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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    Biobased itaconzuur en methacrylzuur : Chemische bouwstenen van de toekomst
    Es, D.S. van - \ 2016
    Fluids Processing Benelux (2016)4. - ISSN 1874-7914 - p. 46 - 47.
    biobased economy - chemie op basis van biologische grondstoffen - chemicaliën uit biologische grondstoffen - zuren - biomassa - glucose - biochemie - biobased economy - biobased chemistry - biobased chemicals - acids - biomass - glucose - biochemistry
    Wageningen UR Food & Biobased Research is van plan een flinke stap te zetten in de productie van biobased itaconzuur en methacrylzuur. Deze zuren kunnen bouwstenen zijn voor hoogwaardige materialen, zoals biobased verf en drukinkt. De stoffen worden geproduceerd uit biomassa (glucose) en vormen alternatieven voor fossiele grondstoffen. Voor verdere ontwikkeling wordt samengewerkt met de Amerikaanse agrifoodproducent Archer Daniels Midland, leverancier voor de verfindustrie EOC Belgium en de Nederlandse verfproducent Van Wijhe Verf. Daan van Es, is senioronderzoeker bij Wageningen UR en treedt op als projectleider.
    Metabolic engineering of Escherichia coli for itaconate production
    Vuoristo, K.S. - \ 2016
    Wageningen University. Promotor(en): Gerrit Eggink; Johan Sanders, co-promotor(en): Ruud Weusthuis. - Wageningen : Wageningen University - ISBN 9789462576001 - 162
    fermentation - escherichia coli - aspergillus niger - biobased chemistry - bioengineering - acids - organic acids - glutamates - tca - production - chemicals - fermentatie - escherichia coli - aspergillus niger - chemie op basis van biologische grondstoffen - bioengineering - zuren - organische zuren - glutamaten - tca - productie - chemicaliën

    Interest in sustainable development together with limited amounts of fossil resources have increased the demand for production of chemicals and fuels from renewable resources. The market potential for bio-based products is growing and a transition from petrochemicals to biomass-based chemicals is ongoing. Itaconic acid is a C5-dicarboxylic acid which can be produced by microbial conversion processes. It can be easily polymerized and is an appealing building block for the chemical industry with many potential applications. However, biobased chemicals have to compete with their petrochemical counterparts, and yield and productivity of the microbial processes are therefore of the utmost importance. Traditionally itaconic acid is produced using the ascomycete Aspergillus terreus. This process is not competitive with petrochemical processes due to high production costs caused by low yields, and difficult and expensive product recovery. Maximizing product yield is important to lower production costs. This thesis looked at ways to reach theoretical maximum yield in a recombinant production host, Escherichia coli.

    Chapter 2 describes the construction of an itaconate biosynthesis pathway in E. coli. The key enzyme of microbial itaconate production is cis-Aconitate decarboxylase (CadA) that converts the citric acid cycle intermediate cis-aconitate into itaconate. We focused on optimizing heterologous expression of cadA from Aspergillus terreus in E. coli. Initially this resulted in low CadA activities and production of trace amounts of itaconate. CadA was primarily present as inclusion bodies, explaining the low activity. The activity was significantly improved by using lower cultivation temperatures and mineral medium and this resulted in enhanced itaconate titres. The itaconate titre was further increased in aerobic bioreactor cultures by introducing citrate synthase and aconitase from Corynebacterium glutamicum and by deleting genes encoding phosphate acetyltransferase and lactate dehydrogenase. The maximum itaconate yield from glucose obtained in this study was only 0.09 mol/mol, due to high flux of carbon to by-products such as acetate and pyruvate. Pyruvate is a precursor molecule for itaconate biosynthesis and its accumulation suggested that the activity of CadA might be one of the rate limiting steps. It was concluded that further optimization of cadA expression, and reduction of acetate formation should be achieved to obtain higher itaconate yield.

    As sufficient cis-aconitate decarboxylase activity is crucial for itaconate production, in chapter 3 ways to increase the activity of CadA were investigated. A recently characterized cis-aconitate decarboxylase of mammalian origin was therefore expressed in E.coli. The novel cis-aconitate decarboxylase from Mus musculus encoded by immunoresponsive gene 1 (irg1) produced comparable amounts of itaconate as CadA from A. terreus. In addition, the effects of codon optimization and harmonization on enzymatic activities of heterologously expressed cadA and irg1 were studied. Codon harmonization increased the activity of CadA in cell free extracts, but this did not result in higher itaconate production in bioreactor cultures. This suggests that other factors such as itaconate transport may limit the production.

