Production of xylonic acid by recombinant Escherichia coli immobilized on magnetic nanoparticles

Conversion of xylose to xylonic acid has obtained growing interest over the years. As the native metabolic pathway of Escherichia coli (E. coli) was unable to convert xylose to xylonic acid, native E. coli has been genetically modified to charter for the production of xylonic acid. However, producti...

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Main Author: Zahari, Farrah Noor Izzati
Format: Thesis
Language:English
Published: 2018
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Online Access:http://eprints.utm.my/id/eprint/85821/1/FarrahNoorIzzatiMSChE2018.pdf
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spelling my-utm-ep.858212020-07-30T07:35:04Z Production of xylonic acid by recombinant Escherichia coli immobilized on magnetic nanoparticles 2018 Zahari, Farrah Noor Izzati TP Chemical technology Conversion of xylose to xylonic acid has obtained growing interest over the years. As the native metabolic pathway of Escherichia coli (E. coli) was unable to convert xylose to xylonic acid, native E. coli has been genetically modified to charter for the production of xylonic acid. However, production of xylonic acid by free cells has encountered some drawbacks that include low yield, lack of stability and reusability of using free cell. Thus, cell immobilization was used for the production of xylonic acid because it can counter the drawbacks of using free cells and elevate the production of xylonic acid. In this study, the parameters affecting the production of xylonic acid by recombinant E. coli immobilized on magnetic nanoparticles were studied. The effect of post induction temperature, Isopropyl ß-D-1-thiogalactopyranoside (IPTG) concentration, xylose concentration, medium pH and expression media towards xylonic acid production, cell density and plasmid stability of the immobilized recombinant E. coli were investigated. The parameters were further optimized by using response surface methodology with the optimum condition of 0.6 mg/mL magnetic nanoparticles at post induction temperature of 30 °C, 0.1 mM IPTG concentration and 50 gL-1 of xylose concentration in expression medium. The immobilized recombinant E. coli produced up to 24.58 gL-1 xylonic acids during one factor at a time screening with the productivity of 1.024 gL-1h-1 and yield of 0.492 g g-1, which has 3-fold increment as compared to free cell. The cells immobilized on the magnetic nanoparticles exhibited a 47 % increment in stability of the plasmid as compared to free cells and can be used for up to 4 times while retaining xylonic acid productivity more than 50 %. Hence, the immobilization of recombinant E. coli using magnetic nanoparticles was demonstrated to increase xylonic acid production, cell stability and reusability. 2018 Thesis http://eprints.utm.my/id/eprint/85821/ http://eprints.utm.my/id/eprint/85821/1/FarrahNoorIzzatiMSChE2018.pdf application/pdf en public http://dms.library.utm.my:8080/vital/access/manager/Repository/vital:131998 masters Universiti Teknologi Malaysia, Faculty of Engineering - School of Chemical & Energy Engineering Faculty of Engineering - School of Chemical & Energy Engineering
institution Universiti Teknologi Malaysia
collection UTM Institutional Repository
language English
topic TP Chemical technology
spellingShingle TP Chemical technology
Zahari, Farrah Noor Izzati
Production of xylonic acid by recombinant Escherichia coli immobilized on magnetic nanoparticles
description Conversion of xylose to xylonic acid has obtained growing interest over the years. As the native metabolic pathway of Escherichia coli (E. coli) was unable to convert xylose to xylonic acid, native E. coli has been genetically modified to charter for the production of xylonic acid. However, production of xylonic acid by free cells has encountered some drawbacks that include low yield, lack of stability and reusability of using free cell. Thus, cell immobilization was used for the production of xylonic acid because it can counter the drawbacks of using free cells and elevate the production of xylonic acid. In this study, the parameters affecting the production of xylonic acid by recombinant E. coli immobilized on magnetic nanoparticles were studied. The effect of post induction temperature, Isopropyl ß-D-1-thiogalactopyranoside (IPTG) concentration, xylose concentration, medium pH and expression media towards xylonic acid production, cell density and plasmid stability of the immobilized recombinant E. coli were investigated. The parameters were further optimized by using response surface methodology with the optimum condition of 0.6 mg/mL magnetic nanoparticles at post induction temperature of 30 °C, 0.1 mM IPTG concentration and 50 gL-1 of xylose concentration in expression medium. The immobilized recombinant E. coli produced up to 24.58 gL-1 xylonic acids during one factor at a time screening with the productivity of 1.024 gL-1h-1 and yield of 0.492 g g-1, which has 3-fold increment as compared to free cell. The cells immobilized on the magnetic nanoparticles exhibited a 47 % increment in stability of the plasmid as compared to free cells and can be used for up to 4 times while retaining xylonic acid productivity more than 50 %. Hence, the immobilization of recombinant E. coli using magnetic nanoparticles was demonstrated to increase xylonic acid production, cell stability and reusability.
format Thesis
qualification_level Master's degree
author Zahari, Farrah Noor Izzati
author_facet Zahari, Farrah Noor Izzati
author_sort Zahari, Farrah Noor Izzati
title Production of xylonic acid by recombinant Escherichia coli immobilized on magnetic nanoparticles
title_short Production of xylonic acid by recombinant Escherichia coli immobilized on magnetic nanoparticles
title_full Production of xylonic acid by recombinant Escherichia coli immobilized on magnetic nanoparticles
title_fullStr Production of xylonic acid by recombinant Escherichia coli immobilized on magnetic nanoparticles
title_full_unstemmed Production of xylonic acid by recombinant Escherichia coli immobilized on magnetic nanoparticles
title_sort production of xylonic acid by recombinant escherichia coli immobilized on magnetic nanoparticles
granting_institution Universiti Teknologi Malaysia, Faculty of Engineering - School of Chemical & Energy Engineering
granting_department Faculty of Engineering - School of Chemical & Energy Engineering
publishDate 2018
url http://eprints.utm.my/id/eprint/85821/1/FarrahNoorIzzatiMSChE2018.pdf
_version_ 1747818459128922112