Estudo da hidrólise de lactose por ß-galactosidase na forma livre e imobilizada
Autor(a) principal: | |
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Data de Publicação: | 1998 |
Tipo de documento: | Dissertação |
Idioma: | por |
Título da fonte: | Repositório Institucional da UFU |
Texto Completo: | https://repositorio.ufu.br/handle/123456789/28984 http://doi.org/10.14393/ufu.di.1998.13 |
Resumo: | The objective of this work was to study the kinetics of lactose hydrolysis using the enzyme galactosidase, in the free and immobilized form. The kinetic studies of the enzyme in the free and immobilized form were conducted in a micro reactor, at 30°C and pH of 6,5. The kinetic model found, for the free enzyme as well as the immobilized form, was the one of Michaelis-Menten. In the case of the free enzyme there was an inhibition by the galactose and the parameters found were Vm = 0,16 g/(Lmin), Km=17,04 g/L and Kj=54,26 g/L. The enzyme ß-galactosidase, when incubated at several pH values, presented better stability at pH 6,5. The optimum temperature was 40°C and the best pH was 6,5. The kinetics of hydrolysis of the lactose was studied in a range between 10 to 150g/L, inside the range of the lactose solubility. The enzymatic activity increased from 10 to llOg/L, and remained stable from this point on. Through a Central Composed Planning System it was possible to study the influence of three variables, temperature, concentration of lactose and pH jointly in the activity of the free enzyme. There was a strong influence of the pH that inhibited the effects of temperature and concentration. When studying the thermal stability of the free enzyme, it was noticed the influence of temperature by determining the time of half live. At 40°C the time of half life of the enzyme was 682,2 min and at 55°C, it was of 1,21 min. The immobilization of the lactase was accomplished using two different supports, an ionic exchange resin (Duolite) and a controlled pore silica (SPC). The enzyme immobilized on SPC had a maximum catalytic activity of l,49g/(g.L.min) and immobilized on Duolite of 0,84 g/(g.L.min). |
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Estudo da hidrólise de lactose por ß-galactosidase na forma livre e imobilizadaStudy of lactose hydrolysis by free and immobilized ß-galactosidaseHidrólise de lactoseß-galactosidaseCNPQ::ENGENHARIASThe objective of this work was to study the kinetics of lactose hydrolysis using the enzyme galactosidase, in the free and immobilized form. The kinetic studies of the enzyme in the free and immobilized form were conducted in a micro reactor, at 30°C and pH of 6,5. The kinetic model found, for the free enzyme as well as the immobilized form, was the one of Michaelis-Menten. In the case of the free enzyme there was an inhibition by the galactose and the parameters found were Vm = 0,16 g/(Lmin), Km=17,04 g/L and Kj=54,26 g/L. The enzyme ß-galactosidase, when incubated at several pH values, presented better stability at pH 6,5. The optimum temperature was 40°C and the best pH was 6,5. The kinetics of hydrolysis of the lactose was studied in a range between 10 to 150g/L, inside the range of the lactose solubility. The enzymatic activity increased from 10 to llOg/L, and remained stable from this point on. Through a Central Composed Planning System it was possible to study the influence of three variables, temperature, concentration of lactose and pH jointly in the activity of the free enzyme. There was a strong influence of the pH that inhibited the effects of temperature and concentration. When studying the thermal stability of the free enzyme, it was noticed the influence of temperature by determining the time of half live. At 40°C the time of half life of the enzyme was 682,2 min and at 55°C, it was of 1,21 min. The immobilization of the lactase was accomplished using two different supports, an ionic exchange resin (Duolite) and a controlled pore silica (SPC). The enzyme immobilized on SPC had a maximum catalytic activity of l,49g/(g.L.min) and immobilized on Duolite of 