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ALENCAR, Suelene Suassuna Silvestre de. "Translocação e bactérias marcadas com 99m técnécio na icterícia obstrutiva experimental em ratos". Universidade Federal de Pernambuco, 2001. https://repositorio.ufpe.br/handle/123456789/19708.
Pełny tekst źródłaMade available in DSpace on 2017-07-17T14:33:58Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Dissertação de Mestrado - Suelene Suassuna Silvestre Alencar.pdf: 1698152 bytes, checksum: 7bc449edbb1386a1875057dc6f3f376f (MD5) Previous issue date: 2001-01-10
Estudo realizado com o objetivo de avaliar a translocação bacteriana (TB) do trato gastrointestinal para órgãos viscerais em ratos submetidos à ligadura do ducto colédoco e submetidos à administração por via oral (gavagem) de E.coli marcada com 99mTecnécio (99mTc-E.coli). Quatro grupos de ratos foram estudados: grupo I (n=10) ligadura do colédoco, grupo II (n=10) controle ou “sham operation”, grupo III (n=12) ligadura do colédoco e gavagem com 99mTcE.coli e grupo IV (n=5) controle ou “sham operation”e gavagem com 99mTc-E.coli. Usando técnica asséptica e sob anestesia, os ratos foram submetidos à laparotomia. Nos ratos dos grupos I e III realizou-se ligadura do colédoco com fio de seda nº 3 zeros e nos ratos dos grupos II e IV apenas manipulação do colédoco com pinça de Adison (sham operation). Após sete dias de observação, os animais dos grupos I e II foram mortos e ressecados fígado, baço, linfonodos mesentéricos e pulmões para exame microbiológico (meios Agar-sangue e Agar Mac Conkey) e exame histopatológico (coloração H.E. e Tricrômico de Masson) por análise morfométrica. O nível de bilirrubina nos grupos ictéricos foi elevado em relação aos do grupo controle. A incidência de bactérias translocadas foi maior no grupo I comparada ao controle p 0,05. Nos animais dos grupos III e IV, após sete dias de observação, foi administrada por via oral (gavagem) 99mTcE.coli e após 24 Hs, os ratos de ambos os grupos foram mortos e seus órgãos retirados para contagem da radioatividade em cintilador gama. Os resultados não mostraram diferença estatisticamente significativa na captação da -E.coli entre os dois grupos (p 0,05). Porém a análise das interações grupo x órgão mostrou diferença entre os grupos ictérico e controle para os órgãos: fígado e pulmão. Os dados disponíveis permitem concluir que em ratos ictéricos por ligadura do colédoco ocorreu translocação de bactérias detectáveis por exame microbiológico. Não ocorreu translocação de bactérias com 99mTc no modelo proposto.
This study was designed to evaluate the bacterial translocation (TB) from the gastrointestinal tract to visceral organs in rats submitted to laparotomy and common bile duct ligation (CBDL). Four groups of rats were studied: group I (n = 10) CBDL; group II (n=10) control or “sham operation”; group III (n= 12) CBDL and 99mTc-E.coli and group IV (n=5) control or “sham operation” e 99mTc-E.coli. All the animals were operated with aseptic technic under intraperitoneal anesthesia with pentobarbital sodium (200mg/Kg). On 7th postoperative day the animals of groups I and II were killed with a letal dosis of anesthetic and the liver, spleen, mesenteric lynfonodes and lungs were ressecated to microbiological (Agar-blood and Agar-Mac Conkey) and histological examination (H.E. and Masson Trichromic) through morphometric analysis. On 7th postoperative day the animals of III and IV groups were submitted to 99mTc-E.coli gavage and after 24 hr they were killed and their organs were ressected. After that, the bacterial radioactivity was mensured through an Automatic count of Gama Radioative – model ANSR (Abott Laboratories). The bilirrubin levels of the jaundiced rats were elevated compared with the control groups. The incidence of bacterial translocation was higher in group I compared with control group (p 0,05). The results showed no significant differences among the jaundiced and control groups to the liver and lungs. The data allow to conclude that in jaundiced rat with ligated bile duct occurred bacterial translocation through microbiological analyses. The model proposed showed no bacterial translocation by the labeled 99mTc technic.
Aoyama, Takashi. "Essential Structure of E.coli Promoter". 京都大学 (Kyoto University), 1987. http://hdl.handle.net/2433/86456.
Pełny tekst źródłaHarrington, Lesley. "Genes controlling anaerobic metabolism in E.coli". Thesis, Imperial College London, 1988. http://hdl.handle.net/10044/1/40623.
Pełny tekst źródłaHolmström, Emelie. "Ni (II) absoption with recombinant E.coli". Thesis, KTH, Skolan för bioteknologi (BIO), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-149310.
Pełny tekst źródłaRen, Xiaojing, i 任晓晶. "Modeling pattern formation of swimming E.coli". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B43704001.
Pełny tekst źródłaLee, Hoyoung. "Evolution of macrolide antibiotics in E.coli /". May be available electronically:, 2008. http://proquest.umi.com/login?COPT=REJTPTU1MTUmSU5UPTAmVkVSPTI=&clientId=12498.
