Biotransformacija katehola u mikroreaktoru katalizirana lakazom

master's thesis

• Title (english): Laccase catalysed catechol biotransformation in a microreactor
• Author: Irena Đukić
• Mentor: Želimir Kurtanjek (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Process Engineering); (Laboratory for Measurement, Regulation and Automatisation); Zagreb
• Defense date and country: 2012-07-06, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Lakaze su enzimi iz skupine oksidoreduktaza koje imaju sposobnost biotransformacije fenolnih spojeve. U ovome radu provedena je biotransformacija katehola lakazom porijeklom iz Trametes versicolor u makro- i mikroreaktoru. Maksimalna konverzija postignuta u šaržnom makroreaktoru iznosila je X = 21,07 % nakon 1400 s, dok je konverzija od X = 16,73 % u mikroreaktoru s mješalima postignuta za vrijeme zadržavanja od 24 s. Prije provedbe šaržnog pokusa u makroreaktoru analizirana je stabilnost otopine katehola čuvane na T = 4 °C i na T = 25 °C čime je dokazana spontana degradacija katehola tijekom vremena. Također je uočeno smanjenje aktivnosti suspenzije lakaze čuvane na T = 4 °C tijekom vremena. Provedena je i analiza difuzivnosti katehola i lakaze u mikrorektoru. Korištenjem korelacijskih modela preuzetih iz literature izračunate su vrijednosti koeficijenata efektivne difuzivnosti za obje molekule. Rješavanjem matematičkog modela za difuziju u mikrorekatoru uočeno je da koeficijent difuzivnosti za katehol dobiven Reddy – Doraiswamy korelacijom daje najbolje slaganje s eksperimentalnim podacima za difuziju katehola u mikroreaktoru.

Abstract (english)

Laccases are enzymes belonging to group of oxidoreductase which have ability to perform biotransformation of phenolic compounds. In this work catechol biotransformation using laccase from Trametes versicolor was performed in macro- and microreactor. Performing experiments in macroscale batch reactor maximum conversion achieved was X = 21.07 % after 1400 s; reducing the reactor scale with the same initial conditions maximum conversion of X = 16.73 % was obtained in microreactor equipped with micromixers for residence time of 24 s. Before batch experiments stability of catechol solutions was analyzed. Catechol solutions were stored on two temperatures T = 4 °C and T = 25 °C. Spontaneous degradation of catechol with time was noticed. Also, decrease of laccase suspension activity on a temperature T = 4 °C was noticed. Diffusivity of catechol and laccase in microreactor was analysed. Using correlation models taken from literature, effective diffusivity coefficients for catechol and laccase were calculated. Performing simulations of mathematical model describing the diffusion in micoreactor it was noticed that diffusivity coefficient calculated using Reddy – Doraiswamy model describes the experimental data the most accurate.

• Keywords: katehol; lakaza; mikroreaktor; biotransformacija; difuzija
• Keywords (english): catechol; laccase; microreactor; biotransformation; diffusion
• Language: croatian
• URN:NBN: urn:nbn:hr:159:131538
• Study programme: Title: Bioprocess Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka bioprocesnog inženjerstva (magistar/magistra inženjer/inženjerka bioprocesnog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-05-09 07:43:08