact than meat substitutes. It is however recommended to do new studies on products with the same system boundaries and functional units to get a more accurate and comparable result.

  • 32.
    Bojler Görling, Martin
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Energy Processes.
    Moghaddam, Elham Ahmadi
    Swedish University of Agricultural Sciences.
    Grönkvist, Stefan
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Energy Processes.
    Hansson, Per-Anders
    Swedish University of Agricultural Sciences .
    Larsson, Mårten
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Energy Processes.
    Nordberg, Åke
    Swedish University of Agricultural Sciences .
    Pre-study of biogas production from low-temperature production of biogas: Report from an f3 R&D project2013Report (Other academic)
  • 33. Bollhoner, Benjamin
    et al.
    Jokipii-Lukkari, Soile
    Bygdell, Joakim
    Stael, Simon
    Adriasola, Mathilda
    KTH, School of Biotechnology (BIO).
    Muniz, Luis
    Van Breusegem, Frank
    Ezcurra, Ines
    KTH, School of Biotechnology (BIO), Industrial Biotechnology.
    Wingsle, Gunnar
    Tuominen, Hannele
    The function of two type II metacaspases in woody tissues of Populus trees2018In: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 217, no 4, p. 1551-1565Article in journal (Refereed)
    Abstract [en]

    Metacaspases (MCs) are cysteine proteases that are implicated in programmed cell death of plants. AtMC9 (Arabidopsis thaliana Metacaspase9) is a member of the Arabidopsis MC family that controls the rapid autolysis of the xylem vessel elements, but its downstream targets in xylem remain uncharacterized. PttMC13 and PttMC14 were identified as AtMC9 homologs in hybrid aspen (Populustremulaxtremuloides). A proteomic analysis was conducted in xylem tissues of transgenic hybrid aspen trees which carried either an overexpression or an RNA interference construct for PttMC13 and PttMC14. The proteomic analysis revealed modulation of levels of both previously known targets of metacaspases, such as Tudor staphylococcal nuclease, heat shock proteins and 14-3-3 proteins, as well as novel proteins, such as homologs of the PUTATIVE ASPARTIC PROTEASE3 (PASPA3) and the cysteine protease RD21 by PttMC13 and PttMC14. We identified here the pathways and processes that are modulated by PttMC13 and PttMC14 in xylem tissues. In particular, the results indicate involvement of PttMC13 and/or PttMC14 in downstream proteolytic processes and cell death of xylem elements. This work provides a valuable reference dataset on xylem-specific metacaspase functions for future functional and biochemical analyses.

  • 34.
    Braun, Sabina
    et al.
    Swedish University of Agricultural Sciences, Department of Soil and Environment.
    Warrinnier, Ruben
    KU Leuven, Belgium.
    Börjesson, Gunnar
    Swedish University of Agricultural Sciences, Department of Soil and Environment.
    Ulén, Barbro
    Swedish University of Agricultural Sciences, Department of Soil and Environment.
    Smolders, Erik
    KU Leuven, Belgium.
    Gustafsson, Jon Petter
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Water and Environmental Engineering.
    Assessing the ability of soil tests to estimate labile phosphorus in agricultural soils: Evidence from isotopic exchange2019In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 337, p. 350-358Article in journal (Refereed)
    Abstract [en]