Pełny tekst źródłaRen, Xiaojing. "Modeling pattern formation of swimming E.coli". Click to view the E-thesis via HKUTO, 2010. http://sunzi.lib.hku.hk/hkuto/record/B43704001.
Pełny tekst źródłaNeelakanta, Girish. "Genome variations in commensal and pathogenic E.coli". [S.l. : s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=974330329.
Pełny tekst źródłaBarbosa, Joana Cristina Pacheco. "Lichenicidin: regulation, expression and bioengineering in E.coli". Master's thesis, Universidade de Aveiro, 2012. http://hdl.handle.net/10773/9548.
Pełny tekst źródłaA lichenicidina e um lantibiotico de classe II, naturalmente produzido por B. licheniformis I89. E constituida por dois peptidos denominados Blia e Blib. Este lantibiotico foi o primeiro a ser expresso completamente in vivo num hospedeiro Gram negativo (Escherichia coli). Neste trabalho, pretendeu-se avaliar o impacto da proteina LicR na biossintese da lichenicidina usando um sistema de expressao heterologa em E. coli. A estirpe de E. coli que nao contem o gene licR parece apresentar uma maior producao de lichenicidin do que a estirpe que contem todo o conjunto de genes envolvidos na sintese da lichenicidin. Assim, LicR parece nao apresentar qualquer funcao regulatoria em E. coli ou esta nao podera ser descrita segundo os mecanismos habituais de regulacao da producao de lantibioticos. Paralelamente um sistema de expressao foi construido para produzir cada um dos peptidos da lichenicidina separadamente, tendo sido comparados os niveis de producao de cada um dos peptidos. Este sistema foi usado com sucesso para produzir o peptido BliƒÀ mas nao apresentando qualquer vantagem sobre os sistemas ao nivel da producao. Finalmente, uma biblioteca de mutagenese do peptido Bliƒ¿ foi construida em E. coli e os clones obtidos foram analisados; a maioria dos clones obtidos apresentou bioatividade reduzida ou nula contra Micrococcus luteus. Alguns destes clones foram sequenciados para determinar qual(ais) a(s) mutacao(oes) presente(s) no gene licA1.
Lichenicidin is a class II lantibiotic, naturally produced by Bacillus licheniformis I89 strain. It is composed by two peptides: Bliα and Bliβ. This was the first lantibiotic to be fully produced in vivo using a Gram negative host (Escherichia coli). Herein, the impact of LicR protein in lichenicidin biosynthesis was assessed, using an E. coli heterologous expression system. It was shown that the E. coli strain without the licR gene presented increased lichenicidin production, when compared with the strain containing the entire gene cluster. Thus, if LicR presents some regulatory function in E. coli, its role cannot be described according to the usually proposed regulation mechanisms involved in lantibiotic production. Also, an expression system was constructed to produce each lichenicidin peptide independently and this expression system was compared with other available systems in terms of production levels. The system was successfully used to obtain Bliβ peptide. However it did not show any advantage over the systems previously developed. Ultimately, a mutagenesis library of Bliα was constructed in E. coli and the clones were analyzed; the majority of the clones showed low or null bioactivity against Micrococcus luteus. Some of these clones were sequenced to determine which mutation(s) was present in the licA1 gene.
Green, Andrew. "The impact of combined sewer overflow removal on the environmental status of a small urban watercourse (Pymme's Brook, North London)". Thesis, University of Hertfordshire, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.323428.
Pełny tekst źródłaFeng, Mei. "Physiological state specific modelling of recombinant E.coli fermentations". Thesis, University of Newcastle Upon Tyne, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.394639.
Pełny tekst źródłaMacpherson, Cindy Josephine. "Plasmid-mediated regulation of the E.coli cell cycle". Thesis, University of Cambridge, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.624602.
Pełny tekst źródłaZahra, Rabaab. "CAG.CTG trinucleotide repeat instability in the E.coli chromosome". Thesis, University of Edinburgh, 2006. http://hdl.handle.net/1842/11667.
Pełny tekst źródłaEriksson, Jenny, Sofia Fasth, Cecilia Orrenius, Plavsic Milica, Andersson Linnéa Yuan i Marcus Westholm. "Goodbye E.coli : Alternativa endotoxinfria produktionssystem till Escherichia coli". Thesis, Uppsala universitet, Institutionen för biologisk grundutbildning, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-411969.
Pełny tekst źródłaMilunov, Dimitrije. "External real time control of E.coli range expansion". Electronic Thesis or Diss., Université Paris Cité, 2023. http://www.theses.fr/2023UNIP7078.
