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Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    Serum Protein N-Glycans in Colostrum and Mature Milk of Chinese Mothers
    Elwakiel, Mohèb ; Bakx, Edwin J. ; Szeto, Ignatius M. ; Li, Yitong ; Hettinga, Kasper A. ; Schols, Henk A. - \ 2020
    Journal of Agricultural and Food Chemistry 68 (2020)25. - ISSN 0021-8561 - p. 6873 - 6883.
    glycoproteins - glycosylation - intestinal mucosal barrier - oligosaccharides

    To study the Chinese human milk N-glycome over lactation, N-glycans were released and separated from serum proteins, purified by solid-phase extraction, and analyzed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS). In total, 66 different putative N-glycans were found in the colostrum (week 1) and mature milk (week 4) of seven Chinese mothers. A clear difference was observed between milk of five secretor and two nonsecretor mothers, based on the type and relative amounts of the individual N-glycans. The relative levels of the total neutral nonfucosylated and the fucosylated N-glycans in milk of five secretor mothers increased and decreased over lactation, respectively. This pattern could not be observed for the milk from the two nonsecretor mothers. Overall, this was the first study that provided detailed information on individual N-glycans in milk among mothers and over time as well as that fucosylation of N-glycans in milk was associated with the mother's secretor status.

    The effect of fiber and prebiotics on children’s gastrointestinal disorders and microbiome
    Wegh, Carrie A.M. ; Schoterman, Margriet H.C. ; Vaughan, Elaine E. ; Belzer, Clara ; Benninga, Marc A. - \ 2017
    Expert Review of Gastroenterology and Hepatology 11 (2017)11. - ISSN 1747-4124 - p. 1031 - 1045.
    children - dietary fiber - functional gastrointestinal disorders - Gut microbiota - oligosaccharides - prebiotics

    Introduction: The bacteria received upon birth are the start of colonization of the approximately 1014 bacteria that are present in the mature human gastrointestinal tract, better known as the microbiota. The gut microbiota is implicated in gastrointestinal health, nutrient metabolism and benefits such as prevention of infection. Dietary fiber, including prebiotics, escape digestion in the small intestine and reach the colon intact, where they are partially or completely fermented by the gut microbiota. Areas covered: The possible interactions between dietary fiber, prebiotics and microbiota are discussed as well as how this relates to functional gastrointestinal disorders. During the first years of life the microbiota have not yet reached a stable state and is sensitive to disturbance by environmental factors. An imbalance in the microbiota early in life is found to be associated with several functional gastrointestinal disorders such as colic, functional abdominal pain, irritable bowel syndrome and constipation. Expert commentary: A better understanding of how gut microbial changes in early-life can impact gastrointestinal health might lead to new treatments or disease prevention. Nutritional strategies with fiber or prebiotics may support health due to modification of colonic microbiota composition and metabolic activity, for example by growth stimulation of Bifidobacterium and Lactobacillus.

    Mining microbiota signatures in human intestinal tract metagenomes
    Tims, S. - \ 2016
    Wageningen University. Promotor(en): Michiel Kleerebezem; Willem de Vos, co-promotor(en): Erwin Zoetendal. - Wageningen : Wageningen University - ISBN 9789462576933 - 264
    gastrointestinal microbiota - intestines - genomes - man - hosts - host guest relations - dna microarrays - gastrointestinal diseases - inflammatory bowel diseases - irritable colon - prebiotics - body mass index - oligosaccharides - microbiota van het spijsverteringskanaal - darmen - genomen - mens - gastheren (dieren, mensen, planten) - relaties tussen gastheer en gast - dna microarrays - maagdarmziekten - chronische darmontstekingen - prikkelbaar colon - prebiotica - quetelet index - oligosacchariden
    Structure and fermentation of natural and manufactured lactose-based oligosaccharides
    Difilippo, E. - \ 2016
    Wageningen University. Promotor(en): Harry Gruppen; Henk Schols. - Wageningen : Wageningen University - ISBN 9789462576155 - 128
    milks - lactose - oligosaccharides - ingestion - bioactive compounds - isolation - characterization - fermentation - colostrum - food analysis - melksoorten - lactose - oligosacchariden - inname - bioactieve verbindingen - isolatie - karakterisering - fermentatie - colostrum - voedselanalyse

