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Sample records for c-di-gmp pel polysaccharide

  1. c-di-GMP and its Effects on Biofilm Formation and Dispersion: a Pseudomonas Aeruginosa Review.

    Science.gov (United States)

    Ha, Dae-Gon; O'Toole, George A

    2015-04-01

    Since its initial discovery as an allosteric factor regulating cellulose biosynthesis in Gluconacetobacter xylinus, the list of functional outputs regulated by c-di-GMP has grown. We have focused this article on one of these c-di-GMP-regulated processes, namely, biofilm formation in the organism Pseudomonas aeruginosa. The majority of diguanylate cyclases and phosphodiesterases encoded in the P. aeruginosa genome still remain uncharacterized; thus, there is still a great deal to be learned about the link between c-di-GMP and biofilm formation in this microbe. In particular, while a number of c-di-GMP metabolizing enzymes have been identified that participate in reversible and irreversible attachment and biofilm maturation, there is a still a significant knowledge gap regarding the c-di-GMP output systems in this organism. Even for the well-characterized Pel system, where c-di-GMP-mediated transcriptional regulation is now well documented, how binding of c-di-GMP by PelD stimulates Pel production is not understood in any detail. Similarly, c-di-GMP-mediated control of swimming, swarming and twitching also remains to be elucidated. Thus, despite terrific advances in our understanding of P. aeruginosa biofilm formation and the role of c-di-GMP in this process since the last version of this book (indeed there was no chapter on c-di-GMP!) there is still much to learn. PMID:26104694

  2. Responses to elevated c-di-GMP levels in mutualistic and pathogenic plant-interacting bacteria.

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    Daniel Pérez-Mendoza

    Full Text Available Despite a recent burst of research, knowledge on c-di-GMP signaling pathways remains largely fragmentary and molecular mechanisms of regulation and even c-di-GMP targets are yet unknown for most bacteria. Besides genomics or bioinformatics, accompanying alternative approaches are necessary to reveal c-di-GMP regulation in bacteria with complex lifestyles. We have approached this study by artificially altering the c-di-GMP economy of diverse pathogenic and mutualistic plant-interacting bacteria and examining the effects on the interaction with their respective host plants. Phytopathogenic Pseudomonas and symbiotic Rhizobium strains with enhanced levels of intracellular c-di-GMP displayed common free-living responses: reduction of motility, increased production of extracellular polysaccharides and enhanced biofilm formation. Regarding the interaction with the host plants, P. savastanoi pv. savastanoi cells containing high c-di-GMP levels formed larger knots on olive plants which, however, displayed reduced necrosis. In contrast, development of disease symptoms in P. syringae-tomato or P. syringae-bean interactions did not seem significantly affected by high c-di-GMP. On the other hand, increasing c-di-GMP levels in symbiotic R. etli and R. leguminosarum strains favoured the early stages of the interaction since enhanced adhesion to plant roots, but decreased symbiotic efficiency as plant growth and nitrogen contents were reduced. Our results remark the importance of c-di-GMP economy for plant-interacting bacteria and show the usefulness of our approach to reveal particular stages during plant-bacteria associations which are sensitive to changes in c-di-GMP levels.

  3. The absence of the Pseudomonas aeruginosa OprF protein leads to increased biofilm formation through variation in c-di-GMP level

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    Emeline eBouffartigues

    2015-06-01

    Full Text Available OprF is the major outer membrane porin in bacteria belonging to the Pseudomonas genus. In previous studies, we have shown that OprF is required for full virulence expression of the opportunistic pathogen Pseudomonas aeruginosa. Here, we describe molecular insights on the nature of this relationship and report that the absence of OprF leads to increased biofilm formation and production of the Pel exopolysaccharide. Accordingly, the level of c-di-GMP, a key second messenger in biofilm control, is elevated in an oprF mutant. By decreasing c-di-GMP levels in this mutant, both biofilm formation and pel gene expression phenotypes were restored to wild-type levels. We further investigated the impact on two small RNAs, which are associated with the biofilm lifestyle, and found that expression of rsmZ but not of rsmY was increased in the oprF mutant and this occurs in a c-di-GMP-dependent manner. Finally, the extracytoplasmic function (ECF sigma factors AlgU and SigX displayed higher activity levels in the oprF mutant. Two genes of the SigX regulon involved in c-di-GMP metabolism, PA1181 and adcA (PA4843, were up-regulated in the oprF mutant, partly explaining the increased c-di-GMP level. We hypothesized that the absence of OprF leads to a cell envelope stress that activates SigX and results in a c-di-GMP elevated level due to higher expression of adcA and PA1181. The c-di-GMP level can in turn stimulate Pel synthesis via increased rsmZ sRNA levels and pel mRNA, thus affecting Pel-dependent phenotypes such as cell aggregation and biofilm formation. This work highlights the connection between OprF and c-di-GMP regulatory networks, likely via SigX (ECF, on the regulation of biofilm phenotypes.

  4. Responses to Elevated c-di-GMP Levels in Mutualistic and Pathogenic Plant-Interacting Bacteria

    OpenAIRE

    Pérez-Mendoza, Daniel; Aragón, Isabel M.; Prada-Ramírez, Harold A.; Romero-Jiménez, Lorena; Ramos, Cayo; Gallegos, María-Trinidad; Sanjuán, Juan

    2014-01-01

    Despite a recent burst of research, knowledge on c-di-GMP signaling pathways remains largely fragmentary and molecular mechanisms of regulation and even c-di-GMP targets are yet unknown for most bacteria. Besides genomics or bioinformatics, accompanying alternative approaches are necessary to reveal c-di-GMP regulation in bacteria with complex lifestyles. We have approached this study by artificially altering the c-di-GMP economy of diverse pathogenic and mutualistic plant-interacting bacteri...

  5. C-di-GMP regulates antimicrobial peptide resistance in Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Chua, Song Lin; Tan, Sean Yang-Yi; Rybtke, Morten Theil;

    2013-01-01

    Bis-(3'-5')-cyclic dimeric GMP (c-di-GMP) is an intracellular second messenger which controls the life styles of many bacteria. A high intracellular level of c-di-GMP induces a biofilm lifestyle, whereas a low intracellular level of c-di-GMP stimulates dispersal of biofilms and promotes a plankto...... current dogma stating that dispersed cells are inevitably more susceptible to antibiotics than their sessile counterparts....

  6. Structural Basis of Ligand Binding by a C-di-GMP Riboswitch

    Energy Technology Data Exchange (ETDEWEB)

    Smith, K.; Lipchock, S; Ames, T; Wang, J; Breaker, R; Strobel, S

    2009-01-01

    The second messenger signaling molecule bis-(3{prime}-5{prime})-cyclic dimeric guanosine monophosphate (c-di-GMP) regulates many processes in bacteria, including motility, pathogenesis and biofilm formation. c-di-GMP-binding riboswitches are important downstream targets in this signaling pathway. Here we report the crystal structure, at 2.7 {angstrom} resolution, of a c-di-GMP riboswitch aptamer from Vibrio cholerae bound to c-di-GMP, showing that the ligand binds within a three-helix junction that involves base-pairing and extensive base-stacking. The symmetric c-di-GMP is recognized asymmetrically with respect to both the bases and the backbone. A mutant aptamer was engineered that preferentially binds the candidate signaling molecule c-di-AMP over c-di-GMP. Kinetic and structural data suggest that genetic regulation by the c-di-GMP riboswitch is kinetically controlled and that gene expression is modulated through the stabilization of a previously unidentified P1 helix, illustrating a direct mechanism for c-di-GMP signaling.

  7. Structural basis of ligand binding by a c-di-GMP riboswitch.

    Science.gov (United States)

    Smith, Kathryn D; Lipchock, Sarah V; Ames, Tyler D; Wang, Jimin; Breaker, Ronald R; Strobel, Scott A

    2009-12-01

    The second messenger signaling molecule bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP) regulates many processes in bacteria, including motility, pathogenesis and biofilm formation. c-di-GMP-binding riboswitches are important downstream targets in this signaling pathway. Here we report the crystal structure, at 2.7 A resolution, of a c-di-GMP riboswitch aptamer from Vibrio cholerae bound to c-di-GMP, showing that the ligand binds within a three-helix junction that involves base-pairing and extensive base-stacking. The symmetric c-di-GMP is recognized asymmetrically with respect to both the bases and the backbone. A mutant aptamer was engineered that preferentially binds the candidate signaling molecule c-di-AMP over c-di-GMP. Kinetic and structural data suggest that genetic regulation by the c-di-GMP riboswitch is kinetically controlled and that gene expression is modulated through the stabilization of a previously unidentified P1 helix, illustrating a direct mechanism for c-di-GMP signaling. PMID:19898477

  8. Structural and Biochemical Determinants of Ligand Binding by the c-di-GMP Riboswitch

    International Nuclear Information System (INIS)

    The bacterial second messenger c-di-GMP is used in many species to control essential processes that allow the organism to adapt to its environment. The c-di-GMP riboswitch (GEMM) is an important downstream target in this signaling pathway and alters gene expression in response to changing concentrations of c-di-GMP. The riboswitch selectively recognizes its second messenger ligand primarily through contacts with two critical nucleotides. However, these two nucleotides are not the most highly conserved residues within the riboswitch sequence. Instead, nucleotides that stack with c-di-GMP and that form tertiary RNA contacts are the most invariant. Biochemical and structural evidence reveals that the most common natural variants are able to make alternative pairing interactions with both guanine bases of the ligand. Additionally, a high-resolution (2.3 (angstrom)) crystal structure of the native complex reveals that a single metal coordinates the c-di-GMP backbone. Evidence is also provided that after transcription of the first nucleotide on the 3(prime)-side of the P1 helix, which is predicted to be the molecular switch, the aptamer is functional for ligand binding. Although large energetic effects occur when several residues in the RNA are altered, mutations at the most conserved positions, rather than at positions that base pair with c-di-GMP, have the most detrimental effects on binding. Many mutants retain sufficient c-di-GMP affinity for the RNA to remain biologically relevant, which suggests that this motif is quite resilient to mutation.

  9. Bacterial c-di-GMP Affects Hematopoietic Stem/Progenitors and Their Niches through STING

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    Hiroshi Kobayashi

    2015-04-01

    Full Text Available Upon systemic bacterial infection, hematopoietic stem and progenitor cells (HSPCs migrate to the periphery in order to supply a sufficient number of immune cells. Although pathogen-associated molecular patterns reportedly mediate HSPC activation, how HSPCs detect pathogen invasion in vivo remains elusive. Bacteria use the second messenger bis-(3′-5′-cyclic dimeric guanosine monophosphate (c-di-GMP for a variety of activities. Here, we report that c-di-GMP comprehensively regulated both HSPCs and their niche cells through an innate immune sensor, STING, thereby inducing entry into the cell cycle and mobilization of HSPCs while decreasing the number and repopulation capacity of long-term hematopoietic stem cells. Furthermore, we show that type I interferon acted as a downstream target of c-di-GMP to inhibit HSPC expansion in the spleen, while transforming growth factor-β was required for c-di-GMP-dependent splenic HSPC expansion. Our results define machinery underlying the dynamic regulation of HSPCs and their niches during bacterial infection through c-di-GMP/STING signaling.

  10. A Minimal Threshold of c-di-GMP Is Essential for Fruiting Body Formation and Sporulation in Myxococcus xanthus.

    Science.gov (United States)

    Skotnicka, Dorota; Smaldone, Gregory T; Petters, Tobias; Trampari, Eleftheria; Liang, Jennifer; Kaever, Volkhard; Malone, Jacob G; Singer, Mitchell; Søgaard-Andersen, Lotte

    2016-05-01

    Generally, the second messenger bis-(3'-5')-cyclic dimeric GMP (c-di-GMP) regulates the switch between motile and sessile lifestyles in bacteria. Here, we show that c-di-GMP is an essential regulator of multicellular development in the social bacterium Myxococcus xanthus. In response to starvation, M. xanthus initiates a developmental program that culminates in formation of spore-filled fruiting bodies. We show that c-di-GMP accumulates at elevated levels during development and that this increase is essential for completion of development whereas excess c-di-GMP does not interfere with development. MXAN3735 (renamed DmxB) is identified as a diguanylate cyclase that only functions during development and is responsible for this increased c-di-GMP accumulation. DmxB synthesis is induced in response to starvation, thereby restricting DmxB activity to development. DmxB is essential for development and functions downstream of the Dif chemosensory system to stimulate exopolysaccharide accumulation by inducing transcription of a subset of the genes encoding proteins involved in exopolysaccharide synthesis. The developmental defects in the dmxB mutant are non-cell autonomous and rescued by co-development with a strain proficient in exopolysaccharide synthesis, suggesting reduced exopolysaccharide accumulation as the causative defect in this mutant. The NtrC-like transcriptional regulator EpsI/Nla24, which is required for exopolysaccharide accumulation, is identified as a c-di-GMP receptor, and thus a putative target for DmxB generated c-di-GMP. Because DmxB can be-at least partially-functionally replaced by a heterologous diguanylate cyclase, these results altogether suggest a model in which a minimum threshold level of c-di-GMP is essential for the successful completion of multicellular development in M. xanthus. PMID:27214040

  11. Genetic reductionist approach for dissecting individual roles of GGDEF proteins within the c-di-GMP signaling network in Salmonella

    OpenAIRE

    Solano, Cristina; García, Begoña; Latasa, Cristina; Toledo-Arana, Alejandro; Zorraquino, Violeta; Valle, Jaione; Casals, Joan; Pedroso, Enrique; Lasa, Iñigo

    2009-01-01

    Bacteria have developed an exclusive signal transduction system involving multiple diguanylate cyclase and phosphodiesterase domain-containing proteins (GGDEF and EAL/HD-GYP, respectively) that modulate the levels of the same diffusible molecule, 3′-5′-cyclic diguanylic acid (c-di-GMP), to transmit signals and obtain specific cellular responses. Current knowledge about c-di-GMP signaling has been inferred mainly from the analysis of recombinant bacteria that either lack or overproduce individ...

  12. Identification, activity and disulfide connectivity of C-di-GMP regulating proteins in Mycobacterium tuberculosis.

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    Kajal Gupta

    Full Text Available C-di-GMP, a bacterial second messenger plays a key role in survival and adaptation of bacteria under different environmental conditions. The level of c-di-GMP is regulated by two opposing activities, namely diguanylate cyclase (DGC and phosphodiesterase (PDE-A exhibited by GGDEF and EAL domain, respectively in the same protein. Previously, we reported a bifunctional GGDEF-EAL domain protein, MSDGC-1 from Mycobacterium smegmatis showing both these activities (Kumar and Chatterji, 2008. In this current report, we have identified and characterized the homologous protein from Mycobacterium tuberculosis (Rv 1354c named as MtbDGC. MtbDGC is also a bifunctional protein, which can synthesize and degrade c-di-GMP in vitro. Further we expressed Mtbdgc in M. smegmatis and it was able to complement the MSDGC-1 knock out strain by restoring the long term survival of M. smegmatis. Another protein Rv 1357c, named as MtbPDE, is an EAL domain protein and degrades c-di-GMP to pGpG in vitro. Rv1354c and 1357c have seven cysteine amino acids in their sequence, distributed along the full length of the protein. Disulfide bonds play an important role in stabilizing protein structure and regulating protein function. By proteolytic digestion and mass spectrometric analysis of MtbDGC, connectivity between cysteine pairs Cys94-Cys584, Cys2-Cys479 and Cys429-Cys614 was determined, whereas the third cysteine (Cys406 from N terminal was found to be free in MtbDGC protein, which was further confirmed by alkylation with iodoacetamide labeling. Bioinformatics modeling investigations also supported the pattern of disulfide connectivity obtained by Mass spectrometric analysis. Cys406 was mutated to serine by site directed mutagenesis and the mutant MtbC406S was not found to be active and was not able to synthesize or degrade c-di-GMP. The disulfide connectivity established here would help further in understanding the structure - function relationship in MtbDGC.

  13. Structural Analysis of the GGDEF-EAL Domain-Containing c-di-GMP Receptor FimX

    Energy Technology Data Exchange (ETDEWEB)

    Navarro, M.; De, N; Bae, N; Wang, Q; Sondermann, H

    2009-01-01

    Bacterial pathogenesis involves social behavior including biofilm formation and swarming, processes that are regulated by the bacterially unique second messenger cyclic di-GMP (c-di-GMP). Diguanylate cyclases containing GGDEF and phosphodiesterases containing EAL domains have been identified as the enzymes controlling cellular c-di-GMP levels, yet less is known regarding signal transmission and the targets of c-di-GMP. FimX, a protein from Pseudomonas aeruginosa that governs twitching motility, belongs to a large subfamily containing both GGDEF and EAL domains. Biochemical and structural analyses reveals its function as a high-affinity receptor for c-di-GMP. A model for full-length FimX was generated combining solution scattering data and crystal structures of the degenerate GGDEF and EAL domains. Although FimX forms a dimer in solution via the N-terminal domains, a crystallographic EAL domain dimer suggests modes for the regulation of FimX by c-di-GMP binding. The results provide the structural basis for c-di-GMP sensing via degenerate phosphodiesterases.

  14. Complex regulatory network encompassing the Csr, c-di-GMP and motility systems of Salmonella Typhimurium

    OpenAIRE

    Jonas, Kristina; Edwards, Adrianne N.; Ahmad, Irfan; Romeo, Tony; Römling, Ute; Melefors, Öjar

    2009-01-01

    Bacterial survival depends on the ability to switch between sessile and motile life styles in response to changing environmental conditions. In many species, this switch is governed by (3′-5′)-cyclic-diguanosine monophosphate (c-di-GMP) a signalling molecule, which is metabolized by proteins containing GGDEF and/or EAL domains. Salmonella Typhimurium contains 20 such proteins. Here, we show that the RNA-binding protein CsrA regulates the expression of eight genes encoding GGDEF, GGDEF-EAL and...

  15. c-di-GMP-abhängige Signal-transduktion bei der Kontrolle der Cellulose-Synthese in Escherichia coli Biofilmen

    OpenAIRE

    Richter, Anja

    2016-01-01

    c-di-GMP stellt einen wichtigen Regulator bei der Kontrolle von Motilität, Virulenz und der Biofilmbildung in Bakterien dar. Aufgrund der Vielfalt c-di-GMP-synthetisierender (Diguanylatzyklasen, DGC) bzw. abbauender (Phosphodiesterasen, PDE) Enzyme, c-di-GMP-bindender Effektoren und zellulärer Antworten etablierte sich die Theorie paralleler Regulationsmodule, die sich aus DGC, PDE, Effektor und Zielmolekül zusammensetzen und spezifische Prozesse wie die Cellulose-Synthese kontrollieren. Währ...

  16. Differential regulation of c-di-GMP metabolic enzymes by environmental signals modulates biofilm formation in Yersinia pestis

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    Gai-Xian eRen

    2016-06-01

    Full Text Available Cyclic diguanylate (c-di-GMP is essential for Yersinia pestis biofilm formation, which is important for flea-borne blockage-dependent plague transmission. Two diguanylate cyclases (DGCs, HmsT and HmsD and one phosphodiesterase (PDE, HmsP are responsible for the synthesis and degradation of c-di-GMP in Y. pestis. Here, we systematically analyzed the effect of various environmental signals on regulation of the biofilm phenotype, the c-di-GMP levels, and expression of HmsT, HmsD and HmsP in Y. pestis. Biofilm formation was higher in the presence of nonlethal high concentration of CaCl2, MgCl2, CuSO4, sucrose, sodium dodecyl sulfonate, or dithiothreitol, and was lower in the presence of FeCl2 or NaCl. In addition, we found that HmsD plays a major role in biofilm formation in acidic or redox environments. These environmental signals differentially regulated expression of HmsT, HmsP and HmsD, resulting in changes in the intracellular levels of c-di-GMP in Y. pestis. Our results suggest that bacteria can sense various environmental signals, and differentially regulates their DGCs and PDEs to coordinately regulate and adapt metabolism of c-di-GMP and biofilm formation to changing environments.

  17. Biofilms and Cyclic di-GMP (c-di-GMP) Signaling: Lessons from Pseudomonas aeruginosa and Other Bacteria.

    Science.gov (United States)

    Valentini, Martina; Filloux, Alain

    2016-06-10

    The cyclic di-GMP (c-di-GMP) second messenger represents a signaling system that regulates many bacterial behaviors and is of key importance for driving the lifestyle switch between motile loner cells and biofilm formers. This review provides an up-to-date compendium of c-di-GMP pathways connected to biofilm formation, biofilm-associated motilities, and other functionalities in the ubiquitous and opportunistic human pathogen Pseudomonas aeruginosa This bacterium is frequently adopted as a model organism to study bacterial biofilm formation. Importantly, its versatility and adaptation capabilities are linked with a broad range of complex regulatory networks, including a large set of genes involved in c-di-GMP biosynthesis, degradation, and transmission. PMID:27129226

  18. A c-di-GMP effector system controls cell adhesion by inside-out signaling and surface protein cleavage.

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    Peter D Newell

    Full Text Available In Pseudomonas fluorescens Pf0-1 the availability of inorganic phosphate (Pi is an environmental signal that controls biofilm formation through a cyclic dimeric GMP (c-di-GMP signaling pathway. In low Pi conditions, a c-di-GMP phosphodiesterase (PDE RapA is expressed, depleting cellular c-di-GMP and causing the loss of a critical outer-membrane adhesin LapA from the cell surface. This response involves an inner membrane protein LapD, which binds c-di-GMP in the cytoplasm and exerts a periplasmic output promoting LapA maintenance on the cell surface. Here we report how LapD differentially controls maintenance and release of LapA: c-di-GMP binding to LapD promotes interaction with and inhibition of the periplasmic protease LapG, which targets the N-terminus of LapA. We identify conserved amino acids in LapA required for cleavage by LapG. Mutating these residues in chromosomal lapA inhibits LapG activity in vivo, leading to retention of the adhesin on the cell surface. Mutations with defined effects on LapD's ability to control LapA localization in vivo show concomitant effects on c-di-GMP-dependent LapG inhibition in vitro. To establish the physiological importance of the LapD-LapG effector system, we track cell attachment and LapA protein localization during Pi starvation. Under this condition, the LapA adhesin is released from the surface of cells and biofilms detach from the substratum. This response requires c-di-GMP depletion by RapA, signaling through LapD, and proteolytic cleavage of LapA by LapG. These data, in combination with the companion study by Navarro et al. presenting a structural analysis of LapD's signaling mechanism, give a detailed description of a complete c-di-GMP control circuit--from environmental signal to molecular output. They describe a novel paradigm in bacterial signal transduction: regulation of a periplasmic enzyme by an inner membrane signaling protein that binds a cytoplasmic second messenger.

  19. The CRP/FNR family protein Bcam1349 is a c-di-GMP effector that regulates biofilm formation in the respiratory pathogen Burkholderia cenocepacia

    DEFF Research Database (Denmark)

    Fazli, Mustafa; O'Connell, Aileen; Nilsson, Martin; Niehaus, Karsten; Dow, J Maxwell; Givskov, Michael; Ryan, Robert P; Tolker-Nielsen, Tim

    2011-01-01

    defect with physiological c-di-GMP levels. The bcam1349 gene is predicted to encode a transcriptional regulator of the CRP/FNR superfamily. Analyses of purified Bcam1349 protein and truncations demonstrated that it binds c-di-GMP in vitro. The Bcam1349 protein was shown to regulate the production of a...

  20. Crystallization and preliminary X-ray diffraction studies of Xanthomonas campestris PNPase in the presence of c-di-GMP

    International Nuclear Information System (INIS)

    Crystals of S1-domain-truncated X. campestris PNPase were grown in the presence of c-di-GMP and diffracted to a resolution of 2.00 Å. Bacterial polynucleotide phosphorylase (PNPase) is a 3′–5′ processive exoribonuclease that participates in mRNA turnover and quality control of rRNA precursors in many bacterial species. It also associates with the RNase E scaffold and other components to form a multi-enzyme RNA degradasome machinery that performs a wider regulatory role in degradation, quality control and maturation of mRNA and noncoding RNA. Several crystal structures of bacterial PNPases, as well as some biological activity studies, have been published. However, how the enzymatic activity of PNPase is regulated is less well understood. Recently, Escherichia coli PNPase was found to be a direct c-di-GMP binding target, raising the possibility that c-di-GMP may participate in the regulation of RNA processing. Here, the successful cloning, purification and crystallization of S1-domain-truncated Xanthomonas campestris PNPase (XcPNPaseΔS1) in the presence of c-di-GMP are reported. The crystals belonged to the monoclinic space group C2, with unit-cell parameters a = 132.76, b = 128.38, c = 133.01 Å, γ = 93.3°, and diffracted to a resolution of 2.00 Å

  1. 3',5'-Cyclic diguanylic acid (c-di-GMP) inhibits basal and growth factor-stimulated human colon cancer cell proliferation

    International Nuclear Information System (INIS)

    The novel cyclic dinucleotide, 3',5'-cyclic diguanylic acid, cGpGp (c-di-GMP), is a naturally occurring small molecule that regulates important signaling mechanisms in prokaryotes. Recently, we showed that c-di-GMP has 'drug-like' properties and that c-di-GMP treatment might be a useful antimicrobial approach to attenuate the virulence and pathogenesis of Staphylococcus aureus and prevent or treat infection. In the present communication, we report that c-di-GMP (≤50 μM) has striking properties regarding inhibition of cancer cell proliferation in vitro. c-di-GMP inhibits both basal and growth factor (acetylcholine and epidermal growth factor)-induced cell proliferation of human colon cancer (H508) cells. Toxicity studies revealed that exposure of normal rat kidney cells and human neuroblastoma cells to c-di-GMP at biologically relevant doses showed no lethal cytotoxicity. Cyclic dinucleotides, such as c-di-GMP, represent an attractive and novel 'drug-platform technology' that can be used not only to develop new antimicrobial agents, but also to develop novel therapeutic agents to prevent or treat cancer

  2. In vitro and in vivo generation and characterization of Pseudomonas aeruginosa biofilm-dispersed cells via c-di-GMP manipulation

    DEFF Research Database (Denmark)

    Chua, Song Lin; Hultqvist, Louise D; Yuan, Mingjun; Rybtke, Morten; Nielsen, Thomas E; Givskov, Michael; Tolker-Nielsen, Tim; Yang, Liang

    2015-01-01

    Bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP) is a global secondary bacterial messenger that controls the formation of drug-resistant multicellular biofilms. Lowering the intracellular c-di-GMP content can disperse biofilms, and it is proposed as a biofilm eradication strategy...... biofilms by reducing the intracellular c-di-GMP content through modulation of phosphodiesterases (PDEs). Unlike conventional protocols that demonstrate biofilm dispersal by biomass quantification, our protocols enable physiological characterization of the dispersed cells. Biomarkers of dispersed cells are...

  3. Crystallization studies of the murine c-di-GMP sensor protein STING

    International Nuclear Information System (INIS)

    Crystals of native and selenomethionine-labelled STING138–344 protein from M. musculus diffracted to resolutions of 2.39 and 2.2 Å, respectively The innate immune response is the first defence system against pathogenic microorganisms, and cytosolic detection of pathogen-derived DNA is believed to be one of the major mechanisms of interferon production. Recently, the mammalian ER membrane protein STING (stimulator of IFNgenes; also known as MITA, ERIS, MPYS and TMEM173) has been found to be the master regulator linking the detection of cytosolic DNA to TANK-binding kinase 1 (TBK1) and its downstream transcription factor IFN regulatory factor 3 (IRF3). In addition, STING itself was soon discovered to be a direct sensor of bacterial cyclic dinucleotides such as c-di-GMP or c-di-AMP. However, structural studies of apo STING and its complexes with these cyclic dinucleotides and with other cognate binding proteins are essential in order to fully understand the roles played by STING in these crucial signalling pathways. In this manuscript, the successful crystallization of the C-terminal domain of murine STING (STING-CTD; residues 138–344) is reported. Native and SeMet-labelled crystals were obtained and diffracted to moderate resolutions of 2.39 and 2.2 Å, respectively

  4. Selective binding of 2'-F-c-di-GMP to Ct-E88 and Cb-E43, new class I riboswitches from Clostridium tetani and Clostridium botulinum respectively.

    Science.gov (United States)

    Luo, Yiling; Zhou, Jie; Wang, Jingxin; Dayie, T Kwaku; Sintim, Herman O

    2013-06-01

    C-di-GMP is a second messenger in bacteria and partly regulates bacterial physiology by binding to class I and II riboswitches. Four class I c-di-GMP riboswitch aptamer candidates, Ct-E88, Cb-17B, Cb-E43 and Cd-630 RNAs, selected from a GEMM RNA sequence motif in the Rfam database, were expressed and experimentally verified to bind to c-di-GMP. The two newly characterized c-di-GMP riboswitches, Ct-E88 and Cb-E43, bound c-di-GMP with nanomolar Kd whereas the affinities of Cb-17B and Cd-630 for c-di-GMP were at least a 100-fold weaker. Interestingly, whereas the three riboswitches (Vc2, Et-E88 and Cb-E43) bound c-di-GMP with similar Kd values, 2'-modified analogs of c-di-GMP differentially bound to these three class I aptamers. For example, 2'-F-c-di-GMP bound Vc2 with a Kd value of 102 nM whereas the Kd value of 2'-F-c-di-GMP-Ct-E88 is 43 μM (422× higher than that for Vc2 RNA), revealing that there are differences in the binding sites of functional class I c-di-GMP riboswitches. PMID:23559271

  5. Diguanylate cyclase null mutant reveals that C-Di-GMP pathway regulates the motility and adherence of the extremophile bacterium Acidithiobacillus caldus.

    Science.gov (United States)

    Castro, Matías; Deane, Shelly M; Ruiz, Lina; Rawlings, Douglas E; Guiliani, Nicolas

    2015-01-01

    An understanding of biofilm formation is relevant to the design of biological strategies to improve the efficiency of the bioleaching process and to prevent environmental damages caused by acid mine/rock drainage. For this reason, our laboratory is focused on the characterization of the molecular mechanisms involved in biofilm formation in different biomining bacteria. In many bacteria, the intracellular levels of c-di-GMP molecules regulate the transition from the motile planktonic state to sessile community-based behaviors, such as biofilm development, through different kinds of effectors. Thus, we recently started a study of the c-di-GMP pathway in several biomining bacteria including Acidithiobacillus caldus. C-di-GMP molecules are synthesized by diguanylate cyclases (DGCs) and degraded by phosphodiesterases (PDEs). We previously reported the existence of intermediates involved in c-di-GMP pathway from different Acidithiobacillus species. Here, we report our work related to At. caldus ATCC 51756. We identified several putative-ORFs encoding DGC and PDE and effector proteins. By using total RNA extracted from At. caldus cells and RT-PCR, we demonstrated that these genes are expressed. We also demonstrated the presence of c-di-GMP by mass spectrometry and showed that genes for several of the DGC enzymes were functional by heterologous genetic complementation in Salmonella enterica serovar Typhimurium mutants. Moreover, we developed a DGC defective mutant strain (Δc1319) that strongly indicated that the c-di-GMP pathway regulates the swarming motility and adherence to sulfur surfaces by At. caldus. Together, our results revealed that At. caldus possesses a functional c-di-GMP pathway which could be significant for ores colonization during the bioleaching process. PMID:25689133

  6. C-di-GMP hydrolysis by Pseudomonas aeruginosa HD-GYP phosphodiesterases: analysis of the reaction mechanism and novel roles for pGpG.

    Directory of Open Access Journals (Sweden)

    Valentina Stelitano

    Full Text Available In biofilms, the bacterial community optimizes the strategies to sense the environment and to communicate from cell to cell. A key player in the development of a bacterial biofilm is the second messenger c-di-GMP, whose intracellular levels are modulated by the opposite activity of diguanylate cyclases and phosphodiesterases. Given the huge impact of bacterial biofilms on human health, understanding the molecular details of c-di-GMP metabolism represents a critical step in the development of novel therapeutic approaches against biofilms. In this study, we present a detailed biochemical characterization of two c-di-GMP phosphodiesterases of the HD-GYP subtype from the human pathogen Pseudomonas aeruginosa, namely PA4781 and PA4108. Upstream of the catalytic HD-GYP domain, PA4781 contains a REC domain typical of two-component systems, while PA4108 contains an uncharacterized domain of unknown function. Our findings shed light on the activity and catalytic mechanism of these phosphodiesterases. We show that both enzymes hydrolyse c-di-GMP in a two-step reaction via the linear intermediate pGpG and that they produce GMP in vitro at a surprisingly low rate. In addition, our data indicate that the non-phosphorylated REC domain of PA4781 prevents accessibility of c-di-GMP to the active site. Both PA4108 and phosphorylated PA4781 are also capable to use pGpG as an alternative substrate and to hydrolyse it into GMP; the affinity of PA4781 for pGpG is one order of magnitude higher than that for c-di-GMP. These results suggest that these enzymes may not work (primarily as genuine phosphodiesterases. Moreover, the unexpected affinity of PA4781 for pGpG may indicate that pGpG could also act as a signal molecule in its own right, thus further widening the c-di-GMP-related signalling scenario.

  7. Diguanylate cyclase null mutant reveals that C-Di-GMP pathway regulates the motility and adherence of the extremophile bacterium Acidithiobacillus caldus.

    Directory of Open Access Journals (Sweden)

    Matías Castro

    Full Text Available An understanding of biofilm formation is relevant to the design of biological strategies to improve the efficiency of the bioleaching process and to prevent environmental damages caused by acid mine/rock drainage. For this reason, our laboratory is focused on the characterization of the molecular mechanisms involved in biofilm formation in different biomining bacteria. In many bacteria, the intracellular levels of c-di-GMP molecules regulate the transition from the motile planktonic state to sessile community-based behaviors, such as biofilm development, through different kinds of effectors. Thus, we recently started a study of the c-di-GMP pathway in several biomining bacteria including Acidithiobacillus caldus. C-di-GMP molecules are synthesized by diguanylate cyclases (DGCs and degraded by phosphodiesterases (PDEs. We previously reported the existence of intermediates involved in c-di-GMP pathway from different Acidithiobacillus species. Here, we report our work related to At. caldus ATCC 51756. We identified several putative-ORFs encoding DGC and PDE and effector proteins. By using total RNA extracted from At. caldus cells and RT-PCR, we demonstrated that these genes are expressed. We also demonstrated the presence of c-di-GMP by mass spectrometry and showed that genes for several of the DGC enzymes were functional by heterologous genetic complementation in Salmonella enterica serovar Typhimurium mutants. Moreover, we developed a DGC defective mutant strain (Δc1319 that strongly indicated that the c-di-GMP pathway regulates the swarming motility and adherence to sulfur surfaces by At. caldus. Together, our results revealed that At. caldus possesses a functional c-di-GMP pathway which could be significant for ores colonization during the bioleaching process.

  8. C-di-GMP regulates Pseudomonas aeruginosa stress response to tellurite during both planktonic and biofilm modes of growth

    DEFF Research Database (Denmark)

    Chua, Song Lin; Sivakumar, Krishnakumar; Rybtke, Morten Levin; Yuan, Mingjun; Andersen, Jens Bo; Nielsen, Thomas E.; Givskov, Michael; Tolker-Nielsen, Tim; Cao, Bin; Kjelleberg, Staffan; Yang, Liang

    2015-01-01

    tellurite (TeO3(2-)) exposure induced the intracellular content of the secondary messenger cyclic di-GMP (c-di-GMP) of Pseudomonas aeruginosa. Two diguanylate cyclases (DGCs), SadC and SiaD, were responsible for the increased intracellular content of c-di-GMP. Enhanced c-di-GMP levels by TeO3(2-) further...... increased P. aeruginosa biofilm formation and resistance to TeO3(2-). P. aeruginosa ΔsadCΔsiaD and PAO1/p(lac)-yhjH mutants with low intracellular c-di-GMP content were more sensitive to TeO3(2-) exposure and had low relative fitness compared to the wild-type PAO1 planktonic and biofilm cultures exposed to...... TeO3(2-). Our study provided evidence that c-di-GMP level can play an important role in mediating stress response in microbial communities during both planktonic and biofilm modes of growth....

  9. Homologs of the LapD-LapG c-di-GMP Effector System Control Biofilm Formation by Bordetella bronchiseptica.

    Directory of Open Access Journals (Sweden)

    Nicolás Ambrosis

    Full Text Available Biofilm formation is important for infection by many pathogens. Bordetella bronchiseptica causes respiratory tract infections in mammals and forms biofilm structures in nasal epithelium of infected mice. We previously demonstrated that cyclic di-GMP is involved in biofilm formation in B. bronchiseptica. In the present work, based on their previously reported function in Pseudomonas fluorescens, we identified three genes in the B. bronchiseptica genome likely involved in c-di-GMP-dependent biofilm formation: brtA, lapD and lapG. Genetic analysis confirmed a role for BrtA, LapD and LapG in biofilm formation using microtiter plate assays, as well as scanning electron and fluorescent microscopy to analyze the phenotypes of mutants lacking these proteins. In vitro and in vivo studies showed that the protease LapG of B. bronchiseptica cleaves the N-terminal domain of BrtA, as well as the LapA protein of P. fluorescens, indicating functional conservation between these species. Furthermore, while BrtA and LapG appear to have little or no impact on colonization in a mouse model of infection, a B. bronchiseptica strain lacking the LapG protease has a significantly higher rate of inducing a severe disease outcome compared to the wild type. These findings support a role for c-di-GMP acting through BrtA/LapD/LapG to modulate biofilm formation, as well as impact pathogenesis, by B. bronchiseptica.

  10. Homologs of the LapD-LapG c-di-GMP Effector System Control Biofilm Formation by Bordetella bronchiseptica

    Science.gov (United States)

    Ambrosis, Nicolás; Boyd, Chelsea D.; O´Toole, George A.; Fernández, Julieta; Sisti, Federico

    2016-01-01

    Biofilm formation is important for infection by many pathogens. Bordetella bronchiseptica causes respiratory tract infections in mammals and forms biofilm structures in nasal epithelium of infected mice. We previously demonstrated that cyclic di-GMP is involved in biofilm formation in B. bronchiseptica. In the present work, based on their previously reported function in Pseudomonas fluorescens, we identified three genes in the B. bronchiseptica genome likely involved in c-di-GMP-dependent biofilm formation: brtA, lapD and lapG. Genetic analysis confirmed a role for BrtA, LapD and LapG in biofilm formation using microtiter plate assays, as well as scanning electron and fluorescent microscopy to analyze the phenotypes of mutants lacking these proteins. In vitro and in vivo studies showed that the protease LapG of B. bronchiseptica cleaves the N-terminal domain of BrtA, as well as the LapA protein of P. fluorescens, indicating functional conservation between these species. Furthermore, while BrtA and LapG appear to have little or no impact on colonization in a mouse model of infection, a B. bronchiseptica strain lacking the LapG protease has a significantly higher rate of inducing a severe disease outcome compared to the wild type. These findings support a role for c-di-GMP acting through BrtA/LapD/LapG to modulate biofilm formation, as well as impact pathogenesis, by B. bronchiseptica PMID:27380521

  11. Crystallization and preliminary X-ray analysis of the flagellar motor ‘brake’ molecule YcgR with c-di-GMP from Escherichia coli

    International Nuclear Information System (INIS)

    The flagellar motor ‘brake’ protein YcgR from E. coli was crystallized with c-di-GMP. The crystals diffracted to 2.3 Å resolution and belonged to space group R3:H, with unit-cell parameters a = b = 93.96, c = 109.61 Å. In Escherichia coli and Salmonella enterica, bis-(3′-5′)-cyclic dimeric guanosine monophosphate (c-di-GMP), a ubiquitous bacterial second-messenger molecule that participates in many cellular processes, can regulate flagellar motor speed and reduce cell swimming velocity by binding to the PilZ-containing protein YcgR. Here, the crystallization and preliminary X-ray crystallographic analysis of YcgR with c-di-GMP are reported. The crystals diffracted to 2.3 Å resolution and belonged to space group R3:H, with unit-cell parameters a = b = 93.96, c = 109.61 Å. The asymmetric unit appeared to contain one subunit with a Matthews coefficient of 3.21 Å3 Da−1. The results reported here provide a sound basis for solving the crystal structure of YcgR with c-di-GMP and revealing its structure–function relationship based on the three-dimensional structure

  12. MrkH, a novel c-di-GMP-dependent transcriptional activator, controls Klebsiella pneumoniae biofilm formation by regulating type 3 fimbriae expression.

    Directory of Open Access Journals (Sweden)

    Jonathan J Wilksch

    2011-08-01

    Full Text Available Klebsiella pneumoniae causes significant morbidity and mortality worldwide, particularly amongst hospitalized individuals. The principle mechanism for pathogenesis in hospital environments involves the formation of biofilms, primarily on implanted medical devices. In this study, we constructed a transposon mutant library in a clinical isolate, K. pneumoniae AJ218, to identify the genes and pathways implicated in biofilm formation. Three mutants severely defective in biofilm formation contained insertions within the mrkABCDF genes encoding the main structural subunit and assembly machinery for type 3 fimbriae. Two other mutants carried insertions within the yfiN and mrkJ genes, which encode GGDEF domain- and EAL domain-containing c-di-GMP turnover enzymes, respectively. The remaining two isolates contained insertions that inactivated the mrkH and mrkI genes, which encode for novel proteins with a c-di-GMP-binding PilZ domain and a LuxR-type transcriptional regulator, respectively. Biochemical and functional assays indicated that the effects of these factors on biofilm formation accompany concomitant changes in type 3 fimbriae expression. We mapped the transcriptional start site of mrkA, demonstrated that MrkH directly activates transcription of the mrkA promoter and showed that MrkH binds strongly to the mrkA regulatory region only in the presence of c-di-GMP. Furthermore, a point mutation in the putative c-di-GMP-binding domain of MrkH completely abolished its function as a transcriptional activator. In vivo analysis of the yfiN and mrkJ genes strongly indicated their c-di-GMP-specific function as diguanylate cyclase and phosphodiesterase, respectively. In addition, in vitro assays showed that purified MrkJ protein has strong c-di-GMP phosphodiesterase activity. These results demonstrate for the first time that c-di-GMP can function as an effector to stimulate the activity of a transcriptional activator, and explain how type 3 fimbriae

  13. The Pel Polysaccharide Can Serve a Structural and Protective Role in the Biofilm Matrix of Pseudomonas aeruginosa

    OpenAIRE

    Colvin, Kelly M.; Gordon, Vernita D.; Murakami, Keiji; Borlee, Bradley R; Wozniak, Daniel J.; Wong, Gerard C. L.; Parsek, Matthew R.

    2011-01-01

    Bacterial extracellular polysaccharides are a key constituent of the extracellular matrix material of biofilms. Pseudomonas aeruginosa is a model organism for biofilm studies and produces three extracellular polysaccharides that have been implicated in biofilm development, alginate, Psl and Pel. Significant work has been conducted on the roles of alginate and Psl in biofilm development, however we know little regarding Pel. In this study, we demonstrate that Pel can serve two functions in bio...

  14. Diguanylate Cyclase Null Mutant Reveals That C-Di-GMP Pathway Regulates the Motility and Adherence of the Extremophile Bacterium Acidithiobacillus caldus

    OpenAIRE

    Castro, Matías; Deane, Shelly M.; Ruiz, Lina; Rawlings, Douglas E.; Guiliani, Nicolas

    2015-01-01

    An understanding of biofilm formation is relevant to the design of biological strategies to improve the efficiency of the bioleaching process and to prevent environmental damages caused by acid mine/rock drainage. For this reason, our laboratory is focused on the characterization of the molecular mechanisms involved in biofilm formation in different biomining bacteria. In many bacteria, the intracellular levels of c-di-GMP molecules regulate the transition from the motile planktonic state to ...

  15. The exopolysaccharide gene cluster Bcam1330-Bcam1341 is involved in Burkholderia cenocepacia biofilm formation, and its expression is regulated by c-di-GMP and Bcam1349

    DEFF Research Database (Denmark)

    Fazli, Mustafa; McCarthy, Yvonne; Givskov, Michael; Ryan, Robert P; Tolker-Nielsen, Tim

    2013-01-01

    In Burkholderia cenocepacia, the second messenger cyclic diguanosine monophosphate (c-di-GMP) has previously been shown to positively regulate biofilm formation and the expression of cellulose and type-I fimbriae genes through binding to the transcriptional regulator Bcam1349. Here, we provide...... evidence that cellulose and type-I fimbriae are not involved in B. cenocepacia biofilm formation in flow chambers, and we identify a novel Bcam1349/c-di-GMP-regulated exopolysaccharide gene cluster which is essential for B. cenocepacia biofilm formation. Overproduction of Bcam1349 in trans promotes wrinkly...... matrix exopolysaccharide and to be essential for flow-chamber biofilm formation. We demonstrate that Bcam1349 binds to the promoter region of genes in the Bcam1330-Bcam1341 cluster and that this binding is enhanced by the presence of c-di-GMP. Furthermore, we demonstrate that overproduction of both c-di-GMP...

  16. Crystallization and preliminary X-ray diffraction characterization of the XccFimXEAL–c-di-GMP and XccFimXEAL–c-di-GMP–XccPilZ complexes from Xanthomonas campestris

    International Nuclear Information System (INIS)

    Crystals of the XccFimXEAL–c-di-GMP and SeMet-XccFimXEAL–c-di-GMP–XccPilZ complexes from X. campestris diffracted to resolutions of 2.5 and 2.7 Å, respectively. c-di-GMP is a major secondary-messenger molecule in regulation of bacterial pathogenesis. Therefore, the c-di-GMP-mediated signal transduction network is of considerable interest. The PilZ domain was the first c-di-GMP receptor to be predicted and identified. However, every PilZ domain binds c-di-GMP with a different binding affinity. Intriguingly, a noncanonical PilZ domain has recently been found to serve as a mediator to link FimXEAL to the PilB or PilT ATPase to control the function of type IV pili (T4P). It is thus essential to determine the structure of the FimXEAL–PilZ complex in order to determine how the binding of c-di-GMP to the FimXEAL domain induces conformational change of the adjoining noncanonical PilZ domain, which may transmit information to PilB or PilT to control T4P function. Here, the preparation and preliminary X-ray diffraction studies of the XccFimXEAL–c-di-GMP and XccFimXEAL–c-di-GMP–XccPilZ complexes from Xcc (Xanthomonas campestris pv. campesteris) are reported. Detailed studies of these complexes may allow a more thorough understanding of how c-di-GMP transmits its effects through the degenerate EAL domain and the noncanonical PilZ domain

  17. E88, a new cyclic-di-GMP class I riboswitch aptamer from Clostridium tetani, has a similar fold to the prototypical class I riboswitch, Vc2, but differentially binds to c-di-GMP analogs.

    Science.gov (United States)

    Luo, Yiling; Chen, Bin; Zhou, Jie; Sintim, Herman O; Dayie, T Kwaku

    2014-03-01

    C-di-GMP has emerged as a ubiquitous second messenger, which regulates the transition between sessile and motile lifestyles and virulence factor expression in many pathogenic bacteria using both RNA riboswitches and protein effectors. We recently showed that two additional class I c-di-GMP riboswitch aptamers (Ct-E88 and Cb-17B) bind c-di-GMP with nanomolar affinity, and that Ct-E88 RNA binds 2'-F-c-di-GMP 422 times less tightly than class I Vc2 RNA. Based on sequence comparison, it was concluded that the global folds of Ct-E88 and Vc2 RNAs were similar and that differences in ligand binding were probably due to differences in binding site architectures. Herein, we utilized EMSA, aptamer sensing spinach modules, SAXS and 1D NMR titration to study the conformational transitions of Ct-E88. We conclude that whereas the global folds of the bound states of Vc2 and Ct-E88 RNAs are similar, the unbound states are different and this could explain differences in ligand affinities between these class I c-di-GMP riboswitches. PMID:24430255

  18. Characterization of the Xylella fastidiosa PD1671 gene encoding degenerate c-di-GMP GGDEF/EAL domains, and its role in the development of Pierce's disease.

    Science.gov (United States)

    Cursino, Luciana; Athinuwat, Dusit; Patel, Kelly R; Galvani, Cheryl D; Zaini, Paulo A; Li, Yaxin; De La Fuente, Leonardo; Hoch, Harvey C; Burr, Thomas J; Mowery, Patricia

    2015-01-01

    Xylella fastidiosa is an important phytopathogenic bacterium that causes many serious plant diseases including Pierce's disease of grapevines. X. fastidiosa is thought to induce disease by colonizing and clogging xylem vessels through the formation of cell aggregates and bacterial biofilms. Here we examine the role in X. fastidiosa virulence of an uncharacterized gene, PD1671, annotated as a two-component response regulator with potential GGDEF and EAL domains. GGDEF domains are found in c-di-GMP diguanylate cyclases while EAL domains are found in phosphodiesterases, and these domains are for c-di-GMP production and turnover, respectively. Functional analysis of the PD1671 gene revealed that it affected multiple X. fastidiosa virulence-related phenotypes. A Tn5 PD1671 mutant had a hypervirulent phenotype in grapevines presumably due to enhanced expression of gum genes leading to increased exopolysaccharide levels that resulted in elevated biofilm formation. Interestingly, the PD1671 mutant also had decreased motility in vitro but did not show a reduced distribution in grapevines following inoculation. Given these responses, the putative PD1671 protein may be a negative regulator of X. fastidiosa virulence. PMID:25811864

  19. Characterization of the Xylella fastidiosa PD1671 gene encoding degenerate c-di-GMP GGDEF/EAL domains, and its role in the development of Pierce's disease.

    Directory of Open Access Journals (Sweden)

    Luciana Cursino

    Full Text Available Xylella fastidiosa is an important phytopathogenic bacterium that causes many serious plant diseases including Pierce's disease of grapevines. X. fastidiosa is thought to induce disease by colonizing and clogging xylem vessels through the formation of cell aggregates and bacterial biofilms. Here we examine the role in X. fastidiosa virulence of an uncharacterized gene, PD1671, annotated as a two-component response regulator with potential GGDEF and EAL domains. GGDEF domains are found in c-di-GMP diguanylate cyclases while EAL domains are found in phosphodiesterases, and these domains are for c-di-GMP production and turnover, respectively. Functional analysis of the PD1671 gene revealed that it affected multiple X. fastidiosa virulence-related phenotypes. A Tn5 PD1671 mutant had a hypervirulent phenotype in grapevines presumably due to enhanced expression of gum genes leading to increased exopolysaccharide levels that resulted in elevated biofilm formation. Interestingly, the PD1671 mutant also had decreased motility in vitro but did not show a reduced distribution in grapevines following inoculation. Given these responses, the putative PD1671 protein may be a negative regulator of X. fastidiosa virulence.

  20. Activation and polar sequestration of PopA, a c-di-GMP effector protein involved in Caulobacter crescentus cell cycle control

    DEFF Research Database (Denmark)

    Ozaki, Shogo; Schalch-Moser, Annina; Zumthor, Ludwig; Manfredi, Pablo; Ebbensgaard, Anna Elisabeth; Schirmer, Tilman; Jenal, Urs

    2014-01-01

    When Caulobacter crescentus enters S-phase the replication initiation inhibitor CtrA dynamically positions to the old cell pole to be degraded by the polar ClpXP protease. Polar delivery of CtrA requires PopA and the diguanylate cyclase PleD that positions to the same pole. Here we present evidence...... that PopA originated through gene duplication from its paralogue response regulator PleD and subsequent co-option as c-di-GMP effector protein. While the C-terminal catalytic domain (GGDEF) of PleD is activated by phosphorylation of the N-terminal receiver domain, functional adaptation has reversed...... PopA to the cell pole in response to c-di-GMP binding. In agreement with the divergent activation and targeting mechanisms, distinct markers sequester PleD and PopA to the old cell pole upon S-phase entry. Together these data indicate that PopA adopted a novel role as topology specificity factor to...

  1. Polysaccharide Nanostructures

    OpenAIRE

    Kontogiorgos, Vassilis

    2014-01-01

    Polysaccharides are carbohydrate polymers where sugar units are linked together through glycosidic linkages. In living organisms polysaccharides are the structural polymers that provide support (e.g., cellulose in plants or chitin in arthropods) or the sources of energy for plant development (e.g., starch). Polysaccharides are routinely used in the food industry, most frequently as thickeners, stabilizers of dispersions (emulsions, foams) or structuring agents of water and air.

  2. Exploiting the commons: cyclic diguanylate regulation of bacterial exopolysaccharide production.

    Science.gov (United States)

    Pérez-Mendoza, Daniel; Sanjuán, Juan

    2016-04-01

    Nowadays, there is increasing interest for bacterial polysaccharides in a wide variety of industrial sectors. This is due to their chemical and reological properties, and also the possibility to be obtained by fermentation processes. Biosynthesis of a growing number of exopolysaccharides (EPS) has been reported to be regulated by the ubiquitous second messenger c-di-GMP in a limited number of bacterial species. Since most bacteria are yet unexplored, it is likely that an unsuspected number and variety of EPS structures activated by c-di-GMP await to be uncovered. In the search of new EPS, manipulation of bacterial c-di-GMP metabolism can be combined with high throughput approaches for screening of large collections of bacteria. In addition, c-di-GMP activation of EPS production and promotion of cell aggregation may have direct applications in environmental industries related with biofuel production or wastewater treatments. PMID:26773798

  3. Characterization of the exopolygalacturonate lyase PelX of Erwinia chrysanthemi 3937.

    Science.gov (United States)

    Shevchik, V E; Kester, H C; Benen, J A; Visser, J; Robert-Baudouy, J; Hugouvieux-Cotte-Pattat, N

    1999-03-01

    Erwinia chrysanthemi 3937 secretes several pectinolytic enzymes, among which eight isoenzymes of pectate lyases with an endo-cleaving mode (PelA, PelB, PelC, PelD, PelE, PelI, PelL, and PelZ) have been identified. Two exo-cleaving enzymes, the exopolygalacturonate lyase, PelX, and an exo-poly-alpha-D-galacturonosidase, PehX, have been previously identified in other E. chrysanthemi strains. Using a genomic bank of a 3937 mutant with the major pel genes deleted, we cloned a pectinase gene identified as pelX, encoding the exopolygalacturonate lyase. The deduced amino acid sequence of the 3937 PelX is very similar to the PelX of another E. chrysanthemi strain, EC16, except in the 43 C-terminal amino acids. PelX also has homology to the endo-pectate lyase PelL of E. chrysanthemi but has a N-terminal extension of 324 residues. The transcription of pelX, analyzed by gene fusions, is dependent on several environmental conditions. It is induced by pectic catabolic products and affected by growth phase, oxygen limitation, nitrogen starvation, and catabolite repression. Regulation of pelX expression is dependent on the KdgR repressor, which controls almost all the steps of pectin catabolism, and on the global activator of sugar catabolism, cyclic AMP receptor protein. In contrast, PecS and PecT, two repressors of the transcription of most pectate lyase genes, are not involved in pelX expression. The pelX mutant displayed reduced pathogenicity on chicory leaves, but its virulence on potato tubers or Saintpaulia ionantha plants did not appear to be affected. The purified PelX protein has no maceration activity on plant tissues. Tetragalacturonate is the best substrate of PelX, but PelX also has good activity on longer oligomers. Therefore, the estimated number of binding subsites for PelX is 4, extending from subsites -2 to +2. PelX and PehX were shown to be localized in the periplasm of E. chrysanthemi 3937. PelX catalyzed the formation of unsaturated digalacturonates by

  4. Polysaccharide Degradation

    Science.gov (United States)

    Stone, Bruce A.; Svensson, Birte; Collins, Michelle E.; Rastall, Robert A.

    An overview of current and potential enzymes used to degrade polysaccharides is presented. Such depolymerases are comprised of glycoside hydrolases, glycosyl transferases, phosphorylases and lyases, and their classification, active sites and action patterns are discussed. Additionally, the mechanisms that these enzymes use to cleave glycosidic linkages is reviewed as are inhibitors of depolymerase activity; reagents which react with amino acid residues, glycoside derivatives, transition state inhibitors and proteinaceous inhibitors. The characterization of various enzymes of microbial, animal or plant origin has led to their widespread use in the production of important oligosaccharides which can be incorporated into food stuffs. Sources of polysaccharides of particular interest in this chapter are those from plants and include inulin, dextran, xylan and pectin, as their hydrolysis products are purported to be functional foods in the context of gastrointestinal health. An alternative use of degraded polysaccharides is in the treatment of disease. The possibility exists to treat bacterial exopolysaccharide with lyases from bacteriophage to produce oligosaccharides exhibiting bioactive sequences. Although this area is currently in its infancy the knowledge is available to investigate further.

  5. Using Light Scattering to Screen Polyelectrolytes (PEL Performance in Flocculation

    Directory of Open Access Journals (Sweden)

    David Hunkeler

    2011-05-01

    Full Text Available Flocculation of precipitated calcium carbonate (PCC was monitored using light diffraction spectroscopy (LDS. Four cationic polyacrylamides of high molar mass and with different degrees of branching, all copolymers of acrylamide (AM and acryloyloxyethyltrimethyl ammonium chloride (Q9, were tested. LDS supplied information about the kinetic curves for flocs growth and also for the flocs structure evolution. Flocculation kinetics, flocs size and structure, flocs resistance and reflocculation capacity could be correlated with the degree of branching of the polyelectrolytes (PEL. Furthermore, PEL with different degrees of branching corresponded to different values for the intrinsic viscosity, indicating differences in the polymer conformation, which explained well the performance differences in flocculation.

  6. Pectate lyase PelI of Erwinia chrysanthemi 3937 belongs to a new family.

    Science.gov (United States)

    Shevchik, V E; Robert-Baudouy, J; Hugouvieux-Cotte-Pattat, N

    1997-12-01

    Erwinia chrysanthemi 3937 secretes five major isoenzymes of pectate lyases encoded by the pel4, pelB, pelC, pelD, and pelE genes and a set of secondary pectate lyases, two of which, pelL and pelZ, have been already identified. We cloned the pelI gene, encoding a ninth pectate lyase of E. chrysanthemi 3937. The pelI reading frame is 1,035 bases long, corresponding to a protein of 344 amino acids including a typical amino-terminal signal sequence of 19 amino acids. The purified mature PelI protein has an isoelectric point of about 9 and an apparent molecular mass of 34 kDa. PelI has a preference for partially methyl esterified pectin and presents an endo-cleaving activity with an alkaline pH optimum and an absolute requirement for Ca2+ ions. PelI is an extracellular protein secreted by the Out secretory pathway of E. chrysanthemi. The PelI protein is very active in the maceration of plant tissues. A pelI mutant displayed reduced pathogenicity on chicory leaves, but its virulence did not appear to be affected on potato tubers or Saintpaulia ionantha plants. The pelI gene constitutes an independent transcriptional unit. As shown for the other pel genes, the transcription of pelI is dependent on various environmental conditions. It is induced by pectic catabolic products and affected by growth phase, oxygen limitation, temperature, nitrogen starvation, and catabolite repression. Regulation of pelI expression appeared to be dependent on the three repressors of pectinase synthesis, KdgR, PecS, and PecT, and on the global activator of sugar catabolism, cyclic AMP receptor protein. A functional KdgR binding site was identified close to the putative pelI promoter. Analysis of the amino acid sequence of PelI revealed high homology with a pectate lyase from Erwinia carotovora subsp. carotovora (65% identity) and low homology with pectate lyases of the phytopathogenic fungus Nectria haematococca (Fusarium solani). This finding indicates that PelI belongs to pectate lyase class

  7. Characterization of the pelL gene encoding a novel pectate lyase of Erwinia chrysanthemi 3937.

    Science.gov (United States)

    Lojkowska, E; Masclaux, C; Boccara, M; Robert-Baudouy, J; Hugouvieux-Cotte-Pattat, N

    1995-06-01

    Erwinia chrysanthemi 3937 secretes five major isoenzymes of pectate lyases encoded by the pelA, pelB, pelC, pelD and pelE genes. Recently, a new set of pectate lyases was identified in E. chrysanthemi mutants deleted of those pel genes. We cloned the pelL gene, encoding one of these secondary pectate lyases of E. chrysanthemi 3937, from a genomic bank of a strain deleted of the five major pel genes. The nucleotide sequence of the region containing the pelL gene was determined. The pelL reading frame is 1275 bases long, corresponding to a protein of 425 amino acids including a typical amino-terminal signal sequence of 25 amino acids. Comparison of the amino acid sequences of PelL and the exo-pectate lyase PelX of E. chrysanthemi EC16 revealed a low homology, limited to 220 residues of the central part of the proteins. No homology was detected with other bacterial pectinolytic enzymes. Regulation of pelL transcription was analysed using gene fusion. As shown for the other pel genes, the transcription of pelL is dependent on various environmental conditions. It is induced by pectic catabolic products and affected by growth phase, temperature, iron starvation, osmolarity, anaerobiosis, nitrogen starvation and catabolite repression. Regulation of pelL expression appeared to be independent of the KdgR repressor, which controls all the steps of pectin catabolism. In contrast, the pecS gene, which is involved in regulation of the synthesis of the major pectate lyases and of cellulase, also appeared to be involved in pelL expression. The PelL protein is able to macerate plant tissue. This enzyme has a basic isoelectric point, presents an endo-cleaving activity on polygalacturonate or partially methylated pectin, with a basic pH optimum and an absolute requirement for Ca2+. The pelL mutant displayed a reduced virulence on potato tubers and Saintpaulia ionantha plants, demonstrating the important role of this enzyme in soft-rot disease. PMID:8577252

  8. The Planetary Emissivity Laboratory (PEL) at DLR, Berlin

    OpenAIRE

    Maturilli, A.; Helbert, J.; d'Amore, M.

    2010-01-01

    The Institute for Planetary Research has an expertise in spectroscopy of minerals, rocks, meteorites, and organic matter, build up in more than two decades. The available equipment allows spectroscopy from the visible to TIR range using bi-conical reflection, transmission and emission spectroscopy. The institute has an outstanding heritage in designing and building infrared remote-sensing instruments for planetary missions. The PEL has been operating in various configurations for the last...

  9. Pneumococcal Polysaccharide Vaccine

    Science.gov (United States)

    Pneumococcal polysaccharide vaccine (PPSV)Treatment of pneumococcal infections with penicillin and other drugs used to be more effective. But ... the disease, through vaccination, even more important. Pneumococcal polysaccharide vaccine (PPSV) protects against 23 types of pneumococcal ...

  10. Expression of bvg-repressed genes in Bordetella pertussis is controlled by RisA through a novel c-di-GMP signaling pathway

    Science.gov (United States)

    The BvgAS two component system of Bordetella pertussis controls virulence factor expression. In addition, BvgAS controls expression of the bvg-repressed genes through the action of the repressor, BvgR. The transcription factor RisA is inhibited by BvgR, and when BvgR is not expressed RisA induces th...

