Staff Publications

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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Uncovering the abilities of Agaricus bisporus to degrade plant biomass throughout its life cycle
Patyshakuliyeva, A. ; Post, H. ; Zhou, M. ; Jurak, E. ; Heck, A.J.R. ; Hilden, K.S. ; Kabel, M.A. ; Makela, M.R. ; Altenaar, M.A.F. ; Vries, R.P. de - \ 2015
Environmental Microbiology 17 (2015)8. - ISSN 1462-2912 - p. 3098 - 3109.
fungus phanerochaete-chrysosporium - ceriporiopsis-subvermispora - mannitol dehydrogenase - fomitopsis-palustris - gene-expression - button mushroom - rot fungi - acid - lignocellulose - insights
The economically important edible basidiomycete mushroom Agaricus bisporus thrives on decaying plant material in forests and grasslands of North America and Europe. It degrades forest litter and con-tributes to global carbon recycling, depolymerizing (hemi-)cellulose and lignin in plant biomass. Relatively little is known about how A. bisporus grows in the controlled environment in commercial production facilities and utilizes its substrate. Using transcriptomics and proteomics, we showed that changes in plant biomass degradation by A. bisporus occur throughout its life cycle. Ligninolytic genes were only highly expressed during the spawning stage day 16. In contrast, (hemi-)cellulolytic genes were highly expressed at the first flush, whereas low expression was observed at the second flush. The essential role for many highly expressed plant biomass degrading genes was supported by exoproteome analysis. Our data also support a model of sequential lignocellulose degradation by wood-decaying fungi proposed in previous studies, concluding that lignin is degraded at the initial stage of growth in compost and is not modified after the spawning stage. The observed differences in gene expression involved in (hemi-)cellulose degradation between the first and second flushes could partially explain the reduction in the number of mushrooms during the second flush
Comparison of Milk Oligosaccharides Pattern in Colostrum of Different Horse Breeds
Difilippo, E. ; Willems, H.A.M. ; Vendrig, J.C. ; Fink-Gremmels, J. ; Gruppen, H. ; Schols, H.A. - \ 2015
Journal of Agricultural and Food Chemistry 63 (2015)19. - ISSN 0021-8561 - p. 4805 - 4814.
neutral oligosaccharides - mass-spectrometry - bovine colostrum - fed babies - lactation - feces - acid
Colostrum oligosaccharides are known to exhibit prebiotic and immunomodulatory properties. Oligosaccharide composition is species-specific, and equine colostrum has been reported to contain unique oligosaccharides. Therefore, equine oligosaccharides (EMOS) from colostrum from different horse breeds were analyzed by CE-LIF, CE-MSn, HILIC-MSn, and exoglycosidase degradation. Sixteen EMOS were characterized and quantified, of which half were neutral and half were acidic. EMOS showed about 63% structural overlap with human milk oligosaccharides, known for their bioactivity. Seven EMOS were not reported before in equine oligosaccharides literature: neutral Gal(ß1–4)HexNAc, Gal(ß1–4)Hex-Hex, ß4'-galactosyllactose, and lactose-N-hexaose, as well as acidic 6'-Sialyl-Hex-Ac-HexNAc, sialyllacto-N-tetraose-a, and disialylacto-N-tetraose (isomer not further specified). In all colostrum samples, the average oligosaccharide concentration ranged from 2.12 to 4.63 g/L; with ß 6'and 3'- galactosyllactose, 3'-sialyllactose, and disialyllactose as the most abundant of all oligosaccharides (27–59, 16–37, 1–8, and 1–6%, respectively). Differences in presence and in abundance of specific EMOS were evident not only between the four breeds but also within the breed.
