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  • 1.
    Ahrenstedt, Lage
    et al.
    KTH, School of Biotechnology (BIO). KTH, School of Biotechnology (BIO), Centres, Albanova VinnExcellence Center for Protein Technology, ProNova.
    Olksanen, Antti
    VTT Technical Research Centre of Finland.
    Salmien, Kristian
    VTT Technical Research Centre of Finland.
    Brumer, Harry
    KTH, School of Biotechnology (BIO), Glycoscience. KTH, School of Biotechnology (BIO), Centres, Albanova VinnExcellence Center for Protein Technology, ProNova.
    Paper dry strength improvement by xyloglucan addition: Wet-end application, spray coating and synergism with borate2008In: Holzforschung, ISSN 0018-3830, Vol. 62, no 1, 8-14 p.Article in journal (Refereed)
    Abstract [en]

    The polysaccharide xyloglucan as a wet-end additive improves paper properties. In the present study, paper strength improvement was analysed for dry handsheets made from chemical, mechanical and recycled pulps coated with xyloglucan in a spray application. Results are compared with sheets made from the same pulps treated with xyloglucan in the wet-end. Kraft pulp handsheets of bleached hardwood and softwood showed significant improvements of tensile, tear and Z-strength by xyloglucan spray treatment versus wet-end application, whereas handsheets of de-inked and thermomechanical pulp were improved only slightly. In both wet-end and spray applications, the effect of xyloglucan addition was intimately related to the presence of non-cellulosic components on the fibre surface. Further strength improvements were obtained for chemical pulps by addition of borax to the spray solution, which were likely to be due to the formation of borate-mediated xyloglucan cross-links. Spray coating of xyloglucan, with or without borax, thus represents a potential new application of this polysaccharide to increase paper dry strength.

  • 2. Alvarez, Francisco J.
    et al.
    Ryman, Kicki
    Hooijmaijers, Cornelis
    KTH, School of Biotechnology (BIO), Glycoscience.
    Bulone, Vincent
    KTH, School of Biotechnology (BIO), Glycoscience.
    Ljungdahl, Per O.
    Diverse Nitrogen Sources in Seminal Fluid Act in Synergy To Induce Filamentous Growth of Candida albicans2015In: Applied and Environmental Microbiology, ISSN 0099-2240, E-ISSN 1098-5336, Vol. 81, no 8, 2770-2780 p.Article in journal (Refereed)
    Abstract [en]

    The pathogenic fungus Candida albicans is the leading cause of vulvovaginal candidiasis (VVC). VVC represents a major quality- of-life issue for women during their reproductive years, a stage of life where the vaginal epithelium is subject to periodic hormonally induced changes associated with menstruation and concomitant exposure to serum as well as potential intermittent contact with seminal fluid. Seminal fluid potently triggers Candida albicans to switch from yeastlike to filamentous modes of growth, a developmental response tightly linked to virulence. Conversely, vaginal fluid inhibits filamentation. Here, we used artificial formulations of seminal and vaginal fluids that faithfully mimic genuine fluids to assess the contribution of individual components within these fluids to filamentation. The high levels of albumin, amino acids, and N-acetylglucosamine in seminal fluid act synergistically as potent inducers of filamentous growth, even at atmospheric levels of CO2 and reduced temperatures (30 degrees C). Using a simplified in vitro model that mimics the natural introduction of seminal fluid into the vulvovaginal environment, a pulse of artificial seminal fluid (ASF) was found to exert an enduring potential to overcome the inhibitory efficacy of artificial vaginal fluid (AVF) on filamentation. These findings suggest that a transient but substantial change in the nutrient levels within the vulvovaginal environment during unprotected coitus can induce resident C. albicans cells to engage developmental programs associated with virulent growth.

  • 3.
    Ampomah, Osei Y.
    et al.
    KTH, School of Biotechnology (BIO), Glycoscience.
    Avetisyan, A.
    Hansen, E.
    Svenson, J.
    Huser, T.
    Jensen, J. B.
    Bhuvaneswari, T. V.
    The thuEFGKAB operon of Rhizobia and Agrobacterium tumefaciens codes for transport of trehalose, maltitol, and isomers of sucrose and their assimilation through the formation of their 3-keto derivatives2013In: Journal of Bacteriology, ISSN 0021-9193, E-ISSN 1098-5530, Vol. 195, no 17, 3797-3807 p.Article in journal (Refereed)
    Abstract [en]

    The thu operon (thuEFGKAB) in Sinorhizobium meliloti codes for transport and utilization functions of the disaccharide trehalose. Sequenced genomes of members of the Rhizobiaceae reveal that some rhizobia and Agrobacterium possess the entire thu operon in similar organizations and that Mesorhizobium loti MAFF303099 lacks the transport (thuEFGK) genes. In this study, we show that this operon is dedicated to the transport and assimilation of maltitol and isomers of sucrose (leucrose, palatinose, and trehalulose) in addition to trehalulose, not only in S. meliloti but also in Agrobacterium tumefaciens. By using genetic complementation, we show that the thuAB genes of S. meliloti, M. loti, and A. tumefaciens are functionally equivalent. Further, we provide both genetic and biochemical evidence to show that these bacteria assimilate these disaccharides by converting them to their respective 3-keto derivatives and that the thuAB genes code for this ketodisaccharide-forming enzyme(s). Formation of 3-ketotrehalose in real time in live S. meliloti is shown through Raman spectroscopy. The presence of an additional ketodisaccharide- forming pathway(s) in A. tumefaciens is also indicated. To our knowledge, this is the first report to identify the genes that code for the conversion of disaccharides to their 3-ketodisaccharide derivatives in any organism.

  • 4.
    Ampomah, Osei Y.
    et al.
    KTH, School of Biotechnology (BIO), Glycoscience.
    Jensen, J. B.
    The trehalose utilization gene thuA ortholog in Mesorhizobium loti does not influence competitiveness for nodulation on Lotus spp2014In: World Journal of Microbiology & Biotechnology, ISSN 0959-3993, E-ISSN 1573-0972, Vol. 30, no 3, 1129-1134 p.Article in journal (Refereed)
    Abstract [en]

    Competitiveness for nodulation is a desirable trait in rhizobia strains used as inoculant. In Sinorhizobium meliloti 1021 mutation in either of the trehalose utilization genes thuA or thuB influences its competitiveness for root colonization and nodule occupancy depending on the interacting host. We have therefore investigated whether mutation in the thuA ortholog in Mesorhizobium loti MAFF303099 also leads to a similar competitive phenotype on its hosts. The results show that M. loti thuA mutant Ml7023 was symbiotically effective and was as competitive as the wild type in colonization and nodule occupancy on Lotus corniculatus and Lotus japonicus. The thuA gene in M. loti was not induced during root colonization or in the infection threads unlike in S. meliloti, despite its induction by trehalose and high osmolarity in in vitro assays.

