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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Erythritol metabolism in a dome mutant of Schizophyllum commune

Braun, Mary Louise January 1969 (has links)
This document only includes an excerpt of the corresponding thesis or dissertation. To request a digital scan of the full text, please contact the Ruth Lilly Medical Library's Interlibrary Loan Department (rlmlill@iu.edu).
2

Optimisation de la production d’érythritol chez la levure non-conventionnelle Yarrowia lipolytica

Carly, Frédéric 09 November 2017 (has links)
L’érythritol est un polyol aux propriétés édulcorantes utilisé comme substitut de sucre par l’industrie agroalimentaire. Le but principal du projet est l’amélioration du procédé de production d’érythritol par génie métabolique. L’idée est de construire des souches surexprimant les gènes liés à la voie de synthèse de l’érythritol. L’objectif principal est donc d’identifier les gènes clés permettant d’augmenter la synthèse d’érythritol et d’évaluer cette dernière en bioréacteur.Parallèlement à cela, un autre objectif est d’identifier les gènes liés au catabolisme de l’érythritol. En effet, Y. lipolytica est capable de produire de l’érythritol, mais aussi de le reconsommer en cas d’absence d’autre source de carbone. L’objectif est donc d’identifier les gènes liés au catabolisme de l’érythritol afin de les déléter, et ainsi obtenir une souche capable de produire de grandes quantités d’érythritol sans le reconsommer en fin de culture.Les résultats obtenus ont permis d’identifier les étapes clés de la voie de synthèse de l’érythritol et d’obtenir des souches à haut rendement et productivité par génie génétique. Par ailleurs, deux gènes de la voie de dégradation de l’érythritol ont pu être identifiés pour la première fois chez une levure. En combinant la surexpression de gènes liés à la synthèse de l’érythritol et la délétion de gènes liés à sa dégradation, une souche présentant une productivité 74% plus importante que la souche sauvage a pu être créée. Par ailleurs, une souche capable de convertir l’érythritol en érythrulose, un autre composé d’intérêt, a également pu être construite. / Doctorat en Sciences agronomiques et ingénierie biologique / info:eu-repo/semantics/nonPublished
3

Role of entF Gene in Iron Acquisition by Brucella abortus 2308

Jain, Neeta 04 June 2009 (has links)
Brucella causes undulant fever in humans and uterine and systemic infection leading to abortions in domestic animals and wild life. For the acquisition of iron in mammalian hosts, species of Brucella are known to produce two siderophores, 2, 3-dihydroxy benzoic acid (2, 3-DHBA) and brucebactin. Inability to synthesize of 2, 3-DHBA affects the ability of pathogen to metabolize erythritol, replicate in trophoblast cells and cause abortion in pregnant ruminant host. The entF gene has been implicated in the unresolved pathway allowing brucebactin biosynthesis in Brucella. The research effort presented in this thesis tries to relate the role of entF in iron acquisition and potential relation with erythritol metabolism by wild type B. abortus 2308. An entF deletion mutant (BAN1) of B. abortus 2308, generated using cre-lox methodology was found to be growth inhibited in iron minimal media compared to wild type strain. Growth inhibition was further enhanced with the addition of an iron chelator or 0.1% erythritol. Compared to wild type strain, no growth inhibition of BAN1 mutant was found in murine J774A.1 macrophages, which suggests that Brucella could acquire iron inside mammalian cells. The entF gene complemented mutant strains of BAN1 (BAN2A and BAN2B) were found to be intermediate in their ability to grow in iron minimal media supplemented with 0.0.05% erythritol, when compared to wild type and BAN1 strain. The results from the present thesis demonstrate that entF gene plays an important role in iron acquisition and erythritol metabolism by B. abortus 2308 under iron limiting conditions. / Master of Science
4

Desenvolvimento e avaliação de cheesecake light potencialmente funcional e simbiótico / Development and evaluation of cheesecake light potentially functional and symbiote