How Does Alkali Aid Protein Extraction in Green Tea Leaf Residue: A Basis for Integrated Biorefinery of Leaves
Zhang, C. ; Sanders, J.P.M. ; Xiao, T.T. ; Bruins, M.E. - \ 2015
PLoS One 10 (2015)7. - ISSN 1932-6203
functional-properties - antioxidant activity - sugar-beet - cell-walls - cellulose - pectins - biomass - acid - degradation - hydrolysis
Leaf protein can be obtained cost-efficiently by alkaline extraction, but overuse of chemicals and low quality of (denatured) protein limits its application. The research objective was to investigate how alkali aids protein extraction of green tea leaf residue, and use these results for further improvements in alkaline protein biorefinery. Protein extraction yield was studied for correlation to morphology of leaf tissue structure, protein solubility and hydrolysis degree, and yields of non-protein components obtained at various conditions. Alkaline protein extraction was not facilitated by increased solubility or hydrolysis of protein, but positively correlated to leaf tissue disruption. HG pectin, RGII pectin, and organic acids were extracted before protein extraction, which was followed by the extraction of cellulose and hemi-cellulose. RGI pectin and lignin were both linear to protein yield. The yields of these two components were 80% and 25% respectively when 95% protein was extracted, which indicated that RGI pectin is more likely to be the key limitation to leaf protein extraction. An integrated biorefinery was designed based on these results. Introduction
Listeria monocytogenes repellence by enzymatically modified PES surfaces
Veen, S. van der; Nady, N. ; Franssen, M.C.R. ; Zuilhof, H. ; Boom, R.M. ; Abee, T. ; Schroën, C.G.P.H. - \ 2015
Journal of Applied Polymer Science 132 (2015)10. - ISSN 0021-8995 - 6 p.
stainless-steel - catalyzed modification - biofilm formation - attachment - growth - membranes - water - acid - functionalization - hydrophobicity
: The effect of enzyme-catalyzed modification of poly(ethersulfone) (PES) on the adhesion and biofilm formation of two Listeria monocytogenes strains is evaluated under static and dynamic flow conditions. PES has been modified with gallic acid, ferulic acid and 4-hydroxybenzoic acid. The surfaces modified with any of these compounds show up to 70% reduced adhesion of L. mono-cytogenes under static conditions and up to 95% under dynamic flow conditions compared with unmodified surfaces. Also, under static conditions the formation of biofilms is reduced by 70%. These results indicate that the brush structures that are formed by the polymers on the PES surface directly influence the ability of microorganisms to interact with the surface, thereby reducing attachment and biofilm formation of L. monocytogenes. Based on these results, it is expected that enzyme-catalyzed surface modification is a promising tool to reduce microbial adhesion and biofilm formation
Quantifying variabiltiy on thermal resistance of Listeria monocytogenes
Chandra Aryani, D. ; Besten, H.M.W. den; Hazeleger, W.C. ; Zwietering, M.H. - \ 2015
International Journal of Food Microbiology 193 (2015). - ISSN 0168-1605 - p. 130 - 138.
heat-resistance - escherichia-coli - salmonella-typhimurium - inactivation parameters - physiological-state - bacillus-cereus - salt stress - shock - growth - acid
Knowledge of the impact of strain variability and growth history on thermal resistance is needed to provide a realistic prediction and an adequate design of thermal treatments. In the present study, apart from quantifying strain variability on thermal resistance of Listeria monocytogenes, also biological variability and experimental variability were determined to prioritize their importance. Experimental variability was defined as the repeatability of parallel experimental replicates and biological variability was defined as the reproducibility of biologically independent reproductions. Furthermore, the effect of growth history was quantified. The thermal inactivation curves of 20 L. monocytogenes strains were fitted using the modified Weibull model, resulting in total 360 D-value estimates. The D-value ranged from 9 to 30 min at 55 °C; from 0.6 to 4 min at 60 °C; and from 0.08 to 0.6 min at 65 °C. The estimated z-values of all strains ranged from 4.4 to 5.7 °C. The strain variability was ten times higher than the experimental variability and four times higher than the biological variability. Furthermore, the effect of growth history on thermal resistance variability was not significantly different from that of strain variability and was mainly determined by the growth phase.