  • 5. Anasontzis, George E.
    et al.
    Pena, Margarita Salazar
    Spadiut, Oliver
    KTH, School of Biotechnology (BIO), Glycoscience. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Brumer, Harry
    KTH, School of Biotechnology (BIO), Glycoscience. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Olsson, Lisbeth
    Effects of temperature and glycerol and methanol-feeding profiles on the production of recombinant galactose oxidase in Pichia pastoris2014In: Biotechnology progress (Print), ISSN 8756-7938, E-ISSN 1520-6033, Vol. 30, no 3, 728-735 p.Article in journal (Refereed)
    Abstract [en]

    Optimization of protein production from methanol-induced Pichia pastoris cultures is necessary to ensure high productivity rates and high yields of recombinant proteins. We investigated the effects of temperature and different linear or exponential methanol-feeding rates on the production of recombinant Fusarium graminearum galactose oxidase (EC 1.1.3.9) in a P. pastoris Mut+ strain, under regulation of the AOX1 promoter. We found that low exponential methanol feeding led to 1.5-fold higher volumetric productivity compared to high exponential feeding rates. The duration of glycerol feeding did not affect the subsequent product yield, but longer glycerol feeding led to higher initial biomass concentration, which would reduce the oxygen demand and generate less heat during induction. A linear and a low exponential feeding profile led to productivities in the same range, but the latter was characterized by intense fluctuations in the titers of galactose oxidase and total protein. An exponential feeding profile that has been adapted to the apparent biomass concentration results in more stable cultures, but the concentration of recombinant protein is in the same range as when constant methanol feeding is employed.

  • 6. Andrade Pires, Amanda do Rocio
    et al.
    Ruthes, Andrea Caroline
    KTH, School of Biotechnology (BIO), Glycoscience. Univ Fed Parana, Brazil.
    Suter Correia Cadena, Silvia Maria
    Iacomini, Marcello
    Cytotoxic effect of a mannogalactoglucan extracted from Agaricus bisporus on HepG2 cells2017In: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 170, 33-42 p.Article in journal (Refereed)
    Abstract [en]

    A mannogalactoglucan (RK2-Ab; M-w, 1.8 x 10(4) g mol(-1)) composed by Man (27.3%), Gal (24.4%) and Glc (48.3%) was extracted and characterized from Agaricus bisporus, and its biological activity was evaluated on human hepatocarcinoma cells (HepG2). The partially-O-methylated alditol acetates together with the NMR data suggest the main chain to be composed of alpha-D-Galp (32.8%) and beta-D-Glcp (37.0%) units (1 -> 6) -linked, with beta-D-Manp (14.6%), as non-reducing end units, substituting the side chains at O-2 (alpha-D-Galp units; 3.3%) and O-2 and O-4 (beta-D-Glcp units; 3.6%). (1 -> 2) -linked beta-D-Glcp (2.7%) and beta-D-Manp (6.0%) can also be observed. RK2-Ab reduced cellular viability of HepG2 cells, by both, the MTT and lactate dehydrogenase release assays, promoted the increase of cytochrome c release and decrease of ATP content. Suggesting that the mannogalactoglucan from A. bisporus may have antitumor activity by inducing apoptosis by the mitochondria death pathway, and could be used in cancer therapy.

  • 7.
    Ansari, Farhan
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Biocomposites. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Salajkova, Michaela
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Biocomposites. KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Zhou, Qi
    KTH, School of Biotechnology (BIO), Glycoscience. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Lars, Berglund
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Biocomposites. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Strong surface treatment effects on reinforcement efficiency in biocomposites based on cellulose nanocrystals in poly(vinyl acetate) matrix2015In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 16, no 12, 3916-3924 p.Article in journal (Refereed)
    Abstract [en]

    In this work, the problem to disperse cellulose nanocrystals (CNC) in hydrophobic polymer matrices has been addressed through application of an environmentally friendly chemical modification approach inspired by clay chemistry. The objective is to compare the effects of unmodified CNC and modified CNC (modCNC) reinforcement, where degree of CNC dispersion is of interest. Hydrophobic functionalization made it possible to disperse wood-based modCNC in organic solvent and cast well-dispersed nanocomposite films of poly(vinyl acetate) (PVAc) with 1-20 wt % CNC. Composite films were studied by infrared spectroscopy (FT-IR), UV-vis spectroscopy, dynamic mechanical thermal analysis (DMTA), tensile testing, and field-emission scanning electron microscopy (FE-SEM). Strongly increased mechanical properties were observed for modCNC nanocomposites. The reinforcement efficiency was much lower in unmodified CNC composites, and specific mechanisms causing the differences are discussed.

  • 8.
    Araújo, Ana Catarina
    et al.
    KTH, School of Biotechnology (BIO), Glycoscience.
    Nakhai, Azadeh
    KTH, School of Biotechnology (BIO), Glycoscience.
    Ruda, M.
    Slättegård, R.
    Gatenholm, P.
    Brumer, Harry
    KTH, School of Biotechnology (BIO), Glycoscience.
    A general route to xyloglucan-peptide conjugates for the activation of cellulose surfaces2012In: Carbohydrate Research, ISSN 0008-6215, E-ISSN 1873-426X, Vol. 354, 116-120 p.Article in journal (Refereed)
    Abstract [en]

    Cellulose is an attractive supporting matrix for diverse biotechnological applications, including chromatography, diagnostics, and tissue replacement/scaffolding, due to its renewable resource status, low cost, and low non-specific interaction with biomolecules. In an effort to expand the biofunctionality of cellulose materials, we present here a versatile method for the synthesis of xyloglucan-peptide conjugates that harness the strong xyloglucan-cellulose binding interaction for gentle surface modification. Xylogluco-oligosaccharide aminoalditols (XGO-NH 2) were coupled to both linear and cyclic peptides, which contained the endothelial cell epitope Arg-Gly-Asp, in a facile two-step approach employing diethyl squarate cross-linking. Subsequent xyloglucan endo-transglycosylase-mediated coupling of the resulting XGO-GRGDS (Gly-Arg-Gly-Asp-Ser) and XGO-c[RGDfK]-PEG-PEG (cyclo[Arg-Gly-Asp-(d-Phe)-Lys]-PEG-PEG; where PEG is 8-amino-3,6-dioxaoctanoic acid) conjugates into high molecular mass xyloglucan yielded xyloglucan-RGD peptide conjugates suitable for cellulose surface activation. Notably, use of XGO-squaramate as a readily accessible, versatile intermediate overcomes previous limitations of solid-phase synthetic approaches to XGO-peptide conjugates, and furthermore allows the method to be generalized to a wide variety of polypeptides and proteins, as well as diverse primary amino compounds.

  • 9.
    Araújo, Ana Catarina
    et al.
    KTH, School of Biotechnology (BIO), Glycoscience.
    Song, Yajing
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Lundeberg, Joakim
    KTH, School of Biotechnology (BIO), Gene Technology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Ståhl, Patrik L.
    Brumer, Harry, III
    KTH, School of Biotechnology (BIO), Glycoscience. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Activated Paper Surfaces for the Rapid Hybridization of DNA through Capillary Transport2012In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 84, no 7, 3311-3317 p.Article in journal (Refereed)
    Abstract [en]

    The development of low-cost, accurate, and equipment-free diagnostic tests is crucial to many clinical, laboratory, and field applications, including forensics and medical diagnostics. Cellulose fiber-based paper is an inexpensive, biodegradable, and renewable resource, the use of which as a biomolecule detection matrix and support confers several advantages compared to traditional materials such as glass. In this context, a new, facile method for the preparation of surface functionalized papers bearing single-stranded probe DNA (ssDNA) for rapid target hybridization via capillary transport is presented. Optimized reaction conditions were developed that allowed the direct, one-step activation of standard laboratory filters by the inexpensive and readily available bifunctional linking reagent, 1,4-phenylenediisothiocyanate. Such papers were thus amenable to subsequent coupling of amine-labeled ssDNA under standard conditions widely used for glass-based supports. The intrinsic wicking ability of the paper matrix facilitated rapid sample elution through arrays of probe DNA, leading to significant, detectable hybridization in the time required for the sample liquid to transit the vertical length of the strip (less than 2 min). The broad applicability of these paper test strips as rapid and specific diagnostics in "real-life" situations was exemplified by the discrimination of amplicons generated from canine and human mitochondrial and genomic DNA in mock forensic samples.

