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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    Down-regulation of acetolactate synthase compromises OI-1- mediated resistance to powdery mildew in tomato
    Gao, D. ; Huibers, R.P. ; Loonen, A.E.H.M. ; Visser, R.G.F. ; Wolters, A.M.A. ; Bai, Y. - \ 2014
    BMC Plant Biology 14 (2014). - ISSN 1471-2229 - 11 p.
    glutamate-dehydrogenase gene - acetohydroxyacid synthase - monogenic-resistance - defense responses - nicotiana-tabacum - ol-genes - arabidopsis - plants - inhibition - biosynthesis
    Background - In a cDNA-AFLP analysis comparing transcript levels between powdery mildew (Oidium neolycopersici)-susceptible tomato cultivar Moneymaker (MM) and near isogenic lines (NILs) carrying resistance gene Ol-1 or Ol-4, a transcript-derived fragment (TDF) M11E69-195 was found to be present in NIL-Ol-1 but absent in MM and NIL-Ol-4. This TDF shows homology to acetolactate synthase (ALS). ALS is a key enzyme in the biosynthesis of branched-chain amino acids valine, leucine and isoleucine, and it is also a target of commercial herbicides. Results - Three ALS homologs ALS1, ALS2, ALS3 were identified in the tomato genome sequence. ALS1 and ALS2 show high similarity, whereas ALS3 is more divergent. Transient silencing of both ALS1 and ALS2 in NIL-Ol-1 by virus-induced gene silencing (VIGS) resulted in chlorotic leaf areas that showed increased susceptibility to O. neolycopersici (On). VIGS results were confirmed by stable transformation of NIL-Ol-1 using an RNAi construct targeting both ALS1 and ALS2. In contrast, silencing of the three ALS genes individually by RNAi constructs did not compromise the resistance of NIL-Ol-1. Application of the herbicide chlorsulfuron to NIL-Ol-1 mimicked the VIGS phenotype and caused loss of its resistance to On. Susceptible MM and On-resistant line NIL-Ol-4 carrying a nucleotide binding site and leucine rich repeat (NB-LRR) resistance gene were also treated with chlorsulfuron. Neither the susceptibility of MM nor the resistance of NIL-Ol-4 was affected. Conclusions - ALS is neither involved in basal defense, nor in resistance conferred by NB-LRR type resistance genes. Instead, it is specifically involved in Ol-1-mediated resistance to tomato powdery mildew, suggesting that ALS-induced change in amino acid homeostasis is important for resistance conferred by Ol-1.
    Responses of supplemental blue light on flowering and stem extension growth of cut chrysanthemum
    Jeong, S.W. ; Hogewoning, S.W. ; Ieperen, W. van - \ 2014
    Scientia Horticulturae 165 (2014). - ISSN 0304-4238 - p. 69 - 74.
    plant-growth - spectral filters - red - morifolium - photosynthesis - gibberellins - phytochrome - end - photoperiod - inhibition
    To determine the effects of blue (B) spectrum supplemental lighting on flower bud formation and stem elongation growth of cut chrysanthemum, plants of ‘Zembla’ cultivar were grown for 42 days under 4 different light treatments. Treatments comprised: RB (11 h of mixed red and blue [RB] light), RB + B (11 h of mixed RB light and then 4 h of supplemental B light), LRB + B (15 h of mixed RB light and then 4 h of supplemental B light) and RB + LB (11 h of mixed RB light and then 13 h of B light) by using light-emitting diodes. Diurnal patterns in the net assimilation rate were observed, depending on light-quality combinations. Under mixed RB light, the net assimilation rate increased rapidly, then slightly decreased under B light, and finally dropped to negative values during darkness. Final stem length was the highest in plants grown under RB + LB, followed by LRB + B, RB + B and then RB treatment. The stem lengths under RB + B, LRB + B and RB + LB were 1.3, 1.5 and 1.7 times longer than that of RB treatment, respectively. However, fully developed flower buds were formed under RB and RB + B treatments only. The extended final stem length of RB + B plants was determined by internode extension. Overall, our results indicate that supplemental B light, at least in part, may promote stem and internode elongation growth without any inhibitory effect on flower bud formation. The results of this study present a useful practical technique for optimizing cut chrysanthemum production in greenhouse horticulture.
