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Invertase, glucose oxidase and catalase for converting sucrose to fructose and gluconic acid through batch and membrane-continuous reactors

SILVA, Aline Ramos da; TOMOTANI, Ester Junko; VITOLO, Michele
Fonte: Universidade de São Paulo, Faculdade de Ciências Farmacêuticas Publicador: Universidade de São Paulo, Faculdade de Ciências Farmacêuticas
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
693.3099%
Conversion of sucrose into fructose and gluconic acid using invertase, glucose oxidase and catalase was studied by discontinuous (sequential or simultaneous addition of the enzymes) and continuous (simultaneous addition of the enzymes in a 100 kDa-ultrafiltration membrane reactor) processes. The following parameters were varied: concentration of enzymes, initial concentration of substrates (sucrose and glucose), pH, temperature and feeding rate (for continuous process). The highest yield of conversion (100%) was attained through the discontinuous (batch) process carried out at pH 4.5 and 37 ºC by the sequential addition of invertase (14.3 U), glucose oxidase (10,000 U) and catalase (59,000 U).; Neste trabalho estudou-se a conversão da sacarose em frutose e ácido glicônico, usando as enzimas invertase, glicose oxidase e catalase, através do emprego de processo descontínuo (com adição sequencial ou simultânea das enzimas) e contínuo (adição simultânea das enzimas em reator com membrana acoplado à membrana de ultrafiltração de 100 kDa). Os parâmetros variados foram: a concentração das enzimas, a concentração inicial dos substratos (sacarose e glicose), o pH, a temperatura e a vazão específica de alimentação (processo contínuo). Obteve-se rendimento de 100%...

Processing optimization of probiotic yogurt containing glucose oxidase using response surface methodology

CRUZ, A. G.; FERIA, J. A. F.; WALTER, E. H. M.; ANDRADE, R. R.; CAVALCANTI, R. N.; OLIVEIRA, C. A. F.; GRANATO, D.
Fonte: ELSEVIER SCIENCE INC Publicador: ELSEVIER SCIENCE INC
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
700.1804%
Exposure to oxygen may induce a lack of functionality of probiotic dairy foods because the anaerobic metabolism of probiotic bacteria compromises during storage the maintenance of their viability to provide benefits to consumer health. Glucose oxidase can constitute a potential alternative to increase the survival of probiotic bacteria in yogurt because it consumes the oxygen permeating to the inside of the pot during storage, thus making it possible to avoid the use of chemical additives. This research aimed to optimize the processing of probiotic yogurt supplemented with glucose oxidase using response surface methodology and to determine the levels of glucose and glucose oxidase that minimize the concentration of dissolved oxygen and maximize the Bifidobacterium longum count by the desirability function. Response surface methodology mathematical models adequately described the process, with adjusted determination coefficients of 83% for the oxygen and 94% for the B. longum. Linear and quadratic effects of the glucose oxidase were reported for the oxygen model, whereas for the B. longum count model an influence of the glucose oxidase at the linear level was observed followed by the quadratic influence of glucose and quadratic effect of glucose oxidase. The desirability function indicated that 62.32 ppm of glucose oxidase and 4.35 ppm of glucose was the best combination of these components for optimization of probiotic yogurt processing. An additional validation experiment was performed and results showed acceptable error between the predicted and experimental results.

Controlled fabrication of gold nanoparticles biomediated by glucose oxidase immobilized on chitosan layer-by-layer films

CASELI, Luciano; SANTOS JR., David S. dos; AROCA, Ricardo F.; OLIVEIRA JUNIOR, Osvaldo Novais de
Fonte: ELSEVIER SCIENCE BV Publicador: ELSEVIER SCIENCE BV
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
682.7447%
The control of size and shape of metallic nanoparticles is a fundamental goal in nanochemistry, and crucial for applications exploiting nanoscale properties of materials. We present here an approach to the synthesis of gold nanoparticles mediated by glucose oxidase (GOD) immobilized on solid substrates using the Layer-by-Layer (LbL) technique. The LbL films contained four alternated layers of chitosan and poly(styrene sulfonate) (PSS), with GOD in the uppermost bilayer adsorbed on a fifth chitosan layer: (chitosan/PSS)(4)/(chitosan/GOD). The films were inserted into a solution containing gold salt and glucose, at various pHs. Optimum conditions were achieved at pH 9, producing gold nanoparticles of ca. 30 nm according to transmission electron microscopy. A comparative study with the enzyme in solution demonstrated that the synthesis of gold nanoparticles is more efficient using immobilized GOD. (C) 2009 Elsevier B.V. All rights reserved.; CNPq; Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); FAPESP; Rede Biomat (Brazil); rede Biomat (Brazil); NSERC (Canada).; Natural Sciences and Engineering Research Council of Canada (NSERC)