Starch facilitates enzymatic wheat gluten hydrolysis
Hardt, N.A. ; Boom, R.M. ; Goot, A.J. van der - \ 2015
Food Science and Technology = Lebensmittel-Wissenschaft und Technologie 61 (2015)2. - ISSN 0023-6438 - p. 557 - 563.
functional-properties - foaming properties - protease - flour - acid
Wheat gluten can be hydrolyzed by either using (vital) wheat gluten or directly from wheat flour. This study investigates the influence of the presence of starch, the main component of wheat, on enzymatic wheat gluten hydrolysis. Wheat gluten present in wheat flour (WFG) and vital wheat gluten (VWG) were hydrolyzed at constant protein concentrations, but subsequently 5.6 times higher amounts of wheat flour. Nevertheless, WFG hydrolysis at 40% total solids resulted in significantly higher degrees of hydrolysis (DH%) than VWG hydrolysis at 7.2% solids. This difference increased to up to 4.5% in 6 h and diminished again for longer reaction times. Possible differences in the gluten composition and the presence of albumins and globulins in wheat flour could not explain the difference in DH% because the addition of starch to VWG increased the rate of hydrolysis similarly. Instead, it was concluded that starch granules impede gluten aggregation, which facilitates the hydrolysis. At higher solid concentrations of up to 70% wheat flour, the positive effect of starch disappeared, because WFG hydrolysis was hindered by mass transfer limitations and lower water activities.
Sustainability assessment of oilseed fractionation processes: A case study on lupin seeds
Berghout, J.A.M. ; Pelgrom, P.J.M. ; Schutyser, M.A.I. ; Boom, R.M. ; Goot, A.J. van der - \ 2015
Journal of Food Engineering 150 (2015). - ISSN 0260-8774 - p. 117 - 124.
functional-properties - exergy analysis - protein - food - feed - fiber - acid
Traditional ingredient production focusses on high purity and yield, resulting in energy- and resource-intensive fractionation processes. We explored alternative fractionation routes for oilseeds by focussing on functionality and optimal resource use. Lupin seeds were taken as model material because they are rich in protein and oil and they can be grown in moderate climate conditions. Dry fractionation yields functional protein-enriched flours without using water, consumes the least energy and exergy losses are low. Purer protein fractions are obtained via conventional wet or aqueous fractionation, but these processes require large amounts of water and an energy-intensive drying step. With the use of exergy analysis, we demonstrate that water and energy consumption can be reduced by replacing drying steps with concentration steps and by combining dry and aqueous fractionation processes. Finally, by valorising side streams, the exergetic efficiency of all fractionation processes increases.
Structure-performance relations of molybdenum- and tungsten carbide catalysts for deoxygenation
Stellwagen, D.R. ; Bitter, J.H. - \ 2015
Green Chemistry 17 (2015)1. - ISSN 1463-9262 - p. 582 - 593.
selective deoxygenation - carbon nanotubes - microalgae oil - hydrodeoxygenation - acid - reduction - oxygen - isomerization - pathways - oxides
This work demonstrates for the first time that carbide particle size is a critical factor for the activity and stability of carbon supported tungsten- and molybdenum carbide catalysts in (hydro-)deoxygenation reactions. The stability of the catalyst was shown to increase for larger particles due to the improved resistance of the metal carbide phase against full oxidation to crystalline metal oxides under reaction conditions. In addition to the improved catalyst stability, supported molybdenum carbides were found to more than double their weight-based catalytic activity upon increasing carbide particle size from 2 to 10 nanometers. The strongly improved (de-)hydrogenation activity of these larger carbide particles also facilitated a new deoxygenation pathway for fatty acids, in which an initial hydrogenation to fatty-aldehyde is combined with a decarbonylation step. This is the first time in which this deoxygenation pathway is observed over supported tungsten- or molybdenum carbide catalysts.
