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Sample records for arabinose

  1. L-arabinose fermenting yeast

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Min; Singh, Arjun; Suominen, Pirkko; Knoshaug, Eric; Franden, Mary Ann; Jarvis, Eric

    2014-09-23

    An L-arabinose utilizing yeast strain is provided for the production of ethanol by introducing and expressing bacterial araA, araB and araD genes. L-arabinose transporters are also introduced into the yeast to enhance the uptake of arabinose. The yeast carries additional genomic mutations enabling it to consume L-arabinose, even as the only carbon source, and to produce ethanol. A yeast strain engineered to metabolize arabinose through a novel pathway is also disclosed. Methods of producing ethanol include utilizing these modified yeast strains.

  2. L-arabinose fermenting yeast

    Science.gov (United States)

    Zhang, Min; Singh, Arjun; Suominen, Pirkko; Knoshaug, Eric; Franden, Mary Ann; Jarvis, Eric

    2013-02-12

    An L-arabinose utilizing yeast strain is provided for the production of ethanol by introducing and expressing bacterial araA, araB and araD genes. L-arabinose transporters are also introduced into the yeast to enhance the uptake of arabinose. The yeast carries additional genomic mutations enabling it to consume L-arabinose, even as the only carbon source, and to produce ethanol. A yeast strain engineered to metabolize arabinose through a novel pathway is also disclosed. Methods of producing ethanol include utilizing these modified yeast strains.

  3. L-arabinose metabolism in Azospirillum brasiliense.

    OpenAIRE

    Novick, N J; Tyler, M.E.

    1982-01-01

    An oxidative pathway by which L-arabinose is converted to alpha-ketoglutarate in crude extracts of Azospirillum brasiliense is demonstrated. Specific activities of enzymes involved in the pathway were determined, and several pathway intermediates were identified.

  4. Metabolism of L-arabinose in plants.

    Science.gov (United States)

    Kotake, Toshihisa; Yamanashi, Yukiko; Imaizumi, Chiemi; Tsumuraya, Yoichi

    2016-09-01

    L-Arabinose (L-Ara) is a plant-specific sugar accounting for 5-10 % of cell wall saccharides in Arabidopsis (Arabidopsis thaliana) and rice (Oryza sativa). L-Ara occurs in pectic arabinan, rhamnogalacturonan II, arabinoxylan, arabinogalactan-protein (AGP), and extensin in the cell walls, as well as in glycosylated signaling peptides like CLAVATA3 and small glycoconjugates such as quercetin 3-O-arabinoside. This review focuses on recent advances towards understanding the generation of L-Ara and the metabolism of L-Ara-containing molecules in plants. PMID:27220955

  5. Metabolic control analysis of Aspergillus niger L-arabinose catabolism

    DEFF Research Database (Denmark)

    de Groot, M.J.L.; Prathumpai, Wai; Visser, J.; Ruijter, G.J.G.

    2005-01-01

    A mathematical model of the L-arabinose/D-xylose catabolic pathway of Aspergillus niger was constructed based on the kinetic properties of the enzymes. For this purpose L-arabinose reductase, L-arabitol dehydrogenase and D-xylose reductase were purified using dye-affinity chromatography, and their...

  6. Sugar-metal ion interactions: The coordination behavior of cesium ion with lactose, D-arabinose and L-arabinose

    Science.gov (United States)

    Jiang, Ye; Xue, Junhui; Wen, Xiaodong; Zhai, Yanjun; Yang, Limin; Xu, Yizhuang; Zhao, Guozhong; Kou, Kuan; Liu, Kexin; Chen, Jia'er; Wu, Jinguang

    2016-04-01

    The novel cesium chloride-lactose complex (CsCl·C12H22O10 (Cs-Lac), cesium chloride-D-arabinose and L-arabinose complexes (CsCl·C5H10O5, Cs-D-Ara and Cs-L-Ara) have been synthesized and characterized using X-ray diffraction, FTIR, FIR, THz and Raman spectroscopies. Cs+ is 9-coordinated to two chloride ions and seven hydroxyl groups from five lactose molecules in Cs-Lac. In the structures of CsCl-D-arabinose and CsCl-L-arabinose complexes, two kinds of Cs+ ions coexist in the structures. Cs1 is 10-coordinated with two chloride ions and eight hydroxyl groups from five arabinose molecule; Cs2 is 9-coordinated to three chloride ions and six hydroxyl groups from five arabinose molecules. Two coordination modes of arabinose coexist in the structures. α-D-arabinopyranose and α-L-arabinopyranose appear in the structures of Cs-D-Ara and Cs-L-Ara complexes. FTIR and Raman results indicate variations of hydrogen bonds and the conformation of the ligands after complexation. FIR and THz spectra also confirm the formation of Cs-complexes. Crystal structure, FTIR, FIR, THz and Raman spectra provide detailed information on the structure and coordination of hydroxyl groups to metal ions in the cesium chloride-lactose, cesium chloride-D- and L-arabinose complexes.

  7. Preparation, spectroscopic and structural analysis of uranium-arabinose complexes

    International Nuclear Information System (INIS)

    The reaction between L-arabinose and hydrated uranyl salts has been investigated in aqueous solution and the solid complexes of the type UO2(L-arabinose)X2·2H2O, where X=Cl-, Br-, and NO3-, have been isolated and characterized. Due to the marked similarities with those of the structurally known Ca(L-arabinose)X2·4H2O and Mg(L-arabinose)X2·4H2O (X=Cl- or Br-) compounds, the UO22+ ion binds obviously to two L-arabinose moieties, through O1, O5 of the first and O3, O4 of the second molecule resulting into a six-coordinated geometry around the uranium ion with no direct U-X (X=Cl-, Br- or NO3-) interaction. The intermolecular hydrogen bonding network of the free L-arabinose is rearranged upon uranium interaction. The β-anomer configuration is predominant in the free L-arabinose, whereas the α-anomer conformation is preferred in the uranium complexes. (Author)

  8. Single zymomonas mobilis strain for xylose and arabinose fermentation

    Science.gov (United States)

    Zhang, Min; Chou, Yat-Chen; Picataggio, Stephen K.; Finkelstein, Mark

    1998-01-01

    This invention relates to single microorganisms which normally do not ferment pentose sugars which are genetically altered to ferment the pentose sugars, xylose and arabinose, to produce ethanol, and a fermentation process utilizing the same. Examples include Zymomonas mobilis which has been transformed with a combination of E. coli genes for xylose isomerase, xylulokinase, L-arabinose isomerase, L-ribulokinase, L-ribulose 5-phosphate 4-epimerase, transaldolase and transketolase. Expression of added genes are under the control of Z. mobilis promoters. These newly created microorganisms are useful for fermenting glucose, xylose and arabinose, produced by hydrolysis of hemicellulose and cellulose or starch, to produce ethanol.

  9. Characterization of an L-arabinose isomerase from Bacillus subtilis

    DEFF Research Database (Denmark)

    Kim, Jin-Ha; Prabhu, Ponnandy; Jeya, Marimuthu;

    2010-01-01

    An isolated gene from Bacillus subtilis str. 168 encoding a putative isomerase was proposed as an L-arabinose isomerase (L-AI), cloned into Escherichia coli, and its nucleotide sequence was determined. DNA sequence analysis revealed an open reading frame of 1,491 bp, capable of encoding a polypep......An isolated gene from Bacillus subtilis str. 168 encoding a putative isomerase was proposed as an L-arabinose isomerase (L-AI), cloned into Escherichia coli, and its nucleotide sequence was determined. DNA sequence analysis revealed an open reading frame of 1,491 bp, capable of encoding...

  10. Extreme thermophilic biohydrogen production from arabinose and glucose

    OpenAIRE

    Abreu, A. A.; Karakashev, Dimitar; Angelidaki, I.; Sousa, D.Z.; Alves, M. M.

    2013-01-01

    Continuous hydrogen production rate from arabinose was significantly higher than from glucose, when higher organic loading rate was used. This fact was associated to higher lactate production in the reactor fed with glucose. The higher concentration of lactate was not a consequence of bacterial community shift, and is likely related to changes in the main metabolic pathways of glucose catabolism.

  11. Improved xylose and arabinose utilization by an industrial recombinant Saccharomyces cerevisiae strain using evolutionary engineering

    DEFF Research Database (Denmark)

    Sanchez, R.G.; Karhumaa, Kaisa; Fonseca, C.;

    2010-01-01

    xylose and arabinose under aerobic and anaerobic conditions. Improved anaerobic ethanol production was achieved at the expense of xylitol and glycerol but arabinose was almost stoichiometrically converted to arabitol. Further characterization of the strain indicated that the selection pressure during...

  12. Integrated Process of Arabinose Biopurification and Xylitol Fermentation Based on the Diverse Action of Candida boidinii

    OpenAIRE

    Fehér, C.; Gazsó, Z.; Gál, B.; Kontra, A.; Barta, Z.; Réczey, K.

    2016-01-01

    Hemicellulosic hydrolysates of agro-residues are promising raw materials for xylitol and arabinose production through biotechnological methods. Two-step acidic fractionation of corn fibre was developed to produce a glucose- and arabinose-rich hydrolysate and a xylose-rich hydrolysate. An integrated process of arabinose biopurification on the glucose- and arabinose-rich hydrolysate and xylitol fermentation on the xylose-rich hydrolysate using Candida boidinii NCAIM Y.01308 was introduced, i...

  13. Microbial Production of Xylitol from L-arabinose by Metabolically Engineered Escherichia coli

    Science.gov (United States)

    An Escherichia coli strain, ZUC99(pATX210), which can produce xylitol from L-arabinose at a high yield has been created by introducing a new bioconversion pathway into cells. This pathway consists of three enzymes: L-arabinose isomerase, which converts L-arabinose to L-ribulose; D-psicose 3-epimer...

  14. Improving L-arabinose utilization of pentose fermenting Saccharomyces cerevisiae cells by heterologous expression of L-arabinose transporting sugar transporters

    Directory of Open Access Journals (Sweden)

    Boles Eckhard

    2011-10-01

    Full Text Available Abstract Background Hydrolysates of plant biomass used for the production of lignocellulosic biofuels typically contain sugar mixtures consisting mainly of D-glucose and D-xylose, and minor amounts of L-arabinose. The yeast Saccharomyces cerevisiae is the preferred microorganism for the fermentative production of ethanol but is not able to ferment pentose sugars. Although D-xylose and L-arabinose fermenting S. cerevisiae strains have been constructed recently, pentose uptake is still a limiting step in mixed sugar fermentations. Results Here we described the cloning and characterization of two sugar transporters, AraT from the yeast Scheffersomyces stipitis and Stp2 from the plant Arabidopsis thaliana, which mediate the uptake of L-arabinose but not of D-glucose into S. cerevisiae cells. A yeast strain lacking all of its endogenous hexose transporter genes and expressing a bacterial L-arabinose utilization pathway could no longer take up and grow with L-arabinose as the only carbon source. Expression of the heterologous transporters supported uptake and utilization of L-arabinose especially at low L-arabinose concentrations but did not, or only very weakly, support D-glucose uptake and utilization. In contrast, the S. cerevisiae D-galactose transporter, Gal2, mediated uptake of both L-arabinose and D-glucose, especially at high concentrations. Conclusions Using a newly developed screening system we have identified two heterologous sugar transporters from a yeast and a plant which can support uptake and utilization of L-arabinose in L-arabinose fermenting S. cerevisiae cells, especially at low L-arabinose concentrations.

  15. Microbial conversion of L-arabinose to xylitol by coexpression of L-arabinose isomerase, D-tagatose 3-epimerase, and L-xylulose reductase in Escherichia coli

    Science.gov (United States)

    A microbial strain has been developed that can produce xylitol from L-arabinose at a high yield by transforming Escherichia coli with a new xylitol biosynthetic pathway consisting of L-arabinose isomerase, D-tagatose 3-epimerase, and L-xylulose reductase. An E. coli strain that heterologously expre...

  16. Overexpression, purification, crystallization and preliminary X-ray crystal analysis of Bacillus pallidusd-arabinose isomerase

    International Nuclear Information System (INIS)

    Recombinant B. pallidusd-arabinose isomerase was crystallized and diffraction data were collected to 2.3 Å resolution. d-Arabinose isomerase catalyzes the isomerization of d-arabinose to d-ribulose. Bacillus pallidusd-arabinose isomerase has broad substrate specificity and can catalyze the isomerization of d-arabinose, l-fucose, l-xylose, l-galactose and d-altrose. Recombinant B. pallidusd-arabinose isomerase was overexpressed, purified and crystallized. A crystal of the enzyme was obtained by the sitting-drop method at room temperature and belonged to the orthorhombic space group P21212, with unit-cell parameters a = 144.9, b = 127.9, c = 109.5 Å. Diffraction data were collected to 2.3 Å resolution

  17. Molecular cloning of the Escherichia coli B L-fucose-D-arabinose gene cluster.

    OpenAIRE

    Elsinghorst, E A; Mortlock, R. P.

    1994-01-01

    To metabolize the uncommon pentose D-arabinose, enteric bacteria often recruit the enzymes of the L-fucose pathway by a regulatory mutation. However, Escherichia coli B can grow on D-arabinose without the requirement of a mutation, using some of the L-fucose enzymes and a D-ribulokinase that is distinct from the L-fuculokinase of the L-fucose pathway. To study this naturally occurring D-arabinose pathway, we cloned and partially characterized the E. coli B L-fucose-D-arabinose gene cluster an...

  18. Regulation of D-arabinose utilization in Escherichia coli K-12.

    OpenAIRE

    Skjold, A C; Ezekiel, D. H.

    1982-01-01

    Studies involving lambda phage transduction of the D-arabinose utilization gene (dar+) in Escherichia coli K-12 indicated the product of this gene to be a transdominant activator. An apparent anomaly regarding this hypothesis exists in that a diploid recessive lysogen (lambda dar-/dar-) can spontaneously become capable of growth on D-arabinose.

  19. Utilization and Transport of L-Arabinose by Non-Saccharomyces Yeasts

    Energy Technology Data Exchange (ETDEWEB)

    Knoshaug, E. P.; Franden, M. A.; Stambuk, B. U.; Zhang, M.; Singh, A.

    2009-01-01

    L-Arabinose is one of the sugars found in hemicellulose, a major component of plant cell walls. The ability to convert L-arabinose to ethanol would improve the economics of biomass to ethanol fermentations. One of the limitations for L-arabinose fermentation in the current engineered Saccharomyces cerevisiae strains is poor transport of the sugar. To better understand L-arabinose transport and use in yeasts and to identify a source for efficient L-arabinose transporters, 165 non-Saccharomyces yeast strains were studied. These yeast strains were arranged into six groups based on the minimum time required to utilize 20 g/L of L-arabinose. Initial transport rates of L-arabinose were determined for several species and a more comprehensive transport study was done in four selected species. Detailed transport kinetics in Arxula adeninivorans suggested both low and high affinity components while Debaryomyces hansenii var. fabryii, Kluyveromyces marxianus and Pichia guilliermondii possessed a single component, high affinity active transport systems.

  20. Photocaged Arabinose: A Novel Optogenetic Switch for Rapid and Gradual Control of Microbial Gene Expression.

    Science.gov (United States)

    Binder, Dennis; Bier, Claus; Grünberger, Alexander; Drobietz, Dagmar; Hage-Hülsmann, Jennifer; Wandrey, Georg; Büchs, Jochen; Kohlheyer, Dietrich; Loeschcke, Anita; Wiechert, Wolfgang; Jaeger, Karl-Erich; Pietruszka, Jörg; Drepper, Thomas

    2016-02-15

    Controlling cellular functions by light allows simple triggering of biological processes in a non-invasive fashion with high spatiotemporal resolution. In this context, light-regulated gene expression has enormous potential for achieving optogenetic control over almost any cellular process. Here, we report on two novel one-step cleavable photocaged arabinose compounds, which were applied as light-sensitive inducers of transcription in bacteria. Exposure of caged arabinose to UV-A light resulted in rapid activation of protein production, as demonstrated for GFP and the complete violacein biosynthetic pathway. Moreover, single-cell analysis revealed that intrinsic heterogeneity of arabinose-mediated induction of gene expression was overcome when using photocaged arabinose. We have thus established a novel phototrigger for synthetic bio(techno)logy applications that enables precise and homogeneous control of bacterial target gene expression. PMID:26677142

  1. D-arabinose metabolism in Escherichia coli B: induction and cotransductional mapping of the L-fucose-D-arabinose pathway enzymes.

    OpenAIRE

    Elsinghorst, E A; Mortlock, R. P.

    1988-01-01

    D-Arabinose is degraded by Escherichia coli B via some of the L-fucose pathway enzymes and a D-ribulokinase which is distinct from the L-fuculokinase of the L-fucose pathway. We found that L-fucose and D-arabinose acted as the apparent inducers of the enzymes needed for their degradation. These enzymes, including D-ribulokinase, appeared to be coordinately regulated, and mutants which constitutively synthesized the L-fucose enzymes also constitutively synthesized D-ribulokinase. In contrast t...

  2. Bioprospecting and evolving alternative xylose and arabinose pathway enzymes for use in Saccharomyces cerevisiae.

    Science.gov (United States)

    Lee, Sun-Mi; Jellison, Taylor; Alper, Hal S

    2016-03-01

    Bioprospecting is an effective way to find novel enzymes from strains with desirable phenotypes. Such bioprospecting has enabled organisms such as Saccharomyces cerevisiae to utilize nonnative pentose sugars. Yet, the efficiency of this pentose catabolism (especially for the case of arabinose) remains suboptimal. Thus, further pathway optimization or identification of novel, optimal pathways is needed. Previously, we identified a novel set of xylan catabolic pathway enzymes from a superior pentose-utilizing strain of Ustilago bevomyces. These enzymes were used to successfully engineer a xylan-utilizing S. cerevisiae through a blended approach of bioprospecting and evolutionary engineering. Here, we expanded this approach to xylose and arabinose catabolic pathway engineering and demonstrated that bioprospected xylose and arabinose catabolic pathways from U. bevomyces offer alternative choices for enabling efficient pentose catabolism in S. cerevisiae. By introducing a novel set of xylose catabolic genes from U. bevomyces, growth rates were improved up to 85 % over a set of traditional Scheffersomyces stipitis pathway genes. In addition, we suggested an alternative arabinose catabolic pathway which, after directed evolution and pathway engineering, enabled S. cerevisiae to grow on arabinose as a sole carbon source in minimal medium with growth rates upwards of 0.05 h(-1). This pathway represents the most efficient growth of yeast on pure arabinose minimal medium. These pathways provide great starting points for further strain development and demonstrate the utility of bioprospecting from U. bevomyces. PMID:26671616

  3. D-arabinose metabolism in Escherichia coli B: induction and cotransductional mapping of the L-fucose-D-arabinose pathway enzymes.

    Science.gov (United States)

    Elsinghorst, E A; Mortlock, R P

    1988-12-01

    D-Arabinose is degraded by Escherichia coli B via some of the L-fucose pathway enzymes and a D-ribulokinase which is distinct from the L-fuculokinase of the L-fucose pathway. We found that L-fucose and D-arabinose acted as the apparent inducers of the enzymes needed for their degradation. These enzymes, including D-ribulokinase, appeared to be coordinately regulated, and mutants which constitutively synthesized the L-fucose enzymes also constitutively synthesized D-ribulokinase. In contrast to D-arabinose-positive mutants of E. coli K-12, in which L-fuculose-1-phosphate and D-ribulose-1-phosphate act as inducers of the L-fucose pathway, we found that these intermediates did not act as inducers in E. coli B. To further characterize the E. coli B system, some of the L-fucose-D-arabinose genes were mapped by using bacteriophage P1 transduction. A transposon Tn10 insertion near the E. coli B L-fucose regulon was used in two- and three-factor reciprocal crosses. The gene encoding D-ribulokinase, designated darK, was found to map within the L-fucose regulon, and the partial gene order was found to be Tn10-fucA-darK-fucI-fucK-thyA. PMID:3056899

  4. Identification and Functional Analysis of the Gene Cluster for l-Arabinose Utilization in Corynebacterium glutamicum▿ †

    OpenAIRE

    Kawaguchi, Hideo; Sasaki, Miho; Vertès, Alain A.; Inui, Masayuki; Yukawa, Hideaki

    2009-01-01

    Corynebacterium glutamicum ATCC 31831 grew on l-arabinose as the sole carbon source at a specific growth rate that was twice that on d-glucose. The gene cluster responsible for l-arabinose utilization comprised a six-cistron transcriptional unit with a total length of 7.8 kb. Three l-arabinose-catabolizing genes, araA (encoding l-arabinose isomerase), araB (l-ribulokinase), and araD (l-ribulose-5-phosphate 4-epimerase), comprised the araBDA operon, upstream of which three other genes, araR (L...

  5. Co-utilization of L-arabinose and D-xylose by laboratory and industrial Saccharomyces cerevisiae strains

    Directory of Open Access Journals (Sweden)

    Boles Eckhard

    2006-04-01

    Full Text Available Abstract Background Fermentation of lignocellulosic biomass is an attractive alternative for the production of bioethanol. Traditionally, the yeast Saccharomyces cerevisiae is used in industrial ethanol fermentations. However, S. cerevisiae is naturally not able to ferment the pentose sugars D-xylose and L-arabinose, which are present in high amounts in lignocellulosic raw materials. Results We describe the engineering of laboratory and industrial S. cerevisiae strains to co-ferment the pentose sugars D-xylose and L-arabinose. Introduction of a fungal xylose and a bacterial arabinose pathway resulted in strains able to grow on both pentose sugars. Introduction of a xylose pathway into an arabinose-fermenting laboratory strain resulted in nearly complete conversion of arabinose into arabitol due to the L-arabinose reductase activity of the xylose reductase. The industrial strain displayed lower arabitol yield and increased ethanol yield from xylose and arabinose. Conclusion Our work demonstrates simultaneous co-utilization of xylose and arabinose in recombinant strains of S. cerevisiae. In addition, the co-utilization of arabinose together with xylose significantly reduced formation of the by-product xylitol, which contributed to improved ethanol production.

  6. The mur4 mutant of arabidopsis is partially defective in the de novo synthesis of uridine diphospho L-arabinose

    Energy Technology Data Exchange (ETDEWEB)

    Burget, E.G.; Reiter, W.D.

    1999-10-01

    To obtain information on the synthesis and function of arabinosylated glycans, the mur4 mutant of arabidopsis was characterized. This mutation leads to a 50% reduction in the monosaccharide L-arabinose in most organs and affects arabinose-containing pectic cell wall polysaccharides and arabinogalactan proteins. Feeding L-arabinose to mur4 plants restores the cell wall composition to wild-type levels, suggesting a partial defect in the de novo synthesis of UDP-L-arabinose, the activated sugar used by arabinosyltransferases. The defect was traced to the conversion of UDP-D-xylose to UDP-L-arabinose in the microsome fraction of leaf material, indicating that mur4 plants are defective in a membrane-bound UDP-D-xylose 4-epimerase.

  7. Arabinose and ferulic acid rich pectic polysaccharides extracted from sugar beet pulp.

    NARCIS (Netherlands)

    Oosterveld, A.; Beldman, G.; Schols, H.A.; Voragen, A.G.J.

    1996-01-01

    Arabinose and ferulic acid rich polysaccharides were extracted from sugar beet pulp using two extraction methods: a sequential extraction with H2O (2 times), NaOH/EDTA (2 times), and 4 M NaOH (2 times; method A) and a sequential extraction in which the NaOH/EDTA extraction was replaced by an autocla

  8. Regulation and control of L-arabinose catabolism in Aspergillus niger

    NARCIS (Netherlands)

    Groot, de M.J.L.

    2005-01-01

    This thesis describes studies on the biochemical properties and regulation of L-arabinose metabolism and arabinan degrading enzymes of Aspergillus niger. We focused on the investigation of the catabolic pathway, firstly by isolating pathway specific regulatory mutants using a newly developed selecti

  9. A novel method to prepare L-Arabinose from xylose mother liquor by yeast-mediated biopurification

    Directory of Open Access Journals (Sweden)

    Lin Shuangjun

    2011-06-01

    Full Text Available Abstract Background L-arabinose is an important intermediate for anti-virus drug synthesis and has also been used in food additives for diets-controlling in recent years. Commercial production of L-arabinose is a complex progress consisting of acid hydrolysis of gum arabic, followed by multiple procedures of purification, thus making high production cost. Therefore, there is a biotechnological and commercial interest in the development of new cost-effective and high-performance methods for obtaining high purity grade L-arabinose. Results An alternative, economical method for purifying L-arabinose from xylose mother liquor was developed in this study. After screening 306 yeast strains, a strain of Pichia anomala Y161 was selected as it could effectively metabolize other sugars but not L-arabinose. Fermentation in a medium containing xylose mother liquor permitted enrichment of L-arabinose by a significant depletion of other sugars. Biochemical analysis of this yeast strain confirmed that its poor capacity for utilizing L-arabinose was due to low activities of the enzymes required for the metabolism of this sugar. Response surface methodology was employed for optimization the fermentation conditions in shake flask cultures. The optimum conditions were: 75 h fermentation time, at 32.5°C, in a medium containing 21% (v/v xylose mother liquor. Under these conditions, the highest purity of L-arabinose reached was 86.1% of total sugar, facilitating recovery of white crystalline L-arabinose from the fermentation medium by simple methods. Conclusion Yeast-mediated biopurification provides a dynamic method to prepare high purity of L-arabinose from the feedstock solution xylose mother liqour, with cost-effective and high-performance properties.

  10. Heterologous expression and characterization of Bacillus coagulans L-arabinose isomerase.

    Science.gov (United States)

    Zhou, Xingding; Wu, Jin Chuan

    2012-05-01

    Bacillus coagulans has been of great commercial interest over the past decade owing to its strong ability of producing optical pure L: -lactic acid from both hexose and pentose sugars including L: -arabinose with high yield, titer and productivity under thermophilic conditions. The L: -arabinose isomerase (L-AI) from Bacillus coagulans was heterologously over-expressed in Escherichia coli. The open reading frame of the L-AI has 1,422 nucleotides encoding a protein with 474 amino acid residues. The recombinant L-AI was purified to homogeneity by one-step His-tag affinity chromatography. The molecular mass of the enzyme was estimated to be 56 kDa by SDS-PAGE. The enzyme was most active at 70°C and pH 7.0. The metal ion Mn(2+) was shown to be the best activator for enzymatic activity and thermostability. The enzyme showed higher activity at acidic pH than at alkaline pH. The kinetic studies showed that the K (m), V (max) and k (cat)/K (m) for the conversion of L: -arabinose were 106 mM, 84 U/mg and 34.5 mM(-1)min(-1), respectively. The equilibrium ratio of L: -arabinose to L: -ribulose was 78:22 under optimal conditions. L: -ribulose (97 g/L) was obtained from 500 g/l of L: -arabinose catalyzed by the enzyme (8.3 U/mL) under the optimal conditions within 1.5 h, giving at a substrate conversion of 19.4% and a production rate of 65 g L(-1) h(-1). PMID:22806043

  11. Biohydrogen production from arabinose and glucose using extreme thermophilic anaerobic mixed cultures

    Directory of Open Access Journals (Sweden)

    Abreu Angela A

    2012-02-01

    Full Text Available Abstract Background Second generation hydrogen fermentation technologies using organic agricultural and forestry wastes are emerging. The efficient microbial fermentation of hexoses and pentoses resulting from the pretreatment of lingocellulosic materials is essential for the success of these processes. Results Conversion of arabinose and glucose to hydrogen, by extreme thermophilic, anaerobic, mixed cultures was studied in continuous (70°C, pH 5.5 and batch (70°C, pH 5.5 and pH 7 assays. Two expanded granular sludge bed (EGSB reactors, Rarab and Rgluc, were continuously fed with arabinose and glucose, respectively. No significant differences in reactor performance were observed for arabinose and glucose organic loading rates (OLR ranging from 4.3 to 7.1 kgCOD m-3 d-1. However, for an OLR of 14.2 kgCOD m-3 d-1, hydrogen production rate and hydrogen yield were higher in Rarab than in Rgluc (average hydrogen production rate of 3.2 and 2.0 LH2 L-1 d-1 and hydrogen yield of 1.10 and 0.75 molH2 mol-1substrate for Rarab and Rgluc, respectively. Lower hydrogen production in Rgluc was associated with higher lactate production. Denaturing gradient gel electrophoresis (DGGE results revealed no significant difference on the bacterial community composition between operational periods and between the reactors. Increased hydrogen production was observed in batch experiments when hydrogen partial pressure was kept low, both with arabinose and glucose as substrate. Sugars were completely consumed and hydrogen production stimulated (62% higher when pH 7 was used instead of pH 5.5. Conclusions Continuous hydrogen production rate from arabinose was significantly higher than from glucose, when higher organic loading rate was used. The effect of hydrogen partial pressure on hydrogen production from glucose in batch mode was related to the extent of sugar utilization and not to the efficiency of substrate conversion to hydrogen. Furthermore, at pH 7.0, sugars

  12. Effect of arabinose concentration on dark fermentation hydrogen production using different mixed cultures

    OpenAIRE

    Danko, Anthony S.; Abreu, A. A.; Alves, M. M.

    2008-01-01

    Dark fermentation hydrogen production from arabinose at concentrations ranging between 0 and 100 g/L was examined in batch assays for three different mixed anaerobic cultures, two suspended sludges (S1, S2) obtained from two different sludge digesters and one granular sludge (G) obtained from a brewery wastewater treatment plant. After elimination of the methanogenic activity by heat treatment, all mixed cultures produced hydrogen, and optimal hydrogen rates and yields were gen...

  13. Biohydrogen production from arabinose and glucose using extreme thermophilic anaerobic mixed cultures

    DEFF Research Database (Denmark)

    De Abreu, Angela Alexandra Valente; Karakashev, Dimitar Borisov; Angelidaki, Irini;

    2012-01-01

    . Results Conversion of arabinose and glucose to hydrogen, by extreme thermophilic anaerobic mixed cultures was studied in continuous (70oC, pH 5.5) and batch (70oC, pH 5.5 and pH 7) assays. Two EGSB reactors, Rarab and Rgluc, were continuously fed with arabinose and glucose, respectively. No significant...... differences in reactor performance were observed for arabinose and glucose organic loading rates (OLR) ranging from 4.3 to 7.1 kgCOD m-3 d-1. However, for an OLR of 14.2 kgCOD m-3 d-1, hydrogen production rate and hydrogen yield were higher in Rarab than in Rgluc (average hydrogen production rate of 3.2 and 2.......0 LH2 L-1 d-1 and hydrogen yield of 1.10 and 0.75 molH2 mol-1substrate for Rarab and Rgluc, respectively). Lower hydrogen production in Rgluc was associated with higher lactate production. DGGE results revealed no significant difference on the bacterial community composition between operational periods...

  14. Induction of L-arabinose isomerase in gamma-irradiated Escherichia coli

    International Nuclear Information System (INIS)

    Gamma irradiation of Escherichia coli B/r caused a dose-dependent inhibition of the capacity of the cells to synthesize L-arabinose isomerase in response to the inducer. At higher doses (18 krad and above), postirradiation incubation led to further inhibition of the capacity to synthesize L-arabinose isomerase, whereas cells receiving lower doses recovered from the damage to the enzyme synthesizing system following incubation. Cyclic AMP partially reversed the inhibitory effect on L-arabinose isomerase induction produced immediately after irradiation by all gamma-ray doses (up to 30 krad), but the enhanced inhibitory effect caused by induction in cells irradiated at higher doses could not be reversed by the nucleotide. It is suggested that although catabolite repression is partly responsible for causing the inhibition of the enzyme synthesizing capacity of the cells observed immediately after gamma irradiation, the enhanced inhibition caused by incubating cells irradiated at higher doses is not due to interference with the control mechanism regulated by catabolite repression

  15. A novel l-arabinose-responsive regulator discovered in the rice-blast fungus Pyricularia oryzae (Magnaporthe oryzae).

    Science.gov (United States)

    Klaubauf, Sylvia; Zhou, Miaomiao; Lebrun, Marc-Henri; de Vries, Ronald P; Battaglia, Evy

    2016-02-01

    In this study we identified the l-arabinose-responsive regulator of Pyricularia oryzae that regulates l-arabinose release and catabolism. Previously we identified the Zn2Cys6 transcription factor (TF), AraR, that has this role in the Trichocomaceae family (Eurotiales), but is absent in other fungi. Candidate Zn2Cys6 TF genes were selected according to their transcript profiles on l-arabinose. Deletion mutants of these genes were screened for their growth phenotype on l-arabinose. One mutant, named Δara1, was further analyzed. Our analysis demonstrated that Ara1 from P. oryzae is the functional analog of AraR from A. niger, while there is no significant sequence similarity between them. PMID:26790567

  16. Comparing the xylose reductase/xylitol dehydrogenase and xylose isomerase pathways in arabinose and xylose fermenting Saccharomyces cerevisiae strains

    Science.gov (United States)

    Bettiga, Maurizio; Hahn-Hägerdal, Bärbel; Gorwa-Grauslund, Marie F

    2008-01-01

    Background Ethanolic fermentation of lignocellulosic biomass is a sustainable option for the production of bioethanol. This process would greatly benefit from recombinant Saccharomyces cerevisiae strains also able to ferment, besides the hexose sugar fraction, the pentose sugars, arabinose and xylose. Different pathways can be introduced in S. cerevisiae to provide arabinose and xylose utilisation. In this study, the bacterial arabinose isomerase pathway was combined with two different xylose utilisation pathways: the xylose reductase/xylitol dehydrogenase and xylose isomerase pathways, respectively, in genetically identical strains. The strains were compared with respect to aerobic growth in arabinose and xylose batch culture and in anaerobic batch fermentation of a mixture of glucose, arabinose and xylose. Results The specific aerobic arabinose growth rate was identical, 0.03 h-1, for the xylose reductase/xylitol dehydrogenase and xylose isomerase strain. The xylose reductase/xylitol dehydrogenase strain displayed higher aerobic growth rate on xylose, 0.14 h-1, and higher specific xylose consumption rate in anaerobic batch fermentation, 0.09 g (g cells)-1 h-1 than the xylose isomerase strain, which only reached 0.03 h-1 and 0.02 g (g cells)-1h-1, respectively. Whereas the xylose reductase/xylitol dehydrogenase strain produced higher ethanol yield on total sugars, 0.23 g g-1 compared with 0.18 g g-1 for the xylose isomerase strain, the xylose isomerase strain achieved higher ethanol yield on consumed sugars, 0.41 g g-1 compared with 0.32 g g-1 for the xylose reductase/xylitol dehydrogenase strain. Anaerobic fermentation of a mixture of glucose, arabinose and xylose resulted in higher final ethanol concentration, 14.7 g l-1 for the xylose reductase/xylitol dehydrogenase strain compared with 11.8 g l-1 for the xylose isomerase strain, and in higher specific ethanol productivity, 0.024 g (g cells)-1 h-1 compared with 0.01 g (g cells)-1 h-1 for the xylose reductase

  17. Comparing the xylose reductase/xylitol dehydrogenase and xylose isomerase pathways in arabinose and xylose fermenting Saccharomyces cerevisiae strains

    Directory of Open Access Journals (Sweden)

    Hahn-Hägerdal Bärbel

    2008-10-01

    Full Text Available Abstract Background Ethanolic fermentation of lignocellulosic biomass is a sustainable option for the production of bioethanol. This process would greatly benefit from recombinant Saccharomyces cerevisiae strains also able to ferment, besides the hexose sugar fraction, the pentose sugars, arabinose and xylose. Different pathways can be introduced in S. cerevisiae to provide arabinose and xylose utilisation. In this study, the bacterial arabinose isomerase pathway was combined with two different xylose utilisation pathways: the xylose reductase/xylitol dehydrogenase and xylose isomerase pathways, respectively, in genetically identical strains. The strains were compared with respect to aerobic growth in arabinose and xylose batch culture and in anaerobic batch fermentation of a mixture of glucose, arabinose and xylose. Results The specific aerobic arabinose growth rate was identical, 0.03 h-1, for the xylose reductase/xylitol dehydrogenase and xylose isomerase strain. The xylose reductase/xylitol dehydrogenase strain displayed higher aerobic growth rate on xylose, 0.14 h-1, and higher specific xylose consumption rate in anaerobic batch fermentation, 0.09 g (g cells-1 h-1 than the xylose isomerase strain, which only reached 0.03 h-1 and 0.02 g (g cells-1h-1, respectively. Whereas the xylose reductase/xylitol dehydrogenase strain produced higher ethanol yield on total sugars, 0.23 g g-1 compared with 0.18 g g-1 for the xylose isomerase strain, the xylose isomerase strain achieved higher ethanol yield on consumed sugars, 0.41 g g-1 compared with 0.32 g g-1 for the xylose reductase/xylitol dehydrogenase strain. Anaerobic fermentation of a mixture of glucose, arabinose and xylose resulted in higher final ethanol concentration, 14.7 g l-1 for the xylose reductase/xylitol dehydrogenase strain compared with 11.8 g l-1 for the xylose isomerase strain, and in higher specific ethanol productivity, 0.024 g (g cells-1 h-1 compared with 0.01 g (g cells-1 h-1

  18. The Effect of D-(−-arabinose on Tyrosinase: An Integrated Study Using Computational Simulation and Inhibition Kinetics

    Directory of Open Access Journals (Sweden)

    Hong-Jian Liu

    2012-01-01

    Full Text Available Tyrosinase is a ubiquitous enzyme with diverse physiologic roles related to pigment production. Tyrosinase inhibition has been well studied for cosmetic, medicinal, and agricultural purposes. We simulated the docking of tyrosinase and D-(−-arabinose and found a binding energy of −4.5 kcal/mol for theup-formof D-(−-arabinose and −4.4 kcal/mol for thedown-form of D-(−-arabinose. The results of molecular dynamics simulation suggested that D-(−-arabinose interacts mostly with HIS85, HIS259, and HIS263, which are believed to be in the active site. Our kinetic study showed that D-(−-arabinose is a reversible, mixed-type inhibitor of tyrosinase (α-value =6.11±0.98, Ki=0.21±0.19 M. Measurements of intrinsic fluorescence showed that D-(−-arabinose induced obvious tertiary changes to tyrosinase (binding constant K=1.58±0.02 M−1, binding number n=1.49±0.06. This strategy of predicting tyrosinase inhibition based on specific interactions of aldehyde and hydroxyl groups with the enzyme may prove useful for screening potential tyrosinase inhibitors.

  19. Use of Trypan blue-Arabinose System in Photogalvanic Cell for Solar Energy Conversion and Storage

    OpenAIRE

    K. M. Gangotri*; Mohan Lal

    2014-01-01

    Photogalvanic effect was studied in the cell containing Trypan blue as photosensitizer in Arabinose-NaOH system. The conversion efficiency of the cell, fill factor and the cell performance were observed 0.80%, 0.23 and 140.0 minutes in dark respectively. The effects of different parameters on the electrical output of the cell were observed and current-voltage (i–V) characteristics of the cell were also studies. The photopotential and photocurrent were observed as 834 mV and 35...

  20. Biohydrogen production from arabinose and glucose using extreme thermophilic anaerobic mixed cultures

    OpenAIRE

    Abreu Angela A; Karakashev Dimitar; Angelidaki Irini; Sousa Diana Z; Alves M.

    2012-01-01

    Abstract Background Second generation hydrogen fermentation technologies using organic agricultural and forestry wastes are emerging. The efficient microbial fermentation of hexoses and pentoses resulting from the pretreatment of lingocellulosic materials is essential for the success of these processes. Results Conversion of arabinose and glucose to hydrogen, by extreme thermophilic, anaerobic, mixed cultures was studied in continuous (70°C, pH 5.5) and batch (70°C, pH 5.5 and pH 7) assays. T...

  1. A mixed diet supplemented with l-arabinose does not alter glycaemic or insulinaemic responses in healthy human subjects.

    Science.gov (United States)

    Halschou-Jensen, Kia; Bach Knudsen, Knud E; Nielsen, Søren; Bukhave, Klaus; Andersen, Jens R

    2015-01-01

    In addition to a yet-to-be published study showing arabinose to have an inhibiting effect on maltase, in vitro studies have shown l-arabinose to exert an inhibiting effect on small-intestinal sucrase and maltase and the consumption of a sucrose-rich drink containing l-arabinose to exert positive effects on postprandial blood glucose, insulin and C-peptide responses in humans. However, the effects of adding l-arabinose to mixed meals on the indices of glucose control are unknown. The purpose of the present study was to investigate whether the positive effects of l-arabinose added to a sugar drink could be reproduced in subjects consuming a mixed meal containing sucrose and/or starch from wheat flour. A total of seventeen healthy men participated in study 1, a randomised, double-blind, cross-over trial. In this study, the subjects consumed two different breakfast meals containing sucrose and starch from wheat flour (meal A) or starch from wheat flour (meal B) supplemented with 0, 5 and 10 % l-arabinose by weight after a 12 h fast. A total of six healthy men participated in study 2, a randomised, double-blind, cross-over trial. In this study, the subjects also consumed meal B served in two different textures and a liquid meal with maltose supplemented with 0 and 20 % l-arabinose. In addition, 1·5 g of paracetamol was chosen as an indirect marker to assess gastric emptying. Postprandial plasma glucose, insulin and C-peptide concentrations were measured regularly for 3 h. The results of the present study showed that the peak plasma concentration, time to reach peak plasma concentration or AUC values of glucose, insulin and C-peptide were not altered after consumption of the test meals. Overall, it was not possible to reproduce the beneficial effects of l-arabinose added to sucrose drinks when l-arabinose was mixed in a solid or semi-solid mixed meal. PMID:25400106

  2. A mixed diet supplemented with l-arabinose does not alter glycaemic or insulinaemic responses in healthy human subjects

    DEFF Research Database (Denmark)

    Halschou-Jensen, Kia; Knudsen, Knud E Bach; Nielsen, Soren;

    2015-01-01

    different textures and a liquid meal with maltose supplemented with 0 and 20% L-arabinose. In addition, 1•5 g of paracetamol was chosen as an indirect marker to assess gastric emptying. Postprandial plasma glucose, insulin and C-peptide concentrations were measured regularly for 3 h. The results...... of the present study showed that the peak plasma concentration, time to reach peak plasma concentration or AUC values of glucose, insulin and C-peptide were not altered after consumption of the test meals. Overall, it was not possible to reproduce the beneficial effects of L-arabinose added to sucrose drinks...

  3. Microbial production of xylitol from xylose and L-arabinose: conversion of L-arabitol to xylitol using bacterial oxidoreductases

    Science.gov (United States)

    Microbial production of xylitol, using hemicellulosic biomass such as agricultural residues, is becoming more attractive for reducing its manufacturing cost. L-arabitol is a particular problem to xylitol production from hemicellulosic hydrolyzates that contain both xylose and L-arabinose because it...

  4. Simultaneous utilization of glucose, xylose and arabinose in the presence of acetate by a consortium of Escherichia coli strains

    Directory of Open Access Journals (Sweden)

    Xia Tian

    2012-06-01

    Full Text Available Abstract Background The efficient microbial utilization of lignocellulosic hydrolysates has remained challenging because this material is composed of multiple sugars and also contains growth inhibitors such as acetic acid (acetate. Using an engineered consortium of strains derived from Escherichia coli C and a synthetic medium containing acetate, glucose, xylose and arabinose, we report on both the microbial removal of acetate and the subsequent simultaneous utilization of the sugars. Results In a first stage, a strain unable to utilize glucose, xylose and arabinose (ALS1392, strain E. coli C ptsG manZ glk crr xylA araA removed 3 g/L acetate within 30 hours. In a subsequent second stage, three E. coli strains (ALS1370, ALS1371, ALS1391, which are each engineered to utilize only one sugar, together simultaneously utilized glucose, xylose and arabinose. The effect of non-metabolizable sugars on the metabolism of the target sugar was minimal. Additionally the deletions necessary to prevent the consumption of one sugar only minimally affected the consumption of a desired sugar. For example, the crr deletion necessary to prevent glucose consumption reduced xylose and arabinose utilization by less than 15% compared to the wild-type. Similarly, the araA deletion used to exclude arabinose consumption did not affect xylose- and glucose-consumption. Conclusions Despite the modest reduction in the overall rate of sugar consumption due to the various deletions that were required to generate the consortium of strains, the approach constitutes a significant improvement in any single-organism approach to utilize sugars found in lignocellulosic hydrolysate in the presence of acetate.

  5. Arabinose-rich polymers as an evolutionary strategy to plasticize resurrection plant cell walls against desiccation.

    Science.gov (United States)

    Moore, John P; Nguema-Ona, Eric E; Vicré-Gibouin, Mäite; Sørensen, Iben; Willats, William G T; Driouich, Azeddine; Farrant, Jill M

    2013-03-01

    A variety of Southern African resurrection plants were surveyed using high-throughput cell wall profiling tools. Species evaluated were the dicotyledons, Myrothamnus flabellifolia and Craterostigma plantagineum; the monocotyledons, Xerophyta viscosa, Xerophyta schlecterii, Xerophyta humilis and the resurrection grass Eragrostis nindensis, as well as a pteridophyte, the resurrection fern, Mohria caffrorum. Comparisons were made between hydrated and desiccated leaf and frond material, with respect to cell wall composition and polymer abundance, using monosaccharide composition analysis, FT-IR spectroscopy and comprehensive microarray polymer profiling in combination with multivariate data analysis. The data obtained suggest that three main functional strategies appear to have evolved to prepare plant cell walls for desiccation. Arabinan-rich pectin and arabinogalactan proteins are found in the resurrection fern M. caffrorum and the basal angiosperm M. flabellifolia where they appear to act as 'pectic plasticizers'. Dicotyledons with pectin-rich walls, such as C. plantagineum, seem to use inducible mechanisms which consist of up-regulating wall proteins and osmoprotectants. The hemicellulose-rich walls of the grass-like Xerophyta spp. and the resurrection grass E. nindensis were found to contain highly arabinosylated xylans and arabinogalactan proteins. These data support a general mechanism of 'plasticising' the cell walls of resurrection plants to desiccation and implicate arabinose-rich polymers (pectin-arabinans, arabinogalactan proteins and arabinoxylans) as the major contributors in ensuring flexibility is maintained and rehydration is facilitated in these plants. PMID:23117392

  6. Comparison of histamine and hyperosmotic arabinose infusion on brain capillary permeability to hydrophilic solutes

    International Nuclear Information System (INIS)

    The effect of bilateral intracarotid infusion of histamine (HA) on capillary permeability-surface area products (PS) of two metabolically inert tracers was determined and compared to that of L(+)arabinose (ARAB) in rat brain. Ringer's solution alone, or with 1 mg/kg HA diphosphate or 1.6M ARAB added, was infused (0.9 ml over 0.5 min) into each external carotid artery (CA). Five minutes later, a bolus of 14C-sucrose and 3H-L-glucose was injected i.v. Estimates of PS for both tracers were computed by the method of Ohno et al after brain concentration was corrected for tracer within cerebral blood vessels. Brain blood volume, based on the 14C-dextran space, was the same (.016 ml/g) in discrete cortical and midbrain regions of all rats except those treated with ARAB. The latter yielded .033 ml/g, presumably due to dextran extravasation. Infusion of ARAB, HA and Ringer's increased the PS's of sucrose and L-glucose by 10x, 8x, and 3x in brain regions perfused by the internal CA's. The ratio, PS-sucrose/PS-L-glucose was unchanged by any treatment. Both ARAB and HA caused transient falls in arterial pressure, but only ARAB caused deaths (3 of 9 rats). While as effective as ARAB in opening the blood-brain barrier, HA may be safer than hyperosmotic shock to enhance delivery of chemotherapeutic agents to brain tumors

  7. Translocation and interactions of L-arabinose in OmpF porin: A molecular dynamics study

    International Nuclear Information System (INIS)

    The passage of a natural substrate, L-arabinose (L-ARA) through Escherichia coli porin embedded in an artificial bilayer, is studied by equilibrium molecular dynamics simulations. We investigate the early stage of translocation process of L-ARA from intra-cellular to extra-cellular side (Int-to-Ext) across the bilayer. The average trajectory path over all L-ARA molecules along with quantum-mechanical configuration-optimizations at PM3 level predict the existence of at least three trapping zones. The common feature within all these zones is that L-ARA remains perpendicular to the channel axis. It is remarkable how the orientation and translational-rotational motion of L-ARA molecule play a role in its transport through OmpF channel. These simulations are important for better understanding of permeation process in OmpF channel. They also provide an insight into the chiral recognition of translocation process in protein nanochannels from substrate and protein prospects and help interpret experiments on permeation process of small dipolar molecules across biological membranes

  8. Estimation of D-Arabinose by Gas Chromatography/Mass Spectrometry as Surrogate for Mycobacterial Lipoarabinomannan in Human Urine.

    Directory of Open Access Journals (Sweden)

    Prithwiraj De

    Full Text Available Globally, tuberculosis is slowly declining each year and it is estimated that 37 million lives were saved between 2000 and 2013 through effective diagnosis and treatment. Currently, diagnosis relies on demonstration of the bacteria, Mycobacterium tuberculosis (Mtb, in clinical specimens by serial sputum microscopy, culture and molecular testing. Commercial immunoassay lateral flow kits developed to detect Mtb lipoglycan lipoarabinomannan (LAM in urine as a marker of active TB exhibit poor sensitivity, especially in immunocompetent individuals, perhaps due to low abundance of the analyte. Our present study was designed to develop methods to validate the presence of LAM in a quantitative fashion in human urine samples obtained from culture-confirmed TB patients. Herein we describe, a consolidated approach for isolating LAM from the urine and quantifying D-arabinose as a proxy for LAM, using Gas Chromatography/Mass Spectrometry. 298 urine samples obtained from a repository were rigorously analyzed and shown to contain varying amounts of LAM-equivalent ranging between ~10-40 ng/mL. To further substantiate that D-arabinose detected in the samples originated from LAM, tuberculostearic acid, the unique 10-methyloctadecanoic acid present at the phosphatidylinositol end of LAM was also analyzed in a set of samples and found to be present confirming that the D-arabinose was indeed derived from LAM. Among the 144 samples from culture-negative TB suspects, 30 showed presence of D-arabinose suggesting another source of the analyte, such as disseminated TB or from non-tuberculosis mycobacterium. Our work validates that LAM is present in the urine samples of culture-positive patients in small but readily detectable amounts. The study further substantiates LAM in urine as a powerful biomarker for active tuberculosis.

  9. Co-utilization of L-arabinose and D-xylose by laboratory and industrial Saccharomyces cerevisiae strains

    OpenAIRE

    Boles Eckhard; Hahn-Hägerdal Bärbel; Wiedemann Beate; Karhumaa Kaisa; Gorwa-Grauslund Marie-F

    2006-01-01

    Abstract Background Fermentation of lignocellulosic biomass is an attractive alternative for the production of bioethanol. Traditionally, the yeast Saccharomyces cerevisiae is used in industrial ethanol fermentations. However, S. cerevisiae is naturally not able to ferment the pentose sugars D-xylose and L-arabinose, which are present in high amounts in lignocellulosic raw materials. Results We describe the engineering of laboratory and industrial S. cerevisiae strains to co-ferment the pento...

  10. Crystal Structure of Escherichia coli L-Arabinose Isomerase (ECAI), The Putative Target of Biological Tagatose Production

    Energy Technology Data Exchange (ETDEWEB)

    Manjasetty,B.; Chance, M.

    2006-01-01

    Escherichia coli L-arabinose isomerase (ECAI; EC 5.3.1.4) catalyzes the isomerization of L-arabinose to L-ribulose in vivo. This enzyme is also of commercial interest as it catalyzes the conversion of D-galactose to D-tagatose in vitro. The crystal structure of ECAI was solved and refined at 2.6 Angstroms resolution. The subunit structure of ECAI is organized into three domains: an N-terminal, a central and a C-terminal domain. It forms a crystallographic trimeric architecture in the asymmetric unit. Packing within the crystal suggests the idea that ECAI can form a hexameric assembly. Previous electron microscopic and biochemical studies supports that ECAI is hexameric in solution. A comparison with other known structures reveals that ECAI adopts a protein fold most similar to E. coli fucose isomerase (ECFI) despite very low sequence identity 9.7%. The structural similarity between ECAI and ECFI with regard to number of domains, overall fold, biological assembly, and active site architecture strongly suggests that the enzymes have functional similarities. Further, the crystal structure of ECAI forms a basis for identifying molecular determinants responsible for isomerization of arabinose to ribulose in vivo and galactose to tagatose in vitro.

  11. Investigation of xylose and arabinose metabolism in Clostridium acetobutylicum ATCC 824 and Clostridium saccharobutylicum NCP 262.

    OpenAIRE

    Lesiak, Justyna Maria

    2015-01-01

    Xylulose kinase (xylB) and arabinose kinase (araK) mutants of Clostridium acetobutylicum and C. saccharobutylicum were investigated and compared to wild type strains, regarding their abilities to metabolize xylose, arabinose and glucose. To create mutants in C. saccharobutylicum, an effective triparental mating system for DNA transfer was developed, and additionally restrictase mutants were constructed and characterized. Furthermore, growth and gene expression of C. acetobutylicum in continuo...

  12. Novel transporters from Kluyveromyces marxianus and Pichia guilliermondii expressed in Saccharomyces cerevisiae enable growth on L-arabinose and D-xylose.

    Science.gov (United States)

    Knoshaug, Eric P; Vidgren, Virve; Magalhães, Frederico; Jarvis, Eric E; Franden, Mary Ann; Zhang, Min; Singh, Arjun

    2015-10-01

    Genes encoding L-arabinose transporters in Kluyveromyces marxianus and Pichia guilliermondii were identified by functional complementation of Saccharomyces cerevisiae whose growth on L-arabinose was dependent on a functioning L-arabinose transporter, or by screening a differential display library, respectively. These transporters also transport D-xylose and were designated KmAXT1 (arabinose-xylose transporter) and PgAXT1, respectively. Transport assays using L-arabinose showed that KmAxt1p has K(m) 263 mM and V(max) 57 nM/mg/min, and PgAxt1p has K(m) 0.13 mM and V(max) 18 nM/mg/min. Glucose, galactose and xylose significantly inhibit L-arabinose transport by both transporters. Transport assays using D-xylose showed that KmAxt1p has K(m) 27 mM and V(max) 3.8 nM/mg/min, and PgAxt1p has K(m) 65 mM and V(max) 8.7 nM/mg/min. Neither transporter is capable of recovering growth on glucose or galactose in a S. cerevisiae strain deleted for hexose and galactose transporters. Transport kinetics of S. cerevisiae Gal2p showed K(m) 371 mM and V(max) 341 nM/mg/min for L-arabinose, and K(m) 25 mM and V(max) 76 nM/mg/min for galactose. Due to the ability of Gal2p and these two newly characterized transporters to transport both L-arabinose and D-xylose, one scenario for the complete usage of biomass-derived pentose sugars would require only the low-affinity, high-throughput transporter Gal2p and one additional high-affinity general pentose transporter, rather than dedicated D-xylose or L-arabinose transporters. Additionally, alignment of these transporters with other characterized pentose transporters provides potential targets for substrate recognition engineering. PMID:26129747

  13. Production of the amino acids l-glutamate, l-lysine, l-ornithine and l-arginine from arabinose by recombinant Corynebacterium glutamicum.

    Science.gov (United States)

    Schneider, Jens; Niermann, Karin; Wendisch, Volker F

    2011-07-10

    Amino acid production processes with Corynebacterium glutamicum are based on media containing glucose from starch hydrolysis or fructose and sucrose as present in molasses. Simultaneous utilization of various carbon sources, including glucose, fructose and sucrose, in blends is a typical characteristic of this bacterium. The renewable non-food carbon source arabinose, which is present in hemicellulosic hydrolysates, cannot be utilized by most C. glutamicum strains. Heterologous expression of the araBAD operon from Escherichia coli in the wild-type and in an l-lysine producing strain of C. glutamicum was shown to enable production of l-glutamate and l-lysine, respectively, from arabinose as sole carbon source. l-Ornithine and l-arginine producing strains were constructed and shown to produce l-ornithine and l-arginine from arabinose when araBAD from E. coli was expressed. Moreover, the recombinant strains produced l-glutamate, l-lysine, l-ornithine and l-arginine respectively, from arabinose also when glucose-arabinose blends were used as carbon sources. PMID:20638422

  14. The acid-tolerant L-arabinose isomerase from the mesophilic Shewanella sp. ANA-3 is highly active at low temperatures

    Directory of Open Access Journals (Sweden)

    Rhimi Moez

    2011-11-01

    Full Text Available Abstract Background L-arabinose isomerases catalyse the isomerization of L-arabinose into L-ribulose at insight biological systems. At industrial scale of this enzyme is used for the bioconversion of D-galactose into D-tagatose which has many applications in pharmaceutical and agro-food industries. The isomerization reaction is thermodynamically equilibrated, and therefore the bioconversion rates is shifted towards tagatose when the temperature is increased. Moreover, to prevent secondary reactions it will be of interest to operate at low pH. The profitability of this D-tagatose production process is mainly related to the use of lactose as cheaper raw material. In many dairy products it will be interesting to produce D-tagatose during storage. This requires an efficient L-arabinose isomerase acting at low temperature and pH values. Results The gene encoding the L-arabinose isomerase from Shewanella sp. ANA-3 was cloned and overexpressed in Escherichia coli. The purified protein has a tetrameric arrangement composed by four identical 55 kDa subunits. The biochemical characterization of this enzyme showed that it was distinguishable by its maximal activity at low temperatures comprised between 15-35°C. Interestingly, this biocatalyst preserves more than 85% of its activity in a broad range of temperatures from 4.0 to 45°C. Shewanella sp. ANA-3 L-arabinose isomerase was also optimally active at pH 5.5-6.5 and maintained over 80% of its activity at large pH values from 4.0 to 8.5. Furthermore, this enzyme exhibited a weak requirement for metallic ions for its activity evaluated at 0.6 mM Mn2+. Stability studies showed that this protein is highly stable mainly at low temperature and pH values. Remarkably, T268K mutation clearly enhances the enzyme stability at low pH values. Use of this L-arabinose isomerase for D-tagatose production allows the achievement of attractive bioconversion rates of 16% at 4°C and 34% at 35°C. Conclusions Here we

  15. Surface activity evaluation of an arabinose ester as water/oil demulsifier at severe conditions of temperature, salinity and pH; Avaliacao da atividade superficial de um ester de arabinose, como desemulsificante agua/oleo, em condicoes severas de temperatura, salinidade e pH

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Mauricio Rodrigues; Garcia, Rosangela Balaban; Santos, Jaciara Alves dos; Vieira, Mariane; Silva, Luciana Carvalho; Campos, Viviane de Oliveira; Silva, Rayane Araujo da; Santos, Telma Pitanga dos [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2008-07-01

    This work had for objective to compare the superficial properties of an arabinose ester, no-ionic, nontoxic, biodegradable, with two commercial products: the first one based on sodium dodecyl sulfate and the second one based on poly-oxy alkylene phenol formaldehyde. The arabinose ester was synthesized on the Petroleum Research Laboratory - UFRN, through enzymatic catalysis by protease from Bacillus subtilis, using arabinose and vegetable oil, in organic medium. In previous work [1], this sugar ester was evaluated as a possible water/oil demulsifier and the results were compared with the results of the commercial product based on poly-oxy alkylene phenol formaldehyde, showing that, for certain reaction conditions, the sugar ester presented better acting (71%) that the commercial product (33%) as demulsifier. In this work, the stability of this arabinose ester was evaluated in severe conditions of temperature, salinity and pH, through superficial tests in a tensiometer, using Wilhelmy plate method and the results were compared with the results obtained for two commercial products above mentioned. (author)

  16. Hg (II) Catalysed Oxidation of D-Arabinose and D-Mannose by Acidic Solution of Potassium Permanganate: Kinetics and Mechanism

    OpenAIRE

    R. Naz; *R. Azmat; Qamar, N; 3N. I. Siddiqi

    2014-01-01

    The kinetics of Hg (II) catalyzed oxidation of D-Arabinose (Ara) and D-Mannose (Man) by potassium permanganate in acidic medium have been studied spectrophotometrically in the temperature range 30-50oC. The reactions exhibit first order kinetics with respect to [Man] and [MnO4-] while second order with [Ara]. The reaction rates were found to be unaffected by the change in [H+]. It has been observed that Hg (II) catalyzed the reaction but as the [Hg(II)] increases, reaction rate becomes indepe...

  17. Structure of the thermophilic l-Arabinose isomerase from Geobacillus kaustophilus reveals metal-mediated intersubunit interactions for activity and thermostability.

    Science.gov (United States)

    Choi, Jin Myung; Lee, Yong-Jik; Cao, Thinh-Phat; Shin, Sun-Mi; Park, Min-Kyu; Lee, Han-Seung; di Luccio, Eric; Kim, Seong-Bo; Lee, Sang-Jae; Lee, Sang Jun; Lee, Sung Haeng; Lee, Dong-Woo

    2016-04-15

    Thermophilic l-arabinose isomerase (AI), which catalyzes the interconversion of l-arabinose and l-ribulose, can be used to produce d-tagatose, a sugar substitute, from d-galactose. Unlike mesophilic AIs, thermophilic AIs are highly dependent on divalent metal ions for their catalytic activity and thermostability at elevated temperatures. However, the molecular basis underlying the substrate preferences and metal requirements of multimeric AIs remains unclear. Here we report the first crystal structure of the apo and holo forms of thermophilic Geobacillus kaustophilus AI (GKAI) in hexamer form. The structures, including those of GKAI in complex with l-arabitol, and biochemical analyses revealed not only how the substrate-binding site of GKAI is formed through displacement of residues at the intersubunit interface when it is bound to Mn(2+), but also revealed the water-mediated H-bonding networks that contribute to the structural integrity of GKAI during catalysis. These observations suggest metal-mediated isomerization reactions brought about by intersubunit interactions at elevated temperatures are responsible for the distinct active site features that promote the substrate specificity and thermostability of thermophilic AIs. PMID:26946941

  18. Hg (II Catalysed Oxidation of D-Arabinose and D-Mannose by Acidic Solution of Potassium Permanganate: Kinetics and Mechanism

    Directory of Open Access Journals (Sweden)

    *1R. Naz

    2014-09-01

    Full Text Available The kinetics of Hg (II catalyzed oxidation of D-Arabinose (Ara and D-Mannose (Man by potassium permanganate in acidic medium have been studied spectrophotometrically in the temperature range 30-50oC. The reactions exhibit first order kinetics with respect to [Man] and [MnO4-] while second order with [Ara]. The reaction rates were found to be unaffected by the change in [H+]. It has been observed that Hg (II catalyzed the reaction but as the [Hg(II] increases, reaction rate becomes independent. Negligible effect of ionic strength (μ on the rate of oxidation has also been noted which supports the presence of at least one neutral specie in the rate determining step. The rate of oxidation was influenced by the change in temperature. Various activation parameters have been calculated. Formic acid and erythronic acid were identified as main oxidation product in case of arabinose while for mannose formic acid and arabinonic acid were identified. A mechanism consistent with the above findings has also been proposed.

  19. Role of materials released from Escherichia coli cells in the catabolite repression of L-arabinose isomerase induced by γ-irradiation

    International Nuclear Information System (INIS)

    Inhibition of L-arabinose isomerase synthesizing capacity of Escherichia coli by γ-irradiation was withdrawn when the irradiated cells were separated by centrifugation from the suspending medium and were suspended in a fresh growth medium. Further, there was an inhibition of the induced enzyme synthesis in unirradiated cells when suspended in the supernatant from γ-irradiated cell suspension. These findings suggested that some inhibitory material(s) was released from γ-irradiated cells into the suspending medium. Incubation of γ-irradiated cells suspended in fresh growth medium led to an exponential decrease in the enzyme synthesizing capacity, which was not caused by release of any inhibitory material. Cyclic AMP could reverse the inhibition of the enzyme synthesizing capacity in unirradiated cells caused by their suspension in the supernatant from γ-irradiated cell suspension immediately following irradiation suggesting that catabolite repression is the cause of the inhibition. Incubation of γ-irradiated cell suspension released the L-arabinose isomerase-synthesizing system from the catabolite repression. (author). 9 refs., 4 figs

  20. Synthesis and modifications of heterocyclic derivatives of D-arabinose: potential inhibitors of glucose-6-phosphate isomerase and glucosamine-6-phosphate synthase

    International Nuclear Information System (INIS)

    The synthesis of -5-(D-arabino-1,2,3,4-tetrahydroxybutyl)tetrazole and -2-(d-arabino-1,2,3,4-tetra-acetoxybutyl)-5-methyl-1,3,4-oxadiazole from d-arabinose is described. Attempts at removing the protecting groups of the oxadiazole derivative were unsuccessful, leading to products resulting from the opening of the oxadiazole ring. The unprotected tetrazole derivative was selectively phosphorylated at the primary hydroxyl group with diethyl phosphoryl chloride. The resulting 5-[d-arabino-4-(diethylphosphoryloxy)-1,2,3-trihydroxybutyl]tetrazole is a protected form of a potential inhibitor of the enzymes glucose-6-phosphate isomerase and glucosamine synthase. (author)

  1. Conversion of hemicellulose sugars catalyzed by formic acid: kinetics of the dehydration of D-xylose, L-arabinose, and D-glucose.

    Science.gov (United States)

    Dussan, Karla; Girisuta, Buana; Lopes, Marystela; Leahy, James J; Hayes, Michael H B

    2015-04-24

    The pre-treatment of lignocellulosic biomass produces a liquid stream of hemicellulose-based sugars, which can be further converted to high-value chemicals. Formosolv pulping and the Milox process use formic acid as the fractionating agent, which can be used as the catalyst for the valorisation of hemicellulose sugars to platform chemicals. The objective of this study was to investigate the reaction kinetics of major components in the hemicelluloses fraction of biomass, that is, D-xylose, L-arabinose and D-glucose. The kinetics experiments for each sugar were performed at temperatures between 130 and 170 °C in various formic acid concentrations (10-64 wt %). The implications of these kinetic models on the selectivity of each sugar to the desired products are discussed. The models were used to predict the reaction kinetics of solutions that resemble the liquid stream obtained from the fractionation process of biomass using formic acid. PMID:25821128

  2. KINETIKA FERMENTASI PADA PRODUKSI XILITOL DENGAN PENAMBAHAN ARABINOSA DAN GLUKOSA SEBAGAI KOSUBSTRAT OLEH Candida shehatae WAY 08 [A Kinetic Study of Xylitol Production with Glucose and Arabinose as Cosubstrate by Candida shehatae WAY 08

    Directory of Open Access Journals (Sweden)

    Wisnu Adi Yulianto1

    2005-12-01

    Full Text Available Xylitol production by Candida shehatae WAY 08 was investigated under two sets of conditions (a with addition of glucose or arabinose as cosubstrate, (b ratio of xylose to cosubstrate at the range of 6:1— 6:3%. The fermentation was performed at 3000/n 500 ml Erlenmeyer flasks placed in a shaker incubator at 200 rpm for 72 h. Biornass concentration was calculated as dry mass. Xylose. cosubstrate. xylitol, ethanol, and acetic acid concentrator ware determined using API. C.The result indicated that addition of arabinose as cosubstrate to xylose within the ratio range of 1:6—3:6% could increase xylitol production. The highest xylitol yield (0,84 gIg and volumetric rate of xylitol production (0.66 g/Lh were achieved at ratio of xylose to arabinose as high as 6:1%. However, addition of glucose as cosubstrate decreased xylitul production. A medium containing 6% glucose as a sole carbon source could achieve the hiqhest ethanol yield(0.32 g/g and growth yièld (0,21/ gIg. wh;/e arabinose as a sole source was metabolized mainly for biomoss formation.

  3. Molecular characterization of two Arabidopsis thaliana glycosyltransferase mutants, rra1 and rra2, which have a reduced residual arabinose content in a polymer tightly associated with the cellulosic wall residue

    DEFF Research Database (Denmark)

    Egelund, Jack; Obel, Nicolai; Ulvskov, Peter;

    2007-01-01

    Two putative glycosyltransferases in Arabidopsis thaliana, designated reduced residual arabinose-1 and -2 (RRA1 and RRA2), are characterized at the molecular level. Both genes are classified in CAZy GT-family-77 and are phylogenetically related to putative glycosyltranferases of Chlamydomonas...

  4. The Aspergillus niger D-xylulose kinase gene is co-expressed with genes encoding arabinan degrading enzymes, and is essential for growth on D-xylose and L-arabinose

    NARCIS (Netherlands)

    Kuyck, van P.A.; Groot, de M.J.L.; Ruijter, G.J.G.; Vries, de R.P.; Visser, J.

    2001-01-01

    The Aspergillus nigerd-xylulose kinase encoding gene has been cloned by complementation of a strain deficient in d-xylulose kinase activity. Expression of xkiA was observed in the presence of l-arabinose, l-arabitol and d-xylose. Expression of xkiA is not mediated by XLNR, the xylose-dependent posit

  5. A method for the production of D-tagatose using a recombinant Pichia pastoris strain secreting β-D-galactosidase from Arthrobacter chlorophenolicus and a recombinant L-arabinose isomerase from Arthrobacter sp. 22c

    Directory of Open Access Journals (Sweden)

    Wanarska Marta

    2012-08-01

    Full Text Available Abstract Background D-Tagatose is a natural monosaccharide which can be used as a low-calorie sugar substitute in food, beverages and pharmaceutical products. It is also currently being tested as an anti-diabetic and obesity control drug. D-Tagatose is a rare sugar, but it can be manufactured by the chemical or enzymatic isomerization of D-galactose obtained by a β-D-galactosidase-catalyzed hydrolysis of milk sugar lactose and the separation of D-glucose and D-galactose. L-Arabinose isomerases catalyze in vitro the conversion of D-galactose to D-tagatose and are the most promising enzymes for the large-scale production of D-tagatose. Results In this study, the araA gene from psychrotolerant Antarctic bacterium Arthrobacter sp. 22c was isolated, cloned and expressed in Escherichia coli. The active form of recombinant Arthrobacter sp. 22c L-arabinose isomerase consists of six subunits with a combined molecular weight of approximately 335 kDa. The maximum activity of this enzyme towards D-galactose was determined as occurring at 52°C; however, it exhibited over 60% of maximum activity at 30°C. The recombinant Arthrobacter sp. 22c L-arabinose isomerase was optimally active at a broad pH range of 5 to 9. This enzyme is not dependent on divalent metal ions, since it was only marginally activated by Mg2+, Mn2+ or Ca2+ and slightly inhibited by Co2+ or Ni2+. The bioconversion yield of D-galactose to D-tagatose by the purified L-arabinose isomerase reached 30% after 36 h at 50°C. In this study, a recombinant Pichia pastoris yeast strain secreting β-D-galactosidase Arthrobacter chlorophenolicus was also constructed. During cultivation of this strain in a whey permeate, lactose was hydrolyzed and D-glucose was metabolized, whereas D-galactose was accumulated in the medium. Moreover, cultivation of the P. pastoris strain secreting β-D-galactosidase in a whey permeate supplemented with Arthrobacter sp. 22c L-arabinose isomerase resulted in a 90% yield

  6. Synthesis and modifications of heterocyclic derivatives of D-arabinose: potential inhibitors of glucose-6-phosphate isomerase and glucosamine-6-phosphate synthase; Sintese e modificacoes de derivados heterociclicos de d-arabinose: potenciais inibidores de glicose-6-fosfato isomerase e de glicosamina-6-fosfato sintase

    Energy Technology Data Exchange (ETDEWEB)

    Viana, Renato Marcio Ribeiro; Prado, Maria Auxiliadora Fontes; Alves, Ricardo Jose [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Fac. de Farmacia. Dept. de Produtos Farmaceuticos]. E-mail: ricardodylan@farmacia.ufmg.br

    2008-07-01

    The synthesis of -5-(D-arabino-1,2,3,4-tetrahydroxybutyl)tetrazole and -2-(d-arabino-1,2,3,4-tetra-acetoxybutyl)-5-methyl-1,3,4-oxadiazole from d-arabinose is described. Attempts at removing the protecting groups of the oxadiazole derivative were unsuccessful, leading to products resulting from the opening of the oxadiazole ring. The unprotected tetrazole derivative was selectively phosphorylated at the primary hydroxyl group with diethyl phosphoryl chloride. The resulting 5-[d-arabino-4-(diethylphosphoryloxy)-1,2,3-trihydroxybutyl]tetrazole is a protected form of a potential inhibitor of the enzymes glucose-6-phosphate isomerase and glucosamine synthase. (author)

  7. Effect of L-arabinose on the postprandial blood glucose and body weight%L-阿拉伯糖对人体血糖水平及体重的影响

    Institute of Scientific and Technical Information of China (English)

    刘杏荣; 朱道辰; 孙鲁; 高永旭; 王成福

    2013-01-01

    Objective To study the effect of L-arabinose on the blood glucose level of adult, and to find out the optimal amount of daily L-arabinose intake for maintaining their health. Methods SO adult were randomly selected and assigned to 5 group with different dose of L-arabinose or placebo, respectively. The preprandial blood glucose level and lh and 2h postprandial blood glucose were detected per 3 days. To investigate the variation of weight, 20 fat person was performed with daily L-arabinose or placebo intake for given daily for six months. Results After 30 days feeding, the decrease of postprandial blood glucose level was observed in group with 3% L-arabinose sample, and the groups with 5% — 10% have a significantly decreasing in the postprandial blood glucose level compared with control group result in (5.60 ±0.08) and (5.24 ±0.12), respectively (P<0.05). The average body weight have a significantly reduce and after six months averagely reduced 5. 5kg, and the control group have no obviously variation. Conclusion The daily consumption of L-arabinose would inhibit the postprandial blood glucose level and slimming down body which have a benefit for heath.%目的 探讨低热量甜味剂L-阿拉伯糖对人体空腹血糖、餐后血糖水平的影响以及对人体的血糖耐受水平影响等生物功能学作用.方法 选取50人(男女各半)随机分为5组,将L-阿拉伯糖与蔗糖以不同配比连续口服30d,记录人体早餐前、早餐后1h、早餐后2h血糖水平变化,观察不同剂量L-阿拉伯糖对人体血糖水平的影响.选取18 ~23岁之间肥胖人群20名,分为干预组和对照组两组,每天三餐前均服用10g L-阿拉伯糖和作为对照的安慰剂,每15日测量体重,观察体重变化,实验持续180d.结果 3%L-阿拉伯糖即能抑制血糖水平,5% ~10%的配比能显著降低餐后血糖(P<0.05),100%与10%配比结果统计学分析无显著差异.食用L-阿拉伯糖组的平均体重持续下降,15d

  8. L-阿拉伯糖对肥胖小鼠减肥的影响%Effects of L-Arabinose on Body Weight-Reducing of Obese Mice

    Institute of Scientific and Technical Information of China (English)

    刘秋晨; 刘艳; 单春乔; 李晶晶; 曹艳子; 江国托; 余丽芸

    2013-01-01

      探讨由大连三仪生物工程研究所利用微生物菌种发酵的方法提取的L-阿拉伯糖对营养性肥胖小鼠减肥的影响。以昆明小鼠为实验动物,建立肥胖模型,之后用L-阿拉伯糖干预治疗,实验期间监测空腹体重,血清甘油三酯、总胆固醇、高密度脂蛋白、脏器指数和脂体比。中剂量组的体重、脂体比、甘油三酯水平和高密度脂蛋白水平与模型对照组比较均有统计学意义(P<0.05或P<0.01)。2 g/kg·BW 剂量的L-阿拉伯糖对于营养性肥胖小鼠有很好的减肥效果,且能有效的降低甘油三酯含量和提高高密度脂蛋白水平。%Investigate the effect on the alimentary obesity mice weight-loss of the L-arabinose which is extracted through microbiological fermentation by Dalian Sanyi biological engineering institute. Use the Kunming mice as the experimental animal, build the obesity model, then utilize the L-arabinose interfere therapy and monitor the fasting on body weight, serum triglyceride, high density lipoprotein, viscera index and the ratio of the lipid and body. The body weight, the lipid-body ratio, Triglyceride and high density lipoprotein level is significant to the control group (P<0.05 or P<0.01) in the mid-dose group. The dose with 2g/kg·BW L-arabinose have dominant influence on the alimentary obesity mice, and furthermore, is competent in decreasing the percentage of triglyceride and elevate the level of high density lipidprotein.