  11. The RNA binding protein CsrA controls c-di-GMP metabolism by directly regulating the expression of GGDEF proteins

    OpenAIRE

    Jonas, Kristina; Edwards, Adrianne N.; Simm, Roger; Romeo, Tony; Römling, Ute; Melefors, Öjar

    2008-01-01

    The carbon storage regulator CsrA is an RNA binding protein that controls carbon metabolism, biofilm formation and motility in various eubacteria. Nevertheless, in Escherichia coli only five target mRNAs have been shown to be directly regulated by CsrA at the post-transcriptional level. Here we identified two new direct targets for CsrA, ycdT and ydeH, both of which encode proteins with GGDEF domains. A csrA mutation caused mRNA levels of ycdT and ydeH to increase more than 10-fold. RNA mobil...

  12. Polysaccharide-Based Vaccines

    Science.gov (United States)

    Santana, Violeta Fernández; Balbin, Yury Valdés; Calderón, Janoi Chang; Icart, Luis Peña; Verez-Bencomo, Vicente

    Capsular polysaccharides (CPS) and lipopolysaccharides from bacteria are employed for the production of vaccines against human diseases. Initial development of CPS as a vaccine was followed by the development and introduction of conjugate polysaccharide-protein vaccines. The principles leading to both developments are reviewed.

  13. Radiation processed polysaccharide products

    International Nuclear Information System (INIS)

    Radiation crosslinking, degradation and grafting techniques for modification of polymeric materials including natural polysaccharides have been providing many unique products. In this communication, typical products from radiation processed polysaccharides particularly plant growth promoter from alginate, plant protector and elicitor from chitosan, super water absorbent containing starch, hydrogel sheet containing carrageenan/CM-chitosan as burn wound dressing, metal ion adsorbent from partially deacetylated chitin were described. The procedures for producing those above products were also outlined. Future development works on radiation processing of polysaccharides were briefly presented. (author)

  14. Reflectance and Transmission Measurements in Support of the Emissivity Measurements in the Planetary Emissivity Laboratory (PEL)

    OpenAIRE

    Maturilli, A.; Helbert, J.; d'Amore, M.

    2010-01-01

    In the PEL a spectral library of emissivity measurements for planetary analogues, at high temperature and vacuum envoronment is built. Reflectance, transmission and emissivity measurement at room pressure and moderate temperatures are routinely performed in support.

  15. Disseny d'una aplicació web administrable pel producte El Puntxes

    OpenAIRE

    Pratsobrerroca Rafael, Sílvia

    2015-01-01

    Disseny d'una aplicació web administrable pel producte El Puntxes. Diseño de una aplicación web administrable por el producto El Puntxes. Bachelor thesis for the Multimedia program on Computer Science.

  16. Membrane-anchored MucR mediates nitrate-dependent regulation of alginate production in Pseudomonas aeruginosa

    KAUST Repository

    Wang, Yajie

    2015-04-29

    Alginates exhibit unique material properties suitable for medical and industrial applications. However, if produced by Pseudomonas aeruginosa, it is an important virulence factor in infection of cystic fibrosis patients. The alginate biosynthesis machinery is activated by c-di-GMP imparted by the inner membrane protein, MucR. Here, it was shown that MucR impairs alginate production in response to nitrate in P. aeruginosa. Subsequent site-specific mutagenesis of MucR revealed that the second MHYT sensor motif (MHYT II, amino acids 121–124) of MucR sensor domain was involved in nitrate sensing. We also showed that both c-di-GMP synthesizing and degrading active sites of MucR were important for alginate production. Although nitrate and deletion of MucR impaired alginate promoter activity and global c-di-GMP levels, alginate yields were not directly correlated with alginate promoter activity or c-di-GMP levels, suggesting that nitrate and MucR modulate alginate production at a post-translational level through a localized pool of c-di-GMP. Nitrate increased pel promoter activity in the mucR mutant while in the same mutant the psl promoter activity was independent of nitrate. Nitrate and deletion of mucR did not impact on swarming motility but impaired attachment to solid surfaces. Nitrate and deletion of mucR promoted the formation of biofilms with increased thickness, cell density, and survival. Overall, this study provided insight into the functional role of MucR with respect to nitrate-mediated regulation of alginate biosynthesis. © 2015 Springer-Verlag Berlin Heidelberg

  17. Escherichia coli BdcA controls biofilm dispersal in Pseudomonas aeruginosa and Rhizobium meliloti

    Directory of Open Access Journals (Sweden)

    Wood Thomas K

    2011-10-01

    Full Text Available Abstract Background Previously we showed that BdcA controls Escherichia coli biofilm dispersal by binding the ubiquitous bacterial signal cyclic diguanylate (c-di-GMP; upon reducing the concentration of c-di-GMP, the cell shifts to the planktonic state by increasing motility, decreasing aggregation, and decreasing production of biofilm adhesins. Findings Here we report that BdcA also increases biofilm dispersal in other Gram-negative bacteria including Pseudomonas aeruginosa, Pseudomonas fluorescens, and Rhizobium meliloti. BdcA binds c-di-GMP in these strains and thereby reduces the effective c-di-GMP concentrations as demonstrated by increases in swimming motility and swarming motility as well as by a reduction in extracellular polysaccharide production. We also develop a method to displace existing biofilms by adding BdcA via conjugation from E. coli in mixed-species biofilms. Conclusion Since BdcA shows the ability to control biofilm dispersal in diverse bacteria, BdcA has the potential to be used as a tool to disperse biofilms for engineering and medical applications.

  18. Enzymatic hydrolysis of nonnutritive polysaccharides

    Energy Technology Data Exchange (ETDEWEB)

    Arai, M.; Murao, S.

    1978-01-01

    A review is presented on the distribution of nonnutritive polysaccharides (cellulose, beta-glucans, hemicellulose, pectin, lignin, etc.) in microorganisms and plants and bacterial enzymes (cellulase, beta-glucanase, hemicellulase, pectinase, etc.) that hydrolyze these nonnutritive polysaccharides.

  19. Pedro Peláez, líder del clero filipino

    Directory of Open Access Journals (Sweden)

    Blanco Andrés, Roberto

    2011-12-01

    Full Text Available This article provides new information on the creole Filipino, Fr. Pedro Pablo Peláez, who, together with Fr. José Burgos, was the most outstanding clergyman in the nineteenth-century Philippines. It discusses Father Peláez’s previously unknown activities in the cabildo of the Manila Cathedral, where he was its most distinguished member. It analyzes his reformist ideas, and explains his work and strategy to defend the Filipino secular clergy, whose rights were being violated by the royal orders of 1848 and 1861. Against the reactionary religious orders, Peláez had a detailed modus operandi to defend the legitimacy of native priests’ control of parishes. Although his activities were cut short by his unexpected death in the earthquake of June 1863, Peláez served as an inspiration to be emulated.

    En este trabajo se intentan aportar algunas claves y datos inéditos sobre la biografía del presbítero criollo filipino Pedro Pablo Peláez, que es, junto con el P. José Burgos, el eclesiástico más destacado de la iglesia de Filipinas del siglo XIX. El trabajo aborda la totalmente desconocida actividad del P. Peláez en el cabildo de la catedral de Manila, donde acabaría siendo con el tiempo su hombre más insigne. Igualmente se analiza el espíritu e ideario reformista de Peláez y sus trabajos y estrategia para defender al clero secular filipino, cuyos derechos estaban siendo vulnerados por una serie de Reales Órdenes (1848 ó 1861 y la actitud reaccionaria de un sector de las órdenes religiosas. Peláez supo articular un modus operandi minucioso y muy efectivo en torno a la legitimidad de los curas filipinos en la dirección de las parroquias del país. Aunque sus actividades cesaron con su inesperada muerte en el terremoto de junio de 1863, Peláez se convirtió en una inspiración y un modelo a seguir.

  20. Systematic analysis of a xenograft mice model for KSHV+ primary effusion lymphoma (PEL.

    Directory of Open Access Journals (Sweden)

    Lu Dai

    Full Text Available Kaposi's sarcoma-associated herpesvirus is the causative agent of primary effusion lymphoma (PEL, which arises preferentially in the setting of infection with human immunodeficiency virus (HIV. Even with standard cytotoxic chemotherapy, PEL continues to cause high mortality rates, requiring the development of novel therapeutic strategies. PEL xenograft models employing immunodeficient mice have been used to study the in vivo effects of a variety of therapeutic approaches. However, it remains unclear whether these xenograft models entirely reflect clinical presentations of KSHV(+ PEL, especially given the recent description of extracavitary solid tumor variants arising in patients. In addition, effusion and solid tumor cells propagated in vivo exhibit unique biology, differing from one another or from their parental cell lines propagated through in vitro culture. Therefore, we used a KSHV(+ PEL/BCBL-1 xenograft model involving non-obese diabetic/severe-combined immunodeficient (NOD/SCID mice, and compared characteristics of effusion and solid tumors with their parent cell culture-derived counterparts. Our results indicate that although this xenograft model can be used for study of effusion and solid lymphoma observed in patients, tumor cells in vivo display unique features to those passed in vitro, including viral lytic gene expression profile, rate of solid tumor development, the host proteins and the complex of tumor microenvironment. These items should be carefully considered when the xenograft model is used for testing novel therapeutic strategies against KSHV-related lymphoma.

  1. Characterization of Brucella polysaccharide B.

    OpenAIRE

    Bundle, D R; Cherwonogrodzky, J W; Perry, M B

    1988-01-01

    Polysaccharide B was extracted from Brucella melitensis 16M and from a rough strain of Brucella abortus 45/20 by autoclaving or trichloroacetic acid extraction of whole cells and by a new method involving mild leaching of cells. The material obtained by either of the established procedures was contaminated by O polysaccharide. The new leaching protocol eliminated this impurity and provided a pure glucan, which was regarded as polysaccharide B. This polysaccharide was found by high-performance...

  2. Structure of polysaccharide antibiotics

    International Nuclear Information System (INIS)

    Study of the structure of antibiotics having two or several sugars in their molecule. One may distinguish: the polysaccharide antibiotics themselves, made up of two or several sugars either with or without nitrogen, such as streptomycin, neomycins, paromomycine, kanamycin, chalcomycin; the hetero-polysaccharide antibiotics made up of one saccharide part linked to an aglycone of various type through a glucoside: macrolide, pigment, pyrimidine purine. Amongst these latter are: erythromycin, magnamycin, spiramycin, oleandomycin, cinerubin and amicetin. The sugars can either play a direct role in biochemical reactions or act as a dissolving agent, as far as the anti-microbe power of these antibiotics is concerned. (author)

  3. Structures of some bacterial polysaccharides with focus on pneumococcal polysaccharides and their associated C-polysaccharide

    OpenAIRE

    Karlsson, Camilla

    1998-01-01

    This thesis describes the chemical structures of the capsular polysaccharides from Streptococcus pneumoniae types 18B, 32F, and 32A. The structure of the pneumococcal common antigen, C-polysaccharide, from a non-capsulated pneumococcal strain, CSR SCS2, is described and the structure of the C-polysaccharide associated with pneumococcal types 18B, 32F, and 32A. Two distinct forms of C-polysaccharide were demonstrated, mono- or disubstituted with phosphorylcholine. In addi...

  4. Deposición de películas de AlN como dispositivos semiconductores

    OpenAIRE

    Julio Cesar Caicedo; Jaime Andrés Pérez Taborda; Willian Aperador Chaparro

    2012-01-01

    Películas de AlN fueron depositados por la técnica de deposición por láser pulsado (PLD), utilizando un láser Nd: YAG con una longitud de onda de 1064 nm. Las películas fueron depositadas en una atmósfera de nitrógeno como gas de trabajo; como cátodo se usó aluminio de alta pureza (99,99%). Las películas fueron depositadas con una fluencia del láser de 2,28 J/cm2 durante 10 minutos sobre sustratos de silicio (100). La presión de trabajo fue de 9 x 10-3 mbar y la temperatura del sustrato se va...

  5. Tractament periodístic-literari de la Guerra Civil espanyola pels corresponsals anglosaxons

    OpenAIRE

    Muñoz Arroyo, Oliver

    2015-01-01

    La Guerra Civil espanyola va suposar pels republicans la primera batalla de la Segona Guerra Mundial, mentre que pels franquistes va ser el preludi d'una tercera guerra mundial entre occident i el comunisme. Espanya va acaparar l'atenció internacional i van començar a arribar corresponsals estrangers per cobrir el conflicte. Aquest treball analitza les cròniques i reportatges de cinc autors anglosaxons (Orwell, Hemingway, Dos Passos, Buckley i Langdon-Davies) que van utilitzar tècniques pròpi...

  6. vPELS: An E-Learning Social Environment for VLSI Design with Content Security Using DRM

    Science.gov (United States)

    Dewan, Jahangir; Chowdhury, Morshed; Batten, Lynn

    2014-01-01

    This article provides a proposal for personal e-learning system (vPELS [where "v" stands for VLSI: very large scale integrated circuit])) architecture in the context of social network environment for VLSI Design. The main objective of vPELS is to develop individual skills on a specific subject--say, VLSI--and share resources with peers.…

  7. 24 CFR 990.165 - Computation of project expense level (PEL).

    Science.gov (United States)

    2010-04-01

    ... with 24 CFR 941.606 for a mixed-finance transaction, then the project covered by the mixed-finance... as reported for FFY 2003 in a PUM amount. (d) Annual inflation factor. The PEL for each project shall... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Computation of project...

  8. Binding of cryptococcal polysaccharide to Cryptococcus neoformans.

    OpenAIRE

    Kozel, T R; Hermerath, C A

    1984-01-01

    Radioiodinated cryptococcal polysaccharide was used to study binding of the soluble polysaccharide to encapsulated and non-encapsulated cryptoccoci. Binding of polysaccharide to non-encapsulated cryptococci occurred rapidly over a 30-min period and was largely complete after 2 h. Bound, labeled polysaccharide was slowly eluted from Cryptococcus neoformans after the addition of unlabeled polysaccharide, indicating reversibility of binding. Non-encapsulated cryptococci bound polysaccharide in t...

  9. La misma película y la película de cada cual. Un estudio sobre el consumo televisivo de cine en tres comunidades habaneras

    OpenAIRE

    Lic. Yanet Toirac García

    1999-01-01

    Un sábado en La Habana es mucho más que el día destinado a los quehaceres domésticos, las reuniones en familia o el descanso corporal. Para muchos habitantes de esta capital caribeña, el relleno de la última noche de la semana se disputa entre quedarse en casa para disfrutar de las películas de la tele o elegir alguna de las alternativas que supone andar la ciudad, algo menguadas en los tiempos que por aquí corren.

  10. Genome sequence of the bacterioplanktonic, mixotrophic Vibrio campbellii strain PEL22A, isolated in the Abrolhos Bank.

    Science.gov (United States)

    Amaral, Gilda Rose S; Silva, Bruno Sergio de O; Santos, Eidy O; Dias, Graciela M; Lopes, Rubens M; Edwards, Robert A; Thompson, Cristiane C; Thompson, Fabiano L

    2012-05-01

    Vibrio campbellii PEL22A was isolated from open ocean water in the Abrolhos Bank. The genome of PEL22A consists of 6,788,038 bp (the GC content is 45%). The number of coding sequences (CDS) is 6,359, as determined according to the Rapid Annotation using Subsystem Technology (RAST) server. The number of ribosomal genes is 80, of which 68 are tRNAs and 12 are rRNAs. V. campbellii PEL22A contains genes related to virulence and fitness, including a complete proteorhodopsin cluster, complete type II and III secretion systems, incomplete type I, IV, and VI secretion systems, a hemolysin, and CTXΦ. PMID:22535939

  11. Genome Sequence of the Bacterioplanktonic, Mixotrophic Vibrio campbellii Strain PEL22A, Isolated in the Abrolhos Bank

    OpenAIRE

    Amaral, Gilda Rose S.; Silva, Bruno Sergio de O.; Santos, Eidy O.; Dias, Graciela M.; Rubens M. Lopes; Edwards, Robert A.; Thompson, Cristiane C; Thompson, Fabiano L

    2012-01-01

    Vibrio campbellii PEL22A was isolated from open ocean water in the Abrolhos Bank. The genome of PEL22A consists of 6,788,038 bp (the GC content is 45%). The number of coding sequences (CDS) is 6,359, as determined according to the Rapid Annotation using Subsystem Technology (RAST) server. The number of ribosomal genes is 80, of which 68 are tRNAs and 12 are rRNAs. V. campbellii PEL22A contains genes related to virulence and fitness, including a complete proteorhodopsin cluster, complete type ...

  12. Evaluación del comportamiento de películas comestibles de quitosano almacenadas bajo condiciones controladas

    OpenAIRE

    Valderrama Bohórquez, Nathalia

    2014-01-01

    El objetivo del presente trabajo de investigación fue obtener y caracterizar películas de quitosano, evaluando el efecto combinado con la inclusión de aceites esenciales de romero y tomillo sobre las propiedades de las películas durante el almacenamiento bajo condiciones controladas. Las películas obtenidas fueron almacenadas a temperaturas de 5, 20, 33°C y humedades relativas de 60, 75, 93% durante cuatro semanas. La adición de aceites esenciales y las condiciones de almacenamiento modificar...

  13. All you can measure at the Planetary Emissivity Laboratory (PEL) at DLR, in Berlin

    OpenAIRE

    Maturilli, A.; Helbert, J.; d'Amore, M.

    2010-01-01

    The Institute for Planetary Research has an expertise in spectroscopy of minerals, rocks, meteorites, and organic matter, build up in more than two decades. The available equipment allows spectroscopy from the visible to TIR range using bi-conical reflection, transmission and emission spectroscopy. The institute has an outstanding heritage in designing and building infrared remote-sensing instruments for planetary missions. The PEL has been operating in various configurations for the last ...

  14. Películas delgadas de CNx formadas por PLD a diferentes temperaturas

    Directory of Open Access Journals (Sweden)

    Jorge Luis Gallego Cano

    2011-01-01

    Full Text Available Películas delgadas de nitruro de carbono (CNx fueron formadas por la técnica de depósito por láser pulsado (PLD, siglas en inglés. Para la ablación incidió sobre la superficie del blanco de grafito pirolítico (99.999% de pureza un láser Nd:YAG (1064 nm, 500 mJ, cuya fluencia del haz se mantuvo a un valor de 10 J¿cm-2. Las películas se formaron sobre sustratos de Si (100 y en una atmósfera de nitrógeno, y a tres valores diferentes de temperatura del sustrato (21, 50 y 200° C. Durante el crecimiento de estas películas se mantuvo la presión del gas ambiente constante (2,66 Pa. También se analizaron las propiedades mecánicas y químicas de las películas mediante microscopia de fuerza atómica (AFM, por sus siglas en inglés, espectroscopia infrarroja (FTIR, energía dispersiva de rayos X (EDX y nanoindentación. El análisis de FTIR revela la presencia de modos activos alrededor de 1108 cm-1, 1465 cm-1, 2270 cm-1, asociados a enlaces simples, dobles y triples de CN, respectivamente. Por medio de EDX, se estudió la composición química de las muestras, encontrándose bajos contenidos de nitrógeno, con una variación entre el 3 y 6 %at. Las propiedades mecánicas fueron evaluadas mediante la técnica de nanoindentación. La mayor dureza de las muestras fue de 14 GPa, obtenida para la muestra formada a una temperatura del sustrato de 200º C.

  15. El Nacionalismo polaco a través de la película Kanal

    Directory of Open Access Journals (Sweden)

    Begoña GUTIÉRREZ SAN MIGUEL

    2014-10-01

    Full Text Available La película Kanal fue dirigida por Andrzej Wajda en el año 1957, basándose en un guión de Jerzy Stefan Stawinski y una interpretación a cargo de actores poco conocidos como Teresa Izewska Stokrotka (Daisy, Tadeusz Janczar Korab/Jacek Wienczyslaw Glinski Zabra, Tadeusz Gwiazdowski Kula (Bullet,Stanislaw Mikuldski Smukly (Slim, Emil Karewicz Madry (Wise, Wladyslaw Sheybal Michal Teresa Berezowska Halinka.

  16. Why Were Polysaccharides Necessary?

    Science.gov (United States)

    Tolstoguzov, Vladimir

    2004-12-01

    The main idea of this paper is that the primordial soup may be modelled by food systems whose structure-property relationship is based on non-specific interactions between denatured biopolymers. According to the proposed hypothesis, polysaccharides were the first biopolymers that decreased concentration of salts in the primordial soup, `compatibilised' and drove the joint evolution of proto-biopolymers. Synthesis of macromolecules within the polysaccharide-rich medium could have resulted in phase separation of the primordial soup and concentration of the polypeptides and nucleic acids in the dispersed phase particles. The concentration of proto-biopolymer mixtures favoured their cross-linking in hybrid supermacromolecules of conjugates. The cross-linking of proto-biopolymers could occur by hydrophobic, electrostatic interactions, H-bonds due to freezing aqueous mixed biopolymer dispersions and/or by covalent bonds due to the Maillard reaction. Cross-linking could have increased the local concentration of chemically different proto-biopolymers, fixed their relative positions and made their interactions reproducible. Attractive-repulsive interactions between cross-linked proto-biopolymer chains could develop pairing of the monomer units, improved chemical stability (against hydrolysis) and led to their mutual catalytic activity and coding. Conjugates could probably evolve to the first self-reproduced entities and then to specialized cellular organelles. Phase separation of the primordial soup with concentration of conjugates in the dispersed particles has probably resulted in proto-cells.

  17. Polysaccharides and bacterial plugging

    Energy Technology Data Exchange (ETDEWEB)

    Fogler, H.S.

    1991-11-01

    Before any successful application of Microbial Enhanced Oil Recovery process can be realized, an understanding of the cells' transport and retentive mechanisms in porous media is needed. Cell transport differs from particle transport in their ability to produce polysaccharides, which are used by cells to adhere to surfaces. Cell injection experiments have been conducted using Leuconostoc cells to illustrate the importance of cellular polysaccharide production as a transport mechanism that hinders cell movement and plugs porous media. Kinetic studies of the Leuconostoc cells, carried out to further understand the plugging rates of porous media, have shown that the cells' growth rates are approximately equal when provided with monosaccharide (glucose and fructose) or sucrose. The only difference in cell metabolism is the production of dextran when sucrose is supplied as a carbon source. Experimentally it has also been shown that the cells' growth rate is weakly dependent upon the sucrose concentration in the media, and strongly dependent upon the concentration of yeast extract. The synthesis of cellular dextran has been found to lag behind cell generation, thus indicating that the cells need to reach maturity before they are capable of expressing the detransucrase enzyme and synthesizing insoluble dextran. Dextran yields were found to be dependent upon the sucrose concentration in the media. 10 refs., 9 figs., 9 tabs.

  18. La restauració digital de pel·lícules

    Directory of Open Access Journals (Sweden)

    Catanese, Rossella

    2014-12-01

    Full Text Available Aquest article tracta sobre la conservació i la restauració de pel·lícules amb tecnologies digitals. Les pel·lícules, com a expressió de la memòria col·lectiva, formen part del patrimoni comú de la humanitat, i mereixen ser preservades i difoses. Per això, la qüestió de la preservació dels materials cinematogràfics està guanyant pes, sobretot si tenim en compte la fragilitat estructural i la curta durada de l'estoc de pel·lícules. L'estat actual del mitjà audiovisual és de transició: a poc a poc l'element analògic i fotoquímic és substituït pel sistema digital. I això influeix molt en les pràctiques de producció i distribució del cinema, i també en els debats teòrics sobre el mitjà: els criteris d'arxivament i els processos de restauració no són una excepció a aquesta lògica.Este artículo trata sobre la conservación y la restauración de películas con tecnologías digitales. Las películas, como expresión de la memoria colectiva, forman parte del patrimonio común de la humanidad, y merecen ser preservadas y difundidas. Por eso, la cuestión de la preservación de los materiales cinematográficos está ganando peso, sobre todo si tenemos en cuenta la fragilidad estructural y la corta duración del stock de películas. El estado actual del medio audiovisual es de transición: poco a poco el elemento analógico y fotoquímico es sustituido por el sistema digital. Lo cual influye mucho en las prácticas de producción y distribución del cine, y también en los debates teóricos sobre el medio: los criterios de archivo y los procesos de restauración no son una excepción a esta lógica.This article focuses on the issues of conservation and restoration of films through digital technologies. Films, as an expression of collective memory, become part of the common heritage of humankind, which deserves to be safeguarded and disseminated. As a consequence of this awareness, the issue of preserving cinematic

  19. La restauración digital de películas

    Directory of Open Access Journals (Sweden)

    Catanese, Rossella

    2014-12-01

    Full Text Available Este artículo trata sobre la conservación y la restauración de películas con tecnologías digitales. Las películas, como expresión de la memoria colectiva, forman parte del patrimonio común de la humanidad, y merecen ser preservadas y difundidas. Por eso, la cuestión de la preservación de los materiales cinematográficos está ganando peso, sobre todo si tenemos en cuenta la fragilidad estructural y la corta duración del stock de películas. El estado actual del medio audiovisual es de transición: poco a poco el elemento analógico y fotoquímico es sustituido por el sistema digital. Lo cual influye mucho en las prácticas de producción y distribución del cine, y también en los debates teóricos sobre el medio: los criterios de archivo y los procesos de restauración no son una excepción a esta lógica.Aquest article tracta sobre la conservació i la restauració de pel·lícules amb tecnologies digitals. Les pel·lícules, com a expressió de la memòria col·lectiva, formen part del patrimoni comú de la humanitat, i mereixen ser preservades i difoses. Per això, la qüestió de la preservació dels materials cinematogràfics està guanyant pes, sobretot si tenim en compte la fragilitat estructural i la curta durada de l'estoc de pel·lícules. L'estat actual del mitjà audiovisual és de transició: a poc a poc l'element analògic i fotoquímic és substituït pel sistema digital. I això influeix molt en les pràctiques de producció i distribució del cinema, i també en els debats teòrics sobre el mitjà: els criteris d'arxivament i els processos de restauració no són una excepció a aquesta lògica.This article focuses on the issues of conservation and restoration of films through digital technologies. Films, as an expression of collective memory, become part of the common heritage of humankind, which deserves to be safeguarded and disseminated. As a consequence of this awareness, the issue of preserving cinematic

  20. Deciphering the components that coordinately regulate virulence factors of the soft rot pathogen Dickeya dadantii.

    Science.gov (United States)

    Wu, Xiaogang; Zeng, Quan; Koestler, Benjamin J; Waters, Christopher M; Sundin, George W; Hutchins, William; Yang, Ching-Hong

    2014-10-01

    The bacterial soft rot pathogen Dickeya dadantii utilizes the type III secretion system (T3SS) to suppress host defense responses, and secretes pectate lyase (Pel) to disintegrate the plant cell wall. A transposon mutagenesis fluorescence-activated cell sorting screen was used to identify mutants with altered promoter activities of the T3SS pilus gene hrpA. Several insertion mutations, resulting in changes in hrpA expression, were mapped to a new locus, opgGH, which encodes the gene cluster responsible for osmoregulated periplasmic glucan (OPG) synthesis proteins. Our data showed that OPG was involved in T3SS and Pel regulation by altering the expression of the regulatory small RNA RsmB. Through genome searching, the mechanism of two novel regulatory components, the RcsCD-RcsB phosphorelay and CsrD on OPG and the rsmB gene, was further investigated. The Rcs phosphorelay and OPG inversely regulated rsmB at transcriptional and post-transcriptional levels, respectively. CsrD exhibited dual functionality in T3SS and Pel regulation by manipulating levels of RsmB RNA and cyclic diguanylate monophosphate (c-di-GMP). CsrD positively regulated the promoter activity of the rsmB gene but negatively controlled RsmB RNA at the post-transcriptional level via OpgGH. In addition, CsrD contains both GGDEF and EAL domains but acted as a c-di-GMP phosphodiesterase. When the expression of the csrD gene was induced, CsrD regulated T3SS expression and Pel production through controlling intracellular c-di-GMP levels. PMID:25180688

  1. A threading receptor for polysaccharides.

    Science.gov (United States)

    Mooibroek, Tiddo J; Casas-Solvas, Juan M; Harniman, Robert L; Renney, Charles M; Carter, Tom S; Crump, Matthew P; Davis, Anthony P

    2016-01-01

    Cellulose, chitin and related polysaccharides are key renewable sources of organic molecules and materials. However, poor solubility tends to hamper their exploitation. Synthetic receptors could aid dissolution provided they are capable of cooperative action, for example by multiple threading on a single polysaccharide molecule. Here we report a synthetic receptor designed to form threaded complexes (polypseudorotaxanes) with these natural polymers. The receptor binds fragments of the polysaccharides in aqueous solution with high affinities (K(a) up to 19,000 M(-1)), and is shown--by nuclear Overhauser effect spectroscopy--to adopt the threading geometry. Evidence from induced circular dichroism and atomic force microscopy implies that the receptor also forms polypseudorotaxanes with cellulose and its polycationic analogue chitosan. The results hold promise for polysaccharide solubilization under mild conditions, as well as for new approaches to the design of biologically active molecules. PMID:26673266

  2. A threading receptor for polysaccharides

    Science.gov (United States)

    Mooibroek, Tiddo J.; Casas-Solvas, Juan M.; Harniman, Robert L.; Renney, Charles M.; Carter, Tom S.; Crump, Matthew P.; Davis, Anthony P.

    2016-01-01

    Cellulose, chitin and related polysaccharides are key renewable sources of organic molecules and materials. However, poor solubility tends to hamper their exploitation. Synthetic receptors could aid dissolution provided they are capable of cooperative action, for example by multiple threading on a single polysaccharide molecule. Here we report a synthetic receptor designed to form threaded complexes (polypseudorotaxanes) with these natural polymers. The receptor binds fragments of the polysaccharides in aqueous solution with high affinities (Ka up to 19,000 M-1), and is shown—by nuclear Overhauser effect spectroscopy—to adopt the threading geometry. Evidence from induced circular dichroism and atomic force microscopy implies that the receptor also forms polypseudorotaxanes with cellulose and its polycationic analogue chitosan. The results hold promise for polysaccharide solubilization under mild conditions, as well as for new approaches to the design of biologically active molecules.

  3. Computer simulation and experimental study of the polysaccharide-polysaccharide interaction in the bacteria Azospirillum brasilense Sp245

    Science.gov (United States)

    Arefeva, Oksana A.; Kuznetsov, Pavel E.; Tolmachev, Sergey A.; Kupadze, Machammad S.; Khlebtsov, Boris N.; Rogacheva, Svetlana M.

    2003-09-01

    We have studied the conformational properties and molecular dynamics of polysaccharides by using molecular modeling methods. Theoretical and experimental results of polysaccharide-polysaccharide interactions are described.

  4. Construcció d'una eina pel tractament automatitzat de fitxers OpenOffice

    OpenAIRE

    Graell Gras, Xavier

    2007-01-01

    Aquest projecte té per objectiu conèixer i manipular fitxers creats amb el paquet ofimàtic de software lliure OpenOffice. Aquests fitxers es guarden en format anomenat OASIS, format que pren com a base l'estàndard XML i l'adapta a les característiques específiques que s'han dissenyat pels documents OpenOffice. Este proyecto tiene por objetivo conocer y manipular ficheros creados con el paquete ofimático de software libre OpenOffice. Estos ficheros se guardan en formato nombrado OASIS, form...

  5. Especificació i disseny d'una aplicació pel ZOO de Barcelona

    OpenAIRE

    Àngel Torras, Marta

    2016-01-01

    Aquest TFG es basa en el disseny i l'especificació d'una aplicació pel Zoo de Barcelona. Es tracta d'una app enfocada a millorar la visita al parc, oferint funcionalitats i informació que permetin a l'usuari gaudir més de la visita al Zoo de Barcelona. This TFG is based on design and especification of an app for Barcelona Zoo. It aims to enhance the visitor's experience, by offering functionality and wider information so that the visit to the Zoo may be better appreciated by anyone using t...

  6. Propiedades ferroeléctricas de películas delgadas de GeSbTe

    OpenAIRE

    J.J. Gervacio Arciniega; E. Prokhorov; F. J. Espinoza Beltrán

    2011-01-01

    El objetivo de este trabajo es investigar y comparar las propiedades ferroeléctricas de películas delgadas de Ge4Sb1Te5 (con propiedades ferroeléctricas bien definidas) y Ge2Sb2Te5 usando técnicas de impedancia, reflexión óptica, XRD, DSC y de microscopia de fuerza por piezorrespuesta. La dependencia de la capacitancia con la temperatura en ambos materiales muestra un cambio abrupto a la temperatura que corresponde a la transición ferroeléctrico-paraeléctrico y la dependencia tipo Curie-Weiss...

  7. "Los chicos arman su película" : Memoria de un relato

    OpenAIRE

    Espora, Evangelina

    2008-01-01

    Durante algunos meses de 2006 y 2007 hemos llevado adelante el proyecto “Los chicos arman su película” aprobado en 2005, con el fin de restituir los derechos a grupos de pibes de comunidades vulnerables.1 Se propone favorecer la integración a través de la acción comunitaria e institucional; fortalecer, mediante el abordaje grupal e interdisciplinario, la participación efectiva de los habitantes para que la restitución de esos derechos se dé en forma activa. A lo largo de todos estos meses, nu...

  8. Machinima un medio híbrido: películas animadas usando videojuegos

    OpenAIRE

    Cedeño Montaña, Ricardo

    2010-01-01

    Este articulo explora un medio digital híbrido que resulta de la mezcla entre jugar videojuegos y producir películas animadas. Machinima surge en la década de 1990 cuando fanáticos de los videojuegos descubren que con los editores de los videojuegos es posible producir secuencias animadas; su práctica consistía en grabar las sesiones de juego para hacer cortos narrativos. En este texto me propongo presentar varias descripciones de machinima que permitan la apreciación de este como un medio h...

  9. Fertilidad y prolificidad en cerdas Pelón Mexicano y blancas mejoradas tratadas con gonadotropinas

    OpenAIRE

    Santos Aguilar Torres; Eunice E. Ramírez Acosta; Danilo Méndez Medina; Rafael Olea Pérez; VJM Berruecos; Jorge Lopez; Alejandro Córdova Izquierdo

    2005-01-01

    Para la determinación de la fertilidad y prolificidad se utilizó un grupo de cerdas Pelón Mexicano (CPM) y un grupo de cerdas blancas mejoradas (CBM) estas fueron tratadas con gonadotropinas para valorar el efecto sobre la fertilidad y prolificidad. Se registro: tamaño de camada (TC), peso de la camada (PC), peso individual de los lechones (PIL), lechones nacidos totales vivos (LNTV), lechones nacidos muertos (LNM), lechones nacidos momificados (LNMm) y sexo. Las cerdas fueron inseminadas art...

  10. Subtype C1 persistent infection of HHV-8 in a PEL patient.

    Science.gov (United States)

    Metaxa-Mariatou, V; Papaioannou, D; Loli, A; Papadopoulou, I; Gazouli, M; Mavroudis, P; Nasioulas, G

    2005-10-01

    PEL, a rare type of lymphoma constituting less than 5% of NHLs, has been recently identified as a distinct clinical and pathological entity among the B-cell lymphomas, with characteristic morphologic, immunophenotypic, molecular and viral features. ICC, PCR, RT-PCR and sequencing were carried out in biologicals samples from a 44-year-old, non-smoker Caucasian male patient of Greek nationality, HIV-1 negative and HCV positive. The ICC results showed CD30 + , Vimentin + , EMA + , Ki67 + , Pankeratin- and negative to B and T antibodies. In addition, HHV-8 was detected in pleural fluid. Examination of blood samples of the patient over a period of nearly two years showed a persistent infection of HHV-8. Phylogenetic analysis revealed a close relation to the C1 variant of HHV-8. The samples was also found EBV negative by PCR. Using a combination of clinical, morphological, immunohistochemical features and molecular biology techniques in this study we document a PEL case with persistent HHV-8 of genotype C1 infection. PMID:16194897

  11. Películas de ZnO piezoeléctricas depositadas por Spray Pirolisis US

    OpenAIRE

    Salvador Alcántara I.; B. Susana Soto C.; L. Antonio Ortega J.; Ruth L. Cabañas T.; S. Jesús Pérez R.; Gregorio Flores C.

    2008-01-01

    El depósito de películas de ZnO con Spray Pirolisis es de mucho interés por la cantidad de aplicaciones de este material y por la simplicidad de la técnica mencionada. El uso del humidificador ultrasónico en lugar del spray neumático, permite obtener películas con mayor control y calidad. A las películas de ZnO obtenidas con esta técnica se les encontró efecto piezoeléctrico; en este trabajo se describe la técnica del depósito, la forma en que se compruebo el efecto piezoeléctrico y se presen...

  12. Radiation processing of polysaccharides

    International Nuclear Information System (INIS)

    Radiation processing is a very convenient tool for imparting desirable effects in polymeric materials and it has been an area of enormous interest in the last few decades. The success of radiation technology for processing of synthetic polymers can be attributed to two reasons namely, their ease of processing in various shapes and sizes, and secondly, most of these polymers undergo crosslinking reaction upon exposure to radiation. In recent years, natural polymers are being looked at with renewed interest because of their unique characteristics, such as inherent biocompatibility, biodegradability and easy availability. Traditionally, the commercial exploitation of natural polymers like carrageenans, alginates or starch etc. has been based, to a large extent, on empirical knowledge. But now, the applications of natural polymers are being sought in knowledge - demanding areas such as pharmacy and biotechnology, which is acting as a locomotive for further scientific research in their structure-function relationship. Selected success stories concerning radiation processed natural polymers and application of their derivatives in the health care products industries and agriculture are reported. This publication will be of interest to individuals at nuclear institutions worldwide that have programmes of R and D and applications in radiation processing technologies. New developments in radiation processing of polymers and other natural raw materials give insight into converting them into useful products for every day life, human health and environmental remediation. The book will also be of interest to other field specialists, readers including managers and decision makers in industry (health care, food and agriculture) helping them to understand the important role of radiation processing technology in polysaccharides

  13. Fungal enzyme sets for plant polysaccharide degradation

    OpenAIRE

    van den Brink, Joost; de Vries, Ronald P

    2011-01-01

    Enzymatic degradation of plant polysaccharides has many industrial applications, such as within the paper, food, and feed industry and for sustainable production of fuels and chemicals. Cellulose, hemicelluloses, and pectins are the main components of plant cell wall polysaccharides. These polysaccharides are often tightly packed, contain many different sugar residues, and are branched with a diversity of structures. To enable efficient degradation of these polysaccharides, fungi produce an e...

  14. ¿Esto no es una película? Jafar Panahi o la necesidad del cine

    OpenAIRE

    Broullón Lozano, Manuel Antonio

    2013-01-01

    Desde el grito desesperado de un cineasta arrestado y suspendido del ejercicio de su profesión, Esto NO es una película (Jafar Panahi, 2011), plantea una profunda y seria reflexión en torno a dos puntos fundamentales de la teoría digital del cine. En primer lugar, porque a pesar de las condiciones de carencia y privación en el momento del rodaje del film, la disponibilidad de una tecnología digital instalada en el espacio doméstico le permite culminar dicha película, aunque sea desde la cland...

  15. Sucrose release from polysaccharide gels.

    Science.gov (United States)

    Nishinari, Katsuyoshi; Fang, Yapeng

    2016-05-18

    Sucrose release from polysaccharide gels has been studied extensively because it is expected to be useful in understanding flavour release from solid foods and to find a new processing method which produces more palatable and healthier foods. We provide an overview of the release of sucrose and other sugars from gels of agar and related polysaccharides. The addition of sucrose to agar solutions leads to the increase in transparency of the resulting gels and the decrease in syneresis, which is attributed to the decrease in mesh size in gels. The syneresis occurring in the quiescent condition and fluid release induced by compression is discussed. The relationship between the sugar release and the structural, rheological and thermal properties of gels is also discussed. Finally, the future research direction is proposed. PMID:26952168

  16. Radiochemistry and radiopolymerization of polysaccharides

    International Nuclear Information System (INIS)

    The effects of gamma radiation on dry state polysaccharides (example: starch) are presented in an overall manner by order of quantitative importance: recombination of radicals to recover the initial macromolecule (cage effect) or smaller molecules which are chemically identical (radiopolymerization) and evolution of radicals to give secondary reactions (formation of radiolysis products). The effect of the botanical origin of the starch studied is briefly discussed, applications and extensions to the case of radiochemically induced modifications to foodstuffs being envisaged

  17. Polysaccharide-Based Micelles for Drug Delivery

    Directory of Open Access Journals (Sweden)

    Nan Zhang

    2013-05-01

    Full Text Available Delivery of hydrophobic molecules and proteins has been an issue due to poor bioavailability following administration. Thus, micelle carrier systems are being investigated to improve drug solubility and stability. Due to problems with toxicity and immunogenicity, natural polysaccharides are being explored as substitutes for synthetic polymers in the development of new micelle systems. By grafting hydrophobic moieties to the polysaccharide backbone, self-assembled micelles can be readily formed in aqueous solution. Many polysaccharides also possess inherent bioactivity that can facilitate mucoadhesion, enhanced targeting of specific tissues, and a reduction in the inflammatory response. Furthermore, the hydrophilic nature of some polysaccharides can be exploited to enhance circulatory stability. This review will highlight the advantages of polysaccharide use in the development of drug delivery systems and will provide an overview of the polysaccharide-based micelles that have been developed to date.

  18. Estudio de la conservación de la papaya (Carica papaya L.) asociado a la aplicación de películas comestibles

    OpenAIRE

    Alessandra Almeida Castro; Jane Delane Reis Pimentel; Danilo Santos Souza; Thaciana Vieira de Oliveira; Mariana da Costa Oliveira

    2011-01-01

    Brasil es un importante productor de papaya, pero sólo una pequeña parte se exporta. Esta fruta es altamente perecedera, por lo que el control de la maduración es esencial para aumentar la vida útil, tanto para el mercado interno como para la exportación. Una alternativa que ha cobrado impulso en el mercado es el uso de películas comestibles biodegradables, entre ellas la película producida a partir de almidón de yuca. En este estudio se evaluó el efecto de una película de almidón de yuca ...

  19. Películas nanoestructuras de PS-b-P4VP con ácido fórmico

    OpenAIRE

    Losada Ambrinos, Raquel

    2015-01-01

    Este trabajo trata de conseguir la mayor variedad de morfologías sobre películas de Si usando como copolímero el PS-b-P4VP y como molécula huésped el ácido fórmico, todo ello modificando diferentes aspectos como la proporción HCOOH/py, la concentración de la disolución del copolímero o la aceleración usada en el spinner. Después de realizar un estudio exhaustivo de todas las películas obtenidas, se cree que se han detectado las morfologías intermedias del proceso d...

  20. Alginato de sodio en el desarrollo de películas comestibles

    Directory of Open Access Journals (Sweden)

    Daniel Alexander Méndez Reyes

    2014-12-01

    Full Text Available Alginato, es un término que se refiere a un grupo de polisacáridos presentes en las algas pardas, los cuales cuentan con una importancia especial para diferentes industrias (alimentaria, textil, farmacéutica, cosmética, entre otras, atribuida a su capacidad para formar geles fuertes en presencia de cationes calcio (Ca+2. El alginato de sodio es la forma más comercializada de alginato y sus aplicaciones en la industria alimentaria hoy en día están generando avances en el desarrollo de nuevos e innovadores biomateriales con características únicas, tales como, propiedades de barrera contra la pérdida de humedad causada por la deshidratación en alimentos de alto contenido de humedad, soporte para el transporte de compuestos antimicrobianos y probioticos entre otros, para mantener la calidad de productos alimentarios en almacenamiento. En este trabajo se recopiló información referente a la incidencia de diferentes polímeros, biocompuestos, aditivos y del proceso de gelificación en la producción de películas comestibles destinadas a la ingeniería del empaque.

  1. Thermal studies on natural polysaccharide

    Institute of Scientific and Technical Information of China (English)

    Sunil B Bothara; Sudarshan Singh

    2012-01-01

    Objective: To characterize thermal property of natural gums obtained from the seeds of Diospyros melonoxylon(D. melonoxylon) Roxb, Buchanania lanzan (B. lanzan) spreng and Manilkara zapota (M. zapota) (Linn.) P. Royen syn. Methods: Natural gums were thermally characterized using differential scanning calorimetry (DSC), differential thermal analysis (DTA) and thermo-gravimetric analysis (TGA) under nitrogen atmosphere. Major thermal transitions as well as activation energies of the major decomposition stages were determined. Elemental analysis was performed in order to determine the composition of carbon, hydrogen, nitrogen and sulfur. Results: DSC traces indicated a major intense exothermic transition (around 200℃) followed by weaker exotherm(s). Thermogravimetric analysis showed two phase of weight loss. The first phase has minor weight loss in samples is attributed to the loss of adsorbed and structural water of biopolymers or due to desorption of moisture as hydrogen bound water to the saccharide structure. The second weight loss event may be attributed to the polysaccharide decomposition. The initial decomposition temperature (IDT) was calculated from thermograms obtained of TGA, seed Polysaccharide of D. melonoxylon (IDT 221.21℃), B. lanzan (IPDT 170.4℃) and M. zapota (IPDT 178.6℃) were obtained. According to the integral procedural decomposition temperature (IPDT) values calculated based on the TGA thermograms; D. melonoxylon (IPDT 563.3℃), B. lanzan (IPDT 598.1℃) and M. zapota (IPDT 600.6℃) were obtained respectively. The elemental analysis study shows that the isolated natural Polysaccharides consist of certain percentage of carbon, nitrogen, sulphur and hydrogen in all the gums. Conclusions: The results of the present investigation reveal that the natural gums are thermally stable and these gums can be used as release modifiers in various dosage forms.

  2. Starch-degrading polysaccharide monooxygenases.

    Science.gov (United States)

    Vu, Van V; Marletta, Michael A

    2016-07-01

    Polysaccharide degradation by hydrolytic enzymes glycoside hydrolases (GHs) is well known. More recently, polysaccharide monooxygenases (PMOs, also known as lytic PMOs or LPMOs) were found to oxidatively degrade various polysaccharides via a copper-dependent hydroxylation. PMOs were previously thought to be either GHs or carbohydrate binding modules (CBMs), and have been re-classified in carbohydrate active enzymes (CAZY) database as auxiliary activity (AA) families. These enzymes include cellulose-active fungal PMOs (AA9, formerly GH61), chitin- and cellulose-active bacterial PMOs (AA10, formerly CBM33), and chitin-active fungal PMOs (AA11). These PMOs significantly boost the activity of GHs under industrially relevant conditions, and thus have great potential in the biomass-based biofuel industry. PMOs that act on starch are the latest PMOs discovered (AA13), which has expanded our perspectives in PMOs studies and starch degradation. Starch-active PMOs have many common structural features and biochemical properties of the PMO superfamily, yet differ from other PMO families in several important aspects. These differences likely correlate, at least in part, to the differences in primary and higher order structures of starch and cellulose, and chitin. In this review we will discuss the discovery, structural features, biochemical and biophysical properties, and possible biological functions of starch-active PMOs, as well as their potential application in the biofuel, food, and other starch-based industries. Important questions regarding various aspects of starch-active PMOs and possible economical driving force for their future studies will also be highlighted. PMID:27170366

  3. Pharmacological Action of Adenophora Polysaccharides

    Institute of Scientific and Technical Information of China (English)

    李泱; 李春红; 唐富天; 李新芳

    2004-01-01

    Adenophora polysaccharides (AP), is an active principle extracted from the root of Adenophorae Potaninii Korsh originated in Gansu Province and isolated with boiling water. AP is isolated and purified from the crude drug by DEAE-cellulose and Sephadex G-200 column, with a white powder and mean molecular weight of 8.3×104 , and [α]D20 of AP is + 68. AP is only composed of glucose judging from the analysis of it with patina chromatography (PC) and gas chromatography-mass spectrometer (GC-MS) methods.

  4. Bioactive polysaccharides and gut microbiome (abstract)

    Science.gov (United States)

    Many polysaccharides have shown the ability to reduce plasma cholesterol or postprandial glycemia. Viscosity in the small intestine seems to be required to slow glucose uptake. Cereal mixed linkage beta-glucans, psyllium, glucomannans, and other polysaccharides also seem to require higher molecula...

  5. Estudio del efecto de una película antimicrobiana en la vida útil del queso Costeño

    Directory of Open Access Journals (Sweden)

    Margarita Rosa Arteaga Márquez

    2015-09-01

    Full Text Available Se estudió el efecto de una película antimicrobiana en la vida útil del queso Costeño elaborado a diferentes concentraciones de cloruro de sodio (2,5 % p/p sin cubrimiento de película; 2,5 y 3,0 % p/p cubierto con película antimicrobiana, almacenado (0, 5, 10, 15, 20, 25 y 30 días a temperaturas de 12 ± 1 ºC y 28 ± 2 ºC. El principio activo fue nisina (16 mg/100 mL de solución. Se realizaron análisis químicos (pH, acidez titulable, materia grasa y humedad, microbiológicos (recuentos de coliformes, Escherichia coli, Staphylococcus aureus coagulasa positiva, detección de Salmonella y recuento de mohos y levaduras y sensoriales (pruebas de ordenación por atributos y de escala hedónica. Los resultados mostraron que para los quesos almacenados a 12 ± 1 ºC, no hubo diferencias estadísticas significativas en el comportamiento del pH, y para la acidez se encontraron diferencias estadísticas significativas los días 15, 20, 25 y 30. Respecto al contenido de cloruro de sodio se obtuvo mayor pérdida de humedad y aumento en el contenido de materia grasa con diferencias estadísticas significativas los días 30 y 5 para los quesos almacenados a 12 ± 1 ºC y 28 ± 2 ºC, respectivamente. La temperatura a 12 ± 1 ºC fue el factor más influyente en la conservación del queso. Los tratamientos con cubrimiento de película fueron aceptados sensorialmente durante los 30 días de estudio y hubo diferencia respecto al sabor los días 20 al 30. El tratamiento control presentó crecimiento visible de mohos y levaduras el día 15. La película antimicrobiana ejerció un efecto inhibitorio sobre Staphyloccocus aureus coagulasa positiva en los quesos.

  6. Two dimensional NMR studies of polysaccharides

    International Nuclear Information System (INIS)

    Polysaccharides are very important components in the immune response system. Capsular polysaccharides and lipopolysaccharides occupy cell surface sites of bacteria, play key roles in recognition and some have been used to develop vaccines. Consequently, the ability to determine chemical structures of these systems is vital to an understanding of their immunogenic action. The authors have been utilizing recently developed two-dimensional homonuclear and heteronuclear correlation spectroscopy for unambiguous assignment and structure determination of a number of polysaccharides. In particular, the 1H-detected heteronuclear correlation experiments are essential to the rapid and sensitive determination of these structures. Linkage sites are determined by independent polarization transfer experiments and multiple quantum correlation experiments. These methods permit the complete structure determination on very small amounts of the polysaccharides. They present the results of a number of structural determinations and discuss the limits of these experiments in terms of their applications to polysaccharides

  7. Autoridades invisibles y autorizaciones visibles en la película argentina Rompecabezas de Natalia Smirnoff

    Directory of Open Access Journals (Sweden)

    Mullaly, Laurence H.

    2013-06-01

    Full Text Available In the Argentinian cinema of the end of the 90’s and beginning of the 21st century, the representations of femininity and masculinity have become richer thanks to alternative visions, most frequently proposed by female directors. Natalia Smirnoff’s film Rompecabezas (Puzzle is a perfect example. It tells the story of an ordinary woman whose psychosexual awakening shakes up the invisible forces that had dictated her life up to that point. Rompecabezas explores the everlasting effect and influence on the patriarchal structures in constructing identity. The aim of this work, rooted in a gender perspective, is to study in what way both hierarchy and symbolic systems operate and to what extent Natalia Smirnoff provides us with a powerful (revision of transformation for women.En el cine argentino de finales de los años 90 y principios del siglo actual, las representaciones de la feminidad y la masculinidad se están enriqueciendo gracias a las visiones alternativas que nos ofrecen en su mayoría directoras. La película de Natalia Smirnoff, que se centra en la trayectoria de una mujer ordinaria cuyo despertar psicosexual choca con las autoridades invisibles que hasta ahora regían su vida, da testimonio de ello. Rompecabezas (Puzzle explora la permanencia y la influencia de las estructuras patriarcales en la construcción de las identidades. A partir de una perspectiva de género, el presente trabajo pretende analizar de qué manera opera el conjunto de las jerarquías y de los sistemas simbólicos y en qué medida Natalia Smirnoff nos proporciona una (revisión transformadora de las mujeres.

  8. An exocellular polysaccharide and its interactions with proteins

    NARCIS (Netherlands)

    Tuinier, R.

    1999-01-01

    In the food industry polysaccharides are used as thickening or gelling agents. Polysaccharides are usually extracted from plants. Micro-organisms are also capable of excreting polysaccharides: exocellular polysaccharides (EPSs). In some cases EPSs are produced in-situ in food products, notably in ac

  9. Rheology of interfacial protein-polysaccharide composites

    Science.gov (United States)

    Fischer, P.

    2013-05-01

    The morphology and mechanical properties of protein adsorption layers can significantly be altered by the presence of surfactants, lipids, particles, other proteins, and polysaccharides. In food emulsions, polysaccharides are primarily considered as bulk thickener but can under appropriate environmental conditions stabilize or destabilize the protein adsorption layer and, thus, the entire emulsion system. Despite their ubiquitous usage as stabilization agent, relatively few investigations focus on the interfacial rheology of composite protein/polysaccharide adsorption layers. The manuscript provides a brief review on both main stabilization mechanisms, thermodynamic phase separation and electrostatic interaction and discusses the rheological response in light of the environmental conditions such as ionic strength and pH.

  10. Radiation processing of polysaccharides for agriculture

    International Nuclear Information System (INIS)

    Radiation of polysaccharides generates various types of degraded fragments by random scission. Polysaccharides can be easily degraded both in powder foam and solution. The radiation degraded polysaccharides induce various kinds of biological activities such as anti-microbial activity, promotion of plant growth, suppression of environmental stress, phytoalexins induction and can be applied not only in agriculture but also in medical fields. In this paper, the biological activities induced by radiation of chitosan, alginate, carrageenan, cellulose and pectin are reviewed for the agricultural use. (author)

  11. Polysaccharides: The “Click” Chemistry Impact

    Directory of Open Access Journals (Sweden)

    Romain Lucas

    2011-09-01

    Full Text Available Polysaccharides are complex but essential compounds utilized in many areas such as biomaterials, drug delivery, cosmetics, food chemistry or renewable energy. Modifications and functionalizations of such polymers are often necessary to achieve molecular structures of interest. In this area, the emergence of the “click” chemistry concept, and particularly the copper-catalyzed version of the Huisgen 1,3-dipolar cycloaddition reaction between terminal acetylenes and azides, had an impact on the polysaccharides chemistry. The present review summarizes the contribution of “click” chemistry in the world of polysaccharides.

  12. An exocellular polysaccharide and its interactions with proteins

    OpenAIRE

    Tuinier, R.

    1999-01-01

    In the food industry polysaccharides are used as thickening or gelling agents. Polysaccharides are usually extracted from plants. Micro-organisms are also capable of excreting polysaccharides: exocellular polysaccharides (EPSs). In some cases EPSs are produced in-situ in food products, notably in acidified milk products. These EPSs function effectively as food thickeners but do not need to be declared in the food label.Systematic physical analysis of an exocellular polysaccharide produced by ...

  13. Evaluation of Phosphorylated Psyllium Seed Polysaccharide as a Release Retardant

    OpenAIRE

    Rao, Monica R. P.; Warrier, Deepa U.; Shivani H. Rao

    2015-01-01

    The aim of the present study was to modify psyllium seed polysaccharide and evaluate the modified polysaccharide as release retardant in tablets employing ciprofloxacin hydrochloride as model drug. Studies on polysaccharide from psyllium husk has been reported but no work has been reported on characterization and modification of the polysaccharide present in the psyllium (Plantago ovata) seed and the use of the modified polysaccharide as a release retardant in tablets. In this study, the seed...

  14. Polysaccharide of the slime glycolipoprotein of Pseudomonas aeruginosa.

    OpenAIRE

    Koepp, L H; Orr, T.; Bartell, P F

    1981-01-01

    The polysaccharide moiety was isolated by mild acid hydrolysis from the slime glycolipoprotein of Pseudomonas aeruginosa strain BI. After gel filtration, the polysaccharide obtained from the Carbohydrate peak fractions was found to be lipid- and protein-free. Analyses indicated that the polysaccharide contained the carbohydrate components of the parent glycolipoprotein. Molecular size of the polysaccharide was estimated by gel filtration as 70,000 to 100,000. The polysaccharide showed no indi...

  15. ¿Nuestro destino está escrito en los genes? : Una mirada desde la película Gattaca

    OpenAIRE

    Paula Sibilia

    2006-01-01

    Este artículo analiza algunas ideas, imágenes y creencias relacionadas con las nuevas "ciencias de la vida", y cuestiona su influencia en las redefiniciones de la condición humana, la salud y la enfermedad que están actualmente en curso en nuestra cultura, a partir de las reflexiones suscitadas por la película Gattaca. Los abusos del "determinismo genético" constituyen el eje central de esa discusión, aliados a una serie de metáforas informáticas y digitales que emanan cada vez con más fuerza...

  16. Traducir el cine, traducir el dialecto: estudio lingüístico de la película Romanzo Criminale

    OpenAIRE

    Mantaro, Chiara

    2010-01-01

    El presente artículo se basa en el análisis de cuatro escenas de la película italiana Romanzo criminale, dirigida por Michele Placido en 2005. El objeto principal de nuestro estudio es la traducción de la variación lingüística en el doblaje español, centrándonos sobre todo en el tratamiento del dialecto, aunque se describan y analicen todas las variedades encontradas en el texto.

  17. Prototipus pel seguiment automàtic d'intrusos guiat per càmera fixa

    OpenAIRE

    Herrera Marí, Josep Oriol

    2014-01-01

    En aquest treball es desenvolupa el programari pel seguiment d'intrusos amb càmera motoritzada (PTZ), d'acord amb un producte comercial de detecció d'intrusos amb càmera fixa. L'aplicació en C++ combina mètodes de la llibreria OpenCv per obtenir l'homografia entre les imatges. L'aplicació detecta punts clau, extrau descriptors, genera correspondència de punts, tria punts claus (desenvolupats per aquest treball) i finalment calcula l'homografia que trasllada coordenades de l'imatge a coordenad...

  18. Extraction Optimization of Polysaccharides from Pitaya Stems

    Institute of Scientific and Technical Information of China (English)

    HE Cong-fen; LI Peng; ZHAO Hua; SONG Li-ya; ZHU Jun; DONG Yin-mao

    2011-01-01

    [Objective] The aim was to describe the extraction of polysaccharides from pitaya stems.[Method] The hot water,enzyme-assisted and microwave-assisted methods were used,with the microwave-assisted extraction being deemed optimal by general evaluation.[Result] The main factors affecting the yield of polysaccharides in the microwave-assisted extraction,by order of magnitude,were as follows:timemicrowave powertemperature;additionally,optimal conditions included a 10 min extraction time,an 80 ℃ extraction temperature and a microwave setting of 200 W.Using these optimal conditions,the yield of PSPS(Polysaccharides from Pitaya Stems) was 1.42%.After purification,the yield of PSPS was 0.74%.[Conclusion] The PSPS was analyzed by IR,MALDI-TOF-MS and an element analysis technique.It was shown to be a polysaccharide mixture,and the molecular weight was between 3 900 and 4 300 Da.

  19. Biochemical Aspects of Non-Starch Polysaccharides

    Directory of Open Access Journals (Sweden)

    Rodica Căpriţă

    2010-05-01

    Full Text Available Polysaccharides are macromolecules of monosaccharides linked by glycosidic bonds. Non-starch polysaccharides (NSP are principally non-α-glucan polysaccharides of the plant cell wall. They are a heterogeneous group of polysaccharides with varying degrees of water solubility, size, and structure. The water insoluble fiber fraction include cellulose, galactomannans, xylans, xyloglucans, and lignin, while the water-soluble fibers are the pectins, arabinogalactans, arabinoxylans, and β-(1,3(1,4-D-glucans (β-glucans. Knowledge of the chemical structure of NSP has permitted the development of enzyme technology to overcome their antinutritional effects. The physiological effects of NSP on the digestion and absorption of nutrients in human and monogastric animals have been attributed to their physicochemical properties: hydration properties, viscosity, cation exchange capacity and organic compound absorptive properties. This paper reviews and presents information on NSPs chemistry, physicochemical properties and physiological effects on the nutrient entrapment.

  20. Role of the LysR-type transcriptional regulator PecT and DNA supercoiling in the thermoregulation of pel genes, the major virulence factors in Dickeya dadantii.

    Science.gov (United States)

    Hérault, Elodie; Reverchon, Sylvie; Nasser, William

    2014-03-01

    Bacteria are colonizers of various environments and host organisms, and they are often subjected to drastic temperature variations. Dickeya dadantii is a pathogen infecting a wide range of plant species. Soft rot, the visible symptom, is mainly due to the production of pectate lyases (Pels) that destroy plant cell walls. The production of Pels is controlled by a complex regulation system that responds to various stimuli, such as the presence of pectin, growth phase and temperature. Despite numerous regulatory studies, the thermoregulation mechanism of Pel production remains unexplained. Here, we show that PecT, a previously identified repressor, modulates pel gene expression in a temperature-dependent manner, and we demonstrate that PecT binding on pel promoters increases concomitantly with temperature. High temperatures relax the DNA in D. dadantii, and remarkably, artificial relaxation of DNA at low temperatures increases PecT binding to DNA. Deletion of pecT augmented the capacity of D. dadantii to initiate soft-rot symptoms at high temperatures. These results reveal that DNA topology and PecT act in concert to fine-tune D. dadantii virulence in response to temperature. This novel combination between DNA topology and a conventional transcriptional regulator extends our understanding of the thermoregulation mechanisms involved in bacterial virulence. PMID:23869858

  1. Cómo hacer cine hoy en Cuba: prostitución y coproducción en “La película de Ana”

    Directory of Open Access Journals (Sweden)

    Karen Genschow

    2016-03-01

    Full Text Available La película de Ana de Daniel Díaz Torres (2012 trata en primer lugar del jineterismo en Cuba, fenómeno que ha determinado ampliamente el contacto entre extranjeros y cubanos desde la apertura al turismo en masas. En la película esto conlleva una reflexión de las relaciones visuales tanto en términos de género como en términos postcoloniales. Mediante la construcción de una película intradiegética ("la película de Ana" se cuestiona la diferencia entre "autenticidad" y puesta en escena y se sugiere, además, que Cuba entera se ha convertido en una especie de "zona de contacto", donde entran en contacto la lógica capitalista y la nostalgia postsoviética y donde lo "auténticamente" cubano aparece como un espectáculo montado para los extranjeros. Al mismo tiempo la película articula una autorreflexión en el sentido de que estas relaciones de poder se evidencian también en las posibilidades de hacer cine hoy en Cuba, que abarcan esencialmente la coproducción con diferentes países europeos.

  2. Candida albicans ethanol stimulates Pseudomonas aeruginosa WspR-controlled biofilm formation as part of a cyclic relationship involving phenazines.