Chemical modification of a nanocrystalline TiO(2) film for efficient electric connection of glucose oxidase

SOUSA, Camila P.; POLO, Andre S.; TORRESI, Roberto M.; TORRESI, Susana I. Cordoba de; ALVES, Wendel A.
Fonte: ACADEMIC PRESS INC ELSEVIER SCIENCE Publicador: ACADEMIC PRESS INC ELSEVIER SCIENCE
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
685.9137%
A novel biosensor for glucose was prepared by adsorption of 1,1`-bis(4-carboxybenzyl)-4,4`-bipyridinium di-bromide compound (H(2)BpybcBr(2)) onto the surface of a nanocrystalline TiO(2) film deposited onto FTO glasses, which was used as a platform to assemble the enzyme glucose oxidase to the electrode surface. The H(2)BpybcBr(2)/TiO(2)/FTO modified electrode was characterized by scanning electron microscopy, X-ray fluorescence image, cyclic voltammograms and spectroelectrochemical measurements. The immobilization of GOD on functionalized TiO(2) film led to stable amperometric biosensing for glucose with a linear range from 153 mu mol L(-1) to 1.30 mmol L(-1) and a detection limit of 51 mu mol L(-1). The apparent Michaelis-Menten constant (K(m)) was estimated to be 3.76 mmol L(-1), which suggested a high enzyme-substrate affinity. The maximum electrode sensitivity was 1.25 mu A mmol L(-1). The study proved that the combination of viologen mediators with TiO(2) film retains the electrocatalytic activity of the enzyme, and also enhances the electron transfer process, and hence regenerating the enzyme in the reaction with glucose. (C) 2010 Elsevier Inc. All rights reserved.; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)[08/53576-9]; INCT in Bioanalytics (FAPESP)[08/57805-2]; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); INCT in Bioanalytics (CNPq)[573672/2008-3]; INCT in Bioanalytics (CNPq); UFABC; UFABC

Triphenylmethane dyes, an alternative for mediated electronic transfer systems in glucose oxidase biofuel cells

H, Camilo E. La Rotta; CINICIATO, Gustavo P. M. K.; GONZALEZ, Ernesto R.
Fonte: ELSEVIER SCIENCE INC Publicador: ELSEVIER SCIENCE INC
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
684.5848%
The bioelectrochemical behavior of three triphenylmethane (TPM) dyes commonly used as pH indicators, and their application in mediated electron transfer systems for glucose oxidase bioanodes in biofuel cells was investigated. Bromophenol Blue, Bromothymol Blue, Bromocresol Green were compared bio-electrochemically against two widely used mediators, benzoquinone and ferrocene carboxy aldehyde. Biochemical studies were performed in terms of enzymatic oxidation, enzyme affinity, catalytic efficiency and co-factor regeneration. The different features of the TPM dyes as mediators are determined by the characteristics in the oxidation/reduction processes studied electrochemically. The reversibility of the oxidation/reduction processes was also established through the dependence of the voltammetric peaks with the sweep rates. All three dyes showed good performances compared to the FA and BQ when evaluated in a half enzymatic fuel cell. Potentiodynamic and power response experiments showed maxima power densities of 32.8 mu W cm(-2) for ferrocene carboxy aldehyde followed by similar values obtained for TPM dyes around 30 mu W cm(-2) using glucose and mediator concentrations of 10 mmol L(-1) and 1.0 mmol L(-1), respectively. Since no mediator consumption was observed during the bioelectrochemical process...