    At early stages of life, infant immature intestine is not fully developed, exposing the new-born to potential diseases. Compounds that can exert beneficial actions on the infant intestine are bioactive lactose-based oligosaccharides (LBOs). The natural source of LBOs is mother milk. When human milk is lacking, dietary supplementation with infant formula fortified with manufactured LBOs, such as galacto-oligosaccharides (GOS), is pursued. GOS have been shown to have several properties in common with HMOs. LBOs composition and intestinal fate is extensively described for humans, whereas they are hardly investigated for domestic animal. In this PhD thesis, composition of LBOs in equine and porcine colostrum were described and new structures were elucidated. The analysis were performed mainly using liquid chromatography and capillary electrophoresis techniques. High inter- and intra-individual variation were found for oligosaccharides present in equine and porcine milk. In vivo fermentation fate of porcine milk oligosaccharides (PMOs) was also described analysing PMOs as found in fecal samples of piglets. The results were correlated to existing literature on HMOs. Dietary oligosaccharides are partially present systemically, as suggested from HMO studies. GOS and PMOs in blood, urine and fecal samples from an in vivo feeding trial on piglet were described. Intact dietary oligosaccharides including GOS and milk oligosaccharides from the piglet diet were found in piglet blood and urine samples. All dietary oligosaccharides were fermented/absorbed in vivo, not being detectable in the piglet fecal samples. On the other hand, GOS in vitro fermentation by piglet inoculum delineate a unique fermentation profile regarding GOS size consumption compared to GOS in vitro fermentation by human fecal inoculum. Similar degradation profile regarding GOS linkage types was observed for GOS fermentation by piglet and human inocula.

