Imobilizacija enzima na mezoporozni SiO2 pripremljen sol-gel postupkom

master's thesis

• Title (english): Enzyme immobilization on mesoporous silica synthesized by sol-gel method
• Author: Antonia Giacobi
• Mentor: Jelena Macan (mentor)
• Committee member: Jelena Macan (predsjednik povjerenstva)
• Committee member: Hrvoje Ivanković (član povjerenstva)
• Committee member: Aleksandra Sander (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2015-06-12, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering; Chemical Engineering in Material Development

Abstract

Mezoporozni SiO2 se zbog svoje velike površine koristi kao nosač za imobilizaciju katalizatora, preciznije enzima, lipaze i celulaze. Lipaza se koristi kao katalizator u procesu proizvodnje biodizela, dok se celulaza koristi kao katalizator u procesu proizvodnje bioetanola. Glavni problem kod korištenja enzima je njihova cijena, pa je imobilizacijom omogućeno njihovo ponovno korištenje i smanjenje cijene proizvodnje.
Za dobivanje mezoporoznog SiO2 korišten je sol-gel postupak. Kao prekursor korišten je tetraetoksisilan, dok su kao predlošci za dobivanje porozne strukture korišteni želatina, surfaktant heksadeciltrimetilamonijev bromid i polimer poli(etilen-glikol)-block-poli(propilen-glikol)-block-poli(etilen-glikol).
Dobiveni uzorci ispitani su infracrvenom spektroskopskom analizom s Fourierovim transformacijama (FTIR), pretražnom elektronskom mikroskopijom (SEM), energijski razlučujućom rendgenskom spektrometrijom (EDS) i termogravimetrijskom analizom (TGA).
Priprema uzoraka s manjom količinom otapala pokazala se uspješnijom ako se koristi surfaktantni predložak, dok želatini i Pluronicu P123 više odgovara veća količina otapala i kiseliji uvjeti.
Prema intenzitetu vrpci na FTIR spektru, lipaza se uspješnije imobilizira od celulaze što potvrđuje i TGA analiza s masenim udjelom imobilizirane lipaze (34 %) i celulaze (30 %). Slične vrijednosti dobivaju se i EDS analizom.

Abstract (english)

Mesoporous silica with high surface area is used as a support for catalyst, or more precisely enzyme immobilization. In this work enzymes used were lipase and cellulase. Lipase is used for biodiesel production and cellulase is used for bioethanol production. The main problem for the production is high enzyme cost. This is solved by immobilization which allows enzyme re-use and decreases the cost of biodiesel and bioethanol production.
Sol-gel method was used to prepare the mesoporous silica. Tetraethoxysilane was used as a precursor and gelatine, hexadecyltrimethylammonium bromide and poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) were used as templates.
Obtained samples were analyzed with Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS) and thermogravimetric analysis (TGA).
Sample preparation with a small amount of solvent is effective when using surfactant as template, while for gelatin and Pluronic P123 a larger quantity of solvent and acidic conditions are preferred.
According to the intensity of FTIR bands, lipase is immobilized more effectively than cellulase, as confirmed by TGA determination of weight of immobilized lipase (34%) and cellulase (30%). Similar values are obtained by EDS analysis.

• Keywords: celulaza; lipaza; mezoporozni SiO2; sol-gel postupak
• Keywords (english): cellulase; lipase; mesoporous silica; sol-gel method
• Language: croatian
• URN:NBN: urn:nbn:hr:149:782449
• Study programme: Title: Chemical Engineering - Graduate study; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka kemijskog inženjerstva (magistar/magistra inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Repository: Repository of Faculty of Chemical Engineering and Technology University of Zagreb
• Created on: 2016-12-06 09:16:46