| dc.creator | Ibrahim,Abdelnasser S.S. | |
| dc.creator | Al-Salamah,Ali A | |
| dc.creator | El-Toni,Ahmed Mohamed | |
| dc.creator | El-Tayeb,Mohamed A | |
| dc.creator | Elbadawi,Yahya B | |
| dc.date | 2014-03-01 | |
| dc.date.accessioned | 2019-05-03T12:45:11Z | |
| dc.date.available | 2019-05-03T12:45:11Z | |
| dc.identifier | https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0717-34582014000200001 | |
| dc.identifier.uri | http://revistaschilenas.uchile.cl/handle/2250/85402 | |
| dc.description | Background Cyclodextrin glucanotransferase (CGTase) from Amphibacillus sp. NPST-10 was covalently immobilized onto amino-functionalized magnetic double mesoporous core-shell silica nanospheres (mag@d-SiO2@m-SiO2-NH2), and the properties of the immobilized enzyme were investigated. The synthesis process of the nanospheres included preparing core magnetic magnetite (Fe3O4) nanoparticles, coating the Fe3O4 with a dense silica layer, followed by further coating with functionalized or non-functionalized mesoporous silica shell. The structure of the synthesized nanospheres was characterized using TEM, XRD, and FT-IR analyses. CGTase was immobilized onto the functionalized and non-functionalized nanospheres by covalent attachment and physical adsorption. Results The results indicated that the enzyme immobilization by covalent attachment onto the activated mag@d-SiO2@m-SiO2-NH2, prepared using anionic surfactant, showed highest immobilization yield (98.1%), loading efficiency (96.2%), and loading capacity 58 µg protein [CGTase]/mg [nanoparticles]) which were among the highest yields reported so far for CGTase. Compared with the free enzyme, the immobilized CGTase demonstrated a shift in the optimal temperature from 50°C to 50-55°C, and showed a significant enhancement in the enzyme thermal stability. The optimum pH values for the activity of the free and immobilized CGTase were pH 8 and pH 8.5, respectively, and there was a significant improvement in pH stability of the immobilized enzyme. Moreover, the immobilized CGTase exhibited good operational stability, retaining 56% of the initial activity after reutilizations of ten successive cycles. Conclusion The enhancement of CGTase properties upon immobilization suggested that the applied nano-structured carriers and immobilization protocol are promising approach for industrial bioprocess for production of cyclodextrins using immobilized CGTase. | |
| dc.format | text/html | |
| dc.language | en | |
| dc.publisher | Pontificia Universidad Católica de Valparaíso | |
| dc.relation | 10.1016/j.ejbt.2014.01.001 | |
| dc.rights | info:eu-repo/semantics/openAccess | |
| dc.source | Electronic Journal of Biotechnology v.17 n.2 2014 | |
| dc.subject | Amphibacillus sp | |
| dc.subject | Cyclodextrin glucanotransferase | |
| dc.subject | Cyclodextrins | |
| dc.subject | Double mesoporous core-shell silica nanospheres | |
| dc.subject | Immobilization | |
| dc.title | Cyclodextrin glucanotransferase immobilization onto functionalized magnetic double mesoporous core-shell silica nanospheres | |
