The Key Laboratory of Dairy Biotechnology and Bioengineering, Department of Food Science and Engineering, Education Ministry of PR China, Inner Mongolia Agricultural University, Hohhot 010018, China.
J Dairy Sci. 2010 Aug;93(8):3858-68. doi: 10.3168/jds.2009-2967.
Lactobacillus casei Zhang, isolated from koumiss in Inner Mongolia of China, is known from previous findings to be tolerant to bile salts. Bile salts secreted by mammals act as a natural antibacterial barrier and may serve as a component of innate immunity, as they have limited antagonistic effect against resident microflora. In this work, we compared the growth and protein expression patterns of L. casei Zhang with and without bile salts. Twenty-six proteins were found to be differentially expressed using 2-dimensional gel electrophoresis. Peptide mass fingerprinting was used to identify these proteins. Further verification by using real-time, quantitative reverse transcription-PCR and bioinformatics analysis showed that the implicated pathways are involved with a complex physiological response under bile salts stress, particularly including cell protection (DnaK and GroEL), modifications in cell membranes (NagA, GalU, and PyrD), and key components of central metabolism (PFK, PGM, CysK, LuxS, PepC, and EF-Tu). These results provide insight on the protein expression pattern of L. casei under bile salts stress and offer a new perspective for the molecular mechanisms involved in stress tolerance and adaptation of bacteria.
从先前的研究中可知，从中国内蒙古的马奶酒中分离出的干酪乳杆菌张株能够耐受胆盐。哺乳动物分泌的胆盐作为一种天然的抗菌屏障，可能是先天免疫的一个组成部分，因为它们对常驻微生物群的拮抗作用有限。在这项工作中，我们比较了有和没有胆盐时干酪乳杆菌张株的生长和蛋白表达模式。使用 2 维凝胶电泳发现 26 种蛋白表达存在差异。肽质量指纹图谱用于鉴定这些蛋白。通过使用实时定量逆转录聚合酶链式反应和生物信息学分析进一步验证表明，所涉及的途径与胆汁盐胁迫下的复杂生理反应有关，特别是包括细胞保护（DnaK 和 GroEL）、细胞膜修饰（NagA、GalU 和 PyrD）以及中心代谢的关键成分（PFK、PGM、CysK、LuxS、PepC 和 EF-Tu）。这些结果提供了干酪乳杆菌张株在胆汁盐胁迫下的蛋白表达模式的见解，并为细菌耐受和适应应激的分子机制提供了新的视角。
