Analysis of injury in the function of cytoplasmic membrane of E. coli causedby high-pressure treatment

高压处理对大肠杆菌细胞质膜功能损伤的分析

• 批准号: 12660086
• 负责人: YAMASAKI Makari
• 金额: $ 2.3万
• 依托单位: Nihon University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12660086/
• 关键词: High-pressure treatment; Echerichia coli; cell division; FtsZ; 細胞分裂阻害

This study was intented to crarify the entity of injury in the function of Esherichia coli cytoplasmic membrane caused by high-pressure treatment and to find more effective sterilization condition in the high-pressure treatment based food-processing.Exponential phase cells of E. coli were mucn more sensitive to high-pressure treatment than those of stationary phase. After the moderate high-pressure treatment of exponential phase cells at 75MPa, 30 min., 37℃, the treated cells were grown in nutrient broth. After the growth for 60 to 90 min., most of cells were found to be elongated to 4 to 8 cell-length. DAPI staining revealed that nuclear regions were partitioned. The recA and sulA mutants of E. coli behaved similarly in the moderate high-pressure treatment. This results clearly show that SOS response was not involvedin this defect of cell division. In the next place, the presence of FtsZ ring was investigated for the elongated cells of about 8 cell-length by using fluorescent dye-coupled anti-FtsZ antibody. On an average, one ring was observed for a elongated cell at one-cell lenght inside from the end. This result shows the shortage of functional FtsZ after high-pressure treatment. It is suggested that the possible most sensitive target of high-pressure treatment is FtsZ protein itself.

本研究旨在阐明高压处理对大肠杆菌细胞膜功能损伤的实质，并寻找高压处理食品加工中更有效的灭菌条件。大肠杆菌对高压处理的敏感性明显高于固定相。对数期细胞经75 MPa、30 min的中高压处理后，37℃下培养。生长60 ~ 90分钟后，发现大多数细胞被拉长至4至8个细胞长度。DAPI染色显示细胞核区域被划分。recA和苏拉突变体。大肠杆菌在中度高压处理中表现相似。这一结果清楚地表明SOS反应与这种细胞分裂缺陷无关。接下来，通过使用荧光染料偶联的抗FtsZ抗体，对约8个细胞长度的伸长细胞研究FtsZ环的存在。平均而言，在从末端向内的一个细胞长度处观察到一个细长细胞的环。该结果显示了高压处理后功能性FtsZ的不足。这表明，高压处理的可能最敏感的目标是FtsZ蛋白本身。