Rodrigues, Antonio Carlos 27 February 2014 (has links)
Este trabalho teve como objetivo o desenvolvimento e a avaliação das propriedades funcionais, físico-químicas, reológicas, sensoriais de preferência pareada (do cheesecake e de sua cor) e microbiológica (contagens de coliformes fecais/totais e da bifidobactéria) do cheesecake manufaturado com farinha de trigo (ou amido de milho ceroso modificado), queijo fresco, sacarose, eritritol (como substituinte parcial de sacarose), ovos in natura, manteiga [ou frutoligossacarídeos (FOS) - prebiótico - como substituinte da manteiga], curcumina e Bifidobacterium animalis subespécie lactis BB-12 (probiótico). A análise estatística dos dados considerou a existência quatro grupos experimentais, sendo: [2 cheesecakes lights (em açúcar e gordura) potencialmente funcional e simbiótico: T1= farinha de trigo e FOS; T2 = AMCM e FOS] e [2 cheesecake light (em açúcar) potencialmente funcional e probiótico: T3 = farinha de trigo e manteiga; T4 = AMCM e manteiga]. Foi estabelecido um tratamento T0 como padrão da Tese, adaptado da formulação da QuarkTorte por Henning Fleissig (Alemanha). As variáveis de resposta foram do tipo quantitativa, considerando unidades formadoras de colônias (UFC) de bactérias láteas, unidade formadora de colônias (UFC) de coliformes totais e fecais, pH, atividade da água, dureza, adesividade, elasticidade, coesividade, gomosidade e mastigabilidade. Estas variáveis de respostas compuseram um modelo de Análise de Variância com medidas repetidas, pois as unidades experimentais foram observadas após 1, 8, 15, 22 e 28 dias. Medidas (como médias, medianas e desvio padrão), gráficos e ANOVA, foram geradas pelo pacote estatístico STATA® - versão 9.0. Os resultados da ANOVA não mostraram resultados estatisticamente significativos que indicassem existir diferenças entre os grupos experimentais [p-value: 0,7981; 0,4204; 0,9974; 0,6825; 0,6401; 0,4800; 0,6469; 0,4258; 0,4615] e nem entre os valores ao longo do tempo, dentro de cada grupo experimental [p-value: 0,1725; 0,0000; 0,4076; 0,8957; 0,8787; 0,0001; 0,6214; 0,8845; 0,6820] [p-value correspondentes respectivamente a: log de UFC de bactérias láteas; pH; atividade de água (aw); mastigabilidade; gomosidade; coesividade; elasticidade; adesividade; dureza]. Não houve proteção do probiótico pelo prebiótico, ao nível de FOS utilizado neste estudo. Foram efetuadas análises sensoriais de preferência pareada para o cheesecake (em três tratamentos: T0, T1 e T2) e para sua cor (em três amostras com curcumina a: 0%, 0,0076% e 0,0152%). O resultado para o cheesecake revelou que: a amostra mais preferida foi a T0; os tratamentos T1 e T2 não diferem entre si quanto à preferência; T0 não difere da T2; T0 difere da T1. O resultado para a cor do cheesecake revelou que: a amostra mais preferida foi a com curcumina a 0,0076%; e que as três amostras são iguais quanto à preferência da cor. O presente estudo dá sua contribuição para ampliar a oferta de alimentos láteos promotores da saúde humana com características: light, potencialmente funcional e simbiótico. / The aim of this work was the development and the evaluation of the functionals, physical-chemistry, rheological and sensorial analysis for the pairwise ranking test (cheesecake and its color), and microbiological properties of the cheesecake manufactured with wheat flour (or modified waxy corn starch - AMCM), fresh cheese, sucrose, erythritol (as sucrose partial substitute), eggs in nature, butter [or frutooligosaccharide (FOS) - prebiotic - as butter fat replacer], curcumin and Bifidobacterium animalis subspecies lactis Bb-12 (probiotic). The statistical analysis of the data was considered the existence four experimental groups: [2 cheesecakes lights (in sucrose and fat) potentially functional and symbiote: T1= wheat flour and FOS; T2 = AMCM and FOS] and [2 cheesecake light (in sucrose) potentially functional and probiotic: T3 = wheat flour and butter; T4 = AMCM and butter]. It was established a treatment T0 as the standard Thesis, adapted the wording of QuarkTorte by Henning Fleissig (Germany). The response variables were type of quantitative, whereas colony forming units (CFU) of lactic bacteria, forming unit colonies (CFU) of total and faecal coliforms, pH, water activity, hardness, adhesiveness, elasticity, cohesiveness, gumminess, chewiness. These variables of responses comprised a model of Analysis of Variance with repeated measures, because the experimental units were observed after 1, 8, 15, 22 and 28 days. Measures (such as average, median and standard deviation), graphics and ANOVA, were generated by statistical package STATA® - version 9.0. The results of the ANOVA showed no statistically significant results that indicate differences between the experimental groups [p-value: 0,7981; 0,4204; 0,9974; 0,6825; 0,6401; 0,4800; 0,6469; 0,4258; 0,4615] and not between the values over time, within each experimental group [p-value: 0,1725; 0,0000; 0,4076; 0,8957; 0,8787; 0,0001; 0,6214; 0,8845; 0,6820] [p-value corresponding respectively to: log of UFC of lactic bacteria; pH; water activity (aw); chewiness, gumminess, cohesiveness, elasticity, adhesiveness and hardness]. There was no protection of probiotic by prebiotic, at the level of FOS used in this study. Were made sensorial analysis of paired preference for the cheesecake (In three treatments: T0, T1 and T2) and to its color (in three samples with curcumin: 0%, 0.0076% and 0.0152%). The result for the color of the cheesecake revealed that: the sample most preferred was with curcumin to 0.0076%; and that the three samples are equal as the color preference. The present study gives its contribution to extend the offer of lactic food human health promoters with characteristics: light, potentially functional and symbiote.
5