    Efficient phosphorus (P) fertilization strategies are essential for intensive crop production with minimal negative environmental impacts. A key factor in sustainable P use is assessment of the plant available soil P pool using soil P tests. This study determined isotopically exchangeable P after six days of reaction with 33PO4 (P-E (6 d)) to determine how accurately two commonly used P tests, Olsen and AL (acid ammonium acetate lactate) can quantify the amount of labile P. Soil samples were taken from both highly P-amended and unamended plots at six sites within the Swedish long-term soil fertility experiments. According to P K-edge XANES spectroscopy, the P speciation was dominated by Al-bound P and organic P, with additional contributions from Fe-bound P and Ca phosphates in most soils. The results showed that the AL test overestimated P-E (6 d) by a factor of 1.70 on average. In contrast, the Olsen test underestimated P-E (6 d), with the mean ratios of P-Olsen to P-E (6 d) being 0.52 for high-P and 0.19 for low-P soils. The 33P/31P ratio in the Olsen extract of a 33PO4 spiked soil was closer to that of a 0.005 mol L−1 CaCl2 soil extract than the corresponding ratio in the AL extract, suggesting that AL extraction solubilized more non-labile P. In conclusion, the AL and Olsen methods are not suitable for direct quantification of the isotopically exchangeable soil P pool after 6 days of equilibration. However, based on the results, Olsen may be superior to AL for classification of soil P status, due to its even performance for calcareous and non-calcareous soils and lower extraction of non-labile P.

  • 35.
    Brodin, Ida
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Gellerstedt, Göran L. F.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Sjöholm, E.
    Membrane separated Kraft lignin as feedstock for chemical products2008In: 2008 Nordic Wood Biorefinery Conference, NWBC 2008 - Proceedings, 2008, p. 194-Conference paper (Refereed)
  • 36. Bygdell, Joakim
    et al.
    Srivastava, Vaibhav
    KTH, School of Biotechnology (BIO), Glycoscience.
    Obudulu, Ogonna
    Srivastava, Manoj K.
    Nilsson, Robert
    Sundberg, Bjorn
    Trygg, Johan
    Mellerowicz, Ewa J.
    Wingsle, Gunnar
    Protein expression in tension wood formation monitored at high tissue resolution in Populus2017In: Journal of Experimental Botany, ISSN 0022-0957, E-ISSN 1460-2431, Vol. 68, no 13, p. 3405-3417Article in journal (Refereed)
    Abstract [en]

    Tension wood (TW) is a specialized tissue with contractile properties that is formed by the vascular cambium in response to gravitational stimuli. We quantitatively analysed the proteomes of Populus tremula cambium and its xylem cell derivatives in stems forming normal wood (NW) and TW to reveal the mechanisms underlying TW formation. Phloem-, cambium-, and wood-forming tissues were sampled by tangential cryosectioning and pooled into nine independent samples. The proteomes of TW and NW samples were similar in the phloem and cambium samples, but diverged early during xylogenesis, demonstrating that reprogramming is an integral part of TW formation. For example, 14-3-3, reactive oxygen species, ribosomal and ATPase complex proteins were found to be up-regulated at early stages of xylem differentiation during TW formation. At later stages of xylem differentiation, proteins involved in the biosynthesis of cellulose and enzymes involved in the biosynthesis of rhamnogalacturonan-I, rhamnogalacturonan-II, arabinogalactan-II and fasciclin-like arabinogalactan proteins were up-regulated in TW. Surprisingly, two isoforms of exostosin family proteins with putative xylan xylosyl transferase function and several lignin biosynthesis proteins were also up-regulated, even though xylan and lignin are known to be less abundant in TW than in NW. These data provided new insight into the processes behind TW formation.

  • 37. Bylesjö, Max
    et al.
    Nilsson, Robert
    Srivastava, Vaibhav
    Umeå University.
    Grönlund, Andreas
    Johansson, Annika I
    Jansson, Steffan
    Karlsson, Jan
    Moritz, Thomas
    Wingsle, Gunnar
    Trygg, Johan
    Integrated analysis of transcript, protein and metabolite data to study lignin biosynthesis in hybrid aspen2009In: Journal of Proteome Research, ISSN 1535-3893, E-ISSN 1535-3907, Vol. 8, no 1, p. 199-210Article in journal (Refereed)
    Abstract [en]

    Tree biotechnology will soon reach a mature state where it will influence the overall supply of fiber, energy and wood products. We are now ready to make the transition from identifying candidate genes, controlling important biological processes, to discovering the detailed molecular function of these genes on a broader, more holistic, systems biology level. In this paper, a strategy is outlined for informative data generation and integrated modeling of systematic changes in transcript, protein and metabolite profiles measured from hybrid aspen samples. The aim is to study characteristics of common changes in relation to genotype-specific perturbations affecting the lignin biosynthesis and growth. We show that a considerable part of the systematic effects in the system can be tracked across all platforms and that the approach has a high potential value in functional characterization of candidate genes.

