Genomic and functional characterization of Lactiplantibacillus plantarum strains isolated from kimchi
김치 유래 유산균 락티플란티바실러스 균주의 유전체 및 기능 분
- 발행기관 강릉원주대학교 일반대학원
- 발행년도 2022
- 학위수여년월 2023. 2
- 학위명 석사
- 학과 및 전공 도움말 일반대학원 KIST강릉분원학.연협동과정
- 세부분야 해당없음
- 실제URI http://www.dcollection.net/handler/kangnung/000000011385
- UCI I804:42001-000000011385
- 본문언어 영어
초록/요약 도움말
As discovering food-derived bacterial strains with functionality, lactic acid bacteria were isolated from traditional Korean fermented foods including cabbage kimchi and watery radish kimchi. Lactiplantibacillus plantarum KLAB-1 and KLAB-2, identified by 16S rRNA sequencing using 27F and 1492R universal primers, displayed remarkable viability under acidic (pH 2.5 and 3.5) and bile (0.2% and 0.5%) conditions after 3 h of incubation at 37℃. Subsequently, genome analysis was performed to clarify the two strains with the probiotic properties of acid and bile tolerance. According to the de novo assembly and annotation of genome sequences, they possessed 3,239,168 bp consisting of 3,027 genes, 64 tRNA, and 16 rRNA (KLAB-1) and 3,327,872 bp with 3,102 CDS, 71 tRNA, and 16 rRNA (KLAB-2), respectively. Regarding the characteristic of only KLAB-2 using inulin as the carbon source, a fos operon required for the utilization of fructooligosaccharides, including inulin, was identified in its genome. Moreover, crude cell-associated biosurfactant (CABS) extracted from KLAB-1 and KLAB-2 displayed significant antimicrobial activities against Staphylococcus aureus ATCC 25923 and Bacillus subtilis ATCC 6633 at 50 mg/ml. The CABS also inhibited the biofilm formation of the above bacterial pathogens at 25 mg/ml. FTIR analysis indicated that the CABS of both strains was mainly composed of glycolipoprotein. As bis(2-ethylhexyl) phthalate (DEHP), one of the plasticizer types, was identified from CABS, it was confirmed that both strains adsorbed DEHP. This result suggested that lactobacillus might be used to detoxify plasticizers in the human body. By demonstrating more beneficial functions, L. plantarum KLAB-1 and KLAB-2 might be developed as probiotic candidates with antibacterial activities or new plasticizer adsorbents.
more목차 도움말
Abstract i
요약 iii
Abbreviations v
Table of Contents vi
List of Tables viii
List of Figures ix
1. INTRODUCTION 1
2. MATERIALS AND METHODS 6
2.1. 16S rRNA sequencing of kimchi-derived microorganisms 6
2.2. Screening for probiotic properties 7
2.3. Whole genome sequencing of the probiotics candidates 8
2.4. Evaluation of various carbohydrate and inulin utilization of the probiotic candidates 9
2.5. Antimicrobial activity of the probiotic candidates 10
2.6. Crude CABS produced by the probiotic candidates 10
2.6.1. Extraction of crude CABS 10
2.6.2. Biological activities of crude CABS 11
2.6.3. Structural analysis of crude CABS and its components 12
2.7. Statistical analysis 13
3. RESULTS AND DISCUSSION 14
3.1. 16S rRNA sequence of kimchi-derived microorganisms 14
3.2. Probiotic screening 16
3.3. L. plantarum KLAB-1 and KLAB-2 whole genome characterization 19
3.4. Various carbohydrate and inulin utilization of the probiotic candidates 31
3.5. Antimicrobial activity of crude CABS produced by the probiotic candidates 39
3.6. Anti-biofilm activity of crude CABS produced by the probiotic candidates 43
3.7. FTIR analysis 45
3.8. NMR analysis 48
3.9. Binding of DEHP on the CABS 55
4. CONCLUSIONS 58
REFERENCES 59
ACKNOWLEDGMENTS 67