  • 10. Ariza, A.
    et al.
    Eklöf, Jens
    KTH, School of Biotechnology (BIO), Glycoscience.
    Spadiut, Oliver
    KTH, School of Biotechnology (BIO), Glycoscience. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Offen, W.A.
    Roberts, S.M.
    Wilson, K.S.
    Brumer, Harry
    KTH, School of Biotechnology (BIO), Glycoscience. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Davies, G.J.
    Structure and Activity of a Paenibacillus polymyxa Xyloglucanase from Glycoside Hydrolase Family 442011In: Journal of Biological Chemistry, ISSN 0021-9258, E-ISSN 1083-351X, Vol. 286, no 39, 33890-33900 p.Article in journal (Refereed)
    Abstract [en]

    The enzymatic degradation of plant polysaccharides is emerging as one of the key environmental goals of the early 21st century, impacting on many processes in the textile and detergent industries as well as biomass conversion to biofuels. One of the well known problems with the use of nonstarch (nonfood)-based substrates such as the plant cell wall is that the cellulose fibers are embedded in a network of diverse polysaccharides, including xyloglucan, that renders access difficult. There is therefore increasing interest in the "accessory enzymes," including xyloglucanases, that may aid biomass degradation through removal of "hemicellulose" polysaccharides. Here, we report the biochemical characterization of the endo-beta-1,4-(xylo)glucan hydrolase from Paenibacillus polymyxa with polymeric, oligomeric, and defined chromogenic aryl-oligosaccharide substrates. The enzyme displays an unusual specificity on defined xyloglucan oligosaccharides, cleaving the XXXG-XXXG repeat into XXX and GXXXG. Kinetic analysis on defined oligosaccharides and on aryl-glycosides suggests that both the -4 and +1 subsites show discrimination against xylose-appended glucosides. The three-dimensional structures of PpXG44 have been solved both in apo-form and as a series of ligand complexes that map the -3 to -1 and +1 to +5 subsites of the extended ligand binding cleft. Complex structures are consistent with partial intolerance of xylosides in the -4' subsites. The atypical specificity of PpXG44 may thus find use in industrial processes involving xyloglucan degradation, such as biomass conversion, or in the emerging exciting applications of defined xyloglucans in food, pharmaceuticals, and cellulose fiber modification.

  • 11.
    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.

  • 12.
    Aspeborg, Henrik
    et al.
    KTH, School of Biotechnology (BIO), Glycoscience.
    Coutinho, Pedro M.
    Wang, Yang
    KTH, School of Biotechnology (BIO), Glycoscience.
    Brumer, Harry
    KTH, School of Biotechnology (BIO), Glycoscience.
    Henrissat, Bernard
    Evolution, substrate specificity and subfamily classification of glycoside hydrolase family 5 (GH5)2012In: BMC Evolutionary Biology, ISSN 1471-2148, Vol. 12, no 1, 186- p.Article in journal (Refereed)
    Abstract [en]

    Background: The large Glycoside Hydrolase family 5 (GH5) groups together a wide range of enzymes acting on beta-linked oligo- and polysaccharides, and glycoconjugates from a large spectrum of organisms. The long and complex evolution of this family of enzymes and its broad sequence diversity limits functional prediction. With the objective of improving the differentiation of enzyme specificities in a knowledge-based context, and to obtain new evolutionary insights, we present here a new, robust subfamily classification of family GH5. Results: About 80% of the current sequences were assigned into 51 subfamilies in a global analysis of all publicly available GH5 sequences and associated biochemical data. Examination of subfamilies with catalytically-active members revealed that one third are monospecific (containing a single enzyme activity), although new functions may be discovered with biochemical characterization in the future. Furthermore, twenty subfamilies presently have no characterization whatsoever and many others have only limited structural and biochemical data. Mapping of functional knowledge onto the GH5 phylogenetic tree revealed that the sequence space of this historical and industrially important family is far from well dispersed, highlighting targets in need of further study. The analysis also uncovered a number of GH5 proteins which have lost their catalytic machinery, indicating evolution towards novel functions. Conclusion: Overall, the subfamily division of GH5 provides an actively curated resource for large-scale protein sequence annotation for glycogenomics; the subfamily assignments are openly accessible via the Carbohydrate-Active Enzyme database at http://www.cazy.org/GH5.html.

  • 13.
    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, 983-997 p.Article 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.

  • 14. Badreddine, Ilham
    et al.
    Lafitte, Claude
    Heux, Laurent
    Skandalis, Nicholas
    Spanou, Zacharoula
    Martinez, Yves
    Esquerre-Tugaye, Marie-Therese
    Bulone, Vincent
    KTH, School of Biotechnology (BIO), Glycoscience.
    Dumas, Bernard
    Bottin, Arnaud
    Cell Wall Chitosaccharides Are Essential Components and Exposed Patterns of the Phytopathogenic Oomycete Aphanomyces euteiches2008In: Eukaryotic Cell, ISSN 1535-9778, E-ISSN 1535-9786, Vol. 7, no 11, 1980-1993 p.Article in journal (Refereed)
    Abstract [en]

    Chitin is an essential component of fungal cell walls, where it forms a crystalline scaffold, and chitooligosaccharides derived from it are signaling molecules recognized by the hosts of pathogenic fungi. Oomycetes are cellulosic fungus-like microorganisms which most often lack chitin in their cell walls. Here we present the first study of the cell wall of the oomycete Aphanomyces euteiches, a major parasite of legume plants. Biochemical analyses demonstrated the presence of ca. 10% N-acetyl-D-glucosamine (GlcNAc) in the cell wall. Further characterization of the GlcNAc-containing material revealed that it corresponds to noncrystalline chitosaccharides associated with glucans, rather than to chitin per se. Two putative chitin synthase (CHS) genes were identified by data mining of an A. euteiches expressed sequence tag collection and Southern blot analysis, and full-length cDNA sequences of both genes were obtained. Phylogeny analysis indicated that oomycete CHS diversification occurred before the divergence of the major oomycete lineages. Remarkably, lectin labeling showed that the Aphanomyces euteiches chitosaccharides are exposed at the cell wall surface, and study of the effect of the CHS inhibitor nikkomycin Z demonstrated that they are involved in cell wall function. These data open new perspectives for the development of antioomycete drugs and further studies of the molecular mechanisms involved in the recognition of pathogenic oomycetes by the host plants.

