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This review presents the advances made concerning the ability of peptides to bestow particular functional properties on various matrices including foods. We focus on systems ranging from model solutions in which peptides are rationally designed to orient their structure and to form hydrogels to mixtures of peptides in complex food matrices. In the latter case, peptides are an integral part of food formulations due to their production in situ or their addition as an ingredient. Examples of complex matrices such as food products, where mixes of peptides are present as hydrolysates with various physico-chemical properties, focus on the ability of peptides to modulate the texture of foods and their functional properties, including solubility, gelation and even emulsifying and foaming properties. Attempts have been made to establish relationships between the physico-chemical and structural characteristics of peptides and their functional properties.

Distillation process of aromatic plants produces a considerable amount of solid residues, which are rich in secondary metabolites known as bioactive compounds. In this context, residues from hydrodistillation of selected aromatic plants such as Mentha piperita L., Cymbopogon citratus Stapf and Eucalyptus camaldulensis Dehnh, have been studied for their total polyphenol content using Folin-Ciocalteu Reagent (FCR) method, total flavonoid content using aluminium chlorid (AlCl3) and antioxidant properties were determined as DPPH radical-scavenging ability (IC50). The anti-termite activity was evaluated by a direct non-choice test. The higher antioxidant activity (IC50 = 0.20 mg/ml) and polyphenols content (224.32 mg GAE/g of dried extract) were showed with E. camaldulensis aqueous extract. However, M. piperita and C. citratus ethanolic extracts showed higher flavonoid content (190.99 and 185.19 mg QE/g of dried extract). The most active extract against termite Reticulitermes flavipes was E. camaldulensis ethanolic extract presenting toxicity at 5% and 10% w/w as concentrations. All these data showed that strategic extraction of residues from hydrodistillation can provide interesting bioactive compounds as novel anti-termite agents in plants protection and allow to give an added-value to aromatic plants.

Tigernut tubers (Cyperus esculentus) are used for the production of vegetable milk, commonly known as &ldquo, Horchata de chufa&rdquo, in Spain. The presence of starch in the tuber limits the yield of the milk, since this carbohydrate gelatinizes during the pasteurization of the milk and leads to the considerable solidification of this drink. The present work aims to improve the yields and extraction practice of the milk by an in situ hydrolysis of starch, using exogenous amylases of industrial or vegetable origin. The obtained results show that sprouting improves the extraction yields of tigernut milk, which goes from 50% to about 70%. This improvement in milk yield corresponds to a hydrolysis of about 35% of the starch in the tuber. The use of exogenous amylases leads to starch hydrolysis rates of 45% and 70%, respectively, for amylolytic extracts from sprouted tigernut tubers and amylase, with the corollary of a natural increase in the sweetness of milk. This technical approach makes it possible to produce a naturally sweetened tigernut milk which easily lends itself to pasteurization without a significant increase in viscosity.

Die vorliegende Arbeit befasst sich mit den Synthesen, Charakterisierungen und umfassenden Reaktivitätsstudien von unterschiedlich substituierten Organosilanolverbindungen, die ausgehend von den niedervalenten Siliziumverbindungen Tetramesityldisilen Mes2Si=SiMes2 (Mes = 2,4,6-Trimethylphenyl) und Hexakisarylcyclotrisilan (ArN2Si)3 (ArN = 2-[(Dimethylamino)methyl]phenyl) dargestellt wurden. Das durch Oxygenierung und Hydrolyse synthetisierte Tetramesitylsiloxandiol Mes2Si(OH)O(OH)SiMes2 wurde hinsichtlich seiner Reaktivität gegenüber Wasser und verschiedenen Ethern untersucht und dabei eingehend durch NMR- und IR-spektroskopische Analysen charakterisiert. Die Isolierung von Einkristallen ermöglichte darüber hinaus die Charakterisierung dreier polymerähnlicher Siloxandiol-Ether-Addukte im Festkörper. Neben Unterschieden der Struktur und Reaktivität in Lösung und im Festkörper konnte zusätzlich durch eine Kooperation mit Prof. Schalley (FU Berlin) anhand eines Gasphasenexperimentes des 18O-markierten Siloxandiolanions, in einem FT-ICR-ESI-Massenspektrometer der vollständige Austausch aller Sauerstoffatome durch Wassermoleküle nachgewiesen werden. Darüber hinaus führte die Einführung intramolekular stabilisierender Liganden wie in dem Siloxandiol ArN2(OH)Si(O)Si(OH)ArN2 zur vollständigen Austauschreaktion in organischen Lösemitteln. Ausgehend von dem [(Dimethylamino)methyl]phenylsubstituierten Cyclotrisilan (ArN2Si)3 konnte das Silylen-Lewispaar ArN2Si–B(C6F5)3 unter Einsatz der starken Lewis-Säure B(C6F5)3 isoliert werden. Durch Hydrolyse wird das Silanolboran ArN2H2OSi–B(C6F5)3 gebildet, das sich durch starke Wasserstoffbrückenbindungen zu den Aminsubstituenten auszeichnet. In Gegenwart von Base, H2O und Luft entsteht nach Dehydrogenierung und Kondensation das Borosiloxan [(HArN2(OB(C6F5)3)Si)2O]. Alle Verbindungen wurden isoliert und vollständig charakterisiert. Zusätzlich ergänzen DFT-Rechnungen (Prof. Kaupp, TU Berlin), die experimentell erhaltenen Beobachtungen., The following thesis deals with the synthesis, characterization and detailed reactivity studies on differently substituted organosilanols, synthesized by the low valent silicon compounds tetramesityldisilene Mes2Si=SiMes2 (Mes = 2,4,6-trimethylphenyl) and hexakisarylcyclotrisilane (ArN2Si)3 (ArN = 2-[(dimethylamino)methyl]phenyl). Oxygenation and hydrolysis of tetramesityldisilene yielded tetramesitylsiloxanediol Mes2Si(OH)O(OH)SiMes2, the reaction behavior of which towards water and various ethers was studied by means of NMR and IR spectroscopy. Additionally, single crystal analysis delivered three different siloxanediol ether polymer-like structures in the solid state. Besides studies in solution and the solid state, gas phase reactions in a FT-ICR-ESI mass spectrometer of the 18O-labelled siloxanediol anion, showed complete exchange of all O-atoms in presence of gaseous water molecules (cooperation with Prof. Schalley, FU Berlin). Furthermore, we could show that altering the ligand system of the siloxanediol to the amine substituted siloxanediol ArN2(OH)Si(O)Si(OH)ArN2, resulted in a complete exchange of all oxygen atoms in solution when H217O was present. Starting from the [(dimethylamino)methyl]phenyl substituted cyclotrisilane (ArN2Si)3, formation of the Lewis acid stabilized silylene-borane ArN2Si–B(C6F5)3 was accomplished. In presence of water the silanolborane ArN2H2OSi–B(C6F5)3 was formed, showing characteristic strong intramolecular hydrogen bonding to its amino ligands. When reacted with a base and water under ambient air, a dehydrogenation reaction followed by condensation leads to the borosiloxane motif [(HArN2(OB(C6F5)3)Si)2O]. All compounds were isolated separately and fully characterized by means of NMR and IR spectroscopy, as well as X-ray diffraction analysis. In cooperation with Prof. Kaupp (TU Berlin), DFT-calculations were carried out to support the achieved experimental data.

International audience; Infant formulas (IF) are the only source of nutrition for infants who cannot be breastfed from their mothers. There is currently a growing interest for these sensitive products, in order to control more carefully their quality and design their composition with regard to sustainable development concern. The aim of this work was to study how a partial substitution of dairy proteins by plant proteins influenced the functionality and the digestibility of IF. Three IF were developed with identical composition, except that 50% of the proteins were whey proteins in the “reference IF”, and pea or faba bean proteins in the “plant IF”. Homogenization and drying steps parameters were investigated at a semi-industrial scale (IF flow rate around 100 kg.h-1). The process influence was assessed through the IF microstructure using confocal microscopy, and the protein digestibility using a dynamic in vitro digestion model. The results showed that the emulsion structure differed depending on the protein type source that did not lead to the same stabilization of the fat droplets. It simultaneously affected the viscosity of the IF and consequently the drying parameters. Last, differences in terms of protein hydrolysis rate were observed mainly during the gastric phase compared to the end of the digestion. This study provides new insights on the impact of the substitution of protein source in IF. It showed that plant protein sources could be good candidates for dairy proteins substitution in IF, both from a processing and nutritional point of view.

Diese Arbeit beschäftigt sich mit den Optimierungspotenzialen eines CFK-Recyclingprozesses. Zusätzlich sollen qualitative Unterschiede zwischen einer Primärfaser und einer recycelten Faser mittels Schliffbild und mikroskopischer Analyse ermittelt werden. Das optimierte Konzept soll einen wesentlichen Teil zur Rohstoffschonung beitragen, indem der Abfall zur qualitativen Ressource wird. Kohlenfaserverstärkter Kunststoff, kurz CFK, hat sich mittlerweile in sehr vielen Branchen verankert, vor allem im Rennsport ist er kaum wegzudenken und wird deshalb auch als schwarzes Gold bezeichnet. Dieses außergewöhnliche Material besitzt mechanische Eigenschaften wie kein zweites. Die Vorteile bestehen in einer hohen Festigkeit und Steifigkeit bei einer vergleichsweise niedrigen Dichte von 1,8 g/cm3. Die Beliebtheit dieses Werkstoffes ist am aktuellen Absatz deutlich erkennbar und auch in Zukunft soll die Beliebtheit des Materials nicht nachlassen. Doch der technologische Fortschritt hat auch eine bedeutende Auswirkung auf die Umwelt, denn der vermehrte Einsatz des schwarzen Goldes führt unvermeidlich zu höheren Abfallströmen. Hier kommt die Schattenseite des Materials zum Vorschein. CFK ist ein Verbundstoff aus Kohlenstofffasern, welche in einer Kunststoffmatrix eingebettet sind. Dies stellt das Abfallmanagement vor deutlichen Herausforderungen, denn ein herkömmliches Verbrennen (Müllverbrennungsanlage) ist nicht möglich, da die verwendeten Temperaturen zu niedrig sind. Auch eine Deponierung ist äußerst komplex, da die Materialien ohne eine Vorbehandlung nicht gelagert werden dürfen. Mit zwei optimierten Recyclingkonzepten wird der Kreislauf der Wiedergewinnung verstärkt. Das erste Optimierungskonzept betrifft die Sortierung von CFK-Produktionsresten, in Abscheidung von Begleitstoffen. Dieser Prozess sorgt im anschließenden Pyrolyseverfahren für eine Sortenreinheit. Das zweite Optimierungskonzept behandelt Post-Consumer-Ware und deren Kennzeichnung. Die Kennzeichnung gibt Aufschluss über die genaue Art des CFK-Materials und deren Eigenschaften. In einem weiteren Schritt werden primäre und recycelte Fasern gegenübergestellt. Analysiert werden dabei vor allem die Oberflächeneigenschaften der einzelnen Fasern. Anhand des Schliffbildes lässt sich mittels mikroskopischer Analyse ein Unterschied erkennen. Die Qualität der recycelten Faser ist nicht vergleichbar mit einer primären Faser. Anwendungen sind jedoch möglich, wenn die Fasern spezifisch auf ihre Eigenschaften beschrieben werden. This scientific paper deals with different potentials for optimization of carbon fibre reinforced plastic. Additionally, certain differences between primary and recycled fibres shall be detected with the help of microsection and microscopic analysis. The optimized concept shall represent an active contribution to conserving raw materials, with which waste material changes to qualitative ressources. It is important to emphasize that carbon fibre reinforced plastic (CFRP) has successfully evolved itself in different industries, especially when it comes to bicycle racing. Therefore it is often called the indispensable black gold. This extraordinary material owns unique characteristics. Certain advantages are a high resistance and stiffness and low density (1,8g/ cm3). According to higher sales its ongoing popularity can be seen. But its technological advancements have a considerable effect on the environment as well, because the more CFRP is produced and used, the more it leads to an increase in waste flows. CFRP, a so-called composite material made of carbon fibres, is additionally embedded in a selected plastic matrix. As a result, the waste management faces enormous challenges, because a conventional waste incineration plant is not able to burn the material – its temperatures are too low. Furthermore, depositing of these materials is a very complex process, because it is not allowed to store them without a specific pre-treatment. With the help of two optimized recycling processes the intensification of raw material recovery can be supported. The first concept is all about the sorting of CFRP-production residues and the filtering of undesired accompanying substances. Subsequently, this process leads to varietal purity during pyrolysis procedure. The second concept approaches post-consumer goods and their identification, because it will only be possible to know the precise product type if you tag it and list its properties. In a further step, primary and recycled fibres are contrasted and surface properties are analyzed. With the aid of microsection and its microscopic analysis, certain differences were recognized. The quality of recycled fibres is not comparable with the one of primary fibres. All in all, recycled fibres will be able to get reused more often if the fibres’ properties are accurately described. Wien, FH Campus Wien, Masterarb., 2019

