群体感应信号分子AI-2高产乳酸菌株筛选及特性研究  

Screening and characterization research of quorum sensing signaling molecule AI-2 high-yield Lactobacillus strains

作　　者：蔡针华 程娜 贾震虎[1] 逄晓阳[2] CAI Zhen-hua;CHENG Na;JIA Zhen-hu;PANG Xiao-yang(School of Life Science, Shanxi Normal University, Linfen 041000, China;Institute of Food Science and Technology CAAS, Beijing 100193 ,China)

机构地区：[1]山西师范大学生命科学学院,山西临汾041000 [2]中国农业科学院农产品加工研究所,北京100193

出　　处：《食品与发酵工业》2018年第1期66-71,共6页Food and Fermentation Industries

基　　金：国家自然科学基金面上项目(31471603);国家科技支撑计划项目(2015BAD16B00);中国农业科学院科技创新工程项目(cxgc-ifst-08)

摘　　要：为深入研究乳酸菌的群体感应系统,对8株乳酸菌产群体感应信号分子自体诱导剂-2(Autoinducer-2,AI-2)情况进行了检测,7株乳酸菌中检测到明显的AI-2信号分子,且其中3株产生AI-2信号极强;对高产AI-2的菌株,通过RT-PCR对乳酸菌luxS基因和LDH基因的表达情况进行了检测,发现高产AI-2的乳酸菌其luxS基因表达较强,而LDH基因表达较弱;最后分析了酸性环境与乳酸菌信号分子AI-2产量的相关性,结果表明培养基酸性越强,乳酸菌产AI-2信号越强。luxS基因是AI-2信号合成的关键基因,AI-2信号分子提高了乳酸菌的耐酸性,有利于乳酸菌通过群体感应信号调控肠道内的酸碱平衡和菌群平衡。Lactobacilli quorum sensing system is an important regulatory pathway for lactic acid bacteria （LAB） to respond to environmental changes and regulate the expression of related genes in vivo. This paper aimed to study the quorum sensing system of LAB. In this study, AI-2 signaling molecule was detected in 8 strains of LAB. Out of the 8 strains, 7 strains showed significant level of AI-2 signal molecules, and 3 of these produced strong AI-2 signal. For strains with high yield of AI-2, luxS and LDH genes expression were evaluated by RT-PCR. The expression level of luxS gene was higher with higher yield of AI-2 strains. On the contrary, the expression of LDH was lower. Finally, the correlation between acidity and AI-2 production was analyzed. The results showed that the more acidic of the cul- ture medium, the stronger the AI-2 signal. The luxS gene is the key gene of AI-2 synthesis. AI-2 signal molecule im- proved the acid resistance of LAB, which is beneficial to LAB to regulate the acid-base and gut micro flora balance in the intestine through the group induction signal. This study laid the foundation for LAB group induction signaling pathway study, and for understanding LAB＇s adhesion and colonization mechanism, in the intestinal environment.

关 键 词：乳酸菌 群体感应 AI-2 LUXS基因 RT-PCR 

分 类 号：TQ921.3[轻工技术与工程—发酵工程]