  9. High yield synthesis of 14C labelled intermediates of the L-type pentose pathway: octulose mono- and biphosphates, sedoheptulose 1,7-bisphosphate and D-arabinose 5-phosphate

    International Nuclear Information System (INIS)

    Methods for the enzymic synthesis, isolation, purification and analysis of the 14C labelled intermediates that are characteristic of the L-type pentose phosphate pathway are described. These are D-glycero D-ido octulose 1,8-bisphosphate and 8-monophosphate; D-glycero D-altro octulose mono- and bisphosphates; sedoheptulose 1,7-bisphosphate and D-arabinose 5-phosphate. The authenticity of each of the 14C-labelled sugar phosphates was confirmed using a variety of chromatographic methods, enzymatic analytic methods and NMR spectroscopy. The 14C labelled compounds are used in investigations involving the search for the identity of the pentose pathway in tissues in vitro, for the measurement of L-type pathway enzyme reactions and for testing the mechanistic predictions of the L-type pathway in vitro. (author)

  10. MICROBIAL PRODUCTION OF XYLITOL FROM L-ARABINOSE

    Science.gov (United States)

    Xylitol is one of the non-sugar sweeteners approved for use in foods and other items in many countries. It has the same order of sweetness as sucrose with fewer calories and no unpleasant aftertaste. It is also well known that xylitol is an anticariogenic sweetener. These properties make xylitol ...

  11. Cloning and characterization of a novel L-arabinose isomerase from Bacillus licheniformis

    DEFF Research Database (Denmark)

    Prabhu, Ponnandy; Tiwari, Manish Kumar; Jeya, Marimuthu;

    2008-01-01

    reading frame of 1,422 bp, capable of encoding a polypeptide of 474 amino acid residues with a calculated isoelectric point of pH 4.8 and a molecular mass of 53,500 Da. The gene was overexpressed in E. coli, and the protein was purified as an active soluble form using Ni-NTA chromatography. The molecular...

  12. Effect of pH on fermentative hydrogen production from L-arabinose using mixed cultures

    OpenAIRE

    Abreu, A. A.; Danko, Anthony S.; Costa, J.C.; Alves, M.M.

    2008-01-01

    Hydrogen is now considered one of the alternatives to fossil fuels. It is preferred to biogas or methane because hydrogen is not chemically bound to carbon and therefore, combustion does not contribute to green house gases or acid rain [1]. One alternative to sustainable H2 energy production from renewable energy sources is through microbiological fermentation. There have been many studies examining the effect of pH in fermentative hydrogen production from glucose and sucrose usin...

  13. Arabinose-rich polymers as an evolutionary strategy to plasticize resurrection plant cell walls against desiccation

    DEFF Research Database (Denmark)

    Moore, John P.; Nguema-Ona, Eric E.; Vicré-Gibouin, Mäite;

    2013-01-01

    A variety of Southern African resurrection plants were surveyed using high-throughput cell wall profiling tools. Species evaluated were the dicotyledons, Myrothamnus flabellifolia and Craterostigma plantagineum; the monocotyledons, Xerophyta viscosa, Xerophyta schlecterii, Xerophyta humilis and the...... resurrection grass Eragrostis nindensis, as well as a pteridophyte, the resurrection fern, Mohria caffrorum. Comparisons were made between hydrated and desiccated leaf and frond material, with respect to cell wall composition and polymer abundance, using monosaccharide composition analysis, FT-IR spectroscopy...... and comprehensive microarray polymer profiling in combination with multivariate data analysis. The data obtained suggest that three main functional strategies appear to have evolved to prepare plant cell walls for desiccation. Arabinan-rich pectin and arabinogalactan proteins are found in the...

  14. Theoretical study on the factors controlling the stability of the borate complexes of ribose, arabinose, lyxose, and xylose

    Czech Academy of Sciences Publication Activity Database

    Šponer, Judit E.; Sumpter, B.G.; Leszczynski, J.; Šponer, Jiří; Fuentes-Cabrera, M.

    2008-01-01

    Roč. 14, č. 32 (2008), s. 9990-9998. ISSN 0947-6539 R&D Projects: GA AV ČR(CZ) IAA400550701; GA AV ČR(CZ) IAA400040802; GA AV ČR(CZ) 1QS500040581; GA MŠk(CZ) LC06030 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : borates * density functional calculations * carbohydrates Subject RIV: AQ - Safety, Health Protection, Human - Machine Impact factor: 5.454, year: 2008

  15. Structure of the effector-binding domain of the arabinose repressor AraR from Bacillus subtilis

    Czech Academy of Sciences Publication Activity Database

    Procházková, Kateřina; Čermáková, Kateřina; Pachl, Petr; Sieglová, Irena; Fábry, Milan; Otwinowski, Z.; Řezáčová, Pavlína

    2012-01-01

    Roč. 68, č. 2 (2012), s. 176-185. ISSN 0907-4449 R&D Projects: GA MŠk ME08016 Institutional research plan: CEZ:AV0Z40550506; CEZ:AV0Z50520514 Keywords : repressor * dimerization * effector binding * isothermal titration calorimetry Subject RIV: CE - Biochemistry Impact factor: 14.103, year: 2012

  16. Laxative Effect of L-arabinose%L-阿拉伯糖润肠通便作用的研究

    Institute of Scientific and Technical Information of China (English)

    杨子明; 董仲玺; 吴建璋; 颜小捷; 李典鹏; 陈海珊; 张厚瑞

    2013-01-01

    研究L-阿拉伯糖对便秘模型小鼠的润肠通便作用.采用盐酸洛哌丁胺建立小鼠便秘模型,通过小鼠小肠推进实验和排便实验,得到小鼠小肠内容物推进率、首次排便时间、6h内排便次数和排便重量及对小鼠粪便形状的影响.与便秘模型组比较,L-阿拉伯糖低、中、高剂量组都能明显提高小肠内容物推进率、缩短小鼠首次排便时间、增加6h内排便次数和重量、软化小鼠粪便.L-阿拉伯糖对便秘模型小鼠有较好的润肠通便效果.

  17. L-阿拉伯糖/半胱氨酸Maillard反应动力学的研究%KINETIC ANALYSIS OF L-ARABINOSE/CYSTEINE MAILLARD REACTION

    Institute of Scientific and Technical Information of China (English)

    侯亚龙; 陈正行; 罗昌荣; 王光雨

    2008-01-01

    本文通过模型体系的建立,研究了L-阿拉伯糖/半胱氨酸Maillard反应动力学.利用高效液相色谱-蒸发光散射检测器,分析了Maillard反应产物,比较了不同反应条件下阿拉伯糖/半胱氨酸模型体系中L-阿拉伯糖的残留情况的反应动力学特征.研究表明,pH 5、120℃条件下,Maillard反应初期L-阿拉伯糖与氨基酸结合迅速,是一个动力学控制过程;随着反应时间的延长,反应速率趋于稳定,反应速率取决于Amadofi化合物分解为产物的速率,是一个热力学控制过程.反应温度对Maillard反应速率的影响大于反应时间,高温可使Maillard反应速率迅速提高.初始pH对Maillard反应影响最大,酸性和弱酸性条件反应缓慢,中性和碱性条件下反应快速.pH5、反应温度120℃时,L-阿拉伯糖的残留率随反应时间的延长而下降,反应时间180 min时残留率为50.53%;pH5、反应时间1 h时,反应温度不同L-阿拉伯糖的残留率不同,在40~100℃范围内残留率变化(70.4%~76.78%)不大,在100~140 ℃范围内随反应温度的上升残留率迅速下降,140 ℃时残留率为27.79%;反应温度120 ℃、反应时间1 h时,酸性条件下不同初始pH,残留率变化不大.但中性及碱性条件下残留率迅速下降,pH 9时残留率为15.1%.结论:反应时间对L-阿拉伯糖的残留率影响远不如反应温度和pH,其中pH的影响最为显著.

  18. On the factors influencing the stability of the borate complexes of ribose, arabinose, lyxose and xylose. A picture from DFT calculations

    Czech Academy of Sciences Publication Activity Database

    Šponer, Judit E.; Sumpter, B.G.; Leszczynski, J.; Šponer, Jiří; Fuentes-Cabrera, M.

    Amsterdam, 2007. s. 296. [12th International Conference on the Applications of Density Functional Theory in Physics and Chemistry. 24.08.2007-30.08.2007, Amsterdam] R&D Projects: GA AV ČR(CZ) IAA400550701 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : aldopentose * borates * DFT Subject RIV: BO - Biophysics

  19. Variation in the composition of carbohydrates in the Dona Paula, Bay (west of India) during May/June 1998

    Digital Repository Service at National Institute of Oceanography (India)

    DeSouza, F.P.; Bhosle, N.B.

    relationships with arabinose and xylose. Conversely, suspended particulate matter showed significant positive relationships with xylose and arabinose and negative relationships with chlorophyll a and glucose. The hexoses to pentoses ratio increased during 7...

  20. pH对阿拉伯糖-半胱氨酸模型体系挥发性风味物质形成的影响%Effects of pH on Formation of Aroma Volatiles in Model System of Arabinose/Cysteine Formation

    Institute of Scientific and Technical Information of China (English)

    侯亚龙; 陈正行; 罗昌荣; 王光雨

    2007-01-01

    利用项空-固相微萃取-气质联用的方法,分析和比较了不同pH对阿拉伯糖/半胱氨酸模型体系挥发性风味物质形成的影响.研究结果表明,中性、弱酸性条件有利于挥发性风味物质的形成.pH5时挥发性风味物质的总量最大且各类挥发性风味物质较丰富;pH7时虽然挥发性风味物质的总量较低但各类挥发性风味物质最丰富;强酸性条件不利于挥发性风味物质的产生;碱性条件虽有利于含氮、硫、氧等的杂环化合物的形成,但挥发性风味物质总量低,pH9时苯系物生成量较多.

  1. Effect of adding oxidated chicken fat to D-Arabinose/L-Cysteine reaction system on chicken flavor%加入氧化鸡脂对D-阿拉伯糖/L-半胱氨酸Maillard反应生成鸡肉风味的影响

    Institute of Scientific and Technical Information of China (English)

    李阳; 金青哲; 罗昌荣; 王兴国

    2008-01-01

    加入氧化鸡油到D-阿拉伯糖/L-半胱氨酸的Maillard反应体系中,采用固相微萃取和气质联用的方法,研究氧化鸡脂对鸡肉风味的影响.反应体系为:(1)空白(D-阿拉伯糖/L-半胱氨酸的Maillard反应),(2)加入未氧化鸡脂到Maillard反应体系,(3)加入氧化鸡脂到Maillard反应体系,(4)MaiUard反应后加入氧化鸡脂,(5)Maillard反应后加入氧化鸡脂并在60℃下保持30min.结果表明,加入鸡脂参与Maillard反应可产生大量的挥发性风味物质,尤其是加入氧化鸡脂,所得到的呋喃、噻吩、酸、含硫物质和噻唑等挥发性组分的种类最多.

  2. GenBank blastx search result: AK060768 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK060768 001-033-A12 AF160811.1 Bacillus stearothermophilus L-arabinose transport, ATP binding protein (ara...G), L-arabinose membrane permease (araH), AraR (araR), L-ribulose 5-phosphate 4-epimerase (ara...D), L-ribulokinase (araB), L-arabinose isomerase (araA), and IS5377 transposase genes, complete cds.|BCT BCT 9e-14 +3 ...

  3. Microbacterium indicum sp. nov., isolated from deep-sea sediment sample from the Chagos Trench, Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Shivaji, S.; Bhadra, B.; Rao, R.S.; Chaturvedi, P.; Pindi, P.K.; Raghukumar, C.

    -arabinose, D-xylose, D-cellobiose, maltose, trehalose, melezitose and sucrose. All four are able to utilize D-glucose, D-fructose, D-galactose, L-arabinose, D-cellobiose, lactose, maltose, sucrose, acetate, L-serine, L-arginine and L-lysine, but not erythritol...

  4. NCBI nr-aa BLAST: CBRC-TTRU-01-1197 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-TTRU-01-1197 ref|YP_001580741.1| major facilitator transporter [Burkholderia multivorans AT ... CC 17616] ref|YP_001945177.1| arabinose polymer ... transporter [Burkholderia multivorans ATCC 17616] ... multivorans ATCC 17616] dbj|BAG42641.1| arabinose polymer ... transporter [Burkholderia multivorans ATCC 17616] ...

  5. Novel monosaccharide fermentation products in Caldicellulosiruptor saccharolyticus identified using NMR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Isern, Nancy G.; Xue, Junfeng; Rao, Jaya V.; Cort, John R.; Ahring, Birgitte K.

    2013-04-03

    Profiles of metabolites produced by the thermophilic obligately anaerobic cellulose-degrading Gram-positive bacterium Caldicellulosiruptor saccharolyticus DSM 8903 strain following growth on different monosaccharides (D-glucose, D-mannose, L-arabinose, D-arabinose, D-xylose, L-fucose, and D-fucose) as carbon sources revealed several unexpected fermentation products, suggesting novel metabolic capacities and unexplored metabolic pathways in this organism. Both 1H and 13C nuclear magnetic resonance (NMR) spectroscopy were used to determine intracellular and extracellular metabolite profiles. Metabolite profiles were determined from 1-D 1H NMR spectra by curve fitting against spectral libraries provided in Chenomx software. To reduce uncertainties due to unassigned, overlapping, or poorly-resolved peaks, metabolite identifications were confirmed with 2-D homonuclear and heteronuclear NMR experiments. In addition to expected metabolites such as acetate, lactate, glycerol, and ethanol, several novel fermentation products were identified: ethylene glycol (from growth on D-arabinose, though not L-arabinose), acetoin and 2,3-butanediol (from D-glucose and L-arabinose), and hydroxyacetone (from D-mannose and L-arabinose). Production of ethylene glycol from D-arabinose was particularly notable, with around 10% of the substrate carbon converted into this uncommon fermentation product. The novel products have not previously been reported to be produced by C. saccharolyticus, nor would they be easily predicted from the current genome annotation, and show new potentials for using this strain for production of bioproducts.

  6. Analysis of microfouling products formed on metallic surfaces exposed in a marine environment

    Digital Repository Service at National Institute of Oceanography (India)

    DeSouza, F.P.; Bhosle, N.B.

    . Capillary gas chromatographic analysis showed the presence of glucose, galactose, mannose, arabinose, xylose, fucose and ribose in both the fouling products and suspended matter. However, there were differences in the relative distribution...

  7. Accelerated pentose utilization by Corynebacterium glutamicum for accelerated production of lysine, glutamate, ornithine and putrescine

    OpenAIRE

    Meiswinkel, Tobias M; Gopinath, Vipin; Lindner, Steffen N.; Nampoothiri, K. Madhavan; Wendisch, Volker F.

    2012-01-01

    Summary Because of their abundance in hemicellulosic wastes arabinose and xylose are an interesting source of carbon for biotechnological production processes. Previous studies have engineered several Corynebacterium glutamicum strains for the utilization of arabinose and xylose, however, with inefficient xylose utilization capabilities. To improve xylose utilization, different xylose isomerase genes were tested in C. glutamicum. The gene originating from Xanthomonas campestris was shown to h...

  8. A new and unexpected domain-domain interaction in the AraC protein.

    Science.gov (United States)

    Cole, Stephanie Dirla; Schleif, Robert

    2012-05-01

    An interaction between the dimerization domains and DNA binding domains of the dimeric AraC protein has previously been shown to facilitate repression of the Escherichia coli araBAD operon by AraC in the absence of arabinose. A new interaction between the domains of AraC in the presence of arabinose is reported here, the regulatory consequences of which are unknown. Evidence for the interaction is the following: the dissociation rate of arabinose-bound AraC from half-site DNA is considerably faster than that of free DNA binding domain, and the affinity of the dimerization domains for arabinose is increased when half-site DNA is bound. In addition, an increase in the fluorescence intensity of tryptophan residues located in the arabinose-bound dimerization domain is observed upon binding of half-site DNA to the DNA binding domains. Direct physical evidence of the new domain-domain interaction is demonstrated by chemical crosslinking and NMR experiments. PMID:22383259

  9. Preliminary study of polysaccharides in the tragacanth of Astragalus gossipinus Fisch and Astragalus keyserlingii Bunge

    Directory of Open Access Journals (Sweden)

    H. Ebrahimzadeh F. Mighani

    1997-08-01

    Full Text Available From the point of gum production, Fabaceae is one of the most richest plant families. Tragacanth is one of the most important gums and has medicianl, industrial and food applications. The soluble and insoloble fractions are 40 and 60% in white gum and 70 and 30% in yellow gum, respectively. These fractions do not show considerable seasonal variations. Total sugar in white gum and yellow gum are 70% and 90% , respectively; monosaccharides in both kind of tragacanths include galacturonic acid, galactose, glucose, arabinose, xylose, fucose, and rhamnose and the amount of xylose in the composition is higher than that of others. Insoluble fraction of white gum, the amount of xylose is more than that of arabinose pJus fucose while in yellow gum its amount is lower than that of arabinose plus fucose. fln insoluble fraction of both kind of tragacanths, the amount of arabinose plus fucose is high. The quality of white gum, in comparison to yellow gum, is better due to the higher in soluble fraction and arabinose plus fucose to xylose in this fraction . The gum tragacartti of both species has a xylan backbone.

  10. Quinoa (Chenopodium quinoa W.) and amaranth (Amaranthus caudatus L.) provide dietary fibres high in pectic substances and xyloglucans.

    Science.gov (United States)

    Lamothe, Lisa M; Srichuwong, Sathaporn; Reuhs, Bradley L; Hamaker, Bruce R

    2015-01-15

    Dietary fibre of quinoa and amaranth was analysed for its insoluble and soluble fibre content, composition, and structure. Total dietary fibre content was 10% for quinoa and 11% for amaranth. For both pseudocereals, 78% of its dietary fibre was insoluble. Insoluble fibre (IDF) from quinoa and amaranth was mainly composed of galacturonic acid, arabinose, galactose, xylose and glucose. Linkage analysis indicated that IDF was composed of homogalacturonans and rhamnogalacturonan-I with arabinan side-chains (∼55-60%), as well as highly branched xyloglucans (∼30%) and cellulose. For both pseudocereals, 22% of total dietary fibre was soluble; a higher proportion than that found in wheat and maize (∼15%). The soluble fibre (SDF) was composed of glucose, galacturonic acid and arabinose; for amaranth, xylose was also a major constituent. Xyloglucans made up ∼40-60% of the SDF and arabinose-rich pectic polysaccharides represented ∼34-55%. PMID:25149016

  11. Enzymatic synthesis of 3-deoxy-d-manno-octulosonic acid (KDO) and its application for LPS assembly.

    Science.gov (United States)

    Wen, Liuqing; Zheng, Yuan; Li, Tiehai; Wang, Peng George

    2016-06-15

    The studies of 3-deoxy-d-manno-octulosonic acid (KDO) have been hindered due to its limited availability. Herein, an efficient enzymatic system for the facile synthesis of KDO from easy-to-get starting materials is described. In this one-pot three-enzyme (OPME) system, d-ribulose 5-phosphate, which was prepared from d-xylose, was employed as starting materials. The reaction process involves the isomerization of d-ribulose 5-phosphate to d-arabinose 5-phosphate catalyzed by d-arabinose 5-phosphate isomerase (KdsD), the aldol condensation of d-arabinose 5-phosphate and phosphoenolpyruvate (PEP) catalyzed by KDO 8-phosphate synthetase (KdsA), and the hydrolysis of KDO-8-phosphate catalyzed by KDO 8-phosphate phosphatase (KdsC). By using this OPME system, 72% isolated yield was obtained. The obtained KDO was further transferred to lipid A by KDO transferase from Escherichia coli (WaaA). PMID:27173798

  12. Influence of Grape Maturity on Complex Carbohydrate Composition of Red Sparkling Wines.

    Science.gov (United States)

    Martínez-Lapuente, Leticia; Apolinar-Valiente, Rafael; Guadalupe, Zenaida; Ayestarán, Belén; Pérez-Magariño, Silvia; Williams, Pascale; Doco, Thierry

    2016-06-22

    This paper studied how grape maturity affected complex carbohydrate composition during red sparkling wine making and wine aging. Grape ripening stage (premature and mature grapes) showed a significant impact on the content, composition, and evolution of polysaccharides and oligosaccharides of sparkling wines. Polysaccharides rich in arabinose and galactose, mannoproteins, rhamnogalacturonans II, and oligosaccharides in base wines increased with maturity. For both maturity stages, polysaccharides rich in arabinose and galactose, and the glucuronic acid glycosyl residue of the oligosaccharides were the major carbohydrates detected in all vinification stages. The total glycosyl content of oligosaccharides decreased during the whole period of aging on yeast lees. The reduction of polysaccharides rich in arabinose and galactose and rhamnogalacturonans type II during the aging was more pronounced in mature samples. To our knowledge, this is the first report of the polysaccharide and oligosaccharide composition of red sparkling wines. PMID:27226011

  13. Screening of lactic acid bacteria for their potential as microbial cell factories for bioconversion of lignocellulosic feedstocks

    DEFF Research Database (Denmark)

    Boguta, Anna Monika; Bringel, Francoise; Martinussen, Jan;

    2014-01-01

    lactic acid bacteria was evaluated regarding their properties with respect to the conversion of lignocellulosic feedstocks. The strains were examined for their ability to utilize xylose and arabinose as well as their resistance towards common inhibitors from pretreated lignocellulosic biomass (furan...... derivatives, phenolic compounds, weak acids). Results: Among 296 tested Lactobacillus and Pediococcus strains, 3 L. pentosus, 1 P. acidilactici and 1 P. pentosaceus isolates were found to be both capable of utilizing xylose and arabinose and highly resistant to the key inhibitors from chemically pretreated...

  14. Recombinant bromelain production in Escherichia coli: process optimization in shake flask culture by response surface methodology

    OpenAIRE

    Muntari, Bala; Amid, Azura; Mel, Maizirwan; Jami, Mohammed S; Hamzah M. Salleh

    2012-01-01

    Bromelain, a cysteine protease with various therapeutic and industrial applications, was expressed in Escherichia coli, BL21-AI clone, under different cultivation conditions (post-induction temperature, L-arabinose concentration and post-induction period). The optimized conditions by response surface methodology using face centered central composite design were 0.2% (w/v) L-arabinose, 8 hr and 25°C. The analysis of variance coupled with larger value of R2 (0.989) showed that the quadratic mod...

  15. Affecting osteoblastic responses with in vivo engineered potato pectin fragments

    DEFF Research Database (Denmark)

    Kokkonen, Hanna; Verhoef, Renè; Kauppinen, Kyösti;

    2012-01-01

    on Petri dishes coated with RG-Is from native or genetically engineered potato tubers. Uncoated tissue culture polystyrene (TCPS) and aminated (AMI) dishes served as controls. MHRPTR_GAL sample was depleted of galactose (9 mol % galactose; 23 mol % arabinose) and MHRPTR_ARA of arabinose (61 mol % galactose...... subtler. However, tetracycline-stained calcium-containing mineral was detected merely only on uncoated TCPS. These results indicate the possibility to affect bone cell growth with in vivo-modified pectin fragments, consecutively providing information on the significance of certain monosaccharides...

  16. Identification of sigma S-regulated genes in Salmonella typhimurium: complementary regulatory interactions between sigma S and cyclic AMP receptor protein.

    OpenAIRE

    Fang, F C; Chen, C Y; Guiney, D G; Xu, Y

    1996-01-01

    sigma S (RpoS)-regulated lacZ transcriptional fusions in Salmonella typhimurium were identified from a MudJ transposon library by placing the rpoS gene under the control of the araBAD promoter and detecting lacZ expression in the presence or absence of arabinose supplementation. Western blot (immunoblot) analysis of bacteria carrying PBAD::rpoS demonstrated arabinose-dependent rpoS expression during all phases of growth. sigma S-dependent gene expression of individual gene fusions was confirm...

  17. 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

  18. Enzymatic depolymerization of gum Tragacanth: Bifidogenic potential of low molecular weight oligosaccharides

    DEFF Research Database (Denmark)

    Ahmadi Gavlighi, Hassan; Michalak, Malwina; Meyer, Anne S.;

    2013-01-01

    Gum tragacanth derived from the plant “goat’s horn” (Astragalus sp.) has a long history of use as a stabilizing, viscosity-enhancing agent in food emulsions. The gum contains pectinaceous arabinogalactans and fucose-substituted xylogalacturonans. In this work, gum tragacanth from Astragalus...... these three fractions also varied with respect to composition and structural elements: HAG1 and HAG2 were enriched in arabinose, galactose, and galacturonic acid, but low in fucose and xylose; whereas HAG3 was high in (terminal) xylose, fucose and 1,4-bonded galacturonic acid, but low in arabinose and...

  19. Enzymatic Hydrolysis of Wheat Arabinoxylan by a Recombinant "Minimal" Enzyme Cocktail Containing beta-Xylosidase and Novel endo-1,4-beta-Xylanase and alpha-L-Arabinofuranosidase Activities

    DEFF Research Database (Denmark)

    Sørensen, Hanne R.; Pedersen, Sven; Jørgensen, Christel T.; Meyer, Anne Boye Strunge

    2007-01-01

    -xylanase from H. insolens (Xyl III), and a GH3 beta-xylosidase from Trichoderma reesei (beta-xyl) released 322 mg of arabinose and 512 mg of xylose per gram of water-soluble wheat arabinoxylan dry matter and 150 mg of arabinose and 266 mg of xylose per gram of water-insoluble wheat arabinoxylan dry matter after...... wheat arabinoxylan substrates were hydrolyzed with a combination of Ultraflo L and Celluclast 1.5 L, two commercially available enzyme preparations produced by H. insolens and T. reesei....

  20. Structural characterization, α-glucosidase inhibitory and DPPH scavenging activities of polysaccharides from guava.

    Science.gov (United States)

    Zhang, Ziling; Kong, Fansheng; Ni, Hui; Mo, Zhixian; Wan, Jian-Bo; Hua, Dehong; Yan, Chunyan

    2016-06-25

    To explore the chemicals responsible for the health benefits of guava, water-soluble polysaccharides were extracted including GP90 and P90. They exhibited excellent α-glucosidase inhibition activity with an EC50 of 2.27μg/mL and 0.18mg/mL. This suggests that their activities were 1379- and 17-fold higher than the positive control. The DPPH scavenging activities of GP90 was even higher than Vc at some concentrations. Upon further isolation, a novel polysaccharide termed GB90-1B was obtained. Monosaccharide analysis, methylation analysis, and NMR were used to analyze the structural characterization of GB90-1B. Structural analysis revealed that its backbone consisted of (1→5)-linked-α-l-arabinose, (1→2,3,5)-linked-α-l-arabinose and (1→3)-linked-α-l-arabinose. Branch linkages included (1→6)-linked-α-d-glucose, (1→)-linked-α-d-glucose and (1→)-linked-α-l-arabinose. The structure of the repeating unit of GP90-1B was predicted. PMID:27083799

  1. Cellulases and hemicellulases from endophytic Acremonium species and its application on sugarcane bagasse hydrolysis

    Science.gov (United States)

    The aim of this work was to have cellulase activity and hemicellulase activity screenings of endophyte Acremonium species (Acremonium zeae EA0802 and Acremonium sp. EA0810). Both fungi were cultivated in submerged culture (SC) containing L-arabinose, D-xylose, oat spelt xylan, sugarcane bagasse, or...

  2. Identification and characterization of a novel arabinoxylanase from wheat flour.

    Science.gov (United States)

    Cleemput, G; Van Laere, K; Hessing, M; Van Leuven, F; Torrekens, S; Delcour, J A

    1997-12-01

    An endogenous wheat (Triticum aestivum) flour endoxylanase was purified to homogeneity from a crude wheat flour extract by ammonium sulfate precipitation and cation-exchange chromatography. The 30-kD protein had an isoelectric point of 9.3 or higher. A sequence of 19 amino acids at the NH2 terminus showed 84.2% identity with an internal sequence of 15-kD grain-softness protein, friabilin. High-performance anion-exchange chromatography and gel-permeation analysis of the hydrolysis products indicated the preferential hydrolysis of highly branched structures by the enzyme; wheat arabinoxylan and rye (Secale cereale) arabinoxylan (high arabinose to xylose ratios) were hydrolyzed more efficiently by this enzyme than oat (Avena sativa) spelt xylan (low arabinose to xylose ratios). The release of the hydrolysis products as a function of time suggested that the endoxylanolytic activity was associated with the release of arabinose units from the polysaccharides, suggesting that the enzyme action is similar to that by endoxylanases from Ceratocystis paradoxa, Aspergillus niger, and Neurospora crassa. Although the enzyme released arabinose from arabinoxylan, it did not hydrolyze p-nitrophenyl-alpha-L-arabinofuranoside. From the above, it follows that the enzyme, called arabinoxylanase, differs from most microbial endoxylanases and from an endoxylanase purified earlier from wheat flour. PMID:9414565

  3. GMAX Yeast Background Strain Made from Industrial Tolerant Saccharomyces Cerevisiae Engineered to Convert Pretreated Lignocellulosic Starch and Cellulosic Sugars Universally to Ethanol Anaerobically

    Science.gov (United States)

    Tailored GMAX yeast background strain technology for universal ethanol production industrially: Production of the stable baseline glucose, mannose, arabinose, xylose-utilizing (GMAX) yeast will be evaluated by taking the genes identified in high-throughput screening for a plasmid-based yeast to util...

  4. Influence of inhibitory compounds and minor sugars on xylitol production by Debaryomyces hansenii.

    Science.gov (United States)

    Sampaio, Fábio C; Torre, Paolo; Passos, Flávia M Lopes; de Moraes, Célia Alencar; Perego, Patrizia; Converti, Attilio

    2007-02-01

    To obtain in-depth information on the overall metabolic behavior of the new good xylitol producer Debaryomyces hansenii UFV-170, batch bioconversions were carried out using semisynthetic media with compositions simulating those of typical acidic hemicellulose hydrolysates of sugarcane bagasse. For this purpose, we used media containing glucose (4.3-6.5 g/L), xylose (60.1-92.1 g/L), or arabinose (5.9-9.2 g/L), or binary or ternary mixtures of them in either the presence or absence of typical inhibitors of acidic hydrolysates, such as furfural (1.0-5.0 g/L), hydroxymethylfurfural (0.01- 0.30 g/L), acetic acid (0.5-3.0 g/L), and vanillin (0.5-3.0 g/L). D. hansenii exhibited a good tolerance to high sugar concentrations as well as to the presence of inhibiting compounds in the fermentation media. It was able to produce xylitol only from xylose, arabitol from arabinose, and no glucitol from glucose. Arabinose metabolization was incomplete, while ethanol was mainly produced from glucose and, to a lesser less extent, from xylose and arabinose. The results suggest potential application of this strain in xyloseto- xylitol bioconversion from complex xylose media from lignocellulosic materials. PMID:17496338

  5. Cell wall composition and digestibility alterations in Brachypodium distachyon achieved through reduced expression of the UDP-arabinopyranose mutase

    Science.gov (United States)

    Nucleotide-activated sugars are essential substrates for plant cell wall carbohydrate-polymer biosynthetic glycosyltransferase enzymes. The most prevalent sugars in grass cell walls include glucose (Glc), xylose (Xyl), and arabinose (Ara). These sugars are biosynthetically related via the uridine di...

  6. NCBI nr-aa BLAST: CBRC-XTRO-01-0245 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-XTRO-01-0245 ref|ZP_00796471.1| COG1172: Ribose/xylose/arabinose/galactoside ABC-type trans ... port systems, permease components [Yersinia pestis Angola ] ZP_00796471.1 2e-83 65% ...

  7. NCBI nr-aa BLAST: CBRC-XTRO-01-0372 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-XTRO-01-0372 ref|ZP_00798597.1| COG1172: Ribose/xylose/arabinose/galactoside ABC-type trans ... port systems, permease components [Yersinia pestis Angola ] ref|ZP_01178289.1| COG1172: Ribose/xylose/arabino ...

  8. Salinity-induced survival strategy of Vibrio cholerae associated with copepods in Cochin backwaters

    Digital Repository Service at National Institute of Oceanography (India)

    Thomas, K.U.; Joseph, N.; Raveendran, O.; Nair, S.

    Oxidase test + 71 Catalase + 65 Mannitol + 50 Sucrose + 67 Arabinose C0 45 Lactose C0 67 Nitrate reduction + 55 Arginine C0 47 Methyl red NA NA Voges–Proskauer + 56 Esculin C0 47 NaCl (0%) C0 79 NaCl (6%) C0 63 NaCl (8%) C0 26 Table 2 Distribution of V...

  9. Carbohydrate analysis of hemicelluloses by gas chromatography-mass spectrometry of acteylated methyl glycosides

    DEFF Research Database (Denmark)

    Sárossy, Zsuzsa; Plackett, David; Egsgaard, Helge

    2012-01-01

    A method based on gas chromatography–mass spectrometry analysis of acetylated methyl glycosides was developed in order to analyze monosaccharides obtained from various hemicelluloses. The derivatives of monosaccharide standards, arabinose, glucose, and xylose were studied in detail and 13C...... the extracted ion chromatograms, accurate quantification of monosaccharide constituents of selected hemicelluloses was demonstrated....

  10. A strain of Meyerozyma guilliermondii isolated from sugarcane juice is able to grow and ferment pentoses in synthetic and bagasse hydrolysate media.

    Science.gov (United States)

    Martini, Cristina; Tauk-Tornisielo, Sâmia Maria; Codato, Carolina Brito; Bastos, Reinaldo Gaspar; Ceccato-Antonini, Sandra Regina

    2016-05-01

    The search for new microbial strains that are able to withstand inhibitors released from hemicellulosic hydrolysis and are also still able to convert sugars in ethanol/xylitol is highly desirable. A yeast strain isolated from sugarcane juice and identified as Meyerozyma guilliermondii was evaluated for the ability to grow and ferment pentoses in synthetic media and in sugarcane bagasse hydrolysate. The yeast grew in xylose, arabinose and glucose at the same rate at an initial medium pH of 5.5. At pH 4.5, the yeast grew more slowly in arabinose. There was no sugar exhaustion within 60 h. At higher xylose concentrations with a higher initial cell concentration, sugar was exhausted within 96 h at pH 4.5. An increase of 350 % in biomass was obtained in detoxified hydrolysates, whereas supplementation with 3 g/L yeast extract increased biomass production by approximately 40 %. Ethanol and xylitol were produced more significantly in supplemented hydrolysates regardless of detoxification. Xylose consumption was enhanced in supplemented hydrolysates and arabinose was consumed only when xylose and glucose were no longer available. Supplementation had a greater impact on ethanol yield and productivity than detoxification; however, the product yields obtained in the present study are still much lower when compared to other yeast species in bagasse hydrolysate. By the other hand, the fermentation of both xylose and arabinose and capability of withstanding inhibitors are important characteristics of the strain assayed. PMID:27038950

  11. Fermentative hydrogen production by new marine Clostridium amygdalinum strain C9 isolated from offshore crude oil pipeline

    Energy Technology Data Exchange (ETDEWEB)

    Jayasinghearachchi, H.S.; Singh, Sneha; Sarma, Priyangshu M.; Lal, Banwari [Environmental and Industrial Biotechnology Division, The Energy and Resource Institute, Darbari Seth Block, Habitat Place, Lodhi Road, New Delhi, 110 003 (India); Aginihotri, Anil [Corporate HSF, Oil and Natural Gas Corporation, New Delhi (India)

    2010-07-15

    The present study investigated hydrogen production potential of novel marine Clostridium amygdalinum strain C9 isolated from oil water mixtures. Batch fermentations were carried out to determine the optimal conditions for the maximum hydrogen production on xylan, xylose, arabinose and starch. Maximum hydrogen production was pH and substrate dependant. The strain C9 favored optimum pH 7.5 (40 mmol H{sub 2}/g xylan) from xylan, pH 7.5-8.5 from xylose (2.2-2.5 mol H{sub 2}/mol xylose), pH 8.5 from arabinose (1.78 mol H{sub 2}/mol arabinose) and pH 7.5 from starch (390 ml H{sub 2}/g starch). But the strain C9 exhibited mixed type fermentation was exhibited during xylose fermentation. NaCl is required for the growth and hydrogen production. Distribution of volatile fatty acids was initial pH dependant and substrate dependant. Optimum NaCl requirement for maximum hydrogen production is substrate dependant (10 g NaCl/L for xylose and arabinose, and 7.5 g NaCl/L for xylan and starch). (author)

  12. Environ: E00448 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available Arabinose [CPD:C00216], Pentose Sterculia scaphigera, Sterculia lychophora, Sterculia [TAX:66667] Malvaceae... (mallow family) Sterculia scaphigera, Sterculia lychophora mature seed (dried) Crude drugs [BR:br08305] Dicot plants: rosids Malvaceae (mallow family) E00448 Sterculia seed ...

  13. Induction, purification, and characterization of two extracellular alpha-L-arabinofuranosidases from Fusarium oxysporum

    DEFF Research Database (Denmark)

    Panagiotou, Gianni; Topakas, E.; Economou, L.;

    2003-01-01

    In the presence of L-arabinose as sole carbon source, Fusarium oxysporum produces two alpha-L-arabinofuranosidases (ABFs) named ABF1 and ABF2, with molecular masses of 200 and 180 kDa, respectively. The two F. oxysporum proteins have been purified to homogeneity. The purified enzymes are composed...

  14. Aspergillus nidulans α-galactosidase of glycoside hydrolase family 36 catalyses the formation of α-galacto-oligosaccharides by transglycosylation

    DEFF Research Database (Denmark)

    Nakai, Hiroyuki; Baumann, Martin; Petersen, B. O.;

    2010-01-01

    transglycosylate monosaccharides without the 6-hydroxymethyl group, i.e. xylose, l-arabinose, l-fucose and l-rhamnose, or with axial 3-OH, i.e. gulose, allose, altrose and l-rhamnose. Structural modelling using Thermotoga maritima GH36 α-galactosidase as the template and superimposition of melibiose from the...

  15. Otariodibacter oris gen. nov., sp. nov., a member of the family Pasteurellaceae isolated from the oral cavity of pinnipeds

    DEFF Research Database (Denmark)

    Hansen, Mie Johanne; Bertelsen, Mads Frost; Christensen, Henrik;

    2012-01-01

    from existing genera of the Pasteurellaceae by the following tests: positive reactions for catalase, oxidase, Voges-Proskauer and indole; no X- or V-factor dependency; and acid production from L-arabinose (slow), L-fucose, maltose and trehalose, but not from dulcitol, D-mannitol, D-mannose or sucrose...

  16. Characterization of Carbohydrate Active Enzymes Involved in Arabinogalactan Protein Metabolism

    DEFF Research Database (Denmark)

    Knoch, Eva

    accounting for up to 90% of the total mass. The glycan contains mostly galactose and arabinose, but glucoronic acid and other less-abundant sugars like rhamnose, xylose and fucose are also found. Although AGPs are important for normal plant growth and are found throughout the plant in virtually all organs...

  17. Solvent engineering and other reaction design methods for favouring enzyme-catalysed synthesis

    DEFF Research Database (Denmark)

    Zeuner, Birgitte

    FAE-catalysed acylation reactions was reviewed. FAE type A from Aspergillus niger and an FAE from a commercial preparation from Humicola insolens, Depol 740L, could not catalyse the esterification of arabinose or xylose with hydroxycinnamates in IL-buffer systems or in surfactantless microemulsion...

  18. Genome-scale consequences of cofactor balancing in engineered pentose utilization pathways in Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Amit Ghosh

    Full Text Available Biofuels derived from lignocellulosic biomass offer promising alternative renewable energy sources for transportation fuels. Significant effort has been made to engineer Saccharomyces cerevisiae to efficiently ferment pentose sugars such as D-xylose and L-arabinose into biofuels such as ethanol through heterologous expression of the fungal D-xylose and L-arabinose pathways. However, one of the major bottlenecks in these fungal pathways is that the cofactors are not balanced, which contributes to inefficient utilization of pentose sugars. We utilized a genome-scale model of S. cerevisiae to predict the maximal achievable growth rate for cofactor balanced and imbalanced D-xylose and L-arabinose utilization pathways. Dynamic flux balance analysis (DFBA was used to simulate batch fermentation of glucose, D-xylose, and L-arabinose. The dynamic models and experimental results are in good agreement for the wild type and for the engineered D-xylose utilization pathway. Cofactor balancing the engineered D-xylose and L-arabinose utilization pathways simulated an increase in ethanol batch production of 24.7% while simultaneously reducing the predicted substrate utilization time by 70%. Furthermore, the effects of cofactor balancing the engineered pentose utilization pathways were evaluated throughout the genome-scale metabolic network. This work not only provides new insights to the global network effects of cofactor balancing but also provides useful guidelines for engineering a recombinant yeast strain with cofactor balanced engineered pathways that efficiently co-utilizes pentose and hexose sugars for biofuels production. Experimental switching of cofactor usage in enzymes has been demonstrated, but is a time-consuming effort. Therefore, systems biology models that can predict the likely outcome of such strain engineering efforts are highly useful for motivating which efforts are likely to be worth the significant time investment.

  19. Amino acid production from rice straw and wheat bran hydrolysates by recombinant pentose-utilizing Corynebacterium glutamicum.

    Science.gov (United States)

    Gopinath, Vipin; Meiswinkel, Tobias M; Wendisch, Volker F; Nampoothiri, K Madhavan

    2011-12-01

    Corynebacterium glutamicum wild type lacks the ability to utilize the pentose fractions of lignocellulosic hydrolysates, but it is known that recombinants expressing the araBAD operon and/or the xylA gene from Escherichia coli are able to grow with the pentoses xylose and arabinose as sole carbon sources. Recombinant pentose-utilizing strains derived from C. glutamicum wild type or from the L-lysine-producing C. glutamicum strain DM1729 utilized arabinose and/or xylose when these were added as pure chemicals to glucose-based minimal medium or when they were present in acid hydrolysates of rice straw or wheat bran. The recombinants grew to higher biomass concentrations and produced more L-glutamate and L-lysine, respectively, than the empty vector control strains, which utilized the glucose fraction. Typically, arabinose and xylose were co-utilized by the recombinant strains along with glucose either when acid rice straw and wheat bran hydrolysates were used or when blends of pure arabinose, xylose, and glucose were used. With acid hydrolysates growth, amino acid production and sugar consumption were delayed and slower as compared to media with blends of pure arabinose, xylose, and glucose. The ethambutol-triggered production of up to 93 ± 4 mM L-glutamate by the wild type-derived pentose-utilizing recombinant and the production of up to 42 ± 2 mM L-lysine by the recombinant pentose-utilizing lysine producer on media containing acid rice straw or wheat bran hydrolysate as carbon and energy source revealed that acid hydrolysates of agricultural waste materials may provide an alternative feedstock for large-scale amino acid production. PMID:21796382

  20. In vitro fermentation of arabinoxylan oligosaccharides and low molecular mass arabinoxylans with different structural properties from wheat (Triticum aestivum L.) bran and psyllium (Plantago ovata Forsk) seed husk.

    Science.gov (United States)

    Pollet, Annick; Van Craeyveld, Valerie; Van de Wiele, Tom; Verstraete, Willy; Delcour, Jan A; Courtin, Christophe M

    2012-02-01

    Ball milling was used for producing complex arabinoxylan oligosaccharides (AXOS) and low molecular mass arabinoxylans (AX) from wheat bran, pericarp-enriched wheat bran, and psyllium seed husk. The arabinose to xylose ratio of the samples produced varied between 0.14 and 0.92, and their average degree of polymerization (avDP) ranged between 42 and 300. Their fermentation for 48 h in an in vitro system using human colon suspensions was compared to enzymatically produced wheat bran AXOS with an arabinose to xylose ratio of 0.22 and 0.34 and an avDP of 4 and 40, respectively. Degrees of AXOS fermentation ranged from 28% to 50% and were lower for the higher arabinose to xylose ratio and/or higher avDP materials. Arabinose to xylose ratios of the unfermented fractions exceeded those of their fermented counterparts, indicating that molecules less substituted with arabinose were preferably fermented. Xylanase, arabinofuranosidase, and xylosidase activities increased with incubation time. Enzyme activities in the samples containing psyllium seed husk AX or psyllium seed husk AXOS were generally higher than those in the wheat bran AXOS preparations. Fermentation gave rise to unbranched short-chain fatty acids. Concentrations of acetic, propionic, and butyric acids increased to 1.9-2.6, 1.9-2.8, and 1.3-2.0 times their initial values, respectively, after 24 h incubation. Results show that the human intestinal microbiota can at least partially use complex AXOS and low molecular mass AX. The tested materials are thus interesting physiologically active carbohydrates. PMID:22224418

  1. 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

  2. Archaeal promoter architecture and mechanism of gene activation.

    Science.gov (United States)

    Peng, Nan; Ao, Xiang; Liang, Yun Xiang; She, Qunxin

    2011-01-01

    Sulfolobus solfataricus and Sulfolobus islandicus contain several genes exhibiting D-arabinose-inducible expression and these systems are ideal for studying mechanisms of archaeal gene expression. At sequence level, only two highly conserved cis elements are present on the promoters: a regulatory element named ara box directing arabinose-inducible expression and the basal promoter element TATA, serving as the binding site for the TATA-binding protein. Strikingly, these promoters possess a modular structure that allows an essentially inactive basal promoter to be strongly activated. The invoked mechanisms include TFB (transcription factor B) recruitment by the ara-box-binding factor to activate gene expression and modulation of TFB recruitment efficiency to yield differential gene expression. PMID:21265754

  3. 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.

  4. Synthesis of thymol glycosides under SCCO2 conditions using amyloglucosidase from Rhizopus mold.

    Science.gov (United States)

    Kumar, Tiruppur Venkatachallam Suresh; Sankar, Kadimi-Udaya; Divakar, Soundar

    2013-08-01

    Enzymatic synthesis of water soluble thymol glycosides were carried out using amyloglucosidase from Rhizopus mold under supercritical carbon dioxide (SCCO2) conditions of 120 bar pressure at 50 °C. Thymol 1 formed glycosides with D-galactose 2, D-mannose 3, D-fructose 4, D-ribose 5 and D-arabinose 6 in yields ranging from 20.6% to 54.2%. Spectral characterization studies revealed that the reaction occurred between the phenolic OH group of thymol and 1-O/2-O groups of D-fructose and C-1 group of D-galactose, D-mannose, D-ribose and D-arabinose resulting in monoglycosylated/arylated derivatives. PMID:24425985

  5. Facile Synthesis of the Naturally Cytotoxic Triterpenoid Saponin Patrinia-Glycoside B-II and Its Conformer

    Directory of Open Access Journals (Sweden)

    Li Ren

    2013-12-01

    Full Text Available The first chemical synthesis of the natural triterpenoid saponin Patrinia-glycoside B-II, namely oleanolic acid 3-O-α-L-rhamnopyranosyl-(1→2-[β-D-gluco-pyranosyl-(1→3]-α-L-arabinopyranoside, has been accomplished in a linear 11-step sequence 11 with 9.4% overall yield. The abnormal 1C4 conformation of the arabinose residue was found to occur via conformational fluctuation during preparation of the intermediates. Molecular mechanism and quantum chemistry calculations showed that Patrinia-glycoside B-II and its conformer 1 cannot interconvert under normal conditions. Preliminary structure-activity relationships studies indicated that the 4C1 chair conformation of the arabinose residue in the unique α-L-rhamnopyranosyl-(1→2-α-L-arabinopyranosyl disaccharide moiety is one of the chief positive factors responsible for its cytotoxic activity against tumors.

  6. European analytical column no. 39. Analytical chemistry and bioanalytical chemistrya yet unshaped social relationship

    DEFF Research Database (Denmark)

    Horvai, George; Worsfold, Paul; Karlberg, Bo;

    2011-01-01

    acceptors 18 different β-xylosyl-oligosaccharides were synthesised in 2–36% (BxlA) and 6–66% (BxlB) yields by transxylosylation. BxlA utilised the monosaccharides d-mannose, d-lyxose, d-talose, d-xylose, d-arabinose, l-fucose, d-glucose, d-galactose and d-fructose as acceptors, whereas BxlB used the same...... except for d-lyxose, d-arabinose and l-fucose. BxlB transxylosylated the disaccharides xylobiose, lactulose, sucrose, lactose and turanose in upto 35% yield, while BxlA gave inferior yields on these acceptors. The regioselectivity was acceptor dependent and primarily involved β-1,4 or 1,6 product linkage...

  7. Enzymatic synthesis of β-xylosyl-oligosaccharides by transxylosylation using two beta-xylosidases of glycoside hydrolase family 3 from Aspergillus nidulans FGSC A4

    DEFF Research Database (Denmark)

    Dilokpimol, Adiphol; Nakai, Hiroyuki; Gotfredsen, Charlotte Held;

    2011-01-01

    alcohols as acceptors 18 different p-xylosyl-oligosaccharides were synthesised in 2-36% (BxlA) and 6-66% (BxlB) yields by transxylosylation. BxlA utilised the monosaccharides D-mannose, D-lyxose, D-talose, D-xylose, D-arabinose, L-fucose, D-glucose, D-galactose and D-fructose as acceptors, whereas Bxl......B used the same except for D-lyxose, D-arabinose and L-fucose. BxlB transxylosylated the disaccharides xylobiose, lactulose, sucrose, lactose and turanose in upto 35% yield, while BxlA gave inferior yields on these acceptors. The regioselectivity was acceptor dependent and primarily involved beta-1,4 or...

  8. Decomposition of wheat bran and ispaghula husk in the stomach and the small intestine of healthy men

    DEFF Research Database (Denmark)

    Andersen, J R; Bukhave, K; Højgaard, L;

    1988-01-01

    for monosaccharides, either free or fiber-bound, by gas-liquid chromatography. Both types of fiber were hydrolyzed in the stomach, but not in the small bowel. Of ispaghula husk, 1-6% was hydrolyzed, as was 5-8% of wheat bran. Intestinal absorption of free arabinose was 85-93%, but excretion of arabinose in the urine......Decomposition of dietary fibers in the stomach and small bowel was studied in 13 healthy male volunteers. Liquid control meals were compared with test meals, which in addition contained a source of fiber (wheat bran or ispaghula husk) in random order. Aspirations were collected from the stomach...... was not greater than after control meals. For further evaluation of gastric hydrolysis six additional healthy male volunteers were studied by serial aspirations from the antral part of the stomach. Hydrolysis was instantaneous for both fibers, and was significantly more pronounced for wheat bran than...

  9. Efficient Epimerization of Aldoses Using Layered Niobium Molybdates.

    Science.gov (United States)

    Takagaki, Atsushi; Furusato, Shogo; Kikuchi, Ryuji; Oyama, S Ted

    2015-11-01

    Both non-acidic LiNbMoO6 and strongly acidic HNbMoO6 efficiently catalyze the epimerization of sugars including glucose, mannose, xylose, and arabinose in water. The reactions over these oxides reached almost equilibrium within a few hours where yields of corresponding epimers from glucose, xylose, and arabinose were 24-29%. The layered mixed oxides functioned as heterogeneous catalysts and could be reused without loss of activity, whereas bulk molybdenum oxide MoO3 was completely dissolved during the reaction. A (13)C substitution experiment showed that the reaction proceeds through a 1,2-rearrangement mechanism. The surface Mo octahedra were responsible for the activity. The layered HNbMoO6 could also afford mannose from cellobiose through hydrolysis and successive epimerization. PMID:26494106

  10. Biochemical and antigenic properties of Streptococcus bovis isolated from pigeons.

    OpenAIRE

    De Herdt, P; Haesebrouck, F; DEVRIESE, L.A.; Ducatelle, R.

    1992-01-01

    Biochemical and serological properties of 60 strains of Streptococcus bovis isolated from healthy pigeons and from pigeons that died from S. bovis septicemia were determined. On the basis of the hemolysis of bovine erythrocytes, the production of polysaccharides on saccharose-containing media, and the fermentation of mannitol, inulin, trehalose, and L-arabinose, the isolates were classified in five biotypes and two subbiotypes. Slide agglutination and microagglutination tests using monospecif...

  11. Isolation of peptide aptamers that inhibit intracellular processes

    OpenAIRE

    Blum, Jonathan H.; Dove, Simon L.; Hochschild, Ann; Mekalanos, John J.

    2000-01-01

    We have developed a method for isolation of random peptides that inhibit intracellular processes in bacteria. A library of random peptides expressed as fusions to Escherichia coli thioredoxin (aptamers) were expressed under the tight control of the arabinose-inducible PBAD promoter. A selection was applied to the library to isolate aptamers that interfered with the activity of thymidylate synthase (ThyA) in vivo. Expression of an aptamer isolated by this method resulted in a ThyA− phenotype t...

  12. Archaeal promoter architecture and mechanism of gene activation

    DEFF Research Database (Denmark)

    Peng, Nan; Ao, Xiang; Liang, Yun Xiang;

    2011-01-01

    Sulfolobus solfataricus and Sulfolobus islandicus contain several genes exhibiting D-arabinose-inducible expression and these systems are ideal for studying mechanisms of archaeal gene expression. At sequence level, only two highly conserved cis elements are present on the promoters: a regulatory...... mechanisms include TFB (transcription factor B) recruitment by the ara-box-binding factor to activate gene expression and modulation of TFB recruitment efficiency to yield differential gene expression....

  13. Evaluation of Carbohydrates in Natural and Cultured Cordyceps by Pressurized Liquid Extraction and Gas Chromatography Coupled with Mass Spectrometry

    OpenAIRE

    Jia Guan; Feng-Qing Yang; Shao-Ping Li

    2010-01-01

    Free and polymeric carbohydrates in Cordyceps, a valued edible mushroom and well-known traditional Chinese medicine, were determined using stepwise pressurized liquid extraction (PLE) extraction and GC-MS. Based on the optimized PLE conditions, acid hydrolysis and derivatization, ten monosaccharides, namely rhamnose, ribose, arabinose, xylose, mannose, glucose, galactose, mannitol, fructose and sorbose in 13 samples of natural and cultured Cordyceps were qualitatively and quantitatively analy...

  14. Bis-Indole Derivatives for Polysaccharide Compositional Analysis and Chiral Resolution of D-, L-Monosaccharides by Ligand Exchange Capillary Electrophoresis Using Borate-Cyclodextrin as a Chiral Selector

    OpenAIRE

    Wen-Bin Yang; Yin-Chen Liu; Kuo-Shiang Liao; Chien-Yuan Kuo

    2011-01-01

    A series of aldo-bis-indole derivatives (aldo-BINs) was prepared by aromatic C-alkylation reactions of aldoses and indole in acetic acid solution. Common monosaccharides such as glucose, mannose, galactose, fucose, xylose, rhamnose, ribose, arabinose and N-acetylglucosamine were smoothly derivatized to form the UV absorbing aldo-BINs. The use of a capillary electrophoretic method to separate these novel aldo-BIN derivatives was established. The capillary electrophoresis conditions were set by...

  15. Circular dichroism readout of sugar recognition in the cleft of a fused-pyridine receptor

    OpenAIRE

    Tamaru, Shun-ichi; Shinkai, Seiji; Khasanov, Alisher B.; Bell, Thomas W.

    2002-01-01

    Dicarboxamide host 2 forms 1:1 complexes with n-octyl pyranosides derived from d-glucose, d-mannose, d-galactose, d-fucose, d-lyxose, and d-arabinose. Association constants (Ka) in the range of 77–940 M−1 were measured in chloroform by means of induced circular dichroism and fluorescence spectroscopy. Variations in Ka values correspond qualitatively to expected differences in hydrogen-bonding abilities of guest hydroxyl groups. Induced circular dichroism effects for...

  16. Anthocyanin pigments in strawberry

    OpenAIRE

    Lopes-da-Silva, M.F.; Escribano-Bailón, M.T.; Perez-Alonso, J.J.; Rivas-Gonzalo, J.C.; Santos-Buelga, Celestino

    2007-01-01

    The anthocyanin composition was analysed in strawberry fruits from five different cultivars (cv. Eris, Oso Grande, Carisma, Tudnew and Camarosa). Twenty-five defined anthocyanin pigments were detected, most of them containing Pelargonidin (Pg) as aglycone; some cyanidin (Cy) derivatives were also found. Glucose and rutinose were the usual substituting sugars, although arabinose and rhamnose were also tentatively identified; some minor anthocyanins showed acylation with aliphatic acids. A rele...

  17. Preparation and Characterization of Pectin Hydroxamates from Citrus Unshiu Peels.

    OpenAIRE

    In Young Bae; Hyun Jae Rha; Suyong Lee; Hyeon Gyu Lee

    2011-01-01

    Pectin was extracted from unshiu orange (Citrus unshiu) peels and was subjected to chemical modification using hydroxamic acid. The structural and physical properties of the resulting derivatives were investigated as a function of hydroxamic acid content (4.68-9.58%). The extracted unshiu orange pectin showed 66.8% degree of esterification, 787.5 mg/g galacturonic acid, and 92 mg/g neutral sugars, which were composed of arabinose (53%), galactose (35%), glucose (5%), rhamnose (5%), and fructo...

  18. Increase in cellulose accumulation and improvement of saccharification by overexpression of arabinofuranosidase in rice.

    Directory of Open Access Journals (Sweden)

    Minako Sumiyoshi

    Full Text Available Cellulosic biomass is available for the production of biofuel, with saccharification of the cell wall being a key process. We investigated whether alteration of arabinoxylan, a major hemicellulose in monocots, causes an increase in saccharification efficiency. Arabinoxylans have β-1,4-D-xylopyranosyl backbones and 1,3- or 1,4-α-l-arabinofuranosyl residues linked to O-2 and/or O-3 of xylopyranosyl residues as side chains. Arabinose side chains interrupt the hydrogen bond between arabinoxylan and cellulose and carry an ester-linked feruloyl substituent. Arabinose side chains are the base point for diferuloyl cross-links and lignification. We analyzed rice plants overexpressing arabinofuranosidase (ARAF to study the role of arabinose residues in the cell wall and their effects on saccharification. Arabinose content in the cell wall of transgenic rice plants overexpressing individual ARAF full-length cDNA (OsARAF1-FOX and OsARAF3-FOX decreased 25% and 20% compared to the control and the amount of glucose increased by 28.2% and 34.2%, respectively. We studied modifications of cell wall polysaccharides at the cellular level by comparing histochemical cellulose staining patterns and immunolocalization patterns using antibodies raised against α-(1,5-linked l-Ara (LM6 and β-(1,4-linked d-Xyl (LM10 and LM11 residues. However, they showed no visible phenotype. Our results suggest that the balance between arabinoxylan and cellulose might maintain the cell wall network. Moreover, ARAF overexpression in rice effectively leads to an increase in cellulose accumulation and saccharification efficiency, which can be used to produce bioethanol.

  19. Sustainability Evaluation of Biodiesel Produced from Microalgae Chlamydomonas sp Grown in Brewery Wastewater

    OpenAIRE

    Mata, Teresa M.; Santos, Janaína; Mendes, Adélio M; Caetano, Nídia S.; Martins, António A.

    2014-01-01

    This study performs a sustainability evaluation of biodiesel from microalga Chlamydomonas sp. grown in 20 % (v/v) of brewery’s wastewater, blended with pentose sugars (xylose, arabinose or ribose resulting from the hydrolysis of brewer’s spent grains (BSG). The life cycle steps considered for the study are: microalgae cultivation, biomass processing and lipids extraction at the brewery site, and its conversion to biodiesel at a dedicated external biofuel’s plant. Three sustainabil...

  20. Steroidal saponins from Agave Attenuata

    International Nuclear Information System (INIS)

    The polar fraction of the extract of Agave Attenuata Solm (family Agavaceae) afforded two steroidal saponins identified on the basis of spectral data as (25S)-sarsasapogenin-3-b-Dglyconside and (25S)-3-b, 22-a, 26-trihydroxy-16, 22-oxycoprostane-3-26 diglyconside. The glyconsidic moiety in the first compound is a disaccharide consists of glucose and galactose while in the second compound, the glyconsidic moieties are glucose and arabinose. (author)

  1. Isolation and chemical characterization of saponins from lucerne seeds (Medicago media Pers.)

    OpenAIRE

    Marian Jurzysta

    2015-01-01

    Saponins of lucerne seeds have been prepared by two different methods. It was found by thin-layer chromatography that these glycosides consist of at least four components with one dominant. Soyasapogenols B, C and E were identified in acid hydrolysate of these saponins and in carbohydrate moiety glucose, galactose, rhamnose, small quantity of arabinose and xylose and glucuronic acid. It was established that saponins of lucerne seeds do not haemolyse red blood cells, contrary to top, root and ...

  2. Isolation, chemical characterization and biological activity of red clover (Trifolium pratense L.) root saponins

    OpenAIRE

    Wiesław Oleszek; Marian Jurzysta

    2014-01-01

    Crystalline saponins were isolated from red clover (Trifolium pratense L.) roots. They were a mixture of two glycosides showing no haemolytic or fungistatic activity. Acid hydrolysis of these saponins yielded soyasapogenols B. C. D. E and F and rhamnose. xylose, arabinose glucose and glucuronic acid as sugar components. They were poorly or not soluble in water and well soluble in ethanol. Water suspensions of these saponins did not affect winter wheat seedling growth.

  3. Carbohydrate utilization and metabolism is highly differentiated in Agaricus bisporus

    OpenAIRE

    Patyshakuliyeva, A.; Jurak, E.; Kohler, A; Baker, A.; Battaglia, E; Bruijn, de, M.E.; Burton, K.S.; Challen, M.P.; Cuotinho, P.M.; Eastwood, D.C.; Gruben, B.S.; Makela, M.R.; Martin, F.; Nadal, M; Brink, van den, A Arno

    2013-01-01

    Background - Agaricus bisporus is commercially grown on compost, in which the available carbon sources consist mainly of plant-derived polysaccharides that are built out of various different constituent monosaccharides. The major constituent monosaccharides of these polysaccharides are glucose, xylose, and arabinose, while smaller amounts of galactose, glucuronic acid, rhamnose and mannose are also present. Results - In this study, genes encoding putative enzymes from carbon metabolism were i...

  4. Thermoanaerobacter pentosaceus sp. nov., an anaerobic, extreme thermophilic, high ethanol-yielding bacterium isolated from household waste

    DEFF Research Database (Denmark)

    Tomás, Ana Faria; Karakashev, Dimitar Borisov; Angelidaki, Irini

    2013-01-01

    approximately 0.5 µm. Optimal growth occurred at 70 °C and pH(25°C) 7, with a maximum growth rate of 0.1 h-1. DNA G+C content was 34.2 mol %. Strain DTU01(T) could ferment arabinose, cellobiose, fructose, galactose, glucose, inulin, lactose, mannose, melibiose, pectin, starch, sucrose, xylan, yeast extract and...

  5. Distinctive biochemical features of Salmonella dublin isolated in California.

    OpenAIRE

    Fierer, J.; Fleming, W

    1983-01-01

    We examined 34 strains of Salmonella dublin that were isolated in California between 1978 and 1982. All were of a characteristic biotype; they did not grow on Simmons citrate or acetate and did not ferment arabinose. Their apparent inability to use citrate as the only carbon source was due to a nutritional requirement for nicotinic acid. Because S. dublin strains are of a characteristic biotype, are host adapted to bovines, and are unusually virulent for humans, we suggest that S. dublin be c...

  6. Solid-phase catalytic reactions of tritium with carbohydrates. Communication 3. Mechanism of isomerization of epimeric pentoses in the course of solid-phase catalytic hydrogenation with tritium

    International Nuclear Information System (INIS)

    The mechanism of isomerization of ribose into arabinose in the solid phase under the action of spillover hydrogen in the course of solid-phase catalytic hydrogenation with tritium was studied. Isomerization of ribose was shown to occur by a complex mechanism similar to acid-catalyzed keto-enol tautomerization of epimeric sugars in solution; the active species in solid-phase catalytic hydrogenation of D-ribose with tritium is spillover hydrogen in the proton form

  7. Preparation, characterization, and biological properties of β-glucans

    OpenAIRE

    Sandeep Rahar; Gaurav Swami; Navneet Nagpal; Manisha A Nagpal; Gagan Shah Singh

    2011-01-01

    β-Glucans are soluble fibers with physiological functions, such as, interference with absorption of sugars and reduction of serum lipid levels. β-glucans are found in different species, such as, Rhynchelytrum repens, Lentinus edodes, Grifola frondosa, Tremella mesenterica, Tremella aurantia, Zea may, Agaricus blazei, Phellinus baummi, Saccharomyces cerevisae (yeast), and Agaricus blazei murell (mushroom). Analysis of the fractions reveals the presence of arabinose, glucose, xylose, and traces...

  8. Kohlenhydrat-Auxiliare in der asymmetrischen Synthese chiraler Stickstoffheterocyclen und Alkaloide

    OpenAIRE

    Kranke, Birgit

    2005-01-01

    In dieser Arbeit wurden durch Verwendung eines stereodifferenzierenden Kohlenhydrat-Auxiliars chirale Stickstoffheterocyclen und enantiomerenreine Piperidin-Alkaloide synthetisiert. Alkaloide mit einer Piperidin-Grundstruktur sind in der Natur weit verbreitet und weisen vielfältige biologische Aktivitäten auf. Zusammen mit synthetischen Derivaten sind sie daher von großem Interesse für die Wirkstoffforschung. Mit dem aus D-Arabinose zugänglichen 2,3,4-Tri-O-pivaloyl-D-arabinosylamin wurden...

  9. Study of batch fermentation of chemical prehydrolyzates from pith with the y-900 strian of Candida utilis

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, C.; Lopez, R.; Llerena, L.

    1979-01-01

    C. utilis Y-900 was grown on pith from sugarcane bagasse that had been treated with 1% H/sub 2/S0/sub 4/ under elevated temperature and pressure. The hydrolyzate contained approximately 90% xylose + arabinose and approximately 10% glucose + galactose, and was supplemented with urea, H/sub 3/P0/sub 4/, and yeast extraction. The yeast consumed 75% of the sugar in 24 h, producing biomass containing 42.7% protein.

  10. Engineering of Corynebacterium glutamicum for xylitol production from lignocellulosic pentose sugars.

    Science.gov (United States)

    Dhar, Kiran S; Wendisch, Volker F; Nampoothiri, Kesavan Madhavan

    2016-07-20

    Xylitol is a non-fermentable sugar alcohol used as sweetener. Corynebacterium glutamicum ATCC13032 was metabolically engineered for xylitol production from the lignocellulosic pentose sugars xylose and arabinose. Direct conversion of xylose to xylitol was achieved through the heterologous expression of NAD(P)H-dependent xylose reductase (xr) gene from Rhodotorula mucilaginosa. Xylitol synthesis from arabinose was attained through polycistronic expression of l-arabinose isomerase (araA), d-psicose 3 epimerase (dpe) and l-xylulose reductase (lxr) genes from Escherichia coli, Agrobacterium tumefaciens and Mycobacterium smegmatis, respectively. Expression of xr and the synthetic araA-dpe-lxr operon under the control of IPTG-inducible Ptac promoter enabled production of xylitol from both xylose and arabinose in the mineral (CGXII) medium with glucose as carbon source. Additional expression of a pentose transporter (araTF) gene enhanced xylitol production by about four-fold compared to the parent strain. The constructed strain Cg-ax3 produced 6.7±0.4g/L of xylitol in batch fermentations and 31±0.5g/L of xylitol in fed-batch fermentations with a specific productivity of 0.28±0.05g/g cdw/h. The strain Cg-ax3 was also validated for xylitol production from pentose rich, acid pre-treated liquor of sorghum stover (SAPL) and the results were comparable in both SAPL (27±0.3g/L) and mineral medium (31±0.5g/L). PMID:27184428

  11. Purification and characterization of alpha-L-arabinofuranosidase from Bacillus stearothermophilus T-6.

    OpenAIRE

    Gilead, S; Shoham, Y.

    1995-01-01

    Bacillus stearothermophilus T-6 produced an alpha-L-arabinofuranosidase when grown in the presence of L-arabinose, sugar beet arabinan, or oat spelt xylan. At the end of a fermentation, about 40% of the activity was extracellular, and enzyme activity in the cell-free supernatant could reach 25 U/ml. The enzymatic activity in the supernatant was concentrated against polyethylene glycol 20000, and the enzyme was purified eightfold by anion-exchange and hydrophobic interaction chromatographies. ...

  12. Synthesis of octitols and the respective amino-derivatives from 'organo-aldols'.

    Science.gov (United States)

    Łęczycka, Katarzyna; Chaciak, Bartosz; Cieplak, Maciej; Cmoch, Piotr; Jarosz, Sławomir

    2015-02-11

    Two diastereoisomeric keto-octoses, obtained in the reaction of 2,3:4,5-diacetone-D-arabinose with protected dihydroxyacetone catalyzed with L- or D-proline, were converted into octitols by stereoselective reduction of the carbonyl group with zinc borohydride and final deprotection. The study on the preparation of the respective amino-derivatives by reductive amination of these organo-adducts is presented; stereochemical aspects of these processes are discussed. PMID:25130931

  13. Kinetics and Regulation Studies of the Production of β-Galactosidase from Kluyveromyces marxianus Grown on Different Substrates

    OpenAIRE

    Rajoka, Muhammad Ibrahim; Khan, Samia; Shahid, Riaz

    2003-01-01

    Lactose-intolerance is manifested in 50 % of the world’s population. This can be remediated by removing lactose from the diet or converting it into glucose and galactose with β-galactosidase (EC 3.2.1.23). In this work, batch production of this enzyme in the presence of lactose, galactose, cellobiose, xylose, arabinose, sucrose and glucose was investigated using Kluyveromyces marxianus in shake flask culture studies. Substrate type and temperature were the independent variables that directly ...

  14. Synthesis and biological activity of new homolupanes and homolupane saponins

    OpenAIRE

    Sidoryk, K.; Korda, A.; Rárová, L. (Lucie); Oklešťková, J. (Jana); Strnad, M; Cmoch, P.; Pakulski, Z.; Gwardiak, K.; Karczewski, R.; Luboradzki, R.

    2015-01-01

    A concise synthesis of 28a-homolupane triterpenes and the corresponding saponins containing D-mannose, D-idose, D-arabinose, and L-rhamnose moieties was elaborated. The overall synthesis of the new triterpenes involved three linear steps starting from readily available 3-O-acetyl-betulinal: elongation of the carbon chain by Wittig reaction followed by enol ether hydrolysis and reduction (or oxidation) of the elongated aldehyde. Saponins were obtained by glycosylation of triterpenes with class...

  15. Synthesis and structure-activity relationship study of cytotoxic lupane-type 3 beta-O-monodesmosidic saponins with an extended C-28 side chain

    OpenAIRE

    Cmoch, P.; Korda, A.; Rárová, L. (Lucie); Oklešťková, J. (Jana); Strnad, M; Luboradzki, R.; Pakulski, Z.

    2014-01-01

    A concise synthesis of lupane triterpenes with an elongated carbon chain at the C-28 position, as well as saponins containing D-mannose, L-arabinose, and L-rhamnose moieties at the C-3 position is described. The overall synthesis of the new triterpenes involved seven linear steps starting from natural betulin: selective protection of a hydroxyl group, oxidation, elongation of the carbon chain by Grignard reaction, and deoxygenation. O-Glycosides were obtained by glycosylation of triterpenes w...

  16. Elucidation of the biosynthesis of the di-C-glycosylflavone isoschaftoside, an allelopathic component from Desmodium spp. that inhibits Striga spp. development.

    Science.gov (United States)

    Hamilton, Mary L; Kuate, Serge P; Brazier-Hicks, Melissa; Caulfield, John C; Rose, Ruth; Edwards, Robert; Torto, Baldwyn; Pickett, John A; Hooper, Antony M

    2012-12-01

    Isoschaftoside, an allelopathic di-C-glycosylflavone from Desmodium spp. root exudates, is biosynthesised through sequential glucosylation and arabinosylation of 2-hydroxynaringenin with UDP-glucose and UDP-arabinose. Complete conversion to the flavone requires chemical dehydration implying a dehydratase enzyme has a role in vivo to complete the biosynthesis. The C-glucosyltransferase has been partially characterised and its activity demonstrated in highly purified fractions. PMID:22959223

  17. [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

  18. Bio-hydrogen production in an EGSB reactor under mesophilic, thermophilic and hyperthermophilic conditions

    OpenAIRE

    Abreu, A. A.; Danko, Anthony S.; Alves, M. M.