    Effect of fructooligosaccharides on gut health in neonatal piglets : VDI-3 Piglet experimen
    Schokker, D. ; Jansen, R. ; Jansman, A.J.M. ; Vastenbouw, S. ; Bree, F.M. de; Bossers, A. ; Rebel, J.M.J. ; Smits, M.A. - \ 2015
    Wageningen : Wageningen UR Livestock Research (Livestock Research report 913) - 39
    piglets - intestines - animal health - oligosaccharides - intestinal microorganisms - immunology - biggen - darmen - diergezondheid - oligosacchariden - darmmicro-organismen - immunologie
    Gut microbial colonization and immune competence development are affected by early-life environmental and dietary interventions. The interplay between microbiota in the intestinal tract and the gut mucosal surfaces of the host is critical for the development of an accurate immune competence. In the present study we intervened during early life of suckling piglets by a daily oral administration of fructooligosaccharides (FOS solution) from day 2 – 14 and investigated the effects on intestinal microbiota composition (by 16S rDNA sequencing) and biological processes of the intestinal mucosal tissue (by genome-wide intestinal gene expression analysis) during the suckling phase.
    Compost Grown Agaricus bisporus Lacks the Ability to Degrade and Consume Highly Substituted Xylan Fragments
    Jurak, E. ; Patyshakuliyeva, A. ; Vries, R.P. de; Gruppen, H. ; Kabel, M.A. - \ 2015
    PLoS ONE 10 (2015)8. - ISSN 1932-6203
    wheat-flour arabinoxylan - h-1-nmr spectroscopy - aspergillus-awamori - enzyme-activities - button mushroom - mode - oligosaccharides - purification
    The fungus Agaricus bisporus is commercially grown for the production of edible mushrooms. This cultivation occurs on compost, but not all of this substrate is consumed by the fungus. To determine why certain fractions remain unused, carbohydrate degrading enzymes, water-extracted from mushroom-grown compost at different stages of mycelium growth and fruiting body formation, were analyzed for their ability to degrade a range of polysaccharides. Mainly endo-xylanase, endo-glucanase, ß-xylosidase and ß-glucanase activities were determined in the compost extracts obtained during mushroom growth. Interestingly, arabinofuranosidase activity able to remove arabinosyl residues from doubly substituted xylose residues and a-glucuronidase activity were not detected in the compost enzyme extracts. This correlates with the observed accumulation of arabinosyl and glucuronic acid substituents on the xylan backbone in the compost towards the end of the cultivation. Hence, it was concluded that compost grown A. bisporus lacks the ability to degrade and consume highly substituted xylan fragments.
    Human milk composition differs in healthy mothers and mothers with celiac disease
    Olivares, M. ; Albrecht, S. ; Palma, G. de; Desamparados Ferrer, M. ; Castillejo, G. ; Schols, H.A. ; Sanz, Y. - \ 2015
    European Journal of Nutrition 54 (2015). - ISSN 1436-6207 - p. 119 - 128.
    breast-milk - cytokine production - allergic disease - ce-lif - childhood - risk - oligosaccharides - infant - metaanalysis - bacteria
    Purpose To investigate whether breast-milk composition and microbiota differ in healthy mothers and mothers with celiac disease (CD) to ultimately contribute to identify additional factors determining CD risk. Methods Breast-milk samples from healthy mothers (n = 12) and mothers with CD (n = 12) were collected. Cytokines and secretory immunoglobulin A (sIgA) were analyzed by bead-arrays and flow cytometry and human milk oligosaccharides (HMOs) were assessed by capillary electrophoresis with laser-induced fluorescence (CE-LIF) detection. Breast-milk microbiota composition was analyzed by conventional and quantitative real-time PCR. Result Breast milk from CD mothers showed significantly lower levels of interleukin (IL) 12p70 (P\0.042), transforming growth factor (TGF)-b1 (P\0.018) and sIgA (P\0.003) and almost significantly lower levels of interferon (IFN)-c (P\0.058). Six mothers in each group belonged to the secretor Le(a-b?) type, one to the secretor Le(a-b-) type and five to the non-secretor Le(a?b-) type. CD mothers of non-secretor Le(a?b-) type showed increased Lacto-N-tetraose content (P\0.042) compared with healthy mothers. CD mothers’ milk showed reduced gene copy numbers of Bifidobacterium spp. (P\0.026) and B. fragilis group (P\0.044). Conclusion CD mothers’ breast milk is characterized by a reduced abundance of immunoprotective compounds (TGF-b1 and sIgA) and bifidobacteria. The reduction in these components could theoretically diminish the protective effects of breast-feeding on the child’s future risk of developing CD.
    Characterization of sugar beet pulp derived oligosaccharides
    Leijdekkers, M. - \ 2015
    Wageningen University. Promotor(en): Harry Gruppen; Henk Schols. - Wageningen : Wageningen University - ISBN 9789462572430 - 162
    suikerbieten - bietenpulp - oligosacchariden - versuikering - bioraffinage - voer - fermentatie - sugarbeet - beet pulp - oligosaccharides - saccharification - biorefinery - feeds - fermentation


    This thesis aimed at characterizing complex mixtures of sugar beet pulp derived oligosaccharides, in order to be able to monitor and optimize the enzymatic saccharification of sugar beet pulp.

    Hydrophilic interaction chromatography with on-line evaporative light scattering detection and multidimensional mass spectrometry (HILIC-ELSD-MSn) was developed as a versatile technique for the characterization of a wide range of neutral and acidic plant cell wall derived oligosaccharides. It was shown that the separation capacity of HILIC for acidic oligosaccharides outperforms other techniques. HILIC-MSn enabled efficient sequence elucidation of oligosaccharides in complex mixtures.

    The enzymatic saccharification of sugar beet pulp was optimized to release the maximum amounts of monomeric galacturonic acid and arabinose with limited concomitant degradation of cellulose, using conditions that are feasible for industrial upscaling. The oligosaccharides that were obtained after hydrolysis were characterized, thereby enabling recognition of enzyme activities additionally needed for the full degradation of recalcitrant oligosaccharides.

    The in vitro fermentation characteristics of sugar beet pectic oligosaccharides (SBPOS) were studied using human and pig fecal inocula. The fate of the different classes of SBPOS, the production of short-chain fatty acids and the changes in human fecal bacterial populations during in vitro fermentation were described. Several modifications in the microbiota composition that are potentially beneficial to host health were observed.