The growing interest in understanding the molecular mechanisms of digestive processes led to an increasing number of different in vivo and in vitro studies focusing on the understanding of food digestion and the physiological impacts on the human body. For this purpose, dedicated analytical methods were developed to characterize and quantify the different intermediate and final products of nutrient hydrolysis. However, one major issue is the comparability of analytical results between different experimental setups and individual labs. The COST action Infogest network (http://www.cost-infogest.eu/) specifically defined the experimental conditions and the corresponding enzymatic tests for a harmonized in vitro digestion protocol based on physiological data from literature. The new protocol increased the reproducibility of results between labs and between different studies. Moreover, the analytical methods developed in parallel, allow for the verification of the progress in nutrient hydrolysis and the variations between different experiments. This book chapter gives a short introduction on the in vitro digestion protocol and describes the analytical methods suited for the assessment of protein digestion during IVD. Moreover, methods for the quantification of lipids and carbohydrates are described. The final part of this chapter offers a selection of analytical results showing the relationship between food digestion and nutrition.

Lignocellulose-derived hydrolyzates typically display a high degree of variation depending on applied biomass source material as well as process conditions. Consequently, this typically results in variable composition such as different sugar concentrations as well as degree and the presence of inhibitors formed during hydrolysis. These key obstacles commonly limit its efficient use as a carbon source for biotechnological conversion. The gram-negative soil bacterium Pseudomonas putida KT2440 is a promising candidate for a future lignocellulose-based biotechnology process due to its robustness and versatile metabolism. Recently, P. putida KT2440_xylAB which was able to metabolize the hemicellulose (HC) sugars, xylose and arabinose, was developed and characterized. Building on this, the intent of the study was to evaluate different lignocellulose hydrolyzates as platform substrates for P. putida KT2440 as a model organism for a bio-based economy. Firstly, hydrolyzates of different origins were evaluated as potential carbon sources by cultivation experiments and determination of cell growth and sugar consumption. Secondly, the content of major toxic substances in cellulose and HC hydrolyzates was determined and their inhibitory effect on bacterial growth was characterized. Thirdly, fed-batch bioreactor cultivations with hydrolyzate as the carbon source were characterized and a diauxic-like growth behavior with regard to different sugars was revealed. In this context, a feeding strategy to overcome the diauxic-like growth behavior preventing accumulation of sugars is proposed and presented. Results obtained in this study represent a first step and proof-of-concept toward establishing lignocellulose hydrolyzates as platform substrates for a bio-based economy., publishedVersion

In this PhD work, we designed a series of precisely-defined water-soluble PVAbased glycopolymer chains with tunable compositions using RAFT copolymerization and selective alcoholysis reactions. In a second approach, we prepared a library of poly(2-ethyl-2-oxazoline)-based glycopolymers by partial acidic hydrolysis and reductive amination reactions with sugar residues. Relying on the establishment of phase diagrams for water/acetone/oil and water/acetone/polymer ternary systems (commercial PVA, PVA or polyoxazoline-based glycopolymers), we identified the conditions of solvent shifting (in the Ouzo and /or the SFME domains) for which oil-filled nanocapsules can be constructed in one step thanks to spontaneous emulsification of the oil and concomitant adsorption of the polymer chains at the interface. Stabilization of the nanocapsules in water was typically achieved by covalent cross-linking of the shell or, in the case of PVA-based materials, by addition of Na2SO4 (salting out). This straightforward nanoprecipitation process was further effortlessly implemented to confer redox-sensitivity to the polymer shell (to trigger the release of actives), decorate the nanocapsules with diverse molecules of interest and to entrap hydrophobic actives within the oily core. Release of the drugs and bioactivity of the nanocapsules were demonstrated., Ce projet de thèse avait pour objectif l’élaboration de glyconanocapsules à cœur huileux par nanoprécipitation à partir de polymères biocompatibles et biodégradables. Dans ce but, nous avons tout d’abord élaboré une série de glycopolymères à base de poly(alcool vinylique) (PVA) par copolymérisation radicalaire de type RAFT suivie d’une réaction d’alcoolyse sélective. En parallèle, nous avons synthétisé une seconde famille de glycopolymères en hydrolysant partiellement des chaînes de poly(2-ethyl-2-oxazoline) (PEOX) et d’autre part, en réalisant une réaction d’animation réductrice entre les amines secondaires obtenues (PEOX-co-PEI) et le lactose. S’appuyant sur les diagrammes de phase des systèmes ternaires eau/acétone/huile et eau/acetone/polymère, nous avons ensuite identifié les conditions de basculement de solvant (dans les domaines Ouzo et SFME) permettant simultanément la formation de nanogouttelettes d’huile et l’adsorption de chaînes polymère à l’interface, conditions essentielles à l’obtention de nanocapsules à cœur huileux. Afin d’assurer leur pérennité en milieu aqueux, l’écorce de ces nano-objets a été réticulée chimiquement et/ou physiquement, dans le cas des nanocapsules à base de PVA par ajout de Na2SO4 (salting out). Enfin, moyennant l’ajout de réactifs et de principes actifs dans les phases aqueuse et organique respectivement, ce procédé de basculement en une étape a permis de construire des glyconanocapsules contenant des molécules de principe actif dissoutes dans le cœur huileux et possédant une membrane polymère réticulée dégradable en conditions réductrices Enfin, Il a été démontré que ces glyconanocapsules sont capables de libérer un principe actif encapsulé en réponse à un stimulus et d’interagir avec certaines lectines.

The present work investigates the potential of flax shives for the production of nanocelluloses. Two methods were investigated in order to produce cellulose nanocrystals (CNC) and cellulose nanofibers (CNF). The CNC production was conducted in two steps: a bleaching step and an exposure to an HCl vapour. Rietveld analysis of the diffractograms and 13C NMR proved that the shape of the crystallites wasn’t affected by the hydrolysis despite a slight co-crystallisation along the hydrophilic faces. FTIR spectroscopy demonstrated ample dependence of the ratio of deuterium-labelled sites with temperature. This ratio depends on the substrate topology. The « native » continuous microfibril topology implies pores that can trap water. In contrast, a discrete rod-like topology cannot trap water: the hydrophilic faces that were “stabilized” by co-crystallisation are unable to trap water. Drying hysteresis is usually observed after an isotopic re-exchange experiment: the labelled polymer chains co-crystallize and some of them become inaccessible to re-exchange. This hysteresis wasn’t observed after hydrolysis. The production of CNF was performed with an ultrafine grinder after swelling. Four swelling agents were selected after an initial screening involving more than 40 different liquids. Optical microscopy and SEM demonstrated the intrinsic difficulty of producing CNF from such a lignin-rich substrate without any pre-treatment. The combination of ultrafine grinding and swelling was however capable of reducing the sample crystallinity to a large extent. FTIR demonstrated that a lignin-rich phase could be produced using this mechanical process., Ce travail a porté sur la production de nanocristaux de cellulose (NCC) et de nanofibres de cellulose (NFC) à partir d’anas de lin.La production de NCC a été réalisée par hydrolyse acide avec de l’HCl gazeux après blanchiment. L’analyse des résultats de DRX et RMN montrent que la forme des cristallites reste inchangée après l’hydrolyse malgré une faible co-cristallisation le long des faces hydrophiles. La spectroscopie IR en température après un échange isotopique montre que le ratio de matériau marqué évolue avec la température de manière différente selon qu’il s’agit d’anas blanchis ou de NCC. Avant hydrolyse, des pores dans lesquels de l’eau est piégée sont mis en évidence. Cette nature de pore est absente des NCC. Lors d’un séchage, une partie des chaînes peut co-cristalliser et piéger une partie des groupements hydroxyles deutéres ; ce piégeage n’est plus mesurable une fois le matériau hydrolysé. Ces résultats montrent une meilleure stabilité des NCC lors de cycles de séchage/humidification.Afin de produire des NFC, une défibrillation mécanique a été réalisée sans délignification préalable et après un gonflement des anas dans des liquides gonflants. La caractérisation microscopique a démontré que la production de suspensions de NFC sans prétraitement supplémentaire des anas n’était pas viable. La DRX prouve néanmoins que les agents gonflants combinés à la défibrillation peuvent diminuer de manière importante la cristallinité du matériau. La spectroscopie IR a démontré que le matériau était séparé en deux phases à l’issue du traitement, et l’une des phases est significativement plus riche en lignine.

Unravelling the mechanisms of food disintegration in the gastrointestinal tract should allow for a better understanding of the effect of food on human health. Several studies have reported the behavior of pure compounds (macronutrients or micronutrients) in digestive conditions. However, micronutrients and macronutrients are not often consumed as pure compounds but mostly embedded into food matrices. The structure of food products is now considered as a key parameter that strongly influences the release of nutrients in the gastrointestinal tract and their bioavailability in the bloodstream. This chapter therefore focuses on how the structure of foods and food constituents affects digestion. It shows that depending on the length scale that is chosen to follow food disintegration, data obtained can vary significantly.

The conformational itineraries taken by carbohydrate residues in the catalytic subsite of retaining glycoside hydrolases (GHs), harness the link between substrate conformation and reactivity. GHs’ active sites may be described as a combination of subsites dedicated to the binding of individual sugar residues and to catalysis. The three-dimensional structure of GH:carbohydrate complexes has demonstrated that carbohydrate ring conformation changes in an ordered manner during catalysis. Here we demonstrate in silico that a link exists between subsite binding dynamics and substrate specificity for β-galactosidases from clan GH-A families GH1, GH2, GH35, GH42 and GH59. Different oligosaccharides were docked in the active site of reference β-galactosidase structures using Vina-Carb. Subsequent molecular dynamics (MD) simulations revealed that these enzymes favor a high degree of flexibility and ring distortion of the substrate the lytic subsite −1. Although the β-galactosidase families examined are structurally and mechanistically related, distinct patterns of ring distortion were unveiled for the different families. For β-galactosidases, three different family-dependent reaction itineraries (1S3 → 4H3‡ → 4C1, 1,4B → 4H3/ 4E‡ → 4C1, and 1S5 → 4E/ 4H5‡ → 4C1) were identified, all compatible with the antiperiplanar lone pair hypothesis (ALPH) for the hydrolysis of β-glycosides. This comparative study reveals the fuzzy character of the changes in carbohydrate ring geometry prior to carbohydrate hydrolysis.