  • 38. Campos Pereira, H.
    et al.
    Ullberg, M.
    Kleja, D. B.
    Gustafsson, Jon Petter
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering. Swedish University of Agricultural Sciences, Sweden.
    Ahrens, L.
    Sorption of perfluoroalkyl substances (PFASs) to an organic soil horizon – Effect of cation composition and pH2018In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 207, p. 183-191Article in journal (Refereed)
    Abstract [en]

    Accurate prediction of the sorption of perfluoroalkyl substances (PFASs) in soils is essential for environmental risk assessment. We investigated the effect of solution pH and calculated soil organic matter (SOM) net charge on the sorption of 14 PFASs onto an organic soil as a function of pH and added concentrations of Al3+, Ca2+ and Na+. Often, the organic C-normalized partitioning coefficients (KOC) showed a negative relationship to both pH (Δlog KOC/ΔpH = −0.32 ± 0.11 log units) and the SOM bulk net negative charge (Δlog KOC = −1.41 ± 0.40 per log unit molc g−1). Moreover, perfluorosulfonic acids (PFSAs) sorbed more strongly than perfluorocarboxylic acids (PFCAs) and the PFAS sorption increased with increasing perfluorocarbon chain length with 0.60 and 0.83 log KOC units per CF2 moiety for C3–C10 PFCAs and C4, C6, and C8 PFSAs, respectively. The effects of cation treatment and SOM bulk net charge were evident for many PFASs with low to moderate sorption (C5–C8 PFCAs and C6 PFSA). However for the most strongly sorbing and most long-chained PFASs (C9–C11 and C13 PFCAs, C8 PFSA and perfluorooctane sulfonamide (FOSA)), smaller effects of cations were seen, and instead sorption was more strongly related to the pH value. This suggests that the most long-chained PFASs, similar to other hydrophobic organic compounds, are preferentially sorbed to the highly condensed domains of the humin fraction, while shorter-chained PFASs are bound to a larger extent to humic and fulvic acid, where cation effects are significant.

  • 39.
    Canales, Javier
    et al.
    University of Malaga.
    Ávila, Concepción
    University of Malaga.
    Cantón, Francisco
    University of Malaga.
    Pacheco-Villalobos, David
    University of Malaga.
    Díaz-Moreno, Sara
    University of Malaga.
    Ariza, David
    University of Cordoba.
    Molina-Rueda, Juan
    University of Malaga.
    Navarro-Cerrillo, Rafael
    University of Cordoba.
    Claros, M.
    University of Malaga.
    Cánovas, Francisco
    University of Malaga.
    Gene expression profiling in the stem of young maritime pine trees: detection of ammonium stress-responsive genes in the apex2011In: Trees, ISSN 0931-1890, E-ISSN 1432-2285, Vol. 26, no 2, p. 609-619Article in journal (Refereed)
    Abstract [en]

    The shoots of young conifer trees represent an interesting model to study the development and growth of conifers from meristematic cells in the shoot apex to differentiated tissues at the shoot base. In this work, microarray analysis was used to monitor contrasting patterns of gene expression between the apex and the base ofmaritime pine shoots. A group of differentially expressed genes were selected and validated by examining their relative expression levels in different sections along thestem, from the top to the bottom. After validation of the microarray data, additional geneexpression analyses were also performed in the shoots of young maritime pine treesexposed to different levels of ammonium nutrition. Our results show that the apex ofmaritime pine trees is extremely sensitive to conditions of ammonium excess or deficiency, as revealed by the observed changes in the expression of stress-responsivegenes. This new knowledge may be used to precocious detection of early symptoms of nitrogen nutritional stresses, thereby increasing survival and growth rates of young treesin managed forests. 

