ImobilizaÃÃo covalente de Ã-Dfrutofuranosidase (invertase) em suporte vÃtreo-cerÃmico

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

Ã-D-Fructofuranosidase (invertase, E.C. 3.2.1.26) of Saccharomyces cerevisiae was covalently immobilized at ceramic support surface synthesized from fly ashes of mineral coal added of glass beads (50-100μm), modified with ?- aminopropiltriethylxisilane (APTS), followed by glutaraldehyde which acts as agent bifuncional responsible for the cross-linked attachment between the enzyme and the inorganic support. At immobilization APTS 2% (v/v) diluted in toluene was used, which promotes an alkilamine covalent attachment type with glutaraldehyde 2.5% (v/v) in Phosphate Sodium Buffer 10mM pH 7.4 after activation process which also attach covalently with the enzyme through Schiffâs base. The derivated immobilized hydrolysis activity stability was obtained in approximately 76.31% at six reuses with 876.42mM of sucrose concentration in Citrate Sodium Buffer 100mM pH 4.6 at 55ÂC in continuous flow injection system. The Michaelis-Menten Kinetics parameters, Kmap and Vmax were estimates, so much for free enzyme 58.7mM and 72.9mM.min-1, respectively, as for the immobilized 78.5mM and 20.32mM/mL.min-1. Was observed too, differences among the maximum values of pH 5 for free and 5.6 for immobilized and temperatures of 55 and 65ÂC to free and immobilized invertase. The thermal stability values of the immobilized invertase were until 60ÂC and pH up to 5.2. The high operational stability and raw material readiness for the synthesis of the support determine the viability of the ceramic support use at the bioreactors construction in a continuous system for the glucose and fructose production from sucrose

ASSUNTO(S)

imobilizaÃÃo covalente cruzada e invertase invertase ceramic cross-link cinzas volantes fly ash cerÃmica bioquimica

ACESSO AO ARTIGO

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