    2007-01-01

    Mesophilic, thermophilic and hyperthermophilic bio-hydrogen production with an expanded granular sludge blanket (EGSB) fed with glucose and arabinose, without methane production, was demonstrated. Homoacetogenesis was observed on reactor when operated under mesophilic (37ºC) conditions but not under thermophilic (55ºC) and hyper-thermophilic conditions (70ºC). It was also found that under thermophilic and hyper-thermophilic conditions glucose is preferentially consumed than ara...

  19. Preliminary study for optimization of enzymatic hydrolysis of waste cellulosic materials

    OpenAIRE

    LUMINITA GEORGESCU; IULIANA LEUŞTEAN; GABRIELA BAHRIM

    2011-01-01

    Lignocellulose is a generic term describing the main constituents in most plants, namely cellulose, hemicelluloses, and lignin. Cellulose is a glucose polysaccharide, hemicelluloses are polysaccharides with a backbone of different hexoses (glucose, mannose, galactose) and pentoses (xylan, arabinose), and lignin is a complex network of different phenyl propane units. The cellulosic materials are potential sources of ethanol. Steps of this process are saccharification of cellulose to reduce sug...

  20. H synthesis from pentoses and biomass in spp.

    OpenAIRE

    Eriksen, Niels T.; Riis, Martin Leegaard; Holm, Nikolaj Kyndby; Iversen, Niels

    2010-01-01

    Abstract We have investigated H2 production on glucose, xylose, arabinose, and glycerol in Thermotoga maritima and T. neapolitana. Both species metabolised all sugars with hydrogen yields of 2.7?3.8 mol mol?1 sugar. Both pentoses were at least comparable to glucose with respect to their qualities as substrates for hydrogen production, while glycerol was not metabolised by either species. Glycerol was also not metabolised by T. elfii. We also demonstrated that T. neapolitana can use...

  1. Demonstration of Chemical Equilibrium through Regeneration of Color in Blue Bottle Experiment

    Directory of Open Access Journals (Sweden)

    *R. Azmat

    2011-03-01

    Full Text Available Concept of equilibrium is very difficult to understand for under graduate students. This experiment has a good visual impact of demonstration of equilibrium and would be one way of stimulating awareness in chemistry. An alkaline solution of arabinose and methylene green in aqueous medium can be used to explain equilibrium visually through reaction of dissolved oxygen which was observed in “BLUE BOTTLE EXPERIMENT” that showed the shift of equilibrium by regeneration of color during shaking and upon standing equilibrium shift in the forward direction and color loss was observed. Shaking the solution raises the concentration of oxygen in the mixture and oxidizes the methylene green back to its blue form. When the dissolved oxygen has been consumed, the methylene green is slowly reduced back to its colorless form by the remaining arabinose and the cycle can be repeated many times by further shaking. The experiment was repeated with various concentrations of dye indicator, arabinose and sodium hydroxide concentration. It was observed that regeneration of color and colorloss is the best visual example of explanation of equilibrium.

  2. Claudin gene expression patterns do not associate with interspecific differences in paracellular nutrient absorption.

    Science.gov (United States)

    Price, Edwin R; Rott, Katherine H; Caviedes-Vidal, Enrique; Karasov, William H

    2016-01-01

    Bats exhibit higher paracellular absorption of glucose-sized molecules than non-flying mammals, a phenomenon that may be driven by higher permeability of the intestinal tight junctions. The various claudins, occludin, and other proteins making up the tight junctions are thought to determine their permeability properties. Here we show that absorption of the paracellular probe l-arabinose is higher in a bat (Eptesicus fuscus) than in a vole (Microtus pennsylvanicus) or a hedgehog (Atelerix albiventris). Furthermore, histological measurements demonstrated that hedgehogs have many more enterocytes in their intestines, suggesting that bats cannot have higher absorption of arabinose simply by having more tight junctions. We therefore investigated the mRNA levels of several claudins and occludin, because these proteins may affect permeability of tight junctions to macronutrients. To assess the expression levels of claudins per tight junction, we normalized the mRNA levels of the claudins to the constitutively expressed tight junction protein ZO-1, and combined these with measurements previously made in a bat and a rodent to determine if there were among-species differences. Although expression ratios of several genes varied among species, there was not a consistent difference between bats and non-flyers in the expression ratio of any particular gene. Protein expression patterns may differ from mRNA expression patterns, and might better explain differences among species in arabinose absorption. PMID:26393434

  3. Continuous Ethanol Fermentation of Pretreated Lignocellulosic Biomasses, Waste Biomasses, Molasses and Syrup Using the Anaerobic, Thermophilic Bacterium Thermoanaerobacter italicus Pentocrobe 411.

    Directory of Open Access Journals (Sweden)

    Rasmus Lund Andersen

    Full Text Available Lignocellosic ethanol production is now at a stage where commercial or semi-commercial plants are coming online and, provided cost effective production can be achieved, lignocellulosic ethanol will become an important part of the world bio economy. However, challenges are still to be overcome throughout the process and particularly for the fermentation of the complex sugar mixtures resulting from the hydrolysis of hemicellulose. Here we describe the continuous fermentation of glucose, xylose and arabinose from non-detoxified pretreated wheat straw, birch, corn cob, sugar cane bagasse, cardboard, mixed bio waste, oil palm empty fruit bunch and frond, sugar cane syrup and sugar cane molasses using the anaerobic, thermophilic bacterium Thermoanaerobacter Pentocrobe 411. All fermentations resulted in close to maximum theoretical ethanol yields of 0.47-0.49 g/g (based on glucose, xylose, and arabinose, volumetric ethanol productivities of 1.2-2.7 g/L/h and a total sugar conversion of 90-99% including glucose, xylose and arabinose. The results solidify the potential of Thermoanaerobacter strains as candidates for lignocellulose bioconversion.

  4. Continuous Ethanol Fermentation of Pretreated Lignocellulosic Biomasses, Waste Biomasses, Molasses and Syrup Using the Anaerobic, Thermophilic Bacterium Thermoanaerobacter italicus Pentocrobe 411.

    Science.gov (United States)

    Andersen, Rasmus Lund; Jensen, Karen Møller; Mikkelsen, Marie Just

    2015-01-01

    Lignocellosic ethanol production is now at a stage where commercial or semi-commercial plants are coming online and, provided cost effective production can be achieved, lignocellulosic ethanol will become an important part of the world bio economy. However, challenges are still to be overcome throughout the process and particularly for the fermentation of the complex sugar mixtures resulting from the hydrolysis of hemicellulose. Here we describe the continuous fermentation of glucose, xylose and arabinose from non-detoxified pretreated wheat straw, birch, corn cob, sugar cane bagasse, cardboard, mixed bio waste, oil palm empty fruit bunch and frond, sugar cane syrup and sugar cane molasses using the anaerobic, thermophilic bacterium Thermoanaerobacter Pentocrobe 411. All fermentations resulted in close to maximum theoretical ethanol yields of 0.47-0.49 g/g (based on glucose, xylose, and arabinose), volumetric ethanol productivities of 1.2-2.7 g/L/h and a total sugar conversion of 90-99% including glucose, xylose and arabinose. The results solidify the potential of Thermoanaerobacter strains as candidates for lignocellulose bioconversion. PMID:26295944

  5. The biosynthesis and wall-binding of hemicelluloses in cellulose-deficient maize cells:An example of metabolic plasticity

    Institute of Scientific and Technical Information of China (English)

    Mara de Castro; Janice G Miller; Jose Luis Acebes; Antonio Encina; Penelope Garca-Angulo; Stephen C Fry

    2015-01-01

    Cell-suspension cultures (Zea mays L., Black Mexican sweet corn) habituated to 2,6-dichlorobenzonitrile (DCB) survive with reduced cellulose owing to hemicellulose network modification. We aimed to define the hemicellulose metabolism modifications in DCB-habituated maize cells showing a mild reduction in cellulose at different stages in the culture cycle. Using pulse-chase radiolabeling, we fed habituated and non-habituated cultures with [3H]arabinose, and traced the distribution of 3H-pentose residues between xylans, xyloglucans and other polymers in several cellular compartments for 5 h. Habituated cells were slower taking up exogenous [3H]arabinose. Tritium was incorporated into polysaccharide-bound arabinose and xylose residues, but habituated cells diverted a higher proportion of their new [3H] xylose residues into (hetero) xylans at the expense of xyloglucan synthesis. During logarithmic growth, habituated cells showed slower vesicular trafficking of polymers, especially xylans. Moreover, habituated cells showed a decrease in the strong wall-binding of all pentose-containing polysaccharides studied; correspondingly, especially in log-phase cultures, habituation increased the proportion of 3H-hemicelluloses ([3H]xylans and [3H]xyloglucan) sloughed into the medium. These findings could be related to the cell walls’ cellulose-deficiency, and consequent reduction in binding sites for hemicelluloses; the data could also reflect the habituated cells’ reduced capacity to integrate arabinox-ylans by extra-protoplasmic phenolic cross-linking, as well as xyloglucans, during wall assembly.

  6. Response of the grass-cutting ant Atta capiguara Gonçalves, 1944 (Hymenoptera: Formicidae to sugars and artificial sweeteners

    Directory of Open Access Journals (Sweden)

    Boaretto Maria Aparecida Castellani

    2003-01-01

    Full Text Available Using of toxic baits made of dehydrated citric pulp to control grass-cutting ants can lead to unsatisfactory results because of the low attractiveness of the substrate to worker ants. This work aimed to identify attractive substances, with potential for incorporation in a matrix of granulated baits for grass-cutting ants, among several kinds of sugars and substances used in artificial sweeteners. Experiments were carried out in mature nests of Atta capiguara (Hym.: Formicidae set in pasture. Studied substances were sucrose, fructose, soluble starch, raffinose, maltose, lactose, sorbose, cellobiose, arabinose, xylose, glucose, galactose, rhamnose, arabinose, melezitose, saccharine and cyclamate (at 5.0% w/v. Later, on maltose, xylose, sucrose, fructose and glucose solutions were included at 5.0%, 7.5%, 10.0% and 20.0% w/v, respectively. Cellulose rectangles were used as vehicle and number of rectangles carried into the colonies was evaluated. Carrying rates were very low with maximum means of 9.6% for lactose and 6.0% for arabinose and cyclamate, at the 5.0% concentration. No differences (P > 0.05 were observed relatively to the control (distilled water. No effects were detected for solution, concentration and for the interaction of these factors. Sugars and artificial sweeteners studied were not attractive to Atta capiguara workers, turning their inclusion as attractants in toxic ant baits not viable.

  7. A sugar biomarker proxy for assessing terrestrial versus aquatic sedimentary input

    Science.gov (United States)

    Hepp, Johannes; Rabus, Max; Laforsch, Christian; Anhäuser, Tobias; Glaser, Bruno; Zech, Michael

    2016-04-01

    Lake sediments are valuable, often continuous and potentially high resolution archives for studying past climate changes. Thereby, one of the crucial questions is often whether the origin of the organic matter in lake sediments is allochthonous (terrestrial) or autochthonous (aquatic). Here we present patterns of neutral sugars of various plants and algae species to answer the question whether the deoxyhexoses (fucose, rhamnose) to pentoses (arabinose, xylose) ratio can serve as a proxy for aquatic versus terrestrial sedimentary lake input, respectively. Our sugar pattern results show that the fucose + rhamnose content plotted against arabinose and xylose in a ternary diagram can be used to distinguish between algae and other (namely aquatic plants, emergent plant, and terrestrial plants) sugar sources. This finding is confirmed by a compilation with sugar data from the literature. Mosses plot within the range of algae. Although the (fucose + rhamnose)/(arabinose + xylose) ratio yields some overlapping between algae and soil/litter samples, we recommend this ratio, particularly when applied within a multiproxy approach, as promising proxy for distinguishing between aquatic vs. terrestrial organic matter in sedimentary archives. Regarding the sugar concentrations of the investigated samples, emergent plants show the highest values as well as the highest variability. Mosses, aquatic plants and algae yield lower sugar concentrations comparable to those of terrestrial plants.

  8. Continuous Ethanol Fermentation of Pretreated Lignocellulosic Biomasses, Waste Biomasses, Molasses and Syrup Using the Anaerobic, Thermophilic Bacterium Thermoanaerobacter italicus Pentocrobe 411

    Science.gov (United States)

    Andersen, Rasmus Lund; Jensen, Karen Møller; Mikkelsen, Marie Just

    2015-01-01

    Lignocellosic ethanol production is now at a stage where commercial or semi-commercial plants are coming online and, provided cost effective production can be achieved, lignocellulosic ethanol will become an important part of the world bio economy. However, challenges are still to be overcome throughout the process and particularly for the fermentation of the complex sugar mixtures resulting from the hydrolysis of hemicellulose. Here we describe the continuous fermentation of glucose, xylose and arabinose from non-detoxified pretreated wheat straw, birch, corn cob, sugar cane bagasse, cardboard, mixed bio waste, oil palm empty fruit bunch and frond, sugar cane syrup and sugar cane molasses using the anaerobic, thermophilic bacterium Thermoanaerobacter Pentocrobe 411. All fermentations resulted in close to maximum theoretical ethanol yields of 0.47–0.49 g/g (based on glucose, xylose, and arabinose), volumetric ethanol productivities of 1.2–2.7 g/L/h and a total sugar conversion of 90–99% including glucose, xylose and arabinose. The results solidify the potential of Thermoanaerobacter strains as candidates for lignocellulose bioconversion. PMID:26295944

  9. L-arabonate and D-galactonate production by expressing a versatile sugar dehydrogenase in metabolically engineered Escherichia coli.

    Science.gov (United States)

    Liu, Huaiwei; Valdehuesa, Kris Niño G; Ramos, Kristine Rose M; Nisola, Grace M; Lee, Won-Keun; Chung, Wook-Jin

    2014-05-01

    The production of L-arabonate and D-galactonate employing a versatile l-arabinose dehydrogenase (AraDH) from Azospirillum brasilense is presented. The promiscuity of AraDH is manifested by its appreciable activity towards L-arabinose and D-galactose as substrates, and NAD(+) and NADP(+) as cofactors. The AraDH was introduced into an engineered Escherichia coli with inactive L-arabinose or D-galactose metabolism, resulting in strains EMA2 and EWG4, respectively. EMA2 produced 43.9 g L(-1)L-arabonate with a productivity of 1.22 g L(-1)h(-1) and 99.1% (mol/mol) yield. After methanol precipitation, 92.6% of L-arabonate potassium salt was recovered with a purity of 88.8%. Meanwhile, EWG4 produced 24.0 g L(-1)D-galactonate, which is 36% higher than that of the strain carrying the specific d-galactose dehydrogenase. Overall results reveal that the versatility of AraDH to efficiently catalyze the formation of L-arabonate and D-galactonate could be a useful tool in advancing industrial viability for sugar acids production. PMID:24713235

  10. Lipid production in batch and fed-batch cultures of Rhodosporidium toruloides from 5 and 6 carbon carbohydrates

    Directory of Open Access Journals (Sweden)

    Wiebe Marilyn G

    2012-05-01

    Full Text Available Abstract Background Microbial lipids are a potential source of bio- or renewable diesel and the red yeast Rhodosporidium toruloides is interesting not only because it can accumulate over 50% of its dry biomass as lipid, but also because it utilises both five and six carbon carbohydrates, which are present in plant biomass hydrolysates. Methods R. toruloides was grown in batch and fed-batch cultures in 0.5 L bioreactors at pH 4 in chemically defined, nitrogen restricted (C/N 40 to 100 media containing glucose, xylose, arabinose, or all three carbohydrates as carbon source. Lipid was extracted from the biomass using chloroform-methanol, measured gravimetrically and analysed by GC. Results Lipid production was most efficient with glucose (up to 25 g lipid L−1, 48 to 75% lipid in the biomass, at up to 0.21 g lipid L−1 h−1 as the sole carbon source, but high lipid concentrations were also produced from xylose (36 to 45% lipid in biomass. Lipid production was low (15–19% lipid in biomass with arabinose as sole carbon source and was lower than expected (30% lipid in biomass when glucose, xylose and arabinose were provided simultaneously. The presence of arabinose and/or xylose in the medium increased the proportion of palmitic and linoleic acid and reduced the proportion of oleic acid in the fatty acids, compared to glucose-grown cells. High cell densities were obtained in both batch (37 g L−1, with 49% lipid in the biomass and fed-batch (35 to 47 g L−1, with 50 to 75% lipid in the biomass cultures. The highest proportion of lipid in the biomass was observed in cultures given nitrogen during the batch phase but none with the feed. However, carbohydrate consumption was incomplete when the feed did not contain nitrogen and the highest total lipid and best substrate consumption were observed in cultures which received a constant low nitrogen supply. Conclusions Lipid production in R. toruloides was lower from arabinose and mixed

  11. The chemoenzymatic synthesis of clofarabine and related 2'-deoxyfluoroarabinosyl nucleosides: the electronic and stereochemical factors determining substrate recognition by E. coli nucleoside phosphorylases.

    Science.gov (United States)

    Fateev, Ilja V; Antonov, Konstantin V; Konstantinova, Irina D; Muravyova, Tatyana I; Seela, Frank; Esipov, Roman S; Miroshnikov, Anatoly I; Mikhailopulo, Igor A

    2014-01-01

    Two approaches to the synthesis of 2-chloro-9-(2-deoxy-2-fluoro-β-D-arabinofuranosyl)adenine (1, clofarabine) were studied. The first approach consists in the chemical synthesis of 2-deoxy-2-fluoro-α-D-arabinofuranose-1-phosphate (12a, (2F)Ara-1P) via three step conversion of 1,3,5-tri-O-benzoyl-2-deoxy-2-fluoro-α-D-arabinofuranose (9) into the phosphate 12a without isolation of intermediary products. Condensation of 12a with 2-chloroadenine catalyzed by the recombinant E. coli purine nucleoside phosphorylase (PNP) resulted in the formation of clofarabine in 67% yield. The reaction was also studied with a number of purine bases (2-aminoadenine and hypoxanthine), their analogues (5-aza-7-deazaguanine and 8-aza-7-deazahypoxanthine) and thymine. The results were compared with those of a similar reaction with α-D-arabinofuranose-1-phosphate (13a, Ara-1P). Differences of the reactivity of various substrates were analyzed by ab initio calculations in terms of the electronic structure (natural purines vs analogues) and stereochemical features ((2F)Ara-1P vs Ara-1P) of the studied compounds to determine the substrate recognition by E. coli nucleoside phosphorylases. The second approach starts with the cascade one-pot enzymatic transformation of 2-deoxy-2-fluoro-D-arabinose into the phosphate 12a, followed by its condensation with 2-chloroadenine thereby affording clofarabine in ca. 48% yield in 24 h. The following recombinant E. coli enzymes catalyze the sequential conversion of 2-deoxy-2-fluoro-D-arabinose into the phosphate 12a: ribokinase (2-deoxy-2-fluoro-D-arabinofuranose-5-phosphate), phosphopentomutase (PPN; no 1,6-diphosphates of D-hexoses as co-factors required) (12a), and finally PNP. The substrate activities of D-arabinose, D-ribose and D-xylose in the similar cascade syntheses of the relevant 2-chloroadenine nucleosides were studied and compared with the activities of 2-deoxy-2-fluoro-D-arabinose. As expected, D-ribose exhibited the best substrate activity

  12. The chemoenzymatic synthesis of clofarabine and related 2′-deoxyfluoroarabinosyl nucleosides: the electronic and stereochemical factors determining substrate recognition by E. coli nucleoside phosphorylases

    Directory of Open Access Journals (Sweden)

    Ilja V. Fateev

    2014-07-01

    Full Text Available Two approaches to the synthesis of 2-chloro-9-(2-deoxy-2-fluoro-β-D-arabinofuranosyladenine (1, clofarabine were studied. The first approach consists in the chemical synthesis of 2-deoxy-2-fluoro-α-D-arabinofuranose-1-phosphate (12a, 2FAra-1P via three step conversion of 1,3,5-tri-O-benzoyl-2-deoxy-2-fluoro-α-D-arabinofuranose (9 into the phosphate 12a without isolation of intermediary products. Condensation of 12a with 2-chloroadenine catalyzed by the recombinant E. coli purine nucleoside phosphorylase (PNP resulted in the formation of clofarabine in 67% yield. The reaction was also studied with a number of purine bases (2-aminoadenine and hypoxanthine, their analogues (5-aza-7-deazaguanine and 8-aza-7-deazahypoxanthine and thymine. The results were compared with those of a similar reaction with α-D-arabinofuranose-1-phosphate (13a, Ara-1P. Differences of the reactivity of various substrates were analyzed by ab initio calculations in terms of the electronic structure (natural purines vs analogues and stereochemical features (2FAra-1P vs Ara-1P of the studied compounds to determine the substrate recognition by E. coli nucleoside phosphorylases. The second approach starts with the cascade one-pot enzymatic transformation of 2-deoxy-2-fluoro-D-arabinose into the phosphate 12a, followed by its condensation with 2-chloroadenine thereby affording clofarabine in ca. 48% yield in 24 h. The following recombinant E. coli enzymes catalyze the sequential conversion of 2-deoxy-2-fluoro-D-arabinose into the phosphate 12a: ribokinase (2-deoxy-2-fluoro-D-arabinofuranose-5-phosphate, phosphopentomutase (PPN; no 1,6-diphosphates of D-hexoses as co-factors required (12a, and finally PNP. The substrate activities of D-arabinose, D-ribose and D-xylose in the similar cascade syntheses of the relevant 2-chloroadenine nucleosides were studied and compared with the activities of 2-deoxy-2-fluoro-D-arabinose. As expected, D-ribose exhibited the best substrate

  13. Influence of substrate on electricity generation of Shewanella loihica PV-4 in microbial fuel cells

    Science.gov (United States)

    2014-01-01

    Background The substrate, serving as carbon and energy source, is one of the major factors affecting the performance of microbial fuel cells (MFCs). We utilized BIOLOG system to rapidly screen substrates for electricigens, and further evaluated influence of these substrates on electricity generation of Shewanella loihica PV-4 in MFCs. Results Three of most favorable substrates (lactate acid, formic acid and cyclodextrin) with OD590/750 of 0.952, 0.880 and 0.849 as well as three of most unfavorable substrates (galactose, arabinose and glucose) with OD590/750 of 0.248, 0.137 and 0.119 were selected by BIOLOG system under aerobic conditions. The chronoamperometry results showed that MFCs fed with these substrates exhibited different current behaviors. Cyclic voltammograms results showed that arabinose, galactose and glucose promoted electron transfer from outer membrane c-Cyts of cells to the electrode surface. Lactic acid, formic acid and cyclodextrin produced lower quantity of electric charge of 10.13 C, 9.83 C and 10.10 C, the corresponding OD600 value was 0.180, 0.286 and 0.152 in BES; while galactose, arabinose and glucose generated higher quantity of electric charge of 12.34 C, 13.42 C and 17.45 C, and increased OD600 values were 0.338, 0.558 and 0.409 in BES. SEMs results showed that plenty of plump and stretched cells as well as appendages were observed when lactic acid, formic acid, and cyclodextrin were utilized as substrates, while sparse cells in short shape were obtained when galactose, arabinose and glucose were used as substrates. Conclusions These results suggest that substrate not only has important role in electrochemical performances of MFCs but also in biological properties of electricigens. Lactic acid, formic acid, and cyclodextrin beneficial for cell growth under aerobic conditions are unfavourable for planktonic cell growth and current generation under anaerobic conditions, while consumptions of galactose, arabinose and glucose adverse to cell

  14. Global microarray analysis of carbohydrate use in alkaliphilic hemicellulolytic bacterium Bacillus sp. N16-5.

    Directory of Open Access Journals (Sweden)

    Yajian Song

    Full Text Available The alkaliphilic hemicellulolytic bacterium Bacillus sp. N16-5 has a broad substrate spectrum and exhibits the capacity to utilize complex carbohydrates such as galactomannan, xylan, and pectin. In the monosaccharide mixture, sequential utilization by Bacillus sp. N16-5 was observed. Glucose appeared to be its preferential monosaccharide, followed by fructose, mannose, arabinose, xylose, and galactose. Global transcription profiles of the strain were determined separately for growth on six monosaccharides (glucose, fructose, mannose, galactose, arabinose, and xylose and four polysaccharides (galactomannan, xylan, pectin, and sodium carboxymethylcellulose using one-color microarrays. Numerous genes potentially related to polysaccharide degradation, sugar transport, and monosaccharide metabolism were found to respond to a specific substrate. Putative gene clusters for different carbohydrates were identified according to transcriptional patterns and genome annotation. Identification and analysis of these gene clusters contributed to pathway reconstruction for carbohydrate utilization in Bacillus sp. N16-5. Several genes encoding putative sugar transporters were highly expressed during growth on specific sugars, suggesting their functional roles. Two phosphoenolpyruvate-dependent phosphotransferase systems were identified as candidate transporters for mannose and fructose, and a major facilitator superfamily transporter was identified as a candidate transporter for arabinose and xylose. Five carbohydrate uptake transporter 1 family ATP-binding cassette transporters were predicted to participate in the uptake of hemicellulose and pectin degradation products. Collectively, microarray data improved the pathway reconstruction involved in carbohydrate utilization of Bacillus sp. N16-5 and revealed that the organism precisely regulates gene transcription in response to fluctuations in energy resources.

  15. Biotechnology by Design: An Introductory Level, Project-Based, Synthetic Biology Laboratory Program for Undergraduate Students.

    Science.gov (United States)

    Beach, Dale L; Alvarez, Consuelo J

    2015-12-01

    Synthetic biology offers an ideal opportunity to promote undergraduate laboratory courses with research-style projects, immersing students in an inquiry-based program that enhances the experience of the scientific process. We designed a semester-long, project-based laboratory curriculum using synthetic biology principles to develop a novel sensory device. Students develop subject matter knowledge of molecular genetics and practical skills relevant to molecular biology, recombinant DNA techniques, and information literacy. During the spring semesters of 2014 and 2015, the Synthetic Biology Laboratory Project was delivered to sophomore genetics courses. Using a cloning strategy based on standardized BioBrick genetic "parts," students construct a "reporter plasmid" expressing a reporter gene (GFP) controlled by a hybrid promoter regulated by the lac-repressor protein (lacI). In combination with a "sensor plasmid," the production of the reporter phenotype is inhibited in the presence of a target environmental agent, arabinose. When arabinose is absent, constitutive GFP expression makes cells glow green. But the presence of arabinose activates a second promoter (pBAD) to produce a lac-repressor protein that will inhibit GFP production. Student learning was assessed relative to five learning objectives, using a student survey administered at the beginning (pre-survey) and end (post-survey) of the course, and an additional 15 open-ended questions from five graded Progress Report assignments collected throughout the course. Students demonstrated significant learning gains (p < 0.05) for all learning outcomes. Ninety percent of students indicated that the Synthetic Biology Laboratory Project enhanced their understanding of molecular genetics. The laboratory project is highly adaptable for both introductory and advanced courses. PMID:26753032

  16. Water extract of Triticum aestivum L. and its components demonstrate protective effect in a model of vascular dementia.

    Science.gov (United States)

    Han, Hyung Soo; Jang, Jung-Hee; Jang, Jae Hee; Choi, Jung Sook; Kim, Yoon Jung; Lee, Chan; Lim, Sun Ha; Lee, Hyeong-Kyu; Lee, Jongwon

    2010-06-01

    Although vascular dementia is the second leading cause of dementia and often underdiagnosed, there are no drugs yet approved for the treatment of vascular dementia. In this study, it is demonstrated that water extract of Triticum aestivum L. (TALE) and some of its components have protective effects against vascular dementia-induced damage by preserving the myelin sheath and inhibiting astrocytic activation. The memory test used a vascular dementia model utilizing bilateral ligation of the carotid arteries of rats. TALE, some of its components, such as starch, total dietary fiber (TDF), arabinoxylan, beta-glucan, and degraded products of arabinoxylan, such as arabinose and xylose, were administered to the animals from day 8 to day 14, following the surgery. Twenty-one days after the surgery, the water maze test was performed for 5 days, and the time taken to find the platform during training trials (mean escape latency) was measured. The mean escape latency was decreased consistently in the TALE-, starch-, TDF-, arabinoxylan-, and arabinose-treated groups, compared with that in the vascular dementia group. To measure brain damage, Luxol fast blue staining and immunohistochemistry of myelin basic protein (MBP) were performed to observe myelin sheath in the white matter, and immunohistochemistry of glial fibrillary acidic protein (GFAP) was performed to observe the astrocytic reaction. Vascular dementia reduced the MBP level and increased the GFAP level. Arabinose effectively inhibited the MBP and GFAP change, whereas arabinoxylan inhibited the GFAP change only. These results suggest that TALE and some of its components can be used as a medicinal material for the development of neuroprotective agents against vascular dementia. PMID:20521983

  17. The Structure and Function of an Arabinan-specific [alpha]-1,2-Arabinofuranosidase Identified from Screening the Activities of Bacterial GH43 Glycoside Hydrolases

    Energy Technology Data Exchange (ETDEWEB)

    Cartmell, Alan; McKee, Lauren S.; Pena, Maria J.; Larsbrink, Johan; Brumer, Harry; Kaneko, Satoshi; Ichinose, Hitomi; Lewis, Richard J.; Vikso-Nielsen, Anders; Gilbert, Harry; Marles-Wright, Jon (Newcastle); (National Food Research Institute); (Novozymes A/S); (RITS); (Georgia)

    2012-03-26

    Reflecting the diverse chemistry of plant cell walls, microorganisms that degrade these composite structures synthesize an array of glycoside hydrolases. These enzymes are organized into sequence-, mechanism-, and structure-based families. Genomic data have shown that several organisms that degrade the plant cell wall contain a large number of genes encoding family 43 (GH43) glycoside hydrolases. Here we report the biochemical properties of the GH43 enzymes of a saprophytic soil bacterium, Cellvibrio japonicus, and a human colonic symbiont, Bacteroides thetaiotaomicron. The data show that C. japonicus uses predominantly exo-acting enzymes to degrade arabinan into arabinose, whereas B. thetaiotaomicron deploys a combination of endo- and side chain-cleaving glycoside hydrolases. Both organisms, however, utilize an arabinan-specific {alpha}-1,2-arabinofuranosidase in the degradative process, an activity that has not previously been reported. The enzyme can cleave {alpha}-1,2-arabinofuranose decorations in single or double substitutions, the latter being recalcitrant to the action of other arabinofuranosidases. The crystal structure of the C. japonicus arabinan-specific {alpha}-1,2-arabinofuranosidase, CjAbf43A, displays a five-bladed {beta}-propeller fold. The specificity of the enzyme for arabinan is conferred by a surface cleft that is complementary to the helical backbone of the polysaccharide. The specificity of CjAbf43A for {alpha}-1,2-L-arabinofuranose side chains is conferred by a polar residue that orientates the arabinan backbone such that O2 arabinose decorations are directed into the active site pocket. A shelflike structure adjacent to the active site pocket accommodates O3 arabinose side chains, explaining how the enzyme can target O2 linkages that are components of single or double substitutions.

  18. Fermentation of dietary fibre components in the rat intestinal tract.

    Science.gov (United States)

    Nyman, M; Asp, N G

    1982-05-01

    1. The fermentative breakdown of dietary fibre from various sources in the intestinal tract was studied using rat balance experiments and gas-liquid chromatograhic analysis of dietary fibre monomers in feed and faces. 2. On a basal diet with 690 g maize starch/kg but no added fibre, small but detectable amounts of polymeric glucose, rhamnose, arabinose, xylose, galactose, mannose and uronic acids, i.e. sugars occurring in dietary fibre, were excreted in faeces. 3. Dietary fibre in wheat bran was rather resistant to fermentation; 63% was recovered in the faeces. Guar gum, on the other hand, was almost completely fermented, whereas 19 and 25% of the uronic acids in low and high methoxylated pectin respectively, were excreted in faeces. The various constituents of sugar-beet dietary fibre (approximately equal amounts of arabinose-based hemicellulose, pectin and non-starch glucan (cellulose)) showed quite variable availability for micro-organisms in that 6-12% of the arabinose, 17-25% of the uronic acids, and 52-58% of the cellulose were recovered in the faeces. 4. Faecal nitrogen excretion increased on addition of any one of the dietary fibre preparations studied, resulting in decreased true and apparent protein digestibility values. 5. The faecal dry weight increment was most pronounced when feeding bran and could then almost be accounted for by the remaining fibre and by protein. The less-prominent bulking effect of guar gum and pectins, that were much more extensively fermented, could be only partly explained by dietary fibre and protein. PMID:6282300

  19. Extraction and characterization of polysaccharides from Semen Cassiae by microwave-assisted aqueous two-phase extraction coupled with spectroscopy and HPLC.

    Science.gov (United States)

    Chen, Zhi; Zhang, Wei; Tang, Xunyou; Fan, Huajun; Xie, Xiujuan; Wan, Qiang; Wu, Xuehao; Tang, James Z

    2016-06-25

    A novel and rapid method for simultaneous extraction and separation of the different polysaccharides from Semen Cassiae (SC) was developed by microwave-assisted aqueous two-phase extraction (MAATPE) in a one-step procedure. Using ethanol/ammonium sulfate system as a multiphase solvent, the effects of MAATPE on the extraction of polysaccharides from SC such as the composition of the ATPS, extraction time, temperature and solvent-to-material ratio were investigated by UV-vis analysis. Under the optimum conditions, the yields of polysaccharides were 4.49% for the top phase, 8.80% for the bottom phase and 13.29% for total polysaccharides, respectively. Compared with heating solvent extraction and ultrasonic assisted extraction, MAATPE exhibited the higher extraction yields in shorter time. Fourier-transform infrared spectra showed that two polysaccharides extracted from SC to the top and bottom phases by MAATPE were different from each other in their chemical structures. Through acid hydrolysis and PMP derivatization prior to HPLC, analytical results by indicated that a polysaccharide of the top phases was a relatively homogeneous homepolysaccharide composed of dominant gucose glucose while that of the bottom phase was a water-soluble heteropolysaccharide with multiple components of glucose, xylose, arabinose, galactose, mannose and glucuronic acid. Molar ratios of monosaccharides were 95.13:4.27:0.60 of glucose: arabinose: galactose for the polysaccharide from the top phase and 62.96:14.07:6.67: 6.67:5.19:4.44 of glucose: xylose: arabinose: galactose: mannose: glucuronic acid for that from the bottom phase, respectively. The mechanism for MAATPE process was also discussed in detail. MAATPE with the aid of microwave and the selectivity of the ATPS not only improved yields of the extraction, but also obtained a variety of polysaccharides. Hence, it was proved as a green, efficient and promising alternative to simultaneous extraction of polysaccharides from SC. PMID

  20. Differential blood-brain barrier permeabilities to [14C]sucrose and [3H]inulin after osmotic opening in the rat

    International Nuclear Information System (INIS)

    The blood-brain barrier (B-BB) in 3-month-old rats was opened unilaterally by infusing 1.8 m L(+)arabinose in water into the internal carotid artery through a catheter in the external carotid. Two poorly penetrating uncharged test radiotracers of differing molecular weight and size, [14C]sucrose (340 daltons, radius 5 A) and [3H]inulin (5500 daltons, radius 15 A), were simultaneously injected i.v. in untreated rats, or rats at 1, 30, or 50 min after infusion of hypertonic arabinose solution. Evans-blue solution was injected 5 min prior to osmotic treatment as a visual indicator of barrier integrity. In regions of uninfused control brains, the [14C]sucrose permeability-surface area (PA) product approximated 10(-5) s-1, whereas PA was not measurable for [3H]inulin. In arabinose-infused animals, PA products on the ipsilateral hemisphere for both [14C]sucrose and [3H]inulin were markedly elevated 6 min after infusion, but decreased by 35 and 55 min. In nearly all regions, statistically significant differences were not found between 6-min [14C]sucrose- and [3H]inulin-PA values (P greater than 0.05). However, at 35 and 55 min in most regions, the PA for [3H]inulin was significantly lower (P less than 0.05) than PA for [14C]sucrose. The results indicated that the B-BB closed more rapidly to larger than to smaller molecules after osmotic treatment and were consistent with a pore model for osmotic B-BB opening

  1. Purification and identification of a novel heteropolysaccharide RBPS2a with anti-complementary activity from defatted rice bran.

    Science.gov (United States)

    Wang, Li; Zhang, Hongbin; Zhang, Xiaoyan; Chen, Zhengxing

    2008-09-01

    A novel heteropolysaccharide RBPS2a with anti-complementary activity was obtained from defatted rice bran by hot water extraction, ethanol precipitation, and purified by gel chromatography after anion-exchange chromatography. This fraction exhibited more potent anti-complementary activity than other polysaccharide fractions. RBPS2a was eluted as a single symmetrical narrow peak on high-performance gel-permeation chromatography (HPGPC) and the average molecular weight was 90,000Da. We found RBPS2a contained 86.7% polysaccharide and 8.7% protein. The amino acid pattern showed that RBPS2a contained large amount of glutamic acid, arginine, aspartic acid, lysine, and alanine. The molar content of the above five amino acids constituted 59.31% of the total amino acids. Gas chromatography of absolute acid hydrolysate of RBPS2a suggested that it was composed of arabinose, xylose, glucose and galactose with a molar ratio of 4:2:1:4. The Fourier-transform infrared spectra (FT-IR) and (1)H, (13)C NMR spectroscopy analysis revealed that RBPS2a had a backbone consisting of β-(1→3)-linked d-galacopyranosyl residues substituted at O-2 with glycosyl residues composed of α-d-xylose-(1→4)-α-d-arabinose-(1→ and α-d-glucose-(1→4)-α-d-arabinose-(1→ linked residues. Furthermore, some of the fractions extracted and purified from defatted rice bran exhibited strong anti-complementary activity. Among these fractions, the purified polysaccharide RBPS2a had the highest activity. PMID:26050177

  2. Improving lactic acid productivity from wheat straw hydrolysates by membrane integrated repeated batch fermentation under non-sterilized conditions

    DEFF Research Database (Denmark)

    Zhang, Yuming; Chen, Xiangrong; Qi, Benkun;

    2014-01-01

    Bacillus coagulans IPE22 was used to produce lactic acid (LA) from mixed sugar and wheat straw hydrolysates, respectively. All fermentations were conducted under non-sterilized conditions and sodium hydroxide was used as neutralizing agent to avoid the production of insoluble CaSO4. In order to...... was successfully realized. The separation of LA from broth by membrane in batch fermentation also decreased feedback inhibition. MIRB was carried out using wheat straw hydrolysates (29.72g/L glucose, 24.69g/L xylose and 5.14g/L arabinose) as carbon source, LA productivity was increased significantly...

  3. Peptide Deformylase in Staphylococcus aureus: Resistance to Inhibition Is Mediated by Mutations in the Formyltransferase Gene

    OpenAIRE

    Margolis, Peter S.; Hackbarth, Corinne J.; Young, Dennis C.; Wang, Wen; Chen, Dawn; Yuan, Zhengyu; White, Richard; Trias, Joaquim

    2000-01-01

    Peptide deformylase, a bacterial enzyme, represents a novel target for antibiotic discovery. Two deformylase homologs, defA and defB, were identified in Staphylococcus aureus. The defA homolog, located upstream of the transformylase gene, was identified by genomic analysis and was cloned from chromosomal DNA by PCR. A distinct homolog, defB, was cloned from an S. aureus genomic library by complementation of the arabinose-dependent phenotype of a PBAD-def Escherichia coli strain grown under ar...

  4. Cadmium Resistance Screening in Nitrilotriacetate-Buffered Minimal Media

    OpenAIRE

    Angle, J. S.; Chaney, R. L.

    1989-01-01

    Media used to determine the MICs of heavy metals for bacteria are unreliable because organic components in the media bind or chelate most of the metal being studied. To define specific metal activity in media and to maintain metal activity at a constant level, HEPES-MES [N-2-hydroxyethylpiperazine-N′ -2-ethanesulfonic acid−2-(N-morpholine)ethanesulfonic acid] salts medium with arabinose medium was modified, and the modified medium was used to examine the MIC of cadmium for Rhizobium fredii US...

  5. Chemical and spectroscopic studies of Cercidium praecox gum exudate.

    Science.gov (United States)

    León de Pinto, G; Martínez, M; Rivas, C

    1994-07-01

    The structure of the polysaccharide from Cercidium praecox (R&P) Harms gum exudate has been studied by Smith degradation, by sugar and methylation analyses, and by 13C NMR spectroscopy. The results showed a (1-->4)-xylan core. Some xylose residues are substituted at O-2 by alpha-D-glucuronic acid and 4-O-methyl-alpha-D-glucuronic acid residues. beta-D-Glucuronic acid is present, probably as terminal residues. The arabinose is present as alpha-L-furanose and beta-L-pyranose. PMID:8062287

  6. Design, Synthesis and Bioactivity of N-Glycosyl-N′-(5-substituted phenyl-2-furoyl) Hydrazide Derivatives

    OpenAIRE

    Zining Cui; Hang Su; Jiazhen Jiang; Xinling Yang; Yoshihiro Nishida

    2014-01-01

    Condensation products of 5-substituted phenyl-2-furoyl hydrazide with different monosaccharides d-glucose, d-galactose, d-mannose, d-fucose and d-arabinose were prepared. The anomerization and cyclic-acyclic isomers were investigated by 1H NMR spectroscopy. The results showed that, except for the d-glucose derivatives, which were in the presence of β-anomeric forms, all derivatives were in an acyclic Schiff base form. Their antifungal and antitumor activities were studied. The bioassay result...

  7. Potential valorization of polymeric substances excreted by Chaetomorpha aerea, a macro-algae harmful to French oyster industry

    OpenAIRE

    Pierre, Guillaume; Sopena, Valérie; Juin, Camille; Mastouri, Amira; Graber, Marianne; Maugard, Thierry

    2011-01-01

    The in vitro antimicrobial activity of the marine green algae Chaetomorpha aerea was investigated against gram-positive bacteria, gram-negative bacteria, and a fungus. The water-soluble extract of algae was composed of a sulfated (6.3%) galactan with a molecular weight of 1.160x106 Da and a global composition close to commercial polysaccharides as dextran sulfate or fucoidan. The polysaccharide was composed of 18% arabinose, 24% glucose, 58% galactose. The re-suspended extracts (methanol, wat...

  8. Purification and characterization of 3-deoxy-D-manno-octulosonate 8-phosphate synthetase from Escherichia coli.

    OpenAIRE

    Ray, P H

    1980-01-01

    3-Deoxy-D-manno-octulosonate (KDO)-8-phosphate synthetase has been purified 450-fold from frozen Escherichia coli B cells. The purified enzyme catalyzed the stoichiometric formation of KDO-8-phosphate and Pi from phosphoenolpyruvate (PEP) and D-arabinose-5-phosphate. The enzyme showed no metal requirement for activity and was inhibited by 1 mM Cd2+, Cu2+, Zn2+, and Hg2+. The inhibition by Hg2+ could be reversed by dithiothreitol. The optimum temperature for enzyme activity was determined to b...

  9. Determination of the absolute configuration of sialic acids in gangliosides from the sea cucumber Cucumaria echinata.

    Science.gov (United States)

    Kisa, Fumiaki; Yamada, Koji; Miyamoto, Tomofumi; Inagaki, Masanori; Higuchi, Ryuichi

    2007-07-01

    Enantiomeric pairs of sialic acid, D- and L-NeuAc (N-acetylneuraminic acid), were converted to D- and L-arabinose, respectively, by chemical degradation. Using this method, the absolute configuration of the sialic acid residues, NeuAc and NeuGc (N-glycolylneuraminic acid), in the gangliosides from the sea cucumber Cucumaria echinata was determined to be the D-form. Although naturally occurring sialic acids have been believed to be the D-form on the basis of biosynthetic evidence, this is the first report of the determination of the absolute configuration of the sialic acid residues in gangliosides using chemical methods. PMID:17603199

  10. Pentose fermentation by recombinant zymomonas

    Science.gov (United States)

    Picataggio, Stephen K.; Zhang, Min; Eddy, Christina K.; Deanda, Kristine A.; Finkelstein, Mark; Mohagheghi, Ali; Newman, Mildred M.; McMillan, James D.

    1998-01-01

    The invention relates to microorganisms which normally do not ferment pentose sugar and which are genetically altered to ferment pentose sugar to produce ethanol, and fermentation processes utilizing the same. Examples include Zymomonas mobilis which has been transformed with combinations of E. coli genes for xylose isomerase, xylulokinase, transaldolase, transketolase, L-arabinose isomerase, L-ribulokinase, and L-ribulose 5-phosphate 4-epimerase. Expression of the added genes are under the control of Zymomonas mobilis promoters. These newly created microorganisms are useful for fermenting pentoses and glucose, produced by hydrolysis of hemicellulose and cellulose, to produce ethanol.

  11. Recombinant Zymomonas for pentose fermentation

    Science.gov (United States)

    Picataggio, Stephen K.; Zhang, Min; Eddy, Christina K.; Deanda, Kristine A.

    1998-01-01

    The invention relates to microorganisms which normally do not ferment pentose sugar and which are genetically altered to ferment pentose sugar to produce ethanol, and fermentation processes utilizing the same. Examples include Zymomonas mobilis which has been transformed with combinations of E. coli genes for xylose isomerase, xylulokinase, transaldolase, transketolase, L-arabinose isomerase, L-ribulokinase, and L-ribulose-5-phosphate 4-epimerase. Expression of the added genes are under the control of Zymomonas mobilis promoters. These newly created microorganisms are useful for fermenting pentoses and glucose, produced by hydrolysis of hemicellulose and cellulose, to produce ethanol.

  12. Strain identification in Rhizobium by starch gel electrophoresis of isoenzymes

    DEFF Research Database (Denmark)

    Engvild, Kjeld Christensen; Nielsen, G.

    1985-01-01

    Sonieated extracts of rhizobia, especiaUy Rhizobium leguminosarum from pea and vetch, were run in horizontal starch gel electrophoresis in the cold. The rhizobia were grown on agar on a slime suppressing substrate of tryptone-yeast extract-CaCl2 with small amounts of mannitol, sorbitol and...... arabinose and other sugars as enzyme inducers. After electrophoresis the gels were separated into several slabs by a gel cutter. Each slab was stained for a particular enzyme. Among numerous enzyme systems tested we found useful variation in esterases (EC 3.1.1.1, EC 3.1.1.2), 3-hydroxybutyrate...

  13. Engineering the pentose phosphate pathway of Saccharomyces cerevisiae for production of ethanol and xylitol

    OpenAIRE

    Toivari, Mervi

    2007-01-01

    The baker s yeast Saccharomyces cerevisiae has a long tradition in alcohol production from D-glucose of e.g. starch. However, without genetic modifications it is unable to utilise the 5-carbon sugars D-xylose and L arabinose present in plant biomass. In this study, one key metabolic step of the catabolic D-xylose pathway in recombinant D-xylose-utilising S. cerevisiae strains was studied. This step, carried out by xylulokinase (XK), was shown to be rate-limiting, because overexpression of the...

  14. Enthalpy and entropy interaction parameters of sodium chloride with some monosaccharides in water

    Institute of Scientific and Technical Information of China (English)

    ZHUO; Kelei; WANG; Jianji; BAI; Guangyue; YAN; Haike; WANG

    2004-01-01

    Dilution enthalpies of sodium chloride and some monosaccharides (glucose, galactose, xylose, arabinose, and fructose) in water and mixing enthalpies of aqueous sodium chloride and these monosaccharide solutions were measured by using an improved precision semimicro-titration calorimeter. Transfer enthalpies of sodium chloride from water to aqueous saccharide solutions were evaluated as well as enthalpy interaction parameters of sodium chloride with these monosaccharides in water. Combined with Gibbs energy interaction parameters, entropy interaction parameters were also obtained. The results show that interactions of the saccharides with sodium chloride depend on the stereochemistry of saccharide molecules. These interaction parameters can identify stereochemical structure of saccharide molecules.

  15. Physico-chemical Properties and Bioactivities of a Glycoconjugate LbGp5B from Lycium barbarum L.

    Institute of Scientific and Technical Information of China (English)

    PENG,Xue-Mei(彭雪梅); PENG,Xue-Mei; QI,Chun-Hui(齐春会); QI,Chun-Hui; TIAN,Geng-Yuan (田庚元); TIAN,Geng-Yuan; ZHANG,Yong-Xiang(张永详); ZHANG,Yong-Xiang

    2001-01-01

    A glycoconjugatedesignated as LbGp5B was isolated from the fruit of Lyciun barbarum L. and purified to homogeneity by gel filtration .LbGp5B is composed of rhamnose (Rha), arabinose (Ara), galactose (Gal), glucose (Glc), galacturonic acid (GalA) and seveateen amino acids. The molecular weight of LbGp5B was determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and by matrix-asisted laser desorption/ionization (MALDI) time of fight (T OF) mass spectrometry (MS). The preliminary experiments showed that LbGp5B promoted splenocyte proliferation in mice and inhihited the peroxidation of low density lipoprotein (LDL).

  16. Xylitol production from xylose mother liquor: a novel strategy that combines the use of recombinant Bacillus subtilis and Candida maltosa

    OpenAIRE

    Jiang Mingguo; Lv Jiyang; Wang Ben; Cheng Hairong; Lin Shuangjun; Deng Zixin

    2011-01-01

    Abstract Background Xylose mother liquor has high concentrations of xylose (35%-40%) as well as other sugars such as L-arabinose (10%-15%), galactose (8%-10%), glucose (8%-10%), and other minor sugars. Due to the complexity of this mother liquor, further isolation of xylose by simple method is not possible. In China, more than 50,000 metric tons of xylose mother liquor was produced in 2009, and the management of sugars like xylose that present in the low-cost liquor is a problem. Results We d...

  17. Cultivation Conditions for Phytase Production from Recombinant Escherichia coli DH5α

    OpenAIRE

    Rafidah Mohd Ariff; Anwar Fitrianto; Mohd Yazid Abd. Manap; Aini Ideris; Azhar Kassim; Afinah Suhairin; Anis Shobirin Meor Hussin

    2013-01-01

    Response surface methodology (RSM) was used to optimize the cultivation conditions for the production of phytase by recombinant Escherichia coli DH5α. The optimum predicted cultivation conditions for phytase production were at 3 hours seed age, a 2.5% inoculum level, an L-arabinose concentration of 0.20%, a cell concentration of 0.3 (as measured at 600 nm) and 17 hours post-induction time with a predicted phytase activity of 4194.45 U/mL. The model was validated and the results showed no sign...

  18. Biochemische Charakterisierung von Pflanzen unterschiedlicher Nutzungsintensität zur Ableitung von Parametern für die Ermittlung des energetischen Futterwertes

    OpenAIRE

    Meak, Pramol

    2002-01-01

    Die exakte Bestimmung des energetischen Futterwertes von Grünland ist für die Praxis von großer Bedeutung. Das am häufigsten angewendete Schätzverfahren auf Basis der chemischen Analyse ist für Grünlandbestände mit geringer Nutzungsintensität nicht anwendbar. Ziel der Arbeit war es zu prüfen, ob andere ausgewählte Zellwandparameter (Xylose, Arabinose, pCA, FA, säurelösliches Lignin, ADL:Gesamtlignin) über ein breites Nutzungsspektrum eine engere Korrelation zur Verdaulichkeit der OS haben als...

  19. Pantethine Rescues Phosphopantothenoylcysteine Synthetase and Phosphopantothenoylcysteine Decarboxylase Deficiency in Escherichia coli but Not in Pseudomonas aeruginosa▿†

    OpenAIRE

    Balibar, Carl J.; Hollis-Symynkywicz, Micah F.; Tao, Jianshi

    2011-01-01

    Coenzyme A (CoA) plays a central and essential role in all living organisms. The pathway leading to CoA biosynthesis has been considered an attractive target for developing new antimicrobial agents with novel mechanisms of action. By using an arabinose-regulated expression system, the essentiality of coaBC, a single gene encoding a bifunctional protein catalyzing two consecutive steps in the CoA pathway converting 4′-phosphopantothenate to 4′-phosphopantetheine, was confirmed in Escherichia c...

  20. 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

  1. Metabolomics of Clostridial Biofuel Production

    Energy Technology Data Exchange (ETDEWEB)

    Rabinowitz, Joshua D [Princeton Univ., NJ (United States); Aristilde, Ludmilla [Cornell Univ., Ithaca, NY (United States); Amador-Noguez, Daniel [Univ. of Wisconsin, Madison, WI (United States)

    2015-09-08

    (xylose or arabinose) to C. acetobutylicum revealed that, as expected, glucose was preferred, with the pentose sugar selectively assimilated into the pentose phosphate pathway (PPP). Simultaneous feeding of xylose and arabinose revealed an unexpected hierarchy among these pentose sugars, with arabinose utilized preferentially over xylose. Pentose catabolism occurred via the phosphoketolase pathway (PKP), an alternative route of pentose catabolism that directly converts xylulose-5-phosphate into acetyl-phosphate and glyceraldehyde-3-phosphate. Taken collectively, these findings reveal two hierarchies in Clostridial pentose metabolism: xylose is subordinate to arabinose, and the PPP is used less than the PKP. Thus, in addition to massively expanding the available data on Clostridial metabolism, we identified three key regulatory points suitable for targeting in future bioengineering efforts: phosphofructokinase for enhancing fermentation, the pyruvate-oxaloacetate node for controlling solventogenesis, and the phosphoketolase reaction for driving pentose catabolism.

  2. Enzymatic Xylose Release from Pretreated Corn Bran Arabinoxylan: Differential Effects of Deacetylation and Deferuloylation on Insoluble and Soluble Substrate Fractions

    DEFF Research Database (Denmark)

    Agger, Jane; Viksø-Nielsen, Ander; Meyer, Anne S.

    2010-01-01

    In the present work enzymatic hydrolysis of arabinoxylan from pretreated corn bran (190 °C, 10 min) was evaluated by measuring the release of xylose and arabinose after treatment with a designed minimal mixture of monocomponent enzymes consisting of α-l-arabinofuranosidases, an endoxylanase, and a...... β-xylosidase. The pretreatment divided the corn bran material 50:50 into soluble and insoluble fractions having A:X ratios of 0.66 and 0.40, respectively. Addition of acetyl xylan esterase to the monocomponent enzyme mixture almost doubled the xylose release from the insoluble substrate fraction and...

  3. Treatment of agave and guayule with sulfur dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Baker, A.J.

    1978-05-01

    Agave, guayule, and extracted guayule were analyzed for lignin, total carbohydrate, enzyme digestibility before and after treating each with SO/sub 2/ gas at 120/sup 0/C for 2 hours. The hydrolyzed carbohydrates in the filtrate from the lignin analysis were also analyzed for relative quantities of glucose, mannose, xylose, arabinose and galactose. The SO/sub 2/ treatment greatly increased the enzyme digestibility of each material. The high level of enzyme digestibility indicates that the SO/sub 2/ treated materials are over 50% rumen digestible.

  4. Influence of food preservation parameters and associated microbiota on production rate, profile and stability of acylated homoserine lactones from food-derived Enterobacteriaceae

    DEFF Research Database (Denmark)

    Flodgaard, Lars; Christensen, Allan Beck; Molin, Søren;

    2003-01-01

    carbon source (glucose,, sucrose, xylose, arabinose, mannose, mannitol and sorbitol), temperature (5 and 25 degreesC), salt concentration (0-7%), pH (6, 7 and 8) and co-existing lactic acid bacteria microflora on the AHL profile and production rate from Serratia proteamaculans strain B5a and Enterobacter...... approximately 6 and therefore only a low degree of pH-induced turnover is expected to occur in this product. Overall, our study demonstrates that food-derived Enterobacteriaceae produce AHLs of the same type and in the same magnitude when grown under food-relevant conditions as when grown in laboratory media at...

  5. Carbohydrates as a reagent in multicomponent reactions: one-pot access to a new library of hydrophilic substituted pyrimidine-fused heterocycles.

    Science.gov (United States)

    Nourisefat, Maryam; Panahi, Farhad; Khalafi-Nezhad, Ali

    2014-12-14

    In this study a multicomponent reaction involving carbohydrate derivatives as the main component in order to prepare a new library of polyhydroxy compounds incorporating pyrimidine-fused heterocycles (PFHs) is introduced. A set of polyhydroxy functionalized PFHs were synthesized using multicomponent reactions of sugar (glucose, galactose, arabinose and lactose), barbituric acid and amines. Also, the three-component condensation reaction between D-glucosamine, aldehyde, and barbituric acid efficiently provided polyhydroxy substituted PFH derivatives in a one-pot reaction under mild and green conditions. These new one-pot reactions gave a range of polyhydroxy substituted PFHs in good to excellent yield. PMID:25317663

  6. Free amino acids and sugars in the flower of Carthamus tinctorius L.

    Directory of Open Access Journals (Sweden)

    Yoshiyuki Takahasi

    2014-02-01

    Full Text Available Qualitative and quantitative analyses of free amino acids and sugars in the extracts from freshly collected florets of Carthamus tinctorius L. were performed by combination of thin-layer chromatography (TLC, automatic amino acid analysis and gas-liquid chromatography (GLC. Sixteen amino acids were detected and their quantitative relations were investigated. Alditol acetate derivatives of free sugars were examined by GLC. The retention time and resolution pattern of the following monosaccharides, rhamnose, arabinose, xylose, mannose and glucose, were ultimately investigated.

  7. Olive stones as a source of fermentable sugars

    Energy Technology Data Exchange (ETDEWEB)

    Heredia-Moreno, A.; Guillen-Bejarano, R.; Fernandez-Bolanos, J.; Rivas-Moreno, M.

    1987-01-01

    The composition of the olive stone and its woody fraction has been investigated for the varieties Gordal, Manzanilla, Hojiblanca and Verdial. The neutral detergent fiber method (NDF) of Van Soest was used to estimate dietary fiber. Cellulose was the main component of the fiber, followed by hemicelluloses and lignin. The NDF was hydrolyzed enzymatically and the sugars identified by gas chromatography. Glucose was the main sugar (46-51% in the stone and 47-63% in the woody fraction), followed by galactose (25%) and xylose (14%). Arabinose and mannose were also detected.

  8. Brevibacterium oceanic sp. nov., isolated from deep-sea sediment of the Chagos Trench, Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Bhadra, B.; Raghukumar, C.; Pindi, P.K.; Shivaji, S.

    (Collins et al., 1980; Jones & Keddie, 1986; Heyrman et al., 2004). Brevibacterium species have been isolated from diverse habitats such as milk products, clinical specimens, soil, sediment, brown algae, paintings and foot lesions of fowl (Wauters et al...-galactose, fructose, mannose, rhamnose, D-orL-arabinose, D-xylose, D-cellobiose, D- melibiose, D-raffinose, maltose, lactose, D-ribose, trehalose, sucrose, D-mannitol, dulcitol, adonitol or inositol. Utilizes malonate, L-proline, L-tyrosine, L-serine, L-arginine, L...

  9. Cryptococcus friedmannii, a new species of yeast from the Antarctic

    Science.gov (United States)

    Vishniac, H. S.

    1985-01-01

    Cryptococcus friedmannii Vishniac sp. nov. from an Antarctic cryptoendolithic community is a psychrophilic basidioblastomycete characterized by cream-colored colonies of cells with smooth, layered walls, budding monopolarly, producing amylose and extracellular proteinase, utilizing nitrate and D-alanine (inter alia) as nitrogen sources and L-arabinose, arbutin, cellobiose, D-glucuronate, maltose, melezitose, salicin, soluble starch, trehalose, and D-xylose as carbon sources. This species differs from all other basidiomycetous yeasts in possessing the following combination of characters: amylose production (positive), assimilation of cellobiose (positive), D-galactose (negative), myo-inositol (negative), D-mannitol (negative), and sucrose (negative).

  10. Production, purification, and characterization of a highly glucose-tolerant novel beta-glucosidase from Candida peltata.

    OpenAIRE

    Saha, B C; Bothast, R J

    1996-01-01

    Candida peltata (NRRL Y-6888) produced beta-glucosidase when grown in liquid culture on various substrates (glucose, xylose, L-arabinose, cellobiose, sucrose, and maltose). An extracellular beta-glucosidase was purified 1,800-fold to homogeneity from the culture supernatant of the yeast grown on glucose by salting out with ammonium sulfate, ion-exchange chromatography with DEAE Bio-Gel A agarose, Bio-Gel A-0.5m gel filtration, and cellobiose-Sepharose affinity chromatography. The enzyme was a...

  11. Synthesis of 1,2[3H]-1,2-epoxy analogue of fructose-6P, an affinity label of Escherichia coli glucosamine-6P synthase

    International Nuclear Information System (INIS)

    1,2-anhydroglucitol-6P, a known inhibitor of glucose-6P isomerase, behaved as a fructose-6P site-directed irreversible inhibitor of bacterial glucosamine-6P synthase. The lack of reproducibility of the aldolase-mediated condensation of dihydroxyacetone phosphate and glycidaldehyde followed by borohydride reduction previously described prompted us to develop a chemical route to this compounds and its radiolabelled counterpart. The compound was synthesized in 13 steps from D-arabinose with a 6% overall yield. Tritium introduction was performed at step 11 (3 → 4) allowing isolation of the title compound of high specific radioactivity. (author)

  12. Antioxidant activity and physicochemical properties of an acidic polysaccharide from Morinda officinalis.

    Science.gov (United States)

    Zhang, Hualin; Li, Jun; Xia, Jingmin; Lin, Sanqing

    2013-07-01

    An acidic polysaccharide APMO was isolated from Morinda officinalis by alkaline solvent extraction followed by fractionation treatments. Its antioxidant activities were evaluated by various methods in vitro, APMO presented excellent capability in scavenging DPPH radicals, chelating ferrous ions and inhibiting hemolysis of rats erythrocyte induced by H2O2, which was stronger than those of Vc at high concentration. Moreover, APMO displayed moderate reducing power. Physicochemical characteristics of APMO were observed by a combination of chemical and instrumental analysis. APMO predominantly consisted of galacturonic acid, arabinose and galactose. Galacturonic acid was assigned to be 1→4 glycosyl linkage in the skeleton of APMO. PMID:23511058

  13. Development of microbial biosensors for food analysis

    DEFF Research Database (Denmark)

    Lukasiak, Justyna

    Microbial biosensors are analytical devices composed of a biological recognition element (microorganism) integrated to a signal transduction element (i.e. bioluminescence), converting a biochemical signal into quantifiable response. Due to their molecular properties they can be diversely designed...... grains. It is a dietary fiber, with potential as a functional food ingredient. In this study, reporter strains targeting specifically L-rhamnose, L-arabinose and Dxylose using three different signal transducers: bioluminescence (luxCDABE), fluorescence (gfp) and ice nucleation (inaZ) were developed...

  14. In vitro and in vivo antioxidant activity of a water-soluble polysaccharide from dendrobium denneanum

    Science.gov (United States)

    Luo, A.; Ge, Z.; Fan, Y.; Chun, Z.; Jin, He X.

    2011-01-01

    The water-soluble crude polysaccharide (DDP) obtained from the aqueous extracts of the stem of Dendrobium denneanum through hot water extraction followed by ethanol precipitation, was found to have an average molecular weight (Mw) of about 484.7 kDa. Monosaccharide analysis revealed that DDP was composed of arabinose, xylose, mannose, glucose and galactose in a molar ratio of 1.00:2.66:8.92:34.20:10.16. The investigation of antioxidant activity both in vitro and in vivo showed that DDP is a potential antioxidant. ?? 2011.

  15. Modulation of Candida albicans Biofilm by Different Carbon Sources.

    Science.gov (United States)

    Pemmaraju, Suma C; Pruthi, Parul A; Prasad, R; Pruthi, Vikas

    2016-06-01

    In the present investigation, the role of carbon sources (glucose, lactate, sucrose, and arabinose) on Candida albicans biofilm development and virulence factors was studied on polystyrene microtiter plates. Besides this, structural changes in cell wall component β-glucan in presence of different carbon sources have also been highlighted. Biofilm formation was analyzed by XTT (2,3-bis[2-Methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide) reduction assay. Glucose-grown cells exhibited the highest metabolic activity during adhesion among all carbon sources tested (p albicans biofilm development and modulate virulence factors and structural organization of cell wall component β-glucan. PMID:26899861

  16. Facile Synthesis of the Naturally Cytotoxic Triterpenoid Saponin Patrinia-Glycoside B-II and Its Conformer

    OpenAIRE

    Li Ren; Yong-Xiang Liu; Dan Lv; Mao-Cai Yan; Han Nie; Yang Liu; Mao-Sheng Cheng

    2013-01-01

    The first chemical synthesis of the natural triterpenoid saponin Patrinia-glycoside B-II, namely oleanolic acid 3-O-α-L-rhamnopyranosyl-(1→2)-[β-D-gluco-pyranosyl-(1→3)]-α-L-arabinopyranoside, has been accomplished in a linear 11-step sequence 11 with 9.4% overall yield. The abnormal 1C4 conformation of the arabinose residue was found to occur via conformational fluctuation during preparation of the intermediates. Molecular mechanism and quantum chemistry calculations showed that Patrinia-gl...

  17. Lethality of a Heat- and Phosphate-Catalyzed Glucose By-Product to Escherichia coli O157:H7 and Partial Protection Conferred by the rpoS Regulon

    OpenAIRE

    Byrd, Jeffrey J.; Cheville, Ann M.; Bose, Jeffrey L.; Kaspar, Charles W.

    1999-01-01

    A by-product of glucose produced during sterilization (121°C, 15 lb/in2, 15 min) at neutral pH and in the presence of phosphate (i.e., phosphate-buffered saline) was bactericidal to Escherichia coli O157:H7 (ATCC 43895). Other six-carbon (fructose and galactose) and five-carbon (arabinose, ribose, and xylose) reducing sugars also produced a toxic by-product under the same conditions. Fructose and the five-carbon sugars yielded the most bactericidal activity. Glucose concentrations of 1% (wt/v...

  18. Isolation of a mutation resulting in constitutive synthesis of L-fucose catabolic enzymes.

    OpenAIRE

    Bartkus, J M; Mortlock, R. P.

    1986-01-01

    A ribitol-positive transductant of Escherichia coli K-12, JM2112, was used to facilitate the isolation and identification of mutations affecting the L-fucose catabolic pathway. Analysis of L-fucose-negative mutants of JM2112 enabled us to confirm that L-fucose-1-phosphate is the apparent inducer of the fucose catabolic enzymes. Plating of an L-fuculokinase-negative mutant of JM2112 on D-arabinose yielded an isolate containing a second fucose mutation which resulted in the constitutive synthes...

  19. Fiber and nonstarch polysaccharide content and variation in common crops used in broiler diets

    DEFF Research Database (Denmark)

    Knudsen, Knud Erik Bach

    2014-01-01

    -glucan (β-glucan), cellulose, and the noncarbohydrate component lignin are the predominant polymers in cereals. They occur in different proportions depending on the species and tissue type. Rye, triticale, wheat, corn, and sorghum are all rich in AX, whereas barley and oats contain a high level of β......-glucan. The AX from rye, wheat, and triticale and β-glucan from barley and oats are to a large extent soluble, whereas the solubility of AX found in corn and sorghum is lower than the other cereals. The ratio of arabinose to xylose gives a crude indication of the AX structure, which varies between the...

  20. Synthesizing labeled compounds

    International Nuclear Information System (INIS)

    A metabolic study is presented of the chemical reactions provided by isotopic labeling and NMR spectroscopy. Synthesis of 13C-labeled D-glucose, a 6-carbon sugar, involves adding a labeled nitrile group to the 5-carbon sugar D-arabinose by reaction with labeled hydrogen cyanide. The product of this reaction is then reduced and hydrolyzed to a mixture of the labeled sugars. The two sugars are separated by absorption chromotography. The synthesis of 13C-labeled L-tyrosine, an amino acid, is also presented

  1. Purification, characterization and in vitro anticoagulant activity of polysaccharides from Gentiana scabra Bunge roots.

    Science.gov (United States)

    Cai, Weirong; Xu, Huiling; Xie, Liangliang; Sun, Jian; Sun, Taotao; Wu, Xiaoyan; Fu, Qinbao

    2016-04-20

    Three water-soluble polysaccharide fractions (GSP-1, GSP-2 and GSP-3) were obtained from Gentiana scabra Bunge roots by DEAE-Sepharose CL-6B and Sepharose CL-6B column chromatography. Their chemical characterizations were determined by high performance gel permeation chromatography (HPGPC), high performance anion exchange chromatography coupled with pulsed amperometric detection (HPAEC-PAD) and Fourier transform infrared (FT-IR) spectrometer. Moreover, their in vitro anticoagulant activities were evaluated by activated partial thromboplastin time (APTT), thrombin time (TT) and prothrombin time (PT) assays. GSP-1 and GSP-2 were composed of rhamnose, arabinose, galactose, glucose and galacturonic acid, while GSP-3 consisted of rhamnose, arabinose, galactose and galacturonic acid with a weight-average molecular weight of 5.8×10(4)Da. In comparison with the control group (saline), GSP, GSP-1, GSP-2 and GSP-3 could prolong APTT and TT, but not PT. Overall, GSP-3 exhibited potent anticoagulant activity and would be expected to be a potential source of anticoagulant. PMID:26876858

  2. Morphological, physico-chemical and structural characterization of mucilage isolated from the seeds of Buchanania lanzan Spreng

    Directory of Open Access Journals (Sweden)

    Sudarshan Singh

    2014-01-01

    Full Text Available Context: Mucilage isolated from the seeds of Buchanania lanzan a wild Indian plant. This mucilage can be commercially exploited, by evaluating physico-chemical properties of this mucilage. Materials and Methods: Various physico-chemical parameter using scanning electron microscopy (SEM, molecular weight, X-ray diffraction (XRD spectrometry, zeta potential (ZP, Fourier transform infrared (FT-IR spectroscopy and 1D ( 1 H and 13 C nuclear magnetic resonance (NMR have been employed to characterize mucilage in the present study. Results: SEM analysis suggests that the mucilage has irregular particle size. Thermogravimetry analysis suggested that mucilage had good thermal stability with two stage decomposition. The weight-average molecular weight of mucilage was determined to be 4883, by gel permeation chromatography. The XRD pattern of the mucilage indicated a completely amorphous structure. The ZP was obtained 1.56 and −9.49 mV in water and 0.1 N NaCl respectively. The major functional groups identified from FT-IR spectrum include 3459/cm (-OH, 1667/cm (Alkenyl C-H and C = C stretch, 1407/cm (-COO- and 1321/cm (-CH 3 CO. Analysis of mucilage by paper chromatography and 1D NMR indicated the presence of rhamnose, arabinose and fructose. Conclusion: The spectral and chromatography analysis of mucilage indicate that the mucilage is composed of basic sugar moiety such as (arabinose, rhamnose, fructose and mannose as complex carbohydrates.

  3. Optimization of extraction, characterization and antioxidant activity of polysaccharides from Brassica rapa L.

    Science.gov (United States)

    Wang, Wei; Wang, Xiaoqing; Ye, Hong; Hu, Bing; Zhou, Li; Jabbar, Saqib; Zeng, Xiaoxiong; Shen, Wenbiao

    2016-01-01

    The root of Brassica rapa L. has been traditionally used as a Uyghur folk medicine to cure cough and asthma by Uyghur nationality in Xinjiang Uygur Autonomous Region of China. In the present study, therefore, extraction optimization, characterization and antioxidant activity in vitro of polysaccharides from the root of B. rapa L. (BRP) were investigated. The optimal extraction conditions with an extraction yield of 21.48 ± 0.41% for crude BRP were obtained as follows: extraction temperature 93°C, extraction time 4.3h and ratio of extraction solvent (water) to raw material 75 mL/g. The crude BRP was purified by chromatographic columns of DEAE-52 cellulose and Sephadex G-100, affording three purified fractions of BRP-1-1, BRP-2-1 and BRP-2-2 with average molecular weight of 1510, 1110 and 838 kDa, respectively. Monosaccharide composition analysis indicated that BRP-1-1 was composed of mannose, rhamnose, glucose, galactose and arabinose, BRP-2-1 was composed of rhamnose, galacturonic acid, galactose and arabinose, and BRP-2-2 was composed of rhamnose and galacturonic acid in a molar ratio of 1.27: 54.92. Furthermore, the crude BRP exhibited relatively higher antioxidant activity in vitro than purified fractions; hence, it could be used as a natural antioxidant in functional foods or medicines. PMID:26499088

  4. 绿茶饮料中茶多糖的构成%The components of tea polysaccarides in soft green tea drink

    Institute of Scientific and Technical Information of China (English)

    屠幼英

    2001-01-01

    The polysaccarides in the soft green tea drink was analyzed by HPLC.The results showed that content of tea polysaccarides was about 3.5% in the total solids.Six kinds of saccarides,i.e.rhamnose,xylose,arabinose,mannose,glucose and galactose were detected.The amounts of arabinose and galactose took up over 80% of the polysaccarides.%用高压液相色谱法(HPLC)测定绿茶饮料中茶叶游离多糖和复合多糖的构成和含量。结果显示,茶多糖总量约为绿茶饮料固形物的3.5%,游离多糖和复合多糖分别为1.9%和1.6%;其中包含了6种糖类:鼠李糖、木糖、阿拉伯糖、葡萄糖、半乳糖和甘露糖;而半乳糖和阿拉伯糖在游离多糖和复合多糖中均占80%以上。

  5. Effect of extraction conditions on the yield and purity of apple pomace pectin precipitated but not washed by alcohol.

    Science.gov (United States)

    Garna, Haikel; Mabon, Nicolas; Robert, Christelle; Cornet, Charlotte; Nott, Katherine; Legros, Hervé; Wathelet, Bernard; Paquot, Michel

    2007-01-01

    A study of the influence of extraction conditions (pH: 1.5 to 2; temperature: 80 to 90 degrees C; extraction time: 1 to 3 h), on the yield and purity of apple pomace pectin without elimination of impurities by alcohol washing was carried out. The alcohol precipitate yields varied from 2.9% to 8.9% depending on the pH. At pH 1.5, these yields were higher than those obtained at pH 2 contrary to the galacturonic acid purity (%w/w). Compounds other than pectins were solubilized from the cell walls of apple pomace at pH 1.5, and they were precipitated with alcohol. The apple pectins obtained from the different extraction procedures were highly methylated (54.5% to 79.5%), especially when the conditions (temperature, pH) were drastic. Similar conclusions can be drawn for the neutral sugar content that decreased at pH 1.5 (arabinose, xylose, and galactose) or at the highest temperatures and extraction times (arabinose and galactose). The phenomenon of demethylation and pectin degradation of neutral sugars chains can be observed at acid pH, and for long extraction times. The presence of high quantities of mannose or fructose, glucose, and xylose in the alcohol precipitate showed that pectin precipitation with ethanol was not specific. PMID:17995865

  6. Cj1411c GENE OF CAMPYLOBACTER JEJUNI 11168 ENCODES FOR A CYTOCHROME P450 INVOLVED IN BACTERIAL CAPSULE SUGAR METABOLISM

    Directory of Open Access Journals (Sweden)

    CORCIONIVOSCHI N.

