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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

Estudo do mecanismo de produ??o de oligossacar?deos com atividades nutrac?uticas a partir da quitosana por hidr?lise enzim?tica com processo fermentativo simult?neo

Pagnoncelli, Maria Giovana Binder 16 October 2008 (has links)
Made available in DSpace on 2014-12-17T15:01:46Z (GMT). No. of bitstreams: 1 MariaGBP.pdf: 1032728 bytes, checksum: 535260d4afcd2c2deeacab5b5006e73c (MD5) Previous issue date: 2008-10-16 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The obtaining of the oligosaccharides from chitosanase, has showed interest of the pharmaceutical area in the last years due their countless functional properties. Although, the great challenge founded out is how to keep a constant and efficient production. The alternative proposed by this present work was to study the viability to develop an integrated technology, with reduced costs. The strategy used was the obtaining of the oligomers through enzymatic hydrolysis using chitosanolitic enzymes obtained straight from the fermented broth, eliminating this way the phases involved in the enzymes purification. The two chitosanases producing strains chosen for the work, Paenibacillus chitinolyticus and Paenibacillus ehimensis, were evaluated according to the behavior in the culture medium with simple sugar and in relation to the pH medium variations. The culture medium for the chitosanases induction and production was developed through addition of soluble chitosan as carbon source. The soluble chitosan was obtained using hydrochloric acid solution 0.1 M and afterwards neutralization with NaOH 10 M. The enzymatic complexes were obtained from induction process in culture medium with 0.2% of soluble chitosan. The enzymes production was verified soon after the consumption of the simple sugars by the microorganisms and the maximum chitosanolitic activity obtained in the fermented broth by Paenibacillus chitinolyticus was 249 U.L-1 and by Paenibacillus ehimensis was 495U.L-1. These two enzymatic complexes showed stability when stored at 20?C for about 91 days. The enzymes in the fermented broth by Paenibacillus chitinolyticus, when exposed at temperature of 55?C and pH 6.0, where the activity is maximum, showed 50% lost of activity after 3 hours Meanwhile, for the complex produced by Paenibacillus ehimensis, after 6 days of exposure, it was detected 100% of the activity. The chito-oligosaccharides obtained by the hydrolysis of a 1% chitosan solution, using the enzymatic complex produced by Paenibacillus chitinolyticus showed larger quantity after 9 hours hydrolysis and using the complex produced by Paenibacillus ehimensis after 20 minutes was observed the chito-ligosacharides with polymerization degree between 3 and 6 units. Evaluating these results, it was verified that the production of chitosan-oligosaccharides is possible, using a simultaneous process / A obten??o de oligossacar?deos, a partir da quitosana, tem despertado interesse da ?rea farmac?utica nos ?ltimos anos devido as suas in?meras propriedades funcionais. Por?m, o grande desafio encontrado ? manter uma produ??o constante e eficiente. A alternativa proposta por este trabalho foi estudar a viabilidade de desenvolver uma tecnologia integrada e de baixo custo. A estrat?gia utilizada foi a obten??o dos olig?meros por meio de hidr?lise enzim?tica utilizando enzimas quitosanol?ticas obtidas diretamente do caldo fermentado, eliminando dessa forma as etapas envolvidas na purifica??o de enzimas. As duas cepas produtoras de quitosanases selecionadas para o trabalho, Paenibacillus chitinolyticus e Paenibacillus ehimensis, foram avaliadas quanto ao comportamento em meio de cultivo contendo a??cares simples e em rela??o as varia??es de pH do meio. O meio de cultivo para a indu??o e produ??o das quitosanases foi desenvolvido atrav?s da adi??o de quitosana sol?vel como fonte de carbono. A quitosana sol?vel foi obtida utilizando solu??o de ?cido clor?drico 0,1 M e posterior neutraliza??o com NaOH 10 M. Os complexos enzim?ticos foram obtidos a partir de processos de indu??o em meio de cultivo contendo 0,2% de quitosana sol?vel. A produ??o das enzimas foi observado logo ap?s o t?rmino do consumo dos a??cares simples pelos microrganismos e a m?xima atividade quitosanol?tica obtida no caldo fermentado pelo Paenibacillus chitinolyticus foi de 249 U.L-1 e pelo Paenibacillus ehimensis foi de 495 U.L-1. Esses dois complexos enzim?ticos apresentaram estabilidade quando armazenadas a -20?C por at? 91 dias. As enzimas presentes no caldo fermentado pelo Paenibacillus chitinolyticus, quando expostas ? temperatura de 55?C e pH 6,0, onde a atividade ? m?xima, apresentaram perda de 50% da atividade ap?s 3 horas. Enquanto que, para o complexo produzido pelo Paenibacillus ehimensis, ap?s 6 dias de exposi??o, 100% da atividade foi detectada. Os quito-oligossacar?deos obtidos a partir da hidr?lise de uma solu??o de 1% de quitosana, utilizando o complexo enzim?tico produzido pelo Paenibacillus chitinolyticus, apresentaram-se em maior quantidade ap?s 9 horas de hidr?lise e utilizando o complexo produzido pelo Paenibacillus ehimensis, ap?s 20 minutos pode-se observar os quito-oligossacar?deos com grau de polimeriza??o entre 3 e 6 unidades. Avaliando esses resultados, foi verificado que ? poss?vel a produ??o de quito-oligossacar?deos utilizando um processo simult?neo

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