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Immobilizing penicillin G acylase using silica-supported ionic liquids / Huacong Zhou in Industrial & engineering chemistry research, Vol. 51 N° 40 (Octobre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13173–13181 Titre : Immobilizing penicillin G acylase using silica-supported ionic liquids : The effects of ionic liquid loadings Type de document : texte imprimé Auteurs : Huacong Zhou, Auteur ; Liangrong Yang, Auteur ; Wei Li, Auteur Année de publication : 2012 Article en page(s) : pp. 13173–13181 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Loading  Ionic  liquid Résumé : The supported ionic liquids (SILs) were prepared via immobilizing silane-functionalized ionic liquids (IL) onto the monodispersive silica nanoparticles, and the composite material was then applied in the immobilization of penicillin G acylase (PGA, EC 3.5.1.11), an important industrial enzyme for the production of semisynthetic antibiotics. This was a novel approach of immobilizing PGA proposed in our previous report, in which we had studied the effects of IL types on the performance of this novel support. Here, we focused on the effects of IL loading on the properties of the SILs and their performance in PGA immobilization. The effects of silica sizes and routes of preparing SILs (the solvent route and the sol-gel route) on IL loading were investigated. The results showed that (1) the IL loading could be tuned efficiently by changing the silica sizes. (2) As compared with the solvent route, the sol-gel route is more simple, time-saving, and ecofriendly in operation. What's more, it has a higher IL loading. Among the factors affecting the IL loading, the reaction time was the most feasible factor to control to tune the IL loading, as compared with the temperature and the dosage of ILs. (3) With the increase of IL loading, the surface ζ-potential of silicas changed from negative to positive, and the isoelectronic point (IEP) increased accordingly, which caused the decrease of the protein loading but the increase of apparent and specific activity. A reusability experiment showed that the sol-gel 1 sample maintained approximately 55% of the initial activity even after 10 consecutive operation cycles under the experimental conditions. This activity was 3.7 times higher than that of the sol-gel 2 sample. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26451467 [article] Immobilizing penicillin G acylase using silica-supported ionic liquids : The effects of ionic liquid loadings [texte imprimé] / Huacong Zhou, Auteur ; Liangrong Yang, Auteur ; Wei Li, Auteur . - 2012 . - pp. 13173–13181. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13173–13181 Mots-clés : Loading  Ionic  liquid Résumé : The supported ionic liquids (SILs) were prepared via immobilizing silane-functionalized ionic liquids (IL) onto the monodispersive silica nanoparticles, and the composite material was then applied in the immobilization of penicillin G acylase (PGA, EC 3.5.1.11), an important industrial enzyme for the production of semisynthetic antibiotics. This was a novel approach of immobilizing PGA proposed in our previous report, in which we had studied the effects of IL types on the performance of this novel support. Here, we focused on the effects of IL loading on the properties of the SILs and their performance in PGA immobilization. The effects of silica sizes and routes of preparing SILs (the solvent route and the sol-gel route) on IL loading were investigated. The results showed that (1) the IL loading could be tuned efficiently by changing the silica sizes. (2) As compared with the solvent route, the sol-gel route is more simple, time-saving, and ecofriendly in operation. What's more, it has a higher IL loading. Among the factors affecting the IL loading, the reaction time was the most feasible factor to control to tune the IL loading, as compared with the temperature and the dosage of ILs. (3) With the increase of IL loading, the surface ζ-potential of silicas changed from negative to positive, and the isoelectronic point (IEP) increased accordingly, which caused the decrease of the protein loading but the increase of apparent and specific activity. A reusability experiment showed that the sol-gel 1 sample maintained approximately 55% of the initial activity even after 10 consecutive operation cycles under the experimental conditions. This activity was 3.7 times higher than that of the sol-gel 2 sample. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26451467

