DnaK伴侣系统对酸土脂环酸芽孢杆菌嗜酸耐热特性的调控作用研究

酸土脂环酸芽孢杆菌具有嗜酸耐热的双重生理特性，能经受酸性条件下的巴氏杀菌过程而存活，DnaK伴侣系统与微生物抗胁迫能力密切相关，进行DnaK伴侣系统对酸土脂环酸芽孢杆菌嗜酸耐热特性的调控作用研究对该菌的危害控制和开发利用等具有重要意义。本课题基于DnaK伴侣系统基因mRNA表达水平的研究结果，拟利用Western-Blot技术检测酸、热逆境下酸土脂环酸芽孢杆菌DnaK伴侣系统蛋白表达差异，从蛋白质水平探讨DnaK伴侣系统在该菌响应酸、热胁迫应激过程中的功能；通过酸土脂环酸芽孢杆菌DnaK伴侣系统基因敲除、基因回补实验，研究DnaK伴侣系统基因协同调控酸土脂环酸芽孢杆菌嗜酸耐热特性的作用；通过异源表达实验研究酸土脂环酸芽孢杆菌DnaK伴侣系统对大肠杆菌抗酸热胁迫能力的影响；以期从分子水平上揭示DnaK伴侣系统对酸土脂环酸芽孢杆菌嗜酸耐热特性的调控机理，为该菌的合理开发利用提供理论和实验依据。

Alicyclobacillus acidoterrestris is a genus of acidophilic and thermophilic resistant bacteria with the ability to survive traditional pasteurization process under the acid condition, it has proved that the DnaK Chaperone System closely related with the stress resistance of organisms, therefore, to investigate the regulating function of DnaK chaperone system on the thermo-acidophilic resistance of Alicyclobacillus acidoterrestris is of great significance for hazard control and utilization of this bacterium. Based on our previous results of mRNA expression of genes in DnaK chaperone system, Western-Blot electrophoresis will be used to assay protein expression differences of DnaK chaperone system of A.acidoterrestris under heat and acid stress conditions and further determine the functions of DnaK chaperone system of A.acidoterrestris responding the heat and acid stress; gene knockout and retro-complementation of DnaK chaperone system in A.acidoterrestris will be performed to analyze the synergistic regulation of DnaK chaperone genes on thermo-acidophilic resistance of A .acidoterrestris; and heterologous gene expression experiment will be used to evaluate the effects of DnaK chaperone system of A.acidoterrestris on the heat and acid tolerance of E. Coli.; which aim at exploring the regulation mechanism of DnaK chaperone system on the thermo-acidophilic resistance of A.acidoterrestris and provide theoretical and experimental basis for the rational development and utilization of A. acidoterrestris.