Isohexide hydroxy esters: synthesis and application of a new class of biobased AB-type building blocks
Thiyagarajan, S. ; Wu, J. ; Knoop, J.R.I. ; Haveren, J. van; Lutz, M. ; Es, D.S. van - \ 2014
RSC Advances : An international journal to further the chemical sciences 4 (2014)89. - ISSN 2046-2069 - p. 47937 - 47950.
isosorbide - polyesters - derivatives - acid
Here we present the synthesis of a new family of sugar derived 1,4: 3,6-dianhydrohexitol based AB-type monomers, containing one methyl ester group and a secondary hydroxyl group in all four possible stereo isomers (RR, RS, SR, SS). Structural characterization of the monomers (5a-d) was established by 1D and 2D NMR analysis, which was further confirmed by single-crystal X-ray structure determination. The application of these monomers in step-growth polymerization afforded fully isohexide based stereo-regular polyesters. Homo polyesters based on the RR and RS monomers were obtained with reasonable molecular weights by melt polymerization (Mn 2400 and 2500 resp.). These materials showed unexpectedly low glass-transition temperatures of 20 degrees C and 15 degrees C respectively. In contrast, the monomers with SR and SS configuration yielded only low molecular weight oligomers. Surprisingly, copolymerization of the RR and SR monomers gave a polyester with higher molecular weight (Mn 4100) and a high T-g of 80 degrees C. These preliminary results show that isohexide hydroxyesters are an intriguing new class of biobased building blocks with many potential applications.
Effect of antimicrobial compounds on cut Gerbera flowers: Poor relation between stem bending and numbers of bacteria in the vase water
Witte, Y. van de; Harkema, H. ; Doorn, W.G. van - \ 2014
Postharvest Biology and Technology 91 (2014). - ISSN 0925-5214 - p. 78 - 83.
jamesonii flowers - essential oils - rose flowers - membranes - longevity - stress - sugars - plants - life - acid
Gerbera flowers (Gerbera jamesonii) often show stem bending. In four cultivars (Tamara, Liesbeth, Cora, and Mickey), we tested the effects on bending of antimicrobial compounds (chlorine bleach, a slow release chlorine compound, 8-hydroxyquinoline citrate [HQC], silver nitrate, carvacrol and thymol), some combined with sugars. At concentrations used for other cut flowers, inclusion in the vase solution of several of the antimicrobial compounds delayed bending, had no effect, or hastened bending. Hastening of bending was found at higher concentrations. It was accompanied with visible damage on the stem ends. Results with HQC indicated high toxicity as it did not delay bending at any of the concentration tested (100-400 mg L-1). At 200 mg L-1 HQC induced growth of bacteria that were not found in the controls. The number of bacteria in the vase water showed a low correlation with bending. Visible toxicity on the stem surface was often associated with a high bacteria count. However, at relatively high concentrations of the antimicrobial compounds stem bending was associated with a low count. This indicated an effect other than bacteria. Water uptake was low in stems that bent early. It is hypothesized that material from dead stem cells resulted in a xylem blockage which led to early bending. Sucrose at 15 g L-1 in combination with an antimicrobial compound (slow release chlorine, HQC) resulted in the absence of stem damage and produced much less bending than the same concentration of the antimicrobial compounds alone. Sucrose apparently counteracted the toxic effects of the antimicrobial chemicals. (C) 2014 Published by Elsevier B.V.
Biocatalytic asymmetric phosphorylation of mevalonate
Matsumi, R. ; Hellriegel, C. ; Schoenenberger, B. ; Milesi, T. ; Oost, J. van der; Wohlgemuth, R. - \ 2014
RSC Advances : An international journal to further the chemical sciences 4 (2014)25. - ISSN 2046-2069 - p. 12989 - 12994.
