The domesticated strain of Lactobacillus casei Zhang with outstanding acid stress resistance was obtained after the adaptive evolution. The intracellular microenvironment analysis found that the domesticated strain can maintain a higher phosphoenolpyruvate-sugar transfer enzyme activity in the acid stress process, and showed higher H+-ATPase activity and intracellular ATP concentration. Proteomics analysis investigated that the acid treatment led to expression changes of cell protein. Compared with the wild strain, the domesticated strain maintained higher metabolic activity. Meanwhile, the domesticated strain kept its physiological activity by a large number of induced stress proteins such as molecular chaperones GroEL, GrpE, and the cold / heat stress protein CspC / DnaK, which effectively improved the acid stress resistance. This study revealed the physiology of lactic acid bacteria cells under acid stress further, and explored the optimal strategy to promote the performance of lactic acid bacteria against acid stress, thereby provided a novel way to enhance their performance on industrial application.%以干酪乳杆菌Lactobacillus casei Zhang为出发菌株,通过适应性进化获得了干酪乳杆菌酸胁迫抗性驯化菌株.对细胞内微环境的检测发现,驯化菌株在酸胁迫过程中能够维持较高的磷酸烯醇式丙酮酸-糖转移酶系统活力,并具有较高的H+ -ATPase活性以及胞内ATP浓度.蛋白质组学分析结果表明,酸胁迫引发了细胞蛋白表达的变化,与原始菌株相比,驯化菌株保持了更高的代谢活性；同时,驯化菌株通过大量诱导应激蛋白如分子伴侣GroEL、GrpE,冷/热应激蛋白CspC、DnaK等维持了细胞的生理活性,有效提高了细胞对酸胁迫的抵御能力.本研究为进一步揭示酸胁迫下乳酸菌细胞的生理应答机制,探寻促进乳酸菌酸胁迫性能提升的最优策略,进而改善其在生产中的应用性能提供了可借鉴的思路.
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