    Methane reduction by plant pigments and antioxidants in rumen fluid involves modifications, e.g. hydrogenatioor degradation of the active compoundsn,
    Becker, P.M. ; Wikselaar, P.G. van; Ilgenfritz, J. ; Beekwilder, M.J. ; Vos, R.C.H. de; Franz, C.H. ; Zitterl-Eglseer, K. - \ 2013
    Wiener Tierarztliche Monatsschrift 100 (2013). - ISSN 0043-535X - p. 295 - 305.
    bacteria - methanogenesis - anthocyanins - cleavage - bilberry - bisdemethoxycurcumin - demethoxycurcumin - resveratrol - inhibition - emissions
    Methane is a major greenhouse gas, and ruminants cause about a quarter of all anthropogenic methane emissions. The objective of this study was to testplant secondary products in terms of their effects on methane production, and to follow active compounds analytically during incubation. In a simplifi ed model of ruminal methane production, a glycerol tripolylactate served as a central metabolites-generating and hydrogen-releasing substrate for rumen prokaryotes. The experimental additives, tested for their interfering potential with methane production, comprised bilberry fruit extract, tomato paste, paprika powder, grape seed extract, turmeric powder, curcumin, catechin, ferulic acid, ferulic acid ethyl ester and resveratrol. Being an unsaturated compound, fumarate, a competing electron acceptor to methane precursors, served as a well-described methane-reducing compound among the experimental additives in the in vitro tests. Methanemitigating effi ciencies were calculated by subtraction of the methane quantity produced in fl asks with the interfering additives from the quantity measured without any additive. Grape seed extract, bilberry fruit extract, turmeric powder, ferulic acid, catechin, and resveratrol reduced the production of methane in vitro. Grape seed extract, bilberry fruit extract, catechin, and resveratrol decreased methane formation to a higher extent than fumarate when added at comparable concentrations. Analysis of the secondary compounds in the assays by means of HPLC and revealed a considerably and in most cases significant (p
    Dietary modulation of plasma angiopoietin-like protein 4 concentrations in healthy volunteers and in patients with type 2 diabetes
    Jonker, J.T. ; Smit, J.W.A. ; Hammer, S. ; Snel, M. ; Meer, R. van der; Lamb, H.J. ; Mattijssen, F.B.J. ; Mudde, C.M. ; Jazet, I.M. ; Dekkers, O.M. ; Roos, A. de; Romijn, J.A. ; Kersten, A.H. ; Rensen, P.C.N. - \ 2013
    American Journal of Clinical Nutrition 97 (2013)2. - ISSN 0002-9165 - p. 255 - 260.
    myocardial triglyceride content - free fatty-acids - lipoprotein-lipase - caloric restriction - diastolic function - angptl4 - mice - hyperlipidemia - inhibition - humans
    Background: Angiopoietin-like protein 4 (ANGPTL4) has been identified as an inhibitor of lipoprotein lipase. Preliminary data suggest that plasma nonesterified fatty acids (NEFAs) raise plasma ANGPTL4 concentrations in humans. Objective: The objective was to assess plasma ANGPTL4 concentrations after various nutritional interventions that increase NEFA concentrations in healthy subjects and in patients with type 2 diabetes mellitus. Design: We studied 4 groups, both at baseline and after 3 d of either fasting (n = 22 healthy men), a very-low-calorie diet (VLCD; n = 10 healthy men and n = 10 patients with diabetes), or a high-fat, high-energy diet (HFED; n = 15 healthy men). Plasma ANGPTL4, NEFA, and triglyceride concentrations were measured. Results: In healthy men, a VLCD increased ANGPTL4 from 13.2 (IQR: 8.1-24.2) at baseline to 18.2 (16.7-33.4) ng/mL (P <0.05), fasting increased ANGPTL4 from 10.6 (7.6-17.6) to 28.0 (23.1-35.0) ng/mL (P <0.05), and an HFED increased ANGPTL4 from 13.9 (8.2-22.0) to 17.2 (11.2-23.6) ng/mL (P <0.05). In men with diabetes, a VLCD also increased ANGPTL4, from 10.9 +/- 2.4 to 19.2 +/- 3.2 ng/mL (P <0.05). All interventions significantly increased plasma NEFAs in both healthy men and patients with diabetes. The change in ANGPTL4 positively correlated with the change in NEFA concentrations (beta = 0.048, P <0.001) and negatively correlated with the change in plasma triglycerides (beta = -0.051, P = 0.01). Conclusions: Three days of either fasting, a VLCD, or an HFED increased plasma ANGPTL4 concentrations in healthy men, concomitantly with increased plasma NEFA concentrations. Similarly, a VLCD in patients with diabetes increased ANGPTL4 concentrations, concomitantly with increased NEFA concentrations. Am J Clin Nutr 2013;97:255-60.