  • 40.
    Carlsson-Kanyama, Annika
    KTH, School of Industrial Engineering and Management (ITM), Industrial Ecology (moved 20130630).
    Collaborative housing and environmental efficiency: The case of food preparation and consumption2004In: International Journal of Sustainable Development, ISSN 0960-1406, E-ISSN 1741-5268, Vol. 7, no 4, p. 341-352Article in journal (Refereed)
    Abstract [en]

    In theory, food handling in collaborative housing systems could have a number of environmental advantages compared with households and food service institutions. This paper explores to what extent some of these theoretical advantages are realized in two collaborative housing units in a major Swedish city. Food-related energy use and waste flows were measured and compared with results from food service institutions and some data relevant for households. Results show that energy use for cooking decreases in collaborative houses compared with households but energy use for food storage increases. Plate and food preparation wastes are low in the studied collaborative houses but food leftovers may be abundant. The latter result depends on how the dining system is organized. A bottleneck for improving the environmental efficiency in collaborative housing is the static view of apartment design held by many architects and real estate owners. Another bottleneck may be the unwillingness of households to make advance commitments to daily dining.

  • 41.
    Cañas, Rafael A
    et al.
    University of Malaga.
    Villalobos, David P
    University of Malaga.
    Díaz-Moreno, Sara
    University of Malaga.
    Cánovas, Francisco M
    University of Malaga.
    Cantón, Francisco R
    University of Malaga.
    Molecular and functional analyses support a role of Ornithine-{delta}-aminotransferase in the provision of glutamate for glutamine biosynthesis during pine germination2008In: Plant Physiology, ISSN 0032-0889, E-ISSN 1532-2548, Vol. 148, no 1, p. 77-88Article in journal (Refereed)
    Abstract [en]

    We report the molecular characterization and functional analysis of a gene (PsdeltaOAT) from Scots pine (Pinus sylvestris) encoding Orn-delta-aminotransferase (delta-OAT; EC 2.6.1.13), an enzyme of arginine metabolism. The deduced amino acid sequence contains a putative N-terminal signal peptide for mitochondrial targeting. The polypeptide is similar to other delta-OATs from plants, yeast, and mammals and encoded by a single-copy gene in pine. PsdeltaOAT encodes a functional delta-OAT as determined by expression of the recombinant protein in Escherichia coli and analysis of the active enzyme. The expression of PsdeltaOAT was undetectable in the embryo, but highly induced at early stages of germination and seedling development in all different organs. Transcript levels decreased in later developmental stages, although an increase was observed in lignified stems of 90-d-old plants. An increase of delta-OAT activity was observed in germinating embryos and seedlings and appears to mirror the observed alterations in PsdeltaOAT transcript levels. Similar expression patterns were also observed for genes encoding arginase and isocitrate dehydrogenase. Transcripts of PsdeltaOAT and the arginase gene were found widely distributed in different cell types of pine organs. Consistent with these results a metabolic pathway is proposed for the nitrogen flow from the megagametophyte to the developing seedling, which is also supported by the relative abundance of free amino acids in embryos and seedlings. Taken together, our data support that delta-OAT plays an important role in this process providing glutamate for glutamine biosynthesis during early pine growth.

  • 42.
    Cerin, Pontus
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.).
    Introducing Value Chain Stewardship (VCS)2006In: International Environmental Agreements: Politics, Law and Economics, ISSN 1567-9764, Vol. 6, no 1, p. 39-61Article in journal (Refereed)
    Abstract [en]