Improving the stability of immobilized penicillin G acylase via the modification of supports with ionic liquids / Huacong Zhou in Industrial & engineering chemistry research, Vol. 51 N° 12 (Mars 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4582–4590 Titre : Improving the stability of immobilized penicillin G acylase via the modification of supports with ionic liquids Type de document : texte imprimé Auteurs : Huacong Zhou, Auteur ; Liangrong Yang, Auteur ; Wei Li, Auteur Année de publication : 2012 Article en page(s) : pp. 4582–4590 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Ionic  liquids  Nanoparticles Résumé : With the aim of improving the stability of penicillin G acylase (PGA), functional ionic liquids (ILs) were used to modify the surface chemistry of the supports on which they were physically adsorbed. Four kinds of ILs—specifically, 1-methyl-3-(triethoxysilylpropyl)-imidazolium salts, with Cl–, BF4–, PF6–, and Tf2N– as the anions (IL-Cl–, BF4–, PF6–, and Tf2N–, respectively)—were used to tune the hydrophilic or hydrophobic properties of the ILs. The synthesized ILs were first immobilized on magnetic silica nanoparticles (Fe3O4/SiO2), and the composite material (Fe3O4/SiO2–IL) was then applied to immobilize PGA via physical adsorption. The amount of protein loading, the specific activity, the immobilization yield, and the stability of immobilized PGA were investigated to evaluate the effects of the ILs on the PGA immobilization. The results showed that PGA immobilized on Fe3O4/SiO2–ILs was more stable than that immobilized on Fe3O4/SiO2 with no IL modification. Among the four kinds of ILs tested, the hydrophilic ILs (IL-Cl–, and IL-BF4–) were superior to the hydrophobic ones (IL-PF6–, and IL-Tf2N–) for PGA immobilization. The reusability of the immobilized PGA on Fe3O4/SiO2–IL (BF4–) was evaluated; a high residual activity (70% of the initial activity) was observed after 9 consecutive operation cycles under the experimental conditions. This activity was 1.8 times higher than that of immobilized PGA on naked Fe3O4/SiO2 (40%). ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202745c [article] Improving the stability of immobilized penicillin G acylase via the modification of supports with ionic liquids [texte imprimé] / Huacong Zhou, Auteur ; Liangrong Yang, Auteur ; Wei Li, Auteur . - 2012 . - pp. 4582–4590. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 12 (Mars 2012) . - pp. 4582–4590 Mots-clés : Ionic  liquids  Nanoparticles Résumé : With the aim of improving the stability of penicillin G acylase (PGA), functional ionic liquids (ILs) were used to modify the surface chemistry of the supports on which they were physically adsorbed. Four kinds of ILs—specifically, 1-methyl-3-(triethoxysilylpropyl)-imidazolium salts, with Cl–, BF4–, PF6–, and Tf2N– as the anions (IL-Cl–, BF4–, PF6–, and Tf2N–, respectively)—were used to tune the hydrophilic or hydrophobic properties of the ILs. The synthesized ILs were first immobilized on magnetic silica nanoparticles (Fe3O4/SiO2), and the composite material (Fe3O4/SiO2–IL) was then applied to immobilize PGA via physical adsorption. The amount of protein loading, the specific activity, the immobilization yield, and the stability of immobilized PGA were investigated to evaluate the effects of the ILs on the PGA immobilization. The results showed that PGA immobilized on Fe3O4/SiO2–ILs was more stable than that immobilized on Fe3O4/SiO2 with no IL modification. Among the four kinds of ILs tested, the hydrophilic ILs (IL-Cl–, and IL-BF4–) were superior to the hydrophobic ones (IL-PF6–, and IL-Tf2N–) for PGA immobilization. The reusability of the immobilized PGA on Fe3O4/SiO2–IL (BF4–) was evaluated; a high residual activity (70% of the initial activity) was observed after 9 consecutive operation cycles under the experimental conditions. This activity was 1.8 times higher than that of immobilized PGA on naked Fe3O4/SiO2 (40%). ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202745c