Porovnání senzorických vlastností džemů slazených steviol-glykosidy a dalšími sladidly

KÜFFNEROVÁ, Nela January 2018 (has links)
The aim of the diploma thesis was evaluation of sensoric attributes of blueberry and current jams sweetened by selected Steviol glycosides and their comparing with other sweeteners. For evaluation of sensoric attributes were used rebaudioside A, stevioside, aspartame, erythritol and sugar beet. Stevia rebaudiana var. Bertoni is a persistent plant, which contains sweetening Steviol glycosides, which have a use in food processing. They are available in the area of EU indicated as E960 since 2011. The most used Steviol glycosides are stevioside and rebaudioside A, which are demarcated with a high sweetness, which could be 200-400 times higher than saccharose. The usage of sweeteners is legislatively allowed, which means it is also allowed to do sensoric analyse and detect perception of added substances in food. These analyses evaluate food with the help of sense - perception. Methodical part of the work contains procedure, used methods for gaining evaluation of data from a sensoric analyse after the degustation of jams, which has taken place with the presence of ten judges - an academic students in the working compartment of University of South Bohemia. Respondents entered their evaluation into protocols, which were prepared in advance. The results of diploma thesis are evaluated by the method of Kramer, which is used for this kind of analyse. The critical scale between 20 and 40 with the value of probability P = 95% was defined according to this method. Evaluation is described with the help of graphs and tables, added with a wordily describtion. Conclusion of analyse of diploma thesis is, that the usage of Steviol glycosides is not most suitable way of sweetening jams. Acceptable valuations of jams containing Steviol glycosides were proven in parameters of colour and aroma. The reasons for less successful evaluation of Steviol glycosides could be due to bad pH of food or badly chosen dosing, without combination of other kinds of sweeteners. The best sensory characteristics traditionally showed sugar beet and aspartame followed by rebaudioside A and stevioside, which were placed on the third and forth place from five used sweeteners. The part of the diploma thesis was an evaluation of questionnaire, where the result was, that asked people preferred fruit ingredient of jams (type of fruit, amount) not their way of sweetening while choosing a jam.
6

Desenvolvimento e avaliação de cheesecake light potencialmente funcional e simbiótico / Development and evaluation of cheesecake light potentially functional and symbiote