    Directory of Open Access Journals (Sweden)

    Annie I Chen

    2014-10-01

    Full Text Available In chronic infections, pathogens are often in the presence of other microbial species. For example, Pseudomonas aeruginosa is a common and detrimental lung pathogen in individuals with cystic fibrosis (CF and co-infections with Candida albicans are common. Here, we show that P. aeruginosa biofilm formation and phenazine production were strongly influenced by ethanol produced by the fungus C. albicans. Ethanol stimulated phenotypes that are indicative of increased levels of cyclic-di-GMP (c-di-GMP, and levels of c-di-GMP were 2-fold higher in the presence of ethanol. Through a genetic screen, we found that the diguanylate cyclase WspR was required for ethanol stimulation of c-di-GMP. Multiple lines of evidence indicate that ethanol stimulates WspR signaling through its cognate sensor WspA, and promotes WspR-dependent activation of Pel exopolysaccharide production, which contributes to biofilm maturation. We also found that ethanol stimulation of WspR promoted P. aeruginosa colonization of CF airway epithelial cells. P. aeruginosa production of phenazines occurs both in the CF lung and in culture, and phenazines enhance ethanol production by C. albicans. Using a C. albicans adh1/adh1 mutant with decreased ethanol production, we found that fungal ethanol strongly altered the spectrum of P. aeruginosa phenazines in favor of those that are most effective against fungi. Thus, a feedback cycle comprised of ethanol and phenazines drives this polymicrobial interaction, and these relationships may provide insight into why co-infection with both P. aeruginosa and C. albicans has been associated with worse outcomes in cystic fibrosis.

  3. Remodeling bacterial polysaccharides by metabolic pathway engineering

    OpenAIRE

    Yi, Wen; Liu, Xianwei; Li, Yanhong; Li, Jianjun; Xia, Chengfeng; Zhou, Guangyan; Zhang, Wenpeng; Zhao, Wei; Chen, Xi; Wang, Peng George

    2009-01-01

    Introducing structural modifications into biomolecules represents a powerful approach to dissect their functions and roles in biological processes. Bacterial polysaccharides, despite their rich structural information and essential roles in bacterium-host interactions and bacterial virulence, have largely been unexplored for in vivo structural modifications. In this study, we demonstrate the incorporation of a panel of monosaccharide analogs into bacterial polysaccharides in a highly homogenou...

  4. Influence of polysaccharides on cement hydration

    OpenAIRE

    Peschard, Arnaud; Govin, Alexandre; Fredon, Emmanuel; Grosseau, Philippe; Fantozzi, Gilles

    2004-01-01

    This paper is about the influence of polysaccharides on cement hydration. Three polysaccharides were studied: a cellulose ether (CE), a starch ether (SE) and a dextrin (YD). In a concentrated media as well as in a dilute media, admixture CE only revealed a slight effect on cement hydration. Portlandite and ettringite formation and gypsum consumption were slowed down by SE adjunction. Admixture YD induced an acceleration of ettringite formation as well as gypsum consumption whereas portiandite...

  5. Caracterización eléctrica de películas delgadas de WO3 depositadas por sputtering no reactivo

    OpenAIRE

    Riech, I.; Acosta, M; E. Flores-Cuevas; V. Rejón-Moo

    2012-01-01

    Se depositaron películas delgadas de trióxido de tungsteno sobre vidrio por la técnica de erosión catódica, variando la presión de trabajo, PAr, desde 20 hasta 80 mTorr. La morfología superficial de las películas preparadas resultó ser muy similar independientemente de la presión de trabajo utilizada. La resistividad eléctrica fue investigada en función de la temperatura en el rango de 300 - 675 K. La película delgada depositada a 20 mTorr mostró un valor de resistividad menor que las otras p...

  6. Caracterización de películas gafchromic EBT2 para uso en dosimetría del cyberknife

    OpenAIRE

    Maya Patiño, Luz Adriana

    2014-01-01

    Se realizó un análisis de los diversos factores que influyen en el proceso de calibración de las películas radiocrómicas como sistema dosimétrico. Con base en estos resultados, se definió un protocolo de calibración para dosimetría del CyberKnife del INDEC, con películas radiocrómicas Gafchromic EBT2 y se halló la curva de calibración dosis vs densidad óptica. Una vez establecida la curva de calibración, se analizaron las películas irradiadas del control de calidad del tratamiento de tres ...

  7. Biochemical characteristics of an alkaline pectate lyase PelA from Volvariella volvacea: roles of the highly conserved N-glycosylation site in its secretion and activity.

    Science.gov (United States)

    Shi, Aiqin; Hu, Hang; Zheng, Fei; Long, Liangkun; Ding, Shaojun

    2015-04-01

    Alkaline pectate lyases have great application potential in the bioscouring of textiles. They are isolated predominantly from bacteria and a few fungi. Here, we report the biochemical characteristics of a novel alkaline pectate lyase PelA from the basidiomycete Volvariella volvacea. The full-length pelA encodes a 321-amino-acid polypeptide containing a putative 18-residue signal peptide and a pectate lyase family 1 catalytic domain. It contains one conserved and one non-conserved potential N-glycosylation site (N-X-S/T) at the residues N95 and N198, respectively. The enzyme showed optimal activity at 60 °C and pH 10, although it was stable between pH 4 and pH 11. Additional Ca(2+) was not required to measure PelA activity in vitro, but it could significantly enhance its activity and thermal stability. The V max values using polygalacturonic acid as substrate were increased from 50.71 to 89.96 IU mg(-1) by the addition of 0.1 mM Ca(2+), whereas the K m values were decreased from 0.681 to 0.514 mg ml(-1). Site-directed mutagenesis revealed PelA has only one N-glycan attached to the residue N95. This N-glycan is crucial to its efficient secretion and activity possibly due to its role in maintaining the secondary structure of PelA. Amino acid substitution at the residue N198 had no effect on PelA secretion, but resulted in a slight (5.16 %) to modest (27.37 %) decrease in specific activity and less thermal stability, indicating the amino acid itself is also important for activity due to it being highly conserved and because of its proximity to the catalytic site. PMID:25341402

  8. Viscoelastic properties of levan polysaccharides

    Science.gov (United States)

    Noll, Kenneth; Rende, Deniz; Ozisik, Rahmi; Toksoy-Oner, Ebru

    2014-03-01

    Levan is a naturally occurring polysaccharide that is composed of β-D-fructofuranose units with β(2-6) linkages between fructose rings. It is synthesized by the action of a secreted levansucrase (EC 2.4.1.10) that converts sucrose into the levan externally (exopolysaccharide). Levan is a homopolysaccharide that is non-toxic, water soluble,, and has anti-tumor activity and low immunological response. Therefore, levan presents great potential to be used as a novel functional biopolymer in foods, feeds, cosmetics, pharmaceutical and chemical industries. Despite these favorable properties, levan has a moderately low mechanical properties and poor film forming capability. In the current study, the agglomeration behavior of levan in water and in saline solutions was investigated at 298 and 310 K by dynamic light scattering and transmission electron microscopy (TEM). The viscoelastic properties of neat and oxidized levan films were studied via nanoindentation experiments in the quasi-static and dynamic modes The material is partially based upon work supported by NSF under Grant Nos. 1200270 and 1003574, and TUBITAK 111M232.

  9. El cine como recurso para el conocimiento de las personas con discapacidad: Veinticinco películas de la última década

    OpenAIRE

    Monjas Casares, María Inés; Arranz Moro, Francisco

    2010-01-01

    [ES] Es indudable el poder del cine para transmitir informaciones, para provocar emociones y para estimular la empatía con los personajes y sus situaciones. Por ese motivo se propone la utilización de películas con protagonistas con discapacidad para favorecer la “visibilidad”, la normalización y el acercamiento a la realidad y a la situación de las personas con discapacidad. Para ello se han seleccionado veinticinco películas de la última década con protagonistas con discapacidad intelectual...

  10. El español de las películas norteamericanas : problemas en el doblaje de 'Las ventajas de ser un marginado'

    OpenAIRE

    Cabrera López, Núria

    2015-01-01

    En este trabajo se pretende analizar el lenguaje del doblaje en español de la película norteamericana Las ventajas de ser un marginado, dirigida por Stephen Chbosky y estrenada en Estados Unidos en 2012. Dedicaremos un capítulo, el tercero, a aclarar qué se entiende por doblaje, un término ambiguo y, en ocasiones, confuso. Hablaremos también de sus fases, así como de los problemas que suelen darse en las películas dobladas del inglés. El cuarto capítulo es el que corresponde al análisis del d...

  11. Polysaccharides and infrared spectra of galactic sources

    International Nuclear Information System (INIS)

    It is shown that observations that are available for a number of astronomical objects over the infrared waveband 2 to 30 μm are reconcilable with the transmittance properties of polysaccharides, and it is considered reasonable to infer the detection of interstellar polysaccharides. The identification of highly complex macromolecules, such as cellulose, which are presumably formed by an abiogenic processing of interstellar formaldehyde, could have a profound bearing on interstellar chemistry, including the evolution of prebiotic molecules. A discussion is presented on the production of organic molecules in the interstellar medium, with special reference to formaldehyde and its polymers; the polysaccharides have structures built up from H2CO units and are probably the most stable polymers formed. Cellulose and starch are particularly stable, because each (H2C0)6 unit formed is able to form part of a very stable ring, with the polysaccharide becoming a chain of hexagonal ring structures. Cellulose can maintain its structure in a vacuum or a low density inert atmosphere probably up to a temperature around 625 to 900 K. Interstellar solid material is strongly absorbing in two infrared bands, centred at 3 and 10 μm, and it has been usual to attribute these absorptions to crystals of water-ice or magnesium silicate, but this presents certain difficulties, and it seems worthwhile to consider whether the infrared properties of interstellar dust might not be attributed to polysaccharides. (U.K.)

  12. Afinamiento de la zona pelúcida mediante láser (AZPL) en ciclos de FIV/ICSI en 2 grupos de edad y su relación con el grosor de la zona pelúcida

    OpenAIRE

    Amorocho Llanos, Beatriz

    2015-01-01

    Introducción: La zona pelúcida (ZP) es una matriz extracelular transparente que rodea la membrana plasmática de los ovocitos de los mamíferos. Para que se produzca la implantación, es necesaria la completa expansión del blastocisto, acompañado por el afinamiento de la ZP y la eclosión del pre-embrión favorecida por la disolución de la ZP. Sin embargo, este proceso no siempre sucede, y si el blastocisto no puede salir de la ZP no será posible que se produzca la implantación. Durante las ...

  13. ¡Luces, cámara, a jugar! Videojuegos basados en películas y películas basadas en videojuegos: particularidades de la localización en diferentes escenarios

    OpenAIRE

    Agulló, Belén

    2015-01-01

    El cine llegó a nuestras vidas hace más de cien años, cuando en 1895 los hermanos Lumière proyectaron la primera película de la historia en la Ciudad de la Luz. Los videojuegos tardaron un poco más en hacer su aparición estelar. No fue hasta 1958 cuando el primer videojuego considerado como tal fue desarrollado en Estados Unidos por el físico William Higinbotham. Se trataba del conocido juego de Tennis for two, que básicamente consistía en un cúmulo de píxeles que formaban dos palitos y una b...

  14. Synthesis and interfacial behavior of polystyrene-polysaccharide diblock copolymers

    NARCIS (Netherlands)

    Bosker, W.T.E.; Ágoston, K.; Cohen Stuart, M.A.; Norde, W.; Timmermans, J.W.; Slaghek, T.M.

    2003-01-01

    Linear block copolymers of polystyrene and polysaccharide were synthesized using a block synthesis method with amino-terminated polystyrene and sodium cyanoborohydride as reducing agent. Different types of polysaccharides, dextrans, and maltodextrins with various molecular weights were used. IR spec

  15. Neisseria meningitidis serogroup A capsular polysaccharide acetyltransferase, methods and compositions

    Energy Technology Data Exchange (ETDEWEB)

    Stephens, David S. (Stone Mountain, GA); Gudlavalleti, Seshu K. (Kensington, MD); Tzeng, Yih-Ling (Atlanta, GA); Datta, Anup K. (San Diego, CA); Carlson, Russell W. (Athens, GA)

    2011-02-08

    Provided are methods for recombinant production of an O-acetyltransferase and methods for acetylating capsular polysaccharides, especially those of a Serogroup A Neisseria meningitidis using the recombinant O-acetyltransferase, and immunogenic compositions comprising the acetylated capsular polysaccharide.

  16. Immobilized phosphorylase for synthesis of polysaccharides from glucose

    Science.gov (United States)

    Marshall, D. L.

    1972-01-01

    Continuous processes for enzymatic production of carbohydrates from glucose are discussed. Key reactant in process is identified as phosphorylase which catalyzes reversible formation or degradation of polysaccharide. Chemical compounds and reactions to synthesize polysaccharides are analyzed.

  17. Rhizobium leguminosarum mutants incapable of normal extracellular polysaccharide production.

    OpenAIRE

    Napoli, C; Albersheim, P

    1980-01-01

    Mutants of Rhizobium leguminosarum which are deficient in normal polysaccharide production have been isolated and characterized. A correlation between diminished production of extracellular polysaccharide and reduced infection and nodulation efficiency has been observed.

  18. Pneumococcal polysaccharide vaccine - what you need to know

    Science.gov (United States)

    ... taken in its entirety from the CDC Pneumococcal Polysaccharide Vaccine Information Statement (VIS): www.cdc.gov/vaccines/ ... statements/ppv.html CDC review information for Pneumococcal Polysaccharide VIS: Page last reviewed: April 24, 2015 Page ...

  19. Influence of polysaccharides on wine protein aggregation.

    Science.gov (United States)

    Jaeckels, Nadine; Meier, Miriam; Dietrich, Helmut; Will, Frank; Decker, Heinz; Fronk, Petra

    2016-06-01

    Polysaccharides are the major high-molecular weight components of wines. In contrast, proteins occur only in small amounts in wine, but contribute to haze formation. The detailed mechanism of aggregation of these proteins, especially in combination with other wine components, remains unclear. This study demonstrates the different aggregation behavior between a buffer and a model wine system by dynamic light scattering. Arabinogalactan-protein, for example, shows an increased aggregation in the model wine system, while in the buffer system a reducing effect is observed. Thus, we could show the importance to examine the behavior of wine additives under conditions close to reality, instead of simpler buffer systems. Additional experiments on melting points of wine proteins reveal that only some isoforms of thaumatin-like proteins and chitinases are involved in haze formation. We can confirm interactions between polysaccharides and proteins, but none of these polysaccharides is able to prevent haze in wine. PMID:26830558

  20. Docere delectando: series, películas y videojuegos como herramientas de innovación docente

    Directory of Open Access Journals (Sweden)

    Pablo León Cruz

    2015-01-01

    Full Text Available Acercar los contenidos recogidos en las programaciones didácticas al alumnado, destacando la utilidad de los mismos y utilizando ejemplos que resulten de interés es necesario para garantizar un aprendizaje eficaz. Así, el uso de ideas procedentes de series de televisión, películas, libros y videojuegos en los contenidos a desarrollar a lo largo de las sesiones de clase supone una apuesta innovadora en la docencia que podría repercutir en la mejora de la calidad de la enseñanza impartida al lograr la motivación del alumnado en clase y facilitar el aprendizaje utilizando ejemplos cercanos y conocidos.

  1. Liposome-Based Delivery Systems in Plant Polysaccharides

    OpenAIRE

    Yitao Wang; Xinsheng Peng; Ping Zhu; Yanfang Zhou; Jingjing Huang; Meiwan Chen

    2012-01-01

    Plant polysaccharides consist of many monosaccharide by α- or β-glycosidic bond which can be extracted by the water, alcohol, lipophile liquid from a variety of plants including Cordyceps sinensis, astragalus, and mushrooms. Recently, many evidences illustrate that natural plant polysaccharides possess various biological activities including strengthening immunity, lowering blood sugar, regulating lipid metabolism, antioxidation, antiaging, and antitumour. Plant polysaccharides have been wide...

  2. Guia de treball de la pel·lícula Te Doy mis Ojos (Icíar Bollaín, 2003)

    OpenAIRE

    Dezcallar, Georgina; Maza, Marina de la; Ruiz, Sergi; Cardona, Anna; Lara, Judit; Laguia, Vicky

    2016-01-01

    Guia de treball, de caràcter orientatiu i no obligatori, de la película Te Doy mis Ojos (Icíar Bollaín, 2003) associada a les assignatures de Pedagogia social (graus d'Educació social, Pedagogia i Treball social) i d'Acció socioeducativa en els serveis socials (grau d'Educació social)

  3. Estudio de la conservación de la papaya (Carica papaya L. asociado a la aplicación de películas comestibles

    Directory of Open Access Journals (Sweden)

    Alessandra Almeida Castro

    2011-06-01

    Full Text Available Brasil es un importante productor de papaya, pero sólo una pequeña parte se exporta. Esta fruta es altamente perecedera, por lo que el control de la maduración es esencial para aumentar la vida útil, tanto para el mercado interno como para la exportación. Una alternativa que ha cobrado impulso en el mercado es el uso de películas comestibles biodegradables, entre ellas la película producida a partir de almidón de yuca. En este estudio se evaluó el efecto de una película de almidón de yuca (2 % sobre la papaya almacenadas a temperatura ambiental (25 ± 2 ºC y a 8 °C, y 82 % de humedad relativa durante 6 días de almacenamiento. Se realizaron análisis de pérdida de peso, color, pH, acidez, carotenoides totales, vitamina C y sólidos solubles totales, cada tres días de almacenamiento. La película comestible de almidón de yuca resultó ser una buena alternativa para la preservación de la papaya durante seis días de almacenamiento, en relación a los parámetros pH, grados Brix, acidez y carotenoides.

  4. Structural and physical properties of sanxan polysaccharide from Sphingomonas sanxanigenens.

    Science.gov (United States)

    Huang, Haidong; Wu, Mengmeng; Yang, Hongpeng; Li, Xiaoyan; Ren, Mengnan; Li, Guoqiang; Ma, Ting

    2016-06-25

    Sphingomonas sanxanigenens, a new species of the genus Sphingomonas, synthesizes extracellular biopolymer termed sanxan. Sanxan polysaccharide was purified from the fermentation broth by Sephacryl S-400 column chromatography. The molecular weight of sanxan polysaccharide was 408kDa by the method of size-exclusion chromatography combined with laser light scattering. Based on FT-IR, periodate oxidation, Smith degradation, composition analysis and nuclear magnetic resonance experiments, the structure of sanxan polysaccharide was elucidated as follows: The solution of sanxan polysaccharide showed properties of high viscosity and shear-thinning. By cooling hot solutions, sanxan polysaccharide could form elastic thermoreversible gel. PMID:27083833

  5. Radiation degradation of marine polysaccharides by low energy electron beam

    International Nuclear Information System (INIS)

    The radiation degradations of marine polysaccharides by both gamma Co-60 and electron beam irradiations are investigated. Polysaccharides and oligosaccharides can be produced by degradation of corresponding polysaccharides including marine polysaccharides such as alginates, chitin chitosan and carrageenan. The viscosity of alginate, chitosan and carrageenan solution decreases markedly with increase of the low energy electron beam irradiation time and the beam current. Furthermore, the viscosity is reduced sharply in short time for polysaccharide solution with low concentration, for instance carrageenan solution of 1%. (author)

  6. Enzymatic production of polysaccharides from gum tragacanth

    DEFF Research Database (Denmark)

    2014-01-01

    Plant polysaccharides, relating to the field of natural probiotic components, can comprise structures similar to human milk oligosaccharides. A method for enzymatic hydrolysis of gum tragacanth from the bush-like legumes of the genus Astragalus, using a combination of pectin hydrolases and a...

  7. Enzymatic production of hyaluronan oligo- and polysaccharides

    NARCIS (Netherlands)

    Kooy, F.K.

    2010-01-01

    Hyaluronan oligo- and polysaccharides are abundant in the human body. Depending on the chain length, hyaluronan is an important structural component or is involved in influencing cell responses during embryonic development, healing processes, inflammation and cancer. Due to these diverse roles of hy

  8. Isolation and Structural Characterisation of Okara Polysaccharides

    Directory of Open Access Journals (Sweden)

    Bo Li

    2012-01-01

    Full Text Available Okara is a byproduct generated during tofu or soymilk production processes. Crude polysaccharide (yield 56.8% was isolated by removing fat, protein and low molecular weight carbohydrates from initial okara. Crude okara polysaccharide was further divided into four soluble fractions and an insoluble residue fraction by extracting with 0.05 M EDTA + NH4 oxalate, 0.05 M NaOH, 1 M NaOH and 4 M NaOH, with yields of 7.7%, 3.6%, 20.7%, 16.0% and 27.9%, respectively. Arabinose, galactose, galacturonic acid, xylose and glucose (only for the insoluble fraction were the major constituent sugars. The primary sugar residues of okara polysaccharides were 1,4-linked β-galactopyranose, 1,5- and 1,3-linked α-arabinofuranose, 1,5-linked α-xylofuranose, 1,2-linked, 1,2,4-linked and terminal α-rhamnopyranose (or fucopyranose, and 1,4-linked β-glucopyranose (only for the insoluble fraction, indicating okara polysaccharides might contain galactan, arabinan, arabinogalactan, xylogalacturonan, rhamnogalacturonan, xylan, xyloglucan and cellulose.

  9. Estudio de la reacción de reducción de oxígeno sobre electrodos mono cristalinos de platino modificados con películas delgadas de polianilina

    OpenAIRE

    Silva Olaya, Alex Ricardo

    2012-01-01

    Se sintetizaron películas de polianilina por voltamperometría cíclica y por cronopotenciometría sobre electrodos de platino de bajo índice de Miller. Las propiedades de estas películas se analizaron mediante voltamperometría cíclica, voltamperometría de onda cuadrada y cronoamperometría. Se observó que las propiedades de estas películas difieren dependiendo del electrodo cristalino de Pt que se use para su electro síntesis, lo que evidencia que la superficie funciona como una plantilla para l...

  10. Producción y caracterización de películas transparentes conductoras de óxido de zinc

    OpenAIRE

    Moreno Montoya, Luis Edgar

    2004-01-01

    En este trabajo se presenta la producción y caracterización de películas delgadas conductoras transparentes de ZnO, utilizando la técnica PAPVD (Plasma assisted Physical Vapor deposition) por arco pulsado. El equipo utilizado para la producción de las películas consta de una cámara de reacción cilíndrica, fabricada en acero inoxidable. Dentro de la cámara se ubican dos electrodos enfrentados, el cátodo que está formado por el material de aporte (zinc) y el ánodo que está constituido por el su...

  11. Estudio descriptivo y comparativo del slang en la traducción para doblaje de la película American History X (Tony Kaye, 1998)

    OpenAIRE

    Estal Daries, Lester

    2014-01-01

    Treball Final de Grau en Traducció i Interpretació. Codi: TI0983. Curs acadèmic 2013-2014 El presente trabajo investiga sobre cómo se traslada el slang del inglés al español en la película American History X, para averiguar si existe una homofuncionalidad entre el texto origen y el texto meta y, si es así, determinar qué estrategias y técnicas lo han hecho posible. Los principales objetivos son describir el slang de la película, describir las técnicas que se han empleado para su traducción...

  12. Projecte de Variant de la carretera BV-2421 al seu pas pel nucli urbà de La Palma de Cervelló

    OpenAIRE

    Prat Roura, Josep

    2013-01-01

    La Palma de Cervelló és un nucli situat a les Serres d'Ordal i que va créixer al voltant de l'actual carretera BV-2421, que exerceix de carrer principal. El creixement de l'urbanització dispersa a municipis veïns com Corbera de Llobregat i Pallejà, i també de La Palma, ha fet que el vehicle privat predomini com a mode de transport. El nucli de La Palma es veu travessat cada dia per un trànsit intens, amb els problemes que això provoca tant pels habitants de La Palma com pels conductors que la...

  13. Separación de polietileno y poliamida de una película coextruida con ambos polímeros

    OpenAIRE

    Aguilar Flórez, Luisa Fernanda; Herrera Zarate, Luis Gabriel

    2009-01-01

    En este estudio se evaluó un proceso para la separación de polietileno y poliamida (nylon 6) de una película coextruida con estos materiales, la cual es producto de la industria de empaques plásticos. La investigación se llevó a cabo a escala de laboratorio y por inmersión de la película en ácido clorhídrico como solvente. Se desarrolló un diseño de experimentos factorial 23 con una réplica, en donde se consideraron el tiempo de inmersión, la concentración del solvente y la temperatura....

  14. Estudio de las películas de paladio como barreras de difusión para contactos ohmicos en semiconductores III-V

    OpenAIRE

    M. Galván-Arellano; I. Kudriavtsev; G. Romero-Paredes; R. Peña-Sierra; J. Díaz-Reyes

    2005-01-01

    Se reporta el desarrollo de una metodología para formar contactos ohmicos en GaSb y GaAs con barrera de difusión de paladio. Se presentan resultados del estudio de las superficies semiconductoras durante la fase de limpieza, y previo al depósito de las aleaciones metálicas de contacto. Se describe la metodología para depositar películas de Pd sobre GaSb y GaAs. Se demuestra la acción de las películas de paladio como barrera de difusión por los resultados del análisis de composición química po...

  15. POLYPEPTIDE AND POLYSACCHARIDE PROCESSING IN HYPERTHERMOPHILIC MICROORGANISMS

    Energy Technology Data Exchange (ETDEWEB)

    KELLY, ROBERT M.

    2008-12-22

    This project focused on the microbial physiology and biochemistry of heterotrophic hyperthermophiles with respect to mechanisms by which these organisms process polypeptides and polysaccharides under normal and stressed conditions. Emphasis is on two model organisms, for which completed genome sequences are available: Pyrococcus furiosus (growth Topt of 98°C), an archaeon, and Thermotoga maritima (growth Topt of 80°C), a bacterium. Both organisms are obligately anaerobic heterotrophs that reduce sulfur facultatively. Whole genome cDNA spotted microarrays were used to follow transcriptional response to a variety of environmental conditions in order to identify genes encoding proteins involved in the acquisition, synthesis, processing and utilization of polypeptides and polysaccharides. This project provided new insights into the physiological aspects of hyperthermophiles as these relate to microbial biochemistry and biological function in high temperature habitats. The capacity of these microorganisms to produce biohydrogen from renewable feedstocks makes them important for future efforts to develop biofuels.

  16. Filtration Behaviour and Fouling Mechanisms of Polysaccharides

    OpenAIRE

    Sondus Jamal; Sheng Chang; Hongde Zhou

    2014-01-01

    This study investigated filtration behaviors of polysaccharides solutions, both alone and in mixture with proteins, in the short-time constant flux filtration with the focus on factors affecting the transmembrane pressure (TMP) increase rate, the irreversible filtration resistance, and the membrane rejection behavior. The results showed that the TMP increase rates in the short-time constant flux filtration of alginate solutions were significantly affected by the calcium addition, alginate con...

  17. Marine origin polysaccharides in drug delivery systems

    OpenAIRE

    Matias J. Cardoso; Costa, Rui R.; Mano, João F.

    2016-01-01

    Oceans are a vast source of natural substances. In them, we find various compounds with wide biotechnological and biomedical applicabilities. The exploitation of the sea as a renewable source of biocompounds can have a positive impact on the development of new systems and devices for biomedical applications. Marine polysaccharides are among the most abundant materials in the seas, which contributes to a decrease of the extraction costs, besides their solubility behavior in aqueous solvents an...

  18. Polysaccharides: The “Click” Chemistry Impact

    OpenAIRE

    Romain Lucas; Daniel Montplaisir; Rachida Zerrouki; Pierre-Antoine Faugeras; François Brouillette; Benjamin Boëns; Pierre-Henri Elchinger

    2011-01-01

    Polysaccharides are complex but essential compounds utilized in many areas such as biomaterials, drug delivery, cosmetics, food chemistry or renewable energy. Modifications and functionalizations of such polymers are often necessary to achieve molecular structures of interest. In this area, the emergence of the “click” chemistry concept, and particularly the copper-catalyzed version of the Huisgen 1,3-dipolar cycloaddition reaction between terminal acetylenes and azides, had an impact on the ...

  19. Representaciones femeninas en el cine: poder y género en la película Rosario Tijeras

    Directory of Open Access Journals (Sweden)

    Azul Kikey Castelli-Olvera

    2015-12-01

    Full Text Available En este trabajo se sostiene que la película Rosario Tijeras es un filme que puede considerarse feminista pues, Rosario Tijeras es una mujer empoderada que cuenta su propia historia. Lo anterior en consideración a que el empoderamiento enfocado desde el movimiento feminista y la perspectiva de género implica que las mujeres accedan en igual medida a los bienes materiales, intelectuales e ideológicos que permitan que tomen decisiones sobre sus cuerpos y sus vidas, se entiende que no en todos los casos el empoderamiento se da de manera positiva sino que puede manifestarse como confrontación con la propia estructura social. En este sentido desempeña un papel fundamental el contexto. Rosario Tijeras vive en un contexto definido por hombres, pero durante el desarrollo de la historia va asumiendo decisiones sobre su cuerpo y sobre su vida aún a costa de su propia seguridad, convirtiéndose en una transgresora. El análisis se realiza a partir de: 1. la propuesta de Scott, quien desagrega los elementos que constituyen la identidad de género y que en este trabajo funcionan como categorías; el análisis semiótico partiendo de Cirlot y Tresidder; y 2. El análisis formal a través de la descripción de antecedentes y uso del lenguaje cinematográfico

  20. Eruption dynamics inferred from microlite crystallization experiments: Application to Plinian and dome-forming eruptions of Mt Pelée (Martinique, Lesser Antilles).

    OpenAIRE

    Martel, Caroline

    2012-01-01

    International audience Decompression experiments have been conducted to simulate syn-eruptive crystallization in the volcanic conduit, in order to infer magma ascent rates and conditions during dome-forming and Plinian eruptions of silicic arc volcanoes. The experiments were carried out starting from Mt Pelée rhyolitic interstitial melt (76 wt. % SiO2) and consisted in three consecutive steps: hydration, decompression, and annealing. Hydration (saturated and undersaturated) was performed a...

  1. Xylanase inhibitors bind to nonstarch polysaccharides.

    Science.gov (United States)

    Fierens, Ellen; Gebruers, Kurt; Courtin, Christophe M; Delcour, Jan A

    2008-01-23

    This study is an in-depth investigation of the interaction between polysaccharides and the proteinaceous xylanase inhibitors, Triticum aestivum xylanase inhibitor (TAXI), xylanase inhibitor protein (XIP), and thaumatin-like xylanase inhibitor (TLXI). The binding affinities of all three known types of xylanase inhibitors from wheat are studied by measuring the residual xylanase inhibition activity after incubation of the inhibitors in the presence of different polysaccharides, such as beta-glucans and (arabino)xylans. The binding affinities of all three xylanase inhibitors for (arabino)xylans increased with a decreasing arabinose/xylose ratio (A/X ratio). This phenomenon was observed both with water-extractable and water-unextractable (arabino)xylans. The inhibitors also interacted with different soluble and insoluble beta-glucans. None of the inhibitors tested had the ability to hydrolyze the polysaccharides investigated. The present findings contribute to the unraveling of the function of xylanase inhibitors in nature and to the prediction of the effect of added xylanases in cereal-based biotechnological processes, such as bread making and gluten-starch separation. PMID:18092758

  2. Marine Origin Polysaccharides in Drug Delivery Systems

    Directory of Open Access Journals (Sweden)

    Matias J. Cardoso

    2016-02-01

    Full Text Available Oceans are a vast source of natural substances. In them, we find various compounds with wide biotechnological and biomedical applicabilities. The exploitation of the sea as a renewable source of biocompounds can have a positive impact on the development of new systems and devices for biomedical applications. Marine polysaccharides are among the most abundant materials in the seas, which contributes to a decrease of the extraction costs, besides their solubility behavior in aqueous solvents and extraction media, and their interaction with other biocompounds. Polysaccharides such as alginate, carrageenan and fucoidan can be extracted from algae, whereas chitosan and hyaluronan can be obtained from animal sources. Most marine polysaccharides have important biological properties such as biocompatibility, biodegradability, and anti-inflammatory activity, as well as adhesive and antimicrobial actions. Moreover, they can be modified in order to allow processing them into various shapes and sizes and may exhibit response dependence to external stimuli, such as pH and temperature. Due to these properties, these biomaterials have been studied as raw material for the construction of carrier devices for drugs, including particles, capsules and hydrogels. The devices are designed to achieve a controlled release of therapeutic agents in an attempt to fight against serious diseases, and to be used in advanced therapies, such as gene delivery or regenerative medicine.

  3. Plant Cell Wall Matrix Polysaccharide Biosynthesis

    Institute of Scientific and Technical Information of China (English)

    Ajay Pal S. Sandhu; Gursharn S. Randhawa; Kanwarpal S. Dhugga

    2009-01-01

    The wall of an expanding plant cell consists primarily of cellulose microfibrils embedded in a matrix of hemi-cellulosic and pectic polysaccharides along with small amounts of structural and enzymatic proteins. Matrix polysacchar-ides are synthesized in the Golgi and exported to the cell wall by exocytosis, where they intercalate among cellulose microfibrUs, which are made at the plasma membrane and directly deposited into the cell wall. Involvement of Golgi glucan synthesis in auxin-induced cell expansion has long been recognized; however, only recently have the genes corresponding to glucan synthases been identified. Biochemical purification was unsuccessful because of the labile nature and very low abundance of these enzymes. Mutational genetics also proved fruitless. Expression of candidate genes identified through gene expression profiling or comparative genomics in heterologous systems followed by functional characterization has been relatively successful. Several genes from the cellulose synthase-like (Cs/) family have been found to be involved in the synthesis of various hemicellulosic glycans. The usefulness of this approach, however, is limited to those enzymes that probably do not form complexes consisting of unrelated proteins. Nonconventional approaches will continue to incre-mentally unravel the mechanisms of Golgi polysaccharide biosynthesis.

  4. Marine Origin Polysaccharides in Drug Delivery Systems.

    Science.gov (United States)

    Cardoso, Matias J; Costa, Rui R; Mano, João F

    2016-02-01

    Oceans are a vast source of natural substances. In them, we find various compounds with wide biotechnological and biomedical applicabilities. The exploitation of the sea as a renewable source of biocompounds can have a positive impact on the development of new systems and devices for biomedical applications. Marine polysaccharides are among the most abundant materials in the seas, which contributes to a decrease of the extraction costs, besides their solubility behavior in aqueous solvents and extraction media, and their interaction with other biocompounds. Polysaccharides such as alginate, carrageenan and fucoidan can be extracted from algae, whereas chitosan and hyaluronan can be obtained from animal sources. Most marine polysaccharides have important biological properties such as biocompatibility, biodegradability, and anti-inflammatory activity, as well as adhesive and antimicrobial actions. Moreover, they can be modified in order to allow processing them into various shapes and sizes and may exhibit response dependence to external stimuli, such as pH and temperature. Due to these properties, these biomaterials have been studied as raw material for the construction of carrier devices for drugs, including particles, capsules and hydrogels. The devices are designed to achieve a controlled release of therapeutic agents in an attempt to fight against serious diseases, and to be used in advanced therapies, such as gene delivery or regenerative medicine. PMID:26861358

  5. Iron oxyhydroxide mineralization on microbial extracellular polysaccharides

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Clara S.; Fakra, Sirine C.; Edwards, David C.; Emerson, David; Banfield, Jillian F.

    2010-06-22

    Iron biominerals can form in neutral pH microaerophilic environments where microbes both catalyze iron oxidation and create polymers that localize mineral precipitation. In order to classify the microbial polymers that influence FeOOH mineralogy, we studied the organic and mineral components of biominerals using scanning transmission X-ray microscopy (STXM), micro X-ray fluorescence ({mu}XRF) microscopy, and high-resolution transmission electron microscopy (HRTEM). We focused on iron microbial mat samples from a creek and abandoned mine; these samples are dominated by iron oxyhydroxide-coated structures with sheath, stalk, and filament morphologies. In addition, we characterized the mineralized products of an iron-oxidizing, stalk-forming bacterial culture isolated from the mine. In both natural and cultured samples, microbial polymers were found to be acidic polysaccharides with carboxyl functional groups, strongly spatially correlated with iron oxyhydroxide distribution patterns. Organic fibrils collect FeOOH and control its recrystallization, in some cases resulting in oriented crystals with high aspect ratios. The impact of polymers is particularly pronounced as the materials age. Synthesis experiments designed to mimic the biomineralization processes show that the polysaccharide carboxyl groups bind dissolved iron strongly but release it as mineralization proceeds. Our results suggest that carboxyl groups of acidic polysaccharides are produced by different microorganisms to create a wide range of iron oxyhydroxide biomineral structures. The intimate and potentially long-term association controls the crystal growth, phase, and reactivity of iron oxyhydroxide nanoparticles in natural systems.

  6. Rheological studies of polysaccharides for skin scaffolds.

    Science.gov (United States)

    Almeida, Nalinda; Mueller, Anja; Hirschi, Stanley; Rakesh, Leela

    2014-05-01

    Polysaccharide hydrogels are good candidates for skin scaffolds because of their inherent biocompatibility and water transport properties. In the current study, hydrogels were made from a mixture of four polysaccharides: xanthan gum, konjac gum, iota-carrageenan, and kappa-carrageenan. Gel formation, strength, and structure of these polysaccharides were studied using rheological and thermal techniques. All gel samples studied were strong gels at all times because of the gradual water loss. However, after 12 h of storage, elastic (G') and loss (G'') moduli of hydrogel mixture containing all the ingredients is of one to two orders of magnitude greater than that of mixtures not containing either xanthan gum or iota-carrageenan, which confirmed the varied levels of gel strength. This is mainly due to the rate of water loss in each of these mixtures, resulting in gels of varying structures and dynamic moduli over a period of time. Iota-carrageenan and xanthan gum differ in their effect on gel strength and stability in combination with konjac gum and kappa-carrageenan. PMID:23703897

  7. Efectos del fenómeno "El Niño 1997-98" sobre los principales recursos pelágicos en la costa peruana

    Directory of Open Access Journals (Sweden)

    Miguel Ñiquen

    2014-06-01

    Full Text Available En el período abril 1997 setiembre 1998 fueron realizados 5 cruceros de evaluación de los recursos pelágicos en la costa peruana, éstos permitieron observar cambios en la composición por especies, distribución, estructura por tamaño, reproducción y niveles poblacionales de los principales recursos pelágicos. Estos cambios guardan similitud con los observados en los eventos El Niño 1972-73 y 1982-83, especialmente en cuanto a la disminución de la biomasa de anchoveta y el incremento de otras especies pelágicas. En el período post-Niño se observó cambios notables en la estructura por tallas de anchoveta, mientras que la sardina, samas a y caballa coincidieron en mostrar buenos reclutamientos. La actividad reproductiva también se incrementó, inclusive en tallas juveniles, destacando la incidencia de sardinas sexualmente maduras con longitudes de 18-20 cm, situación que no había sido antes registrada.

  8. Evaluation of phosphorylated psyllium seed polysaccharide as a release retardant

    Directory of Open Access Journals (Sweden)

    Monica R P Rao

    2015-01-01

    Full Text Available The aim of the present study was to modify psyllium seed polysaccharide and evaluate the modified polysaccharide as release retardant in tablets employing ciprofloxacin hydrochloride as model drug. Studies on polysaccharide from psyllium husk has been reported but no work has been reported on characterization and modification of the polysaccharide present in the psyllium (Plantago ovata seed and the use of the modified polysaccharide as a release retardant in tablets. In this study, the seed gum was modified using sodium trimetaphosphate as crosslinking agent. Sustained release matrix tablets of ciprofloxacin hydrochloride were prepared by wet granulation using various drug-polymer ratios. The polymers investigated were psyllium polysaccharide, phosphorylated psyllium polysaccharide and widely used release retardant hydroxypropyl methylcellulose K100M. The tablets were evaluated for hardness, friability, drug content, swelling profile and in vitro dissolution studies. The matrix tablets containing 1:3 proportion of drug-phosphorylated psyllium polysaccharide was found to have higher hardness as compared to tablets containing 1:1 and 1:2 proportions. The results of swelling behavior in water showed that the tablets containing 1:3 drug:phosphorylated psyllium polysaccharide ratio had swelling comparable to that of tablets containing 1:3 drug:hydroxypropyl methylcellulose ratio. The in vitro dissolution studies shows that the dissolution rate was retarded from 98.41 to 37.6% in 6 h with increase in concentration of phosphorylated psyllium polysaccharide from 100 to 300 mg. Formulations containing psyllium polysaccharide showed complete drug release in 8 h whereas those formulated with phosphorylated psyllium polysaccharide exhibited extended drug release over the 12 h period. Drug release kinetic studies revealed that drug release followed Korsmeyer-Peppas model.

  9. Oligo- and polysaccharide synthesis by Rhizobium leguminosarum and Rhizobium meliloti.

    OpenAIRE

    Breedveld, M W

    1992-01-01

    Rhizobium and Agrobacterium species are capable of synthesizing a variety of extracellular and cellular oligo- and polysaccharides. Changes in environmental conditions may all affect the composition, physical properties, and relative amounts of oligo- and polysaccharides. Interest in the field of Rhizobium polys accharides has resulted from a development in two distinct areas, (i) the role of oligo- and polysaccharides in the microbe- plant interaction, and (ii) studies on the physico- chemic...

  10. Structural Analysis of Polysaccharide from Cladonia furcatar and Its Activities

    Institute of Scientific and Technical Information of China (English)

    CHEN; Qian

    2001-01-01

    Cladonia furcatar is a member of the lichens genus Cladonia. Japanese scientific researchers [1] made a great achievement in selecting lichens as anticancer agent and polysaccharides are generally considered to be their main bioactive constituents. Recently, Iacomini et al[2] have investigated the members of the genus Cladonia, a mannose-containing polysaccharide was isolated from Cladoniafurcatar. We now report the new chemical structure of polysaccharide from Cladoniafurcatar and its activities.  ……

  11. Structural Analysis of Polysaccharide from Cladonia furcatar and Its Activities

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ Cladonia furcatar is a member of the lichens genus Cladonia. Japanese scientific researchers [1] made a great achievement in selecting lichens as anticancer agent and polysaccharides are generally considered to be their main bioactive constituents. Recently, Iacomini et al[2] have investigated the members of the genus Cladonia, a mannose-containing polysaccharide was isolated from Cladoniafurcatar. We now report the new chemical structure of polysaccharide from Cladoniafurcatar and its activities.

  12. Improved coupling of bacterial polysaccharides to macromolecules and solid supports

    DEFF Research Database (Denmark)

    2013-01-01

    The invention relates to a method of producing a polysaccharide-carrier conjugate comprising coupling a polysaccharide to a carrier, said polysaccharide comprising at least one monosaccharide unit comprising a keto-carboxy group according to the formula -C(=O)COOR, where R is either hydrogen or C1...... the present invention relates to the use of the compound or solid surface in the preparation of an assay device for the detection of antibodies against gram negative bacteria....

  13. Evaluation of Phosphorylated Psyllium Seed Polysaccharide as a Release Retardant.

    Science.gov (United States)

    Rao, Monica R P; Warrier, Deepa U; Rao, Shivani H

    2015-01-01

    The aim of the present study was to modify psyllium seed polysaccharide and evaluate the modified polysaccharide as release retardant in tablets employing ciprofloxacin hydrochloride as model drug. Studies on polysaccharide from psyllium husk has been reported but no work has been reported on characterization and modification of the polysaccharide present in the psyllium (Plantago ovata) seed and the use of the modified polysaccharide as a release retardant in tablets. In this study, the seed gum was modified using sodium trimetaphosphate as crosslinking agent. Sustained release matrix tablets of ciprofloxacin hydrochloride were prepared by wet granulation using various drug-polymer ratios. The polymers investigated were psyllium polysaccharide, phosphorylated psyllium polysaccharide and widely used release retardant hydroxypropyl methylcellulose K100M. The tablets were evaluated for hardness, friability, drug content, swelling profile and in vitro dissolution studies. The matrix tablets containing 1:3 proportion of drug-phosphorylated psyllium polysaccharide was found to have higher hardness as compared to tablets containing 1:1 and 1:2 proportions. The results of swelling behavior in water showed that the tablets containing 1:3 drug:phosphorylated psyllium polysaccharide ratio had swelling comparable to that of tablets containing 1:3 drug:hydroxypropyl methylcellulose ratio. The in vitro dissolution studies shows that the dissolution rate was retarded from 98.41 to 37.6% in 6 h with increase in concentration of phosphorylated psyllium polysaccharide from 100 to 300 mg. Formulations containing psyllium polysaccharide showed complete drug release in 8 h whereas those formulated with phosphorylated psyllium polysaccharide exhibited extended drug release over the 12 h period. Drug release kinetic studies revealed that drug release followed Korsmeyer-Peppas model. PMID:26798177

  14. Life Cycle Assessment of Polysaccharide Materials: A Review

    OpenAIRE

    Shen, L.; Patel, M.K.

    2008-01-01

    Apart from conventional uses of polysaccharide materials, such as food, clothing, paper packaging and construction, new polysaccharide products and materials have been developed. This paper reviews life cycle assessment (LCA) studies in order to gain insight of the environmental profiles of polysaccharide products (e.g. viscose or natural fibre polymer composites) in comparison with their conventional counterparts (e.g. cotton or petrochemical polymers). The application areas covered are text...

  15. Immunogenic properties of Klebsiella pneumoniae type 2 capsular polysaccharide.

    OpenAIRE

    Robert, A.; Jouin, H; Fournier, J M

    1986-01-01

    The immunoprotective activity of Klebsiella pneumoniae K2 cell surface preparations and purified capsular polysaccharide was tested in mice. The 50% protective dose (PD50), expressed as capsular polysaccharide content, was 2 ng for cell surface preparations and 50 ng for purified capsular polysaccharide. Both preparations lost their immunoprotective activity after alkali treatment. Immune sera were raised in rabbits immunized with cell surface preparations. The precipitating and hemagglutinat...

  16. Hydrodynamic investigation of polysaccharides and their interaction with casein

    OpenAIRE

    Morris, Gordon Alistair

    2001-01-01

    Polysaccharide systems (pectin, carrageenan, guar, locust bean gum, xanthan and xylan) have been characterised using a variety of hydrodynamic techniques including sedimentation velocity, sedimentation equilibrium, size exclusion chromatography - multi-angle laser light scattering (SEC-MALLS), and viscometry. Results suggest that the polysaccharides selected are, in general, rigid or semi-rigid molecules with a large hydrated volume, this is important in relation to polysaccharide structure -...

  17. Antibacterial and antiviral study of dialdehyde polysaccharides

    Science.gov (United States)

    Song, Le

    Concerns for microbial contamination and infection to the general population, especially the spread of drug-resistant microorganisms, have greatly increased. Polymeric biocides have been found to be a feasible strategy to inactivate drug-resistant bacteria. However, current polymeric biocide systems involve multi-step chemical reactions and they are not cost-effective. Desirable antimicrobial systems need to be designed to be environmentally friendly, broad-spectrum effective against microorganisms, flexible for various delivery methods and economically affordable. We demonstrated that dialdehyde polysaccharides (including dialdehyde starch and dialdehdye cellulose) were broad-spectrum polymeric biocides against gram-positive/negative bacteria, bacteriophages and human virus. These polymers can be easily converted from starch and cellulose through one-step periodate oxidation. Destructions of microorganism by dialdehyde polysaccharides have been achieved in aqueous suspension or by solid surface contact. The dialdehdye functions of dialdehdye polysaccharides were found to be the dominant action against microorganism. The reactivity of the dialdehyde functionality was found to be pH-dependent as well as related to the dispersion of dialdehyde polysaccharides. Degradation of dialdehyde starch during cooking was confirmed. Degradation of dialdehyde starch was more liable in alkaline condition. Carboxylic acid and conjugated aldehyde functionalities were the two main degradation products, confirmed from the spectroscopic studies. The pH effect on the polysaccharide structure and the corresponding antimicrobial activity was very complicated. No decisive conclusions could be obtained from this study. Liner inactivation kinetics was found for dialdehyde starch aqueous suspension against bacteria. This linear inactivation kinetics was derived from the pseudo-first chemical reaction between the dialdehyde starch and the bacteria. The established inactivation kinetics was

  18. [Improvement on microwave technology of extracting polysaccharide from yacon leaves].

    Science.gov (United States)

    Li, Jing-wei; Liu, Jian; Yang, Yong; Zheng, Ming-min; Rong, Ting-zhao

    2007-11-01

    According to the extraction ratio of polysaccharide in yacon leaves, the comparison between microwave extraction and traditional hot water extraction was conducted, and the two-factor and three-level experiment on the microwave extraction of polysaccharide from yacon leaves was investigated. The result showed that the extraction ratio of polysaccharide by using microwave extraction was better than that by using traditional hot water extraction. Moreover, according to the result of variance analysis and multiple comparison, the optimum conditions for extraction of polysaccharide by using microwave technology from yacon leaves were as follows: 280W microwave power for 2 times and 15 minutes at every time. PMID:18323219

  19. Mapping the polysaccharide degradation potential of Aspergillus niger

    DEFF Research Database (Denmark)

    Andersen, Mikael Rørdam; Giese, Malene; de Vries, Ronald P.;

    2012-01-01

    potential of a given fungus for polysaccharide degradation. Results: Through the compilation of information from 203 articles, we have systematized knowledge on the structure and degradation of 16 major types of plant polysaccharides to form a graphical overview. As a case example, we have combined this...... expression from this organism. One such example is the identification of a full set of extracellular polysaccharide-acting genes for the degradation of oat spelt xylan. Conclusions: The mapping of plant polysaccharide structures along with the corresponding enzymatic activities is a powerful framework for...

  20. Antiviral polysaccharides isolated from Hong Kong brown seaweed Hydroclathrus clathratus

    Institute of Scientific and Technical Information of China (English)

    WANG; Hui; OOI; Engchoon; Vincent; ANG; Put; O; Jr.

    2007-01-01

    Two relatively pure polysaccharides H3-a1 and H3-b1 had been isolated from the brown seaweed Hydroclathrus clathratus. They were characterized by HPLC, ultraviolet scanning, gas chromatography, infrared spectroscopy and elemental analysis, and shown to be two different sulfated polysaccharides with different monosaccharide content, but both with high relative molecular mass. They contained some proteins and uronic acid respectively. The sulfate content and bioactivity of these polysaccharides varied during purification. The fractions derived from the hot water extract also exhibited low anticoagulant effect. This is the first time that the antiherpetic and anticoagulant activities were evaluated for the polysaccharides from the Hong Kong brown seaweed Hydroclathrus clathratus.

  1. Extraction, chemical analysis of Angelica sinensis polysaccharides and antioxidant activity of the polysaccharides in ischemia-reperfusion rats.

    Science.gov (United States)

    Zhang, Song; He, Ben; Ge, Junbo; Li, Huibin; Luo, Xiuying; Zhang, Hui; Li, Yuhui; Zhai, Changlin; Liu, Pingang; Liu, Xin; Fei, Xuetao

    2010-11-01

    Angelica sinensis polysaccharides were analyzed using high performance liquid chromatography (HPLC) and Fourier Transform Infrared (FT-IR). The major sugar of the polysaccharide was saccharose (18.55%); and the sugar constituted about 83% of the monomer content. Glucose and fructose were found as minor components of the polysaccharides. The FT-IR spectra of A. sinensis polysaccharides are used for determination of their structural features. The FT-IR spectrum of A. sinensis polysaccharides showed bands at 1641 cm(-1), 1415 cm(-1), 1050 cm(-1) and 926 cm(-1) characteristic for the carboxylic group. Absorptions at 2920-2930 cm(-1) are attributed to asymmetrical stretching vibration of CH(2)-group. Medium stretch observed in the range 1650-1400 cm(-1) is assigned to C-C stretching of polysaccharides. Cardioprotective effects of A. sinensis polysaccharides were evaluated by using myocardial ischemia/reperfusion (IR) rats. A. sinensis polysaccharides treatment significantly reduced myocardial infarction size, enhanced CT-1 and antioxidant enzymes activity, downregulated caspase-12 mRNA expression in rats. The study strongly suggests the cardioprotective activity of A. sinensis polysaccharides in limiting ischemia-reperfusion induced myocardial injury. PMID:20691723

  2. Immunomodulatory dietary polysaccharides: a systematic review of the literature

    Directory of Open Access Journals (Sweden)

    Nelson Erika D

    2010-11-01

    Full Text Available Abstract Background A large body of literature suggests that certain polysaccharides affect immune system function. Much of this literature, however, consists of in vitro studies or studies in which polysaccharides were injected. Their immunologic effects following oral administration is less clear. The purpose of this systematic review was to consolidate and evaluate the available data regarding the specific immunologic effects of dietary polysaccharides. Methods Studies were identified by conducting PubMed and Google Scholar electronic searches and through reviews of polysaccharide article bibliographies. Only articles published in English were included in this review. Two researchers reviewed data on study design, control, sample size, results, and nature of outcome measures. Subsequent searches were conducted to gather information about polysaccharide safety, structure and composition, and disposition. Results We found 62 publications reporting statistically significant effects of orally ingested glucans, pectins, heteroglycans, glucomannans, fucoidans, galactomannans, arabinogalactans and mixed polysaccharide products in rodents. Fifteen controlled human studies reported that oral glucans, arabinogalactans, heteroglycans, and fucoidans exerted significant effects. Although some studies investigated anti-inflammatory effects, most studies investigated the ability of oral polysaccharides to stimulate the immune system. These studies, as well as safety and toxicity studies, suggest that these polysaccharide products appear to be largely well-tolerated. Conclusions Taken as a whole, the oral polysaccharide literature is highly heterogenous and is not sufficient to support broad product structure/function generalizations. Numerous dietary polysaccharides, particularly glucans, appear to elicit diverse immunomodulatory effects in numerous animal tissues, including the blood, GI tract and spleen. Glucan extracts from the Trametes versicolor

  3. Simulating thermal stress features on hot planetary surfaces in vacuum at high temperature facility in the PEL laboratory

    Science.gov (United States)

    Maturilli, A.; Ferrari, S.; Helbert, J.; D'Incecco, P.; D'Amore, M.

    2011-12-01

    In the Planetary Emissivity Laboratory (PEL) at the Institute for Planetary Research of the German Aerospace Center (DLR) in Berlin, we set-up a simulation chamber for the spectroscopic investigation of minerals separates under Mercurial conditions. The chamber can be evacuated to 10-4 bar and the target samples heated to 700 K within few minutes, thanks to the innovative inductive heating system. While developing the protocol for the high temperature spectroscopy measurements we discovered interesting "morphologies" on the sample surfaces. The powders are poured into stainless steel cups of 50 mm internal diameter, 8 mm height and 3 mm depth, having a 5 mm thick base (thus leaving 3 mm free space for the minerals), and rim 1 mm thick. We selected several minerals of interest for Mercurial surface composition and for each of them we analyzed various grain size separates, to study the influence of grain dimensions to the process of thermal stressing. We observed that for the smaller grain size separate (0-25 μm) the thermal stress mainly induces large depressions and fractures, while on larger grain sizes (125-250 μm) small depressions and a cratered surface. Our current working hypothesis is that these features are mainly caused by thermal stress induced by a radiatively quickly cooling surface layer covering the much hotter bulk material. Further investigation is ongoing to understand the processes better. The observed morphologies exhibit surprising similarities to features observed at planetary scale size for example on Mercury and even on Venus. Especially the high resolution images provided currently from MESSENGER'S Mercury Dual Imaging System (MDIS) instrument has revealed plains dominated by polygonal fractures whose origin still have to be determined. Our laboratory analogue studies might in the future provide some insight into the processes creating those features

  4. INTERACTION OF IONIC LIQUIDS WITH POLYSACCHARIDES

    Directory of Open Access Journals (Sweden)

    Tim Liebert

    2008-05-01

    Full Text Available The use of ionic liquids (ILs in the field of cellulose chemistry opens up a broad variety of new opportunities. Besides the regeneration of the biopolymer to fibers, films, and beads, this new class of cellulose solvents is particularly useful for the homogeneous chemical modification of the polysaccharide. In this review, the potential of ILs as a reaction medium for the homogeneous cellulose functionalization is discussed. It is shown that numerous conversions proceed very efficiently and the ILs may be recycled. But it is also demonstrated that some side reactions have to be considered.

  5. Voltammetry of Os(VI)-modified polysaccharides

    Czech Academy of Sciences Publication Activity Database

    Trefulka, Mojmír; Paleček, Emil

    2010-01-01

    Roč. 22, č. 16 (2010), s. 1837-1845. ISSN 1040-0397 R&D Projects: GA AV ČR(CZ) GPP301/10/P548; GA MŠk(CZ) LC06035 Grant ostatní: GA AV ČR(CZ) KAN400310651 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : chemical modification of polysaccharides * electroactive labels * osmium(VI) complexes Subject RIV: BO - Biophysics Impact factor: 2.721, year: 2010

  6. Constant current chronopotentiometric stripping of sulphated polysaccharides

    Czech Academy of Sciences Publication Activity Database

    Strmečki, S.; Plavšić, M.; Ćosović, B.; Ostatná, Veronika; Paleček, Emil

    2009-01-01

    Roč. 11, č. 10 (2009), s. 2032-2035. ISSN 1388-2481 R&D Projects: GA ČR(CZ) GA301/07/0490; GA ČR(CZ) GP202/07/P497; GA MŠk(CZ) LC06035 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : sulphated polysaccharides * ióta-carrageenan * catalysis of hydrogen evolution Subject RIV: BO - Biophysics Impact factor: 4.243, year: 2009

  7. Electrocatalytic detection of polysaccharides at picomolar concentrations

    Czech Academy of Sciences Publication Activity Database

    Paleček, Emil; Trefulka, Mojmír

    2011-01-01

    Roč. 136, č. 2 (2011), s. 321-326. ISSN 0003-2654 R&D Projects: GA MŠk(CZ) ME09038; GA AV ČR KAN400310651; GA AV ČR(CZ) GPP301/10/P548; GA MŠk(CZ) LC06035; GA ČR(CZ) GAP301/11/2055 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : electrochemical detection of polysaccharides * Os(VI)-bipyridine complex * cyclic voltammography Subject RIV: BO - Biophysics Impact factor: 4.230, year: 2011

  8. Radiation Induced Degradation of Galactomannan Polysaccharides

    International Nuclear Information System (INIS)

    Galactomannans are neutral polysaccharides that occur in substantial amounts in the endosperm of the seeds of some leguminous plants. Structurally they consist of a β(1-4)-D-mannose backbone to which galactose units are attached α(1-6). Among various galactomannans known, guar gum (GG), tara gum (TG) and locust bean gum (LBG) are the most widely used in applications in, for example, the food, pharmaceutical, and chemical industries as thickening agents or stabilizers due mainly to the high viscosity they impart at low concentrations. In many industrial applications, the use of low molecular weight polysaccharides is essential. For example, guar solutions, which are used as hydraulic fracturing fluids in oil and gas recovery, need to be degraded to facilitate the outflow of oil. In addition, to understand the solution properties of guar as well as other water-soluble biopolymers, it is often necessary to degrade the native polymer to prepare samples with various molecular weights (MW. Degradation of polysaccharides has been widely studied. Though acid and enzymatic hydrolysis are most common, other methods such as thermal, γ-irradiation, extrusion, ultrasonication and free radical degradation are also reported. In this study, radiation induced degradation of galactomannan polysaccharides has been investigated. GG, TG and LBG samples were irradiated with gamma rays in air at ambient temperature in the solid state at low dose rate. The change in their molecular weights was determined by SEC analysis and the change in their viscosity values as a function of temperature and irradiation dose was determined. Chain scission yields, G(S), and degradation rates were calculated. As a result of irradiation the molecular weight and viscosity of all galactomannans sharply decreased up to 50 kGy, no significant change was observed beyond this dose value. We observed that mannose-to-galactose ratio is an important factor controlling the G(S) and degradation rate of

  9. Methods of saccharification of polysaccharides in plants

    Science.gov (United States)

    Howard, John; Fake, Gina

    2014-04-29

    Saccharification of polysaccharides of plants is provided, where release of fermentable sugars from cellulose is obtained by adding plant tissue composition. Production of glucose is obtained without the need to add additional .beta.-glucosidase. Adding plant tissue composition to a process using a cellulose degrading composition to degrade cellulose results in an increase in the production of fermentable sugars compared to a process in which plant tissue composition is not added. Using plant tissue composition in a process using a cellulose degrading enzyme composition to degrade cellulose results in decrease in the amount of cellulose degrading enzyme composition or exogenously applied cellulase required to produce fermentable sugars.

  10. Enzymatic synthesis of oligo- and polysaccharide fatty acid esters

    NARCIS (Netherlands)

    Broek, van den L.A.M.; Boeriu, C.G.

    2013-01-01

    Amphiphilic oligo- and polysaccharides (e.g. polysaccharide alkyl or alkyl-aryl esters) form a new class of polymers with exceptional properties. They function as polymeric surfactants, whilst maintaining most of the properties of the starting polymeric material such as emulsifying, gelling, and fil

  11. Polysaccharides isolated from Acai fruit induce innate immune responses.

    Directory of Open Access Journals (Sweden)

    Jeff Holderness

    Full Text Available The Açaí (Acai fruit is a popular nutritional supplement that purportedly enhances immune system function. These anecdotal claims are supported by limited studies describing immune responses to the Acai polyphenol fraction. Previously, we characterized γδ T cell responses to both polyphenol and polysaccharide fractions from several plant-derived nutritional supplements. Similar polyphenol and polysaccharide fractions are found in Acai fruit. Thus, we hypothesized that one or both of these fractions could activate γδ T cells. Contrary to previous reports, we did not identify agonist activity in the polyphenol fraction; however, the Acai polysaccharide fraction induced robust γδ T cell stimulatory activity in human, mouse, and bovine PBMC cultures. To characterize the immune response to Acai polysaccharides, we fractionated the crude polysaccharide preparation and tested these fractions for activity in human PBMC cultures. The largest Acai polysaccharides were the most active in vitro as indicated by activation of myeloid and γδ T cells. When delivered in vivo, Acai polysaccharide induced myeloid cell recruitment and IL-12 production. These results define innate immune responses induced by the polysaccharide component of Acai and have implications for the treatment of asthma and infectious disease.

  12. Characterisation of cell wall polysaccharides in bilberries and black currants

    NARCIS (Netherlands)

    Hilz, H.

    2007-01-01

    During berry juice production, polysaccharides are released from the cell walls and cause thickening and high viscosity when the berries are mashed. Consequences are a low juice yield and a poor colour. This can be prevented by the use of enzymes that degrade these polysaccharides. To use these enzy

  13. In vitro antioxidant activity of polysaccharide from Gardenia jasminoides ellis

    Science.gov (United States)

    Fan, Y.; Ge, Z.; Luo, A.

    2011-01-01

    A water-soluble polysaccharide, GP, was isolated from Gardenia jasminoides Ellis through hot water extraction followed by ethanol precipitation. The in vitro free radicals scavenging tests exhibited that GP has significant scavenging abilities especially for ABTS, DPPH, and hydroxyl radicals, which suggests that the polysaccharide GP is a novel antioxidant. ?? 2011 Academic Journals.