    Dietary protein, blood pressure and renal function in renal transplant recipients
    Berg, E. van den; Engberink, M.F. ; Brink, E.J. ; Baak, M.A. van; Gans, R.O.B. ; Navis, G. ; Bakker, S.J.L. - \ 2013
    The British journal of nutrition 109 (2013)8. - ISSN 0007-1145 - p. 1463 - 1470.
    kidney-transplantation - cardiovascular-disease - sodium-intake - follow-up - hypertension - restriction - association - progression - failure - inhibition
    Hypertension is highly prevalent among renal transplant recipients (RTR) and a risk factor for graft failure and cardiovascular events. Protein intake has been claimed to affect blood pressure (BP) in the general population and may affect renal function. We examined the association of dietary protein with BP and renal function in RTR. We included 625 RTR (age 53 (SD 13) years; 57% male). Protein intake was assessed with a FFQ, differentiating between animal and plant protein. BP was measured according to a strict protocol. Creatinine clearance and albuminuria were measured as renal parameters. Protein intake was 83 (SD 12) g/d, of which 63% derived from animal sources. BP was 136 (SD 17) mmHg systolic (SBP) and 83 (SD 11) mmHg diastolic (DBP). Creatinine clearance was 66 (SD 26) ml/min; albuminuria 41 (10-178) mg/24 h. An inverse, though statistically insignificant, association was found between the total protein intake and both SBP (beta = -2.22 mmHg per SD, P=0.07) and DBP (beta = -0.48 mmHg per SD, P=0.5). Protein intake was not associated with creatinine clearance. Although albuminuria was slightly higher in the highest tertile of animal protein intake compared with the lowest tertile (66 v. 33 mg/d, respectively, P=0.03), linear regression analyses did not reveal significant associations between dietary protein and albuminuria. Protein intake exceeded the current recommendations. Nevertheless, within the range of protein intake in our RTR population, we found no evidence for an association of dietary protein with BP and renal function. Intervention studies focusing on different protein types are warranted to clarify their effect on BP and renal function in RTR.
    Fate of Listeria monocytogenes in Gouda microcheese: No growth, and substantial inactivation after extended ripening times
    Wemmenhove, E. ; Stampelou, I. ; Hooijdonk, A.C.M. van; Zwietering, M.H. ; Wells-Bennik, M.H.J. - \ 2013
    International Dairy Journal 32 (2013)2. - ISSN 0958-6946 - p. 192 - 198.
    cheddar cheese - inoculum size - lactic-acid - behavior - manufacture - inhibition - survival - storage - milk - ph
    This challenge study demonstrates that Listeria monocytogenes does not grow in Gouda cheese: during the first 8 weeks of ripening no growth was observed and between 8 and 52 weeks viable numbers declined significantly in a well-established Gouda microcheese system. Cheese milk was artificially contaminated just prior to addition of the starter culture. Three individual L. monocytogenes strains were used, including strains originating from cheese, a cheese plant environment and a reference strain. During curd formation, viable numbers of L. monocytogenes increased by 0.5 log cfu g-1, resulting from entrapment in the curd. No growth was observed during the first 8 weeks of ripening. A significant decline in the viable numbers of L. monocytogenes was observed in Gouda cheese that was ripened for longer than 8 weeks. Two factors that could possibly control the fate of L. monocytogenes in Gouda cheese were lactic acid and water activity.
    Integration of first and second generation biofuels: Fermentative hydrogen production from wheat grain and straw
    Panagiotopoulos, I.A. ; Bakker, R.R.C. ; Vrije, G.J. de; Claassen, P.A.M. ; Koukios, E.G. - \ 2013
    Bioresource Technology 128 (2013). - ISSN 0960-8524 - p. 345 - 350.
    thermophiles caldicellulosiruptor-saccharolyticus - dilute-acid pretreatment - thermotoga-neapolitana - extreme thermophiles - bioethanol production - biomass - inhibition - conversion - ethanol - pulp
    Integrating of lignocellulose-based and starch-rich biomass-based hydrogen production was investigated by mixing wheat straw hydrolysate with a wheat grain hydrolysate for improved fermentation. Enzymatic pretreatment and hydrolysis of wheat grains led to a hydrolysate with a sugar concentration of 93.4 g/L, while dilute-acid pretreatment and enzymatic hydrolysis of wheat straw led to a hydrolysate with sugar concentration 23.0 g/L. Wheat grain hydrolysate was not suitable for hydrogen production by the extreme thermophilic bacterium Caldicellulosiruptor saccharolyticus at glucose concentrations of 10 g/L or higher, and wheat straw hydrolysate showed good fermentability at total sugar concentrations of up to 10 g/L. The mixed hydrolysates showed good fermentability at the highest tested sugar concentration of 20 g/L, with a hydrogen production of 82–97% of that of the control with pure sugars. Mixing wheat grain hydrolysate with wheat straw hydrolysate would be beneficial for fermentative hydrogen production in a biorefinery.
