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Immobilization of alfa-amylase on polyaniline and magnetic particles modified by polyaniline

dc.contributor.advisorKnežević-Jugović, Zorica
dc.contributor.otherGvozdenović, Milica
dc.contributor.otherBezbradica, Dejan
dc.contributor.otherAntov, Mirjana
dc.creatorRadovanović, Mirjana N.
dc.date.accessioned2023-04-07T13:33:24Z
dc.date.available2023-04-07T13:33:24Z
dc.date.issued2018
dc.identifier.urihttps://nardus.mpn.gov.rs/handle/123456789/10189
dc.identifier.urihttp://eteze.bg.ac.rs/application/showtheses?thesesId=6187
dc.identifier.urihttps://fedorabg.bg.ac.rs/fedora/get/o:18780/bdef:Content/download
dc.identifier.urihttp://vbs.rs/scripts/cobiss?command=DISPLAY&base=70036&RID=1024064458
dc.identifier.urihttps://redun.educons.edu.rs/handle/123456789/16
dc.description.abstractCilj ove disertacije bio je imobilizacija α-amilaze na polianilinu i magnetnim česticama modifikovanim polianilinom metodom adsorpcije radi dobijanja višefunkcionalnog biokatalizatorskog sistema pogodnog za višekratnu hidrolizu skroba. Istraživanja u okviru ove teze mogu se podeliti u tri dela. U prvom delu rada izvršena je sinteza i karakterizacija čestica nosača i karakterizacija α-amilaze iz Bacillus licheniformis enzimskog preparata Termamyl. Magnetne čestice (MAG) sintetisane su koprecipitacijom FeCl3 i FeSO4 u baznoj sredini, a zatim obložene polianilinskom prevlakom (MAG-PANI). Čestice polianilina (PANI) sintetisane su hemijski na granici faza dvofaznog sistema voda/hloroform. Ispitane su morfološke osobine, magnetna svojstva, IR spektri, raspodela veličine čestica i zeta potencijala MAG i MAG-PANI. Pokazano je da su sintetisani aglomerati nanočestica MAG i MAG-PANI. Površina magnetnih čestica uniformno je presvučena polianilinom vlaknaste strukture. Čestice MAG karakteriše bimodalna, a MAG-PANI trimodalna raspodela veličina čestica. U drugom delu rada izvršena je imobilizacija enzima α-amilaze na česticama MAG, MAG-PANI i PANI. Određeni su optimalni uslovi imobilizacije na MAG-PANI: vreme, početna koncentracija enzima, rN i temperatura. Ispitivanjem kinetičkih parametara Km i Vm utvrđeno je da imobilisana α-amilaza na MAG-PANI pokazuje veći afinitet prema supstratu nego imobilisana α-amilaza na MAG, a niži afinitet od slobodne α-amilaze. Utvrđen je Lengmirov (Langmuir) model adsorpcije α-amilaze na česticama MAG-PANI. U trećem delu rada ispitana je stabilnost imobilisane α-amilaze, mogućnost upotrebe kroz više ciklusa kao i operativna stabilnost u protočnom bioreaktoru sa kontinualnim i povratnim tokom. Utvrđena je rN stabilizacija α-amilaze imobilizacijom na MAG česticama i pomeranje temperaturnog optimuma imobilizacijom na MAG-PANI. Imobilisana α-amilaza na MAG-PANI zadržala je oko 55,5% početne aktivnosti nakon 9 ciklusa korišćenja i oko 80,3% početne aktivnosti nakon 50 dana čuvanja. Vreme polu-života biokatalizatora pri kontinualnim uslovima rada bilo je 6,2 h.sr
dc.description.abstractThe aim of this dissertation is to examine immobilization α-amylase on polyaniline and magnetic particles coated with polyaniline via adsorption in order to obtain a more stable biocatalyst system, with the possibility of repeated use with easy separation from the reaction medium. This thesis can be divided into three parts. In the first part, the synthesis and characterization of the carrier particles was carried out. Magnetic particles (MAG) were synthesized by co-precipitation of FeCl3 and FeSO4 in the base medium. Magnetic particles are coated with a polyaniline (MAG-PANI). Polyaniline particles (PANI) are synthesized chemically at the interface of the water/chloroform system. Morphological, magnetic properties, IR spectrums, particle size distribution and zeta potential of the buffer suspension of the carrier particles were examined. It has been shown that the agglomerates of MAG and MAG-PANI nanoparticles are synthesized. The surface of the magnetic particles is coated uniformly with polyaniline fibrous structure. MAG particles are present in bimodal, and MAG-PANI is a trimodal particle size distribution. In the second part of the work, immobilization of the α-amylase enzymes onto MAG, MAG-PANI and PANI was carried out. The optimal immobilization conditions at MAG-PANI were determined: time, initial concentration of enzymes, pH and temperature. Certain kinetic parameters: Km and Vm immobilized α-amylases show a higher affinity for immobilized α- amylase on MAG-PANI compared to α-amylase immobilized on MAG and lower both of immobilisates than free α-amylase. Langmuir adsorption model of α-amylase was determined for particles MAG-PANI. In the third part of the dissertation, рН, temperature and operational stability of α- amylase immobilized on MAG-PANI particles in recycle packed bed reactor and continuous packed bed reactor without recycling has been studied. Immobilized enzyme particles MAGPANI retained about 55.5% of initial activity after 9 successive use cycles and about 80.3% of initial activity after 50 days. In a bioreactor with a packed bed MAG-PANI-A can be used over several cycles with the increase in the time required for the hydrolysis of the same amount of starch. The half-life of the biocatalyst under continuous working conditions was 6.2 h.en
dc.languagesr
dc.publisherUniverzitet u Beogradu, Tehnološko-metalurški fakultet
dc.relationinfo:eu-repo/grantAgreement/MESTD/Integrated and Interdisciplinary Research (IIR or III)/46010/RS//
dc.rightsopenAccess
dc.subjectα-amilazasr
dc.subjectpolianilinsr
dc.subjectmagnetne česticesr
dc.subjectimobilizacijasr
dc.subjectα-amylaseen
dc.subjectpolyanilineen
dc.subjectmagnetic particlesen
dc.subjectimmobilizationen
dc.titleImobilizacija alfa-amilaze na polianilinu i magnetnim česticama modifikovanim polianilinomsr
dc.titleImmobilization of alfa-amylase on polyaniline and magnetic particles modified by polyanilineen
dc.typedoctoralThesis
dc.identifier.fulltexthttp://redun.educons.edu.rs/bitstream/id/17/13.pdf
dc.identifier.rcubhttps://hdl.handle.net/21.15107/rcub_nardus_10189
dc.identifier.rcubt-3147
dc.type.versionpublishedVersion


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