liver phosphomevalonate kinase - substrate-specificity - zur biosynthese - pig-liver - isopentenyl pyrophosphate - quantitative nmr - acid - cholesterol - purification - terpene
The excellent selectivity of the mevalonate kinase-catalyzed phosphorylation of mevalonate simplifies lengthy multi-step routes to (R)-mevalonate-5-phosphate to a one-step biocatalytic reaction, because the phosphate group can be transferred directly and without any additional reaction steps involving introduction and removal of protecting groups. By adjusting the required reaction time for complete conversion, the kinetic resolution of racemic mevalolactone can be easily used for the preparation of (S)-mevalonate and (R)-mevalonate-5-phosphate. A new recombinant mevalonate kinase has been prepared by the expression of the mevalonate kinase gene from the hyperthermophilic archaeon Thermococcus kodakarensis in Escherichia coli and by the subsequent purification. Direct quantitative 31P-NMR kinetic analysis has been utilized to characterize the enantioselectivity of the mevalonate kinase. This method is useful for determining the biocatalyst's utility for the synthesis of enantiomerically pure (R)-mevalonate-5-phosphate as well as for biocatalytic process development.
Reciprocal crosstalk between jasmonate and salicylate defence-signalling pathways modulates plant volatile emission and herbivore host-selection behaviour
Wei, J. ; Loon, J.J.A. van; Gols, R. ; Menzel, T.R. ; Li, N. ; Kang, L. ; Dicke, M. - \ 2014
Journal of Experimental Botany 65 (2014)12. - ISSN 0022-0957 - p. 3289 - 3298.
mediated interactions - specialist herbivore - tetranychus-urticae - induced resistance - parasitic wasps - cotton plants - spider-mites - insect - acid - pathogen
The jasmonic acid (JA) and salicylic acid (SA) signalling pathways, which mediate induced plant defence responses, can express negative crosstalk. Limited knowledge is available on the effects of this crosstalk on host-plant selection behaviour of herbivores. We report on temporal and dosage effects of such crosstalk on host preference and oviposition-site selection behaviour of the herbivorous spider mite Tetranychus urticae towards Lima bean (Phaseolus lunatus) plants, including underlying mechanisms. Behavioural observations reveal a dynamic temporal response of mites to single or combined applications of JA and SA to the plant, including attraction and repellence, and an antagonistic interaction between SA- and JA-mediated plant responses. Dose-response experiments show that concentrations of 0.001mM and higher of one phytohormone can neutralize the repellent effect of a 1mM application of the other phytohormone on herbivore behaviour. Moreover, antagonism between the two signal-transduction pathways affects phytohormone-induced volatile emission. Our multidisciplinary study reveals the dynamic plant phenotype that is modulated by subtle changes in relative phytohormonal titres and consequences for the dynamic host-plant selection by an herbivore. The longer-term effects on plant–herbivore interactions deserve further investigation.
Adipose tissue metabolism and inflammation are differently affected by weight loss in obese mice due to either a high-fat diet restriction or change to a low-fat diet
Hoevenaars, F.P.M. ; Keijer, J. ; Herreman, L. ; Palm, I.F. ; Hegeman, M.A. ; Swarts, J.J.M. ; Schothorst, E.M. van - \ 2014
Genes & Nutrition 9 (2014). - ISSN 1555-8932 - 11 p.
nicotinamide nucleotide transhydrogenase - c57bl/6j mice - mitochondrial biogenesis - energy restriction - insulin-resistance - glucose - acid - expression - health - gene
Restriction of a high-fat diet (HFD) and a change to a low-fat diet (LFD) are two interventions that were shown to promote weight loss and improve parameters of metabolic health in obesity. Examination of the biochemical and molecular responses of white adipose tissue (WAT) to these interventions has not been performed so far. Here, male C57BL/6JOlaHsd mice, harboring an intact nicotinamide nucleotide transhydrogenase gene, were fed a purified 40 energy% HFD for 14 weeks to induce obesity. Afterward, mice were divided into three dietary groups: HFD (maintained on HFD), LFD (changed to LFD with identical ingredients), and HFD-CR (restricted to 70 % of the HFD). The effects of the interventions were examined after 5 weeks. Beneficial effects were seen for both HFD-CR and LFD (compared to HFD) regarding physiological parameters (body weight and fat mass) and metabolic parameters, including circulating insulin and leptin levels. Macrophage infiltration in WAT was reduced by both interventions, although more effectively by HFDCR. Strikingly, molecular parameters in WAT differed between HFD-CR and LFD, with increased activation of mitochondrial carbohydrate and fat metabolism in HFDCR mice. Our results confirm that restriction of the amount of dietary intake and reduction in the dietary energy content are both effective in inducing weight loss. The larger decrease in WAT inflammation and increase in mitochondrial carbohydrate metabolism may be due to a larger degree of energy restriction in HFD-CR, but could also be due to superior effectiveness of dietary restriction in weight loss strategies.