  • 15. Barbieri, Shayla Fernanda
    et al.
    Ruthes, Andrea C.
    KTH, School of Biotechnology (BIO), Glycoscience.
    de Oliveira Petkowicz, Carmen Lucia
    Bueno de Godoy, Rossana Catie
    Sassaki, Guilherme Lanzi
    Santana Filho, Arquimedes Paixao
    Meira Silveira, Joana Lea
    Extraction, purification and structural characterization of a galactoglucomannan from the gabiroba fruit (Campomanesia xanthocarpa Berg), Myrtaceae family2017In: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 174, 887-895 p.Article in journal (Refereed)
    Abstract [en]

    In this study, we isolated and structurally characterized, for the first time, a galactoglucomannan (GGM) from the pulp of gabiroba, a Myrtaceae family species. The HPSEC-MALLS-RI analysis showed a homogeneous polysaccharide with molar mass of 25,340 g mol(-1). The monosaccharide composition showed that the GGM consisted of Man:Glc:Gal in a molar ratio of 1:1:0.6. Methylation and 1D and 2D NMR analyses suggested that the main chain of the GGM consisted of beta-D-Glcp and beta-D-Manp units (1 -> 4)-linked. The alpha-D-Galp substitutions occur mainly at O-6 position of beta-D-Manp units. The glycosidic linkages of the GGM were evident by the presence of the characteristic signals of 4-O-substituted residues at delta 78.6/3.69 for both beta-D-Glcp and beta-D-Manp. Furthermore, the 0-6 substitutions for both beta-D-Glcp and beta-D-Manp units were confirmed by signals at delta 67.1/4.00 and 3.93. The interglycosidic correlations, obtained through the analysis of the HMBC spectrum, further confirm the structure. (C) 2017 Elsevier Ltd. All rights reserved.

  • 16.
    Baumann, Martin J.
    et al.
    KTH, School of Biotechnology (BIO).
    Eklöf, Jens M.
    KTH, School of Biotechnology (BIO), Glycoscience.
    Michel, Gurvan
    Kallas, Åsa M.
    KTH, School of Biotechnology (BIO).
    Teeri, Tuula T.
    KTH, School of Biotechnology (BIO), Glycoscience.
    Czjzek, Mirjam
    Brumer, Harry
    KTH, School of Biotechnology (BIO), Glycoscience.
    Structural evidence for the evolution of xyloglucanase activity from xyloglucan endo-transglycosylases: Biological implications for cell wall metabolism2007In: The Plant Cell, ISSN 1040-4651, E-ISSN 1532-298X, Vol. 19, no 6, 1947-1963 p.Article in journal (Refereed)
    Abstract [en]

    High-resolution, three-dimensional structures of the archetypal glycoside hydrolase family 16 (GH16) endo-xyloglucanases Tm-NXG1 and Tm-NXG2 from nasturtium (Tropaeolum majus) have been solved by x-ray crystallography. Key structural features that modulate the relative rates of substrate hydrolysis to transglycosylation in the GH16 xyloglucan-active enzymes were identified by structure-function studies of the recombinantly expressed enzymes in comparison with data for the strict xyloglucan endo-transglycosylase Ptt-XET16-34 from hybrid aspen ( Populus tremula 3 Populus tremuloides). Production of the loop deletion variant Tm-NXG1-Delta YNIIG yielded an enzyme that was structurally similar to Ptt- XET16-34 and had a greatly increased transglycosylation: hydrolysis ratio. Comprehensive bioinformatic analyses of XTH gene products, together with detailed kinetic data, strongly suggest that xyloglucanase activity has evolved as a gain of function in an ancestral GH16 XET to meet specific biological requirements during seed germination, fruit ripening, and rapid wall expansion.

  • 17.
    Baumann, Martin J.
    et al.
    KTH, School of Biotechnology (BIO).
    Eklöf, Jens
    KTH, School of Biotechnology (BIO).
    Michel, G.
    Kallas, Åsa
    KTH.
    Teeri, Tuula
    KTH, School of Biotechnology (BIO).
    Czjzek, Mirjam
    KTH.
    Brumer, Harry
    KTH, School of Biotechnology (BIO), Glycoscience.
    Structural analysis of nasturtium NXG reveals the evolution of GH16 xyloglucanase activity from XETs: biological implications for cell wall metabolismManuscript (Other academic)
  • 18. Bello, M. A.
    et al.
    Ruiz-León, Y.
    Sandoval-Sierra, J. V.
    Rezinciuc, Svetlana
    KTH, School of Biotechnology (BIO), Glycoscience.
    Diéguez-Uribeondo, J.
    Scanning electron microscopy (SEM) protocols for problematic plant, oomycete, and fungal samples2017In: Journal of Visualized Experiments, ISSN 1940-087X, E-ISSN 1940-087X, Vol. 2017, no 120, e55031Article in journal (Refereed)
    Abstract [en]

    Common problems in the processing of biological samples for observations with the scanning electron microscope (SEM) include cell collapse, treatment of samples from wet microenvironments and cell destruction. Using young floral tissues, oomycete cysts, and fungi spores (Agaricalesas examples, specific protocols to process delicate samples are described here that overcome some of the main challenges in sample treatment for image capture under the SEM. Floral meristems fixed with FAA (Formalin-Acetic-Alcohol) and processed with the Critical Point Dryer (CPD) did not display collapsed cellular walls or distorted organs. These results are crucial for the reconstruction of floral development. A similar CPD-based treatment of samples from wet microenvironments, such as the glutaraldehyde-fixed oomycete cysts, is optimal to test the differential growth of diagnostic characteristics (e.g., the cyst spines) on different types of substrates. Destruction of nurse cells attached to fungi spores was avoided after rehydration, dehydration, and the CPD treatment, an important step for further functional studies of these cells. The protocols detailed here represent low-cost and rapid alternatives for the acquisition of good-quality images to reconstruct growth processes and to study diagnostic characteristics.

  • 19. Belmonte, Rodrigo
    et al.
    Wang, Tiehui
    Duncan, Gary J.
    Skaar, Ida
    Melida, Hugo
    KTH, School of Biotechnology (BIO), Glycoscience.
    Bulone, Vincent
    KTH, School of Biotechnology (BIO), Glycoscience.
    van West, Pieter
    Secombes, Christopher J.
    Role of Pathogen-Derived Cell Wall Carbohydrates and Prostaglandin E-2 in Immune Response and Suppression of Fish Immunity by the Oomycete Saprolegnia parasitica2014In: Infection and Immunity, ISSN 0019-9567, E-ISSN 1098-5522, Vol. 82, no 11, 4518-4529 p.Article in journal (Refereed)
    Abstract [en]

    Saprolegnia parasitica is a freshwater oomycete that is capable of infecting several species of fin fish. Saprolegniosis, the disease caused by this microbe, has a substantial impact on Atlantic salmon aquaculture. No sustainable treatment against saprolegniosis is available, and little is known regarding the host response. In this study, we examined the immune response of Atlantic salmon to S. parasitica infection and to its cell wall carbohydrates. Saprolegnia triggers a strong inflammatory response in its host (i. e., induction of interleukin-1 beta(1) [IL-1 beta(1)], IL-6, and tumor necrosis factor alpha), while severely suppressing the expression of genes associated with adaptive immunity in fish, through downregulation of T-helper cell cytokines, antigen presentation machinery, and immunoglobulins. Oomycete cell wall carbohydrates were recognized by fish leukocytes, triggering upregulation of genes involved in the inflammatory response, similar to what is observed during infection. Our data suggest that S. parasitica is capable of producing prostaglanding E-2 (PGE(2)) in vitro, a metabolite not previously shown to be produced by oomycetes, and two proteins with homology to vertebrate enzymes known to play a role in prostaglandin biosynthesis have been identified in the oomycete genome. Exogenous PGE(2) was shown to increase the inflammatory response in fish leukocytes incubated with cell wall carbohydrates while suppressing genes involved in cellular immunity (gamma interferon [IFN-gamma] and the IFN-gamma-inducible protein [gamma-IP]). Inhibition of S. parasitica zoospore germination and mycelial growth by two cyclooxygenase inhibitors (aspirin and indomethacin) also suggests that prostaglandins may be involved in oomycete development.