Pełny tekst źródłaAdvances in microfluidics, sensory technology and synthetic and molecular biology enabled the rise of a novel scientific field in which fundamentals of control theory can be applied to externally control and regulate cellular bioprocesses-cybergenetics. So far, cybergenetics was able to successfully control complex multi-stable and adaptive gene networks at the population and the single cell level, but challenges in the control of biological multiagent-like system composed of multiple interactive components have not yet been addressed. In this study we focused on dense biofilm like colonies of E.coli which were grown inside the multilayered microfluidic device whose geometry enabled the growth of the colonies in one direction. Similarly to biofilms, it is widely known that dense E.coli colonies exhibit remarkable levels of spatial organization that come as a consequence of the complex interplay between nutrient and chemical gradients and metabolic interactions between different layers of the colony. These interactions make both dense colonies and biofilms more resistant to antimicrobial agents treatment consequently making them difficult to eradicate. Thus can we and at which extent we could externally control this system remains an open question. To answer this we firstly quantitively analyzed the growth patterns inside the colony to understand the dynamics of the system. We used three different strategies to perturb the colony and to see the impact on the spatial growth patterns - modulation of RNA polymerase by inducible promoter and biochemical modulation of the cellular resources by nutrient change and antibiotics. Since the cells were nonmotile, the invasion speed of the colony could be regarded as a global descriptor of the colony spatial growth dynamics. Thus having this in mind we finally used the understanding of the systems dynamics, knowledge of colonies response to various stimulus and a custom made control platform to externally control the invasion speed of the colony
Molle, Virginie. "The whiD and bldM loci of Streptomyces coelicolor A3(2)". Thesis, University of East Anglia, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327448.
Pełny tekst źródłaDurany, Türk Olga. "Producció de Fuculosa-1-Fosfat aldolasa recombinant en E.coli". Doctoral thesis, Universitat Autònoma de Barcelona, 2003. http://hdl.handle.net/10803/5302.
Pełny tekst źródłaEl projecte en que s'emmarca aquesta tesi aposta per l'estudi d'aquest grup de biocatalitzadors i pretén contribuir al desenvolupament pràctic de les aldolases centrant-se en els aspectes de producció dels enzims i en el desenvolupament de metodologia per a la seva utilització en síntesi quiral.
En aquesta memòria de tesi doctoral s'estudia la millora de producció de l'aldolasa Fuc-1-PA en E.coli, com enzim model d'aquesta família d'aldolases depenents de DHAP. L'objectiu és definir un procés optimitzat i reproduïble per a la seva obtenció a escala productiva. Amb aquest objectiu global, es consideren els principals aspectes que condicionen la sobreexpressió de proteïnes recombinants E.coli. Primer, s'estudia la influència de la composició del medi de cultiu en el creixement i sobreexpressió recombinant. Segon, es treballa en el desenvolupament d'una estratègia de cultiu semicontínua adequada per assolir cultius d'alta densitat cel.lular de forma reproduïble. Un cop fixades les condicions d'operació per al creixement segons aquesta estratègia semicontínua, és possible definir els criteris d'inducció per maximitzar la producció de Fuc-1-PA al procés. Finalment, s'aborda la millora genètica del procés provant un nou sistema d'expressió recombinant desenvolupat pensant en la seva aplicació a escala de producció.
Nowadays, a considerable number of wild-type enzymes catalazing formation of stereo chemically defined C-C bond as natural function have been discovered. These enzymes have opened new possibilities in quiral chemistry field as they could mean a solution for problems impossible to be solved right now with conventional organic chemistry alternatives. These enzymes are, basically, aldolases and transketolases. It is important to point here out that it is known a four members DHAP dependent aldolases family which is able to catalyze the formation of a new C-C bond which results in the formation of two new quiral centers with complementary and perfectly defined stereochemistry. Hanging on the aldolase employed in the new C-C bond synthesis it is obtained specifically one of the four possibles diastereoysomers. This family has been considered really interesting as synthetic tool.
The project this thesis work is related to, is focused on the study of these biocatalyzers group and its main goal is the practical knowledge of aldolases: learn new techniques for maximize their production and make it possible their final application as quiral synthetic tools.
In this work, improvements in Fuculose-1-phosphate aldolase production are studied, as enzyme model of this four members family. The final goal fixed for this work is define a optimizated and reproducible process for its production at industrial scale. To obtain this final goal, here are studied the most important points affecting recombinant proteins production in E. coli. First, study of growth media composition influence in growth and recombinant overexpression. Second, search of a new semi-continues fermentation strategy which allows obtain high cell density cultures in a reproducible way. Once, growth conditions have been fixed related to this new semi continues fermentation strategy, it is possible to work on induction criteria definition in order to maximize Fuc-1-FA production. Finally, work has been focused on genetic improvement of the process. We have tested a new recombinant expression system for industrial scale application: ORT expression System.
Elderkin, Sarah Louise. "Functional analysis of the E.coli phage shock protein PspA". Thesis, Imperial College London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.407101.
Pełny tekst źródłaFox, Simon George. "Expression of catalytic antibody C3 esterase scFv in E.coli". Thesis, University College London (University of London), 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.322119.
Pełny tekst źródłaDuboff, James Steven. "The role of indole in plasmid replication in E.coli". Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.607877.