Probiotic yogurts manufactured with increased glucose oxidase levels: Postacidification, proteolytic patterns, survival of probiotic microorganisms, production of organic acid and aroma compounds

Cruz, A. G.; Castro, W. F.; Faria, J. A. F.; Lollo, P. C. B.; Amaya-Farfan, J.; Freitas, M. Q.; Rodrigues, D.; Oliveira, C. A. F.; Godoy, H. T.
Fonte: ELSEVIER SCIENCE INC; NEW YORK Publicador: ELSEVIER SCIENCE INC; NEW YORK
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
696.43%
We investigated the effect of increased glucose oxidase concentration as a technological option to decrease oxidative stress during the processing of probiotic yogurts. Probiotic yogurts were produced with increased concentrations of glucose oxidase (0, 250, 500, 750, or 1,000 mg/kg) and submitted to physicochemical and microbiological analysis at 1, 15, and 30 d of refrigerated storage. Higher concentrations of glucose oxidase (750 and 1,000 mg/kg) and a longer storage time were found to have an influence on the characteristics of the probiotic yogurt, contributing to more extensive post-acidification, an increase in the dissolved oxygen level, and higher proteolysis. In addition, increased production of aroma compounds (diacetyl and acetaldehyde) and organic acids (mainly lactic acid) and a decrease in the probiotic bacteria count were reported. The use of glucose oxidase was a feasible option to minimize oxidative stress in probiotic yogurts. However, supplementation with excessive amounts of the enzyme may be ineffective, because insufficient substrate (glucose) is present for its action. Consumer tests should be performed to evaluate changes in the sensory attributes of the probiotic yogurts with increased supplementation of glucose oxidase. In addition...

Efeito da adição de xilanase, glicose oxidase e acido ascorbico na qualidade do pão de forma de farinha de trigo de grão inteiro.; Effect of adding xylanase, glucose oxidase and ascorbic acid on the quality of loaf bread made using whole-wheat flour.

Camila Batista da Silva
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 27/04/2007 PT
Relevância na Pesquisa
701.2238%
A demanda por produtos integrais está crescendo a cada dia no Brasil e no mundo. Isso se deve principalmente ao fato destes alimentos estarem relacionados com a saúde. A relação entre dieta e incidência de doenças crônicodegenerativas tem levado os consumidores a se preocuparem mais com a alimentação. Porém, apesar da grande procura por esses alimentos funcionais, a população prefere aqueles que mantenham as características sensoriais dos produtos originais. O objetivo deste trabalho foi estudar a influência da adição de xilanase, glicose oxidase e ácido ascórbico na qualidade do pão de forma, utilizando farinha de trigo de grão inteiro. Nesta farinha foram realizadas análises de composição centesimal, granulometria, teor e índice de glúten, farinografia, extensografia, viscosidade de pasta e falling number. Foi elaborado um delineamento composto central rotacional com três variáveis independentes: xilanase (x1), glicose oxidase (x2) e ácido ascórbico (x3). O delineamento incluiu dezessete ensaios: oito pontos fatoriais, seis pontos axiais e três repetições do ponto central. Os resultados foram analisados por Metodologia de Superfície de Resposta. As variáveis dependentes foram as propriedades reológicas da farinha e as características do pão. Os pães de forma foram analisados quanto ao volume específico...

Efeito da glicose oxidase sobre a viabilidade de bactérias probióticas em iogurte; Effect of the glucose oxidase on the stability of probiotic yougurt

Adriano Gomes da Cruz
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 29/06/2010 PT
Relevância na Pesquisa
692.4656%
A incorporação e a viabilidade de bactérias probióticas em alimentos ao longo do seu período de estocagem, que resultem em benefício para a saúde do consumidor, é um desafio constante para as indústrias de alimentos, requerendo a compreensão dos fatores intrínsecos e extrínsecos ao processamento. A exposição ao oxigênio apresenta-se como um fator relevante, na medida em que esse grupo microbiano apresenta metabolismo anaeróbio e/ou microaerófio, o que pode resultar em morte celular e perda da funcionalidade do produto. Este trabalho teve o objetivo de avaliar o efeito da glicose oxidase sobre o aumento da sobrevivência das bactérias probióticas em iogurte, bem como em seus parâmetros de qualidade e aceitação sensorial. Foi observado o efeito potencial da glicose oxidase na redução do oxigênio dissolvido no iogurte bem como na manutenção da sua funcionalidade, sem interferência nos parâmetros de qualidade e aceitação sensorial do produto; The incorporation and viability of probiotic bacteria in processed food during its storage period is a constant challenge for the food industry, and thus requiring an understanding of intrinsic and extrinsic factors in relation to processing. The oxygen exposure is presented as a relevant factor...

