交互保护对干酪乳杆菌ATCC 393TM存活的影响

Influence of cross-protection in Lactobacillus casei ATCC 393

摘要:

摘要：【目的】以干酪乳杆菌典型株ATCC 393TM (Lactobacillus casei ATCC? 393TM) 为实验菌株，研究其在多重胁迫环境下的交互保护应答机制。【方法】比较不同亚适应条件（热、H2O2、酸、胆盐）处理后菌体细胞在热致死条件(>60oC)及氧致死条件H2O2 (>5 mmol/L)下的存活率变化，并集中考察了最佳亚适应条件－酸适应的不同处理方式对细胞交互保护存活率、胞内pH以及脂肪酸含量的影响。【结果】交互保护对干酪乳杆菌ATCC 393生理活性的影响因亚适应及致死条件而异：

Abstract:

Abstract: [Objective] In this study, we investigated the cross-protection of Lactobacillus casei ATCC? 393TM under multi-stress conditions. [Methods] Cells pre-adapted to mild conditions (heat, H2O2, acid or bile salts) were then treated at lethal temperature (>60 oC) or hydrogen peroxide stress (>5 mmol/L). Furthermore, the changes of survival rate, intracellular pH and membrane fatty acid under lethal conditions with or without acid adaption were compared. [Results] The cross-protection in Lactobacillus casei ATCC 393TM were affected by different stress conditions cell encountered. Acid pre-adaption, especially hydrochloride treatment, would increase the resistance of cells to lethal heat and peroxide stresses significantly, with the survival rate of 305-fold and 173-fold, respectively. Further study suggested that the effect of acid pre-adaption might be related to the regulation on intracellular pH and the saturation of cell membrane. [Conclusion] In this study, hydrochloride adaption was the best inducer for the cross-protection of Lactobacillus casei ATCC 393TM to maintain relatively stable physiological status of cells. The results above supplied a novel way to investigate the relationship between different protective mechanisms in L. casei under different kinds of stresses.