Pełny tekst źródłaWarner, Stuart A. "Roles of recombination in trinucleotide repeat instability in E.coli". Thesis, University of Edinburgh, 2002. http://hdl.handle.net/1842/13211.
Pełny tekst źródłaAlmeida, Diana Margarida Silva. "Contaminação microbiológica de alimentos : o caso particular de E.coli". Master's thesis, Universidade de Aveiro, 2013. http://hdl.handle.net/10773/11459.
Pełny tekst źródłaQuando alimentos contaminados por Escherichia coli (E. coli) são ingeridos, podem manifestar-se várias doenças provocadas pela bactéria ou por toxinas por ela produzidas. Para além de poder constituir uma ameaça à saúde do consumidor, a presença de E. coli em alimentos pode ser indicativa de contaminação fecal e de processos de higienização inadequados. Pelas suas características nutricionais, pH e água disponível, a carne picada é um alimento particularmente suscetível a contaminação microbiológica, principalmente pela bactéria E. coli. Devido a este facto, é exigido por decreto-lei descrito na Portaria 699:2008 “Ministérios da economia e da inovação e da agricultura, do desenvolvimento rural e das pescas”, que os estabelecimentos comerciais de venda de carnes realizem mensalmente ensaios de enumeração desta bactéria em amostras de carne picada, devendo ser avaliadas 5 amostras por cada estabelecimento. De acordo com esta legislação, o conjunto das amostras é considerado insatisfatório se alguma delas apresentar concentrações de E. coli superiores a 5,0 x 102 UFC/g ou se mais do que 2 amostras apresentarem concentrações entre 5,0 x 101 e 5,0 x 102 UFC/g. Desta forma, numa primeira parte do trabalho do presente estágio (que englobou o período de outubro de 2012 a maio de 2013), foi feita uma avaliação da incidência de E. coli em carnes picadas provenientes de 22 talhos diferentes, da região de Aveiro, no período de julho de 2011 a fevereiro de 2013. No conjunto dos 22 talhos, foram encontrados níveis da bactéria E. coli em não conformidade com a legislação vigente em 25% das avaliações mensais das amostras de carne picada. Em 2 dos 22 talhos, foi verificado um número máximo de 9 meses em que as amostras apresentaram resultados insatisfatórios, enquanto em apenas um talho foi verificada a conformidade das amostras em todos os meses considerados neste estudo. Nos vários estabelecimentos, em cada mês considerado, foram verificadas apenas algumas correlações entre valores indicativos de higienização inadequada de superfícies e manipuladores, e amostras de carne picada em não-conformidade. Tal averiguação é indicativa de que a maioria das contaminações tem origem em processos anteriores à chegada da carne ao estabelecimento, como o processo de abate dos animais, processamento das carcaças e/ou aplicação de temperaturas inadequadas durante o armazenamento e transporte da carne. Uma segunda parte do trabalho no laboratório YourLAB Segurança Alimentar consistiu em avaliar a presença de microrganismos indicadores e microrganismos patogénicos, em alimentos confecionados e frescos, recolhidos entre julho de 2011 e fevereiro de 2013 em diversos estabelecimentos distintos. Não foram detetados microrganismos patogénicos nas amostras de refeições e produtos alimentares analisados, com as exceções de uma amostra de requeijão em que foi detetada e confirmada a presença de Salmonella spp, e de algumas das amostras analisadas ao longo do período considerado, em que foi detetada a presença de esporos de Clostridium sulfito-redutores. Destas últimas amostras fazem parte produtos confecionados como um pastel bola de Berlim e frango estufado com batata e legumes, e produtos frescos, ou ainda crus, como croissants de ovo e de chocolate congelados. Relativamente a microrganismos indicadores, foram encontradas algumas amostras (de produtos confecionados e produtos frescos) insatisfatórias de acordo com os valores guia publicados em Portugal, pelo Instituto Nacional de Saúde de Dr. Ricardo Jorge, podendo indicar a ocorrência de contaminação fecal, uma confeção inadequada do produto, e/ou uma contaminação pós-confeção.