Introduction et but de l’étude Les protéines généralement utilisées dans les formules infantiles proviennent du lait de vache et sont majoritairement des protéines de lactosérum afin de se rapprocher de la composition du lait maternel. Cependant, certaines protéines végétales offrent également de bonnes propriétés nutritionnelles et pourraient constituer d’intéressants substituts dans un contexte de compétition d’usage des protéines de lactosérum. Le but de cette étude était de comprendre l’impact de la substitution des protéines de lactosérum par des protéines végétales sur le degré d’hydrolyse et sur la bioaccessibilité des acides aminés. Matériels et Méthode Quatre protéines végétales ont été sélectionnées (PV1 à PV4) en raison de leur composition en acides aminés essentiels adaptée aux besoins du nourrisson. Elles ont été utilisées pour développer des formules infantiles de composition identique à la référence (R), à ceci près que les protéines de lactosérum étaient remplacées par une des quatre protéines végétales. Les cinq formules infantiles ont ensuite été soumises à un modèle de digestion in vitro gastro-intestinale en conditions statiques (Ménard et al. 2018). Le degré d’hydrolyse des protéines était mesuré par la méthode OPA (O-phtaldialdehyde). Les acides aminés libres ont été quantifiés par chromatographie échangeuse de cations. Résultats Tableau 1. Teneur en acides aminés libres et degré d’hydrolyse en point final de digestion de cinq formules infantiles Formules infantiles Thréonine (%) Isoleucine (%) Leucine(%) Lysine (%) AAS (%) AAA (%) Degré d’hydrolyse (%) R 12,6±0,7 19,1±0,6 47,9±2,9 71,1±3,2 23,6 ±2,6 79,6 ±3,7 53,0±6,1 PV1 5,8±0,1*** 1,9±0,2*** 12,1±0,7*** 16,9±0,9*** 9,1 ±1,2*** 21,1±0,9*** 29,0±4,1*** PV2 15,7±1,2* 20,9±0,7 51,4±1,6 72,6±1,1 22,0 ±2,3 74,8 ±5,2 65,6±1,2 PV3 14,9±4,0 17,2±1,1 49,7±4,9 73,1±4,4 24,1 ±4,8 75,5 ±5,3 45,4±4,4 PV4 11,8±2,3 16,4±2,8* 45,6±5,1* 68,7±6,6 25,8 ±6,8 71,1 ±8,2 40,2±2,7* Les différences entre les valeurs moyennes des formules PV1 à 4 par rapport à R sont considérées significatives lorsque p < 0.05 (t-Test : *0,05 ; **0,01 ; ***0,001). AAS (acides aminés soufrés) ; AAA (acides aminés aromatiques) Les formules PV2 et PV3 libèrent autant d’acides aminés que la référence (R) et présentent un degré d’hydrolyse équivalent (p>0.05). En revanche, la formule PV4 se distingue de R par une moindre libération d’isoleucine et de leucine et présente également un degré d’hydrolyse plus faible. Enfin, la formule PV1 conduit à des valeurs très inférieures à celles obtenues avec R pour toutes les variables étudiées. Conclusion Il est établi que la cinétique de digestion des protéines dans une matrice et par conséquence, la libération des acides aminés et leur absorption peuvent être influencées notamment par sa composition en protéines (Le Feunteun et al., 2014). De manière concordante, nous montrons ici que la nature des protéines des formules infantiles aurait un effet sur la protéolyse. Ainsi, parmi les quatre formules « végétalisées » testées, seules PV2 et PV3 sembleraient être nutritionnellement comparables à la référence. Des digestions in vitro en conditions dynamiques (plus proches des conditions physiologiques) seront réalisées prochainement afin de compléter ces résultats quant à la qualité nutritionnelle de ces formules infantiles innovantes.

Die vorliegende Dissertation behandelt die Synthese und Charakterisierung neuartiger hetero- und homoleptischer Carboxylato- und Sulfonatobismut(III)verbindungen, die Potential für antimikrobielle Anwendungen und/oder als Präkursoren für röntgenopake organisch-anorganische Hybridmaterialien aufweisen. Als Ausgangsstoffe dienten Arylbismutane, deren supramolekulare Strukturen in Abhängigkeit der funktionellen Gruppe am organischen Substituenten mit dem Ziel der Analyse intermolekularer Metall∙∙∙π(Aryl)-Wechselwirkungen sowie deren Einfluss auf die Ausbildung von Polymorphen diskutiert werden. Die Einstellung der Reaktionsbedingungen bei den Umsetzungen dieser Organobismutverbindungen mit Carbon- oder Sulfonsäuren erlaubt die gezielte Synthese carboxylato- oder sulfonatosubstituierter Koordinationspolymere des Bismuts unter milden Bedingungen. Neben der Beschreibung der Strukturen wird das Verhalten dieser Verbindungen in Lösung besprochen. Zur Aufklärung der Bildungsmechanismen von Bismutoxidoclustern wurden Hydrolyse- und Kondensationsstudien ausgehend von Lösungen der Bismutcarboxylate und -sulfonate sowie polynuklearer Modellverbindungen durchgeführt. Die in diesem Verlauf isolierten, funktionalisierten Bismutoxidospezies vertiefen die Erkenntnisse zum strukturellen Aufbau sowie zum Reaktionsverhalten der nanoskaligen Moleküle. Dabei werden u. a. die Symmetrieelemente der Bismutoxidocluster sowie Clusterabbaureaktionen beschrieben. Die Charakterisierung der synthetisierten Verbindungen erfolgte mittels Einkristallröntgenstrukturanalyse, Pulverröntgendiffraktometrie, Infrarot- und Kernspinresonanzspektroskopie sowie thermischen Analysemethoden.

Ein Screening europäischer Heilkräuter wurde durchgeführt um Pflanzen mit hohen Gerbstoffgehalten zu identifizieren. Weiter wurde der Quercetin-Gehalt der besten Pflanzen durch Hydrolyse der Extrakte analysiert. Mineralsäuren werden in einem herkömmlichen Hydrolyseverfahren verwendet um Quercetin zu gewinnen. Dies erfordert einen Neutralisationsschritt mit basischen Salzen nach der Hydrolyse. Die Neutralisation von Mineralsäuren bildet Salze in hohen Konzentrationen, die entfernt werden müssen. Um diesen Neutralisierungsschritt zu vermeiden, wurde eine alternative Methode - \(CO_{2}\) intensivierte Hydrolyse - untersucht. Ein neuer H+-Faktor wurde eingeführt, der den Einfluss von \(H^{+}\)-Ionen und Konzentrationen der Modellsubstanz im \(CO_{2}\)-intensivierten Hydrolyseprozess beschreibt. Für die Anwendung der \(CO_{2}\)-intensivierten Hydrolyse auf Pflanzenextrakte wurden \(\textit {Arctostaphylus uva-ursi}\) und \(\it Fragaria\) auf das Potenzial eines kombinierten Produktionsprozesses hydrolysierter Extrakte untersucht. A screening study of European medicinal herbs was conducted to identify plants with high tannin contents. Furthermore, the quercetin content of the four best plants was analyzed by hydrolyzing the extracts. Mineral acids are used in a conventional hydrolysis process to obtain quercetin. This requires a neutralization step with alkalines or salts after hydrolyzing. The neutralization of mineral acids form salts in high concentrations which have to be removed. To avoid this neutralization step an alternative methodology – \(CO_{2}\)-intensified hydrolysis – was investigated. A new \(H^{+}\)-factor was introduced describing the influence of H+ ions and concentrations of the model substance in the \(CO_{2}\)-intensified hydrolysis process. For applying the \(CO_{2}\)-intensified hydrolysis on plant extracts, \(\textit {Arctostaphylus uva-ursi}\) and \(\it Fragaria\) were investigated on the potential of a combined production process of hydrolyzed extracts.

In solid-state anaerobic digestion, so-called ss-AD, biogas production is inhibited at high total solids contents. Such inhibition is likely caused by a slow diffusion of dissolved reaction intermediates that locally accumulate. In this study, we investigated the effect of H2 and CO2 partial pressure on ss-AD. Partial pressure of H2 and/or CO2 was artificially fixed, from 0 to 1 557mbars for H2 and from 0 to 427mbars for CO2. High partial pressure of H2 showed a significant effect on methanogenesis, while CO2 had no impact. At high [Formula: see text] , the overall substrate degradation decreased with no accumulation of metabolites from acidogenic bacteria, indicating that the hydrolytic activity was specifically impacted. Interestingly, such inhibition did not occur when CO2 was added with H2. This result suggests that CO2 gas transfer is probably a key factor in ss-AD from biomass.

The use of fossil fuels (non-renewable energy) is responsible for the increase of the concentration of greenhouse gases in the atmosphere. Among the considered alternatives, hydrogen is seen as the most attractive energy vector. Production and storage of hydrogen is one of the key challenges in developing the hydrogen economy.The first objective of this thesis deal with the synthesis and characterization of magnesium-based ternary compounds in the RE-TM-Mg ternary system (with RE = Rare Earth and TM = transition metals) which could be good candidates for hydrogen storage. These compounds could also have other applications than the hydrogen storage in the future such as light structured material. The NdNiMg15 compound has been the subject of a completed study. This phase crystallizes with a tetragonal symmetry (a= 10.0602(1) and c= 7.7612(2) Å and a space group P4/nmm). It showed an antiferromagnetic ordering at 9 K and a reversible hydrogen storage capacity of 4 %mass. This phase exhibited a hardening effect respect to magnesium compound.The second objective of this thesis concerns the hydrogen production by hydrolysis of i) RE-TM-Mg ternary compounds, which could be considered as an economic and energetic possibility to valorize the waste of these compounds and ii) RE-TM-Mg ternary mixtures prepared by ball milling. The grinding creates defects thus promoting the corrosion of the metals. In addition, the hydrogen production by hydrolysis of the Mg-NdNiMg15 composites (70, 80 and 90 %mass. Mg) was carried out and compared with that of the NdNiMg15 compound (64 %mass. Mg). The main corrosion mechanism determined from the electrochemical measurements of the composites is the galvanic corrosion.; L’utilisation des combustibles fossiles est responsable de l’augmentation de la concentration en gaz à effet de serre dans l’atmosphère. Parmi les solutions de remplacement envisagées, l’hydrogène constitue un vecteur d’énergie très intéressant. Toutefois, cette solution ne sera envisageable que lorsque les problématiques liées à la production de l’hydrogène et à son stockage seront résolues.Le premier objectif de cette thèse porte sur la synthèse et la caractérisation de composés ternaires à base de magnésium dans le système ternaire TR-M-Mg (avec TR = Terres Rares et M = métaux de transition) qui pourraient être de bons candidats pour le stockage de l’hydrogène. Ces composés pourraient de plus avoir d’autres applications, notamment comme matériaux de structure, du fait de leur très faible densité. La composition NdNiMg15 a fait l’objet d’une étude complète. Cette phase cristallise selon une symétrie quadratique avec a= 10,0602(1) et c= 7,7612(2) Å et un groupe d’espace P4/nmm. Un ordre antiferromagnétique à 9 K est observé et la capacité massique de stockage réversible est de 4 %mass. Cette nouvelle phase a montré un effet durcissant sur le magnésium.Le deuxième objectif de cette thèse concerne la production d’hydrogène par hydrolyse i) des composés ternaires TR-M-Mg qui pourrait être considérée comme une possibilité économique et énergétique pour valoriser les déchets de ces composés et ii) des mélanges ternaires TR-M-Mg élaborés par broyage mécanique. Le broyage a permis la création des défauts favorisant ainsi la corrosion des métaux. De plus, la production d'hydrogène par hydrolyse des composites Mg-NdNiMg15 (70, 80 et 90 %mass. Mg) a été réalisée et comparée à celle du composé NdNiMg15 (64 %mass. en Mg). Le mécanisme de corrosion principal déduit des essais électrochimiques sur les composites est la corrosion galvanique.