    IgG antibodies in food allergy influence allergen-antibody complex formation and binding to B cells: a role for complement receptors
    Meulenbroek, L.A. ; Jong, R.J. ; Hartog Jager, C.F. den; Monsuur, H.N. ; Wouters, D. ; Nauta, A. ; Knippels, L.M. ; Neerven, R.J.J. van; Ruiter, B. ; Leusen, J.H. ; Hack, C.E. ; Bruijnzeel-Koomen, C.A. ; Knulst, A.C. ; Garssen, J. ; Hoffen, E. van - \ 2013
    The Journal of Immunology 191 (2013)7. - ISSN 0022-1767 - p. 3526 - 3533.
    immune-responses - antigen presentation - blocking antibodies - natural antibody - peanut allergy - double-blind - fc regions - t-cells - activation - inhibition
    Allergen-IgE complexes are more efficiently internalized and presented by B cells than allergens alone. It has been suggested that IgG Abs induced by immunotherapy inhibit these processes. Food-allergic patients have high allergen-specific IgG levels. However, the role of these Abs in complex formation and binding to B cells is unknown. To investigate this, we incubated sera of peanut- or cow's milk-allergic patients with their major allergens to form complexes and added them to EBV-transformed or peripheral blood B cells (PBBCs). Samples of birch pollen-allergic patients were used as control. Complex binding to B cells in presence or absence of blocking Abs to CD23, CD32, complement receptor 1 (CR1, CD35), and/or CR2 (CD21) was determined by flow cytometry. Furthermore, intact and IgG-depleted sera were compared. These experiments showed that allergen-Ab complexes formed in birch pollen, as well as food allergy, contained IgE, IgG1, and IgG4 Abs and bound to B cells. Binding of these complexes to EBV-transformed B cells was completely mediated by CD23, whereas binding to PBBCs was dependent on both CD23 and CR2. This reflected differential receptor expression. Upon IgG depletion, allergen-Ab complexes bound to PBBCs exclusively via CD23. These data indicated that IgG Abs are involved in complex formation. The presence of IgG in allergen-IgE complexes results in binding to B cells via CR2 in addition to CD23. The binding to both CR2 and CD23 may affect Ag processing and presentation, and (may) thereby influence the allergic response.
    Activity and viability of methanogens in anaerobic digestion of unsaturated and saturated long-chain fatty acids
    Sousa, D.Z. ; Salvador, A.F. ; Ramos, J. ; Guedes, A.P. ; Barbosa, S. ; Stams, A.J.M. ; Alves, M.M. ; Pereira, M.A. - \ 2013
    Applied and Environmental Microbiology 79 (2013)14. - ISSN 0099-2240 - p. 4239 - 4245.
    16s ribosomal-rna - microbial communities - calcium addition - waste-water - oleic-acid - bacteria - inhibition - sludge - bioreactors - diversity
    Lipids can be anaerobically digested to methane, but methanogens are often considered to be highly sensitive to the long-chain fatty acids (LCFA) deriving from lipids hydrolysis. In this study, the effect of unsaturated (oleate [C18:1]) and saturated (stearate [C18:0] and palmitate [C16:0]) LCFA toward methanogenic archaea was studied in batch enrichments and in pure cultures. Overall, oleate had a more stringent effect on methanogens than saturated LCFA, and the degree of tolerance to LCFA was different among distinct species of methanogens. Methanobacterium formicicum was able to grow in both oleate- and palmitate-degrading enrichments (OM and PM cultures, respectively), whereas Methanospirillum hungatei only survived in a PM culture. The two acetoclastic methanogens tested, Methanosarcina mazei and Methanosaeta concilii, could be detected in both enrichment cultures, with better survival in PM cultures than in OM cultures. Viability tests using live/dead staining further confirmed that exponential growth-phase cultures of M. hungatei are more sensitive to oleate than are M. formicicum cultures; exposure to 0.5 mM oleate damaged 99% ± 1% of the cell membranes of M. hungatei and 53% ± 10% of the cell membranes of M. formicicum. In terms of methanogenic activity, M. hungatei was inhibited for 50% by 0.3, 0.4, and 1 mM oleate, stearate, and palmitate, respectively. M. formicicum was more resilient, since 1 mM oleate and >4 mM stearate or palmitate was needed to cause 50% inhibition on methanogenic activity
    Effect of substrate and cation requirement on anaerobic volatile fatty acid conversion rates at elevated biogas pressure
    Lindeboom, R.E.F. ; Ferrer, I. ; Weijma, J. ; Lier, J.B. van - \ 2013
    Bioresource Technology 150 (2013). - ISSN 0960-8524 - p. 60 - 66.
