高盐胁迫条件下嗜盐四联球菌生理应答及盐胁迫抗性机制解析

项目名称： 高盐胁迫条件下嗜盐四联球菌生理应答及盐胁迫抗性机制解析

项目编号： No.31301546

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 农业科学

项目作者： 吴重德

作者单位： 四川大学

项目金额： 25万元

中文摘要： 盐胁迫是高盐食品发酵过程中广泛存在的一种环境胁迫，严重影响食品微生物制造的效率。本课题以嗜盐四联球菌CGMCC3792为研究对象，从细胞生理特性和组学分析的角度考察细胞在不同盐浓度胁迫条件下胞内微环境(关键酶活性、胞内pH、ATP、NAD+/NADH)、物质代谢、细胞膜生理特性(膜脂肪酸组成、膜流动性)、基因转录水平和蛋白质表达水平上的差异，全面系统地阐释嗜盐四联球菌盐胁迫条件下的生理应答和调控机制，并在此基础上提出定向调控细胞盐胁迫抗性的策略，通过分子生物学手段，导入调控细胞盐胁迫抗性的关键基因，构建具有高盐胁迫抗性的工程菌，并对其耐盐性能进行验证。研究结果将有助于深入理解嗜盐四联球菌耐盐生理机制，并为构建高胁迫抗性的乳酸菌奠定理论基础。

中文关键词： 嗜盐四联球菌；盐胁迫；细胞微环境；调控机制；

英文摘要： Salt stress is an environmental condition commonly encountered during the fermentation of high-salt foods, which seriously impair the efficiency of food manufacture. In this study, the differences in intracellular micro-environment (activities of key enzymes, intracellular pH, ATP, NAD+/NADH), intracellular metabolites, cell membrane characterization (distribution of fatty acids, membrane fluidity), genes transcription, and proteins expression were investigated based on physiological and omics analysis by using Tetragenococcus halophilus as an initial strain. The physiological responses and regulatory mechanisms of T. halophilu during salt stress were revealed, and based on this, the directed strategies to improve salt tolerance were proposed. The key gene, which was involved in salt tolerance was introduced into the host strain. The mutant, which exhibited high resistance to salt stress was constructed and the tolerance to salt stress was validated. Results presented in this study may contribute to the understanding of salt tolerance mechanisms employed by T. halophilus and provide theoretical basis for the construction of stress-resistant lactic acid bacteria.

英文关键词： Tetragenococcus haliphilus；salt stress；cellular micro-environment；regulatory mechanisms；