    2007-01-01

    Full Text Available After isolation in 1970s, Campylobacter jejuni become the most commonlyrecognized cause of bacterial gastroenteritis in man. In animals is frequently foundin bovines on ovines. Publishing of the genome sequence of Campylobacter jejuni11168 (Parkhill, 2000 revealed the presence of only one cytochrome P450 in anoperon involved in sugar and cell surface biosynthesis. The gene name is Cj1411c, is1359 bp long and encodes 453 aa. The sequence is strictly conserved inCampylobacter jejuni RM221. Similarities with two cytochrome P450s, one formSilicobacter sp. and one form Poloromonas sp., were identified. These two enzymesare known to be involved in ascorbate and aldarate metabolism. The recombinantconstruct allowed the expression of active P450 enzyme with a 450 nm peak whenbinds CO. The protein was purified in proportion of ~ 70 %. By deleting the P450gene from the Campylobacter jejuni 11168 genome clear changes in cellmorphology were identified cells becoming wider and shorter. The capsular sugarprofile of the NCI strain reveals the presence of arabinose which was not found inthe wild type strain. The arabinose was identified by both High Performance LiquidChromatography (HPLC and Nuclear Magnetic Resonance (NMR.

  7. Heterologous production and characterization of a chlorogenic acid esterase from Ustilago maydis with a potential use in baking.

    Science.gov (United States)

    Nieter, Annabel; Kelle, Sebastian; Takenberg, Meike; Linke, Diana; Bunzel, Mirko; Popper, Lutz; Berger, Ralf G

    2016-10-15

    Ustilago maydis, an edible mushroom growing on maize (Zea mays), is consumed as the food delicacy huitlacoche in Mexico. A chlorogenic acid esterase from this basidiomycete was expressed in good yields cultivating the heterologous host Pichia pastoris on the 5L bioreactor scale (reUmChlE; 45.9UL(-1)). In contrast to previously described chlorogenic acid esterases, the reUmChlE was also active towards feruloylated saccharides. The enzyme preferred substrates with the ferulic acid esterified to the O-5 position of arabinose residues, typical of graminaceous monocots, over the O-2 position of arabinose or the O-6 position of galactose residues. Determination of kcat/Km showed that the reUmChlE hydrolyzed chlorogenic acid 18-fold more efficiently than methyl ferulate, p-coumarate or caffeate. Phenolic acids were released by reUmChlE from natural substrates, such as destarched wheat bran, sugar beet pectin and coffee pulp. Treatment of wheat dough using reUmChlE resulted in a noticeable softening indicating a potential application of the enzyme in bakery and confectionery. PMID:27173527

  8. Box-Behnken design for extraction optimization, characterization and in vitro antioxidant activity of Cicer arietinum L. hull polysaccharides.

    Science.gov (United States)

    Ye, Zipeng; Wang, Wei; Yuan, Qingxia; Ye, Hong; Sun, Yi; Zhang, Hongcheng; Zeng, Xiaoxiong

    2016-08-20

    The optimal extraction conditions with a yield of 5.37±0.15% for extraction of polysaccharides from chickpea (Cicer arietinum L.) hull (CHPS) were determined as extraction temperature 99°C, extraction time 2.8h and ratio of water to raw material 24mL/g. Three fractions of CHPS-1, CHPS-2 and CHPS-3, with average molecular weight of 3.1×10(6), 1.5×10(6) and 7.8×10(5)Da, respectively, were obtained from crude CHPS by chromatography of DEAE Fast Flow and Sephadex G-100. CHPS-1 was composed of mannose, rhamnose, galactose, galacturonic acid, glucose and arabinose, CHPS-2 was composed of mannose, rhamnose, galacturonic acid, galactose, xylose and arabinose, CHPS-3 was composed of galacturonic acid, galactose and rhamnose. CHPS-3 showed the strongest reducing power and protective effect on H2O2-induced oxidative injury in PC12 cells and highest scavenging activities against DPPH and ABTS radicals, while CHPS-2 showed the highest scavenging activity against superoxide anion radical. PMID:27178941

  9. Ethanol Production from Various Sugars and Cellulosic Biomass by White Rot Fungus Lenzites betulinus.

    Science.gov (United States)

    Im, Kyung Hoan; Nguyen, Trung Kien; Choi, Jaehyuk; Lee, Tae Soo

    2016-03-01

    Lenzites betulinus, known as gilled polypore belongs to Basidiomycota was isolated from fruiting body on broadleaf dead trees. It was found that the mycelia of white rot fungus Lenzites betulinus IUM 5468 produced ethanol from various sugars, including glucose, mannose, galactose, and cellobiose with a yield of 0.38, 0.26, 0.07, and 0.26 g of ethanol per gram of sugar consumed, respectively. This fungus relatively exhibited a good ethanol production from xylose at 0.26 g of ethanol per gram of sugar consumed. However, the ethanol conversion rate of arabinose was relatively low (at 0.07 g of ethanol per gram sugar). L. betulinus was capable of producing ethanol directly from rice straw and corn stalks at 0.22 g and 0.16 g of ethanol per gram of substrates, respectively, when this fungus was cultured in a basal medium containing 20 g/L rice straw or corn stalks. These results indicate that L. betulinus can produce ethanol efficiently from glucose, mannose, and cellobiose and produce ethanol very poorly from galactose and arabinose. Therefore, it is suggested that this fungus can ferment ethanol from various sugars and hydrolyze cellulosic materials to sugars and convert them to ethanol simultaneously. PMID:27103854

  10. Purification, characterization and anti-proliferation activities of polysaccharides extracted from Viscum coloratum (Kom.) Nakai.

    Science.gov (United States)

    Chai, Yangyang; Zhao, Min

    2016-09-20

    Three polysaccharides, VCP1, VCP2 and VCP3 were isolated from Viscum coloratum (Kom.) Nakai using DEAE-cellulose chromatography. VCP1 (32KDa) was composed of glucose, galactose, arabinose, rhamnose and mannose, while VCP2 (280KDa) and VCP3 (21KDa) were consisted of glucose, galactose, arabinose, rhamnose, mannose, glucuronic acid and galacturonic acid. The optical rotation was measured at 20+1°C. The characteristic absorptive bands of purified fraction were determined by FT-IR. (13)C NMR spectroscopy analysis showed that VCP1 was a neutral polysaccharide, and VCP2 and VCP3 were RG-I type pectin. The linkage patterns of VCP2 were evaluated by methylation analysis: 1,5-linked Araf, 1,4-linked Galp, 1,2-linked Rhap, and 1,2,4-linked Rhap. The degree of esterification was 50%. The anti-proliferation ability against HepG2 cells and HepG2.2.15 cells of VCP2 was stronger than VCP1 and VCP3. So the polysaccharides from Viscum coloratum (Kom.) Nakai could be used as potential natural sources with inhibiting tumor cells proliferation. PMID:27261737

  11. Effect of water deficit on the cell wall of the date palm (Phoenix dactylifera 'Deglet nour', Arecales) fruit during development.

    Science.gov (United States)

    Gribaa, Ali; Dardelle, Flavien; Lehner, Arnaud; Rihouey, Christophe; Burel, Carole; Ferchichi, Ali; Driouich, Azeddine; Mollet, Jean-Claude

    2013-05-01

    Date palm (Phoenix dactylifera) is an important crop providing a valuable nutrition source for people in many countries including the Middle East and North Africa. In recent years, the amount of rain in North Africa and especially in the Tunisian palm grove areas has dropped significantly. We investigated the growth and cell wall remodelling of fruits harvested at three key development stages from trees grown with or without water supply. During development, cell wall solubilization and remodelling was characterized by a decrease of the degree of methylesterification of pectin, an important loss of galactose content and a reduction of the branching of xylan by arabinose in irrigated condition. Water deficit had a profound effect on fruit size, pulp content, cell wall composition and remodelling. Loss of galactose content was not as important, arabinose content was significantly higher in the pectin-enriched extracts from non-irrigated condition, and the levels of methylesterification of pectin and O-acetylation of xyloglucan were lower than in irrigated condition. The lower levels of hydrophobic groups (methylester and O-acetyl) and the less intensive degradation of the hydrophilic galactan, arabinan and arabinogalactan in the cell wall may be implicated in maintaining the hydration status of the cells under water deficit. PMID:23176574

  12. Polymyxin resistance of Pseudomonas aeruginosa phoQ mutants is dependent on additional two-component regulatory systems

    DEFF Research Database (Denmark)

    Gutu, Alina D; Sgambati, Nicole; Strasbourger, Pnina;

    2013-01-01

    systems, ColRS and CprRS. Deletion of the colRS genes, individually or in tandem, abrogated the polymyxin resistance of a ΔphoQ mutant, as did individual or tandem deletion of cprRS. Individual deletion of colR or colS in a ΔphoQ mutant also suppressed 4-amino-L-arabinose addition to lipid A, consistent...... with the known role of this modification in polymyxin resistance. Surprisingly, tandem deletion of colRS or cprRS in the ΔphoQ mutant or individual deletion of cprR or cprS failed to suppress 4-amino-L-arabinose addition to lipid A, indicating that this modification alone is not sufficient for Pho......PQ-mediated polymyxin resistance in P. aeruginosa. Episomal expression of colRS or cprRS in tandem or of cprR individually complemented the Pm resistance phenotype in the ΔphoQ mutant, while episomal expression of colR, colS, or cprS individually did not. Highly polymyxin-resistant phoQ mutants of P. aeruginosa...

  13. Dilute Sulfuric Acid Pretreatment of Agricultural and Agro-Industrial Residues for Ethanol Production

    Science.gov (United States)

    Martin, Carlos; Alriksson, Björn; Sjöde, Anders; Nilvebrant, Nils-Olof; Jönsson, Leif J.

    The potential of dilute-acid prehydrolysis as a pretreatment method for sugarcane bagasse, rice hulls, peanut shells, and cassava stalks was investigated. The prehydrolysis was performed at 122°C during 20, 40, or 60 min using 2% H2SO4 at a solid-to-liquid ratio of 1∶10. Sugar formation increased with increasing reaction time. Xylose, glucose, arabinose, and galactose were detected in all of the prehydrolysates, whereas mannose was found only in the prehydrolysates of peanut shells and cassava stalks. The hemicelluloses of bagasse were hydrolyzed to a high-extent yielding concentrations of xylose and arabinose of 19.1 and 2.2 g/L, respectively, and a xylan conversion of more than 80%. High-glucose concentrations (26-33.5 g/L) were found in the prehydrolysates of rice hulls, probably because of hydrolysis of starch of grain remains in the hulls. Peanut shells and cassava stalks rendered low amounts of sugars on prehydrolysis, indicating that the conditions were not severe enough to hydrolyze the hemicelluloses in these materials quantitatively. All prehydrolysates were readily fermentable by Saccharomyces cerevisiae. The dilute-acid prehydrolysis resulted in a 2.7-to 3.7-fold increase of the enzymatic convertibility of bagasse, but was not efficient for improving the enzymatic hydrolysis of peanut shells, cassava stalks, or rice hulls.

  14. Turnover of galactans and other cell wall polysaccharides during development of flax plants

    International Nuclear Information System (INIS)

    We investigated the synthesis and turnover of cell wall polysaccharides of the flax (Linum usitatissimum L.) plant during development of the phloem fibers. One-month-old flax plants were exposed to a 40-min pulse with 14CO2 followed by 8-h, 24-h, and 1-month periods of chase with ambient CO2, and radioactivity in cell wall sugars was determined in various plant parts. The relative radioactivity of glucose in noncellulosic polysaccharides was the highest compared with all other cell wall sugars immediately after the pulse and decreased substantially during the subsequent chase. The relative radioactivities of the other cell wall sugars changed with differing rates, indicating turnover of specific polysaccharides. Notably, after 1 month of chase there was a marked decrease in the proportional mass and total radioactivity in cell wall galactose, indicating a long-term turnover of the galactans enriched in the fiber-containing tissues. The ratio of radiolabeled xylose to arabinose also increased during the chase, indicating a turnover of arabinose-containing polymers and interconversion to xylose. The pattern of label redistribution differed between organs, indicating that the cell wall turnover processes are tissue- and cell-specific

  15. Endogeneous β-D: -xylosidase and α-L: -arabinofuranosidase activity in flax seed mucilage.

    Science.gov (United States)

    Rasmussen, Louise E; Meyer, Anne S

    2010-12-01

    Flax seed mucilage (FM) contains a mixture of highly doubly substituted arabinoxylan as well as rhamnogalacturonan I with unusual side group substitutions. Treatment of FM with a GH11 Bacillus subtilis XynA endo 1,4-β-xylanase (BsX) gave limited formation of reducing ends but when BsX and FM were incubated together on different wheat arabinoxylan substrates and birchwood xylan, significant amounts of xylose were released. Moreover, arabinose was released from both water-extractable and water-unextractable wheat arabinoxylan. Since no xylose or arabinose was released by BsX addition alone on these substrates, nor without FM or BsX addition, the results indicate the presence of endogenous β-D: -xylosidase and α-L: -arabinofuranosidase activities in FM. FM also exhibited activity on both p-nitrophenyl α-L: -arabinofuranoside (pNPA) and p-nitrophenyl β-D: -xylopyranoside (pNPX). Based on K ( M ) values, the FM enzyme activities had a higher affinity for pNPX (K ( M ) 2 mM) than for pNPA (K ( M ) 20 mM). PMID:20703806

  16. Isolation and Characterization of Phenolic Compounds and Anthocyanins from Murta (Ugni molinae Turcz. Fruits. Assessment of Antioxidant and Antibacterial Activity

    Directory of Open Access Journals (Sweden)

    Maria Paula Junqueira-Gonçalves

    2015-03-01

    Full Text Available Berry fruit consumption has become important in the promotion of human health, mainly due to their phenolic compounds, which have been associated with protection against different pathologies, as well as antimicrobial and other biological activities. Consequently, there has been a growing interest in identifying natural antioxidants and antimicrobials from these plants. This study aimed to characterize the phenolic chemical composition and anthocyanin profile of murta (Ugni molinae Turcz. fruit, and to evaluate the antioxidant and antimicrobial activity of its extracts (ethanolic and methanolic. LC/MS of the ethanolic extracts showed the presence of three major compounds: caffeic acid 3-glu, quercetin-3-glu and quercetin, while in the methanolic acid extract they were cyanidin-3-glucoside, pelargonidin-3-arabinose and delphinidin-3-glucoside. The antioxidant activity of ethanolic extracts (DPPH· and ORAC assays was higher than that of methanol acid extracts or purified anthocynins. Furthermore, the methanol acid extract showed an inhibitory activity against the bacteria E. coli and S. typhi similar to that of standard antibiotics. The results suggest that the antioxidant activity of the ethanolic extract is regulated by the high content of phenolic compounds and the fruit’s characteristic color is due to the content of pelargonidin-3-arabinose and delphinidin-3-glucoside. The obtained results demonstrated the appreciable antioxidant and antibacterial activities, providing opportunities to explore murta extracts as biopreservatives.

  17. Process optimization and kinetic modelling of cyclic (1→3, 1→6)-β-glucans production from Bradyrhizobium japonicum MTCC120.

    Science.gov (United States)

    Nair, Anju V; Gummadi, Sathyanarayana N; Doble, Mukesh

    2016-05-20

    Cyclic (1→3, 1→6)-β-glucans are water soluble, biocompatible polymers with potential applications in food and pharmaceutical industries but have not yet been exploited due to their poor yield. In the present study statistical experimental design methodology was employed to improve their production. Initial screening indicated arabinose and peptone as best carbon and nitrogen source respectively, for glucan production. Arabinose and osmolyte concentrations as well as pH significantly contributed to the glucan production. Central composite design indicated a significant interaction between osmolyte concentration and pH on glucan production. The maximum amount of cyclic glucan produced was 6.7g/L in a 2.5L reactor in batch conditions. The logistic equation for cell growth and Luedeking-Piret equation for glucan production could satisfactorily simulate the batch kinetics data. Cyclic β-glucans could efficiently encapsulate a hydrophobic molecule, curcumin and increase its solubility in water, thus indicating that these glucans have potential as drug delivery systems. PMID:27046066

  18. Chemical structure and antioxidant activity of a new exopolysaccharide produced from Micrococcus luteus

    Directory of Open Access Journals (Sweden)

    Mohsen Mohamed Selim Asker

    2014-12-01

    Full Text Available An exopolysaccharide (EPS reaching a maximum of 13 g/L was isolated from Micrococcus luteus by ethanol precipitation. The crude EPS was purified by chromatography on DEAE-cellulose and Sephacryl S-200, affording a polysaccharide active fraction (AEP with a molecular weight of ∼137 kDa. AEP was investigated by a combination of chemical and chromatographic methods including FTIR, HPLC, periodate oxidation, methylation and GC–MS. Data obtained indicated that AEP was composed of mannose, arabinose, glucose and glucuronic acid in a molar ratio of 3.6:2.7:2.1:1.0, respectively. The main backbone consists of mannose units linked with (1→6-glycosidic bonds and arabinose units linked with (1→5-glycosidic bonds. There is a side chain consisting of mannose units linked with (1→6-glycosidic bonds at C3, when all glucose and most of glucuronic acid are found in the side chain. The in vitro antioxidant assay showed that AEP possesses DPPH radical-scavenging activity, with an EC50 value of 180 μg/mL.

  19. Rapid Verification of Terminators Using the pGR-Blue Plasmid and Golden Gate Assembly.

    Science.gov (United States)

    Bradshaw, Jace C; Gongola, Allea Belle; Reyna, Nathan S

    2016-01-01

    The goal of this protocol is to allow for the rapid verification of bioinformatically identified terminators. Further, the plasmid (pGR-Blue) is designed specifically for this protocol and allows for the quantification of terminator efficiency. As a proof of concept, six terminators were bioinformatically identified in the mycobacteriophage Bernal13. Once identified, terminators were then made as oligonucleotides with the appropriate sticky ends and annealed together. Using Golden Gate Assembly (GGA), terminators were then cloned into pGR-Blue. Under visible light, false positive colonies appear blue and positively transformed colonies are white/yellow. After induction of an arabinose inducible promoter (pBad) with arabinose, colony strength can be determined by measuring the ratio of green fluorescent protein (GFP) produced to red fluorescent protein (RFP) produced. With pGR-Blue, the protocol can be completed in as little as three days and is ideal in an educational setting. Additionally, results show that this protocol is useful as a means for understanding in silico predictions of terminator efficiency related to the regulation of transcription. PMID:27167700

  20. Isolation and characterization of phenolic compounds and anthocyanins from Murta (Ugni molinae Turcz.) fruits. Assessment of antioxidant and antibacterial activity.

    Science.gov (United States)

    Junqueira-Gonçalves, Maria Paula; Yáñez, Lina; Morales, Carolina; Navarro, Muriel; A Contreras, Rodrigo; Zúñiga, Gustavo E

    2015-01-01

    Berry fruit consumption has become important in the promotion of human health, mainly due to their phenolic compounds, which have been associated with protection against different pathologies, as well as antimicrobial and other biological activities. Consequently, there has been a growing interest in identifying natural antioxidants and antimicrobials from these plants. This study aimed to characterize the phenolic chemical composition and anthocyanin profile of murta (Ugni molinae Turcz.) fruit, and to evaluate the antioxidant and antimicrobial activity of its extracts (ethanolic and methanolic). LC/MS of the ethanolic extracts showed the presence of three major compounds: caffeic acid 3-glu, quercetin-3-glu and quercetin, while in the methanolic acid extract they were cyanidin-3-glucoside, pelargonidin-3-arabinose and delphinidin-3-glucoside. The antioxidant activity of ethanolic extracts (DPPH· and ORAC assays) was higher than that of methanol acid extracts or purified anthocynins. Furthermore, the methanol acid extract showed an inhibitory activity against the bacteria E. coli and S. typhi similar to that of standard antibiotics. The results suggest that the antioxidant activity of the ethanolic extract is regulated by the high content of phenolic compounds and the fruit's characteristic color is due to the content of pelargonidin-3-arabinose and delphinidin-3-glucoside. The obtained results demonstrated the appreciable antioxidant and antibacterial activities, providing opportunities to explore murta extracts as biopreservatives. PMID:25838172

  1. Optimization of acid hydrolysis from the hemicellulosic fraction of Eucalyptus grandis residue using response surface methodology.

    Science.gov (United States)

    Canettieri, Eliana Vieira; de Moraes Rocha, George Jackson; de Carvalho, João Andrade; de Almeida e Silva, João Batista

    2007-01-01

    Biotechnological conversion of biomass into fuels and chemicals requires hydrolysis of the polysaccharide fraction into monomeric sugars. Hydrolysis can be performed enzymatically and with dilute or concentrate mineral acids. The present study used dilute sulfuric acid as a catalyst for hydrolysis of Eucalyptus grandis residue. The purpose of this paper was to optimize the hydrolysis process in a 1.4 l pilot-scale reactor and investigate the effects of the acid concentration, temperature and residue/acid solution ratio on the hemicellulose removal and consequently on the production of sugars (xylose, glucose and arabinose) as well as on the formation of by-products (furfural, 5-hydroxymethylfurfural and acetic acid). This study was based on a model composition corresponding to a 2(3) orthogonal factorial design and employed the response surface methodology (RSM) to optimize the hydrolysis conditions, aiming to attain maximum xylose extraction from hemicellulose of residue. The considered optimum conditions were: H(2)SO(4) concentration of 0.65%, temperature of 157 degrees C and residue/acid solution ratio of 1/8.6 with a reaction time of 20 min. Under these conditions, 79.6% of the total xylose was removed and the hydrolysate contained 1.65 g/l glucose, 13.65 g/l xylose, 1.55 g/l arabinose, 3.10 g/l acetic acid, 1.23 g/l furfural and 0.20 g/l 5-hydroxymethylfurfural. PMID:16473004

  2. Structure and antigenicity of the phosphorylated lipopolysaccharide antigens from the leprosy and tubercle bacilli.

    Science.gov (United States)

    Hunter, S W; Gaylord, H; Brennan, P J

    1986-09-15

    A family of major arabinose- and mannose-containing phosphorylated lipopolysaccharides was isolated from Mycobacterium leprae and Mycobacterium tuberculosis. The only antigenic member of the family, lipoarabinomannan (LAM)-B, was purified by anion exchange and gel filtration chromatography in detergent and recovered in large quantities (15 mg/g of bacteria). It yielded a broad diffuse band on polyacrylamide gel electrophoresis but appeared homogeneous by this criterion and gel filtration. Besides arabinose and mannose, it contained glycerol and a polyol phosphate and was acylated by lactate, succinate, palmitate, and 10-methyloctadecanoate. The phosphate was released by alkalinolysis and identified by thin layer chromatography and gas chromatography-mass spectrometry as myoinositol 1-phosphate. Thus, the group-specific "arabinomannan" of the genus Mycobacterium in the native state is acylated, contains the substituents of phosphatidylinositol, and is apparently membrane associated. LAM-B is one of the dominant immunogens of the leprosy bacillus reacting readily with antibodies from lepromatous leprosy patients and monoclonal antibodies in plate and nitrocellulose enzyme-linked immunosorbent assay and on electrophoretic immunoblots. It is immunologically cross-reactive with a like product from M. tuberculosis. LAM-B is clearly the pervasive "glycoprotein" antigen of the leprosy bacillus and may be the long sought lipoteichoic acid-like polymer of Mycobacterium with a role in cell wall physiology, macrophage recognition, and perhaps an involvement in cross-protective immunity. PMID:3091602

  3. Construction of plasmid-free Escherichia coli for the production of arabitol-free xylitol from corncob hemicellulosic hydrolysate.

    Science.gov (United States)

    Su, Buli; Zhang, Zhe; Wu, Mianbin; Lin, Jianping; Yang, Lirong

    2016-01-01

    High costs and low production efficiency are a serious constraint to bio-based xylitol production. For industrial-scale production of xylitol, a plasmid-free Escherichia coli for arabitol-free xylitol production from corncob hemicellulosic hydrolysate has been constructed. Instead of being plasmid and inducer dependent, this strain relied on multiple-copy integration of xylose reductase (XR) genes into the chromosome, where their expression was controlled by the constitutive promoter P43. In addition, to minimize the flux from L-arabinose to arabitol, two strategies including low XR total activity and high selectivity of XR has been adopted. Arabitol was significantly decreased using plasmid-free strain which had lower XR total activity and an eight point-mutations of XR with a 27-fold lower enzyme activity toward L-arabinose was achieved. The plasmid-free strain in conjunction with this mutant XR can completely eliminate arabitol formation in xylitol production. In fed-batch fermentation, this plasmid-free strain produced 143.8 g L(-1) xylitol at 1.84 g L(-1) h(-1) from corncob hemicellulosic hydrolysate. From these results, we conclude that this route by plasmid-free E. coli has potential to become a commercially viable process for xylitol production. PMID:27225023

  4. Accelerated pentose utilization by Corynebacterium glutamicum for accelerated production of lysine, glutamate, ornithine and putrescine.

    Science.gov (United States)

    Meiswinkel, Tobias M; Gopinath, Vipin; Lindner, Steffen N; Nampoothiri, K Madhavan; Wendisch, Volker F

    2013-03-01

    Because of their abundance in hemicellulosic wastes arabinose and xylose are an interesting source of carbon for biotechnological production processes. Previous studies have engineered several Corynebacterium glutamicum strains for the utilization of arabinose and xylose, however, with inefficient xylose utilization capabilities. To improve xylose utilization, different xylose isomerase genes were tested in C. glutamicum. The gene originating from Xanthomonas campestris was shown to have the highest effect, resulting in growth rates of 0.14 h(-1), followed by genes from Bacillus subtilis, Mycobacterium smegmatis and Escherichia coli. To further increase xylose utilization different xylulokinase genes were expressed combined with X. campestris xylose isomerase gene. All combinations further increased growth rates of the recombinant strains up to 0.20 h(-1) and moreover increased biomass yields. The gene combination of X. campestris xylose isomerase and C. glutamicum xylulokinase was the fastest growing on xylose and compared with the previously described strain solely expressing E. coli xylose isomerase gene delivered a doubled growth rate. Productivity of the amino acids glutamate, lysine and ornithine, as well as the diamine putrescine was increased as well as final titres except for lysine where titres remained unchanged. Also productivity in medium containing rice straw hydrolysate as carbon source was increased. PMID:23164409

  5. Fermentation of carbohydrate in rat ileal excreta is enhanced with cecal inocula compared with fecal inocula.

    Science.gov (United States)

    Monsma, D J; Marlett, J A

    1996-02-01

    The differential fermentative capacities of microflora from two regions of the large bowel and how fermentation was altered by prior exposure of the microflora to the substrate to be fermented were studied using an in vitro fermentation system. Bacterial inocula were prepared from cecal contents and feces from three groups of rats fed purified diets containing 100 g/kg dietary fiber from canned peas or psyllium seed husk, or a nonpurified diet containing 170 g/kg dietary fiber. The substrate for all fermentations was ileal excreta from colectomized rats fed a purified diet containing 100 g/kg dietary fiber from canned peas. Anaerobic fermentations were conducted for 0, 3, 6, 12, 24, 48 and 96 h. Sugars of the unfermented polysaccharides were measured by gas chromatography following acid hydrolysis; disappearance was the measure of fermentation. Independent of inoculum source, > 90% of the starch and arabinose and 75% of the uronic acids, but psyllium seed husk fermented starch faster (P < 0.05) and non-starch glucose, arabinose and uronic acids more slowly (P < 0.05) than inocula adapted to peas or nonpurified diet. Bacterial efficiency of carbohydrate utilization, the increase in muramic acid/mole carbohydrate fermented, was greatest (P < 0.05) with cecal inocula adapted to peas. We conclude that using cecal microflora as the inoculum source provides a more accurate index of fermentation during transit through the large bowel and that noncellulosic and storage polysaccharides of the plant cell wall are utilized before cellulose. PMID:8632231

  6. The gel-forming polysaccharide of psyllium husk (Plantago ovata Forsk).

    Science.gov (United States)

    Fischer, Milton H; Yu, Nanxiong; Gray, Gary R; Ralph, John; Anderson, Laurens; Marlett, Judith A

    2004-08-01

    The physiologically active, gel-forming fraction of the alkali-extractable polysaccharides of Plantago ovata Forsk seed husk (psyllium seed) and some derived partial hydrolysis products were studied by compositional and methylation analysis and NMR spectroscopy. Resolving the conflicting claims of previous investigators, the material was found to be a neutral arabinoxylan (arabinose 22.6%, xylose 74.6%, molar basis; only traces of other sugars). With about 35% of nonreducing terminal residues, the polysaccharide is highly branched. The data are compatible with a structure consisting of a densely substituted main chain of beta-(1-->4)-linked D-xylopyranosyl residues, some carrying single xylopyranosyl side chains at position 2, others bearing, at position 3, trisaccharide branches having the sequence L-Araf-alpha-(1-->3)-D-Xylp-beta-(1-->3)-l-Araf. The presence of this sequence is supported by methylation and NMR data, and by the isolation of the disaccharide 3-O-beta-D-xylopyranosyl-L-arabinose as a product of partial acid hydrolysis of the polysaccharide. PMID:15261594

  7. The isolation and the characterization of two polysaccharides from the branch bark of mulberry (Morus alba L.).

    Science.gov (United States)

    Qiu, Fan; He, Tian-Zhen; Zhang, Yu-Qing

    2016-07-01

    Two water-soluble polysaccharides termed MBBP-1 and MBBP-2 were isolated from the branches of the mulberry tree (Morus alba L.) using hot water extraction and purified on Anion-exchange DEAE52-cellulose and Sephadex G-100 column. MBBP-1 was shown to be composed of rhamnose, xylose, arabinose, mannose, glucose and galactose in the molar ratio of 4.53:2.49:4.38:4.67:17.85:5.88. MBBP-2 was composed of rhamnose, xylose, arabinose, mannose, glucose, galactose and galacturonic acid in the molar ratio of 26.85:13.8:3.14:4.4:6.1:3.19:4.9. Their structural characteristics were further investigated by FI-IR spectroscopy, Smith degradation, methylation analysis and NMR spectroscopy. Based on the data obtained, MBBP-1 had a backbone mainly consisting of (1 → 3)-linked glucose. MBBP-2 had a backbone mainly consisting of (1 → 3)-linked rhamnose and (1 → 2, 4)-linked xylose. Antioxidant assays indicated that antioxidant activities of MBBP-2 were significantly stronger than those of MBBP-1, and this was likely in relation to the different content of 8.2 % galacturonic acid in MBBP-2. PMID:27255450

  8. Overexpression and export of Vibrio anguillarum metalloprotease in Escherichia coli

    Institute of Scientific and Technical Information of China (English)

    Zhang Fengli; Chi Zhenming; Chen Jixiang; Wu Longfei; Liang Likun

    2007-01-01

    Vibrio anguillarum metalloprotease, an extracellular zinc metalloprotease involved in the virulence mechanism of Vibrio anguillarum, is synthesized from the empA gene as a 611-residue precursor and naturally secreted via Sec secretion pathway in Vibrio anguillarum. In this study, heterologous expression of the empA gene encoding metallopmtease and export of the recombinant metalloprotease in Escherichia coliwere examined. The empA gene was subcloned into pBAD24 with arabinose promoter and sequenced. The sequence encoded a polypeptide(611 amino acids)consisting of four domains: a signal peptide, an Nterminal propeptide, a mature region and a C-terminal propeptide. The empA gene inserted in plasmid pBAD24 was overexpressed in TOP10 strain of E. Coli after arabinose induction. The 36kDa polypeptide of the recombinant metalloprotease as the mature protease was further confirmed by SDS-PAGE and immunoblotting. It was found that recombinant metalloprotease with the EmpA activity and antigenicity wasexported into the periplasm of Escherichia coli cells via Sec translocation pathway, whereas it was secreted into extracellular environments in V. Anguillarum. The results imply that the expression, export and processing mechanism of the protein in E. Coli are similar to those in V. Anguillarum.

  9. Low-energy collisionally activated dissociation of pentose-borate complexes

    Science.gov (United States)

    Pepi, Federico; Garzoli, Stefania; Tata, Alessandra; Giacomello, Pierluigi

    2010-01-01

    Pentose-borate 1:1 complexes were generated in the ESI source of a triple quadrupole and ion trap mass spectrometer by electrospray ionization of Na2B4O7 and pentose (arabinose, lyxose, ribose, xylose) 2:1 solution in CH3CN/H2O. The study of their low-energy collisionally activated dissociation (CAD) demonstrated that ribose and lyxose are preferentially complexed at the C2-C3 cis-diol function whereas arabinose and xylose are esterified at the C1-C2 hydroxyl groups. No evidence was found of the stronger affinity for ribose to borate. The ribose probiotic rule can be explained by considering its peculiar capability, among the investigated pentoses, to almost totally complex the borate anion at the C2-C3 hydroxyl group, thus enabling the subsequent stages of nucleotide assembly, such as phosphorylation and linkage to the nucleobases. Finally, the differences observed in the pentose-borate complex CAD spectra can be used for the mass spectrometric discrimination of isomeric pentoses in complex mixtures.

  10. Biogeochemical characteristics of sedimenting particles in Dona Paula Bay, India

    Science.gov (United States)

    D'souza, Fraddry; Garg, Anita; Bhosle, Narayan B.

    2003-10-01

    Sedimenting particles were collected at weekly intervals from October to May during 1995-1997 at a station in the coastal waters of Dona Paula Bay on the west coast of India. Sedimenting particles were analysed for concentration and composition of total sedimented particulate matter (TPM), biogenic silica (BSi) and total neutral carbohydrates (TCHO). TPM, BSi and TCHO fluxes showed seasonal and annual variations. Fluxes of BSi showed significant correlations with the fluxes of TCHO and fucose indicating that at the study site diatoms were associated with the production of carbohydrates. However, a high content of arabinose plus xylose (˜56% of TCHO without glucose) in some samples and their negative correlations with fucose may suggest terrestrial inputs. Sedimenting particles depleted in glucose content were enriched in rhamnose, fucose, xylose, mannose and galactose. A principal component analysis based on log-normalized wt% of monosaccharides established three factors that contributed 78% of total variance. The first factor was mostly controlled by the abundance of arabinose and xylose while the second and third factors were dependent on fucose, galactose, mannose and rhamnose. Carbohydrate composition data suggest that the nature and sources of organic matter at the study site varied over the period of study.

  11. Composition of Lycium barbarum polysaccharides and their apoptosis-inducing effect on human hepatoma SMMC-7721 cells

    Directory of Open Access Journals (Sweden)

    Qian Zhang

    2015-11-01

    Full Text Available Background: Lycium barbarum polysaccharide (LBP is a natural functional component that has a variety of biological activities. The molecular structures and apoptosis-inducing activities on human hepatoma SMMC-7721 cells of two LBP fractions, LBP-d and LBP-e, were investigated. Results: The results showed that LBP-d and LBP-e both consist of protein, uronic acid, and neutral sugars in different proportions. The structure of LBP was characterized by gas chromatography, periodate oxidation, and Smith degradation. LBP-d was composed of eight kinds of monosaccharides (fucose, ribose, rhamnose, arabinose, xylose, mannose, galactose, and glucose, while LBP-e was composed of six kinds of monosaccharides (fucose, rhamnose, arabinose, mannose, galactose, and glucose. LBP-d and LBP-e blocked SMMC-7721 cells at the G0/G1 and S phases with an inhibition ratio of 26.70 and 45.13%, respectively, and enhanced the concentration of Ca2 + in the cytoplasm of SMMC-7721. Conclusion: The contents of protein, uronic acid, and galactose in LBP-e were much higher than those in LBP-d, which might responsible for their different bioactivities. The results showed that LBP can be provided as a potential chemotherapeutic agent drug to treat cancer.

  12. Multivariate analysis of buckwheat sourdough fermentations for metabolic screening of starter cultures.

    Science.gov (United States)

    Capuani, Alessandro; Stetina, Mandy; Gstattenbauer, Anja; Behr, Jürgen; Vogel, Rudi F

    2014-08-18

    This study investigated the metabolic activity of 35 strains of lactic acid bacteria (LAB), which were able to grow in buckwheat sourdoughs and delivers a detailed explanation of LAB metabolism in that environment. To interpret the high-dimensional dataset, descriptive statistics and linear discriminant analysis (LDA) were used. Heterofermentative LAB showed a clear different metabolism than facultative (f.) heterofermentative and homofermentative LAB, which were more similar. Heterofermentative LAB were mainly characterized by high free SH groups and acetic acid production; they were also able to consume arabinose and glucose. Homofermenters were mainly characterized by lower free amino nitrogen content and they did not show a good capacity to consume arabinose and fructose. Except for the heterofermentative Weissella cibaria strain, only homofermentative strains showed high ornithine yields. Some f. heterofermentative strains differed from homofermentative due to the high lactic acid production as well as low glucose and arginine consumption. LAB containing more genes encoding peptidase activities and genes involved in aroma production showed a high consumption of free amino acids. Strain-dependent activities could be clearly distinguished from group dependent ones (homofermentative, f. heterofermentative and heterofermentative), e.g., some Lactobacillus paracasei and Lactobacillus plantarum strains showed the highest carbohydrate consumption. However, some microbial activities were more strain-dependent than group-dependent. Multivariate analysis of raw data delivered a detailed and clear explanation of LAB metabolism in buckwheat sourdough fermentations. PMID:24992519

  13. Influence of variables in the hydrothermal treatment of rice straw on the composition of the resulting fractions.

    Science.gov (United States)

    Rodríguez, Alejandro; Moral, Ana; Sánchez, Rafael; Requejo, Ana; Jiménez, Luis

    2009-10-01

    The influence of the hydrothermal treatment conditions of rice straw (temperature--150-190 degrees C , time--0-20 min after reaching the operation temperature, and liquid/solid ratio--6-8), on the composition of liquid and solid fractions was studied. Polynomial models were found for to reproduce the experimental results with errors less than 6%. Operating to 190 degrees C, 15 min and 9 liquid/solid ratio was obtained high values of glucose (1.92 g/L), xylose (3.97 g/L), arabinose (0.99 g/L) and acetic acid (1.96 g/L), what allows to save capital when not operating with the maximum time and/or liquid/solid ratio; yield in the solid fraction is 88.1% and lignin content 24.43%. If what it is required to obtain good values of yield (96.46%) and lignin content, is necessary to operate to 150 degrees C, obtaining lower concentrations glucose (1.11%), xylose (2.78%), arabinose (0.56%) and acetic acid (0.39%). Ethanolamine pulping of solid fraction of hydrothermal treatment provides pulp with higher or similar properties to those obtained of pulping rice straw with ethanolamine or soda. PMID:19467587

  14. Heat stress causes alterations in the cell-wall polymers and anatomy of coffee leaves (Coffea arabica L.).

    Science.gov (United States)

    Lima, Rogério Barbosa; dos Santos, Tiago Benedito; Vieira, Luiz Gonzaga Esteves; Ferrarese, Maria de Lourdes Lúcio; Ferrarese-Filho, Osvaldo; Donatti, Lucélia; Boeger, Maria Regina Torres; Petkowicz, Carmen Lúcia de Oliveira

    2013-03-01

    Coffee plants were subjected to heat stress (37 °C) and compared with control plants (24 °C). Cell wall polysaccharides were extracted using water (W), EDTA (E) and 4M NaOH (H30 and H70). In addition, monolignols were analyzed, and the leaves were observed by microscopy. Plants under heat stress accumulated higher contents of arabinose and galactose in fraction W. Xylose contents were observed to decrease in H30 fractions after the heat stress, whereas galactose and uronic acid increased. H70 fractions from plants exposed to heat stress showed increased xylose contents, whereas the contents of arabinose and glucose decreased. Differences in the molar-mass profiles of polysaccharides were also observed. The primary monolignol contents increased after the heat stress. Structural alterations in palisade cells and ultrastructural damage in chloroplasts were also observed. Our results demonstrate that the chemical profile of coffee cell-wall polymers and structural cell anatomy change under heat stress. PMID:23465912

  15. Revisiting the structural features of arabinoxylans from brewers' spent grain.

    Science.gov (United States)

    Coelho, Elisabete; Rocha, M Angélica M; Moreira, Ana S P; Domingues, M Rosário M; Coimbra, Manuel A

    2016-03-30

    The brewers' spent grain (BSG) arabinoxylans (AX) have been described to be composed by a backbone of (β1→4)-linked xylose residues containing only single units of arabinose as side chains. However, this is not in accordance with the structural features of AX from other cereal sources. Aiming to disclose the possibility of additional structural details, fractions enriched in AX were obtained by sequential extraction from BSG. The AX richest fraction was hydrolysed with xylanase, fractioned by size-exclusion chromatography, and analysed by electrospray tandem mass spectrometry (ESI-MS(n)). Methylation analysis showed that the amount of terminally linked arabinose residues was not in accordance with the number of xylose branching points. This was due to the presence of O-acetyl, hexose, hexuronic acid, and methylated uronic acid residues. AXs presenting these structural features can be a potential source of a large screening prebiotic, providing, in the same molecule, areas of fast and slow probiotic fermentation rates. PMID:26794960

  16. ANALYSIS OF RICIN TOXIN PREPARATIONS FOR CARBOHYDRATE AND FATTY ACID ABUNDANCE AND ISOTOPE RATIO INFORMATION

    Energy Technology Data Exchange (ETDEWEB)

    Wunschel, David S.; Kreuzer-Martin, Helen W.; Antolick, Kathryn C.; Colburn, Heather A.; Moran, James J.; Melville, Angela M.

    2009-12-01

    This report describes method development and preliminary evaluation for analyzing castor samples for signatures of purifying ricin. Ricin purification from the source castor seeds is essentially a problem of protein purification using common biochemical methods. Indications of protein purification will likely manifest themselves as removal of the non-protein fractions of the seed. Two major, non-protein, types of biochemical constituents in the seed are the castor oil and various carbohydrates. The oil comprises roughly half the seed weight while the carbohydrate component comprises roughly half of the remaining “mash” left after oil and hull removal. Different castor oil and carbohydrate components can serve as indicators of specific toxin processing steps. Ricinoleic acid is a relatively unique fatty acid in nature and is the most abundant component of castor oil. The loss of ricinoleic acid indicates a step to remove oil from the seeds. The relative amounts of carbohydrates and carbohydrate-like compounds, including arabinose, xylose, myo-inositol fucose, rhamnose, glucosamine and mannose detected in the sample can also indicate specific processing steps. For instance, the differential loss of arabinose relative to mannose and N-acetyl glucosamine indicates enrichment for the protein fraction of the seed using protein precipitation. The methods developed in this project center on fatty acid and carbohydrate extraction from castor samples followed by derivatization to permit analysis by gas chromatography-mass spectrometry (GC-MS). Method descriptions herein include: the source and preparation of castor materials used for method evaluation, the equipment and description of procedure required for chemical derivatization, and the instrument parameters used in the analysis. Two types of derivatization methods describe analysis of carbohydrates and one procedure for analysis of fatty acids. Two types of GC-MS analysis is included in the method development, one

  17. Molar extinction coefficients of some carbohydrates in aqueous solutions

    Indian Academy of Sciences (India)

    K Singh; G K Sandhu; B S Lark; S P Sud

    2002-03-01

    Molar extinction coefficients of some carbohydrates viz. L-arabinose (C5H10O5), D-glucose (C6H12O6), D-mannose (C6H12O6), D-galactose (C6H12O6), D(-) fructose (C6H12O6) and maltose (C12H24O12) in aqueous solutions have been determined at 81, 356, 511, 662, 1173 and 1332 keV by gamma ray transmission method in a narrow beam good geometry set-up. These coefficients have been found to depend upon the photon energy following a 4-parameter polynomial. These extinction coefficients for different sugars having the same molecular formula have same values varying within experimental uncertainty. Within concentration ranges studied, Beer–Lambert law is obeyed very well.

  18. 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...

  19. TiO2-catalyzed synthesis of sugars from formaldehyde in extraterrestrial impacts on the early Earth

    Science.gov (United States)

    Civiš, Svatopluk; Szabla, Rafał; Szyja, Bartłomiej M.; Smykowski, Daniel; Ivanek, Ondřej; Knížek, Antonín; Kubelík, Petr; Šponer, Jiří; Ferus, Martin; Šponer, Judit E.

    2016-03-01

    Recent synthetic efforts aimed at reconstructing the beginning of life on our planet point at the plausibility of scenarios fueled by extraterrestrial energy sources. In the current work we show that beyond nucleobases the sugar components of the first informational polymers can be synthesized in this way. We demonstrate that a laser-induced high-energy chemistry combined with TiO2 catalysis readily produces a mixture of pentoses, among them ribose, arabinose and xylose. This chemistry might be highly relevant to the Late Heavy Bombardment period of Earth’s history about 4–3.85 billion years ago. In addition, we present an in-depth theoretical analysis of the most challenging step of the reaction pathway, i.e., the TiO2-catalyzed dimerization of formaldehyde leading to glycolaldehyde.

  20. G-lignin and hemicellulosic monosaccharides distinctively affect biomass digestibility in rapeseed.

    Science.gov (United States)

    Pei, Yanjie; Li, Yuyang; Zhang, Youbing; Yu, Changbing; Fu, Tingdong; Zou, Jun; Tu, Yuanyuan; Peng, Liangcai; Chen, Peng

    2016-03-01

    In this study, total 19 straw samples from four Brassica species were determined with a diverse cell wall composition and varied biomass enzymatic digestibility under sulfuric acid or lime pretreatment. Correlation analysis was then performed to detect effects of cell wall compositions and wall polymer features (cellulose crystallinity, hemicellulosic monosaccharides and lignin monomers) on rapeseeds biomass digestibility. As a result, coniferyl alcohol (G-lignin) showed a strongly negative effect on biomass saccharification, whereas hemicellulosic monosaccharides (fucose, galactose, arabinose and rhamnose) were positive factors on lignocellulose digestions. Notably, chemical analyses of four typical pairs of samples indicated that hemicellulosic monosaccharides and G-lignin may coordinately influence biomass digestibility in rapeseeds. In addition, Brassica napus with lower lignin content exhibited more efficiency on both biomass enzymatic saccharification and ethanol production, compared with Brassica junjea. Hence, this study has at first time provided a genetic strategy on cell wall modification towards bioenergy rapeseed breeding. PMID:26748046

  1. Effects of Soluble Lignin on the Formic Acid-Catalyzed Formation of Furfural: A Case Study for the Upgrading of Hemicellulose.

    Science.gov (United States)

    Dussan, Karla; Girisuta, Buana; Lopes, Marystela; Leahy, James J; Hayes, Michael H B

    2016-03-01

    A comprehensive study is presented on the conversion of hemicellulose sugars in liquors obtained from the fractionation of Miscanthus, spruce bark, sawdust, and hemp by using formic acid. Experimental tests with varying temperature (130-170 °C), formic acid concentration (10-80 wt %), carbohydrate concentrations, and lignin separation were carried out, and experimental data were compared with predictions obtained by reaction kinetics developed in a previous study. The conversions of xylose and arabinose into furfural were inherently affected by the presence of polymeric soluble lignin, decreasing the maximum furfural yields observed experimentally by up to 24 %. These results were also confirmed in synthetic mixtures of pentoses with Miscanthus and commercial alkali lignin. This observation was attributed to side reactions involving intermediate stable sugar species reacting with solubilized lignin during the conversion of xylose into furfural. PMID:26805656

  2. Statistical model semiquantitatively approximates arabinoxylooligosaccharides' structural diversity.

    Science.gov (United States)

    Dotsenko, Gleb; Nielsen, Michael Krogsgaard; Lange, Lene

    2016-05-13

    A statistical model describing the random distribution of substituted xylopyranosyl residues in arabinoxylooligosaccharides is suggested and compared with existing experimental data. Structural diversity of arabinoxylooligosaccharides of various length, originating from different arabinoxylans (wheat flour arabinoxylan (arabinose/xylose, A/X = 0.47); grass arabinoxylan (A/X = 0.24); wheat straw arabinoxylan (A/X = 0.15); and hydrothermally pretreated wheat straw arabinoxylan (A/X = 0.05)), is semiquantitatively approximated using the proposed model. The suggested approach can be applied not only for prediction and quantification of arabinoxylooligosaccharides' structural diversity, but also for estimate of yield and selection of the optimal source of arabinoxylan for production of arabinoxylooligosaccharides with desired structural features. PMID:27043469

  3. The effect of dietary carbohydrate composition on apparent total tract digestibility, feed mean retention time, nitrogen and water balance in horses

    DEFF Research Database (Denmark)

    Jensen, R B; Austbø, Dag; Knudsen, Knud Erik Bach;

    2014-01-01

    obtained by partly substituting mature hay and barley with sugar beet pulp (SBP), a soluble fibre source. The diets investigated were hay only (HAY), hay (85% of dry matter intake (DMI)) and molassed SBP (15% of DMI) (SBP), hay (68% of DMI) and barley (32% of DMI) (BAR), and hay (68% of DMI), barley (26...... of the constituent sugars galactose and arabinose (P<0.01). Feeding the HAY and SBP diets resulted in a lower TMRT owing to a higher DF intake than the BAR and BAR+SBP diets (P<0.01). There was no difference in water intake between HAY and SBP, but faecal dry matter was lower for HAY than the other...... substituting hay or barley with SBP, and that highly fermentable pectin-rich soluble DF from SBP maintains high nutrient utilization in horses....

  4. pH catalyzed pretreatment of corn bran for enhanced enzymatic arabinoxylan degradation

    DEFF Research Database (Denmark)

    Agger, Jane; Johansen, Katja Salomon; Meyer, Anne S.

    2011-01-01

    Corn bran is mainly made up of the pericarp of corn kernels and is a byproduct stream resulting from the wet milling step in corn starch processing. Through statistic modeling this study examined the optimization of pretreatment of corn bran for enzymatic hydrolysis. A low pH pretreatment (pH 2......, 150°C, 65min) boosted the enzymatic release of xylose and glucose and maximized biomass solubilization. With more acidic pretreatment followed by enzymatic hydrolysis the total xylose release was maximized (at pH 1.3) reaching ∼50% by weight of the original amount present in destarched corn bran, but...... the enzyme catalyzed xylose release was maximal after pretreatment at approx. pH 2. The total glucose release peaked after pretreatment of approx. pH 1.5 with an enzymatic release of approx. 68% by weight of the original amounts present in destarched corn bran. For arabinose the enzymatic release was...

  5. Preparation of uniformly labeled NMR samples in Escherichia coli under the tight control of the araBAD promoter: expression of an archaeal homolog of the RNase P Rpp29 protein.

    Science.gov (United States)

    Boomershine, William P; Raj, M L Stephen; Gopalan, Venkat; Foster, Mark P

    2003-04-01

    We report the first use of the tightly regulated araBAD promoter for generating uniformly labeled samples for NMR. The araBAD promoter provides a distinct advantage over that of the most commonly used protein overexpression systems in bacteria (e.g., in pET vectors: T7lac), in that it provides much tighter control over basal expression. However, use of araBAD-regulated expression for preparation of uniformly labeled protein samples for NMR is complicated by the fact that glucose (the most commonly used carbon source in defined minimal media) indirectly represses transcription, and thus, cannot be used. After experimenting with alternative media, we found that uniformly labeled NMR samples can be prepared using the highly regulated arabinose-inducible promoter and that suitable yields can be obtained in defined minimal media containing glycerol, not glucose, as the carbon source. PMID:12699688

  6. 气相色谱-质谱法研究当归多糖的糖链联接方式

    Institute of Scientific and Technical Information of China (English)

    徐桂云; 陈汝贤

    2004-01-01

    X-C-3- Ⅱ, a polysaccharide having immunologic adjuvanticity was extracted and purified from the roots of Angelica sinensis (Oliv) Diels. Its linkage was elucidated by selective hydrolysis and GC-MS analysis of its derivatives, as well as its 1H and 13C NMR spectra. This polysaccharide was composed of arabinose, galactose, glucose and fructose with a molar ratio of 1 : 1 : 4 : 9, and it had a highly branched structure with a fructofuranosyl backbone. The sequence of the repeating unit of X-C-3- Ⅱ was deduced. To our best knowledge, this is the first report of the fructose residue in polysaccharides from the rootsof Angelica sinensis (Oliv) Diels.

  7. Structural Characterization of a Polysaccharide From the Roots of Angelica Sinensis (Oliv) Diels by Gas Chromatography-Mass Spectrometry%气相色谱-质谱法研究当归多糖的糖链联接方式

    Institute of Scientific and Technical Information of China (English)

    徐桂云; 陈汝贤

    2004-01-01

    X-C-3- Ⅱ, a polysaccharide having immunologic adjuvanticity was extracted and purified from the roots of Angelica sinensis (Oliv) Diels. Its linkage was elucidated by selective hydrolysis and GC-MS analysis of its derivatives, as well as its 1H and 13C NMR spectra. This polysaccharide was composed of arabinose, galactose, glucose and fructose with a molar ratio of 1 : 1 : 4 : 9, and it had a highly branched structure with a fructofuranosyl backbone. The sequence of the repeating unit of X-C-3- Ⅱ was deduced. To our best knowledge, this is the first report of the fructose residue in polysaccharides from the rootsof Angelica sinensis (Oliv) Diels.

  8. Evaluation of nonionic adsorbent resins for removal of inhibitory compounds from corncob hydrolysate for ethanol fermentation.

    Science.gov (United States)

    Hatano, Ken-ichi; Aoyagi, Naokazu; Miyakawa, Takuya; Tanokura, Masaru; Kubota, Kenji

    2013-12-01

    The aim of this study was to investigate the effect of XAD4-column treatment on removal of several fermentation inhibitors from corncob hydrolysate (CH). From analysis using a model hydrolysate, more than 99% of 5-hydroxy-methyl furfural, furfural and vanillin were removed by this treatment, and more than 97% of the total xylose, glucose and arabinose remained in the detoxified CH (DCH). The resulting DCH was tested as a substrate for ethanol production by Saccharomyces cerevisiae and Pichia stipitis. The highest ethanol levels for S. cerevisiae were 1.40 and 4.92 g l(-1) in CH and DCH, respectively. For P. stipitis, the levels were 0 and 4.73 g l(-1) in the CH and DCH media, respectively. The levels of alcohol volumetric productivity in the DCH medium were 0.374 and 0.200 g l(-1)h(-1) for S. cerevisiae and P. stipitis, respectively. PMID:24094738

  9. Fingerprinting profile of polysaccharides from Lycium barbarum using multiplex approaches and chemometrics.

    Science.gov (United States)

    Liu, Wei; Xu, Jinnan; Zhu, Rui; Zhu, Yiqing; Zhao, Yang; Chen, Pei; Pan, Chun; Yao, Wenbing; Gao, Xiangdong

    2015-07-01

    Techniques including ultraviolet-visible spectra (UV), high performance size-exclusion chromatography (HPSEC), Fourier-transform infrared spectroscopy (FT-IR) and pre-column derivatization high-performance liquid chromatography (PCD-HPLC) were used in the fingerprinting analysis of Lycium barbarum polysaccharides (LBPs) from different locations and varieties. Multiple fingerprinting profiles were used to evaluate the similarity and classification of different LBPs with the help of chemometrics. The results indicated that sixteen batches of LBPs had good consistency, and fingerprinting techniques were simple and robust for quality control of LBPs as well as related products. In addition, fingerprinting techniques combined with chemometrics could also be used to identify different cultivation locations of LBPs samples. Finally, four monosaccharides (galacturonic acid, glucose, galactose and arabinose) and the absorptions of stretching vibration of ester carbonyl groups as well as NH variable angle vibration of -CONH- could be selected as herbal markers to distinguish different samples. PMID:25847838

  10. 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

  11. Purification and characterization of a carbohydrate: acceptor oxidoreductase from Paraconiothyrium sp. that produces lactobionic acid efficiently.

    Science.gov (United States)

    Kiryu, Takaaki; Nakano, Hirofumi; Kiso, Taro; Murakami, Hiromi

    2008-03-01

    A carbohydrate:acceptor oxidoreductase from Paraconiothyrium sp. was purified and characterized. The enzyme efficiently oxidized beta-(1-->4) linked sugars, such as lactose, xylobiose, and cellooligosaccharides. The enzyme also oxidized maltooligosaccharides, D-glucose, D-xylose, D-galactose, L-arabinose, and 6-deoxy-D-glucose. It specifically oxidized the beta-anomer of lactose. Molecular oxygen and 2,6-dichlorophenol indophenol were reduced by the enzyme as electron acceptors. The Paraconiothyrium enzyme was identified as a carbohydrate:acceptor oxidoreductase according to its specificity for electron donors and acceptors, and its molecular properties, as well as the N-terminal amino acid sequence. Further comparison of the amino acid sequences of lactose oxidizing enzymes indicated that carbohydrate:acceptor oxidoreductases belong to the same group as glucooligosaccharide oxidase, while they differ from cellobiose dehydrogenases and cellobiose:quinone oxidoreductases. PMID:18323642

  12. Properties and extraction of pectin-enriched materials from sugar beet pulp by ultrasonic-assisted treatment combined with subcritical water.

    Science.gov (United States)

    Chen, Hai-ming; Fu, Xiong; Luo, Zhi-gang

    2015-02-01

    Pectin-enriched material (PEM) was extracted from sugar beet pulp using subcritical water combined with ultrasonic-assisted treatment. Optimisation of the reaction parameters for maximum extraction yield of PEM was carried out using response surface methodology. Optimum modification conditions were as follows: liquid/solid ratio 44.03, extraction temperature 120.72°C, extraction time 30.49min and extraction pressure 10.70MPa. Under optimal conditions, the maximum yield of PEM was 24.63%. The composition of the PEM was determined. The data showed that the contents of galacturonic acid and arabinose were 59.12% and 21.66%, respectively. The flow behaviours were investigated by a rheometer. The effects of PEM on the pasting and thermal properties of maize starch were also conducted. The results showed that the addition of PEM increased pasting temperature and decreased other pasting parameters. Increasing PEM concentrations resulted in increased gelatinisation temperature and enthalpy. PMID:25172714

  13. Optimization of reaction conditions for enzymatic viscosity reduction and hydrolysis of wheat arabinoxylan in an industrial ethanol fermentation residue

    DEFF Research Database (Denmark)

    Sørensen, H.R.; Pedersen, S.; Meyer, Anne Boye Strunge

    2006-01-01

    arabinoxylan in the different vinasse fractions irrespective of the state of solubility of the substrate material. The levels of liberated arabinose and xylose increased with increased dry matter concentration during enzymatic hydrolysis in the vinasse and the vinasse supernatant, but at the same time......, increased substrate dry matter concentrations gave corresponding linear decreases in the hydrolytic efficiency as evaluated from levels of monosaccharide release per weight unit dry matter. The study thus documents that enzymatic arabinoxylan hydrolysis of the vinasse significantly decreases the vinasse......This study examined enzyme-catalyzed viscosity reduction and evaluated the effects of substrate dry matter concentration on enzymatic degradation of arabinoxylan in a fermentation residue, "vinasse", resulting from industrial ethanol manufacture on wheat. Enzymatic catalysis was accomplished with a...

  14. Carbohydrate composition of peach palm (Bactris gasipaes Kunth) by-products flours.

    Science.gov (United States)

    Bolanho, Beatriz Cervejeira; Danesi, Eliane Dalva Godoy; Beléia, Adelaide Del Pino

    2015-06-25

    The flours obtained from peach palm by-products are rich in dietary fiber (62-71%) and they can be used as food ingredients. The aim of this work was to investigate the carbohydrate composition of the flours processed from the residual parts (stem and median sheath) of a hearts-of-palm industry. The flours were fractionated, based on their solubility, whose monomeric compounds were determined. The fraction containing mostly cellulose (S5) was the most abundant (26-28%), followed by the sum of fractions (S2, 53, S4) extracted with alkaline solutions (21-22%). The S1 fraction contained the highest percentage of uronic acids, which characterizes the presence of pectin. Xylose and arabinose were found in high proportion in S2 and S3 fractions. The S4 and S5 fractions, rich in glucose, were the main portion of the cell wall material and correspond to the insoluble fraction of the dietary fiber. PMID:25839811

  15. Characterization of cell wall polysaccharides of cherry (Prunus cerasus var. Schattenmorelle) fruit and pomace.

    Science.gov (United States)

    Kosmala, Monika; Milala, Joanna; Kołodziejczyk, Krzysztof; Markowski, Jarosław; Mieszczakowska, Monika; Ginies, Christian; Renard, Catherine M G C

    2009-12-01

    The polysaccharide composition of cell wall of sour cherry (Prunus cerasus var. Schattenmorelle) fruit and pomace was investigated. Furthermore, the alcohol insoluble solids composition of 'Kelleriis' and 'Dobreczyn Botermo' varieties were studied too. Yield of alcohol insoluble solids for fruits was lower than 10%, and for pomaces circa 50%. Uronic acid was the main pectin component of alcohol insoluble solids. Enzymes used as juice processing aids decreased the content of uronic acid. Araban and galactan side chains bonded tightly to cellulose presence was suggested by high content of arabinose and galactose in hemicellulose fraction. The process of drying at below 70 degrees C did not influence polysaccharide composition of sour cherry pomaces. Alcohol insoluble solids of fruits expressed higher hydration properties than of pomaces. PMID:19757068

  16. Immunostimulatory Effects of Polysaccharides Isolated from Makgeolli (Traditional Korean Rice Wine

    Directory of Open Access Journals (Sweden)

    Chang-Won Cho

    2014-04-01

    Full Text Available Makgeolli is a traditional Korean rice wine, reported to have various biological functions. In this study, the immunostimulatory activity of a polysaccharide from makgeolli (PSM was investigated. The polysaccharide fraction was isolated from makgeolli by hot water extraction, ethanol precipitation, dialysis, and lyophilization. The major constituents in PSM were neutral sugars (87.3%. PSM was composed of five different sugars, glucose, mannose, galactose, xylose, and arabinose. In normal mice, PSM treatment increased the spleen index (p < 0.05 as well as splenocyte proliferation (p < 0.05 in combination with concanavalin A or lipopolysaccharide. The immunostimulatory activities of PSM were also examined in cyclophosphamide (CY-induced immunosuppressed mice. Mice treated with PSM exhibited increased splenocyte proliferation (p < 0.05, natural killer cell activity, and white blood cell counts (p < 0.01 compared with immunosuppressed mice. These results indicate that PSM can enhance immune function in normal mice and CY-induced immunosuppressed mice.

  17. 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

  18. Potential for using thermophilic anaerobic bacteria for bioethanol production from hemicellulose

    DEFF Research Database (Denmark)

    Sommer, P.; Georgieva, Tania I.; Ahring, Birgitte Kiær

    2004-01-01

    A limited number of bacteria, yeast and fungi can convert hemicellulose or its monomers (xylose, arabinose, mannose and galactose) into ethanol with a satisfactory yield and productivity. In the present study we tested a number of thermophilic enrichment cultures, and new isolates of thermophilic...... anaerobic bacterial strains growing optimally at 70-80degreesC for their ethanol production from D-Xylose. The new isolates came from different natural and man-made systems such as hot springs, paper pulp mills and brewery waste water. The test was composed of three different steps; (i) test for conversion...... Of D-Xylose into ethanol; (ii) test for viability and ethanol production in pretreated wheat straw hemicellulose hydrolysate; (iii) test for tolerance against high D-xylose concentrations. A total of 86 enrichment cultures and 58 pure cultures were tested and five candidates were selected which...

  19. 半纤维素水解产物的分离研究%Research on the Isolation of HemicelIulose Hydrolysate

    Institute of Scientific and Technical Information of China (English)

    田心健; 王川

    2001-01-01

    Isolations of hemicellulose hydrolysate are researched. In proper conditions, the hemicellulose is hydrolyzed by hemicellulase.The hemicelluloses hydrolysate could be isolated on a polyacrylamide (Bio-Gel P-2)chromatography and paper chromatography, some samples such as xylo-oligosaccharide,xylose,arabinose,mannose and so on.%对半纤维素水解产物的分离进行了研究。在适当的条件下,半纤维素被半纤维素酶水解后,用聚丙烯酰胺凝胶(Bio-Gel P-2)柱层析法及纸上分配层析法分离半纤维素的水解产物,可以得到木低聚糖、木糖、阿拉伯糖和甘露糖等组分。

  20. Component Analysis and Free Radicals Scavenging Activity of Cicer arietinum L. Husk Pectin

    Directory of Open Access Journals (Sweden)

    Alfonso A. Gardea

    2010-10-01

    Full Text Available A pectin (CAP was extracted from the husk of Cicer arietinum L.. Monosaccharide analysis of CAP revealed the dominance of galacturonic acid and smaller amounts of galactose, arabinose, rhamnose, glucose, xylose and mannose. Viscosimetric analysis showed that the intrinsic viscosity ([η] and the molecular weight (MW of CAP were 296 mL/g and 105 kDa, respectively. The degree of esterification (DE = 10% was determined by FTIR spectroscopy. CAP exhibited a dose-dependent free radical scavenging activity, as shown by its DPPH radical inhibition. At 1.0 mg/mL CAP exhibited a scavenging rate of 29% on DPPH radicals. The evaluation of antioxidant activity suggested that CAP had good potential for DPPH radical scavenging activity and should be explored as a novel potential antioxidant.

  1. Enzymatic Cross-Linking of Alkali Extracted Arabinoxylans: Gel Rheological and Structural Characteristics

    Directory of Open Access Journals (Sweden)

    Agustin Rascón-Chu

    2011-09-01

    Full Text Available Ferulated arabinoxylans were alkali-extracted from wheat bran at different incubation times (0.0, 0.5, 1.0, 1.5 and 2.0 h. Wheat bran ferulated arabinoxylans (WBAX arabinose-to-xylose ratio, ferulic acid content, intrinsic viscosity and viscosimetric molecular weight values decreased as the incubation time of extraction increased. WBAX enzymatic cross-linking capability was affected by incubation time while an increase in WBAX concentration from 5 to 6% (w/v favored gelation. The WBAX gels formed presented a macroporous structure with mesh size ranging from 40 to 119 nm and hardness values varying from 1.7 to 5 N.

  2. Accumulation of recalcitrant xylan in mushroom-compost is due to a lack of xylan substituent removing enzyme activities of Agaricus bisporus.

    Science.gov (United States)

    Jurak, Edita; Patyshakuliyeva, Aleksandrina; Kapsokalyvas, Dimitris; Xing, Lia; van Zandvoort, Marc A M J; de Vries, Ronald P; Gruppen, Harry; Kabel, Mirjam A

    2015-11-01

    The ability of Agaricus bisporus to degrade xylan in wheat straw based compost during mushroom formation is unclear. In this paper, xylan was extracted from the compost with water, 1M and 4M alkali. Over the phases analyzed, the remaining xylan was increasingly substituted with (4-O-methyl-)glucuronic acid and arabinosyl residues, both one and two arabinosyl residues per xylosyl residue remained. In the 1M and 4M KOH soluble solids of spent compost, 33 and 49 out of 100 xylosyl residues, respectively, were substituted. The accumulation of glucuronic acid substituents matched with the analysis that the two A. bisporus genes encoding for α-glucuronidase activity (both GH115) were not expressed in the A. bisporus mycelium in the compost during fruiting. Also, in a maximum likelihood tree it was shown that it is not likely that A. bisporus possesses genes encoding for the activity to remove arabinose from xylosyl residues having two arabinosyl residues. PMID:26256360

  3. Final classification of Bisgaard taxon 9 as Actinobacillus arthritidis sp nov and recognition of a novel genomospecies for equine strains of Actinobacillus lignieresii

    DEFF Research Database (Denmark)

    Christensen, Henrik; Bisgaard, Magne; Angen, Øystein; Olsen, John Elmerdahl

    2002-01-01

    Phenotypic characterization of bacteria from diseased and healthy horses identified 18 isolates as Bisgaard taxon 9 and 11 isolates as Actinobacillus lignieresii. All strains of taxon 9 were alpha-galactosidase- and raffinose-positive and showed variable fermentation of (+)L-arabinose and (-)D-sorbitol....... Strains of A. lignieresii were negative for these characteristics, with the exception of raffinose. Two strains from the (-)D-sorbitol-negative group of taxon 9 showed a 16S rRNA similarity of 99.6%, while 99.5% similarity was found between two strains of the (-)D-sorbitol-positive group. DNA......-DNA hybridization between the two strains representing the (-)D-sorbitol-negative group showed 98% binding, and their closest relationship was to a strain of A. lignieresii (64%). The two strains of the (-)D-sorbitol-positive group showed 83% binding and were related to the (-)D-sorbitol-negative group at a 76% DNA...

  4. Liquefaction and saccharification of mandarin orange

    Energy Technology Data Exchange (ETDEWEB)

    Nishio, N.; Oku, Y.; Kawamura, D.; Nagai, S.

    1979-01-01

    Liquefaction and saccharification of mandarin orange peel with H/sub 2/SO/sub 4/ in an autoclave and with macerating enzymes from Aspergillus niger were studied. The acid hydrolysis with 0.8N H/sub 2/SO/sub 4/ under 1 kg/square cm for 15 minutes yielded 0.36 grams of reducing sugars from 1 gram of dried orange peel, approximately 36% of which was identified as glucose. Enzymic hydrolysis with 0.2% crude enzyme at 40 degrees for 24 hours yielded 0.59 grams of reducing sugars/g peal, consisting mainly of glucose, arabinose, and galacturonic acid. Comparison of the macerating enzyme with commercial available cellulase and pectinase indicated that the macerating enzyme of A. niger contained mainly pectinase with a little cellulase.

  5. Liquefaction and saccharification of mandarin orange

    Energy Technology Data Exchange (ETDEWEB)

    Nishio, N.; Oku, Y.; Kawamura, D.; Nagai, S.

    1979-01-01

    Liquefaction and saccharification of mandarin orange peel with H2SO4 in an autoclave and with macerating enzymes from Aspergillus niger were studied. The acid hydrolysis with 0.8N H2SO4 under 1 kg/square cm for 15 minutes yielded 0.36 grams of reducing sugars from 1 gram of dried orange peel, approximately 36% of which was identified as glucose. Enzymic hydrolysis with 0.2% crude enzyme at 40 degrees for 24 hours yielded 0.59 grams of reducing sugars/g peal, consisting mainly of glucose, arabinose, and galacturonic acid. Comparison of the macerating enzyme with commercial available cellulase and pectinase indicated that the macerating enzyme of A. niger contained mainly pectinase with a little cellulase.

  6. 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.

  7. A strict anaerobic extreme thermophilic hydrogen-producing culture enriched from digested household waste

    DEFF Research Database (Denmark)

    Karakashev, Dimitar Borisov; Kotay, Shireen Meher; Trably, Eric;

    2009-01-01

    The aim of this study was to enrich, characterize and identify strict anaerobic extreme thermophilic hydrogen (H-2) producers from digested household solid wastes. A strict anaerobic extreme thermophilic H-2 producing bacterial culture was enriched from a lab-scale digester treating household...... wastes at 70 degrees C. The enriched mixed culture consisted of two rod-shaped bacterial members growing at an optimal temperature of 80 degrees C and an optimal pH 8.1. The culture was able to utilize glucose, galactose, mannose, xylose, arabinose, maltose, sucrose, pyruvate and glycerol as carbon...... from digested household wastes. This study provided a culture with a potential to be applied in reactor systems for extreme thermophilic H-2 production from complex organic wastes....

  8. Differentiation of Tetragenococcus populations occurring in products and manufacturing processes of puffer fish ovaries fermented with rice-bran.

    Science.gov (United States)

    Kobayashi, T; Kimura, B; Fujii, T

    2000-06-01

    Tetragenococcus strains isolated from the manufacturing process of Japanese puffer fish ovaries fermented with rice-bran were characterized and differentiated phenotypically and genotypically. A total of 413 Tetragenococcus isolates were evaluated. On the basis of five representative substrates, the isolates were grouped into seven groups. An RFLP (restriction fragment length polymorphisms) analysis of the 16S rRNA gene of representative strains of major groups revealed that they could be grouped into two groups: one was identified as the most prominent halophilic lactic acid coccus, Tetragenococcus halophilus, and the other as T. muriaticus, which has recently been added to the genus Tetragenococcus as a new species. Physiologically, the major differences between the two groups were found in the ability to grow in medium not supplemented with NaCl and the fermentation of L-arabinose, sucrose and D-mannitol, and several other carbohydrates. PMID:10857547

  9. Simultaneous assay of neutral sugars and amino sugars by an automatic sugar analyzer: applications to glycoproteins.

    Science.gov (United States)

    Kellich, G; Ziegler, D

    1975-04-01

    The simultaneous assay of neutral sugars and amino sugars commonly found in glycoproteins is described. The automatic sugar analyzer used for the determination is based on the ion-exchange chromatography of sugar-borate complexes on a strong anion-exchange resin. The sugars are identified with the orcinol/sulfuric acid reagent. While less than 40 nmol of mannose, fucose, galactose, glucose, xylose, or arabinose is sufficient for analysis at least 200 nmol mannosamine, glucosamine, or galactosamine is required; acidic monosaccharides cannot be determined. The technique of sugar analysis is applied to structural studies on natural compounds, e.g. the monosaccharide composition of lichenan and the carbohydrate moiety of the glycoproteins ovomucoid and Collocalia mucoid. PMID:1150155

  10. Lipid production by Cryptococcus curvatus on hydrolysates derived from corn fiber and sweet sorghum bagasse following dilute acid pretreatment.