The present study investigated proteolysis combined with heat treatment to make hen Egg White (EW) an efficient emulsifier. EW was hydrolyzed by protease (Thermoase®) at various Enzyme Concentrations (EC) (w/w, 0.1%, 0.2%, 0.4%, 0.8%), followed by heating at 90°C for 8 min. Results showed that optimal emulsifying ability and stability, determined by measurement of emulsion turbidity, were obtained when EC was 0.4%, followed by heat treatment at 90°C. The hydrolysate thus prepared had higher emulsifying ability and stability than either native egg white (nEW) or small molecular weight EW peptides (Runpep®), close to the properties of Egg Yolk (EY) which was a reference as a food emulsifier. Surface hydrophobicity (H0) was found to be linearly related to the emulsifying activity and stability of hydrolyzed egg white proteins.

Le travail présenté dans ce mémoire porte sur l’étude du fonctionnement de la station de traitement des graisses Bora Bora qui traite les effluents en milieu aérobie.Elle est située en face du centre d’enfouissement technique. L’intérêt de l’avoir installé en ce lieu a été de vouloir traiter en même temps que les graisses, le lixiviat du CET. La finalité du travail sera d’étudier les performances du procédé dans différentes conditions et de déterminer les conditions pour un fonctionnement optimal et pérenne de la station de traitement. Cette étude se fera selon deux scenarii :-Traitement des graisses ;-Traitement des graisses et des lixiviats.Un ensemble de paramètres seront mesurés au cours de l’étude pour suivre la qualité physico-chimique de l’effluent.

Lignocellulosic biomass is the most abundant renewable raw material on the earth and it is so far the most suitable and promising resource for the production of biofuels to replace long-term use of fossil oil. This research aims to convert lignocellulose-based industrial residuals, fibre sludge (FS) from a pulp mill and pine sawdust (PSD) from a sawmill, into platform sugars by two different bifunctionalised pretreatments of lignocellulosic biomass. The bifunctionalised pretreatment combines the ordinary pretreatment (deconstruction) of lignocellulosic biomass with lignocellulosic polysaccharides saccharification. The outcome from both pretreatments can be further transformed into biofuels and chemicals. PSD and FS were converted into platform sugars by acid-catalysed mechanical depolymerisation in a planetary ball mill in the first part of this research. The efficiency of the conversion was mainly affected by the transferred energy caused by collisions, the total milling time, acid concentration and moisture content in the reaction. Approximately 30 wt% of the sugars was yielded from PSD and FS both in the short milling process with a low acid/substrate (A/S) concentration without any prior treatment. The second part of this research focuses upon the conversion of FS into platform sugars using hydroxyalkylimidazolium hydrogen sulphate ionic liquids (ILs). Around 29 wt% of the sugars was produced from FS using an IL/water mixture. The added water acted as a co-solvent and played a critical role in the utilisation of these ILs. The blended water reduced the viscosity of the ILs and enhanced the mass transfer between solvent and solute. In addition, the anions of the ILs provided their acidic property in an aqueous solution and offered an acidic environment for hydrolysis simultaneously. Tiivistelmä Lignosellulossapohjainen biomassa on runsaimmin saatavilla oleva ja yksi lupaavimmista raaka-aineista biopolttoaineiden valmistukseen korvaamaan fossiilisia polttoaineita. Väitöskirjassa tutkitaan teollisuuden lignoselluloosapohjaisten sivutuotteiden, selluteollisuuden kuitulietteen ja sahateollisuuden sahanpurun (mäntypuru), muuntamista sokereiksi kahdella erilaisella ns. bifunktionaalisella esikäsittelyllä, joissa yhdistyvät lignoselluloosabiomassan perinteinen esikäsittely (hajotus) ja polysakkaridien sokeroituminen. Muodostuneet sokerit voidaan edelleen muuntaa biopolttoaineiksi ja -kemikaaleiksi. Tutkimuksen ensimmäisessä vaiheessa sahanpuru ja kuituliete muunnettiin sokereiksi happokatalysoidussa mekaanisessa käsittelyssä, joka tehtiin kuulamyllyssä. Reaktiossa katalyyttisen käsittelyn tehokkuuteen vaikuttivat erityisesti jauhatuksen kineettinen energia, jauhatusaika, happokonsentraatio ja reaktioseoksen kosteus. Tulosten perusteella todettiin, että ilman lähtöaineen esikäsittelyä sekä sahanpurun että kuitulietteen sokerisaanto oli noin 30 massa% lyhyen, matalassa happokonsentraatiossa tehdyn jauhatuksen jälkeen. Tutkimuksen toisessa vaiheessa kuituliete muutettiin sokereiksi käyttämällä ionista liuotinta (IL), hydroksialkyyli-imidatsoliumvetysulfaattia. Sokerisaanto kuitulietteestä oli noin 29 massa% IL-vesiseoksessa. Vesi toimi reaktiossa apuliuottimena ja sen rooli on keskeinen ionisten liuottimien käytössä. Sekoittunut vesi laski ionisen liuottimen viskositeettia sekä edisti aineensiirtoa liuottimen ja liukenevan aineen välillä. IL:n anionit lisäsivät happamuutta vesiliuoksessa ja mahdollistivat happamat olosuhteet samanaikaiselle hydrolyysille. Abstract Biomasse aus Lignocellulose ist der am häufigsten vorkommende nachwachsende Rohstoff der Erde und wird aktuell als eine der besten Alternativen für die Produktion von Biokraftstoffen gesehen. Diese sollen langfristig die fossilen Öl-basierten Produkte ersetzen. Diese Forschungsarbeit untersucht die Herstellung von Zucker aus Lignocellulose basierten Abfällen. Faserschlamm aus der Zellstoffindustrie und Kiefern-Sägemehl aus der Holzverarbeitung wurden durch zwei unterschiedliche Bifunktionelle Vorbehandlungen aufgespalten. Diese Bifunktionelle Vorbehandlung kombiniert zwei Schritte in einem Prozess; die gewöhnliche Dekonstruktion der Biomasse und die Verzuckerung von Polysacchariden aus der Lignocellulose. Das so erzeugte Produkt dient als Ausgangsstoff für die weitere Herstellung von Biokraftstoffen und Chemikalien. Im ersten Teil dieser Forschungsarbeit wurden Kiefern-Sägemehl und Faserschlamm in einer Planeten-Kugelmühle zermahlen und gleichzeitig durch eine Säure depolymerisiert. Der Wirkungsgrad dieser säurekatalysierten mechanischen Depolymerisation wurde hauptsächlich durch die Übertragung der Reibungsenergie, der Mahldauer der Zerkleinerung, der Konzentration der Säure und der Feuchtegehalt der Proben beeinflusst. Etwa 30 wt% Zucker wurde so durch den kurzen Zermahlungsprozess aus Kiefern-Sägemehl und Faserschlamm gewonnen. Dabei wurden die Proben nicht vorbehandelt und enthielten eine geringe Säure/Probe Konzentration. Der zweite Teil der Forschungsarbeit untersucht die Umwandlung von Faserschlamm in Zucker mittels der Ionischen Flüssigkeit (ILs) Hydroxyalkyl Imidazolium Hydrogensulfat. Aus den Faserschlamm Proben konnte 29 wt% Zucker durch eine Mischung von ILs und Wasser gewonnen werden. Das zugesetzte Wasser spielte als Co-Lösemittel eine wichtige Rolle in der Nutzung der Ionischen Flüssigkeit, dessen Viskosität so reduziert wurde. Dies führte zu einem erhöhten Stoffübergang zwischen dem Lösemittel und dem Solvat. Zusätzlich sorgten die Anionen der Ionischen Flüssigkeit für ein saures Milieu in der wässrigen Lösung und ermöglichten so eine gleichzeitige Hydrolyse.

The first aim of this work is to study the degradation of an industrial polyesterurethane (PURm) by radio-oxidation and then by leaching in an alkaline aqueous solution. The second aim is to measure the complexing power of hydrosoluble degradation products (HDP) with actinides. To reach these goals, PURm was first characterized and then radio-oxidized at room temperature with gamma-rays up to 10 MGy. Second, it was leached at pH 13.3 at different temperature values. Numerous analytical techniques were employed in order to characterize the HDP which were obtained. Europium(III) was used as an analogue of actinides(III) and the behavior of HDP with europium(III) was analyzed by time-resolved luminescence spectroscopy (TRLS). Whatever the received dose by PURm, adipic acid and butane-1,4-diol are the two main HDP in leachates. The leaching data acquired at 40 and 60°C, on the 1 MGy radio-oxidized PURm, correlate with the model given by Yoon et al. (1997). However, the data at room temperature (22°C in average) are not in agreement with the model. Nevertheless, it seems that the plateau which was reached at long-term leaching is the same whatever the temperature used in this study.The results allow to conclude that the predominant mechanism occurring during the leaching of unirradiated and radio-oxidized PURm in an alkaline medium is the hydrolysis of the soft segments ester groups.The complexation of europium(III) by HDP in alkaline medium was demonstrated. The measurement of the complexing power and the identification of ligands was achieved under certain conditions.; L’objectif de ce travail est d’étudier la dégradation d’un polyesteruréthane industriel (PURm) par radio-oxydation puis par lixiviation en solution aqueuse à pH basique, dans le but d’évaluer le pouvoir complexant des produits de dégradation hydrosolubles (PDH) avec les actinides. Afin d’atteindre ces objectifs, le PURm a été caractérisé puis radio-oxydé à température ambiante aux rayonnements gamma jusqu’à 10 MGy. Il a ensuite été lixivié à pH 13,3 à différentes températures. De nombreuses techniques analytiques ont été employées afin de caractériser les PDH obtenus. De l’europium(III), simulant les actinides(III), a été mis en solution avec les PDH et l’interaction Eu-PDH a été analysée par spectrofluorimétrie laser à résolution temporelle (SLRT).Quelle que soit la dose reçue par le PURm, l’acide adipique et le butane-1,4-diol sont les deux PDH majoritaires dans les lixiviats. Les données de lixiviation acquises à 40 et 60°C, sur le PURm radio-oxydé jusqu’à 1 MGy, corrèlent avec le modèle proposé par Yoon et al. (1997). Cependant, les données à température ambiante (22°C en moyenne) ne sont pas en accord avec ce modèle. Il semble néanmoins qu’aux temps de lixiviation longs, le plateau atteint soit similaire quelle que soit la température employée dans cette étude.Les résultats obtenus permettent de conclure que le mécanisme prédominant lors de la lixiviation en milieu basique du PURm non irradié et radio-oxydé est l’hydrolyse des groupes esters des segments souples.La complexation de l’europium(III) par les PDH à pH basique a été mise en évidence. La détermination de la constante de complexation et l’identification des ligands, dans certaines conditions, a été réalisée.