When food contaminated with Escherichia coli (E. coli) is ingested, several diseases caused by the bacteria itself or by the toxins it produces may occur. Moreover, the presence of E. coli in foods may be indicative of inadequate hygiene processes. Minced meat is particularly susceptible to microbiological contamination by E. coli, due mostly to their available nutrients and water, and aw. Therefore, the Portuguese law expressed in Portaria 699:2008 – “Ministérios da economia e da inovação e da agricultura, do desenvolvimento rural e das pescas”, requires the enumeration of this bacteria in 5 samples of minced meat, each month, in each commercial establishment. Accord to this law, the samples are in non compliance if more than two samples exhibit a concentration of E. coli between 5,0 x 101 e 5,0 x 102 CFU/g, or if any sample exceed the value 5,0 x 102 CFU/g. In the first part in this study, an assessment of the incidence of E. coli in minced meat was carried out for 22 different butchers, in the Aveiro region, from July of 2011 to February of 2013. Considering all collection sits, 25% of the samples have shown to be in non-compliance with current legislation. The number of occurrences of non-conforming minced meat samples reached a maximum of 9 in 2 of the 22 the butchers, whereas only one butcher showed all results satisfactory during the study period. The possibility of unacceptable values of E. coli in ground beef correlated with unsatisfactory values in surface and handlers swabs (indicative of poor sanitation) was investigated, but found not the be the case. This finding is indicative that most of the contamination originates in processes prior to the arrival of the meat at the butcher store, like the process of slaughter and application of inappropriate temperatures during storage and transportation of meat. A second part of the study work carried out in the laboratory YourLAB S. A., consisted in the assessment of the indicator microorganisms incidence and the presence of pathogenic microorganisms in several types of fresh and cooked food samples, collected in various commercial establishments between July 2011 and February of 2013. No pathogens were detected in meal and other food samples, with the exceptions of one sample of cottage cheese in which was confirmed the presence of Salmonella spp. and the presence of sulphite-reducing Clostridium spores in some samples over the period considered. Those samples included cooked products like a cake “bola de berlim” and stewed chicken with potatoes and vegetables, and fresh products such as frozen croissants. Unsatisfactory values of indicator microorganisms were found in some samples of both cooked and fresh products, according to the table of guide values published in Portugal, by the “Instituto Nacional de Saúde Dr. Ricardo Jorge”, indicating fecal contamination, inadequate cooking or a post-processing infection.
Sjöberg, Gustav. "MFA för att öka produktiviteten av 3HB av rekombinant E.coli". Thesis, KTH, Skolan för bioteknologi (BIO), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-163703.
Pełny tekst źródłaBalbi, Kevin Jon. "Patterns of short-term genome evolution in E.coli and Shigellae". Thesis, University of Bath, 2009. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.512374.
Pełny tekst źródłaLoftus, Katherine Marie. "Studies of the Structure and Function of E.coli Aspartate Transcarbamoylase". Thesis, Boston College, 2006. http://hdl.handle.net/2345/580.
Pełny tekst źródłaE.coli Aspartate transcarbamoylase (ATCase) is the allosteric enzyme that catalyzes the committed step of the de novo pyrimidine biosynthesis pathway. ATCase facilitates the reaction between L-aspartate and carbamoyl phosphate to form N-carbamoyl-L-aspartate and inorganic phosphate. The holoenzyme is a dodecamer, consisting of two trimers of catalytic chains, and three dimers of regulatory chains. ATCase is regulated homotropically by its substrates, and heterotropically by the nucleotides ATP, CTP, and UTP. These nucleotides bind to the regulatory chains, and alter the activity of the enzyme at the catalytic site. ATP activates the rate of ATCase's reaction, while CTP inhibits it. Additionally, UTP and CTP act together to inhibit the enzyme synergistically, each nucleotide enhancing the inhibitory effects of the other. Two classes of CTP binding sites have been observed, one class with a high affinity for CTP, and one with a low affinity. It has been theorized that the asymmetry of the binding sites is intrinsic to each of the three regulatory dimers. It has been hypothesized that the second observed class of CTP binding sites, are actually sites intended for UTP. To test this hypothesis, and to gain more information about heterotropic regulation of ATCase and signal transmission in allosteric enzymes, the construction of a hybrid regulatory dimer was proposed. In the successfully constructed hybrid, each of the three regulatory dimers in ATCase would contain one regulatory chain with compromised nucleotide binding. This project reports several attempts at constructing the proposed hybrid, but ultimately the hybrid enzyme was not attained. This project also reports preliminary work on the characterization of the catalytic chain mutant D141A. This residue is conserved in ATCase over a wide array of species, and thus was mutated in order to ascertain its significance
Thesis (BS) — Boston College, 2006
Submitted to: Boston College. College of Arts and Sciences
Discipline: Chemistry
Discipline: College Honors Program
Лохматова, Т. М., Р. П. Боровик i О. В. Чеботар. "Чутливість музейного штаму E.coli до комбінацій антимікробних засобів з емоксипіном". Thesis, Сумський державний університет, 2016. http://essuir.sumdu.edu.ua/handle/123456789/45033.
Pełny tekst źródłaSi, Yang. "Fluorescent Nanomaterials for Bioimaging and Biosensing : Application on E.coli Bacteria". Thesis, Cachan, Ecole normale supérieure, 2015. http://www.theses.fr/2015DENS0038/document.
