초록 ▼

o Bacteriocin생산 젖산균의 탐색 및 bacteriocin 분리 정제 기술 - 항균범위 식중독균, pH와 열 안정성이 강한 균주 선정후 분리동정 및 생리적 특성 규명- 박테리오신의 분리정제 및 1,2 차구조 분석확립 o Bacteriocin의 대량 생산을 위한 최적 발효조건 설정및 Mutant 펩타이드 합성에 의한 Bacteriocin Peptide 개량 - 생산 젖산균주 등의 발효조건 확립 - 펩타이드합성법에 의한 mutant 단백질을 합성하여 구조와 기능성 변화여부 추적 o 고 기능성 신 bacteriocin의 개발및

o Bacteriocin생산 젖산균의 탐색 및 bacteriocin 분리 정제 기술 - 항균범위 식중독균, pH와 열 안정성이 강한 균주 선정후 분리동정 및 생리적 특성 규명- 박테리오신의 분리정제 및 1,2 차구조 분석확립 o Bacteriocin의 대량 생산을 위한 최적 발효조건 설정및 Mutant 펩타이드 합성에 의한 Bacteriocin Peptide 개량 - 생산 젖산균주 등의 발효조건 확립 - 펩타이드합성법에 의한 mutant 단백질을 합성하여 구조와 기능성 변화여부 추적 o 고 기능성 신 bacteriocin의 개발및 생산 분자생물학적 균주 개량을 통한 bacteriocin 개량 - mutagenesis법에 분자생물학적으로 mutant 미생물을 육종하여 균주개선 연구 - 최종단백질 디자인 - 개선된 bacteriocin 응용성 연구

Abstract ▼

A bacteriocin-producing strain was isolated from kimchi and identified as Leuconostoc mesenteroides subsp. cremoris. The bacteriocin was inhibitory against many strains of Gram-positive bacteria and several strains of Gram-negative bacteria. Especially,Pseudomonas fluorescens was inhibited by bacter

A bacteriocin-producing strain was isolated from kimchi and identified as Leuconostoc mesenteroides subsp. cremoris. The bacteriocin was inhibitory against many strains of Gram-positive bacteria and several strains of Gram-negative bacteria. Especially,Pseudomonas fluorescens was inhibited by bacteriocin from this strain. The bacteriocin waspartially stabile to heat (≤80℃) and active between pH's 5.0 and 10.0. The bacteriocin was composed of only protein. Anaerobic culture rather than aerobic culture is better for bacteriocin producing. The bacteriocin was purified by pH mediated cell adsorption-desorption method and semi-preparative RP-HPLC. The molecular weight of the bacteriocin determined by MS was 4,621 Da. The 41 amino acid sequence of the bacteriocin determined. The another bacteriocin from kimchi, designed as Pediocin AcM, from Pediococcus acidilactici M, was rapidly purified to homogeneity by the same method mentioned above. It gave a single band and a single peak on SDS-PAGE and HPLC analysis, respectively. The protein was found to be highly pure and the molecular weight was determined as 4,618 Da. High concentration of the bacteriocin (>50㎕/ml) showed good resistance to extremes of pH (1-12) and temperature(121℃). Pediocin AcM was deduced to be a monomer with an intra-peptide disulfide bond from the results of reversed-phase analytical HPLC analysis after reduction, oxidation and trypsin digestion. Its primary structure, homologous to those of other reported pediocins, consists of 44 residues. There were four cysteines, two of which linked into a disulfide bond (9Cys and 14Cys). The pKa value computed from the sequence information is 9.7. The pediocin was remarkably stable at wide pH range (pH 2-10) and high temperature (121℃, 15min). The activity-conformation relationship was further studied by circular dichroism (CD) analysis. The CD spectra of the native protein in water is suggestive of a loose random coil which explains its flexibility and stability in extreme pH and temperature conditions. At increasing ethanol concentration, it showed decreasing activity. Activity loss at 80% ethanol was shown as a conformational change into a more folded structure resembling that of α-helix. Three peptide hydrolyzates were purified by reversed phase HPLC after reduction with dithiothreitol and subsequent hydrolysis with trypsin. One of the hydrolyzates showed a α-helix configuration while the other two were perfect random coils.

목차 Contents

• 본문...15
• 제1장 서론...15
• 제2장 국내외 기술현황...18
• 제3장 연구개발 수행 내용 및 결과...20
• 제1절 연구수행 방법...20
• 제2절 연구결과...23
• 제3절 Bacteriocin의 분리 및 정제 분석...27
• 제4절 Pediocin의 1,2차구조 분석과 구조와 Bacteriocidal Activity와의 관계...38
• 제5절 김치에서 bacteriocin 분리 및 특성 연구 (Ⅰ)...51
• 제6절 김치에서 bacteriocin 분리 및 특성 연구 (Ⅱ)...72
• 제7절 펨타이드의 합성 및 분리...95
• 제4장 연구개발목표 달성도 및 대외기여도...103
• 제5장 연구개발결과의 활용성과 및 계획...104
• 제6장 기타 중요변동사항...106
• 제7장 참고문헌...107
• 최종보고서 요약...113