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국회도서관 홈으로 정보검색 소장정보 검색

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Title Page

ABSTRACT

Contents

CHAPTER I. (제목없음) 11

A. INTRODUCTION 12

B. MATERIALS & METHODS 15

1. Structure of the micro-plasma jet and plasma discharge system 15

2. Structure and manufacturing of underwater plasma device 15

3. Bacterial strain and treatment of plasma 15

4. LIVE/DEAD bacterial viability assay 16

5. Scanning electron microscopy (SEM) 17

6. Measurement of ROS 17

7. Scavenger assay using antioxidants 18

8. Measuring Cell Viability/Cytotoxicity: WST 18

9. Statistical analysis 19

C. RESULTS 20

1. Experimental set up of non-thermal atmospheric plasma 20

2. Anti-microbial effects of PBS/N₂ and PBS/Air Plasma 20

3. LIVE/DEAD Bacterial Viability assay 21

4. Duration test of non-thermal PBS/N2Plasma and PBS/Air Plasma activity 22

5. Anti-bacterial effects depending on the storage temperature of the PBS/N2Plasma 22

6. Scanning electron microscopy (SEM) 23

7. Involvement of ROS in bacterial inhibition of PBS/N₂Plasma against S.aureus 24

8. Structure and manufacturing of underwater plasma device 25

9. Antimicrobial effects of underwater plasma devices equipped with bubblers 26

10. Comparison of antimicrobial effects according to underwater plasma treatment time 27

11. Duration of underwater plasma according to bubbler porosity 27

12. Observation of underwater plasma treated bacterial cells with scanning electron microscopy (SEM) 28

13. Evaluation of Cytotoxic Effects by the WST assay 29

14. Involvement of ROS in bacterial inhibition of underwater plasma against S.aureus 29

D. DISCUSSION 31

CHAPTER II. (제목없음) 57

A. INTRODUCTION 58

B. MATERIALS & METHODS 61

1. Bacterial strain and biofilm formation 61

2. Swimming motility 61

3. Swarming motility 62

4. Confocal Laser Scanning Microscopy (CLSM) 62

C. RESULTS 64

1. Motility assays; swimming and swarming motility 64

2. Inhibitory efficacy of non-thermal atmospheric plasma on the biofilm of P. aeruginosa PA01 65

3. Inhibition efficacy of non-thermal plasma against Pst DC3000 under various conditions. 66

4. Scanning electron microscopy (SEM) 67

5. Optical density of the dissolved biofilm 67

6. Inhibitory efficacy of non-thermal atmospheric plasma on the biofilm of Pst DC3000 according to the application methods 68

7. 3D analysis on anti-biofilm efficacy of PBS/N 2 Plasma against Pst DC3000 using CLSM 69

8. Combination of antibiotic and PBS/N₂Plasma 70

D. DISCUSSION 72

CHAPTER III. (제목없음) 93

A. INTRODUCTION 94

B. MATERIALS & METHODS 97

1. Growth conditions of Bacterial strain and biofilm formation 97

2. Bacterial strain and GFP tagging 97

3. Semi-in vivo assay 98

C. RESULTS 99

1. Inhibition efficacy of non-thermal plasma against Pseudomonas and Pectobacterium under various conditions. 99

2. Inhibitory efficacy of PBS/N₂Plasma on vegetative cell and biofilm of soft- rot bacteria 100

3. Semi-in vivo evaluation of inhibitory activity 100

D. DISCUSSION 102

F. REFERENCES 113

국문요약 118

List of Figures

CHAPTER I 36

Figure 1. Schematic view of the experimental shows the non-thermal atmospheric... 36

Figure 2. Optical emission spectrum when plasma is discharged using N 2 and... 37

Figure 3. To investigate the inhibitory effect of the plasma, PBS solution was pre-... 38

Figure 4. Both P. aeruginosa PA01 and S. aureus, control is untreated, and plasma... 39

Figure 5. Both biofilm of P. aeruginosa PA01 and S. aureus, control is untreated,... 40

Figure 6. Inhibition efficacy of PBS/N₂Plasma and PBS/Air Plasma were examined... 41

Figure 7. Inhibition efficacy of non-thermal plasma against P. aeruginosa PA01... 42

Figure 8. Inhibition efficacy of non-thermal plasma against S. aureus under various... 43

Figure 9. Scanning electron microscope images showing the effects of... 44

Figure 10. Scanning electron microscope images showing the effects of... 45

Figure 11. Detection of ROS in PBS/N₂Plasma, and the scavenging effect of... 46

Figure 12. The underwater plasma device consists of two electrode substrates and a... 47

Figure 13. N₂ gas was used for the discharge gas which was supplied to the device... 48

Figure 14. Optical emission spectrum of N₂plasma jet blocked from the ambient... 49

Figure 15. Anti- antimicrobial effects of underwater plasma devices equipped with... 50

Figure 16. Inhibition efficacy of underwater plasma against pathogenic bacteria... 51

Figure 17. Inhibition efficacy of underwater plasma were examined up to 48 hours.... 52

Figure 18. Scanning electron microscopy (SEM) images of the effects of... 53

Figure 19. Evaluation of Cytotoxic Effects by the WST assay 54

Figure 20. Concentration of ROS detected in underwater plasma solutions. 55

Figure 21. Scavenging effect of various antioxidants on antimicrobial activity of... 56

CHAPTER II 76

Figure 1. Growth curves of P. aeruginosa PAO1. The growth curves of the P.... 76

Figure 2. Swimming motility of P. aeruginosa PAO1 on a semisolid agarose plate. 77

Figure 3. Swarming motility of P. aeruginosa PAO1. The cells were inoculated... 78