    HILIC was also coupled to traveling-wave ion mobility mass spectrometry to enable the simultaneous separation and characterization of complex mixtures of various isomeric pectic oligosaccharides. The developed method was used to characterize isomeric sugar beet rhamnogalacturonan I derived oligosaccharides carrying a glucuronic acid substituent, thereby identifying novel structural features of sugar beet pectin.

    Characterisation of a novel endo-xyloglucanase (XcXGHA) from Xanthomonas that accommodates a xylosyl-substituted glucose at subsite -1
    Feng, T. ; Yan, K.P. ; Mikkelsen, M.D. ; Meyer, A.S. ; Schols, H.A. ; Westereng, B. ; Mikkelsen, J.D. - \ 2014
    Applied Microbiology and Biotechnology 98 (2014)23. - ISSN 0175-7598 - p. 9667 - 9679.
    polysaccharide-degrading enzymes - geotrichum sp m128 - plant-cell walls - substrate-specificity - glycoside hydrolase - structural basis - oligosaccharides - expression - cloning - endo-beta-1,4-glucanase
    A xyloglucan-specific endo-1,4ß-glucanase (XcXGHA) from Xanthomonas citri pv. mangiferaeindicae has been cloned, expressed in Escherichia coli, purified and characterised. The XcXGHA enzyme belongs to CAZy family GH74 and has catalytic site residues conserved with other xyloglucanases in this family. At its optimal reaction conditions, pH 7.0 and 40 °C, the enzyme has a k cat/K M value of 2.2¿×¿107 min-1 M-1 on a tamarind seed xyloglucan substrate. XcXGHA is relatively stable within a broad pH range (pH 4–9) and up to 50 °C (t 1/2, 50 °C of 74 min). XcXGHA is proven to be xyloglucan-specific, and a glycan microarray study verifies that XcXGHA catalyses cleavage of xyloglucan extracted from both monocot and dicot plant species. The enzyme catalyses hydrolysis of tamarind xyloglucan in a unique way by cleaving XXXG into XX and XG (X is xylosyl-substituted glucose; G is unsubstituted glucose), is able to degrade more complex xyloglucans and notably is able to cleave near more substituted xyloglucan motifs such as L [i.e. a-l-Fucp-(1¿¿¿2)-ß-d-Galp-(1¿¿¿2)-a-d-Xylp-(1¿¿¿6)-ß-d-Glcp]. LC-MS/MS analysis of product profiles of tamarind xyloglucan which had been catalytically degraded by XcXGHA revealed that XcXGHA has specificity for X in subsite -1. The 3D model suggests that XcXGHA consists of two seven-bladed ß-propeller domains with the catalytic center formed by the interface of these two domains, which is conserved in xyloglucanases in the GH74 family. However, the XcXGHA has two amino acids (D264 and R472) that differ from the conserved residues of other GH74 xyloglucanases. These two amino acids were predicted to be located on the opposite side of the active site pocket, facing each other and forming a closing surface above the active site pocket. These two amino acids may contribute to the unique substrate specificity of the XcXGHA enzyme.
    Physiological and biochemical responses of Ricinus communis seedlings to different temperatures: a metabolomics approach
    Ribeiro de Jesus, P.R. ; Fernandez, L.G. ; Delmondez de Castro, R. ; Ligterink, W. ; Hilhorst, H.W.M. - \ 2014
    BMC Plant Biology 14 (2014). - ISSN 1471-2229 - 14 p.
    abiotic stress tolerance - castor-oil - phenotypic plasticity - plant-responses - arabidopsis - growth - metabolism - tool - oligosaccharides - biodiesel
    Background Compared with major crops, growth and development of Ricinus communis is still poorly understood. A better understanding of the biochemical and physiological aspects of germination and seedling growth is crucial for the breeding of high yielding varieties adapted to various growing environments. In this context, we analysed the effect of temperature on growth of young R. communis seedlings and we measured primary and secondary metabolites in roots and cotyledons. Three genotypes, recommended to small family farms as cash crop, were used in this study. Results Seedling biomass was strongly affected by the temperature, with the lowest total biomass observed at 20°C. The response in terms of biomass production for the genotype MPA11 was clearly different from the other two genotypes: genotype MPA11 produced heavier seedlings at all temperatures but the root biomass of this genotype decreased with increasing temperature, reaching the lowest value at 35°C. In contrast, root biomass of genotypes MPB01 and IAC80 was not affected by temperature, suggesting that the roots of these genotypes are less sensitive to changes in temperature. In addition, an increasing temperature decreased the root to shoot ratio, which suggests that biomass allocation between below- and above ground parts of the plants was strongly affected by the temperature. Carbohydrate contents were reduced in response to increasing temperature in both roots and cotyledons, whereas amino acids accumulated to higher contents. Our results show that a specific balance between