    Science.gov (United States)

    Liang, Yanna; Jarosz, Kimberly; Wardlow, Ashley T; Zhang, Ji; Cui, Yi

    2014-08-01

    Corn fiber and sweet sorghum bagasse (SSB) are both pre-processed lignocellulosic materials that can be used to produce liquid biofuels. Pretreatment using dilute sulfuric acid at a severity factor of 1.06 and 1.02 released 83.2 and 86.5 % of theoretically available sugars out of corn fiber and SSB, respectively. The resulting hydrolysates derived from pretreatment of SSB at SF of 1.02 supported growth of Cryptococcus curvatus well. In 6 days, the dry cell density reached 10.8 g/l with a lipid content of 40 % (w/w). Hydrolysates from corn fiber, however, did not lead to any significant cell growth even with addition of nutrients. In addition to consuming glucose, xylose, and arabinose, C. curvatus also utilized formic acid, acetic acid, 4-hydroxymethylfurfural, and levulinic acid for growth. Thus, C. curvatus appeared to be an excellent yeast strain for producing lipids from hydrolysates developed from lignocellulosic feedstocks. PMID:24928546

  11. In vitro assessment of the prebiotic potential of Aloe vera mucilage and its impact on the human microbiota.

    Science.gov (United States)

    Gullón, Beatriz; Gullón, Patricia; Tavaria, Freni; Alonso, José Luis; Pintado, Manuela

    2015-02-01

    Aloe vera mucilage is reported to be rich in acemannan that is a polysaccharide with a backbone of β-(1→4)-D-mannose residues acetylated at the C-2 and C-3 positions and contains some side chains of galactose and arabinose attached to the C-6 carbon. The evaluation of the prebiotic potential of Aloe vera mucilage was carried out by in vitro fermentation using intestinal microbiota from six healthy donors as the inoculum. The prebiotic activity was assessed through the quantification of short chain fatty acids (SCFA) and the evaluation of dynamic bacterial population in mixed faecal cultures by fluorescence in situ hybridization (FISH). Our findings support the possible incorporation of the Aloe vera mucilage in the development of a variety of food products known as prebiotics aimed at improving gastrointestinal health. PMID:25504136

  12. Sugar Utilization Potential of Micropolyspora Isolated from Extreme Environment

    Directory of Open Access Journals (Sweden)

    A. B. Koli

    2012-01-01

    Full Text Available Problem statement: Waste water of various industries contain large amount of organic compounds which are continuously added in sea via river which causes water pollution. There is need to degrade the organic content to abate water pollution. Approach: To stabilize the organic content in sea water, there was need to search such an organism which was efficient to degrade organic content. We had screened the actinomycetes having potential to degrade organic compounds. Results: Total six isolates of Micropolyspora were obtained, from which all isolates were found to utilize galactose, 50% isolates were able to utilize arabinose, fructose and xylose. 83% of isolates showed mannitol utilization while 67% isolates uses lactose as carbon source and 33% isolates utilizes rhamnose. Conclusion/Recommendation: From the study performed, we conclude that, obtained most of Micropolyspora isolate may be used for the stabilization of organic content and hence in abatement of pollution.

  13. Subcritical Water Extraction of Monosaccharides from Oil Palm Fronds Hemicelluloses

    International Nuclear Information System (INIS)

    Oil palm plantations in Malaysia generate more than 36 million tones of pruned and felled oil palm fronds (OPF) and are generally considered as waste. The composition of monosaccharide in oil palm frond can be extracted using hydrothermal treatment for useful applications. The objectives of this study were to quantify the yield of monosaccharides at various reaction conditions; temperature 170 to 200 degree Celsius, pressure from 500 psi to 800 psi, reaction time from 5 to 15 min using subcritical water extraction and to determine the composition of oil palm frond hemicelluloses at optimum condition. The monosaccharides composition of oil palm frond hemicelluloses were analysed using High Performance Liquid Chromatography (HPLC). The highest yield of monosaccharides can be extracted from OPF at temperature of 190 degree Celsius, pressure of 600 psi and 10 min of contact time which is xylose the most abundant composition (11.79 %) followed with arabinose (2.82 %), glucose (0.61 %) and mannose (0.66 %). (author)

  14. Estudo de interações proteína-carbohidrato em sistemas bacterianos

    OpenAIRE

    Henriques, Pedro Ricardo Morgado

    2014-01-01

    Bacillus subtilis tem a capacidade de utilizar arabinoligossacáridos presentes na parede das células vegetais, através de um consórcios de enzimas envolvidas na hidrólise enzimática dos mesmos. A captação destes carbohidratos por parte do Bacillus subtilis depende de dois transportadores membranares AraE e AraNPQ-MsmX. Após a captação de L-arabinose e arabinoligossacáridos, estes substratos serão metabolizados pelos produtos enzimáticos codificados por genes pertencentes ao operão responsável...

  15. Tyrosine Phosphorylation of the UDP-Glucose Dehydrogenase of Escherichia coli Is at the Crossroads of Colanic Acid Synthesis and Polymyxin Resistance

    DEFF Research Database (Denmark)

    Lacour, S.; Bechet, E.; Cozzone, A.J.;

    2008-01-01

    -kinases have been characterized. BY-kinases have been shown to participate in various physiological processes. Nevertheless, we are at a very early stage of defining their importance in the bacterial cell. In Escherichia coli, two BY-kinases, Wzc and Etk, have been characterized biochemically. Wzc has been...... shown to phosphorylate the UDP-glucose dehydrogenase Ugd in vitro. Not only is Ugd involved in the biosynthesis of extracellular polysaccharides, but also in the production of UDP-4-amino-4-deoxy-L-arabinose, a compound that renders E. coli resistant to cationic antimicrobial peptides. Methodology....../Principal Findings: Here, we studied the role of Ugd phosphorylation. We first confirmed in vivo the phosphorylation of Ugd by Wzc and we demonstrated that Ugd is also phosphorylated by Etk, the other BY-kinase identified in E. coli. Tyrosine 71 (Tyr71) was characterized as the Ugd site phosphorylated by both Wzc...

  16. Studies on Isolation and Composition of Polysaccharide SZYP-1 from Cornus officinalis Sieb. et Zucc%山茱萸多糖SZYP-1的分离与组成研究

    Institute of Scientific and Technical Information of China (English)

    陈汝贤; 徐桂云; 张瑞; 许鸿章; 刘叶民; 鲁敏

    2001-01-01

    从中药山茱萸Cornus offcinalis Sieb. et Zucc. 中分离得到多糖组分SZYP-1,利用毛细管电泳法分析确定SZYP-1的糖基组成为鼠李糖、甘露糖、阿拉伯糖、半乳糖和半乳糖醛酸,摩尔比为7.8∶0.6∶8.3∶2.7∶13.8。%Polysaccharide SZYP-1 had been obtained from Cornus officinalis Sieb. et Zucc., The composition was identifed by capillary electrophoresis, they are rhamnose, mannose, arabinose, galacose and galacturonic acid. The molar ratio of these sugars was determined as 7.8∶0.6∶8.3∶2.7∶13.8.

  17. Regulatory switches for hierarchical use of carbon sources in E. coli

    Directory of Open Access Journals (Sweden)

    Ruth S. Perez-Alfaro

    2014-09-01

    Full Text Available In this work we study the preferential use of carbon sources in the bacterium Escherichia coli. To that end we engineered transcriptional fusions of the reporter gene gfpmut2, downstream of transcription-factor promoters, and analyzed their activity under several conditions. The chosen transcription factors are known to regulate catabolic operons associated to the consumption of alternative sugars. The obtained results indicate the following hierarchical order of sugar preference in this bacterium: glucose > arabinose > sorbitol > galactose. Further dynamical results allowed us to conjecture that this hierarchical behavior might be operated by at least the following three regulatory strategies: 1 the coordinated activation of the corresponding operons by the global regulator catabolic repressor protein (CRP, 2 their asymmetrical responses to specific and unspecific sugars and, 3 the architecture of the associated gene regulatory networks.

  18. Optimization of reaction conditions for enzymatic viscosity reduction and hydrolysis of wheat arabinoxylan in an industrial ethanol fermentation residue

    DEFF Research Database (Denmark)

    Sørensen, H.R.; Pedersen, S.; Meyer, Anne Boye Strunge

    2006-01-01

    This study examined enzyme-catalyzed viscosity reduction and evaluated the effects of substrate dry matter concentration on enzymatic degradation of arabinoxylan in a fermentation residue, "vinasse", resulting from industrial ethanol manufacture on wheat. Enzymatic catalysis was accomplished with...... viscosity and that a compromise in the dry matter must be found if enzymatic efficiency must be balanced with monosaccharide yields.......This study examined enzyme-catalyzed viscosity reduction and evaluated the effects of substrate dry matter concentration on enzymatic degradation of arabinoxylan in a fermentation residue, "vinasse", resulting from industrial ethanol manufacture on wheat. Enzymatic catalysis was accomplished with a...... increased enzyme dosage and treatment time at pH 5, 50 degrees C, 5 wt % vinasse dry matter. After 24 It of enzymatic treatment, 76-84%, 75-80%, and 43-47%, respectively, of the theoretically maximal arabinose, xylose, and glucose releases were achieved, indicating that the viscosity decrease was a result...

  19. The structurally effect of surface coated rhamnogalacturonan I on response of the osteoblast-like cell line SaOS-2

    DEFF Research Database (Denmark)

    Svava, Rikke; Gurzawska, Katarzyna; Yihau, Yu;

    2014-01-01

    the quality of RG-I, the nature of the binding, the fine structure of RG-I, and its effect on SaOS-2 cell line cultured on coated surfaces was investigated. SaOS-2 cells are osteoblast-like cells and a well-established in vitro model of bone-matrix forming osteoblasts. Purification by gel filtration...... could remove small fragments of galacturonic acid (GalA) and binding studies showed that the purity of the RG-I molecules was important for the quality of the coating. The structure of RG-I and osteoblast-like cells' viability were positively correlated so that high content of 1,4-linked galactose (Gal......) and a low content of arabinose in the RG-I molecules favored cell viability. These results indicate that coating of implants with RG-I affect osseointegration positively....

  20. Pretreatment and enzymatic hydrolysis of corn fiber

    Energy Technology Data Exchange (ETDEWEB)

    Grohmann, K. [USDA Citrus and Subtropical Products Research Labs., Winter Haven, CT (United States); Bothast, R.J. [National Center for Agricultural Utilization Research, Peoria, IL (United States)

    1996-10-01

    Corn fiber is a co-product of the corn wet milling industry which is usually marketed as a low value animal feed ingredient. Approximately 1.2 x 10{sup 6} dry tons of this material are produced annually in the United States. The fiber is composed of kernel cell wall fractions and a residual starch which can all be potentially hydrolyzed to a mixture of glucose, xylose, arabinose and galactose. We have investigated a sequential saccharification of polysaccharides in corn fiber by a treatment with dilute sulfuric acid at 100 to 160{degrees}C followed by partial neutralization and enzymatic hydrolysis with mixed cellulose and amyloglucosidase enzymes at 45{degrees}C. The sequential treatment achieved a high (approximately 85%) conversion of all polysaccharides in the corn fiber to monomeric sugars, which were in most cases fermentable to ethanol by the recombinant bacterium Escherichia coli KOll.

  1. Chemical Characteristics and Antioxidant Properties of Crude Water Soluble Polysaccharides from Four Common Edible Mushrooms

    Directory of Open Access Journals (Sweden)

    Pei-Long Sun

    2012-04-01

    Full Text Available Four crude water soluble polysaccharides, CABP, CAAP, CFVP and CLDP, were isolated from common edible mushrooms, including Agaricus bisporus, Auricularia auricula, Flammulina velutipes and Lentinus edodes, and their chemical characteristics and antioxidant properties were determined. Fourier Transform-infrared analysis showed that the four crude polysaccharides were all composed of β-glycoside linkages. The major monosaccharide compositions were D-galactose, D-glucose and D-mannose for CABP, CAAP and CLDP, while CFVP was found to consist of L-arabinose, D-galactose, D-glucose and D-mannose. The main molecular weight distributions of CABP and the other three polysaccharides were 66.0 × 104 Da, respectively. Antioxidant properties of the four polysaccharides were evaluated in in vitro systems and CABP showed the best antioxidant properties. The studied mushroom species could potentially be used in part of well-balanced diets and as a source of antioxidant compounds.

  2. Biopolímero produzido a partir da cana-de-áçucar para cicatrização cutânea

    OpenAIRE

    Coelho Maria Cristina de Oliveira Cardoso; Carrazoni Patrícia Gallindo; Monteiro Vanda Lúcia da Cunha; Melo Francisco de Assis Dutra; Mota Rinaldo Aparecido; Tenório Filho Fernando

    2002-01-01

    Um polissacarídeo extracelular foi produzido por via microbiológica, através da bactéria ZSP isolada no Laboratório de Microbiologia Industrial da Estação Experimental de Cana-de-Açúcar do Carpina/UFRPE, apresentando excepcional capacidade de processo. Os principais monossacarídeos presentes na fração solúvel foram glicose (87,6%), xilose (8,6%), manose (0,8%), ribose (1,7%), galactose (0,1%), arabinose (0,4%) e o ácido glucurônico (0,8%). Devido ao alto índice de traumatismos que acomete os ...

  3. Biopolímero produzido a partir da cana-de-áçucar para cicatrização cutânea Sugar cane biopolymer in cutaneous healing

    OpenAIRE

    Maria Cristina Oliveira Cardoso Coelho; Patrícia Gallindo Carrazoni; Vanda Lúcia da Cunha Monteiro; Francisco de Assis Dutra Melo; Rinaldo Aparecido Mota; Fernando Tenório Filho

    2002-01-01

    Um polissacarídeo extracelular foi produzido por via microbiológica, através da bactéria ZSP isolada no Laboratório de Microbiologia Industrial da Estação Experimental de Cana-de-Açúcar do Carpina/UFRPE, apresentando excepcional capacidade de processo. Os principais monossacarídeos presentes na fração solúvel foram glicose (87,6%), xilose (8,6%), manose (0,8%), ribose (1,7%), galactose (0,1%), arabinose (0,4%) e o ácido glucurônico (0,8%). Devido ao alto índice de traumatismos que acomete os ...

  4. Structural characterization and anti-fatigue activity of polysaccharides from the roots of Morinda officinalis.

    Science.gov (United States)

    Zhang, Hua-Lin; Li, Jun; Li, George; Wang, Dong-mei; Zhu, Long-ping; Yang, De-po

    2009-04-01

    Three polysaccharides MP-1, MP-2, and MP-3 were isolated from hot water extract of Chinese medicine Morinda officinalis through 95% ethanol precipitation and gel-filtration chromatography (DEAE-Sepharose CL-6B column and Sephadex G-75 or G-100 column). MP-1 was identified as an inulin-type fructan with simple linear (2-->1)-linked structure. Both MP-2 and MP-3 were acidic polysaccharides which consisted predominantly of galacturonic acid, arabinose and galactose. Partial structure characterization of MP-3 was carried out by partial acid hydrolysis and periodate oxidation. The total polysaccharides of the herb were tested in mice weight-loaded swimming model and were found to have anti-fatigue activity. PMID:19150459

  5. Ribose and related sugars from ultraviolet irradiation of interstellar ice analogs

    Science.gov (United States)

    Meinert, Cornelia; Myrgorodska, Iuliia; de Marcellus, Pierre; Buhse, Thomas; Nahon, Laurent; Hoffmann, Søren V.; d'Hendecourt, Louis Le Sergeant; Meierhenrich, Uwe J.

    2016-04-01

    Ribose is the central molecular subunit in RNA, but the prebiotic origin of ribose remains unknown. We observed the formation of substantial quantities of ribose and a diversity of structurally related sugar molecules such as arabinose, xylose, and lyxose in the room-temperature organic residues of photo-processed interstellar ice analogs initially composed of H2O, CH3OH, and NH3. Our results suggest that the generation of numerous sugar molecules, including the aldopentose ribose, may be possible from photochemical and thermal treatment of cosmic ices in the late stages of the solar nebula. Our detection of ribose provides plausible insights into the chemical processes that could lead to formation of biologically relevant molecules in suitable planetary environments.

  6. Controlled enzyme catalyzed heteropolysaccharide degradation

    DEFF Research Database (Denmark)

    Rasmussen, Louise Enggaard

    The work presented in this PhD thesis has provided a better understanding of the enzyme kinetics and quantitative phenomena of the hydrolysis of xylan substrates by selected pure enzyme preparations. Furthermore, the options for producing specific substituted xylooligosaccharides from selected...... substrates by specific xylanase treatment have been examined. The kinetics of the enzymatic degradation of water-extractable wheat arabinoxylan (WE-AX) during designed treatments with selected monocomponent enzymes was investigated by monitoring the release of xylose and arabinose. The results of different...... effects between -xylosidase and the α-L-arabinofuranosidases on the xylose release were low as compared to the effect of xylanase addition with β-xylosidase, which increased the xylose release by ~25 times in 30 minutes. At equimolar addition levels of the four enzymes, the xylanase activity was thus rate...

  7. Extracellular lipase production by a sapwood-staining fungus, Ophiostoma piceae.

    Science.gov (United States)

    Gao, Y; Breuil, C

    1995-11-01

    The extracellular lipase production of a sapwood-staining fungus, Ophiostoma piceae, grown in liquid media, was optimally active at pH 5.5 and 37°C. Although glucose, fructose, sucrose, starch and dextrin, as carbon sources for growth gave similar mycelial yields, which were higher than those obtained with arabinose, galactose or raffinose, the cells growing on those carbohydrates produced little extracellular lipase. However, both high biomass and lipase activity were obtained when plant oils (olive, soybean, corn, sunflower seed, sesame, cotton seed or peanut) were used as carbon sources. Among the nitrogen sources examined, Casamino acids gave the best growth, whereas (NH4)2SO4 gave the best lipase production. The highest lipase productivity seen was obtained in a medium with olive oil as carbon source and a combination of (NH4)2SO4and peptone as nitrogen source. PMID:24415011

  8. 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.

  9. Measurements of particulate sugars at urban and forested suburban sites

    Science.gov (United States)

    Tominaga, Sae; Matsumoto, Kiyoshi; Kaneyasu, Naoki; Shigihara, Ado; Katono, Koichi; Igawa, Manabu

    2011-04-01

    Neutral sugars (arabinose, fucose, galactose, glucose, mannose, rhamnose, and xylose) in fine and coarse aerosols were measured at urban and forested suburban sites in Japan. The most dominant compound in the sugar group was glucose at both sites. Size partitioning of the sugars generally showed dominance in the fine mode range but shifted toward the coarse mode range in summer. Seasonal trends in the sugar concentrations in the fine and coarse mode ranges were opposite: higher concentrations of fine mode sugars were found in winter, although coarse mode sugars increased in summer. Fine mode glucose consisted dominantly of the combined form, whereas free glucose increased in the coarse mode range. Although the sources of the sugars in the aerosols remain largely uncertain, primary biogenic particles can be considered as candidates of main sources of the sugars in both coarse and fine mode ranges.

  10. Effect of soil carbohydrates on nutrient availability in natural forests and cultivated lands in Sri Lanka

    Science.gov (United States)

    Ratnayake, R. R.; Seneviratne, G.; Kulasooriya, S. A.

    2013-05-01

    Carbohydrates supply carbon sources for microbial activities that contribute to mineral nutrient production in soil. Their role on soil nutrient availability has not yet been properly elucidated. This was studied in forests and cultivated lands in Sri Lanka. Soil organic matter (SOM) fractions affecting carbohydrate availability were also determined. Soil litter contributed to sugars of plant origin (SPO) in croplands. The negative relationship found between clay bound organic matter (CBO) and glucose indicates higher SOM fixation in clay that lower its availability in cultivated lands. In forests, negative relationships between litter and sugars of microbial origin (SMO) showed that litter fuelled microbes to produce sugars. Fucose and glucose increased the availability of Cu, Zn and Mn in forests. Xylose increased Ca availability in cultivated lands. Arabinose, the main carbon source of soil respiration reduced the P availability. This study showed soil carbohydrates and their relationships with mineral nutrients could provide vital information on the availability of limiting nutrients in tropical ecosystems.

  11. New evidences on efficacy of boronic acid-based derivatization method to identify sugars in plant material by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Faraco, Marianna; Fico, Daniela; Pennetta, Antonio; De Benedetto, Giuseppe E

    2016-10-01

    This work presents an analytical procedure based on gas chromatography-mass spectrometry which allows the determination of aldoses (glucose, mannose, galactose, arabinose, xylose, fucose, rhamnose) and chetoses (fructose) in plant material. One peak for each target carbohydrate was obtained by using an efficient derivatization employing methylboronic acid and acetic anhydride sequentially, whereas the baseline separation of the analytes was accomplished using an ionic liquid capillary column. First, the proposed method was optimized and validated. Successively, it was applied to identify the carbohydrates present in plant material. Finally, the procedure was successfully applied to samples from a XVII century painting, thus highlighting the occurrence of starch glue and fruit tree gum as polysaccharide materials. PMID:27474277

  12. A review about the development of fucoidan in antitumor activity: Progress and challenges.

    Science.gov (United States)

    Wu, Lei; Sun, Jing; Su, Xitong; Yu, Qiuli; Yu, Qiuyang; Zhang, Peng

    2016-12-10

    Fucoidan is composed of l-fucose, sulfate groups and one or more small proportions of d-xylose, d-mannose, d-galactose, l-rhamnose, arabinose, glucose, d-glucuronic acid and acetyl groups in different kinds of brown seaweeds. Many reports have demonstrated that fucoidan has antitumor activities on various cancers. However, until now, few reviews have discussed the antitumor activity of fucoidan and few reports have summarized detailed molecular mechanisms of its actions and antitumor challenges of fucoidan specially. In this review, the antitumor signaling pathway mechanisms related to fucoidan are elucidated as much detail as possible. Besides, the factors affecting the anticancer effects of fucoidan, the structural characteristics of fucoidan with anticancer activities and the challenges for the further development of fucoidan are also summarized and evaluated. The existing similar and different conclusions are summarized in an attempt to provide guidelines to help further research, and finally contribute to go into market as chemotherapeumtics. PMID:27577901

  13. Presence of a low molecular weight lectin in the coelomic fluid of the sea urchin Paracentrotus lividus

    Directory of Open Access Journals (Sweden)

    F Drago

    2009-02-01

    Full Text Available A low molecular weight (MW lectin (Paracentrotus lividus small lectin, PlSL has been found in the sea urchin, Paracentrotus lividus. After gel electrophoresis under denaturing conditions, PlSL exhibits a MW of 13 kDa, while its hemagglutinating activity is Ca2+-independent and inhibited by D-Glucose, L-Rhamnose, D-Arabinose, L-Fucose and N-Acetyl-D-glucosamine. Electrophoretic analysis of the coleomic fluid of P. lividus reveals that the presence of PlSL increases following immune challenge with bacteria, whereas it is annulled as a consequence of osmotic stress. Interestingly, two other putative inducible hemagglutinins of an approximate MW of 11 and 32 kDa were retrieved in concomitance with the stress-promoted disappearance of PlSL.

  14. Production and recovery of monosaccharides from lignocellulose hot water extracts in a pulp mill biorefinery.

    Science.gov (United States)

    Sainio, Tuomo; Kallioinen, Mari; Nakari, Olli; Mänttäri, Mika

    2013-05-01

    Processing of hemicelluloses obtained with pressurized hot water extraction (PHWE) from Scots pine to monosaccharides and other chemicals was investigated experimentally. A process scheme consisting of ultrafiltration, acid hydrolysis, and chromatographic separation was proposed and evaluated. A two-stage ultrafiltration was found necessary for efficient fractionation of the wood extract. It was shown that the monosaccharides can be released from a concentrated hemicellulose fraction with sulfuric acid hydrolysis without a significant loss of yield due to decomposition of monosaccharides. Acid hydrolysate was successfully fractionated with ion exchange chromatography and the hydrolysis acid was recovered for reuse. The product fractions obtained include polyphenols and high molar mass hemicelluloses (from UF stage 1), arabinose (from UF stage 2), as well as acetic acid and a mixture of monosaccharides (xylose, galactose, mannose, glucose) from chromatography. PMID:23069608

  15. Lyoluminescence of saccharides for radiation dose determination (personnel dosimetry) in armed forces

    International Nuclear Information System (INIS)

    The chemiluminescence of saccharides is a method for determination of γ-doses (lyoluminescence). The aim of these investigations is to find a substance for a cheap personnel dosemeter for the range between 0.5-6 Gy. This first revier describes the mechanical, optical and electronic device. The optimal parameters for investigation were determined. Bi-destilled water serves as a solvent without chemical luminescence enhancement. Each measurement was performed by use of 50 mg saccharide and 1.5 ml water. The luminescence was observed using single photon counting during 10 s. 24 saccharides of several producers were investigated, predose and sensitivity were compared. Five samples were selected for further treatment: arabinose, trehalose, fructose and two glucoses of chosen producers because of their dynamics. (orig.) With 22 refs., 3 tabs., 25 figs

  16. Bioethanol production from residual lignocellulosic materials: A review – Part 1

    Directory of Open Access Journals (Sweden)

    CRISTIAN-TEODOR BURUIANA

    2013-08-01

    Full Text Available Lignocellulosic materials (LCM are produced in large quantities and without clear application and their use as raw material for bioethanol production shows economic and ecologic benefits. LCM are composed mainly of three polymers: cellulose made up of glucose units, hemicellulose made up of several sugars (as xylose or arabinose, and lignin made up of phenylpropane units, interconnected in a strong structure. Pretreatment is an important step for bioethanol production from LCM, causing the solubilisation of hemicellulosic fraction (leading to the recovery of hemicellulose-derived saccharides in order to obtain a solid phase enriched in cellulose and more susceptible to enzymatic attack. This study provides a comparative data regarding the chemical composition of various LCM used for bioethanol production, as well as different pretreatment technologies for improving the enzymatic hydrolysis of LCM.

  17. Total recovery of the waste of two-phase olive oil processing: isolation of added-value compounds.

    Science.gov (United States)

    Fernández-Bolaños, Juan; Rodríguez, Guillermo; Gómez, Esther; Guillén, Rafael; Jiménez, Ana; Heredia, Antonia; Rodríguez, Rocío

    2004-09-22

    A process for the value addition of solid waste from two-phase olive oil extraction or "alperujo" that includes a hydrothermal treatment has been suggested. In this treatment an autohydrolysis process occurs and the solid olive byproduct is partially solubilized. From this water-soluble fraction can be obtained besides the antioxidant hydroxytyrosol several other compounds of high added value. In this paper three different samples of alperujo were characterized and subjected to a hydrothermal treatment with and without acid catalyst. The main soluble compounds after the hydrolysis were represented by monosaccharides xylose, arabinose, and glucose; oligosaccharides, mannitol and products of sugar destruction. Oligosaccharides were separated by size exclusion chromatography. It was possible to get highly purified mannitol by applying a simple purification method. PMID:15366831

  18. Synthesis, spectroscopic and biological studies of transition metal complexes of novel schiff bases derived from cephradine and sugars

    International Nuclear Information System (INIS)

    Fe(II), Co(II) and Ni(II) metal complexes of novel schiff bases derived from Cephradine and sugars (D-Glucose, L. Arabinose and D-Galactose) were synthesized and characterized by elemental analysis, magnetic susceptibility, thermal analysis, electronic absorption and FT-IR spectral studies. It has been found that schiff bases behave as bi-dentate-ligands forming complexes with 1:2 (metal:ligand) stoichiometry. the neutral nature of the complexes was confirmed by their low conductance values. The biological activities of complexes have been evaluated against two gram negative (Escherichia coli and Pseudomonas aeruginosa) and two gram positive (Bacillus subtilis and staphylococcus aureus) bacteria by Agar diffusion disc method. It has been found that the complexes have higher activity as compared to the pure Cephradine against the same bacteria. (author)

  19. Fermentation of lignocellulosic sugars to acetic acid by Moorella thermoacetica.

    Science.gov (United States)

    Ehsanipour, Mandana; Suko, Azra Vajzovic; Bura, Renata

    2016-06-01

    A systematic study of bioconversion of lignocellulosic sugars to acetic acid by Moorella thermoacetica (strain ATCC 39073) was conducted. Four different water-soluble fractions (hydrolysates) obtained after steam pretreatment of lignocellulosic biomass were selected and fermented to acetic acid in batch fermentations. M. thermoacetica can effectively ferment xylose and glucose in hydrolysates from wheat straw, forest residues, switchgrass, and sugarcane straw to acetic acid. Xylose and glucose were completely utilized, with xylose being consumed first. M. thermoacetica consumed up to 62 % of arabinose, 49 % galactose and 66 % of mannose within 72 h of fermentation in the mixture of lignocellulosic sugars. The highest acetic acid yield was obtained from sugarcane straw hydrolysate, with 71 % of theoretical yield based on total sugars (17 g/L acetic acid from 24 g/L total sugars). The lowest acetic acid yield was observed in forest residues hydrolysate, with 39 % of theoretical yield based on total sugars (18 g/L acetic acid from 49 g/L total sugars). Process derived compounds from steam explosion pretreatment, including 5-hydroxymethylfurfural (0.4 g/L), furfural (0.1 g/L) and total phenolics (3 g/L), did not inhibit microbial growth and acetic acid production yield. This research identified two major factors that adversely affected acetic acid yield in all hydrolysates, especially in forest residues: (i) glucose to xylose ratio and (ii) incomplete consumption of arabinose, galactose and mannose. For efficient bioconversion of lignocellulosic sugars to acetic acid, it is imperative to have an appropriate balance of sugars in a hydrolysate. Hence, the choice of lignocellulosic biomass and steam pretreatment design are fundamental steps for the industrial application of this process. PMID:26992903

  20. Extraction, Isolation, Structural Characterization and Anti-Tumor Properties of an Apigalacturonan-Rich Polysaccharide from the Sea Grass Zostera caespitosa Miki

    Directory of Open Access Journals (Sweden)

    Youjing Lv

    2015-06-01

    Full Text Available An apigalacturonan (AGA-rich polysaccharide, ZCMP, was isolated from the sea grass Zostera caespitosa Miki. The depolymerized fragments derived from ZCMP were obtained by either acidic degradation or pectinase degradation, and their structures were characterized by electrospray ionization collision-induced-dissociation mass spectrometry (ESI-CID-MS2 and nuclear magnetic resonance (NMR spectroscopy. The average molecular weight of ZCMP was 77.2 kD and it consisted of galacturonic acid (GalA, apiosefuranose (Api, galactose (Gal, rhamnose (Rha, arabinose (Ara, xylose (Xyl, and mannose (Man, at a molar ratio of 51.4꞉15.5꞉6.0꞉11.8꞉4.2꞉4.4꞉4.2. There were two regions of AGA (70% and rhamnogalacturonan-I (RG-Ι, 30% in ZCMP. AGA was composed of an α-1,4-D-galactopyranosyluronan backbone mainly substituted at the O-3 position by single Api residues. RG-Ι possessed a backbone of repeating disaccharide units of →4GalAα1,2Rhaα1→, with a few α-L-arabinose and β-D-galactose residues as side chains. The anti-angiogenesis assay showed that ZCMP inhibited the migratory activity of human umbilical vein endothelial cell (HUVECs, with no influence on endothelial cells growth. ZCMP also promoted macrophage phagocytosis. These findings of the present study demonstrated the potential anti-tumor activity of ZCMP through anti-angiogenic and immunoregulatory pathways.

  1. Glucuronoarabinoxylan structure in the walls of Aechmea leaf chlorenchyma cells is related to wall strength.

    Science.gov (United States)

    Ceusters, Johan; Londers, Elsje; Brijs, Kristof; Delcour, Jan A; De Proft, Maurice P

    2008-09-01

    In CAM-plants rising levels of malic acid in the early morning cause elevated turgor pressures in leaf chlorenchyma cells. Under specific conditions this process is lethal for sensitive plants resulting in chlorenchyma cell burst while other species can cope with these high pressures and do not show cell burst under comparable conditions. The non-cellulosic polysaccharide composition of chlorenchyma cell walls was investigated and compared in three cultivars of Aechmea with high sensitivity for chlorenchyma cell burst and three cultivars with low sensitivity. Chlorenchyma layers were cut from the leaf and the non-cellulosic carbohydrate fraction of the cell wall fraction was analyzed by gas-liquid chromatography. Glucuronoarabinoxylans (GAXs) were the major non-cellulosic polysaccharides in Aechmea. The fine structure of these GAXs was strongly related to chlorenchyma wall strength. Chlorenchyma cell walls from cultivars with low sensitivity to cell burst were characterized by an A/X ratio of ca. 0.13 while those from cultivars with high sensitivity showed an A/X ratio of ca. 0.23. Xylose chains from cultivars with high cell burst sensitivity were ca. 40% more substituted with arabinose compared to cultivars with low sensitivity for cell burst. The results indicate a relationship in vivo between glucuronoarabinoxylan fine structure and chlorenchyma cell wall strength in Aechmea. The evidence obtained supports the hypothesis that GAXs with low degrees of substitution cross-link cellulose microfibrils, while GAXs with high degrees of substitution do not. A lower degree of arabinose substitution on the xylose backbone implies stronger cell walls and the possibility of withstanding higher internal turgor pressures without cell bursting. PMID:18632122

  2. Structure and Physical Properties of Natural Gellous Materials

    Science.gov (United States)

    Yudianti, Rike; Indrarti, Lucia; Azuma, Jun-Ichi

    This study presents two types of natural gellous materials as cellulose resources including gellous material synthesized by Acetobacter xylinum in fermentation process of coconut water with common name Bacterial Cellulose (BC) and gellous material isolated from seed of Ocimum americanum called hydrogel. Morphological surface of BC and hydrogel was observed by Scanning Electron Microscope (SEM). These images show randomly arrangement of fibres in three dimensional network having length of 1-5 µm and 3-12µm, respectively in forming a dense reticulated structure. Hydrated fibres were observed evidently by Atomic Force Microscope (AFM) showing that BC and hydrogel have fibres in nanometer scale diameter, 7-10 and 2-3 nm, respectively. At glance, X-Ray diffraction profile of hydrogel shows broadening peaks at 2θ, 16° and 22°. While BC has peaks at 2θ, 14.7, 16.7, 20.5 and 22.5°, attributed to lattice diffractions (100), (010), and (110), respectively. The sharp profile present in BC lead to ordered structure, confirmed by higher crystallinity degree of BC (75%) compared to that`s of hydrogel (35%). Water Holding Capacity (WHC) of BC and hydrogel has values about 5.5 and 39.2 mL g-1, respectively while swelling ability of BC and hydrogel in water is 6.2 and 102.2%, respectively. Neutral sugar compositions of BC resulted in less 0.1% arabinose and rhamnose, 1.1% galactose, 98.5% glucose, 0.2 xylose and 0.2 mannose indicating high cellulose content. Meanwhile, hydrogel contains 11.9% (arabinose), 4.5% (rhamnose), 18.6% (galactose), 50.5% (glucose), 13.2% (xylose), 1.3% (mannose) indicating high hemicellulose contents leading to branching of arabinogalactan attached to cellulose.

  3. CARACTERIZAÇÃO BIOQUÍMICA DE AMOSTRAS DE Haemophilus parasuis ISOLADAS DE SUÍNOS NA REGIÃO SUL DO BRASIL

    Directory of Open Access Journals (Sweden)

    Maria Aparecida Vasconcelos Paiva Brito

    1994-12-01

    Full Text Available O objetivo deste trabalho foi caracterizar amostras não hemolíticas de bactérias do gênero Haemophilus isoladas de suínos. As bactérias foram isoladas de material clínico de animais com suspeita da doença de Glässer, de leitões aparentemente sadios provenientes de quatro rebanhos com suspeita clínica desta doença e de casos de poliartrites. Além das características culturais e morfotintoriais, foram utilizados os seguintes testes para a identificação: dependência de NAD(fator V, CAMP, produção de hemolisina, indol, urease e catalase, redução do nitrato e produção de ácido dos carboidratos: glicose, sacarose, arabinose e manose. Dezessete dentre 24 amostras foram classificadas como Haemophilus parasuis (dez isoladas de animais clinicamente doentes e sete de leitões normais. Cinco destas amostras foram classificadas nos sorogrupos 2, 4, 7, ND4 e uma foi não tipável. Quatro das 24 amostras apresentaram características do grupo taxonômico C (teste de arabinose positivo e três produziram urease. Os testes realizados não permitiram distinguir as amostras urease positivas do gênero Haemophilus das amostras não hemolíticas de Actinobacilius pleuropneumoniae. Mais de 60% das amostras apresentaram sensibilidade in vitro a: ampicilina, cefalotina, cloranfenicol, danofioxacina, nitrofurantoína, penicilina G, polimixina B e tetraciclina.

  4. Do assorted approaches aid in estimation of uronic acids? Case studies on Tinospora sinensis polysaccharides.

    Science.gov (United States)

    Kumar, Vineet; Nagar, Shipra; Tripathi, Y C

    2014-09-01

    Polysaccharides containing uronic acids are of immense biological significance. Colorimetric methods using different chromogens have been explored for uronic acid estimation in polysaccharides but these methods counter numerous difficulties, when neutral sugars are present in substantial amount. The uronic acid content of cold water-soluble polysaccharide (CWSP) and hot water-soluble polysaccharide (HWSP) isolated from Tinospora sinensis, widely known for marked therapeutic significance has been studied. The uronic acid was quantitatively estimated by spectrophotometric methods using carbazole, 3-phenylphenol and 3,5-dimethylphenol (DMP) vis-a-vis gas-liquid chromatography (GLC) analysis. Galacturonic acid in CWSP and HWSP was estimated as 1.41% and 1.20% respectively. The findings bring to light, the efficacy of chromogens and also reveal to what extent, they could be relied upon. The results also indicated higher specificity and selectivity of DMP over carbazole and 3-phenylphenol. However, GLC analysis despite time consuming remains the finest method for precise estimation of uronic acids. Further, GLC analysis of alditol acetates indicated the monosugar composition of L-rhamnose, L-arabinose, D-mannose, D-galactose and D-glucose in molar ratio 0.178, 0.259, 0.140, 1.045 and 98.377 in CWSP and L-rhamnose, L-arabinose, D-xylose, D-mannose, D-galactose and D-glucose in molar ratio 0.608, 0.628, 0.978, 0.227, 0.111 and 97.448 in HWSP respectively. PMID:25034757

  5. Fluorescence resonance energy transfer sensors for quantitative monitoring of pentose and disaccharide accumulation in bacteria

    Directory of Open Access Journals (Sweden)

    Looger Loren L

    2008-06-01

    Full Text Available Abstract Background Engineering microorganisms to improve metabolite flux requires detailed knowledge of the concentrations and flux rates of metabolites and metabolic intermediates in vivo. Fluorescence resonance energy transfer sensors represent a promising technology for measuring metabolite levels and corresponding rate changes in live cells. These sensors have been applied successfully in mammalian and plant cells but potentially could also be used to monitor steady-state levels of metabolites in microorganisms using fluorimetric assays. Sensors for hexose and pentose carbohydrates could help in the development of fermentative microorganisms, for example, for biofuels applications. Arabinose is one of the carbohydrates to be monitored during biofuels production from lignocellulose, while maltose is an important degradation product of starch that is relevant for starch-derived biofuels production. Results An Escherichia coli expression vector compatible with phage λ recombination technology was constructed to facilitate sensor construction and was used to generate a novel fluorescence resonance energy transfer sensor for arabinose. In parallel, a strategy for improving the sensor signal was applied to construct an improved maltose sensor. Both sensors were expressed in the cytosol of E. coli and sugar accumulation was monitored using a simple fluorimetric assay of E. coli cultures in microtiter plates. In the case of both nanosensors, the addition of the respective ligand led to concentration-dependent fluorescence resonance energy transfer responses allowing quantitative analysis of the intracellular sugar levels at given extracellular supply levels as well as accumulation rates. Conclusion The nanosensor destination vector combined with the optimization strategy for sensor responses should help to accelerate the development of metabolite sensors. The new carbohydrate fluorescence resonance energy transfer sensors can be used for in vivo

  6. Kallotenue papyrolyticum gen. nov., sp. nov., a cellulolytic and filamentous thermophile that represents a novel lineage (Kallotenuales ord. nov., Kallotenuaceae fam. nov.) within the class Chloroflexia

    Energy Technology Data Exchange (ETDEWEB)

    Cole, Jesse; Gieler, Brandon; Heisler, Devon; Palisoc, Maryknoll; Williams, Amanda; Dohnalkova, Alice; Ming, Hong; Yu, Tian T.; Dodsworth, Jeremy A.; Li, Wen J.; Hedlund, Brian P.

    2013-08-15

    Several closely-related, thermophilic, and cellulolytic bacterial strains, designated JKG1T, JKG2, JKG3, JKG4, and JKG5, were isolated from a cellulolytic enrichment (corn stover) incubated in the water column of Great Boiling Spring, NV. Strain JKG1T had cells of a diameter of 0.7 - 0.9 μm and length of ~2.0 μm that formed non-branched multicellular filaments reaching >300 μm. Spores were not formed and dense liquid cultures were red. The temperature range for growth was 45-65 °C, with an optimum of 55 °C. The pH range for growth was 5.6-9.0, with an optimum of 7.5. JKG1T grew as an aerobic heterotroph, utilizing glucose, sucrose, xylose, arabinose, cellobiose, carboxymethylcellulose, filter paper, microcrystalline cellulose, xylan, starch, casamino acids, tryptone, peptone, yeast extract, acetate, citrate, lactate, pyruvate, and glycerol as sole carbon sources, and was not observed to photosynthesize. The cells stained Gram-negative. Phylogenetic analysis using 16S rRNA gene sequences placed the new isolates in the class Chloroflexia, but distant from other cultivated members, with the highest sequence identity of 82.5% to Roseiflexus castenholzii. The major quinone was menaquinone-9; no ubiquinones were detected. The major cellular fatty acids (>5%) were C18:0, anteiso-C17:0, iso-C18:0, and iso-C17:0. C16:0, iso-C16:0, and C17:0. The peptidoglycan amino acids were alanine, ornithine, glutamic acid, serine, and asparagine. Whole-cell sugars included mannose, rhamnose, glucose, galactose, ribose, arabinose, and xylose. Morphological, phylogenetic, and chemotaxonomic results suggest that JKG1T is representative of a new lineage within the class Chloroflexia, which we propose to designate Kallotenue papyrolyticum gen. nov., sp. nov., Kallotenuaceae fam. nov., Kallotenuales ord. nov.

  7. Expression and purification of recombinant truncated human keratinocyte growth factor-1

    International Nuclear Information System (INIS)

    Objective: To construct the genetic engineering bacteria highly expressing 23 amino acids human keratinocyte growth factor-1 (rhKGF1dest23) missing N terminal, and provide experimental data for development of new drug for treatment of oral mucositis after radiotherapy and chemotherapy. Methods: PCR was used to synthese 23 amino acids rhKGF1dest23 missing N terminal and sumo gene fragments, and construct four kinds of recombinant prokaryotic expression vectors: pET22b-rhKGF1dest23, pET22b-sumo-rhKGF1dest23, pET3c-rhKGF1dest23 and pET3c-sumo-rhKGF1dest23, then they were transformed into prokaryotic expression host bacteria: Rosetta (DE3) plysS, BL21 (DE3), BL21 (DE3) Star plysS, origima(DE3) and BL21AI, the best expression combination of plasmid and host strain of rhKGF1dest23 protein was screened and purified by CM ion-exchange and heparin affinity chromatography and identified with Western blotting. Results: pET22b-rhKGF1dest23 plasmid and the BL21AI host bacteria was the best combination of expression, after induced by IPTG and arabinose, the majority of recombinant protein was expressed in soluble form, accounting for about 12% of the total bacterial proteins. Its purity reached to more than 95% of the protein after two steps chromatography, then conformed with Western blotting. Conclusion: Human genetic engineering bacteria of KGF1dest23 is successfully constructed and induced by IPTG and arabinose, then after CM weak cation exchange and heparin affinity chromatography, the purified rhKGF1dest23 protein is obtained. (authors)

  8. Inhibition by Natural Dietary Substances of Gastrointestinal Absorption of Starch and Sucrose in Rats 2. Subchronic Studies

    Directory of Open Access Journals (Sweden)

    Harry G. Preuss, Bobby Echard, Debasis Bagchi, Sidney Stohs

    2007-01-01

    Full Text Available Acute oral consumption of various natural inhibitors of amylase (bean and hibiscus extracts and sucrase (L-arabinose reduce absorption of starch and sucrose respectively in rats and pigs measured by lessened appearance of circulating glucose levels. The present subchronic study was designed to determine whether these selected inhibitors of gastrointestinal starch and sucrose absorption (so-called “carb blockers” remain effective with continued use and to assess their metabolic influences after prolonged intake. Sprague-Dawley rats were gavaged twice daily over nine weeks with either water or an equal volume of water containing a formula that included bean and hibiscus extracts and L-arabinose. To estimate CHO absorption, control and treated Sprague-Dawley rats were gavaged with either water alone or an equal volume of water containing glucose, rice starch, sucrose, or combined rice starch and sucrose. Circulating glucose was measured at timed intervals over four hours. The ability to decrease starch and sucrose absorption use. No toxic effects (hepatic, renal, hematologic were evident. Blood chemistries revealed significantly lower circulating glucose levels and a trend toward decreased HbA1C in the nondiabetic rats receiving the natural formulation compared to control. Subchronic administration of enzyme inhibitors was also associated with many metabolic changes including lowered systolic blood pressure and altered fluid-electrolyte balance. We postulate that proper intake of natural amylase and sucrase inhibitors may be useful in the prevention and treatment of many chronic disorders associated with perturbations in glucose-insulin homeostasis secondary to the rapid absorption of refined CHO.

  9. Hydrophilic solute transport across the rat blood-brain barrier

    International Nuclear Information System (INIS)

    Brain capillary permeability-surface area products (PS) of hydrophilic solutes ranging in size from 180 to 5,500 Daltons were measured in rats according to the method of Ohno, Pettigrew and Rapoport. The distribution volume of 70 KD dextran at 10 minutes after i.v. injection was also measured to determine the residual volume of blood in brain tissue at the time of sacrifice. Small test solutes were injected in pairs in order to elucidate whether their transfer into the brain proceeds by diffusion through water- or lipid-filled channels or by vesicular transport. This issue was examined in rats whose blood-brain barrier (BBB) was presumed to be intact (untreated) and in rats that received intracarotid infusions to open the BBB (isosmotic salt (ISS) and hyperosmolar arabinose). Ohno PS values of 3H-inulin and 14C-L-glucose in untreated rats were found to decrease as the labelling time was lengthened. This was evidence that a rapidly equilibrating compartment exists between blood and brain that renders the Ohno two-compartment model inadequate for computing true transfer rate constants. When the data were reanalyzed using a multi-compartment graphical analysis, solutes with different molecular radii were found to enter the brain at approximately equal rates. Furthermore, unidirectional transport is likely to be initiated by solute adsorption to a glycocalyx coat on the luminal surface of brain capillary endothelium. Apparently, more inulin than L-glucose was adsorbed, which may account for its slightly faster transfer across the BBB. After rats were treated with intracarotid infusions of ISS or hyperosmolar arabinose, solute PS values were significantly increased, but the ratio of PS for each of the solute pairs approached that of their free-diffusion coefficients

  10. Extensin and Arabinogalactan-Protein Biosynthesis: Glycosyltransferases, Research Challenges, and Biosensors

    Science.gov (United States)

    Showalter, Allan M.; Basu, Debarati

    2016-01-01

    Recent research, mostly in Arabidopsis thaliana, has led to the identification and characterization of the glycosyltransferases responsible for the biosynthesis of two of the most functionally important and abundant families of plant cell wall proteins, extensins, and arabinogalactan-proteins. Extensin glycosylation involves monogalactosylation of serine residues by O-α-serine galactosyltransferase and the addition of oligoarabinosides one to five arabinose units in length to contiguous hydroxyproline residues by a set of specific arabinosyltransferase enzymes, which includes hydroxyproline O-β-arabinosyltransferases, β-1,2-arabinosyltransferases, and at least one α-1,3-arabinosyltransferase. AGP glycosylation, however, is much more complex and involves the addition of large arabinogalactan polysaccharide chains to non-contiguous hydroxyproline residues. These arabinogalactan chains are composed of β-1,3-galactan backbones decorated with β-1,6-galactose side chains that are further modified with α-arabinose as well as other sugars, including β-(methyl)glucuronic acid, α-rhamnose, and α-fucose. Specific sets of hydroxyproline O-β-galactosyltransferases, β-1,3-galactosyltransferases, β-1,6-galactosyltransferases, α-arabinosyltransferases, β-glucuronosyltransferases, α-rhamnosyltransferases, and α-fucosyltransferases are responsible for the synthesis of these complex structures. This mini-review summarizes the EXT and AGP glycosyltransferases identified and characterized to date along with corresponding genetic mutant data, which addresses the functional importance of EXT and AGP glycosylation. In one case, genetic mutant data indicate that the carbohydrate moiety of arabinogalactan-proteins may serve as an extracellular biosensor or signal for normal cellular growth. Finally, future research challenges with respect to understanding the function of these enzymes more completely and discovering and characterizing additional glycosyltransferases

  11. Enzymatic hydrolysis of potato pulp

    Directory of Open Access Journals (Sweden)

    Mariusz Lesiecki

    2012-03-01

    Full Text Available Background. Potato pulp constitutes a complicated system of four types of polysaccharides: cellulose, hemicellulose, pectin and starch. Its composition makes it a potential and attractive raw material for the production of the second generation bioethanol. The aim of this research project was to assess the usefulness of commercial enzymatic preparations for the hydrolysis of potato pulp and to evaluate the effectiveness of hydrolysates obtained in this way as raw materials for ethanol fermentation. Material  and methods. Sterilised potato pulp was subjected to hydrolysis with commercial enzymatic preparations. The effectiveness of the preparations declared as active towards only one fraction of potato pulp (separate amylase, pectinase and cellulase activity and mixtures of these preparations was analysed. The monomers content in hydrolysates was determined using HPLC method. Results.  The application of amylolytic enzymes for potato pulp hydrolysis resulted in the release of only 18% of raw material with glucose as the dominant (77% constituent of the formed product. In addition, 16% galactose was also determined in it. The hydrolysis of the cellulose fraction yielded up to 35% raw material and the main constituents of the obtained hydrolysate were glucose (46% and arabinose (40%. Simultaneous application of amylolytic, cellulolytic and pectinolytic enzymes turned out to be the most effective way of carrying out the process as its efficiency in this case reached 90%. The obtained hydrolysate contained 63% glucose, 25% arabinose and 12% other simple substances. Conclusion. The application of commercial enzymatic preparations made it possible to perform potato pulp hydrolysis with 90% effectiveness. This was achieved by the application of a complex of amylolytic, cellulolytic and pectinolytic enzymes and the hydrolysate obtained in this way contained, primarily, glucose making it a viable substrate for ethanol fermentation.

  12. Compositional changes in cell wall polysaccharides from apple fruit callus cultures modulated by different plant growth regulators.

    Science.gov (United States)

    Alayón-Luaces, Paula; Ponce, Nora M A; Mroginski, Luis A; Stortz, Carlos A; Sozzi, Gabriel O

    2012-04-01

    The cell wall composition of apples callus cultures showed changes in the presence of 5 mg l(-1) of three different plant growth regulators (PGRs), namely picloram, abscisic acid and gibberellic acid. Although the structural functions of cell walls do not generally allow for pronounced variations of the total pectin and matrix glycan content, this work provides evidence that the addition of these plant growth regulators can rule, at least partly, cell wall metabolism in apple callus cultures. The chelator- and carbonate-extracts always had the analytical characteristics of pectins, with high proportions of uronic acids, arabinose and galactose as the main monosaccharides, and a significant proportion of rhamnose, but the cross-linking glycan fractions were still rich in RG-I-like material. The application of PGRs produced shifts of uronic acid and neutral sugars between fractions. Arabinose was the neutral sugar exhibiting more variations in apple callus cell wall. Picloram and abscisic acid produced an increase of the uronic acid contents of the cell walls. The AIRs obtained from calluses treated with different PGRs did not show large amounts of high molecular weight products, as determined by size-exclusion chromatography. For the carbonate-extract only the callus treated with picloram displayed two separated peaks for products of different molecular weights. The chromatographic profiles for the 4% KOH-extract displayed two peaks for all the treatments, one very sharp with high molecular weight, and another one wider of smaller molecular weight, whereas the difference between treatments can only be appraised through the areas of the peaks. This is the first report on cell wall composition from fruit calluses supplemented with different PGRs. PMID:22325878

  13. The Effect of pH Control on Acetone-Butanol-Ethanol Fermentation by Clostridium acetobutylicum ATCC 824 with Xylose and D-Glucose and D-Xylose Mixture

    Institute of Scientific and Technical Information of China (English)

    Wei Jiang; Zhiqiang Wen; Mianbin Wu; Hong Li; Jun Yang; Jianping Lin; Yijun Lin; Lirong Yang; Peilin Cen

    2014-01-01

    D-Glucose, L-arabinose, D-mannose, D-xylose, and cellobiose are saccharification products of lignocellulose and important carbon sources for industrial fermentation. The fermentation efficiency with each of the five sugars and the mixture of the two most dominant sugars, D-glucose and D-xylose, was evaluated for acetone-butanol-ethanol (ABE) fermentation by Clostridium acetobutylicum ATCC 824. The utilization efficacy of the five reducing sugars was in the order of D-glucose, L-arabinose, D-mannose, D-xylose and cellobiose. D-Xylose, the second most abundant component in lignocellulosic hydrolysate, was used in the fermentation either as sole carbon source or mixed with glucose. The results indicated that maintaining pH at 4.8, the optimal pH value for solventogenesis, could increase D-xylose consumption when it was the sole carbon source. Different media con-taining D-glucose and D-xylose at different ratios (1:2, 1:5, 1.5:1, 2:1) were then attempted for the ABE fermenta-tion. When pH was at 4.8 and xylose concentration was five times that of glucose, a 256.9%increase in xylose utilization and 263.7%increase in solvent production were obtained compared to those without pH control. These results demonstrate a possible approach combining optimized pH control and D-glucose and D-xylose ratio to increase the fermentation efficiency of lignocellulosic hydrolysate.

  14. Demonstration by heterologous expression that the Leishmania SCA1 gene encodes an arabinopyranosyltransferase.

    Science.gov (United States)

    Goswami, Mamta; Dobson, Deborah E; Beverley, Stephen M; Turco, Salvatore J

    2006-03-01

    In part of the life cycle within their sand fly vector, Leishmania major parasites first attach to the fly's midgut through their main surface adhesin lipophosphoglycan (LPG) and later resynthesize a structurally distinct LPG that results in detachment and eventual transmission. One of these structural modifications requires the addition of alpha1,2-D-arabinopyranose caps to beta1,3-galactose side chains in the phosphoglycan repeat unit domain of LPG. We had previously identified two side chain arabinose genes (SCA1/2) that were involved in the alpha1,2-D-Arap capping. SCA1/2 exhibit canonical glycosyltransferase motifs, and overexpression of either gene leads to elevated microsomal alpha1,2-D-ArapT activity, resulting in arabinopyranosylation of beta1,3-Gal side chains in LPG (hereafter called side chain D-arabinopyranosyltransferase [sc-D-ArapT]). Heterologous expression in a null arabinose background was used to determine whether the SCA1 gene encodes the actual sc-D-ArapT. SCA1 expression constructs introduced into both mammalian COS-7 cells and the baculovirus-sf9 cell system exhibited considerable expression of the protein. However, functional sc-D-ArapT activity was observed only in the latter. In in vitro assays incubated with guanidine 59-diphosphate (GDP)-D-[3H]Arap as the sugar donor and utilizing exogenous LPG as an acceptor, significant sc-D-ArapT activity was observed when microsomes from the baculovirus-sf9 cells were incubated in presence of the LPG acceptor. No activity was observed in the absence of LPG. These results demonstrate that SCA1 encodes a sc-D-ArapT and provide the first example of heterologous expression of a D-ArapT gene. PMID:16272216

  15. Optimizing dilute-acid pretreatment of rapeseed straw for extraction of hemicellulose.

    Science.gov (United States)

    Jeong, Tae-Su; Um, Byung-Hwan; Kim, Jun-Seok; Oh, Kyeong-Keun

    2010-05-01

    Biological conversion of biomass into fuels and chemicals requires hydrolysis of the polysaccharide fraction into monomeric sugars prior to fermentation. Hydrolysis can be performed enzymatically or with mineral acids. In this study, dilute sulfuric acid was used as a catalyst for the pretreatment of rapeseed straw. The purpose of this study is to optimize the pretreatment process in a 15-mL bomb tube reactor and investigate the effects of the acid concentration, temperature, and reaction time. These parameters influence hemicellulose removal and production of sugars (xylose, glucose, and arabinose) in the hydrolyzate as well as the formation of by-products (furfural, 5-hydroxymethylfurfural, and acetic acid). Statistical analysis was based on a model composition corresponding to a 3(3) orthogonal factorial design and employed the response surface methodology to optimize the pretreatment conditions, aiming to attain maximum xylan, mannan, and galactan (XMG) extraction from hemicellulose of rapeseed straw. The obtained optimum conditions were: H2SO4 concentration of 1.76% and temperature of 152.6 degrees C with a reaction time of 21 min. Under these optimal conditions, 85.5% of the total sugar was recovered after acid hydrolysis (78.9% XMG and 6.6% glucan). The hydrolyzate contained 1.60 g/L glucose, 0.61 g/L arabinose, 10.49 g/L xylose, mannose, and galactose, 0.39 g/L cellobiose, 0.94 g/L fructose, 0.02 g/L 1,6-anhydro-glucose, 1.17 g/L formic acid, 2.94 g/L acetic acid, 0.04 g/L levulinic acid, 0.04 g/L 5-hydroxymethylfurfural, and 0.98 g/L furfural. PMID:20087686

  16. Evolution of Xylan Substitution Patterns in Gymnosperms and Angiosperms: Implications for Xylan Interaction with Cellulose.

    Science.gov (United States)

    Busse-Wicher, Marta; Li, An; Silveira, Rodrigo L; Pereira, Caroline S; Tryfona, Theodora; Gomes, Thiago C F; Skaf, Munir S; Dupree, Paul

    2016-08-01

    The interaction between cellulose and xylan is important for the load-bearing secondary cell wall of flowering plants. Based on the precise, evenly spaced pattern of acetyl and glucuronosyl (MeGlcA) xylan substitutions in eudicots, we recently proposed that an unsubstituted face of xylan in a 2-fold helical screw can hydrogen bond to the hydrophilic surfaces of cellulose microfibrils. In gymnosperm cell walls, any role for xylan is unclear, and glucomannan is thought to be the important cellulose-binding polysaccharide. Here, we analyzed xylan from the secondary cell walls of the four gymnosperm lineages (Conifer, Gingko, Cycad, and Gnetophyta). Conifer, Gingko, and Cycad xylan lacks acetylation but is modified by arabinose and MeGlcA. Interestingly, the arabinosyl substitutions are located two xylosyl residues from MeGlcA, which is itself placed precisely on every sixth xylosyl residue. Notably, the Gnetophyta xylan is more akin to early-branching angiosperms and eudicot xylan, lacking arabinose but possessing acetylation on alternate xylosyl residues. All these precise substitution patterns are compatible with gymnosperm xylan binding to hydrophilic surfaces of cellulose. Molecular dynamics simulations support the stable binding of 2-fold screw conifer xylan to the hydrophilic face of cellulose microfibrils. Moreover, the binding of multiple xylan chains to adjacent planes of the cellulose fibril stabilizes the interaction further. Our results show that the type of xylan substitution varies, but an even pattern of xylan substitution is maintained among vascular plants. This suggests that 2-fold screw xylan binds hydrophilic faces of cellulose in eudicots, early-branching angiosperm, and gymnosperm cell walls. PMID:27325663

  17. Evaluation of wheat stillage for ethanol production by recombinant Zymomonas mobilis

    Energy Technology Data Exchange (ETDEWEB)

    Davis, L.; Peiris, P. [University of Western Sydney, Penrith (Australia). School of Science, Food and Horticulture; Young-Jae Jeon; Svenson, C.; Rogers, P. [University of New South Wales, Sydney (Australia). School of Biotechnology and Biomolecular Sciences; Pearce, J. [Manildra Group, Bomaderry (Australia)

    2005-07-01

    Stillage is the main residue from the starch-to-ethanol fermentation process.Carbohydrates (hemicellulose and cellulose) comprise approximately 50% (w/w)of the total components of stillage. Conversion of the hemicellulose and cellulose to fermentable sugars and then to ethanol has the potential to significantly increase the efficiency of the process. The hydrolysis of stillage to fermentable sugars was optimised using 2% (v/v) H{sub 2}SO{sub 4} at 100{sup o}C for 5.5 h and produced 18 g/L xylose, 11.5 g/L arabinose and 6.5 g/L glucose from 120 g/L stillage. Further hydrolysis using enzymes increased the release of glucose by 61%. Furfural, acetate and lactate were the main inhibitors present in the acid hydrolysate of stillage. The lignin-derived inhibitors hydroxymethylfuraldehyde, hydroxybenzaldehyde, vanillin and syringaldehyde were not detected. Neutralisation of the hydrolysate with lime to pH 5 decreased the concentration of furfural by 50%. Fermentation of hydrolysate supplemented with glucose 10 g/L, by recombinant Zymomonas mobilis ZM4(pZB5), produced 11 g/L of ethanol after 70 h, with residual xylose 12 g/L. Supplementation of the hydrolysate with 5 g/L yeast extract and 40 g/L glucose produced 28 g/L ethanol with 2.6 g/L residual xylose after 18 h. Arabinose was not utilised by this particular recombinant strain. From the results, Z. mobilis ZM4(pZB5) may be a suitable candidate for the fermentation of both glucose and xylose in stillage acid hydrolysates. (author)

  18. Centrifugal partition chromatography in a biorefinery context: Separation of monosaccharides from hydrolysed sugar beet pulp.

    Science.gov (United States)

    Ward, David P; Cárdenas-Fernández, Max; Hewitson, Peter; Ignatova, Svetlana; Lye, Gary J

    2015-09-11

    A critical step in the bioprocessing of sustainable biomass feedstocks, such as sugar beet pulp (SBP), is the isolation of the component sugars from the hydrolysed polysaccharides. This facilitates their subsequent conversion into higher value chemicals and pharmaceutical intermediates. Separation methodologies such as centrifugal partition chromatography (CPC) offer an alternative to traditional resin-based chromatographic techniques for multicomponent sugar separations. Highly polar two-phase systems containing ethanol and aqueous ammonium sulphate are examined here for the separation of monosaccharides present in hydrolysed SBP pectin: l-rhamnose, l-arabinose, d-galactose and d-galacturonic acid. Dimethyl sulfoxide (DMSO) was selected as an effective phase system modifier improving monosaccharide separation. The best phase system identified was ethanol:DMSO:aqueous ammonium sulphate (300gL(-1)) (0.8:0.1:1.8, v:v:v) which enabled separation of the SBP monosaccharides by CPC (200mL column) in ascending mode (upper phase as mobile phase) with a mobile phase flow rate of 8mLmin(-1). A mixture containing all four monosaccharides (1.08g total sugars) in the proportions found in hydrolysed SBP was separated into three main fractions; a pure l-rhamnose fraction (>90%), a mixed l-arabinose/d-galactose fraction and a pure d-galacturonic acid fraction (>90%). The separation took less than 2h demonstrating that CPC is a promising technique for the separation of these sugars with potential for application within an integrated, whole crop biorefinery. PMID:26278358

  19. Extensin and Arabinogalactan-Protein Biosynthesis: Glycosyltransferases, Research Challenges, and Biosensors.

    Science.gov (United States)

    Showalter, Allan M; Basu, Debarati

    2016-01-01

    Recent research, mostly in Arabidopsis thaliana, has led to the identification and characterization of the glycosyltransferases responsible for the biosynthesis of two of the most functionally important and abundant families of plant cell wall proteins, extensins, and arabinogalactan-proteins. Extensin glycosylation involves monogalactosylation of serine residues by O-α-serine galactosyltransferase and the addition of oligoarabinosides one to five arabinose units in length to contiguous hydroxyproline residues by a set of specific arabinosyltransferase enzymes, which includes hydroxyproline O-β-arabinosyltransferases, β-1,2-arabinosyltransferases, and at least one α-1,3-arabinosyltransferase. AGP glycosylation, however, is much more complex and involves the addition of large arabinogalactan polysaccharide chains to non-contiguous hydroxyproline residues. These arabinogalactan chains are composed of β-1,3-galactan backbones decorated with β-1,6-galactose side chains that are further modified with α-arabinose as well as other sugars, including β-(methyl)glucuronic acid, α-rhamnose, and α-fucose. Specific sets of hydroxyproline O-β-galactosyltransferases, β-1,3-galactosyltransferases, β-1,6-galactosyltransferases, α-arabinosyltransferases, β-glucuronosyltransferases, α-rhamnosyltransferases, and α-fucosyltransferases are responsible for the synthesis of these complex structures. This mini-review summarizes the EXT and AGP glycosyltransferases identified and characterized to date along with corresponding genetic mutant data, which addresses the functional importance of EXT and AGP glycosylation. In one case, genetic mutant data indicate that the carbohydrate moiety of arabinogalactan-proteins may serve as an extracellular biosensor or signal for normal cellular growth. Finally, future research challenges with respect to understanding the function of these enzymes more completely and discovering and characterizing additional glycosyltransferases

  20. Improvement of DNA minicircle production by optimization of the secondary structure of the 5'-UTR of ParA resolvase.

    Science.gov (United States)

    Šimčíková, Michaela; Alves, Cláudia P A; Brito, Liliana; Prather, Kristala L J; Prazeres, Duarte M F; Monteiro, Gabriel A

    2016-08-01

    The use of minicircles in gene therapy applications is dependent on the availability of high-producer cell systems. In order to improve the performance of minicircle production in Escherichia coli by ParA resolvase-mediated in vivo recombination, we focus on the 5' untranslated region (5'-UTR) of parA messenger RNA (mRNA). The arabinose-inducible PBAD/araC promoter controls ParA expression and strains with improved arabinose uptake are used. The 27-nucleotide-long 5'-UTR of parA mRNA was optimized using a predictive thermodynamic model. An analysis of original and optimized mRNA subsequences predicted a decrease of 8.6-14.9 kcal/mol in the change in Gibbs free energy upon assembly of the 30S ribosome complex with the mRNA subsequences, indicating a more stable mRNA-rRNA complex and enabling a higher (48-817-fold) translation initiation rate. No effect of the 5'-UTR was detected when ParA was expressed from a low-copy number plasmid (∼14 copies/cell), with full recombination obtained within 2 h. However, when the parA gene was inserted in the bacterial chromosome, a faster and more effective recombination was obtained with the optimized 5'-UTR. Interestingly, the amount of this transcript was 2.6-3-fold higher when compared with the transcript generated from the original sequence, highlighting that 5'-UTR affects the level of the transcript. A Western blot analysis confirmed that E. coli synthesized higher amounts of ParA with the new 5'-UTR (∼1.8 ± 0.7-fold). Overall, these results show that the improvements made in the 5'-UTR can lead to a more efficient translation and hence to faster and more efficient minicircle generation. PMID:27147534

  1. Metabolites produced by probiotic Lactobacilli rapidly increase glucose uptake by Caco-2 cells

    Directory of Open Access Journals (Sweden)

    Buddington Randal K

    2010-01-01

    Full Text Available Abstract Background Although probiotic bacteria and their metabolites alter enterocyte gene expression, rapid, non-genomic responses have not been examined. The present study measured accumulation of tracer (2 μM glucose by Caco-2 cells after exposure for 10 min or less to a chemically defined medium (CDM with different monosaccharides before and after anaerobic culture of probiotic Lactobacilli. Results Growth of L. acidophilus was supported by CDM with 110 mM glucose, fructose, and mannose, but not with arabinose, ribose, and xylose or the sugar-free CDM. Glucose accumulation was reduced when Caco-2 cells were exposed for 10 min to sterile CDM with glucose (by 92%, mannose (by 90%, fructose (by 55%, and ribose (by 16%, but not with arabinose and xylose. Exposure of Caco-2 cells for 10 min to bacteria-free supernatants prepared after exponential (48 h and stationary (72 h growth phases of L. acidophilus cultured in CDM with 110 mM fructose increased glucose accumulation by 83% and 45%, respectively; exposure to a suspension of the bacteria had no effect. The increase in glucose accumulation was diminished by heat-denaturing the supernatant, indicating the response of Caco-2 cells is triggered by as yet unknown heat labile bacterial metabolites, not by a reduction in CDM components that decrease glucose uptake. Supernatants prepared after anaerobic culture of L. gasseri, L. amylovorus, L. gallinarum, and L. johnsonii in the CDM with fructose increased glucose accumulation by 83%, 32%, 27%, and 14%, respectively. Conclusion The rapid, non-genomic upregulation of SGLT1 by bacterial metabolites is a heretofore unrecognized interaction between probiotics and the intestinal epithelium.

  2. TOTAL USE OF OLIVE TREE PRUNINGS BY MEANS OF HYDROTHERMAL AND COMBUSTION PROCESSES

    Directory of Open Access Journals (Sweden)

    Alejandro Rodriguez

    2011-11-01

    Full Text Available The aim of this work is to chemically characterize olive tree prunings and use the material in hydrothermal and combustion processes. The influence of the hydrothermal treatment conditions, with and without acid catalyst, of the main fraction of olive tree prunings (stems with a diameter > 1 cm (temperature 150 to 190ºC, time 0 to 20 minutes after reaching the operation temperature, liquid/solid ratio 6 to 8, and sulphuric acid concentration -0.1 to 0.5%, on the composition of resulting liquid fraction and on the solid yield of resulting solid fraction were studied. A polynomial model was found to reproduce the glucose and arabinose concentration, as well as the experimental results for solid yield with errors less than 20% at worst (< 10-12% in 90-95% of all cases. Good content values of glucose (5.33% and arabinose (2.76%, and an acceptable value of the solid fraction yield (57.96% were obtained operating with following values of temperature, time, liquid/solid ratio, and sulfuric acid concentration: 186ºC, 18 min, 7:1, and 0.1%, respectively. With these values are saved, with respect to the use of higher values for operating variables, 2.1% energy, 80% sulfuric acid, and more than 10% of capital facilities. Residual fraction of olive tree prunings (leaves and stems with a diameter < 1 cm had a heating value of 18699 kJ/kg, a flame temperature of 1207-2234 ºC, and a dew point temperature of combustion gasses of 45-53 ºC.

  3. Characterisation of cell-wall polysaccharides from mandarin segment membranes.

    Science.gov (United States)

    Coll-Almela, Luis; Saura-López, Domingo; Laencina-Sánchez, José; Schols, Henk A; Voragen, Alfons G J; Ros-García, José María

    2015-05-15

    In an attempt to develop a process of enzymatic peeling of mandarin segments suitable for use on an industrial scale, the cell wall fraction of the segment membrane of Satsuma mandarin fruits was extracted to obtain a chelating agent-soluble pectin fraction (ChSS), a dilute sodium hydroxide-soluble pectin fraction (DASS), a 1M sodium hydroxide-soluble hemicellulose fraction (1MASS), a 4M sodium hydroxide-soluble hemicellulose fraction (4MASS) and a cellulose-rich residue (3.1, 0.9, 0.4, 0.7 and 1.6%w/w of fresh membrane, respectively). The ChSS pectin consisted mainly of galacturonic acid followed by arabinose and galactose. The DASS fraction contained less galacturonic acid and more neutral sugars than ChSS. Eighty-nine percent of the galacturonic acid present in the segment membranes was recovered in the above two pectin fractions. The two hemicellulosic fractions consisted of two different molecular weight populations, which also differed in their sugar composition. Arabinose, xylose, mannose, galactose and glucose were the main sugar constituents of these hemicellulose fractions. In addition to an (arabino)xylan and a xyloglucan, the presence of an arabinogalactan is suggested by the sugar composition of both hemicelluloses. The pectin fractions were also characterised by their degradability by the pectic enzymes polygalacturonase, pectinmethylesterase and rhamnogalacturonan hydrolase. However the degree of degradation of the pectin fractions by enzymes differed, and the amount of the polymeric materials resistant to further degradation and the oligomeric products also differed. Using pectic enzymes it is possible to obtain peeled mandarin segments ready to eat or for canning. PMID:25577048

  4. Changes in cell wall architecture of wheat coleoptiles grown under continuous hypergravity conditions

    Science.gov (United States)

    Wakabayashi, K.; Soga, K.; Kamisaka, S.; Hoson, T.

