20.500.12556/DKUM-41881 IMOBILIZACIJA HOLESTEROL OKSIDAZE NA MAGHEMITNE NANODELCE MODIFICIRANE S HITOZANOM IMMOBILIZATION OF CHOLESTEROL OXIDASE ONTO MAGHEMITE NANOPARTICLES MODIFIED WITH CHITOSAN Namen diplomskega dela je sinteza magnetnih maghemitnih nanodelcev, prevlečenih s hitozanom po treh različnih postopkih in imobilizacija specifičnega biokatalizatorja, holesterol oksidaze, na tako pripravljen nosilec. Primerjali smo ohranjeno aktivnost encima holesterol oksidaze po končanem procesu imobilizacije in učinkovitost imobilizacije encima na maghemitne nanodelce, prevlečene s hitozanom po treh različnih postopkih. S spreminjanjem procesnih pogojev smo želeli ugotoviti kateri delci bi bili najprimernejši za imobilizacijo encima holesterol oksidaze. Spreminjali smo koncentracijo mrežnega povezovalca glutaraldehida, hitrost stresanja in vrsto stresanja pri imobilizaciji encima, vrsto mrežnega povezovalca in koncentracijo encima holesterol oksidaze. Zanimala nas je tudi stabilnost imobiliziranega encima v primerjavi s prostim encimom in vpliv večkratne uporabe imobiliziranega encima na ohranjeno aktivnost encima. Najvišjo ohranjeno aktivnost in učinkovitost smo dosegli pri imobilizaciji encima na maghemitne nanodelce, prevlečene s hitozanom po tretjem postopku (metoda kovalentne vezave) in dodatku mrežnega povezovalca PEHA (0,02 M). Najboljše pogoje smo dosegli pri koncentraciji encima 1 mg/mL, pri hitrosti stresanja 300 rpm in času imobilizacije 24 ur. Tako imobiliziran encim smo lahko ponovno uporabili in z njim smo izvedli deset ciklov. Po 122 urah pa encim ni bil več aktiven. The purpose of the diploma thesis is the synthesis of magnetic maghemite nanoparticles coated with chitosan after three different procedures and immobilization of a specific biocatalyst, cholesterol oxidase, on a ready carrier. We compared the preserved activity of the enzyme cholesterol oxidase after the immobilization process and the efficiency of enzyme immobilization on maghemite nanoparticles coated with chitosan after three different procedures. By varying process conditions, we wanted to determine which particles would be most suitable for immobilization of the enzyme cholesterol oxidase. We changed the concentration of a crosslinker glutaraldehyde, the speed of shaking and the type of shaking at the immobilization of an enzyme, the type of a crosslinker and the concentration of the enzyme cholesterol oxidase. We were interested in the stability of the immobilized enzyme in comparison to the free enzyme, and the influence of the multiple use of an immobilized enzyme on a preserved activity of an enzyme. We have achieved the highest preserved activity and efficiency at the immobilization of an enzyme on the maghemite nanoparticles, coated with chitosan, after the third procedure (the method of covalent bonding) and with the addition of a crosslinker PEHA (0,02 M). We have achieved the best conditions were at a concentration of an enzyme 1 mg/mL, at a shaking speed of 300 rpm; and an immobilization for 24 hours. Thus immobilized enzyme could we re-use for ten cycles. After 122 hours enzyme was no longer active. imobilizacija encima holesterol oksidaza maghemitni nanodelci ohranjena aktivnost encima učinkovitost imobilizacije enzyme immobilization cholesterol oxidase maghemite nanoparticles preserved enzyme activity immobilization efficiency true true false [S. Tominc] Slovenski jezik Angleški jezik Diplomsko delo 2013-09-06 13:39:37 2013-09-26 14:33:30 2022-05-05 03:08:51 2021-04-26 03:26:12 2013 0 Maribor 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 577.15:537.622(043.2) 17478678 URN:SI:UM:DK:FZ9ORJQQ UNI_Tominc_Sara_2013.pdf UNI_Tominc_Sara_2013.pdf 1 A257C2345290DBD6CFFE7CD02D04374E 8708b762613d1e506e4f7fff28c1671f65d9e21421d5ef3a00ad90c720bfdb4e 63be9379-7c0a-11eb-bb7a-00155d0001ca https://dk.um.si/Dokument.php?lang=slv&id=59249 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0