The first aim of this work is to study the degradation of an industrial polyesterurethane (PURm) by radio-oxidation and then by leaching in an alkaline aqueous solution. The second aim is to measure the complexing power of hydrosoluble degradation products (HDP) with actinides. To reach these goals, PURm was first characterized and then radio-oxidized at room temperature with gamma rays up to 10 MGy. Second, it was leached at pH 13.3 at different temperature values. Numerous analytical techniques were employed in order to characterize the HDP. Europium(III) was used as an analogue of actinides(III) and the behavior of HDP with europium(III) was analyzed by time-resolved luminescence spectroscopy (TRLS). Whatever the received dose by PURm, the two main HDP are adipic acid and butane-1,4-diol. The leaching data acquired at 40 and 60°C, on the 1 MGy radio-oxidized PURm, correlate with the model given by Yoon et al. (1997). On the contrary, the data at room temperature (22°C in average) are not in agreement with the model. Nevertheless, it seems that the plateau which was reached after a long period of leaching is the same whatever the temperature used in this study. The results allow to conclude that the predominant mechanism occurring during the leaching of unirradiated and radio-oxidized PURm in an alkaline medium is the hydrolysis of the soft segments ester groups. The complexation of europium(III) by HDP in alkaline medium was demonstrated. The measurement of the complexing power and the identification of ligands was achieved under certain conditions.; L’objectif de ce travail est d’étudier la dégradation d’un polyesteruréthane industriel (PURm) par radio-oxydation puis par lixiviation en solution aqueuse à pH basique, dans le but d’évaluer le pouvoir complexant des produits de dégradation hydrosolubles (PDH) avec les actinides. Afin d’atteindre ces objectifs, le PURm a été caractérisé puis radio-oxydé à température ambiante sous rayonnements gamma jusqu’à 10 MGy. Il a ensuite été lixivié à pH 13,3 à différentes températures. De nombreuses techniques analytiques ont été employées afin de caractériser les PDH obtenus. De l’europium(III), simulant les actinides(III), a été mis en solution avec les PDH et l’interaction Eu-PDH a été analysée par spectrofluorimétrie laser à résolution temporelle (SLRT). Quelle que soit la dose reçue par le PURm, l’acide adipique et le butane-1,4-diol sont les deux PDH majoritaires. Les données de lixiviation acquises à 40 et 60°C, sur le PURm radio-oxydé jusqu’à 1 MGy, corrèlent avec le modèle proposé par Yoon et al. (1997). Par contre, les données à température ambiante (22°C en moyenne) ne sont pas en accord avec ce modèle. Il semble néanmoins que le taux de dégradation maximal atteint par le polymère soit similaire quelle que soit la température employée dans cette étude. Les résultats obtenus permettent de conclure que le mécanisme prédominant lors de la lixiviation en milieu basique du PURm non irradié et radio-oxydé est l’hydrolyse des groupes esters des segments souples. La complexation de l’europium(III) par les PDH à pH basique a été mise en évidence. La détermination de la constante de complexation et l’identification des ligands, dans certaines conditions, ont été réalisées.

The first aim of this work is to study the degradation of an industrial polyesterurethane (PURm) by radio-oxidation and then by leaching in an alkaline aqueous solution. The second aim is to measure the complexing power of hydrosoluble degradation products (HDP) with actinides. To reach these goals, PURm was first characterized and then radio-oxidized at room temperature with gamma rays up to 10 MGy. Second, it was leached at pH 13.3 at different temperature values. Numerous analytical techniques were employed in order to characterize the HDP. Europium(III) was used as an analogue of actinides(III) and the behavior of HDP with europium(III) was analyzed by time-resolved luminescence spectroscopy (TRLS). Whatever the received dose by PURm, the two main HDP are adipic acid and butane-1,4-diol. The leaching data acquired at 40 and 60°C, on the 1 MGy radio-oxidized PURm, correlate with the model given by Yoon et al. (1997). On the contrary, the data at room temperature (22°C in average) are not in agreement with the model. Nevertheless, it seems that the plateau which was reached after a long period of leaching is the same whatever the temperature used in this study. The results allow to conclude that the predominant mechanism occurring during the leaching of unirradiated and radio-oxidized PURm in an alkaline medium is the hydrolysis of the soft segments ester groups. The complexation of europium(III) by HDP in alkaline medium was demonstrated. The measurement of the complexing power and the identification of ligands was achieved under certain conditions., L’objectif de ce travail est d’étudier la dégradation d’un polyesteruréthane industriel (PURm) par radio-oxydation puis par lixiviation en solution aqueuse à pH basique, dans le but d’évaluer le pouvoir complexant des produits de dégradation hydrosolubles (PDH) avec les actinides. Afin d’atteindre ces objectifs, le PURm a été caractérisé puis radio-oxydé à température ambiante sous rayonnements gamma jusqu’à 10 MGy. Il a ensuite été lixivié à pH 13,3 à différentes températures. De nombreuses techniques analytiques ont été employées afin de caractériser les PDH obtenus. De l’europium(III), simulant les actinides(III), a été mis en solution avec les PDH et l’interaction Eu-PDH a été analysée par spectrofluorimétrie laser à résolution temporelle (SLRT). Quelle que soit la dose reçue par le PURm, l’acide adipique et le butane-1,4-diol sont les deux PDH majoritaires. Les données de lixiviation acquises à 40 et 60°C, sur le PURm radio-oxydé jusqu’à 1 MGy, corrèlent avec le modèle proposé par Yoon et al. (1997). Par contre, les données à température ambiante (22°C en moyenne) ne sont pas en accord avec ce modèle. Il semble néanmoins que le taux de dégradation maximal atteint par le polymère soit similaire quelle que soit la température employée dans cette étude. Les résultats obtenus permettent de conclure que le mécanisme prédominant lors de la lixiviation en milieu basique du PURm non irradié et radio-oxydé est l’hydrolyse des groupes esters des segments souples. La complexation de l’europium(III) par les PDH à pH basique a été mise en évidence. La détermination de la constante de complexation et l’identification des ligands, dans certaines conditions, ont été réalisées.

Few reports describe the effect of lactose hydrolysis on the properties of milk powder during production and storage. Hence, the aim of this study was to evaluate the effects of five different levels of enzymatic lactose hydrolysis during the production and storage of milk powder. As the lactose hydrolysis rate increased, adhesion to the drying chamber also increased, due to higher levels of particle agglomeration. Additionally, more brown powder was obtained when the lactose hydrolysis rate was increased, which in turn negatively affected rehydration ability. Using Raman spectroscopy, crystallization of the lactose residues in various samples was assessed over 6 weeks of accelerated aging at a room temperature environment with 75.5% of air moisture. Products with 25% or greater lactose hydrolysis showed no signs of crystallization, in contrast to the non-hydrolyzed sample.

Purification d'acide férulique obtenu par hydrolyse de son de blé. 16. Congrès de la Société Française de Génie des Procédés

8ème colloque - Tendances des Applications en Mathématiques Tunisie, Algérie et Maroc, Hammamet, TUN, 10-/05/2017 - 13/05/2017; International audience; In this symposium, we present mathematical analyses of models related to the growth and coexistence of species of micro-organisms in the chemostat. These works were carried out within the TREASURE network. The symposium consists in 4 presentations : Anaerobic digestion (by N. Abdellatif), Synthrophic relationship in the chemostat (by Y. Daoud), Intra and interspecific competition in the chemostat (by C. Lobry) and Flocculation in the Chemostat (by R. Fekih-Salem).; Dans ce symposium, nous présentons une analyse mathématique de modèles de croissance et de coexistence d’espèces de micro-organismes dans le chemostat. Ces travaux ont été réalisés dans le cadre du réseau TREASURE. Ce symposium consiste en 4 présentations : La digestion anaérobie (par N. Abdellatif), la relation synthrophique dans le chemostat (par Y. Daoud), la compétition intra et interspécifique dans le chemostat (par C. Lobry) et la flocculation dans le Chemostat (par R. Fekih Salem)

In this work, the fate and biodegradation of slowly biodegradable organic matter contained in wastewaters were investigated. The hydrolysis process was particularly targeted as many sources proved that it controls the fate of the considered substrate. First, a synopsis of the literature results related to this topic as well as internal results were investigated especially in terms of respirometric aspects (OUR measurement) in order to identify differences and/or similarities between the experiments and, thus, address gaps in knowledge of the mechanisms that are involved in the hydrolysis of this matter. Then, in the second part of this thesis, experimental data from batch respirometric tests (performed in our laboratory), involving typical slowly biodegradable matter that are found in wastewaters (e.g. Particulate settleable solids, toilet paper…), were confronted to conventional (IAWQ models) and non-conventional models to evaluate the efficiencies of those models to describe the hydrolysis step. In the third part of this thesis, based on hypotheses, a novel conceptual framework was developed in order to enhance the description of the hydrolysis process. The physical properties (density, size, shape) of the components (bacteria and substrate) were taken into account in this model. Finally, in the fourth and last chapter of this thesis, the specific role of each bacterial population involved in the biodegradation of slowly biodegradable organic matter was assessed. It was here clearly evidenced that the hydrolysis of PSS in activated sludge processes appears more influenced by the initially adsorbed bacteria onto the sewage than by the added AS-inoculum concentration.; Dans cette thèse, la biodégradation et le devenir des matières organiques lentement biodégradables contenues dans les eaux usées ont été étudiés. La thèse s’est particulièrement penchée sur l’étude du processus d’hydrolyse dans la mesure où plusieurs auteurs considèrent qu’il s’agit du processus limitant durant la dégradation des matières considérées. L’analyse des résultats de la littérature en complétés de ceux que nous avons obtenu en laboratoire a permis d’identifier et ainsi souligner les manques par rapport aux mécanismes qui régissent la dégradation des matières organiques lentement biodégradables. Ensuite, nous avons confronté ces résultats expérimentaux (expériences réalisées en batch sur des substrats type « particules décantables ») aux modèles conventionnels du traitement des eaux mais aussi à d’autres modèles moins usuels afin d’évaluer les performances de ces derniers à décrire l’hydrolyse des différents substrats. La difficulté de ces modèles à décrire la diversité des situations rencontrées nous a amené à développer un nouveau modèle qui tient compte des propriétés physiques et géométriques du substrat et qui permettrait d’améliorer la caractérisation du processus d’hydrolyse. Enfin, nous nous sommes intéressés à la distinction d’une biomasse hydrolytique dans la masse cellulaire totale et de déterminer son origine. Il a été clairement démontré que l’hydrolyse des PSS dans les procédés à boues activées était plus impactée par les bactéries indigènes, initialement adsorbées dans le réseau, que par les bactéries exogènes, en provenance d’un inoculum de boue activées.

Heterotrimere G-Proteine sind molekulare Schalter, die eine Vielzahl an physiologisch relevanten Prozessen, wie Sehen, Riechen und die Blutdruckregulation steuern. In dieser Arbeit wurden molekulare Mechanismen des Einschaltens (Austausch von Guanosindiphosphat (GDP) zu Guanosintriphosphat (GTP)) und des Ausschaltens (GTP Hydrolyse) dieser Proteine untersucht. Dazu wurde vor allem die zeitaufgelöste FTIR-Spektroskopie benutzt, die als Messergebnis detaillierte strukturelle Informationen in Form von Infrarotspektren liefert. Zur Dekodierung dieser Information wurden molekularmechanische (MM-) und gekoppelte quantenmechanische/molekularmechanische (QM/MM-) Simulationen durchgeführt. Hiermit war es möglich, die spektrale Information in einen dreidimensionalen Film des aktiven Zentrums zu übersetzen und strukturelle Details von Ein- und Ausschalten aufzuklären. Dazu gehört unter anderem der Mechanismus des intrinschen Arginin Fingers heterotrimerer G-Proteine während der GTP-Hydrolyse. Heterotrimeric G-Proteins are molecular switches in cells that maintain a plethora of physiological processes like vision, scent and blood pressure regulation. In this thesis, molecular mechanisms of the on-switch (exchange from guanosine diphosphate (GDP) to guanosine triphosphate (GTP)) and the off-switch (GTP hydrolysis) of these proteins were investigated. Particularly time-resolved FTIR spectroscopy was applied, that resolves molecular reactions in the form of infrared spectra. For decoding these spectra, biomolecular simulations (molecular mechanics (MM) and coupled quantum mechanics / molecular mechanics (QM/MM)) were applied, that translated the spectral information into a three-dimensional movie of the active center. Detailed mechanisms of the on- and the off-switch were thereby elucidated, among others the mechanism of the intrinsic arginine finger in heterotrimeric G-Proteins during GTP hydrolysis.