    After a decade of international negotiations to limit greenhouse gas (GHG) emissions, a sufficient number of countries have ratified the Kyoto agreement. However, even with this positive development there is a formidable challenge since, according to the World Resource Institute (WRI 2004), For the most part, developed nations have failed to attain the non-binding emission reductions they committed to in the original climate treaty in 1992, Ensuring adherence to the reductions stated in the treaty by these nations may become an immense managerial task, not to mention the enforcement of sanctions. Instead of national emission targets the approach of this paper is to focus on trade within selected industry sectors - i.e. housing and transport - responsible for most of the world's GHG emissions. This paper shows that vehicle manufacturers - the design owners - may use their information advantages to influence customers to focus on other aspects of the vehicle than costs during use. Expanding the environmental responsibility of the design owners to coincide with the area of environmental impacts will convert emissions cost into a production cost. It is indicated in this paper that when applying the estimated costs for GHG emissions to the vehicle user, strong enough incentives are not given to drive technological change, but if the responsibility is allocated to the design owner the very same additional costs will be an incentive for the designer to use its information advantage to innovate away from those emissions-rendering technologies. A value chain stewardship (VCS) is, thus, established.

  • 43. Cerutti, P. O.
    et al.
    Sola, P.
    Chenevoy, A.
    Iiyama, M.
    Yila, J.
    Zhou, W.
    Djoudi, H.
    Atyi, R. E.
    Gautier, D. J.
    Gumbo, D.
    Kuehl, Y.
    Levang, P.
    Martius, C.
    Matthews, R.
    Nasi, R.
    Neufeldt, H.
    Njenga, M.
    Petrokofsky, G.
    Saunders, M.
    Shepherd, G.
    Sonwa, D. J.
    Sundberg, Cecilia
    Van Noordwijk, M.
    The socioeconomic and environmental impacts of wood energy value chains in Sub-Saharan Africa: A systematic map protocol2015In: Environmental Evidence, ISSN 2047-2382, E-ISSN 2047-2382, Vol. 4, no 1, article id 4Article in journal (Refereed)
    Abstract [en]

    Background: The vast majority of households in Sub-Saharan Africa (SSA) depend on wood energy - comprising firewood and charcoal - for their daily energetic needs. Such consumption trends are expected to remain a common feature of SSA's wood energy production and supply chains, at least in the short- to medium-terms. Notwithstanding its importance, wood energy generally has low priority in SSA national policies. However, the use of wood energy is often considered a key driver of unsustainable management and negative environmental consequences in the humid and dry forests. To date, unsystematic assessments of the socio-economic and environmental consequences of wood energy use have underplayed its significance, thus further hampering policy debates. Therefore, a more balanced approach which considers both demand and supply dynamics is needed. This systematic map aims at providing a comprehensive approach to understanding the role and impacts of wood energy across all regions and aspects in SSA. Methods: The objective of this systematic map is to collate evidence from studies of environmental and socio-economic impacts of wood energy value chains, by considering both demand and supply within SSA. The map questions are framed using a Populations, Exposure, Comparators and Outcomes (PECO) approach. We name the supply and demand of wood energy as the "exposure," composed of wood energy production, harvesting, processing, and consumption. The populations of interest include both the actors involved in these activities and the forest sites where these activities occur. The comparator is defined as those cases where the same wood energy activities occur with i) available/accessible alternative energy sources, ii) regulatory frameworks that govern the sector and iii) alternative technologies for efficient use. The outcomes of interest encompass both socioeconomic and environmental impacts that can affect more than the populations named above. For instance, in addition to the direct socioeconomic impacts felt by participants in the wood energy value chain, forest dwellers may experience livelihood changes due to forest degradation caused by external harvesters. Moreover, intensified deforestation in one area may concurrently lead to forest regeneration in another.

  • 44.
    Cetecioglu, Zeynep
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Resource recovery.
    Dolfing, Jan
    Newcastle Univ, Sch Engn, Newcastle Upon Tyne NE1 7RU, Tyne & Wear, England..
    Taylor, Jessica
    Univ Warwick, Sch Life Sci, Coventry CV4 7AL, W Midlands, England..
    Purdy, Kevin J.
    Univ Warwick, Sch Life Sci, Coventry CV4 7AL, W Midlands, England..
    Eyice, Ozge
    Queen Mary Univ London, Sch Biol & Chem Sci, London E1 4NS, England..
    COD/sulfate ratio does not affect the methane yield and microbial diversity in anaerobic digesters2019In: Water Research, ISSN 0043-1354, E-ISSN 1879-2448, Vol. 155, no A Z, 1986, APPLIED AND ENVIRONMENTAL MICROBIOLOGY, V51, P572 rdy KJ, 2003, FEMS MICROBIOLOGY ECOLOGY, V44, P361, p. 444-454Article in journal (Refereed)
    Abstract [en]