    high-calorific biogas - digestion process - bacteria - hydrogen - fermentation - temperature - competition - inhibition - propionate - archaea
    This work studied the anaerobic conversion of neutralized volatile fatty acids (VFA) into biogas under Autogenerative High Pressure Digestion (AHPD) conditions. The effects of the operating conditions on the biogas quality, and the substrate utilisation rates were evaluated using 3 AHPD reactors (0.6 L); feeding a concentration of acetate and VFA (1–10 g COD/L) corresponding to an expected pressure increase of 1–20 bar. The biogas composition improved with pressure up to 4.5 bar (>93% CH4), and stabilized at 10 and 20 bar. Both, acetotrophic and hydrogenotrophic methanogenic activity was observed. Substrate utilisation rates of 0.2, 0.1 and 0.1 g CODCH4/g VSS/d for acetate, propionate and butyrate were found to decrease by up to 50% with increasing final pressure. Most likely increased Na+-requirement to achieve CO2 sequestration at higher pressure rather than end-product inhibition was responsible.
    New strigolactone mimics: structure-activity relationship and mode of action as germinating stimulants for parasitic weeds.
    Zwanenburg, B. ; Nayak, S.K. ; Charnikhova, T. ; Bouwmeester, H.J. - \ 2013
    Bioorganic and Medicinal Chemistry Letters 23 (2013)18. - ISSN 0960-894X - p. 5182 - 5186.
    seed-germination - orobanche-minor - plant hormones - am fungi - striga-hermonthica - red-clover - analogs - inhibition - ring - phelipanche
    Strigolactones (SLs) are new plant hormones with varies important bio-functions. This Letter deals with germination of seeds of parasitic weeds. Natural SLs have a too complex structure for synthesis. Therefore, there is an active search for SL analogues and mimics with a simpler structure with retention of activity. SL analogues all contain the D-ring connected with an enone moiety through an enol ether unit. A new mechanism for the hydrolysis SL analogues involving bidentate bound water and an a,ß-hydrolase with a Ser-His-Asp catalytic triad has been proposed. Newly discovered SL mimics only have the D-ring with an appropriate leaving group at C-5. A mode of action for SL mimics was proposed for which now supporting evidence is provided. As predicted an extra methyl group at C-4 of the D-ring blocks the germination of seeds of parasitic weeds.
    Four Hypotheses to Explain Axillary Budbreak after Removal of Flower Shoots in a Cut-rose Crop
    Wubs-Timmermans, A.M. ; Heuvelink, E. ; Marcelis, L.F.M. ; Okello, R.C. ; Buck-Sorlin, G.H. ; Vos, J. - \ 2013
    Journal of the American Society for Horticultural Science 138 (2013)4. - ISSN 0003-1062 - p. 243 - 252.
    photosynthetic photon flux - bud burst - plant architecture - light control - growth - inhibition - auxin - age - arabidopsis - temperature
    When flower-bearing shoots in cut-rose (Rosa ×hybrida) are harvested (removed), a varying number of repressed axillary buds on the shoot remainder start to grow into new shoots (budbreak). Besides removing within-shoot correlative inhibition, it is hypothesized that shoot removal leads to 1) increased light intensity lower in the crop canopy; 2) changes in the light spectrum (particularly red:far-red ratio); and 3) changed source:sink ratio (i.e., the ratio between supply and demand of assimilates). As a fourth hypothesis it is proposed that the degree of budbreak on a shoot remainder is also influenced by the correlative inhibition exerted by other shoots on the plant. It is the goal of this work to determine which of these four hypotheses is most important for budbreak in a cut-rose crop. Four experiments were conducted, in which these factors were varied by leaf removal, removal of mature shoots, varying the number of young shoots, shading of the crop, and application of direct light on the buds. Increase in source:sink ratio was not consistently associated with higher budbreak. If source:sink ratio was decreased by removal of leaves or a mature shoot, budbreak showed even a tendency to increase. Budbreak was subject to correlative inhibition exerted by other shoots on the plant. Treatments where more light reached the bud (as a result of less shoots, no shading of the crop, application of local light) increased budbreak. Increased red:far-red ratio had the same result as more light reaching the bud but was often interrelated with light intensity. It was concluded that after removal of the flower-bearing shoot, among the factors tested, light intensity on the buds was an important and consistent factor explaining budbreak on the shoot remainder, whereas the effect of light spectrum should be further investigated
    The anti-browning agent sulfite inactivates Agaricus bisporus tyrosinase through covalent modification of the copper-B site
    Kuijpers, T.F.M. ; Gruppen, H. ; Sforza, S. ; Berkel, W.J.H. van; Vincken, J.P. - \ 2013
    FEBS Journal 280 (2013)23. - ISSN 1742-464X - p. 6184 - 6195.