Antonio Carlos Rodrigues 27 February 2014 (has links)
Este trabalho teve como objetivo o desenvolvimento e a avaliação das propriedades funcionais, físico-químicas, reológicas, sensoriais de preferência pareada (do cheesecake e de sua cor) e microbiológica (contagens de coliformes fecais/totais e da bifidobactéria) do cheesecake manufaturado com farinha de trigo (ou amido de milho ceroso modificado), queijo fresco, sacarose, eritritol (como substituinte parcial de sacarose), ovos in natura, manteiga [ou frutoligossacarídeos (FOS) - prebiótico - como substituinte da manteiga], curcumina e Bifidobacterium animalis subespécie lactis BB-12 (probiótico). A análise estatística dos dados considerou a existência quatro grupos experimentais, sendo: [2 cheesecakes lights (em açúcar e gordura) potencialmente funcional e simbiótico: T1= farinha de trigo e FOS; T2 = AMCM e FOS] e [2 cheesecake light (em açúcar) potencialmente funcional e probiótico: T3 = farinha de trigo e manteiga; T4 = AMCM e manteiga]. Foi estabelecido um tratamento T0 como padrão da Tese, adaptado da formulação da QuarkTorte por Henning Fleissig (Alemanha). As variáveis de resposta foram do tipo quantitativa, considerando unidades formadoras de colônias (UFC) de bactérias láteas, unidade formadora de colônias (UFC) de coliformes totais e fecais, pH, atividade da água, dureza, adesividade, elasticidade, coesividade, gomosidade e mastigabilidade. Estas variáveis de respostas compuseram um modelo de Análise de Variância com medidas repetidas, pois as unidades experimentais foram observadas após 1, 8, 15, 22 e 28 dias. Medidas (como médias, medianas e desvio padrão), gráficos e ANOVA, foram geradas pelo pacote estatístico STATA® - versão 9.0. Os resultados da ANOVA não mostraram resultados estatisticamente significativos que indicassem existir diferenças entre os grupos experimentais [p-value: 0,7981; 0,4204; 0,9974; 0,6825; 0,6401; 0,4800; 0,6469; 0,4258; 0,4615] e nem entre os valores ao longo do tempo, dentro de cada grupo experimental [p-value: 0,1725; 0,0000; 0,4076; 0,8957; 0,8787; 0,0001; 0,6214; 0,8845; 0,6820] [p-value correspondentes respectivamente a: log de UFC de bactérias láteas; pH; atividade de água (aw); mastigabilidade; gomosidade; coesividade; elasticidade; adesividade; dureza]. Não houve proteção do probiótico pelo prebiótico, ao nível de FOS utilizado neste estudo. Foram efetuadas análises sensoriais de preferência pareada para o cheesecake (em três tratamentos: T0, T1 e T2) e para sua cor (em três amostras com curcumina a: 0%, 0,0076% e 0,0152%). O resultado para o cheesecake revelou que: a amostra mais preferida foi a T0; os tratamentos T1 e T2 não diferem entre si quanto à preferência; T0 não difere da T2; T0 difere da T1. O resultado para a cor do cheesecake revelou que: a amostra mais preferida foi a com curcumina a 0,0076%; e que as três amostras são iguais quanto à preferência da cor. O presente estudo dá sua contribuição para ampliar a oferta de alimentos láteos promotores da saúde humana com características: light, potencialmente funcional e simbiótico. / The aim of this work was the development and the evaluation of the functionals, physical-chemistry, rheological and sensorial analysis for the pairwise ranking test (cheesecake and its color), and microbiological properties of the cheesecake manufactured with wheat flour (or modified waxy corn starch - AMCM), fresh cheese, sucrose, erythritol (as sucrose partial substitute), eggs in nature, butter [or frutooligosaccharide (FOS) - prebiotic - as butter fat replacer], curcumin and Bifidobacterium animalis subspecies lactis Bb-12 (probiotic). The statistical analysis of the data was considered the existence four experimental groups: [2 cheesecakes lights (in sucrose and fat) potentially functional and symbiote: T1= wheat flour and FOS; T2 = AMCM and FOS] and [2 cheesecake light (in sucrose) potentially functional and probiotic: T3 = wheat flour and butter; T4 = AMCM and butter]. It was established a treatment T0 as the standard Thesis, adapted the wording of QuarkTorte by Henning Fleissig (Germany). The response variables were type of quantitative, whereas colony forming units (CFU) of lactic bacteria, forming unit colonies (CFU) of total and faecal coliforms, pH, water activity, hardness, adhesiveness, elasticity, cohesiveness, gumminess, chewiness. These variables of responses comprised a model of Analysis of Variance with repeated measures, because the experimental units were observed after 1, 8, 15, 22 and 28 days. Measures (such as average, median and standard deviation), graphics and ANOVA, were generated by statistical package STATA® - version 9.0. The results of the ANOVA showed no statistically significant results that indicate differences between the experimental groups [p-value: 0,7981; 0,4204; 0,9974; 0,6825; 0,6401; 0,4800; 0,6469; 0,4258; 0,4615] and not between the values over time, within each experimental group [p-value: 0,1725; 0,0000; 0,4076; 0,8957; 0,8787; 0,0001; 0,6214; 0,8845; 0,6820] [p-value corresponding respectively to: log of UFC of lactic bacteria; pH; water activity (aw); chewiness, gumminess, cohesiveness, elasticity, adhesiveness and hardness]. There was no protection of probiotic by prebiotic, at the level of FOS used in this study. Were made sensorial analysis of paired preference for the cheesecake (In three treatments: T0, T1 and T2) and to its color (in three samples with curcumin: 0%, 0.0076% and 0.0152%). The result for the color of the cheesecake revealed that: the sample most preferred was with curcumin to 0.0076%; and that the three samples are equal as the color preference. The present study gives its contribution to extend the offer of lactic food human health promoters with characteristics: light, potentially functional and symbiote.
7