    Modifications of cell wall structure of wheat coleoptiles in response to continuous hypergravity (300 g) treatment were investigated. Length of coleoptiles exposed to hypergravity for 2-4 days from germination stage was 60-70% of that of 1 g control. The net amounts of cell wall polysaccharides, such as hemicellulose and cellulose, of hypergravity-treated coleoptiles increased as much as those of 1 g control coleoptiles during the incubation period. As a result, the levels of cell wall polysaccharides per unit length of coleoptile, which mean the thickness of cell walls, largely increased under hypergravity conditions. Particularly, the amounts of hemicellulosic polymers with middle molecular mass (0.2-1 MDa) largely increased from day 2 to 3 under hypergravity conditions. The major sugar components of the hemicellulose fraction are arabinose, xylose and glucose. The ratios of arabinose and xylose to glucose were higher in hypergravity-treated coleoptiles than in control coleoptiles. The fractionation of hemicellulosic polymers into the neutral and acidic polymers by the anion-exchange column showed that the levels of acidic polymers (mainly composed of arabinoxylans) in cell walls of hypergravity-treated coleoptiles were higher than those of control coleoptiles. In addition to wall polysaccharides, the amounts of cell wall-bound phenolics, such as ferulic acid and diferulic acid, substantially increased during the incubation period both in 1 g control and hypergravity-treated coleoptiles. Especially, the levels of diferulic acid which cross-links hemicellulosic polymers were higher in hypergravity-treated coleoptiles than in control coleoptiles during the incubation period. These results suggest that hypergravity stimuli from the germination stage bias the type of synthesized hemicellulosic polysaccharides, although they do not restrict the net synthesis of cell wall constituents in wheat coleoptiles. The stimulation of the synthesis of arabinoxylans and of the

  5. Comparison of different pretreatment methods for separation hemicellulose from straw during the lignocellulosic bioethanol production

    Science.gov (United States)

    Eisenhuber, Katharina; Krennhuber, Klaus; Steinmüller, Viktoria; Kahr, Heike; Jäger, Alexander

    2013-04-01

    The combustion of fossil fuels is responsible for 73% of carbon dioxide emissions into the atmosphere and consequently contributes to global warming. This fact has enormously increased the interest in the development of methods to reduce greenhouse gases. Therefore, the focus is on the production of biofuels from lignocellulosic agricultural residues. The feedstocks used for 2nd generation bioethanol production are lignocellulosic raw materials like different straw types or energy crops like miscanthus sinensis or arundo donax. Lignocellulose consists of hemicellulose (xylose and arabinose), which is bonded to cellulose (glucose) and lignin. Prior to an enzymatic hydrolysis of the polysaccharides and fermentation of the resulting sugars, the lignocelluloses must be pretreated to make the sugar polymers accessible to enzymes. A variety of pretreatment methods are described in the literature: thermophysical, acid-based and alkaline methods.In this study, we examined and compared the most important pretreatment methods: Steam explosion versus acid and alkaline pretreatment. Specific attention was paid to the mass balance, the recovery of C 5 sugars and consumption of chemicals needed for pretreatment. In lab scale experiments, wheat straw was either directly pretreated by steam explosion or by two different protocols. The straw was either soaked in sulfuric acid or in sodium hydroxide solution at different concentrations. For both methods, wheat straw was pretreated at 100°C for 30 minutes. Afterwards, the remaining straw was separated by vacuum filtration from the liquid fraction.The pretreated straw was neutralized, dried and enzymatically hydrolyzed. Finally, the sugar concentrations (glucose, xylose and arabinose) from filtrate and from hydrolysate were determined by HPLC. The recovery of xylose from hemicellulose was about 50% using the sulfuric acid pretreatment and less than 2% using the sodium hydroxide pretreatment. Increasing concentrations of sulfuric acid

  6. 若干双子叶与单子叶植物细胞壁果胶结构单糖组成特征研究%Comparison of pectin structural monosaccharides in cell wall of dicotyledon and monocotyledon

    Institute of Scientific and Technical Information of China (English)

    程小乔; 李科; 陈雪梅; 蒋湘宁; 盖颖

    2012-01-01

    To study the angiosperm pectin monosaccharide components and content in primary cell wall as well as its relation with plants’ systematics between dicotyledon and monocotyledon,gas chromatograph-mass spectrometry ( GC / MS) was performed to detect the pectin monosaccharide components and content in 22 angiosperms and the data were analyzed by principal component analysis ( PCA ) ,Student’s test and Shannon-Weiner index analysis. Seven monosaccharides were found in angiosperm pectin including xylose,rhamnose,fucose,arabinose,galactose,glucose and mannose. The pectin was particularly rich in rhamnose,arabinose and galactose,but with little fucose and mannose. Five pectin monosaccharides were screened from 22 plants by PCA,and they were xylose,arabinose,rhamnose,galactose,and glucose respectively. Two-dimensional chart and Student’s test showed that the significantly different content of xylose or galactose in pectin could provide a reference for distinguishing class dicotyledon from class monocotyledon ( P 〈 0. 01 ) . The Shannon-Wiener index showed the more diversities of monosaccharide in dicotyledon than monocotyledon ( P 〈 0. 01) . Taken together,the different content of pectin monosaccharide could provide a reference for the angiosperms’ systematics between dicotyledon and monocotyledon.%为了系统研究被子植物初生壁果胶结构单糖的组成成分及其与被子植物两纲分类的关系,结合单糖单一环式的衍生化方法,采用GC/MS测定22种被子植物初生壁果胶中单糖组分及含量,并对测得的结果进行主成分、t检验和香农一威纳指数分析。结果表明:被子植物细胞壁果胶由木糖、鼠李糖、岩藻糖、阿拉伯糖、半乳糖、葡萄糖、甘露糖7种单糖组成,其中鼠李糖、阿拉伯糖和半乳糖含量较高;岩藻糖和甘露糖含量极少。主成分分析筛选出决定22种被子植物间糖含量差异的5种果胶单糖分别为:木糖、阿拉伯糖

  7. 鹿蹄草多糖LTC-Ⅱ分离纯化及结构性质研究%Studies on separation, purification and structure characteristics of a polysaccharide LTC-Ⅱ from Pyrola corbieri

    Institute of Scientific and Technical Information of China (English)

    莫正昌; 吴兰芳; 杨娟; 王道平

    2011-01-01

    Objective: To characterize the structure of polysaccharide LTC-Ⅱ obtained from Pyrola corbieri.Method: The polysaccharide was extracted from P.corbieri by hot water and ethanol precipitation.Crude polysaccharide was purified by DEAE-Cellulose chromatography and Sephacryl S-300 HR column chromatography.The purity and molecular weight of polysaccharide was determined by gel permeation chromatography.UV, IR, optical rotation, complete acid hydrolysis, periodate oxydation, Smith degradation, partial acid hydrolysis and methylation analysis were applied to determine the structural features.Result: A homogeneous fraction LTC-Ⅱ was obtained and its relative molecular mass was 22 000 Da.It consisted of arabinose, mannose, glucose, galactose in the molar ratio of 35.2∶1.0:13.4∶4.2.LTC-Ⅱ had a backbone consisting glucose, mannose, galactose and mainly contained (1→6)-linkaged glucose.The side chain possessed arabinose, glucose, galactose and mainly contained (1→5)-linkaged arabinose.The terminal sugar were mainly glucose and galactose.Conclusion: Studies on the preliminary characterization of polysaccharide LTC-Ⅱ from P.corbieri for the first time.%目的:研究鹿蹄草多糖LTC-Ⅱ的结构性质.方法:热水提取,乙醇沉淀制备鹿蹄草粗多糖,粗多糖经DEAE-纤维素和Sephacryl S-300 HR柱色谱分离纯化.采用高效凝胶渗透色谱法鉴定纯度并测定相对分子质量;紫外、红外、旋光、完全酸水解、高碘酸氧化及Smith降解、部分酸水解、甲基化分析对纯多糖组分进行结构性质研究.结果:得到一多糖纯组分LTC-Ⅱ,其相对分子质量为22 000 Da.单糖组成为阿拉伯糖、甘露糖、葡萄糖、半乳糖,其摩尔比为35.2:1.0:13.4:4.2,LTC-Ⅱ主链由甘露糖、葡萄糖和半乳糖组成,以(1→6)连接的葡萄糖为主,分支侧链由阿拉伯糖、葡萄糖和半乳糖组成,以(1→5)连接的阿拉伯糖为主,葡萄糖和半乳糖位于分子的末端.结论:首次对鹿蹄

  8. Comportamento fisiológico de sementes osmocondicionadas de Platymiscium pubescens Micheli (tamboril-da-mata

    Directory of Open Access Journals (Sweden)

    Borges Eduardo Euclydes de Lima e

    2002-01-01

    Full Text Available O objetivo deste trabalho foi investigar alterações fisiológicas e bioquímicas em sementes osmocondicionadas de tamboril-da-mata (Platymiscium pubescens Micheli. Foram analisados o crescimento do eixo embrionário, a germinação, as alterações na parede celular, a mobilização de carboidratos e proteínas e a atividade de a-galactosidase. Observou-se que o teor de umidade das sementes da testemunha aumentou continuamente até 96 horas de embebição, enquanto as mantidas nas soluções de PEG estabilizaram-se a partir de 48 horas. A germinação ocorreu somente nas sementes mantidas em água, alcançando 30% em 120 horas. As sementes mantidas em solução-0,4 MPa de PEG por 120 horas tiveram 66% de germinação quando transferidas para água, sendo a maior em relação aos demais potenciais. A massa fresca e o comprimento do embrião aumentaram significativamente durante o período de 120 horas em solução de PEG (-0,4 MPa/120 horas, porém a massa seca teve incremento não-significativo. Os teores de arabinose e xilose em membranas lavadas com água decresceram significativamente durante o osmocondicionamento. A galactose não foi detectada na membrana em 120 horas. A arabinose mostrou ser a principal constituinte da membrana. A atividade de a-galactosidase mostrou diferença significativa durante o período de 120 horas. Os teores de ramnose, arabinose e xilose alteraram-se significativamente na fração péctica, enquanto a ramnose foi a única na fração hemicelulósica. A glicose foi detectada somente nessa última fração. Os teores de glicose no embrião e cotilédones alteraram-se significativamente durante o osmocondicionamento. Os teores de estaquiose e de rafinose não tiveram alterações significativas nos cotilédones, enquanto o de sacarose reduziu-se significativamente, mantendo-se mais alto do que os dos outros dois oligossacarídeos. O teor de proteína decresceu significativamente nas 120 horas de

  9. Preferential uptake of ribose by primitive cells might explain why RNA was favored over its analogs

    Science.gov (United States)

    Pohorille, Andrew; Wei, Chenyu

    Permeation of molecules through membranes is a fundamental process in biological systems, which not only involves mass and signal transfers between the interior of a contemporary cell and its environment, but was also of crucial importance in the origin of life. In the absence of complex protein transporters, nutrients and building blocks of biopolymers must have been able to permeate membranes at sufficient rates to support primordial metabolism and cel-lular reproduction. From this perspective one class of solutes that is of special interest are monosaccharides, which serve not only as nutritional molecules but also as building blocks for information molecules. In particular, ribose is a part of the RNA backbone, but RNA analogs containing a number of other sugars have also been shown to form stable duplexes. Why, among these possibilities, ribose (and, subsequently, deoxyribose) was selected for the backbone of information polymers is still poorly understood. It was recently found that ribose permeates membranes an order of magnitude faster than its diastereomers, arabinose and xylose [1]. On this basis it was hypothesized that differences in membrane permeability to aldopentoses provide a mechanism for preferential delivery of ribose to primitive cells for subsequent, selective incorporation into nucleotides and their polymers. However, the origins of these unusually large differences had not been well understood. We addressed this issue in molecular dynamics simulations combined with free energy calculations. It was found that the free energy barrier for transferring ribose from water to the bilayer is lower by 1.5-2 kcal/mol than the barrier for transferring the other two aldopentoses. The calculated [2] and measured [1] permeability coefficients are in an excellent agreement. The sugar structures that permeate the membrane are -pyranoses, with a possible contribution of the -anomer for arabinose. The furanoid form of ribose is not substantially involved in

  10. Xylitol production from xylose mother liquor: a novel strategy that combines the use of recombinant Bacillus subtilis and Candida maltosa

    Science.gov (United States)

    2011-01-01

    Background Xylose mother liquor has high concentrations of xylose (35%-40%) as well as other sugars such as L-arabinose (10%-15%), galactose (8%-10%), glucose (8%-10%), and other minor sugars. Due to the complexity of this mother liquor, further isolation of xylose by simple method is not possible. In China, more than 50,000 metric tons of xylose mother liquor was produced in 2009, and the management of sugars like xylose that present in the low-cost liquor is a problem. Results We designed a novel strategy in which Bacillus subtilis and Candida maltosa were combined and used to convert xylose in this mother liquor to xylitol, a product of higher value. First, the xylose mother liquor was detoxified with the yeast C. maltosa to remove furfural and 5-hydromethylfurfural (HMF), which are inhibitors of B. subtilis growth. The glucose present in the mother liquor was also depleted by this yeast, which was an added advantage because glucose causes carbon catabolite repression in B. subtilis. This detoxification treatment resulted in an inhibitor-free mother liquor, and the C. maltosa cells could be reused as biocatalysts at a later stage to reduce xylose to xylitol. In the second step, a recombinant B. subtilis strain with a disrupted xylose isomerase gene was constructed. The detoxified xylose mother liquor was used as the medium for recombinant B. subtilis cultivation, and this led to L-arabinose depletion and xylose enrichment of the medium. In the third step, the xylose was further reduced to xylitol by C. maltosa cells, and crystallized xylitol was obtained from this yeast transformation medium. C. maltosa transformation of the xylose-enriched medium resulted in xylitol with 4.25 g L-1·h-1 volumetric productivity and 0.85 g xylitol/g xylose specific productivity. Conclusion In this study, we developed a biological method for the purification of xylose from xylose mother liquor and subsequent preparation of xylitol by C. maltosa-mediated biohydrogenation of xylose

  11. Alkalitalea saponilacus gen. nov., sp. nov., an obligately anaerobic, alkaliphilic, xylanolytic bacterium from a meromictic soda lake.

    Science.gov (United States)

    Zhao, Baisuo; Chen, Shulin

    2012-11-01

    A Gram-positive, obligately anaerobic, motile, slender, flexible rod, designated SC/BZ-SP2(T), was isolated from mixed alkaline water and sediment of Soap Lake, Washington State, USA. Strain SC/BZ-SP2(T) formed salmon to pink colonies and was alkaliphilic. The isolate grew at pH(35 °C) 7.5-10.5 (optimum pH(35 °C) 9.7), at 8-40 °C (optimum 35-37 °C) and with 0.35-1.38 M Na(+) (optimum 0.44-0.69 M Na(+)). The isolate utilized L-arabinose, D-ribose, D-xylose, D-fructose, D-mannose, D-galactose, cellobiose, maltose, sucrose, trehalose, sorbitol, xylan, malate and yeast extract as carbon and energy sources; best growth was observed with L-arabinose, cellobiose, maltose and trehalose. The major fermentation products from beechwood xylan were propionate and acetate. The dominant fatty acids were iso-C(15:0), anteiso-C(15:0), iso-C(17:0) 3-OH, C(17:0) 3-OH and C(15:0) 3-OH. The cell-wall sugars were ribose, xylose, galactose and glucose. Thiosulfate and sulfite could be reduced to sulfide. The genomic DNA G+C content was 39.5 ± 0.9 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain SC/BZ-SP2(T) belonged to the family Marinilabiliaceae of the order Bacteroidales, class Bacteroidia. The most closely related strains were Alkaliflexus imshenetskii Z-7010(T) (91.8% 16S rRNA gene sequence similarity), Marinilabilia salmonicolor Cy s1(T) (91.0%) and Anaerophaga thermohalophila Fru22(T) (90.4%). On the basis of phenotypic, chemotaxonomic and phylogenetic features, strain SC/BZ-SP2(T) represents a novel species in a new genus of the family Marinilabiliaceae, for which the name Alkalitalea saponilacus gen. nov., sp. nov. is proposed. The type strain of Alkalitalea saponilacus is SC/BZ-SP2(T) (=ATCC BAA-2172(T) =DSM 24412(T)). PMID:22199219

  12. Bacterial utilization of L-sugars and D-amino acids

    Science.gov (United States)

    Pikuta, Elena V.; Hoover, Richard B.; Klyce, Brig; Davies, Paul C. W.; Davies, Pauline

    2006-08-01

    The fact that organotrophic organisms on Earth use L-amino acids and D-sugars as an energy source is recognized as one of the universal features of life. The chirality of organic molecules with asymmetric location of group-radicals was described a relatively long time ago. Louis Pasteur observed that abiotic (chemical) processes produced mixtures with equal numbers (racemic) of the two forms but that living organisms possessed a molecular asymmetry that included only one of the enantiomers (homochirality). He speculated that the origin of the asymmetry of chiral biomolecules might hold the key to the nature of life. All of the amino acids in proteins (except for Glycine which is symmetrical) exhibit the same absolute steric configuration as L-glyceraldehyde. D-amino acids are never found in proteins, although they do exist in nature and are often found in polypeptide antibiotics. Constitutional sugars of cells, opposite to the amino acids, are the D-enantiomers, and the appearance of L-sugars in Nature is extremely rare. Notwithstanding this fact, the metabolism of some bacteria does have the capability to use amino acids and sugars with alternative chirality. This property may be caused by the function of specific enzymes belonging to the class of isomerases (racemases, epimerases, isomerases, tautomerases). In our laboratory, we have investigated several anaerobic bacterial strains, and have found that some of these bacteria are capable of using D-amino acids and L-sugars. Strain BK1 is capable of growth on D-arginine, but its growth characteristics on L-arginine are approximately twice as high. Another alkaliphilic strain SCA T (= ATCC BAA-1084 T = JCM 12857 T = DSM 17722 T = CIP 107910 T) was found to be capable of growth on L-ribose and L-arabinose. It is interesting that this strain was incapable of growth on D-arabinose, which suggests the involvement of some alternative mechanism of enzyme activity. In this paper, we describe the preliminary results of

  13. 离子液体1-烯丙基-3-甲基咪唑分离毛竹半纤维素研究%Isolation of hemicelluloses by 1-allyl-3-methyl imidazole ionic liquids from bamboo

    Institute of Scientific and Technical Information of China (English)

    林妲; 彭红; 阮榕生; 余紫苹; 刘玉环

    2012-01-01

    以毛竹为原料,通过1-烯丙基-3-甲基咪唑室温离子液体([Amim]Cl)直接分离半纤维素,并利用红外光谱检测、热动力学分析、中性糖成分检测、糖醛酸含量测定和一维核磁共振成像等分析手段证明氯化1-烯丙基-3-甲基咪唑离子液体可直接分离毛竹半纤维素.所得组分中不含有木质素杂质但混有少量纤维素和果胶质,毛竹半纤维素结构是以(1→4)-β-D-木聚糖为主链,以阿拉伯糖和4-O-甲基-α-D-葡糖醛酸为侧链的木聚糖,其中阿拉伯糖以C-3位与木聚糖主链相连,4-O-甲基-α-D-葡糖醛酸则以O-2位与木糖主链相连.%In this paper, hemicellulose was directly separated through the l-allyl-3-methyl imidazolium room temperature ionic liquid ( [Amim]Cl) from Moso bamboo. The structures of the hemicelluloses were elucidated by FTIR, thermal analysis,l3 CNMR spectroscopy, content of neutral sugars and uronic acids. The results show that the room temperature ionic liquid treatment are effective on the separation of hemicelluloses from bamboo, and the components mixed with a small amount of pectin but not contain lignin and cellulose. The hemicellulosic fraction has a backbone of ( 1→4)-β-D-xylan and aere branched mainly through arabinose and 4-0-methyl-a-D-glucuronic acid,which arabinose at C-3 position of main chain and 4-0-methyl-a-Z)-glucuronic acid at 0-2 position.

  14. Effect of superfine comminution on reducing sugar components in corn stalk enzymatic hydrolysate%超微粉碎预处理对玉米秸杆酶解液中还原糖组分的影响

    Institute of Scientific and Technical Information of China (English)

    赵晓燕; 朱海涛; 张桂香; 张立金; 何磊

    2015-01-01

    The compositions of five different monosaccharides in corn stalk enzymatic hydrolysate were an-alyzed by HPLC.They were arabinose,mannose,galactose,glucose and fructose,in which glucose and fructose were the main compositions.The results showed that the reducing sugar composition contents in corn stalk powder with a particle >1 200 mesh was higher than that with a particle size 100 ~200 mesh. The content of arabinose,galactose,glucose,mannose and fructose in enzymatic hydrolysate with particle size of >1 200 mesh increased 48.38%、64.29%、37.63%、70.07% and 22.34%,respectively.In addition,three new unknown response peaks occurred in the chromatograms,which might be fucose,su-crose and cellobiose.%HPLC 分析了玉米秸杆微粉酶解液中5种单糖组成,主要包括阿拉伯糖、甘露糖、半乳糖、葡萄糖、果糖,其中以葡糖糖与果糖为主。结果表明:粒径大于1200目的玉米秸杆粉酶解液还原糖单糖组分与100~200目的相比,其含量明显高,阿拉伯糖、半乳糖、葡萄糖、甘露糖和果糖分别提高了48.38%、64.29%、37.63%、70.07%和22.34%。此外,在超微细秸杆粉的酶解液 HPLC 色谱图上出现三个新的未知响应峰,推测可能为岩藻糖、庶糖与纤维二糖。

  15. Structure and Dynamics of Brachypodium Primary Cell Wall Polysaccharides from Two-Dimensional 13C Solid-State Nuclear Magnetic Resonance Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Tuo [Ames Lab., Ames, IA (United States); Salazar, Andre [Iowa State Univ., Ames, IA (United States); Zabotina, Olga A. [Iowa State Univ., Ames, IA (United States); Hong, Mei [Ames Lab., Ames, IA (United States)

    2014-04-10

    The polysaccharide structure and dynamics in the primary cell wall of the model grass Brachypodium distachyon are investigated for the first time using solid-state nuclear magnetic resonance (NMR). While both grass and non-grass cell walls contain cellulose as the main structural scaffold, the former contains xylan with arabinose and glucuronic acid substitutions as the main hemicellulose, with a small amount of xyloglucan (XyG) and pectins, while the latter contains XyG as the main hemicellulose and significant amounts of pectins. We labeled the Brachypodium cell wall with 13C to allow two-dimensional (2D) 13C correlation NMR experiments under magic-angle spinning. Well-resolved 2D spectra are obtained in which the 13C signals of cellulose, glucuronoarabinoxylan (GAX), and other matrix polysaccharides can be assigned. The assigned 13C chemical shifts indicate that there are a large number of arabinose and xylose linkages in the wall, and GAX is significantly branched at the developmental stage of 2 weeks. 2D 13C–13C correlation spectra measured with long spin diffusion mixing times indicate that the branched GAX approaches cellulose microfibrils on the nanometer scale, contrary to the conventional model in which only unbranched GAX can bind cellulose. The GAX chains are highly dynamic, with average order parameters of 0.4. Biexponential 13C T1 and 1H T relaxation indicates that there are two dynamically distinct domains in GAX: the more rigid domain may be responsible for cross-linking cellulose microfibrils, while the more mobile domain may fill the interfibrillar space. This dynamic heterogeneity is more pronounced than that of the non-grass hemicellulose, XyG, suggesting that GAX adopts the mixed characteristics of XyG and pectins. Moderate differences in cellulose rigidity are observed between the Brachypodium and Arabidopsis cell walls

  16. Xylitol production from xylose mother liquor: a novel strategy that combines the use of recombinant Bacillus subtilis and Candida maltosa

    Directory of Open Access Journals (Sweden)

    Jiang Mingguo

    2011-02-01

    Full Text Available Abstract Background Xylose mother liquor has high concentrations of xylose (35%-40% as well as other sugars such as L-arabinose (10%-15%, galactose (8%-10%, glucose (8%-10%, and other minor sugars. Due to the complexity of this mother liquor, further isolation of xylose by simple method is not possible. In China, more than 50,000 metric tons of xylose mother liquor was produced in 2009, and the management of sugars like xylose that present in the low-cost liquor is a problem. Results We designed a novel strategy in which Bacillus subtilis and Candida maltosa were combined and used to convert xylose in this mother liquor to xylitol, a product of higher value. First, the xylose mother liquor was detoxified with the yeast C. maltosa to remove furfural and 5-hydromethylfurfural (HMF, which are inhibitors of B. subtilis growth. The glucose present in the mother liquor was also depleted by this yeast, which was an added advantage because glucose causes carbon catabolite repression in B. subtilis. This detoxification treatment resulted in an inhibitor-free mother liquor, and the C. maltosa cells could be reused as biocatalysts at a later stage to reduce xylose to xylitol. In the second step, a recombinant B. subtilis strain with a disrupted xylose isomerase gene was constructed. The detoxified xylose mother liquor was used as the medium for recombinant B. subtilis cultivation, and this led to L-arabinose depletion and xylose enrichment of the medium. In the third step, the xylose was further reduced to xylitol by C. maltosa cells, and crystallized xylitol was obtained from this yeast transformation medium. C. maltosa transformation of the xylose-enriched medium resulted in xylitol with 4.25 g L-1·h-1 volumetric productivity and 0.85 g xylitol/g xylose specific productivity. Conclusion In this study, we developed a biological method for the purification of xylose from xylose mother liquor and subsequent preparation of xylitol by C. maltosa

  17. Biopolímero produzido a partir da cana-de-áçucar para cicatrização cutânea Sugar cane biopolymer in cutaneous healing

    Directory of Open Access Journals (Sweden)

    Maria Cristina de Oliveira Cardoso Coelho

    2002-01-01

    Full Text Available Um polissacarídeo extracelular foi produzido por via microbiológica, através da bactéria ZSP isolada no Laboratório de Microbiologia Industrial da Estação Experimental de Cana-de-Açúcar do Carpina/UFRPE, apresentando excepcional capacidade de processo. Os principais monossacarídeos presentes na fração solúvel foram glicose (87,6%, xilose (8,6%, manose (0,8%, ribose (1,7%, galactose (0,1%, arabinose (0,4% e o ácido glucurônico (0,8%. Devido ao alto índice de traumatismos que acomete os animais domésticos e a busca por alternativas simples, econômicas e capazes de proporcionar condições ideais para cicatrização, foram realizados os testes com o biopolímero produzido a partir da cana-de-açúcar em animais portadores de feridas cutâneas, a fim de avaliar a reepitelização. Observou-se o aumento do tecido de granulação, controle da infecção e diminuição do tempo de cicatrização, permitindo concluir que o biopolímero contribui para o processo cicatricial, podendo ser utilizado em feridas cutâneas.An extracelular polysaccharide was produced through microbiology, using the ZSP bacteria isolated in the Industrial Microbiological Laboratory of the Sugar cane Experimental Station at Carpina/UFRPE, Pernambuco, Brazil, presenting exceptional process capacity. The principal monosaccharides present in the ¹soluble fraction were glucose (87.6%, xylose (8.6%, mannose (0.8%, ribose (1.7%, galactose (0.1%, arabinose (0.4% and the glucuronic acid (0.8%. Due to the high rate of injuries that occur with domestic animals and the search for simple, economical alternatives that would be capable of giving ideal conditions for the healing process, extensive testing was done with the biopolymer produced by sugar cane in animals that had cutaneous wounds, so as to evaluate the reepitelization process. It was observed from the testing results that there was better skin granulation, better infection control, and less healing time, which

  18. Optimization of fermentation conditions to remove glucose in xylose mother liquid by saccharomyces cerevisiae%酿酒酵母脱除木糖母液葡萄糖发酵条件优化

    Institute of Scientific and Technical Information of China (English)

    崔淑芬; 黄伟红; 孙鲁; 杜瑞锋; 曹玉华

    2012-01-01

    木糖母液是木糖结晶后的副产物,主要成分为木糖,还有葡萄糖、阿拉伯糖及半乳糖等多种杂糖.采用酿酒酵母发酵法可以去除木糖母液中的葡萄糖,提高其中木糖及阿拉伯糖的纯度,以便进行后续分离,提高木糖母液的利用率.本研究的主要工艺路线:采用酿酒活性干酵母为种子,按照0.3%的接种量接种至扩繁培养基中,在温度为30℃、转速为150rpm的条件下,恒温振荡培养15~18h,然后,用离心机将菌体从培养液中分离,将菌泥转移至稀释到18%浓度的木糖母液中进行发酵,去除葡萄糖.发酵温度为34℃、振荡转速为200rpm、发酵时间为8h,葡萄糖浓度降至0.2%以下.去除葡萄糖后的木糖母液,经过高效液相色谱检测,得知发酵脱糖前后木糖母液中除葡萄糖以外的其他成分及其含量基本不变.%Xylose mother liquid is a kind of by - product of xylose crystallization. Hie main constituent is xylose, and other impurities, such as glucose, arabinose and galactose. Saccharomyces cerevisiae can remove glucose in xylose mother liquid to increase the purity of xylose and arabinose, and better utilized the xylose mother liquid. The main parameters are; saccharomyces cerevisiae as start cultur, 0.3% inoculation concemtrion, 3CC , 150rpm, 15 - 18 hours. Separated by centrifuge, the yeast cells transferred to 18% concentration of xylose mother liquid at 341, 200rpm, fermented for 8 hours. The glucose concentration was decrease below 0. 2%. Chromatographic detection verified that glucose was removed and other compositions stayed unchanged.

  19. ANALYSIS OF MONOSACCHARIDE COMPOSITION IN CRYSTALLIZATION SOLUTION OF XYLOSE BY PRECOLUMN DERIVATIZATION-HPLC%柱前衍生化-高效液相色谱法分析木糖结晶母液的单糖组成

    Institute of Scientific and Technical Information of China (English)

    孟海波; 高绍丰; 张海燕; 孟汉卿

    2011-01-01

    The reversed - phase high performance liquid chromatographic ( HPLC) method of pre-column - derivatization with l-phenyl-3-methyl-5-pyrazolone (PMP) was developed to separate the traditional eight monosaccharides and detect the monosac-charide composition of crystallization solution of xylose. The results showed that crystallization solution of xylose consisted of mannose, rharanose, cellobiose, glucose, galactose, xylose, arabinose, fucose, and the dominant component monosaccharides were glucose, ga-lactose, xylose and arabinose. Peak height was used to quantify. The concentration of eight kinds of monosaccharide was liner with correspond peak area with correlation coefficients (r2) of 0.9897 -0.9994. The detection limit was 0.002 1 -0.003 1 mg/mL. The recovery was 98.4% - 101.0% , and relative standard deviation of detection results was 0.66% -0.21 % (n = 6). The HPLC method is simple, rapid, sensitive, convenient and can be applied to the quality control of crytallization solution of xylose.%采用1-苯基-甲基-吡唑啉酮(PMP)柱前衍生化-反相高效液相色谱(HPLC)法建立了8种常见单糖的分离模式,并用于木糖结晶母液单糖组成的定量分析.结果表明:木糖结晶母液至少由甘露糖、鼠李糖、纤维二糖、葡萄糖、半乳糖、木糖、阿拉伯糖及岩藻糖8种单糖组成,其中以葡萄糖、半乳糖、木糖和阿拉伯糖为主.以峰高定量,8种单糖的浓度与相应的峰高呈良好的线性关系,相关系数r2在0.9897 -0.9994范围内,方法检出限为0.0021-0.0031 mg/mL,回收率为98.4% -101.0%,测定结果的相对标准偏差为0.66%-1.21%(n=6).该方法简单、快速、灵敏,可用于木糖结晶母液的质量控制.

  20. Oxygen isotope ratios (18O/16O) of hemicellulose-derived sugar biomarkers in plants, soils and sediments as paleoclimate proxy II: Insight from a climate transect study

    Science.gov (United States)

    Tuthorn, Mario; Zech, Michael; Ruppenthal, Marc; Oelmann, Yvonne; Kahmen, Ansgar; Valle, Héctor Francisco del; Wilcke, Wolfgang; Glaser, Bruno

    2014-02-01

    The oxygen isotopic composition of precipitation (δ18Oprec) is well known to be a valuable (paleo-)climate proxy. Paleosols and sediments and hemicelluloses therein have the potential to serve as archives recording the isotopic composition of paleoprecipitation. In a companion paper (Zech et al., 2014) we investigated δ18Ohemicellulose values of plants grown under different climatic conditions in a climate chamber experiment. Here we present results of compound-specific δ18O analyses of arabinose, fucose and xylose extracted from modern topsoils (n = 56) along a large humid-arid climate transect in Argentina in order to answer the question whether hemicellulose biomarkers in soils reflect δ18Oprec. The results from the field replications indicate that the homogeneity of topsoils with regard to δ18Ohemicellulose is very high for most of the 20 sampling sites. Standard deviations for the field replications are 1.5‰, 2.2‰ and 1.7‰, for arabinose, fucose and xylose, respectively. Furthermore, all three hemicellulose biomarkers reveal systematic and similar trends along the climate gradient. However, the δ18Ohemicellulose values (mean of the three sugars) do not correlate positively with δ18Oprec (r = -0.54, p fucose and xylose do not simply reflect δ18Oprec but rather δ18Oleaf water. The correlation between measured δ18Ohemicellulose and modeled δ18Oleaf water is highly significant (r = 0.81, p < 0.001, n = 20). This finding can be attributed to the evaporative 18O enrichment of leaf water during transpiration. Model sensitivity tests using a Péclet-modified Craig-Gordon (PMCG) model corroborate that relative air humidity is a very rigorous climate parameter influencing δ18Oleaf water, whereas temperature is of minor importance. While oxygen exchange and degradation effects on δ18O values of hemicelluloses sugar biomarkers seem to be negligible (Zech et al., 2012), further effects that need to be considered when interpreting δ18Ohemicellulose

  1. Effects of Marsdenia tenacissima polysaccharide on the immune regulation and tumor growth in H22 tumor-bearing mice.

    Science.gov (United States)

    Jiang, Shuang; Qiu, Limin; Li, Yiquan; Li, Lu; Wang, Xingyun; Liu, Zhi; Guo, Yan; Wang, Haotian

    2016-02-10

    One water-soluble polysaccharide (Marsdenia tenacissima polysaccharide, MTP), with an average molecular weight of 4.9 × 10(4) Da, was isolated from the dried rattan of M. tenacissima. MTP contained 93.8% carbohydrates, 5.6% proteins and 21.3% uronic acid, and were composed of arabinose, mannose, galactose, xylose, glucuronic acid at a molar ratio of 9.1, 17.7, 30.2, 22.4 and 20.6. The experiments on the animals showed that MTP could increase the serum hemolysin, promote the formation of antibody-forming cells and improve the phagocytosis of mononuclear macrophage in normal mice. Meanwhile, MTP could also inhibit the growth of tumor in H22 tumor-bearing mice dose-dependently, and increase the spleen index, thymus index and serum albumin level in the mice. In addition, MTP could elevate the serum level of TNF-α and IL-2, increase the activity of GSH-Px, CAT and SOD in the liver tissue, and reduce the content of VEGF and MDA. These results suggest that MTP can regulate the immune function in mice and suppress the growth of tumor in H22 tumor-bearing mice, and its antitumor activity may be related to its antioxidant and immunomodulatory effects. PMID:26686104

  2. Characterization and immunoenhancement activities of Eucommia ulmoides polysaccharides.

    Science.gov (United States)

    Feng, Haibo; Fan, Jing; Song, Zhenhui; Du, Xiaogang; Chen, Ying; Wang, Jishuang; Song, Guodong

    2016-01-20

    The aim of this study is to investigate the physicochemical properties, monosaccharide composition and immunomodulatory effects of Eucommia ulmoides Oliv. polysaccharide. The average molecular weight (Mw) of EUPS was 11.4632 × 10(5)Da. The monosaccharide components of EUPS were glucose, fructose, mannose, fucose, galactose and arabinose with a relative mass of 36.6%, 16.6%, 14.2%, 15.7%, 9.5% and 7.4%, respectively. In in vitro experiments, EUPS (1.2-75 μg/mL) treatment of dendritic cells (DC) increased their surface expression of MHC I/II, CD80, CD40, and CD86 and indicated that EUPS induced DC maturation. Furthermore, EUPS also significantly enhanced lymphocyte proliferation and significantly enhanced cytokine (IL-4 and IFN-γ) production. In in vivo experiments, our data showed that EUPS could significantly enhance the FMDV-specific IgG, IgG1, IgG2a, and IgG2b antibody titers and T cell proliferation. Together, these results suggest that EUPS is a strong immunostimulant. PMID:26572415

  3. Structural and immunological feature of rhamnogalacturonan I-rich polysaccharide from Korean persimmon vinegar.

    Science.gov (United States)

    Kim, Hoon; Hong, Hee-Do; Suh, Hyung-Joo; Shin, Kwang-Soon

    2016-08-01

    The crude polysaccharide (KPV-0) isolated from Korean persimmon vinegar was fractionated using gel filtration chromatography to enhance the immunostimulatory activity and to identify the structural features of active fraction. Among three fractions, KPV-I obtained in a void volume, demonstrated the potent production of macrophage-stimulating mediators, including tumor necrosis factor-α, interleukin (IL)-6, IL-12, and nitric oxide. KPV-I showed a combined single peak with high molecular weight of 55,000Da by high performance size exclusion chromatography. Component sugar analysis revealed that KPV-I contained mainly of arabinose, mannose, galactose, rhamnose and galacturonic acid. Single radial gel diffusion assay using β-glucosyl Yariv reagent showed that KPV-I contained arabinogalactan protein with 13.7%. Methylation analysis indicated that KPV-I contained 21 kinds of neutral glycosidic linkages, which seemed to be composed three kinds of polysaccharide; that is a rhamnogalacturonan-I (65-70%) derived from persimmon as a raw material, a mannan (20-25%) derived from fermentation-associated microorganisms, and a linear glucans (less than 10%). In conclusion, polysaccharide isolated from persimmon vinegar could augment the macrophage stimulation, and a large amounts of RG-I polysaccharide derived from persimmon is likely a crucial role in expression of the activity in persimmon vinegar. PMID:27131731

  4. In Vitro Antioxidant, Anticoagulant and Antimicrobial Activity and in Inhibition of Cancer Cell Proliferation by Xylan Extracted from Corn Cobs

    Directory of Open Access Journals (Sweden)

    Hugo Alexandre Oliveira Rocha

    2011-12-01

    Full Text Available Xylan is one of most abundant polymer after cellulose. However, its potential has yet to be completely recognized. Corn cobs contain a considerable reservoir of xylan. The aim of this work was to study some of the biological activities of xylan obtained from corn cobs after alkaline extraction enhanced by ultrasonication. Physical chemistry and infrared analyses showed 130 kDa heteroxylan containing mainly xylose:arabinose: galactose:glucose (5.0:1.5:2.0:1.2. Xylan obtained exhibited total antioxidant activity corresponding to 48.5 mg of ascorbic acid equivalent/g of xylan. Furthermore, xylan displayed high ferric chelating activity (70% at 2 mg/mL. Xylan also showed anticoagulant activity in aPTT test. In antimicrobial assay, the polysaccharide significantly inhibited bacterial growth of Klebsiella pneumoniae. In a test with normal and tumor human cells, after 72 h, only HeLa tumor cell proliferation was inhibited (p < 0.05 in a dose-dependent manner by xylan, reaching saturation at around 2 mg/mL, whereas 3T3 normal cell proliferation was not affected. The results suggest that it has potential clinical applications as antioxidant, anticoagulant, antimicrobial and antiproliferative compounds.

  5. 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

  6. Breaking down the wall: fractionation of mycobacteria.

    Science.gov (United States)

    Rezwan, Mandana; Lanéelle, Marie-Antoinette; Sander, Peter; Daffé, Mamadou

    2007-01-01

    Mycobacterium spp. possess a complex cell envelope that consists of a plasma membrane, a peptidoglycan-arabinogalactan complex which in turn is esterified by mycolic acids that form with other non-bound lipids an asymmetric permeability barrier and an outer layer, also called a capsule in the case of pathogenic species. In order to investigate the functional roles of the cell envelope components, especially those of the major pathogens Mycobacterium tuberculosis and Mycobacterium leprae, it is necessary to fractionate the envelope by breaking the unusual wall that covers these bacteria. To this aim we first compared the efficiency of high pressure (cell disrupter/French press) with those of pathogen-compatible breakage methods such as sonication, bead beater and lysozyme treatment using the non-pathogenic Mycobacterium smegmatis. When the distribution of various specific markers of the cell envelope compartments, which include mycolic acids, arabinose, NADH oxidase activity, cell wall and cytosolic proteins, were determined sonication combined with lysozyme treatment was found to be the best option. The protocol of subcellular fractionation was then validated for pathogenic species by applying the method to Mycobacterium bovis BCG cells, an attenuated strain of the M. tuberculosis complex. PMID:16839634

  7. Biosorption and degradation of decabromodiphenyl ether by Brevibacillus brevis and the influence of decabromodiphenyl ether on cellular metabolic responses.

    Science.gov (United States)

    Wang, Linlin; Tang, Litao; Wang, Ran; Wang, Xiaoya; Ye, Jinshao; Long, Yan

    2016-03-01

    There is global concern about the effects of decabromodiphenyl ether (BDE209) on environmental and public health. The molecular properties, biosorption, degradation, accumulation, and cellular metabolic effects of BDE209 were investigated in this study to identify the mechanisms involved in the aerobic biodegradation of BDE209. BDE209 is initially absorbed by wall teichoic acid and N-acetylglucosamine side chains in peptidoglycan, and then, BDE209 is transported and debrominated through three pathways, giving tri-, hepta-, octa-, and nona-bromodiphenyl ethers. The C-C bond energies decrease as the number of bromine atoms on the diphenyl decreases. Polybrominated diphenyl ethers (PBDEs) inhibit protein expression or accelerate protein degradation and increase membrane permeability and the release of Cl(-), Na(+), NH4 (+), arabinose, proteins, acetic acid, and oxalic acid. However, PBDEs increase the amounts of K(+), Mg(2+), PO4 (3-), SO4 (2-), and NO3 (-) assimilated. The biosorption, degradation, accumulation, and removal efficiencies when Brevibacillus brevis (1 g L(-1)) was exposed to BDE209 (0.5 mg L(-1)) for 7 days were 7.4, 69.5, 16.3, and 94.6 %, respectively. PMID:26555880

  8. Structures and anti-HSV-2 activities of neutral polysaccharides from an edible plant, Basella rubra L.

    Science.gov (United States)

    Dong, Cai-Xia; Hayashi, Kyoko; Mizukoshi, Yusuke; Lee, Jung-Bum; Hayashi, Toshimitsu

    2012-01-01

    Four neutral polysaccharides (BRN-1, BRN-2, BRN-3 and BRN-4) were isolated from the hot water extract of the aerial part of Basella rubra L. They were found to consist of a large amount of D-galactose (81.0-92.4%) and small amounts of L-arabinose (5.4-7.8%), D-glucose (2.2-11.0%) and mannose (~2.9%). Linkage analysis revealed that all these neutral polysaccharides might be arabinogalactan type I polysaccharides in different molecular weight and chain length. Among them, only BRN-3 showed antiviral activity against herpes simplex virus type 2 (HSV-2) with 50% inhibitory concentration of 55 μg/mL without showing the cytotoxicity up to 2300 μg/mL. Furthermore, the main antiviral target of BRN-3 was shown to be the inhibition of virus adsorption to host cells. This is the first report on the neutral polysaccharide with anti-HSV-2 activity obtained from B. rubra L. PMID:22085753

  9. Optimization, characterization, and biological activity of polysaccharides from Berberis dasystachya Maxim.

    Science.gov (United States)

    Han, Lijuan; Suo, Yourui; Yang, Yongjing; Meng, Jing; Hu, Na

    2016-04-01

    In this study, the extraction of water-soluble polysaccharides (BDPs) from Berberis dasystachya Maxim using dynamic microwave-assisted extraction (DMAE) was discussed. A Box-Behnken design combined with response surface methodology has been employed to optimize extraction parameters of DMAE. The BDPs have been analyzed in order to identify a variety of chemical properties. Antioxidant and anti-tumor activities in vitro have been studied by DPPH, ABTS, reducing power assay, and MTT assay, respectively. The results obtained showed that the optimal extraction conditions were as follows: ratio of water to raw material (X1) 25.84mg/L, extraction power (X2) 433.13W, extraction time (X3) 35.18min, and the maximum yield of extraction was 6.472±0.384%, which was in good agreement with the predicted value. The physicochemical tests demonstrated that the BDPs mainly consist of rhamnose, arabinose, xylose, mannose, glucose and lactose in a molar ratio of 1:17.3:1.33:7:2.33:1.78; the average molecular weight of the BDPs was estimated to be from 2.95×10(5) and 1.52×10(3)Da, respectively. Furthermore, the BDPs exhibited effective antioxidant and anti-proliferative properties in vitro. Such pharmaceutical activities could prove useful for potential future applications involving the berries of B. dasystachya Maxim. PMID:26484601

  10. Effective pretreatment of sugarcane bagasse with combination pretreatment and its hydrolyzates as reaction media for the biosynthesis of ethyl (S)-4-chloro-3-hydroxybutanoate by whole cells of E. coli CCZU-K14.

    Science.gov (United States)

    He, Yu-Cai; Zhang, Dan-Ping; Di, Jun-Hua; Wu, Yin-Qi; Tao, Zhi-Cheng; Liu, Feng; Zhang, Zhi-Jun; Chong, Gang-Gang; Ding, Yun; Ma, Cui-Luan

    2016-07-01

    In this study, sugarcane bagasse (SB) was pretreated with combination pretreatment (e.g., sequential KOH extraction and ionic liquid soaking, sequential KOH extraction and Fenton soaking, or sequential KOH extraction and glycerol soaking). After the enzymatic hydrolysis of pretreated SBs, it was found that all these three concentrated hydrolyzates could be used for the asymmetric bioreduction of ethyl 4-chloro-3-oxobutanoate (COBE) into ethyl (S)-4-chloro-3-hydroxybutanoate [(S)-CHBE]. Compared with glucose, arabinose and cellobiose couldn't promote the initial reaction rate, and xylose could increase the intracellular NADH content. Moreover, it was the first report that hydrolyzates could be used for the effective biosynthesis of (S)-CHBE (∼500g/L; 98.0% yield) from 3000 COBE by whole cells of Escherichia coli CCZU-K14 in the presence of β-CD (0.4mol β-CD/mol COBE), l-glutamine (200mM) and glycine (500mM). In conclusion, it is a new alternative to utilize bioresource for the synthesis of key chiral intermediate (S)-CHBE. PMID:27060248

  11. Isolation and characterization of novel bacteria containing acc deaminase from the rhizosphere resource on dry-farming lands

    International Nuclear Information System (INIS)

    Soil-microbe-plant interactions are known to be intricate and they can greatly influence the crop vigor and yield. Plant growth promoting rhizobacteria (PGPR) containing ACC deaminase can markedly affect plant metabolic processes under stress conditions. In the present study, we isolated 300 bacterial strains from the rhizosphere of maize or apple grown in drought-hit soil including four different locations of the Loess Plateau, China. Of all isolated strains, four with ACC deaminase activity (ranging from 28.88 to 155.12 nmol alpha-ketobutyrate mg-1 h-1) were further studied by determining their biological characters and sequencing the 16S rRNA gene. All four strains showed positive performance in terms of arabinose, citrate utilization, urease, indol, glucose and melibiose. In connection with the results of biochemical characters and phylogenetic analysis, these strains commonly belong to three different genera: Klebsiella, Pseudomonas and Raoultella and four different species: Klebsiella oxytoca, Klebsiella variicola, Pseudomonas fluorescens and Raoultella planticola. Although some researchers have reported their performance under stress conditions, we are the first to report Klebsiella oxytoca, Klebsiella variicola and Raoultella planticola containing ACC deaminase under drought stress. These findings are a reasonable explanation to their superb ability of causing stress-resistance in maize (Zea mays) or apple (Malus domestica) plants. The presence of diverse PGPR possessing potential ACC deaminase activity may be beneficial for enhancing crop production under different stress conditions. (author)

  12. Hoyosella altamirensis gen. nov., sp. nov., a new member of the order Actinomycetales isolated from a cave biofilm.

    Science.gov (United States)

    Jurado, Valme; Kroppenstedt, Reiner M; Saiz-Jimenez, Cesáreo; Klenk, Hans-Peter; Mouniée, Delphine; Laiz, Leonila; Couble, Andrée; Pötter, Gabriele; Boiron, Patrick; Rodríguez-Nava, Verónica

    2009-12-01

    A novel actinomycete, strain OFN S31(T), was isolated from a complex biofilm in the Altamira Cave, Spain. A polyphasic study was carried out to clarify the taxonomic position of this strain. Phylogenetic analysis with 16S rRNA gene sequences of representatives of the genera Corynebacterium, Dietzia, Gordonia, Millisia, Mycobacterium, Nocardia, Rhodococcus, Segniliparus, Skermania, Tsukamurella and Williamsia indicated that strain OFN S31(T) formed a distinct taxon in the 16S rRNA gene tree that was more closely associated with the Mycobacterium clade. The type strain of Mycobacterium fallax was the closest relative of strain OFN S31(T) (95.6 % similarity). The cell wall contained meso-diaminopimelic acid, arabinose and galactose, which are characteristic components of cell-wall chemotype IV of actinomycetes. The sugars of the peptidoglycan were acetylated. The polar lipid pattern was composed of phosphatidylinositol, phosphatidylglycerol, phosphatidylethanolamine and diphosphatidylglycerol. Strain OFN S31(T) is characterized by the absence of mycelium and mycolic acids. Strain OFN S31(T) had MK-8 as the major menaquinone. The DNA G+C content was 49.3 mol%, the lowest found among all taxa included in the suborder Corynebacterineae. Based on morphological, chemotaxonomic, phenotypic and genetic characteristics, strain OFN S31(T) is considered to represent a novel species of a new genus, for which the name Hoyosella altamirensis gen. nov., sp. nov. is proposed. The type strain of Hoyosella altamirensis is strain OFN S31(T) (=CIP 109864(T) =DSM 45258(T)). PMID:19643882

  13. Anomer-Specific Recognition and Dynamics in a Fucose-Binding Lectin.

    Science.gov (United States)

    Antonik, Paweł M; Volkov, Alexander N; Broder, Ursula N; Re, Daniele Lo; van Nuland, Nico A J; Crowley, Peter B

    2016-03-01

    Sugar binding by a cell surface ∼29 kDa lectin (RSL) from the bacterium Ralstonia solanacearum was characterized by NMR spectroscopy. The complexes formed with four monosaccharides and four fucosides were studied. Complete resonance assignments and backbone dynamics were determined for RSL in the sugar-free form and when bound to l-fucose or d-mannose. RSL was found to interact with both the α- and the β-anomer of l-fucose and the "fucose like" sugars d-arabinose and l-galactose. Peak splitting was observed for some resonances of the binding site residues. The assignment of the split signals to the α- or β-anomer was confirmed by comparison with the spectra of RSL bound to methyl-α-l-fucoside or methyl-β-l-fucoside. The backbone dynamics of RSL were sensitive to the presence of ligand, with the protein adopting a more compact structure upon binding to l-fucose. Taking advantage of tryptophan residues in the binding sites, we show that the indole resonance is an excellent reporter on ligand binding. Each sugar resulted in a distinct signature of chemical shift perturbations, suggesting that tryptophan signals are a sufficient probe of sugar binding. PMID:26845253

  14. Structural Characterization and Biological Activities of Polysaccharides from Olive Mill Wastewater.

    Science.gov (United States)

    Nadour, Malika; Laroche, Celine; Pierre, Guillaume; Delattre, Cedric; Moulti-Mati, Farida; Michaud, Philippe

    2015-09-01

    Olive mill wastewater (OMWW), the main waste product of olive oil extraction process, was investigated as a source of polysaccharides. The yield of alcohol insoluble residue (AIR) was 20.5 % based on the dry matter of OMWW. Extraction with water gave water soluble (WSF) and insoluble (WIF) fractions from AIR with yields of 13.3 % (w/w) and 3.7 % (w/w) based on the dry matter, respectively. Chemical composition and monosaccharide analysis indicated that glucose was the main monosaccharide of these extracts in addition to galactose, arabinose, rhamnose, and galacturonic acid. Prebiotic and antioxidant activities of polysaccharidic fractions from OMWW were evaluated. Results gave evidence for their scavenging capacity toward the 2,2'-diphenyl-1-picrylhydrazyle (DPPH) (IC50 value of 89.43 μg/mL) and hydroxyl radicals (IC50 value of 158.70 μg/mL), resistance toward artificial human gastric juice, and ability to be fermented by Lactobacilli strains. PMID:26189104

  15. First total synthesis of (+)-broussonetine W: glycosidase inhibition of natural product & analogs.

    Science.gov (United States)

    Song, Ying-Ying; Kinami, Kyoko; Kato, Atsushi; Jia, Yue-Mei; Li, Yi-Xian; Fleet, George W J; Yu, Chu-Yi

    2016-06-14

    The first total synthesis of (+)-broussonetine W (4), a naturally-occurring pyrrolidine iminosugar isolated from the traditional Chinese medical plant Broussonetia kazinoki SIEB (Moraceae), has been completed through a concise synthetic route starting from the readily available d-arabinose derived cyclic nitrone 10 in 11 steps and 31% overall yield, with regioselective installation of the α,β-unsaturated ketone functional group by the elimination of HBr from α-bromoketone as the key step. A number of analogs of (+)-broussonetine W (4) with variable side chain length, different polyhydroxylated pyrrolidine core configurations or saturated cyclohexanones have also been prepared to explore the glycosidase inhibition and the preliminary structure-activity relationship of this intriguing class of compounds. Glycosidase inhibition studies identified the natural product (+)-broussonetine W (4) as a selective and potent inhibitor of β-galactosidase (IC50 = 0.03 μM), while its enantiomer was a selective and potent inhibitor of α-glucosidase (IC50 = 0.047 μM). It was found that the configuration of the polyhydroxylated pyrrolidine ring played a key role on their glycosidase inhibitory activities. The length of side chain and α,β-unsaturated ketone functional group also exhibited some effect on their glycosidase inhibition. PMID:27184090

  16. Non-cellulosic polysaccharides help to reveal the history of thick organic surface layers on calcareous Alpine soils

    Science.gov (United States)

    Prietzel, Jörg; Spielvogel, Sandra

    2015-04-01

    We investigated the potential of non-cellulosic polysaccharides (NCP) as biomarkers to identify the plant types that dominate present and past litter input into organic surface covers on calcareous Alpine soils and to reveal historic vegetation changes. At two sites in the Alps, NCP monomers were quantified in different organs of site-dominating plants, the Oa horizon of four Folic Leptosols, and different sections of thick organic surface layers of four Folic Histosols on calcareous bedrock. The dominating plant types at our study sites differ markedly in their NCP composition and (galactose + mannose)/(arabinose + xylose) [GM/AX] ratio (grasses and sedges: 0.2; dicots Fagus and Vaccinium: 0.2-0.6; conifers Abies, Picea, Pinus: 0.7-2.4; mosses: 5). For all except one soil, the NCP signature of the uppermost Oa horizon reflects the present vegetation. For all Histosol O horizons, NCP signatures indicate a dominance of conifer litter throughout their development (up to 1,500 years). Different NCP and GM/AX depth profiles reflect specific patterns of O layer genesis. From those results we conclude that NCP and GM/AX depth profiles in organic surface covers of soils provide important information about dominating litter sources in the past and can be valuable tools to reveal historic vegetation and/ or land use changes.

  17. Phenotypic and genotypic characterization of Xanthomonas campestris strains isolated from cabbage, kale and broccoli

    Directory of Open Access Journals (Sweden)

    Popović Tatjana

    2013-01-01

    Full Text Available Thirty-six strains of Xanthomonas campestris pv. campestris (Xcc isolated from cabbage, kale and broccoli were identified according to their pathogenicity, phenotypic and genotypic characterization. Pathogenicity was confirmed by the injection method with a hypodermic syringe into the mesophilic tissue of cabbage leaves. All strains were Gramnegative, aerobic, catalase-positive, oxidase-negative, grew at 35°C, produced levan, H2S and indole, did not reduce nitrate, hydrolyzed Tween 80, starch, gelatin and esculin and did not show tolerance to 0.1 and 0.02% TTC. The strains produced acid from d-arabinose, arginine, dulcitol, galactose, d-glucose, maltose, mannose, sorbitol, sucrose and xylose. The genetic characterization was based on the sequence analyses of 16S rDNA and ERIC and BOX PCR. Strains of different pathovars were also used to compare PCR resulting patterns. BOX-PCR of the strains from kale and broccoli, obtained using (GTG5 primer, yielded patterns with a high similarity level to pathovar reference strain Xcc. The strains from cabbage yielded BOX and ERIC product patterns, distinguishing them from the other tested strains and reference strains. 16S rDNA of the representative strains was closely related to Xcc strain ATCC 33913. ERIC PCR and BOX using (GTG5 primer generated different Xcc patterns and were effective in distinguishing strains from different plant hosts. [Projekat Ministarstva nauke Republike Srbije, br. III43010 i br. III46007

  18. Effect of Extraction Conditions on the Saccharide (Neutral and Acidic) Composition of the Crude Pectic Extract from Various Agro-Industrial Residues.

    Science.gov (United States)

    Babbar, Neha; Roy, Sandra Van; Wijnants, Marc; Dejonghe, Winnie; Caligiani, Augusta; Sforza, Stefano; Elst, Kathy

    2016-01-13

    The influence of different extraction methodologies was assessed on the composition of both neutral (arabinose, rhamnose, galactose) and acidic (galacturonic acid) pectic polysaccharides obtained from four agro-industrial residues, namely, berry pomace (BP), onion hulls (OH), pressed pumpkin (PP), and sugar beet pulp (SBP). For acidic pectic polysaccharides, the extraction efficiency was obtained as BP (nitric acid-assisted extraction, 2 h, 62.9%), PP (enzymatic-assisted extraction, 12 h, 75.0%), SBP (enzymatic-assisted extraction, 48 h, 89.8%; and nitric acid-assisted extraction, 4 h, 76.5%), and OH (sodium hexametaphosphate-assisted extraction, 0.5 h, 100%; and ammonium oxalate-assisted extraction, 0.5 h, 100%). For neutral pectic polysaccharides, the following results were achieved: BP (enzymatic-assisted extraction, 24 h, 85.9%), PP (nitric acid-assisted extraction, 6 h, 82.2%), and SBP (enzymatic assisted extraction, 48 h, 97.5%; and nitric acid-assisted extraction, 4 h, 83.2%). On the basis of the high recovery of pectic sugars, SBP and OH are interesting candidates for the further purification of pectin and production of pectin-derived products. PMID:26652767

  19. Biohydrogen Production from Xylose by Aanaerobic Mixed Cultures in Elephant Dung

    Directory of Open Access Journals (Sweden)

    Khanittha FIALA

    2014-05-01

    Full Text Available Xylose was used to produce hydrogen by anaerobic mixed cultures in elephant dung. The elephant dung was subjected to heat shock (90 ºC for 3 h and acid (pH 3.0 - 4.0 for 24 h followed by neutralization pretreatments before using it as a seed inoculum. The results showed that the seed inoculum pretreatment by heat shock produced higher hydrogen gas than acid seed inoculum pretreatment, while untreated seed inoculum gave the lowest hydrogen production. Therefore, seed inoculum by heat shock was suitable for hydrogen production from xylose, arabinose and glucose. It was found that xylose was a preferred pentose sugar for hydrogen production, in which the results were comparable to those of glucose. The initial pH of 8.0 was found to be optimal for hydrogen production from xylose, in which a maximum hydrogen production of 371 mL H2/g VSS and a yield of 1.62 mol H2/mol xylose were obtained. Microbial community analysis by denaturing gradient gel electrophoresis (DGGE revealed that, under the optimum initial pH of 8.0, the predominant hydrogen producers were Clostridium acetobutylicum and Ethanoligenens sp. In addition, lactic acid bacteria i.e. Bifidobacterium minimum and Bifidobacterium sp. were observed, which coincided with the small amount of lactic acid detected at this optimum initial pH.

  20. Fifteenth symposium on biotechnology for fuels and chemicals: Program and abstracts

    Energy Technology Data Exchange (ETDEWEB)

    1993-07-01

    This collection contains 173 abstracts from presented papers and poster sessions. The five sessions of the conference were on the subjects of: (1) Thermal, Chemical, and Biological Processing, (2) Applied Biological Research, (3) Bioprocessing Research (4), Process Economics and Commercialization, and (5) Environmental Biotechnology. Examples of specific topics in the first session include the kinetics of ripening cheese, microbial liquefaction of lignite, and wheat as a feedstock for fuel ethanol. Typical topics in the second session were synergism studies of bacterial and fungal celluloses, conversion of inulin from jerusalem artichokes to sorbitol and ethanol by saccharomyces cerevisiae, and microbial conversion of high rank coals to methane. The third session entertained topics such as hydrodynamic modeling of a liquid fluidized bed bioreactor for coal biosolubilization, aqueous biphasic systems for biological particle partitioning, and arabinose utilization by xylose-fermenting yeast and fungi. The fourth session included such topics as silage processing of forage biomass to alcohol fuels, economics of molasses to ethanol in India, and production of lactic acid from renewable resources. the final session contained papers on such subjects as bioluminescent detection of contaminants in soils, characterization of petroleum contaminated soils in coral atolls in the south Pacific, and landfill management for methane generation and emission control.

  1. Preliminary study for optimization of enzymatic hydrolysis of waste cellulosic materials

    Directory of Open Access Journals (Sweden)

    LUMINITA GEORGESCU

    2011-07-01

    Full Text Available Lignocellulose is a generic term describing the main constituents in most plants, namely cellulose, hemicelluloses, and lignin. Cellulose is a glucose polysaccharide, hemicelluloses are polysaccharides with a backbone of different hexoses (glucose, mannose, galactose and pentoses (xylan, arabinose, and lignin is a complex network of different phenyl propane units. The cellulosic materials are potential sources of ethanol. Steps of this process are saccharification of cellulose to reduce sugars, under enzymes action and to reduce sugars fermentation by yeast to obtain ethanol.The aim of this study is to examine the influence of substrateconcentration, temperature and pH upon enzymatic saccharification ofwaste cellulosic materials, based on office paper, newspaper andcardboard, in ratio of 1:1:1 (w/w and reducing sugar accumulationdynamics in optimised conditions. The study has established optimalparameters: the ratio of enzyme:substrate as 0.5 EU/g substrate,temperature 48°C, pH 4.8 and addition of surfactant Tween 80 inproportion of 0.3 %, reported to the total volume of liquid. The reducing sugar yield was 35 mg reducing sugars/ g dry weight cellulosic waste.

  2. Ethanol Production by Selected Intestinal Microorganisms and Lactic Acid Bacteria Growing under Different Nutritional Conditions.

    Science.gov (United States)

    Elshaghabee, Fouad M F; Bockelmann, Wilhelm; Meske, Diana; de Vrese, Michael; Walte, Hans-Georg; Schrezenmeir, Juergen; Heller, Knut J

    2016-01-01

    To gain some specific insight into the roles microorganisms might play in non-alcoholic fatty liver disease (NAFLD), some intestinal and lactic acid bacteria and one yeast (Anaerostipes caccae, Bacteroides thetaiotaomicron, Bifidobacterium longum, Enterococcus fecalis, Escherichia coli, Lactobacillus acidophilus, Lactobacillus fermentum, Lactobacillus plantarum, Weissella confusa, Saccharomyces cerevisiae) were characterized by high performance liquid chromatography for production of ethanol when grown on different carbohydrates: hexoses (glucose and fructose), pentoses (arabinose and ribose), disaccharides (lactose and lactulose), and inulin. Highest amounts of ethanol were produced by S. cerevisiae, L. fermentum, and W. confusa on glucose and by S. cerevisiae and W. confusa on fructose. Due to mannitol-dehydrogenase expressed in L. fermentum, ethanol production on fructose was significantly (P fermentative, mannitol-dehydrogenase negative lactic acid bacterium, may promote NAFLD through ethanol produced from sugar fermentation, while other intestinal bacteria and homo- and hetero-fermentative but mannitol-dehydrogenase positive lactic acid bacteria may not promote NAFLD. Also, our studies indicate that dietary factors interfering with gastrointestinal microbiota and microbial metabolism may be important in preventing or promoting NAFLD. PMID:26858714

  3. Production and partial characterization of exopolysaccharides produced by two Lactobacillus suebicus strains isolated from cider.

    Science.gov (United States)

    Ibarburu, Idoia; Puertas, Ana Isabel; Berregi, Iñaki; Rodríguez-Carvajal, Miguel A; Prieto, Alicia; Dueñas, Ma Teresa

    2015-12-01

    Many lactic acid bacteria synthesize extracellular polysaccharides (exopolysaccharides, EPSs) with a large variation in structure and potential functional properties. Although EPS production can produce detrimental effects in alcoholic beverages, these polymers play an important role in the rheological behavior and texture of fermented products. In this work, EPS production by two Lactobacillus suebicus strains, which were isolated from ropy ciders, was examined in a semidefined medium. The existence of priming glycosyltransferase encoding genes was detected by PCR. In addition, the preliminary characterization of the polymers was undertaken. Molecular masses were determined by size exclusion chromatography revealing the presence of two peaks, corresponding to polymers of high- and low-molecular-weight in all fractions. The composition of the EPS fractions was analyzed by gas chromatography-mass spectrometry after acid hydrolysis, revealing that they contained glucose, galactose, N-acetylglucosamine and phosphate, although in different ratios, suggesting that a mixture of polysaccharides is being synthesized. We also examined the influence of the sugar source (glucose, ribose, xylose, or arabinose) and pH conditions on growth and EPS production. PMID:26241490

  4. Optimization of the extraction of polysaccharides from tobacco waste and their biological activities.

    Science.gov (United States)

    Jing, Yanqiu; Gao, Yuzhen; Wang, Weifeng; Cheng, Yuyuan; Lu, Ping; Ma, Cong; Zhang, Yuehua

    2016-10-01

    A response surface methodology was used to optimize the parameters for extracting the polysaccharides from tobacco waste (TWPs) using hot water. The extraction process, carried out under the following optimized parameters: an extraction temperature of 90°C, a ratio of water to raw material of 54, and an extraction time of 115min, allowed an experimental yield of 28.32±1.78%. The chemical composition analysis showed that TWPs were composed of mannose, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose and arabinose with the following molecular ratio: 1.00:2.69:1.29:2.29:5.23:6.90:3.92. The molecular weights of its four major fractions were 0.558, 1.015, 16.286, and 151.194kDa. Bioactivity experiments showed that TWPs not only decreased the reactive oxygen species level in salt-stressed tomato seedlings, but also possessed significant antioxidant activities in vitro. Antioxidant activity in vivo further showed that TWPs could significantly increase the activities of antioxidant enzymes including superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT), and decrease the level of malondialodehyde (MDA). In addition, according to the acute toxicity test, TWPs did not cause behavioral changes or any death of mice. This study provides an effective method to utilize tobacco waste resources. PMID:27211300

  5. Optimization extraction of polysaccharide from Tunisian Zizyphus lotus fruit by response surface methodology: Composition and antioxidant activity.

    Science.gov (United States)

    Mkadmini Hammi, Khaoula; Hammami, Majdi; Rihouey, Christophe; Le Cerf, Didier; Ksouri, Riadh; Majdoub, Hatem

    2016-12-01

    Response surface methodology using a Box-Behnken design was employed to optimize extraction temperature, extraction time and ratio of water to material to obtain a maximum polysaccharide yield with high uronic acid content and antioxidant property from edible Zizyphus lotus fruit. The optimal conditions were: extraction time of 3h 15min, extraction temperature of 91.2°C and water to solid ratio of 39mL/g. Under these conditions, the experimental extraction yield, uronic acid content and 2,2-diphenyl-1-picrylhydrazyl scavenging ability (IC50) were 18.88%, 41.89 and 0.518mg/mL, respectively. Chemical analysis revealed that the extract was composed of 97.92% carbohydrate of which 41.89% is uronic acid. The extracted polysaccharides, with an average molecular weight of 2720kDa, are composed of arabinose, rhamnose, glucose, fructose, galactose and xylose. Moreover, the polysaccharides exhibited a significant reducing power and anti-lipid peroxidation activities. PMID:27374558

  6. Inhibitory effects of xylitol on gastric emptying and food intake

    Energy Technology Data Exchange (ETDEWEB)

    Shafer, R.B.; Levine, A.S.; Marlette, J.M.; Morley, J.E.

    1985-05-01

    The authors have previously shown, using a 99m-Tc scrambled egg meal, that pentose sugars (i.e. xylose and arabinose) markedly prolong gastric emptying. Others have reported that slowing of gastric emptying may decrease appetite and thus decrease food intake. In the present study, the authors utilized the effects of xylitol (an FDA-approved pentose sugar) on gastric emptying to study the correlation between gastric emptying and food intake. Initially, gastric emptying was measured in human volunteers utilizing a standardized 99m-Tc-scrambled egg meal washed with 50 cc tap water. Results demonstrated a significant reduction in food intake (892 +- 65 kcal with water vs 654 +- 26 kcal following the ingestion of 25 gm xylitol (p<0.05). We conclude that the effect of pentose sugars in prolonging gastric emptying directly influences food intake and contributes to early satiety. The data suggest a role of xylitol as an essentially non-caloric food additive potentially important in diet control.

  7. Inhibitory effects of xylitol on gastric emptying and food intake

    International Nuclear Information System (INIS)

    The authors have previously shown, using a 99m-Tc scrambled egg meal, that pentose sugars (i.e. xylose and arabinose) markedly prolong gastric emptying. Others have reported that slowing of gastric emptying may decrease appetite and thus decrease food intake. In the present study, the authors utilized the effects of xylitol (an FDA-approved pentose sugar) on gastric emptying to study the correlation between gastric emptying and food intake. Initially, gastric emptying was measured in human volunteers utilizing a standardized 99m-Tc-scrambled egg meal washed with 50 cc tap water. Results demonstrated a significant reduction in food intake (892 +- 65 kcal with water vs 654 +- 26 kcal following the ingestion of 25 gm xylitol (p<0.05). We conclude that the effect of pentose sugars in prolonging gastric emptying directly influences food intake and contributes to early satiety. The data suggest a role of xylitol as an essentially non-caloric food additive potentially important in diet control

  8. Optimization of Ultrasonic-Assisted Extraction Process of Polysaccharides from American Ginseng and Evaluation of Its Immunostimulating Activity

    Institute of Scientific and Technical Information of China (English)

    YANG Xiu-shi; WANG Li-jun; DONG Chuan; Edmund Man King Lui; REN Gui-xing

    2014-01-01

    Ultrasonic-assisted extraction (UAE) of American ginseng polysaccharides (AGP) was investigated using response surface methodology. Three-factor-three-level Box-Behnken design was employed to optimize the ultrasonic power, extraction time and ratio of water to raw material to obtain a high AGP yield. The analysis of variance and response surface plots indicated that ultrasonic power was the most important factor affecting the extraction yield. The optimal conditions were ultrasonic power 400 W, extraction time 71 min, and ratio of water to raw material 33 mL g-1. Under these conditions, the yield of AGP was 8.09%, which was agreed closely to the predicted value. Gas chromatography (GC) analysis showed that AGP was composed of arabinose, rhamnose, galactose, glucose, and galacturonic acid. Fourier transform infrared spectra revealed the general characteristic absorption peaks of AGP. In addition, AGP exhibited good immunostimulating activities by up-regulating the production of nitric oxide and cytokines. Compared with hot water extraction, UAE required shorter extraction time and gave a higher extraction yield, without changing the structure and immunostimulating activity of AGP. The results indicated that UAE could be an effective and advisable technique for the large scale production of plant polysaccharides.

  9. Extraction Optimization, Preliminary Characterization and Bioactivities in Vitro of Ligularia hodgsonii Polysaccharides.

    Science.gov (United States)

    Song, Xueping; Tang, Jun

    2016-01-01

    The optimization extraction, preliminary characterization and bioactivities of Ligularia hodgsonii polysaccharides were investigated. Based on single-factor experiments and orthogonal array test, the optimum extraction conditions were obtained as follows: extraction time 3 h, temperature 85 °C, water/raw material ratio 36. Further Sevag deproteinization and dialysis yielded the dialyzed Ligularia hodgsonii polysaccharides (DLHP, 19.2 ± 1.4 mg/g crude herb). Compositional analysis, size-exclusion chromatography connected with multi-angle laser light-scattering and refractive index (SEC-MALLS-RI), Fourier transform infrared (FT-IR) and ¹H nuclear magnetic resonance (NMR) spectroscopy were employed for characterization of the polysaccharides. DLHP was found to have a major component with a weight-average molecular weight of 1.17 × 10⁵ Da, mainly comprising of glucose, galactose, arabinose, mannose, rhamnose, glucuronic acid and galacturonic acid. By in vitro antioxidant activity assays, DLHP presented remarkable scavenging capacities towards 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and hydroxyl radicals, and ferrous ions chelating ability. Moreover, it exhibited appreciable anti-hyperglycemic activity as demonstrated by differential inhibition of α-glucosidase and α-amylase. The results indicated that DLHP could potentially be a resource for antioxidant and hypoglycemic agents. PMID:27213369

  10. Extraction, Purification and Primary Characterization of Polysaccharides from Defatted Peanut (Arachis hypogaea) Cakes.

    Science.gov (United States)

    Liu, Hongzhi; Jiang, Nan; Liu, Li; Sheng, Xiaojing; Shi, Aimin; Hu, Hui; Yang, Ying; Wang, Qiang

    2016-01-01

    The hot-water extraction, purification and characterization of polysaccharides from defatted peanut cake (PPC) were investigated in this study. A Box-Behnken factorial design (BBD) was used to investigate the effects of three independent variables, namely extraction temperature (X₁), extraction time (X₂) and ratio of water to raw material (X₃). The optimum conditions were 85 °C, 3 h and 20:1 (mL/g) respectively. Regression analysis was done to reveal the experimental results which include 34.97% extraction rate while the value verified under these conditions was 34.49%. The crude PPC was sequentially further purified by Sephadex G-100 chromatography, and one purified fraction was obtained. The PPC purified fraction was characterized by FT-IR, HPAEC; SEC-MALLS. The average molecular weight of the PPC purified fraction was 2.383 × 10⁵ Da. The polysaccharide was mainly composed of glucose, galactose, arabinose and xylose. The PPC have the typical absorption of polysaccharide. PMID:27258246

  11. Functional and Preliminary Characterisation of Hydrocolloid from Tamarillo (Solanum betaceum Cav. Puree

    Directory of Open Access Journals (Sweden)

    Kharidah Muhammad

    2012-06-01

    Full Text Available Hydrocolloid from tamarillo (Solanum betaceum Cav. puree was extracted using water and characterised for the first time. Proximate compositions of the extracted hydrocolloid were also determined. Functional characteristics such as water-holding capacity, oil-holding capacity, emulsifying activity, emulsion stability, foaming capacity and stability of the hydrocolloid were evaluated in comparison to that of commercial hydrocolloids. Its functional groups and degree of esterification were determined using Fourier Transform Infrared (FT-IR spectroscopy. Monosaccharide profiling was done using reverse-phase high pressure liquid chromatography (RP-HPLC. Screening of various fruits for high hydrocolloid yield after water extraction resulted in tamarillo giving the highest yield. The yield on dry weight basis was 8.30%. The hydrocolloid constituted of 0.83% starch, 21.18% protein and 66.48% dietary fibre with 49.47% degree of esterification and the monosaccharides identified were mannose, ribose, rhamnose, galacturonic acid, glucose, galactose, xylose and arabinose. Higher oil-holding capacity, emulsifying activity and emulsion stability compared to commercial hydrocolloids propose its possible application as a food emulsifier and bile acid binder. Foaming capacity of 32.19% and good foam stabilisation (79.36% of initial foam volume after 2 h of foam formation suggest its promising application in frothy beverages and other foam based food products. These findings suggest that water-extracted tamarillo hydrocolloid can be utilised as an alternative to low methoxyl pectin.

  12. Immunomodulatory and Antioxidant Effects of Polysaccharides from Gynostemma pentaphyllum Makino in Immunosuppressed Mice

    Directory of Open Access Journals (Sweden)

    Xiaoya Shang

    2016-08-01

    Full Text Available The immunomodulatory and antioxidant activities of crude polysaccharides extracted from Gynostemma pentaphyllum Makino (GPMPP were investigated. GPMPP was composed of rhamnose, arabinose, xylose, mannose, glucose and galactose in the molar ratio of 1.39:3.76:1.00:1.64:4.98:5.88. In vivo studies showed GPMPP significantly increased the spleen and thymus indices, activated the macrophage phagocytosis and NK cells, and exhibited activity on none or Con A/LPS-stimulated splenocytes in a dose-dependent manner in C57BL/6 mice. Moreover, GPMPP elevated CD4+ T lymphocyte counts as well as the CD4+/CD8+ ratio dose-dependently, and it increased IL-2 level in the sera and spleen of Cy-immunosuppressed mice. Furthermore, GPMPP significantly increased the SOD, GSH-Px, T-AOC, GSH and CAT level, and decreased the MDA level. The results showed that GPMPP might play an important role in prevention of oxidative damage in immunological system. These findings indicate GPMPP has immunomodulatory activity in vivo and seems to be an effective natural immunomodulatory agent.