Studying food digestion in humans through clinical trials is difficult for economical, ethical and technical reasons. In vitro alternatives are thus used for screening different foods and for a better understanding of the mechanisms of the digestive process. To date, there are only few models for simulating infant digestion and most of them lack of physiological relevance. Thanks to an extensive literature review of the in vivo infant digestive conditions, a gastrointestinal static in vitro model was developed for infants born at term and aged of 28 days. The oral phase was omitted due to the liquid nature of infant formula but also because carbohydrate digestion was not monitored here. The following parameters were determined: pH, ratio of meal to secretions, enzyme units of pepsin and gastric lipase (added as rabbit gastric extract) and of pancreatin (porcine source), and biliary salt molarity. Gastric and intestinal phases lasted 60 min each. The model was applied to the digestion of a commercial infant formula. Kinetics of digestion and end-points were compared with those obtained while submitting the same formula to the adult standardised protocol of in vitro static digestion1.Gastric and intestinal digesta were sampled regularly. Proteolysis kinetics were followed by SDS-PAGE and NMR and lipolysis kinetics by thin layer and gas chromatography. The structure evolution during the gastric phase was evaluated by confocal laser scanning microscopy and laser light scattering. As a result, the kinetics of proteolysis and lipolysis differed according to the physiological stage likely due to the reduced level of enzymes in the infant model and the higher gastric pH at the infant stage. This model is of interest for scientists or companies studying the digestion of infant food.

Digestion is a highly organized sequence of biochemical, enzymatic and mechanical processes needed to release nutrients, such as peptides or free amino acids from proteins structuring complex food matrices. During the gastric phase, they are gradually denatured through the acid released into the stomach and hydrolysed by pepsin. At the intestinal phase of digestion, proteases, such as trypsin, chymotrypsin, elastase and others, are secreted to further degrade the proteins and peptides until they are absorbed through the intestinal epithelium. Static or dynamic in vitro digestion models are widely used to study this step-by-step degradation of proteins to peptides and free amino acids, raising the question on the differences between digestion models. Generation and destruction of specific peptides during in vitro digestion of skim milk powder, following either the static international consensus COST Infogest digestion protocol or the dynamic digestion model DIDGI were compared, and verified in vivo in pigs. The hydrolysis of the five most abundant milk proteins during digestion – their peptides and free amino acids – were investigated by gel electrophoresis, mass spectrometry and HPLC after the gastric and the intestinal -phase. Moreover, time-resolved in vitro digestion experiment, generation and degradation of specific peptides and release of free amino acids were followed in the two in vitro digestion models and compared with the digestion in pigs. The protein specific hydrolysis for each digestion was visualized and compared by generation of abundance-dependent peptide patterns. Highly abundant peptides observed after complete digestion indicate digestion-resistant protein sequences and represent interesting sources of bioactive peptides or allergenic epitopes. Partial-least-square data analysis (PLS-DA) comparing static and dynamic in vitro digestion with the in vivo pig data showed a high correlation of gastric and intestinal samples at the peptide level. The same analysis at the level of free amino acids showed a good correlation at the gastric phase. However, at the intestinal level, the three models formed distinct groups which could be due to absorption mechanisms in the in vivo situation.

Gowe is a traditional Beninese fermented red sorghum beverage made from a blend of malted and precooked nonmalted flour. The main objective of this work was to evaluate the degradation of starch during the production of gowe and to characterise the organic acid and sugar profiles of the product obtained using starter cultures. Inoculation was performed with strains of Lactobacillus fermentum or Weissella confusa and of Kluyveromyces marxianus or Pichia anomala used singly or in combination. Size exclusion chromatography revealed that starch was hydrolysed into high molecular weight dextrins (DP over 35), oligosaccharides and glucose, mainly due to the malting and precooking steps. Glucose was the main free sugar, and lactic acid was the main organic acid. The choice of the inoculation strain directly influenced the acidity but also indirectly the sugar content of the resulting gowe and will thus affect consumer acceptability. (Resume d'auteur)

Gowe is a sweetish paste of malted, fermented, and cooked sorghum and/or maize flour, consumed in its pure state, but preferentially as a beverage after homogenizing with water, sugar, milk, and ice. A survey was carried out at different localities in the traditional gowe producing areas to investigate the diversity of the processing techniques, consumers¿ characteristics, and the quality attributes. Producers and sellers were women exclusively while consumers cut across all classes of age, socio-cultural groups, and educational levels. Gowe varied in cereal and processing techniques, with maize and sorghum being used either singly or in combination (maize/sorghum ratio varying from 1 to 3) through four processes. Apart from the alternative process which leaves out the malting step, gowe processing techniques aim at producing sweetish and acidic tasting products through malting, saccharification, and fermentation. A principal component analysis plot of quality criteria of gowe indicated that the preference of consumers was directly associated with the perceptions of producers.

Sub-critical water is widely accepted as an environmentally benign solvent, for extraction but also as a catalytic medium therefore has the potential to support processing of multiple components found in biomass. The manuscript demonstrates the versatility of sub-critical water as a generic medium to support hydrolysis of rice bran (carbohydrates) and sunflower oil (lipid substrates), substrates that possess very different physio-chemically properties within a continuous flow process configuration. Response surface methodologies (RSM) were used to assist modelling the multiple process parameters that impact sub-critical water mediate hydrolysis of sunflower oil. Successful validation, of the models illustrate that 100% FFA yield would be achieved at temperature 385 °C; pressure 20 MPa; residence time of 35 min; oil to water ratio 1:1.8 (v/v) represents 65% water. Experiments conducted under these conditions yielded 93.5%, thereby confirming the utility of the RSM as a tool to assist in process development.

Ziel dieser Dissertation war es, sowohl mittels klassischer Kraftfeld-Molekulardynamik Simulationen als auch hybrider quantenmechanischer/molekularmechanischer (QM/MM) Simulationen die Funktionsmechanismen von Membranproteinen zu studieren. Dabei konnte der konformationelle Kopplungsmechanismus des ABC Transporters BtuCD-F durch die Berechnung von Entropien und Kräfteverteilungen aufgedeckt werden. Des Weiteren wurde die Hydrolyse von ATP zu ADP in diesem Protein studiert. Es wurden mittels der PMF-Methode Freie Energien für den Reaktionsvorgang berechnet. Dabei konnte gezeigt werden, dass eine Glutamat-Seitenkette des Proteins in der Reaktion als katalytische Base agiert. Die Ergebnisse beider Studien lassen konkrete Rückschlüsse auf den Transportmechanismus von BtuCD-F zu. Im Rahmen dieser Arbeit wurde außerdem die Lipidexposition des Membranproteins EmrE berechnet. Die Ergebnisse stützen die Hypothese der anti-parallelen Struktur von EmrE.

