Immobilization/stabilization on Eupergit C of the β-galactosidase from B. circulans and an α-galactosidase from Aspergillus oryzae

Hernáiz, María J.; Crout, David H. G.

doi:10.1016/s0141-0229(00)00150-2

Cited by 112 publications

(75 citation statements)

References 18 publications

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“…Lower efficiencies for immobilised laccase and catalase from Lentinus edodes on Eupergit C were also reported by D'Annibale et al (2000) and Alptekin et al (2010), respectively. Several authors have suggested that this effect could be related to diffusion substrate limitations, substrate partitioning, lower accessibility of the substrate to the active site, protein conformational changes, internal mass transport constraint and/or substrate/product adsorption onto the carrier surface (Davis and Burns 1992;Hernaiz and Crout 2000;Rekuc et al 2010;Yamak et al 2009). …”

Section: Determination Of Apparent Kinetic Parametersmentioning

confidence: 99%

“…Under these circumstances, the operation time of the reactor might be increased in order to assure high levels of dye removal. This decrease on the removal percentages may be related to an enzyme inactivation produced by operational conditions, diffusion problems caused by dye or products adsorption onto the carrier surface and the potential clogging phenomena caused by insoluble products formed (Hernaiz and Crout 2000;Rekuc et al 2010). In order to verify that assumption, the residual activity after the fourth cycle was determined after washing the biocatalyst with 0.1 M phosphate buffer (pH 7).…”

Section: Decolourisation Of a Model Synthetic Dye By Immobilised Laccasementioning

confidence: 99%

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Immobilisation of laccase on Eupergit supports and its application for the removal of endocrine disrupting chemicals in a packed-bed reactor

et al. 2011

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Laccase from Myceliophthora thermophila was covalently immobilised on Eupergit C and Eupergit C 250L yielding specific activities of up to 17 and 80 U/g, respectively. Due to its superior activity, Eupergit C 250L was chosen for further research. The somewhat lower catalytic efficiency (based on the ratio between the turnover number and the Michaelis constant, k cat /K M ) of the immobilised enzyme in comparison with that of the free enzyme was balanced by its increased stability and broader operational window related to temperature and pH. The feasibility of the immobilised laccase was tested by using a packed bed reactor (PBR) operating in consecutive cycles for the removal of Acid Green 27 dye as model substrate. High degrees of elimination were achieved (88, 79, 69 and 57% in 4 consecutive cycles), while the levels of adsorption on the support varied from 18 to 6%, proving that dye removal took place mainly due to the action of the enzyme. Finally, a continuous PBR with the solid biocatalyst was applied for the treatment of a solution containing the following endocrine disrupting chemicals: estrone (E1), 17b-estradiol (E2) and 17a-ethinylestradiol (EE2). At steady-state operation, E1 was degraded by 65% and E2 and EE2 were removed up to 80% and only limited adsorption of these compounds on the support, between 12 and 22%, was detected. In addition, a 79% decrease in estrogenic activity was detected in the effluent of the enzymatic reactor while only 14% was attained by inactivated laccase.

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Section: Determination Of Apparent Kinetic Parametersmentioning

confidence: 99%

Section: Decolourisation Of a Model Synthetic Dye By Immobilised Laccasementioning

confidence: 99%

Immobilisation of laccase on Eupergit supports and its application for the removal of endocrine disrupting chemicals in a packed-bed reactor

et al. 2011

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“…Além disso, a imobilização, permite ultrapassar as desvantagens da solubilidade do meio reacional e da instabilidade operacional durante o uso industrial das mesmas, tornando os catalisadores ideais para o desenvolvimento de uma indústria química sustentável, capaz de sintetizar compostos complexos e úteis, sob condições suaves e economicamente mais rentáveis. Essas vantagens tornam as reações catalisadas por enzimas imobilizadas potencialmente competitivas, frente ao uso de catalisadores químicos (Guisan, 2013;Mendes, 2009;Guisan, 2006;Hernaiz e Crout, 2000).…”