  13. Optimization of Mycelia Selenium Polysaccharide Extraction from Agrocybe cylindracea SL-02 and Assessment of their Antioxidant and Anti-Ageing Activities.

    Science.gov (United States)

    Liu, Min; Jing, Huijuan; Zhang, Jianjun; Che, Gen; Zhou, Meng; Gao, Zheng; Li, Shangshang; Ren, Zhenzhen; Hao, Long; Liu, Yu; Jia, Le

    2016-01-01

    The aim of the present study was to optimize the purification of mycelia selenium polysaccharides (MSPS) from Agrocybe cylindracea SL-02 and characterize their in vitro antioxidant and in vivo anti-ageing activities. The Box-Behnken experimental design (BBD) was evaluated, which showed that the optimum conditions included an extraction temperature of 94.99°C, a pH of 9 and a precipitation temperature of 12°C, and the predicted yield was 11.036 ± 0.31%. The in vitro antioxidant assay demonstrated that MSPS had potential effects on scavenging and enhanced the reducing power of reactive oxygen species. The in vivo anti-ageing evaluation showed that MSPS significantly reduced the malonaldehyde (MDA) contents and total cholesterol (CHOL) levels, and remarkably improved the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and total antioxidant capacity (T-AOC) in mice in response to D-galactose-induced ageing. Furthermore, the characteristic analysis of MSPS indicated a selenium content of 1.76 ± 0.10 mg/g at a concentration of 6 μg/mL in liquid media and a monosaccharide composition of rhamnose, arabinose, mannose, glucose and galactose at a molar ratio of 29:3:1:18.8:2.7. These results suggest that MSPS might be suitable for functional foods and natural drugs on preventing the ageing progress induced by toxic chemicals. PMID:27532123

  14. Immunomodulatory and Antioxidant Effects of Polysaccharides from Gynostemma pentaphyllum Makino in Immunosuppressed Mice.

    Science.gov (United States)

    Shang, Xiaoya; Chao, Yu; Zhang, Yuan; Lu, Chengyuan; Xu, Chunlan; Niu, Weining

    2016-01-01

    The immunomodulatory and antioxidant activities of crude polysaccharides extracted from Gynostemma pentaphyllum Makino (GPMPP) were investigated. GPMPP was composed of rhamnose, arabinose, xylose, mannose, glucose and galactose in the molar ratio of 1.39:3.76:1.00:1.64:4.98:5.88. In vivo studies showed GPMPP significantly increased the spleen and thymus indices, activated the macrophage phagocytosis and NK cells, and exhibited activity on none or Con A/LPS-stimulated splenocytes in a dose-dependent manner in C57BL/6 mice. Moreover, GPMPP elevated CD4⁺ T lymphocyte counts as well as the CD4⁺/CD8⁺ ratio dose-dependently, and it increased IL-2 level in the sera and spleen of Cy-immunosuppressed mice. Furthermore, GPMPP significantly increased the SOD, GSH-Px, T-AOC, GSH and CAT level, and decreased the MDA level. The results showed that GPMPP might play an important role in prevention of oxidative damage in immunological system. These findings indicate GPMPP has immunomodulatory activity in vivo and seems to be an effective natural immunomodulatory agent. PMID:27548135

  15. Antioxidant activity and optimization of extraction of polysaccharide from the roots of Dipsacus asperoides.

    Science.gov (United States)

    Tan, Li-Hong; Zhang, Dan; Yu, Bao; Zhao, Sheng-Ping; Wang, Jian-Wei; Yao, Ling; Cao, Wei-Guo

    2015-11-01

    Polysaccharide extraction from Dipsacus asperoides roots (DAP) was proved to possess strong antioxidant activities, including 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-Azobis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical scavenging activities, inhibiting β-carotene bleaching and strong reducing power. Cell assay demonstrated that the crude DAP possessed antioxidant activity and were effective against H2O2-induced L02 cells injury. Then, response surface methodology (RSM) was applied to optimize the ultrasonic extraction of DAP. The optimum variables given by central composite design (CCD) were as follows: ratio of water to raw material, 38.61mL/g; ultrasonic power, 308.68W; extraction time, 38.61min; and extraction temperature, 89°C. Under these conditions, the maximum yield of DAP obtained was 7.12±0.45%. Moreover, high performance liquid chromatography (HPLC) analysis suggested that the monosaccharide compositions of DAP contained primarily mannose, ribose, glucose, galactose, xylose and arabinose, with a molar ratio of 0.22:0.48:2.29:0.34:1.39:1.41. The results of the present study showed that DAP could be considered as potential sources of natural antioxidants. PMID:26277747

  16. Soybean seeds and its by-product okara as sources of dietary fibre. Measurement by AOAC and Englyst methods.

    Science.gov (United States)

    Redondo-Cuenca, Araceli; Villanueva-Suárez, Ma José; Mateos-Aparicio, Inmaculada

    2008-06-01

    The composition of soybean seeds and its by-product okara has been studied in this work. Dietary fibre was analysed by Englyst et al. method, by enzymatic-gravimetric methods of AOAC and by the quantification of the monomers obtained from the AOAC residues after acid hydrolysis (AOAC plus hydrolysis). Total dietary fibre by the enzymatic-gravimetric methods of AOAC in okara (55.48g/100g dry matter) is more than twice that of soybean seeds (24.37g/100g dry matter). The proportion IF/SF is 11 in okara and 6 in soybean seeds. Dietary fibre results from enzymatic-gravimetric AOAC methods are higher in okara and soybean seed samples than those from the Englyst method (okara: 41.14g/100g dry matter; soybean seeds: 15.05g/100g dry matter), and AOAC plus hydrolysis (okara: 44.91g/100g dry matter; soybean seeds: 16.38g/100g dry matter). In the case of the insoluble fibre from both samples, AOAC plus hydrolysis gives significantly (p<0.001) higher values than the Englyst method, whilst for soluble fibre the opposite occurs (p<0.001). The main monomers in soybean seeds and okara fibre are glucose, galactose, uronic acids, arabinose and xylose. The proportion of each monomer is similar in soybean seeds and okara, so the healthy properties of soybean seeds fibre are also claimed for okara. PMID:26065777

  17. Improvement of the AOAC 2009.01 total dietary fibre method for bread and other high starch containing matrices.

    Science.gov (United States)

    Brunt, K; Sanders, P

    2013-10-01

    The dietary fibre (DF) content in wheat grain based food products have been established with both the classical AOAC 985.29 dietary fibre and the new AOAC 2009.01 total dietary fibre protocol. There is a good agreement between the high molecular weight dietary fibre (HMWDF) contents measured with the AOAC 2009.01 method and (DF) content measured with the classical AOAC 985.29 method in wheat grain based food products. With the AOAC 2009.01 method also a significant amount of low molar weight dietary fibre (LMWDF), ranging from 1% to 3% w/w, was measured which is not quantified with the AOAC 985.29 method. With semi-preparative GPC the LMWDF (DP⩾3) fractions in the wheat grain based food products were isolated. The monosaccharide composition of the dissolved LMWDF constituents was determined. Glucose was by far the most abundant monosaccharide present with arabinose, galactose, xylose and mannose as minor constituents. It appeared that the LMWDF contains still not fully converted digestible starch/malto-oligosaccharide fragments with DP⩾3, which are erroneously quantified as LMWDF. By introducing an extra AMG hydrolysis step in the AOAC 2009.01 protocol after evaporation of the ethanol and dissolving the residue in deionised water, these malto-oligosaccharides are fully hydrolysed resulting in that way in a correct and lower LMWDF content. PMID:23601409

  18. Preparative separation of minor saponins from Platycodi Radix by high-speed counter-current chromatography.

    Science.gov (United States)

    Ha, In J; Kang, Minseok; Na, Yun C; Park, Youmie; Kim, Yeong S

    2011-10-01

    Platycosides (PSs), the saponins found in the root of Platycodon grandiflorum (Jacq.) A. DC. (Platycodi Radix), are typically composed of oleanene backbones with two side chains; one is a 3-O-glucose linked by a glycosidic bond, and the other is a 28-O-arabinose-rhamnose-xylose-apiose linked by an ester bond. Minor saponins, acetylated isomers of the major saponin on either the 2'' or 3'' position of rhamnose, were isolated from Platycodi Radix using a multi-step process including high-speed counter-current chromatography (HSCCC) and preparative reversed-phase high-performance liquid chromatography (RP-HPLC). After the separation of the major components, the enriched minor saponin fraction was used for this study. A two-phase solvent system consisting of chloroform-methanol-isopropanol-water (3:2:2:3, v/v) was used for HSCCC. HSCCC separation of the enriched minor saponin fraction yielded 2''-O-acetylplatycodin D, 3''-O-acetylpolygalacin D, 2''-O-acetylpolygalacin and a mixture of 3''-O-acetylplatycodin D and polygalacin D. The mixture fraction from HSCCC separation was further purified by preparative RP-HPLC, giving 3''-O-acetylplatycodin D and polygalacin D at a purity of over 98.9%. The developed method provides the preparative and rapid separation of minor saponins in the crude extract of Platycodi Radix. To the best of our knowledge, this is the first on the separation of acetylated PSs by HSCCC. PMID:21812112

  19. Gum in apricot (Prunus armeniaca L. shoots induced by methyl jasmonate

    Directory of Open Access Journals (Sweden)

    Marian Saniewski

    2013-12-01

    Full Text Available It has been well known that some fungal pathogens (Monilia laxa, M. fructigena, Cytospora cincta, larvae of Grapholita molesta and plant hormone - ethylene, induce gummosis in apricot shoots. Methyl jasmonate (JA-Me was also found to induce gummosis in apricot shoots as well as biotic and abiotic factors mentioned above. In order to know the mode of action of JA-Me on gum induction and/or formation, chemical composition of polysaccharides (after hydrolysis in gums of apricot shoots induced by JA-Me compared with those by ethephon and their mixture, and naturally occurring ones was studied, resulted in the succesful identification of monosaccharides, and the similarity of a composition consisting of xylose, arabinose and galactose at molar ratio 1:10:14, respectively. These results suggest that beside different inducers of gum in apricot the mechanism of polysaccharides biosynthesis of gums is the same or similar. The physiological role for JA-Me on gum induction and/or formation in apricot shoots, and other species are also discussed.

  20. Efficient utilization of pentoses for bioproduction of the renewable two-carbon compounds ethylene glycol and glycolate.

    Science.gov (United States)

    Pereira, Brian; Li, Zheng-Jun; De Mey, Marjan; Lim, Chin Giaw; Zhang, Haoran; Hoeltgen, Claude; Stephanopoulos, Gregory

    2016-03-01

    The development of lignocellulose as a sustainable resource for the production of fuels and chemicals will rely on technology capable of converting the raw materials into useful compounds; some such transformations can be achieved by biological processes employing engineered microorganisms. Towards the goal of valorizing the hemicellulose fraction of lignocellulose, we designed and validated a set of pathways that enable efficient utilization of pentoses for the biosynthesis of notable two-carbon products. These pathways were incorporated into Escherichia coli, and engineered strains produced ethylene glycol from various pentoses, including simultaneously from D-xylose and L-arabinose; one strain achieved the greatest reported titer of ethylene glycol, 40g/L, from D-xylose at a yield of 0.35g/g. The strategy was then extended to another compound, glycolate. Using D-xylose as the substrate, an engineered strain produced 40g/L glycolate at a yield of 0.63g/g, which is the greatest reported yield to date. PMID:26711083

  1. Biofuel production from plant biomass derived sugars

    Energy Technology Data Exchange (ETDEWEB)

    Cripps, R.

    2007-03-15

    This report details the results of a project that aimed to develop a recombinant thermophilic microorganism able to produce ethanol in a commercial yield from mixed C5 (xylose and arabinose) and C6 (mainly glucose) sugar substrates typically found in biomass hydrolysates. The main focus of the project was on producing a stable recombinant which formed ethanol as its major product and did not produce significant quantities of by-products. The costs of bioethanol could be substantially reduced if cheap plant-based feedstocks could be utilised. This study focussed on a strain of Geobacillus thermoglucosidasius known to be a thermophilic ethanol producer and developed the genetic manipulation techniques necessary to engineer its metabolism such that unwanted products (mainly organic acids) were no longer formed and ethanol became the overwhelming product. An appropriate genetic took kit to allow the required metabolic engineering was acquired and used to inactivate the genes of the metabolic pathways involved in the formation of the organic acids (e.g. lactic acid) and to up-regulate genes concerned with the formation of ethanol. This allowed the flow of metabolites derived from the sugar substrates to be redirected to the desired product. Stable mutants lacking the ability to form lactic acid were created and shown to give enhanced levels of ethanol, with yields from glucose approaching those achieved in yeast fermentations and low by-product formation.

  2. Characterization of mammalian glucose transport proteins using photoaffinity labeling techniques

    International Nuclear Information System (INIS)

    A carrier-free radioiodinated phenylazide derivative of forskolin, 3-iodo-4-azidophenethylamido-7-O-succinyl-deacetyl-forskolin ([125I]IAPS-forskolin), has been shown to be a highly selective photoaffinity probe for the human erythrocyte glucose transported and the glucose transport proteins found in several mammalian tissues and cultured cells where the glucose transport protein is present at a low concentration. The photoincorporation of [125I]IAPS-forskolin into these glucose transporters was blocked by D- (but not L-) glucose, cytochalasin B, and forskolin. In addition to labeling the mammalian glucose transport proteins, [125I]IAPS-forskolin also labeled the L-arabinose transporter from E. coli. In muscle and adipose tissues, glucose transport is markedly increased in response to insulin. [125I]IAPS-forskolin was shown to selectivity tag the glucose transporter in membranes derived from these cells. In addition, the covalent derivatization of the transport protein in subcellular fractions of the adipocyte has provided a means to study the hormonal regulation of glucose transport. [125I]IAPS-forskolin has also been used to label the purified human erythrocyte glucose transporter. The site of insertion has therefore been localized by analysis of the radiolabeled peptides which were produced following chemical and proteolytic digestion of the labeled transport protein

  3. Characterization of mammalian glucose transport proteins using photoaffinity labeling techniques

    Energy Technology Data Exchange (ETDEWEB)

    Wadzinski, B.E.

    1989-01-01

    A carrier-free radioiodinated phenylazide derivative of forskolin, 3-iodo-4-azidophenethylamido-7-O-succinyl-deacetyl-forskolin (({sup 125}I)IAPS-forskolin), has been shown to be a highly selective photoaffinity probe for the human erythrocyte glucose transported and the glucose transport proteins found in several mammalian tissues and cultured cells where the glucose transport protein is present at a low concentration. The photoincorporation of ({sup 125}I)IAPS-forskolin into these glucose transporters was blocked by D- (but not L-) glucose, cytochalasin B, and forskolin. In addition to labeling the mammalian glucose transport proteins, ({sup 125}I)IAPS-forskolin also labeled the L-arabinose transporter from E. coli. In muscle and adipose tissues, glucose transport is markedly increased in response to insulin. ({sup 125}I)IAPS-forskolin was shown to selectivity tag the glucose transporter in membranes derived from these cells. In addition, the covalent derivatization of the transport protein in subcellular fractions of the adipocyte has provided a means to study the hormonal regulation of glucose transport. ({sup 125}I)IAPS-forskolin has also been used to label the purified human erythrocyte glucose transporter. The site of insertion has therefore been localized by analysis of the radiolabeled peptides which were produced following chemical and proteolytic digestion of the labeled transport protein.

  4. Chemical composition and functional properties of gum exudates from the trunk of the almond tree (Prunus dulcis).

    Science.gov (United States)

    Mahfoudhi, N; Chouaibi, M; Donsì, F; Ferrari, G; Hamdi, S

    2012-06-01

    The physicochemical components and functional properties of the gum exudates from the trunk of the almond tree (Prunus dulcis) have been investigated, along with the emulsification and foaming properties. The gum exudates are composed on dry weight basis by 2.45% of proteins, 0.85% of fats and 92.36% of carbohydrates. The latter consist of arabinose, xylitol, galactose and uronic acid (46.8 : 10.9 : 35.5 : 6.0 mass ratio) with traces of rhamnose, mannose and glucose. Moreover, gum exudates are rich in minerals, such as sodium, potassium, magnesium, calcium and iron. The emulsifying capacity was studied for a 20% w/w olive oil in water emulsion as a function of gum concentration (from 3% to 12% w/w in the aqueous phase) as well as pH levels (from 3.0 to 10.0). The most stable and homogeneous emulsion was prepared with an 8% w/w aqueous almond gum solution at a pH between 5.0 and 8.0. In particular, for the same formulation, the emulsion processed by high pressure homogenization (5 passes at 200 MPa) resulted to be extremely stable under accelerated ageing, exhibiting no significant change in droplet size distribution for 14 days at 55 °C. All the tested systems exhibited an extremely low foaming capacity. PMID:22701057

  5. Pantethine rescues phosphopantothenoylcysteine synthetase and phosphopantothenoylcysteine decarboxylase deficiency in Escherichia coli but not in Pseudomonas aeruginosa.

    Science.gov (United States)

    Balibar, Carl J; Hollis-Symynkywicz, Micah F; Tao, Jianshi

    2011-07-01

    Coenzyme A (CoA) plays a central and essential role in all living organisms. The pathway leading to CoA biosynthesis has been considered an attractive target for developing new antimicrobial agents with novel mechanisms of action. By using an arabinose-regulated expression system, the essentiality of coaBC, a single gene encoding a bifunctional protein catalyzing two consecutive steps in the CoA pathway converting 4'-phosphopantothenate to 4'-phosphopantetheine, was confirmed in Escherichia coli. Utilizing this regulated coaBC strain, it was further demonstrated that E. coli can effectively metabolize pantethine to bypass the requirement for coaBC. Interestingly, pantethine cannot be used by Pseudomonas aeruginosa to obviate coaBC. Through reciprocal complementation studies in combination with biochemical characterization, it was demonstrated that the differential characteristics of pantethine utilization in these two microorganisms are due to the different substrate specificities associated with endogenous pantothenate kinase, the first enzyme in the CoA biosynthetic pathway encoded by coaA in E. coli and coaX in P. aeruginosa. PMID:21551303

  6. Pantethine Rescues Phosphopantothenoylcysteine Synthetase and Phosphopantothenoylcysteine Decarboxylase Deficiency in Escherichia coli but Not in Pseudomonas aeruginosa▿†

    Science.gov (United States)

    Balibar, Carl J.; Hollis-Symynkywicz, Micah F.; Tao, Jianshi

    2011-01-01

    Coenzyme A (CoA) plays a central and essential role in all living organisms. The pathway leading to CoA biosynthesis has been considered an attractive target for developing new antimicrobial agents with novel mechanisms of action. By using an arabinose-regulated expression system, the essentiality of coaBC, a single gene encoding a bifunctional protein catalyzing two consecutive steps in the CoA pathway converting 4′-phosphopantothenate to 4′-phosphopantetheine, was confirmed in Escherichia coli. Utilizing this regulated coaBC strain, it was further demonstrated that E. coli can effectively metabolize pantethine to bypass the requirement for coaBC. Interestingly, pantethine cannot be used by Pseudomonas aeruginosa to obviate coaBC. Through reciprocal complementation studies in combination with biochemical characterization, it was demonstrated that the differential characteristics of pantethine utilization in these two microorganisms are due to the different substrate specificities associated with endogenous pantothenate kinase, the first enzyme in the CoA biosynthetic pathway encoded by coaA in E. coli and coaX in P. aeruginosa. PMID:21551303

  7. Influence of composition on the biological activity of pectic polysaccharides from leek

    Directory of Open Access Journals (Sweden)

    MANOL OGNYANOV

    2013-01-01

    Full Text Available Water-soluble and acid-soluble pectic polysaccharides with significant immunostimulating activity were isolated from alcohol-insoluble solids (AIS of leek. Pectic polysaccharides characterized with high anhydrouronic acid content and common pectic sugars – L-arabinose, D-galactose, D-glucose, and L-rhamnose. It was accomplished that D-galactose content was the highest, which allowed the assumption that pectin sugar side chains were from galactan type. Enzyme modification of acid-extracted pectin was realized. Different pectin-degrading enzymes were used. The first modified pectic fraction, obtained after endopolygalacturonase action and alcohol precipitation contained rhamnogalacturonan I and had high D-galactose content. The second fraction obtained from the first, after β-galactosidase treatment characterized with low D-galactose content. Probably this was result from β-galactosidase hydrolysis of pectin side chains. It was proved by the action of β-galactosidase that galactan side chains were mainly composed of β-(1→4-linked D-galactose. It was accomplished that rhamnogalacturonan I had higher immunostimulating activity than the initial pectic polysaccharide, which confirmed the statement that pectin hairy regions were responsible for the biological activity. The second fraction had lower D-galactose content and lower activity than the first. Probably galactan side chains were responsible for the immunostimulating activity.

  8. Hormonal regulation of gummosis and composition of gums from bulbs of hyacinth (Hyacinthus orientalis).

    Science.gov (United States)

    Miyamoto, Kensuke; Kotake, Toshihisa; Boncela, Anna Jarecka; Saniewski, Marian; Ueda, Junichi

    2015-02-01

    Hyacinth (Hyacinthus orientalis) bulbs infected by Fusarium oxysporum showed the symptoms of gummosis. The purpose of this study was to clarify the hormonal regulation of gummosis and composition of gums from hyacinth bulbs. The application of ethephon (2-chloroethylphosphonic acid), an ethylene-releasing compound, at 2% (w/w, in lanolin) induced gummosis in hyacinth bulbs. Methyl jasmonate (JA-Me) at 1.5% (w/w, in lanolin) induced gummosis as well. Simultaneous application of JA-Me and ethephon further enhanced gummosis. Molecular mass distribution of hyacinth gums analyzed by gel permeation chromatography indicated that the gums were mainly homogenous polysaccharides with an average molecular weight of ca. 30kDa. Analysis of the sugar composition of the gums after hydrolysis revealed that the majority were arabinose (ca. 35%) and galactose (ca. 40%) together with small amounts of fucose, rhamnose and uronic acids (ca. 5%, respectively), suggesting that the gums are pectic arabinogalactans. These results indicate that jasmonates (JAs) interact with ethylene to stimulate sugar metabolism, producing pectic arabinogalactans, and vice versa, leading to gummosis. These findings, together with those from our previous studies in tulips (Tulipa gesneriana) and grape hyacinth (Muscari armeniacum), revealed that sugar metabolism and hormonal regulation relating to gummosis are different among species of bulbous plants. PMID:25462960

  9. cDNA cloning,sequence analysis,and recombinant expression of akitonin beta,a C-type lectin-like protein from Agkistrodon acutus

    Institute of Scientific and Technical Information of China (English)

    Xiang-dong ZHA; Jing LIU; Kang-sen XU

    2004-01-01

    AIM: To clone the cDNA of a new member of snake venom C-type lectin-like proteins, to study its structurefunction relationships and to achieve its recombinant production. METHODS: PCR primers were designed based on the homology and cDNA was amplified by RT-PCR using total RNA from snake venom gland as the template.The PCR products were cloned into the plasmid pGEM-T and sequenced. The deduced protein sequence was analyzed with some bioinformatic programs. A recombinant expression plasmid was constructed using pBADTOPO as vector and transformed into E. coli TOP10 competent cells. RESULTS: A novel cDNA sequence encoding akitonin β was found and accepted by GenBank (accession number AF387100). Akitonin β consists of a typical carbohydrate recognition domain (CRD) of C-type lectins, and it is homologous with other snake venom C-type lectin-like proteins. It was predicted to be a platelet antagonist. Upon induction with arabinose rAkitonin β expressing in E coli was achieved at a high level (superior to 150 mg/L). The recombinant fusion protein exhibited inhibitory activities on rat platelet aggregation in vitro. CONCLUSION: A new member of snake venom C-type lectin-like proteins was discovered and characterized, and an efficient recombinant expression system was established for its production.

  10. Classification of wheat varieties based on structural features of arabinoxylans as revealed by endoxylanase treatment of flour and grain.

    Science.gov (United States)

    Ordaz-Ortiz, José Juan; Devaux, Marie-Françoise; Saulnier, Luc

    2005-10-19

    Arabinoxylans (AX) are cell wall polysaccharides of complex structure involved in many aspects of wheat flour end uses. The study of the variations of AX structure can lead to the identification of genes involved in their biosynthesis, and thus in the control of the various aspects of grain quality related to their presence. A method is proposed to identify AX variations directly in whole grain by enzymatic degradation. An endoxylanase from Trichoderma viride was used to extract AX from a collection of 20 wheat cultivars (Triticum aestivum L.). Enzymatic degradation products were analyzed by HPAEC and multivariate analysis techniques (principal component analysis, canonical correlation analysis, and cluster analysis) were applied to analyze chromatographic data. The method evidenced variations in the proportion of mono- and disubstitution of the xylan backbone by arabinose side chains, allowing classification of the different varieties according to the structural features of AX. A similar classification was obtained starting from flour or whole grain, indicating that the method was specific of AX from endosperm tissues. In conclusion, the method combining endoxylanase treatment of wheat grain and the analysis of degradation products, e.g., enzymatic fingerprinting, can be applied to collections of wheat cultivars, and possibly other cereals in order to establish quantitative trait loci related to the biosynthesis of AX. PMID:16218687

  11. Optimization of polysaccharides extraction from watermelon rinds: Structure, functional and biological activities.

    Science.gov (United States)

    Romdhane, Molka Ben; Haddar, Anissa; Ghazala, Imen; Jeddou, Khawla Ben; Helbert, Claire Boisset; Ellouz-Chaabouni, Semia

    2017-02-01

    In the present work, optimization of hot water extraction, structural characteristics, functional properties, and biological activities of polysaccharides extracted from watermelon rinds (WMRP) were investigated. The physicochemical characteristics and the monosaccharide composition of these polysaccharides were then determined using chemical composition analysis, Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) and gas chromatography-flame ionization detection (GC-FID). SEM images showed that extracted polysaccharides had a rough surface with many cavities. GC-FID results proved that galactose was the dominant sugar in the extracted polysaccharides, followed by arabinose, glucose, galacturonic acid, rhamnose, mannose, xylose and traces of glucuronic acid. The findings revealed that WMRP displayed excellent antihypertensive and antioxidant activities. Those polysaccharides had also a protection effect against hydroxyl radical-induced DNA damage. Functional properties of extracted polysaccharides were also evaluated. WMRP showed good interfacial dose-dependent proprieties. Overall, the results suggested that WMRP presents a promising natural source of antioxidants and antihypertensive agents. PMID:27596431

  12. Neutral monosaccharides from a hypersaline tropical environment: Applications to the characterization of modern and ancient ecosystems

    Science.gov (United States)

    Moers, M. E. C.; Larter, S. R.

    1993-07-01

    Surficial and buried sediment samples from a hypersaline lagoon-sabkha system (Abu Dhabi, United Arab Emirates) were analysed for carbohydrates (as neutral monosaccharides) to distinguish and characterise various types of recent and ancient tropical ecosystems on a molecular level. The samples consisted of surficial and buried microbial mats, lagoonal sediments containing seagrass ( Halodule uninervis), and mangrove ( Avicennia marina) paleosoils and handpicked mangrove leaves, ranging in age from contemporary to ca. 6000 yr Bp. Analysis of quantitative neutral monosaccharide data by multivariate techniques shows that various groups can be distinguished: intact vascular plant material (mangrove leaf) contains high amounts of arabinose and glucose and hardly any partially methylated monosaccharides, whereas microbial mats in general and lagoonal seagrass sediments show high contributions of fucose, ribose, mannose, galactose and partially methylated monosaccharides. Moreover, surficial microbial mats consisting of filamentous cyanobacteria ( Microcoleus chtonoplastes, Lyngbya aestuarii) can be distinguished from other mats and sediments containing coccoid cyanobacteria ( Entophysalis major) and/or fermenting, sulphate reducing, and methanogenic bacteria on the basis of high contributions of specific groups of partially methylated monosaccharides and other "minor" saccharides. The neutral monosaccharides present in mangrove paleosoils are for a substantial part derived from microorganisms.

  13. Carbohydrate speciation and Py-MS mapping of peat samples from a subtropical open marsh environment

    Science.gov (United States)

    Moers, M. E. C.; Boon, J. J.; de Leeuw, J. W.; Baas, M.; Schenck, P. A.

    1989-08-01

    Neutral carbohydrates were determined as alditol acetates in the hydrolysates of fractionated peat samples from different depths from Rookery Branch (Florida Everglades), and of a Mariscus rhizome. The fine grained samples showed a major contribution of microbial sugars indicated by comparatively low total carbohydrate yields together with high relative contributions of galactose, mannose, ribose, fucose, rhamnose, partially methylated aldoses, amino sugars, heptoses, tetroses, glycerol, allose and altrose. The coarse grained samples showed a major contribution of vascular plant sugars indicated by comparatively high total carbohydrate yields together with high relative contributions of glucose, xylose and arabinose. Analysis of the fractionated peat samples by Curie point pyrolysis-mass spectrometry and multivariate analysis of the pyrolysis data yielded two discriminant functions. Depth profiles for the first discriminant function show a relative accumulation of lignified vascular plant material with increasing depth in coarse and fine grained samples. The finest grained samples show most of the markers indicative for microbial activity and the presence of refractory fine grained matter and least of the lignin markers. Plots of the second discriminant function versus depth reveal an initial increase in markers for modified lignin, indicating degradation. The deepest sample, however, again shows increased characteristics for intact vascular plant polysaccharides. The results from both wet chemical analysis and Py-MS suggest the presence of living and/or senescent rootlets at the deepest level in the peat.

  14. Chemical characterization of high molecular weight dissolved organic matter in fresh and marine waters

    Science.gov (United States)

    Repeta, Daniel J.; Quan, Tracy M.; Aluwihare, Lihini I.; Accardi, AmyMarie

    2002-03-01

    The high molecular weight fraction of dissolved organic matter in a suite of lakes, rivers, seawater, and marine sediment interstitial water samples was collected by ultrafiltration and characterized by molecular level and spectroscopic techniques. Proton nuclear magnetic resonance spectra of all samples show a high degree of similarity, with major contributions from carbohydrates, bound acetate, and lipids. Molecular level analyses of neutral sugars show seven monosaccharides, rhamnose, fucose, arabinose, xylose, mannose, glucose, and galactose, to be abundant, and to occur in comparable relative amounts in each sample. Previous studies have emphasized the distinctive composition of dissolved humic substances in fresh and marine waters, and have attributed these differences to sources and transformations of organic matter unique to each environment. In contrast we find a large fraction of freshwater high molecular weight dissolved organic matter (HMWDOM; > 1kD) to be indistinguishable from marine HMWDOM in bulk and molecular-level chemical properties. Aquatic HMWDOM is similar in chemical composition to biologically derived acylated heteropolysaccharides isolated from marine algal cultures, suggesting a biological source for some fraction of persistent HMWDOM. High molecular weight DOC contributes 51 ± 26% of the total DOC, and monosaccharides 18 ± 8% of the total HMWDOC in our freshwater samples. These contributions are on average higher and more variable, but not significantly different than for surface seawater (30% and 16% respectively). Biogeochemical processes that produce, accumulate, and recycle DOM may therefore share important similarities and be broadly comparable across a range of environmental settings.

  15. A study on an oligotrophic bacteria and its ecological characteristics in an arid desert area

    Institute of Scientific and Technical Information of China (English)

    PAN HuiXia; CHENG ZhengMing; ZHANG XueMei; MU ShuYong; QI XiaoLing; WANG Fang

    2007-01-01

    An oligotrophic bacterium was isolated from the biological soil crust underlayer in the Xinjiang Gurbantunggut Desert. It was numbered SGB-5, G+. Cell size is (0.328-0.746) μm×(0.171-0.240) μm.Raised colony is white, roundness and its diameter is 5 mm. The strain is a facultative aerobe. It was able to grow in conditions of 1 -15 mg·C·L-1 culture medium at 10-50℃. The strain's optimum growth temperature is 37℃. The range of its optimum growth pH is 8-9. A large amount of extracellular mucopolysaccharide was secreted during growth. The chemical composition of this mucopolysaccharide consists of arabinose, X sugar, glucose, galactose and mannitol. Mole ratio of these sugars is 1:14:19: 6:14. The viscosity of the mucopolysaccharide can reach 6300 mPa·s, when the strain is cultivated for 72 h. After the culture solution in which viscosity was 1500 mPa·s was sprinkled on the quicksand surface, 6 mm bacteria crust of conglutinating sand was formed. This crust could not only stabilize sand, but could also potentially slow the rate of the soil water evaporation.

  16. Tamarind Seed Xyloglucans Promote Proliferation and Migration of Human Skin Cells through Internalization via Stimulation of Proproliferative Signal Transduction Pathways

    Directory of Open Access Journals (Sweden)

    W. Nie

    2013-01-01

    Full Text Available Xyloglucans (XGs of Tamarindus indica L. Fabaceae are used as drug vehicles or as ingredients of cosmetics. Two xyloglucans were extracted from T. indica seed with cold water (TSw and copper complex precipitation (TSc. Both were analyzed in regard to composition and influence on cell viability, proliferation, cell cycle progression, migration, MAPK phosphorylation, and gene expression of human skin keratinocytes (NHEK and HaCaT and fibroblasts (NHDF in vitro. TSw and TSc differed in molecular weight, rhamnose content, and ratios of xylose, arabinose, galactose, and glucose. Both XGs improved keratinocytes and fibroblast proliferation, promoted the cell cycle, and stimulated migration and intracellular enzyme activity of NHDF after endosomal uptake. Only TSw significantly enhanced HaCaT migration and extracellular enzyme activity of NHDF and HaCaT. TSw and TSc predominantly enhanced the phosphorylation of molecules that referred to Erk signaling in NHEK. In NHDF parts of the integrin signaling and SAPK/JNK pathway were affected. Independent of cell type TSw marginally regulated the expression of genes, which referred to membrane proteins, cytoskeleton, cytokine signaling, and ECM as well as to processes of metabolism and transcription. Results show that T. indica xyloglucans promote skin regeneration by a direct influence on cell proliferation and migration.

  17. Tamarind Seed Xyloglucans Promote Proliferation and Migration of Human Skin Cells through Internalization via Stimulation of Proproliferative Signal Transduction Pathways.

    Science.gov (United States)

    Nie, W; Deters, A M

    2013-01-01

    Xyloglucans (XGs) of Tamarindus indica L. Fabaceae are used as drug vehicles or as ingredients of cosmetics. Two xyloglucans were extracted from T. indica seed with cold water (TSw) and copper complex precipitation (TSc). Both were analyzed in regard to composition and influence on cell viability, proliferation, cell cycle progression, migration, MAPK phosphorylation, and gene expression of human skin keratinocytes (NHEK and HaCaT) and fibroblasts (NHDF) in vitro. TSw and TSc differed in molecular weight, rhamnose content, and ratios of xylose, arabinose, galactose, and glucose. Both XGs improved keratinocytes and fibroblast proliferation, promoted the cell cycle, and stimulated migration and intracellular enzyme activity of NHDF after endosomal uptake. Only TSw significantly enhanced HaCaT migration and extracellular enzyme activity of NHDF and HaCaT. TSw and TSc predominantly enhanced the phosphorylation of molecules that referred to Erk signaling in NHEK. In NHDF parts of the integrin signaling and SAPK/JNK pathway were affected. Independent of cell type TSw marginally regulated the expression of genes, which referred to membrane proteins, cytoskeleton, cytokine signaling, and ECM as well as to processes of metabolism and transcription. Results show that T. indica xyloglucans promote skin regeneration by a direct influence on cell proliferation and migration. PMID:24106497

  18. Structure and antioxidative property of a polysaccharide from an ammonium oxalate extract of Phellinus linteus.

    Science.gov (United States)

    Yan, Jing-Kun; Wang, Yao-Yao; Wang, Zhen-Bin; Ma, Hai-Le; Pei, Juan-Juan; Wu, Jian-Yong

    2016-10-01

    In this paper, the novel polysaccharide PL-A11 was purified from an ammonium oxalate extract of Phellinus linteus mycelia. Its physicochemical properties, structural characteristics, and antioxidant activities were investigated. Results showed that PL-A11 had a weight-average molecular weight (Mw) of 13.8kDa and was mainly composed of arabinose, xylose, mannose, and glucose in a molar ratio of 1.1:1.3:1.0:6.6. The backbone of PL-A11 was composed of (1→4)-α-d-glucopyranosyl, (1→2)-α-d-xylopyranosyl, and (1→3)-α-d-arabinofuranosyl residues, whereas the (1→6)-α-d-mannopyranosyl residues formed branches at the O-2 position with 1-linked-α-d-glucopyranosyl terminal residues. From the antioxidative activity tests in vivo, the administration of PL-A11 obviously enhanced the activity of antioxidant enzymes and significantly reduced the level of malondiadehyde (MDA) in the serum and liver of d-galactose-treated aging mice in a dose-dependent manner, as well as effectively stimulated the immune system of aging mice. These findings implied that PL-A11 could be developed as a potential antioxidant for applications in the functional food, pharmaceutical, cosmetic or nutraceutical industries. PMID:27212213

  19. Studies on Tinospora cordifolia monosugars and correlation analysis of uronic acids by spectrophotometric methods and GLC.

    Science.gov (United States)

    Kumar, Vineet; Nagar, Shipra

    2014-01-01

    Cold water-soluble (CWSP) and hot water soluble polysaccharides (HWSP) from Tinospora cordifolia stems were isolated and purified in 2.99% and 1.99% yield respectively. Complete hydrolysis followed by paper chromatography and GLC analysis indicated the presence of L-rhamnose, L-arabinose, D-xylose, D-mannose, D-galactose and D-glucose in molar ratio of 0.857, 1.106, 0.727, 0.526, 0.708 and 95.763 in CWSP and 0.697, 0.777, 2.048, 0.777, 0.292 and 95.408 in HWSP. The uronic acid content in the polysaccharide has been studied extensively using assorted approaches. It was quantitatively estimated by GLC analysis and spectrophotometric methods using carbazole, m-hydroxydiphenyl and 3,5-dimethylphenol as colorimetric reagents. GLC analyses indicated galacturonic acid content of 3.06% and 5.16% in CWSP and HWSP respectively. Estimation of uronic acid using 3,5-dimethylphenol corroborated the above analysis. The study resulted in composition of constituent monosugars of CWSP and HWSP and co-relation analysis of uronic acid content, leading to an unambiguous structural analysis. PMID:24274509

  20. Comparative Chemistry of Propolis from Eight Brazilian Localities

    Directory of Open Access Journals (Sweden)

    A. A. Righi

    2013-01-01

    Full Text Available Propolis is a complex honeybee product with resinous aspect, containing plant exudates and beeswax. Their color, texture, and chemical composition vary, depending on the location of the hives and local flora. The most studied Brazilian propolis is the green (alecrim-do-campo type, which contains mainly prenylated phenylpropanoids and caffeoylquinic acids. Other types of propolis are produced in Brazil, some with red color, others brown, grey, or black. The aim of the present work was to determine the chemical profiles of alcohol and chloroform extracts of eight samples of propolis, corresponding to six Brazilian regions. Methanol and chloroform extracts were obtained and analyzed by HPLC/DAD/ESI/MS and GC/MS. Two chemical profiles were recognized among the samples analyzed: (1 black Brazilian propolis, characterized chiefly by flavanones and glycosyl flavones, stemming from Picos (Piauí state and Pirenópolis (Goiás state; (2 green Brazilian propolis, characterized by prenylated phenylpropanoids and caffeoylquinic acids, stemming from Cabo Verde (Bahia state, Lavras and Mira Bela (Minas Gerais state, Pariquera-Açu and Bauru (São Paulo state, and Ponta Grossa (Paraná state. The present work represents the first report of prenylated flavonoids in Brazilian propolis and schaftoside (apigenin-8-C-glucosyl-6-C-arabinose in green propolis.

  1. Comparative chemistry of propolis from eight brazilian localities.

    Science.gov (United States)

    Righi, A A; Negri, G; Salatino, A

    2013-01-01

    Propolis is a complex honeybee product with resinous aspect, containing plant exudates and beeswax. Their color, texture, and chemical composition vary, depending on the location of the hives and local flora. The most studied Brazilian propolis is the green (alecrim-do-campo) type, which contains mainly prenylated phenylpropanoids and caffeoylquinic acids. Other types of propolis are produced in Brazil, some with red color, others brown, grey, or black. The aim of the present work was to determine the chemical profiles of alcohol and chloroform extracts of eight samples of propolis, corresponding to six Brazilian regions. Methanol and chloroform extracts were obtained and analyzed by HPLC/DAD/ESI/MS and GC/MS. Two chemical profiles were recognized among the samples analyzed: (1) black Brazilian propolis, characterized chiefly by flavanones and glycosyl flavones, stemming from Picos (Piauí state) and Pirenópolis (Goiás state); (2) green Brazilian propolis, characterized by prenylated phenylpropanoids and caffeoylquinic acids, stemming from Cabo Verde (Bahia state), Lavras and Mira Bela (Minas Gerais state), Pariquera-Açu and Bauru (São Paulo state), and Ponta Grossa (Paraná state). The present work represents the first report of prenylated flavonoids in Brazilian propolis and schaftoside (apigenin-8-C-glucosyl-6-C-arabinose) in green propolis. PMID:23690840

  2. Development of near infrared spectroscopy models for the quantitative prediction of the lignocellulosic components of wet Miscanthus samples.

    Science.gov (United States)

    Hayes, Daniel J M

    2012-09-01

    Miscanthus samples were scanned over the visible and near infrared wavelengths at several stages of processing (wet-chopped, air-dried, dried and ground, and dried and sieved). Models were developed to predict lignocellulosic and elemental constituents based on these spectra. The dry and sieved scans gave the most accurate models; however the wet-chopped models for glucose, xylose, and Klason lignin provided excellent accuracies with root mean square error of predictions of 1.27%, 0.54%, and 0.93%, respectively. These models can be suitable for most applications. The wet models for arabinose, Klason lignin, acid soluble lignin, ash, extractives, rhamnose, acid insoluble residue, and nitrogen tended to have lower R(2) values (0.80+) for the validation sets and the wet models for galactose, mannose, and acid insoluble ash were less accurate, only having value for rough sample screening. This research shows the potential for online analysis at biorefineries for the major lignocellulosic constituents of interest. PMID:22771552

  3. Purification, characterization and biological activity of a novel polysaccharide from Inonotus obliquus.

    Science.gov (United States)

    Chen, Yiyong; Huang, Youru; Cui, Zhumei; Liu, Jingjing

    2015-08-01

    A novel water-soluble polysaccharide IP3a was successfully isolated and purified from I. obliquus by DEAE-cellulose, Sepharose CL-6B and Sephadex G-200 column chromatography. Chemical characterization and antitumor and immunoregulatory activity of IP3a were investigated. IP3a consisted of rhamnose, arabinose, glucose and galactose in a molar ratio of 2.5:4.6:1.0:2.6 with an average molecular weight of 48,820 Da. IP3a exhibited no significant antitumor activities in vitro. However, IP3a could not only inhibit the growth of transplantable Jurkat tumor in mice significantly, but also could enhance the splenocyte proliferation and lymphocyte proliferation induced by ConA and LPS in a dose-dependent manner. At the same time, IP3a could promote cytokine secretion (IL-2, IL-6, IL-12 and TNF-α) and macrophage phagocytosis in mice. In addition, IP3a could increase Bax expression and inhibit Bcl-2 expression significantly. These results suggested that antitumor mechanisms of IP3a might be associated with improving immune response in vivo and inducing apoptosis of tumor cells in vitro. IP3a might be utilized as a potential therapeutic agent against lymphoma cancer with immunomodulatory activity. PMID:26026982

  4. Optimization of hydroxyl radical scavenging activity of exo-polysaccharides from Inonotus obliquus in submerged fermentation using response surface methodology.

    Science.gov (United States)

    Chen, Hui; Xu, Xiangqun; Zhu, Yang

    2010-04-01

    The objectives of this study were to investigate the effect of fermentation medium on the hydroxyl radical scavenging activity of exo-polysaccharides from Inonotus obliquus by response surface methodology. A two-level fractional factorial design was used to evaluate the effect of different components of medium. Corn flour, peptone, and KH2PO4 were important factors significantly affecting hydroxyl radical scavenging activity. These selected variables were subsequently optimized using path of steepest ascent (descent), a central composite design, and response surface analysis. The optimal medium composition was (% w/v): corn flour 5.30, peptone 0.32, KH2PO4 0.26, MgSO4 0.02, and CaCl2 0.01. Under the optimal condition, the hydroxyl radical scavenging rate (49.4%) was much higher than that using either basal fermentation medium (10.2%) and single variable optimization of fermentation medium (35.5%). The main monosaccharides components of the RSM optimized polysaccharides are rhamnose, arabinose, xylose, mannose, glucose and galactose with molar proportion at 1.45%, 3.63%, 2.17%, 15.94%, 50.00%, and 26.81%. PMID:20467262

  5. Evaluation of Carbohydrates in Natural and Cultured Cordyceps by Pressurized Liquid Extraction and Gas Chromatography Coupled with Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Jia Guan

    2010-06-01

    Full Text Available Free and polymeric carbohydrates in Cordyceps, a valued edible mushroom and well-known traditional Chinese medicine, were determined using stepwise pressurized liquid extraction (PLE extraction and GC-MS. Based on the optimized PLE conditions, acid hydrolysis and derivatization, ten monosaccharides, namely rhamnose, ribose, arabinose, xylose, mannose, glucose, galactose, mannitol, fructose and sorbose in 13 samples of natural and cultured Cordyceps were qualitatively and quantitatively analyzed and compared with myo-inositol hexaacetate as internal standard. The results showed that natural C. sinensis contained more than 7.99% free mannitol and a small amount of glucose, while its polysaccharides were usually composed of mannose, glucose and galactose with a molar ratio of 1.00:16.61~3.82:1.60~1.28. However, mannitol in cultured C. sinensis and cultured C. militaris were less than 5.83%, and free glucose was only detected in a few samples, while their polysaccharides were mainly composed of mannose, glucose and galactose with molar ratios of 1.00:3.01~1.09:3.30~1.05 and 1.00:2.86~1.28:1.07~0.78, respectively. Natural and cultured Cordyceps could be discriminated by hierarchical clustering analysis based on its free carbohydrate contents.

  6. Bis-Indole Derivatives for Polysaccharide Compositional Analysis and Chiral Resolution of D-, L-Monosaccharides by Ligand Exchange Capillary Electrophoresis Using Borate-Cyclodextrin as a Chiral Selector

    Directory of Open Access Journals (Sweden)

    Wen-Bin Yang

    2011-02-01

    Full Text Available A series of aldo-bis-indole derivatives (aldo-BINs was prepared by aromatic C-alkylation reactions of aldoses and indole in acetic acid solution. Common monosaccharides such as glucose, mannose, galactose, fucose, xylose, rhamnose, ribose, arabinose and N-acetylglucosamine were smoothly derivatized to form the UV absorbing aldo-BINs. The use of a capillary electrophoretic method to separate these novel aldo-BIN derivatives was established. The capillary electrophoresis conditions were set by using borate buffer (100 mM at high pH (pH 9.0. The limit of determination was assessed to be 25 nM. The enantioseparation of D, L-pairs of aldo-BINs based on chiral ligand-exchange capillary electrophoresis technology was also achieved by using modified hydroxypropyl-β-cyclodextrin as the chiral selector in the presence of borate buffer. This aldose labeling method was applied successfully to the compositional and configurational analysis of saccharides, exemplified by a rapid and efficient method to simultaneously analyze the composition and configuration of saccharides from the medicinal herbs Cordyceps sinensis and Dendrobium huoshanense.

  7. Structural elucidation of a pectin from flowers of Lonicera japonica and its antipancreatic cancer activity.

    Science.gov (United States)

    Lin, Liyan; Wang, Peipei; Du, Zhenyun; Wang, Wucheng; Cong, Qifei; Zheng, Changping; Jin, Can; Ding, Kan; Shao, Chenghao

    2016-07-01

    To investigate polysaccharide structure from Lonicera japonica, and study its effects on behavior of pancreatic cells, a homogenous polysaccharide, LJ-02-1, was extracted and purified from flowers of L. japonica by DEAE-cellulose and Sephacryl S-200HR column. The molecular weight was estimated to be 54kDa. Monosaccharide composition was determined to be rhamnose, galacturonic acid, galactose and arabinose in the molar ratio of 10.77:7.88:15.45:65.89 by analyzing the PMP derivatives of the monosaccharides from 2M trifluoracetic acid hydrolysis via HPLC. Based on methylation analysis, partial acid hydrolysis, and NMR spectra, the polysaccharide was elucidated to be a rhamnogalacturonan backbone and substituted partly at C-4 of rhamnose. The branches were determined to be T- and 1,4,6-linked β-d-Galp, T- and 1,5-linked α-l-Araf. The polysaccharide might inhibit BxPC-3 and PANC-1 pancreatic cancer cells growth at the concentration of 1mg/mL with inhibitory ratio of 66.7% and 52.1%, respectively. PMID:27000440

  8. The FRIABLE1 gene product affects cell adhesion in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Lutz Neumetzler

    Full Text Available Cell adhesion in plants is mediated predominantly by pectins, a group of complex cell wall associated polysaccharides. An Arabidopsis mutant, friable1 (frb1, was identified through a screen of T-DNA insertion lines that exhibited defective cell adhesion. Interestingly, the frb1 plants displayed both cell and organ dissociations and also ectopic defects in organ separation. The FRB1 gene encodes a Golgi-localized, plant specific protein with only weak sequence similarities to known proteins (DUF246. Unlike other cell adhesion deficient mutants, frb1 mutants do not have reduced levels of adhesion related cell wall polymers, such as pectins. Instead, FRB1 affects the abundance of galactose- and arabinose-containing oligosaccharides in the Golgi. Furthermore, frb1 mutants displayed alteration in pectin methylesterification, cell wall associated extensins and xyloglucan microstructure. We propose that abnormal FRB1 action has pleiotropic consequences on wall architecture, affecting both the extensin and pectin matrices, with consequent changes to the biomechanical properties of the wall and middle lamella, thereby influencing cell-cell adhesion.

  9. Endo-xylanase and endo-cellulase-assisted extraction of pectin from apple pomace.

    Science.gov (United States)

    Wikiera, Agnieszka; Mika, Magdalena; Starzyńska-Janiszewska, Anna; Stodolak, Bożena

    2016-05-20

    Pectins were extracted from apple pomace with monoactive preparation of endo-xylanase and endo-cellulase. The process was conducted for 10h in conditions of pH 5.0 at 40°C, with constant shaking. Endo-xylanase application resulted in the highest extraction efficiency of pectins (19.8%). The obtained polymer was characterised by a very high molecular mass, high level of neutral sugars - mainly arabinose, galactose and glucose, and very high DM (73.4). It also contained the highest level of protein and phenols. Pectin extracted with endo-cellulase had 1.5 fold lower molecular mass but contained significantly more GalA (70.5%) of a high degree of methylation (66.3%). The simultaneous application of both enzymatic preparations resulted in their cooperation, leading to a decrease of both the extraction efficiency and the molecular mass of pectin. However, this pectin was distinguished by the highest GalA (74.7%) and rhamnose contents. PMID:26917391

  10. Intestinal Water Absorption Varies with Expected Dietary Water Load among Bats but Does Not Drive Paracellular Nutrient Absorption.

    Science.gov (United States)

    Price, Edwin R; Brun, Antonio; Gontero-Fourcade, Manuel; Fernández-Marinone, Guido; Cruz-Neto, Ariovaldo P; Karasov, William H; Caviedes-Vidal, Enrique

    2015-01-01

    Rapid absorption and elimination of dietary water should be particularly important to flying species and were predicted to vary with the water content of the natural diet. Additionally, high water absorption capacity was predicted to be associated with high paracellular nutrient absorption due to solvent drag. We compared the water absorption rates of sanguivorous, nectarivorous, frugivorous, and insectivorous bats in intestinal luminal perfusions. High water absorption rates were associated with high expected dietary water load but were not highly correlated with previously measured rates of (paracellular) arabinose clearance. In conjunction with these tests, we measured water absorption and the paracellular absorption of nutrients in the intestine and stomach of vampire bats using luminal perfusions to test the hypothesis that the unique elongated vampire stomach is a critical site of water absorption. Vampire bats' gastric water absorption was high compared to mice but not compared to their intestines. We therefore conclude that (1) dietary water content has influenced the evolution of intestinal water absorption capacity in bats, (2) solvent drag is not the only driver of paracellular nutrient absorption, and (3) the vampire stomach is a capable but not critical location for water absorption. PMID:26658415

  11. Vegetable fiber fermentation by human fecal bacteria: cell wall polysaccharide disappearance and short-chain fatty acid production during in vitro fermentation and water-holding capacity of unfermented residues.

    Science.gov (United States)

    Bourquin, L D; Titgemeyer, E C; Fahey, G C

    1993-05-01

    Dietary fiber from eight vegetables (broccoli, carrot, cauliflower, celery, cucumber, lettuce, onion and radish) was analyzed for chemical composition and potential in vitro fermentation by human fecal bacteria. Total dietary fiber concentration of substrates ranged from 34.9 (broccoli) to 5.8 (cucumber) g/kg edible matter. Substrate fiber fractions were composed primarily of pectic substances and cellulose with smaller concentrations of hemicelluloses and lignin. Total dietary fiber residues isolated from substrates were fermented in vitro for 24 h with fecal bacteria obtained from each of three human volunteers. Substrate dry matter disappearance during fermentation was highest for carrot (63.7%) and lowest for cucumber (49.4%). Averaged across all substrates, disappearances of arabinose, galactose, glucose, mannose, xylose and uronic acids during fermentation were 96, 90, 54, 68, 51 and 97%, respectively. Short-chain fatty acid (SCFA) production during substrate fermentation averaged 10.5 mmol SCFA/g dry matter fermented. Averaged across all substrates, production of the major SCFA, acetate, propionate and butyrate, occurred in the molar ratio 76:14:10. Potential water-holding capacity of substrates was not influenced by fiber source and averaged 2.04 g H2O/g original substrate dry matter. Extent of substrate fermentation, SCFA production and substrate potential water-holding capacity were significantly different among inoculum donors, indicating that considerable inter-individual variation exists in the potential in vivo fermentation of vegetable fiber. PMID:8387579

  12. [Optimization of liquid ammonia treatment for enzymatic hydrolysis of Saccharum arundinaceum to fermentable sugars].

    Science.gov (United States)

    Liu, Jianjun; Peng, Hehuan; Zhao, Xiangjun; Cheng, Cheng; Chen, Feng; Shao, Qianjun

    2013-03-01

    China has abundant available marginal land that can be used for cultivation of lignocellulosic energy plants. Saccharum arundinaceum Retz. is a potential energy crop with both high biomass yield and low soil fertility requirements. It can be planted widely as cellulosic ethanol feedstock in southern China. In the present work Saccharum arundinaceum was pretreated by liquid ammonia treatment (LAT) to overcome biomass recalcitrance, followed by enzymatic hydrolysis. The monosaccharide contents (glucose, xylose, and arabinose) of the enzymatic hydrolysate were determined by high performance liquid chromatography. Experimental results show that the optimal LAT pretreatment conditions were 130 0C, 2:1 (W/W) ammonia to biomass ratio, 80% moisture content (dry weight basis) and 5 min residence time. Approximately 69.34% glucan and 82.60% xylan were converted after 72 h enzymatic hydrolysis at 1% glucan loading using 15 FPU/(g of glucan) of cellulase. The yields of glucose and xylose were 573% and 1 056% higher than those of the untreated biomass, and the LAT-pretreated substrates obtained an 8-fold higher of total monosaccharide yield than untreated substrates. LAT pretreatment was an effective to increase the enzymatic digestibility of Saccharum arundinaceum compared to acid impregnated steam explosion and similar to that of acid treatment and ammonia fiber expansion treatment. PMID:23789274

  13. Application and comparison of four selected procedures for the isolation of cell-wall material from the skin of grapes cv. Monastrell

    Energy Technology Data Exchange (ETDEWEB)

    Apolinar-Valiente, R., E-mail: tokay04@hotmail.com [Departamento de Tecnologia de Alimentos, Nutricion y Bromatologia, Facultad de Veterinaria, Universidad de Murcia, Campus de Espinardo, 30100 Murcia (Spain); Romero-Cascales, I., E-mail: miromero@um.es [Departamento de Tecnologia de Alimentos, Nutricion y Bromatologia, Facultad de Veterinaria, Universidad de Murcia, Campus de Espinardo, 30100 Murcia (Spain); Lopez-Roca, J.M., E-mail: jmlroca@um.es [Departamento de Tecnologia de Alimentos, Nutricion y Bromatologia, Facultad de Veterinaria, Universidad de Murcia, Campus de Espinardo, 30100 Murcia (Spain); Gomez-Plaza, E., E-mail: encarnag@um.es [Departamento de Tecnologia de Alimentos, Nutricion y Bromatologia, Facultad de Veterinaria, Universidad de Murcia, Campus de Espinardo, 30100 Murcia (Spain); Ros-Garcia, J.M., E-mail: jmros@um.es [Departamento de Tecnologia de Alimentos, Nutricion y Bromatologia, Facultad de Veterinaria, Universidad de Murcia, Campus de Espinardo, 30100 Murcia (Spain)

    2010-02-15

    In order to choose an appropriate cell-wall material (CWM) isolation procedure in grapes cv. Monastrell, four different standard procedures have been tested, and a comparison made of the amount of cell-wall material obtained, its composition and morphology. The CWM was isolated as the 70% ethanol insoluble residue (de Vries method), as the absolute ethanol insoluble residue filtered sequentially through nylon mesh (Nunan method), as the insoluble residue in sodium deoxycholate-phenol-acetic acid-water (Selvendran method) and as the N-[2-hydroxyethyl]-piperazine-N'-2-ethanesulfonic acid (HEPES) insoluble residue (Vidal method). All extractions were done in triplicate and the efficiency of the extractive procedure established. Carbohydrates, proteins, and phenolic compounds were analysed, as the main constituents of CWM. The morphology of the isolated CWM was visualized by scanning electron microscopy (SEM). The Selvendran method had the highest efficiency, while the Nunan method had the lower one. Regarding the carbohydrates composition, the four different CWM were rich in uronic acids and glucose, together with varying amounts of arabinose, xylose, mannose and galactose. The Selvendran method had the lower value of total carbohydrates and the CWM shows more plasmatic membrane impurities in SEM images. The chemical results of the Vidal and de Vries methods were quite similar, but the Vidal method was more time consuming than the de Vries method. According to the results, the de Vries method was chosen to produce a representative cell-wall material fraction from Monastrell grapes skin.

  14. 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

  15. Purification and characterization of a novel polysaccharide-peptide complex from Clinacanthus nutans Lindau leaves.

    Science.gov (United States)

    Huang, Danmin; Li, Yunhong; Cui, Fengjie; Chen, Jun; Sun, Jiamin

    2016-02-10

    A novel polysaccharide-peptide complex CNP-1-2 with molecular weight of 9.17 × 10(4) Da was obtained from Clinacanthus nutans Lindau leaves by hot water extraction, ethanol precipitation, and purification with Superdex 200 and DEAE-Sepharose Fast Flow column chromatography. CNP-1-2 exhibited the highest growth inhibitory effect on human gastric cancer cells SGC-7901 with inhibition ratio of 92.34% and stimulated activation of macrophages with NO secretion level of 47.53 μmol/L among the polysaccharide fractions. CNP-1-2 comprised approximately 87.25% carbohydrate and 9.37% protein. Monosaccharide analysis suggested that CNP-1-2 was composed of L-rhamnose, l-arabinose, D-mannose, D-glucose and D-galactose with a molar ratio of 1.30:1.00:2.56:4.95:5.09. Methylation analysis, FT-IR, and (1)H NMR spectroscopy analysis revealed that CNP-1-2 might have a backbone consisting of 1,4-linked Glcp, 1,3-linked Glcp, 1,3-linked Manp, 1,4-linked Galp, 1,2,6-linked Galp and 1,2,6-linked Galp. Its side chain might be composed of 1-linked Araf, 1,6-linked Galp and 1-linked Rhap residues. AFM (atomic force micrograph) analysis revealed that CNP-1-2 had the molecular aggregation along with branched and entangled structure. PMID:26686182

  16. Structural characterization and anticancer activity of cell-bound exopolysaccharide from Lactobacillus helveticus MB2-1.

    Science.gov (United States)

    Li, Wei; Xia, Xiudong; Tang, Weizhi; Ji, Juan; Rui, Xin; Chen, Xiaohong; Jiang, Mei; Zhou, Jianzhong; Zhang, Qiuqin; Dong, Mingsheng

    2015-04-01

    A novel cell-bound exopolysaccharide (c-EPS) was isolated from Lactobacillus helveticus MB2-1 by ultrasonic extraction, anion exchange, and gel filtration chromatography before being structurally characterized. The c-EPS is a heteropolysaccharide with an average molecular weight of 1.83 × 10(5) Da and is composed of glucose, mannose, galactose, rhamnose, and arabinose at a molar ratio of 3.12:1.01:1.00:0.18:0.16. Methylation analysis and nuclear magnetic resonance analysis revealed that the c-EPS is a linear glucomannogalactan containing repeating units of → 6)-β-D-Manp-(1 → 3)-β-D-Glcp-(1 → 3)-β-D-Glcp-(1 → 3)-β-D-Glcp-(1 → 4)-α-D-Galp-(1 → and trace amounts of Rhap-(1 → and (1 → 4)-Arap residues. Complex formation with Congo red demonstrated a triple-strand helical conformation for the c-EPS. Scanning electron microscopy of the c-EPS revealed many regular feather-like structural units. Topographical examination of c-EPS by atomic force microscopy revealed that the c-EPS formed rounded-to-spherical lumps with different sizes and chain formations. Furthermore, preliminary in vitro tests revealed that c-EPS significantly inhibited the proliferation of HepG-2, BGC-823, and especially HT-29 cancer cells. PMID:25798529

  17. Label-free Quantitative Proteomics for the Extremely Thermophilic Bacterium Caldicellulosiruptor obsidiansis Reveal Distinct Abundance Patterns upon Growth on Cellobiose, Crystalline Cellulose, and Switchgrass

    Energy Technology Data Exchange (ETDEWEB)

    Giannone, Richard J [ORNL; Lochner, Adriane [ORNL; Keller, Martin [ORNL; Antranikian, Garabed [Technische Universitat Hamburg-Harburg (Hamburg University of Technology); Graham, David E [ORNL; Hettich, Robert {Bob} L [ORNL

    2011-01-01

    Mass spectrometric analysis of Caldicellulosiruptor obsidiansis cultures grown on four different carbon sources identified 65% of the cells predicted proteins in cell lysates and supernatants. Biological and technical replication together with sophisticated statistical analysis were used to reliably quantify protein abundances and their changes as a function of carbon source. Extracellular, multifunctional glycosidases were significantly more abundant on cellobiose than on the crystalline cellulose substrates Avicel and filter paper, indicating either disaccharide induction or constitutive protein expression. Highly abundant flagellar, chemotaxis, and pilus proteins were detected during growth on insoluble substrates, suggesting motility or specific substrate attachment. The highly abundant extracellular binding protein COB47-0549 together with the COB47-1616 ATPase might comprise the primary ABC-transport system for cellooligosaccharides, while COB47-0096 and COB47-0097 could facilitate monosaccharide uptake. Oligosaccharide degradation can occur either via extracellular hydrolysis by a GH1 {beta}-glycosidase or by intracellular phosphorolysis using two GH94 enzymes. When C. obsidiansis was grown on switchgrass, the abundance of hemicellulases (including GH3, GH5, GH51, and GH67 enzymes) and certain sugar transporters increased significantly. Cultivation on biomass also caused a concerted increase in cytosolic enzymes for xylose and arabinose fermentation.

  18. Evolved resistance to colistin and its loss due to genetic reversion in Pseudomonas aeruginosa.

    Science.gov (United States)

    Lee, Ji-Young; Park, Young Kyoung; Chung, Eun Seon; Na, In Young; Ko, Kwan Soo

    2016-01-01

    The increased reliance on colistin for treating multidrug-resistant Gram-negative bacterial infections has resulted in the emergence of colistin-resistant Pseudomonas aeruginosa. We attempted to identify genetic contributors to colistin resistance in vitro evolved isogenic colistin-resistant and -susceptible strains of two P. aeruginosa lineages (P5 and P155). Their evolutionary paths to acquisition and loss of colistin resistance were also tracked. Comparative genomic analysis revealed 13 and five colistin resistance determinants in the P5 and P155 lineages, respectively. Lipid A in colistin-resistant mutants was modified through the addition of 4-amino-L-arabinose; this modification was absent in colistin-susceptible revertant strains. Many amino acid substitutions that emerged during the acquisition of colistin resistance were reversed in colistin-susceptible revertants. We demonstrated that evolved colistin resistance in P. aeruginosa was mediated by a complicated regulatory network that likely emerges through diverse genetic alterations. Colistin-resistant P. aeruginosa became susceptible to the colistin upon its withdrawal because of genetic reversion. The mechanisms through which P. aeruginosa acquires and loses colistin resistance have implications on the treatment options that can be applied against P. aeruginosa infections, with respect to improving bactericidal efficacy and preventing further resistance to antibiotics. PMID:27150578

  19. Spectrum of activity and mechanisms of resistance of various nucleoside derivatives against gammaherpesviruses.

    Science.gov (United States)

    Coen, Natacha; Duraffour, Sophie; Topalis, Dimitri; Snoeck, Robert; Andrei, Graciela

    2014-12-01

    The susceptibilities of gammaherpesviruses, including Epstein-Barr virus (EBV), Kaposi's sarcoma-associated herpesvirus (KSHV), and animal rhadinoviruses, to various nucleoside analogs was investigated in this work. Besides examining the antiviral activities and modes of action of antivirals currently marketed for the treatment of alpha- and/or betaherpesvirus infections (including acyclovir, ganciclovir, penciclovir, foscarnet, and brivudin), we also investigated the structure-activity relationship of various 5-substituted uridine and cytidine molecules. The antiviral efficacy of nucleoside derivatives bearing substitutions at the 5 position was decreased if the bromovinyl was replaced by chlorovinyl. 1-β-D-Arabinofuranosyl-(E)-5-(2-bromovinyl)uracil (BVaraU), a nucleoside with an arabinose configuration of the sugar ring, exhibited no inhibitory effect against rhadinoviruses but was active against EBV. On the other hand, the fluoroarabinose cytidine analog 2'-fluoro-5-iodo-aracytosine (FIAC) showed high selectivity indices against gammaherpesviruses that were comparable to those of brivudin. Additionally, we selected brivudin- and acyclovir-resistant rhadinoviruses in vitro and characterized them by phenotypic and genotypic (i.e., sequencing of the viral thymidine kinase, protein kinase, and DNA polymerase) analysis. Here, we reveal key amino acids in these enzymes that play an important role in substrate recognition. Our data on drug susceptibility profiles of the different animal gammaherpesvirus mutants highlighted cross-resistance patterns and indicated that pyrimidine nucleoside derivatives are phosphorylated by the viral thymidine kinase and purine nucleosides are preferentially activated by the gammaherpesvirus protein kinase. PMID:25267682

  20. Nocardia casuarinae sp. nov., an actinobacterial endophyte isolated from root nodules of Casuarina glauca.

    Science.gov (United States)

    Ghodhbane-Gtari, Faten; Nouioui, Imen; Salem, Karima; Ktari, Amir; Montero-Calasanz, Maria del Carmen; Tisa, Louis S; Klenk, Hans-Peter; Gtari, Maher

    2014-06-01

    An actinobacterium strain BMG51109a was isolated from surface sterilized root nodules of Casuarina glauca collected in Tunisia. The 16S rRNA gene sequence of strain BMG51109a showed most similarity (96.53-96.55 %) to the type strains of Nocardia transvalensis, N. aobensis and N. elegans. Chemotaxonomic analysis supported the assignment of the strain to Nocardia genus. The major menaquinone was MK-8(H4c) while the polar lipid profile contained diphosphatidylglycerol, phosphatidylmonomethylethanolamine, glycophospholipid, phosphatidylinositol, one uncharacterized phospholipid and three glycolipids. Whole-cell sugar analysis revealed the presence of meso-diaminopimelic acid, arabinose and galactose as diagnostic sugars, complemented by glucose, mannose and ribose. The major cellular fatty acids were tuberculostearic, oleic, palmitoleic and stearic acids. Physiological and biochemical tests showed that strain BMG51109a could be clearly distinguished from its closest phylogenetic neighbours. On the basis of these results, strain BMG51109a(T) (= DSM 45978(T) = CECT 8469(T)) is proposed as the type strain of the novel species Nocardia casuarinae sp. nov. PMID:24715251

  1. Nutritional Profile and Carbohydrate Characterization of Spray-Dried Lentil, Pea and Chickpea Ingredients

    Directory of Open Access Journals (Sweden)

    Susan M. Tosh

    2013-07-01

    Full Text Available Although many consumers know that pulses are nutritious, long preparation times are frequently a barrier to consumption of lentils, dried peas and chickpeas. Therefore, a product has been developed which can be used as an ingredient in a wide variety of dishes without presoaking or precooking. Dried green peas, chickpeas or lentils were soaked, cooked, homogenized and spray-dried. Proximate analyses were conducted on the pulse powders and compared to an instant mashed potato product. Because the health benefits of pulses may be due in part to their carbohydrate content, a detailed carbohydrate analysis was carried out on the pulse powders. Pulse powders were higher in protein and total dietary fibre and lower in starch than potato flakes. After processing, the pulse powders maintained appreciable amounts of resistant starch (4.4%–5.2%. Total dietary fibre was higher in chickpeas and peas (26.2% and 27.1% respectively than lentils (21.9%, whereas lentils had the highest protein content (22.7%. Pulse carbohydrates were rich in glucose, arabinose, galactose and uronic acids. Stachyose, a fermentable fibre, was the most abundant oligosaccharide, making up 1.5%–2.4% of the dried pulse powders. Spray-drying of cooked, homogenized pulses produces an easy to use ingredient with strong nutritional profile.

  2. Identification of Cultured and Natural Astragalus Root Based on Monosaccharide Mapping

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    Ke Li

    2015-09-01

    Full Text Available As the main substances responsible for immunomodulatory activity, saccharides can be used as quality indicators for Astragalus root (RA. Saccharide content is commonly determined by ultraviolet spectroscopy, which lacks species specificity and has not been applied in the Chinese Pharmacopoeia. Monosaccharide mapping based on trifluoroacetic acid (TFA hydrolysis can be used for quantitative analysis of saccharide compositions. In addition, species specificity can be evaluated by analysis of the mapping characteristics. In this study, monosaccharide mapping of soluble saccharides in the cytoplasm and polysaccharides in the cell wall of 24 batches of RA samples with different growth patterns were obtained based on TFA hydrolysis followed by gas chromatography-mass spectrometry. Results indicated that the mapping and the molar ratios of saccharide compositions of the cultured and natural RA samples were different for both cytoplasm and cell wall. For example, the molar ratio of mannose and arabinose was more than 3.5:1 in cytoplasm in cultured RA, whereas the ratio was less than 3.5:1 in natural RA. This research not only lays a foundation for screening indicators for RA, but also provided new ways of evaluating the quality of Chinese medicinal materials in which saccharides are the main bioactive substances.

  3. Evaluation of a Native Preparation of HCV Core Protein (2-122 For Potential Applications in Immunization, Diagnosis and Mab Production

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    MR Aghasadeghi

    2006-05-01

    Full Text Available Infection with hepatitis C virus (HCV is a worldwide problem. Among HCV proteins, core antigen (Ag, besides its importance for diagnostic application is a prime candidate for component of a vaccine. Herein, we report results of studies on production of the hydrophilic domain of core Ag (2-122 in native conformation by an arabinose induction system in E.coli and the primary characterization of this recombinant protein for applications in diagnosis, immunization and mAb production. Recombinant core (r-Core was able to detect anti-core antibodies in HCV positive serum samples in a dilution rate of 1/3200. It was also capable to elicit a potent anti-HCV humoral immune response in BALB/c mice. Finally, we established two stable clones of hybridoma which shown to produce specific and sensitive mAbs against the core protein. HCV core was able to elicit a broad range of antibody specificities depending on the immunogen conformation. Therefore, it may be possible to get new mAbs with higher affinities towards native conformation of core Ag.

  4. 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

  5. An efficient amperometric transketolase assay: towards inhibitor screening.

    Science.gov (United States)

    Touisni, Nadia; Charmantray, Franck; Hélaine, Virgil; Hecquet, Laurence; Mousty, Christine

    2014-12-15

    This paper describes an innovative amperometric biosensor for the in vitro determination of activity of transketolase from Escherichia coli (TKec) using commercially available TK substrates, namely d-fructose-6-phosphate a physiological donor and glycolaldehyde the best non-phosphorylated acceptor. A galactose oxidase (GAOx) biosensor, based on the immobilization of this enzyme within laponite clay, allows amperometric detection of L-erythrulose released upon TK-catalyzed reaction. A calibration curve has been established from 0.01 to 0.1 U ml(-1) TKec concentration in solution. These data are comparable to that obtained by a fluorometric method. In order to ensure a higher sensitivity and re-usability of the system, an original bienzymatic sensing system was further developed based on apoenzyme TKec and GAOx separately immobilized on the electrode surface. The inner sensing layer contains GAOx@laponite and the outer layer TKec@layered double hydroxide biohybrid. The biosensor response was validated by the determination of KD(app) for thiamine diphosphate, the TK cofactor and the inhibition action of two commercially available products, pyrophosphate, a TK cofactor analog and d-arabinose-5-phosphate, a substrate analog. PMID:24984289

  6. Evaluation of different lignocellulosic biomass pretreatments by phenotypic microarray-based metabolic analysis of fermenting yeast

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    Stuart Wilkinson

    2016-03-01

    Full Text Available Advanced generation biofuel production from lignocellulosic material (LCM was investigated.  A range of different thermo-chemical pre-treatments were evaluated with different LCM. The pre-treatments included; alkaline (5% NaOH at 50°C, acid (1% H2SO4 at 121°C and autohydrolytical methods (200°C aqueous based hydrothermal and were evaluated using samples of miscanthus, wheat-straw and willow. The liberation of sugars, presence of inhibitory compounds, and the degree of enhancement of enzymatic saccharification was accessed. The suitability of the pre-treatment generated hydrolysates (as bioethanol feedstocks for Saccharomyces cerevisiae was also accessed using a phenotypic microarray that measured yeast metabolic output. The use of the alkaline pre-treatment liberated more glucose and arabinose into both the pre-treatment generated hydrolysate and also the hydrolysate produced after enzymatic hydrolysis (when compared with other pre-treatments. However, hydrolysates derived from use of alkaline pre-treatments were shown to be unsuitable as a fermentation medium due to issues with colloidal stability (high viscosity.  Use of acid or autohydrolytical pre-treatments liberated high concentrations of monosaccharides regardless of the LCM used and the hydrolysates had good fermentation performance with measurable yeast metabolic output. Acid pre-treated wheat straw hydrolysates were then used as a model system for larger scale fermentations to confirm both the results of the phenotypic microarray and its validity as an effective high-throughput screening tool.

