20.500.12556/DKUM-95702 Stabilizacija superoksid dismutaze (sod) iz Pleurotus ostreatus magistrsko delo Stabilization of superoxide dismutase (sod) from Pleurotus ostreatus Magistrsko delo obravnava stabilizacijo encima superoksid dismutaze (SOD), izoliranega iz Pleurotus ostreatus, užitne gobe z odličnimi antioksidativnimi lastnostmi. Glavni namen raziskave je bil proučiti metode sproščanja intracelularnih encimov iz micelija P. ostreatus, nato pa razviti sistem enkapsulacije izolirane SOD za njeno stabilizacijo. Celice P. ostreatus smo odprli z uporabo dveh različnih metod: s konvencionalno metodo mehanske homogenizacije z rotor-stator homogenizatorjem in z izpostavitvijo superkritičnemu ogljikovemu dioksidu (SC CO2). Učinkovitost celične lize smo ovrednotili z Bradfordovo metodo, s katero smo določili koncentracijo sproščenih intracelularnih encimov, nato pa še z modificirano Marklundovo metodo, s katero smo določili aktivnost izolirane SOD. Encimski ekstrakt smo nato enkapsulirali v alginatne kroglice, ki smo jih izpostavili simulirani želodčni (SGF) in simulirani črevesni tekočini (SIF), da bi in vitro proučili sproščanje SOD v telo. Za karakterizacijo površinskih in strukturnih lastnosti ter kemijske sestave alginatnih kroglic smo uporabili vrstični elektronski mikroskop z emisijsko disperzijsko spektroskopijo (SEM-EDS). Prisotnost funkcionalnih skupin v alginatnih kroglicah smo določili s Fourierjevo transformacijsko infrardečo spektroskopijo (FTIR). Rezultati so pokazali, da je mehanska homogenizacija pri lizi celičnih sten bolj učinkovita. Z njo smo dosegli sprostitev 4,07 mg proteinov na g P. ostreatus, medtem ko s SC CO2 le 0,0629 mg proteinov na g P. ostreatus. Specifična aktivnost SOD je bila pri obeh metodah primerljiva. Natrijev alginat se je izkazal kot odlično enkapsulacijsko sredstvo, ki vzdrži pH pogoje želodca in omogoči postopno sproščanje aktivne SOD v tankem črevesju, kar je ključnega pomena za potencialno peroralno aplikacijo. V SGF se je zaradi kislih pogojev sproščena SOD takoj deaktivirala, medtem ko je bila v SIF najvišja specifična aktivnost SOD dosežena po 180 min izpostavitve. Tedaj je za mehansko homogeniziran vzorec znašala 86,2 % začetne specifične aktivnosti enkapsuliranega vzorca, za SC CO2 vzorec pa 91,4 %. Na podlagi dobljenih rezultatov smo zaključili, da odpiranje celic z mehansko homogenizacijo in enkapsulacija v alginat nudita obetavno strategijo za kontrolirano dostavo encima SOD v tarčna področja znotraj prebavnega trakta. The master's thesis deals with the stabilization of the enzyme superoxide dismutase (SOD) isolated from Pleurotus ostreatus, an edible mushroom with excellent antioxidant properties. The main purpose of the research was to study the methods of releasing intracellular enzymes from the mycelium of P. ostreatus, and then to develop an encapsulation system for isolated SOD for its stabilization. P. ostreatus cells were opened using two methods: the conventional method of mechanical homogenization with a rotor-stator homogenizer and by exposure to supercritical carbon dioxide (SC CO2). The efficiency of cell lysis was evaluated using the Bradford method to determine the concentration of released intracellular enzymes, and then using the modified Marklund method to measure the activity of isolated SOD. The enzyme extract was then encapsulated in alginate beads, which were exposed to simulated gastric (SGF) and simulated intestinal fluid (SIF) to study the release of SOD into the body in vitro. Scanning electron microscopy with emission dispersive spectroscopy (SEM-EDS) was used to characterize the surface and structural properties and chemical composition of alginate beads. The presence of functional groups in alginate beads was determined by Fourier transform infrared spectroscopy (FTIR). The results showed that mechanical homogenization was more effective in lysis of cell walls. It achieved the release of 4.07 mg of proteins per g of P. ostreatus, while SC CO2 only achieved 0.0629 mg of proteins per g of P. ostreatus. The specific SOD activity was comparable in both methods. Sodium alginate proved to be an excellent encapsulation agent that withstands the pH conditions of the stomach and allows for the gradual release of active SOD in the small intestine, which is crucial for potential oral application. In SGF, the released SOD was immediately deactivated due to acidic conditions, while in SIF, the highest specific SOD activity was reached after 180 min of exposure. At that time, the mechanically homogenized sample had 86.2% of the initial specific activity of the encapsulated sample, and the SC CO2 sample had 91.4%. Based on the obtained results, we concluded that opening the cells by mechanical homogenization and encapsulation in alginate offer a promising strategy for the controlled delivery of the SOD enzyme to target areas within the digestive tract. Based on the results obtained, we concluded that opening cells by mechanical homogenization and encapsulation in alginate offer a promising strategy for the controlled delivery of the SOD enzyme to target areas within the digestive tract. Pleurotus ostreatus antioksidativni stres superoksid dismutaza enkapsulacija alginatne kroglice Pleurotus ostreatus antioxidant stress superoxide dismutase encapsulation alginate beads true true false [L. Kuselj] Slovenski jezik Angleški jezik Magistrsko delo/naloga 2025-10-13 16:31:32 2025-11-20 09:11:18 2025-12-13 03:07:56 0000-00-00 00:00:00 2025 0 Maribor 0 Maribor 1 spletni vir (1 datoteka PDF (IX, 40 str.)) 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 577.151:635.8(043.2) 261093379 MAG_Kuselj_Luna_2025.pdf MAG_Kuselj_Luna_2025.pdf 1 9F19C4AFBCCB81390E6B1430768237F2 11fb645cf08b6da4e6dcff92062fabbc04ead8b70a050c3d51ddb1ed47fbf175 1233f9f4-a862-11f0-9756-00155d000105 https://dk.um.si/Dokument.php?lang=slv&id=199820 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0