  14. Life cycle assessment of polysaccharide materials: a review

    NARCIS (Netherlands)

    Shen, L.; Patel, M.K.

    2008-01-01

    Apart from conventional uses of polysaccharide materials, such as food, clothing, paper packaging and construction, new polysaccharide products and materials have been developed. This paper reviews life cycle assessment (LCA) studies in order to gain insight of the environmental profiles of polysacc

  15. Structural Features and Healthy Properties of Polysaccharides Occurring in Mushrooms

    Directory of Open Access Journals (Sweden)

    Eva Guillamón

    2012-12-01

    Full Text Available Polysaccharides from mushrooms have attracted a great deal of attention due to the many healthy benefits they have demonstrated, such as immunomodulation, anticancer activity, prevention and treatment of cardiovascular diseases, antiviral and antimicrobial effects, among others. Isolation and purification of polysaccharides commonly involve several steps, and different techniques are actually available in order to increase extraction yield and purity. Studies have demonstrated that the molecular structure and arrangement significantly influence the biological activity; therefore, there is a wide range of analytical techniques for the elucidation of chemical structures. Different polysaccharides have been isolated from mushrooms, most of them consisting of β-linked glucans, such as lentinan from Lentinus edodes, pleuran from Pleurotus species, schizophyllan from Schizophyllum commune, calocyban from Calocybe indica, or ganoderan and ganopoly from Ganoderma lucidum. This article reviews the main methods of polysaccharide isolation and structural characterization, as well as some of the most important polysaccharides isolated from mushrooms and the healthy benefits they provide.

  16. Modified polysaccharides as alternative binders for foundry industry

    Directory of Open Access Journals (Sweden)

    K. Kaczmarska

    2016-10-01

    Full Text Available Polysaccharides constitute a wide group of important polymers with many commercial applications, for example food packaging, fibres, coatings, adhesives etc. This review is devoted to the presentation of polysaccharide application in foundry industry. In this paper the selected properties of foundry moulding sand and core sand containing modified polysaccharides as binders are presented according to foreign literature data. Also, author’s own research about effect of using moulding sand binder consisting of modified polysaccharide (modified starch or its composition with non-toxic synthetic polymers are discussed. Based on technologies taken under consideration in this paper, it could be concluded that polysaccharides are suitable as an alternative for use as binder in foundry moulding applications.

  17. Bacterial Extracellular Polysaccharides Involved in Biofilm Formation

    Directory of Open Access Journals (Sweden)

    Elena P. Ivanova

    2009-07-01

    Full Text Available Extracellular polymeric substances (EPS produced by microorganisms are a complex mixture of biopolymers primarily consisting of polysaccharides, as well as proteins, nucleic acids, lipids and humic substances. EPS make up the intercellular space of microbial aggregates and form the structure and architecture of the biofilm matrix. The key functions of EPS comprise the mediation of the initial attachment of cells to different substrata and protection against environmental stress and dehydration. The aim of this review is to present a summary of the current status of the research into the role of EPS in bacterial attachment followed by biofilm formation. The latter has a profound impact on an array of biomedical, biotechnology and industrial fields including pharmaceutical and surgical applications, food engineering, bioremediation and biohydrometallurgy. The diverse structural variations of EPS produced by bacteria of different taxonomic lineages, together with examples of biotechnological applications, are discussed. Finally, a range of novel techniques that can be used in studies involving biofilm-specific polysaccharides is discussed.

  18. Primary structure and configuration of tea polysaccharide

    Institute of Scientific and Technical Information of China (English)

    ZHOU Peng; XIE Mingyong; NIE Shaoping; WANG Xiaoru

    2004-01-01

    The monosaccharide composition of a tea polysaccharide(TGC)was determined by GC-MS method.Furthermore,the primary structure of tea polysaccharide and its configuration in the aqueous solution were investigated utilizing a combination of classical chemical methods and modern instrumental techniques including GC-MS,Proton NMR,UV and CD.The results indicate that TGC consists of 6 monosaccharides: Rha,Ara,Xyl,Glu,Man and Gal.The configuration of TGC in water solution is proposed to be an ordered helix.The possible primary structure of TGC was outlined as below: the basic structure of the main chain consists of Rha,Glu and Gal units.All three monosaccharides can potentially be connected to branch chains consisting of mainly Ara,and the linkages could be in β1 →2,β1 →3,β2→3 forms.When branch chain is absent in the basic structure of the main chain the linkage consists of only β1→3; Xyl exists at the terminal end of either the main chain or the branch chain with β1 → linkage.

  19. Microanalysis of Plant Cell Wall Polysaccharides

    Institute of Scientific and Technical Information of China (English)

    Nicolai Obel; Veronika Erben; Tatjana Schwarz; Stefan Kühne; Andrea Fodor; Markus Pauly

    2009-01-01

    Oligosaccharide Mass Profiling (OLIMP) allows a fast and sensitive assessment of cell wall polymer structure when coupled with Matrix Assisted Laser Desorption Ionisation Time Of Flight Mass Spectrometry (MALDI-TOF MS). The short time required for sample preparation and analysis makes possible the study of a wide range of plant organs, revealing a high degree of heterogeneity in the substitution pattern of wall polymers such as the cross-linking glycan xyloglucan and the pectic polysaccharide homogalacturonan. The high sensitivity of MALDI-TOF allows the use of small amounts of samples, thus making it possible to investigate the wall structure of single cell types when material is collected by such methods as laser micro-dissection. As an example, the analysis of the xyloglucan structure in the leaf cell types outer epidermis layer, entire epidermis cell layer, palisade mesophyll cells, and vascular bundles were investigated. OLIMP is amenable to in situ wall analysis, where wall polymers are analyzed on unprepared plant tissue itself without first iso-lating cell walls. In addition, OLIMP enables analysis of wall polymers in Golgi-enriched fractions, the location of nascent matrix polysaccharide biosynthesis, enabling separation of the processes of wall biosynthesis versus post-deposition apo-plastic metabolism. These new tools will make possible a semi-quantitative analysis of the cell wall at an unprecedented level.

  20. Verificación experimental de las correlaciones de transferencia de calor por ebullición en película, en piscina, en torno a esferas

    OpenAIRE

    Arévalo Ramírez, Rubén; Rebollo Medrano, Luis; Abánades Velasco, Alberto; Muñoz Antón, Javier; Omaña, Rubén; Pérez, Orlando

    2007-01-01

    La ebullición en película es el mecanismo de transferencia de calor básico que acopla térmicamente un líquido y una superficie caliente cuando existe una gran diferencia de temperatura entre ambos. El conocimiento preciso del comportamiento de este mecanismo térmico en torno a esferas es necesario para el análisis de seguridad de escenarios industriales en los que exista contacto entre un líquido y un material fundido fragmentado, generalmente en piezas esferoidales, y resulta esencial para g...

  1. Características endocrinas, moleculares y de parámetros de crecimiento asociados a la obesidad del cerdo Pelón Mexicano

    OpenAIRE

    Carmen Camacho-Rea; Carlos G. Gutiérrez; Arechavaleta-Velasco, Miguel E.; Laura Díaz-Cueto; Fabián J. Arechavaleta-Velasco; Roberto Martínez Rodríguez; Clemente Lemus-Flores; Rogelio A. Alonso-Morales

    2008-01-01

    Para determinar el potencial del cerdo Pelón Mexicano (CPM) en el estudio de la obesidad, se realizó un estudio entre el CPM y cerdos Landrace-Yorkshire (CLY). Se midieron concentraciones séricas de leptina e insulina y se determinó su correlación con el espesor de grasa dorsal (EGD). Se evaluó el consumo de alimento (CA), el EGD, la ganancia diaria de peso y la expresión de genes que codifican para leptina, el receptor de leptina, adiponectina y el receptor activado por proliferadores de per...

  2. Determinación de la vida de anaquel del chocolate de mesa sin azúcar en una película de polipropileno biorientado

    OpenAIRE

    Chica Cardona, Bibiana Andrea; Osorio Saldarriaga, Sandra Liliana

    2003-01-01

    El presente trabajo tuvo como objetivo determinar la durabilidad del chocolate de mesa sin azúcar, empacado en una película de polipropileno biorientado a diferentes condiciones de almacenamiento (dos temperaturas y dos humedades relativas), aplicando vida de anaquel acelerada al producto. Se determinaron los parámetros cinéticos (n, K, Ko y Ea) y por medio del modelo de Arrhenius se halló el tiempo de vida útil del chocolate. Paralelamente se obtuvieron las curvas de adsorción del choc...

  3. Películas delgadas de Al2O3 sobre silicio preparadas por ablación láser

    Directory of Open Access Journals (Sweden)

    Lamagna, A.

    1998-04-01

    Full Text Available Al2O3 thin films were fabricated by pulsed laser deposition (PLD on Si3N4/Si, to improve the thermal and electrical isolation of gas sensing devices. The microstructure of the films is analyzed as a function of the deposition conditions (laser fluence, oxygen pressure, target-substrate distance and substrate temperature. X-ray analysis shows that only a sharp peak that coincides with the corundum (116 reflection can be observed in all the films. But, when they are annealed at temperatures above 1,200°C, a change in the crystalline structure of some films occurs. The stoichiometry and morphology of the films with and without thermal treatment are compared using environmental scanning electron microscopy (SEM and EDAX analysis.

    Se depositaron películas delgadas de Al2O3 por ablación láser sobre Si3N4/Si para utilizarlas como aislante térmico y eléctrico en dispositivos sensores de gases. Se analiza la microestructura de estas películas en función de las condiciones de la deposición (densidad de energía del láser, presión de oxígeno, distancia blanco-substrato y temperatura del substrato. Los estudios de difracción de rayos X, utilizando geometría de ángulo rasante, muestran que sólo puede observarse la reflexión coincidente con la (116 del corundum. Cuando las películas se tratan térmicamente a temperaturas superiores a 1.200°C sufren un cambio en su cristalinidad que depende de las condiciones de la deposición. Utilizando microscopía electrónica de barrido (SEM y análisis por EDAX, se comparan la estequiometría y la morfología de las películas con y sin tratamiento térmico.

  4. Revisión general de la transferencia de calor por ebullición en película en piscina

    OpenAIRE

    Arévalo Ramírez, Rubén; Rebollo Medrano, Luis; Abánades Velasco, Alberto; Muñoz Antón, Javier; Omaña, Rubén; Pérez, Orlando

    2007-01-01

    La ebullición en película es el mecanismo de transferencia de calor básico que acopla térmicamente un líquido, saturado o subenfriado, y una superficie caliente cuando existe una gran diferencia de temperatura entre ambos. Dicho mecanismo presenta la complejidad física asociada a la existencia de una capa límite convectiva de vapor en torno a la superficie caliente, así como al acoplamiento térmico radiante entre la superficie y los dos medios participativos que la rodean (vapor y líquido). E...

  5. Intervenciones feministas en el cine documental: conocimientos situados y (auto)representaciones de g??nero en pel??culas de Alina Marazzi y Maricarmen de Lara

    OpenAIRE

    Calder??n Sandoval, Orianna

    2013-01-01

    En esta tesis reviso pel??culas de Alina Marazzi (1964, Italia) y Maricarmen de Lara (1957, M??xico) dentro del debate sobre el realismo cinematogr??fico y la experimentaci??n formal en el cine documental feminista. Mi hip??tesis es que las intervenciones feministas en No les pedimos un viaje a la luna (1986) y ??M??s vale ma??a que fuerza? (2007) de Maricarmen de Lara, as?? como en Un???ora sola ti vorrei (2002) y Vogliamo anche le rose (2007) de Alina Marazzi, se manifiestan ...

  6. Análisis molecular, proteómico y filogenético de lazona pelúcida de mamíferos

    OpenAIRE

    Moros Nicolás, Carla

    2015-01-01

    INTRODUCCIÓN La zona pelúcida (ZP) es una matriz traslúcida, glicoproteica y acelular que rodea los ovocitos de los mamíferos implicada en importantes procesos durante la fecundación. Se ha considerado que la ZP estaba constituida por tres glicoproteínas (ZP1, ZP2 y ZP3) teniendo en cuenta estudios realizados en el ratón. Sin embargo, estudios posteriores demostraron que la ZP de cerda y de vaca también presentaba tres glicoproteínas, pero no estando presente en estos casos ZP1, siendo la...

  7. A vueltas con la alfabetización visual: lenguaje y significado en las películas de Wes Anderson

    Directory of Open Access Journals (Sweden)

    José Gabriel Ferreras Rodríguez

    2008-01-01

    Full Text Available El presente artículo tiene por objetivo discutir algunos elementos del concepto de la alfabetización visual, aplicando, luego, las herramientas de análisis de imágenes a las películas de Wes Anderson, como ejemplos del manejo intencional de las imágenes para transmitir determinados significados. The present article aims to discuss, firstly, some elements encompassed in the definition of visual literary and, secondly, to apply some image analysis tools to Wes Anderson’s movies, as examples of intentional pictorial organization so as to convey specific meanings.

  8. El Portfolio Europeo de las Lenguas (PEL): herramienta de evaluación de la composición escrita en español como lengua extranjera

    OpenAIRE

    López de la Torre, Juan Antonio

    2013-01-01

    Introducción Esta tesis pretende dar respuesta a uno de los desafíos que enfrentan los profesores de lenguas segundas (L2): mejorar la calidad de la evaluación de la expresión escrita. Partimos de la base del Marco Común Europeo de Referencia para las Lenguas (MCER), publicado por el Consejo de Europa con la intención de orientar la enseñanza y evaluación de lenguas, y del Portfolio Europeo de las Lenguas (PEL), cuyo propósito es aplicar en el aula los principios del MCER. Nos preguntam...

  9. Películas delgadas basadas en TIO2 y MOx/TIO2 con aplicaciones fotoelectroquímicas y ópticas

    OpenAIRE

    Gracia Torres, Francisco

    2005-01-01

    Durante los últimos años, la preparación de materiales en forma de película delgada ha sido objeto de un gran número de investigaciones debido a su enorme interés tecnológico. Los enormes avances de la última década hacen cada vez más complicado satisfacer las demandas que exige el diseño de nuevos dispositivos. Por ejemp lo, el considerable grado de miniaturización que están adquiriendo los dispositivos de estado sólido, especialmente en campos como la microelectrónica, comunicaciones y alma...

  10. Películas y recubrimientos comestibles: una alternativa favorable en la conservación poscosecha de frutas y hortalizas

    OpenAIRE

    Daybelis Fernández Valdés; Silvia Bautista Baños; Dayvis Fernández Valdés; Arturo Ocampo Ramírez; Annia García Pereira; Alejandro Falcón Rodríguez

    2015-01-01

    El creciente interés de los consumidores hacia productos sanos, nutritivos, naturales y que beneficiosos para la salud, ha orientado y motivado investigaciones hacia el desarrollo de películas y recubrimientos comestibles aplicados a productos hortofrutícolas, como una alternativa para cubrir estas necesidades. Estos se aplican con el objetivo de extender la vida útil de los alimentos y proveen la posibilidad de mejorar la seguridad del producto mediante la limitación de transferencia de hume...

  11. El videoforum como estrategia de intervención psicosocial en la familia (66 películas para el debate)

    OpenAIRE

    Núñez Domínguez, Trinidad

    1998-01-01

    Partimos de una breve descripción sobre cómo es la familia actual y ofrecemos un reper torio de películas que giran en torno a la temática familiar. Presentamos el videoforum como instrumento de trabajo cuyo objetivo fundamental es promover la reflexión sobre esta temá tica: relaciones familiares, los hijos, la pareja, la comunicación. De esta manera, considera mos el videoforum como una estrategia de intervención psicosocial

  12. Exposición de adolescentes de escuela secundaria de la Argentina y México a escenas de tabaco en películas de cine: una estimación poblacional

    Directory of Open Access Journals (Sweden)

    María V. Salgado

    2016-04-01

    Full Text Available Introducción: el tabaquismo en películas promueve el inicio de tabaquismo en adolescentes Objetivo: estimar el nivel de exposición a imágenes de tabaco contenidas en películas vistas por adolescentes de Argentina y México Métodos: Se realizó una encuesta a alumnos de primer año del secundario de Argentina y México. Se analizaron las 100 películas con mayor recaudación en cada año del periodo 2009-2013 (Argentina y 2010-2014 (México. A cada participante se le asignó una muestra aleatoria de 50 de estas películas, preguntándosele si la había visto. Se estimó el número total de adolescentes que habían visto cada película en cada país, y se multiplicó por el número de escenas que contenían tabaco (ocurrencias en cada película para así obtener el número de impresiones crudas de tabaco vista por los adolescentes escolarizados de cada país. Resultados: Se analizaron 422 films en Argentina y 433 en México. Más de 500 millones de imágenes de tabaco fueron vistas por la población joven de cada país, lo que promedia 128 y 121 minutos de escenas con tabaquismo por cada adolescente en Argentina y México respectivamente. Si bien los films calificados para mayores de 15/16/18 años tenían mayor promedio por película de escenas de tabaco, las películas calificadas para menores de esta edad fueron responsables de la mayor cantidad de escenas de tabaquismo vistas por adolescentes (67,3% en Argentina y 54,4% en México debido a su mayor audiencia. Conclusiones: A nivel poblacional son las películas para niños las máximas responsables de la carga de tabaco vista por adolescentes.

  13. The immunostimulating role of lichen polysaccharides: a review.

    Science.gov (United States)

    Shrestha, Gajendra; St Clair, Larry L; O'Neill, Kim L

    2015-03-01

    The immune system has capacity to suppress the development or progression of various malignancies including cancer. Research on the immunomodulating properties of polysaccharides obtained from plants, microorganisms, marine organisms, and fungi is growing rapidly. Among the various potential sources, lichens, symbiotic systems involving a fungus and an alga and/or a cyanobacterium, show promise as a potential source of immunomodulating compounds. It is well known that lichens produce an abundance of structurally diverse polysaccharides. However, only a limited number of studies have explored the immunostimulating properties of lichen polysaccharides. Published studies have shown that some lichen polysaccharides enhance production of nitrous oxide (NO) by macrophages and also alter the production levels of various proinflammatory and antiinflammatory cytokines (IL-10, IL-12, IL-1β, TNF-α, and IFN-α/β) by macrophages and dendritic cells. Although there are only a limited number of studies examining the role of lichen polysaccharides, all results suggest that lichen polysaccharides can induce immunomodulatory responses in macrophages and dendritic cells. Thus, a detailed evaluation of immunomodulatory capacity of lichen polysaccharides could provide a unique opportunity for the discovery of novel therapeutic agents. PMID:25339289

  14. Optimization for ultrasonic-microwave synergistic extraction of polysaccharides from Cornus officinalis and characterization of polysaccharides.

    Science.gov (United States)

    Yin, Xiulian; You, Qinghong; Jiang, Zhonghai; Zhou, Xinghai

    2016-02-01

    Ultrasonic-microwave synergistic extraction (UMSE) of polysaccharides from Cornus officinalis was optimized by response surface methodology (RSM). The effect of four different factors on the yield of C. officinalis polysaccharides (COP) was studied. RSM results showed that the optimal conditions were extraction time of 31.49823 min, microwave power of 99.39769 W, and water-to-raw material ratio of 28.16273. The COP yield was 11.38±0.31% using the modified optimal conditions, which was consistent with the value predicted by the model. The crude COP was purified by DEAE-Cellulose 52 chromatography and Sephadex G-100 chromatography. Five fractions, namely, crude COP, COP-1, COP-2, COP-3, and COP-4, were obtained. Monosaccharide composition analysis revealed that the COP was composed of glucose, arabinose, fucose, xylose, mannose, and rhamnose. Preliminary structural characterizations of COP were conducted by scanning electron microscopy and Fourier transform infrared spectroscopy. PMID:26627604

  15. New polysaccharide-based polymer electrolytes; Nouveaux electrolytes polymeres a base de polysaccharides

    Energy Technology Data Exchange (ETDEWEB)

    Velasquez-Morales, P.; Le Nest, J.F.; Gandini, A. [Ecole Francaise de Papeterie et des Industries Graphique, 38 - Saint Martin d`Heres (France)

    1996-12-31

    Polysaccharides like cellulose and chitosan are known for their filmic properties. This paper concerns the synthesis and the study of chitosan-based polymer electrolytes. A preliminary work concerns the study of glucosamine reactivity. The poly-condensation of chitosan ethers (obtained by reaction with ethylene oxide or propylene oxide) with bifunctional and monofunctional oligo-ethers leads to the formation of thin lattices (10 {mu}m) having excellent mechanical properties. The presence of grafted polyether chains along the polysaccharide skeleton allows to modify the vitreous transition temperature and the molecular disorder of the system. Two type of polymer electrolytes have been synthesized: electrolytes carrying a dissolved alkaline metal salt and ionomers. The analysis of their thermal, dynamical mechanical, nuclear magnetic relaxation, electrical, and electrochemical properties shows that this new class of polymer electrolytes has the same performances as ethylene poly-oxide based amorphous lattices plus the advantage of having good filmic properties. Abstract only. (J.S.)

  16. Enzymatic method for improving the injectability of polysaccharides. [US Patent Application

    Science.gov (United States)

    Griffith, W.L.; Compere, A.L.; Holleman, J.W.

    A method for enhancing the ability of polysaccharides in aqueous solution to flow through a porous medium comprises contacting the polysaccharides with an endoenzyme capable of hydrolyzing at least one of the linkages of the sugar units of the polysaccharides and maintaining the polysaccharides in contact with the enzyme under hydrolysis conditions for a time sufficient to decrease the tendency of the polysaccharides to plug the porous medium yet insufficient to decrease the viscosity of the aqueous polysaccharides by more than 25%. The partially hydrolyzed polysaccharides are useful as thickening agents for flooding water used to recover oil from oil-containing subterranean formations.

  17. Cholesterol and fat lowering with hydrophobic polysaccharide derivatives.

    Science.gov (United States)

    Čopíková, Jana; Taubner, Tomáš; Tůma, Jan; Synytsya, Andriy; Dušková, Dagmar; Marounek, Milan

    2015-02-13

    Hydrophobic derivatives of highly methylated citrus pectin, chitosan and cellulose were prepared and tested as potential cholesterol lowering agents. Elemental analysis and spectroscopic methods confirmed high substitution degree for all of them. Substitution with long alkyl/acyl groups led to significant changes in physical and thermal properties of modified polysaccharides. Sorption of cholate and cholesterol by these polysaccharide-based sorbents was estimated in comparison with the synthetic drug cholestyramine. It was found that modified polysaccharides have high affinity to cholesterol. By contrast, cholestyramine was effective only in cholate sorption. PMID:25458291

  18. Antigenicity and protective effects of type 3 pneumococcal polysaccharide in rats.

    OpenAIRE

    Hodges, G R; Worley, S E; Degener, C E; Clark, G M

    1980-01-01

    The response to type 3 pneumococcal polysaccharide vaccination, the protective effect of type 3 pneumococcal polysaccharide vaccination, and the ability of hemagglutinating antibody to type 3 pneumococcal polysaccharide to cross the blood-brain barrier were studied in rats. Hemagglutinating antibody response to vaccination with type 3 pneumococcal polysaccharide was found to be dependent on the dose and route of inoculation. Intraperitoneal vaccination with type 3 pneumococcal polysaccharide ...

  19. Immunological evaluation of meningococcal group C polysaccharide-tetanus toxoid conjugate in mice.

    OpenAIRE

    Beuvery, E C; van Delft, R W; Miedema, F; Kanhai, V; Nagel, J.

    1983-01-01

    Neisseria meningitidis group C polysaccharide-tetanus toxoid conjugate was prepared to obtain the polysaccharide component in a thymus-dependent form and to preserve the immunogenic properties of the tetanus toxoid component. Biochemical and immunochemical analyses of this conjugate revealed that (i) it was composed of equal amounts of polysaccharide and protein; (ii) the antigenic activity of the polysaccharide component was greatly reduced; (iii) it contained about 10% free polysaccharide; ...

  20. Immunogenicity in animals of a polysaccharide-protein conjugate vaccine against type III group B Streptococcus.

    OpenAIRE

    Wessels, M R; Paoletti, L C; Kasper, D L; DiFabio, J L; Michon, F; Holme, K; Jennings, H J

    1990-01-01

    The native capsular polysaccharide of type III group B Streptococcus elicits a specific antibody response in only 60% of nonimmune human subjects. To enhance the immunogenicity of this polysaccharide, we coupled the type III polysaccharide to tetanus toxoid. Prior to coupling, aldehyde groups were introduced on the polysaccharide by controlled periodate oxidation, resulting in the conversion of 25% of the sialic acid residues of the polysaccharide to residues of the 8-carbon analogue of siali...

  1. Reconstitution of emulsifying activity of Acinetobacter calcoaceticus BD4 emulsan by using pure polysaccharide and protein.

    OpenAIRE

    N. Kaplan; Zosim, Z; Rosenberg, E

    1987-01-01

    Acinetobacter calcoaceticus BD4 and BD413 produce extracellular emulsifying agents when grown on 2% ethanol medium. For emulsifying activity, both polysaccharide and protein fractions were required, as demonstrated by selective digestion of the polysaccharide with a specific bacteriophage-borne polysaccharide depolymerase, deproteinization of the extracellular emulsifying complex with hot phenol, and reconstitution of emulsifier activity with pure polysaccharide and a polysaccharide-free prot...

  2. Structural Properties of Group B Streptococcal Type III Polysaccharide Conjugate Vaccines That Influence Immunogenicity and Efficacy

    OpenAIRE

    Wessels, Michael R.; Paoletti, Lawrence C.; Guttormsen, Hilde-Kari; Michon, Francis; D’Ambra, Anello J.; Kasper, Dennis L.

    1998-01-01

    In this study, we tested the hypothesis that the immunogenicity and protective efficacy of polysaccharide-protein conjugate vaccines are influenced by three variables: (i) molecular size of the conjugate, (ii) molecular size of the polysaccharide used for conjugation, and (iii) extent of polysaccharide-to-protein cross-linking. Type III group B Streptococcus capsular polysaccharide was linked by reductive amination at multiple sites to tetanus toxoid to create a polysaccharide-protein conjuga...

  3. Nutraceutical functionalities of polysaccharides from marine invertebrates.

    Science.gov (United States)

    Choi, Byeong-Dae; Choi, Yeung Joon

    2012-01-01

    Many researchers are seeking functional materials from marine resources. These marine resources can be used as traditional food additives, and specifically, these are based on polysaccharides. To date, there is a big opportunity to develop new high-value added products with indispensable functional characteristics, which can be used in nutraceuticals either as additives or supplements. Also, a crossover in the pharmaceutical market may be established. Some glycosaminoglycans (GAGs) mimetic-type molecules are already being utilized in the field of nutrition as well as in the cosmetics industry. This chemical is used as a dietary supplement to maintain the structure and function of cartilages, for the relief of pain caused by osteoarthritic joints, and can also be used as an anti-inflammatory agent. Recently, in relation to the prevalence of mad cow disease and avian influenza, the production of GAGs from marine invertebrates offers new market opportunities as compared with that obtained from bovine or avian livestock. PMID:22361178

  4. An Acidic Polysaccharide from Tribulus terrestris

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    An aqucous acidic polysaccharide, named rhamnogalacturonan (designated as TTP-D2)was isolated from Tribulus terrestris L by means of DEAE-cellulose chromatography and gel filtration. The molecular mass of TTP-D2 was estimated to be 26 KDa by gel filtration. TTP-D2 is composed of galacturonic acid, rhamnose, arabinose, galactose, fucose, mannosc, xylose and glucose in a ratio of 71.4: 13.5: 5.6: 4.9: 3.1: 1.9: 1.9: 1.0. The main chain structure of TTP-D2 was elucidated as an acidic hetero-polysaccharidc with the connection of α-(l-4) galacturonic acid with α-(1-3) rhamnose by GC analysis of partially hydrolyzed products and the determination of 1H, 13C-NMR spectra.

  5. An Acidic Polysaccharide from Tribulus terrestris

    Institute of Scientific and Technical Information of China (English)

    HaiShengCHEN; WingNangLEUNG; 等

    2002-01-01

    An aqueous acidic polysaccharide, named rhamnogalacturonan (designated as TIP-D2) was isolated from Tribulus terrestris L by means of DEAE-cellulose chromatography and gel filtration. The molecular mass of TTP-D2 was estimated to be 26 KDa by gel filtration.TTP-D2 is composed of galacturonic acid, rhamnose, arabinose, galactose,fucose,mannose,xylose and glucose in a ratio of 71.4:13.5:5.6:4.9:3.1:1.9:1.9:1.0. The main chain structure of TTP-D2 was elucidated as an acidic hetero-polysaccaride with the connection of α-(1-4) galacturonic acid with α-(1-3) rhamnose by GC analysis of partially hydrolyzed products and determination of 1H,13C-NMR spectra.

  6. Utilization of polysaccharides by radiation processing

    International Nuclear Information System (INIS)

    Radiation treatment has been applied for improvement or pasteurization of agro-resources to recycle the resources and to reduce the pollution of environment. By using the radiation effect for pasteurization, upgrading of cellulosic wastes of oil palm to animal feeds and mushroom has been studied under the bilateral research cooperation between JAERI and MINT (Malaysian Institute for Nuclear Technology Research). The necessary dose for pasteurization of oil palm empty fruit bunch (EFB), which is a main cellulosic by-product of palm oil industry, was determined as 10 kGy. After pasteurization, the EFB substrate was inoculated with Pleurotus sajor-caju and fermented for 1 month. The digestibility and nutritional value of fermented products were evaluated as ruminant feeds and the mushroom can be produced as by-product. For the improvement of resources, radiation effects on polysaccharides such as chitosan, sodium alginate, carrageenan, cellulose, pectin have been investigated to induce the biological activities. These carbohydrates were easily degraded by irradiation and induced various kinds of biological activities. The anti-bacterial activity and elicitor activity of chitosan were induced by irradiation. The induction of phytoalexins was also observed by irradiated pectin but the higher elicitor activity for pisatin was obtained by chitosan than pectin. For the plant growth promotion, alginate derived from brown marine algae, chitosan and ligno-cellulosic extracts show a strong activity. carrageenan derived from red marine algae can promote growth of rice and the highest effect was obtained with kappa carrageenan irradiated at 100 kGy. Furthermore, some radiation degraded polysaccharides suppressed the damage of environmental stress on plants. (author)

  7. Utilization of polysaccharides by radiation processing

    Energy Technology Data Exchange (ETDEWEB)

    Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2000-03-01

    Radiation treatment has been applied for improvement or pasteurization of agro-resources to recycle the resources and to reduce the pollution of environment. By using the radiation effect for pasteurization, upgrading of cellulosic wastes of oil palm to animal feeds and mushroom has been studied under the bilateral research cooperation between JAERI and MINT (Malaysian Institute for Nuclear Technology Research). The necessary dose for pasteurization of oil palm empty fruit bunch (EFB), which is a main cellulosic by-product of palm oil industry, was determined as 10 kGy. After pasteurization, the EFB substrate was inoculated with Pleurotus sajor-caju and fermented for 1 month. The digestibility and nutritional value of fermented products were evaluated as ruminant feeds and the mushroom can be produced as by-product. For the improvement of resources, radiation effects on polysaccharides such as chitosan, sodium alginate, carrageenan, cellulose, pectin have been investigated to induce the biological activities. These carbohydrates were easily degraded by irradiation and induced various kinds of biological activities. The anti-bacterial activity and elicitor activity of chitosan were induced by irradiation. The induction of phytoalexins was also observed by irradiated pectin but the higher elicitor activity for pisatin was obtained by chitosan than pectin. For the plant growth promotion, alginate derived from brown marine algae, chitosan and ligno-cellulosic extracts show a strong activity. carrageenan derived from red marine algae can promote growth of rice and the highest effect was obtained with kappa carrageenan irradiated at 100 kGy. Furthermore, some radiation degraded polysaccharides suppressed the damage of environmental stress on plants. (author)

  8. Películas y recubrimientos comestibles: una alternativa favorable en la conservación poscosecha de frutas y hortalizas

    Directory of Open Access Journals (Sweden)

    Daybelis Fernández Valdés

    2015-01-01

    Full Text Available El creciente interés de los consumidores hacia productos sanos, nutritivos, naturales y que beneficiosos para la salud, ha orientado y motivado investigaciones hacia el desarrollo de películas y recubrimientos comestibles aplicados a productos hortofrutícolas, como una alternativa para cubrir estas necesidades. Estos se aplican con el objetivo de extender la vida útil de los alimentos y proveen la posibilidad de mejorar la seguridad del producto mediante la limitación de transferencia de humedad, oxígeno y compuestos responsables del sabor, color y aroma. El empleo de películas y recubrimientos comestibles a base de polisacáridos, proteínas, lípidos, aditivos y compuestos activos ha jugado un papel importante en la industria de alimentos y han demostrado ser efectivos en la conservación de frutas y hortalizas controlando transferencia de gases, crecimiento microbiano, así como manteniendo las características deseadas por los consumidores como, apariencia fresca, firmeza, brillo, color, calidad y valor comercial. La finalidad de esta revisión bibliográfica es demostrar que la utilización de cubiertas comestibles ayuda a la conservación y calidad de frutas y hortalizas.

  9. Exposición de adolescentes de escuela secundaria de la Argentina y México a escenas de tabaco en películas de cine: una estimación poblacional

    OpenAIRE

    SALGADO, MARÍA V.; Adriana Pérez; Erika N. Abad Vivero; Thrasher, James F.; SARGENT, James D.; Raúl Mejía

    2016-01-01

    Introducción: el tabaquismo en películas promueve el inicio de tabaquismo en adolescentes Objetivo: estimar el nivel de exposición a imágenes de tabaco contenidas en películas vistas por adolescentes de Argentina y México Métodos: Se realizó una encuesta a alumnos de primer año del secundario de Argentina y México. Se analizaron las 100 películas con mayor recaudación en cada año del periodo 2009-2013 (Argentina) y 2010-2014 (México). A cada participante se le asignó una muestra aleat...

  10. Netikrosios miltligės (Peronospora viciae (Berk) Caspary) įtaka miškinio pelėžirnio (Lathyrus sylvestris L.) morfologiniams ir sėklų produktyvumo rodikliams

    OpenAIRE

    Reipaitė, Aurelija

    2014-01-01

    Baigiamajame darbe 2012–2013 m. tirta netikrosios miltligės (Peronospora viciae (Berk) Caspary) įtaka skirtingos geografinės kilmės miškinio pelėžirnio (Lathyrus sylvestris L.) cenopopuliacijų morfologiniams ir sėklų produktyvumo rodikliams. Darbo objektas – iš skirtingų Lietuvos rajonų surinktos dvylika miškinio pelėžirnio cenopopuliacijų, augančių vienodos agrotechnikos sąlygomis. Darbo tikslas – įvertinti netikrosios miltligės įtaką skirtingų cenopopuliacijų miškinio pelėžirnio morfo...

  11. Comparison of Polysaccharides from Two Species of Ganoderma

    Directory of Open Access Journals (Sweden)

    Yu-Ping Tang

    2012-01-01

    Full Text Available Ganoderma lucidum and Ganoderma sinense, known as Lingzhi in Chinese, are commonly used Chinese medicines with excellent beneficial health effects. Triterpenes and polysaccharides are usually considered as their main active components. However, the content of triterpenes differs significantly between the two species of Ganoderma. To date, a careful comparison of polysaccharides from the two species of Ganoderma has not been performed. In this study, polysaccharides from fruiting bodies of two species of Lingzhi collected from different regions of China were analyzed and compared based on HPSEC-ELSD and HPSEC-MALLS-RI analyses, as well as enzymatic digestion and HPTLC of acid hydrolysates. The results indicated that both the HPSEC-ELSD profiles and the molecular weights of the polysaccharides were similar. Enzymatic digestion showed that polyshaccharides from all samples of Lingzhi could be hydrolyzed by pectinase and dextranase. HPTLC profiles of their TFA hydrolysates colored with different reagents and their monosaccharides composition were also similar.

  12. Antioxidant activities of five polysaccharides from Inonotus obliquus.

    Science.gov (United States)

    Huang, Sheng-quan; Ding, Shaodong; Fan, Liuping

    2012-06-01

    Five polysaccharides (IOP1b, IOP2a, IOP2c, IOP3a and IOP4) were isolated and purified from Inonotus obliquus by DEAE-Sepharose fast flow and SepharoseCL-6B column chromatography. Their chemical and physical characteristics were determined and antioxidant activities were investigated on the basis of hydroxyl radical assay, superoxide radical assay and ferric-reducing antioxidant power assay. The results showed that five polysaccharides exhibited antioxidant activities, and the higher content of uronic acid and proteinous substances, the stronger antioxidant activities of polysaccharides. Besides, molecular weights of polysaccharides also influence their antioxidant activities. IOP3a and IOP4 showed higher antioxidant properties than IOP1b, IOP2a and IOP2c. PMID:22484729

  13. Synbiotic matrices derived from plant oligosaccharides and polysaccharides

    Science.gov (United States)

    A porous synbiotic matrix was prepared by lyophilization of alginate and pectin or fructan oligosaccharides and polysaccharides cross-linked with calcium. These synbiotic matrices were excellent physical structures to support the growth of Lactobacillus acidophilus (1426) and Lactobacillus reuteri (...

  14. Cholesterol and fat lowering with hydrophobic polysaccharide derivatives

    Czech Academy of Sciences Publication Activity Database

    Čopíková, J.; Taubner, T.; Tůma, J.; Synytsya, A.; Dušková, Dagmar; Marounek, Milan

    2015-01-01

    Roč. 116, č. 1 (2015), s. 207-214. ISSN 0144-8617 Institutional support: RVO:67985904 Keywords : hydrophobically modified polysaccharides * structure * thermal analysis Subject RIV: ED - Physiology Impact factor: 4.074, year: 2014

  15. Anti-diabetic polysaccharides from natural sources: A review.

    Science.gov (United States)

    Wang, Peng-Cheng; Zhao, Shan; Yang, Bing-You; Wang, Qiu-Hong; Kuang, Hai-Xue

    2016-09-01

    Diabetes mellitus (DM) is a metabolic disease attracted worldwide concerns, which severely impairs peoples' quality of life and is attributed to several life-threatening complications, including atherosclerosis, nephropathy and retinopathy. The current therapies for DM include mainly oral anti-diabetic drugs and insulin. However, continuous use of these causes insulin resistance and side-effects, and the demand of effective, nontoxic and affordable drugs for DM patients is eager. Several previous studies have shown that non-toxic biological macromolecules, mainly polysaccharides, possess prominent efficacies on DM. Based on these encouraging observations, a great deal of efforts have been focused on discovering anti-diabetic polysaccharides for the development of effective therapeutics for DM. This review focuses on the advancements in the anti-diabetic efficacy of various natural polysaccharides and polysaccharide complexes from 2010 to 2015. PMID:27185119

  16. Radiation-chemical degradation of cellulose and other polysaccharides

    International Nuclear Information System (INIS)

    Results of studies on the radiation-chemical transformations of cellulose, its ethers, and some other polysaccharides (xylan, starch, dextran, chitin, chitosan, and heparin) are discussed. Ionising radiation causes the degradation of these compounds accompanied by decomposition of the pyranose ring and formation of compounds with carbonyl and carboxy groups, as well as formation of hydrogen, carbon dioxide, and carbon monoxide. The efficiency of degradation increases considerably with temperature and depends on the structure of the polysaccharide and the nature of its substituents. A mechanism of the radiation-chemical transformations of cellulose and other polysaccharides is suggested. The prospects of using radiation-chemical methods for processing of cellulose and other polysaccharides in industry and agriculture are considered. The bibliography includes 213 references.

  17. Impact of a pectic polysaccharide on oenin copigmentation mechanism.

    Science.gov (United States)

    Fernandes, Ana; Brás, Natércia F; Oliveira, Joana; Mateus, Nuno; de Freitas, Victor

    2016-10-15

    Copigmentation plays an important role in the colors provided by anthocyanins. However, little attention has been paid to the interaction between anthocyanins and cell wall compounds (e.g. polysaccharides) and the impact of this interaction on anthocyanins color, a fundamental issue to be considered in industrial applications of these pigments as food colorants. The copigmentation binding constants (KCP) for the interaction between malvidin-3-O-glucoside and (+)-catechin in the presence of low methoxylated pectic polysaccharide were determined. The values obtained showed that in the presence of pectic polysaccharide the copigmentation binding constants decreased. These results probably suggest the occurrence of competition equilibrium in which the presence of pectin limited the association between catechin and oenin. (1)H NMR studies revealed that the dissociation constant determined for these complexes was very similar in absence and presence of 1.5g/L pectin with this polysaccharide apparently not affecting the strength of anthocyanin-catechin binding. PMID:27173529

  18. Actinobacillus actinomycetemcomitans Y4 capsular-polysaccharide-like polysaccharide promotes osteoclast-like cell formation by interleukin-1 alpha production in mouse marrow cultures.

    OpenAIRE

    Nishihara, T.; Ueda, N; Amano, K; Ishihara, Y; Hayakawa, H.; Kuroyanagi, T; Ohsaki, Y; Nagata, K.; Noguchi, T

    1995-01-01

    The mechanism of osteoclast-like cell formation induced by periodontopathic bacterium Actinobacillus actinomycetemcomitans Y4 (serotype b) capsular-polysaccharide-like polysaccharide (capsular-like polysaccharide) was examined in a mouse bone marrow culture system. When mouse bone marrow cells were cultured with A. actinomycetemcomitans Y4 capsular-like polysaccharide for 9 days, many multinucleated cells were formed. The multinucleated cells showed several characteristics of osteoclasts, inc...

  19. Elaboración, caracterización y comparación de películas comestibles en base a aislado de proteínas de suero lácteo (WPI)

    OpenAIRE

    Rosa Márquez; Daniela Escobar; Angelina Sala; Carlos Silvera

    2011-01-01

    El incremento del interés en alimentos de alta calidad con mayor vida útil y un menor impacto a nivel ambiental ha llevado al estudio y desarrollo de películas y coberturas comestibles y/o biodegradables. Éstas son una excelente alternativa de empaque de alimentos por su carácter biodegradable, flexible y su poder para actuar como envases activos. En base a esto y a la gran producción lechera en Uruguay, en el presente trabajo se elaboraron y estudiaron películas en base a WPI, como una alter...

  20. Efecto de la adición, tipo y concentracion de nanoarcilla sobre las propiedades mecánicas y de barrera de películas biodegradables basados en quitosano

    OpenAIRE

    Garde Izquierdo, Gaizka

    2014-01-01

    La aplicación más innovadora de las películas y recubrimientos biodegradables es su empleo como matrices portadoras de distintos aditivos funcionales capaces de aumentar la seguridad, vida comercial y calidad de los alimentos. La efectividad este tipo de películas reside en el control de la migración de sus agentes activos hacia la superficie de los productos sobre los que se disponen, ayudando a la dosificación del aditivo y al mantenimiento de las concentraciones efectivas lo...

  1. Evaluación del uso de ciclodextrinas para el control de la difusión de componentes activos desde películas comestibles a sistemas alimentarios

    OpenAIRE

    Eguinoa Gallo, Andoni

    2014-01-01

    El trabajo desarrollado durante el proyecto fin de máster se enmarca dentro del desarrollo de nuevas películas y/o recubrimientos comestibles para la mejora de la calidad, así como de la vida útil de unos determinados alimentos. En concreto, se han llevado a cabo películas/recubrimientos de proteína de suero de leche (WPI, whey protein isolate) que se caracterizan por sus buenas propiedades (transparentes, inodoros, insípidos) y ser excelentes barreras frente al oxígeno. Éstos se han empl...

  2. Heterologous Expression of the Pneumococcal Serotype 14 Polysaccharide in Lactococcus lactis Requires Lactococcal epsABC Regulatory Genes▿ †

    OpenAIRE

    Nierop Groot, M.N.; Godefrooij, J.; Kleerebezem, M.

    2007-01-01

    The pneumococcal serotype 14 polysaccharide was produced in Lactococcus lactis by coexpressing pneumococcal polysaccharide type 14-specific genes (cpsFGHIJKL(14)) with the lactococcal regulatory and priming glucosyltransferase-encoding genes specific for B40 polysaccharide (epsABCD(B40)). The polysaccharide produced by Lactococcus was secreted in the medium, simplifying downstream processing and polysaccharide isolation from culture broth

  3. Pectin, a versatile polysaccharide present in plant cell walls

    OpenAIRE

    Voragen, A.G.J.; Coenen, G.J.; Verhoef, R.P.; Schols, H.A.

    2009-01-01

    Pectin or pectic substances are collective names for a group of closely associated polysaccharides present in plant cell walls where they contribute to complex physiological processes like cell growth and cell differentiation and so determine the integrity and rigidity of plant tissue. They also play an important role in the defence mechanisms against plant pathogens and wounding. As constituents of plant cell walls and due to their anionic nature, pectic polysaccharides are considered to be ...

  4. Demonstration of Polysaccharide Capsule in Campylobacter jejuni Using Electron Microscopy

    OpenAIRE

    Karlyshev, Andrey V.; McCrossan, Maria V.; Wren, Brendan W.

    2001-01-01

    Recently, we reported that Campylobacter jejuni, an important gastrointestinal pathogen, has the genetic determinants to produce a capsular polysaccharide (Karlyshev et al., Mol. Microbiol. 35:529–541, 2000). Despite these data, the presence of a capsule in these bacteria has remained controversial. In this study we stain C. jejuni cells with the cationic dye Alcian blue and demonstrate for the first time by electron microscopy that C. jejuni cells produce a polysaccharide capsule that is ret...

  5. Voltammetry of Os(VI)-modified polysaccharides at carbon electrodes

    Czech Academy of Sciences Publication Activity Database

    Trefulka, Mojmír; Paleček, Emil

    2009-01-01

    Roč. 21, č. 15 (2009), s. 1763-1766. ISSN 1040-0397 R&D Projects: GA ČR(CZ) GA301/07/0490; GA MŠk(CZ) LC06035 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : chemical modification of polysaccharides * Os(VI)L-polysaccharide adducts * pyrolytic graphite electrodes Subject RIV: BO - Biophysics Impact factor: 2.630, year: 2009

  6. Antioxidant properties of cell wall polysaccharides of Stevia rebaudiana leaves

    OpenAIRE

    Mediesse Kengne Francine; Woguia Alice Louise; Fogue Souopgui Pythagore; Atogho-Tiedeu Barbara; Simo Gustave; Thaddée Boudjeko

    2014-01-01

    Objective: To examine the total phenolic and protein contents, and the antioxidant activities of cell wall polysaccharide fractions of Stevia rebaudiana leaves. Methods: Three different polysaccharide-enriched fractions, namely FPE (extract with 50 mmol/ L ethylene diamine tetra acetic acid), FPK (extract with 0.05 mol/L KOH) and FH (extract with 4 mol/L KOH) were extracted from Stevia rebaudiana leaves. The antioxidant activity of these fractions was evaluated based on thei...

  7. Characterisation of cell wall polysaccharides in bilberries and black currants

    OpenAIRE

    Hilz, H

    2007-01-01

    During berry juice production, polysaccharides are released from the cell walls and cause thickening and high viscosity when the berries are mashed. Consequences are a low juice yield and a poor colour. This can be prevented by the use of enzymes that degrade these polysaccharides. To use these enzymes most efficiently, the structure and composition of the cell walls had to be known. This thesis describes a detailed composition of the cell walls of bilberries and black currants. The obtained ...

  8. Effect of Nitrogen on Polysaccharide Production in a Porphyridium sp

    OpenAIRE

    Arad, Shoshana (Malis); Friedman, Orit (Dahan); Rotem, Avi

    1988-01-01

    Porphyridium cultures grown on either nitrate or ammonium as the nitrogen source showed similar patterns of growth and cell wall polysaccharide production. The effect of nitrogen on growth and cell wall polysaccharide production was studied by applying three regimens of supply: batch mode, in which nitrate was supplied at the beginning of the experiment and became depleted at day 6; continual mode, in which nitrate was added daily; and deficient mode, in which the cells were cultured in a nit...

  9. Safety Assessment of Microbial Polysaccharide Gums as Used in Cosmetics.

    Science.gov (United States)

    Fiume, Monice M; Heldreth, Bart; Bergfeld, Wilma F; Belsito, Donald V; Hill, Ronald A; Klaassen, Curtis D; Liebler, Daniel C; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Andersen, F Alan

    2016-07-01

    The Cosmetic Ingredient Review Expert Panel assessed the safety of 34 microbial polysaccharide gums for use in cosmetics, finding that these ingredients are safe in cosmetic formulations in the present practices of use and concentration. The microbial polysaccharide gums named in this report have a variety of reported functions in cosmetics, including emulsion stabilizer, film former, binder, viscosity-increasing agent, and skin-conditioning agent. The Panel reviewed available animal and clinical data in making its determination of safety. PMID:27383198

  10. Immunomodulatory Activity and Partial Characterisation of Polysaccharides from Momordica charantia

    OpenAIRE

    Yuan-Yuan Deng; Yang Yi; Li-Fang Zhang; Rui-Fen Zhang; Yan Zhang; Zhen-Cheng Wei; Xiao-Jun Tang; Ming-Wei Zhang

    2014-01-01

    Momordica charantia Linn. is used as an edible and medicinal vegetable in sub-tropical areas. Until now, studies on its composition and related activities have been confined to compounds of low molecular mass, and no data have been reported concerning the plant’s polysaccharides. In this work, a crude polysaccharide of M. charantia (MCP) fruit was isolated by hot water extraction and then purified using DEAE-52 cellulose anion-exchange chromatography to produce two main fractions MCP1 and M...

  11. Liposome-Based Delivery Systems in Plant Polysaccharides

    International Nuclear Information System (INIS)

    Plant polysaccharides consist of many monosaccharide by α or β glycosidic bond which can be extracted by the water, alcohol, lipophile liquid from a variety of plants including Cordyceps sinensis, astragalus, and mushrooms. Recently, many evidences illustrate that natural plant polysaccharides possess various biological activities including strengthening immunity, lowering blood sugar, regulating lipid metabolism, anti oxidation, anti aging, and antitumour. Plant polysaccharides have been widely used in the medical field due to their special features and low toxicity. As an important drug delivery system, liposomes can not only encapsulate small-molecule compound but also big-molecule drug; therefore, they present great promise for the application of plant polysaccharides with unique physical and chemical properties and make remarkable successes. This paper summarized the current progress in plant polysaccharides liposomes, gave an overview on their experiment design method, preparation, and formulation, characterization and quality control, as well as in vivo and in vitro studies. Moreover, the potential application of plant polysaccharides liposomes was prospected as well.

  12. Liposome-Based Delivery Systems in Plant Polysaccharides

    Directory of Open Access Journals (Sweden)

    Meiwan Chen

    2012-01-01

    Full Text Available Plant polysaccharides consist of many monosaccharide by α- or β-glycosidic bond which can be extracted by the water, alcohol, lipophile liquid from a variety of plants including Cordyceps sinensis, astragalus, and mushrooms. Recently, many evidences illustrate that natural plant polysaccharides possess various biological activities including strengthening immunity, lowering blood sugar, regulating lipid metabolism, antioxidation, antiaging, and antitumour. Plant polysaccharides have been widely used in the medical field due to their special features and low toxicity. As an important drug delivery system, liposomes can not only encapsulate small-molecule compound but also big-molecule drug; therefore, they present great promise for the application of plant polysaccharides with unique physical and chemical properties and make remarkable successes. This paper summarized the current progress in plant polysaccharides liposomes, gave an overview on their experiment design method, preparation, and formulation, characterization and quality control, as well as in vivo and in vitro studies. Moreover, the potential application of plant polysaccharides liposomes was prospected as well.

  13. Antitussive activity of polysaccharides isolated from the Malian medicinal plants.

    Science.gov (United States)

    Sutovská, M; Franová, S; Priseznaková, L; Nosálová, G; Togola, A; Diallo, D; Paulsen, B S; Capek, P

    2009-04-01

    From the leaves of popular Malian medicinal plants Trichilia emetica (TE) and Opilia celtidifolia (OC), and fruits of Crossopteryx febrifuga (CF) water and water-ethanol soluble polysaccharide materials were isolated. The results of chemical analysis of the crude polysaccharides showed the dominance of the arabinogalactan ( approximately 54%) and the rhamnogalacturonan ( approximately 30%) in T. emetica leaves, the arabinogalactan ( approximately 60%), the rhamnogalacturonan ( approximately 14%) and the glucuronoxylan ( approximately 14%) in O. celtidifolia leaves, and pectic type of polysaccharides ( approximately 75%) with a lower content of the arabinogalactan ( approximately 17%) in C. febrifuga fruits. The plant polysaccharides showed various biological effects on the citric acid-induced cough reflex and reactivity of airways smooth muscle in vivo conditions. T. emetica and O. celtidifolia polysaccharides possessed significant cough-suppressive effect on chemically induced cough. Furthermore, values of specific airways resistance pointed on bronchodilatory property of polysaccharides isolated from O. celtidifolia. However, the crude extract from C. febrifuga in the same dose as T. emetica and O. celtidifolia did not influence the experimentally induced cough as well as reactivity of airways smooth muscle despite of the fact that the water-ethanol extract is recommended for cough therapy in Mali in the form of syrup. PMID:19150368

  14. Characterization of active polysaccharides of HemoHIM

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Kwang Sun; Shin, Myeong Suk; Bae, Beom Seon; Hwang, Yong Cheol [Kyonggi University, Suwon (Korea, Republic of); Ryu, Kwang Won [Chungju University, Chungju (Korea, Republic of)

    2007-07-15

    In this study, we aimed to elucidate the detailed structure and active moiety of polysaccharide, one of the active constituents of immune and hematopoietic modulating activities of HemoHIM. We first isolated the polysaccharide fractions from the hot water extracts of the each ingredient herbs (A. gigas, P. janonica, C. officinale) of HemoHIM and their mixture. These polysaccharides were composed of neutral (85.32-92.73%) and acidic (4.25-7.88%) saccharides, proteins (0.16-4.02%), and polyphenols (2.09-5.37%). The hydrolytic analysis of polysaccharide fractions showed that they commonly showed higher arabinose, galactose, and galacturonic acid contents. These result suggested that these polysaccharides may have higher contents of rhamnogalacturonan among pectic substances and the main active moiety is composed of polysaccharides. The anion exchange chromatography of HemoHIM and each ingredient herb extract using DEAE-Sepharose FF (Cl- form) column resulted in 1 non-adsorption and 8 adsorption fractions. The analysis of immune activity (lymphocyte proliferation) on these fractions showed that the fractions obtained by higher salt concentration carried the higher activity, but all fractions showed considerable immune activity

  15. Correlation Between Chain Architecture and Hydration Water Structure in Polysaccharides.

    Science.gov (United States)

    Grossutti, Michael; Dutcher, John R

    2016-03-14

    The physical properties of confined water can differ dramatically from those of bulk water. Hydration water associated with polysaccharides provides a particularly interesting example of confined water, because differences in polysaccharide structure provide different spatially confined environments for water sorption. We have used attenuated total reflection infrared (ATR-IR) spectroscopy to investigate the structure of hydration water in films of three different polysaccharides under controlled relative humidity (RH) conditions. We compare the results obtained for films of highly branched, dendrimer-like phytoglycogen nanoparticles to those obtained for two unbranched polysaccharides, hyaluronic acid (HA), and chitosan. We find similarities between the water structuring in the two linear polysaccharides and significant differences for phytoglycogen. In particular, the results suggest that the high degree of branching in phytoglycogen leads to a much more well-ordered water structure (low density, high connectivity network water), indicating the strong influence of chain architecture on the structuring of water. These measurements provide unique insight into the relationship between the structure and hydration of polysaccharides, which is important for understanding and exploiting these sustainable nanomaterials in a wide range of applications. PMID:26859153

  16. Phosphorylation of psyllium seed polysaccharide and its characterization.

    Science.gov (United States)

    Rao, Monica R P; Warrier, Deepa U; Gaikwad, Snehal R; Shevate, Prachi M

    2016-04-01

    Psyllium is widely used as a medicinally active natural polysaccharide for treating conditions like constipation, diarrhea, and irritable bowel syndrome, inflammatory bowel disease, ulcerative colitis and colon cancer. Studies have been performed to characterize and modify the polysaccharide obtained from psyllium seed husk and to evaluate its use as a pharmaceutical excipient, but no studies have been performed to evaluate the properties of the polysaccharide present in psyllium seeds. The present study focuses on phosphorylation of psyllium seed polysaccharide (PPS) using sodium tri-meta phosphate as the cross-linking agent. The modified phosphorylated psyllium seed polysaccharide was then evaluated for physicochemical properties, rheological properties, spectral analysis, thermal analysis, crosslinking density and acute oral toxicity studies. The modified polysaccharide (PhPPS) has a high swelling index due to which it can be categorized as a hydrogel. The percent increase in swelling of PhPPS as compared to PPS was found to be 90.26%. The PPS & PhPPS mucilages of all strengths were found to have shear thinning properties. These findings are suggestive of the potential use of PhPPS as gelling & suspending agent. PhPPS was found to have a mucoadhesive property which was comparable with carbopol. PMID:26769088

  17. Correlation Between Chain Architecture and Hydration Water Structure in Polysaccharides

    Science.gov (United States)

    Grossutti, Michael; Dutcher, John

    The physical properties of confined water can differ dramatically from those of bulk water. Hydration water associated with polysaccharides provides a particularly important example of confined water, with differences in polysaccharide structure providing different spatially confined environments for water adsorption. We have used attenuated total reflection infrared (ATR-IR) spectroscopy to investigate the structure of hydration water in films of three different polysaccharides under controlled relative humidity (RH) conditions. We compare the results obtained for films of highly branched, monodisperse phytoglycogen nanoparticles to those obtained for two unbranched polysaccharides, hyaluronic acid (HA) and chitosan. We find similarities between water structuring in the two linear polysaccharides, and significant differences for phytoglycogen. In particular, the phytoglycogen nanoparticles exhibited high network water connectivity, and a large increase in the fraction of multimer water clusters with increasing RH, whereas the water structure for HA and chitosan was found to be insensitive to changes in RH. These measurements provide unique insight into the relationship between the chain architecture and hydration of polysaccharides.

  18. Characterization of active polysaccharides of HemoHIM

    International Nuclear Information System (INIS)

    In this study, we aimed to elucidate the detailed structure and active moiety of polysaccharide, one of the active constituents of immune and hematopoietic modulating activities of HemoHIM. We first isolated the polysaccharide fractions from the hot water extracts of the each ingredient herbs (A. gigas, P. janonica, C. officinale) of HemoHIM and their mixture. These polysaccharides were composed of neutral (85.32-92.73%) and acidic (4.25-7.88%) saccharides, proteins (0.16-4.02%), and polyphenols (2.09-5.37%). The hydrolytic analysis of polysaccharide fractions showed that they commonly showed higher arabinose, galactose, and galacturonic acid contents. These result suggested that these polysaccharides may have higher contents of rhamnogalacturonan among pectic substances and the main active moiety is composed of polysaccharides. The anion exchange chromatography of HemoHIM and each ingredient herb extract using DEAE-Sepharose FF (Cl- form) column resulted in 1 non-adsorption and 8 adsorption fractions. The analysis of immune activity (lymphocyte proliferation) on these fractions showed that the fractions obtained by higher salt concentration carried the higher activity, but all fractions showed considerable immune activity

  19. Marine Derived Polysaccharides for Biomedical Applications: Chemical Modification Approaches

    Directory of Open Access Journals (Sweden)

    Paola Laurienzo

    2008-09-01

    Full Text Available Polysaccharide-based biomaterials are an emerging class in several biomedical fields such as tissue regeneration, particularly for cartilage, drug delivery devices and gelentrapment systems for the immobilization of cells. Important properties of the polysaccharides include controllable biological activity, biodegradability, and their ability to form hydrogels. Most of the polysaccharides used derive from natural sources; particularly, alginate and chitin, two polysaccharides which have an extensive history of use in medicine, pharmacy and basic sciences, and can be easily extracted from marine plants (algae kelp and crab shells, respectively. The recent rediscovery of poly-saccharidebased materials is also attributable to new synthetic routes for their chemical modification, with the aim of promoting new biological activities and/or to modify the final properties of the biomaterials for specific purposes. These synthetic strategies also involve the combination of polysaccharides with other polymers. A review of the more recent research in the field of chemical modification of alginate, chitin and its derivative chitosan is presented. Moreover, we report as case studies the results of our recent work concerning various different approaches and applications of polysaccharide-based biomaterials, such as the realization of novel composites based on calcium sulphate blended with alginate and with a chemically modified chitosan, the synthesis of novel alginate-poly(ethylene glycol copolymers and the development of a family of materials based on alginate and acrylic polymers of potential interest as drug delivery systems.

  20. La narración oral escénica en La contadora de películas de Hernán Rivera Letelier

    Directory of Open Access Journals (Sweden)

    Rehab Abdel Salam

    2015-02-01

    Full Text Available El trabajo presente analiza el concepto de la narración oral escénica, un término acuñado por el teórico y narrador oral Francisco Garzón Céspedes, en La contadora de películas (2009 del autor chileno Hernán Rivera Letelier (1950. La esencia de la narración oral escénica es la oralidad; es una oralidad que narra y que trasciende lo conversacional interpersonal para ser oral artística en un espacio oral escénico y con un público interlocutor. La contadora de películas es una novela autobiográfica que retrata a una protagonista  que cuenta relatos basados en las películas que ve en el cine de su pueblo a un público que, al principio se limita a los miembros de su familia y paulatinamente va abarcando a los habitantes de la oficina salitrera en que vive. Esta narradora oral aplica los principios  fundamentales de la narración oral escénica tanto en sus aspectos técnicos como temáticos. La protagonista se dispone de las cualidades personales y profesionales necesarias para un buen narrador oral escénico tales como la invención, la imaginación, la improvisación, la interacción con el público, la memoria, entre otras. A nivel técnico, aplica los principios de composición escénica; crea énfasis en su figura como narradora; maneja lo vocal con sus diferentes componentes y utiliza los diferentes tipos de lenguaje no verbal. Palabras clave: Narración oral-Narración oral escénica- Oralidad- Hernán Rivera  Letelier- Novela chilena.