  • 20. Berglund, Jennie
    et al.
    Angles d’Ortoli, Thibault
    Vilaplana, Francisco
    KTH, School of Biotechnology (BIO), Glycoscience.
    Widmalm, Göran
    Bergenstråhle-Wohlert, Malin
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Lawoko, Martin
    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.
    Lindström, Mikael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Wohlert, Jakob
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    A molecular dynamics study of the effect of glycosidiclinkage type in the hemicellulose backbone on the molecularchain 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.

  • 21.
    Berglund, Lars
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Biocomposites.
    Sehaqui, Houssine
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Biocomposites.
    Zhou, Qi
    KTH, School of Biotechnology (BIO), Glycoscience.
    Cellulose-based materials comprising nanofibrillated cellulose from native cellulose2011Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    The present invention relates to cellulose-based materials comprising nanofibrillated cellulose (NFC) from native cellulose. exhibiting highly superior properties as compared to other cellulose-based materials, a method for preparing such cellulose-based material, and uses thereof are also disclosed.

  • 22.
    Berglund, Lars
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Biocomposites.
    Zhou, Qi
    KTH, School of Biotechnology (BIO), Glycoscience.
    Kochumalayil, Joby Jose
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Biocomposites.
    Oxygen barrier for packaging applications2011Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    The present invention relates to composite material of xyloglucan and clay for use as a coating material. The invention also relates to a method of producing the coating.

  • 23. Bessueille, Laurence
    et al.
    Bulone, Vincent
    KTH, School of Biotechnology (BIO), Glycoscience.
    A survey of cellulose biosynthesis in higher plants2008In: PLANT BIOTECHNOLOGY, ISSN 1342-4580, Vol. 25, no 3, 315-322 p.Article in journal (Refereed)
    Abstract [en]

    Cellulose plays a central role in plant development and its biosynthesis represents one of the most important biochemical processes in plant biology. However, the corresponding molecular mechanisms are not well understood, despite the progress made in the past years in the identification of genes that code for the catalytic subunits of the cellulose synthases and other proteins potentially involved in cellulose formation. A major bottleneck is the high instability of the cellulose synthase complexes and their location in the plasma membrane. Additional efforts are currently being made to unravel the mechanisms of cellulose biosynthesis. Indeed, understanding how cellulose is formed and how its crystallinity is achieved is relevant not only for studying plant development, but also for improving the digestibility of the plant biomass, which is foreseen as an alternative to fossil fuels for the production of energy. This review summarizes the major unanswered questions related to the process of cellulose biosynthesis, and describes the recent progress that has been made in the area through the combination of biochemical approaches and molecular genetics.

  • 24. Bessueille, Laurence
    et al.
    Sindt, Nicolas
    Guichardant, Michel
    Djerbi, Soraya
    Teeri, Tuula T.
    KTH, School of Biotechnology (BIO), Glycoscience.
    Bulone, Vincent
    KTH, School of Biotechnology (BIO), Glycoscience.
    Plasma membrane microdomains from hybrid aspen cells are involved in cell wall polysaccharide biosynthesis2009In: Biochemical Journal, ISSN 0264-6021, E-ISSN 1470-8728, Vol. 420, 93-103 p.Article in journal (Refereed)
    Abstract [en]

    Detergent-resistant plasma membrane microdomains [DRMs (detergent-resistant membranes)] were isolated recently from several plant species. As for animal cells, a large range of cellular functions, such as signal transduction, endocytosis and protein trafficking, have been attributed to plant lipid rafts and DRMs. The data available are essentially based on protcomics and more approaches need to be undertaken to elucidate the precise function of individual populations of DRMs in plants. We report here the first isolation of DRMs from purified plasma membranes of a tree species, the hybrid aspen Populus tremula x tremuloides, and their biochemical characterization. Plasma membranes were solubilized with Triton X-100 and the resulting DRMs were isolated by flotation in sucrose density gradients. The DRMs were enriched in sterols, sphingolipids and glycosylphosphatidylinositol-anchored proteins and thus exhibited similar properties to DRMs from other species. However, they contained key carbohydrate synthases involved in cell wall polysaccharide biosynthesis, namely callose [(1 -> 3)-beta-D-glucan] and cellulose synthases. The association of these enzymes with DRMs was demonstrated using specific glucan synthase assays and antibodies, as well as biochemical and chemical approaches for the characterization of the polysaccharides synthesized in vitro by the isolated DRMs. More than 70% of the total glucan synthase activities present in the original plasma membranes was associated with the DRM fraction. In addition to shedding light on the lipid environment of callose and cellulose synthases, our results demonstrate the involvement of DRMs in the biosynthesis of important cell wall polysaccharides. This novel concept suggests a function of plant membrane microdomains in cell growth and morphogenesis.

  • 25.
    Bi, Ran
    et al.
    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.
    Azhar, Shoaib
    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.
    Mckee, Lauren
    KTH, School of Biotechnology (BIO), Glycoscience. 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, Wood Chemistry and Pulp Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Culture Filtrates from a Soil Organism Enhances Extractability of Polymers from Fiberised Spruce WoodManuscript (preprint) (Other academic)
  • 26.
    Bi, Ran
    et al.
    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.
    Berglund, Jennie
    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.
    Vilaplana, Francisco
    KTH, School of Biotechnology (BIO), Glycoscience. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    McKee, Lauren
    KTH, School of Biotechnology (BIO), Glycoscience. 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, Wood Chemistry and Pulp Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    The Degree Of Acetylation Affects The Microbial Degradability Of HemicellulosesManuscript (preprint) (Other academic)
  • 27.
    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.
    McKee, Lauren S.
    KTH, School of Biotechnology (BIO), Glycoscience. 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.
    The degree of acetylation affects the microbial degradability of mannans2016In: Polymer degradation and stability, ISSN 0141-3910, E-ISSN 1873-2321, Vol. 133, 36-46 p.Article 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.

  • 28.
    Bi, Ran
    et al.
    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.
    Spadiut, Oliver
    KTH, School of Biotechnology (BIO), Glycoscience. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Brumer, Harry
    KTH, School of Biotechnology (BIO), Glycoscience. 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, Wood Chemistry and Pulp Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Isolation and identification of microorganisms from soil able to live on lignin as acarbon source and to produce enzymes which cleave the β-o-4 bond in a lignin model compound2012In: Cellulose Chemistry and Technology, ISSN 0576-9787, Vol. 46, no 3-4, 227-242 p.Article in journal (Refereed)
    Abstract [en]

    Several strains of fungi were isolated and identified from Scandinavian soil using agar plates with lignin as a carbon source. The strains grew significantly faster on this medium than on control plates without lignin. Different types of technical lignins were used, some of which contained trace amounts of sugars, even if the increased growth rate seemed not related to the sugar content. Some strains were cultivated in shaking flask cultures with lignin as a carbon source, with lignin apparently consumed by microbes - while accumulation of the microorganism biomass occurred. The cell-free filtrates of these cultures could reduce the apparent molecular weights of lignosulphonates, while the culture filtrate of one strain could cleave the beta-O-4 bond in a lignin model compound.