    Anaerobic digestion of organic matter is the major route of biomethane production. However, in the presence of sulfate, sulfate-reducing bacteria (SRB) typically outcompete methanogens, which may reduce or even preclude methane production from sulfate-containing wastewaters. Although sulfate reduction and methanogenesis can occur simultaneously, our limited understanding of the microbiology of anaerobic digesters treating sulfate-containing wastewaters constrains improvements in the production of methane from these systems. This study tested the effects of carbon sources and chemical oxygen demand-to-sulfate ratio (COD/SO42-) on the diversity and interactions of SRB and methanogens in an anaerobic digester treating a high-sulfate waste stream. Overall, the data showed that sulfate removal and methane generation occurred in varying efficiencies and the carbon source had limited effect on the methane yield. Importantly, the results demonstrated that methanogenic and SRB diversities were only affected by the carbon source and not by the COD/SO42- ratio. 

  • 45. Cho, Sung Hyun
    et al.
    Purushotham, Pallinti
    Fang, Chao
    Maranas, Cassandra
    Diaz-Moreno, Sara M
    KTH, School of Biotechnology (BIO), Glycoscience.
    Bulone, Vincent
    KTH, School of Biotechnology (BIO), Glycoscience.
    Zimmer, Jochen
    Kumar, Manish
    Nixon, B. Tracy
    Synthesis and Self-Assembly of Cellulose Microfibrils from Reconstituted Cellulose Synthase2017In: Plant Physiology, ISSN 0032-0889, E-ISSN 1532-2548, Vol. 175, no 1, p. 146-156Article in journal (Refereed)
    Abstract [en]

    Cellulose, the major component of plant cell walls, can be converted to bioethanol and is thus highly studied. In plants, cellulose is produced by cellulose synthase, a processive family-2 glycosyltransferase. In plant cell walls, individual beta-1,4-glucan chains polymerized by CesA are assembled into microfibrils that are frequently bundled into macrofibrils. An in vitro system in which cellulose is synthesized and assembled into fibrils would facilitate detailed study of this process. Here, we report the heterologous expression and partial purification of His-tagged CesA5 from Physcomitrella patens. Immunoblot analysis and mass spectrometry confirmed enrichment of PpCesA5. The recombinant protein was functional when reconstituted into liposomes made from yeast total lipid extract. The functional studies included incorporation of radiolabeled Glc, linkage analysis, and imaging of cellulose microfibril formation using transmission electron microscopy. Several microfibrils were observed either inside or on the outer surface of proteoliposomes, and strikingly, several thinner fibrils formed ordered bundles that either covered the surfaces of proteoliposomes or were spawned from liposome surfaces. We also report this arrangement of fibrils made by proteoliposomes bearing CesA8 from hybrid aspen. These observations describe minimal systems of membrane-reconstituted CesAs that polymerize beta-1,4-glucan chains that coalesce to form microfibrils and higher-ordered macrofibrils. How these micro-and macrofibrils relate to those found in primary and secondary plant cell walls is uncertain, but their presence enables further study of the mechanisms that govern the formation and assembly of fibrillar cellulosic structures and cell wall composites during or after the polymerization process controlled by CesA proteins.