Effect of processing on the diffusion of alkaloids and quality of lupinus mutabilis sweet
Carvajal Larenas, F.E. ; Boekel, M.A.J.S. van; Koziol, M. ; Nout, M.J.R. ; Linnemann, A.R. - \ 2014
Journal of Food Processing and Preservation 38 (2014)4. - ISSN 0145-8892 - p. 1461 - 1471.
quinolizidine alkaloids - bacterial removal - seed - digestibility - extraction - proteins - carbon - acid
Cold water processing by soaking, cooking and washing has been used for hundreds of years to produce debittered lupine in the Andean region. The process of debittering lupine (Lupinus mutabilis Sweet) was investigated at semi-industrial village-scale and laboratory scale in Ecuador. The process took 5.7 1.0 days, removed 94.9% of the total alkaloids, used water at almost 62 times the weight of the raw dry and bitter lupine, and caused a 22% loss of total solids, principally fat, minerals and carbohydrates. During the debittering process the microbiological quality deteriorated. Mathematical modeling based on Fickian diffusion suggested that the diffusion coefficient of alkaloids would be expected to be between 10-10 and 10-11 m2/s because the lupine endosperm is a polymer matrix whose properties change during processing. Of the process operations, cooking was the most efficient at removing alkaloids both in terms of time and water used, followed by soaking and washing.
Purification, Characterization, and Prebiotic Properties of Pectic Oligosaccharides from Orange Peel Wastes
Gómez, B. ; Gullón, B. ; Remoroza, C.A. ; Schols, H.A. ; Parajó, J.C. ; Alonso, J.L. - \ 2014
Journal of Agricultural and Food Chemistry 62 (2014)40. - ISSN 0021-8561 - p. 9769 - 9782.
in-vitro fermentation - butyrate-producing bacteria - human fecal microbiota - human gut - polysaccharides - fermentability - pretreatment - hydrolysis - product - acid
Pectic oligosaccharides (POS) were obtained by hydrothermal treatment of orange peel wastes (OPW) and purified by membrane filtration to yield a refined product containing 90 wt % of the target products. AraOS (DP 3–21), GalOS (DP 5–12), and OGalA (DP 2–12, with variable DM) were identified in POS mixtures, but long-chain products were also present. The prebiotic potential of the concentrate was assessed by in vitro fermentation using human fecal inocula. For comparative purposes, similar experiments were performed using orange pectin and commercial fructo-oligosaccharides (FOS) as substrates for fermentation. The dynamics of selected microbial populations was assessed by fluorescent in situ hybridization (FISH). Gas generation, pH, and short-chain fatty acid (SCFA) production were also measured. Under the tested conditions, all of the considered substrates were utilized by the microbiota, and fermentation resulted in increased numbers of all the bacterial groups, but the final profile of the microbial population depended on the considered carbon source. POS boosted particularly the numbers of bifidobacteria and lactobacilli, so that the ratio between the joint counts of both genera and the total cell number increased from 17% in the inocula to 27% upon fermentation. SCFA generation from POS fermentation was similar to that observed with FOS, but pectin fermentation resulted in reduced butyrate generation.