    In chapter 4, proof of principle for an anaerobic fermentation process for the production of itaconic acid was obtained by using the mixed acid fermentation pathway of E. coli. Itaconic acid production was redox balanced by co-producing succinate or ethanol with H2 and CO2. Expression of cadA together with citrate synthase (gltA) and aconitase (acnA) from Corynebacterium glutamicum resulted in 0.66 mM (1.2 % Cmol) itaconate under anaerobic conditions. Unexpectedly, strains started to produce significant amounts of glutamate when the itaconate pathway was introduced. As glutamate production depends on the availability of nitrogen in the medium, a nitrogen-limited medium was tested to diminish glutamate production. This enhanced the production of itaconate to up to 2.9 mM (5.4 % C mol %). Here, anaerobic production of itaconate from glucose was reported for the first time. The observed itaconate yields and productivities were still modest. Eliminating the pathways to major by-products like glutamate, succinate, and acetate, and enhancing the pathway between pyruvate and itaconate is crucial to obtain a cost-competitive anaerobic itaconic acid process production.

    To investigate how itaconate production can be improved, the insights from the previous chapters together with existing scientific literature were combined with our pathway design proposals in chapter 5. The tricarboxylic acid (TCA) cycle is an important source of precursors for biobased chemicals. The opinion article takes a closer look at the metabolic engineering of TCA cycle for the production of chemicals high yield. For most TCA cycle products the maximum pathway yield is much lower than the theoretical maximum yield. For succinate, this was solved by creating two pathways to the product, using both branches of the TCA cycle, connected by the glyoxylate shunt. A similar solution cannot be applied directly for production of compounds from the oxidative branch of the TCA cycle because irreversible reactions are involved: the conversion of acetyl-CoA and glyoxylate to malate in the glyoxylate shunt and the conversion of 2-oxoglutarate into succinyl-CoA in the TCA cycle. This way, the pathway yield for products originating from the oxidative TCA cycle branch such as citrate, itaconate and L-glutamate becomes identical to the theoretical maximum. Future research should focus on implementing these solutions in suitable production hosts, and increasing the ATP yield of the production pathways. This will minimize the oxygen requirement of the process, or even allow for anaerobic operation, and should lead to reduced operational costs and maximal product yields.

    In chapter 6 the implications of the overall results of this thesis for the current research status of itaconate production are presented. Solutions to optimize itaconate production strains and production process were proposed.

