摘要
通过生物学方法检测坚强肠球菌SQ-3-2是否产生群体感应信号分子AI-2,并对检测条件进行优化。将坚强肠球菌SQ-3-2培养上清液加入到由哈维氏弧菌BB170构成的特异性报告系统中,使用多功能酶标仪化学发光模式检测荧光强度,通过与AB培养基空白对照进行荧光强度的比较得出坚强肠球菌SQ-3-2是否产生具有活性的AI-2信号分子,同时依据荧光强度的大小对加样比和酸碱度两个条件进行优化。研究结果表明,坚强肠球菌SQ-3-2培养上清液中含有AI-2信号分子,随着菌体密度的增加信号分子AI-2的浓度也随之增大,在对数期末期达到最大值。方法优化实验证明最佳检测条件为待测样品pH=7,加样比例为1∶100。实验为进一步研究坚强肠球菌SQ-3-2的Lux S系统打下基础。同时,方法优化实验为检测各类乳酸菌是否分泌AI-2信号分子提供了一定的实验基础和理论依据。
To explore that if the Enterococcus durans SQ-3-2 produces the quorum-sensing signal autoinducer-2 by utilizing a biological assay and optimize the test condition at the same time. The experiment employed a biolumi- nescent bacterial reporter strain called Vibrio harveyi BB170, which produces light in response to AI-2. We collected the cell-free culture fluids and added them to the V. harveyi BB170 reporter strain. The resulting light production was measured using a luminometer or scintillation counter. AI-2 activity was deduced according to the induction of lumi- nescence of V. harveyi BB170. The fluorescence of the V. harveyi increased after adding the cell-free culture fluids of E. durans SQ-3-2 and based on the fluorescence intensity of different sample experiment condition was optimized. We found that the E. durans SQ-3-2 produces the quorum-sensing signal AI-2. With the increase of cell density, concen- tration of signaling molecule AI-2 increased and the maximum value was reached in logarithmic period. Optimal tes- ting condition was sample pH = 7 and sample ratio of 1 ： 100. Experiment lays the foundation to further study of func- tion of AI-2 from E. durans SQ-3-2. At the same time, the optimized experimental conditions for detection of quorum- sensing signal AI-2 of various kinds of lactic acid bacteria is the experimental foundation.
出处
《食品与发酵工业》
CAS
CSCD
北大核心
2013年第2期168-173,共6页
Food and Fermentation Industries
基金
国家自然科学基金资助项目(31060222)