Ercella succinigenes gen. nov., sp. nov., an anaerobic succinate-producing bacterium
Gelder, A.H. van; Sousa, D.Z. ; Rijpstra, W.I. ; Damsté, J.S. ; Stams, A.J.M. ; Sanchez Andrea, I. - \ 2014
International Journal of Systematic and Evolutionary Microbiology 64 (2014)7. - ISSN 1466-5026 - p. 2449 - 2454.
ribosomal-rna genes - acid - heterogeneity - fermentation - sequences - biofuels - glycerol - industry - operons - genomes
A novel anaerobic succinate-producing bacterium, strain ZWBT, was isolated from sludge collected from a biogas desulfurization bioreactor (Eerbeek, the Netherlands). Cells were non-spore-forming, motile, slightly curved rods (0.4–0.5 µm in diameter and 2–3 µm in length), and stained Gram-negative. The temperature range for growth was 25–40 °C, with an optimum at 37 °C. The pH range for growth was 7.0–9.0, with an optimum at pH 7.5. Strain ZWBT was able to ferment glycerol and several carbohydrates mainly to H2, succinate and acetate. Sulfur and fumarate could be used as electron acceptors by strain ZWBT. The G+C content of the genomic DNA was 37.6 mol%. The most abundant fatty acids were iso-C14¿:¿0 and iso-C16¿:¿0 DMA. On the basis of 16S rRNA gene sequence similarity, strain ZWBT belongs to the family Ruminococcaceae and it is distantly related to Saccharofermentans acetigenes JCM 14006T (92.1¿%). Based on the physiological features and phylogenetic analysis, strain ZWBT represents a novel species of a new genus, for which the name Ercella succinigenes gen. nov., sp. nov. is proposed. The type strain of Ercella succinigenes is ZWBT (¿=¿DSM 27333T¿=¿JCM 19283T).
Genetic diversity of nitrogen use efficiency in spinach (Spinacia oleraces L.) cultivars using the Ingestad model on hydroponics
Chan-Navarrete, R. ; Kawai, A. ; Dolstra, O. ; Lammerts Van Bueren, E. ; Linden, C.G. van der - \ 2014
Euphytica 199 (2014)1-2. - ISSN 0014-2336 - p. 155 - 166.
nitrate accumulation - crop plants - growth - vegetables - nutrition - photosynthesis - leaves - yield - acid - allocation
Spinach is a leafy vegetable that requires a high N fertilization to have a satisfactory yield and quality, in part because it has poor nitrogen use efficiency (NUE). Therefore, there is a need to breed for cultivars with an excellent NUE. To this end the genetic diversity for NUE-related traits was studied in a diverse set of commercial cultivars. This set was evaluated in a hydroponic system using the Ingestad model; the system was set at a relative growth rate of 0.14 and 0.18 g g-1 day-1 (low and high N, respectively). Experiments were performed at low and high plant density. Traits monitored for single plants included fresh and dry weight, leaf area, specific leaf area, dry weight ratio between root and shoot, and chlorophyll content. The high density experiment showed more genotypic variation for the observed traits than the low density one. Biomass production was considerably lower at low than at high N. Path analysis revealed that leaf area had the highest direct effect on NUE, while specific leaf area was an important trait determining variation in NUE at low N. Slow and fast growing genotypes were shown to use different strategies to utilize N, and these strategies are expressed differently at high and low N availability. This indicates that improving spinach for NUE is feasible using the analysed genotypes as source material, and different strategies can be targeted for adaptation of spinach cultivars to low N conditions.
Quercetin decreases high-fat diet induced body weight gain and accumulation of hepatic and circulating lipids in mice
Hoek-van den Hil, E.F. ; Schothorst, E.M. van; Stelt, I. van der; Swarts, J.J.M. ; Venema, D.P. ; Sailer, M. ; Vervoort, J.J.M. ; Hollman, P.C.H. ; Rietjens, I. ; Keijer, J. - \ 2014
Genes & Nutrition 9 (2014). - ISSN 1555-8932 - 8 p.
