Antibacterial and anti-biofilm effects of postbiotic mediator derived from Jeotgal isolate Lactiplantibacillus plantarum KMC12 against Streptococcus mutans = Streptococcus mutans에 대한 젓갈에서 분리한 Lactiplantibacillus plantarum KMC12에서 유래된 postbiotic mediator의 항균 및 항바이오필름 효과

목차 (Table of Contents)

• 1. Introduction 1
• 2. Materials and methods 6
• 2.1. Bacterial strains, culture media, and growth conditions 6
• 2.2. Inhibition of S. mutans bacterial growth in the presence of cell free supernatant (CFS) from the lactic acid bacteria (LAB) strains 6
• 2.3. Safety evaluation of KMC12 7
• 2.3.1. Hemolysis activity of KMC12 7
• 2.3.2. Antibiotic susceptibility of KMC12 using E-TEST 7
• 2.4. Preparation of KMC12 neutralized postbiotic mediator (nPM) 8
• 2.5. Determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of KMC12 nPM 9
• 2.6. Effect of KMC12 nPM on S. mutans membrane permeability 10
• 2.7. Inhibitory effect of KMC12 nPM on S. mutans biofilm formation 10
• 2.8. Quantification of biofilm-related genes expression by real-time quantitative PCR (RT-qPCR) 11
• 2.9. Determination of inhibitory effect of KMC12 nPM on S. mutans on extracellular polysaccharide (EPS) production 14
• 2.10. Cell culture and treatments 14
• 2.11. Cytotoxicity of KMC12 nPM in Caco-2 cells 15
• 2.12. Statistical analysis 16
• 3. Results and discussion 17
• 3.1. Inhibition of S. mutans growth in the presence of CFS from the LAB strains 17
• 3.2. Safety evaluation of KMC12 20
• 3.2.1. Hemolysis activity of KMC12 20
• 3.2.2. Antibiotic susceptibility of KMC12 22
• 3.3. Antibacterial activity of KMC12 nPM 24
• 3.4. Cell membrane destruction effect of KMC12 nPM 27
• 3.5. Anti-biofilm activity of KMC12 nPM 29
• 3.6. Inhibitory effect of KMC12 nPM on the expression levels of biofilm-related genes 32
• 3.7. Inhibitory effect of KMC12 nPM on EPS production 38
• 3.8. Effect of KMC12 nPM on the degree of LDH release from Caco-2 cells ·· 40
• 4. Conclusion 42
• References 44
• 국문초록 51
• Appendix 53