  • 46.
    Choong, Ferdinand X.
    et al.
    Karolinska Inst, Dept Neurosci, Swedish Med Nanosci Ctr, SE-17177 Stockholm, Sweden..
    Back, Marcus
    Linkoping Univ, IFM, Dept Chem, SE-58183 Linkoping, Sweden..
    Schulz, Anette
    Karolinska Inst, Dept Neurosci, Swedish Med Nanosci Ctr, SE-17177 Stockholm, Sweden..
    Nilsson, K. Peter. R.
    Linkoping Univ, IFM, Dept Chem, SE-58183 Linkoping, Sweden..
    Edlund, Ulrica
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Richter-Dahlfors, Agneta
    Karolinska Inst, Dept Neurosci, Swedish Med Nanosci Ctr, SE-17177 Stockholm, Sweden..
    Stereochemical identification of glucans by oligothiophenes enables cellulose anatomical mapping in plant tissues2018In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 8, article id 3108Article in journal (Refereed)
    Abstract [en]

    Efficient use of plant-derived materials requires enabling technologies for non-disruptive composition analysis. The ability to identify and spatially locate polysaccharides in native plant tissues is difficult but essential. Here, we develop an optical method for cellulose identification using the structure-responsive, heptameric oligothiophene h-FTAA as molecular fluorophore. Spectrophotometric analysis of h-FTAA interacting with closely related glucans revealed an exceptional specificity for beta-linked glucans. This optical, non-disruptive method for stereochemical differentiation of glycosidic linkages was next used for in situ composition analysis in plants. Multi-laser/multi-detector analysis developed herein revealed spatial localization of cellulose and structural cell wall features such as plasmodesmata and perforated sieve plates of the phloem. Simultaneous imaging of intrinsically fluorescent components revealed the spatial relationship between cell walls and other organelles, such as chloroplasts and lignified annular thickenings of the trachea, with precision at the sub-cellular scale. Our non-destructive method for cellulose identification lays the foundation for the emergence of anatomical maps of the chemical constituents in plant tissues. This rapid and versatile method will likely benefit the plant science research fields and may serve the biorefinery industry as reporter for feedstock optimization as well as in-line monitoring of cellulose reactions during standard operations.

  • 47. Cifuentes, Carolina
    et al.
    Bulone, Vincent
    KTH, School of Biotechnology (BIO), Glycoscience.
    Emons, Anne Mie C.
    Biosynthesis of Callose and Cellulose by Detergent Extracts of Tobacco Cell Membranes and Quantification of the Polymers Synthesized in vitro2010In: J INTEGR PLANT BIOL, ISSN 1672-9072, Vol. 52, no 2, p. 221-233Article in journal (Refereed)
    Abstract [en]

    The conditions that favor the in vitro synthesis of cellulose from tobacco BY-2 cell extracts were determined. The procedure leading to the highest yield of cellulose consisted of incubating digitonin extracts of membranes from 11-day-old tobacco BY-2 cells in the presence of 1 mM UDP-glucose, 8 mM Ca2+ and 8 mM Mg2+. Under these conditions, up to nearly 40% of the polysaccharides synthesized in vitro corresponded to cellulose, the other polymer synthesized being callose. Transmission electron microscopy analysis revealed the occurrence of two types of structures in the synthetic reactions. The first type consisted of small aggregates with a diameter between 3 and 5 nm that associated to form fibrillar strings of a maximum length of 400 nm. These structures were sensitive to the acetic/nitric acid treatment of Updegraff and corresponded to callose. The second type of structures was resistant to the Updegraff reagent and corresponded to straight cellulose microfibrils of 2-3 nm in diameter and 200 nm to up to 5 mu m in length. In vitro reactions performed on electron microscopy grids indicated that the minimal rate of microfibril elongation in vitro is 120 nm/min. Measurements of retardance by liquid crystal polarization microscopy as a function of time showed that small groups of microfibrils increased in retardance by up to 0.047 nm/min per pixel, confirming the formation of organized structures.