    Alternatieven voor zwavelzuur in chemische luchtwassers = Alternatives for the use of sulphuric acid in air scrubbers
    Starmans, D.A.J. ; Melse, R.W. - \ 2011
    Lelystad : Wageningen UR Livestock Research (Rapport / Wageningen UR Livestock Research 385) - 19
    luchtreinigers - luchtfilters - stallen - ammoniakemissie - ammoniak - zuren - organische zuren - air cleaners - air filters - stalls - ammonia emission - ammonia - acids - organic acids
    This report provides an overview of the acids that can be used in air scrubbers for ammonia removal, including organic acids, in stables. Emphasis is put on safety, efficiency and cost of the acids.
    In vitro and in vivo virulence of Salmonella Typhimurium DT104: a parallelogram approach
    Berk, P.A. - \ 2008
    Wageningen University. Promotor(en): Tjakko Abee; Marcel Zwietering, co-promotor(en): R. Jonge. - [S.l. : S.n. - ISBN 9789085049340 - 167
    salmonella typhimurium - virulentie - zuren - weerstand - stressreactie - antibioticaresistentie - salmonella typhimurium - virulence - acids - resistance - stress response - antibiotic resistance
    Salmonella is present in different food products. In this research it is concluded that Salmonella, which can survive the stomach of humans better (acid resistant bacteria), have a higher probability of causing an infection than Salmonella strains that are less able to survive the stomach (acid sensitive bacteria). The probability of such an infection is determined using different model systems. Effects on an infection with cultured human and rat intestinal cells were comparable to results obtained with a rat model. The probability of infection calculated with the results from both model systems agree with data from human experiments conducted in the fifties and with epidemiological dose response data. If these results can be founded by additional research, with different Salmonella species, it could be possible to reduce the amount of animal experiments in the future.
    Comments of RIVO to the report "Bromophenols: cause off-flavour in marinated herring and other foods"
    Schelvis-Smit, A.A.M. ; Kotterman, M.J.J. - \ 2005
    onbekend : RIVO Milieu en Voedselveiligheid (Report / RIVO-Netherlands Institute for Fisheries Research no. C002/05) - 8
    geur en smaak - geurstoffen en smaakstoffen - visproducten - haringen - zuren - marineren - flavour - flavour compounds - fish products - herrings - acids - marinating
    In commission of GAB Robins Scully Tyrrell Ltd RIVO has evaluated the report of Jan W. Henfling. Identified in the documentation with nr: 1740-1747 + 1749-1756 + 1758-1759 RIVO has dealt mainly with those topics and opinions that are plainly not correct, not justifiable or misleading. Topics or opinions raised by Jan W. Henfling, which are not discussed in this RIVO report, do not necessarily reflect the opinion of RIVO. In this evaluation, the report will be discussed page by page. Again, it has never been scientifically proven that phenol in acetic acid was the cause of off-flavour in fishery products. To the opinion of RIVO the final conclusion in the Henfling-report is not stated by any solid evidence.
    RAPID: Gaat versproeien van zuur onder de roosters de vorming van ammoniak tegen?
    Starmans, D.A.J. ; Smolders, M.M.A.H.H. - \ 2003
    Praktijkkompas. Varkens 17 (2003)4. - ISSN 1570-8578 - p. 18 - 18.
    varkenshouderij - emissie - ammoniak - milieubeleid - luchtverontreiniging - stallen - spuitapparatuur - toepassing - zuren - landbouwkundig onderzoek - proeven op proefstations - europese unie - proefboerderijen - pig farming - emission - ammonia - environmental policy - air pollution - stalls - spraying equipment - application - acids - agricultural research - station tests - european union - experimental farms
    In samenwerking met het Instituut voor Milieu- en Agritechniek (IMAG) Wageningen heeft Praktijkcentrum Sterksel een van haar afdelingen voor vleesvarkens uitgerust met een sproeisysteem onder de roosters om de mest te kunnen besproeien met een zuur middel ter vermindering van de ammoniakuitstoot. De door de Europese Unie gesponsorde RAPID-proef is in juni gestart en zal één ronde duren.
    Mycorrhizal weathering: A true case of mineral plant nutrition?
    Breemen, N. van; Finlay, R. ; Lundstr"m, U. ; Jongmans, A.G. ; Giesler, R. ; Olssson, M. - \ 2000
    Biogeochemistry 49 (2000). - ISSN 0168-2563 - p. 53 - 67.
    podzolgronden - zuren - plantenvoeding - plant-water relaties - voedingsstoffenopname (planten) - bodem - mineralenvoeding - podzolic soils - acids - plant nutrition - plant water relations - nutrient uptake - soil - mineral nutrition
    Advances in understanding the podzolization process resulting from a multidisciplinary study of three coniferous forest soils in the Nordic Countries
    Lundström, U.S. ; Breemen, N. van; Bain, D.C. ; Hees, P.A.W. van; Giesler, R. ; Gustafsson, J.P. ; Ilvesniemi, H. ; Karltun, E. ; Melkerud, P.A. ; Olsson, M. ; Riise, G. ; Wahlberg, O. ; Bergelin, A. ; Bishop, K. ; Finlay, R. ; Jongmans, A.G. ; Magnusson, T. ; Mannerkoski, H. ; Nordgren, A. ; Nyberg, L. ; Starr, M. ; Tau Strand, L. - \ 2000
    Geoderma 94 (2000). - ISSN 0016-7061 - p. 335 - 353.
    podzolgronden - bodemvorming - bodemkarteringen - zuren - podzolic soils - soil formation - soil surveys - acids
    Microbieel verzuren van vleesvarkensmest door toevoeging van aardappelzetmeel
    Hendriks, J.G.L. ; Vrielink, M.G.M. - \ 1997
    Rosmalen : Praktijkonderzoek varkenshouderij (Proefverslag / Praktijkonderzoek Varkenshouderij P4.19) - 8
    luchtverontreiniging - ammoniak - emissie - vervluchtiging - dierlijke meststoffen - drijfmest - zetmeelverwerkende industrie - aardappelzetmeel - zuren - varkens - air pollution - ammonia - emission - volatilization - animal manures - slurries - starch industry - potato starch - acids - pigs
    Uit eerder onderzoek is gebleken dat de ammoniakemissie bij vleesvarkens tot 1,32 kg ammoniak per dierplaats per jaar kan worden gereduceerd door toepassing van microbieel verzuren van de varkensmest. Hierbij werden eenmalig melkzuurbacteriën aan de mest toegevoegd, die wekelijks werden gevoed met gemalen tarwe.
    Vermindering van de ammoniakemissie uit een ligboxenstal door een eb/vloedsysteem met aangezuurde mest
    Kroodsma, W. ; Bleijenberg, R. ; Ogink, N.W.M. - \ 1996
    WAgeningen : IMAG-DLO (Rapport / Dienst Landbouwkundig Onderzoek, Instituut voor Milieu- en Agritechniek 96-03) - ISBN 9789054061403 - 24
    luchtverontreiniging - ammoniak - emissie - vervluchtiging - dierlijke meststoffen - drijfmest - zuren - stallen - rundveehouderij - air pollution - ammonia - emission - volatilization - animal manures - slurries - acids - stalls - cattle husbandry
    Voedingszuren in eieren : ontwikkeling van een gaschromatografische methode
    Essers, M.L. ; Muuse, B.G. - \ 1988
    Wageningen : RIKILT (Rapport / RIKILT 89.22) - 12
    zuren - eieren - eierproducten - gaschromatografie - acids - eggs - egg products - gas chromatography
    Onderzoek is gedaan om een minder bewerkelijke en snellere methode te verkrijgen voor de bepaling van enkele organische zuren in eiprodukten.
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