高压脉冲电场作用下细菌细胞损伤的分子机制

As a non-thermal technology for food processing, pulsed electric field (PEF) technology deserves much attention as an alternative to tranditional thermal pasteurization. At present, the knowledge on the mechanism of microbial inactivation by PEF treatment still keeps unclearly. Especially, little has been know about the involvement of cell injury leading to cell inactivation. The main aspects of this in this project include: to study the types and generation mechanisms of inner-cellular damaging effects, a DNA damage research model will be applied to analysis of DNA/RNA fragments, mutations and free radical oxidative damage, and be used to study the correlations and effects combined with cell walls and PEF induced cell-damaging effects by analyzing the damaged cell morphology. Finally, we will analyze the correlations between the cell inactivation and the accumulation of cell injury. This project aims to elucidate the types of cell-damaging effects and the biological pathways underlying PEF treatment, and to evaluate the core effects and key factors under PEF bactericidal mechanism. Further, the biological mechanisms of cell-damaging effects under PEF treatment will be illustrated. This study will give theoretical and experimental basis to explain PEF bactericidal mechanisim, and provide strong theoretical support for PEF application and promotion.

高压脉冲电场（PEF）灭菌技术是一种潜力巨大经济实用的非热杀菌技术，也是食品加工新技术的研究热点之一。目前PEF技术确切的杀菌机制尤其是细胞生物学损伤与失活之间的关系这一科学问题尚未得到有效解决。本项目就上述科学问题展开研究，主要研究内容包括建立细菌DNA损伤模型，通过DNA/RNA损伤、突变和自由基氧化损伤的鉴定和分析，以及细胞结构损伤分析，研究细胞内损伤发生类型及产生分子机制，并分析损伤积累与细胞失活之间的相关性。本项目旨在阐明PEF作用下细胞损伤效应类型及生物学发生途径，评价PEF杀菌机制中核心损伤效应及关键因素，进而阐述PEF作用下细胞损伤效应的分子机制。本研究将为揭示高压脉冲电场杀菌机制奠定实验和理论基础，也为此项技术应用推广提供更有力的理论支持。

高压脉冲电场是一项具有巨大潜力的食品药品非热加工技术。本项目系统研究该技术对微生物的作用损伤，优化灭菌参数并建立杀菌动力学模型。通过正交试验，分析了高压脉冲电场各个参数对于杀菌效果的影响权重，在此基础上利用Weibull分布模型分析不同物理量参数及它们的交互作用诱导微生物的致死规律，建立用于预测高压脉冲电场对微生物灭菌效果的数学模型，指导实际生产中的推广应用。本项目研究结果证实PEF处理对酵母细胞具有提高活性、亚致死和致死多重损伤效应。低于6kV/cm电场强度处理有助于提高酵母细胞内非特异性内酯酶活性，酵母的生存率提高，而高强度的PEF能够对工业生产中残留的酿酒酵母进行灭活处理。通过酵母细胞活性分析，发酵活性检测，代谢产物检测和基因转录分析，进一步探讨PEF对酵母发酵活性诱导的分子机制。本项目在理论研究基础上，设计并实施一套在线连续液态明胶灭菌装置，在企业建立示范应用生产线一条，探索高压脉冲电场的产业化应用及推广。本项目的选题研究是对高压脉冲电场非热食品加工技术的全新应用突破，对该技术的发展具有重要的理论和实际指导意义。