Pełny tekst źródłaBacteria are the most abundant organisms in the world. Investigations and studies on bacteria can be beneficial to medical research, water resources research and food industry. Fluorescent sensing and labeling are commonly used for bioanalytical purposes. In the quest for very bright and stable labels, novel polymer-based, self-stabilized, fluorescent nanoparticles (FNPs, 60 nm) and fluorescent polymer chains (FPCs, 5 nm) have been developed. In the first part, a methodology to insert these FNPs into E.coli bacteria was developed. To control if the FNPs are indeed internalized, we developed a protocol based upon FNPs luminescence quenching by methylene blue. In the second part, a "sandwich" system is built. By using a streptavidin-biotin link, a bridge between particles (FNP), specific antibodies and bacteria is built. SPR, fluorescent images and SEM images demonstrated the interaction of biotin conjugated FNPs with E.coli bacteria. In the third part, interactions of fluorescent polymer chains with bacteria are investigated. Green fluorescent polymer chains (GFPCs) can easily enter into E.coli bacteria. GFPCs can label the cytoplasm but not the DNA. Red fluorescent polymer chains (RFPCs) can label the membrane of E.coli bacteria easily and efficiently. Both FPCs are highly water-soluble, bright and non-toxic, they are novel fluorescent labels for internal and external biological labeling of bacteria. In the last part, it is demonstrated that pH sensitive FANPs can be used to measure the growth of E.coli. They detect rapidly and accurately bacterial growth by signaling the change of pH resulting from cellular metabolism. Moreover, these particles allow for continuous monitoring a large number of samples for high-throughput screening applications. The studied fluorescent nanomaterials are promising tools for biosensing and bioimaging applications due to their brightness, high photostability and rich functionalisation ability
Burger, Adélle. "The E.coli RNA degradosome analysis of molecular chaperones and enolase". Thesis, Rhodes University, 2010. http://hdl.handle.net/10962/d1004009.
Pełny tekst źródłaCassels, Eoin. "Characterisation of the E.coli and Pseudomonas aeruginosa TolA-TolB interaction". Thesis, University of York, 2012. http://etheses.whiterose.ac.uk/3890/.
Pełny tekst źródłaGarrido, Franco Marta. "Structural and functional studies of pyridoxine 5'-phostate synthase from e.coli". Doctoral thesis, Universitat Autònoma de Barcelona, 2002. http://hdl.handle.net/10803/3469.
Pełny tekst źródłaCon el uso de un derivado de mercurio fue posible el resolver la estructura cristalina de la enzima de E. coli por el método del "single isomorphous replacement with anomalous scattering" y el refinar la estructura a 2.0 Å de resolución. El monómero corresponde al plegamiento TIM o barril (_/_)8, con la incorporación de tres hélices extra que median los contactos entre intersubunidades en el octámero. El octámero representa el estado fisiológicamente relevante, que fué observado tanto en el cristal como en solución, y que esta organizado como un tetrámero de dímeros activos. La caracterización de la estructura cristalográfica de la enzima con sustratos, análogos de sustrato y productos unidos permitió la identificación del centro activo y la propuesta de un mecanismo detallado. Los rasgos catalíticos más remarcables son: (1) el cierre del centro activo una vez se han unido los sustratos, de manera que el bolsillo de unión queda aislado del solvente y los intermediarios de la reacción quedan así estabilizados; (2) la existencia de dos sitios de unión de fosfato bien definidos; (3) y un canal de agua que penetra el núcleo del barril _ y permite liberar las moléculas de agua formadas durante la reacción.
La cantidad de información presentada debería permitir el diseño de inhibidores de la piridoxina 5'-fosfato sintasa basados en su estructura. Es interesante el destacar que entre las bacterias que contienen el gen pdxJ se encuentran unos cuantos patógenos bien conocidos. La resistencia de bacterias contra antibióticos está aumentando cada vez más, hecho que se está convirtiendo en un auténtico problema. Por este motivo, es necesario el desarrollar medicamentos antibacterianos con un alto grado de especificidad y la piridoxina 5'-fosfato sintasa parece ser una diana muy prometedora.
Pyridoxal 5'-phosphate is the biocatalytically active form of vitamin B6, being one of nature's most versatile cofactors that plays a central role in the metabolism of amino acids. Whereas microorganisms and plants can synthetise vitamin B6 de novo, mammals have to obtain one of the B6 vitamers with their diet. The Escherichia coli biosynthetic machinery is the, by far, best characterised and it consists in four pdx proteins. PdxJ, also referred to as pyridoxine 5'-phosphate synthase, is the key enzyme in this pathway. It catalyses the last step, the complicated ring-closure reaction between 1-deoxy-D-xylulose-5-phosphate and aminoacetone-3-phosphate yielding pyridoxine 5'-phosphate. Sequence comparison of PdxJ from different species revealed a remarkable high degree of conservation indicating the paramount physiological importance of this enzyme.
With the use of one mercury heavy-atom derivative, it was possible to solve the crystal structure of the E. coli enzyme by the single isomorphous replacement method with anomalous scattering and to refine the structure at 2.0 Å resolution. The monomer folds as a TIM or (_/_)8 barrel, with the incorporation of three extra helices that mediate intersubunits contacts within the octamer. The octamer represents the physiological relevant state that was observed in the crystal and in solution, and that is organised as a tetramer of active dimers. Characterisation of the enzyme crystal structure with bound substrates, substrate analogues, and products allowed the identification of the active site and the proposal of a detailed reaction mechanism. The most important catalytic features are: (1) active site closure upon substrate binding, in order to isolate the specificity pocket from the solvent und thus stabilise the reaction intermediates; (2) the existence of two well-defined phosphate binding sites; (3) and a water channel that penetrates the _ barrel core and allows the release of waters in the closed state.
