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Seven commercial titanium dioxide pigments and two other well-defined TiO2 materials (TiMs) were physicochemically characterised using asymmetric flow field flow fractionation (aF4) for separation, various techniques to determine size distribution and inductively coupled plasma mass spectrometry (ICPMS) for chemical characterization. The aF4-ICPMS conditions were optimised and validated for linearity, limit of detection, recovery, repeatability and reproducibility, all indicating good performance. Multi-element detection with aF4-ICPMS showed that some commercial pigments contained zirconium co-eluting with titanium in aF4. The other two TiMs, NM103 and NM104, contained aluminium as integral part of the titanium peak eluting in aF4. The materials were characterised using various size determination techniques: retention time in aF4, aF4 hyphenated with multi-angle laser light spectrometry (MALS), single particle ICPMS (spICPMS), scanning electron microscopy (SEM) and particle tracking analysis (PTA). PTA appeared inappropriate. For the other techniques, size distribution patterns were quite similar, i.e. high polydispersity with diameters from 20 to >700 nm, a modal peak between 200 and 500 nm and a shoulder at 600 nm. Number-based size distribution techniques as spICPMS and SEM showed smaller modal diameters than aF4-UV, from which mass-based diameters are calculated. With aF4-MALS calculated, light-scattering-based “diameters of gyration” (Øg) are similar to hydrodynamic diameters (Øh) from aF4-UV analyses and diameters observed with SEM, but much larger than with spICPMS. A Øg/Øh ratio of about 1 indicates that the TiMs are oblate spheres or fractal aggregates. SEM observations confirm the latter structure. The rationale for differences in modal peak diameter is discussed.

Honey has potent activity against both antibioticsensitive and -resistant bacteria, and is an interesting agent for topical antimicrobial application to wounds. As honey is diluted by wound exudate, rapid bactericidal activity up to high dilution is a prerequisite for its successful application. We investigated the kinetics of the killing of antibioticresistant bacteria by RS honey, the source for the production of Revamil® medical-grade honey, and we aimed to enhance the rapid bactericidal activity of RS honey by enrichment with its endogenous compounds or the addition of antimicrobial peptides (AMPs). RS honey killed antibiotic-resistant isolates of Pseudomonas aeruginosa, Staphylococcus epidermidis, Enterococcus faecium, and Burkholderia cepacia within 2 h, but lacked such rapid activity against methicillin-resistant S. aureus (MRSA) and extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli. It was not feasible to enhance the rapid activity of RS honey by enrichment with endogenous compounds, but RS honey enriched with 75 µM of the synthetic peptide Bactericidal Peptide 2 (BP2) showed rapid bactericidal activity against all species tested, including MRSA and ESBL E. coli, at up to 10–20-fold dilution. RS honey enriched with BP2 rapidly killed all bacteria tested and had a broader spectrum of bactericidal activity than either BP2 or honey alone.

Background - In this study the efficacy of using marine macroalgae as a source for polyunsaturated fatty acids, which are associated with the prevention of inflammation, cardiovascular diseases and mental disorders, was investigated. Methods - The fatty acid (FA) composition in lipids from seven sea weed species from the North Sea (Ulva lactuca, Chondrus crispus, Laminaria hyperborea, Fucus serratus, Undaria pinnatifida, Palmaria palmata, Ascophyllum nodosum) and two from tropical seas (Caulerpa taxifolia, Sargassum natans) was determined using GCMS. Four independent replicates were taken from each seaweed species. Results - Omega-3 (n-3) and omega-6 (n-6) polyunsaturated fatty acids (PUFAs), were in the concentration range of 2-14 mg/g dry matter (DM), while total lipid content ranged from 7-45 mg/g DM. The n-9 FAs of the selected seaweeds accounted for 3%-56% of total FAs, n-6 FAs for 3%-32% and n-3 FAs for 8%-63%. Red and brown seaweeds contain arachidonic (C20:4, n-6) and/or eicosapentaenoic acids (EPA, C20:5, n-3), the latter being an important "fish" FA, as major PUFAs while in green seaweeds these values are low and mainly C16 FAs were found. A unique observation is the presence of another typical "fish" fatty acid, docosahexaenoic acid (DHA, C22:6, n-3) at ˜ 1 mg/g DM in S. natans. The n-6: n-3 ratio is in the range of 0.05-2.75 and in most cases below 1.0. Environmental effects on lipid-bound FA composition in seaweed species are discussed. Conclusion - Marine macroalgae form a good, durable and virtually inexhaustible source for polyunsaturated fatty acids with an (n-6) FA: (n-3) FA ratio of about 1.0. This ratio is recommended by the World Health Organization to be less than 10 in order to prevent inflammatory, cardiovascular and nervous system disorders. Some marine macroalgal species, like P. palmata, contain high proportions of the "fish fatty acid" eicosapentaenoic acid (EPA, C20:5, n-3), while in S. natans also docosahexaenoic acid (DHA, C22:6, n-3)

In deze studie is een inventarisatie gemaakt van mogelijke grondstoffen en technologieën voor de productie van duurzame eiwitproducten voor humane voeding; eiwitproducten die ter vervanging van minder duurzame vleesproducten geconsumeerd kunnen worden. De studie is uitgevoerd in opdracht van het Ministerie van LNV, programma duurzame voedselsystemen.