  • 29.
    Bi, Ran
    et al.
    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.
    Spadiut, Oliver
    KTH, School of Biotechnology (BIO), Glycoscience. 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.
    Brumer, Harry
    KTH, School of Biotechnology (BIO), Glycoscience. 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, Wood Chemistry and Pulp Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Isolation and identification of microorganisms from soil able to live on lignin as a carbon source and to produce enzymes which cleave beta-O-4 bond in a lignin model compound2012In: Cellulose Chemistry and Technology, ISSN 0576-9787, Vol. 46, no 3-4, 227-242 p.Article in journal (Refereed)
    Abstract [en]

    Several strains of fungi were isolated and identified from Scandinavian soil using agar plates with lignin as a carbon source. The strains grew significantly faster on this medium than on control plates without lignin. Different types of technical lignins were used, some of which contained trace amounts of sugars, even if the increased growth rate seemed not related to the sugar content. Some strains were cultivated in shaking flask cultures with lignin as a carbon source, with lignin apparently consumed by microbes - while accumulation of the microorganism biomass occurred. The cell-free filtrates of these cultures could reduce the apparent molecular weights of lignosulphonates, while the culture filtrate of one strain could cleave the beta-O-4 bond in a lignin model compound.

  • 30.
    Bi, Ran
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Spadiut, Oliver
    KTH, School of Biotechnology (BIO), Glycoscience.
    Lawoko, Martin
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Brumer, Harry
    KTH, School of Biotechnology (BIO), Glycoscience.
    Henriksson, Gunnar
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Isolation and identification of microorganisms from soil able to utilize lignin as single carbon source2011In: Proceedings of the 16th International Symposium of wood, fiber and pulp chemistry, 2011, 1091-1095 p.Conference paper (Refereed)
  • 31.
    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.
    Spaduit, Oliver
    KTH, School of Biotechnology (BIO). KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Brumer, Harry III
    KTH, School of Biotechnology (BIO), Glycoscience. 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.
    Isolation and identification of microorganisms from soil  able to ive on lignin as carbon source and produce enzymes that cleave beta-O-4mbond in lignin2011In: Cellulose Chemistry and Technology, ISSN 0576-9787Article in journal (Refereed)
    Abstract [en]

    Twenty one strains of micro organism from Scandinavian soil had been isolated that could utilize lignin as only carbon source and 11 strains of them were identified. Different types of technical lignins were used.5 faster growing strains were cultivated in shaking flask cultures with ligninosulfonate as sole carbon source,and lignin appeared to be consumed after several days while mycelia was observed accumulated.Cell free filtrates of the 5 faster growing strains could lower the apparent molecular weights of lignosulphonates and the culture filtrate of one strain could cleave the lignin model compound with.The significances of the results are discussed.

  • 32. Biscaia, S. M. P.
    et al.
    Carbonero, E. R.
    Bellan, D. L.
    Borges, B. S.
    Costa, C. R.
    Rossi, G. R.
    Goncalves, J. P.
    Melo, C. M.
    Livero, F. A. R.
    Ruthes, Andrea C.
    KTH, School of Biotechnology (BIO), Glycoscience.
    Zotz, R.
    Silva, E. V.
    Oliveira, C. C.
    Acco, A.
    Nader, H. B.
    Chammas, R.
    Iacomini, M.
    Franco, C. R. C.
    Trindade, E. S.
    Safe therapeutics of murine melanoma model using a novel antineoplasic, the partially methylated mannogalactan from Pleurotus eryngii2017In: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 178, 95-104 p.Article in journal (Refereed)
    Abstract [en]

    A heteropolysaccharide was isolated by cold aqueous extraction from edible mushroom Pleurotus eryngii ("King Oyster") basidiocarps and its biological properties were evaluated. Structural assignments were carried out using mono-and bidimensional NMR spectroscopy, monosaccharide composition, and methylation analyses. A man-nogalactan having a main chain of (1 -> 6)-linked alpha-D-galactopyranosyl and 3-O-methyl-alpha-D-galactopyranosyl residues, both partially substituted at OH-2 by beta-D-Manp (MG-Pe) single-unit was found. Biological effects of mannogalactan from P. eryngii (MG-Pe) were tested against murine melanoma cells. MG-Pe was non-cytotoxic, but reduced in vitro melanoma cells invasion. Also, 50 mg/kg MG-Pe administration to melanoma-bearing C57BL/6 mice up to 10 days decreased in 60% the tumor volume compared to control. Additionally, no changes were observed when biochemical profile, complete blood cells count (CBC), organs, and body weight were analyzed. Mg-Pe was shown to be a promising anti-melanoma molecule capable of switching melanoma cells to a non-invasive phenotype with no toxicity to melanoma-bearing mice.

  • 33. Bottin, Armaud
    et al.
    Brown, Christian
    KTH, School of Biotechnology (BIO), Glycoscience.
    Mélida, Hugo
    KTH, School of Biotechnology (BIO), Glycoscience.
    Bulone, Vincent
    KTH, School of Biotechnology (BIO), Glycoscience.
    The phytopathogenic oomycete Aphanomyces euteiches contains two distinct N-acetylglucosaminyltransferase activities that form chitin-like saccharides in vitroManuscript (preprint) (Other academic)
  • 34. Bouzenzana, Jamel
    et al.
    Pelosi, Ludovic
    Briolay, Anne
    Briolay, Jerome
    Bulone, Vincent
    KTH, School of Biotechnology (BIO), Glycoscience.
    Identification of the first Oomycete annexin as a (1 -> 3)-beta-D-glucan synthase activator2006In: Molecular Microbiology, ISSN 0950-382X, E-ISSN 1365-2958, Vol. 62, no 2, 552-565 p.Article in journal (Refereed)
    Abstract [en]

    (1 -> 3)-beta-D-Glucans are major components of the cell walls of Oomycetes and as such they play an essential role in the morphogenesis and growth of these microorganisms. Despite the biological importance of (1 -> 3)-beta-D-glucans, their mechanisms of biosynthesis are poorly understood. Previous studies on (1 -> 3)-beta-D-glucan synthases from Saprolegnia monoica have shown that three protein bands of an apparent molecular weight of 34, 48 and 50 kDa co-purify with enzyme activity. However, none of the corresponding proteins have been identified. Here we have identified, purified, sequenced and characterized a protein from the 34 kDa band and clearly shown that it has all the biochemical properties of proteins from the annexin family. In addition, we have unequivocally demonstrated that the purified protein is an activator of (1 -> 3)-beta-D-glucan synthase. This represents a new type of function for proteins belonging to the annexin family. Two other proteins from the 48 and 50 kDa bands were identified as ATP synthase subunits, which most likely arise from contaminations by mitochondria during membrane preparation. The results, which are discussed in relation with the possible regulation mechanisms of (1 -> 3)-beta-D-glucan synthases, represent a first step towards a better understanding of cell wall polysaccharide biosynthesis in Oomycetes.