Processing optimization of probiotic yogurt containing glucose oxidase using response surface methodology

CRUZ, A. G.; FERIA, J. A. F.; WALTER, E. H. M.; ANDRADE, R. R.; CAVALCANTI, R. N.; OLIVEIRA, C. A. F.; GRANATO, D.
Fonte: ELSEVIER SCIENCE INC Publicador: ELSEVIER SCIENCE INC
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
700.1804%
Exposure to oxygen may induce a lack of functionality of probiotic dairy foods because the anaerobic metabolism of probiotic bacteria compromises during storage the maintenance of their viability to provide benefits to consumer health. Glucose oxidase can constitute a potential alternative to increase the survival of probiotic bacteria in yogurt because it consumes the oxygen permeating to the inside of the pot during storage, thus making it possible to avoid the use of chemical additives. This research aimed to optimize the processing of probiotic yogurt supplemented with glucose oxidase using response surface methodology and to determine the levels of glucose and glucose oxidase that minimize the concentration of dissolved oxygen and maximize the Bifidobacterium longum count by the desirability function. Response surface methodology mathematical models adequately described the process, with adjusted determination coefficients of 83% for the oxygen and 94% for the B. longum. Linear and quadratic effects of the glucose oxidase were reported for the oxygen model, whereas for the B. longum count model an influence of the glucose oxidase at the linear level was observed followed by the quadratic influence of glucose and quadratic effect of glucose oxidase. The desirability function indicated that 62.32 ppm of glucose oxidase and 4.35 ppm of glucose was the best combination of these components for optimization of probiotic yogurt processing. An additional validation experiment was performed and results showed acceptable error between the predicted and experimental results.

Probiotic yogurts manufactured with increased glucose oxidase levels: Postacidification, proteolytic patterns, survival of probiotic microorganisms, production of organic acid and aroma compounds

Cruz, A. G.; Castro, W. F.; Faria, J. A. F.; Lollo, P. C. B.; Amaya-Farfan, J.; Freitas, M. Q.; Rodrigues, D.; Oliveira, C. A. F.; Godoy, H. T.
Fonte: Elsevier; New York Publicador: Elsevier; New York
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
696.43%
We investigated the effect of increased glucose oxidase concentration as a technological option to decrease oxidative stress during the processing of probiotic yogurts. Probiotic yogurts were produced with increased concentrations of glucose oxidase (0, 250, 500, 750, or 1,000 mg/kg) and submitted to physicochemical and microbiological analysis at 1, 15, and 30 d of refrigerated storage. Higher concentrations of glucose oxidase (750 and 1,000 mg/kg) and a longer storage time were found to have an influence on the characteristics of the probiotic yogurt, contributing to more extensive post-acidification, an increase in the dissolved oxygen level, and higher proteolysis. In addition, increased production of aroma compounds (diacetyl and acetaldehyde) and organic acids (mainly lactic acid) and a decrease in the probiotic bacteria count were reported. The use of glucose oxidase was a feasible option to minimize oxidative stress in probiotic yogurts. However, supplementation with excessive amounts of the enzyme may be ineffective, because insufficient substrate (glucose) is present for its action. Consumer tests should be performed to evaluate changes in the sensory attributes of the probiotic yogurts with increased supplementation of glucose oxidase. In addition...