  1. Nucleotide binding by the widespread high-affinity cyclic di-GMP receptor MshEN domain.

    Science.gov (United States)

    Wang, Yu-Chuan; Chin, Ko-Hsin; Tu, Zhi-Le; He, Jin; Jones, Christopher J; Sanchez, David Zamorano; Yildiz, Fitnat H; Galperin, Michael Y; Chou, Shan-Ho

    2016-01-01

    C-di-GMP is a bacterial second messenger regulating various cellular functions. Many bacteria contain c-di-GMP-metabolizing enzymes but lack known c-di-GMP receptors. Recently, two MshE-type ATPases associated with bacterial type II secretion system and type IV pilus formation were shown to specifically bind c-di-GMP. Here we report crystal structure of the MshE N-terminal domain (MshEN1-145) from Vibrio cholerae in complex with c-di-GMP at a 1.37 Å resolution. This structure reveals a unique c-di-GMP-binding mode, featuring a tandem array of two highly conserved binding motifs, each comprising a 24-residue sequence RLGxx(L/V/I)(L/V/I)xxG(L/V/I)(L/V/I)xxxxLxxxLxxQ that binds half of the c-di-GMP molecule, primarily through hydrophobic interactions. Mutating these highly conserved residues markedly reduces c-di-GMP binding and biofilm formation by V. cholerae. This c-di-GMP-binding motif is present in diverse bacterial proteins exhibiting binding affinities ranging from 0.5 μM to as low as 14 nM. The MshEN domain contains the longest nucleotide-binding motif reported to date. PMID:27578558

  2. Detection of polysaccharide antigens of Candida albicans interfering with specific antibodies in human sera

    International Nuclear Information System (INIS)

    A double antibody sandwich radioimmunoassay was developed for the detection of circulating polysaccharide antigens of Candida albicans. The sensitivity of the assay for polysaccharides was 1 ng/mL. The in-vitro interference of specific polysaccharide antibodies, even from sera with low antibody levels, could be demonstrated. The sensitivity of the antigen detection decreased proportionally to the amount of polysaccharide antibodies in the sera. The sensitivity of the assay was almost completely restored by heating the sera. This procedure destroyed antibodies and the released polysaccharide antigens were detectable in the test system by using radiolabelled anti-polysaccharide antibodies. (author)

  3. Serological characterization of Streptococcus mutans serotype polysaccharide g and its different molecular weight forms.

    OpenAIRE

    Takada, K; Wyszomirska, J; Shiota, T

    1984-01-01

    The serotype polysaccharide g from Streptococcus mutans 6715 was found to cross-react with serotype polysaccharide a from S. mutans HS6 and serotype polysaccharide d from S. mutans B13. Double immunodiffusion experiments indicated that the serotype polysaccharide g consisted of the following: (i) the type-specific g site; (ii) a cross-reactive site g-a that was in common with polysaccharide a; (iii) a cross-reactive site g-d that was in common with polysaccharide d; and (iv) a cross-reactive ...

  4. Antioxidant properties of cell wall polysaccharides of Stevia rebaudiana leaves

    Directory of Open Access Journals (Sweden)

    Mediesse Kengne Francine

    2014-12-01

    Full Text Available Objective: To examine the total phenolic and protein contents, and the antioxidant activities of cell wall polysaccharide fractions of Stevia rebaudiana leaves. Methods: Three different polysaccharide-enriched fractions, namely FPE (extract with 50 mmol/ L ethylene diamine tetra acetic acid, FPK (extract with 0.05 mol/L KOH and FH (extract with 4 mol/L KOH were extracted from Stevia rebaudiana leaves. The antioxidant activity of these fractions was evaluated based on their ability to scavenge DPPH (1, 1-diphenyl-2-picryl hydrazyl free radical, to reduce ferric power, to chelate ferrous ion and to protect human DNA. Results: The results indicated that protein content was found to be higher in FPK polysaccharide enriched fraction (47.48 µg per mg of FPK. Furthermore, the phenolic compound analysis according to the Folin-Ciocalteu method was higher in FPK (17.71 µg ferulic acid. The DPPH maximal inhibition percentage of the three polysaccharide-enriched fractions at 400 µg/mL was 27.66%, 59.90% and 23.21% respectively for FPE, FPK and FH. All the polysaccharide fractions exhibited a ferric reducing power except the FH one. The three fractions also exhibited lipid peroxidation inhibition, and they completely reverted the DNA damage induced by H2O2/FeCl2. FPK showed the strongest scavenging activity against the DPPH radical, the best chelating ability and lipid peroxidation inhibition. Conclusions: Stevia cell wall polysaccharide fractions are potent protective agents against oxidative stress. The analysis revealed major differences in the antioxidant activity in the three polysaccharides fractions. However, the 0.05 mol/L KOH pectin fraction (FPK showed better antioxidant activity.

  5. The Anti-Oxidant and Antitumor Properties of Plant Polysaccharides.

    Science.gov (United States)

    Jiao, Rui; Liu, Yingxia; Gao, Hao; Xiao, Jia; So, Kwok Fai

    2016-01-01

    Oxidative stress has been increasingly recognized as a major contributing factor in a variety of human diseases, from inflammation to cancer. Although certain parts of signaling pathways are still under investigation, detailed molecular mechanisms for the induction of diseases have been elucidated, especially the link between excessive oxygen reactive species (ROS) damage and tumorigenesis. Emerging evidence suggests anti-oxidant therapy can play a key role in treating those diseases. Among potential drug resources, plant polysaccharides are natural anti-oxidant constituents important for human health because of their long history in ethnopharmacology, wide availability and few side effects upon consumption. Plant polysaccharides have been shown to possess anti-oxidant, anti-inflammation, cell viability promotion, immune-regulation and antitumor functions in a number of disease models, both in laboratory studies and in the clinic. In this paper, we reviewed the research progress of signaling pathways involved in the initiation and progression of oxidative stress- and cancer-related diseases in humans. The natural sources, structural properties and biological actions of several common plant polysaccharides, including Lycium barbarum, Ginseng, Zizyphus Jujuba, Astragalus lentiginosus, and Ginkgo biloba are discussed in detail, with emphasis on their signaling pathways. All of the mentioned common plant polysaccharides have great potential to treat oxidative stress and cancinogenic disorders in cell models, animal disease models and clinical cases. ROS-centered pathways (e.g. mitochondrial autophagy, MAPK and JNK) and transcription factor-related pathways (e.g. NF-[Formula: see text]B and HIF) are frequently utilized by these polysaccharides with or without the further involvement of inflammatory and death receptor pathways. Some of the polysaccharides may also influence tumorigenic pathways, such as Wnt and p53 to play their anti-tumor roles. In addition, current

  6. Antioxidant properties of cell wall polysaccharides of Stevia rebaudiana leaves

    Institute of Scientific and Technical Information of China (English)

    Mediesse Kengne Francine; Woguia Alice Louise; Fogue Souopgui Pythagore; Atogho-Tiedeu Barbara; Simo Gustave; Thadde Boudjeko

    2014-01-01

    Objective: To examine the total phenolic and protein contents, and the antioxidant activities of cell wall polysaccharide fractions of Stevia rebaudiana leaves.Methods:L ethylene diamine tetra acetic acid), FPK (extract with 0.05 mol/L KOH) and FH (extract with 4 mol/L KOH) were extracted from Stevia rebaudiana leaves. The antioxidant activity of these fractions was evaluated based on their ability to scavenge DPPH (1, 1-diphenyl-2-picryl hydrazyl) free radical, to reduce ferric power, to chelate ferrous ion and to protect human DNA. Three different polysaccharide-enriched fractions, namely FPE (extract with 50 mmol/Results: The results indicated that protein content was found to be higher in FPK polysaccharide enriched fraction (47.48 µg per mg of FPK). Furthermore, the phenolic compound analysis according to the Folin-Ciocalteu method was higher in FPK (17.71 µg ferulic acid). The DPPH maximal inhibition percentage of the three polysaccharide-enriched fractions at 400 µg/mL was 27.66%, 59.90% and 23.21% respectively for FPE, FPK and FH. All the polysaccharide fractions exhibited a ferric reducing power except the FH one. The three fractions also exhibited lipid peroxidation inhibition, and they completely reverted the DNA damage induced by H2O2/FeCl2. FPK showed the strongest scavenging activity against the DPPH radical, the best chelating ability and lipid peroxidation inhibition.Conclusions: Stevia cell wall polysaccharide fractions are potent protective agents against oxidative stress. The analysis revealed major differences in the antioxidant activity in the three polysaccharides fractions. However, the 0.05 mol/L KOH pectin fraction (FPK) showed better antioxidant activity.

  7. Producción y caracterización de películas poliméricas realizadas mediante descargas glow d.c.

    OpenAIRE

    Botero Londoño, Mónica Andrea

    2003-01-01

    La polimerización por plasma se define como la formación de un material polimérico bajo la influencia del plasma (cuarto estado de la materia), es utilizada para la producción de nuevos materiales y para la modificación de superficies poliméricas. En este trabajo las películas poliméricas de acetileno y nitrógeno fueron obtenidas utilizando la polimerización por plasma. El plasma fue producido en una cámara de reacción de geometría cilíndrica, con electrodos enfrentados conectados a una fuent...

  8. Effect of sunlight radiation, rainfall and droplet spectra of sprays on persistence of Bacillus thuringiensis deposits after application of DiPel 76AF formulation onto conifers

    International Nuclear Information System (INIS)

    The Effect of sunlight radiation, rainfall and droplet spectra of sprays on per ‐sistence of a Bacillus thuringiensis subspp. kurstaki (Btk) formulation, DiPel? 76AF, was examined after application onto spruce [Picea glauca (Moench) Voss] foliage. The investigation consisted of three studies: (i) Study I: a laboratory microcosm study to examine the photostability of DiPel 76AF deposits on foliage after different periods of exposure to two radiation intensities, (ii) Study II: a laboratory microcosm study to examine the rainfastness of foliar deposits after exposure to different amounts of rainfall consisting of two separate droplet spectra, and (iii) Study III: a field microcosm study to investigate the influence of two different droplet spectra of DiPel 76AF sprays on foliar persistence of Btk under natural weathering conditions. In all studies, persistence of Btk was investigated both by bioassay [using spruce budworm (Choristoneura fumiferana Clemens)] and total protein assay.The findings of Study I indicated that bioactivity of foliar deposits decreased with increasing duration of exposure to radiation, and with increasing radiation intensity. The half‐life (DT50, the exposure period required for 50% of the initial bioactivity to disappear) was 5.1 d for the low intensity, and 3.9 d for the higher intensity. In contrast with the bioassay results, the total protein levels [determined by the bicinchoninic acid (BCA) method] showed no decrease with increasing duration of exposure, or with increasing radiation intensity.The findings of Study II indicated that bioactivity of foliar deposits decreased with increasing cumulative rainfall. A new term, RF50 [the amount of rain (in mm) required to washoff 50% of the initial deposit], was introduced to understand the relationship between rainfall intensity and reduction in bioactivity. When the same amount of rain was applied in different droplet sizes, the RF50 value was high (5.2 mm) for the small rain droplets, and

  9. Los arquetipos de género en las películas infantiles. Una propuesta de taller para el alumnado de Educación Primaria

    OpenAIRE

    Gómez Beltrán, Iván

    2013-01-01

    Debido al avance teórico de los Estudios de Género, es necesario que se replanteen los procesos pedagógicos por los cuales se transmite a la infancia, a través de entretenimientos considerados fútiles, una dañina ideología patriarcal desde los primeros años de vida. Por ello, con este trabajo se propone un modelo de taller para alumnado de Educación Primaria de entre 10 y 12 años. Con la colaboración de los y las tutoras legales y a través del análisis de tres películas de la compañía Disney ...

  10. Estudio de la dinámica de poblaciones pelágicas de peces mediante técnicas hidroacústicas

    OpenAIRE

    Carrera, P.

    2015-01-01

    La presente Tesis ha analizado mediante técnicas hidroacústicas aspectos de la ecología de las poblaciones pelágicas tales como comportamiento frente a buques de investigación; proceso y patrones de agregación y distribución espacial; migración; y estimación de la abundancia, dinámica y hábitats. Los datos han procedido principalmente de las campañas de prospección acústico-pesquero llevadas a cabo por el Instituto Español de Oceanografía en primavera en el litoral norte español y...

  11. Evaluación química y sensorial de morcón de Cerdo Pelón Mexicano y Cerdo Mejorado

    OpenAIRE

    Lissette Beatriz Pérez Casas; María de la Salud Rubio Lozano; Danilo Méndez Median; Jessica Feldman Katz; Francisca Aida Iturbe Chiñas

    1999-01-01

    El objetivo de este proyecto fue evaluar las características químicas y sensoriales del morcón (producto cárnico tipo español de alta calidad, elaborado con las puntas de lomo del cerdo) a partir de la utilización de carne de Cerdo Pelón Mexicano (CPM), y compararlo con el elaborado con carne de Cerdo Mejorado (CM). Los productos elaborados de los dos tipos de cerdos fueron madurados durante 4 semanas. Los muestreos de las piezas de morcón se tomaron cada 7 días. Los análisis químicos que se ...

  12. Dios, la muerte y el más allá en el cine contemporáneo. Una mirada a las películas con ojos de fe.

    OpenAIRE

    Caballero, J L

    2009-01-01

    Reseña de Pedro SÁNCHEZ RODRÍGUEZ, Dios, la muerte y el más allá en el cine contemporáneo. Una mirada a las películas con ojos de fe, PPC, Madrid 2007, 316 pp., 14,5 X 22, ISBN 978-84-288-2022-6.

  13. Presencia de agregaciones reproductivas pelágicas del poliqueto Platynereis australis (Schmarda, 1861 (Nereididae en aguas someras subantárticas de Magallanes, Chile

    Directory of Open Access Journals (Sweden)

    Juan I Cañete

    2013-03-01

    Full Text Available Se reporta la presencia de agregaciones masivas nocturnas constituidas por individuos epítocos (heteronereidos del poliqueto Platynereis australis asociados a praderas de Macrocystis pyrifera en varias localidades (7 en la zona de canales magallánicos y fueguinos, sur de Chile (53°-55°S, 67°-73°W, en 2006 y 2007. Los especímenes adultos presentaron cambios morfológicos en 2/3 de la parte posterior del cuerpo, presentando parapodios modificados y grandes ojos coalescentes. La región pre-natatoria consiste de 19 a 22 segmentos, mientras que la zona epítoca se compone de 60 a 90 segmentos setígeros. Los especímenes se encontraban sexualmente maduros y las hembras presentaron huevos de tamaño entre 135 y 155 µm de diámetro, indicando una madurez simultánea en la cavidad celómica de cada segmento epítoco. Las agregaciones pelágicas fueron observadas en todos los lugares visitados en primavera. Observaciones efectuadas durante otoño indicaron la presencia de heteronereidos en tubos adheridos a frondas de Macrocystis, situación que podría constituir una etapa intermedia entre la fase bentónica y pelágica. Sin embargo, se requieren mayores estudios para clarificar dicho comportamiento. Se discute la estrecha asociación entre Platynereis y los bosques de M. pyrifera en las diferentes etapas de su ciclo de vida.

  14. Los protagonistas de las películas colombianas 1990-2003.The stars of the Colombian films 1990-2003

    Directory of Open Access Journals (Sweden)

    Jerónimo León Rivera Betancur

    Full Text Available ResumenEl cine colombiano es el objeto de estudio de este artículo, que parte de los resultados de la investigación “Personajes, acciones y escenarios en el cine colombiano de 1970-2005”, realizada en la Universidad de Medellín (Colombia entre 2005 y 2007. Se trata de un artículo de revisión en el que se hace un análisis narrativo de la representación de personajes protagónicos en las películas colombianas de la década de 1990 hasta 2003 (año de la puesta en marcha de la ley del cine en Colombia. Se abordan algunas películas de la muestra y en cada una se hace un análisis de los personajes más representativos.AbstractThe Colombian cinema is the object of study of this article, which departs from the results of the research "Prominent figures, actions and scenes in the Colombian cinema of 1970-2005 ", realized in the University of Medellin (Colombia from 2005 to 2007. It is an article of review a narrative analysis of the representation of leading prominent figures in the Colombian movies of the decade of 1990 until 2003 (year of the putting in march of the law of the cinema in Colombia. Some movies of the sample are approached and in each one there is done an analysis of the most representative prominent figures.

  15. Toll-like receptor 4-related immunostimulatory polysaccharides: Primary structure, activity relationships, and possible interaction models.

    Science.gov (United States)

    Zhang, Xiaorui; Qi, Chunhui; Guo, Yan; Zhou, Wenxia; Zhang, Yongxiang

    2016-09-20

    Toll-like receptor (TLR) 4 is an important polysaccharide receptor; however, the relationships between the structures and biological activities of TLR4 and polysaccharides remain unknown. Many recent findings have revealed the primary structure of TLR4/MD-2-related polysaccharides, and several three-dimensional structure models of polysaccharide-binding proteins have been reported; and these models provide insights into the mechanisms through which polysaccharides interact with TLR4. In this review, we first discuss the origins of polysaccharides related to TLR4, including polysaccharides from higher plants, fungi, bacteria, algae, and animals. We then briefly describe the glucosidic bond types of TLR4-related heteroglycans and homoglycans and describe the typical molecular weights of TLR4-related polysaccharides. The primary structures and activity relationships of polysaccharides with TLR4/MD-2 are also discussed. Finally, based on the existing interaction models of LPS with TLR4/MD-2 and linear polysaccharides with proteins, we provide insights into the possible interaction models of polysaccharide ligands with TLR4/MD-2. To our knowledge, this review is the first to summarize the primary structures and activity relationships of TLR4-related polysaccharides and the possible mechanisms of interaction for TLR4 and TLR4-related polysaccharides. PMID:27261743

  16. Hot-compressed water extraction of polysaccharides from soy hulls.

    Science.gov (United States)

    Liu, Hua-Min; Wang, Fei-Yun; Liu, Yu-Lan

    2016-07-01

    The polysaccharides of soy hulls were extracted by hot-compressed water at temperatures of 110 from 180°C and various treatment times (10-150min) in a batch system. It was determined that a moderate temperature and short time are suitable for the preparation of polysaccharides. The structure of xylan and the inter- and intra-chain hydrogen bonding of cellulose fibrils in the soy hulls were not significantly broken down. The polysaccharides obtained were primarily composed of α-L-arabinofuranosyl units, 4-O-methyl-glucuronic acid units and α-D-galactose units attached with substituted units. A sugar analysis indicated that arabinose was the major component, constituting 35.6-46.9% of the polysaccharide products extracted at 130°C, 140°C, and 150°C. This investigation contributes to the knowledge of the polysaccharides of soy by-products, which can reduce the environmental impact of waste from the food industries. PMID:26920272

  17. The Application of Polysaccharide Biocomposites to Repair Cartilage Defects

    Directory of Open Access Journals (Sweden)

    Feng Zhao

    2014-01-01

    Full Text Available Owing to own nature of articular cartilage, it almost has no self-healing ability once damaged. Despite lots of restore technologies having been raised in the past decades, no repair technology has smoothly substituted for damaged cartilage using regenerated cartilage tissue. The approach of tissue engineering opens a door to successfully repairing articular cartilage defects. For instance, grafting of isolated chondrocytes has huge clinical potential for restoration of cartilage tissue and cure of chondral injury. In this paper, SD rats are used as subjects in the experiments, and they are classified into three groups: natural repair (group A, hyaluronic acid repair (group B, and polysaccharide biocomposites repair (hyaluronic acid hydrogel containing chondrocytes, group C. Through the observation of effects of repairing articular cartilage defects, we concluded that cartilage repair effect of polysaccharide biocomposites was the best at every time point, and then the second best was hyaluronic acid repair; both of them were better than natural repair. Polysaccharide biocomposites have good biodegradability and high histocompatibility and promote chondrocytes survival, reproduction, and spliting. Moreover, polysaccharide biocomposites could not only provide the porous network structure but also carry chondrocytes. Consequently hyaluronic acid-based polysaccharide biocomposites are considered to be an ideal biological material for repairing articular cartilage.

  18. Isolation, Purification and Bioactivities of Polysaccharides from Irpex lacteus

    Institute of Scientific and Technical Information of China (English)

    ZHANG Na; LIU Yan; LU Jia-hui; WANG Juan; YANG Shuang; ZHANG Nan; MENG Qing-fan; TENG Li-rong

    2012-01-01

    Irpex lacteus has been widely used for treating chronic glomerulonephritis as a traditional Chinese medicine.Seven water-soluble polysaccharide fractions(ILN Ⅰ,ILN Ⅱ,ILN Ⅲ,ILA Ⅰ,ILA Ⅱ,ILB Ⅰ and ILB Ⅱ)were isolated and purified from Irpex lacteus by hot-water extraction,deproteinization,decolorization,dicthy laminoethyl(DEAE)-cellulose ion exchange and sephadex G100 chromatographies,respectively.The average molecular weights and monosaccharide composition of these polysaccharide fractions greatly differed from each other.The antitumor and antinephritis activities of the seven polysaccharide fractions were evaluated.It was found that ILN Ⅲ displayed significant inhibition effects on both humar hepatocellular liver carcinoma(HepG2)and hentietta lacks(HeLa)tumor cells with IC50 values of 60.95 and 99.95 μg/mL,respectively.ILA Ⅰ exhibited significant inhibition effects on murine mesangial cells(HBZT-1)with an IC50 value of 185.06 μg/mL.The inhibition effects of other polysaccharide fractions on these three cells were significantly different.These results suggest that the polysaccharide fractions isolated from Irpex lacteus have potential antitumor and antinephritis activities.

  19. Marine Polysaccharide Networks and Diatoms at the Nanometric Scale

    Directory of Open Access Journals (Sweden)

    Tea Mišić Radić

    2013-10-01

    Full Text Available Despite many advances in research on photosynthetic carbon fixation in marine diatoms, the biophysical and biochemical mechanisms of extracellular polysaccharide production remain significant challenges to be resolved at the molecular scale in order to proceed toward an understanding of their functions at the cellular level, as well as their interactions and fate in the ocean. This review covers studies of diatom extracellular polysaccharides using atomic force microscopy (AFM imaging and the quantification of physical forces. Following a brief summary of the basic principle of the AFM experiment and the first AFM studies of diatom extracellular polymeric substance (EPS, we focus on the detection of supramolecular structures in polysaccharide systems produced by marine diatoms. Extracellular polysaccharide fibrils, attached to the diatom cell wall or released into the surrounding seawater, form distinct supramolecular assemblies best described as gel networks. AFM makes characterization of the diatom polysaccharide networks at the micro and nanometric scales and a clear distinction between the self-assembly and self-organization of these complex systems in marine environments possible.

  20. ISOLATION AND CHARACTERIZATION OF SOLUBLE POLYSACCHARIDES FROM CALAMAGROSTIS ANGUSTIFOLIA KOM

    Directory of Open Access Journals (Sweden)

    Xue-Fei Cao

    2011-06-01

    Full Text Available Sequential treatments of dewaxed Calamagrostis angustifolia Kom with water (60 ºC and 90 ºC, 70% ethanol, and 70% ethanol containing 0.2%, 1.0%, 2.0%, 4.0%, and 8.0% NaOH at a solid to liquid ratio of 1:25 (g/mL at 80 ºC for 3 h yielded 36.2% soluble polysaccharides of the dry dewaxed material. The eight polysaccharide fractions obtained were comparatively studied by sugar analysis, GPC, FT-IR, 1H and 13C-NMR, and 2D-NMR (HSQC spectroscopy. The results showed that the water-soluble polysaccharides might contain noticeable amounts of β-D-glucan, as well as some pectic substances and galactoarabinoxylan. 70% ethanol-soluble polysaccharide was mainly arabinogalactan. The five alkali-soluble hemicelluloses were mainly galactoarabinoxylans. The Ara/Xyl and Ara/Gal values of H5-H8 fractions decreased with the increment of NaOH concentration from 1.0% to 8.0%. Meanwhile, the molecular weights had a declining trend from ~60,000 to ~40,000 g/mol. The smaller sized and more branched polysaccharides tended to be extracted in the early stages under milder conditions, and the larger molecular sized and more linear hemicelluloses tended to be isolated under more highly alkaline conditions.

  1. Microcalorimetry studies on the antibacterial effect of crude monkshood polysaccharide.

    Science.gov (United States)

    Lin, Gui-mei; Liu, Lian; Shao, Wei

    2011-07-01

    In this paper, crude monkshood polysaccharide was isolated from Radix Aconiti Lateralis Preparata. The effects of crude monkshood polysaccharide on Escherichia coli and Staphylococcus aureus were investigated by microcalorimetry. The power-time curves of the bacterial growth at various concentrations (c) of crude monkshood polysaccharide were plotted with a TAM air isothermal microcalorimeter at 37 °C. The growth rate constant (μ), inhibitory ratio (I), peak-height (P(m)), and peak-time (t(m)) were calculated. From the data, the relationship between μ and c also was established. The growth rate constant μ decreased with the increasing concentrations of crude monkshood polysaccharide. Moreover, P(m) reduced and t(m) increased with increasing concentrations. The experimental results revealed that crude monkshood polysaccharide had inhibitory activity towards S. aureus and E. coli. Results obtained from our study strongly suggest that microcalorimetry is a fast, simple, and more sensitive technology that can be easily performed to study the effect of drugs on bacteria. PMID:21726063

  2. Construction of Vector Harboring Pectin Lyase C Gene and Its Expression in E. coli%果胶裂解酶基因PelC表达载体的构建及原核表达分析

    Institute of Scientific and Technical Information of China (English)

    邓伟科; 郭安平; 刘恩平; 王炎松; 郭运玲; 孔华; 阳辛凤; 贺立卡

    2009-01-01

    A complete open reading frame of pectin lyase C (PelC) cloned from a pectinase-producing strain BTC105 isolated and collected in the laboratory was constructed on a plasmid pET28a and transferred into E. coli BL21 (DE3) to carry out fuse expression; and flask shaking fermented in LB (Luria-Bertani) , induced with 1 mmol/L IPTG (iso-propyl β-D-1-thiogalactopyranoside). The results showed that the recombinant plasmid pET28a-pelC was constructed successfully and PelC has mainly expressed in E. coli BL21 (DE3). The optimal pH of the enzyme was 5.4, optimal temperature at 50℃, Ca~(2+) stimulated strongly on the enzyme activity, however, Cu~(2+) completely inhibited the activity.%从实验室分离保存的1株产果胶酶的菌株(BTC105)中克隆果胶裂解酶基因(PelC)完整开放阅读框,通过载体构建,将目的基因连接到表达载体pET28a上,转化大肠埃希菌BL21(DE3)进行融合表达,在LB(Luria-Bertani)中进行摇瓶发酵,1 mmol/L IPTG(异丙基-β-D-硫代半乳糖苷)诱导.结果表明,构建了表达载体pET28a-pelC,果胶裂解酶主要在胞内表达,酶活最适pH为5.4,最适温度为50℃,Ca~(2+)对酶活促进作用最为明显,Cu~(2+)完全抑制了酶的活性.

  3. Hypoglycemic effect of Ganoderma lucidum polysaccharides

    Institute of Scientific and Technical Information of China (English)

    Hui-na ZHANG; Zhi-bin LIN

    2004-01-01

    AIM: To investigate the hypoglycemic effect of Ganoderma lucidum polysaccharides (Gl-PS) in the normal fasted mice and its possible mechanism. METHODS: Normal fasted mice were given a single dose of Gl-PS 25, 50, and 100 mg/kg by ip and the serum glucose was measured at 0, 3, and 6 h after administration. Gl-PS 1 00 mg/kg were also given by ip and the serum glucose and insulin levels were measured at 0 min, 30 min, 1 h, 3 h, 6 h, and 12 h.Pancreatic islets were isolated and incubated with glucose 5.6 mmol/L and different concentration of Gl-PS, the insulin content of islets and insulin release were examined. The islets fluorescent intensity of [Ca2+]i was also studied with a confocal microscope. Verapamil and egtazic acid were used to testify whether the insulin-releasing effect of Gl-PS was mediated by its ability to raise the Ca2+ influx. RESULTS: Gl-PS dose-dependently lowered the serum glucose levels at 3 h and 6 h after administration. Gl-PS 100 mg/kg raised the circulating insulin levels at 1 h after administration. In vitro, Gl-PS had no effect on islets insulin content, but it stimulated the insulin release after incubation with glucose 5.6 mmol/L. Confocal microscope showed that Gl-PS 100 mg/L had the capacity to raise the [Ca2+] i. The insulin-releasing effect of Gl-PS was inhibited by verapamil/egtazic acid. CONCLUSION:Gl-PS possesses the hypoglycemic effect on normal mice; one mechanism is through its insulin-releasing activity due to a facilitation of Ca2+ inflow to the pancreatic β cells.

  4. Application of gamma irradiation for the enhanced physiological properties of polysaccharides from seaweeds

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jong-il; Kim, Hyun-Joo; Kim, Jae-Hun; Byun, Myung-Woo [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580185 (Korea, Republic of); Soo Chun, Byeong; Hyun Ahn, Dong [Department of Food Science and Biotechnology, Pukyong National University, Busan 608737 (Korea, Republic of); Hwang, Young-Jeong [Division of Food Science, Jinju International University, Jinju 660759 (Korea, Republic of); Kim, Duk-Jin [Division of Food Engineering and Nutrition, Daegu University, Daegu 712714 (Korea, Republic of); Kim, Gwang Hoon [Department of Biology, Kongju National University, Chungnam 314701 (Korea, Republic of); Lee, Ju-Woon [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580185 (Korea, Republic of)], E-mail: sjwlee@kaeri.re.kr

    2009-07-15

    Polysaccharides from seaweeds, fucoidan and laminarin, were irradiated with gamma rays, and their structural changes and anti-oxidative activities were investigated. The gamma irradiation decreased the average molecular weights of polysaccharides, and UV spectra of irradiated polysaccharides showed increases in the numbers of carboxyl and carbonyl groups and double bonds. DPPH radical scavenging ability and reducing power of the gamma irradiated polysaccharides were significantly higher than those non-irradiated.

  5. Group B Streptococcus type II polysaccharide-tetanus toxoid conjugate vaccine.

    OpenAIRE

    Paoletti, L C; Wessels, M R; Michon, F; DiFabio, J; Jennings, H J; Kasper, D L

    1992-01-01

    Group B streptococci (GBS) are the most common cause of bacterial sepsis and meningitis in neonates in the United States. Although the capsular polysaccharide of GBS is an important virulence factor, it is variably immunogenic in humans. In this report, we have increased the immunogenicity of GBS type II polysaccharide by coupling it to tetanus toxoid (TT). Like other GBS capsular polysaccharides, the type II polysaccharide has side chains terminating in sialic acid. Controlled periodate oxid...

  6. Characterization of serological cross-reactivity between polysaccharide antigens of Streptococcus mutans serotypes c and d.

    OpenAIRE

    Grossi, S.; Prakobphol, A; Linzer, R; Campbell, L K; Knox, K W

    1983-01-01

    Immunological assays with antisera prepared against purified Streptococcus mutans serotype c polysaccharide demonstrated that a cross-reacting determinant on c polysaccharide reacted with the wall-associated rhamnose-glucose polysaccharide from S. mutans serotype d. Studies with 60 antisera prepared against chemostat cultures of S. mutans Ingbritt (c) demonstrated that the rhamnose-glucose polysaccharide cross-reactive determinant was consistently expressed on c antigen under a variety of gro...

  7. The Potential of Brittle Star Extracted Polysaccharide in Promoting Apoptosis via Intrinsic Signaling Pathway

    OpenAIRE

    Baharara, Javad; Amini, Elaheh

    2015-01-01

    Background: Anti-cancer potential of marine natural products such as polysaccharides represented therapeutic potential in oncological researches. In this study, total polysaccharide from brittle star [Ophiocoma erinaceus (O. erinaceus)] was extracted and chemopreventive efficacy of Persian Gulf brittle star polysaccharide was investigated in HeLa human cervical cancer cells. Methods: To extract polysaccharide, dried brittle stars were ground and extracted mechanically. Then, detection of poly...

  8. Application of gamma irradiation for the enhanced physiological properties of polysaccharides from seaweeds

    International Nuclear Information System (INIS)

    Polysaccharides from seaweeds, fucoidan and laminarin, were irradiated with gamma rays, and their structural changes and anti-oxidative activities were investigated. The gamma irradiation decreased the average molecular weights of polysaccharides, and UV spectra of irradiated polysaccharides showed increases in the numbers of carboxyl and carbonyl groups and double bonds. DPPH radical scavenging ability and reducing power of the gamma irradiated polysaccharides were significantly higher than those non-irradiated.

  9. The Selenylation Modification of Epimedium Polysaccharide and Isatis Root Polysaccharide and the Immune-enhancing Activity Comparison of Their Modifiers.

    Science.gov (United States)

    Li, Xiuping; Hou, Ranran; Yue, Chanjuan; Liu, Jie; Gao, Zhenzhen; Chen, Jin; Lu, Yu; Wang, Deyun; Liu, Cui; Hu, Yuanliang

    2016-05-01

    Epimedium polysaccharide (EPS) and isatis root polysaccharide (IRPS) were extracted, purified, and selenizingly modified by nitric acid-sodium selenite method to obtain nine selenizing EPSs (sEPSs), sEPS1-sEPS9 and nine selenizing IRPSs (sIRPSs), sIRPS1-sIRPS9, respectively. Their effects on chicken peripheral lymphocyte proliferation in vitro were compared by MTT assay. The results showed that selenium polysaccharides at appropriate concentration could promote lymphocyte proliferation more significantly than unmodified polysaccharides, sEPS5 and sIRPS5 with stronger actions were picked out and injected into the chickens vaccinated with Newcastle disease vaccine in vivo tests. The peripheral lymphocyte proliferation and serum antibody titer were determined. The results showed that sEPS5 and sIRPS5 could elevate serum antibody titer and promote lymphocyte proliferation more significantly than unmodified polysaccharides, sEPS5 possessed the strongest efficacy. These results indicate that selenylation modification can significantly enhance the immune-enhancing activity of EPS and IRPS, and sEPS5 can be as a new-type immunopotentiator of chickens. PMID:26432450

  10. Bioactivity and Applications of Sulphated Polysaccharides from Marine Microalgae

    Science.gov (United States)

    de Jesus Raposo, Maria Filomena; de Morais, Rui Manuel Santos Costa; de Morais, Alcina Maria Miranda Bernardo

    2013-01-01

    Marine microalgae have been used for a long time as food for humans, such as Arthrospira (formerly, Spirulina), and for animals in aquaculture. The biomass of these microalgae and the compounds they produce have been shown to possess several biological applications with numerous health benefits. The present review puts up-to-date the research on the biological activities and applications of polysaccharides, active biocompounds synthesized by marine unicellular algae, which are, most of the times, released into the surrounding medium (exo- or extracellular polysaccharides, EPS). It goes through the most studied activities of sulphated polysaccharides (sPS) or their derivatives, but also highlights lesser known applications as hypolipidaemic or hypoglycaemic, or as biolubricant agents and drag-reducers. Therefore, the great potentials of sPS from marine microalgae to be used as nutraceuticals, therapeutic agents, cosmetics, or in other areas, such as engineering, are approached in this review. PMID:23344113

  11. Optimization of enzyme assisted extraction of polysaccharides from Ganoderma lucidum

    Institute of Scientific and Technical Information of China (English)

    Xu Chunhua; Tian Zhenle; Zhang Chenju; Yu Xiaobing; Zheng Huihua

    2014-01-01

    In the present work,an enzyme assisted extraction method is used to isolate crude polysaccharides from Ganoderma lucidum. The isolating effect was optimized with orthographic graph statistic method with three levels and four independent variables. Complex enzyme,extraction temperature,extraction time and ex-traction pH were combined to obtain the best possible combination to get maximum amount of extract and crude polysaccharides yield. The optimum extraction conditions were:complex enzyme amount of 3%(w/v),extrac-tion temperature at 45℃,extraction time of 3 h and extraction pH at 7. Under these conditions,the experimen-tal amount of extract is 8.9%and the yield of crude polysaccharides is 1.1%,which are in close agreement with the value predicted by the model.

  12. Bioactivity and Applications of Sulphated Polysaccharides from Marine Microalgae

    Directory of Open Access Journals (Sweden)

    Rui Manuel Santos Costa de Morais

    2013-01-01

    Full Text Available Marine microalgae have been used for a long time as food for humans, such as Arthrospira (formerly, Spirulina, and for animals in aquaculture. The biomass of these microalgae and the compounds they produce have been shown to possess several biological applications with numerous health benefits. The present review puts up-to-date the research on the biological activities and applications of polysaccharides, active biocompounds synthesized by marine unicellular algae, which are, most of the times, released into the surrounding medium (exo- or extracellular polysaccharides, EPS. It goes through the most studied activities of sulphated polysaccharides (sPS or their derivatives, but also highlights lesser known applications as hypolipidaemic or hypoglycaemic, or as biolubricant agents and drag-reducers. Therefore, the great potentials of sPS from marine microalgae to be used as nutraceuticals, therapeutic agents, cosmetics, or in other areas, such as engineering, are approached in this review.

  13. Marine Polysaccharides from Algae with Potential Biomedical Applications

    Directory of Open Access Journals (Sweden)

    Maria Filomena de Jesus Raposo

    2015-05-01

    Full Text Available There is a current tendency towards bioactive natural products with applications in various industries, such as pharmaceutical, biomedical, cosmetics and food. This has put some emphasis in research on marine organisms, including macroalgae and microalgae, among others. Polysaccharides with marine origin constitute one type of these biochemical compounds that have already proved to have several important properties, such as anticoagulant and/or antithrombotic, immunomodulatory ability, antitumor and cancer preventive, antilipidaemic and hypoglycaemic, antibiotics and anti-inflammatory and antioxidant, making them promising bioactive products and biomaterials with a wide range of applications. Their properties are mainly due to their structure and physicochemical characteristics, which depend on the organism they are produced by. In the biomedical field, the polysaccharides from algae can be used in controlled drug delivery, wound management, and regenerative medicine. This review will focus on the biomedical applications of marine polysaccharides from algae.

  14. Bioactivity and applications of sulphated polysaccharides from marine microalgae.

    Science.gov (United States)

    Raposo, Maria Filomena de Jesus; de Morais, Rui Manuel Santos Costa; Bernardo de Morais, Alcina Maria Miranda

    2013-01-01

    Marine microalgae have been used for a long time as food for humans, such as Arthrospira (formerly, Spirulina), and for animals in aquaculture. The biomass of these microalgae and the compounds they produce have been shown to possess several biological applications with numerous health benefits. The present review puts up-to-date the research on the biological activities and applications of polysaccharides, active biocompounds synthesized by marine unicellular algae, which are, most of the times, released into the surrounding medium (exo- or extracellular polysaccharides, EPS). It goes through the most studied activities of sulphated polysaccharides (sPS) or their derivatives, but also highlights lesser known applications as hypolipidaemic or hypoglycaemic, or as biolubricant agents and drag-reducers. Therefore, the great potentials of sPS from marine microalgae to be used as nutraceuticals, therapeutic agents, cosmetics, or in other areas, such as engineering, are approached in this review. PMID:23344113

  15. Microwave-assisted extraction of polysaccharides from solanum nigrum

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiao-qing; LIU-qin; JIANG xin-yu; ZENG fan

    2005-01-01

    The microwave-assisted method was used to extract polysaccharides from solanum nigrum. The optimum experimental parameters, mechanism of the extraction and the effect of microwave-assisted extraction process on the structures of polysaccharides were investigated. The extract was analyzed by the modified phenol-sulfuric acid method at 490 nm. The optimum experimental parameters were obtained by orthogonal experiments as follows: extraction time 15 min, microwave radiation power 455 W and the process ratio of materials mass to solvent volume 1∶20. The results show that compared with the conventional reflux extraction, the microwave-assisted extraction has a higher yield in shorter time, with no effect on the finally obtained polysaccharides as seen from the FT-IR spectra. The scanning electron microscopy images reveal that the mechanism of the extraction is related to the structural changes of the plant cells in different extracting conditions.

  16. Polysaccharide-Based Membranes in Food Packaging Applications.

    Science.gov (United States)

    Ferreira, Ana R V; Alves, Vítor D; Coelhoso, Isabel M

    2016-01-01

    Plastic packaging is essential nowadays. However, the huge environmental problem caused by landfill disposal of non-biodegradable polymers in the end of life has to be minimized and preferentially eliminated. The solution may rely on the use of biopolymers, in particular polysaccharides. These macromolecules with film-forming properties are able to produce attracting biodegradable materials, possibly applicable in food packaging. Despite all advantages of using polysaccharides obtained from different sources, some drawbacks, mostly related to their low resistance to water, mechanical performance and price, have hindered their wider use and commercialization. Nevertheless, with increasing attention and research on this field, it has been possible to trace some strategies to overcome the problems and recognize solutions. This review summarizes some of the most used polysaccharides in food packaging applications. PMID:27089372

  17. Components and activity of polysaccharides from coarse tea.

    Science.gov (United States)

    Wang Dongfeng, W; Wang Chenghong, W; Li Jun, L; Zhao Guiwen, Z

    2001-01-01

    Coarse tea contained a high content of polysaccharide complex. Composed of polysaccharide and protein, the polysaccharide complex from tea (TPS) belonged to glycoprotein with the molecular weight () of (10.7-11.0) x 10(4). When mice (7 weeks old, C57BL/8) were injected with TPS, the levels of blood glucose (BG) in normal mice and model mice with high BG were decreased significantly by averages of 13.54 and 22.18%, respectively. The antibody concentration (OD(413 nm)) in the mice injected with 2.4 mg/mL TPS was increased evidently by 44.93% (p prohibited the body from producing too much IL-1 in AA rats. Treatment of diabetes with coarse tea in both China and Japan may be related to TPS and the content of TPS in coarse tea. PMID:11170619

  18. A hierarchical classification of polysaccharide lyases for glycogenomics.

    Science.gov (United States)

    Lombard, Vincent; Bernard, Thomas; Rancurel, Corinne; Brumer, Harry; Coutinho, Pedro M; Henrissat, Bernard

    2010-12-15

    Carbohydrate-active enzymes face huge substrate diversity in a highly selective manner using only a limited number of available folds. They are therefore subjected to multiple divergent and convergent evolutionary events. This and their frequent modularity render their functional annotation in genomes difficult in a number of cases. In the present paper, a classification of polysaccharide lyases (the enzymes that cleave polysaccharides using an elimination instead of a hydrolytic mechanism) is shown thoroughly for the first time. Based on the analysis of a large panel of experimentally characterized polysaccharide lyases, we examined the correlation of various enzyme properties with the three levels of the classification: fold, family and subfamily. The resulting hierarchical classification, which should help annotate relevant genes in genomic efforts, is available and constantly updated at the Carbohydrate-Active Enzymes Database (http://www.cazy.org). PMID:20925655

  19. Effect of polysaccharides on the gelatinization properties of cornstarch dispersions.

    Science.gov (United States)

    Xu, Zhiting; Zhong, Fang; Li, Yue; Shoemaker, Charles F; Yokoyama, Wallace H; Xia, Wenshui

    2012-01-18

    Konjac glucomannan (KG, neutral), carboxymethylcellulose (CMC, negatively charged), and chitosan (positively charged) were added to cornstarch dispersions to study the effect of polysaccharide-starch interactions on starch gelatinization properties. Pasting and retrogradation properties were measured with a rheometer and DSC. Swelling properties of the starch granules were determined by solubility index, swelling power, and particle size distribution. Depending on the nature of the different polysaccharides, viscosities of cornstarch dispersions were affected differently. The particle size distributions were not influenced by the addition of any of the polysaccharides. Swelling results showed that the KG and CMC molecules interacted with the released or partly released amylose in the cornstarch dispersions. This was correlated with the short-term retrogradation of the starch pastes being retarded by the additions of KG and CMC. However, the chitosan molecules appeared not to associate with the amylose, so the retrogradation of the chitosan-cornstarch dispersions was not retarded. PMID:22224479

  20. Polysaccharides of higher fungi: Biological role, structure, and antioxidative activity

    Directory of Open Access Journals (Sweden)

    Kozarski Maja S.

    2014-01-01

    Full Text Available Fungal polysaccharides attract a lot of attention due to their multiple challenging biological properties, such as: anti-tumor, anti-viral, anticomplementary, anticoagulant, hypolipidemic and immunomodulatory and immune-stimulatory activities, which all together make them suitable for application in many quite distinctive areas, such as food industry, biomedicine, cosmetology, agriculture, environmental protection and waste water management. This article presents results with respect to biological properties, structure and procedures related to the isolation and activation of polysaccharides of higher fungi. It is considered and presented along with a review of the critical antioxidative activity and possible influence of the structural composition of polysaccharide extracts (isolated from these higher fungi upon their antioxidative properties.

  1. Characterization of the Kingella kingae polysaccharide capsule and exopolysaccharide.

    Directory of Open Access Journals (Sweden)

    Kimberly F Starr

    Full Text Available Recent evidence indicates that Kingella kingae produces a polysaccharide capsule. In an effort to determine the composition and structure of this polysaccharide capsule, in the current study we purified capsular material from the surface of K. kingae strain 269-492 variant KK01 using acidic conditions to release the capsule and a series of steps to remove DNA, RNA, and protein. Analysis of the resulting material by gas chromatography and mass spectrometry revealed N-acetyl galactosamine (GalNAc, 3-deoxy-D-manno-oct-2-ulosonic acid (Kdo, and galactose (Gal. Further analysis by NMR demonstrated two distinct polysaccharides, one consisting of GalNAc and Kdo with the structure →3-β-GalpNAc-(1→5-β-Kdop-(2→ and the other containing galactose alone with the structure →5-β-Galf-(1→. Disruption of the ctrA gene required for surface localization of the K. kingae polysaccharide capsule resulted in elimination of GalNAc and Kdo but had no effect on the presence of Gal in bacterial surface extracts. In contrast, deletion of the pamABCDE locus involved in production of a reported galactan exopolysaccharide eliminated Gal but had no effect on the presence of GalNAc and Kdo in surface extracts. Disruption of ctrA and deletion of pamABCDE resulted in a loss of all carbohydrates in surface extracts. These results establish that K. kingae strain KK01 produces a polysaccharide capsule with the structure →3-β-GalpNAc-(1→5-β-Kdop-(2→ and a separate exopolysaccharide with the structure →5-β-Galf-(1→. The polysaccharide capsule and the exopolysaccharide require distinct genetic loci for surface localization.

  2. The framework of polysaccharide monooxygenase structure and chemistry.

    Science.gov (United States)

    Span, Elise A; Marletta, Michael A

    2015-12-01

    Polysaccharide monooxygenases, or PMOs (also known as lytic PMOs or LPMOs), are a group of enzymes discovered in recent years to catalyze the oxidative degradation of carbohydrate polymers. The PMO catalytic domain has a β-sandwich fold that bears a strong resemblance to both immunoglobulin (Ig) and fibronectin type III (FnIII) domains. PMOs are secreted by fungi and bacteria, and there is recent evidence for their roles in pathogenesis, in addition to biomass processing. This review addresses the biological origins and functions of emerging PMO families, as well as describes the aspects of PMO structure that support the chemistry of copper-catalyzed, oxidative polysaccharide degradation. PMID:26615470

  3. On the catalytic mechanisms of lytic polysaccharide monooxygenases.

    Science.gov (United States)

    Walton, Paul H; Davies, Gideon J

    2016-04-01

    Lytic polysaccharide monooxygenases (LPMOs) are recently discovered copper-containing oxygenases. LPMOs oxidise recalcitrant polysaccharides such as chitin and cellulose, thereby making these substrates more tractable to canonical chitinase or cellulase action. As such, LPMOs are attracting much attention not only for their capacity to greatly increase the efficiency of production of cellulosic-based biofuels, but also for the new questions they pose about the mechanisms of biological oxidation of recalcitrant substrates. This review draws together the current thinking on the catalytic mechanisms of LPMOs and other copper catalysed oxygenations and provides a blueprint for further investigation into the mechanisms of action of these intriguing enzymes. PMID:27094791

  4. Analysis of Polysaccharides in Shii - Take fiom Guizhou

    Institute of Scientific and Technical Information of China (English)

    MO Liping; XIONG Jian; YE Jun; LI Lin

    2001-01-01

    @@ Polysaccharides, special those with physiological actions and nutrition, are widely used as an important resources for food, medicine industries, health etc. Herba Glossogynes Tenuifoliae (Shii-Take) is rich in polysaccharides with physiological actions and nutrition. Guizhou lies to the southwest of China, Natural resources abound in this province, in which there is high output and many species of Shii-Fake. So study in the Shii-Take is favor of reasonably utilizing the natural resources and getting high addvalue products. And what is more, It is necessary for energetically developing west economy.

  5. Increasing Stringiness of Low Fat Mozzarella Cheese Using Polysaccharides

    OpenAIRE

    Oberg, Erik N.

    2013-01-01

    We examined the ability of polysaccharides to function as fat mimetics in low-fat (LF) mozzarella string cheese to improve functionality by acting like fat globules to separate protein fibers during cheese extrusion. Low-fat mozzarella cheese curd made from 273 kg of 0.7% fat milk was salted at a rate of 10 g/kg then divided into 3.6-kg batches that were hand-stretched in 5% brine at 80° C and formed into a homogeneous mass. The hot cheese was hand mixed with a hot 80° polysaccharide slurry, ...

  6. Process for the production of xanthane type polysaccharides. Procede de production de polysaccharides de type xanthane

    Energy Technology Data Exchange (ETDEWEB)

    Leproux, V.; Peignier, M.; Cros, P.; Beucherie, J.; Kennel, Y.

    1990-10-02

    A fermentation process is disclosed in which microorganisms are readily grown in an emulsion medium. The invention has an objective of creating stable biopolymer emulsions which can contain up to 60% biopolymer, more particularly from 3 to 60 wt % of polysaccharides. An aqueous nutrient medium containing a carbon-hydrogen source is fermented by microorganisms so as to form an oil-in-water emulsion in the midst of which the fermentation is carried out. The nutrients, consisting of such substances as sugars, sources of organic nitrogen and/or minerals, and trace elements needed for growth, can be present at concentrations of up to 200 g/l. The microorganism used for fermentation is chosen from among the bacteria which ferment carbohydrates, preferably Xanthomonas. The oil phase may consist of any mineral or vegetable oil which is immiscible with water, preferably in an amount less than 30% of the total medium. The dispersion and stabilization of the oil phase in the water phase is favored by the presence of surfactants, preferably non-ionic. After separate sterilization of the oil and water phases, an emulsion is formed and fermentation is started in a conventional manner. According to one particular aspect of the invention, the emulsion obtained after completion of fermentation is concentrated by elimination of water so as to obtain an emulsion containing preferably 15-60 wt % polysaccharides. The emulsions of the invention are particularly applicable for treating petroleum formations and for preparing fluids used in enhanced recovery processes. Experiments are described to illustrate the invention. 2 tabs.

  7. The Formation of Biofilms by Pseudomonas aeruginosa: A Review of the Natural and Synthetic Compounds Interfering with Control Mechanisms

    Directory of Open Access Journals (Sweden)

    Tsiry Rasamiravaka

    2015-01-01

    Full Text Available P. aeruginosa is an opportunistic pathogenic bacterium responsible for both acute and chronic infections. Beyond its natural resistance to many drugs, its ability to form biofilm, a complex biological system, renders ineffective the clearance by immune defense systems and antibiotherapy. The objective of this report is to provide an overview (i on P. aeruginosa biofilm lifestyle cycle, (ii on the main key actors relevant in the regulation of biofilm formation by P. aeruginosa including QS systems, GacS/GacA and RetS/LadS two-component systems and C-di-GMP-dependent polysaccharides biosynthesis, and (iii finally on reported natural and synthetic products that interfere with control mechanisms of biofilm formation by P. aeruginosa without affecting directly bacterial viability. Concluding remarks focus on perspectives to consider biofilm lifestyle as a target for eradication of resistant infections caused by P. aeruginosa.

  8. Inorganic Phosphate Limitation Modulates Capsular Polysaccharide Composition in Mycobacteria.

    Science.gov (United States)

    van de Weerd, Robert; Boot, Maikel; Maaskant, Janneke; Sparrius, Marion; Verboom, Theo; van Leeuwen, Lisanne M; Burggraaf, Maroeska J; Paauw, Nanne J; Dainese, Elisa; Manganelli, Riccardo; Bitter, Wilbert; Appelmelk, Ben J; Geurtsen, Jeroen

    2016-05-27

    Mycobacterium tuberculosis is protected by an unusual and highly impermeable cell envelope that is critically important for the successful colonization of the host. The outermost surface of this cell envelope is formed by capsular polysaccharides that play an important role in modulating the initial interactions once the bacillus enters the body. Although the bioenzymatic steps involved in the production of the capsular polysaccharides are emerging, information regarding the ability of the bacterium to modulate the composition of the capsule is still unknown. Here, we study the mechanisms involved in regulation of mycobacterial capsule biosynthesis using a high throughput screen for gene products involved in capsular α-glucan production. Utilizing this approach we identified a group of mutants that all carried mutations in the ATP-binding cassette phosphate transport locus pst These mutants collectively exhibited a strong overproduction of capsular polysaccharides, including α-glucan and arabinomannan, suggestive of a role for inorganic phosphate (Pi) metabolism in modulating capsular polysaccharide production. These findings were corroborated by the observation that growth under low Pi conditions as well as chemical activation of the stringent response induces capsule production in a number of mycobacterial species. This induction is, in part, dependent on σ factor E. Finally, we show that Mycobacterium marinum, a model organism for M. tuberculosis, encounters Pi stress during infection, which shows the relevance of our findings in vivo. PMID:27044743

  9. Interpenetrating polymer network hydrogels based on polysaccharides for biomedical applications

    NARCIS (Netherlands)

    Pescosolido, L.

    2011-01-01

    The main theme of this thesis is the development and the characterization of interpenetrating polymer network hydrogels (IPNs) based on biodegradable and biocompatible polysaccharides, in particular alginate, hyaluronic acid and dextran. The suitability of these novel systems as pharmaceutical and b

  10. Pectin, a versatile polysaccharide present in plant cell walls

    NARCIS (Netherlands)

    Voragen, A.G.J.; Coenen, G.J.; Verhoef, R.P.; Schols, H.A.

    2009-01-01

    Pectin or pectic substances are collective names for a group of closely associated polysaccharides present in plant cell walls where they contribute to complex physiological processes like cell growth and cell differentiation and so determine the integrity and rigidity of plant tissue. They also pla

  11. Thermal decomposition of natural polysaccharides: Chitin and chitosan

    Directory of Open Access Journals (Sweden)

    Kuchina Yu.A.

    2015-03-01

    Full Text Available The results of the thermal analysis of shrimp’s chitin and chitosan have been presented (samples of polysaccharide differed by the deacetylation degree have been studied. The thermal analysis has been carried out by differential thermogravimetry and differential scanning calorimetry. Activation energy of process of chitin and chitosan thermal destruction has been calculated

  12. Solid-state NMR studies of polysaccharide systems

    Czech Academy of Sciences Publication Activity Database

    Spěváček, Jiří; Brus, Jiří

    Graz : Austrian Centre for Electron MIcroscopy and Nanoanalysis, 2007. s. 19. [European Symposium on Polymer Spectroscopy /17./. 09.9.2007-12.09.2007, Seggauberg Leibnitz] R&D Projects: GA ČR GA525/05/0273 Institutional research plan: CEZ:AV0Z40500505 Keywords : polysaccharide * chitin/glucan complex * starch Subject RIV: CD - Macromolecular Chemistry

  13. Extraction, Characterization and Immunological Activity of Polysaccharides from Rhizoma gastrodiae.

    Science.gov (United States)

    Chen, Juncheng; Tian, Shan; Shu, Xiaoying; Du, Hongtao; Li, Na; Wang, Junru

    2016-01-01

    A response surface and Box-Behnken design approach was applied to augment polysaccharide extraction from the residue of Rhizoma gastrodiae. Statistical analysis revealed that the linear and quadratic terms for three variables during extraction exhibited obvious effects on extraction yield. The optimum conditions were determined to be a liquid-to-solid ratio of 54 mL/g, an extraction temperature of 74 °C, an extraction time of 66 min, and three extractions. These conditions resulted in a maximum Rhizoma gastrodiae polysaccharide (RGP) extraction yield of 6.11% ± 0.13%. Two homogeneous polysaccharides (RGP-1a and RGP-1b) were obtained using DEAE cellulose-52 and Sephadex G-100 columns. The preliminary characterization of RGP-1a and RGP-1b was performed using HPLC-RID, HPGPC, and FTIR. Tests of the immunological activity in vitro showed that the two polysaccharides could significantly stimulate macrophages to release NO and enhance phagocytosis in a dose-dependent manner. In particular, RGP-1b (200 μg/mL) and LPS (2 μg/mL) had almost the same influence on the NO production and phagocytic activity of RAW 264.7 macrophages (p > 0.05). All the data obtained indicate that RGP-1a and RGP-1b have the potential to be developed as a health food. PMID:27347944

  14. Polysaccharide Colloids as Smart Vehicles in Cancer Therapy.

    Science.gov (United States)

    Caro, Carlos; Pozo, David

    2015-01-01

    Cancer disease is one of the leading causes of morbidity and mortality worldwide, with approximately 14 million new cases and around 8 million cancer-related deaths yearly. Estimates expect to increase these figures over the next few years. Therefore, it is very important to develop more effective and targeted therapies. Polysaccharides are widely used for biomedical and pharmaceutical applications due to their interesting properties, and can be utilised in the production of nanovehicles for drug delivery, since they frequently extend the half-life and improve the stability of chemotherapeutic agents in bloodstream allowing them to reach the tumour tissue. Moreover, polysaccharide-based nanovehicles are generally expected to increase the therapeutic benefit by reducing the undesired side effects and promoting a more efficient cellular uptake. Here, we highlight the application of various polysaccharides as nanovehicles in cancer therapy, focusing mainly on in vivo applications and describing the main advantages of each designed system in a critical way. The use of different polysaccharides interacting with metal nanoparticles to develop new nanovehicles for cancer therapy will also be discussed. PMID:26290210

  15. Immunization of immunosuppressed patients with pneumococcal polysaccharide vaccine

    International Nuclear Information System (INIS)

    The antibody response after immunization with capsular polysaccharides of Streptococcus pneumoniae of patients with Hodgkin's disease or with carcinoma of the head and neck was studied. Patients with Hodgkin's disease who were immunized prior to the institution of immunosuppressive therapy were capable of responding to each of the pneumococcal polysaccharides evaluated. The level of antibody achieved by the patients is lower than that of normal control subjects. Nevertheless, absolute values were in the range that would be expected to result in protection. The duration of antibody response was not evaluated. Patients with carcinoma of the head and neck did not demonstrate a significant increase in antibody levels after vaccination, which was done at the time of radiation therapy. Two years after immunization antibody levels were lower with recovery at three years. However, these changes were not statistically significant. Decreased levels of antibody to pneumococcal polysaccharide types not present in the vaccine were observed. Studies of patients with carcinoma of the heat and neck demonstrated that radiation therapy has a profound immunosuppressive effect on antibody levels. More selective immunosuppressive therapy and/or an increase in the immunogenicity of the polysaccharides in the vaccine are required for protection of patients with malignancy

  16. Polysaccharides of higher fungi: Biological role, structure, and antioxidative activity

    OpenAIRE

    Kozarski Maja S.; Klaus Anita S.; Nikšić Miomir P.; van Griensven Leo J.L.D.; Vrvić Miroslav M.; Jakovljević Dragica M.

    2014-01-01

    Fungal polysaccharides attract a lot of attention due to their multiple challenging biological properties, such as: anti-tumor, anti-viral, anticomplementary, anticoagulant, hypolipidemic and immunomodulatory and immune-stimulatory activities, which all together make them suitable for application in many quite distinctive areas, such as food industry, biomedicine, cosmetology, agriculture, environmental protection and waste water management. This article pr...

  17. Extraction, Characterization and Immunological Activity of Polysaccharides from Rhizoma gastrodiae

    Directory of Open Access Journals (Sweden)

    Juncheng Chen

    2016-06-01

    Full Text Available A response surface and Box-Behnken design approach was applied to augment polysaccharide extraction from the residue of Rhizoma gastrodiae. Statistical analysis revealed that the linear and quadratic terms for three variables during extraction exhibited obvious effects on extraction yield. The optimum conditions were determined to be a liquid-to-solid ratio of 54 mL/g, an extraction temperature of 74 °C, an extraction time of 66 min, and three extractions. These conditions resulted in a maximum Rhizoma gastrodiae polysaccharide (RGP extraction yield of 6.11% ± 0.13%. Two homogeneous polysaccharides (RGP-1a and RGP-1b were obtained using DEAE cellulose-52 and Sephadex G-100 columns. The preliminary characterization of RGP-1a and RGP-1b was performed using HPLC-RID, HPGPC, and FTIR. Tests of the immunological activity in vitro showed that the two polysaccharides could significantly stimulate macrophages to release NO and enhance phagocytosis in a dose-dependent manner. In particular, RGP-1b (200 μg/mL and LPS (2 μg/mL had almost the same influence on the NO production and phagocytic activity of RAW 264.7 macrophages (p > 0.05. All the data obtained indicate that RGP-1a and RGP-1b have the potential to be developed as a health food.

  18. Mapping the polysaccharide degradation potential of Aspergillus niger

    NARCIS (Netherlands)

    Andersen, M.R.; Giese, M.; De Vries, R.P.; Nielsen, J.

    2012-01-01

    Background The degradation of plant materials by enzymes is an industry of increasing importance. For sustainable production of second generation biofuels and other products of industrial biotechnology, efficient degradation of non-edible plant polysaccharides such as hemicellulose is required. For

  19. Directional control of diffusion and swelling in megamolecular polysaccharide hydrogels.

    Science.gov (United States)

    Joshi, G; Okeyoshi, K; Okajima, M K; Kaneko, T

    2016-07-01

    Directional control of diffusion and swelling in megamolecular polysaccharide hydrogels is demonstrated by focusing on the anisotropic structures for water absorption. Due to the presence of a layered structure in the hydrogel, the directional control for diffusion parallel to the planar direction and swelling in the lateral direction are possible. PMID:27223843

  20. Immunization of immunosuppressed patients with pneumococcal polysaccharide vaccine

    Energy Technology Data Exchange (ETDEWEB)

    Ammann, A.J.; Schiffman, G.; Addiego, J.E.; Wara, W.M.; Wara, D.W.

    The antibody response after immunization with capsular polysaccharides of Streptococcus pneumoniae of patients with Hodgkin's disease or with carcinoma of the head and neck was studied. Patients with Hodgkin's disease who were immunized prior to the institution of immunosuppressive therapy were capable of responding to each of the pneumococcal polysaccharides evaluated. The level of antibody achieved by the patients is lower than that of normal control subjects. Nevertheless, absolute values were in the range that would be expected to result in protection. The duration of antibody response was not evaluated. Patients with carcinoma of the head and neck did not demonstrate a significant increase in antibody levels after vaccination, which was done at the time of radiation therapy. Two years after immunization antibody levels were lower with recovery at three years. However, these changes were not statistically significant. Decreased levels of antibody to pneumococcal polysaccharide types not present in the vaccine were observed. Studies of patients with carcinoma of the heat and neck demonstrated that radiation therapy has a profound immunosuppressive effect on antibody levels. More selective immunosuppressive therapy and/or an increase in the immunogenicity of the polysaccharides in the vaccine are required for protection of patients with malignancy.