  • 35. Briolay, Anne
    et al.
    Bouzenzana, Jamel
    Guichardant, Michel
    Deshayes, Christian
    Sindt, Nicolas
    Bessueille, Laurence
    Bulone, Vincent
    KTH, School of Biotechnology (BIO), Glycoscience.
    Cell Wall Polysaccharide Synthases Are Located in Detergent-Resistant Membrane Microdomains in Oomycetes2009In: Applied and Environmental Microbiology, ISSN 0099-2240, E-ISSN 1098-5336, Vol. 75, no 7, 1938-1949 p.Article in journal (Refereed)
    Abstract [en]

    The pathways responsible for cell wall polysaccharide biosynthesis are vital in eukaryotic microorganisms. The corresponding synthases are potential targets of inhibitors such as fungicides. Despite their fundamental and economical importance, most polysaccharide synthases are not well characterized, and their molecular mechanisms are poorly understood. With the example of Saprolegnia monoica as a model organism, we show that chitin and (1 -> 3)-beta-D-glucan synthases are located in detergent-resistant membrane microdomains (DRMs) in oomycetes, a phylum that comprises some of the most devastating microorganisms in the agriculture and aquaculture industries. Interestingly, no cellulose synthase activity was detected in the DRMs. The purified DRMs exhibited similar biochemical features as lipid rafts from animal, plant, and yeast cells, although they contained some species-specific lipids. This report sheds light on the lipid environment of the (1 -> 3)-beta-D-glucan and chitin synthases, as well as on the sterol biosynthetic pathways in oomycetes. The results presented here are consistent with a function of lipid rafts in cell polarization and as platforms for sorting specific sets of proteins targeted to the plasma membrane, such as carbohydrate synthases. The involvement of DRMs in the biosynthesis of major cell wall polysaccharides in eukaryotic microorganisms suggests a function of lipid rafts in hyphal morphogenesis and tip growth.

  • 36.
    Brown, Christian
    KTH, School of Biotechnology (BIO), Glycoscience.
    Characterization of specific domains of the cellulose and chitin synthases from pathogenic oomycetes2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Some oomycetes species are severe pathogens of fish or crops. As such, they are responsible for important losses in the aquaculture industry as well as in agriculture. Saprolegnia parasitica is a major concern in aquaculture as there is currently no method available for controlling the diseases caused by this microorganism. The cell wall is an extracellular matrix composed essentially of polysaccharides, whose integrity is required for oomycete viability. Thus, the enzymes involved in the biosynthesis of cell wall components, such as cellulose and chitin synthases, represent ideal targets for disease control. However, the biochemical properties of these enzymes are poorly understood, which limits our capacity to develop specific inhibitors that can be used for blocking the growth of pathogenic oomycetes.

    In our work, we have used Saprolegnia monoica as a model species for oomycetes to characterize two types of domains that occur specifically in oomycete carbohydrate synthases: the Pleckstrin Homology (PH) domain of a cellulose synthase and the so-called ‘Microtubule Interacting and Trafficking’ (MIT) domain of chitin synthases. In addition, the chitin synthase activity of the oomycete phytopathogen Aphanomyces euteiches was characterized in vitro using biochemical approaches.

    The results from our in vitro investigations revealed that the PH domain of the oomycete cellulose synthase binds to phosphoinositides, microtubules and F-actin. In addition, cell biology approaches were used to demonstrate that the PH domain co-localize with F-actin in vivo. The structure of the MIT domain of chitin synthase (CHS) 1 was solved by NMR. In vitro binding assays performed on recombinant MIT domains from CHS 1 and CHS 2 demonstrated that both proteins strongly interact with phosphatidic acid in vitro. These results were further supported by in silico data where biomimetic membranes composed of different phospholipids were designed for interaction studies. The use of a yeast-two-hybrid approach suggested that the MIT domain of CHS 2 interacts with the delta subunit of Adaptor Protein 3, which is involved in protein trafficking. These data support a role of the MIT domains in the cellular targeting of CHS proteins. Our biochemical data on the characterization of the chitin synthase activity of A. euteiches suggest the existence of two distinct enzymes responsible for the formation of water soluble and insoluble chitosaccharides, which is consistent with the existence of two putative CHS genes in the genome of this species.

    Altogether our data support a role of the PH domain of cellulose synthase and MIT domains of CHS in membrane trafficking and cellular location.

  • 37.
    Brown, Christian
    et al.
    KTH, School of Biotechnology (BIO), Glycoscience.
    Leijon, Felicia
    KTH, School of Biotechnology (BIO), Glycoscience.
    Bulone, Vincent
    Radiometric and spectrophotometric in vitro assays of glycosyltransferases involved in plant cell wall carbohydrate biosynthesis2012In: Nature Protocols, ISSN 1754-2189, Vol. 7, no 9, 1634-1650 p.Article in journal (Refereed)
    Abstract [en]

    Most of the glycosyltransferases (GTs) that catalyze the formation of plant cell wall carbohydrates remain to be biochemically characterized. This can be achieved only if specific assays are available for these enzymes. Here we present a protocol for in vitro assays of processive and nonprocessive membrane-bound GTs. The assays are either based on the use of radioactive nucleotide sugars (NDP sugars; e.g., UDP-[U-C-14] glucose) and the quantification of the radiolabeled monosaccharides incorporated into soluble or insoluble carbohydrates, or on the coupling of the GT reaction with that of pyruvate kinase (PK) and the oxidation of NADH by lactate dehydrogenase (LDH). The radiometric assays are more suitable for exploratory work on poorly characterized enzymes, whereas the spectrophotometric assays require the availability of highly enriched GTs. Both assays can be performed within 1 d, depending on the number of fractions to be assayed or reaction mixtures to be tested.

  • 38.
    Brown, Christian
    et al.
    KTH, School of Biotechnology (BIO), Glycoscience.
    Szpryngie, Scarlett
    Kuang, Guanglin
    Srivastava, Vaibhav
    KTH, School of Biotechnology (BIO), Glycoscience.
    Ye, Weihua
    McKee, Lauren S.
    KTH, School of Biotechnology (BIO), Glycoscience.
    Tu, Yaoquan
    Mäler, Lena
    Bulone, Vincent
    KTH, School of Biotechnology (BIO), Glycoscience.
    Structural and functional characterization of the “Microtubule Interacting and Trafficking": domains of two oomycetes chitin synthasesManuscript (preprint) (Other academic)
  • 39.
    Brumer, Harry
    KTH, School of Biotechnology (BIO), Glycoscience.
    Enzymatic functionalization of cellulosic fibres for textile and other applications: Xyloglucan as a molecular anchor2010In: Advances in Textile Biotechnology, Elsevier, 2010, 266-287 p.Chapter in book (Refereed)
    Abstract [en]

    The inherent recalcitrance of paracrystalline cellulose, which restricts the performance and applications of cellulosic biofibres, has been circumvented by a biomimetic approach that avoids the limitations inherent in direct chemical methods for cellulose modification. The unique ability of the plant enzyme xyloglucan endo-transglycosylase (XET) to produce chemo-enzymatically functionalized xyloglucan (XG) polysaccharides was harnessed together with the inherently strong interaction of XG with cellulose to surface-anchor the XG derivatives. An overview of the use of XG-XET technology in the functionalization of diverse cellulosic substrates is presented. Specific examples are given to highlight the potential of the system for future applications in textiles, pulp and paper, and biomedicine.