The amount of information here presented should permit the structure-based design of pyridoxine 5'-phosphate synthase inhibitors. Interestingly, among bacteria that contain the pdxJ gene there are several well-known pathogens. More and more, the bacterial resistance against antibiotics is increasing and therefore becoming a real problem. Thus, it is necessary the development of highly specific antibacterial drugs and pyridoxine 5'-phosphate synthase seems to be a promising novel target.
Schmidt, Bastian. "Veränderungen im LPS-Muster von E.coli Shigella durch cld pHS_-1tn2". [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=980061172.
Pełny tekst źródłaGudzuhn, Andrej. "Virulenzfaktoren von E.coli aus gewaschenen Kolonbiopsien von Patienten mit kolorektalen Neoplasien". [S.l.] : [s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=972574433.
Pełny tekst źródłaOdeyemi, Babatunde O. "Hydrodynamic cavitation : effects of cavitation on inactivation of Escherichia coli (E.coli)". Thesis, Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/11009.
Pełny tekst źródłaBartolo, Natalie Di. "In vitro folding and assembly of the E.Coli ABC transporter BTUCD". Thesis, University of Bristol, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.492472.
Pełny tekst źródłaBruneaux, Luke Julien. "Multiple Unnecessary Protein Sources and Cost to Growth Rate in E.coli". Thesis, Harvard University, 2013. http://dissertations.umi.com/gsas.harvard:11041.
Pełny tekst źródłaPhysics
Lim, Ping Ping. "Structure-function analysis of the #beta# subunit of E.coli RNA polymerase". Thesis, University of Nottingham, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.306106.
Pełny tekst źródłaGokce, Isa. "Expression of CFTR and its transmembrane domains in E.coli and yeast". Thesis, University of Newcastle Upon Tyne, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299633.
Pełny tekst źródłaLiang, Yi. "Studies of E.Coli YIDC and other factors for membrane protein insertion". The Ohio State University, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=osu1110228536.
Pełny tekst źródłaGudzuhn, Andrej. "Virulenzfaktoren von E.coli aus gewaschenen Kolonbiopsien von Patienten mit kolorektalen Neoplasien". Doctoral thesis, Humboldt-Universität zu Berlin, Medizinische Fakultät - Universitätsklinikum Charité, 2004. http://dx.doi.org/10.18452/15059.
Pełny tekst źródłaBackground: Pathogenesis of non-hereditary colorectal neoplasia is poorly understood. The differences in regional incidence indicate an influence of environmental factors, as socio-economic conditions, nutrition and intestinal flora. An intracellular flora with a predominance of Escherichia coli in colon biopsies has been described in these patients. Methods: We studied virulence factors of Escherichia coli isolated from washed colonoscopic biopsies of 43 patients with colorectal carcinoma and adenoma. 100 strains of E.coli were isolated and used for detection of a broad range of virulence genes by PCR encoding: s-fimbriae (sfa), pyelonephritis-associated pili (pap), hemolysin A (hlyA), heatstable and heatlable toxins (ST, LT, EAST), verotoxin (stx), invasionplasmidantigen (ipaH), intimin (eae), cytolethal distending toxin (cdt) and cytotoxic necrotizing factor 1 (cnf1). E.coli from biopsies of 55 patients with inflammatory bowel disease (IBD) and non-specific colitis, of 16 patients with irritable bowel syndrom (IBS) and from stool samples of 29 healthy individuals were isolated and examined as controls. Results: The prevalence of virulent strains bearing at least one of the tested genes was 69% in colorectal carcinoma and 58% in colorectal adenoma, but only 25 to 39% of IBD and IBS patients and healthy individuals (p
Schmidt, Bastian. "Veränderungen im LPS-Muster von E.coli Shigella durch cld pHS-2". Doctoral thesis, Humboldt-Universität zu Berlin, Medizinische Fakultät - Universitätsklinikum Charité, 2006. http://dx.doi.org/10.18452/15463.
Pełny tekst źródłaIn nine out of fourteen serogroups of E. Coli Flexneri (SF) a pHS-2 plasmid has been isolated. There is a positive correlation between pHS-2-positive SF and the occurence of reactive arthritis (ReA) which is a complication of bacterial dysentery. Different authors reduce the widespread appearance of ReA by pHS-2-positive SF to an increased serum resistance caused by a cld(pHS-2)-gene. The cld(pHS-2)-gene ist the longest of 18 open reading frames in pHS-2 and it is the coding for a 35 kD protein which has been identified as a chain length determinant because of its function. Cld(pHS-2) plays a decisive role in the production of lipopolysaccharides (LPS) of the VL-type. LPS of the VL-type produce O antigen with more than 70-80 repeat units, and protect the bacterial outer membrane from complement factors and serum antibodies by a higher serum resistance. In this research the cld(pHS-2)-gene was integrated in a pHS-2-negative SF serogroup 6 to prove that cld(pHS-2) is able to modify the LPS pattern (destribution) of pHS-2-negative SF in a characteristic manner. The expression of cld(pHS-2) in SF serogroup 6 as an isolated protein failed, but the expression of cld(pHS-2) as a fusion protein was successful. In contrast to the pHS-2-negative SF our SF serogroup 6 mutant was able to produce LPS of the VL-type with 80-90 repeat units. Despite the slight effect, a specific influence of cld(pHS-2) as a fusion protein on LPS pattern and the bacterial phaenotype has to be confirmed.