0,84 g/(g.L.min).Dissertação (Mestrado)O objetivo deste trabalho foi estudar a cinética de hidrólise de lactose através da enzima ß-galactosidase, na forma livre e imobilizada. Os estudos cinéticos da enzima na forma livre e imobilizada foram realizados em um microrreator de mistura a 30°C e pH 6,5. O modelo cinético encontrado, tanto para a enzima livre como imobilizada, foi o de Michaelis-Menten. No caso da enzima livre, houve inibição pela galactose e os parâmetros encontrados foram Vm= 0,16 g/(Lmin), Km=17,04g/L e Ki=54,26g/L. A enzima ß-galactosidase quando incubada em diversos valores de pH apresentou melhor estabilidade em pH 6,5. A temperatura ótima encontrada foi de 40°C e o pH ótimo 6,5. A cinética de hidrólise da lactose foi estudada na faixa de 10 a 150g/L, dentro da faixa de solubilidade da lactose. A atividade enzimática foi crescente de 10 a HOg/L, estabilizando-se a partir desse ponto. Pelo Planejamento Composto Central, montado para estudar a influência das três variáveis, temperatura, concentração de lactose e pH, conjuntamente na atividade da enzima livre, percebeu-se uma marcante influência do pH, inibindo o efeito da temperatura e concentração. Ao estudar a estabilidade térmica da enzima livre, percebeu-se a sensibilidade desta em relação à temperatura pela determinação do tempo de meia vida. A 40°C, o tempo de meia vida da enzima foi 682,2 min e a 55°C foi de 1.21 min. A imobilização da lactase foi realizada utilizando-se dois suportes diferentes, a resina de troca iônica, de nome comercial Duolite e sílica de porosidade controlada (SPC). A enzima imobilizada em SPC apresentou uma atividade catalítica máxima de 1,49 g/(g.L.min) e imobilizada em Duolite de 0,84 g/(g.L.min).Universidade Federal de UberlândiaBrasilPrograma de Pós-graduação em Engenharia QuímicaRibeiro, Eloízio Júliohttp://lattes.cnpq.br/7396213263599744Araújo, Euclides Honório deCardoso, Vicelma LuizMiranda, Tânia Lúcia SantosTomás, Claudia Maria2020-03-13T12:43:46Z2020-03-13T12:43:46Z1998info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfTOMÁS, Cláudia Maria. Estudo da hidrólise de lactose por ß-galactosidase na forma livre e imobilizada. 1998. 69 f. Dissertação (Mestrado em Engenharia Química) - Universidade Federal de Uberlândia, Uberlândia, 2020. DOI http://doi.org/10.14393/ufu.di.1998.13https://repositorio.ufu.br/handle/123456789/28984http://doi.org/10.14393/ufu.di.1998.13porhttp://creativecommons.org/licenses/by-nc-nd/3.0/us/info:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFUinstname:Universidade Federal de Uberlândia (UFU)instacron:UFU2021-09-29T16:55:30Zoai:repositorio.ufu.br:123456789/28984Repositório InstitucionalONGhttp://repositorio.ufu.br/oai/requestdiinf@dirbi.ufu.bropendoar:2021-09-29T16:55:30Repositório Institucional da UFU - Universidade Federal de Uberlândia (UFU)false |
dc.title.none.fl_str_mv |
Estudo da hidrólise de lactose por ß-galactosidase na forma livre e imobilizada Study of lactose hydrolysis by free and immobilized ß-galactosidase |
title |
Estudo da hidrólise de lactose por ß-galactosidase na forma livre e imobilizada |
spellingShingle |
Estudo da hidrólise de lactose por ß-galactosidase na forma livre e imobilizada Tomás, Claudia Maria Hidrólise de lactose ß-galactosidase CNPQ::ENGENHARIAS |
title_short |
Estudo da hidrólise de lactose por ß-galactosidase na forma livre e imobilizada |
title_full |
Estudo da hidrólise de lactose por ß-galactosidase na forma livre e imobilizada |
title_fullStr |
Estudo da hidrólise de lactose por ß-galactosidase na forma livre e imobilizada |
title_full_unstemmed |
Estudo da hidrólise de lactose por ß-galactosidase na forma livre e imobilizada |
title_sort |
Estudo da hidrólise de lactose por ß-galactosidase na forma livre e imobilizada |
author |
Tomás, Claudia Maria |
author_facet |
Tomás, Claudia Maria |
author_role |
author |
dc.contributor.none.fl_str_mv |
Ribeiro, Eloízio Júlio http://lattes.cnpq.br/7396213263599744 Araújo, Euclides Honório de Cardoso, Vicelma Luiz Miranda, Tânia Lúcia Santos |
dc.contributor.author.fl_str_mv |