Isolierung von DNA und Konstruktion einer Metagenombank aus dem Sediment des Flusses Leine: partielle Sequenzierung und Annotation des Metagenoms sowie Analyse der mikrobiellen Diversität / Isolation of DNA and construction of a metagenomic library of the River Leine sediment: partial sequencing and annotation of the metagenome and analysis of the phylogenetic diversity

Schmitz, Jessica Estelle 25 January 2005 (has links)
No description available.
8

Structural studies to inform antimicrobial drug discovery and the basis of immunity against T6 effectors

O'Rourke, Patrick January 2013 (has links)
Work presented in this thesis is in two parts. Part one: The X-ray crystal structures of potential antimicrobial drug targets. The protein IspF (2C-methyl-D-erythritol-2,4-cyclodiphosphate synthase, EC: 4.6.1.12) from two pathogens (Burkholderia cenocepacia and Plasmodium falciparum) has been investigated. IspF is an enzyme of isoprenoid-precursor biosynthesis and is considered to be a potential drug target. The results of structural and fragment-screening efforts presented here inform early stage drug discovery efforts. The structure of the PabC protein (4-amino-4-deoxychorismate lyase, EC: 4.1.3.38) from the Gram-negative pathogen Pseudomonas aeruginosa was also determined. PabC is involved in the production of para-aminobenzoic acid on the path to folate. Comparisons with previously solved PabC structures identified a spatially conserved tyrosine residue in the active site and suggest that a re-evaluation of a published mechanism is warranted. Part two: Immunity proteins in the Gram-negative Type VI secretion system. The X-ray crystal structures of the proteins Rap1a and Rap2a from Serratia marcescens, inhibitors of the peptidoglycan amidase toxins secreted by some Gram-negative bacteria employing the Type VI secretion pathway, were determined by molecular replacement and analysed.
9

Selective C-O Bond Hydrogenolysis Of Polyols Over Supported Bi(Metallic) Catalysts In Aqueous Phase / Valorisation d'hémicelluloses en polyols pour la préparation de polyesters ou résines alkydes

