GIST Repository
College of Engineering
Department of Environment and Energy Engineering
3. Theses(Master)
Bio-Fenton Systems with Glucose Oxidase Expressed in Pichia pastoris for Degradation of Dyes and Lignin
- Abstract
- The Fenton reaction is an efficient and sustainable approach for the degradation of recalcitrant pollutants, such as lignin and synthetic dyes. This process relies on hydroxyl radicals (•OH), which possess with standard reduction potential of +2.8 V and non-specifically oxidize organic compounds to acquire electrons. The generation of hydroxyl radicals requires hydrogen peroxide (H₂O₂) and Fe²⁺/Fe³⁺ as key reactants. Based on this mechanism, the present study aims to enhance the degradation efficiency of recalcitrant pollutants by establishing a Bio-Fenton system using Pichia pastoris X-33 engineered to express glucose oxidase (GOX) for the continuous in-situ production of H₂O₂.
In this study, the pPICZα-A expression vector was employed to drive the expression of extracellular of glucose oxidase (GOX) from Penicillium amagasakiense in P. pastoris X-33. Additionally, the CTA1 gene encoding catalase in P. pastoris was knocked out to prevent the decomposition of H₂O₂ generated by the glucose oxidase activity. A Bio-Fenton system incorporating Fe(III)-citrate (0.5 mM) as a catalyst was applied to degrade guaiacylglycerol-β-guaiacyl ether (GGGE), a lignin model compound derived from wood, as well as synthetic dyes such as methylene blue and indigo carmine. The results showed that GGGE was degraded by over 80% within 7 days, and methylene blue and indigo carmine were successfully degraded within 120 minutes and 72 hours, respectively.
This study demonstrates the potential of a Bio-Fenton system based on the sustainable supply of H₂O₂ from microbial sources as an efficient and environmentally friendly technology for treating recalcitrant pollutants. The findings highlight its applicability in advancing green and sustainable approaches to pollutant management.
- Issued Date
- 2025
- Type
- Thesis
- Alternative Author(s)
- Sanghyeok Lee
- Department
- 대학원 환경에너지공학부
- Advisor
- Hur, Hor-Gil
- Table Of Contents
- ABSTRACT i
CONTENTS iii
LIST OF FIGURES vi
LIST OF TABLES ix
CHAPTER I. Literature Review 1
1.1. Characteristic of hydrogen peroxide-producing microorganisms 2
1.1.1. Mechanism of glucose oxidase and catalase enzymes 7
1.1.2. Application of the Fenton reaction for hydrogen peroxide-producing
microorganisms 10
2.1. Lignocellulosic biomass and lignin 13
2.2. Valorization of lignin biomass strategy through depolymerization 18
2.3. Utilization of biotic reactions for the depolymerization of lignin 24
CHAPTER II. Bio-Fenton Systems with Glucose Oxidase Expressed in Pichia pastoris for Degradation of Dye and Lignin 29
2.1. Graphical abstract 30
2.2. Introduction 32
2.2. Materials and Methods 35
2.2.1. Chemicals, media, and yeast strain 35
2.2.2. Expression of glucose oxidase from P. amagasakiense in P. pastoris 36
2.2.2.1. Vector construction for GOX expression in P. pastoris X-33 36
2.2.2.2. Transformation of P. pastoris 39
2.2.2.3. Confirmation of GOX expression in P. pastoris 42
2.2.2.4. Comparative analysis of GOX from P. pastoris and A. niger 43
2.2.3. Optimization for glucose oxidase secreting system of P. pastoris 44
2.2.4. GOX act on Guaiacylglycerol-β-guaiacyl ether (GGGE), lignin biomass 46
2.2.5. HPLC analysis of GGGE 48
2.2.6. Extraction of lignin biomass from soft, hard wood 49
2.2.7. HPLC Q-ToF MS analysis for the characterization of metabolites produced from
Bio-Fenton degradation of lignin compounds 50
2.2.8. Knockout of CTA1 Gene 52
2.2.9. Catalase knockout act on methylene blue, indigo carmine 56
2.3. Results and Discussions 57
2.3.1. Expression and screening of P. pastoris X-33 with pPICZα-A-GOX 57
2.3.2. Quantification of H2O2 production in P. Pastoris X-33-GOX 60
2.3.3. Comparative analysis of GOX from P. Pastoris and A. niger 64
2.3.4. Application of Bio-Fenton reaction by P. pastoris secreting glucose oxidase to the
degradation of GGGE and lignin extracts from softwood and hardwood 66
2.3.5. Identification of metabolites from the Bio-Fenton reaction of GGGE and extracted
lignin from wood by P. pastoris 71
2.3.6. Characterization of P. pastoris X-33-GOX-△CAT 76
2.3.7. Application of Bio-Fenton reaction by P. pastoris X-33-GOX-△CAT to the
degradation of methylene blue, indigo carmine 80
2.4. Conclusion 87
References 88
- Degree
- Master
- Appears in Collections:
- Department of Environment and Energy Engineering > 3. Theses(Master)
- 파일 목록
-
-
관련 파일이 존재하지 않습니다.
-
Items in Repository are protected by copyright, with all rights reserved, unless otherwise indicated.