  1. Biochemical evaluation of antioxidant activity and polysaccharides fractions in seaweeds

    Directory of Open Access Journals (Sweden)

    A. Tariq

    2015-01-01

    Full Text Available In the present study ethanol and water extracts of 15 seaweeds, Dictyota dichotoma var. velutricata, Dictyota indica, Iyengaria stellata, Padina pavonia, Sargassum swartzii, Sargassum variegatum, Stoechospermum marginatum, Stokeyia indica, Jolyna laminarioides, Caulerpa taxifolia, Halimeda tuna, Ulva fasciata, Ulva lactuca, Solieria robusta, and Melanothamnus afaqhusainii, were evaluated for their antioxidant potential by ABTS or 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid, superoxide and total antioxidant capacity (TAC assays.  The activity was concentration dependent and the variation in antioxidant potential was also observed by different assays in both extracts.  Ethanol extract of D. dichotoma var. velutricata, D. indica and S. marginatum demonstrated highest activity by TAC assay.  The antioxidant potential in organic solvent fractions of seaweeds namely P. pavonia, S. swartzii, S. marginatum and M. afaqhusainii was also determined and chloroform fraction of all the four seaweeds showed highest activity by superoxide assay.  Antioxidant activity of extracted fractions of polysaccharides from S. indica, C. taxifolia and D. dichotoma var. velutricata was also evaluated by superoxide method.  Polysaccharide fractions of S. indica obtained from HCl (at 700C and room temperature and water extract demonstrated highest activity respectively.  All the polysaccharide fractions of C. taxifolia showed excellent activity except CaClF70°C. Polysaccharide fractions of D. dichotoma var. velutricata also exhibited very good activity.

  2. Polysaccharide degradation systems of the saprophytic bacterium Cellvibrio japonicus.

    Science.gov (United States)

    Gardner, Jeffrey G

    2016-07-01

    Study of recalcitrant polysaccharide degradation by bacterial systems is critical for understanding biological processes such as global carbon cycling, nutritional contributions of the human gut microbiome, and the production of renewable fuels and chemicals. One bacterium that has a robust ability to degrade polysaccharides is the Gram-negative saprophyte Cellvibrio japonicus. A bacterium with a circuitous history, C. japonicus underwent several taxonomy changes from an initially described Pseudomonas sp. Most of the enzymes described in the pre-genomics era have also been renamed. This review aims to consolidate the biochemical, structural, and genetic data published on C. japonicus and its remarkable ability to degrade cellulose, xylan, and pectin substrates. Initially, C. japonicus carbohydrate-active enzymes were studied biochemically and structurally for their novel polysaccharide binding and degradation characteristics, while more recent systems biology approaches have begun to unravel the complex regulation required for lignocellulose degradation in an environmental context. Also included is a discussion for the future of C. japonicus as a model system, with emphasis on current areas unexplored in terms of polysaccharide degradation and emerging directions for C. japonicus in both environmental and biotechnological applications. PMID:27263016

  3. Comparison of antioxidant and antiproliferation activities of polysaccharides from eight species of medicinal mushrooms.

    Science.gov (United States)

    Chen, Peiying; Yong, Yangyang; Gu, Yifan; Wang, Zeliang; Zhang, Shizhu; Lu, Ling

    2015-01-01

    Polysaccharides from mushrooms including Pleurotus eryngii, P. ostreatus, P. nebrodensis, Lentinus edodes, Hypsizygus marmoreus, Flammulina velutipes, Ganoderma lucidum, and Hericium erinaceus were isolated by water extraction and alcohol precipitation. Our results suggest that all tested polysaccharides have the significant antioxidant capacities of scavenging free radicals (1,1-diphenyl-2-picrylhydrazyl and hydroxyl radicals). Among them, the H. erinaceus polysaccharide exhibits the highest 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activity, whereas the L. edodes polysaccharide shows the strongest scavenging ability for hydroxyl radicals. Furthermore, using the MCF-7 breast cancer cell line and HeLa cells, all 8 selected polysaccharides are able to inhibit the proliferation of tumor cells, but the strength of inhibition varied depending on the mushroom species and the concentration used. Notably, G. lucidum polysaccharide shows the highest inhibition activity on MCF-7 cells. By comparison, H. erinaceus polysaccharide has the strongest inhibitory effect on HeLa cells. Moreover, high-performance liquid chromatography with a carbohydrate analysis column showed significant differences in polysaccharide components among these mushrooms. Thus our data suggest that the different species of mushrooms have the variable functions because of their own specific polysaccharide components. The 8 mushroom polysaccharides have the potential to be used as valuable functional food additives or sources of therapeutic agents for antioxidant and cancer treatments, especially polysaccharides from H. erinaceus, L. edodes, and G. lucidum. PMID:25954912

  4. Non-cellulosic polysaccharides from cotton fibre are differently impacted by textile processing

    DEFF Research Database (Denmark)

    Runavot, Jean-Luc; Guo, Xiaoyuan; Willats, William George Tycho;

    2014-01-01

    Cotton fibre is mainly composed of cellulose, although non-cellulosic polysaccharides play key roles during fibre development and are still present in the harvested fibre. This study aimed at determining the fate of non-cellulosic polysaccharides during cotton textile processing. We analyzed non......-cellulosic cotton fibre polysaccharides during different steps of cotton textile processing using GC-MS, HPLC and comprehensive microarray polymer profiling to obtain monosaccharide and polysaccharide amounts and linkage compositions. Additionally, in situ detection was used to obtain information on polysaccharide...... localization and accessibility. We show that pectic and hemicellulosic polysaccharide levels decrease during cotton textile processing and that some processing steps have more impact than others. Pectins and arabinose-containing polysaccharides are strongly impacted by the chemical treatments, with most being...

  5. Interferência dos sucos de uva integral e reconstituído na estrutura das proteínas salivares e da película dental adquirida do esmalte

    OpenAIRE

    Archetti, Felipe Belmonte

    2014-01-01

    Resumo: A saliva é um fluido da cavidade oral composta por íons e macromoléculas como proteínas e glicoproteínas, entre outras. A adsorção das proteínas da saliva sobre a superfície eletronegativa da hidroxiapatita conduz a formação da película adquirida que protege a estrutura dental de componentes ácidos da dieta. Este trabalho visa avaliar o efeito do suco de uva na estrutura das proteínas salivares e composição da película dental adquirida do esmalte. A saliva estimulada foi coletada e mi...

  6. Abundancia y reproducción del pelícano pardo (Pelecanus occidentalis) en dos pequeñas bahías del Pacífico central, México

    OpenAIRE

    Salvador Hernández-Vázquez; Eduardo Iñigo-Elias; J. Ángel Hinojosa Larios; Braulio Durand Martínez; Rojo-Vázquez, J.A; Carmen Valadez González

    2011-01-01

    La abundancia y reproducción del pelícano pardo (Pelecanus occidentalis) se estudió en dos bahías del pacífico central Mexicano, Bahía de Navidad y Bahía Chamela, ubicadas en la costa de Jalisco. De diciembre de 2007 a noviembre de 2009 se registró mensualmente el número de pelícanos pardos en ambas bahías, así como el número de nidos, huevos y pollos en la isla Cocinas. Se midió mensualmente la temperatura superficial del agua, nutrientes (NO2 -, NO3 -, NH4 + y PO4 -) y la productividad prim...

  7. Diseño de una película de quitosán como sistema terapéutico farmacéutico alternativo para el tratamiento de úlceras cutáneas

    OpenAIRE

    Pulido Barrios, Ariadna Lisbeth

    2012-01-01

    El objetivo principal del presente estudio consistió en el diseño de películas poliméricas de quitosán, como alternativa terapéutica en el transporte de sustancias activas para el tratamiento de úlceras cutáneas. Las películas fueron preparadas por la técnica de vertimiento en placa, optimizando las condiciones para su obtención. Se evaluó como sistema el polímero catiónico de quitosán con dos pesos moleculares, bajo y mediano, empleando dos solventes, ácido acético y ácido láctico para su pr...

  8. Fabricación de películas delgadas de CU2 S mediante una reacción de sustitución iónica

    Directory of Open Access Journals (Sweden)

    Gerardo Gordillo Guzmán

    2010-12-01

    Full Text Available Se formaron películas delgadas de sulfuro cuproso (CU2S topotaxialmente sobre películas delgadas de sulfuro de cadmio (CdS mediante una reacción de intercambio de iones de Cu (I provenientes de una solución de CuCI con Iones de Cd (lI de la red de sulfuro de cadmio. Dos tipos diferentes de soluciones de CuCI fueron investigados y los resultados experimentales se evaluaron por medio de medidas de la característica corriente- voltaje (I-V de las celdas solares de CU2 S/CdS obtenidas. Eficiencias de conversión de 4.5% se lograron con dichas celdas solares.

  9. Hvers vegna keyrir hann ekki um á bláum Ópel? : Greining á sambandi manns og náttúru í sviðsetningum Ragnars Kjartanssonar.

    OpenAIRE

    Gígja Hólmgeirsdóttir 1987

    2015-01-01

    Í þessari hugleiðingu verður leitast við að svara hvers vegna Ragnar Kjartansson kýs að keyra um á gömlum Cadillac í stað nýrri bílategundar á borð við Ópel Astra. Samanburðurinn er sprottinn af hversdagslegu atviki sem gerðist í miðborg Reykjavíkur og hefur að gera með sviðsetningu listamannsins á sjálfum sér. Greiningin mun hverfast um hugmyndaheim bílaauglýsingar Bílabúðar Benna á Ópel Astra og verða sviðsetningar Ragnars settar í samhengi við hana. Í upphafi verður stuttlega farið yfi...

  10. El portafolis europeu de llengües en versió electrònica (ePEL+14: percepció preliminar del professorat universitari de la Xarxa Vives The electronic European Language Portfolio (eELP+14: first impressions of university teaching staff in the Vives Network El Portfolio Europeo de las Lenguas en versión electrónica (ePEL+14: percepción preliminar del profesorado universitario de la Red Vives

    Directory of Open Access Journals (Sweden)

    Olatz López Fernández

    2013-04-01

    Full Text Available Aquest article presenta el portafolis europeu de llengües en versió electrònica (ePEL+14 recentment validat pel Consell d'Europa. El propòsit és descriure aquesta innovació educativa en la docència universitària dels Erasmus Intensive Language Courses (EILC i conèixer l'opinió dels professors universitaris de llengua catalana de la Xarxa Vives participants en la primera preexperimentació amb aquesta innovació en el curs 2011-2012. Es va dur a terme una enquesta després d’un taller de l'ePEL+14 en els EILC. El qüestionari ad hoc contenia quatre dimensions: variables sociodemogràfiques, coneixement previ del PEL i ePEL, materials de suport per implementar-ho i conseqüències del seu ús en l'aprenentatge de la llengua. La valoració va ser positiva, especialment per l'adequació de l'eina tecnològica i les funcionalitats informatives i pedagògiques per a l’aprenent de llengües. No obstant això, també assenyalen una influència moderada en l’aprenentatge de la llengua i cultura. ____________________________________________________ Nous présentons ici le Portfolio européen des Langues en version électronique (ePEL+14 récemment validé par le Conseil de l'Europe. Le but est de décrire cette innovation éducative dans l'enseignement universitaire des Erasmus Intensive Language Courses (EILC et de faire connaître l'opinion des enseignants du supérieur de langue catalane du réseau Vives participant à la première pré-expérimentation avec cette innovation au cours de l'année universitaire 2011-2012. Nous avons réalisé une enquête après un atelier de l'ePEL+14 dans les EILC. Le questionnaire ad hoc comportait quatre dimensions: variables socio-démographiques; connaissance préalable du PEL et de l'ePEL; matériels de support pour la mise en œuvre; et conséquences de son utilisation dans l'apprentissage de la langue. L'évaluation a été positive, tout spécialement quant à l'adéquation de l

  11. Comparison of radioimmunoassay and enzyme-linked immunosorbent assay in measurement of antibodies to Neisseria meningitidis group A capsular polysaccharide.

    OpenAIRE

    Beuvery, E C; Kayhty, M H; Leussink, A B; Kanhai, V

    1984-01-01

    Antibodies to meningococcal group A polysaccharide were determined by radioimmunoassay (RIA) and enzyme-linked immunosorbent assay (ELISA) in serum samples from 16 adults vaccinated with bivalent meningococcal group A and C polysaccharide vaccine. The specific antibody levels in the serum samples were expressed as micrograms of antibody protein per milliliter of serum. For RIA the polysaccharide was radiolabeled extrinsically with 125I. Both native polysaccharide and polysaccharide labeled wi...

  12. Rabbit antibodies to the cell wall polysaccharide of Streptococcus pneumoniae fail to protect mice from lethal challenge with encapsulated pneumococci.

    OpenAIRE

    Szu, S C; Schneerson, R; Robbins, J B

    1986-01-01

    A conjugate, composed of the cell wall polysaccharide (C polysaccharide) of Streptococcus pneumoniae and bovine serum albumin (BSA), was prepared with the bifunctional agent N-succinimidyl-3-(2-pyridyldithio)-propionate. Analysis with monoclonal antibodies provided evidence that the phosphocholine (PC) moiety of the C polysaccharide was retained during the conjugation procedure. The C polysaccharide-BSA conjugate elicited antibodies to C polysaccharide in rabbits; no PC-specific antibodies we...

  13. El cine y la generación de conocimiento en la educación empresarial: estudio de caso con la película Los Coristas

    Directory of Open Access Journals (Sweden)

    Alfredo Gorrochotegui

    2009-05-01

    Full Text Available Se describe la experiencia del uso de una película (“Los Coristas” como recurso didáctico para enseñar conductasde liderazgo a un grupo de trabajadores de una empresa de producción de alimentos, con el fin de prepararlospara la posterior compresión de un modelo específico de competencias de liderazgo. Antes de la observación de lapelícula se les entregó la ficha técnica de la misma, así como un cuestionario que debían contestar después de ver ellargometraje. A partir de las respuestas de dos participantes, se analiza si efectivamente son observables conductas deliderazgo en los personajes, y si éstas logran producir valoraciones y conclusiones que luego sirviesen para estudiarlas competencias de liderazgo. La experiencia con este grupo en particular, permitió validar que la observación de unapelícula y el uso del cine-foro facilitan procesos de reflexión, producción de ideas y preparación para introducirse ennuevas teorías y en la creación de conocimiento en el área organizacional.

  14. Representación de género. Las películas españolas contemporáneas de adolescentes (2009-2014 

    Directory of Open Access Journals (Sweden)

    C Álvarez-Hernández

    2015-12-01

    Full Text Available Introducción. El presente estudio partió de los múltiples informes sobre los elevados índices de Desigualdad de Género en nuestra sociedad y de la gran influencia del relato audiovisual para la configuración de la misma. Nos planteamos si los largometrajes contemporáneos de producción española y de adolescentes reproducían esa imagen de género desigual. Metodología. Se estudió a los protagonistas de las películas más vistas con un elenco de adolescentes de más del 50% entre los años 2009-2014, analizando el número de personajes masculinos y femeninos en ellos y la reproducción de ocho estereotipos de género. Resultados. Los resultados manifestaron la reproducción de una imagen de género desigual, con estereotipos argumentales y de definición de personajes y roles que no hacen sino alimentar la creación y continuación de una imagen colectiva en los espectadores adolescentes sobre cómo son los hombres y las mujeres, contribuyendo a perpetuar la desigualdad de género.

  15. Efeito da aplicação de película de fécula de mandioca na conservação pós-colheita de tomate

    Directory of Open Access Journals (Sweden)

    Damasceno Simone

    2003-01-01

    Full Text Available O presente trabalho teve por objetivo avaliar a qualidade e a vida útil pós-colheita de frutos de Tomate (Lycopersicon esculentum Mill utilizando recobrimento com película de fécula de mandioca. Após a seleção os frutos foram mergulhados em suspensões a 2 e 3% de fécula de mandioca, secos ao ar e armazenados em condição ambiente, onde a temperatura e a umidade relativa do período variaram de 16 a 21ºC e 51 a 91%, respectivamente. O experimento foi constituído de dois lotes de frutos, sendo o primeiro o grupo não-destrutivo (avaliação de perda de massa. O segundo lote de frutos, constituiu o grupo destrutivo no qual analisou-se textura, pH e sólidos solúveis totais. Os frutos foram avaliados aos 0, 4, 8, 11, 14, 18 e 22 dias. O delineamento experimental foi inteiramente casualizado, com cinco repetições para o primeiro grupo e três repetições para o grupo destrutivo. Os dados experimentais obtidos foram submetidos à analise de variância e as médias comparadas através do teste de Tukey ao nível de 5% de probabilidade. Os tratamentos não influenciaram significativamente a perda de massa e a textura. Entretanto, os frutos recobertos com película a 3% apresentaram melhor aparência do que os frutos testemunha e com película a 2%. O efeito das películas portanto, não foi prejudicial, apenas estético.

  16. Tratamiento Superficial de Acero Galvanizado con Películas Híbridas formadas por 3-(trimetoxisililpropil metacrilato (TMSPMA y Tetraetoxisilano (TEOS Surface Treatment of Galvanized Steel with Hybrid Films formed by 3-(trimethoxysilyl methacrylate (TMSPMA and Tetraethoxysilane (TEOS

    Directory of Open Access Journals (Sweden)

    Sandra R Kunst

    2012-01-01

    Full Text Available Acero galvanizado fue revestido con una película híbrida a partir de una solución formada por los precursores silanos 3-(trimetoxisililpropil metacrilato (TMSPMA y tetraetoxisilano (TEOS con adición de cerio. El uso de capas hibridas orgánico-inorgánico representa una alternativa ambientalmente aceptable para mejorar la resistencia de una serie de materiales metálicos frente a los procesos corrosivos. Se emplearon tres tiempos de inmersión (2, 10 y 15 minutos y se caracterizaron las películas mediante microscopia electrónica de barrido, evaluando también el carácter hidrofóbico de las películas. El comportamiento electroquímico de los revestimientos obtenidos fue determinado por el monitoreo del potencial de circuito abierto, polarización potenciodinámica e impedancia electroquímica. Los resultados que se obtuvo evidenciaron el efecto del tiempo de permanencia dentro de la solución en la uniformidad de la película y consecuentemente sobre la resistencia a la corrosión del mismo.Galvanized steel was coated with a hybrid film obtained from a solution formed by silane precursor 3-(trimethoxysilyl methacrylate (TMSPMA and tetraethoxysilane (TEOS with addition of cerium. The use of hybrid organic-inorganic layers represents an environmentally friendly alternative to improve resistance against corrosion of a series of metallic materials. Three immersion times (2, 10 and 15 minutes were used and the films were characterized by scanning electron microscope evaluating film wetability was at the same time. The electrochemical behavior of the coatings obtained was evaluated by open circuit potential, potentiodynamic polarization and electrochemical impedance. The results showed the effect of immersion time in the solution on the film uniformity and consequently on the corrosion resistance of these films.

  17. La traducció de cançons per al doblatge i l'adaptació musical en pel·lícules d'animació: anàlisi de les versions catalana i espanyola de tres pel·lícules nord-americanes contemporànies per a tots els públics

    OpenAIRE

    Brugué, Lydia

    2013-01-01

    En esta tesis doctoral interdisciplinaria se unen tres campos de estudio: el cine de animación, la música cinematográfica y la traducción de canciones para el doblaje y la adaptación musical. La tesis está dividida en dos partes: en la primera, se presenta el estado de la cuestión de los tres campos de estudio citados anteriormente; en la segunda parte, se presentan las fichas artísticas y técnicas, así como el análisis traductológico del corpus: tres películas de animación para todos los púb...

  18. The Cyclic AMP-Vfr Signaling Pathway in Pseudomonas aeruginosa Is Inhibited by Cyclic Di-GMP

    DEFF Research Database (Denmark)

    Almblad, Henrik; Harrison, Joe J; Rybtke, Morten;

    2015-01-01

    a direct result of elevated c-di-GMP content. Overproduction of c-di-GMP causes a decrease in the transcription of virulence factor genes that are regulated by the global virulence regulator Vfr. The low level of Vfr-dependent transcription is caused by a low level of its coactivator, cyclic AMP (c...

  19. Clearance of Pseudomonas aeruginosa Foreign-Body Biofilm Infections through Reduction of the Cyclic Di-GMP Level in the Bacteria

    DEFF Research Database (Denmark)

    Christensen, Louise D.; van Gennip, Maria; Rybtke, Morten Theil; Wu, Hong; Chiang, Wen-Chi; Alhede, Morten; Høiby, Niels; Nielsen, Thomas Eiland; Givskov, Michael; Tolker-Nielsen, Tim

    2013-01-01

    be used for biofilm control in vivo. We constructed a Pseudomonas aeruginosa strain in which a reduction in the c-di-GMP level can be achieved via induction of the Escherichia coli YhjH c-di-GMP phosphodiesterase. Initial experiments showed that induction of yhjH expression led to dispersal of the...

  20. Multiple diguanylate cyclase-coordinated regulation of pyoverdine synthesis in Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Chen, Yicai; Yuan, Mingjun; Mohanty, Anee;

    2015-01-01

    The nucleotide signalling molecule bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP) plays an essential role in regulating microbial virulence and biofilm formation. C-di-GMP is synthesized by diguanylate cyclase (DGC) enzymes and degraded by phosphodiesterase (PDE) enzymes. One intri...

  1. A systematic analysis of the role of GGDEF-EAL domain proteins in virulence and motility in Xanthomonas oryzae pv. oryzicola.

    Science.gov (United States)

    Wei, Chao; Jiang, Wendi; Zhao, Mengran; Ling, Junjie; Zeng, Xin; Deng, Jun; Jin, Dongli; Dow, John Maxwell; Sun, Wenxian

    2016-01-01

    The second messenger c-di-GMP is implicated in regulation of various aspects of the lifestyles and virulence of Gram-negative bacteria. Cyclic di-GMP is formed by diguanylate cyclases with a GGDEF domain and degraded by phosphodiesterases with either an EAL or HD-GYP domain. Proteins with tandem GGDEF-EAL domains occur in many bacteria, where they may be involved in c-di-GMP turnover or act as enzymatically-inactive c-di-GMP effectors. Here, we report a systematic study of the regulatory action of the eleven GGDEF-EAL proteins in Xanthomonas oryzae pv. oryzicola, an important rice pathogen causing bacterial leaf streak. Mutational analysis revealed that XOC_2335 and XOC_2393 positively regulate bacterial swimming motility, while XOC_2102, XOC_2393 and XOC_4190 negatively control sliding motility. The ΔXOC_2335/XOC_2393 mutant that had a higher intracellular c-di-GMP level than the wild type and the ΔXOC_4190 mutant exhibited reduced virulence to rice after pressure inoculation. In vitro purified XOC_4190 and XOC_2102 have little or no diguanylate cyclase or phosphodiesterase activity, which is consistent with unaltered c-di-GMP concentration in ΔXOC_4190. Nevertheless, both proteins can bind to c-di-GMP with high affinity, indicating a potential role as c-di-GMP effectors. Overall our findings advance understanding of c-di-GMP signaling and its links to virulence in an important rice pathogen. PMID:27053282

  2. Sulfated Polysaccharides Purified from Two Species of Padina Improve Collagen and Epidermis Formation in the Rat

    Science.gov (United States)

    Kordjazi, Moazameh; Shabanpour, Bahareh; Zabihi, Ebrahim; Faramarzi, Mohammad Ali; Feizi, Farideh; Ahmadi Gavlighi, Hassan; Feghhi, Mohammad Amin; Hosseini, Seyed Abbas

    2013-01-01

    Sulfated polysaccharides have shown promising effects on wound healing processes along with many other biological activities. The sulfated polysaccharides extracted from two algae species habitats in Persian Gulf were studied in vivo for their effects on collagen formation and epidermal regeneration. The polysaccharides were purified from aqueous extracts of P. tetrastromatica and P. boergesenii using CaCl2 and ethanol precipitation. The sulfate content of each polysaccharide was determined. Two identical wounds (either burn or excision) were made on the back of 4 groups of male Wistar rats (10 rats per group) under anesthesia. The algal polysaccharide ointments (2%) were applied twice daily on one side and the other wound was treated with Eucerin (as control). The rats were sacrificed on day 7 or 14, and then the wound samples were examined for epidermal thickness by light microscope. Furthermore, hydroxyproline content (as a marker of collagen formation) was spectro-photometrically measured. The polysaccharides purified from P. boergesenii had higher sulfate content (32.6±1%) compared to P. tetrastromatica (19±1%). Both algal polysaccharides showed some improvements in collagen formation (hydroxyproline content) and epidermal thickness in both wound models compared to the vehicle. The sulfated polysaccharides purified from P. tetrastromatica and P. boergesenii seaweeds are able to induce collagen formation and epidermal regeneration in the two wound models. The superior healing properties of P. boergesenii polysaccharides might be correlated to its higher sulfate content. Both algal polysaccharides are good candidates for wound healing clinical trials. PMID:24551807

  3. Rheological characterization of levan polysaccharides from Microbacterium laevaniformans.

    Science.gov (United States)

    Bae, In Young; Oh, Im-Kyung; Lee, Suyong; Yoo, Sang-Ho; Lee, Hyeon Gyu

    2008-01-01

    Levan polysaccharides were produced from Microbacterium laevaniformans and its rheological behaviors were characterized as a function of concentration and temperature. The intrinsic viscosity of the purified levan was determined to be 0.38dL/g at 25 degrees C which was relatively higher than that of levans from other microbial sources. The flow behaviors of the levan solutions were characterized by the increase in the shear stress, giving more increments in the shear rate. Thus, the levan solutions exhibited the pseudoplastic behavior, which was characterized by the power law model. In addition, the flow behaviors of the levans were satisfactorily fitted to the Arrhenius equation where the activation energy of flow (Ea) decreased from 24.07 to 13.53kJ/mol (R2=0.98-0.99) with increasing concentrations. Moreover, the exponential equation was favorably applied to describe the effect of concentration on the apparent viscosity of the levan polysaccharides. PMID:17931701

  4. Fermentation of polysaccharides by Klebsiella and other facultative bacilli

    Energy Technology Data Exchange (ETDEWEB)

    Ochuba, G.U.; Von Riesen, V.L.

    1980-05-01

    Fermentations of 10 polysaccharides by species of the family Enterobacteriaceae were examined. Algin, guar, karaya, xanthan, and xylan were not fermented by any of the strains tested. Most of the activity was found in the tribe Klebsielleae. Klebseilla oxytoca fermented amylopectin (97% of the strains studied), carrageenan (100%), inulin (68%), polypectate (100%), and tragacanth (100%). Klebsiella pneumoniae fermented amylopectin (91%), carrageenan (100%), and tragacanth (86%). Carraggeenan was also fermented by Enterobacter aerogenes (100%), Enterobacter agglomerans (63%), Enterobacter cloacae (95%), and pectobacterium (38%). pectobacterium shared polypectate fermentation (100%) with K. oxytoca. With one exception, Serratia strains were negative on all polysaccharides. These results, along with other evidence, indicate that (i) the genus Klebsiella is biochemically the most versatile genus of the tribe, (ii) because of its distinct characteristics, K. oxytoca warrants species designation separate from K. pneumoniae, and (iii) some food additives generally considered indigestible can be metabolized by a few species of facultative bacilli, whereas others appear to be resistant.

  5. Extracellular Polysaccharides Produced by Yeasts and Yeast-Like Fungi

    Science.gov (United States)

    van Bogaert, Inge N. A.; de Maeseneire, Sofie L.; Vandamme, Erick J.

    Several yeasts and yeast-like fungi are known to produce extracellular polysaccharides. Most of these contain D-mannose, either alone or in combination with other sugars or phosphate. A large chemical and structural variability is found between yeast species and even among different strains. The types of polymers that are synthesized can be chemically characterized as mannans, glucans, phosphoman-nans, galactomannans, glucomannans and glucuronoxylomannans. Despite these differences, almost all of the yeast exopolysaccharides display some sort of biological activity. Some of them have already applications in chemistry, pharmacy, cosmetics or as probiotic. Furthermore, some yeast exopolysaccharides, such as pullulan, exhibit specific physico-chemical and rheological properties, making them useful in a wide range of technical applications. A survey is given here of the production, the characteristics and the application potential of currently well studied yeast extracellular polysaccharides.

  6. Carbohydrase Systems of Saccharophagus degradans Degrading Marine Complex Polysaccharides

    Directory of Open Access Journals (Sweden)

    Maxim Suvorov

    2011-04-01

    Full Text Available Saccharophagus degradans 2-40 is a γ-subgroup proteobacterium capable of using many of the complex polysaccharides found in the marine environment for growth. To utilize these complex polysaccharides, this bacterium produces a plethora of carbohydrases dedicated to the processing of a carbohydrate class. Aiding in the identification of the contributing genes and enzymes is the known genome sequence for this bacterium. This review catalogs the genes and enzymes of the S. degradans genome that are likely to function in the systems for the utilization of agar, alginate, α- and β-glucans, chitin, mannans, pectins, and xylans and discusses the cell biology and genetics of each system as it functions to transfer carbon back to the bacterium.

  7. Isolation, purification and antioxidant activities of polysaccharides from Grifola frondosa.

    Science.gov (United States)

    Chen, Gui-tang; Ma, Xue-mei; Liu, Sheng-to; Liao, Yan-li; Zhao, Guo-qang

    2012-06-01

    The crude polysaccharides (GFP) were isolated from the fruiting bodies of Grifola frondosa and purified by DEAE cellulose-52 chromatography and Sephadex G-100 size-exclusion chromatography in that order. Three main fractions, GFP-1, GFP-2 and GFP-3, were obtained through the isolation and purification steps. Then the antioxidant activities of these three fractions were investigated in vitro. The results showed that GFP-1, GFP-2 and GFP-3 possessed significant inhibitory effects on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, hydroxyl radical and superoxide radical; their reducing power, ferrous ions chelating effect and the inhibition ability of the rat liver lipid oxidation where also strong. These results suggest that G. frondosa polysaccharides could be a suitable natural antioxidant and may be the functional foods for humans. PMID:24750604

  8. The pretreatment effects on the antioxidant activity of jujube polysaccharides

    Science.gov (United States)

    Qu, Chenling; Yu, Songcheng; Jin, Huali; Wang, Jinshui; Luo, Li

    2013-10-01

    Pretreatment is vital to keep the bioactivities of polysaccharides. In this paper, the effects of hot water, ultrasonic and microwave extraction, as well as the effects of protein and pigment removal steps, on the antioxidant activity of water soluble polysaccharides in jujube (WSPJ) were studied. Hydroxyl free radical (rad OH) scavenging activity was adopted to determine the antioxidant activity of WSPJ. The results showed that rad OH scavenging activity of WSPJ extracted by ultrasonic wave was higher than that extracted by hot water and by microwave. Furthermore, power parameter in both ultrasonic and microwave extraction affected the rad OH scavenging activity dramatically. On the other hand, Sevag reagent was better than trichloroacetic acid (TCA), TCA with 1-butanol (TCA-B) and hydrochloric acid for protein removal, and H2O2 was better than active carbon for pigment removal to keep the antioxidant activity of WSPJ.

  9. Tomato Derived Polysaccharides for Biotechnological Applications: Chemical and Biological Approaches

    Directory of Open Access Journals (Sweden)

    Barbara Nicolaus

    2008-06-01

    Full Text Available Recent studies concerning the isolation and purification of exopolysaccharides from suspension-cultured tomato (Lycopersicon esculentum L. var. San Marzano cells and the description of a simple, rapid and low environmental impact method with for obtaining polysaccharides from solid tomato-processing industry wastes are reported. Their chemical composition, rheological properties and partial primary structure were determined on the basis of spectroscopic analyses (UV, IR, GC-MS, 1H-, 13C-NMR. Moreover, the anticytotoxic activities of exopolysaccharides obtained from cultured tomato cells were tested in a brine shrimp bioassay and the preparation of biodegradable film by chemical processing of polysaccharides from solid tomato industry waste was also reported.

  10. Modification of cell wall polysaccharides during retting of cassava roots.

    Science.gov (United States)

    Ngolong Ngea, Guillaume Legrand; Guillon, Fabienne; Essia Ngang, Jean Justin; Bonnin, Estelle; Bouchet, Brigitte; Saulnier, Luc

    2016-12-15

    Retting is an important step in traditional cassava processing that involves tissue softening of the roots to transform the cassava into flour and various food products. The tissue softening that occurs during retting was attributed to the degradation of cell wall pectins through the action of pectin-methylesterase and pectate-lyase that possibly originated from a microbial source or the cassava plant itself. Changes in cell wall composition were investigated during retting using chemical analysis, specific glycanase degradation and immuno-labelling of cell wall polysaccharides. Pectic 1,4-β-d-galactan was the main cell wall polysaccharide affected during the retting of cassava roots. This result suggested that better control of pectic galactan degradation and a better understanding of the degradation mechanism by endogenous endo-galactanase and/or exogenous microbial enzymes might contribute to improve the texture properties of cassava products. PMID:27451197

  11. Effects of Ganoderma lucidum polysaccharides on diabetic nephropathy in mice

    Institute of Scientific and Technical Information of China (English)

    Chao-yongHE; Zhi-binLIN

    2004-01-01

    AIM: To study the effects of Ganoderma lucidum polysaccharides (GL-PS) on the renal damage in streptozotocin-induced diabetic mice. METHODES: Nine weeks old male C57 BI/6J mice were made diabetes with two or three consecutive intraperitoneal injection of streptozotocin, 72 h later, hyperglycemic mice with glucose levels higher than glucose 300 mg/dL were used. The diabetic mice were randomly divided into three groups and administrated intragastrically with vehicle or Gl-PS (125 mg/

  12. Pneumococcal vaccination of older adults: Conjugate or polysaccharide?

    OpenAIRE

    Fedson, David S; Guppy, Martin J.

    2013-01-01

    Invasive pneumococcal disease continues to be important problem for older adults. Pneumococcal polysaccharide vaccine (PPV23) has a clinical effectiveness of 43–81%, and following primary vaccination and revaccination, antibody responses last 5–10 y. Hyporesponsiveness to a second dose of vaccine has not been shown to be a significant problem. The use of pneumococcal conjugate vaccines (initially PCV7; more recently PCV13) has led to a dramatic fall in the incidence of conjugate vaccine-type ...

  13. Polysaccharides as Alternative Moisture Retention Agents for Shrimp.

    Science.gov (United States)

    Torti, Michael J; Sims, Charles A; Adams, Charles M; Sarnoski, Paul J

    2016-03-01

    Phosphates are used as moisture retention agents (MRAs) by the shrimp industry. Although they are effective, phosphates are expensive, need to be listed on a food label, and overuse can often lead to a higher product cost for consumers. Polysaccharides were researched as alternative MRAs. Polysaccharides are usually inexpensive, are considered natural, and can have nutritional benefits. Research was conducted to determine whether polysaccharides yielded similar functional impacts as phosphates. Treatments included a 0.5% fibercolloid solution isolated from citrus peel, an 8% pectin solution, a 0.5% xanthan gum (XG) solution, a 1% carboxymethyl cellulose solution, and conventionally used 4% sodium tripolyphosphate (STP). Experimental treatments were compared to a distilled water control to gauge effectiveness. Freezing, boiling, and oven drying studies were performed to determine how moisture retention in shrimp differed using these different treatments. Water activity was measured to determine any potential differences in shelf life. Solution uptake was also determined to understand how well the treatments enhanced water binding. For moisture loss by freezing, 4% STP and the 0.5% fibercolloid solution functioned the best. The 4% STP treated shrimp lost the least amount of moisture during boiling. The 0.5% fibercolloid and 0.5% XG treatment outperformed phosphates in respect to moisture uptake ability. None of the treatments had a major effect on water activity. All treatments were rated similar in consumer sensory acceptability tests except for pectin, which was rated lower by the sensory panel. Overall, polysaccharides were found to be viable alternatives to phosphates. PMID:26849189

  14. Bioactivity and Applications of Sulphated Polysaccharides from Marine Microalgae

    OpenAIRE

    Rui Manuel Santos Costa de Morais; Maria Filomena de Jesus Raposo; Alcina Maria Miranda Bernardo de Morais

    2013-01-01

    Marine microalgae have been used for a long time as food for humans, such as Arthrospira (formerly, Spirulina), and for animals in aquaculture. The biomass of these microalgae and the compounds they produce have been shown to possess several biological applications with numerous health benefits. The present review puts up-to-date the research on the biological activities and applications of polysaccharides, active biocompounds synthesized by marine unicellular algae, which are, most of the ti...

  15. Solid-state NMR studies of polysaccharide systems

    Czech Academy of Sciences Publication Activity Database

    Spěváček, Jiří; Brus, Jiří

    2008-01-01

    Roč. 265, č. 1 (2008), s. 69-76. ISSN 1022-1360. [European Symposium on Polymer Spectroscopy /17./. Seggauberg Leibnitz, 09.9.2007-12.09.2007] R&D Projects: GA ČR GA525/05/0273 Institutional research plan: CEZ:AV0Z40500505 Keywords : biodegradable polymers * chitin/glucan complex * polysaccharides * solid-state NMR Subject RIV: CD - Macromolecular Chemistry

  16. Solid-state NMR studies of polysaccharide systems

    Czech Academy of Sciences Publication Activity Database

    Spěváček, Jiří; Brus, Jiří

    Tarragona : Institute de Ciencia de Materiales de Aragón, 2007. s. 140. [Euromar Magnetic Resonance Conference. 01.06.2007-05.06.2007, Tarragona] R&D Projects: GA ČR GA525/05/0273 Institutional research plan: CEZ:AV0Z40500505 Keywords : polysaccharide * chain/glucan complex * starch /polycaprolactone blend * solid-state NMR Subject RIV: CD - Macromolecular Chemistry

  17. Size-exclusion chromatography (SEC) of branched polymers and polysaccharides

    OpenAIRE

    Gaborieau, Marianne; Castignolles, Patrice

    2010-01-01

    Branched polymers are among the most important polymers, ranging from polyolefins to polysaccharides. Branching plays a key role in the chain dynamics. It is thus very important for application properties such as mechanical and adhesive properties and digestibility. It also plays a key role in viscous properties, and thus in the mechanism of the separation of these polymers in size-exclusion chromatography (SEC). Critically reviewing the literature, particularly on SEC of polyolefins, polyacr...

  18. Hydrolysis of Polysaccharides with 77% Sulfuric Acid for Quantitative Saccharification

    OpenAIRE

    UÇAR, Güneş; Balaban, Mualla

    2003-01-01

    Classical standard hydrolysis of polysaccharides with 72% sulfuric acid was modified in 2 manners. In order to avoid treatment in an autoclave at 120 °C under pressure, wood or pulp material was first swollen in cold 77% acid followed by hydrolysis steps in diluted acid solutions. Further, the neutralization of the hydrolyzate with dilute barium hydroxide was carried out in heated mother liquor ensuring a crystalline precipitate of barium sulfate. Digestion enables the separation of clear ali...

  19. Metabolic engineering of microbes for oligosaccharide and polysaccharide synthesis

    OpenAIRE

    Chen Rachel; Ruffing Anne

    2006-01-01

    Abstract Metabolic engineering has recently been embraced as an effective tool for developing whole-cell biocatalysts for oligosaccharide and polysaccharide synthesis. Microbial catalysts now provide a practical means to derive many valuable oligosaccharides, previously inaccessible through other methods, in sufficient quantities to support research and clinical applications. The synthesis process based upon these microbes is scalable as it avoids expensive starting materials. Most impressive...

  20. High molecular weight polysaccharide that binds and inhibits virus

    Science.gov (United States)

    Konowalchuk, Thomas W

    2014-01-14

    This invention provides a high molecular weight polysaccharide capable of binding to and inhibiting virus and related pharmaceutical formulations and methods on inhibiting viral infectivity and/or pathogenicity, as well as immunogenic compositions. The invention further methods of inhibiting the growth of cancer cells and of ameliorating a symptom of aging. Additionally, the invention provides methods of detecting and/or quantifying and/or isolating viruses.

  1. Affinity purification of polysaccharide degrading enzymes with crosslinked substrates.

    OpenAIRE

    Rozie, H.J.

    1992-01-01

    The aim of this work was to find economically favourable, affinity based, purification methods for several polysaccharide splitting bulk enzymes. The framework in which this study is done is described in Chapter 1.Chapter 2 describes the adsorption of endo-polygalacturonase (endoPG) from a commercial enzyme preparation (Rapidase) to calcium alginate beads. Approximately 75% of the various polygalacturonase activities from Rapidase can be adsorbed at pH 4.4 by calcium alginate beads as well as...

  2. Complex polysaccharides as PCR inhibitors in feces: Helicobacter pylori model.

    OpenAIRE

    Monteiro, L; Bonnemaison, D; Vekris, A. (A.); Petry, K G; Bonnet, J; Vidal, R.; Cabrita, J; Mégraud, F.

    1997-01-01

    A model was developed to study inhibitors present in feces which prevent the use of PCR for the detection of Helicobacter pylori. A DNA fragment amplified with the same primers as H. pylori was used to spike samples before extraction by a modified QIAamp tissue method. Inhibitors, separated on an Ultrogel AcA44 column, were characterized. Inhibitors in feces are complex polysaccharides possibly originating from vegetable material in the diet.

  3. Complex polysaccharides as PCR inhibitors in feces: Helicobacter pylori model.

    Science.gov (United States)

    Monteiro, L; Bonnemaison, D; Vekris, A; Petry, K G; Bonnet, J; Vidal, R; Cabrita, J; Mégraud, F

    1997-04-01

    A model was developed to study inhibitors present in feces which prevent the use of PCR for the detection of Helicobacter pylori. A DNA fragment amplified with the same primers as H. pylori was used to spike samples before extraction by a modified QIAamp tissue method. Inhibitors, separated on an Ultrogel AcA44 column, were characterized. Inhibitors in feces are complex polysaccharides possibly originating from vegetable material in the diet. PMID:9157172

  4. INFLUENCE OF SOLUBLE POLYSACCHARIDE ON THE ADHERENCE OF PARTICULATE SOILS

    OpenAIRE

    Toure, Yetioman; Rouxhet, Paul G.; Dupont-Gillain, C. Christine; Sindic, Marianne

    2011-01-01

    The removal of particulate soils from solid surfaces is the key process of cleaning many industrial devices, such as heat exchangers and spray dryers (food and pharmaceutical sector), and may be influenced by the presence of solutes, in particular of macromolecules. The present study deals with the influence of soluble polysaccharide on the adherence of particulate fouling of open surfaces and on subsequent cleaning. Model substrates differing by hydrophobicity (glass and polystyrene) were so...

  5. INFLUENCE OF SOLUBLE POLYSACCHARIDE ON THE ADHERENCE OF PARTICULATE SOILS

    OpenAIRE

    Toure, Yetioman; Rouxhet, G. Paul; Dupont-Gillain, C. Christine; Sindic, Marianne

    2011-01-01

    The removal of particulate soils from solid surfaces is the key process of cleaning many industrial devices, such as heat exchangers and spray dryers (food and pharmaceutical sector), and may be influenced by the presence of solutes, in particular of macromolecules. The present study deals with the influence of soluble polysaccharide on the adherence of particulate fouling of open surfaces and on subsequent cleaning. Model surfaces differing by hydrophobicity (glass and polystyrene) were soil...

  6. Extraction and purification of the polysaccharides in Hippohaere rhamnoides L.

    Institute of Scientific and Technical Information of China (English)

    XU Yaqin; JIN Ting; YU Zeyuan; FU Hong

    2007-01-01

    The different extraction technology and purification technology of Hippohpae rhamoides polysaccharides were researched in the paper. The best method of papain extraction were obtained, the ratio of papain 2%, pH at 5.5, temperature at 45℃ and extraction time of 20 min were suitable for papain extraction. The highest content of Hippohpae rhamoides polysaccharides was 44.28 mg·g-1. The optimum process of ultrasonic extraction were obtained, namely extracted for 55 min at 480 W with the material ratio of 1:20. The highest content of Hippohpae rhamoides polysaccharides was 48.63 mg·g-1. The results showed that the ultrasonic and papain extraction together was the best method, the content was 54.30 mg·g-1. After the removing protein, pigment and dialysis. Two fraction were separated from the purified Hippohpae rhamoides by DEAE-cellulose chromatography, the main fraction was collected finally. The fraction was identified by Sepharose CL-4B gel filtration. Ultraviolet spectrometry, freeze-thawing analysis showed that fraction was purified. Its molecular weight was probably 109.4 ku.

  7. Immunomodulatory Activity and Partial Characterisation of Polysaccharides from Momordica charantia

    Directory of Open Access Journals (Sweden)

    Yuan-Yuan Deng

    2014-08-01

    Full Text Available Momordica charantia Linn. is used as an edible and medicinal vegetable in sub-tropical areas. Until now, studies on its composition and related activities have been confined to compounds of low molecular mass, and no data have been reported concerning the plant’s polysaccharides. In this work, a crude polysaccharide of M. charantia (MCP fruit was isolated by hot water extraction and then purified using DEAE-52 cellulose anion-exchange chromatography to produce two main fractions MCP1 and MCP2. The immunomodulatory effects and physicochemical characteristics of these fractions were investigated in vitro and in vivo. The results showed that intragastric administration of 150 or 300 mg·kg−·d−1 of MCP significantly increased the carbolic particle clearance index, serum haemolysin production, spleen index, thymus index and NK cell cytotoxicity to normal control levels in cyclophosphamide (Cy-induced immunosuppressed mice. Both MCP1 and MCP2 effectively stimulated normal and concanavalin A-induced splenic lymphocyte proliferation in vitro at various doses. The average molecular weights of MCP1 and MCP2, which were measured using high-performance gel permeation chromatography, were 8.55 × 104 Da and 4.41 × 105 Da, respectively. Both fractions exhibited characteristic polysaccharide bands in their Fourier transform infrared spectrum. MCP1 is mainly composed of glucose and galactose, and MCP2 is mainly composed of glucose, mannose and galactose. The results indicate that MCP and its fractions have good potential as immunotherapeutic adjuvants.

  8. Purification, Characterization and Biological Activity of Polysaccharides from Dendrobium officinale

    Directory of Open Access Journals (Sweden)

    Kaiwei Huang

    2016-05-01

    Full Text Available Polysaccharide (DOPA from the stem of D. officinale, as well as two fractions (DOPA-1 and DOPA-2 of it, were isolated and purified by DEAE cellulose-52 and Sephacryl S-300 chromatography, and their structural characteristics and bioactivities were investigated. The average molecular weights of DOPA-1 and DOPA-2 were 394 kDa and 362 kDa, respectively. They were mainly composed of d-mannose, d-glucose, and had a backbone consisting of 1,4-linked β-d-Manp and 1,4-linked β-d-Glcp with O-acetyl groups. Bioactivity studies indicated that both DOPA and its purified fractions (DOPA-1 and DOPA-2 could activate splenocytes and macrophages. The D. officinale polysaccharides had stimulatory effects on splenocytes, T-lymphocytes and B-lymphocytes, promoting the cell viability and NO production of RAW 264.7 macrophages. Furthermore, DOPA, DOPA-1 and DOPA-2 were found to protect RAW 264.7 macrophages against hydrogen peroxide (H2O2-induced oxidative injury by promoting cell viability, suppressing apoptosis and ameliorating oxidative lesions. These results suggested that D. officinale polysaccharides possessed antioxidant activity and mild immunostimulatory activity.

  9. Purification, Characterization and Biological Activity of Polysaccharides from Dendrobium officinale.

    Science.gov (United States)

    Huang, Kaiwei; Li, Yunrong; Tao, Shengchang; Wei, Gang; Huang, Yuechun; Chen, Dongfeng; Wu, Chengfeng

    2016-01-01

    Polysaccharide (DOPA) from the stem of D. officinale, as well as two fractions (DOPA-1 and DOPA-2) of it, were isolated and purified by DEAE cellulose-52 and Sephacryl S-300 chromatography, and their structural characteristics and bioactivities were investigated. The average molecular weights of DOPA-1 and DOPA-2 were 394 kDa and 362 kDa, respectively. They were mainly composed of d-mannose, d-glucose, and had a backbone consisting of 1,4-linked β-d-Manp and 1,4-linked β-d-Glcp with O-acetyl groups. Bioactivity studies indicated that both DOPA and its purified fractions (DOPA-1 and DOPA-2) could activate splenocytes and macrophages. The D. officinale polysaccharides had stimulatory effects on splenocytes, T-lymphocytes and B-lymphocytes, promoting the cell viability and NO production of RAW 264.7 macrophages. Furthermore, DOPA, DOPA-1 and DOPA-2 were found to protect RAW 264.7 macrophages against hydrogen peroxide (H₂O₂)-induced oxidative injury by promoting cell viability, suppressing apoptosis and ameliorating oxidative lesions. These results suggested that D. officinale polysaccharides possessed antioxidant activity and mild immunostimulatory activity. PMID:27248989

  10. Recombinant expression of Streptococcus pneumoniae capsular polysaccharides in Escherichia coli

    Science.gov (United States)

    Kay, Emily J.; Yates, Laura E.; Terra, Vanessa S.; Cuccui, Jon; Wren, Brendan W.

    2016-01-01

    Currently, Streptococcus pneumoniae is responsible for over 14 million cases of pneumonia worldwide annually, and over 1 million deaths, the majority of them children. The major determinant for pathogenesis is a polysaccharide capsule that is variable and is used to distinguish strains based on their serotype. The capsule forms the basis of the pneumococcal polysaccharide vaccine (PPV23) that contains purified capsular polysaccharide from 23 serotypes, and the pneumococcal conjugate vaccine (PCV13), containing 13 common serotypes conjugated to CRM197 (mutant diphtheria toxin). Purified capsule from S. pneumoniae is required for pneumococcal conjugate vaccine production, and costs can be prohibitively high, limiting accessibility of the vaccine in low-income countries. In this study, we demonstrate the recombinant expression of the capsule-encoding locus from four different serotypes of S. pneumoniae within Escherichia coli. Furthermore, we attempt to identify the minimum set of genes necessary to reliably and efficiently express these capsules heterologously. These E. coli strains could be used to produce a supply of S. pneumoniae serotype-specific capsules without the need to culture pathogenic bacteria. Additionally, these strains could be applied to synthetic glycobiological applications: recombinant vaccine production using E. coli outer membrane vesicles or coupling to proteins using protein glycan coupling technology. PMID:27110302

  11. Acidification increases microbial polysaccharide degradation in the ocean

    Science.gov (United States)

    Piontek, J.; Lunau, M.; Händel, N.; Borchard, C.; Wurst, M.; Engel, A.

    2010-05-01

    With the accumulation of anthropogenic carbon dioxide (CO2), a proceeding decline in seawater pH has been induced that is referred to as ocean acidification. The ocean's capacity for CO2 storage is strongly affected by biological processes, whose feedback potential is difficult to evaluate. The main source of CO2 in the ocean is the decomposition and subsequent respiration of organic molecules by heterotrophic bacteria. However, very little is known about potential effects of ocean acidification on bacterial degradation activity. This study reveals that the degradation of polysaccharides, a major component of marine organic matter, by bacterial extracellular enzymes was significantly accelerated during experimental simulation of ocean acidification. Results were obtained from pH perturbation experiments, where rates of extracellular α- and β-glucosidase were measured and the loss of neutral and acidic sugars from phytoplankton-derived polysaccharides was determined. Our study suggests that a faster bacterial turnover of polysaccharides at lowered ocean pH has the potential to reduce carbon export and to enhance the respiratory CO2 production in the future ocean.

  12. Antioxidative properties of crude polysaccharides from Inonotus obliquus.

    Science.gov (United States)

    Mu, Haibo; Zhang, Amin; Zhang, Wuxia; Cui, Guoting; Wang, Shunchun; Duan, Jinyou

    2012-01-01

    The mushroom Inonotus obliquus has been widely used as a folk medicine in Russia, Poland and most of the Baltic countries. In this study, water-soluble and alkali-soluble crude polysaccharides (IOW and IOA) were isolated from I. obliquus, and the carbohydrate-rich fractions IOW-1 and IOA-1 were obtained respectively after deproteination and depigmentation. Their contents, such as neutral carbohydrate, uronic acid and protein, were measured. Their antioxidant properties against chemicals-induced reactive species (ROS) including 1,1'-Diphenyl-2-picrylhydrazyl (DPPH) radical, hydroxyl radical and superoxide anion radical, as well as their protective effects on H(2)O(2)-induced PC12 cell death were investigated. Results showed that I. obliquus polysaccharides can scavenge all ROS tested above in a dose-dependent manner. IOA and its product IOA-1 could rescue PC12 cell viability from 38.6% to 79.8% and 83.0% at a concentration of 20μg/mL. Similarly, IOW and its product IOW-1 at the same dose, can also increase cell viability to 84.9% and 88.6% respectively. The antioxidative activities of water-soluble and alkali-soluble polysaccharide constituents from I. obliquus might contribute to diverse medicinal and nutritional values of this mushroom. PMID:22942760

  13. Composition and bioactivity of polysaccharides from Inula britannica flower.

    Science.gov (United States)

    Hong, Tie; Zhao, Jing; Dong, Man; Meng, Yixiao; Mu, Jiaye; Yang, Zhen

    2012-11-01

    In this paper, the composition and biological activities of polysaccharides from Inula britannica flower IBP obtained by water extraction were investigated. The properties and chemical compositions of IBP were analyzed with HPLC and IR methods. The results showed that IBP consisted of two kinds of polysaccharides with the molecular weight of 3500 Da, 700 Da. IBP consisted of mannose, glucuronic acid, rhamnose, galacturonic acid, glucose, galactose, arabinose with a molar ratio of 4.1:1:1.4:2.7:14.6:6.3:7.9. The IR spectrum of IBP revealed the typical characteristics of polysaccharides and protein. IBP was administered orally at three doses [100, 200 and 400 mg/kg body weight] for 14 days to the diabetic mice induced by alloxan. The body weight, plasma glucose, serum triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C) and liver glycogen were evaluated in normal and alloxan-induced diabetic mice. IBP could dose-dependently significantly increase the body weight of diabetic mice, and reverse the decrease of plasma glucose, glycogen and the decrease of blood lipid of diabetic mice as compared to those in control group. These results indicated that IBP could be developed to a potential anti-diabetic drug in the future. PMID:22728640

  14. Sulfated Seaweed Polysaccharides as Multifunctional Materials in Drug Delivery Applications.

    Science.gov (United States)

    Cunha, Ludmylla; Grenha, Ana

    2016-03-01

    In the last decades, the discovery of metabolites from marine resources showing biological activity has increased significantly. Among marine resources, seaweed is a valuable source of structurally diverse bioactive compounds. The cell walls of marine algae are rich in sulfated polysaccharides, including carrageenan in red algae, ulvan in green algae and fucoidan in brown algae. Sulfated polysaccharides have been increasingly studied over the years in the pharmaceutical field, given their potential usefulness in applications such as the design of drug delivery systems. The purpose of this review is to discuss potential applications of these polymers in drug delivery systems, with a focus on carrageenan, ulvan and fucoidan. General information regarding structure, extraction process and physicochemical properties is presented, along with a brief reference to reported biological activities. For each material, specific applications under the scope of drug delivery are described, addressing in privileged manner particulate carriers, as well as hydrogels and beads. A final section approaches the application of sulfated polysaccharides in targeted drug delivery, focusing with particular interest the capacity for macrophage targeting. PMID:26927134

  15. Influence of a cationic polysaccharide on starch functionality.

    Science.gov (United States)

    Raguzzoni, Josiane C; Delgadillo, Ivonne; Lopes da Silva, José A

    2016-10-01

    Fundamental rheology, differential scanning calorimetry and infrared spectroscopy have been used to evaluate the effect of a cationic polysaccharide, chitosan, on the gelatinization, gel formation and retrogradation of maize starch samples, under acidic aqueous conditions. Moderate acidic conditions (0.1molL(-1) acetic acid) have shown a (slight) positive effect on starch gelatinization process and structure development. The presence of chitosan increased the DSC onset gelatinization temperature and also shifted the onset of the storage modulus increase to higher temperatures. Formation of the starch gel, mainly gelation of the leached-out amylose, is somehow hindered by the presence of the cationic polysaccharide and, therefore, the retrogradation of starch at very early stage can be delayed by addition of chitosan. However, long-term retrogradation was slightly increased. FTIR pectroscopy did not reveal any significant interaction between both polysaccharides what is in accordance with the observed rheological behavior. Small additions of chitosan to starch-rich systems may be a useful strategy to obtain new textures with novel phase transition behaviors. PMID:27312647

  16. Characterization of diferuloylated pectic polysaccharides from quinoa (Chenopodium quinoa WILLD.).

    Science.gov (United States)

    Wefers, Daniel; Gmeiner, Bianca M; Tyl, Catrin E; Bunzel, Mirko

    2015-08-01

    In plants belonging to the order of Caryophyllales, pectic neutral side chains can be substituted with ferulic acid. The ability of ferulic acid to form intra- and/or intermolecular polysaccharide cross-links by dimerization was shown by the isolation and characterization of diferulic acid oligosaccharides from monocotyledonous plants. In this study, two diferulic acid oligosaccharides were isolated from the enzymatic hydrolyzate of seeds of the dicotyledonous pseudocereal quinoa by gel permeation chromatography and preparative HPLC and unambiguously identified by LC-MS(2) and 1D/2D NMR spectroscopy. The isolated oligosaccharides are comprised of 5-5- and 8-O-4-diferulic acid linked to the O2-position of the nonreducing residue of two (1→5)-linked arabinobioses. To get insight into the structure and the degree of phenolic acid substitution of the diferuloylated polysaccharides, polymeric sugar composition, glycosidic linkages, and polysaccharide-bound monomeric phenolic acids and diferulic acids were analyzed. This study demonstrates that diferulic acids are involved into intramolecular and/or intermolecular cross-linking of arabinan chains and may have a major impact on cell wall architecture of quinoa and other dicotyledonous plants of the order of Caryophyllales. PMID:25983037

  17. Structure versus anticoagulant and antithrombotic actions of marine sulfated polysaccharides

    Directory of Open Access Journals (Sweden)

    Vitor Hugo Pomin

    2012-08-01

    Full Text Available Marine sulfated polysaccharides (MSP, such as sulfated fucans (SF, sulfated galactans (SG and glycosaminoglycans (GAG isolated from either algae or invertebrate animals, are highly anionic polysaccharides capable of interacting with certain cationic proteins, such as (co-factors of the coagulation cascade during clotting-inhibition processes. These molecular complexes between MSP and coagulation-related proteins might, at first glance, be assumed to be driven mostly by electrostatic interactions. However, a systematic comparison using several novel sulfated polysaccharides composed of repetitive oligosaccharides with clear sulfation patterns has shown that these molecular interactions are regulated essentially by the stereochemistry of the glycans (which depends on a conjunction of anomericity, monosaccharide, conformational preference, and glycosylation and sulfation sites, rather than just a simple consequence of their negative charge density (mainly the number of sulfate groups. Here, we present an overview of the structure-function relationships of MSP, correlating their structures with their potential anticoagulant and antithrombotic actions, since pathologies related to the cardiovascular system are one of the major causes of illness and mortality in the world.

  18. Acidification increases microbial polysaccharide degradation in the ocean

    Directory of Open Access Journals (Sweden)

    J. Piontek

    2009-12-01

    Full Text Available With the accumulation of anthropogenic carbon dioxide (CO2, a proceeding decline in seawater pH has been induced that is referred to as ocean acidification. The ocean's capacity for CO2 storage is strongly affected by biological processes, whose feedback potential is difficult to evaluate. The main source of CO2 in the ocean is the decomposition and subsequent respiration of organic molecules by heterotrophic bacteria. However, very little is known about potential effects of ocean acidification on bacterial degradation activity. This study reveals that the degradation of polysaccharides, a major component of marine organic matter, by bacterial extracellular enzymes was significantly accelerated during experimental simulation of ocean acidification. Results were obtained from pH perturbation experiments, where rates of extracellular α- and β-glucosidase were measured and the loss of neutral and acidic sugars from phytoplankton-derived polysaccharides was determined. Our study suggests that a faster bacterial turnover of polysaccharides at lowered ocean pH has the potential to affect the cycling of organic carbon in the future ocean by weakening the biological carbon pump and increasing the respiratory production of CO2.

  19. Acidification increases microbial polysaccharide degradation in the ocean

    Directory of Open Access Journals (Sweden)

    J. Piontek

    2010-05-01

    Full Text Available With the accumulation of anthropogenic carbon dioxide (CO2, a proceeding decline in seawater pH has been induced that is referred to as ocean acidification. The ocean's capacity for CO2 storage is strongly affected by biological processes, whose feedback potential is difficult to evaluate. The main source of CO2 in the ocean is the decomposition and subsequent respiration of organic molecules by heterotrophic bacteria. However, very little is known about potential effects of ocean acidification on bacterial degradation activity. This study reveals that the degradation of polysaccharides, a major component of marine organic matter, by bacterial extracellular enzymes was significantly accelerated during experimental simulation of ocean acidification. Results were obtained from pH perturbation experiments, where rates of extracellular α- and β-glucosidase were measured and the loss of neutral and acidic sugars from phytoplankton-derived polysaccharides was determined. Our study suggests that a faster bacterial turnover of polysaccharides at lowered ocean pH has the potential to reduce carbon export and to enhance the respiratory CO2 production in the future ocean.

  20. Novel imaging technologies for characterization of microbial extracellular polysaccharides

    Directory of Open Access Journals (Sweden)

    Magnus Borstad Lilledahl

    2015-05-01

    Full Text Available Understanding of biology is underpinned by the ability to observe structures at various length scales. This is so in a historical context and is also valid today. Evolution of novel insight often emerges from technological advancement. Recent developments in imaging technologies that is relevant for characterization of extracullar microbiological polysaccharides are summarized. Emphasis is on scanning probe and optical based techniques since these tools offers imaging capabilities under aqueous conditions more closely resembling the physiological state than other ultramicroscopy imaging techniques. Following the demonstration of the scanning probe microscopy principle, novel operation modes to increase data capture speed towards video rate, exploitation of several cantilever frequencies, and advancement of utilization of specimen mechanical properties as contrast, also including their mode of operation in liquid, have been developed on this platform. Combined with steps in advancing light microscopy with resolution beyond the far field diffraction limit, non-linear methods and combinations of the various imaging modalities, the potential ultramicroscopy toolbox available for characterization of exopolysaccharides are richer than ever. Examples of application of such ultramicroscopy strategies range from imaging of isolated microbial polysaccharides, structures being observed when they are involved in polyelectrolyte complexes, aspects of their enzymatic degradation and cell surface localization of secreted polysaccharides. These, and other examples, illustrate that the advancement in imaging technologies relevant for exopolysaccharides characterization supports characterization of structural aspects.