amino acids, carbohydrates and organic acids in the cotyledons and roots seems to be an important trait for faster and more efficient growth of genotype MPA11. Conclusions An increase in temperature triggers the mobilization of carbohydrates to support the preferred growth of the aerial parts, at the expense of the roots. A shift in the carbon-nitrogen metabolism towards the accumulation of nitrogen-containing compounds seems to be the main biochemical response to support growth at higher temperatures. The biochemical changes observed in response to the increasing temperature provide leads into understanding plant adaptation to harsh environmental conditions, which will be very helpful in developing strategies for R. communis crop improvement research.
    To pool or not to pool? Impact of the use of individual and pooled fecal samples for in vitro fermentation studies
    Aguirre, M. ; Ramiro Garcia, J. ; Koenen, M.E. ; Venema, K. - \ 2014
    Journal of Microbiological Methods 107 (2014). - ISSN 0167-7012 - p. 1 - 7.
    human large-intestine - gut microbiota - model - bacteria - oligosaccharides - metabolism - products - patterns - starch - core
    This study investigated the stability and the activity of the microbiota from a single and a pool of donors in the TNO in vitro model of the colon (TIM-2 system). Our findings demonstrate the suitability of the preparation of a pool of fecal sample to be used for fermentation experiments.
    Expression of natural human b1,4-GalT1 variants and of non-mammalian homologues in plants leads to differences in galactosylation of N-glycans
    Hesselink, T. ; Rouwendal, G.J.A. ; Henquet, M.G.L. ; Florack, D.E.A. ; Helsper, J.P.F.G. ; Bosch, H.J. - \ 2014
    Transgenic Research 23 (2014)5. - ISSN 0962-8819 - p. 717 - 728.
    golgi-apparatus - murine beta-1,4-galactosyltransferase - beta 1,4-galactosyltransferase - transgenic plants - gene - cells - localization - antibodies - oligosaccharides - glycoproteins
    b1,4-Galactosylation of plant N-glycans is a prerequisite for commercial production of certain biopharmaceuticals in plants. Two different types of galactosylated N-glycans have initially been reported in plants as the result of expression of human b1,4-galactosyltransferase 1 (GalT). Here we show that these differences are associated with differences at its N-terminus: the natural short variant of human GalT results in hybrid type N-glycans, whereas the long form generates bi-antennary complex type N-glycans. Furthermore, expression of non-mammalian, chicken and zebrafish GalT homologues with N-termini resembling the short human GalT N-terminus also induce hybrid type N-glycans. Providing both non-mammalian GalTs with a 13 amino acid N-terminal extension that distinguishes the two naturally occurring forms of human GalT, acted to increase the levels of biantennary galactosylated N-glycans when expressed in tobacco leaves. Replacement of the cytosolic tail and transmembrane domain of chicken and zebrafish GalTs with the corresponding region of rat a2,6-sialyltransferase yielded a gene whose expression enhanced the level of bi-antennary galactosylation even further.
    Isomalto/Malto-Polysaccharide, A Novel Soluble Dietary Fiber Made Via Enzymatic Conversion of Starch
    Leemhuis, H. ; Dobruchowska, J.M. ; Ebbelaar, M. ; Faber, F. ; Buwalda, P.L. ; Maarel, M.J.E.J. ; Kamerling, J.P. ; Dijkhuizen, L. - \ 2014
    Journal of Agricultural and Food Chemistry 62 (2014)49. - ISSN 0021-8561 - p. 12034 - 12044.
    including resistant starch - lactobacillus-reuteri 121 - structural-characterization - amylose content - chain-length - oligosaccharides - enzymes - 4,6-alpha-glucanotransferase - dextransucrase - dextranase
    Dietary fibers are at the forefront of nutritional research because they positively contribute to human health. Much of our processed foods contain, however, only small quantities of dietary fiber, because their addition often negatively affects the taste, texture, and mouth feel. There is thus an urge for novel types of dietary fibers that do not cause unwanted sensory effects when applied as ingredient, while still positively contributing to the health of consumers. Here, we report the generation and characterization of a novel type of soluble dietary fiber with prebiotic properties, derived from starch via enzymatic modification, yielding isomalto/malto-polysaccharides (IMMPs), which consist of linear (a1 ¿ 6)-glucan chains attached to the nonreducing ends of starch fragments. The applied Lactobacillus reuteri 121 GTFB 4,6-a-glucanotransferase enzyme synthesizes these molecules by transferring the nonreducing glucose moiety of an (a1 ¿ 4)-glucan chain to the nonreducing end of another (a1 ¿ 4)-a-glucan chain, forming an (a1 ¿ 6)-glycosidic linkage. Once elongated in this way, the molecule becomes a better acceptor substrate and is then further elongated with (a1 ¿ 6)-linked glucose residues in a linear way. Comparison of 30 starches, maltodextrins, and a-glucans of various botanical sources, demonstrated that substrates with long and linear (a1 ¿ 4)-glucan chains deliver products with the highest percentage of (a1 ¿ 6) linkages, up to 92%. In vitro experiments, serving as model of the digestive power of the gastrointestinal tract, revealed that the IMMPs, or more precisely the IMMP fraction rich in (a1 ¿ 6) linkages, will largely pass the small intestine undigested and therefore end up in the large intestine. IMMPs are a novel type of dietary fiber that may have health promoting activity.