The predominant storage form of phosphorus (P) in plant seeds and grains is phytate (InsP6). To cleave the phosphate group and, thus, make the bound P available for absorption by the animal, the enzyme phytase is required. Rumen microorganisms show substantial phytase activity, however, recent studies have suggested that the extent of InsP6 hydrolysis in ruminants is variable leading to an incomplete hydrolysis of InsP6 in specific conditions followed by the excretion of P from undegraded InsP6. As P is an essential element for the metabolism in animals it is important to ensure that the animals’ requirements are met. Diets for ruminants are often supplemented with mineral P (Pi). However, the global phosphate resources are finite and the excretion of surplus P contributes to eutrophication of surface water when applied to the farmland with manure in excessive amounts. Thus, dietary P supply is of environmental concern. Better knowledge about ruminal InsP6 hydrolysis could help to optimise the utilisation of InsP6 and, thus, reduce the use of Pi as well as unnecessary excretion of P. Hence, the objectives of the present thesis were to examine the InsP6 hydrolysis from different feedstuffs in ruminants and to identify factors that might affect the extent of InsP6 hydrolysis. In the first study, the total digestive tract disappearance of InsP6 from diets differing in amount and source of P was determined in lactating dairy cows. The results confirmed the high potential of rumen microorganisms to hydrolyse InsP6, but the composition of the diet influenced the extent of hydrolysis in vivo. In the second study, two in vitro experiments were conducted in order to determine the InsP6 hydrolysis from maize grain and RSM. In experiment 1, two diets differing in P- and InsP6-P concentration were fed to the donor animals of rumen fluid. In experiment 2, a diet similar to the high P diet of experiment 1 was fed to the donor animals of rumen fluid and the rumen fluid was mixed with artificial saliva containing Pi (PI: 120 mg Pi/l) or no Pi. Maize and RSM were incubated for 3, 6, 12, and 24 h in both experiments and the InsP6 concentration was analysed in fermenter fluids and bag residues. InsP6 disappearance from maize proceeded faster than from RSM. The disappearance of InsP6 was higher when the diet with high P concentration was fed (experiment 1) and lower when the rumen fluid was mixed with Pi containing buffer (experiment 2). In the third study, the in situ disappearance of InsP6 from five different concentrates was examined. Maize, wheat, RSM, heat treated RSM (hRSM), and soybean meal were incubated in the rumen of fistulated dairy cows fed with three diets differing in P- and InsP6-P concentration. Concentrations of InsP6 and isomers of InsP5, InsP4, and InsP3 were determined in the bag residues after 2, 4, 8, 16, and 24 h of incubation. The disappearance of InsP6 from cereals proceeded faster than from oilseed meals, however, averaged over the diets, after 24 h of incubation 95% had disappeared from all concentrates except for hRSM (57%). Feeding the diet with high InsP6 concentrations increased InsP6 disappearance from oilseed meals but not from cereals, while feeding the high Pi diet did not influence ruminal InsP6 hydrolysis from any concentrate. The results derived from analysis of lower InsPs suggested that intrinsic plant phytase activity plays only a minor role in the rumen and that active phytases in the rumen react differently to changes in the ruminal environment. The results of the present thesis suggest that the composition of the diet fed to ruminants affects the extent of ruminal InsP6 hydrolysis. While high InsP6 concentrations have the potential to increase InsP6 hydrolysis, a decrease of InsP6 hydrolysis can occur after addition of Pi to the diet. Differences in the pace of InsP6 hydrolysis between concentrates occurred which could be of importance at high ruminal passage rates when the time available for ruminal hydrolysis decreases. Phosphor (P) wird in pflanzlichen Samen und Körnern überwiegend als Phytat (InsP6) gespeichert. Um die Phosphatgruppe abzuspalten und so den darin gebundenen P für die Absorption verfügbar zu machen, wird das Enzym Phytase benötigt. Ruminale Mikroorganismen weisen eine nicht unerhebliche Phytaseaktivität auf, Studien der letzten Jahre zeigten allerdings, dass auch beim Wiederkäuer die InsP6-Hydrolyse beeinträchtigt werden kann und entsprechend P aus nicht abgebautem InsP6 ausgeschieden wird. Genauere Erkenntnisse zur ruminalen InsP6-Hydrolyse können dazu beitragen, die Verwertung von InsP6 zu optimieren. Ziel dieser Arbeit war es daher, die Hydrolyse von InsP6 aus unterschiedlichen Futtermitteln beim Wiederkäuer näher zu untersuchen und Faktoren zu identifizieren, die die InsP6-Hydrolyse beeinflussen können. Im Rahmen der ersten Studie wurde der InsP6-Abbau aus verschiedenen Rationen im Gesamtverdauungstrakt laktierender Milchkühe bestimmt. Die Rationen unterschieden sich hinsichtlich der P-Konzentration und P-Quelle. Die Ergebnisse bestätigen das hohe Potential der Mikroorganismen im Pansen zur InsP6-Hydrolyse, die Zusammensetzung der Ration beeinflusste allerdings das Ausmaß des Abbaus in vivo. Für die zweite Studie wurden zur Bestimmung der InsP6-Hydrolyse aus Mais und RSM zwei in vitro Experimente durchgeführt. In Experiment 1 wurden die Spendertiere des Pansensaftes mit zwei Rationen angefüttert, die sich hinsichtlich der P- und InsP6-Konzentration unterschieden. In Experiment 2 wurden die Tiere mit einer Ration angefüttert, die mit der P-reichen Ration aus Experiment 1 vergleichbar war und der Pansensaft mit P-haltigem (120 mg P/l) oder P-freiem Puffer gemischt. Mais und RSM wurden jeweils für 3, 6, 12 und 24 h inkubiert und anschließend die InsP6-Konzentration in der Fermenterflüssigkeit und im Futterrückstand bestimmt. Die InsP6-Hydrolyse verlief bei Mais schneller als bei RSM und war bei Fütterung der P-reichen Ration höher als bei Fütterung der P-armen Ration, die Zulage von mineralischem P über den Puffer führte zu einem Rückgang der Hydrolyse. In der dritten Studie wurde der ruminale Abbau von InsP6 aus fünf verschiedenen Futtermitteln untersucht. Die Inkubation von Mais, Weizen, RSM, hitzebehandeltem RSM und Sojaextraktionsschrot erfolgte bei Fütterung dreier unterschiedlicher Rationen. Die InsP6-Konzentration sowie die Konzentrationen der Isomere von InsP5, InsP4 und InsP3 wurden in den Beutelrückständen nach 2, 4, 8, 16 und 24 h gemessen. Der InsP6-Abbau verlief bei Getreide schneller als bei den Ölschroten, nach 24 h Inkubation war jedoch bei allen Futtermitteln 95% des InsP6 aus den Beuteln verschwunden. Einzig bei Inkubation von hRSM waren nach 24 h lediglich 57% des InsP6 abgebaut. Bei Fütterung der InsP6-reichen Ration stieg der InsP6-Abbau bei den Ölschroten an. Dieser Effekt war bei den Getreiden nicht nachzuweisen. Die Fütterung einer Ration mit Zulage von mineralischem P zeigte dagegen bei keinem der untersuchten Futtermittel einen Einfluss auf den ruminalen in situ Abbau von InsP6. Die Konzentrationen der Isomere der niederen InsPs in den Inkubationsrückständen ließen vermuten, dass die endogene pflanzliche Phytaseaktivität im Pansen eine untergeordnete Rolle spielt. Zudem scheinen die im Pansen aktiven Phytasen auf Rationsänderungen unterschiedlich zu reagieren. Die Ergebnisse der vorliegenden Arbeit legen den Schluss nahe, dass die Zusammensetzung der an Wiederkäuer verfütterten Rationen das Ausmaß der ruminalen InsP6-Hydrolyse beeinflussen kann. Hohe InsP6-Konzentrationen in der Ration scheinen den Abbau von InsP6 zu steigern während eine Zulage von mineralischem P einen negativen Einfluss haben kann. Des Weiteren waren Unterschiede hinsichtlich der Geschwindigkeit, in der der InsP6-Abbau voranschritt, zwischen den untersuchten Futtermitteln zu erkennen. Dies könnte vor allem bei hohen Passageraten für das Ausmaß des ruminalen InsP6-Abbaus von Bedeutung sein, wenn weniger Zeit zur Hydrolyse zur Verfügung steht.

The Arkométha ® process is a system treating organic wastes in several sectors working at high solid concentration and being temperature phased. The present work focuses on the performances of the different phases of the process in treating agricultural wastes. In a first time, the hydrolysis sector has been studied. The most influent parameters have been identified (temperature and retention time), using design of experience. They have been tested afterwards at a pilot scale in order to assess the influence on solubilization and later methane production. Then, tests have been conducted at the lab scale in continuous mode using serial reactors. The methanogenic compartment, composed by two to three sectors has been studied highlighting the efficiency of each sector. The effect of temperature has also been studied, with a strong impact. The two compartments being used in series enabled the study of the complete process. This allowed highlighting some risks linked with certain temperatures combinations. On the other hand, a comparison with a single step reactor has been made. Beside the analysis of the relative performances of each compartment, a major result of this work lies in the distinction between hydrolysis and solubilization. Eventually, we showed that the gain brought by the hydrolysis compartment is not only related to solubilization of organic matter, but also in the increase in kinetics in the downwards sectors. Interestingly, while temperature has a major role in solubilization, it is of less importance in improving the degradation kinetics, where the retention time becomes of higher importance., Le procédé Arkométha® est un système de digestion anaérobie de rejets organiques fonctionnant en voie épaisse et comprenant plusieurs compartiments phasés en température. Ce travail s’est intéressé aux performances des différentes phases du procédé pour le traitement de résidus agricoles. Dans un premier temps, le compartiment d’hydrolyse a été étudié. Les paramètres les plus influents ont été identifiés (température et durée de l’hydrolyse) à l’aide d’un plan d’expérience. Ils ont ensuite été testés sur un pilote afin d’évaluer leur influence sur la solubilisation et la production de méthane ultérieure. Des tests ont alors été conduits à l’échelle laboratoire en mode continu au moyen de réacteurs en séries. Le compartiment méthanogène, constitué de deux à trois secteurs, a été étudié en mettant en évidence l’efficacité de chaque secteur. L’effet de la température a ici également été étudié, avec un impact important. Les deux compartiments ont été mis en série permettant l’étude du procédé complet. Ceci a permis de mettre en lumière certains risques liés à des combinaisons de température peu favorables. Par ailleurs, une comparaison avec un procédé mono-étape a été effectuée. Outre l’étude des performances de chaque compartiment et l’analyse de leur articulation, un résultat intéressant de ce travail réside dans l’affinement de la notion d’hydrolyse dans le cadre de la méthanisation en voie épaisse, communément confondue avec la solubilisation. En effet, nous avons montré que le gain apporté par l’utilisation d’un réacteur séquencé avec un compartiment dédié à l’hydrolyse ne réside pas dans l’amélioration de la solubilisation, mais dans l’augmentation conséquente de la cinétique de méthanisation dans les étapes suivantes. De façon intéressante, alors que la température joue un rôle primordial dans la solubilisation de la matière organique, elle est relativement peu influente pour l’amélioration de la cinétique de dégradation, où le temps de séjour devient prépondérant.

With a production of 39 million metric tons each year, rice is one of the main agricultural products of Vietnam. Thus, rice straw is a significant by-product, whose use in a biorefinery process would contribute to the bio-based transformation of the Vietnamese and South East Asian economy. In order to find novel efficient enzyme mixtures for the hydrolysis of rice straw and other agricultural residues, we took advantage of the rapidly evolving biodiversity of Vietnam and screened 1100 new fungal isolates from soil and decaying plant tissues for their CMCase activity. We selected 36 strains and evaluated them for their cellulases, xylanases, and accessory enzymes activities. Most of these isolates belonged to the genera Aspergillus and Trichoderma. We identified a few promising isolates, such as A. brunneoviolaceus FEC 156, A. niger FEC 130 and FEC 705, and A. tubingensis FEC 98, FEC 110 and FEC 644, whose produced enzyme mixtures released a mass fraction of the sugar content of alkali-treated rice straw higher than 20%, compared to 10% for Trichoderma reesei RUT C-30. We verified that the black Aspergilli are particularly efficient in their saccharification ability. We also identified strains that although they produced low amounts of cellulases and xylanases, their enzyme mixtures had high saccharification efficiencies, indicating the importance of the synergy effect, rather than the amount of enzymes available. Our results highlight the intra-species variation, especially in the Trichoderma genus, regarding the biomass degradation characteristics and the associated range of enzymatic activities. (C) 2017 The Author(s). Published by Elsevier Ltd.

Karbonfangst- og lagring (CCS) blir ansett som en uunnværlig teknologi i arbeidet med å redusere de antropogene utslippene av karbondioksid (CO2) til atmosfæren i løpet av de neste tiårene. Blant de ulike metodene for karbonfangst er kalsiumlooping en av teknologiene som har vist mest lovende resultater for fangst av CO2 fra store punktutslippskilder. Karbonfangst i saltsmelter (CCMS) er en relativt ny teknologi videreutviklet fra konvensjonell kalsiumlooping. Teknologien er en høytemperaturprosess som tar utgangspunkt i en inert saltsmelte bestående av uorganiske halidmetaller som fungerer som bærende medium for en helt eller delvis løst sorbent. I saltsmelten oppstår raske gass-væske-interaksjoner som bidrar til økt reaktivitet mellom sorbenten og CO2-gassen. Prosessen tar utgangspunkt i den reversible reaksjonen mellom kalsiumoksid (CaO) og CO2, som danner kalsiumkarbonat (CaCO3). Ved hjelp av termiske svingninger kan CaCO3 dekomponere endotermisk slik at ren CO2 frigis og CaO regenereres, slik at prosessen kan fortsette i gjentatte absorpsjons- og desorpsjonssykluser. I tillegg til økt reaksjonskinetikk, vil man ved bruk av saltsmelter unngå problemene med partikkeldegradering som observeres i konvensjonell Ca-looping med faste sorbentpartikler. Til nå har det blitt utført flere studier på karbonfangst i saltsmelter som viser svært lovende resultater ved bruk av saltsmelter for fangst av CO2 fra røykgass. Før teknologien utvikles videre er det imidlertid flere aspekter som må studeres nærmere. Hovedmålet med analysene utført i denne oppgaven var å studere saltsmeltens reaktivitet mot vann. Alle reelle røykgasser inneholder vanndamp. Dersom denne vanndampen reagerer med anionene i saltsmelten kan det føre til dannelse av hydrogenklorid (HCl) og hydrogenfluorid (HF). Dette er forbindelser som er uønsket og strengt regulert gjennom faste utslippsgrenser. Hvorvidt hydrolyse av saltene fører til dannelse av gasser som HCl og HF er derfor vesentlig for den videre utviklingen av CCMS. På tross av at hydrolyse ikke er termodynamisk favorisert for saltene benyttet i studien viser analysene at hydrolyse forekommer. Resultatene viser sterk temperaturavhengighet for dannelsen av hydrogenkloridgass og hydrogenfluoridgass. Uavhengig av temperatur dannes hydrogenklorid i større mengder enn hydrogenfluorid. Også innholdet av kalsiumoksid er avgjørende for grad av hydrolyse. Smeltens stabilitet øker med økende mengde oksid i smelten. Carbon capture and storage (CCS) is considered an important technology in the reduction of fossil carbon emitted to the atmosphere from anthropogenic sources. Among the different capture technologies in development, Ca-looping is considered one of the most promising. Carbon capture in molten salts (CCMS) is a relatively novel technology further developed from conventional Ca-looping. By using a molten salt consisting of inorganic halide salts as carrying medium for the dissolved or partly dissolved sorbent, the reactivity of carbon dioxide (CO2) with calcium oxide (CaO) can be improved due to rapid gas-liquid interactions in the molten state. In addition, the observed particle degradation in conventional Ca-looping with solid sorbents is avoided. The process is based on the reversible reaction between CaO and CO2, which forms calcium carbonate (CaCO3). CaCO3 can further undergo endothermic decomposition and release CO2, as well as regenerate CaO so that the process can go on in repeated cycles. All real flue gases contain water vapour. If the water vapour reacts with the anions in the molten salt this can lead to formation of hydrogen chloride (HCl) and hydrogen fluoride (HF). These compounds are both undesirable and potentially hazardous, hence their emissions are restricted by strict regulations. Whether hydrolysis leads to formation of gases such as HCl and HF is of great importance for the further development of CCMS. The main aim with the analyses performed in this work was to examine the molten salts reactivity against water. Despite the fact that hydrolysis is thermodynamically non-favourable for the salts used in this study, the analyses show that hydrolysis does occur. The results show strong temperature dependence for the formation of hydrogen chloride and hydrogen fluoride. Regardless of temperature, hydrogen chloride is formed in larger quantities than hydrogen fluoride. The amount of calcium oxide in the molten salt is of great importance to which extent hydrolysis occurs. The stability of the melt increases with increasing amount of oxide present in the molten salt. M-KB

