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cortezi_m_me_rcla.pdf: 1518114 bytes, checksum: e094ed383a63910c8cfd742b0e61829f (MD5) / Universidade Estadual Paulista (UNESP) / A enzima Dextranasacarase (EC 2.4. 1. 5) catalisa a sintese de dextrana a partir da sacarose. Varias especies do genero Leuconostoc, Lactobacillus e Streptococcus sao conhecidas por sintetizar dextranasacarase extracelular sob condicoes apropriadas. O polimero dextrana apresenta varias aplicacoes comerciais nas industrias farmaceuticas, mais comumente utilizada como expansor do plasma sanguineo e no tratamento de anemias, quimicas e de alimentos. O objetivo deste trabalho foi o estudo da producao da enzima dextranasacarase por uma nova cepa de Leuconostoc mesenteroides (FT 045 B) isolada de Usina de Producao de Alcool e Acucar. Diferentes composicoes de meio de cultura foram estudados para a producao de dextranasacarase, mostrando que o meio M5, contendo 2% m/v de K2HPO4, produziu maior atividade enzimatica (5,67 UDS/mL), quando comparado aos outros meios estudados. As melhores temperaturas para a producao da enzima foram 23 e 25C, obtendo uma atividade de 3,2 UDS/mL. Fermentacoes utilizando melaco como fonte de carbono, Resumo 2 mostraram que a concentracao de 97,3 g/L resultou em 11,6 UDS/mL. Quando sacarose foi usada como fonte de carbono, as concentracoes de 3 e 4% m/v resultaram em atividades enzimatica proximas, 10,8 e 10,7 respectivamente. A adicao de tween 80 na concentracao de 5% aumentou em 6% a producao da enzima. A producao de dextrana gin vitroh pela enzima livre de celulas (11,5 UDS/mL) adicionada a sacarose (600g/L) mostrou um aumento da viscosidade apos 24 horas de reacao em (10.397,38 poise). A caracterizacao da dextrana atraves de FTIR possibilitou observar que o polimero sintetizado pela enzima de Leuconostoc mesenteroides FT 045 B apresenta os mesmos grupos quando comparada com as dextranas padroes de massas molares 515.000 e 9.300 Da. A massa molar media do polimero sintetizado foi determinada utilizando um viscosimetro de Ostwald, permitindo obter um valor de aproximadamente de 647000 Da. / Dextransucrase (sucrose: 1,6-¿-D-glucan 6-¿glucosyltransferase EC 2.4.1.5) is the enzyme that catalyzes the synthesis of dextran from sucrose. Several species of the genera Leuconostoc, Lactobacillus and Streptococcus are known to synthesis an extracellular dextransucrase under appropriate conditions. The polymer dextran has various commercial applications in the pharmaceutical area, most commonly as a blood volume expander and in the treatment of anaemia, chemistry and foods. The goal of this work was to study a newly isolated strain of Leuconostoc mesenteroides (FT 045 B) from a Brazilian Alcohol and Sugar Plant Industry with relation a dextransucrase enzyme production. Different media compositions used for dextransucrase production showed that media M5 containing 2% of K2HPO4 produced higher enzymatic activity (5.67 U/mL) when compared to the other media. The best temperatures for enzyme production in batch fermentation were 23 and 25C showing enzymatic activity of 3.2 U/mL. Fermentation runned with molasses as a carbon source at concentration of 97.3 g/L for L. mesenteroides FT045B resulted in Introducao 4 11.6 U/mL enzymatic activity. When sucrose was used as a carbon source, concentration of 3 and 4% showed respectively 10.8 and 10.7 U/mL of dextransucrase activity. The use of Tween 80 in concentration of 5% increased the enzyme production in 6%. The dextran production gin vitroh by crude enzyme cell free (11.5 U/mL) in sucrose 600 g/L showed an increase in viscosity after 24 hours of reaction (10,394.38 poise). Dextran characterization by FTIR showed that the polymer synthesized by Leuconostoc mesenteroides FT045B enzyme has the same groups when compared with the standard dextrans (515.000Da and 9.300Da). Mw determination of synthesized dextran by production enzyme through Ostwald viscometer showed a value of 647000 Da.
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.unesp.br:11449/95016 |
| Date | 07 1900 |
| Creators | Cortezi, Mariana [UNESP] |
| Contributors | Universidade Estadual Paulista (UNESP), Contiero, Jonas [UNESP] |
| Publisher | Universidade Estadual Paulista (UNESP) |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | 82 f. : il., gráfs. |
| Source | Aleph, reponame:Repositório Institucional da UNESP, instname:Universidade Estadual Paulista, instacron:UNESP |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | -1, -1 |
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