    Separation of Whey Proteins using Cascaded Ultrafiltration
    Patil, N.V. ; Janssen, A.E.M. ; Boom, R.M. - \ 2014
    Separation Science and Technology 49 (2014)15. - ISSN 0149-6395 - p. 2280 - 2288.
    tangential flow filtration - membrane cascades - nanofiltration cascades - monoclonal-antibody - bed chromatography - beta-lactoglobulin - fractionation - purification - oligosaccharides - configuration
    Whey protein isolate, containing a-Lactalbumin and ß-Lactoglobulin, was separated by using a continuous three-stage ultrafiltration cascade system. Single-stage experiments were optimized to enable good and stable cascade operation. Three different cascade configurations, a non-constrained ideal system (Configuration A), and adapted version (Configuration B), and a countercurrent cascade (Configuration C) were experimentally tested and compared. The countercurrent cascade system showed the traditional trade-off between yield and purity. Both the adapted cascade system and the non-constrained ideal cascade gave better performance in terms of recovery and purity and show potential for application, albeit for different purposes.
    Unfermented recalcitrant polysaccharide structures from rapeseed (Brassica napus) meal in pigs
    Pustjens, A.M. ; Vries, S. de; Bakuwel, M. ; Gruppen, H. ; Gerrits, W.J.J. ; Kabel, M.A. - \ 2014
    Industrial Crops and Products 58 (2014). - ISSN 0926-6690 - p. 271 - 279.
    cell-wall polysaccharides - nonstarch polysaccharides - canola-meal - growing pigs - poultry - digestibility - xyloglucan - enzyme - oligosaccharides - microbiome
    Unprocessed and acid-extruded rapeseed meal (RSM) was fed to pigs as the only source of non-starch polysaccharides (NSP) and protein. Unfermented carbohydrate structures were analyzed. Acid-extrusion seemed to increase rigidness of the NSP-matrix in vivo, without affecting NSP-fermentability. Water-soluble NSP were almost completely fermented in the colon. From the water-insoluble unfermented carbohydrates 46–68% (w/w) was analyzed as the polysaccharides rhamnogalacturonan, (branched) arabinan, XXXG-type xyloglucan, linear xylan, galactomannan, and cellulose. A major fraction (35–54% w/w) of the unfermented carbohydrates was unexpectedly released as small uronyl-rich carbohydrates (
    Effect of Soluble and Insoluble Fibers within the in Vitro Fermentation of Chicory Root Pulp by Human Gut Bacteria
    Ramasamy, U. ; Venema, K. ; Schols, H.A. ; Gruppen, H. - \ 2014
    Journal of Agricultural and Food Chemistry 62 (2014)28. - ISSN 0021-8561 - p. 6794 - 6802.
    human colonic microbiota - large-intestine - dietary modulation - genomic analysis - system - oligosaccharides - fermentability - metabolism - prebiotics - cellulose
    The aim of this research was to study the in vitro fermentation of chicory root pulp (CRP) and ensiled CRP (ECRP) using human fecal inoculum. Analysis of carbohydrate levels in fermentation digests showed that 51% of all CRP carbohydrates were utilized after 24 h of fermentation. For ECRP, having the same cell wall polysaccharide composition as CRP, but with solubilization of 4 times more of CRP pectin due to ensiling, the fermentation was quicker than with CRP as 11% more carbohydrates were utilized within the first 12 h. The level of fiber utilization for ECRP after 24 h was increased by 8% compared to CRP. This effect on fiber utilization from ECRP seemed to arise from (i) increased levels of soluble pectin fibers (arabinan, homogalacturonan, and galactan) and (ii) ahypothesized more open structure of the remaining cell walls in ECRP, which was more accessible to degradation than the CRP cell wall network. KEYWORDS: chicory root pulp, ensiled chicory root pulp, insoluble
    Galacto-oligosaccharides to counter the side effects of antibiotic treatments
    Ladirat, S.E. - \ 2014
    Wageningen University. Promotor(en): Harry Gruppen; Henk Schols. - Wageningen : Wageningen University - ISBN 9789461738394 - 160
    oligosacchariden - darmmicro-organismen - bifidobacterium longum - antibiotica - prebiotica - amoxicilline - oligosaccharides - intestinal microorganisms - bifidobacterium longum - antibiotics - prebiotics - amoxicillin