  1. Thermal analysis of some natural polysaccharide materials by isoconversional method.

    Science.gov (United States)

    Iqbal, Mohammad S; Massey, Shazma; Akbar, Jamshed; Ashraf, Chaudhary M; Masih, Rashid

    2013-09-01

    Isoconversional thermal analysis of some important polysaccharides from functional foods is reported. Various thermal parameters including apparent activation energy (Ea), pre-exponential factor (A) were worked out, and the fitness of data to different models describing the degradation kinetics of polysaccharides was studied. The polysaccharides from Mimosa pudica (MP), Plantago ovata (PO), Argyreia speciosa (AS), Acacia nilotica (AN), P. ovata husk (HK) and Acacia modesta (AM) exhibited multistep degradation while those from Astragalus gummifer (AG), Salvia aegyptiaca (SA) and Ocimum basicilicum (OB) degraded mainly in single step. Generally, the degradation was exothermal. The average Ea values as determined by Flynn-Wall-Ozawa method were found to be in the range 132-187 kJ mol(-1). The mean comprehensive index of thermal stability (ITS) fell in the range 0.33-0.43. All the materials under investigation except those from SA and AS appear to be as stable as some of the important commercial materials used as pharmaceutical ingredients. Model-fitting analysis revealed that the major degradation step follows first-order kinetics. PMID:23578630

  2. Polysaccharide extraction from Sphallerocarpus gracilis roots by response surface methodology.

    Science.gov (United States)

    Ma, Tingting; Sun, Xiangyu; Tian, Chengrui; Luo, Jiyang; Zheng, Cuiping; Zhan, Jicheng

    2016-07-01

    The extraction process of Sphallerocarpus gracilis root polysaccharides (SGRP) was optimized using response surface methodology with two methods [hot-water extraction (HWE) and ultrasonic-assisted extraction (UAE)]. The antioxidant activities of SGRP were determined, and the structural features of the untreated materials (HWE residue and UAE residue) and the extracted polysaccharides were compared by scanning electron microscopy. Results showed that the optimal UAE conditions were extraction temperature of 81°C, extraction time of 1.7h, liquid-solid ratio of 17ml/g, ultrasonic power of 300W and three extraction cycles. The optimal HWE conditions were 93°C extraction temperature, 3.6h extraction time, 21ml/g liquid-solid ratio and three extraction cycles. UAE offered a higher extraction yield with a shorter time, lower temperature and a lower solvent consumption compared with HWE, and the extracted polysaccharides possessed a higher antioxidant capacity. Therefore, UAE could be used as an alternative to conventional HWE for SGRP extraction. PMID:27032488

  3. Recent Advances in Nanocomposite Materials of Graphene Derivatives with Polysaccharides

    Directory of Open Access Journals (Sweden)

    Zoi Terzopoulou

    2015-02-01

    Full Text Available This review article presents the recent advances in syntheses and applications of nanocomposites consisting of graphene derivatives with various polysaccharides. Graphene has recently attracted much interest in the materials field due to its unique 2D structure and outstanding properties. To follow, the physical and mechanical properties of graphene are then introduced. However it was observed that the synthesis of graphene-based nanocomposites had become one of the most important research frontiers in the application of graphene. Therefore, this review also summarizes the recent advances in the synthesis of graphene nanocomposites with polysaccharides, which are abundant in nature and are easily synthesized bio-based polymers. Polysaccharides can be classified in various ways such as cellulose, chitosan, starch, and alginates, each group with unique and different properties. Alginates are considered to be ideal for the preparation of nanocomposites with graphene derivatives due to their environmental-friendly potential. The characteristics of such nanocomposites are discussed here and are compared with regard to their mechanical properties and their various applications.

  4. Immunomodulatory activity and partial characterisation of polysaccharides from Momordica charantia.

    Science.gov (United States)

    Deng, Yuan-Yuan; Yi, Yang; Zhang, Li-Fang; Zhang, Rui-Fen; Zhang, Yan; Wei, Zhen-Cheng; Tang, Xiao-Jun; Zhang, Ming-Wei

    2014-01-01

    Momordica charantia Linn. is used as an edible and medicinal vegetable in sub-tropical areas. Until now, studies on its composition and related activities have been confined to compounds of low molecular mass, and no data have been reported concerning the plant's polysaccharides. In this work, a crude polysaccharide of M. charantia (MCP) fruit was isolated by hot water extraction and then purified using DEAE-52 cellulose anion-exchange chromatography to produce two main fractions MCP1 and MCP2. The immunomodulatory effects and physicochemical characteristics of these fractions were investigated in vitro and in vivo. The results showed that intragastric administration of 150 or 300 mg·kg-·d⁻¹ of MCP significantly increased the carbolic particle clearance index, serum haemolysin production, spleen index, thymus index and NK cell cytotoxicity to normal control levels in cyclophosphamide (Cy)-induced immunosuppressed mice. Both MCP1 and MCP2 effectively stimulated normal and concanavalin A-induced splenic lymphocyte proliferation in vitro at various doses. The average molecular weights of MCP1 and MCP2, which were measured using high-performance gel permeation chromatography, were 8.55×10⁴ Da and 4.41×10⁵ Da, respectively. Both fractions exhibited characteristic polysaccharide bands in their Fourier transform infrared spectrum. MCP1 is mainly composed of glucose and galactose, and MCP2 is mainly composed of glucose, mannose and galactose. The results indicate that MCP and its fractions have good potential as immunotherapeutic adjuvants. PMID:25178064

  5. Tamarind seed polysaccharide: A promising natural excipient for pharmaceuticals

    Directory of Open Access Journals (Sweden)

    Joshny Joseph

    2012-01-01

    Full Text Available The natural polymers always have exceptional properties which make them distinct from the synthetic polymers and tamarind seed polysaccharide (TSP is one such example which shows more valuable properties making it a useful excipient for a wide range of applications. TSP is a natural polysaccharide obtained from the seeds of Tamarindus indica, recently gaining a wide potential in the field of pharmaceutical and cosmetic industries. Its isolation and characterisation involve simple techniques resulting in cost-effective yield in its production. TSP shows uniqueness in its high drug holding capacity, high swelling index and high thermal stability, especially necessary for various novel drug delivery systems. It also plays the role of stabiliser, thickener, binder, release retardant, modifier, suspending agent, viscosity enhancer, emulsifying agent, as a carrier for novel drug delivery systems in oral, buccal, colon, ocular systems, nanofabrication, wound dressing and is also becoming an important part of food, cosmetics, confectionery and bakery. Various studies and experiments have been carried out to prove its multi-functional potentiality, from which it can be concluded that TSP can be a promising natural polysaccharide having enormous applications. This review focuses on the diversity of applications of TSP.

  6. [Effects of tree species on polysaccharides content of epiphytic Dendrobium officinale].

    Science.gov (United States)

    Guo, Ying-Ying; Zhu, Yan; Si, Jin-Ping; Liu, Jing-Jing; Wu, Cheng-Yong; Li, Hui

    2014-11-01

    To reveals the effects of tree species on polysaccharides content of epiphytic Dendrobium officinale. The polysaccharides content of D. officinale attached to living tress in wild or stumps in bionic-facility was determined by phenol-sulfuric acid method. There were extremely significant differences of polysaccharides content of D. officinale attached to different tree species, but the differences had no relationship with the form and nutrition of barks. The polysaccharides content of D. officinale mainly affected by the light intensity of environment, so reasonable illumination favored the accumulation of polysaccharides. Various polysaccharides content of D. officinal from different attached trees is due to the difference of light regulation, but not the form and nutrition of barks. PMID:25775797

  7. Sulphation can enhance the antioxidant activity of polysaccharides produced by Enterobacter cloacae Z0206.

    Science.gov (United States)

    Jin, Mingliang; Wang, Youming; Huang, Ming; Lu, Zeqing; Wang, Yizhen

    2014-01-01

    The protective effects of sulfated polysaccharide derivatives produced by Enterobacter cloacae Z0206 against H₂O₂-induced oxidative damage in RAW264.7 murine macrophages as well as the possible mechanisms governing the protective effects were studied. Sulfated polysaccharides protected RAW264.7 cells from oxidative damage and apoptosis induced by H₂O₂ by protecting the cellular structure; improving the activity of antioxidant enzymes, such as superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px); and inhibiting caspase-3 activation and DNA fragmentation. In addition, the sulfated polysaccharides conferred higher levels of protection from H₂O₂-induced oxidative damage in RAW264.7 murine macrophages compared to the native polysaccharide lacking sulfation. These results indicated that sulfated modifications might be an effective approach to enhance the antioxidant activity of polysaccharides produced by E. cloacae Z0206, and the sulfated derivatives of these polysaccharides may act as potent antioxidant agents. PMID:24274552

  8. Study of the association of an O-specific polysaccharide from Pseudomonas fluorescens with antibodies

    International Nuclear Information System (INIS)

    The O-specific polysaccharide has been isolated from the lipopolysaccharide-protein complex of Pseudomonas fluorescens by mild acid hydrolysis followed by gel chromatography of the carbohydrate fraction of Sephadex G-50. According to 13C NMR spectroscopy, the polysaccharide is constructed of regularly repeating trisaccharide units including three 6-deoxyhexose residues two of which are amino sugars. An investigation has been performed of the interaction of the polysaccharide with specific antibodies and univalent Fab fragments of the antibodies. For the isolation of the antibodies and Fab fragments and their fractionation with respect to affinity we used an immunosorbent based on the polysaccharide bound to Sepharose 4B. It was established that antibodies to the polysaccharide were heterogeneous to some extent in relation to their affinity, and their interaction with polysaccharide had a cooperative nature

  9. Study of the association of an O-specific polysaccharide from Pseudomonas fluorescens with antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Solov' eva, T.F.; Naberezhnykh, G.A.; Mazur, A.K.; Khomenko, V.A.; Ovodoy, Yu.S.

    1986-12-01

    The O-specific polysaccharide has been isolated from the lipopolysaccharide-protein complex of Pseudomonas fluorescens by mild acid hydrolysis followed by gel chromatography of the carbohydrate fraction of Sephadex G-50. According to /sup 13/C NMR spectroscopy, the polysaccharide is constructed of regularly repeating trisaccharide units including three 6-deoxyhexose residues two of which are amino sugars. An investigation has been performed of the interaction of the polysaccharide with specific antibodies and univalent Fab fragments of the antibodies. For the isolation of the antibodies and Fab fragments and their fractionation with respect to affinity we used an immunosorbent based on the polysaccharide bound to Sepharose 4B. It was established that antibodies to the polysaccharide were heterogeneous to some extent in relation to their affinity, and their interaction with polysaccharide had a cooperative nature.

  10. Marine Polysaccharides: A Source of Bioactive Molecules for Cell Therapy and Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Anne-Marie Fischer

    2011-09-01

    Full Text Available The therapeutic potential of natural bioactive compounds such as polysaccharides, especially glycosaminoglycans, is now well documented, and this activity combined with natural biodiversity will allow the development of a new generation of therapeutics. Advances in our understanding of the biosynthesis, structure and function of complex glycans from mammalian origin have shown the crucial role of this class of molecules to modulate disease processes and the importance of a deeper knowledge of structure-activity relationships. Marine environment offers a tremendous biodiversity and original polysaccharides have been discovered presenting a great chemical diversity that is largely species specific. The study of the biological properties of the polysaccharides from marine eukaryotes and marine prokaryotes revealed that the polysaccharides from the marine environment could provide a valid alternative to traditional polysaccharides such as glycosaminoglycans. Marine polysaccharides present a real potential for natural product drug discovery and for the delivery of new marine derived products for therapeutic applications.

  11. Efecto de la temperatura sobre películas de un aislado proteico del suero bovino (WPI adsorbidas sobre la interfase aceite-agua

    Directory of Open Access Journals (Sweden)

    Rodríguez Patino, Juan M.

    2002-09-01

    ómetro dinámico de gota, en unión de la observación microscópica y posterior análisis de la imagen de una gota que tiene adsorbida a la proteína sobre su superficie. Las variables estudiadas fueron la temperatura (en el intervalo comprendido entre 20 y 80 ºC y la concentración de proteína en el seno de la fase acuosa (en el intervalo comprendido entre 1.10-1 y 1.10-5% en peso. Durante el tratamiento térmico, (a la película de WPI presenta un comportamiento viscoelástico, con un ángulo de fase distinto de cero, (b se incrementa el carácter elástico de la interfase, (c se produce un incremento del módulo dilatacional superficial (E y (d una disminución de la tensión interfacial. La variación de E con el tiempo puede cuantificarse mediante ecuaciones de primer orden que pueden relacionarse con dos mecanismos cinéticos, asociados con la gelificación de WPI sobre la interfase aceite-agua. El tratamiento térmico produce cambios irreversibles en la película de WPI adsorbida sobre la interfase. Se han observado cambios significativos en las características interfaciales y en la imagen de la gota a concentraciones de proteína tan bajas como 1.10-5% en peso.

  12. Analytical Model for Electronic Transport in Semiconductor Thin Films Modelo analítico para el transporte electrónico en películas delgadas semiconductoras

    Directory of Open Access Journals (Sweden)

    M Torres-Luengo

    2013-11-01

    ás, la teoría de tunelamiento cuántico de portadores a través de la barrera de potencial. Dado que la estructura de las películas delgadas de trióxido de Molibdeno (MoO3 obtenidas por atomización pirolítica es de tipo granular y de tamaño nanométrico, el modelo analítico explica el comportamiento de la característica Corriente - Voltaje (I-V de las películas. 

  13. Comportamiento de películas delgadas de níquel y óxido de níquel en NaCl al 3 %

    Directory of Open Access Journals (Sweden)

    Magaña, C. R.

    2006-02-01

    Full Text Available The aim of this work is to study the behaviour of both: a nickel thin film deposited on steel AISI 1018 (UNS G 10180 and a superior nickel oxide electrochemically obtained on the film; with the purpose of decreasing the corrosion rate of low carbon steel immersed in a solution of NaCl 3% wt, thus efficient anticorrosive protection could be obtained. Two film deposition techniques were used: electrochemical and magnetron DC sputtering; and the protective properties of deposited films exposed to the aggressive media, were evaluated. The characterization of different films was carried out by using electrochemical techniques: polarization curves and electrochemical impedance.

    Este trabajo se enfoca al comportamiento que presenta una película delgada de níquel depositada sobre acero al carbón AISI 1018 (UNS G 10180 y un óxido superior del mismo níquel, con el propósito de disminuir la velocidad de corrosión del acero cuando se expone a una solución de NaCl al 3 % y obtener así una protección anticorrosiva alternativa eficaz. En este trabajo se comparan dos técnicas de depósito: electroquímico y decapado catódico o Magnetron DC Sputtering, y se evalúa la protección a la corrosión de cada depósito frente al medio agresivo. La caracterización de los diferentes depósitos se realizó a través de técnicas electroquímicas, (curvas de polarización y espectroscopia de impedancia.

  14. PLAYHIST: Jugando con la Historia. Transformación de película interactiva en juego histórico para el aprendizaje

    Directory of Open Access Journals (Sweden)

    Pablo Aguirrezabal

    2014-10-01

    Full Text Available Dentro de los espacios museísticos y centros de interpretación, una de cuyas funciones principales es la preservación y divulgación de los recursos históricos, es importante conectar con el público visitante con unas formas de comunicación modernas, accesibles, interesantes y con las que esté familiarizado. Con este objetivo, la introducción de nuevas tecnologías que faciliten las tareas de ilustrar, enseñar, interesar al visitante es clave. A través del experimento PLAYHIST, Tecnalia pretende la transformación de una película interactiva sobre la Antigua Grecia en un juego serio histórico multijugador, que sobre el mismo entorno del Tholos en el Hellenic Cosmos de Atenas (Grecia, tratará de demostrar que el aprendizaje por parte de los visitantes en museos y centros culturales puede incrementarse a través de la introducción del concepto de gamificación de los contenidos históricos. Dentro de este experimento se definirán una serie de métricas que afectan tanto al servicio, como a la experiencia de usuario y el aprendizaje. Estas métricas se recogerán tanto con los componentes software del juego como a través de cuestionarios a los propios visitantes. El análisis posterior de los datos recogidos dará una pista sobre si el concepto de “Learning by playing” es válido en este tipo de centros culturales.

  15. Propriedades físicas de painéis aglomerados de madeira produzidos com adição de película de polipropileno biorientado

    Directory of Open Access Journals (Sweden)

    Laurenn B. de Macedo

    2015-07-01

    Full Text Available No Brasil, as últimas décadas foram marcadas pela crescente produção de paineis de madeira seguida pelo aumento do consumo nacional; isto descreve o quão promissora é a área devido à sua grande potencialidade quanto ao desenvolvimento de novos produtos e tecnologias; como exemplo disto existe a possibilidade de mistura entre materiais lignocelulósicos e os diversos resíduos produzidos pela sociedade. Entre tais resíduos o plástico é o que apresenta maior abundância nos descartes domésticos. Neste contexto, o presente trabalho objetivou determinar propriedades físicas de paineis aglomerados homogêneos confeccionados com partículas de madeira de Eucalyptus sp e Pinus sp e de embalagens de película de polipropileno biorientado tendo, como adesivo, a resina poliuretana à base de óleo de mamona. Foram avaliadas as propriedades: inchamento em espessura e absorção de água, com corpo de prova com e sem impermeabilização, e massa específica. Concluiu-se que, dos fatores investigados, apenas o uso do impermeabilizante foi significativo. De acordo com a ANSI A208.1 (ANS, 1999 os paineis produzidos são classificados como de alta massa específica (H. Relativamente ao inchamento em espessura por 2 h, os paineis atenderam ao exigido pela NBR 14810 (ABNT, 2013 para espessura de 8 a 13 mm.

  16. Fractionation, partial characterization and bioactivity of water-soluble polysaccharides and polysaccharide-protein complexes from Pleurotus geesteranus.

    Science.gov (United States)

    Zhang, Mei; Zhu, Lin; Cui, Steve W; Wang, Qi; Zhou, Ting; Shen, Hengsheng

    2011-01-01

    Fractionation and purification of mushroom polysaccharides is a critical process for mushroom clinical application. After a hot-water treatment, the crude Pleurotus geesteranus (PG) was further fractionated into four fractions (PG-1, -2, -3, -4) using gradient precipitation with water and ammonia sulphate. By controlling the initial polymer concentration and ratio of solvents, this process produced PG fractions with high chemical uniformity and narrow Mw distribution without free proteins. Structurally, PG-1 and PG-2 are pure homopolysaccharide mainly composed of glucose; and PG-3 and PG-4 are heteropolysaccharide-protein complexes. PG-2, a high M(w) fraction mainly composed of glucose presented significant cytotoxicity at the concentration of 200 and 100 μg/ml to human breast cancer cells. Here, we report a new mushroom polysaccharides extraction and fractionation method, with which we produced four fractions of PG with PG-2 appearing effective anti-tumour activity. PMID:20850471

  17. Pneumococcal Conjugate Vaccines Overcome Splenic Dependency of Antibody Response to Pneumococcal Polysaccharides

    OpenAIRE

    Breukels, Mijke A.; Zandvoort, Andre; van den Dobbelsteen, Germie P. J. M.; van den Muijsenberg, Adrie; Lodewijk, Monique E.; Beurret, Michel; Pieter A Klok; Timens, Wim; Rijkers, Ger T.

    2001-01-01

    Protection against infections with Streptococcus pneumoniae depends on the presence of antibodies against capsular polysaccharides that facilitate phagocytosis. Asplenic patients are at increased risk for pneumococcal infections, since both phagocytosis and the initiation of the antibody response to polysaccharides take place in the spleen. Therefore, vaccination with pneumococcal polysaccharide vaccines is recommended prior to splenectomy, which, as in the case of trauma, is not always feasi...

  18. Obtaining of pectin polysaccharides from secondary resources of food industry by rapid extraction

    International Nuclear Information System (INIS)

    Present article is devoted to obtaining of pectin polysaccharides from secondary resources of food industry by rapid extraction. The method of rapid extraction under the pressure of pectin polysaccharides from secondary resources of food industry was elaborated. The additional information on macromolecule structure of pectin of various vegetative raw materials was obtained. The prospect of application the elaborated method for obtaining of pectin polysaccharides from secondary resources of food industry with high output yield, optimal parameters and low cost was proved.

  19. Determination of polysaccharide yield from the fruiting bodies and mycelium of selected mushroom species

    International Nuclear Information System (INIS)

    Numerous polysaccharides and polysaccharides-protein complexes have been isolated from mushrooms and used as a source of therapeutic agents. The mycelium of Pleurotus sajor caju, Pleurotus tuber-regium, black ganoderma, and the fruiting bodies of Pleurotus sajor caju and Pleurotus florida were used to determine the percentage of polysaccharides obtained from the mushroom raw material. Hot water extraction method was used followed by refrigerated centrifuge and lyophilization. The yield from the various species will be compared. (Author)

  20. Immunochemical and Biological Characterization of Three Capsular Polysaccharides from a Single Bacteroides fragilis Strain

    OpenAIRE

    Wiltrud M Kalka-Moll; Wang, Ying(School of Physics, Shandong University, Jinan, 250100, PR China); Comstock, L. E.; Gonzalez, Sylvia E.; Tzianabos, Arthur O.; Dennis L Kasper

    2001-01-01

    Although Bacteroides fragilis accounts for only 0.5% of the normal human colonic flora, it is the anaerobic species most frequently isolated from intra-abdominal and other infections with an intestinal source. The capsular polysaccharides of B. fragilis are part of a complex of surface polysaccharides and are the organism's most important virulence factors in the formation of intra-abdominal abscesses. Two capsular polysaccharides from strain NCTC 9343, PS A1 and PS B1, have been characterize...

  1. Extraction, Characterization, and Molecular Weight Determination of Senna tora (L.) Seed Polysaccharide

    OpenAIRE

    Pawar, Harshal A.; Lalitha, K. G.

    2015-01-01

    The objective of the present work was extraction of polysaccharide from Senna tora L. seed and its characterization as a pharmaceutical excipient. Polysaccharide extraction was based on mechanical separation of the endosperm of seeds of Senna tora, water dissolution, centrifugation, and precipitation with acetone. Standard procedures were used to study the viscosity, micromeritic properties, and microbial bioburden. Accelerated stability study was carried out on isolated polysaccharide for si...

  2. Use of fluorescent ANTS to examine the BBB-permeability of polysaccharide

    OpenAIRE

    Kevin Christopher; Vishruti Makani; Wesley Judy; Erica Lee; Nicolas Chiaia; Dong Shik Kim; Joshua Park

    2015-01-01

    Recently, some polysaccharides showed therapeutic potentials for the treatment of neurodegenerative diseases while the most important property, their permeability to the blood brain barrier (BBB) that sheathes the brain and spinal cord, is not yet determined. The determination has been delayed by the difficulty in tracking a target polysaccharide among endogenous polysaccharides in animal. We developed an easy way to examine the BBB-permeability and, possibly, tissue distribution of a target ...

  3. Adjuvant activity of Chinese herbal polysaccharides in inactivated veterinary rabies vaccines.

    Science.gov (United States)

    Liu, Ye; Zhang, Shoufeng; Zhang, Fei; Hu, Rongliang

    2012-04-01

    Four botanical polysaccharide preparations (from Astragalus, Echinacea, wolfberry, and kelp) were evaluated as immunopotentiators/adjuvants of a veterinary rabies vaccine. Results showed that lymphocyte proliferation and some cytokines were significantly elevated, with cellular immune responses skewed towards Th1 and Tc1. All four polysaccharides produced accelerated and enhanced effects on rabies-neutralizing antibody responses in mice and dogs. The results also indicated that certain botanical polysaccharides could be used in rabies vaccine formulations for early and persistent prophylaxis. PMID:22326819

  4. Effects of sweet cassava polysaccharide extracts on endurance exercise in rats

    OpenAIRE

    Yen, Chia Hung; Tsao, Te Hung; Huang, Cheng Uan; Yang, Chang Bin; Kuo, Chung Sheng

    2013-01-01

    Background Sweet cassava tubers have abundant carbohydrates consisting of monosaccharides and polysaccharides. In addition, polysaccharides extracted from plants improve sports performance, according to recent studies. We therefore examined whether the administration of sweet cassava polysaccharides (SCPs) benefited endurance performance in rats Methods Male Sprague–Dawley rats (n = 30, 7 weeks old) were divided into three groups: control (C), exercise (Ex), and exercise plus SCPs administrat...

  5. Effect of Atracylodes Rhizome Polysaccharide in Rats with Adenine-Induced Chronic Renal Failure

    OpenAIRE

    Yang, C.; C. Liu; Zhou, Q.; Xie, Y. C.; Qiu, X. M.; X. Feng

    2015-01-01

    The aim of the study was to elucidate the therapeutic effects of Atracylodes rhizome polysaccharide on adenine-induced chronic renal failure in rats. Fifty male Sprague Dawley rats were selected and randomly divided in to 5 groups (n=10 rats per group): The normal control group, the chronic renal failure pathological control group, the dexamethasone treatment group and two Atracylodes rhizome polysaccharide treatment groups, treated with two different concentrations of the polysaccharide, the...

  6. Formation of Novel Polysaccharides by Bradyrhizobium japonicum Bacteroids in Soybean Nodules

    OpenAIRE

    Streeter, John G.; Salminen, Seppo O.; Whitmoyer, Robert E.; Carlson, Russell W

    1992-01-01

    Certain strains of Bradyrhizobium japonicum form a previously unknown polysaccharide in the root nodules of soybean plants (Glycine max (L.) Merr.). The polysaccharide accumulates inside of the symbiosome membrane—the plant-derived membrane enclosing the bacteroids. In older nodules (60 days after planting), the polysaccharide occupies most of the symbiosome volume and symbiosomes become enlarged so that there is little host cytoplasm in infected cells. The two different groups of B. japonicu...

  7. Trans locus inhibitors limit concomitant polysaccharide synthesis in the human gut symbiont Bacteroides fragilis

    OpenAIRE

    Chatzidaki-Livanis, Maria; Weinacht, Katja G.; Comstock, Laurie E.

    2010-01-01

    Bacteroides is an abundant genus of bacteria of the human intestinal microbiota. Bacteroides species synthesize a large number of capsular polysaccharides (PS), a biological property not shared with closely related oral species, suggesting importance for intestinal survival. Bacteroides fragilis, for example, synthesizes eight capsular polysaccharides per strain, each of which phase varies via inversion of the promoters located upstream of seven of the eight polysaccharide biosynthesis operon...

  8. Characterization and Antihyperglycemic Activity of a Polysaccharide from Dioscorea opposita Thunb Roots

    OpenAIRE

    2015-01-01

    A polysaccharide DOTP-80 from Dioscorea opposita Thunb was obtained by using the method of acid water-extraction and ethanol-precipitation. After being purified by chromatography, the structure characteristics of DOTP-80 were established. Based on the calibration curve obtained with standard dextrans, the molecular weight of the polysaccharide fraction DOTP-80 was calculated to be 123 kDa. The results of Infrared spectrum (FT-IR) indicated that the polysaccharide contained the α-configuration...

  9. PolysacDB: A Database of Microbial Polysaccharide Antigens and Their Antibodies

    OpenAIRE

    Abhijit Aithal; Arun Sharma; Shilpy Joshi; Raghava, Gajendra P S; Varshney, Grish C.

    2012-01-01

    Vaccines based on microbial cell surface polysaccharides have long been considered as attractive means to control infectious diseases. To realize this goal, detailed systematic information about the antigenic polysaccharide is necessary. However, only a few databases that provide limited knowledge in this area are available. This paper describes PolysacDB, a manually curated database of antigenic polysaccharides. We collected and compiled comprehensive information from literature and web reso...

  10. [Determination of constituents of polysaccharide and contents of saccharide from Mongolian medicine Agari-8].

    Science.gov (United States)

    Zhao, Yu-Ying; Song, Juan-Juan; Zhao, Yu-Qin; Xu, Xiu-Ting; Hai, Ping

    2007-04-01

    The water soluble polysaccharide was extracted from Agari-8, and the contents of the water soluble polysaccharide were determined by phenyl hydrate-sulfuric acid method. The average recovery was 101.80%. The RSD was 0. 92Y. The components of the water soluble polysaccharide were identified by gas chromatography with: arabinose, xylose, mannose and glucose in the molar ratio of 0.40 : 0.10 : 5.67 : 22.78. Their IR and UV spectra were studied. PMID:17608211

  11. Controlling the burst release of amorphous drug-polysaccharide nanoparticle complex via crosslinking of the polysaccharide chains.

    Science.gov (United States)

    Nguyen, Minh-Hiep; Tran, The-Thien; Hadinoto, Kunn

    2016-07-01

    High-payload amorphous drug-polysaccharide nanoparticle complex (or nanoplex in short) represents a new class of supersaturating drug delivery systems intended for bioavailability enhancement of poorly-soluble drugs. Not unlike other nanoscale amorphous formulations, the nanoplex exhibits fast dissolution characterized by a burst drug release pattern. While the burst release is ideal for supersaturation generation in the presence of crystallization inhibitor, it is not as ideal for passive targeting drug delivery applications in which the nanoplex must be delivered by itself. Herein we developed nanoplex exhibiting controlled release via crosslinking of the polysaccharide chains onto which the drug molecules were electrostatically bound to. Curcumin and chitosan were used, respectively, as the drug and polysaccharide models with amine-reactive disuccinimidyl tartrate as the crosslinking agent. The crosslinked nanoplex exhibited improved morphology (i.e. smaller size, more spherical, and higher uniformity) that signified its more condensed structure. A twenty-fold reduction in the initial burst release rate with a threefold reduction in the overall dissolution rate was obtained after crosslinking. The slower dissolution was attributed to the more condensed structure of the crosslinked nanoplex that enhanced its dissociation stability in phosphate buffered saline. The reduction in the dissolution rate was proportional to the degree of crosslinking that was governed by the crosslinker to amine ratio. The crosslinking caused slight reductions in the payload and zeta potential of the nanoplex, but with no adverse effect on the cytotoxicity. This proof-of-concept study successfully demonstrated the use of polysaccharide crosslinking to control the drug release from high-payload amorphous drug nanoplex. PMID:27179586

  12. Metabolic engineering of microbes for oligosaccharide and polysaccharide synthesis

    Directory of Open Access Journals (Sweden)

    Chen Rachel

    2006-07-01

    Full Text Available Abstract Metabolic engineering has recently been embraced as an effective tool for developing whole-cell biocatalysts for oligosaccharide and polysaccharide synthesis. Microbial catalysts now provide a practical means to derive many valuable oligosaccharides, previously inaccessible through other methods, in sufficient quantities to support research and clinical applications. The synthesis process based upon these microbes is scalable as it avoids expensive starting materials. Most impressive is the high product concentrations (up to 188 g/L achieved through microbe-catalyzed synthesis. The overall cost for selected molecules has been brought to a reasonable range (estimated $ 30–50/g. Microbial synthesis of oligosaccharides and polysaccharides is a carbon-intensive and energy-intensive process, presenting some unique challenges in metabolic engineering. Unlike nicotinamide cofactors, the required sugar nucleotides are products of multiple interacting pathways, adding significant complexity to the metabolic engineering effort. Besides the challenge of providing the necessary mammalian-originated glycosyltransferases in active form, an adequate uptake of sugar acceptors can be an issue when another sugar is necessary as a carbon and energy source. These challenges are analyzed, and various strategies used to overcome these difficulties are reviewed in this article. Despite the impressive success of the microbial coupling strategy, there is a need to develop a single strain that can achieve at least the same efficiency. Host selection and the manner with which the synthesis interacts with the central metabolism are two important factors in the design of microbial catalysts. Additionally, unlike in vitro enzymatic synthesis, product degradation and byproduct formation are challenges of whole-cell systems that require additional engineering. A systematic approach that accounts for various and often conflicting requirements of the synthesis holds

  13. Activation of intrinsic apoptotic signaling pathway in cancer cells by Cymbopogon citratus polysaccharide fractions.

    Science.gov (United States)

    Thangam, Ramar; Sathuvan, Malairaj; Poongodi, Arasu; Suresh, Veeraperumal; Pazhanichamy, Kalailingam; Sivasubramanian, Srinivasan; Kanipandian, Nagarajan; Ganesan, Nalini; Rengasamy, Ramasamy; Thirumurugan, Ramasamy; Kannan, Soundarapandian

    2014-07-17

    Essential oils of Cymbopogon citratus were already reported to have wide ranging medical and industrial applications. However, information on polysaccharides from the plant and their anticancer activities are limited. In the present study, polysaccharides from C. citratus were extracted and fractionated by anion exchange and gel filtration chromatography. Two different polysaccharide fractions such as F1 and F2 were obtained, and these fractions were found to have distinct acidic polysaccharides as characterized by their molecular weight and sugar content. NMR spectral analysis revealed the presence of (1→4) linked b-d-Xylofuranose moiety in these polysaccharides. Using these polysaccharide fractions F1 and F2, anti-inflammatory and anticancer activities were evaluated against cancer cells in vitro and the mechanism of action of the polysaccharides in inducing apoptosis in cancer cells via intrinsic pathway was also proposed. Two different reproductive cancer cells such as Siha and LNCap were employed for in vitro studies on cytotoxicity, induction of apoptosis and apoptotic DNA fragmentation, changes in mitochondrial membrane potential, and profiles of gene and protein expression in response to treatment of cells by the polysaccharide fractions. These polysaccharide fractions exhibited potential cytotoxic and apoptotic effects on carcinoma cells, and they induced apoptosis in these cells through the events of up-regulation of caspase 3, down-regulation of bcl-2 family genes followed by cytochrome c release. PMID:24702929

  14. Protective effect of polysaccharides on simulated microgravity-induced functional inhibition of human NK cells.

    Science.gov (United States)

    Huyan, Ting; Li, Qi; Yang, Hui; Jin, Ming-Liang; Zhang, Ming-Jie; Ye, Lin-Jie; Li, Ji; Huang, Qing-Sheng; Yin, Da-Chuan

    2014-01-30

    Polysaccharides are believed to be strong immunostimulants that can promote the proliferation and activity of T cells, B cells, macrophages and natural killer (NK) cells. This study aimed to investigate the effects of five polysaccharides (Grifola frondosa polysaccharide (GFP), lentinan (LNT), G. lucidum polysaccharide (GLP), Lycium barbarum polysaccharide (LBP) and yeast glucan (YG)) on primary human NK cells under normal or simulated microgravity (SMG) conditions. Our results demonstrated that polysaccharides markedly promoted the cytotoxicity of NK cells by enhancing IFN-γ and perforin secretion and increasing the expression of the activating receptor NKp30 under normal conditions. Meanwhile polysaccharides can enhance NK cell function under SMG conditions by restoring the expression of the activating receptor NKG2D and reducing the early apoptosis and late apoptosis/necrosis. Moreover, the antibody neutralization test showed that CR3 may be the critical receptor involved in polysaccharides induced NK cells activation. These findings indicated that polysaccharides may be used as immune regulators to promote the health of the public and astronauts during space missions. PMID:24299844

  15. Method to conjugate polysaccharide antigens to surfaces for the detection of antibodies

    DEFF Research Database (Denmark)

    Boas, Ulrik; Lind, Peter; Riber, Ulla

    2014-01-01

    A new generic method for the conjugation of lipopolysaccharide (LPS)-derived polysaccharide antigens from gram-negative bacteria has been developed using Salmonella as a model. After removal of lipid A from the LPS by mild acidolysis, the polysaccharide antigen was conjugated to polystyrene...... against Salmonella typhimurium and Salmonella dublin. The presented method was compared with a similar method for conjugation of Salmonella polysaccharide antigens to surfaces. Here, the new method showed higher antigen coupling efficiency by detecting low concentrations of antibodies. Furthermore, the...... polysaccharide-conjugated beads showed preserved bioactivity after 1 year of use....

  16. Biocatalytic cross-linking of pectic polysaccharides for designed food functionality

    DEFF Research Database (Denmark)

    Zaidel, Dayang Norulfairuz Abang; Meyer, Anne S.

    2012-01-01

    Recent research has demonstrated how cross-linking of pectic polysaccharides to obtain gel formation can be promoted by enzymatic catalysis reactions, and provide opportunities for functional upgrading of pectic polysaccharides present in agro-industrial sidestreams. This review highlights the me...... specific enzymatic reactions, and highlights the most recent data concerning enzyme catalyzed engineering of cross-links for in situ structural design of functional properties of foods.......Recent research has demonstrated how cross-linking of pectic polysaccharides to obtain gel formation can be promoted by enzymatic catalysis reactions, and provide opportunities for functional upgrading of pectic polysaccharides present in agro-industrial sidestreams. This review highlights...

  17. Structure of the polysaccharides from the lipopolysaccharide of Azospirillum brasilense Jm125A2.

    Science.gov (United States)

    Sigida, Elena N; Fedonenko, Yuliya P; Shashkov, Alexander S; Zdorovenko, Evelina L; Konnova, Svetlana A; Ignatov, Vladimir V; Knirel, Yuriy A

    2015-10-30

    Two polysaccharides were obtained by mild acid degradation of the lipopolysaccharide of associative nitrogen-fixing bacteria Azospirillum brasilense Jm125A2 isolated from the rhizosphere of a pearl millet. The following structures of the polysaccharides were established by sugar and methylation analyses, Smith degradation, and (1)H and (13)C NMR spectroscopy: [Formula: see text] Structure 1 has been reported earlier for a polysaccharide from A. brasilense S17 (Fedonenko YP, Konnova ON, Zdorovenko EL, Konnova SA, Zatonsky GV, Shaskov AS, Ignatov VV, Knirel YA. Carbohydr Res 2008;343:810-6), whereas to our knowledge structure 2 has not been hitherto found in bacterial polysaccharides. PMID:26343325

  18. Polysaccharides purified from wild Cordyceps activate FGF2/FGFR1c signaling

    Science.gov (United States)

    Zeng, Yangyang; Han, Zhangrun; Yu, Guangli; Hao, Jiejie; Zhang, Lijuan

    2015-02-01

    Land animals as well as all organisms in ocean synthesize sulfated polysaccharides. Fungi split from animals about 1.5 billion years ago. As fungi make the evolutionary journey from ocean to land, the biggest changes in their living environment may be a sharp decrease in salt concentration. It is established that sulfated polysaccharides interact with hundreds of signaling molecules and facilitate many signaling transduction pathways, including fibroblast growth factor (FGF) and FGF receptor signaling pathway. The disappearance of sulfated polysaccharides in fungi and plants on land might indicate that polysaccharides without sulfation might be sufficient in facilitating protein ligand/receptor interactions in low salinity land. Recently, it was reported that plants on land start to synthesize sulfated polysaccharides in high salt environment, suggesting that fungi might be able to do the same when exposed in such environment. Interestingly, Cordyceps, a fungus habituating inside caterpillar body, is the most valued traditional Chinese Medicine. One of the important pharmaceutical active ingredients in Cordyceps is polysaccharides. Therefore, we hypothesize that the salty environment inside caterpillar body might allow the fungi to synthesize sulfated polysaccharides. To test the hypothesis, we isolated polysaccharides from both lava and sporophore of wild Cordyceps and also from Cordyceps militaris cultured without or with added salts. We then measured the polysaccharide activity using a FGF2/FGFR1c signaling-dependent BaF3 cell proliferation assay and found that polysaccharides isolated from wild Cordyceps activated FGF2/FGFR signaling, indicating that the polysaccharides synthesized by wild Cordyceps are indeed different from those by the cultured mycelium.

  19. Polysaccharides Purified from Wild Cordyceps Activate FGF2/FGFR1c Signaling

    Institute of Scientific and Technical Information of China (English)

    ZENG Yangyang; HAN Zhangrun; YU Guangli; HAO Jiejie; ZHANG Lijuan

    2015-01-01

    Land animals as well as all organisms in ocean synthesize sulfated polysaccharides. Fungi split from animals about 1.5 billion years ago. As fungi make the evolutionary journey from ocean to land, the biggest changes in their living environment may be a sharp decrease in salt concentration. It is established that sulfated polysaccharides interact with hundreds of signaling molecules and facilitate many signaling transduction pathways, including fibroblast growth factor (FGF) and FGF receptor signaling pathway. The disappearance of sulfated polysaccharides in fungi and plants on land might indicate that polysaccharides without sulfation might be sufficient in facilitating protein ligand/receptor interactions in low salinity land. Recently, it was reported that plants on land start to synthesize sulfated polysaccharides in high salt environment, suggesting that fungi might be able to do the same when ex-posed in such environment. Interestingly, Cordyceps, a fungus habituating inside caterpillar body, is the most valued traditional Chi-nese Medicine. One of the important pharmaceutical active ingredients in Cordyceps is polysaccharides. Therefore, we hypothesize that the salty environment inside caterpillar body might allow the fungi to synthesize sulfated polysaccharides. To test the hypothesis, we isolated polysaccharides from both lava and sporophore of wild Cordyceps and also fromCordyceps militaris cultured without or with added salts. We then measured the polysaccharide activity using a FGF2/FGFR1c signaling-dependent BaF3 cell proliferation assay and found that polysaccharides isolated from wild Cordyceps activated FGF2/FGFR signaling, indicating that the polysaccha-rides synthesized by wild Cordyceps are indeed different from those by the cultured mycelium.

  20. Kes "teeb" uudiseid? / Ruta Pels

    Index Scriptorium Estoniae

    Pels, Ruta, 1960-

    2006-01-01

    Ilmunud ka: Buhgalterskije Novosti, 2006, nr. 1, lk. 57-58. Global Media Monitoring Projecti (GMMP) 2005. aasta 16. veebruari meediauuringust, mille eesmärk oli selgitada naiste esindatus massiteabevahendites. Eesti uuringu tulemustest. Tabel. Diagramm

  1. Protocol per a la implantació d’eines didàctiques virtuals: competències i habilitats adquirides pels estudiants

    Directory of Open Access Journals (Sweden)

    Laura Guitart

    2011-06-01

    Full Text Available L’adaptació al nou espai europeu d’educació superior (EEES ha plantejat alguns canvis en l’enfocament de la formació universitària al nostre país. On abans era el docent el protagonista, ara és l’estudiant el que pren el rol d’actor principal de la seva formació, i l’aprenentatge s’orienta cap a una autonomia i reflexió més grans. En aquest escenari, les noves tecnologies ofereixen un ampli ventall d’opcions per millorar els processos formatius. En aquests sentit, el Grup d’Innovació Docent G•IDEA ha participat activament en aquest procés d’adaptació des de ja fa uns quants anys, i ha creat una sèrie de recursos docents digitals que han estat àmpliament provats en diversos ensenyaments de la Facultat d’Economia i Empresa de la Universitat de Barcelona. L’objectiu d’aquest article és presentar el protocol dissenyat per l’equip d’investigadors del G•IDEA per implantar aquestes eines didàctiques (webquestes i exercicis tutoritzats, i també els resultats d’una enquesta de satisfacció sobre les competències i habilitats adquirides pels nostres estudiants en la utilització dels recursos. Els resultats mostren, d’una banda, que no ha estat possible crear un mateix protocol aplicable a tots els recursos, a causa de les diferències en els objectius didàctics de les distintes eines docents implantades. D’altra banda, la valoració que els estudiants fan de la utilització de les eines és molt positiva, tot i que hi ha algunes diferències entre els recursos analitzats. Conèixer la valoració que l’alumnat fa d’aquests recursos permet al grup d’investigadors poder-los millorar i adequar al perfil dels estudiants perquè aquests en puguin treure el màxim profit possible.

  2. La maldad genera cuentos de hadas: Análisis de la película de Guillermo del Toro El Laberinto del Fauno

    Directory of Open Access Journals (Sweden)

    Labrador Ben, Julia María

    2011-04-01

    Full Text Available The Labyrinth Of The Faun (2006 by Guillermo del Toro is a film built on two planes that intertwine constantly: the real plane that matches with the 1944 Spanish post-war when a group of military men commanded by Vidal merciless chase the maquis in the area, and the imaginary plane, thought by Ofelia in parallel, as a sort of escape in front of the negative events she is enduring or that surround her life. When the surrounding evilness is extreme, to escape to a world of fantasy becomes a way out in order to survive; anyway it is only a partial solution as the negative reality will burst to a large or lesser extent into this imaginary world and, unfortunately, this will not be avoided. Guillermo del Toro creates a fiction that, even if originated by evilness, adopts a shape closer to the goodness: a fairy tale. Nevertheless, not everything is goodness in this a priori idyllic world.El laberinto del fauno (2006 de Guillermo del Toro es una película con dos planos que se entrecruzan constantemente: el real, que se corresponde con la España de posguerra de 1944, en el que unos militares capitaneados por Vidal persiguen sin piedad a los maquis de la zona, y el imaginario, ideado por Ofelia en paralelo como evasión ante los acontecimientos negativos que vive o que la rodean. Cuando la maldad circundante es extrema, huir a un mundo de fantasía se convierte en una salida para sobrevivir, pero sólo es una solución parcial, porque la realidad negativa irrumpirá con mayor o menor medida en ese mundo imaginario y no siempre se podrá evitar. Guillermo del Toro plantea una ficción que tiene su origen en la maldad, pero adquiere una forma mucho más cercana a lo contrario, un cuento de hadas, sin embargo, no todo va a ser bondad en ese mundo inicialmente idílico.

  3. «Amor és tal que, si us obre la porta, / tart s’esdevé que pels altres la tanque»: una reinterpretació de la Tragèdia de Caldesa

    OpenAIRE

    Martos Sánchez, Josep Lluís

    2003-01-01

    A partir d'altres passatges de l'obra de Corella, s'explicita la clau de lectura de la tragèdia de Caldesa i s'explica la tradició de la metàfora antropològica sobre la qual es construeix. Aquest treball s'ha dut a terme en el marc dels projectes d'investigació BFF-2002-1254 i BFF-2002-01273, finançats pel Ministerio de Ciencia y Tecnología.

  4. Estudio de factibilidad de una línea de negocio para la fabricación y comercialización nacional de máquinas de corte de película flexible

    OpenAIRE

    Jaramillo Vargas, María Fernanda; Cano, Alberto Elías

    2013-01-01

    El estudio fue realizado para determinar la factibilidad de la creación de una línea de negocio para la fabricación y comercialización nacional de máquinas de corte de película flexible, incluyendo los estudios del sector, mercado, técnico (también llamado de ingeniería), legal, económico, de riesgos y ambiental; teniendo en cuenta dos opciones básicas de fabricación consideradas por los inversionistas como son la maquila (con terceros) y el taller propio -- Para el estudio se utilizaron fuen...

  5. La ladrona de libros : Reseña de una película de Brian Percivel sobre un libro de Markus Zusak, USA - Alemania, 20th Century Fox, 2013

    OpenAIRE

    Urtasun, Carolina

    2014-01-01

    “La ladrona de libros”, película de Brian Percivel basada en una novela de Zusak, cuenta la historia de una niña alemana, Liesel, a quien sus padres dejan en adopción antes de huir de la Alemania nazi tiempo antes de la Segunda Guerra Mundial. Liesel es acogida por una pareja de mediana edad, con la que aprende a convivir y a leer. El primer día de clases en la escuela sus compañeros se burlan de ella porque, en lugar de su nombre, escribe apenas unas grandes cruces en el pizarrón. Sin emb...

  6. Proceso de decisión del consumidor: factores explicativos del visionado de películas en sala de cine de los jóvenes universitarios españoles

    OpenAIRE

    Rodríguez-Rabadán Benito, David

    2014-01-01

    El objetivo general es analizar el proceso de toma de decisiones del consumidor (o espectador cinematográfico) sobre el visionado de una película en sala de cine, desde la perspectiva del marketing y, más concretamente, utilizando las técnicas de estudio del comportamiento del consumidor para determinar las fases que lo componen e identificar las variables del proceso de compra (entendiendo "compra" como el resultado de un proceso de decisión que culmina asistiendo a la sala de cine para ver ...

  7. La recepci??n del humor audiovisual traducido : estudio comparativo de fragmentos de las versiones doblada y subtitulada al espa??ol de la pel??cula "Duck Soup", de los hermanos Marx

    OpenAIRE

    Fuentes Luque, Adri??n

    2001-01-01

    La presente tesis doctoral consiste en un estudio original e innovador sobre la recepci??n de la traducci??n del humor y las referencias culturales en los dos modos principales de traducci??n audiovisual: doblaje y subtitulaci??n. Para ello se han utilizado como corpus fragmentos de las versiones doblada y subtitulada al espa??ol peninsular de la pel??cula Duck Soup(1933), de los Hermanos Marx, elegidos por su representatividad y carga humor??stica y cultural. La originalidad e innovaci??...

  8. Análisis del flujo de un biopolímero soluble en agua durante el procesamiento por moldeo y análisis de las propiedades de las películas resultantes

    OpenAIRE

    Vogelsang Suárez, David Felipe

    2013-01-01

    En la presente investigación se estudió la producción de películas poliméricas de dextrano mediante el proceso de tape casting. Se evaluó el comportamiento reológico de soluciones de dextrano en agua y el efecto de la incorporación de sorbitol y carragenina en la solución. Los ensayos de reología dinámica dieron como resultado que las soluciones acuosas de dextrano presentaron comportamiento viscoelástico, el cual se acentuaba a concentraciones superiores al 20% de biopolímero. Se encontró...

  9. El doblaje en películas de animación: análisis práctico de las operaciones traductoras en el caso de Gru, mi villano favorito

    OpenAIRE

    Águeda Maté, Vanesa

    2015-01-01

    El presente Trabajo Fin de Grado pretende abordar las operaciones traductoras que pueden llevarse a cabo en el proceso de doblaje de una película de animación destinada a un público infantil. Para cumplir dicho objetivo, en el marco teórico hemos analizado el doblaje como modalidad de traducción audiovisual, sus diferentes fases, así como los factores que debemos tener en cuenta para doblar este tipo de productos. Después de plasmar los fundamentos teóricos, hemos realizado un análisis prácti...

  10. Tuberculosis y cine: una aproximación a través de la fantasía de más de 400 películas

    OpenAIRE

    García Sánchez, José Elías; García Sánchez, Enrique; García Merino, Enrique

    2010-01-01

    Se repasa la presencia de la tuberculosis en el cine a través de más de 400 películas. Se ofrece la ficha técnica de las cintas y la forma en que se plasma la enfermedad en la mayoría de ellas. Se señala la época en la que transcurre la acción, hecho que tiene un marcado interés clínico-epidemiológico.

  11. Estudio de la difusión del carvacrol y el eugenol desde películas de proteína de suero lácteo a diferentes simulantes alimentarios

    OpenAIRE

    Otín Acín, José Miguel

    2011-01-01

    El presente Trabajo fin de Master está enmarcado en el desarrollo de películas comestibles antimicrobianas capaces de aumentar la seguridad y vida comercial de productos alimentarios frescos a través del control de la difusión de agentes antimicrobianos contenidos en su formulación. El objetivo fundamental de este trabajo fue la caracterización de las cinéticas de liberación de compuestos activos retenidos en matrices basadas en proteína aislada de suero lácteo. La liberació...

  12. Cien años de grabaciones comerciales de música colombiana los discos de “pelón y marín” (1908) y su contexto

    OpenAIRE

    Bermúdez, Egberto

    2014-01-01

    Este articulo explora el contexto social, cultural ypolitico de las más tempranas grabaciones comercialesde musica popular colombiana, realizadas por el duetoantioqueño de Pelón y Marín en la Ciudad de Méxicoen los últimos meses de 1908. Este momento coincidecon la consolidacion de la presencia politica y culturalde los Estados Undies en Latinaomerca y el Caribe.Pretende explorar tambien la presencia de músicos yartistas colombianos en el extranjero y la relacion desus repertorios con el repe...

  13. Optimized extraction, composition, antioxidant and antimicrobial activities of exo and intracellular polysaccharides from submerged culture of Cordyceps cicadae

    OpenAIRE

    SHARMA, SAPAN KUMAR; GAUTAM, NANDINI; Atri, Narender Singh

    2015-01-01

    Background Cordyceps cicadae is known as Jin Chan Hua in Traditional Chinese Medicine and known to possess different pharmacological activities. Presently, it was collected from the wild and isolated. Mycelial culture was optimized for extraction of polysaccharides under submerged culture conditions. Besides antioxidant, antibacterial activities of extracted polysaccharides were tested for first time. Methods Exo-polysaccharides (EPS) and intracellular polysaccharides (IPS) production was tes...

  14. A Study on the Extraction and Purification Process of Lily Polysaccharide and Its Anti-Tumor Effect

    OpenAIRE

    Han, Hong-Ping; Xie, Hui-chun

    2013-01-01

    The objective of this paper was to extract and purify lily polysaccharide and to study its anti-H22 hepatoma effect in mice. Orthogonal experimental method was used to analyze the factors influencing the extraction and purification of lily polysaccharide, and the anti-tumor effect of lily polysaccharide was studied by acting it on H22-bearing mice. The results showed that the size of influence of various factors on the extraction results of lily polysaccharide were extraction time, extraction...

  15. Reexamination of the presence and linkage of 3-hydroxybutyryl substituents in the acidic capsular polysaccharide of Rhizobium trifolii 0403.

    OpenAIRE

    Hollingsworth, R I; Dazzo, F B; Mort, A J

    1987-01-01

    We resolved previous conflicting results concerning the presence of 3-hydroxybutyryl substituents on the extracellular acidic polysaccharide from Rhizobium trifolii 0403. These substituents were indeed present in the polysaccharide and in the oligosaccharide fragments obtained by hydrogen fluoride solvolysis of the extracellular and capsular polysaccharides of the bacteria grown on plates. The 3-hydroxybutyrate substituent could be removed from the polysaccharide by 10 mM sodium deuteroxide w...

  16. Fingerprint profiling of polysaccharide kefiran extracted from kefir grains biomass

    OpenAIRE

    POP, CARMEN; M. Rotar, Ancuta; C. Salanțӑ, Liana; A. Semeniuc, Cristina; Socaciu, Carmen; Sindic, Marianne

    2015-01-01

    Kefiran is a water-soluble polysaccharide extracted from kefir grains biomass. The identification and quantification of kefiran monosaccharides were carried out by HPTLC after the complete acid hydrolysis of kefiran solutions. The mobile phase was a mixture of n-propanol: acetic acid: water (70:20:10, v/v). For derivatization was used p-aminobenzoic acid and o-phosphoric acid in methanol. The identified HPTLC fractions were glucose (Rf 0.71) and galactose (Rf 0.66), which indicates a high pur...

  17. Lycium barbarum Polysaccharides Reduce Exercise-Induced Oxidative Stress

    OpenAIRE

    Tao Ma; Qiongxia Chai; Junlai Zhou; Xiaozhong Shan

    2011-01-01

    The purpose of the present study was to investigate the effects of Lycium barbarum polysaccharides (LBP) on exercise-induced oxidative stress in rats. Rats were divided into four groups, i.e., one control group and three LBP treated groups. The animals received an oral administration of physiological saline or LBP (100, 200 and 400 mg/kg body weight) for 28 days. On the day of the exercise test, rats were required to run to exhaustion on the treadmill. Body weight, endurance time, malondialde...

  18. Chemical Characteristic of Bioactive Polysaccharides Isolated from Ornithogalum caudatum Ait.

    Institute of Scientific and Technical Information of China (English)

    SHI Lei; LI Juan; LIU Wen-Xiang; WANG Yong; LIU Zhi-qiang; LIU Shu-ying

    2003-01-01

    A water-soluble crude extract prepared from Ornithogalum caudatum Ait.(OCA) showing a high immunomodulating activitiy was isolated and characterized by virtue of gel filtration and column chromatography. The presence of the monosaccharides has been established by the chemical analysis. The quantitative analysis of the alditol acetate derivatives of them showed the ratios of the monosaccharides analyzed by means of GC respectively. The concentrations of protein(280 nm) and carbohydrate(496 nm) were detected respectively. The information of the molecular weight from the pure polysaccharide was obtained by several standard Dextrans from the Sephadex chromatography.

  19. Extracellular polysaccharide production in Bacillus licheniformis SVD1 and its immunomodulatory effect

    Directory of Open Access Journals (Sweden)

    J. Susan van Dyk

    2012-11-01

    Full Text Available Bacillus licheniformis SVD1 exhibited highest production of three different polysaccharides when sucrose was used as the carbon source for polysaccharide production and yeast extract was used as the nitrogen source. Polysaccharides were characterized using size exclusion chromatography (SEC, thin layer chromatography (TLC, gas chromatography with mass spectrometry (GCMS, and Fourier Transform Infrared (FTIR analysis. Field emission scanning electron microscopy (FESEM and transmission electron microscopy (TEM were used to examine the topography of the cells and polysaccharides. The cell-associated polysaccharides were composed of galactose, while two different polysaccharides were present in the extracellular medium, one of 2,000 kDa (EPS1, consisting of fructose monomers and identified as a levan with (2→6-linkages and (1→2-branching linkages. The other extracellular polysaccharide (EPS2 consisted of mannose and galactose and had a range of sizes as identified through SEC. All three polysaccharides displayed an immune modulatory effect as measured using Interleukin 6 (IL6 and tumor necrosis factor alpha (TNFα.

  20. Sorption properties of pectin polysaccharides obtained form the wastes of food industry

    International Nuclear Information System (INIS)

    Present article is devoted to sorption properties of pectin polysaccharides obtained form the wastes of food industry. The comparative analysis of quantitative parameters of combining of cooper and lead by pectin polysaccharides, obtained from different raw sources was conducted. It was defined that micro gel and low methylated pectin have the most cooper and lead binding ability.

  1. Structural characterization and biomedical properties of sulfated polysaccharide from the gladius of Sepioteuthis lessoniana (Lesson, 1831).

    Science.gov (United States)

    Seedevi, Palaniappan; Moovendhan, Meivelu; Vairamani, Shanmugam; Shanmugam, Annian

    2016-04-01

    Sulfated polysaccharide was extracted from the internal shell (gladius) of Sepioteuthis lessoniana. The sulfated polysaccharide contained 61.3% of carbohydrate, 0.8% of protein, 28.2% of ash and 1.33% of moisture respectively. The elemental composition was analyzed using CHNS/O analyzer. The molecular weight of sulfated polysaccharide determined through PAGE was found to be as 66kDa. Monosaccharides analysis revealed that sulfated polysaccharide was composed of rhamnose, galactose, xylose and glucose. The structural features of sulfated polysaccharide were analyzed by FT-IR and NMR spectroscopy. Further the sulfated polysaccharide was evaluated for its antibacterial activity against selected human clinical pathogens, namely Staphylococcus aureus, Klebsiella pneumoniae, Salmonella typhi, Vibrio cholerae, Klebsiella oxytoca, Escherichia coli, Salmonella paratyphi, Proteus mirabilis, Vibrio parahaemolyticus and Streptococcus pyogenes using agar well diffusion method. The polysaccharide has showed good antibacterial activity and MIC and MBC have also been evaluated. The anticancer activity was tested against HeLa cell line by MTT assay. The Cytotoxic Concentration (CC50) was observed as 700μg/ml and the maximum anticancer activity of 62.89% was recorded at 200μg/ml; whereas, the lowest of 9.87% was observed at 25μg/ml. In conclusion, the sulfated polysaccharide is an alternate, non-toxic and cheap source of substance that showed good antibacterial and anticancer acitivity. PMID:26724686

  2. Effects of solution conditions on characteristics and size exclusion chromatography of pneumococcal polysaccharides and conjugate vaccines.

    Science.gov (United States)

    Hadidi, Mahsa; Buckley, John J; Zydney, Andrew L

    2016-11-01

    Molecular properties of bacterial polysaccharides and protein-polysaccharide conjugates play an important role in the efficiency and immunogenicity of the final vaccine product. Size exclusion chromatography (SEC) is commonly used to analyze and characterize biopolymers, including capsular polysaccharides. The objective of this work was to determine the effects of solution ionic strength and pH on the SEC retention of several capsular polysaccharides from S. pneumoniae bacteria in their native and conjugated forms. The retention time of the charged polysaccharides increased with increasing ionic strength and decreasing pH due to compaction of the polysaccharides associated with a reduction in the intramolecular electrostatic interactions. The calculated radius of gyration was in good agreement with model calculations based on the worm-like chain model accounting for the increase in chain stiffness and excluded volume of the charged polysaccharide at low ionic strength. These results provide important insights into the effects of solution ionic strength on physical properties and SEC behavior of capsular polysaccharides and their corresponding conjugates. PMID:27516244

  3. The evidence for use of pneumococcal conjugate over polysaccharide in children

    OpenAIRE

    Borrow, Ray

    2013-01-01

    Pneumococcal glycoconjugate vaccines are now used in infant immunization schedules, globally. Pneumococcal polysaccharide vaccines are still, however, advised from the second year of life to provide broader serotype coverage. The use of these polysaccharide vaccines has been under review, especially for children.

  4. Monoclonal antibody to Streptococcus mutans type e cell wall polysaccharide antigen.

    OpenAIRE

    Kato, H; Ota, F; K. Fukui; Yagawa, K

    1986-01-01

    A monoclonal antibody against the polysaccharide antigen of Streptococcus mutans serotype e was prepared. It was found that beta-methyl-D-glucopyranoside and cellobiose markedly inhibited the precipitin reaction, whereas maltose showed no inhibition. The beta-glucosyl moiety of the type e polysaccharide seems to be the predominant antigenic determinant of the antigen.

  5. Recombinant plants provide a new approach to the production of bacterial polysaccharide for vaccines.

    Directory of Open Access Journals (Sweden)

    Claire M Smith

    Full Text Available Bacterial polysaccharides have numerous clinical or industrial uses. Recombinant plants could offer the possibility of producing bacterial polysaccharides on a large scale and free of contaminating bacterial toxins and antigens. We investigated the feasibility of this proposal by cloning and expressing the gene for the type 3 synthase (cps3S of Streptococcus pneumoniae in Nicotinia tabacum, using the pCambia2301 vector and Agrobacterium tumefaciens-mediated gene transfer. In planta the recombinant synthase polymerised plant-derived UDP-glucose and UDP-glucuronic acid to form type 3 polysaccharide. Expression of the cps3S gene was detected by RT-PCR and production of the pneumococcal polysaccharide was detected in tobacco leaf extracts by double immunodiffusion, Western blotting and high-voltage paper electrophoresis. Because it is used a component of anti-pneumococcal vaccines, the immunogenicity of the plant-derived type 3 polysaccharide was tested. Mice immunised with extracts from recombinant plants were protected from challenge with a lethal dose of pneumococci in a model of pneumonia and the immunised mice had significantly elevated levels of serum anti-pneumococcal polysaccharide antibodies. This study provides the proof of the principle that bacterial polysaccharide can be successfully synthesised in plants and that these recombinant polysaccharides could be used as vaccines to protect against life-threatening infections.

  6. Characterisation of antioxidant and antiproliferative acidic polysaccharides from Chinese wolfberry fruits

    NARCIS (Netherlands)

    He, N.W.; Yang, X.B.; Jiao, Y.D.; Tian, L.; Zhao, Y.

    2012-01-01

    Wolfberry fruit polysaccharides (WFPs) were isolated by hot-water extraction and ethanol precipitation. With HPLC analysis, WFPs were for the first time identified as acidic polysaccharides with galacturonic acid being the main component monosaccharide (24.9%), followed by galactose (21.3%), arabino

  7. Optimization of ultrasonic circulating extraction of polysaccharides from Asparagus officinalis using response surface methodology.

