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Master's Dissertation
DOI
10.11606/D.9.2003.tde-08102006-175534
Document
Author
Full name
Luiz Carlos Martins das Neves
E-mail
Institute/School/College
Knowledge Area
Date of Defense
Published
São Paulo, 2003
Supervisor
Committee
Vitolo, Michele (President)
Carvalho, Joao Carlos Monteiro de
Maiorano, Alfredo Eduardo
Title in Portuguese
Obtenção da enzima glicose 6-fosfato desidrogenase utilizando 'Saccharomyces cerevisiae' W303-181
Keywords in Portuguese
enzima glicose 6-fosfato desidrogenase
processo descontínuo alimentado
Saccharomyces cerevisiae
Abstract in Portuguese
A glicose 6-fosfato desidrogenase (G6PDH) é a primeira enzima do processo oxidativo da via das pentoses fosfato e apresenta diversas aplicações industriais. Foram avaliadas as influências de algumas variáveis sobre a produção de G6PDH. No Processo Descontínuo variaram-se a concentração da fonte de carbono, relação carbono-nitrogênio, concentração de aminoácidos e nucleotídeos , pH e a vazão de ar fornecida. A variação na atividade enzimática indicou que as condições do meio são importantes na obtenção desta enzima, tendo sido obtida atividade específica máxima de 86 U/g cél e produtividade de 10,5 U/L.h. No Processo Descontínuo-Alimentado variaram-se o sistema de adição e os nutrientes alimentados. A atividade específica máxima obtida foi 72 U/g cél e a produtividade foi 47 U/L.h. Os resultados indicaram o controle da concentração de glicose em 5g/L para uma melhor produtividade e a necessidade de maiores estudos a fim de otimizar o processo.
Title in English
Production of glucose 6-phosphate dehydrogenase from Saccharomyces cerevisiae W303-181
Keywords in English
fed-batch process
glucose 6-phosphate dehydrogenase enzyme
Saccharomyces cerevisiae
Abstract in English
The glucose 6-phosphate dehydrogenase (G6PDH) is the first enzyme of the pentose phosphate pathway, converting glucose-6-phosphate into 6-phosphogluconate. Besides its importance in biochemistry and medical studies, this enzyme is used in several analytical methods, industrial and commercial application. In this work the influence of several variables in the production of Glucose-6-Phosphate Dehydrogenase in batch and fed-batch processes were studied. In batch cultures the variables were the glucose concentration (10 and 20 g/L), the C:N ratio (3.5 and 6.7 g/g), the aminoacids and nucleotides concentrations (10 and 20 mg/L), pH (4.6 and 5.7) and the aeration (0, 0.8, 1.7 and 2.2 vvm). It was observed that the G6PDH activity varied according to the conditions of the culture. Specific Activity value of 86 U/g cell and productivity of 10,5 U/L.h were attained when the test was carried out as follows: 30oC, pH 5.7, 400 rpm, 2.2 vvm, C:N ratio of 6.7, glucose concentration of 10 g/L, aminoacids (Tryptophan and Hystidine) and nucleotides (Adenine and Uracil) concentrations of 20 mg/L. Nevertheless, the fed-batch process was more efficient and productive than the batch process. The productivity obtained in the best fed-batch condition (glucose addition by an increasing exponential mode) was 47 U/L.h, more than four folds the productivity of the batch culture. So that, by maintaining the glucose concentration in the medium below 5 g/L, the productivity should be improved. However, more studies are needed for optimizing the G6PDH production in a Fed-Batch process. In the fed-batch cultures the feeding conditions and kind of feeding were studied. It was observed that the best fed-batch G6PDH specific activity (72 U/g of cell when the glucose was added in a decreasing linear mode) was lower than that attained in the batch cultures.
 
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Agradecimentos.pdf (18.22 Kbytes)
ANEXO.pdf (127.67 Kbytes)
ApendiceI.pdf (58.97 Kbytes)
ApendiceII.pdf (32.16 Kbytes)
ApendiceIII.pdf (119.78 Kbytes)
ApendiceIV.pdf (34.65 Kbytes)
ApendiceV.pdf (35.63 Kbytes)
ApendiceVI.pdf (75.01 Kbytes)
Capa.pdf (14.12 Kbytes)
Conclusoes.pdf (20.37 Kbytes)
DiscussaoParteI.pdf (313.18 Kbytes)
DiscussaoParteII.pdf (248.29 Kbytes)
IndicedeFiguras.pdf (33.97 Kbytes)
IndicedeTabelas.pdf (28.68 Kbytes)
Introducao.pdf (25.88 Kbytes)
MaterialeMetodos.pdf (524.73 Kbytes)
Objetivos.pdf (16.05 Kbytes)
RevisaoBibliografica.pdf (203.66 Kbytes)
Sumario.pdf (28.10 Kbytes)
Publishing Date
2006-12-07
 
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