Physical Education College, Zhengzhou University, Zhengzhou, 450001, China.
School of Life Sciences, Zhengzhou University, Zhengzhou, 450001, China.
World J Microbiol Biotechnol. 2023 May 15;39(8):197. doi: 10.1007/s11274-023-03627-y.
Our previous study indicated that ethanol-induced intracellular extracts (E-IEs) of Lactococcus lactis subsp. Lactis IL1403 (L. lactis IL1403) alleviated hangovers more effectively in mice than untreated intracellular extracts (U-IEs), but the material basis was unclear. Considering that stress-related proteins might play a significant role, the effects of ethanol induction on probiotic properties of L. lactis IL1403 and the associated stress response mechanism were initially explored in this study. E-IEs of L. lactis IL1403 showed better biological activities, significantly increased bacteria survival rates in oxidative stress environments, increased ADH activity, and enhanced proliferation in RAW264.7 and AML-12 cells. Proteomic analyses revealed that 414 proteins were significantly changed in response to ethanol induction. The expression of proteins involved in the universal stress response, DNA repair, oxidative stress response, and ethanol metabolism was rapidly upregulated under ethanol stress, and quantitative real-time PCR (qRT-PCR) results were consistent with proteomic data. KEGG pathway analysis indicated that citrate metabolism, starch and sucrose metabolism, and pyruvate metabolism were significantly enriched during ethanol stress to increase energy requirements and survival rates of stressed cells. Based on this observation, the active induction is an effective strategy for increasing the biological activity of L. lactis IL1403. Exploring the molecular mechanism and material basis of their functions in vivo can help us understand the adaptive regulatory mechanism of microorganisms.
我们之前的研究表明，相比于未经处理的细胞内提取物（U-IEs），乳球菌乳酸亚种 IL1403（L. lactis IL1403）的乙醇诱导细胞内提取物（E-IEs）在小鼠体内更能有效地缓解宿醉，但具体的物质基础尚不清楚。考虑到应激相关蛋白可能发挥着重要作用，本研究初步探讨了乙醇诱导对 L. lactis IL1403 益生菌特性的影响及其相关的应激响应机制。E-IEs 表现出更好的生物活性，能显著提高益生菌在氧化应激环境中的存活率，增加 ADH 活性，并增强 RAW264.7 和 AML-12 细胞的增殖。蛋白质组学分析显示，有 414 种蛋白质对乙醇诱导有明显变化。在乙醇胁迫下，与普遍应激反应、DNA 修复、氧化应激反应和乙醇代谢相关的蛋白质表达迅速上调，实时荧光定量 PCR（qRT-PCR）结果与蛋白质组学数据一致。KEGG 通路分析表明，柠檬酸代谢、淀粉和蔗糖代谢以及丙酮酸代谢在乙醇胁迫下显著富集，以增加应激细胞的能量需求和存活率。基于这一观察结果，活性诱导是提高 L. lactis IL1403 生物活性的有效策略。探索其在体内的功能的分子机制和物质基础有助于我们了解微生物的适应性调节机制。
