Proefschrift--Utrecht. / "References": p. [87]-88.

Thesis (M. Med. Sc.)--University of Hong Kong, 2005.

Thesis (M. Phil.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

Zugl.: Dresden, Techn. Universiẗat, Diss., 2005.

Berlin, Freie Universiẗat, Diss., 2000. / Dateiformat: zip, Dateien im PDF-Format.

Universiẗat, Diss., 2004--Heidelberg.

Made available in DSpace on 2014-10-09T12:25:11Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:56:16Z (GMT). No. of bitstreams: 1 00295.pdf: 4244087 bytes, checksum: 9d7f4393a43870daecfe85d8677288c9 (MD5) / Tese (Doutoramento) / IEA/T / Universidade Estadual de Campinas - UNICAMP/SP

Neste trabalho foi desenvolvido um novo bioprocesso para a síntese de lactosacarose, um candidato a prebiótico. A lactosacarose foi produzida por transgalactosilação, catalisada pela β-galactosidase de Bacillus circulans imobilizada em macroesfera de quitosana, utilizando a lactose e a sacarose como substratos. No processo de imobilização, os resultados indicam que a melhor razão entre a concentração de enzima e de suporte foi de 200 mg.g-1. A estabilidade térmica da enzima imobilizada foi determinada e comparada com a estabilidade térmica da enzima livre em temperaturas de 50, 60 e 70 °C e para esta última foi verificada a estabilidade na presença e ausência de substrato. A imobilização aumentou de 10 a 260 vezes a estabilidade térmica da enzima, sendo este efeito inversamente relacionado com a temperatura. A otimização das condições de produção indica, para a β-galactosidase imobilizada e livre, que a melhor condição de produção de lactosacarose e de oligossacarídeos totais, ocorre na temperatura de 30 °C e pH 7,0. Nesta condição, após 24 h, foi alcançada a produção de 79 g.L-1 de lactosacarose, 35 g.L-1 de galacto-oligossacarídeos (GOS) e 260 g.L-1 de oligossacarídeos totais. O processo de imobilização possibilitou a reutilização da enzima imobilizada por 30 ciclos, mantendo aproximadamente 95% da concentração inicial de lactosacarose, GOS e oligossacarídeos totais produzidos inicialmente. Portanto, o bioprocesso de imobilização de β-galactosidase de Bacillus circulans em macroesfera de quitosana pode ser considerado um potencial catalisador para produção industrial de lactosacarose. / This work developed a new process for the synthesis of lactosucrose, a candidate for prebiotic. The lactosucrose was produced by transgalactosylation that was catalyzed by a Bacillus circulans β-galactosidase immobilized on macrospheres of chitosan using lactose and sucrose as substrates. In the process of immobilization, the results indicate that the best ratio of the concentration of enzyme and carrier was 200 mg.g-1. The thermal stability of the immobilized enzyme was determined and compared with the thermal stability of the free enzyme at temperatures of 50, 60 and 70 °C and for the latter was verified stability in the presence and absence of substrate. The immobilization increased (10-260 times) the thermal stability of the enzyme, which is inversely related to the temperature. The results of the experiment optimization of lactosucrose production conditions indicate point out that, for free and immobilized β-galactosidase, the best condition lactosucrose production and total oligosaccharides occurs at a temperature of 30 °C and pH 7.0. In this condition, after 24 h, producing 79 g.L-1 lactosucrose was reached, 35 g.L-1 galactooligosaccharides (GOS) and 260 g.L-1 of total oligosaccharides. The immobilization process enabled the reuse of immobilized enzyme for 30 cycles, maintaining approximately 95% of the initial concentration of lactosucrose, GOS and total oligosaccharides produced initially. Therefore, the bioprocess of β-galactosidase from Bacillus circulans immobilization on macrospheres of chitosan can be considered a potential catalyst for industrial.