Section: Introductionunclassified

Imobilização De Uma Protease Obtida De Bacillus Sp. P45

Fadanni¹,

Reis²,

Brandelli³

et al. 2015

Anais Do Congresso Brasileiro De Engenharia Química Em Iniciação Científica - Cobeq IC 2015

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RESUMO -As enzimas proteolíticas constituem um dos mais importantes grupos de enzimas comerciais, atuando como catalisadores na indústria de detergentes, no processamento de alimentos, na indústria de couro, dentro outras aplicações. Essas enzimas apresentam vantagens sobre o uso de catalisadores químicos convencionais, pois exibem alta atividade catalítica e alto grau de especificidade pelo substrato. As aplicações industriais das enzimas são limitadas por vários fatores, tais como elevado custo, instabilidade em pH e temperatura elevados e sua disponibilidade. Dentre muitas abordagens tecnológicas, a imobilização de enzimas apresenta vantagem sobre sistemas de enzimas livres convencionais, no que diz respeito à estabilidade operacional e maior eficiência de catálise A protease parcialmente purificada obtida de Bacillus sp. P45 foi imobilizada através de diferentes métodos e utilizando diferentes suportes. Foram avaliadas 3 diferentes metodologias com a finalidade de avaliar a capacidade de adsorção dos suportes. Os resultados mais promissores para imobilização da enzima foram com o emprego de quitosana e glutaraldeído e Amberlite IR 120, com atividade enzimática de 12,69 e 6,25 U/g de suporte, respectivamente. INTRODUÇÃOAs enzimas apresentam uma série de características que fazem seu uso vantajoso, em comparação com produtos químicos convencionais. O primeiro deles é uma alta eficiência catalítica, frequentemente superior aos catalisadores químicos, além de apresentar um elevado grau de especificidade, não só pela reação entre os substratos, por partes semelhantes de moléculas (regioespeficidade) e também entre os isômeros ópticos (estereoespeficidade). Essas especificidades garantem que a reação catalisada não é perturbada por reações secundárias, resultando na formação do produto final desejado, enquanto que a produção de subprodutos indesejáveis é eliminada. Isto proporciona um maior rendimento da reação, reduzindo os custos de produção (Krajewska, 2004;Basílio, 1994; Zentgraf e Ahern, 1991).Além disso, as enzimas geralmente atuam em condições moderadas de temperatura, pressão e pH, com velocidades de reação na mesma ordem dos catalisadores químicos em condições extremas. Devido a esse conjunto de vantagens, desde 1960, as enzimas tem sido

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“…The enzyme was reported to have stronger hydrolytic activity than transferase activity and produced a high proportion of trisaccharide in the synthetic GOS mixtures [1,2,7]. Some techniques have been developed for immobilization of ß-galactosidase including non-covalent adsorption, covalent binding, entrapment and encapsulation [1][2][3][8][9][10][11]. The newly developed synthetic micro porous membrane adsorbers as chromatographic media are an attractive alternative to traditionally used packed bed chromatography, which has several limitations [12].…”

Section: Introductionmentioning

confidence: 99%

Membrane chromatography reactor system for the continuous synthesis of galactosyl-oligosaccharides

Engel¹,

Ebrahimi²,

Czermak

2008

Desalination

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Immobilization/stabilization on Eupergit C of the β-galactosidase from B. circulans and an α-galactosidase from Aspergillus oryzae

Cited by 112 publications

References 18 publications

Immobilisation of laccase on Eupergit supports and its application for the removal of endocrine disrupting chemicals in a packed-bed reactor

Immobilisation of laccase on Eupergit supports and its application for the removal of endocrine disrupting chemicals in a packed-bed reactor

Imobilização De Uma Protease Obtida De Bacillus Sp. P45

Membrane chromatography reactor system for the continuous synthesis of galactosyl-oligosaccharides

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