    Antibiotic treatments are known to disturb the composition and metabolic activity of the human gut microbiota and, therefore, may lead to gut disorders. In this thesis, it was investigated whether and by which mechanisms galacto-oligosaccharides (GOS), a prebiotic known to stimulate the growth of bifidobacteria and to positively influence human health, may counter the negative effects of antibiotics on the microbiota.

    First, a high throughput approach combining the in vitro fermentation screening platform with a phylogenetic microarray read-outs was shown to be reliable to simultaneously analyse the effects of several often-used antibiotics on the intestinal microbiota. Then, using the same approach, the recovery of the composition and metabolic activity of the microbiota treated with four selected antibiotics upon GOS addition was shown to be antibiotic and dose dependant. The addition of GOS to an amoxicillin (AMX)-treated microbiota was considered successful as, after a decrease of the levelofBifidobacterium species, the recovery of mainly Bifidobacterium longum, was observed. The growth of bifidobacteria and the production of the beneficial butyrate tended to be higher upon addition of small GOS (dimers-trimers) than upon large GOS in non-treated microbiota (tetramers to hexamers). On the contrary in AMX-treated microbiota, the growth of bifidobacteria and production of butyrate tented to be higher upon addition of large GOS than upon addition of small GOS. The positive results of GOS on AMX-treated microbiota during in vitro experiments were evidenced in a double-blind randomized parallel intervention study involving 12 healthy adults.

    Overall, the addition of GOS, especially the large oligosaccharides, allowed the recovery of B. longum and, subsequently, stimulated the activity of the microbiota through cross-feeding after an AMX treatment.