cardiovascular-disease - gene-expression - c57bl/6j mice - acid - risk - hepatocytes - metabolism - flavonoids - obesity - women
Dietary flavonoids may protect against cardiovascular diseases (CVD). Increased circulating lipid levels and hepatic lipid accumulation are known risk factors for CVD. The aim of this study was to investigate the effects and underlying molecular mechanisms of the flavonoid quercetin on hepatic lipid metabolism in mice with high-fat diet induced body weight gain and hepatic lipid accumulation. Adult male mice received a 40 energy% high-fat diet without or with supplementation of 0.33 % (w/w) quercetin for 12 weeks. Body weight gain was 29 % lower in quercetin fed mice (p <0.01), while the energy intake was not significantly different. Quercetin supplementation lowered hepatic lipid accumulation to 29 % of the amount present in the control mice (p <0.01). 1H nuclear magnetic resonance serum lipid profiling revealed that the supplementation significantly lowered serum lipid levels. Global gene expression profiling of liver showed that cytochrome P450 2b (Cyp2b) genes, key target genes of the transcription factor constitutive androstane receptor (Car; official symbol Nr1i3), were downregulated. Quercetin decreased high-fat diet induced body weight gain, hepatic lipid accumulation and serum lipid levels. This was accompanied by regulation of cytochrome P450 2b genes in liver, which are possibly under transcriptional control of CAR. The quercetin effects are likely dependent on the fat content of the diet.
Evaluation of using spot urine to replace 24 h urine sodium and potassium excretions
Hooft Van Huysduynen, E.J.C. ; Hulshof, P.J.M. ; Lee, L. van; Geelen, A. ; Feskens, E.J.M. ; Veer, P. van 't; Woerkum, C.M.J. van; Vries, J.H.M. de - \ 2014
Public Health Nutrition 17 (2014)11. - ISSN 1368-9800 - p. 2505 - 2511.
24-hour - collections - completeness - creatinine - magnesium - calcium - samples - marker - acid
Objective The most accurate method to estimate Na and K intakes is to determine 24 h urinary excretions of these minerals. However, collecting 24 h urine is burdensome. Therefore it was studied whether spot urine could be used to replace 24 h urine samples. Design Participants collected 24 h urine and kept one voiding sample separate. Na, K and creatinine concentrations were analysed in both 24 h and spot urine samples. Also 24 h excretions of Na and K were predicted from spot urine concentrations using the Tanaka and Danish methods. Setting In 2011 and 2012, urine samples were collected and brought to the study centre at Wageningen University, the Netherlands. Subjects Women (n 147) aged 19–26 years. Results According to p-aminobenzoic acid excretions, 127 urine collections were complete. Correlations of Na:creatinine, K:creatinine and Na:K between spot urine and 24 h urine were 0·68, 0·57 and 0·64, respectively. Mean 24 h Na excretion predicted with the Tanaka method was higher (difference 21·2 mmol/d, P
Sub-chronic toxicity study in rats orally exposed to nanostructured silica
Zande, M. van der; Vandebriel, R.J. ; Groot, M.J. ; Kramer, E.H.M. ; Herrera Riviera, Z.E. ; Rasmussen, K. ; Ossenkoppele, J.S. ; Tromp, P. ; Gremmer, E.R. ; Peters, R.J.B. ; Hendriksen, P.J. ; Marvin, H.J.P. ; Hoogenboom, L.A.P. ; Peijnenburg, A.A.C.M. ; Bouwmeester, H. - \ 2014
Particle and Fibre Toxicology 11 (2014). - ISSN 1743-8977
in-vivo biodistribution - expression profiles - liver fibrosis - nanoparticles - absorption - elimination - injection - foods - acid - size
Synthetic Amorphous Silica (SAS) is commonly used in food and drugs. Recently, a consumer intake of silica from food was estimated at 9.4 mg/kg bw/day, of which 1.8 mg/kg bw/day was estimated to be in the nano-size range. Food products containing SAS have been shown to contain silica in the nanometer size range (i.e. 5 – 200 nm) up to 43% of the total silica content. Concerns have been raised about the possible adverse effects of chronic exposure to nanostructured silica.
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