    glutathione conjugate formation - crystal-structure - mushroom tyrosinase - polyphenol oxidase - chlorogenic acid - plant - inhibition - metabolism - thioether - sequence
    Sulfite salts are widely used as antibrowning agents in food processing. Nevertheless, the exact mechanism by which sulfite prevents enzymatic browning has remained unknown. Here, we show that sodium hydrogen sulfite (NaHSO3 ) irreversibly blocks the active site of tyrosinase from the edible mushroom Agaricus bisporus, and that the competitive inhibitors tropolone and kojic acid protect the enzyme from NaHSO3 inactivation. LC-MS analysis of pepsin digests of NaHSO3 -treated tyrosinase revealed two peptides showing a neutral loss corresponding to the mass of SO3 upon MS(2) fragmentation. These peptides were found to be homologous peptides containing two of the three histidine residues that form the copper-B-binding site of mushroom tyrosinase isoform PPO3 and mushroom tyrosinase isoform PPO4, which were both present in the tyrosinase preparation used. Peptides showing this neutral loss behavior were not found in the untreated control. Comparison of the effects of NaHSO3 on apo-tyrosinase and holo-tyrosinase indicated that inactivation is facilitated by the active site copper ions. These data provide compelling evidence that inactivation of mushroom tyrosinase by NaHSO3 occurs through covalent modification of a single amino-acid residue, probably via addition of HSO3 (-) to one of the copper-coordinating histidines in the copper-B site of the enzyme
    Improving medium chain fatty acid productivity using chain elongation by reducing the hydraulic retention time in an upflow anaerobic filter
    Grootscholten, T.I.M. ; Steinbusch, K.J.J. ; Hamelers, H.V.M. ; Buisman, C.J.N. - \ 2013
    Bioresource Technology 136 (2013). - ISSN 0960-8524 - p. 735 - 738.
    clostridium-kluyveri - carboxylic-acids - ethanol - biomass - fermentation - inhibition - reduction
    The expansion of biofuel production can lead to an array of negative environmental impacts. Therefore, the European Union (EU) has recently imposed sustainability criteria on biofuel production in the Renewable Energy Directive (RED). In this article, we analyse the effectiveness of the sustainability criteria for climate change mitigation and biodiversity conservation. We first use a global agriculture and forestry model to investigate environmental effects of the EU member states National Renewable Energy Action Plans (NREAPs) without sustainability criteria. We conclude that these targets would drive losses of 2.2 Mha of highly biodiverse areas and generate 95 Mt CO 2 eq of additional greenhouse gas (GHG) emissions. However, in a second step, we demonstrate that the EU biofuel demand could be satisfied ‘sustainably’ according to RED despite its negative environmental effects. This is because the majority of global crop production is produced ‘sustainably’ in the sense of RED and can provide more than 10 times the total European biofuel demand in 2020 if reallocated from sectors without sustainability criteria. This finding points to a potential policy failure of applying sustainability regulation to a single sector in a single region. To be effective this policy needs to be more complete in targeting a wider scope of agricultural commodities and more comprehensive in its membership of countries.