    Enzymatic synthesis of oligo- and polysaccharide fatty acid esters
    Broek, L.A.M. van den; Boeriu, C.G. - \ 2013
    Carbohydrate Polymers 93 (2013)1. - ISSN 0144-8617 - p. 65 - 72.
    catalyzed cellulose acetylation - organic media - vinyl esters - regioselective esterification - water activity - lipase - acylation - solvents - transesterification - oligosaccharides
    Amphiphilic oligo- and polysaccharides (e.g. polysaccharide alkyl or alkyl-aryl esters) form a new class of polymers with exceptional properties. They function as polymeric surfactants, whilst maintaining most of the properties of the starting polymeric material such as emulsifying, gelling, and film forming properties combined with partial water solubility or permeability. At present carbohydrate fatty acid esters are generally obtained by chemical methods using toxic solvents and organic and inorganic catalysts that leave residual traces in the final products. Enzymatic reactions offer an attractive alternative route for the synthesis of polysaccharide esters. In this review the state of the art of enzymatic synthesis of oligo- and polysaccharides fatty esters has been described.
    A novel bacterial enzyme with D-glucuronyl C5-epimerase activity
    Raedts, J.G.J. ; Lundgren, M. ; Kengen, S.W.M. ; Li, J.P. ; Oost, J. van der - \ 2013
    Journal of Biological Chemistry 288 (2013)34. - ISSN 0021-9258 - p. 24332 - 24339.
    l-iduronic acid - heparan-sulfate - heparin/heparan sulfate - escherichia-coli - biosynthesis - polysaccharide - glycosaminoglycans - oligosaccharides - purification - database
    Glycosaminoglycans are biologically active polysaccharides that are found ubiquitously in the animal kingdom. The biosynthesis of these complex polysaccharides involves complicated reactions that turn the simple glycosaminoglycan backbone into highly heterogeneous structures. One of the modification reactions is the epimerization of D-glucuronic acid to its C5-epimer L-iduronic acid, which is essential for the function of heparan sulfate. Although L-iduronic acid residues have been shown to exist in polysaccharides of some prokaryotes, there has been no experimental evidence for the existence of a prokaryotic D-glucuronyl C5-epimerase. This work for the first time reports on the identification of a bacterial enzyme with D-glucuronyl C5-epimerase activity. A gene of the marine bacterium Bermanella marisrubri sp. RED65 encodes a protein (RED65_08024) of 448 amino acids that has an overall 37% homology to the human D-glucuronic acid C5-epimerase. Alignment of this peptide with the human and mouse sequences revealed a 60% similarity at the carboxyl terminus. The recombinant protein expressed in Escherichia coli showed epimerization activity toward substrates generated from heparin and the E. coli K5 capsular polysaccharide, thereby providing the first evidence for bacterial D-glucuronyl C5-epimerase activity. These findings may eventually be used for modification of mammalian glycosaminoglycans
    Effects of Carbohydrates on the oNPG Converting Activity of ß-Galactosidases
    Warmerdam, A. ; Wang, J. ; Boom, R.M. ; Janssen, A.E.M. - \ 2013
    Journal of Agricultural and Food Chemistry 61 (2013)26. - ISSN 0021-8561 - p. 6458 - 6464.
    bacillus-circulans - physiological consequences - enzymatic-synthesis - aspergillus-oryzae - lactose hydrolysis - oligosaccharides - confinement
    The effects of high concentrations of carbohydrates on the o-nitrophenyl ß-D-galactopyranoside (oNPG) converting activity of ß-galactosidase from Bacillus circulans are studied to get a better understanding of the enzyme behavior in concentrated and complicated systems in which enzymatic synthesis of galacto-oligosaccharides is usually performed. The components that were tested were glucose, galactose, lactose, sucrose, trehalose, raffinose, Vivinal GOS, dextran-6000, dextran-70 000, and sarcosine. Small carbohydrates act as acceptors in the reaction. This speeds up the limiting step, which is binding of the galactose residue with the acceptor and release of the product. Simultaneously, both inert and reacting additives seem to cause some molecular crowding, which results in a higher enzyme affinity for the substrate. The effect of molecular crowding on the enzyme activity is small compared to the effect of carbohydrates acting in the reactions as acceptors. The effects of reactants on ß-galactosidases from B. circulans, A. oryzae, and K. lactis are compared. KEYWORDS: galacto-oligosaccharides, GOS, ß-galactosidase, Bacillus circulans, enzyme activity, carbohydrates, crowding, galactosyl transfer, transgalactosylation, Aspergillus oryzae, Kluyveromyces lactis
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