Hydrogen peroxide generation with immobilized glucose oxidase for textile bleaching

Tzanov, Tzanko; Costa, Silgia; Gübitz, Georg M.; Paulo, Artur Cavaco
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2002 ENG
Relevância na Pesquisa
680.02836%
Glucose oxidase was covalently immobilized on commercially available alumina and glass supports, with a high level of protein recovery. The operational stability of the alumina carrier was an advantage over the glass support, though the rate of generation of hydrogen peroxide in the case of the latter was higher. The immobilization technique provided repeated application of the enzyme even in low concentration, and the hydrogen peroxide generated in the enzymatic reaction was successively used for textile bleaching

Decolourization of paprika dye effluent with hydrogen peroxide produced by glucose oxidase

Gonçalves, Idalina; Silva, Carla Manuela Pereira Marinho da; Paulo, Artur Cavaco
Fonte: Informa Healthcare Publicador: Informa Healthcare
Tipo: Artigo de Revista Científica
Publicado em //2012 ENG
Relevância na Pesquisa
680.02836%
Hydrogen peroxide was produced from bran by a two-step process using cellulase/xylanase and glucose oxidase, sequentially. The decolourization efficiency of the produced reagent was tested using paprika oil dye (effluent from industrial source) and high levels of colour removal (96%) were achieved after saponification pre-treatment and hydrogen peroxide application. The method is economically and environmentally advantageous since lower energy and chemical input are needed and wastewater pollution is considerably reduced. At the same time, the utilization of waste materials was successfully achieved.

Effect of glucose oxidase incorporation in chitosan edible films properties

Lopes, M. I.; Martins, Joana; Fonseca, L. P.; Vicente, A. A.
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em //2011 ENG
Relevância na Pesquisa
690.3546%
Demand for biodegradable and environmentally friendly packaging has draw attention into the development of biodegradable, polymer based edible packaging films. Edible films’ functionality can be enhanced by incorporating active substances such as biocatalysts. The main objective of this work was to evaluate the effect of GOx incorporation in the mechanical and barrier properties of chitosan edible films. Films were prepared by the casting method using 2% (w/v) chitosan with 25% (w/w) glycerol, containing 1.1% (v/v) of a glucose oxidase solution (0.02% (w/v)). Water vapor, oxygen and carbon dioxide permeabilities were evaluated and Fourier Transform InfraRed (FTIR) analysis was performed. The results of the mechanical tests showed that tensile strength and elongation-at-break values of chitosan films increased with the incorporation of glucose oxidase (from 9.6 to 10.6 MPa and from 65.5 to 71.6 %, respectively), however no significant (p<0.05) changes were observed. From permeability tests it was observed that the barrier properties of chitosan films were not affected by the enzyme incorporation. FTIR analysis showed a specific chemical interaction between functional groups of glucose oxidase and bioactive groups of chitosan. These results suggest that chitosan films with incorporated GOx could be used as active packaging as a strategy for extension of food’s shelf-life.

Partition of glucose oxidase from Aspergillus niger in aqueous two-phase systems based on salt and polyethylene glycol

Singh,Jagdish; Verma,Neelam
Fonte: Instituto de Tecnologia do Paraná - Tecpar Publicador: Instituto de Tecnologia do Paraná - Tecpar
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2010 EN
Relevância na Pesquisa
682.7447%
The aim of this work was to study the isolation of glucose oxidase (GOx) from Aspergillus niger in aqueous two phase system consisting of PEG 7500 (150g l-1), potassium phosphate (175 g l-1, K2HPO4 +KH2PO4) and glucose (10 gl-1), the enzyme was partitioned in polymer phase. By sequential extraction GOx (69.2%) was recovered in polymer phase by 11.8 fold purification, giving a yield of 129U mg protein-¹.