    Science.gov (United States)

    Zhao, Qingsheng; Kennedy, John F; Wang, Xiaodong; Yuan, Xiaofan; Zhao, Bing; Peng, Youshun; Huang, Yunxiang

    2011-08-01

    Polysaccharides were extracted from Asparagus officinalis. A novel ultrasonic circulating extraction (UCE) technology was applied for the polysaccharide extraction. Three-factor-three-level Box-Behnken design was employed to optimize ultrasonic power, extraction time and the liquid-solid ratio to obtain a high polysaccharide yield. The optimal extraction conditions were as follows: ultrasonic power was 600 W, extraction time was 46 min, the liquid-solid ratio was 35 mL/g. Under these conditions, the experimental yield of polysaccharides was 3.134%, which was agreed closely to the predicted value. The average molecular weight of A. officinalis polysaccharide was about 6.18×10(4) Da. The polysaccharides were composed of glucose, fucose, arabinose, galactose and rhamnose in a ratio of 2.18:1.86:1.50:0.98:1.53. Compared with hot water extraction (HWE), UCE showed time-saving, higher yield and no influence on the structure of asparagus polysaccharides. The results indicated that ultrasonic circulating extraction technology could be an effective and advisable technique for the large scale production of plant polysaccharides. PMID:21549748

  8. Structure of an immunoactive polysaccharide isolated from Korean mulberry fruit (Morus alba L.)

    Czech Academy of Sciences Publication Activity Database

    Bleha, R.; Lee, J. S.; Capek, P.; Pohl, Radek; Kim, H. B.; Choi, D. J.; Lee, S.; Lee, J.; Jang, S. J.; Synytsya, A.; Park, Y. I.

    Prague: Czech Chemical Society, 2014 - (Řápková, R.; Čopíková, J.; Šárka, E.), s. 21-26 ISBN 978-80-86238-70-8. [International Conference on Polysaccharides-Glycoscience /10./. Prague (CZ), 22.10.2014-24.10.2014] Institutional support: RVO:61388963 Keywords : pectic polysaccharides Subject RIV: CC - Organic Chemistry

  9. Characterization of Bacterial Polysaccharide Capsules and Detection in the Presence of Deliquescent Water by Atomic Force Microscopy

    OpenAIRE

    Su, Hai-Nan; Chen, Zhi-Hua; Liu, Sheng-Bo; Qiao, Li-Ping; Chen, Xiu-Lan; He, Hai-Lun; Zhao, Xian; Zhou, Bai-Cheng; Zhang, Yu-Zhong

    2012-01-01

    We detected polysaccharide capsules from Zunongwangia profunda SM-A87 with atomic force microscopy (AFM). The molecular organization of the capsules at the single-polysaccharide-chain level was reported. Furthermore, we found that with ScanAsyst mode the polysaccharide capsules could be detected even in the presence of deliquescent water covering the capsule.

  10. Antigenic polysaccharides of bacteria. 14. Structure of the O-specific polysaccharide chain of the lipopolysaccharide of pseudomonas aeruginosa O12 (Lanyi)

    International Nuclear Information System (INIS)

    The mild-alkaline hydrolysis of the lipopolysaccharide of Pseudomonas aeruginosa O12 (Lanyi classification) has given the O-specific polysaccharide, which is constructed of D-ribose and N-acetyl-D-galactosamine residues. The disaccharide structure for the repeating unit of this polysaccharide has been established by a nondestructive method as the result of the complete deciphering of its 1H and 13C NMR spectra using homonuclear and selective heteronuclear 13C {1H} double resonance

  11. A wide diversity of sulfated polysaccharides are synthesized by different species of marine sponges.

    Science.gov (United States)

    Zierer, M S; Mourão, P A

    2000-09-01

    Sulfated polysaccharides were extracted from four species of marine sponges by exhaustive papain digestion. These compounds were purified by anion-exchange and gel-filtration chromatography. Analysis of the purified polysaccharides revealed a species-specific variation in their chemical composition and also in their molecular masses. In the species Aplysina fulva we found a sulfated glucan with a glycogen-like structure. The other three species contained sulfated polysaccharides with variable proportions of galactose, fucose, arabinose and hexuronic acid and also with different degrees of sulfation. Although the complex nature of these polysaccharides did not allow complete structure determination, we detected the occurrence of 4-sulfated residues of fucose and arabinose in the species Dysidea fragilis. The biological role of these sulfated polysaccharides requires further investigation. They may be involved in the species-specific aggregation of sponge cells and/or in the structural integrity of sponge, resembling the proteoglycans of mammalian connective tissues. PMID:11028788

  12. Physical modifications of polysaccharide from Inonotus obliquus and the antioxidant properties.

    Science.gov (United States)

    Zhang, Ning; Chen, Haixia; Ma, Lishuai; Zhang, Yu

    2013-03-01

    Physical modification of polysaccharides exerted better biological properties because of the change of physicochemical properties. Polysaccharides from Inonotus obliquus (IOPS) were modified by acid, alkali hydrolysis, thermal and ultrasonic treatment in this study. The physicochemical and antioxidant properties of IOPS and its physical modified products were comparatively investigated by chemical methods, gas chromatography, size exclusion chromatography, scanning electron micrograph, circular dichroism spectra, and ferric reducing power assay and lipid peroxidation inhibition assay, respectively. Results showed that physicochemical and antioxidant properties of IOPS were changed after the physical modification of acid, alkali hydrolysis, thermal and ultrasonic treatment. Thermal treated polysaccharide (Th-IOPS) and ultrasonic treated polysaccharide (Ul-IOPS) showed the properties of lower molecular weight distribution, lower intrinsic viscosity, a hyperbranched conformation, and higher antioxidant abilities on ferric-reducing power and lipid peroxidation inhibition activity compared with the native polysaccharide IOPS. Th-IOPS and Ul-IOPS might be explored as a novel potential antioxidant for food industry. PMID:23270834

  13. Chemical modification and antioxidant activities of polysaccharide from mushroom Inonotus obliquus.

    Science.gov (United States)

    Ma, Lishuai; Chen, Haixia; Zhang, Yu; Zhang, Ning; Fu, Lingling

    2012-06-20

    Chemical modification polysaccharides exerted potent biological property which was related to the physicochemical properties. In the present study, polysaccharides from Inonotus obliquus were modified by suflation, acetylation and carboxymethylation. The physicochemical and antioxidant properties of I. obliquus polysaccharide (IOPS) and its derivatives were comparatively investigated by chemical methods, gas chromatography, size exclusion chromatography, scanning electron micrograph, infrared spectra and circular dichroism spectra, and ferric reducing power assay and lipid peroxidation inhibition assay, respectively. Results showed that physicochemical and antioxidant properties of IOPS were differed each other after the chemical modification of suflation, acetylation and carboxymethylation. Among the three derivatives, acetylationed polysaccharide (Ac-IOPS) resulted in lower molecular weight distribution, lower intrinsic viscosity, a hyperbranched conformation, higher antioxidant abilities on ferric-reducing power and lipid peroxidation inhibition activity compared with the native polysaccharide IOPS. Ac-IOPS might be explored as a novel potential antioxidant for human consumption. PMID:24750732

  14. Structural determination of the polysaccharide isolated from biofilms produced by a clinical strain of Klebsiella pneumoniae.

    Science.gov (United States)

    Cescutti, Paola; De Benedetto, Gianluigi; Rizzo, Roberto

    2016-07-22

    Klebsiella pneumoniae are Gram negative opportunistic pathogens producing capsular (K) polysaccharides. Seventy-seven different K antigens have been described and they are the basis for K serotyping. Capsular polysaccharides are important virulence factors and have a relevant role for the structure of biofilm communities. Nevertheless, little information is available on the polysaccharides produced in biofilm matrices by Klebsiella spp. In the present study, a clinical isolate of Klebsiella pneumoniae was grown both on cellulose membranes deposited on agar plates, where it formed an adherent biofilm, and in liquid medium, where it formed floating biofilms (flocs). Extraction and purification of the polysaccharide fraction showed that only one main carbohydrate polymer was present in both adherent biofilms and flocs. Composition and linkage analysis, Smith degradation followed by ESI-MS, 1D and 2D NMR spectroscopy revealed that the polysaccharide belong to the type K24 and has the following structure. PMID:27182661

  15. Rapid analysis of polysaccharides contents in Glycyrrhiza by near infrared spectroscopy and chemometrics.

    Science.gov (United States)

    Zhang, Ci-Hai; Yun, Yong-Huan; Fan, Wei; Liang, Yi-Zeng; Yu, Yue; Tang, Wen-Xian

    2015-08-01

    A method for quantitative analysis of the polysaccharides contents in Glycyrrhiza was developed based on near infrared (NIR) spectroscopy, and by adopting the phenol-sulphuric acid method as the reference method. This is the first time to use this method for predicting polysaccharides contents in Glycyrrhiza. To improve the predictive ability (or robustness) of the model, the competitive adaptive reweighted sampling (CARS) mathematical strategy was used for selecting relevance wavelengths. By using the restricted relevance wavelengths, the PLS model was more efficient and parsimonious. The coefficient of determination of prediction (Rp(2)) and the root mean square error of prediction (RMSEP) of the obtained optimum models were 0.9119 and 0.4350 for polysaccharides. The selected relevance wavelengths were also interpreted. It proved that all the wavelengths selected by CARS were related to functional groups of polysaccharide. The overall results show that NIR spectroscopy combined with chemometrics can be efficiently utilised for analysis of polysaccharides contents in Glycyrrhiza. PMID:26093314

  16. In Vitro Antioxidant Activities of Sulfated Derivatives of Polysaccharides Extracted from Auricularia auricular

    Science.gov (United States)

    Zhang, Hua; Wang, Zhen-Yu; Yang, Lin; Yang, Xin; Wang, Xue; Zhang, Zhi

    2011-01-01

    In this research, two types of sulfated polysaccharide derivatives were successfully synthesized. Their antioxidant activities were investigated by employing various established in vitro systems. In addition, the degree of sulfation was evaluated using ion-chromatography and IR spectra. The results verify that, when employing scavenging superoxide radical tests, both the sulfation of acid Auricularia auricular polysaccharides (SAAAP) and the sulfation of neutral Auricularia auricular polysaccharides (SNAAP) derivatives possessed considerable antioxidant activity and had a more powerful antioxidant competence than that of the native non-sulfated polysaccharides (AAAP and NAAP). On the other hand, AAAP and NAAP exhibited stronger activity on scavenging both the hydroxyl radical and lipid peroxidation. Available data obtained with in vitro measurements indicates that the sulfated groups of AAAP and NAAP played an important role on antioxidant activity. In sum, the research demonstrates that the antioxidant activity of sulfated polysaccharide derivatives in vitro has a potential significance for seeking new natural antioxidant protective agents. PMID:21686185

  17. Structural characterization and antioxidant activities of polysaccharides from Citrus aurantium L.

    Science.gov (United States)

    Wang, Qiu Hong; Shu, Zun Peng; Xu, Bing Qing; Xing, Na; Jiao, Wen Juan; Yang, Bing You; Kuang, Hai Xue

    2014-06-01

    Three polysaccharide fractions were obtained from Citrus aurantium L. (CAL) by sequential extraction with cold water, hot water, and 1.0M NaOH, respectively. The fractions were denoted CALA, CALB, and CALC. Structural characterization was conducted by physicochemical property, FTIR, and SEM analyses. Antioxidant activities in vivo and in vitro were also evaluated. CALB, which showed the highest activity, was further isolated to afford four purified polysaccharides (CALB-1-4) by various ion exchange and gel-filtration chromatography. Meanwhile, the purified polysaccharides were subjected to composition analysis and screened by antioxidant activity in vitro. Among the four purified polysaccharides, CALB-3 had the highest antioxidant activity and its structure was analyzed by FTIR, SEM and AFM microscopy. Overall, these results indicated that polysaccharides from CAL had potential therapeutic applications in the medical and food industries because of their antioxidant activities. PMID:24631547

  18. Lycium barbarum polysaccharides promotes in vivo proliferation of adult rat retinal progenitor cells

    Directory of Open Access Journals (Sweden)

    Hua Wang

    2015-01-01

    Full Text Available Lycium barbarum is a widely used Chinese herbal medicine prescription for protection of optic nerve. However, it remains unclear regarding the effects of Lycium barbarum polysaccharides, the main component of Lycium barbarum, on in vivo proliferation of adult ciliary body cells. In this study, adult rats were intragastrically administered low- and high-dose Lycium barbarum polysaccharides (1 and 10 mg/kg for 35 days and those intragastrically administered phosphate buffered saline served as controls. The number of Ki-67-positive cells in rat ciliary body in the Lycium barbarum polysaccharides groups, in particular low-dose Lycium barbarum polysaccharides group, was significantly greater than that in the phosphate buffered saline group. Ki-67-positive rat ciliary body cells expressed nestin but they did not express glial fibrillary acidic protein. These findings suggest that Lycium barbarum polysaccharides can promote the proliferation of adult rat retinal progenitor cells and the proliferated cells present with neuronal phenotype.

  19. Antiviral Potential of Algae Polysaccharides Isolated from Marine Sources: A Review

    Directory of Open Access Journals (Sweden)

    Azin Ahmadi

    2015-01-01

    Full Text Available From food to fertilizer, algal derived products are largely employed in assorted industries, including agricultural, biomedical, food, and pharmaceutical industries. Among different chemical compositions isolated from algae, polysaccharides are the most well-established compounds, which were subjected to a variety of studies due to extensive bioactivities. Over the past few decades, the promising results for antiviral potential of algae-derived polysaccharides have advocated them as inordinate candidates for pharmaceutical research. Numerous studies have isolated various algal polysaccharides possessing antiviral activities, including carrageenan, alginate, fucan, laminaran, and naviculan. In addition, different mechanisms of action have been reported for these polysaccharides, such as inhibiting the binding or internalization of virus into the host cells or suppressing DNA replication and protein synthesis. This review strives for compiling previous antiviral studies of algae-derived polysaccharides and their mechanism of action towards their development as natural antiviral agents for future investigations.

  20. A unique variant of streptococcal group O-antigen (C-polysaccharide) that lacks phosphocholine

    DEFF Research Database (Denmark)

    Bergström, N; Jansson, P.-E.; Kilian, Mogens;

    2003-01-01

    previously characterized forms of C-polysaccharide, which all contain one or two choline residues per repeat. The following structure of the repeating unit of the SK598 polysaccharide was established: where AAT is 2-acetamido-4-amino-2,4,6-trideoxy-d-galactose. This structure is identical to the double......Streptococcus mitis strain SK598, which represents a subgroup of biovar 1, possesses a unique variant of the C-polysaccharide found in the cell wall of all strains of Streptococcus pneumoniae and in some strains of S. mitis. This new variant lacks the choline methyl groups in contrast to the...... choline-substituted form of C-polysaccharide, except that it is substituted with ethanolamine instead of choline. This extends the number of recognized C-polysaccharide variants to four....

  1. In vitro fermentation of sulfated polysaccharides from E. prolifera and L. japonica by human fecal microbiota.

    Science.gov (United States)

    Kong, Qing; Dong, Shiyuan; Gao, Jian; Jiang, Chaoyu

    2016-10-01

    In vitro fermentation of the sulfated polysaccharides from seaweeds Enteromorpha prolifera and Laminaria japonica and their prebiotic effects on human fecal microbiota were investigated in this study. The sulfated polysaccharides were fermented in vitro for 48h by human fecal cultures. When 0.8g MWCOL (polysaccharides MWCOmicroflora balance, because the beneficial strains (Lactobacillus and Bifidobacterium) were both significantly higher than those in control group (p<0.05). As far as we know, this is the first report that consumption of sulfated polysaccharides from E. prolifera and L. japonica is beneficial to the ecosystem of the intestinal tract by increasing the populations of probiotics and short chain fatty acids. Furthermore, our reports indicated that molecular weight of sulfated polysaccharide from marine algae is related to its prebiotic effects. PMID:27316763

  2. Specificity of the immune response to the group B polysaccharide of Neisseria meningitidis.

    Science.gov (United States)

    Lifely, M R; Esdaile, J

    1991-11-01

    A panel of monoclonal antibodies (mAb) and polyclonal sera of murine, human and equine origin, of IgM isotype and with specificity for Neisseria meningitidis group B polysaccharide, an alpha(2----8)-linked homopolymer of sialic acid, were examined for their antigenic and biological specificities. The nature of the antigenic determinants on B polysaccharide was investigated using a series of N-acyl derivatives of B polysaccharide, two sialic acid polymers containing alpha(2----9)-linkages and a series of polynucleotides. The panel of antibodies recognized an array of unrelated antigenic determinants on the B polysaccharide, despite its structural simplicity, and all but one were highly effective in an in vitro bactericidal assay and/or in an in vivo murine passive protection model. There was no evidence that B polysaccharide induced antibody capable of blocking biological activity (blocking antibody). PMID:1722773

  3. Micropatterned polysaccharide surfaces via laser ablation for cell guidance

    Energy Technology Data Exchange (ETDEWEB)

    Barbucci, Rolando; Lamponi, Stefania; Pasqui, Daniela; Rossi, Antonella; Weber, Elisabetta

    2003-03-03

    Micropatterned materials were obtained by a controlled laser ablation of a photoimmobilised homogeneous layer of hyaluronic acid (Hyal) and its sulphated derivative (HyalS). The photoimmobilisation was performed by coating the polysaccharide, adequately functionalised with a photoreactive group, on aminosilanised glass substrate and immobilising it on the surface under UV light. Hyal or HyalS photoimmobilised samples were then subjected to laser ablation with wavelengths in the UV regions in order to drill the pattern. Four different patterns with stripes of 100, 50, 25 and 10 {mu}m were generated. A chemical characterisation by attenuated total reflection/Fourier transform infrared (ATR/FT-IR) and time of flight-secondary ions mass spectrometry (TOF-SIMS) confirmed the success of the laser ablation procedure and the presence of alternating stripes of polysaccharide and native glass. The exact dimensions of the stripes were determined by atomic force microscopy. The analysis of cell behaviour in terms of adhesion, proliferation and movement using mouse fibroblasts (3T3 line) and bovine aortic endothelial cells (BAEC) was also performed.

  4. Structure of polysaccharide antibiotics; Structure des antibiotiques polysaccharidiques

    Energy Technology Data Exchange (ETDEWEB)

    Matutano, L. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1966-07-01

    Study of the structure of antibiotics having two or several sugars in their molecule. One may distinguish: the polysaccharide antibiotics themselves, made up of two or several sugars either with or without nitrogen, such as streptomycin, neomycins, paromomycine, kanamycin, chalcomycin; the hetero-polysaccharide antibiotics made up of one saccharide part linked to an aglycone of various type through a glucoside: macrolide, pigment, pyrimidine purine. Amongst these latter are: erythromycin, magnamycin, spiramycin, oleandomycin, cinerubin and amicetin. The sugars can either play a direct role in biochemical reactions or act as a dissolving agent, as far as the anti-microbe power of these antibiotics is concerned. (author) [French] Etude de la structure des antibiotiques qui possedent dans leur molecule deux ou plusieurs sucres. On distingue: les antibiotiques polysaccharidiques proprement dits, constitues de deux eu plusieurs sucres azotes ou non, tels que streptomycines, neomycines, paromomycines, kanamycine, chalcomycine; les antibiotiques heteropolysaccharidiques formes d'une partie saccharidique liee glycosidiquement a un aglycone de nature diverse: macrolide - pigment - purine pyrimidine. On compte parmi ceux-ci: erythroraycine rnagnamycine, spiromycine, oleandomycine, cinerubine et amicetine. Dans le pouvoir antimicrobien de ces antibiotiques les sucres peuvent jouer soit un role direct dans les reactions biochimiques, soit agir comme solubilisant. (auteur)

  5. Synthesis of polysaccharide chemical gels by gamma-irradiation

    International Nuclear Information System (INIS)

    Recently many biodegradable hydrogel systems have been developed in the area of controlled drug delivery. In previous studies, the authors prepared biodegradable hydrogels by crosslinking natural polymers, such as albumin and dextran, using gamma-irradiation. Natural polymers were functionalized by introducing double bonds through reaction with glycidyl acrylate. The functionalized polymers were then crosslinked to form chemical gels by exposure to gamma-irradiation. In this study, they examined the ability of various polysaccharides to form chemical gels by gamma-irradiation. Dextran, alginic acid, hyaluronic acid, benzyl esters of hyaluronic acid, and gellan were functionalized. The effects of the polymer concentration and the gamma-irradiation dose on the hydrogel formation were examined. All the polysaccharides used formed chemical gels, although the extent of gel formation was different. For alginic acid, hyaluronic acid, and benzyl ester of hyaluronic acid at 25% of esterification degree, the chemical gels were formed at lower polymer concentration and at lower gamma-irradiation dose, if the solution was acidified to pH 3. The ability to form chemical gels with various natural polymers would be useful in the development of controlled drug delivery systems

  6. A Novel Tissue Adhesive Composed of Modified Gelatin and Polysaccharides

    Institute of Scientific and Technical Information of China (English)

    Xiumei MO; Hiroo IWATA; Yoshito IKADA

    2000-01-01

    A two-component adhesive glue was prepared from gelatin and polysaccharides. Gelatin was modified with ethylenediamine (ED) in the presence of water soluble carbodiimine (WSC) to introduce more amino groups into the original gelatin, while dextran and hydroxyethyl-starch (HES) were oxidized by sodium periodate to convert neighbouring hydroxyl groups into dialdehyde groups. Upon mixing the two polymer components in aqueous solution, Schiff's base reaction occurred between the amino groups in the modified gelatin and the aldehyde groups in the modified polysaccharides to give intermolecular crosslinking and gel formation. This new glue showed a capability to stop bleeding and seal tissues when a cut liver of rat was used for hemostatic experiments. It could also form a gel much faster than fibrin glue in in-vitro experiments. The fastest gel formation took place within 2 sec and the bonding strength to porcine skin was about 225gf/cm2 when an amino-gelatin (55% amino) and an aldehyde-HES (>84% dialdehyde) was mixed. In contrast, the gelation time and bonding strength of fibrin gluewere 5 seconds and 120gf/cm2, respectively. The effective adhesive properties have also been identified by the animal experiments of rat.

  7. Representative parameter of immunostimulatory ginseng polysaccharide to predict radioprotection

    International Nuclear Information System (INIS)

    According to the increase in the use of radiotherapy to cancer patients, many approaches have been tried to develop new agents for the protection of surrounding normal tissues. However, it is still few applied in the clinic as a radioprotector. We aim to find a representative parameter for radioprotection to easily predict the activity of in vivo experiment from the results of in vitro screening. The polysaccharide extracted from Panax ginseng was used in this study because the immunostimulator has been regarded as one of the radioprotective agent category and was already reported having a promising radioprotective activity through the increase of hematopoietic cells and the production of several cytokines. Mitogenic activity, AK cells activity and nitric oxide production were monitored for the in vitro immunological assay, and endogenous Colony-Forming Unit (e-CFU) was measured as in vivo radioprotective parameter. The immunological activity was increased by the galactose contents of ginseng polysaccharide dependently. The result of this study suggests that mitogenic activity of splenocytes demonstrated a good correlation with in vivo radioprotective effect, and may be used as a representative parameter to screen the candidates for radioprotector

  8. A novel chemistry for conjugating pneumococcal polysaccharides to Luminex microspheres.

    Science.gov (United States)

    Schlottmann, Sonela A; Jain, Neil; Chirmule, Narendra; Esser, Mark T

    2006-02-20

    Here we describe a novel method to conjugate pneumococcal polysaccharides (PnPS) to Luminex microspheres for use in serological assays. 4-(4,6-dimethoxy[1,3,5]triazin-2-yl)-4-methyl-morpholinium (DMTMM) modification of PnPS and conjugation to carboxyl functional groups on Luminex microspheres (COOH-DMTMM method) was shown to be a reproducible chemistry that efficiently conjugated PnPS to Luminex microspheres without affecting the antigenicity of a broad set of PnPS. The COOH-DMTMM method was compared to three other methods for robustness, reproducibility and effect on PnPS antigenicity in a multiplexed assay format. The other methods examined included adsorption of the unmodified PnPS to Luminex microspheres, oxidation of the PnPS to conjugate them to amino-modified microspheres using carbodiimide chemistry and poly-l-lysine modification of the PnPS before conjugating to carboxy Luminex microspheres using carbodiimide chemistry. Of the four methods, the COOH-DMTMM chemistry was shown to be a robust methodology, producing stable PnPS coupled microspheres with a 4-log dynamic range and low cross-reactivity when used in a PnPS-specific IgG serology assay. This novel chemistry should be useful for developing serological assays to measure antibodies to polysaccharides for use in vaccine and epidemiology studies. PMID:16448665

  9. Polysaccharides from Arctium lappa L.: Chemical structure and biological activity.

    Science.gov (United States)

    Carlotto, Juliane; de Souza, Lauro M; Baggio, Cristiane H; Werner, Maria Fernanda de P; Maria-Ferreira, Daniele; Sassaki, Guilherme L; Iacomini, Marcello; Cipriani, Thales R

    2016-10-01

    The plant Arctium lappa L. is popularly used to relieve symptoms of inflammatory disorders. A crude polysaccharide fraction (SAA) resulting of aqueous extraction of A. lappa leaves showed a dose dependent anti-edematogenic activity on carrageenan-induced paw edema, which persisted for up to 48h. Sequential fractionation by ultrafiltration at 50kDa and 30kDa cut-off membranes yielded three fractions, namely RF50, RF30, and EF30. All these maintained the anti-edematogenic effect, but RF30 showed a more potent action, inhibiting 57% of the paw edema at a dose of 4.9mg/kg. The polysaccharide RF30 contained galacturonic acid, galactose, arabinose, rhamnose, glucose, and mannose in a 7:4:2:1:2:1 ratio and had a Mw of 91,000g/mol. Methylation analysis and NMR spectroscopy indicated that RF30 is mainly constituted by a type I rhamnogalacturonan branched by side chains of types I and II arabinogalactans, and arabinan. PMID:27311502

  10. Scleroglucan: A Versatile Polysaccharide for Modified Drug Delivery

    Directory of Open Access Journals (Sweden)

    Franco Alhaique

    2005-01-01

    Full Text Available Scleroglucan is a natural polysaccharide, produced by fungi of the genus Sclerotium, that has been extensively studied for various commercial applications (secondary oil recovery, ceramic glazes, food, paints, etc. and also shows several interesting pharmacological properties. This review focuses its attention on the use of scleroglucan, and some derivatives, in the field of pharmaceutics and in particular for the formulation of modified-release dosage forms. The reported investigations refer mainly to the following topics: natural scleroglucan suitable for the preparation of sustained release tablets and ocular formulations; oxidized and crosslinked scleroglucan used as a matrix for dosage forms sensitive to environmental conditions; co-crosslinked scleroglucan/gellan whose delivery rate can be affected by calcium ions. Furthermore, a novel hydrogel obtained with this polysaccharide and borate ions is described, and the particular structure of this hydrogel network has been interpreted in terms of conformational analysis and molecular dynamics. Profound attention is devoted to the mechanisms involved in drug release from the tested dosage forms that depend, according to the specific preparation, on swelling and/or diffusion. Experimental data are also discussed on the basis of a mathematical approach that allows a better understanding of the behavior of the tested polymeric materials.

  11. Efecto de la temperatura de substrato en las propiedades estructurales, ópticas y ferroelóctricas de películas delgadas de BaTiO3 depositadas por RF sputtering

    Directory of Open Access Journals (Sweden)

    A. Márquez-Herrera

    2012-01-01

    Full Text Available Se crecieron películas delgadas de Titanato de Bario (BaTiO3 sobre substratos de cuarzo y nicromel, utilizando un blanco de BaTiO3 mediante la técnica erosión catódica por radiofrecuencia. Variamos la temperatura de substrato con el fin de determinar su efecto sobre las propiedades estructurales, ópticas y ferroeléctricas de las muestras. Los resultados de la difracción de Rayos-X indicaron que las muestras tuvieron una estructura tetragonal, aumentando su cristalinidad conforme se aumentó la temperatura de substrato. El ancho de banda prohibida disminuyo con el aumento en la temperatura de substrato, mostrando un decremento abrupto a 494.8±C. Las propiedades ferroeléctricas de las películas mostraron una dependencia con la temperatura de substrato, obteniéndose la mejor respuesta a 494.8±C.

  12. Elaboración, caracterización y comparación de películas comestibles en base a aislado de proteínas de suero lácteo (WPI

    Directory of Open Access Journals (Sweden)

    Rosa Márquez

    2011-05-01

    Full Text Available El incremento del interés en alimentos de alta calidad con mayor vida útil y un menor impacto a nivel ambiental ha llevado al estudio y desarrollo de películas y coberturas comestibles y/o biodegradables. Éstas son una excelente alternativa de empaque de alimentos por su carácter biodegradable, flexible y su poder para actuar como envases activos. En base a esto y a la gran producción lechera en Uruguay, en el presente trabajo se elaboraron y estudiaron películas en base a WPI, como una alternativa de uso de los subproductos de la industria láctea de alto valor agregado. Algunos plastificantes como glicerol y sorbitol modifican las propiedades de las proteínas insertándose dentro de su estructuratridimensional, y utilizados en pequeñas cantidades introducen cambios significativos. El objetivo del presente trabajo fue la elaboración, caracterización y comparación de películas comestibles según sus propiedades mecánicas de tensión. Para ello se utilizaron dos concentraciones distintas de WPI (8 % y 10 % y tres proporciones de WPI/plastificante: 1,6/1; 2,0/1 y 2,3/1. La disminución tanto de la cantidad de proteína como de plastificante en las películas produjo un aumento de las fuerzas y stress máximos y a la ruptura. Las películas más elásticas se obtienen con la mayor cantidad de plastificante estudiada (1,6/1, obteniéndose una elongación de hasta un 60 % con un 8 % de WPI en la película. Las películas realizadas con sorbitol presentan mayores fuerzas y tensiones que las de glicerol, manteniéndose en ambos casos la tendencia a la disminución de dichas propiedades con el aumento de plastificante. La elasticidad aumenta a mayor proporción de cualquiera de los plastificantes estudiados y las películas que contienen glicerol son más elásticas que las que contienen sorbitol.AbstractIncreasing interest in high-quality food products with increased shelf life and reduced environmental impact has encouraged the study and

  13. Las leyes de la atracción en los títulos de las películas de cine. Un caso de análisis de la vía heurística en la comunicación de masas

    OpenAIRE

    Pastor, Lluís

    2011-01-01

    Este artículo plantea una aproximación sobre los elementos cognitivos que se utilizan en los títulos de las películas para persuadir a un público local para que vaya a ver la película. El estudio se centra en los títulos de las películas extranjeras que han sido modificados en su traducción al español antes de ser exhibidas al público. El marco teórico que se ha utilizado para llevar a cabo la investigación es el de la cognición social. Esta corriente teórica, a medio camino de la psicología ...

  14. Análisis de los avances digitales para el desarrollo e integración de la animación tradicional y la animación generada por ordenador en películas históricas

    OpenAIRE

    DÍAZ GARCÍA, MARÍA AMOR

    2011-01-01

    El presente trabajo se centra en el análisis de la transformación que ha experimentado la industria cinematográfica de animación debido a los nuevos avances digitales para producir películas de animación 3D y los nuevos programas digitales para la realización de películas 2D, y en cómo los grandes estudios de animación han aplicado estas nuevas tecnologías y logrado integrar la animación tradicional y digital en la realización de películas históricas. La importancia de esta investigación resi...

  15. Influence of fermentation conditions on polysaccharide production and the activities of enzymes involved in the polysaccharide synthesis of Cordyceps militaris.

    Science.gov (United States)

    Zhu, Zhen-Yuan; Liu, Xiao-Cui; Dong, Feng-Ying; Guo, Ming-Zhu; Wang, Xiao-Ting; Wang, Zheng; Zhang, Yong-Min

    2016-05-01

    The influence of different fermentation conditions on intracellular polysaccharide (IPS) production and activities of the phosphoglucomutase (PGM), UDPG-pyrophosphorylase (UGP), phosphoglucose isomerase (PGI), UDPG-dehydrogenase (UGD), and glucokinase (GK) implicated in metabolite synthesis in Cordyceps militaris was evaluated. The highest IPS production (327.57 ± 6.27 mg/100 mL) was obtained when the strain was grown in the optimal medium containing glucose (40 g · L(-1)), beef extract (10 g · L(-1)), and CaCO3 (0.5 g · L(-1)), and the initial pH and temperature were 7 and 25 °C, respectively. The activities of PGM, UGP, and PGI were proved to be influenced by the fermentation conditions. A strong correlation between the activities of these enzymes and the production of IPS was found. The transcription level of the pgm gene (encoding PGM) was 1.049 times and 1.467 times compared to the ugp gene and pgi gene (encoding UGP and PGI), respectively, in the optimal culture medium. This result indicated that PGM might be the highly key enzyme to regulate the biosynthesis of IPS of C. militaris in a liquid-submerged culture. Our study might be helpful for further research on the pathway of polysaccharide biosynthesis aimed to improve the IPS production of C. militaris. PMID:26685672

  16. Comparative evaluation of polysaccharides isolated from Astragalus, oyster mushroom, and yacon as inhibitors of α-glucosidase.

    Science.gov (United States)

    Zhu, Zhen-Yuan; Zhang, Jing-Yi; Chen, Li-Jing; Liu, Xiao-Cui; Liu, Yang; Wang, Wan-Xiao; Zhang, Yong-Min

    2014-04-01

    The incidence of diabetes has increased considerably, and become the third serious chronic disease following cancer and cardiovascular diseases. Though acarbose, metformin, and 1-deoxynojirimycin have good efficacy for clinical application as hypoglycemic drugs, their expensive costs and some degree of side effects have limited their clinical application. Recently, increasing attention has concentrated on the polysaccharides from natural plant and animal sources for diabetes. In order to illustrate the pharmaceutical activity of polysaccharides as natural hypoglycemic agents, polysaccharides isolated from Astragalus, oyster mushroom, and Yacon were evaluated for their inhibitory effects on α-glucosidase. Polysaccharides were extracted and purified from Astragalus, Oyster mushroom, and Yacon with hot water at 90 °C for 3 h, respectively. The total sugar content of the polysaccharide was determined by the phenol-sulfuric acid method. The α-glucosidase inhibitory activity was measured by the glucose oxidase method. The results exhibited that the inhibitory effects on α-glucosidase were in decreasing order, Astragalus > oyster mushroom > Yacon. The α-glucosidase inhibition percentage of Astragalus polysaccharide and oyster mushroom polysaccharide were over 40% at the polysaccharide concentration of 0.4 mg·mL(-1). The IC50 of Astragalus polysaccharide and oyster mushroom polysaccharide were 0.28 and 0.424 mg·mL(-1), respectively. The information obtained from this work is beneficial for the use polysaccharides as a dietary supplement for health foods and therapeutics for diabetes. PMID:24863354

  17. Stable nano-sized emulsions produced from soy protein and soy polysaccharide complexes.

    Science.gov (United States)

    Yin, Baoru; Deng, Wei; Xu, Keke; Huang, Luwen; Yao, Ping

    2012-08-15

    In this research, a simple, green and effective strategy was developed to produce long-term stable oil in water emulsion from soy protein and soy polysaccharide. Soy protein and soy polysaccharide formed dispersible complexes at pH around 3.25 aqueous solution through electrostatic and hydrophobic interactions. A high pressure homogenization produced the protein/polysaccharide complex emulsion having a droplet size about 250 nm. A heat treatment of the emulsion resulted in the protein denaturation, forming irreversible oil-water interfacial films composed of soy protein/soy polysaccharide complexes. The droplets of the emulsion were characterized by dynamic light scattering, ζ-potential, transmission electron microscopy, polysaccharide digestion via pectinase, and confocal laser scanning microscopy observation via dual fluorescence probes. As a result of the polysaccharide being fixed on the droplet surface, the emulsions exhibited long-term stability in the media containing pH values of 2-8 and 0.2 mol/L NaCl. The stable soy protein/soy polysaccharide complex emulsion is a suitable food-grade delivery system in which lipophilic bioactive compounds can be encapsulated. PMID:22682324

  18. Comparison of Physicochemical Characteristics and Anticoagulant Activities of Polysaccharides from Three Sea Cucumbers

    Directory of Open Access Journals (Sweden)

    Shengmin Wang

    2013-02-01

    Full Text Available In order to search for sulfated polysaccharides in different invertebrate connective tissues and to examine their biological activities, we have isolated three types of polysaccharides from the body wall of the three sea cucumbers Holothuria edulis, Apostichopus japonicas and Holothuria nobilis. The physicochemical properties and anticoagulant activities of these polysaccharides were examined and compared. The chemical composition analysis and nuclear magnetic resonance (NMR analysis indicate that two types of polysaccharides, sulfated fucan and fucosylated chondroitin sulfate (FuCS, were found in all of the three species and in addition a neutral glycan was observed in H. edulis. The neutral α-glucan was firstly obtained from sea cucumber. The same type of polysaccharides from different species of sea cucumbers have similar physicochemical properties and anticoagulant activities, but those of different types of glycans are significantly different, possibly due to their different monosaccharide compositions, electric charges and average molecular weights. The FuCSs have stronger anticoagulant activities than the sulfated fucans, although the molecular sizes of the FuCSs are lower than those of the sulfated fucans, whereas the neutral glucan has no activity, as expected from the absence of sulfate. Thus, anticoagulant activities of the different type of polysaccharides are likely to relate to monosaccharide composition and sulfate content. Preliminary analysis suggests that the sulfation patterns of the FuCSs may result in the difference in anticoagulant activities. Our data could help elucidate the structure-activity relationship of the sea cucumber polysaccharides.

  19. Effect of extraction method on structure and antioxidant activity of Hohenbuehelia serotina polysaccharides.

    Science.gov (United States)

    Li, Xiaoyu; Wang, Lu

    2016-02-01

    The impacts of four extraction methods (hot water, enzyme assistance, ultrasonic assistance and ultrasonic-enzyme assistance) on the extraction yields, preliminary structure and antioxidant activities of the Hohenbuehelia serotina polysaccharides (HW-HSP, EA-HSP, UA-HSP and UEA-HSP) were systematically investigated. The yield of the polysaccharides (20.70±0.17%) obtained by ultrasonic-enzyme assistance was higher than the polysaccharides by other methods'. Four kinds of polysaccharides possessed the different preliminary structural characteristics including molecular weight distributions, monosaccharide compositions, crystallization and spiral structures, while different surface morphology. Through the measurements of antioxidant activities in vitro, UEA-HSP exhibited the most significant scavenging capacities on non-physiological ABTS free radicals and physiological hydroxyl radicals. These data showed that ultrasonic-enzyme assistance was more beneficial to enhance the extraction yields of the polysaccharides, and obtain higher bioactive polysaccharides. The results also suggested that H. serotina polysaccharides possessed potential healthcare application in food field due to their antioxidant activities. PMID:26627599

  20. Physical characteristics and antioxidant effect of polysaccharides extracted by boiling water and enzymolysis from Grifola frondosa.

    Science.gov (United States)

    Fan, Yina; Wu, Xiangyang; Zhang, Min; Zhao, Ting; Zhou, Ye; Han, Liang; Yang, Liuqing

    2011-06-01

    Grifola frondosa has been widely consumed in China and other Asian countries. Recent studies on G. frondosa have focused on the activities of polysaccharides extracted by water, and the activities of polysaccharides extracted by enzymolysis have not been studied. In this work, the relationship between the physical properties and antioxidant activity of polysaccharides extracted from G. frondosa by boiling water and enzymolysis was studied. Five polysaccharide extracts from the fruit body of G. frondosa were prepared by different extracting methods including boiling water, single enzyme enzymolysis with three different single enzymes (cellulose, pectinase, and pancreatin), and combined enzyme enzymolysis (cellulose:pectinase:pancreatin; 2:2:1). Characteristics such as the viscosity, Mw, polysaccharide content, protein content, infrared spectra, and antioxidant activities of the extracts were evaluated. The highest antioxidant activity was exhibited by the extracts prepared by combined enzyme extraction. The correlation analysis between antioxidant activity and polysaccharide content, protein content, Mw or viscosity indicated that the Mw had a more important role in antioxidant activity. Overall, the results indicate that the combined enzyme polysaccharide extracts can be developed as a new potential natural antioxidant. PMID:21458482

  1. Straightforward approach to graft bioactive polysaccharides onto polyurethane surfaces using an ionic liquid

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Development of a facile chemical process for PU surface derivatization. • Direct grafting of seaweed polysaccharides onto isothiocyanated PU surface. • Use of a selected ionic liquid as solvent and catalyst. - Abstract: Surface properties directly affect the performance of a material in a biological environment. In this study, the goal was to develop a simple procedure allowing the grafting of antibacterial polysaccharides onto biomedical grade polyurethanes (e.g. Tecothane®). Thus, a straightforward chemical pathway involving an isothiocyanate–alcohol reaction in an ionic liquid (IL) was developed. PU isothiocyanted surfaces (PU–NCS) were first prepared by reacting p-phenylene diisothiocyanate with the surface urethane groups. Then, unmodified bioactive seaweed polysaccharides were directly grafted onto the surface, in mild conditions. The selected IL, i.e. 1-ethyl-3-methyl imidazolium phosphate, was of particular interest since this liquid worked as solvent for p-phenylene diisothiocyanate and the polysaccharides and as catalyst for the grafting reactions. Successful grafting of the different polysaccharides was attested by changes in the surface functional groups, using X-ray photoelectron spectroscopy (XPS). Atomic force microscopy (AFM) showed that polysaccharide grafting, slightly increased the surface roughness from 1.9 to more than 7 nm. Contact angle with water decreased from 88° (for native PU) to around 75° after polysaccharide grafting, attesting a more hydrophilic surface. This procedure would be transposed to the grafting onto PU surfaces of any macromolecule of interest bearing hydroxyl, thiol or amine groups

  2. Sulfated Polysaccharides in Marine Sponges: Extraction Methods and Anti-HIV Activity

    Directory of Open Access Journals (Sweden)

    Ana I. S. Esteves

    2011-01-01

    Full Text Available The extraction, fractionation and HIV-1 inhibition potential of polysaccharides extracted from three species of marine sponges, Erylus discophorus, Cliona celata and Stelletta sp., collected in the Northeastern Atlantic, is presented in this work. The anti-HIV activity of 23 polysaccharide pellets and three crude extracts was tested. Crude extracts prepared from Erylus discophorus specimens were all highly active against HIV-1 (90 to 95% inhibition. Cliona celata pellets showed low polysaccharide content (bellow 38.5% and almost no anti-HIV activity (<10% inhibition. Stelletta sp. pellets, although quite rich in polysaccharide (up to 97.3%, showed only modest bioactivity (<36% HIV-1 inhibition. Erylus discophorus pellets were among the richest in terms of polysaccharide content (up to 98% and the most active against HIV-1 (up to 95% inhibition. Chromatographic fractionation of the polysaccharide pellet obtained from a specimen of Erylus discophorus (B161 yielded only modestly active fractions. However, we could infer that the active molecule is most probably a high molecular weight sulfated polysaccharide (>2000 kDa, whose mechanism is possibly preventing viral attachment and entry (fusion inhibitor.

  3. Salt Effect on the Antioxidant Activity of Red Microalgal Sulfated Polysaccharides in Soy-Bean Formula

    Directory of Open Access Journals (Sweden)

    Ariela Burg

    2015-10-01

    Full Text Available Sulfated polysaccharides produced by microalgae, which are known to exhibit various biological activities, may potentially serve as natural antioxidant sources. To date, only a few studies have examined the antioxidant bioactivity of red microalgal polysaccharides. In this research, the effect of different salts on the antioxidant activities of two red microalgal sulfated polysaccharides derived from Porphyridium sp. and Porphyridium aerugineum were studied in a soy bean-based infant milk formula. Salt composition and concentration were both shown to affect the polysaccharides’ antioxidant activity. It can be postulated that the salt ions intefer with the polysaccharide chains’ interactions and alter their structure, leading to a new three-dimensional structure that better exposes antiooxidant sites in comparison to the polysaccharide without salt supplement. Among the cations that were studied, Ca2+ had the strongest enhancement effect on antioxidant activities of both polysaccharides. Understanding the effect of salts on polysaccharides’ stucture, in addition to furthering knowledge on polysaccharide bioactivities, may also shed light on the position of the antioxidant active sites.

  4. Straightforward approach to graft bioactive polysaccharides onto polyurethane surfaces using an ionic liquid

    Energy Technology Data Exchange (ETDEWEB)

    Bigot, Sandra [Normandie Université, INSA de Rouen, CNRS UMR 6270 FR 3038, Avenue de l’université BP08, 76801 Saint-Etienne du Rouvray (France); Louarn, Guy [Institut des Matériaux Jean Rouxel (IMN), UMR 6502, CNRS-Université de Nantes, 2 rue de la Houssinière, BP 32229, 44322 Nantes (France); Kébir, Nasreddine, E-mail: nasreddine.kebir@insa-rouen.fr [Normandie Université, INSA de Rouen, CNRS UMR 6270 FR 3038, Avenue de l’université BP08, 76801 Saint-Etienne du Rouvray (France); Burel, Fabrice [Normandie Université, INSA de Rouen, CNRS UMR 6270 FR 3038, Avenue de l’université BP08, 76801 Saint-Etienne du Rouvray (France)

    2014-09-30

    Graphical abstract: - Highlights: • Development of a facile chemical process for PU surface derivatization. • Direct grafting of seaweed polysaccharides onto isothiocyanated PU surface. • Use of a selected ionic liquid as solvent and catalyst. - Abstract: Surface properties directly affect the performance of a material in a biological environment. In this study, the goal was to develop a simple procedure allowing the grafting of antibacterial polysaccharides onto biomedical grade polyurethanes (e.g. Tecothane{sup ®}). Thus, a straightforward chemical pathway involving an isothiocyanate–alcohol reaction in an ionic liquid (IL) was developed. PU isothiocyanted surfaces (PU–NCS) were first prepared by reacting p-phenylene diisothiocyanate with the surface urethane groups. Then, unmodified bioactive seaweed polysaccharides were directly grafted onto the surface, in mild conditions. The selected IL, i.e. 1-ethyl-3-methyl imidazolium phosphate, was of particular interest since this liquid worked as solvent for p-phenylene diisothiocyanate and the polysaccharides and as catalyst for the grafting reactions. Successful grafting of the different polysaccharides was attested by changes in the surface functional groups, using X-ray photoelectron spectroscopy (XPS). Atomic force microscopy (AFM) showed that polysaccharide grafting, slightly increased the surface roughness from 1.9 to more than 7 nm. Contact angle with water decreased from 88° (for native PU) to around 75° after polysaccharide grafting, attesting a more hydrophilic surface. This procedure would be transposed to the grafting onto PU surfaces of any macromolecule of interest bearing hydroxyl, thiol or amine groups.

  5. Antioxidant and anticoagulant activity of sulfated polysaccharide from Gracilaria debilis (Forsskal).

    Science.gov (United States)

    Sudharsan, Sadhasivam; Subhapradha, Namasivayam; Seedevi, Palaniappan; Shanmugam, Vairamani; Madeswaran, Perumal; Shanmugam, Annaian; Srinivasan, Alagiri

    2015-11-01

    Sulfated polysaccharide was isolated from Gracilaria debilis and purified through gel chromatography and their molecular weight was determined through AGE and PAGE. The total sugars in the crude, fractionated and purified polysaccharide were estimated as 52.65%, 59.70% and 67.60%, respectively. The ash and moisture content of crude and purified polysaccharide was found to be 14.2% and 23.5% and the polysaccharide was free from protein contamination. The sulfate and uronic acid contents in the crude, fractionated and purified were estimated as 14.08%, 15.33% and 16.01% and 10.12%, 13.56%, 16.70%. The elemental composition including carbon (crude - 23.12%, purified - 21.05%), hydrogen (crude - 3.4%, purified - 4.13%) and nitrogen (crude - 1.22%, purified - 0.56%) were also analyzed. The anticoagulant activity of the sulfated polysaccharide through APTT and PT was estimated at 14.11 and 8.23IU/mg. The purified polysaccharide with the molecular mass of 20kDa showed highest antioxidant activity (38.57%, 43.48% and 38.88%) in all the assays tested such as DPPH hydroxyl radical, superoxide radical, hydroxyl radical scavenging activities and the structural property was analyzed through FT-IR and (1)H NMR spectrum. The results together suggest that the isolated low molecular weight sulfated polysaccharide will demonstrate as a enormously available alternative natural source of antioxidant for industrial uses. PMID:26424206

  6. Bioactivities of water-soluble polysaccharides from Jisongrong mushroom: anti-breast carcinoma cell and antioxidant potential.

    Science.gov (United States)

    Zhou, Lin-Bin; Chen, Bin

    2011-01-01

    Polysaccharides were extracted from Jisongrong mushroom. Jisongrong polysaccharides was a water-soluble compound. Its molecular weight was about 7.4×10(4) Da. HPLC analysis showed that this polysaccharides was composed of mannose, ribose, rhamnose, glucose, xylose, galactose and arabinose in the molar contents of 3.3, 17.3, 6.0, 12.4, 98.4 and 2.1 μM, respectively. In the range of 2800-3500 cm(-1), peaks at 2958 and 3407 cm(-1) belonging to -C-H of -CH2 groups, were observed in polysaccharides. When Jisongrong polysaccharides were orally administrated to rats for 2 months, level of lipid peroxidation products and activities of antioxidant enzymes in the blood were significantly decreased and enhanced compared to control rats. Moreover, Jisongrong polysaccharides still markedly inhibited cancer cells proliferation. These results suggested that Jisongrong polysaccharides possess a strong antioxidant and antitumour activities. PMID:20850472

  7. The cyclic-di-GMP signaling pathway in the Lyme disease spirochete, Borrelia burgdorferi

    Directory of Open Access Journals (Sweden)

    Elizabeth A. Novak

    2014-05-01

    Full Text Available In nature, the Lyme disease spirochete Borrelia burgdorferi cycles between the unrelated environments of the Ixodes tick vector and mammalian host. In order to survive transmission between hosts, B. burgdorferi must be able to not only detect changes in its environment, but also rapidly and appropriately respond to these changes. One manner in which this obligate parasite regulates and adapts to its changing environment is through cyclic-di-GMP (c-di-GMP signaling. c-di-GMP has been shown to be instrumental in orchestrating the adaptation of B. burgdorferi to the tick environment. B. burgdorferi possesses only one set of c-di-GMP-metabolizing genes (one diguanylate cyclase and two distinct phosphodiesterases and one c-di-GMP-binding PilZ-domain protein designated as PlzA. While studies in the realm of c-di-GMP signaling in B. burgdorferi have exploded in the last few years, there are still many more questions than answers. Elucidation of the importance of c-di-GMP signaling to B. burgdorferi may lead to the identification of mechanisms that are critical for the survival of B. burgdorferi in the tick phase of the enzootic cycle as well as potentially delineate a role (if any c-di-GMP may play in the transmission and virulence of B. burgdorferi during the enzootic cycle, thereby enabling the development of effective drugs for the prevention and/or treatment of Lyme disease.

  8. Crystal structure of the YajQ-family protein XC_3703 from Xanthomonas campestris pv. campestris.

    Science.gov (United States)

    Zhao, Zhixin; Wu, Zhen; Zhang, Jun

    2016-09-01

    As an important bacterial second messenger, bis-(3',5')-cyclic diguanylate (cyclic di-GMP or c-di-GMP) has been implicated in numerous biological activities, including biofilm formation, motility, survival and virulence. These processes are manipulated by the binding of c-di-GMP to its receptors. XC_3703 from the plant pathogen Xanthomonas campestris pv. campestris, which belongs to the YajQ family of proteins, has recently been identified as a potential c-di-GMP receptor. XC_3703, together with XC_2801, functions as a transcription factor activating virulence-related genes, which can be reversed by the binding of c-di-GMP to XC_3703. However, the structural basis of how c-di-GMP regulates XC_3703 remains elusive. In this study, the structure of XC_3703 was determined to 2.1 Å resolution using the molecular-replacement method. The structure of XC_3703 consists of two domains adopting the same topology, which is similar to that of the RNA-recognition motif (RRM). Arg65, which is conserved among the c-di-GMP-binding subfamily of the YajQ family of proteins, together with Phe80 in domain II, forms a putative c-di-GMP binding site. PMID:27599864

  9. Evaluation of Macroalgae Sulfated Polysaccharides on the Leishmania (L. amazonensis Promastigote

    Directory of Open Access Journals (Sweden)

    Marcos Hikari Toyama

    2013-03-01

    Full Text Available The sulfated polysaccharides from Solieria filiformis (Sf, Botryocladia occidentalis (Bo, Caulerpa racemosa (Cr and Gracilaria caudata (Gc were extracted and extensively purified. These compounds were then subjected to in vitro assays to evaluate the inhibition of these polysaccharides on the growth of Leishmania (L. amazonensis promastigotes. Under the same assay conditions, only three of the four sulfated polysaccharides were active against L. amazonensis, and the polysaccharide purified from Cr was the most potent (EC50 value: 34.5 μg/mL. The polysaccharides derived from Bo and Sf demonstrated moderate anti-leishmanial activity (EC50 values of 63.7 μg/mL and 137.4 μg/mL. In addition, we also performed in vitro cytotoxic assays toward peritoneal macrophages and J774 macrophages. For the in vitro cytotoxicity assay employing J774 cells, all of the sulfated polysaccharides decreased cell survival, with CC50 values of 27.3 μg/mL, 49.3 μg/mL, 73.2 μg/mL, and 99.8 μg/mL for Bo, Cr, Gc, and Sf, respectively. However, none of the sulfated polysaccharides reduced the cell growth rate of the peritoneal macrophages. These results suggest that macroalgae contain compounds with various chemical properties that can control specific pathogens. According to our results, the assayed sulfated polysaccharides were able to modulate the growth rate and cell survival of Leishmania (L. amazonensis promastigotes in in vitro assays, and these effects involved the interaction of the sulfated polysaccharides on the cell membrane of the parasites.

  10. Analysis of chemical components of shiitake polysaccharides and its anti-fatigue effect under vibration.

    Science.gov (United States)

    Li, Xiaoling; Zhang, Hongbo; Xu, Haibo

    2009-11-01

    The shiitake polysaccharides were obtained from shiitake mushroom. Four fractions were isolated from the polysaccharides using a Sephadex G-100 gel column. Chemical components of the two main fractions were determined by thin layer chromatography (TLC), and high performance liquid chromatography (HPLC). F1 was composed of rhamnose, glucose, and mannose. F3 was composed of xylose, mannose, arabinose and galactose. The obtained results still showed that administration of shiitake polysaccharides could improve muscle's comfortability of animals under a long period of vibration. The above findings might be applicable to studies of vibration ergonomics. PMID:19643126

  11. Antioxidant and Immunoregulatory Activity of Polysaccharides from Quinoa (Chenopodium quinoa Willd.)

    OpenAIRE

    Yang Yao; Zhenxing Shi; Guixing Ren

    2014-01-01

    The water-extractable (QWP) and the alkali-extractable (QAP) polysaccharides from quinoa (named QWP and QAP, respectively) and their four polysaccharide sub-fractions (QWP-1, QWP-2, QAP-1 and QAP-2), were isolated and purified by anion-exchange and gel filtration chromatography. QWP-1 and QWP-2 were composed of Rha, Ara, Gal and GalA. QAP-1 and QAP-2 were composed of Rha, Ara, Man, Gal and GalA. Antioxidant and immunoregulatory activities of the polysaccharides were evaluated. The results s...

  12. Analgesic Activity of a Glucan Polysaccharide Isolated from Agaricus blazei Murill

    OpenAIRE

    Maria Leônia C. Gonzaga; Menezes, Thiago M. F.; de Souza, José R. R.; Nágila M. P. S. Ricardo; Ana L. P. Freitas; Sandra de A. Soares

    2013-01-01

    A water soluble polysaccharide and its selective precipitated fractions (F1, F2, and F3) were isolated from hot water extract of fruiting bodies of Agaricus blazei Murril known as Agaricus brasiliensis to evaluate the analgesic activity of the materials in Swiss mice. The isolated material and its fractions were characterized by two-dimensional COSY and HMQC spectra as β-(1→6)-α-(1→4)-glucan-bound-protein polysaccharide constituted mainly by β-(1→6) glucan. The glucan-protein polysaccharide a...

  13. Anti-inflammatory and immunomodulatory activities of polysaccharide from Chlorella stigmatophora and Phaeodactylum tricornutum.

    Science.gov (United States)

    Guzmán, S; Gato, A; Lamela, M; Freire-Garabal, M; Calleja, J M

    2003-06-01

    Crude polysaccharide extracts were obtained from aqueous extracts of the microalgae Chlorella stigmatophora and Phaeodactylum tricornutum. The crude extracts were fractionated by ion-exchange chromatography on DEAE-cellulose columns. The molecular weights of the polysaccharides in each fraction were estimated by gel filtration on Sephacryl columns. The crude polysaccharide extracts of both microalgae showed anti-inflammatory activity in the carrageenan-induced paw edema test. In assays of effects on the delayed hyper-sensitivity response, and on phagocytic activity assayed in vivo and in vitro, the C. stigmatophora extract showed immunosuppressant effects, while the P. tricornutum extract showed immunostimulatory effects. PMID:12820237

  14. Chemical analysis of a polysaccharide of unripe (green) tomato (Lycopersicon esculentum).

    Science.gov (United States)

    Chandra, Krishnendu; Ghosh, Kaushik; Ojha, Arnab K; Islam, Syed S

    2009-11-01

    A polysaccharide (PS-I) isolated from the aqueous extract of the unripe (green) tomatoes (Lycopersicon esculentum) consists of D-galactose, D-methyl galacturonate, D-arabinose, L-arabinose, and L-rhamnose. Structural investigation of the polysaccharide was carried out using total acid hydrolysis, methylation analysis, periodate oxidation study, and NMR studies ((1)H, (13)C, DQF-COSY, TOCSY, NOESY, ROESY, HMQC, and HMBC). On the basis of above-mentioned experiments the structure of the repeating unit of the polysaccharide (PS-I) was established as: [structure: see text]. PMID:19765690

  15. Molecular Weight and Monosaccharide Composition of Astragalus Polysaccharides

    Directory of Open Access Journals (Sweden)

    Pei-Pei Wang

    2008-10-01

    Full Text Available Two polysaccharides (APS-I and APS-II were isolated from the water extract of Radix Astragali and purified through ethanol precipitation, deproteination and by ion-exchange and gel-filtration chromatography. Their molecular weight was determined using high performance liquid chromatography and gel permeation chromatography (HPLC-GPC and their monosaccharide composition was analyzed by TLC and HPLC methods, using a refractive index detector (RID and an NH2 column. It was shown that APS-I consisted of arabinose and glucose and APS-II consisted of rhamnose, arabinose and glucose, in a molar ratio of 1:3.45 and 1:6.25:17.86, respectively. The molecular weights (Mw of APS-I and APS-II were 1,699,100 Da and 1,197,600 Da, respectively.

  16. Antioxidative and renoprotective effects of residue polysaccharides from Flammulina velutipes.

    Science.gov (United States)

    Lin, Lin; Cui, Fangyuan; Zhang, Jianjun; Gao, Xia; Zhou, Meng; Xu, Nuo; Zhao, Huajie; Liu, Min; Zhang, Chen; Jia, Le

    2016-08-01

    Three extractable polysaccharides including Ac-RPS, Al-RPS and En-RPS were extracted from the residue of Flammulina velutipes and their antioxidative and renoprotective effects on STZ-induced mice were investigated. Biochemical and antioxidant analysis showed that the En-RPS had potential effects in decreasing the serum levels of CRE, BUN, ALB and GLU significantly, increasing the renal activities of SOD, CAT and GSH-Px remarkably, and reducing the renal contents of MDA prominently. Furthermore, the histopathological observations also displayed that En-RPS could alleviate kidney damage. These results demonstrated that En-RPS extracted from the residue of F. velutipes possessed potent antioxidant activities, and could be used as a promising therapeutic agent for inhibiting the progression of diabetic nephropathy. In addition, the monosaccharide compositions of these three RPS were also analyzed. PMID:27112888

  17. Fixation of soil surface contamination using natural polysaccharides

    Energy Technology Data Exchange (ETDEWEB)

    Sackschewsky, M.R.

    1993-09-01

    Natural polysaccharides were evaluated as alternatives to commercially available dust-control agents for application in buried-waste and contaminated-soil remediation situations. Materials were identified and evaluated with specific criteria in mind: the materials must be environmentally benign and must not introduce any additional hazardous materials; they must be effective for at least 2 or 3 days, but they do not necessarily have to be effective for more than 2 to 3 weeks; they should be relatively resistant to light traffic; they must not interfere with subsequent soil treatment techniques, especially soil washing; and they must be relatively inexpensive. Two products, a pregelled potato starch and a mixture of carbohydrates derived from sugar beets, were selected for evaluation. Testing included small- and large-scale field demonstrations, laboratory physical property analyses, and wind-tunnel evaluations.

  18. Enzyme-like Activities of Algal Polysaccharide - Cerium Complexes

    Institute of Scientific and Technical Information of China (English)

    WANG Dongfeng; SUN Jipeng; DU Dehong; YE Shen; WANG Changhong; ZHOU Xiaoling; XUE Changhu

    2005-01-01

    Water-soluble algal polysaccharides (APS) (alginic acid, fucoidan and laminaran) possess many pharmacological activities. The results of this study showed that the APS- Ce4+ complexes have some enzyme-like activities. Fucoidan and its complex with Cea+ have activities similar to those of SOD. The activities of laminaran, alginic acid and their complexes are not measurable. The APS do not show measurable activities in the digestion of plasmid DNA. In contrast, the APS- Ce4+complexes show these measurable activities under the comparable condition when APS bind Ce4 + and form homogenous solutions. The laminaran- Ce4 + complex shows the most obvious activity in the digestion of plasmid DNA, pNPP and chloropyrifos under neutral conditions.

  19. Drugs composed of polysaccharides obtained from lipopolysaccharides extracted from bacteria

    International Nuclear Information System (INIS)

    This invention concerns a protection and control agent against irradiation in living beings, composed of polysaccharides, called PS, obtained from lipopolysaccharides (LPS), which in turn are extracted from Gram-negative bacteria after separation of the major part and preferably all the initial lipid content of these LPS's. The molecular weight of the PS ingredients, once purified, is between 8,000 and 35,000 and mainly around 10,000. They contain: around 50 to 70% carbon hydrates by weight; around 1 to 8% hexoamines by weight; around 1 to 5% amino-compounds, among which 1 to 2% amino-acids by weight less than 1% and preferably no fatty acids or lipids and their phosphorus content is around 0.2 to 0.5% by weight

  20. Fixation of soil surface contamination using natural polysaccharides

    International Nuclear Information System (INIS)

    Natural polysaccharides were evaluated as alternatives to commercially available dust-control agents for application in buried-waste and contaminated-soil remediation situations. Materials were identified and evaluated with specific criteria in mind: the materials must be environmentally benign and must not introduce any additional hazardous materials; they must be effective for at least 2 or 3 days, but they do not necessarily have to be effective for more than 2 to 3 weeks; they should be relatively resistant to light traffic; they must not interfere with subsequent soil treatment techniques, especially soil washing; and they must be relatively inexpensive. Two products, a pregelled potato starch and a mixture of carbohydrates derived from sugar beets, were selected for evaluation. Testing included small- and large-scale field demonstrations, laboratory physical property analyses, and wind-tunnel evaluations