With the accumulation of scientific information in natural science, even experts can find difficult to keep integrating new piece of information. It is critical to explore modelling solutions able to capture information scattered in publications as a computable representation form. Traditional modelling techniques are important in that regard, but relying on numerical information comes with limitations for integrating results from distinct studies, high-level representations can be more suited. We present an approach to stepwise construct mechanistic explanation from selected scientific papers using the Qualitative Reasoning framework. As a proof of concept, we apply the approach to modelling papers about cellulose hydrolysis mechanism, focusing on the causal explanations for the decreasing of hydrolytic rate. Two explanatory QR models are built to capture classical explanations for the phenomenon. Our results show that none of them provides sufficient explanation for a set of basic experimental observations described in the literature. Combining the two explanations into a third one allowed to get a new and sufficient explanation for the experimental results. In domains where numerical data are scarce and strongly related to the experimental conditions, this approach can aid assessing the conceptual validity of an explanation and support integration of knowledge from different sources.

Ras-Proteine sind kleine intrazelluläre Regulatorproteine, die zur Superfamilie der kleinen GTPasen gehören. Das primäre Ziel dieser Arbeit war es, die Hydrolysemechanismen von verschiedenen Ras-Isoformen und -Mutanten mit ATR-FTIR-Spektroskopie und zeitaufgelöster Transmissions-FTIR-Spektroskopie aufzuklären. Die onkogenen Ras-Mutanten G12V, G13V und Q61A, sowie die Off-Mutante Y32A und der Komplex aus K16A mit dem GEF SOS wurden in dieser Arbeit untersucht. Für G12V und G13V wurden Veränderungen der Phosphatschwingungen und eventuell am Magnesiumion beobachtet. Des Weiteren wurden Messungen mit Aluminiumfluorid an Ras durchgeführt, um das Analogon des Übergangszustandes beobachten zu können, wobei Spektren für Ras mit und ohne RasGAP gewonnen wurden. Für die Isoform KRas 4B wurden der Hydrolysemechanismus und das Verhalten auf einer negativ geladenen Lipidmembran beobachtet. Der Hydrolysemechanismus von immobilisierten NRas-Proteinen auf einer Lipidmembran wurde ebenfalls untersucht.

This thesis project was carried out in order to develop a hydrothermal processfor the surface treatment of ceramic fibres which are integrated into the fabrication of ceramicmatrix composites (CMCs). A conventional process was developed by Safran Ceramics tomodify the surface chemistry of the Nicalon fibres following 3 steps. The main step consistsin dissolving the oxidised phases at the fibre surface by the use of strong acids. As aconsequence, the chemical homogeneity of the surface is enhanced and a microporouscarbon film is generated helping its compatibilization with the pyrocarbon interphase that isdeposited in between the fibres and the matrix. It was suggested to substitute thisconventional process by a hydrothermal treatment. Indeed, as water displays tunablephysico-chemical properties regarding the temperature and pressure conditions, it waspossible to recover fibres demonstrating reproducible and similar characteristics. Theefficiency and competitivity of the hydrothermal treatment have been assessed throughoptimised surface properties obtained after one single step. Next, the mechanisminvestigation revealed a selective attack of the Si atoms contained in the fibre via hydrolysisreactions. Then, the thermodynamic study pointed out the fact that the process wasdominated by a kinetic regim. Finally, the mechanical caracterisation of the CMCs made ofhydrothermal treated fibres showed results which met all the requirements. These finalobservations allowed us to complete the qualification of the hydrothermal process to treat thesurface of Nicalon fibres., Cette thèse s’inscrit dans une volonté d’adapter un procédé hydrothermal au traitement de la surface de fibres céramiques utilisées lors de la fabrication des composites à matrice céramique (CMCs). Le procédé conventionnel développé par la société Safran Ceramics se réalise en plusieurs étapes dont la principale consiste à dissoudre les phases oxydées de la surface des fibres Nicalon dans des bains d’acides. En conséquence, leurs propriétés chimiques de surface sont homogènes et un film de carbone microporeux est généré à la surface des fibres afin d’améliorer sa compatibilité chimique avec l’interphase de pyrocarbone qui y est déposée. Nous avons proposé de substituer ce procédé par un traitement par voie hydrothermale. En effet, l’eau possédant des propriétés physicochimiques ajustables en fonction des paramètres pression et température, il a été possible de modifier les propriétés de surface des fibres Nicalon d’une manière identique être productible au procédé conventionnel. L’efficacité et la compétitivité de ce traitement ont pu être démontrées par l’obtention de fibres avec des propriétés de surface optimales en une seule étape. Par la suite, l’étude du mécanisme réactionnel a révélé une attaque sélective des atomes de Si de la fibre selon des réactions d’hydrolyse. Puis, l’étude thermodynamique réalisée a mis en avant un régime à dominante cinétique. Finalement, les propriétés mécaniques des composites fabriqués à partir de tissus de fibres traités selon ce nouveau procédé ont été conformes aux objectifs. Ceci nous a donc permis de qualifier le traitement des fibres Nicalon par voie hydrothermale.

Prenatal exposure to bisphenol A (BPA) is suspected to induce adverse effects later in life. In this context, the goal of this thesis was to evaluate the human fetal exposure to BPA. Using a pharmacokinetic (PK) approach, we showed that BPA glucuronide (BPAG), the main metabolite of BPA that remains trapped in the fetal compartment, is slowly eliminated through its back conversion into BPA. A humanized PK model developed from these data predicted steady BPAG fetal plasma concentrations of 40ng/L in late pregnancy, i.e. about 1000 folds higher than corresponding BPA concentrations. A proteomic analysis of fetal tissues has shown that equimolar BPAG or BPA fetal exposures trigger similar physiological shifts in the ovine model, suggesting that BPAG hydrolysis might expose fetal tissues to BPA at levels of functional significance. It is concluded that BPAG levels in human cord blood are relevant indicators of fetal exposure to BPA during late pregnancy and should be taken into account for risk assessment; L’exposition au bisphénol A (BPA) au cours du développement fœtal est suspectée d’être impliquée dans l’initiation d’effets biologiques. Dans ce contexte, l’objectif de cette thèse est d’évaluer l’exposition humaine fœtale au BPA. Une étude pharmacocinétique (PK) réalisée sur le modèle du fœtus ovin a montré que le BPA glucuronide (BPAG), métabolite majeur du BPA piégé dans le compartiment fœtal, est lentement éliminé via sa réactivation en BPA. A partir de ces données PK, le développement d’un modèle PK humanisé a permis de prédire des concentrations plasmatiques fœtales de BPAG maintenues autour de 40ng/L chez le fœtus humain en fin de grossesse, soit environ 1000 fois supérieures aux concentrations en BPA correspondantes. Une analyse protéomique de tissus fœtaux ovins a montré qu’une même dose molaire de BPAG ou de BPA affecte des voies physiologiques similaires, suggérant que l’hydrolyse du BPAG pourrait exposer les tissus à des concentrations en BPA compatibles avec l’expression d’un effet biologique. L’ensemble de ces résultats indique que les concentrations de BPAG dans le sang de cordon constituent un marqueur pertinent de l’exposition fœtale au BPA et qu’elles doivent être prises en compte dans l’évaluation du risque

Det har i de siste få tiårene vært en økende interesse for bioaktive peptider. Bioaktive peptider er kortere proteinkjeder, som har vist seg for å ha noen gunstige egenskaper. De kan utvinnes fra alt av proteinholdige matvarer. Til nå har forskningen først og fremst vært på melk. Det finnes flere metoder for å kunne utvinne disse peptidene på, men denne oppgaven kommer til å omhandle enzymatisk hydrolyse for utvinning av peptider. I denne oppgaven ble det forsøkt å danne en kalibrering slik at en kan bruke fourier transform infrared spectroscopy (FTIR) for å kunne gi et mål på proteinenes størrelse. Dette ble gjort med high performance liquid chromatography (HPLC) med størrelseskromatografi (SEC) som referansemetode. Først ble det utført hydrolyse av tre forskjellige hydrolysator-oppsett. Det er: 1) kyllingfilet i et begerglassoppsett, 2) kyllingfilet og 3) skjærebein av kylling i en ofte brukt hydrolysator. Disse prøvene ble analysert med verktøyene FTIR og HPLC SEC. Videre ble informasjonen fra begge kildene behandlet, validert og satt sammen ved hjelp av partial least square regression analysis (PLS) hvor det ble gjort et forsøk i å finne sammenhengen. Det viste seg at det er mulig å finne noen former for trender i valideringen og at det kunne være teoretisk mulig finne en sammenheng mellom de gitte kildene til informasjon. PLS-informasjonen endte opp med R^2 på 0.8 og oppover med bruk av parametre for molekylstørrelse og mengde mot informasjon fra FTIR. Likevel er det momenter som tyder på at metoden fortsatt trenger videreutvikling. In the past few decades there has been a growing interest for bioactive peptides. Bioac-tive peptides are shorter chains of proteins which have proven to yield some advantageous propertie,s but the recent research has primarly been on milk. There are different methods by which peptides are prepared. This thesis is describing enzymatic hydrolysis in preparation of peptides. The intention of this thesis has been an attempt of making a calibration, thus obtaining means for potential qualitative and quantitative information about peptides, using Fourier Transform Infrared Spectroscopy (FTIR). As reference measureens High Performance Liquid Chromatography (HPLC) and Size Exclusion Cromatography (SEC) were used. The experiment framework is performing enzymatic hydrolosis with three different setups. Those setups were 1) using chicken filet in a bottle with beaker, 2) chicken filet in a commonly used hydrolysator and 3) cut chicken bone in a hydrolysator. The samples were analyzed by means of FTIR and HPLC SEC. Then the information from those tools were processed, validated and put together, using the statistical tool known as partial least square regression analysis (PLS), which makes qualified attempts of finding the correlation between data obtained from the different analyzing setups mentioned above. The overall, integrated result shows that it is possible to find trends in the validation process, and that it is theoretically possible to link information between the given information sources. The use of FTIR to monitor the hydrolosis process was proven to be possible with a R^2 value on 0.8 and upwards. However, from the information obtained from the experiment, it were shown that the hydrolosis process most likely needs further development. M- KB