Production of rabbit antibodies against purified Glucose oxidase

Zia,Muhammad Anjum; Ain,Qurat-ul; Iftikhar,Tehreema; Abbas,Rao Zahid; Rahman,Khalil-ur
Fonte: Instituto de Tecnologia do Paraná - Tecpar Publicador: Instituto de Tecnologia do Paraná - Tecpar
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2012 EN
Relevância na Pesquisa
695.6437%
Glucose oxidase is an active oxygen species generating enzyme produced from Aspergillus niger grown in submerged fermentation. Disintegration of the mycelium resulted in high glucose oxidase activity that was subjected to ammonium sulfate precipitation at 60-85% saturation rates that resulted to 6.14 U mg -1 specific activity. Purification of enzyme by anion exchange column (DEAE-Cellulose) resulted into 22.53 U mg-1 specific activity and 10.27 fold purification. This was applied to sephadex G-200 column for gel filtration chromatography. It was observed that enzyme achieved 59.37 U mg-1of specific activity with 27.08 fold purity and 64.36% recovery. Purified glucose oxidase was injected into rabbits through intravenous route, to raise the glucose oxidase antibodies. After 30 days incubation period, the rabbits were slaughtered and serum was separated from blood. The antibodies were isolated by ammonium sulfate precipitation and confirmed by agar gel precipitation test. This could be a convenient and low cost alternate assay for the estimation of glucose oxidase in biological fluids. Moreover, such antibodies against the said enzyme could be used in various therapeutic and diagnostic applications.

Evaluation of Antimicrobial Activity of Glucose Oxidase from Aspergillus niger EBL-A and Penicillium notatum

Zia,Muhammad Anjum; Riaz,Ayesha; Rasul,Samreen; Abbas,Rao Zahid
Fonte: Instituto de Tecnologia do Paraná - Tecpar Publicador: Instituto de Tecnologia do Paraná - Tecpar
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2013 EN
Relevância na Pesquisa
688.02445%
This work aimed to study the production and purification of glucose oxidase by Aspergillus niger and Penicillium notatum using corn steep liquor as the substrate and evaluate its antimicrobial activity for use in pharmaceutical and food industries. The enzyme was purified by ammonium sulfate precipitation (60-85%), DEAE-cellulose ion exchange and Sephadex G-200 size exclusion chromatography. The crude enzyme extracts of A. niger and P. notatum showed 2.32 and 5.53 U mg-1 specific activities, respectively, which after desalting was 15.52 and 12.05 U mg-1, and after ion exchange and gel filtration chromatography was 29.09 - 62 and 25.72 - 59.37 U mg-1 for A. niger and P. notatum, respectively. The antimicrobial activity was determined by disc diffusion method against selected microbial strains where glucose oxidase from A. niger showed anti-bacterial activity, while no fungicidal effects were shown by both A. niger and P. notatum glucose oxidases.

Invertase, glucose oxidase and catalase for converting sucrose to fructose and gluconic acid through batch and membrane-continuous reactors

Silva,Aline Ramos da; Tomotani,Ester Junko; Vitolo,Michele
Fonte: Universidade de São Paulo, Faculdade de Ciências Farmacêuticas Publicador: Universidade de São Paulo, Faculdade de Ciências Farmacêuticas
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2011 EN
Relevância na Pesquisa
688.02445%
Conversion of sucrose into fructose and gluconic acid using invertase, glucose oxidase and catalase was studied by discontinuous (sequential or simultaneous addition of the enzymes) and continuous (simultaneous addition of the enzymes in a 100 kDa-ultrafiltration membrane reactor) processes. The following parameters were varied: concentration of enzymes, initial concentration of substrates (sucrose and glucose), pH, temperature and feeding rate (for continuous process). The highest yield of conversion (100%) was attained through the discontinuous (batch) process carried out at pH 4.5 and 37 ºC by the sequential addition of invertase (14.3 U), glucose oxidase (10,000 U) and catalase (59,000 U).

Eignung lyophilisierter Glucose-Oxidase-haltiger Liposomen zur Korrektur der NADPH-Oxidase-Defizienz bei Granulozyten; Suitability of glucose oxidase containing liposomes for the correction of NADPH oxidase deficiency in granulocytes