Said, Achraf 09 October 2017 (has links)
L'étude a porté sur la conversion en presence de catalyseurs bimétaliques supportes de trois molécules modèles de polyols (érythritol, xylitol et sorbitol) en phase aqueuse à 150-240 ° C sous 30-120 bar de H2 pour obtenir sélectivement des produits linéaires C4, C5 et C6 désoxygénés qui sont des précurseurs de polymèrs. L'activité catalytique dépend fortement de la nature du support utilisé (TiO2 vs ZrO2) et la plus grande sélectivité pour les produits désoxygénés linéaires voulus C4, C5 et C6 à une conversion de 80% est de 71, 66 et 54%, respectivement, en présence de catalyseur mixte à base de rhodium et du rhenium à 200 ° C sous 80-120 bar. Les caractérisations des catalyseurs par chimisorption de CO, MET-EDX, TGA-MS et XPS suggèrent une distribution et une réductibilité différentes des espèces de Re sur les nanoparticules Rh supportées en fonction du support permettant d'expliquer ces différences / The aim of our research project reports a study of heterogeneously catalyzed conversion of three polyol model molecules (erythritol, xylitol, and sorbitol) in aqueous phase at 150-240 °C under 30-120 bar of H2 to obtain selectively linear deoxygenated C4, C5, and C6 products used as precursors for polymer applications. The activity was strongly dependent on the nature of the support (TiO2 vs ZrO2) and the highest selectivity to the desired linear deoxygenated C4, C5, and C6 products at 80% conversion reached 71, 66, and 54%, respectively, in the presence of Rh–ReOx bimetallic catalysts at 200°C under 80-120 bar. The characterizations of the catalysts by CO chemisorption, TEM-EDX, TGA-MS, and XPS suggest a different distribution and reducibility of Re species over the supported Rh nanoparticles depending on the support that can explain these differences
10

Implication de facteurs de transcription de type doigt de zinc et de la famille des WRKY dans la régulation de la voie du MEP et de la biosynthèse des alcaloïdes indoliques monoterpéniques de Catharanthus roseus / Involvment of transcription factors of the zinc finger and the WRKY families in the regulation of the MEP pathway and the MIA biosynthesis in Catharanthus roseus

Chebbi, Mouadh 19 February 2015 (has links)
Les alcaloïdes indoliques monoterpéniques (AIM) sont des molécules à propriétés anti-tumorales extraites de Catharanthus roseus. Leur coût de production et les besoins encore importants de ces médicaments en chimiothérapie, en font des cibles majeures pour la recherche de stratégies de production plus efficaces. L’objectif de ce travail vise à identifier de nouveaux facteurs de transcription (FT) régulateurs de la production des AIM. Cette étude porte plus particulièrement sur la caractérisation fonctionnelle et l’implication dans la régulation de la biosynthèse des AIM, de protéines de la famille des WRKY (CrWRKYs) et des protéines de type doigt de zinc (ZCTs) précédemment isolées au sein de l’EA2106 « Biomolécules et Biotechnologies Végétales ». Nos expériences ont révélé que, parmi ces protéines, CrWRKY22, CrWRKY32, ZCT1 et ZCT2 agissent en tant que facteurs de transcription et plus spécifiquement interagissent avec le promoteur du gène Crhds. Ce dernier code une enzyme de la voie du méthyl érythritol phosphate (MEP) considérée limitante pour la production des AIM. Ces travaux ont permis d’identifier de nouveaux FT ciblant la voie du MEP dont la régulation via les FT est encore peu élucidée à ce jour et d’envisager leur utilisation en ingénierie métabolique pour augmenter la production d’AIM par la modulation du flux terpénique chez C. roseus. / Monoterpene indole alkaloids (MIA) are molecules with anti-cancer properties from Catharanthus roseus. Their production cost and the important need in chemiotherapy make them major targets for the research of more efficient production strategies. The aim of this work is to identify new transcription factors (TF) that regulate MIA production. This study focuses especially on the functional characterization and the involvement in the MIA biosynthesis regulation, of proteins previously isolated in the EA2106 “Plant Biocompounds and Biotechnology” laboratory: 3 proteins that belong to the WRKY family (CrWRKYs) and 3 zinc finger proteins named ZCTs. Our experiments revealed that among them, CrWRKY22, CrWRKY32, ZCT1 and ZCT2 act as transcription factors and more specifically interact with the promoter of Crhds gene. Crhds encodes an enzyme of the methyl erythritol phosphate (MEP) pathway that is considered as limiting for MIA production. Our work allowed identifying new TFs targeting the MEP pathway those regulation through TFs is mostly unknown. Using such transcription factors in metabolic engineering could be now considered increasing MIA production by the modulation of terpenoid flux in C. roseus.

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