Study of lipid bilayer behaviour modified by substrate interactions

Biological membranes rarely exist as free-floating structures but are often confined and supported by various cellular assemblies such as the cytoskeleton and the extracellular matrix. It has already been shown that biological and polymeric substrates can modulate the morphology and response to various stimuli of supported lipid bilayers significantly. The interaction between such structures and the membrane are obviously important yet remain poorly understood even in minimal or synthetic systems. The work of this thesis utilises a variety of fluorescence microscopy and atomic force microscopy (AFM) techniques to investigate the behaviour and structure of supported lipid bilayers, in particular how interfacial features of their support substrate influence and modulate their morphology and biophysical properties. First, surface modification of polydimethylsiloxane is systematically explored, in particular how the interfacial properties of such a polymer substrate can be modified to create fully and partially plasma-treated interfaces that stably support lipid bilayers. Lipid patch formation on such substrates is then investigated, revealing that the membrane undergoes significant morphological reorganisation after vesicle fusion has completed forming a lipid patch. The underlying mechanisms can be altered by substrate interactions following different pathways for fully and partially plasma-treated PDMS substrates. Furthermore, partially plasma-treated substrates are demonstrated to be capable of specifically depleting cholesterol from supported lipid membranes, while stably supporting the other remaining phospholipid species. Studies of cholesterol depletion of lipid patches possessing liquid-ordered and disordered domains reveal a disruption in domains structure, with the partitioning of fluorescent dyes into regions from which they were previously excluded. This structure perturbation was found to be reversible upon the reinsertion of cholesterol into the bilayer. Many of the discussed mechanisms are only observed in the presence of a substrate, emphasising the importance of substrate interactions in both functional biomembranes and the development of supported membrane technologie

Razvoj polisaharida iz probiotika kao dodataka hrani

Microbial polysaccharides with nutraceutical potential and bioactive properties have been investigated in detail during the last few decades. There is an increasing demand in food industries for live microbes or polysaccharides produced by them which assert health benefits other than dietetic constituents. Although there are a large number of exopolysaccharide (EPS)-producing bacteria, the titers are low for commercialization. This manuscript deals with the polysaccharides produced by probiotic strains, with major emphasis on the EPSs, their properties, applications and some of the strategies adopted which would be helpful in better understanding of the process in the near future. Research on the improved EPS biosynthesis is essential for obtaining high yields. Therefore, to reach commercialization, metabolic engineering must be applied.Posljednjih su nekoliko desetljeća potanko istraživani mikrobni polisaharidi koji imaju bioaktivna, hranjiva i farmakološka svojstva. U prehrambenoj industriji postoji sve veća potreba za primjenom živih mikroorganizama ili mikrobnih polisaharida koji, osim hranjivih, imaju i ljekovita svojstva. Iako postoji mnogo vrsta bakterija koje proizvode egzopolisaharide, proizvedene su količine nedovoljne za komercijalnu uporabu. U radu su prikazani polisaharidi iz probiotičkih sojeva, a osobito egzopolisaharidi, njihova svojstva i primjena, te navedene strategije razvoja proizvodnje što bi mogle pridonijeti razumijevanju procesa. Ispitivanje biosinteze egzopolisaharida prijeko je potrebno da bi se postigli veći prinosi, što znači da se primjenom metoda metaboličkog inženjerstva može osigurati isplativa proizvodnja polisaharida

Etude de la clarification de la bière de garde par microfiltration tangentielle – Application de la technologie RVF.

In: 6ième Colloque PROSETIA, Versailles – St Cyr, 19-21 Mars 2001Etude de la clarification de la bière de garde par microfiltration tangentielle – Application de la technologie RVF.. 6. Colloque PROSETI

Razvoj polisaharida iz probiotika kao dodataka hrani

Microbial polysaccharides with nutraceutical potential and bioactive properties have been investigated in detail during the last few decades. There is an increasing demand in food industries for live microbes or polysaccharides produced by them which assert health benefits other than dietetic constituents. Although there are a large number of exopolysaccharide (EPS)-producing bacteria, the titers are low for commercialization. This manuscript deals with the polysaccharides produced by probiotic strains, with major emphasis on the EPSs, their properties, applications and some of the strategies adopted which would be helpful in better understanding of the process in the near future. Research on the improved EPS biosynthesis is essential for obtaining high yields. Therefore, to reach commercialization, metabolic engineering must be applied.Posljednjih su nekoliko desetljeća potanko istraživani mikrobni polisaharidi koji imaju bioaktivna, hranjiva i farmakološka svojstva. U prehrambenoj industriji postoji sve veća potreba za primjenom živih mikroorganizama ili mikrobnih polisaharida koji, osim hranjivih, imaju i ljekovita svojstva. Iako postoji mnogo vrsta bakterija koje proizvode egzopolisaharide, proizvedene su količine nedovoljne za komercijalnu uporabu. U radu su prikazani polisaharidi iz probiotičkih sojeva, a osobito egzopolisaharidi, njihova svojstva i primjena, te navedene strategije razvoja proizvodnje što bi mogle pridonijeti razumijevanju procesa. Ispitivanje biosinteze egzopolisaharida prijeko je potrebno da bi se postigli veći prinosi, što znači da se primjenom metoda metaboličkog inženjerstva može osigurati isplativa proizvodnja polisaharida