Tomás, Claudia Maria |
dc.subject.por.fl_str_mv |
Hidrólise de lactose ß-galactosidase CNPQ::ENGENHARIAS |
topic |
Hidrólise de lactose ß-galactosidase CNPQ::ENGENHARIAS |
description |
The objective of this work was to study the kinetics of lactose hydrolysis using the enzyme galactosidase, in the free and immobilized form. The kinetic studies of the enzyme in the free and immobilized form were conducted in a micro reactor, at 30°C and pH of 6,5. The kinetic model found, for the free enzyme as well as the immobilized form, was the one of Michaelis-Menten. In the case of the free enzyme there was an inhibition by the galactose and the parameters found were Vm = 0,16 g/(Lmin), Km=17,04 g/L and Kj=54,26 g/L. The enzyme ß-galactosidase, when incubated at several pH values, presented better stability at pH 6,5. The optimum temperature was 40°C and the best pH was 6,5. The kinetics of hydrolysis of the lactose was studied in a range between 10 to 150g/L, inside the range of the lactose solubility. The enzymatic activity increased from 10 to llOg/L, and remained stable from this point on. Through a Central Composed Planning System it was possible to study the influence of three variables, temperature, concentration of lactose and pH jointly in the activity of the free enzyme. There was a strong influence of the pH that inhibited the effects of temperature and concentration. When studying the thermal stability of the free enzyme, it was noticed the influence of temperature by determining the time of half live. At 40°C the time of half life of the enzyme was 682,2 min and at 55°C, it was of 1,21 min. The immobilization of the lactase was accomplished using two different supports, an ionic exchange resin (Duolite) and a controlled pore silica (SPC). The enzyme immobilized on SPC had a maximum catalytic activity of l,49g/(g.L.min) and immobilized on Duolite of 0,84 g/(g.L.min). |
publishDate |
1998 |
dc.date.none.fl_str_mv |
1998 2020-03-13T12:43:46Z 2020-03-13T12:43:46Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
TOMÁS, Cláudia Maria. Estudo da hidrólise de lactose por ß-galactosidase na forma livre e imobilizada. 1998. 69 f. Dissertação (Mestrado em Engenharia Química) - Universidade Federal de Uberlândia, Uberlândia, 2020. DOI http://doi.org/10.14393/ufu.di.1998.13 https://repositorio.ufu.br/handle/123456789/28984 http://doi.org/10.14393/ufu.di.1998.13 |
identifier_str_mv |
TOMÁS, Cláudia Maria. Estudo da hidrólise de lactose por ß-galactosidase na forma livre e imobilizada. 1998. 69 f. Dissertação (Mestrado em Engenharia Química) - Universidade Federal de Uberlândia, Uberlândia, 2020. DOI http://doi.org/10.14393/ufu.di.1998.13 |
url |
https://repositorio.ufu.br/handle/123456789/28984 http://doi.org/10.14393/ufu.di.1998.13 |
dc.language.iso.fl_str_mv |
por |
language |
por |
dc.rights.driver.fl_str_mv |
http://creativecommons.org/licenses/by-nc-nd/3.0/us/ info:eu-repo/semantics/openAccess |
rights_invalid_str_mv |
http://creativecommons.org/licenses/by-nc-nd/3.0/us/ |
eu_rights_str_mv |
openAccess |
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application/pdf |
dc.publisher.none.fl_str_mv |
Universidade Federal de Uberlândia Brasil Programa de Pós-graduação em Engenharia Química |
publisher.none.fl_str_mv |
Universidade Federal de Uberlândia Brasil Programa de Pós-graduação em Engenharia Química |
dc.source.none.fl_str_mv |
reponame:Repositório Institucional da UFU instname:Universidade Federal de Uberlândia (UFU) instacron:UFU |
instname_str |
Universidade Federal de Uberlândia (UFU) |
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UFU |
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UFU |
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Repositório Institucional da UFU |
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Repositório Institucional da UFU |
repository.name.fl_str_mv |
Repositório Institucional da UFU - Universidade Federal de Uberlândia (UFU) |
repository.mail.fl_str_mv |
diinf@dirbi.ufu.br |
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1805569702808780800 |