    Recovery and concentration of phenolic compounds in blood orange juice by membrane operations
    Destani, F. ; Cassano, A. ; Fazio, A. ; Vincken, J.P. ; Gebriele, B. - \ 2013
    Journal of Food Engineering 117 (2013)3. - ISSN 0260-8774 - p. 263 - 271.
    osmotic distillation - antioxidant activity - bioactive compounds - citrus flavonoids - anthocyanins - cancer - evaporation - inhibition - extracts - kinetics
    Cross-flow ultrafiltration (UF) and osmotic distillation (OD) were implemented on laboratory scale to obtain formulations of interest for food and/or pharmaceutical industry starting from the blood orange juice produced in the Calabria region. The freshly squeezed juice, after a depectinization step, was submitted to an UF process in order to recover natural antioxidants, such as hydroxycinnamic acids, hydroxybenzoic acids, flavanones, flavan-3-ols, and anthocyanins. The UF permeate, with an initial total soluble solids (TSS) content of 10.5°Brix, was concentrated by OD up to a final concentration of 61.4°Brix. The performance of both processes was analyzed in terms of productivity (permeate fluxes in UF and evaporation fluxes in OD) and quality of clarified and concentrated samples through the identification and quantization of phenolic compounds. The UF membrane showed a rejection towards the identified phenolic compounds in the range 0.4–6.9% and a little decrease of the TAA (8.2%) was observed in the UF permeate in comparison with the fresh juice. Phenolic compounds were also well preserved in the retentate of the OD process as demonstrated by the constant value of the ratio between the concentration of phenolic compounds in the OD retentate and the concentration of these compounds in the UF permeate stream (in the range 5.54–6.39).
    Comparative analyses of seeds of wild fruits or Rubus and Sambucus species from Southern Italy: fatty acid composition of the oil, total phenolic content, antioxidant and anti-inflammatory properties of the methanolic extracts
    Fazio, A. ; Plastina, P. ; Meijerink, J. ; Witkamp, R.F. ; Gabriele, B. - \ 2013
    Food Chemistry 140 (2013)4. - ISSN 0308-8146 - p. 817 - 824.
    chemical-composition - bioactive compounds - berry fruits - nitric-oxide - capacity - inhibition - anthocyanins - cultivar - disease - health
    Fruit seeds are byproducts from fruit processing. Characterisation of the bioactive compounds present in seeds and evaluation of their potential biological properties is therefore of particular importance in view of a possible valorisation of seeds as a source of health beneficial components. In this work, we have analysed the seeds of Sambucus and Rubus species in order to identify their bioactive components and to determine the antioxidant and anti-inflammatory activities of the extracts. We first analysed their oil content, in order to assess the fatty acid profile and tocopherol content. Moreover, the methanolic extracts of the seeds were analysed for their total phenolic contents and antioxidant capacities. Polyphenols were identified by HPLC–ESI–MS/MS analysis. Furthermore, extracts were evaluated for their inhibitory effects on the production of LPS-induced inflammatory mediators (NO, CCL-20) in RAW 264.7 cells. Our findings show that the methanolic extracts from Rubus seeds have strong antioxidant and anti-inflammatory properties and could therefore represent an attractive source of bioactive compounds for food, cosmetic, or pharmaceutical applications.
    THC reduces the anticipatory nucleus accumbens response to reward in subjects with a nicotine addiction
    Jansma, J.M. ; Hell, H.H. van; Vanderschuren, L.J.M.J. ; Bossong, M.G. ; Jager, G. ; Kahn, R.S. ; Ramsey, N.F. - \ 2013
    Translational Psychiatry 3 (2013). - ISSN 2158-3188 - 10 p.
    endogenous cannabinoid anandamide - increasing monetary reward - endocannabinoid system - drug-addiction - cb1 receptors - brain - dependence - rats - inhibition - humans
    Recent evidence has implicated the endocannabinoid (eCB) system in nicotine addiction. The eCB system also has an important role in reward mechanisms, and nicotine addiction has been associated with aberrant reward processing. Motivated by this evidence, we tested the hypothesis that eCB modulation of reward processing is altered in subjects with a nicotine addiction (NAD). For this purpose, we compared reward-related activity in NAD with healthy controls (HC) in a pharmacological magnetic resonance imaging (MRI) study using ¿9-tetrahydrocannabinol (THC) administration to challenge the eCB system. Eleven HC and 10 NAD participated in a 3-T functional MRI (fMRI) study with a double-blind, cross-over, placebo-controlled design, using a Monetary Incentive Delay (MID) paradigm with three reward levels. Reward activity in the nucleus accumbens (NAcc) and caudate putamen during anticipation and feedback of reward was compared after THC and placebo. fMRI results indicated a significant reduction of reward anticipation activity in the NAcc in NAD after THC administration, which was not present in HC. This is indicated by a significant group by drug by reward interaction. Our data show that THC significantly reduces the NAcc response to monetary reward anticipation in NAD. These results suggest that nicotine addiction is associated with altered eCB modulation of reward processing in the NAcc. This study adds important human data to existing evidence implicating the eCB system in nicotine addiction.