Integration of Microalgae in a Wastewater Treatment Plant

The aim of this study is evaluated the employment of a digestate of a conventional wastewater treatment plant us the only source of nutrient in the cultivation of microalgae culture of Scenedesmus and Chlorella in an open pond photobioreactor. Firstly it was studied batch operation mode to understand the behavior of the culture. After that the reactor started to operate in continuous. The percentage of ammonium removal was 97 %. The percentage of that ammonium which was destined to microalgae growth was 58.1 %. 22 % of this NH4 was stripped to the atmosphere. Indeed the use of digestate for growth microalgae with light sun and aerea to provide oxygen is viable.Departamento de Ingeniería Química y Tecnología del Medio AmbienteGrado en Ingeniería Químic

Láminas y membranas de cambio iónico a base de celulosa injertada con polímeros acrílicos

Tesis inédita de la Universidad de Madrid, Facultad de Ciencias, leída el 2 de julio de 1971.Universidad de MadridTRUEProQuestpu

Étude de faisabilité pour le réemploi des fluides de coupe pour l'usinage de pièces chez Verbom Inc. à Valcourt

La gestion des matières dangereuses résiduelles au Canada est régie par un cadre légal à trois niveaux d’intervenants : les municipalités, les provinces et le fédéral. Verbom Inc. emploie un mélange aqueux à base d’huile CIMPULSE 45 MP comme fluide de refroidissement des machines à commande numérique. L’utilisation de ces produits et la production de déchets liquides qui en découle soulèvent des défis sociaux, économiques et environnementaux importants. Elle produit ainsi annuellement près de 12 000 litres de déchets liquides. L’objectif ultime de cette étude est d’évaluer la faisabilité du réemploi des fluides de coupe des machines à commande numérique de l’usine U1 de Verbom Inc. à Valcourt. Pour ce faire, le cadre général québécois est déterminé avant d’analyser les options de traitement existant pour le réemploi des fluides de coupe puis de spécifier le scénario qui sied au contexte spécifique de l’entreprise. Neuf procédés de traitement sont comparés à travers une analyse multicritère en lien avec les objectifs de ce travail; c’est-à-dire, qui préserve les caractéristiques de la solution traitée en respectant les exigences environnementales, économiques et sociales. Il s’agit des traitements physicochimique, biologique aérobie et anaérobie, thermique, membranaire, par coalescence et écrémage, magnétique et par centrifugation. Ainsi, quatre critères comportant 11 sous-critères sont identifiés à cette fin. Il s’agit de l’efficacité technique de la méthode de traitement, du volet social, de l’aspect économique et de l’environnement. Les résultats de l’analyse montrent que le procédé membranaire par microfiltration ou ultrafiltration est le mieux adapté pour le traitement et le réemploi des fluides de coupes aqueux de type solution vraie ou fluide synthétique. Cette option répond en grande partie aux objectifs de cette étude, car sur le plan de l’efficacité technique, elle préserve les propriétés refroidissantes et lubrifiantes de la solution traitée puis assure une simplicité de manœuvre. Au niveau du respect des exigences de développement durable, elle émet peu de contaminants et de nuisances dans l’environnement, consomme moins d’énergie, assure une utilisation en toute sécurité et les couts d’investissements et d’exploitation sont modérés. Néanmoins, il est recommandé de procéder à quelques ajustements notamment par l’ajout d’additifs anticorrosifs, antibactériens et antimousses. Une étude plus poussée pourrait contribuer à mieux caractériser le perméat de microfiltration et ultrafiltration et déterminer avec exactitude la nature et les proportions des ajustements pour parfaire la réemployabilité de la solution traitée

Integrated risk management in water supply

The aim of the masters degree thesis was to develop the integrated risk management method which is mostly based on our own research and practical experiences. Beside scientific literature review from actual field of research, problematic of existing risk management methods in Slovenia and European union was exposed. Water supply system was divided in different sub-systems, parts and elements in order to simplify risk analysis. Based on system fragmentation, the database of potenti al hazards was established in order to help utility as a risk assessment tool for hazards, that threatens quality and quantity of drinking water from source to tap. Applicative character of database allows simplicity of maintenance and updating. Method was successfully validated on practical example of water supply system Preţganje and it enabled excellent risk picture. Integrated risk management approach was used as an upgrade of existing obligatory HACCP system. Based on hazard database and risk assessment, typical preventive and corrective measures were proposed, that will provide better risk management practice for the utility

Recovery of pickling acid solutions by membrane technology: the EU REWACEM Project

Resource recovery from industrial waste water by cutting edge membrane technologie