Figure 4. The effect of the 50-fold dilution of the PBS/N₂Plasma treatment on... 79

Figure 5. Inhibitory efficacy of N₂Plasma on biofilm of P. aeruginosa PA01... 80

Figure 6. Inhibitory efficacy of N₂Plasma on biofilm of P. aeruginosa PA01... 81

Figure 7. Inhibitory efficacy of N₂Plasma on biofilm of P. aeruginosa PA01... 82

Figure 8. CLSM imaging analysis on biofilms of P. aeruginosa PA01 after the... 83

Figure 9. Inhibition efficacy of non-thermal plasma against Pst DC3000 under... 84

Figure 10. Scanning electron microscopy (SEM) images of the inhibition efficacy... 85

Figure 11. Biofilm growth was assessed by crystal violet staining and quantified at... 86

Figure 12. Inhibitory efficacy of N₂Plasma on biofilm of Pst DC3000 according to... 87

Figure 13. Inhibitory efficacy of N₂Plasma on biofilm of Pst DC3000 according to... 88

Figure 14. Inhibitory efficacy of N₂Plasma on biofilm of Pst DC3000 according to... 89

Figure 15. CLSM imaging analysis on biofilms of Pst DC3000 after the... 90

Figure 16. Combination of antibiotic and PBS/N₂Plasma in the liquid cultured P.... 91

Figure 17. LIVE/DEAD Bacterial Viability assay showed inactivation of P.... 92

CHAPTER III 104

Figure 1. Inhibition efficacy of non-thermal plasma against P. marginalis and P.... 104

Figure 2. Inhibitory efficacy of PBS/N₂Plasma on vegetative cell and biofilm of... 105

Figure 3. Inhibitory efficacy of PBS/N₂Plasma on vegetative cell and biofilm of... 106

Figure 4. Fluorescent image using VISIRAYS. GFP-P. carotovorum 10057 mixed... 107

Figure 5. Fluorescent image using VISIRAYS. GFP-P. carotovorum 10057 mixed... 108

Figure 6. Fluorescent image using VISIRAYS. GFP-P. carotovorum 10057 mixed... 109

Figure 7. Fluorescent image using VISIRAYS. GFP-P. carotovorum 10057 mixed... 110

Figure 8. Fluorescent image using VISIRAYS. GFP-P. carotovorum 10057 mixed... 111

Figure 9. Fluorescent image using VISIRAYS. GFP-P. carotovorum 10057 mixed... 112

초록보기

 미생물의 생장 제어는 인류의 삶에 필수적이며, 농업, 의학, 식품 과학을 포함한 다양한 분야에서 생화학적 및 분자·세포학적 지식의 응용으로 이루어져왔다. 물리학, 화학 및 생물학적으로 활용된 미생물 제어 방법들이 꾸준히 연구되고 있으나, 병원균이 형성하는 생물막에서 유도된 세균성 질병의 제어는 난제로 남아있다.

최근 기존 화학 물질에 비해 높은 반응성과 광범위한 병원균 억제효과, 무독성과 안정성 그리고 항생제 내성을 극복할 수 있다는 장점으로 플라즈마가 항생물질의 대안책으로 제시되고 있다. 플라즈마는 우리 생활의 다양한 분야에서 응용되고 있으며, 그 중요성이 점점 높아져 가고 있다.

본 논문에서는 물리학적 미생물 제어법인 대기압 저온 플라즈마의 항균 활성 및 생물막 형성 저해 효과를 확인하였다. 또, 항균효과의 효율성을 증대시키기 위해 항균활성의 생화학적, 세포학적 특성에 대해 연구하였다.

플라즈마의 항균 활성 특성을 연구하기 위해 장치의 종류, 처리 조건 및 다양한 가스 소스를 이용하여 항균 효과를 비교하였다. 특히, 질소를 가스 소스로 하는 플라즈마를 PBS에 전처리하여(PBS/N₂Plasma) 적용했을 때 보다 효과적으로 병원균을 억제하였다. 또, 항균 활성은 -80 ℃ 저장조건에서 3개월 동안 효과가 유지 되어 다양한 방안으로 활용이 가능하다. 항산화제 처리 실험을 통해 ROS가 플라즈마의 미생물 억제 활성에 관여하며, H₂O₂와 singlet oxygen이 억제 활성에 영향을 주는 주요 활성 인자임을 밝혔다. 플라즈마의 질병 제어 효과는 GFP를 삽입한 작물 병원균을 이용한 semi-in vivo 실험을 통해 연구 되었으며, PBS/N₂Plasma 처리가 작물의 질병 증상을 유의미하게 감소시키는 효과를 보여주었다.

다공성 버블러를 포함한 수중 플라즈마 장치는 병원균에 대한 효과적인 억제 뿐만 아니라 한번에 다량의 플라즈마 용액의 생산이 가능하다. 특히, 50% 버블러 수중 플라즈마는 강한 항균 활성을 보임에도 세포 독성 효과가 현저히 낮아 분자생물학 및 의학 분야에서 상당히 실용적이며 유망하다.

플라즈마의 처리는 병원균의 성장뿐만 아니라 그들이 형성하는 생물막을 효과적으로 억제하는 것이 확인되었다. 형광 현미경 및 공초점 레이저 스캐닝 현미경(CLSM)을 사용하여 생물막의 저해 효과를 가시화하고 분석하였다. 그 결과, 3D CLSM 이미지를 통해 플라즈마의 항균 활성이 생물막 내부 세포에 영향을 줄만큼 충분히 투과됨을 확인하였다. 즉, 플라즈마의 탁월한 투과율이 생물막의 효과적인 제어에 기여함을 보여 준다.