    Chicken dendritic cells are susceptible to highly pathogenic avian influenza viruses which induce strong cytokine responses
    Vervelde, L. ; Reemens, S.S. ; Haarlem, D.A. van; Post, J. ; Claassen, E.A.W. ; Rebel, J.M.J. ; Jansen, C.A. - \ 2013
    Developmental and Comparative Immunology 39 (2013)3. - ISSN 0145-305X - p. 198 - 206.
    ns1 protein - a virus - swine influenza - gene-expression - infection - interferon - activation - pathobiology - recognition - inhibition
    Infection with highly pathogenic avian influenza (HPAI) in birds and mammals is associated with severe pathology and increased mortality. We hypothesize that in contrast to low pathogenicity avian influenza (LPAI) infection, HPAI infection of chicken dendritic cells (DC) induces a cytokine deregulation which may contribute to their highly pathogenic nature. Infection of DC with LPAI H7N1 and H5N2 resulted in viral RNA and NP expression without increase in time, in contrast to HPAI H7N1 and H5N2 mRNA expression. No increase in IFN mRNA was detected after infection with LPAI, but after LPAI H5N2, and not LPAI H7N1, infection the level of bioactive IFNa/ß significantly increased. After HPAI H7N1 and H5N2 infection, significant increases in IL-8, IFN-a, IFN-¿ mRNA expression and in TLR1, 3, and 21 mRNA were observed. This enhanced activation of DC after HPAI infection may trigger deregulation of the immune response as seen during HPAI infection in chickens.
    Effect of ammonia on the anaerobic hydrolysis of cellulose and tributyrin
    Vasconcelos Fernandes, T. ; Keesman, K.J. ; Zeeman, G. ; Lier, J.B. van - \ 2012
    Biomass and Bioenergy 47 (2012). - ISSN 0961-9534 - p. 316 - 323.
    thermophilic digestion - methanogenic sludge - bounded noise - cow manure - kinetics - inhibition - nitrogen - identification - waste
    Ammonia nitrogen is one of the most common inhibitors in the anaerobic digestion of complex wastes containing high concentrations of ammonia like animal manures, blackwater and waste oil from gastronomy. The inhibiting effect of ammonia on methanogenesis has been well established. In contrast, the knowledge on the effect of ammonia on organic matter hydrolysis is rather limited. This study focuses on evaluating the effect of ammonia on the hydrolysis of carbohydrates and lipids, which are commonly found in biomass. Batch digestion of tributyrin and cellulose at varying ammonia concentrations were performed, using biomass adapted to 4.9 g NH4+–N.l-1. From this experimental study it was concluded that total ammonia nitrogen in the range of 2.4–7.8 g NH4+–N.l-1 (283–957 mg NH3–N.l-1) does not inhibit the hydrolysis of tributyrin or cellulose. This result is further confirmed by mathematical analysis of the estimated variation of the first-order hydrolysis constant as a function of the total ammonia concentration.
    Effect of hydrogen and carbon dioxide on carboxylic acids patterns in mixed culture fermentation
    Arslan, D. ; Steinbusch, K.J.J. ; Diels, L. ; Wever, H. De; Buisman, C.J.N. ; Hamelers, H.V.M. - \ 2012
    Bioresource Technology 118 (2012). - ISSN 0960-8524 - p. 227 - 234.
    acidogenic fermentation - biohydrogen production - anaerobic-bacteria - waste-water - fatty-acids - degradation - communities - inhibition - hydrolysis - industrial
    This study investigated the carboxylate spectrum from mixed culture fermentation of three organic waste streams after supplying 2 bar hydrogen and carbon dioxide or a mixture of these two gases to the headspace. Under any modified headspace, propionate production was ceased and butyrate, caproate and the total carboxylate concentrations were higher than in the reactors with N2 headspace (control). Production of one major compound was achieved under hydrogen and carbon dioxide mixed headspace after 4 weeks of incubation. Both the highest acetate concentration (17.4 g COD/l) and the highest fraction (87%) were observed in reactors with mixed hydrogen and carbon dioxide headspace independent of the substrate used. In the control reactor, acetate made up maximum 67% of the total products. For other products, the highest concentration and fraction were seldom observed together. Selective butyrate production reaching a 75% fraction was found under the carbon dioxide headspace on the carbohydrate rich waste.
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