  7. Co-utilization of glycerol and lignocellulosic hydrolysates enhances anaerobic 1,3-propanediol production by Clostridium diolis.

    Science.gov (United States)

    Xin, Bo; Wang, Yu; Tao, Fei; Li, Lixiang; Ma, Cuiqing; Xu, Ping

    2016-01-01

    Anaerobic fermentation using lignocellulosic hydrolysates as co-substrates is an economically attractive method to enhance 1,3-propanediol (1,3-PD) production by increasing the conversion yield from glycerol. Lignocellulosic hydrolysates contain the mixed sugars that are primarily glucose, xylose, and arabinose. Therefore, these three individual sugars were used, separately, as co-substrates with glycerol, in 1,3-PD production by a Clostridium diolis strain DSM 15410, resulting in an 18%-28% increase in the 1,3-PD yield. Co-fermentation of the mixed sugars and glycerol obtained a higher intracellular NADH/NAD(+) ratio and increased the 1,3-PD yield by 22% relative to fermentation of glycerol alone. Thereafter, two kinds of lignocellulosic hydrolysates, corn stover hydrolysate and corncob molasses, were individually co-fermented with glycerol. The maximum 1,3-PD yield from glycerol reached 0.85 mol/mol. Fed-batch co-fermentation was also performed, improving the 1,3-PD yield (from 0.62 mol/mol to 0.82 mol/mol). These results demonstrate that the co-fermentation strategy is an efficient and economical way to produce 1,3-PD from glycerol. PMID:26750307

  8. Structural characterisation and rheological properties of a polysaccharide from sesame leaves (Sesamum radiatum Schumach. & Thonn.).

    Science.gov (United States)

    Nep, E I; Carnachan, S M; Ngwuluka, N C; Kontogiorgos, V; Morris, G A; Sims, I M; Smith, A M

    2016-11-01

    A polysaccharide from the leaves of Sesamum radiatum was extracted by maceration in deionized water followed by ethanol precipitation then chemically and physically characterised. Monosaccharide composition and linkages were determined by high performance anion exchange chromatography (HPAEC), gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR) spectroscopy respectively. Sesamum gum was composed of glucuronic acid, mannose, galactose, and xylose with trace quantities of glucose, rhamnose and arabinose. Proton and (13)C NMR spectroscopy, and linkage analysis revealed a glucuronomannan based structure comprising a backbone of →4)-β-d-GlcpA-(1→2)-α-d-Manp-(1→ with side-chains of galactose and xylose. Hydrated sesamum gum displayed temperature independent viscoelastic properties with no thermal hysteresis. Intrinsic viscosity was determined to be 3.31 and 4.40dLg(-1) in 0.1M NaCl and deionised water respectively, while the critical concentration was determined to be 0.1% w/v. The characterisation performed in this study will help direct potential applications of this material in foods and pharmaceuticals. PMID:27516302

  9. Modification of Pectin and Hemicellulose Polysaccharides in Relation to Aril Breakdown of Harvested Longan Fruit

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    Duoduo Wang

    2013-11-01

    Full Text Available To investigate the modification of cell wall polysaccharides in relation to aril breakdown in harvested longan fruit, three pectin fractions (WSP, water soluble pectin; CSP, CDTA-soluble pectin; ASP, alkali soluble pectin and one hemicellulose fraction (4 M KOH-SHC, 4 M KOH-soluble hemicellulose were extracted, and their contents, monosaccharide compositions and molecular weights were evaluated. As aril breakdown intensified, CSP content increased while ASP and 4 M KOH-SHC contents decreased, suggesting the solubilization and conversion of cell wall components. Furthermore, the molar percentage of arabinose (Ara, as the main component of the side-chains, decreased largely in CSP and ASP while that of rhamnose (Rha, as branch point for the attachment of neutral sugar side chains, increased during aril breakdown. Analysis of (Ara + Gal/Rha ratio showed that the depolymerization of CSP and ASP happened predominantly in side-chains formed of Ara residues. For 4 M KOH-SHC, more backbones were depolymerized during aril breakdown. Moreover, it was found that the molecular weights of CSP, ASP and 4 M KOH-SHC polysaccharides tended to decrease as aril breakdown intensified. These results suggest that both enhanced depolymerization and structural modifications of polysaccharides in the CSP, ASP and 4 M KOH-SHC fractions might be responsible for aril breakdown of harvested longan fruit.

  10. Monosaccharides as silicon chelators: pentacoordinate bis(diolato)(phenyl)silicates with the cis-furanose isomers of common pentoses and hexoses.

    Science.gov (United States)

    Klüfers, Peter; Kopp, Florian; Vogt, Martin

    2004-09-20

    Five-coordinate phenylsilicates are formed from the reaction of trimethoxy(phenyl)silane with monosaccharides in methanol in the presence of a stoichiometric amount of base. Five complexes have been isolated and characterized with two ketoses and three aldopentoses. The silicon central atom in [K([18]crown-6)][PhSi(beta-D-Fruf 2,3H-2)2].MeOH (1, Fru=fructose) is part of two chelate rings, with the ligands being beta-D-fructofuranose-O2,O3 dianions. The beta-furanose isomer is best suited for silicon ligation because it exhibits a torsion angle close to 0 degrees for the most acidic diol function, thus assuring a flat chelate ring. The same structural principles are also found in [K([18]crown-6)][PhSi(beta-D-Araf1,2H-2)2].2 MeOH (2, Ara=arabinose), [K([18]crown-6)][PhSi(alpha-D-Ribf1,2H-2)2] (3, Rib=ribose), [K([18]crown-6)][PhSi(alpha-D-Xylf1,2H-2)2]. acetone (4, Xyl=xylose), and [K([18]crown-6)][PhSi(alpha-D-Rulf2,3H-2)2] (5, Rul=ribulose). PMID:15378633

  11. Fermentation of dried distillers' grains and solubles (DDGS) hydrolysates to solvents and value-added products by solventogenic clostridia.

    Science.gov (United States)

    Ezeji, Thaddeus; Blaschek, Hans P

    2008-08-01

    Pretreatment and hydrolysis of lignocellulosic biomass using either dilute acid, liquid hot water (LHW), or ammonium fiber expansion (AFEX) results in a complex mixture of sugars such as hexoses (glucose, galactose, mannose), and pentoses (xylose, arabinose). A detailed description of the utilization of representative mixed sugar streams (pentoses and hexoses) and their sugar preferences by the solventogenic clostridia (Clostridium beijerinckii BA101, C. acetobutylicum 260, C. acetobutylicum 824, Clostridium saccharobutylicum 262, and C. butylicum 592) is presented. In these experiments, all the sugars were utilized concurrently throughout the fermentation, although the rate of sugar utilization was sugar specific. For all clostridia tested, the rate of glucose utilization was higher than for the other sugars in the mixture. In addition, the availability of excess fermentable sugars in the bioreactor is necessary for both the onset and the maintenance of solvent production otherwise the fermentation will become acidogenic leading to premature termination of the fermentation process. During an investigation on the effect of some of the known lignocellulosic hydrolysate inhibitors on the growth and ABE production by clostridia, ferulic and p-coumaric acids were found to be potent inhibitors of growth and ABE production. Interestingly, furfural and HMF were not inhibitory to the solventogenic clostridia; rather they had a stimulatory effect on growth and ABE production at concentrations up to 2.0g/L. PMID:17967532

  12. Extraction and Characterization of Highly Gelling Low Methoxy Pectin from Cashew Apple Pomace

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    Beda M. Yapo

    2013-12-01

    Full Text Available Investigation on the pectic substances of cashew (Anacardium occidentale L. apple under different acid-extraction conditions (pH 1.0, 1.5, and 2.0 showed that more than 10%–25% of A. occidentale pectins (AOP could be extracted, depending on the extractant strength. The extracted AOP contained high amounts of galacturonic acid (GalA: 69.9%–84.5% with some neutral sugars of which rhamnose (Rha: 1.3%–2.5%, arabinose (Ara: 2.6%–5.4%, and galactose (Gal: 4.7%–8.6% were the main constituents. The degree of methoxylation (DM was in the range of 28%–46% and was only slightly affected by the extractant strength, thereby indicating isolation of naturally low methoxy pectins (LMP. In terms of gelling capability, AOP yielded firmer Ca2+-mediated LMP gels than commercial citrus LMP with comparable DM. Cashew apple pomace, therefore, appears to be a potentially viable source for possible production of “non-chemically or enzymatically-tailored” LMP.

  13. Characterization and degradation of pectin derived from Budimka apple

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    MILOS V. NIKOLIC

    2008-02-01

    Full Text Available The characterization of apple pectin and its oligogalacturonic fractions derived from the autochthones apple variety Budimka, characteristic for central Serbia, is described in this paper. After extraction, the apple pectin was subjected to controlled enzymatic hydrolysis by polygalacturonase (PG and pectin lyase (PL from Aspergillus niger and then fractionated by ion-exchange column chromatography on Dowex 1X-8 (200–400 mesh. Saturated oligogalacturonic acids, obtained by controlled hydrolysis with PG, were efficiently separated by elution with a gradient of Na acetate buffer (pH 6.0, while unsaturated oligogalacturonic acids, obtained by controlled hydrolysis with PL, were separated on the same resin, using a gradient of Na formate buffer (pH 4.7 as the eluent. The yields of the fractions with the particular degree of polymerization (DP were also determined. The total content of neutral saccharides in the original Budimka apple pectin was detected by HPLC analysis of the 4-nitrobenzoyl derivatives of the sugar, and amounted to 5.31 %. Among the neutral saccharides, contents of galactose, glucose, rhamnose, arabinose, xylose and mannose were detected.

  14. Influence of Carbohydrates on Secondary Metabolism in Fusarium avenaceum

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    Jens Laurids Sørensen

    2013-09-01

    Full Text Available Fusarium avenaceum is a widespread pathogen of important crops in the temperate climate zones that can produce many bioactive secondary metabolites, including moniliformin, fusarin C, antibiotic Y, 2-amino-14,16-dimethyloctadecan-3-ol (2-AOD-3-ol, chlamydosporol, aurofusarin and enniatins. Here, we examine the production of these secondary metabolites in response to cultivation on different carbon sources in order to gain insight into the regulation and production of secondary metabolites in F. avenaceum. Seven monosaccharides (arabinose, xylose, fructose, sorbose, galactose, mannose, glucose, five disaccharides (cellobiose, lactose, maltose, sucrose and trehalose and three polysaccharides (dextrin, inulin and xylan were used as substrates. Three F. avenaceum strains were used in the experiments. These were all able to grow and produce aurofusarin on the tested carbon sources. Moniliformin and enniatins were produced on all carbon types, except on lactose, which suggest a common conserved regulation mechanism. Differences in the strains was observed for production of fusarin C, 2-AOD-3-ol, chlamydosporol and antibiotic Y, which suggests that carbon source plays a role in the regulation of their biosynthesis.

  15. Deletion of alcohol dehydrogenase 2 gene in Pachysolen tannophilus improves ethanol production from corn stover hydrolysates

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    Sen Yang

    2015-12-01

    Full Text Available Although ethanol derived from lignocellulosic biomass is a promising alternative biofuel, the conversion rate of xylose to ethanol by fermentation is not ideal due to the low efficiency of many common yeasts in utilizing xylose. Pachysolen tannophilus can convert hexose and pentose such as L-arabinose, xylose and glucose in lignocellulosic hydrolysates to ethanol simultaneously. To increase the conversion of corn stover hydrolysates to bioethanol, the effect of alcohol dehydrogenase 2 gene (adh2 deletion in P. tannophilus on bioethanol production from corn stover hydrolysates was investigated. Two adh2 deletants (heterozygote ND and homozygote MC were constructed by using the short flanking homology PCR (SFH-PCR. The ND and MC strains showed lower alcohol dehydrogenase 2 (ADH2 activity than the initial strain P-01. In the fermented pentose and hexose sugars of MC and ND, the ethanol concentrations (g/L reached 15.8 and 18.9 versus14.6 of the initial P-01, while in the corn stover hydrolysate medium, the ethanol concentrations (g/L were 9.1 for MC and 9.8 for ND versus 7.5 for the initial strain P-01. This research provides useful information for improving the conversion efficiency of hexose and pentose to bioethanol by Pachysolen tannophilus.

  16. Prospecting for Energy-Rich Renewable Raw Materials: Sorghum Stem Case Study

    Science.gov (United States)

    Betts, Natalie S.; Tan, Hwei-Ting; Lim, Wai Li; Ermawar, Riksfardini A.; Nguyen, Hai Yen; Shirley, Neil J.; Lahnstein, Jelle; Corbin, Kendall; Fincher, Geoffrey B.; Knauf, Vic; Burton, Rachel A.

    2016-01-01

    Sorghum vegetative tissues are becoming increasingly important for biofuel production. The composition of sorghum stem tissues is influenced by genotype, environment and photoperiod sensitivity, and varies widely between varieties and also between different stem tissues (outer rind vs inner pith). Here, the amount of cellulose, (1,3;1,4)-β-glucan, arabinose and xylose in the stems of twelve diverse sorghum varieties, including four photoperiod-sensitive varieties, was measured. At maturity, most photoperiod-insensitive lines had 1% w/w (1,3;1,4)-β-glucan in stem pith tissue whilst photoperiod-sensitive varieties remained in a vegetative stage and accumulated up to 6% w/w (1,3;1,4)-β-glucan in the same tissue. Three sorghum lines were chosen for further study: a cultivated grain variety (Sorghum bicolor BTx623), a sweet variety (S. bicolor Rio) and a photoperiod-sensitive wild line (S. bicolor ssp. verticilliflorum Arun). The Arun line accumulated 5.5% w/w (1,3;1,4)-β-glucan and had higher SbCslF6 and SbCslH3 transcript levels in pith tissues than did photoperiod-insensitive varieties Rio and BTx623 (bioethanol yields. This information opens new avenues of research to generate sorghum lines optimised for biofuel production. PMID:27232754

  17. Development of a versatile and stable internal control system for RT-qPCR assays.

    Science.gov (United States)

    Felder, Eva; Wölfel, Roman

    2014-11-01

    RT-qPCR, an established method for the detection of RNA viruses, requires internal RNA controls for the correct interpretation of PCR results. Robust and versatile RT-PCR controls can be achieved for example by packaging RNA into a virus-derived protein shell. In this study a MS2-based internal control system was developed, that allows stable and universal packing of different RNAs into non-infectious, non-lytic MS2-based viral like particles (VLPs). Two competitive internal controls for a hantavirus assay and a Crimean-Congo Hemorrhagic Fever Virus (CCHFV) assay were cloned for the expression of VLPs. The expression of VLPs containing the RNA of interest could be induced with arabinose in Escherichia coli. The VLPs proved to be temperature resistant and could be frozen and thawed several times without degradation. Distinction of IC RNA from the target RNA was facilitated by a clear shift in the melting temperature or by specific hybridization signals. Furthermore, target and IC PCR amplification could be easily distinguished by their size in gel-electrophoretic analyses. Limits of detection were determined, demonstrating that the application of the IC did not reduce the sensitivity of the target RT-qPCR reactions. The system can be adapted to nearly any required sequence, resulting in a highly flexible method with broad range applications. PMID:25072380

  18. Effects of extraction condition on structural features and anticoagulant activity of F. vesca L. conjugates.

    Science.gov (United States)

    Pawlaczyk, Izabela; Lewik-Tsirigotis, Marta; Capek, Peter; Matulová, Mária; Sasinková, Vlasta; Dąbrowski, Paweł; Witkiewicz, Wojciech; Gancarz, Roman

    2013-01-30

    From the air-dried Wild strawberry (Fragaria vesca L., family Rosaceae) leaves five water-soluble glycoconjugates Fv I-V by different extraction conditions have been isolated. Effects of extraction steps/agents on chemical composition and anticoagulant activity of Fv I-V were examined. Dark brown F. vesca conjugates Fv I-V were recovered in 4.5-8.4% yields, based on dry herb. Isolates were composed of carbohydrate, phenolic and protein components. Fv I-V displayed on HPLC broad molecule-mass distribution patterns with dominance of low molecule-masses 9-14 kDa. Their carbohydrate parts revealed high hexuronic acids content (35-60%) while the dominant neutral sugars - galactose, arabinose and rhamnose were found in lower amounts and indicated the presence of rhamnogalacturonans associated with arabinogalactans in all F. vesca preparations. In all Fv I-V isolates high polyphenolic contents were determined, whereas proteins were found in low amounts only. In in vitro experiments on human pooled plasma Fv I-V showed at higher concentrations complete inhibition of plasma clot formation and the most active conjugates in aPTT, PT and TT tests were shown to be Fv I and Fv III, containing the highest amounts of phenolics. PMID:23218362

  19. The microstructure and formation of biological soil crusts in their early developmental stage

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yuanming

    2005-01-01

    The biological soil crust serves as one of the biological factors contributing to the sand fixation in the Gurbantunggut Desert, the largest fixed and semi-fixed desert in China. This study was conducted to investigate the microstructure and formation of biological soil crusts which develop as a result of occurrence of cryptogams. One year after removal of biological soil crusts, the exposed surface could be fixed by bacteria, which make sand particles cohere by exopolysaccharides. The exopolysaccharides were mainly composed of glucose, mannitol, arabinose and galactose. The intension of pressure for this kind of crust is 13.42±1.38 Pa. After four-year recovery of the exposed sandy surface, the biological soil crust resulting from the colonization of soil surface by communities of filamentous cyanobacteria were mainly dominated by Microcoleus, which occurred as a cluster of filaments surrounded by a gelatinous sheath. At this developmental stage, the main contributors for sand fixation were changed from bacteria to filamentous cyanobacteria. Microscopic examination of this kind of crust revealed an intricate network of filamentous cyanobacteria and extracellular polymer secretions, which binds and entraps mineral particles and finer particles on the filament surface. These effects enhance soil cohesion and resistance to erosion. The intension of pressure for this kind of crust is 32.53±3.08 Pa.

  20. In situ enzyme aided adsorption of soluble xylan biopolymers onto cellulosic material.

    Science.gov (United States)

    Chimphango, Annie F A; Görgens, J F; van Zyl, W H

    2016-06-01

    The functional properties of cellulose fibers can be modified by adsorption of xylan biopolymers. The adsorption is improved when the degree of biopolymers substitution with arabinose and 4-O-methyl-glucuronic acid (MeGlcA) side groups, is reduced. α-l-Arabinofuranosidase (AbfB) and α-d-glucuronidase (AguA) enzymes were applied for side group removal, to increase adsorption of xylan from sugarcane (Saccharum officinarum L) bagasse (BH), bamboo (Bambusa balcooa) (BM), Pinus patula (PP) and Eucalyptus grandis (EH) onto cotton lint. The AguA treatment increased the adsorption of all xylans by up to 334%, whereas, the AbfB increased the adsorption of the BM and PP by 31% and 44%, respectively. A combination of AguA and AbfB treatment increased the adsorption, but to a lesser extent than achieved with AguA treatment. This indicated that the removal of the glucuronic acid side groups provided the most significant increase in xylan adsorption to cellulose, in particular through enzymatic treatment. PMID:27083357

  1. Covalently Cross-Linked Arabinoxylans Films for Debaryomyces hansenii Entrapment.

    Science.gov (United States)

    González-Estrada, Ramsés; Calderón-Santoyo, Montserrat; Carvajal-Millan, Elizabeth; Ascencio Valle, Felipe de Jesús; Ragazzo-Sánchez, Juan Arturo; Brown-Bojorquez, Francisco; Rascón-Chu, Agustín

    2015-01-01

    In the present study, wheat water extractable arabinoxylans (WEAX) were isolated and characterized, and their capability to form covalently cross-linked films in presence of Debaryomyces hansenii was evaluated. WEAX presented an arabinose to xylose ratio of 0.60, a ferulic acid and diferulic acid content of 2.1 and 0.04 µg∙mg(-1) WEAX, respectively and a Fourier Transform Infra-Red (FT-IR) spectrum typical of WEAX. The intrinsic viscosity and viscosimetric molecular weight values for WEAX were 3.6 dL∙g(-1) and 440 kDa, respectively. The gelation of WEAX (1% w/v) with and without D. hansenii (1 × 10(7) CFU∙cm(-2)) was rheologically investigated by small amplitude oscillatory shear. The entrapment of D. hansenii decreased gel elasticity from 1.4 to 0.3 Pa, probably by affecting the physical interactions between WEAX chains. Covalently cross-linked WEAX films containing D. hansenii were prepared by casting. Scanning electron microscopy images show that WEAX films containing D. hansenii were porous and consisted of granular-like and fibre microstructures. Average tensile strength, elongation at break and Young's modulus values dropped when D. hansenii was present in the film. Covalently cross-lined WEAX containing D. hansenii could be a suitable as a functional entrapping film. PMID:26102070

  2. Characterization of Water Extractable Arabinoxylans from a Spring Wheat Flour: Rheological Properties and Microstructure

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    Alma Campa-Mada

    2013-07-01

    Full Text Available In the present study water extractable arabinoxylans (WEAX from a Mexican spring wheat flour (cv. Tacupeto F2001 were isolated, characterized and gelled and the gel rheological properties and microstructure were investigated. These WEAX presented an arabinose to xylose ratio of 0.66, a ferulic acid and diferulic acid content of 0.526 and 0.036 µg/mg WEAX, respectively and a Fourier Transform Infra-Red (FT-IR spectrum typical of arabinoxylans. The intrinsic viscosity and viscosimetric molecular weight values for WEAX were 3.5 dL/g and 504 kDa, respectively. WEAX solution at 2% (w/v formed gels induced by a laccase as cross-linking agent. Cured WEAX gels registered storage (G’ and loss (G’’ modulus values of 31 and 5 Pa, respectively and a diferulic acid content of 0.12 µg/mg WEAX, only traces of triferulic acid were detected. Scanning electron microscopy analysis of the lyophilized WEAX gels showed that this material resembles that of an imperfect honeycomb.

  3. Covalently Cross-Linked Arabinoxylans Films for Debaryomyces hansenii Entrapment

    Directory of Open Access Journals (Sweden)

    Ramsés González-Estrada

    2015-06-01

    Full Text Available In the present study, wheat water extractable arabinoxylans (WEAX were isolated and characterized, and their capability to form covalently cross-linked films in presence of Debaryomyces hansenii was evaluated. WEAX presented an arabinose to xylose ratio of 0.60, a ferulic acid and diferulic acid content of 2.1 and 0.04 µg∙mg−1 WEAX, respectively and a Fourier Transform Infra-Red (FT-IR spectrum typical of WEAX. The intrinsic viscosity and viscosimetric molecular weight values for WEAX were 3.6 dL∙g−1 and 440 kDa, respectively. The gelation of WEAX (1% w/v with and without D. hansenii (1 × 107 CFU∙cm−2 was rheologically investigated by small amplitude oscillatory shear. The entrapment of D. hansenii decreased gel elasticity from 1.4 to 0.3 Pa, probably by affecting the physical interactions between WEAX chains. Covalently cross-linked WEAX films containing D. hansenii were prepared by casting. Scanning electron microscopy images show that WEAX films containing D. hansenii were porous and consisted of granular-like and fibre microstructures. Average tensile strength, elongation at break and Young’s modulus values dropped when D. hansenii was present in the film. Covalently cross-lined WEAX containing D. hansenii could be a suitable as a functional entrapping film.

  4. Structural and physicochemical characteristics of a novel water-soluble gum from Lallemantia royleana seed.

    Science.gov (United States)

    Razavi, Seyed Mohammad Ali; Cui, Steve W; Ding, Huihuang

    2016-02-01

    In this study, the structural information (monosaccharide compositions, molecular weight parameters & FTIR analysis), chemical composition (moisture, protein, ash, carbohydrate & uronic acids), rheological properties, and surface activity of Lallemantia royleana seeds mucilage (BSG) were determined. The results showed BSG contains 8.51% (w.b.) moisture, 8.24% (d.b.) ash, 2.71% (d.b.) protein, 75.87% (d.b.) carbohydrate and 20.33% (d.b.) uronic acids. Monosaccharide analysis revealed the presence of arabinose (37.88%), galactose (33.54%), rhamnose (18.44%), xylose (6.02%) and glucose (4.11%) in the BSG polysaccharide. Although BSG had similar molecular weight (1.294×10(6) Da) compared to most seed gums, the intrinsic viscosity (23.06 dL/g) and gyration radius (104.84 nm) were higher. The BSG exhibited a strong shear-thinning behavior (n<0.29) over the shear rate range of 0.01 to 1000 s(-1). Flow behavior data was correlated with different time-independent models, which provided a good description of BSG rheological properties. Dynamic mechanical spectra demonstrated BSG is a typical of weak gel, which its rheological parameters were superior to those of many commercial gums. The FTIR spectra of the BSG polymer showed the presence of carboxyl groups, which may serve as binding sites for ions. BSG exhibited the ability to reduce the surface tension of water at concentrations lower than 0.75%. PMID:26645141

  5. Cotton GalT1 encoding a putative glycosyltransferase is involved in regulation of cell wall pectin biosynthesis during plant development.

    Directory of Open Access Journals (Sweden)

    Li-Xia Qin

    Full Text Available Arabinogalactan proteins (AGPs, are a group of highly glycosylated proteins that are found throughout the plant kingdom. To date, glycosyltransferases that glycosylate AGP backbone have remained largely unknown. In this study, a gene (GhGalT1 encoding a putative β-1,3-galactosyltransferase (GalT was identified in cotton. GhGalT1, belonging to CAZy GT31 family, is the type II membrane protein that contains an N-terminal transmembrane domain and a C-terminal galactosyltransferase functional domain. A subcellular localization assay demonstrated that GhGalT1 was localized in the Golgi apparatus. RT-PCR analysis revealed that GhGalT1 was expressed at relatively high levels in hypocotyls, roots, fibers and ovules. Overexpression of GhGalT1 in Arabidopsis promoted plant growth and metabolism. The transgenic seedlings had much longer primary roots, higher chlorophyll content, higher photosynthetic efficiency, the increased biomass, and the enhanced tolerance to exogenous D-arabinose and D-galactose. In addition, gas chromatography (GC analysis of monosaccharide composition of cell wall fractions showed that pectin was changed in the transgenic plants, compared with that of wild type. Three genes (GAUT8, GAUT9 and xgd1 involved in pectin biosynthesis were dramatically up-regulated in the transgenic lines. These data suggested that GhGalT1 may be involved in regulation of pectin biosynthesis required for plant development.

  6. Anti-tumoral effect of the mitochondrial target domain of Noxa delivered by an engineered Salmonella typhimurium.

    Directory of Open Access Journals (Sweden)

    Jae-Ho Jeong

    Full Text Available Bacterial cancer therapy relies on the fact that several bacterial species are capable of targeting tumor tissue and that bacteria can be genetically engineered to selectively deliver therapeutic proteins of interest to the targeted tumors. However, the challenge of bacterial cancer therapy is the release of the therapeutic proteins from the bacteria and entry of the proteins into tumor cells. This study employed an attenuated Salmonella typhimurium to selectively deliver the mitochondrial targeting domain of Noxa (MTD as a potential therapeutic cargo protein, and examined its anti-cancer effect. To release MTD from the bacteria, a novel bacterial lysis system of phage origin was deployed. To facilitate the entry of MTD into the tumor cells, the MTD was fused to DS4.3, a novel cell-penetrating peptide (CPP derived from a voltage-gated potassium channel (Kv2.1. The gene encoding DS4.3-MTD and the phage lysis genes were placed under the control of PBAD , a promoter activated by L-arabinose. We demonstrated that DS4.3-MTD chimeric molecules expressed by the Salmonellae were anti-tumoral in cultured tumor cells and in mice with CT26 colon carcinoma.

  7. Upgrading of biorenewables to high energy density fuels

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, John C [Los Alamos National Laboratory; Batista, Enrique R [Los Alamos National Laboratory; Chen, Weizhong [Los Alamos National Laboratory; Currier, Robert P [Los Alamos National Laboratory; Dirmyer, Matthew R [Los Alamos National Laboratory; John, Kevin D [Los Alamos National Laboratory; Kim, Jin K [Los Alamos National Laboratory; Keith, Jason [Los Alamos National Laboratory; Martin, Richard L [Los Alamos National Laboratory; Pierpont, Aaron W [Los Alamos National Laboratory; Silks Ill, L. A. " " Pete [Los Alamos National Laboratory; Smythe, Mathan C [Los Alamos National Laboratory; Sutton, Andrew D [Los Alamos National Laboratory; Taw, Felicia L [Los Alamos National Laboratory; Trovitch, Ryan J [Los Alamos National Laboratory; Vasudevan, Kalyan V [Los Alamos National Laboratory; Waidmann, Christopher R [Los Alamos National Laboratory; Wu, Ruilian [Los Alamos National Laboratory; Baker, R. Thomas [UNIV OF OTTAWWA; Schlaf, Marcel [UNIV OF GUELPH

    2010-12-07

    According to a recent report, lignocellulose is the most abundant renewable biological resource on earth, with an annual production of {approx} 200 x 10{sup 9} tons. Conversion of lignocellulosics derived from wood, agricultural wastes, and woody grasses into liquid fuels and value-added chemical feedstocks is an active area of research that has seen an explosion of effort due to the need to replace petroleum based sources. The carbohydrates D-glucose (C{sub 6}), L-arabinose (C{sub 5}), and D-xylose (C{sub 5}) are readily obtained from the hydrolysis of lignocellulose and constitute the most abundant renewable organic carbon source on the planet. Because they are naturally produced on such a large scale, these sugars have the greatest potential to displace petrochemical derived transportation fuel. Recent efforts in our laboratories aimed towards the production of high energy density transportation fuels from carbohydrates have been structured around the parameters of selective carbohydrate carbon chain extension chemistries, low reaction temperatures, and the desired use of water or neat substrate as the solvent. Some of our efforts in this regard will be presented.

  8. Analysis of amino acid substitutions in AraC variants that respond to triacetic acid lactone.

    Science.gov (United States)

    Frei, Christopher S; Wang, Zhiqing; Qian, Shuai; Deutsch, Samuel; Sutter, Markus; Cirino, Patrick C

    2016-04-01

    The Escherichia coli regulatory protein AraC regulates expression of ara genes in response to l-arabinose. In efforts to develop genetically encoded molecular reporters, we previously engineered an AraC variant that responds to the compound triacetic acid lactone (TAL). This variant (named "AraC-TAL1") was isolated by screening a library of AraC variants, in which five amino acid positions in the ligand-binding pocket were simultaneously randomized. Screening was carried out through multiple rounds of alternating positive and negative fluorescence-activated cell sorting. Here we show that changing the screening protocol results in the identification of different TAL-responsive variants (nine new variants). Individual substituted residues within these variants were found to primarily act cooperatively toward the gene expression response. Finally, X-ray diffraction was used to solve the crystal structure of the apo AraC-TAL1 ligand-binding domain. The resolved crystal structure confirms that this variant takes on a structure nearly identical to the apo wild-type AraC ligand-binding domain (root-mean-square deviation 0.93 Å), suggesting that AraC-TAL1 behaves similar to wild-type with regard to ligand recognition and gene regulation. Our results provide amino acid sequence-function data sets for training and validating AraC modeling studies, and contribute to our understanding of how to design new biosensors based on AraC. PMID:26749125

  9. Sugar Profile of Kernels as a Marker of Origin and Ripening Time of Peach (Prunus persicae L.).

    Science.gov (United States)

    Stanojević, Marija; Trifković, Jelena; Akšić, Milica Fotirić; Rakonjac, Vera; Nikolić, Dragan; Šegan, Sandra; Milojković-Opsenica, Dušanka

    2015-12-01

    Large amounts of fruit seeds, especially peach, are discarded annually in juice or conserve producing industries which is a potential waste of valuable resource and serious disposal problem. Regarding the fact that peach seeds can be obtained as a byproduct from processing companies their exploitation should be greater and, consequently more information of cultivars' kernels and their composition is required. A total of 25 samples of kernels from various peach germplasm (including commercial cultivars, perspective hybrids and vineyard peach accessions) differing in origin and ripening time were characterized by evaluation of their sugar composition. Twenty characteristic carbohydrates and sugar alcohols were determined and quantified using high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC/PAD). Sucrose, glucose and fructose are the most important sugars in peach kernels similar to other representatives of the Rosaceae family. Also, high amounts of sugars in seeds of promising hybrids implies that through conventional breeding programs peach kernels with high sugar content can be obtained. In addition, by the means of several pattern recognition methods the variables that discriminate peach kernels arising from diverse germplasm and different stage of maturity were identified and successful models for further prediction were developed. Sugars such as ribose, trehalose, arabinose, galactitol, fructose, maltose, sorbitol, sucrose, iso-maltotriose were marked as most important for such discrimination. PMID:26497505

  10. Some physico-chemical properties of Prunus armeniaca L. gum exudates.

    Science.gov (United States)

    Fathi, Morteza; Mohebbi, Mohebbat; Koocheki, Arash

    2016-01-01

    The objectives of this paper were to investigate some physicochemical properties of Prunus armeniaca L. gum exudates (PAGE). PAGE had, on average, 66.89% carbohydrate, 10.47% uronic acids, 6.9% moisture (w.b.), 2.91% protein, 4% ash and 1.59% fat. PAGE was composed of monosaccharides including l-arabinose, d-galactose, xylose, mannose and rhamnose in molar percentages of 41.52%, 23.72%, 17.82%, 14.40% and 2.54%, respectively. Elemental analysis showed that PAGE had high values of nutrients. FTIR analysis demonstrated the presence of carboxyl, hydroxyl and methyl groups and glycoside bonds. The weight average molecular weight, number average molecular weight and polydispersity index were found to be approximately 5.69 × 10(5)g/mol, 4.33 g/mol and 1.31, respectively. Rheological measurement of PAGE solutions as a function of concentration (8, 10 and 12% (w/w)) and temperature (10, 20, 30 and 40°C) demonstrated that the gum solutions had a non Newtonian shear thinning behaviour. Intrinsic viscosity for PAGE in deionized water was 3.438 dl/g based on Kramer equation. PMID:26434520

  11. Antihyperlipidemic and hepatoprotective activities of residue polysaccharide from Cordyceps militaris SU-12.

    Science.gov (United States)

    Wang, Liqin; Xu, Nuo; Zhang, Jianjun; Zhao, Huajie; Lin, Lin; Jia, Shouhua; Jia, Le

    2015-10-20

    Cordyceps militaris has been artificially cultivated in China, and the great amounts of produced medium residue were discarded after the harvest. The aims of this work were to analyze the structure of the residue polysaccharide (RPS) of C. militaris SU-12, and to investigate the pharmacological effects of RPS on lipid metabolism and oxidative stress. RPS was composed of glucose, arabinose and mannose with a ratio of 62:1.6:1 by gas chromatography analysis, and the Mw (weight-average molecular weight), Mn (number-average molecular weight) and Mz (z-average molecular weight) of RPS were 2.86×10(3), 6.85×10(2), and 1.97×10(4)Da, respectively. The mice experiments demonstrated that RPS could reduce the levels of blood and liver lipid, and improve the glutamate pyruvate transaminase and antioxidant activity. The histopathological observations of mice livers indicated that RPS could attenuate liver cell injury. Results suggest that the RPS might be used as a potential antihyperlipidemic, hepatoprotective and antioxidant product. PMID:26256194

  12. Genomic analysis of six new Geobacillus strains reveals highly conserved carbohydrate degradation architectures and strategies

    Directory of Open Access Journals (Sweden)

    Phillip eBrumm

    2015-05-01

    Full Text Available In this work we report the whole genome sequences of six new Geobacillus xylanolytic strains along with the genomic analysis of their capability to degrade carbohydrates.. The six sequenced Geobacillus strains described here have a range of GC contents from 43.9% to 52.5% and clade with named Geobacillus species throughout the entire genus. We have identified a ~200 kb unique super-cluster in all six strains, containing five to eight distinct carbohydrate degradation clusters in a single genomic region, a feature not seen in other genera. The Geobacillus strains rely on a small number of secreted enzymes located within distinct clusters for carbohydrate utilization, in contrast to most biomass-degrading organisms which contain numerous secreted enzymes located randomly throughout the genomes. All six strains are able to utilize fructose, arabinose, xylose, mannitol, gluconate, xylan, and α-1,6-glucosides. The gene clusters for utilization of these seven substrates have identical organization and the individual proteins have a high percent identity to their homologs. The strains show significant differences in their ability to utilize inositol, sucrose, lactose, α-mannosides, α-1,4-glucosides and arabinan.

  13. Inhibition of food-related pathogenic bacteria by god-transformed Penicillium nalgiovense strains.

    Science.gov (United States)

    Geisen, R

    1999-08-01

    Two strains of Penicillium nalgiovense, which carried the god gene of Aspergillus niger and had increased glucose oxidase (GOD) activity compared with the wild-type strain, were tested for their ability to suppress the growth of certain food-related pathogenic bacteria. In contrast to the wild type, which showed no antibacterial effect when grown in mixed culture with different bacteria, the two transformed strains were highly antagonistic. The strain that expressed higher amounts of GOD in general had higher inhibitory activity. Both strains showed antibacterial activity against Listeria monocytogenes, Salmonella Enteritidis, and Staphylococcus aureus. The inhibitory activity was dependent on the glucose concentration in the medium. S. aureus was completely inhibited at 1% glucose in the presence of the higher GOD-producing transformant. In contrast, if arabinose was used as a carbon source, no inhibition occurred. If catalase was added to the medium, the inhibitory activity of the transformants was completely inactivated, indicating that the hydrogen peroxide produced was responsible for the antibacterial activity of the transformants. PMID:10456750

  14. Bypassing the Pentose Phosphate Pathway: Towards Modular Utilization of Xylose.

    Directory of Open Access Journals (Sweden)

    Kulika Chomvong

    Full Text Available The efficient use of hemicellulose in the plant cell wall is critical for the economic conversion of plant biomass to renewable fuels and chemicals. Previously, the yeast Saccharomyces cerevisiae has been engineered to convert the hemicellulose-derived pentose sugars xylose and arabinose to d-xylulose-5-phosphate for conversion via the pentose phosphate pathway (PPP. However, efficient pentose utilization requires PPP optimization and may interfere with its roles in NADPH and pentose production. Here, we developed an alternative xylose utilization pathway that largely bypasses the PPP. In the new pathway, d-xylulose is converted to d-xylulose-1-phosphate, a novel metabolite to S. cerevisiae, which is then cleaved to glycolaldehyde and dihydroxyacetone phosphate. This synthetic pathway served as a platform for the biosynthesis of ethanol and ethylene glycol. The use of d-xylulose-1-phosphate as an entry point for xylose metabolism opens the way for optimizing chemical conversion of pentose sugars in S. cerevisiae in a modular fashion.

  15. 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

  16. Microvirga subterranea gen. nov., sp. nov., a moderate thermophile from a deep subsurface Australian thermal aquifer.

    Science.gov (United States)

    Kanso, Sungwan; Patel, Bharat K C

    2003-03-01

    A strictly aerobic bacterium, strain Fail4T, was isolated from free-flowing geothermal waters of a bore (bore register no. 3768) tapping the Great Artesian Basin of Australia. The non-sporulating, Gram-negative cells of strain Fail4T produced light-pink colonies, were rod-shaped (1 x 1.5-4 microm) and were motile by a single polar flagellum. Strain Fail4T grew optimally at 41 degrees C at a pH of 7.0 and had an absolute requirement for yeast extract. The strain grew on casein hydrolysate, tryptone, gelatin, xylose and acetate in a medium supplemented with 0.06 or 0.006% yeast extract. Weak acid production was detected from glucose and arabinose. Catalase was produced. Nitrite was produced from nitrate. Strain Fail4T was sensitive to antibiotics that inhibit growth of bacteria. The G + C content was 63.5 +/- 0.5 mol%. Strain Fail4T was a member of the class 'Alphaproteobacteria', phylum Proteobacteria, placed almost equidistantly between Methylobacterium species, Chelatococcus asaccharovorans and Bosea thiooxidans (similarity value of 93%) as its nearest phylogenetic relatives. Phylogenetic and phenotypic evidence suggest that strain Fail4T (=ATCC BAA-295T = DSM 14364T) should be placed as the type strain of a species in a newly created genus, for which the name Microvirga subterranea gen. nov., sp. nov. is proposed. PMID:12710604

  17. Structure of polysaccharides from mycelium and culture medium of Phellinus nigricans using submerged fermentation

    Institute of Scientific and Technical Information of China (English)

    LI Xia; JIAO LiLi; ZHANG Xu; TIAN WenMin; CHEN Shan; ZHANG LiPing

    2008-01-01

    Two water-soluble polysaccharides, PNW1 and PNM1, were respectively isolated from the mycelium and its culture medium of Phellinus nigricans using submerged fermentation before determining their effects on inhibiting the growth of transplantable tumors in mice. The results of the pharmaceutical experiments showed that oral administration of PNW1 and PNM1 (at a dose of 400 mg/kg) inhibited the growth of tumor of mice-transplanted Sarcoma 180 in vivo. Moreover, a higher inhibition ratio of PNW1 (74.70%) was obtained as compared with PNM1 (55.84%). The averaged molecular weight of PNW1 and PNM1 was determined to be 33 and 29 kD, respectively. Both PNW1 and PNM1 were consisted of glu-cose, galactose, mannose, arabinose and fucose. The major structural features of PNW1 and PNM1 were elucidated using partial acid hydrolysis, periodate oxidation, Smith degradation,13C-NMR, me-thylation and GC-MS. On the basis of these results, the repeating units of PNW1 and PNM1 were estab-lished.

  18. Structure of polysaccharides from mycelium and culture medium of Phellinus nigricans using submerged fermentation

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Two water-soluble polysaccharides, PNW1 and PNM1, were respectively isolated from the mycelium and its culture medium of Phellinus nigricans using submerged fermentation before determining their effects on inhibiting the growth of transplantable tumors in mice. The results of the pharmaceutical experiments showed that oral administration of PNW1 and PNM1 (at a dose of 400 mg/kg) inhibited the growth of tumor of mice-transplanted Sarcoma 180 in vivo. Moreover, a higher inhibition ratio of PNW1 (74.70%) was obtained as compared with PNM1 (55.84%). The averaged molecular weight of PNW1 and PNM1 was determined to be 33 and 29 kD, respectively. Both PNW1 and PNM1 were consisted of glu- cose, galactose, mannose, arabinose and fucose. The major structural features of PNW1 and PNM1 were elucidated using partial acid hydrolysis, periodate oxidation, Smith degradation, 13C-NMR, me- thylation and GC-MS. On the basis of these results, the repeating units of PNW1 and PNM1 were estab- lished.

  19. In vitro digestion and fermentation properties of linear sugar-beet arabinan and its oligosaccharides.

    Science.gov (United States)

    Moon, Jin Seok; Shin, So Yeon; Choi, Hye Sun; Joo, Wooha; Cho, Seung Kee; Li, Ling; Kang, Jung-Hyun; Kim, Tae-Jip; Han, Nam Soo

    2015-10-20

    This study was conducted to investigate the prebiotic effects of linear arabino-oligosaccharides (LAOS) and debranched (linear) sugar beet arabinan (LAR) for the development of new prebiotics. LAOS were prepared from LAR by enzymatic hydrolysis with endo-arabinanase from Bacillus licheniformis, followed by removal of the arabinose fraction by incubation with resting cells of Leuconostoc mesenteroides. The resulting LAOS contained DP2 (28.7%), DP3 (49.9%), DP4 (20.1%), and DP5 (1.16%). A standardized digestibility test showed that LAOS and LAR were not digestible. Individual cultures of 24 strains of gastrointestinal bacteria showed that LAOS and LAR stimulated growth of Lactobacillus brevis, Bifidobacterium longum, and Bacteroides fragilis. In vitro batch fermentation using human fecal samples showed that LAOS had higher bifidogenic properties than LAR; LAOS increased the population of bifidobacteria which produced short-chain fatty acids (SCFAs). LAOS was fermented slowly compared to fructo-oligosaccharides and this may permit SCFA production in the distal colon. This study demonstrates that LAOS prepared from LAR are promising dietary substrates for improvement of human intestinal health. PMID:26256159

  20. Perfil químico da parede celular e suas implicações na digestibilidade de Brachiaria brizantha e Brachiaria humidicola Chemical profile of cell wall and its implications on Brachiaria brizantha and Brachiaria humidicola digestibility

    Directory of Open Access Journals (Sweden)

    Cláudio José F. Alves de Brito

    2003-12-01

    Full Text Available No presente trabalho foram determinadas a composição química e a digestibilidade de diversas frações de Brachiaria brizantha e Brachiaria humidicola, após 70 dias de crescimento. O delineamento experimental foi inteiramente casualizado com cinco repetições para cada espécie. As plantas coletadas foram subdivididas nas frações apical, mediana e basal para as folhas e mediana e basilar para caules, de acordo com sua localização. Foram determinadas as concentrações de fibra em detergente neutro (FDN, proteína bruta (PB, lignina, ácido p_cumárico, ácido ferúlico e açúcares neutros (glicose, xilose e arabinose e a digestibilidade in situ após 48 horas de período de incubação ruminal. As diferentes frações das espécies estudadas apresentam distinta composição química, cujos efeitos são observados na digestibilidade. A B. brizantha apresentou maiores concentrações de FDN no caule e PB nas folhas. Isto resultou em coeficientes de digestibilidade maiores em relação à B. humidicola. A diferença de digestibilidade entre caule e folhas e nas frações mais velhas pode estar relacionada ao tipo de condensação da lignina presente nos tecidos. Evidências na concentração e na proporção dos ácidos p_cumárico e ferúlico sugerem esta relação. A concentração de ácidos fenólicos esteve relacionada com a digestibilidade da matéria seca e a lignina com a digestibilidade da FDN. A análise dos ácidos fenólicos pode se constituir em importante ferramenta para avaliar o grau de condensação da lignina na parede celular dos diferentes tecidos das plantas forrageiras. A concentração de açúcares neutros não apresentou um padrão definido na composição dos diferentes tecidos. A arabinose foi o único açúcar que apresentou relações com a digestibilidade da matéria seca e com a concentração de ácidos fenólicos.In the present paper the chemical composition and digestibility of several Brachiaria

  1. Generation of transgenic wheat (Triticum aestivum L.) accumulating heterologous endo-xylanase or ferulic acid esterase in the endosperm

    Energy Technology Data Exchange (ETDEWEB)

    Harholt, Jesper; Bach, Inga C; Lind-Bouquin, Solveig; Nunan, Kylie J.; Madrid, Susan M.; Brinch-Pedersen, Henrik; Holm, Preben B.; Scheller, Henrik V.

    2009-12-08

    Endo-xylanase (from Bacillus subtilis) or ferulic acid esterase (from Aspergillus niger) were expressed in wheat under the control of the endosperm specific 1DX5 glutenin promoter. Constructs both with and without the endoplasmic reticulum retention signal KDEL were used. Transgenic plants were recovered in all four cases but no qualitative differences could be observed whether KDEL was added or not. Endo-xylanase activity in transgenic grains was increased between two and three fold relative to wild type. The grains were shriveled and had a 25-33% decrease in mass. Extensive analysis of the cell walls showed a 10-15% increase in arabinose to xylose ratio, a 50% increase in the proportion of water extractable arabinoxylan, and a shift in the MW of the water extractable arabinoxylan from being mainly larger than 85 kD to being between 2 kD and 85 kD. Ferulic acid esterase expressing grains were also shriveled and the seed weight was decreased by 20-50%. No ferulic acid esterase activity could be detected in wild type grains whereas ferulic acid esterase activity was detected in transgenic lines. The grain cell walls had 15-40% increase in water unextractable arabinoxylan and a decrease in monomeric ferulic acid between 13 and 34%. In all the plants the observed changes are consistent with a plant response that serves to minimize the effect of the heterologously expressed enzymes by increasing arabinoxylan biosynthesis and cross-linking.

  2. Gastro protective and H(+), K(+)-ATPase/H. pylori inhibitory properties of pectic polysaccharides from potato.

    Science.gov (United States)

    Badanavalu Chandrashekar, Kavitha; Dharmesh, Shylaja Mallaiah

    2016-03-01

    Polysaccharide is one among the important classes of biological polymers that is reported to exhibit disease preventive properties. The present study describes the isolation of galactans and confirmation of the same by sugar analysis and determination of anti-ulcer effect of Potato Galactan Polysaccharide (PGP). Data indicated that PGP possessed sugar composition of rhamnose (2%), arabinose (3%), mannose (3%), galactose (94%) and uronic acid (17%) confirming that PGP thus isolated is a galactan. PGP exhibited potent H(+), K(+)-ATPase inhibitory activity (IC50 420 μg/mL) in vitro as opposed to lansoprazole, a known antiulcer drug with IC50 19.3 μg/mL. The antiulcer potency of PGP was evaluated in ethanol stress induced gastric ulcer model in vivo. About 84% reduction in ulcer index; enhanced mucosal recovery, normalization of H(+), K(+)-ATPase, antioxidant and antioxidant enzymes substantiated the antiulcer potentials of PGP. Mucosal recovery could be attributed to cytoprotective and DNA protective ability of PGP that can help in mucosal layer regeneration. Further, PGP was also effective in inhibiting Helicobacter pylori as per growth inhibition assay followed by scanning electron microscopic studies suggesting that PGP is effective in curbing the growth of H. pylori, which is responsible for ∼70% of gastric ulcer/cancer incidences. PMID:26704999

  3. Enzymatic generation of galactose-rich oligosaccharides/oligomers from potato rhamnogalacturonan I pectic polysaccharides.

    Science.gov (United States)

    Khodaei, Nastaran; Karboune, Salwa

    2016-04-15

    Potato pulp by-product rich in galactan-rich rhamnogalacturonan I (RG I) was investigated as a new source of oligosaccharides with potential prebiotic properties. The efficiency of selected monocomponent enzymes and multi-enzymatic preparations to generate oligosaccharides/oligomers from potato RG I was evaluated. These overall results of yield were dependent on the activity profile of the multi-enzymatic preparations. Highest oligo-RG I yield of 93.9% was achieved using multi-enzymatic preparation (Depol 670L) with higher hydrolytic activity toward side chains of RG I as compared to its backbone. Main oligo-RG I products were oligosaccharides with DP of 2-12 (79.8-100%), while the oligomers with DP of 13-70 comprised smaller proportion (0.0-20.2%). Galactose (58.9-91.2%, w/w) was the main monosaccharide of oligo-RG I, while arabinose represented 0.0-12.1%. An understanding of the relationship between the activity profile of multi-enzymatic preparations and the yield/DP of oligo-RG I was achieved. This is expected to provide the capability to generate galacto- and galacto(arabino) oligosaccharides and their corresponding oligomers from an abundant by-product. PMID:26616968

  4. Preparation, characterization, and biological properties of β-glucans.

    Science.gov (United States)

    Rahar, Sandeep; Swami, Gaurav; Nagpal, Navneet; Nagpal, Manisha A; Singh, Gagan Shah

    2011-04-01

    β-Glucans are soluble fibers with physiological functions, such as, interference with absorption of sugars and reduction of serum lipid levels. β-glucans are found in different species, such as, Rhynchelytrum repens, Lentinus edodes, Grifola frondosa, Tremella mesenterica, Tremella aurantia, Zea may, Agaricus blazei, Phellinus baummi, Saccharomyces cerevisae (yeast), and Agaricus blazei murell (mushroom). Analysis of the fractions reveals the presence of arabinose, glucose, xylose, and traces of rhamnose and galactose. The presence of β-glucan in these fractions is confirmed by hydrolyzing the polymers with endo-β-glucanase from Bacillus subtilis, followed by high-performance liquid chromatography (HPLC) analysis of the characteristic oligosaccharides produced. The 4 M KOH fractions from different tissues are subjected to gel permeation chromatography on Sepharose 4B, with separation of polysaccharides, with different degrees of polymerization, the highest molecular mass (above 2000 kDa) being found in young leaves. The molecular mass of the leaf blade polymers is similar (250 kDa) to that of the maize coleoptiles β-glucan used for comparison. The 4 M KOH fraction injected into rats with streptozotocin-induced diabetes has shown hypoglycemic activity, reducing blood sugar to normal levels for approximately 24 hours. This performance is better than that obtained with pure β-glucan from barley, which decreases blood sugar levels for about four hours. These results suggest that the activity of β-glucans is responsible for the use of this plant extract as a hypoglycemic drug in folk medicine. PMID:22171300

  5. Preparation, characterization, and biological properties of β-glucans

    Directory of Open Access Journals (Sweden)

    Sandeep Rahar

    2011-01-01

    Full Text Available β-Glucans are soluble fibers with physiological functions, such as, interference with absorption of sugars and reduction of serum lipid levels. β-glucans are found in different species, such as, Rhynchelytrum repens, Lentinus edodes, Grifola frondosa, Tremella mesenterica, Tremella aurantia, Zea may, Agaricus blazei, Phellinus baummi, Saccharomyces cerevisae (yeast, and Agaricus blazei murell (mushroom. Analysis of the fractions reveals the presence of arabinose, glucose, xylose, and traces of rhamnose and galactose. The presence of β-glucan in these fractions is confirmed by hydrolyzing the polymers with endo-β-glucanase from Bacillus subtilis, followed by high-performance liquid chromatography (HPLC analysis of the characteristic oligosaccharides produced. The 4 M KOH fractions from different tissues are subjected to gel permeation chromatography on Sepharose 4B, with separation of polysaccharides, with different degrees of polymerization, the highest molecular mass (above 2000 kDa being found in young leaves. The molecular mass of the leaf blade polymers is similar (250 kDa to that of the maize coleoptiles β-glucan used for comparison. The 4 M KOH fraction injected into rats with streptozotocin-induced diabetes has shown hypoglycemic activity, reducing blood sugar to normal levels for approximately 24 hours. This performance is better than that obtained with pure β-glucan from barley, which decreases blood sugar levels for about four hours. These results suggest that the activity of β-glucans is responsible for the use of this plant extract as a hypoglycemic drug in folk medicine.

  6. Purification and Partial Characterization of a Novel Anti-tumor Glycoprotein from Cultured Mycelia of Grifola frondosa.

    Science.gov (United States)

    Cui, Fengjie; Zan, Xinyi; Li, Yunhong; Yang, Yan; Sun, Wenjing; Zhou, Qiang; Yu, Silian; Dong, Ying

    2013-10-25

    A novel glycoprotein GFG-3a with the molecular weight of 88.01 kDa and potent anti-tumor activity was isolated from the cultured mycelia of Grifola frondosa GF9801. GFG-3a was heat-sensitive with the decreasing anti-proliferative activity after treated from 56°C to 100°C for 10-120min. GFG-3a was a glycoprotein with O-glycosylation and contained 6.20% carbohydrate composed of D-arabinose, D-fructose, D-mannose, and D-glucose with a molar ratio of 1.33:4.51:2.46:1.00. FT-IR and NMR spectra proved that GFG-3a contained protein and carbohydrate portions with 3-O-methyl-galactose residues, (1→4)-linked β- galactose residues, and β-linked glucose residues. Circular dichroism (CD) revealed that GFG-3a was a predominantly β-sheet glycoprotein with a relatively small α-helical content. Protein sequencing and 3D model of GFG-3a were finally obtained by using MALDI-TOF-MS, NCBI blast search and online SWISS-MODLE Workspace service. Our findings will be a reference for the further structure-activity relationship analysis of the mushroom glycoproteins. PMID:24512992

  7. Structural characterization and inhibition on α-d-glucosidase activity of non-starch polysaccharides from Fagopyrum tartaricum.

    Science.gov (United States)

    Wang, Xiao-Ting; Zhu, Zhen-Yuan; Zhao, Liang; Sun, Hui-Qing; Meng, Meng; Zhang, Jin-Yu; Zhang, Yong-Min

    2016-11-20

    In the present study, the crude polysaccharide was extracted from Fagopyrum tartaricum and purified by Sephadex G-25 and G-75 column to produce a polysaccharide fraction termed TBP-II. Its average molecular weight was 26kDa. The structural characterization of TBP-II was investigated by gas chromatography, periodate oxidation-Smith degradation, Methylation and NMR. Congo red was applied to explore its advanced structures. The results revealed that chemical composition and structural characteristic of TBP-II was mainly consisted of galactose, arabinose, xylose and glucose with a molar ratio of 0.7:1:6.3:74.2. The backbone of TBP-II was composed of (1→4)-linked α-d-glucopyranosyl (Glcp), while the branches comprised of (1→3)-linked α-d-glucopyranosyl (Glcp), (1→6)-linked α-d-galactopyranosyl (Galp) and (1→2,4)-linked α-d-rhamnopyranosyl (Rhap). The structure of TBP-II was 1,3 and 1,6-branched-galactorhamnoglucan that had a linear backbone of (1→4)-linked α-d-glucopyranose (Glcp). Using Congo red assay showed that it was absent of triple helix structure. The α-d-glucosidase inhibitory activity of TBP-II was determined using acarbose as positive control. The result showed that the inhibition rate depended on the concentration of polysaccharides. PMID:27561539

  8. Characterization of Aloeride, a new high-molecular-weight polysaccharide from Aloe vera with potent immunostimulatory activity.

    Science.gov (United States)

    Pugh, N; Ross, S A; ElSohly, M A; Pasco, D S

    2001-02-01

    We have characterized a new immunostimulatory polysaccharide called Aloeride from commercial aloe vera (Aloe barbadensis) juice. Aloeride is between 4 and 7 million Da, and its glycosyl components include glucose (37.2%), galactose (23.9%), mannose (19.5%), and arabinose (10.3%). At 0.5 microg/mL Aloeride increased NF-kappa B directed luciferase expression in THP-1 human monocytic cells to levels 50% of those achieved by maximal concentrations (10 microg/mL) of LPS. Aloeride induced the expression of the mRNAs encoding IL-1beta and TNF-alpha to levels equal to those observed in cells maximally activated by LPS. Acemannan, the major carbohydrate component from aloe, used at 200 microg/mL in the macrophage assay resulted in negligible NF-kappa B activation. Analysis of acemannan and Aloeride using size-exclusion chromatography suggests that the low activity of acemannan is due to trace amounts of Aloeride. Although Aloeride comprises only 0.015% of the aloe juice dry weight, its potency for macrophage activation accounts fully for the activity of the crude juice. PMID:11262067

  9. Biomolecular Mechanisms of Pseudomonas aeruginosa and Escherichia coli Biofilm Formation

    Directory of Open Access Journals (Sweden)

    Garry Laverty

    2014-07-01

    Full Text Available Pseudomonas aeruginosa and Escherichia coli are the most prevalent Gram-negative biofilm forming medical device associated pathogens, particularly with respect to catheter associated urinary tract infections. In a similar manner to Gram-positive bacteria, Gram-negative biofilm formation is fundamentally determined by a series of steps outlined more fully in this review, namely adhesion, cellular aggregation, and the production of an extracellular polymeric matrix. More specifically this review will explore the biosynthesis and role of pili and flagella in Gram-negative adhesion and accumulation on surfaces in Pseudomonas aeruginosa and Escherichia coli. The process of biofilm maturation is compared and contrasted in both species, namely the production of the exopolysaccharides via the polysaccharide synthesis locus (Psl, pellicle Formation (Pel and alginic acid synthesis in Pseudomonas aeruginosa, and UDP-4-amino-4-deoxy-l-arabinose and colonic acid synthesis in Escherichia coli. An emphasis is placed on the importance of the LuxR homologue sdiA; the luxS/autoinducer-II; an autoinducer-III/epinephrine/norepinephrine and indole mediated Quorum sensing systems in enabling Gram-negative bacteria to adapt to their environments. The majority of Gram-negative biofilms consist of polysaccharides of a simple sugar structure (either homo- or heteropolysaccharides that provide an optimum environment for the survival and maturation of bacteria, allowing them to display increased resistance to antibiotics and predation.

  10. Lower cell wall pectin solubilisation and galactose loss during early fruit development in apple (Malus x domestica) cultivar 'Scifresh' are associated with slower softening rate.

    Science.gov (United States)

    Ng, Jovyn K T; Schröder, Roswitha; Brummell, David A; Sutherland, Paul W; Hallett, Ian C; Smith, Bronwen G; Melton, Laurence D; Johnston, Jason W

    2015-03-15

    Substantial differences in softening behaviour can exist between fruit even within the same species. Apple cultivars 'Royal Gala' and 'Scifresh' soften at different rates despite having a similar genetic background and producing similar amounts of ethylene during ripening. An examination of cell wall metabolism from the fruitlet to the ripe stages showed that in both cultivars pectin solubilisation increased during cell expansion, declined at the mature stage and then increased again during ripening. This process was much less pronounced in the slower softening 'Scifresh' than in 'Royal Gala' at every developmental stage examined, consistent with less cell separation and softening in this cultivar. Both cultivars also exhibited a progressive loss of pectic galactan and arabinan side chains during development. The cell wall content of arabinose residues was similar in both cultivars, but the galactose residue content in 'Scifresh' remained higher than that of 'Royal Gala' at every developmental stage. The higher content of cell wall galactose residue in 'Scifresh' cell walls correlated with a lower β-galactosidase activity and more intense immunolabelling of RG-I galactan side chains in both microscopy sections and glycan microarrays. A high cell wall galactan content has been associated with reduced cell wall porosity, which may restrict access of cell wall-modifying enzymes and thus maintain better structural integrity later in development. The data suggest that the composition and structure of the cell wall at very early development stages may influence subsequent cell wall loosening, and may even predispose the wall's ensuing properties. PMID:25602611

  11. Development of complete hydrolysis of pectins from apple pomace.

    Science.gov (United States)

    Wikiera, Agnieszka; Mika, Magdalena; Starzyńska-Janiszewska, Anna; Stodolak, Bożena

    2015-04-01

    Enzymatically extracted pectins have a more complex structure than those obtained by conventional methods. As a result, they are less susceptible to hydrolysis, which makes the precise determination of their composition difficult. The aim of the study was to develop a method of complete hydrolysis of enzymatically extracted apple pectins. Substrates were pectins isolated from apple pomace by the use of xylanase and multicatalytic preparation Celluclast and apple pomace. Hydrolysis was performed by a chemical method with 2M TFA at 100 °C and 120 °C and a combined acidic/enzymatic method. After hydrolysis, the contents of galacturonic acid and neutral sugars were measured by HPLC. Complete hydrolysis of polygalacturonic acid occurred after 2.5h incubation with 2M TFA at 120 °C. The efficient hydrolysis of neutral sugars in pectins was performed with 2M TFA at 100 °C for 2.5h. Monomers most susceptible to concentrated acid were rhamnose, mannose and arabinose. PMID:25442606

  12. Compositional characterisation of soluble apple polysaccharides, and their antioxidant and hepatoprotective effects on acute CCl4-caused liver damage in mice.

    Science.gov (United States)

    Yang, Xingbin; Yang, Su; Guo, Yurong; Jiao, Yadong; Zhao, Yan

    2013-06-01

    Water-soluble apple peel polysaccharides (APP) and apple flesh polysaccharides (AFP) were isolated from Pink Lady fruits, and their in vitro antioxidant capacities were characterised by DPPH(), HO(), and O(2)(-) systems, and ferric-reducing antioxidant power assay. Oral administration of APP at 250 and 500 mg/kg bw in mice was shown to be as effective as AFP in lowering the CCl(4)-caused increases of serum alanine aminotransferase, aspartate aminotransferase and lactic dehydrogenase activities, and hepatic malondialdehyde level, and antagonising the decreases in antioxidant superoxide dismutase and glutathione peroxidase activities caused by CCl(4) (p<0.05). Histopathological examinations further confirmed that both APP and AFP could protect the liver from CCl(4)-induced histological alteration. HPLC analysis also showed similar profiles of monosaccharide composition for APP and AFP with arabinose, galactose and galacturonic acid being main component monosaccharides. All of these findings demonstrate that the extracts of both APP and AFP possess antioxidant and hepatoprotective potential. PMID:23411241

  13. Production of extracellular alkaline protease from Bacillus subtilis RSKK96 with solid state fermentation

    Directory of Open Access Journals (Sweden)

    Nurullah Akcan

    2011-09-01

    Full Text Available The production of extracellular alkaline protease by producing Bacillus subtilis RSKK96 was studied with solid state fermentation (SSF. Different agro residues as substrate were studied for enzyme production. The highest enzyme production was expressed with lentil husk as units per mass of dry substrate (3937.0 U/mg. Production parameters were optimized as incubation time 120 h, extraction medium Triton-X100 1%, initial moisture content 30%, initial pH 9.0. The high level of alkaline protease was obtained in the medium containing arabinose followed by lactose, galactose, and fructose. Among various nitrogen sources, beef extract was found to be the best inducer of alkaline protease, while other nitrogen sources repressed enzyme production. Among metal salts FeSO4.7H2O and MgSO4.7H2O was found to increase protease production. The maximum enzyme production (5759.2 U/mg was observed with lentil husk in 1000 mL of fermentation medium volume.

  14. Generation of organic acids and monosaccharides by hydrolytic and oxidative transformation of food processing residues.

    Science.gov (United States)

    Fischer, Klaus; Bipp, Hans-Peter

    2005-05-01

    Carbohydrate-rich biomass residues, i.e. sugar beet molasses, whey powder, wine yeast, potato peel sludge, spent hops, malt dust and apple marc, were tested as starting materials for the generation of marketable chemicals, e.g. aliphatic acids, sugar acids and mono-/disaccharides. Residues were oxidized or hydrolyzed under acidic or alkaline conditions applying conventional laboratory digestion methods and microwave assisted techniques. Yields and compositions of the oxidation products differed according to the oxidizing agent used. Main products of oxidation by 30% HNO(3) were acetic, glucaric, oxalic and glycolic acids. Applying H(2)O(2)/CuO in alkaline solution, the organic acid yields were remarkably lower with formic, acetic and threonic acids as main products. Gluconic acid was formed instead of glucaric acid throughout. Reaction of a 10% H(2)O(2) solution with sugar beet molasses generated formic and lactic acids mainly. Na(2)S(2)O(8) solutions were very inefficient at oxidizing the residues. Glucose, arabinose and galactose were formed during acidic hydrolysis of malt dust and apple marc. The glucose content reached 0.35 g per gram of residue. Important advantages of the microwave application were lower reaction times and reduced reagent demands. PMID:15607197

  15. [3H]Methotrexate loss from the rat brain following enhanced uptake by osmotic opening of the blood-brain barrier

    International Nuclear Information System (INIS)

    Right brain regions of anesthetized rats were loaded with [3,5,7-3H]methotrexate ([3H]MTX) or with [14C]sucrose by infusing the tracers into the right carotid artery, after the blood-brain barrier had been opened by right carotid infusion of a hypertonic arabinose solution. During the 6 hr following the procedure, the [3H]MTX concentration in 7 right-sided brain regions, when normalized to the plasma concentration integral during tracer infusion, fell, with an average half-time of 4.8 hr as compared to less than 20 min for the initial rate of loss [14C]sucrose. Right-left brain concentration differences 3 hr after treatment were statistically significant (p less than 0.05) for [3H]MTX but not for [14C]sucrose. The results indicate that intracerebral [3H]MTX is lost more slowly than is intracerebral [14C]sucrose, possibly because [3H]MTX enters brain cells, whereas [14C]sucrose remains largely extracellular

  16. Nutritive activity of soluble rice brain arabinoxylans in broiler diets.

    Science.gov (United States)

    Annison, G; Moughan, P J; Thomas, D V

    1995-07-01

    1. A soluble material (703 g/kg non-starch polysaccharide, 141 g/kg starch and 166 g/kg protein) of low viscosity (termed RB-NSP), was isolated in large quantities from defatted Australian rice bran using a mild alkaline extraction and ethanol precipitation. 2. The soluble non-starch polysaccharide fraction of RB-NSP comprised arabinose (0.40 mol%), xylose (0.32 mol%) galactose (0.17 mol%), glucose (0.08 mol%) and mannose (0.03 mol%). 3. RB-NSP was included at graded concentrations (0, 20, 40 and 60 g/kg) in a sorghum/casein basal diet and the diet fed to male broilers in a classical balance trial to determine apparent metabolisable energy (AME). The AME values recorded were 13.26, 13.85, 14.26 and 14.00 MJ/kg DM with a significant correlation (r = 0.65, P protein which were both high (0.98-0.99 and 0.88-0.89, respectively). 5. It was concluded that the RB-NSP may have been a substrate for hindgut fermentation in the broiler but that it possessed no anti-nutritive activity. PMID:7583378

  17. Isolation and identification of a pathogen of silkworm Bombyx mori.

    Science.gov (United States)

    Tao, Heng-Ping; Shen, Zhong-Yuan; Zhu, Feng; Xu, Xiao-Fang; Tang, Xu-Dong; Xu, Li

    2011-03-01

    A pathogenic bacterial strain, ST-1, was isolated from a naturally infected silkworm. The strain was identified on the basis of its physiological and biochemical properties and the results of sequence analysis of its 16S rRNA gene. The results of the 16S rRNA gene sequence analysis revealed that ST-1 shared the highest sequence identity (more than 99%) with Pseudomonas chlororaphis subsp. aurantiaca. ST-1 bacteria were gram-negative and 0.7-0.9 × 1.3-1.5 μm long, short rods with rounded ends. The strain could utilize sodium citrate, malonate, D-glucose, sucrose, D-fructose, D-mannose, and L-arabinose. Pathogenicity of ST-1 for silkworm could be depicted as a linear regression of the logarithm (y) of ST-1 concentration against probability (x) (y = 0.4040 + 0.0600x). The median lethal concentration (LC(50)) was 2.12 × 10(4) cfu/ml. In conclusion, ST-1 was identified as Ps. chlororaphis subsp. aurantiaca. This is the first report that Ps. aurantiaca is a pathogen for silkworm Bombyx mori. PMID:21046395

  18. Potential utilization of Citrullus lanatus var. Colocynthoides waste as a novel source of pectin.

    Science.gov (United States)

    Korish, Mohamed

    2015-04-01

    The Citrullus lanatus var. Colocynthoides is an ancestor type of watermelon. It was investigated as a new source of pectin. It was cultivated in Egypt for seeds only, while the remaining fruits are discarded as waste. Effect of different extraction conditions such as pH, solid: liquid ratio, temperature and extraction time on pectin yield of Citrullus lanatus var. Colocynthoides waste was investigated in the present study. The highest yield (19.75 % w/w) was achieved at pH 2, solid: liquid ratio1:15 and 85 °C, for 60 min. Methylation degree and galacturonic acid content of extracted pectin were 55.25 %, w/w and 76.84 %, w/w. The main neutral sugars were galactose followed by arabinose and rhamnose. In addition, glucose, xylose and mannose existed as constituents in the pectin hydrolysate. The results indicated that Citrullus lanatus var. Colocynthoide waste is a potential new source of pectin. PMID:25829625

  19. Isolation, Structural Characterization, and Valorization of Pectic Substances from Algerian Argan Tree Leaves (Argania spinosa (L. Skeels

    Directory of Open Access Journals (Sweden)

    Kadda Hachem

    2015-01-01

    Full Text Available Pectic polysaccharides were solubilized from Algerian argan tree leaves by sequential extraction with water at 100°C (water-soluble pectin; AL-WSP and EDTA solution at 80°C (chelating-soluble pectin; AL-CSP. Both AL-WSP and AL-CSP were rich in arabinose (28% and 74.5%, resp. and had a high content of uronic acid (38.5% and 21.5%, resp.. Pectic substances were deesterified and fractionated by anion exchange chromatography, giving five fractions for each extract. Most of the fractions were characterized by methylation analysis and then analyzed by 13C nuclear magnetic resonance spectroscopy. The results showed that AL-WSP consisted of rhamnogalacturonan type I, with arabinan and galactan branching at the O-4 position of the main rhamnose chain, while AL-CSP consisted of rhamnogalacturonan type I and a block of homogalacturonan. Antioxidant activities of AL-WSP and AL-CSP were evaluated by electronic spin resonance. The results showed that the antioxidant potential of AL-WSP (8.1% and AL-CSP (−1.2% was significantly lower than that of vitamin E.

  20. 荔枝壳多糖特性研究%Characterization of Litchi Pericarp Polysaccharide

    Institute of Scientific and Technical Information of China (English)

    杨宝; 赵谋明; 刘洋; 李宝珍

    2005-01-01

    多糖是荔枝壳的重要活性成分,本研究采用阴离子交换柱和凝胶过滤柱对荔枝壳多糖进行分离纯化.凝胶渗透色谱测定其分子量为14000 Dal.通过气相色谱测定其单糖组成为甘露糖、半乳糖和少量的阿拉伯糖,分子链由1,2键、1,3键和1,6键组成,不含1,4键.红外光谱分析表明甘露糖以β-D-甘露糖形式存在,不含羧基基团.%Polysaccharide was an important functional composition in litchi pericarp. Anion exchange column and gel filtration column were used to isolate and purify the major polysaccharide extracted from litchi pericarp. The profile of gel permeation chromatography (GPC) showed its molecular weight as 14000 Dal. Monose composition of the major polysaccharide was determined by using gas chromatography (GC).It mainly comprised mannose and galactose,and arabinose. Its structure was further identified by using infrared (IR) spectra.