40 research outputs found

    Optimal Conditions for Continuous Immobilization of Pseudozyma hubeiensis (Strain HB85A) Lipase by Adsorption in a Packed-Bed Reactor by Response Surface Methodology

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    This study aimed to develop an optimal continuous process for lipase immobilization in a bed reactor in order to investigate the possibility of large-scale production. An extracellular lipase of Pseudozyma hubeiensis (strain HB85A) was immobilized by adsorption onto a polystyrene-divinylbenzene support. Furthermore, response surface methodology (RSM) was employed to optimize enzyme immobilization and evaluate the optimum temperature and pH for free and immobilized enzyme. The optimal immobilization conditions observed were 150 min incubation time, pH 4.76, and an enzyme/support ratio of 1282 U/g support. Optimal activity temperature for free and immobilized enzyme was found to be 68°C and 52°C, respectively. Optimal activity pH for free and immobilized lipase was pH 4.6 and 6.0, respectively. Lipase immobilization resulted in improved enzyme stability in the presence of nonionic detergents, at high temperatures, at acidic and neutral pH, and at high concentrations of organic solvents such as 2-propanol, methanol, and acetone

    Immobilization of Peroxidase onto Magnetite Modified Polyaniline

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    The present study describes the immobilization of horseradish peroxidase (HRP) on magnetite-modified polyaniline (PANImG) activated with glutaraldehyde. After the optimization of the methodology, the immobilization of HRP on PANImG produced the same yield (25%) obtained for PANIG with an efficiency of 100% (active protein). The optimum pH for immobilization was displaced by the effect of the partition of protons produced in the microenvironment by the magnetite. The tests of repeated use have shown that PANImG-HRP can be used for 13 cycles with maintenance of 50% of the initial activity

    Antioxidant and anitoperoxidative effect of polypeptides from common beans (Phaseolus vulgaris, cv BRS Pontal) / Efeito antioxidante e anitoperoxidativo dos polipéptidos do feijão comum (Phaseolus vulgaris, cv BRS Pontal)

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    Common beans have high content of protein and can be used as source for obtaining bioactive peptides which are compounds that exhibit an effect on body functions or conditions and may influence human health. This study was undertaken to examine the antioxidant and antiperoxidative potential of naturally-occurring peptides from easy-to-cook (ETC) and hard-to-cook (HTC) beans (Phaseolus vulgaris, cv BRS Pontal). The extracted proteins were partially purified using ultrafiltration membranes. Thereafter, the antioxidant activity of the produced fractions was analyzed by DPPH and FRAP methods. The lipid peroxidation was measured by thiobarbituric acid reactive substances (TBARS) analysis. Results evidenced that the antioxidant potential was highly improved after ultrafiltration, especially for those fractions containing molecules with low molecular weight. Peptide fractions (F3-10kDa) from ETC beans exhibited a better ability to inhibit the reactive oxygen species formation when compared to the synthetic antioxidant BHT, which corroborates their antioxidant role and protection against lipid peroxidation. Regarding the peptide fractions from HTC beans, the samples had similar lipid peroxidation to BHT in the tested concentration range (200 to 600?g). The HTC phenomenon did not seem to affect definitively the bioactivity of the bioactive peptides, suggesting that it is possible to use these components as an alternative for the use of the grains affected by the hardening process

    Educomunicação e suas áreas de intervenção: Novos paradigmas para o diálogo intercultural

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    oai:omp.abpeducom.org.br:publicationFormat/1O material aqui divulgado representa, em essência, a contribuição do VII Encontro Brasileiro de Educomunicação ao V Global MIL Week, da UNESCO, ocorrido na ECA/USP, entre 3 e 5 de novembro de 2016. Estamos diante de um conjunto de 104 papers executivos, com uma média de entre 7 e 10 páginas, cada um. Com este rico e abundante material, chegamos ao sétimo e-book publicado pela ABPEducom, em seus seis primeiros anos de existência. A especificidade desta obra é a de trazer as “Áreas de Intervenção” do campo da Educomunicação, colocando-as a serviço de uma meta essencial ao agir educomunicativo: o diálogo intercultural, trabalhado na linha do tema geral do evento internacional: Media and Information Literacy: New Paradigms for Intercultural Dialogue

    PRODUÇÃO DE POLÍMEROS BIODEGRADÁVEIS REFORÇADOS COM FIBRAS NATURAIS E SUA APLICAÇÃO EM DESIGN DE PRODUTOS

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    Neste estudo foram produzidos materiais biodegradáveis em que o polímero plástico álcool polivinílico (PVA) foi reforçado com a adição de polissacarídeo de goma de cajueiro (PEJU) e pó de serragem. As formulações foram testadas a fim de ajustar a viscosidade e estabilidade da suspensão, bem como a estabilidade estrutural dos materiais obtidos. A introdução de PEJU conferiu maior viscosidade e adesividade à suspensão, com consequente melhora na maneabilidade dos materiais. O pó de serragem tratado por autoclavagem em meio aquoso, ácido ou básico apresentou diferentes características, sendo o material obtido por autoclavagem em meio ácido o que apresentou melhor desempenho na formulação dos compósitos e na modelagem do produto final. Foram produzidas peças de xadrez com compósitos contendo pó de serragem autoclavado em meio básico tingido com corante verde e com compósitos contendo pó de serragem autoclavado em meio ácido. Os materiais produzidos neste estudo apresentam boas perspectivas de aplicação em design de produtos, com potencial para manufatura de diferentes produtos em função das características variadas que foram obtidas
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