Hauschild, Oliver
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
DE_DE
Relevância na Pesquisa
701.67875%
Neutrophile Granulozyten stellen die erste zelluläre Barriere bei der Abwehr pathogener Keime dar. Ihre mikrobizide Fähigkeit beruht zu großen Teilen auf der Bildung reaktiver Sauerstoffverbindungen im "oxidativen burst". Dieser ist in erster Linie das Ergebnis des Zusammenspiels der Enzyme Myeloperoxidase und NADPH-Oxidase. Von beiden Enzymen sind angeborene Defekte bekannt. Dabei bleibt die Myeloperoxidasedefizienz klinisch meist inapparent, während die NADPH-Oxidase-Defizienz zum schweren Krankheitsbild der Septischen Granulomatose führt. Durch H2O2-generierende Glucose-Oxidase-haltige Liposomen (GOL) kann die Funktionalität neutrophiler Granulozyten in vitro rekonstituiert werden. Die GOL sind in wässriger Lösung allerdings nur von begrenzter Haltbarkeit. Die Lyophilisation stellt einen Ansatz zur Verbesserung der liposomalen Haltbarkeit dar. Im Rahmen des ersten Teils dieser Arbeit wurde untersucht, ob die Wirkungen lyophilisierter GOL auf Neutrophile mit denen konventionell hergestellter vergleichbar sind. In Aufnahmeuntersuchungen mittels FACS-Analyse konnte gezeigt werden, dass lyophilisierte Liposomen in vergleichbarem Maße wie konventionell hergestellte Liposomen selektiv durch phagozytäre Zellen aufgenommen wurden. Weiterhin wurden Untersuchungen zur Abklärung der intrazellulären Lokalisation von Liposomen durchgeführt. Mit Hilfe der konfokalen Lasermikroskopie konnte nachgewiesen werden...

Enhancement glucose oxidase production by solid-state fermentation of Aspergillus niger on polyurethane foams using mussel processing wastewaters

Mirón, Jesús; Vázquez, José Antonio; González Fernández, Pilar; Murado García, Miguel Anxo
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 918459 bytes; application/pdf
ENG
Relevância na Pesquisa
680.02836%
7 pages, 6 figures, 1 table; In the present work, studies of glucose oxidase (GOD) production in solid-state fermentation on polyurethane foams, using mussel processing wastewaters (MPW) as culture media, were carried out. Initially, the results generated in this experimental modality were compared with those that were obtained in conventional submerged fermentation. Later on, cultures were tested in solid state with fed-batch performance, defining suitable conditions of operation. These conditions were finally corroborated in experiments with a bioreactor of own design, in which GOD production was improved 13 times regarding to the initial cultures.; Peer reviewed

Invertase, glucose oxidase and catalase for converting sucrose to fructose and gluconic acid through batch and membrane-continuous reactors

Silva, Aline Ramos da; Tomotani, Ester Junko; Vitolo, Michele
Fonte: Universidade de São Paulo. Faculdade de Ciências Farmacêuticas Publicador: Universidade de São Paulo. Faculdade de Ciências Farmacêuticas
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; ; ; ; Formato: application/pdf
Publicado em 01/06/2011 ENG
Relevância na Pesquisa
693.3099%
Neste trabalho estudou-se a conversão da sacarose em frutose e ácido glicônico, usando as enzimas invertase, glicose oxidase e catalase, através do emprego de processo descontínuo (com adição sequencial ou simultânea das enzimas) e contínuo (adição simultânea das enzimas em reator com membrana acoplado à membrana de ultrafiltração de 100 kDa). Os parâmetros variados foram: a concentração das enzimas, a concentração inicial dos substratos (sacarose e glicose), o pH, a temperatura e a vazão específica de alimentação (processo contínuo). Obteve-se rendimento de 100%, quando a conversão foi conduzida por processo descontínuo em pH 4,5 e a 37 ºC com adição seqüencial das enzimas invertase (14,3 U), glicose oxidase (10.000 U) e catalase (59.000 U).; Conversion of sucrose into fructose and gluconic acid using invertase, glucose oxidase and catalase was studied by discontinuous (sequential or simultaneous addition of the enzymes) and continuous (simultaneous addition of the enzymes in a 100 kDa-ultrafiltration membrane reactor) processes. The following parameters were varied: concentration of enzymes, initial concentration of substrates (sucrose and glucose), pH, temperature and feeding rate (for continuous process). The highest yield of conversion (100%) was attained through the discontinuous (batch) process carried out at pH 4.5 and 37 ºC by the sequential addition of invertase (14.3 U)...