Covalent immobilization of invertase on polyurethane, plast-film and ferromagnetic Dacron

Abstract

Invertase was covalently immobilized on polyurethane (PU), inox plate covered with plast-film layer and ferromagnetic azide-Dacron. The immobilization processes, physico-chemical parameters and a model for coupling reactions were studied. The preliminary studies for selection of the support showed that the best activity was obtained for PU treated with HCl, polyethylenimine and glutaraldehyde (156.7+/-4.9 U/g support). All plast-film-invertase derivatives did not show activity and the Dacron-invertase derivative showed an activity of 105.39 U/g support. The invertase immobilized in presence of substrate (10% w/v sucrose) was the most efficient (832.74+/-1.48 U/g support). The optimal pH was shifted from 4.5 (free enzyme) to 5.0 (immobilized derivative) and optimal temperature was not affected. Activation energy values of free enzyme, Dacron-invertase and PU-invertase were 32.4+/-0.34 kJ/mol, 33.4+/-0.36 kJ/mol and 44.0+/-0.67 kJ/mol, respectively. The PU-invertase could be used over 2 months without considerable activity loss (68.5% activity retention) and retained 12.6% (287.97+/-27.9U/g support) of the activity after five cycles.

High sucrolytic activity by invertase immobilized onto magnetic diatomaceous earth nanoparticles

“…In the present study, the mDE-APTES-invertase presented the highest specific activity (3358 U mg −1 protein) in comparison to the values of the other studies. The works that reached the highest specific activities found in the literature used as matrix for invertase immobilization the poly(ethyleneoxide)/polypyrrole (PEO-co-PPy) with a specific activity equal to 1389 U mg −1 protein and the Ferromagnetic azide-Dacron with 1053 U mg −1 protein [24], [25]. The other derivatives presented in Table 3 yielded specific activities in the range from 0.12 to 701 U mg −1 protein.…”

Immobilization of chloroperoxidase onto highly hydrophilic polyethylene chains via bio-conjugation: Catalytic properties and stabilities

“…This makes the conjugated-enzyme more suitable for use. Thus, the catalytic performance of the conjugated CPO was not significantly affected too much by the applied immobilization protocols Cadena et al, 2010).…”

EFEITO DA ESTABILIDADE DE ESTOCAGEM DA LIPASE COMERCIAL DE Candida antarctica B (CALB) NA FORMA LIVRE E IMOBILIZADA POR CONFINAMENTO EM SUPORTE DE POLIURETANO

“…Já o uso da invertase imobilizada em PU obteve uma estabilidade por um período de 60 dias, sem perda considerável atividade (68,5 % de retenção da atividade) (Cadena et al, 2010). Muruci et al (2012) estudaram a enzima de Aspergillus niger em fermentação semi-sólida obterem em 30 dias de estocagem sob refrigeração, a enzima manteve-se com 52,2 % de atividade residual, porém, com 120 dias houve uma perda de 94 % de sua atividade residual.…”