  • 40.
    Brumer, Harry
    et al.
    KTH, School of Biotechnology (BIO), Glycoscience.
    Rutland, Mark
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Sinnott, M. L.
    Teeri, Tuula T.
    KTH, School of Biotechnology (BIO), Glycoscience.
    Zhou, Qi
    KTH, School of Biotechnology (BIO), Glycoscience.
    Cross-Linking Involving a Polymeric Carbohydrate Material2005Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    The present invention relates to a method of cross-linking a polymeric carbohydrate material with a second material by means of a soluble carbohydrate polymer and a crosslinking agent. The present invention furthermore relates to the resulting cross-linked material, to uses of the cross-linked material, as well as to a kit comprising the soluble carbohydrate polymer and the cross-linking agent.

  • 41.
    Bulone, Vincent
    KTH, School of Biotechnology (BIO), Glycoscience.
    Analysis of 1,3-beta-glucans and cellulose synthesized in vitro: a key step towards the characterization of glucan synthases2007In: Cellulose: molecular and structural biology / [ed] R.M. Brown Jr; I.M. Saxena, Springer, 2007, 123-145 p.Chapter in book (Refereed)
  • 42.
    Bulone, Vincent
    KTH, School of Biotechnology (BIO), Glycoscience.
    Bacterial cellulose-based biomimetic composites2010In: Biopolymers / [ed] M. Elnashar, Sciyo, 2010, 345-368 p.Chapter in book (Refereed)
  • 43.
    Bulone, Vincent
    KTH, School of Biotechnology (BIO), Glycoscience.
    Biosynthetic enzymes for (1,3)-β-glucans and (1,3;1,6)-β-glucans in protozoans and chromistans. biochemical characterization and molecular biology2009In: Chemistry, biochemistry and biology of 1,3-beta-glucans and related polysaccharides / [ed] A. Bacic, B.A. Stone and G.B. Fincher, Elsevier, 2009, 233-258 p.Chapter in book (Refereed)
    Abstract [en]

    This chapter discusses the biochemical characterization and molecular biology of biosynthetic enzymes for (1,3)-β-glucans and (1,3:1,6)-β-Glucans in Protozoans and Chromistans. The biosynthesis of linear β-glucans is generally considered to involve several steps. The process starts with the synthesis of an initiator of polymerization or primer, followed by the transfer of the primer to a membrane-bound synthase. The latter catalyses the repetitive transfer of glucosyl units from an activated sugar donor to the acceptor-i.e. the primer or the elongating chain-until the polymerization stops. Most molecular events occurring during the biosynthesis of (1,3)-β-glucans and (1,3;1,6)-β-Glucans in Protozoans and Chromistans are not well understood. The process for which most biochemical data have been accumulated is the polymerization of linear (1,3)-β-glucan chains. The ability to synthesize β-glucans in vitro represents a very useful tool for assaying glucan synthases during enzyme purification. This is also useful in identifying the type of effectors that might influence enzyme activity in vivo and thus regulate the biosynthesis of the polysaccharides.

  • 44.
    Bulone, Vincent
    KTH, School of Biotechnology (BIO), Glycoscience.
    Cellulose biosynthesis in higher plants2011In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 241Article in journal (Other academic)
  • 45.
    Bulone, Vincent
    KTH, School of Biotechnology (BIO), Glycoscience.
    Unraveling the secrets of cellulose biosynthesis in plants using biochemical approaches: prospects for the future2006In: The science and lore of the plant cell wall: Biosynthesis, structure and function / [ed] Takahisa Hayashi, BrownWalker Press, 2006, 87-96 p.Chapter in book (Refereed)
  • 46.
    Bulone, Vincent
    et al.
    KTH, School of Biotechnology (BIO), Glycoscience.
    Guerriero, Gea
    De Block, Marck
    Meulewaeter, Frank
    Methods for manufacturing plant cell walls comprising chitin2010Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    Methods and means are provided for the modification of the reactivity of plant secondary cell walls, particularly in cotton cell walls found in cotton fibers. This can be conveniently achieved by expressing a chimeric gene encoding a Saprolegnia monoica chitin synthase in cotton plants.

  • 47. Butchosa, Nria
    et al.
    Brown, Christian
    KTH, School of Biotechnology (BIO), Glycoscience.
    Bulone, Vincent
    KTH, School of Biotechnology (BIO), Glycoscience.
    Berglund, Lars A.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Biocomposites. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Zhou, Qi
    KTH, School of Biotechnology (BIO), Glycoscience. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Antimicrobial activity of biocomposites based on bacterial cellulose and chitin nanoparticles2012In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 243Article in journal (Other academic)
  • 48.
    Butchosa, Nuria
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Brown, Christian
    KTH, School of Biotechnology (BIO), Glycoscience.
    Larsson, Per Tomas
    KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Berglund, Lars A.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Biocomposites. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Bulone, Vincent
    KTH, School of Biotechnology (BIO), Glycoscience.
    Zhou, Qi
    KTH, School of Biotechnology (BIO), Glycoscience. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Nanocomposites of bacterial cellulose nanofibers and chitin nanocrystals: fabrication, characterization and bactericidal activity2013In: Green Chemistry, ISSN 1463-9262, E-ISSN 1463-9270, Vol. 15, no 12, 3404-3413 p.Article in journal (Refereed)
    Abstract [en]

    An environmentally friendly approach was implemented for the production of nanocomposites with bactericidal activity, using bacterial cellulose (BC) nanofibers and chitin nanocrystals (ChNCs). The antibacterial activity of ChNCs prepared by acid hydrolysis, TEMPO-mediated oxidation or partial deacetylation of a-chitin powder was assessed and the structure of the ChNC nanoparticles was characterized by X-ray diffraction, atomic force microscopy, and solid-state C-13-NMR. The partially deacetylated ChNCs (D-ChNC) showed the strongest antibacterial activity, with 99 +/- 1% inhibition of bacterial growth compared to control samples. Nanocomposites were prepared from BC nanofibers and D-ChNC by (i) in situ biosynthesis with the addition of D-ChNC nanoparticles in the culture medium of Acetobacter aceti, and (ii) post-modification by mixing D-ChNC with disintegrated BC in an aqueous suspension. The structure and mechanical properties of the BC/D-ChNC nanocomposites were characterized by Fourier transform infrared spectroscopy, elemental analysis, field-emission scanning electron microscopy, and an Instron universal testing machine. The bactericidal activity of the nanocomposites increased with the D-ChNC content, with a reduction in bacterial growth by 3.0 log units when the D-ChNC content was 50%. D-ChNC nanoparticles have great potential as substitutes for unfriendly antimicrobial compounds such as heavy metal nanoparticles and synthetic polymers to introduce antibacterial properties to cellulosic materials.

  • 49.
    Butchosa, Nuria
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Biocomposites.
    Leijon, Felicia
    KTH, School of Biotechnology (BIO), Glycoscience.
    Bulone, Vincent
    KTH, School of Biotechnology (BIO), Glycoscience.
    Zhou, Qi
    KTH, School of Biotechnology (BIO), Glycoscience. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Enhancing toughness of cellulose nanofibrils through the expression of cellulose-binding modules in plantManuscript (preprint) (Other academic)
  • 50.
    Butchosa, Nuria
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Biocomposites.
    Zhou, Qi
    KTH, School of Biotechnology (BIO), Glycoscience. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Water redispersible nanofibrillated cellulose adsorbed with carboxymethyl cellulose2014In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 247, 130-CELL- p.Article in journal (Other academic)
1234567 1 - 50 of 332
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