  • 48.
    Clergeot, Pierre-Henri
    et al.
    Stockholm University.
    Rivetti, Claudia
    Stockholm University.
    Hamiduzzaman, M. Md.
    Stockholm University.
    Ekengren, Sophia
    Stockholm University.
    The corky root rot pathogen, Pyrenochaeta lycopersici manipulates tomato roots with molecules secreted early during their interaction2012In: Acta Agriculturae Scandinavica - Section B, ISSN 0906-4710, E-ISSN 1651-1913, Vol. 62, no 4, p. 300-310Article in journal (Refereed)
    Abstract [en]

    Corky root rot is a ubiquitous soil-borne disease of tomato caused by the pathogen Pyrenochaeta lycopersici. This filamentous fungus is found on the roots of many crops and can persist in the soil up to 15 years as microsclerotia. High prevalence of corky root rot can be partly explained by the endurance and the broad host range of P. lycopersici, but how this fungus can gain access to host roots is still poorly understood, as its competitive saprophytic ability is very low. We have combined microscopy and reporter gene techniques to investigate the tomato-P. lycopersici interaction in vitro, and discovered the pathogen secretes molecules that change the direction of root growth and induce cell necrosis specifically in the apical part of the root of tomato ( apex, elongation zone and beginning of the root hair zone). Moreover, we found that the fungus preferentially infects immature root cells that are sensitive to these secreted fungal molecules, whereas infection is blocked in mature and insensitive parts of the root. Our study sheds light on novel and important features of the biology of this pathogen, which could contribute to its fitness in the rhizosphere.

  • 49. Corbin, Kendall R.
    et al.
    Hsieh, Yves S. Y.
    University of Adelaide, Australia.
    Betts, Natalie S.
    Byrt, Caitlin S.
    Henderson, Marilyn
    Stork, Jozsef
    DeBolt, Seth
    Fincher, Geoffrey B.
    Burton, Rachel A.
    Grape marc as a source of carbohydrates for bioethanol: Chemical composition, pre-treatment and saccharification.2015In: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 193, p. 76-83, article id S0960-8524(15)00816-0Article in journal (Refereed)
    Abstract [en]

    Global grape production could generate up to 13 Mt/yr of wasted biomass. The compositions of Cabernet Sauvignon (red marc) and Sauvignon Blanc (white marc) were analyzed with a view to using marc as raw material for biofuel production. On a dry weight basis, 31-54% w/w of the grape marc consisted of carbohydrate, of which 47-80% was soluble in aqueous media. Ethanol insoluble residues consisted mainly of polyphenols, pectic polysaccharides, heteroxylans and cellulose. Acid and thermal pre-treatments were investigated for their effects on subsequent cellulose saccharification. A 0.5M sulfuric acid pre-treatment yielded a 10% increase in the amount of liberated glucose after enzymatic saccharification. The theoretical amount of bioethanol that could be produced by fermentation of grape marc was up to 400 L/t. However, bioethanol from only soluble carbohydrates could yield 270 L/t, leaving a polyphenol enriched fraction that may be used in animal feed or as fertilizer.

  • 50. Coucheney, E.
    et al.
    Eckersten, H.
    Hoffmann, H.
    Jansson, Per Erik
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Gaiser, T.
    Ewert, F.
    Lewan, E.
    Key functional soil types explain data aggregation effects on simulated yield, soil carbon, drainage and nitrogen leaching at a regional scale2018In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 318, p. 167-181Article in journal (Refereed)
    Abstract [en]

    The effects of aggregating soil data (DAE) by areal majority of soil mapping units was explored for regional simulations with the soil-vegetation model CoupModel for a region in Germany (North Rhine-Westphalia). DAE were analysed for wheat yield, drainage, soil carbon mineralisation and nitrogen leaching below the root zone. DAE were higher for soil C mineralization and N leaching than for yield and drainage and were strongly related to the presence of specific soils within the study region. These soil types were associated to extreme simulated output variables compared to the mean variable in the region. The spatial aggregation of these key functional soils within sub-regions additionally influenced the DAE. A spatial analysis of their spatial pattern (i.e. their presence/absence, coverage and aggregation) can help in defining the appropriate grid resolution that would minimize the error caused by aggregating soil input data in regional simulations.

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