Routinematige inspecties binnen het fytosanitaire domein vinden doorgaans plaats door middel van steekproefsgewijze visuele inspecties van de producten. Hierbij wordt gelet op de symptomen en/of aanwezigheid van schadelijke organismen. De vraag is, of er geen sneller, goedkoop èn betrouwbaar alternatief is. De onderzochte technologieën zijn onderverdeeld in: detectie van beeld; detectie van geur; detectie van geluid. Een tweede fase heeft het doel gehad de potentie, haalbaarheid en beperkingen van een deze detectietechnieken voor routinematige inspecties in beeld te brengen, ondersteund door experimentele gegevens en hands-on ervaringen.

In this study, we show that introduction of human N-acetylglucosaminyltransferase (GnT)-III gene into tobacco plants leads to highly efficient synthesis of bisected N-glycans. Enzymatically released N-glycans from leaf glycoproteins of wild-type and transgenic GnT-III plants were profiled by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) in native form. After labeling with 2-aminobenzamide, profiling was performed using normal-phase high-performance liquid chromatography with fluorescence detection, and glycans were structurally characterized by MALDI-TOF/TOF-MS and reversephase nano-liquid chromatography-MS/MS. These analyses revealed that most of the complex-type N-glycans in the plants expressing GnT-III were bisected and carried at least two terminal N-acetylglucosamine (GlcNAc) residues in contrast to wild-type plants, where a considerable proportion of N-glycans did not contain GlcNAc residues at the nonreducing end. Moreover, we have shown that the majority of N-glycans of an antibody produced in a plant expressing GnT-III is also bisected. This might improve the efficacy of therapeutic antibodies produced in this type of transgenic plant.

Van 25 augustus 2005 tot 1 januari 2012 zijn biologische boeren verplicht om het aandeel biologisch geproduceerd voer in het totaal aan diervoer te verhogen van 85 naar 100%. In dit Engelstalige rapport worden de karakteristieken en mogelijkheden van biologisch geproduceerde eiwithoudende gewassen beschreven

Van 25 augustus 2005 tot 1 januari 2012 zijn biologische boeren verplicht om het aandeel biologisch geproduceerd voer in het totaal aan diervoer te verhogen van 85 naar 100%. In dit Engelstalige rapport worden de karakteristieken en mogelijkheden van biologisch geproduceerde eiwithoudende gewassen beschreven

Van 25 augustus 2005 tot 1 januari 2012 zijn biologische boeren verplicht om het aandeel biologisch geproduceerd voer in het totaal aan diervoer te verhogen van 85 naar 100%. In dit Engelstalige rapport worden de karakteristieken en mogelijkheden van biologisch geproduceerde eiwithoudende gewassen beschreven

N-glycosylation of a mAb may have a major impact on its therapeutic merits. Here, we demonstrate that expression of a hybrid enzyme (called xylGalT), consisting of the N-terminal domain of Arabidopsis thaliana xylosyltransferase and the catalytic domain of human -1,4-galactosyltransferase I (GalT), in tobacco causes a sharp reduction of N-glycans with potentially immunogenic core-bound xylose (Xyl) and fucose (Fuc) residues as shown by Western blot and MALDI-TOF MS analysis. A radioallergosorbent test inhibition assay with proteins purified from leaves of WT and these transgenic tobacco plants using sera from allergic patients suggests a significant reduction of potential immunogenicity of xylGalT proteins. A mAb purified from leaves of plants expressing xylGalT displayed an N-glycan profile that featured high levels of galactose, undetectable xylose, and a trace of fucose. Hence, a transgenic plant expressing the hybrid GalT might yield more effective and safer monoclonals for therapeutic purposes than WT plants and even transgenic plants expressing the unchanged GalT.

Vegetable oils are an important commodity world-wide with an annual production of about 70 million tonnes. Oilseed rape is one of the four major crops, providing about 10% of the total production. Quality of vegetable oils is determined by the fatty acid composition of the triacylglycerols (TAG) that constitute such oils. These fatty acids comprise a range of chain lengths and desaturated and oxidised residues. A small group of fatty acids dominates the edible oils which are the predominant products, whereas other specific types of fatty acids are used in specialised applications and generally occur in small crops and wild species. One of these fatty acids is erucic acid (22:1), a very long chain monounsaturated fatty acid, which naturally occurs in species of the Brassicaceae.Synthesis of all fatty acids requires a group of enzymes, most of which have been isolated from a number of species. After synthesis of the primary fatty acids, palmitic (16:0), stearic (18:0) and oleic acid (18:1), in the plastids, they are exported as their CoA-esters into the cytoplasm, where modification and incorporation in lipids occurs. This requires another group of enzymes, some of which, like desaturases and acyltransferases, have been isolated and characterised but most of the species specific modifying enzymes have not been isolated yet. However, little is known about the mechanisms that regulate and coordinate the expression and activity of these enzymes. This thesis focuses on the accumulation of 22:1 and the regulation of the elongase synthesising this fatty acid from 18:1.It has been reported that 22:1 levels can be influenced by growth temperature (Canvin, 1965) but little was known about the regulatory mechanism and timing of this influence. We compared the accumulation of oil and 22:1 in seeds of different cultivars at two temperatures, 15 and 25°C. It was shown that the level of 22:1 in seeds increases from 30 to 40 mol% with a temperature decrease from 25 to 15°C in only o

Promotores : M. Sassen en J. Veerkamp, Contains fulltext : mmubn000001_02526477x.pdf (publisher's version ) (Open Access)

Promotores : M. Sassen en J. Veerkamp, Contains fulltext : mmubn000001_02526477x.pdf (publisher's version ) (Open Access)