Camilleri, Raymond Stephen. "Molecular genetic and biochemical studies of the D1-processing protease of Arabidopsis Thaliana". Thesis, Royal Holloway, University of London, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.322223.
Pełny tekst źródłaScott, Christopher John. "Investigation of expression methodologies for the dissection of the catalytic mechanism of interleukin-1#beta#-converting enzyme". Thesis, Queen's University Belfast, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.325991.
Pełny tekst źródłaMesquita, M. M. F. "Bacterial and bacteriophage investigations using the mussel Mytilus edulis". Thesis, University of Newcastle Upon Tyne, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380755.
Pełny tekst źródłaChapman, Peter Alan. "Purification of the verotoxins of Escherichia coli and production of antitoxins for use in a diagnostic test". Thesis, University of Sheffield, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244433.
Pełny tekst źródłaCasadei, Maria Aurelia. "The effect of high hydrostatic pressure on Escherichia coli membrane structure and function". Thesis, University of Reading, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312583.
Pełny tekst źródłaJin, Kai. "Studies of the scale-up of production and recovery of recombinant proteins formed as inclusion bodies". Thesis, University College London (University of London), 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324597.
Pełny tekst źródłaBaker, Karen Anne. "Mechanisms of protein translocation in Escherichia coli". Thesis, University of Leicester, 1987. http://hdl.handle.net/2381/34434.
Pełny tekst źródłaSaviolli, Juliana Yuri. "Pesquisa e Caracterização de Escherichia coli patogênica (E.coli produtora de toxina Shiga - STEC; E.coli aviária patogênica - APEC) de fragatas (Fregata magnificens) da Costa do Estado de São Paulo". Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/10/10133/tde-10082010-143759/.
Pełny tekst źródłaThe present study is to investigate and characterize pathogenic Escherichia coli (E. coli Shiga toxin-producing - STEC avian pathogenic E. coli - APEC) on frigates (Fregata magnificens) from the coast of São Paulo and contribute to the understanding of epidemiological aspects in this important group of zoonotic bacterial diseases, the colibacillosis. To this, there were three scientific expeditions to two nesting sites of frigates in the state of Sao Paulo, the main island of Alcatraz (24 ° 06\'S - 45 ° 41\'W) and Castilho´s island (25 ° 16\'S - 47 ° 57\'W), in which it was collected a total of 42 samples of swabs, and 21 cloacal and choanal 21, coming from 18 offspring of indeterminate sex, 2 adult females and 1 adult male frigate. Of the 42 clinical samples studied, 18 were identified with growth of E.coli. Of these, 67 strains were isolated, which were then tested for virulence genes and characterization of phylogenetic groups by PCR technique. Then the strains that exhibited virulence factors were analyzed by serotyping. To investigate the patterns of resistance and sensitivity to antimicrobial susceptibility tests were performed for 18 different types of antimicrobials for one strain of each selected sample of E. coli. The results showed that it was possible to identify 15 different profiles of virulence, tested positive for the following genes: fimH (98.3%), malX (52.4%) traT (31.1%), cvaC (22.9 %), fyuA (19.6%), ibeA (19.6%), aer (13.1%) and papC (13.1%). Most isolates of frigates was characterized between phylogenetic groups D and B2, and the main serotypes were O1:H6, O2:H7, O25:H4, and O102:H10. For resistance to antibiotics, 60.1%% of the isolates were sensitive to 18 different antimicrobial agents tested on the other hand, the antimicrobial with the highest resistance was to tetracycline, which has proved ineffective in 20.1% of the samples studied. So far not been identified in STEC strains studied subjects on the other hand, isolates harbor genes that characterize ExPEC. These results show that most of the strains are potentially pathogenic to birds and may represent significant risk to health of sea birds, including how to configure agents relevant, emphasizing the importance of investigating the possible involvement of wild birds, especially navies in the epidemiological chain of diseases caused by E.coli. Such information could guide the research of selected diseases in populations of the frigates, as well as basing the adoption of any action in relation to aspects of animal and human health, which have the frigates as a link.
Khandaker, MD Shahjahan Ali. "Economic analysis of diseases caused by VTEC (verotoxin producing e.coli) in Australia /". St. Lucia, Qld, 2002. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17335.pdf.
Pełny tekst źródłaChahar, Sanjay [Verfasser]. "Functional characterization and molecular evolution of E.coli DNA methyltransferase (EcoDam) / Sanjay Chahar". Bremen : IRC-Library, Information Resource Center der Jacobs University Bremen, 2010. http://d-nb.info/1034988166/34.
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