Dans l’espèce équine, les mécanismes de la fécondation sont mal connus. Afin de mieux les comprendre, nous avons développé une approche comparative entre les équins (faibles taux de fécondation in vitro : 0-60%) et les porcins (forts taux : 80–90%). Notre but était d’identifier les différences et les similitudes entre ces deux modèles opposés afin de mettre en évidence des éléments clés de la fécondation. Nous avons montré que 1) la zone pellucide de l’ovocyte est un élément clé dans l’interaction des gamètes, 2) sa composition et sa structure sont différentes entre les espèces équine et porcine, 3) chaque vertébré a son propre jeu de protéines permettant l’interaction des gamètes, 4) la ß-1,4-galactosyltransferase n’est pas nécessaire pour cette interaction dans les espèces équine et porcine, contrairement aux bovins, 5) les sécrétions de l’oviducte participent aux mécanismes de la fécondation équine, mais les protéines impliquées n’ont pas pu être identifiée. / In equine species, the mechanisms of fertilization remain largely enigmatic. In order to clarify these mechanisms, we have developped a comparative strategy between equine (low in vitro fertilization rates: 0- 60%) and porcine (high rates: 80-90%) species. Our objective was to identify differences and similarities between these two opposite models in order to highlight key components of fertilization. We showed that 1) the zona pellucida is a determining element in gamete interaction, 2) its composition and its structure are different between equine and porcine species, 3) each vertebrate has its own protein-set involved in gamete interaction, 4) the ß-1,4-galactosyltransferase is not necessary for gamete interaction in the horse and the pig, contrary to the bovine, 5) the secretions of oviduct cells take part in the mechanism of equine fertilization, but the proteins involved remain to be identified.

Del mes de enero al mes de octubre del año 2008 en el Servicio de Microbiología del Hospital Nacional Guillermo Almenara Irigoyn – ESSALUD, se colectaron 186 cepas de Pseudomonas aeruginosa resistentes al Imipenem (IMP) y al Meropenem (MEM) o con resistencia Intermedia a los dos antibióticos o a uno de ellos. Utilizando el Método Fenotípico de Doble Difusión en Disco con Monodiscos de EDTA; se llegó a detectar 13 cepas de P. aeruginosa positivas para MBLs, correspondiente al 6.99 % de las cepas testadas; de las cuales, el 53.84 % de la sinergia (efecto de la metaloenzima) se manifestó en el disco de Meropenem, el 30.75 % se manifestó en ambos discos (Imipenem y Meropenem) y solo el 15.38 % se manifestó en el disco de Imipenem. El 100 % de cepas de P. aeruginosa en las que se detectó las metaloenzimas provinieron de pacientes hospitalizados, de estos aislados el 69.76 % correspondieron al sexo masculino; el 61. 53 % de casos corresponden a pacientes cuyas edades están entre 70 a 90 años, y sólo el 14.14% de casos fueron en menores de 1 año y jóvenes. Las muestras biológicas en las que aisló a P. aeruginosa productora de MBLs fueron: orina, aspirado bronquial, BAL, herida no operatoria, secreción otica, líquido de diálisis peritoneal y sangre; fue orina en la que se aisló el mayor número de casos: 46. 15 %; en el Servicio de Medicina‐1, se detecto más casos 30.76 %, seguido de Cardiología y UCI con 23.07 %. Se detectó la enzima MBLs en cepas peruanas de Pseudomonas aeruginosa y se estableció la incidencia en 6.99 %, la cual es inferior a las reportadas por otros países, por lo cual se debe hacer estudios multicentricos para establecer la incidencia real. / In the study, 186 samples of Pseudomonas aeruginosa strains resistant to the Imipenem (IMP) and the Meropenem (MEM) or with Intermediate resistance to both antibiotic and one of them were collected in the Service of Microbiology of the Guillemo Almenara Irigoyen National Hospital ‐ ESSALUD from the month of January to the month of October of the year 2008. Using the Phenotypical Method of Double Disc Diffusion with Monodiscs of EDTA; 13 positive strains of Pseudomonas aeruginosas for MBLS were detected (6.99 % of the sampled strains): of them, the 53.85% of the synergy (effect of metal‐enzyme) was present in the disc of Meropenem, the 30.75% was present in both discs (Imipenem and Meropenem) and only the 15.38% was present in the disc of Imipenem. The 100% of the P. aeruginosa strains in which metal‐enzyme was detected belonged to hospitalized patients and the 69.76% of them belonged to masculine sex. The 61.54 % of cases correspond to patients whose ages are between 70 to 90 years, and only the 15.38% of the cases were in minors of 1 year and young people. The biological samples, in which the producing P. aeruginosa of MBLs was isolated, were: urine, inhaled bronchial, BAL, non operating wound, ear secretion, liquid of dialysis peritoneal and blood; but it was in the urine in that the greater number of cases was isolated the 46. 15 %. In the Service of Medicine‐1 were detected mayor number of cases (23.07%) followed for Cardiology and UCI (23.07%). The MBLs enzyme was detected in Pseudomonas aeruginosa peruvian strains. The incident was of 6.99% that is lower tanning the incident reported in other countries. For which Multicentral studies must be done for establish the real incident. / Tesis