电子束辐照对李斯特菌胞内组分及相关基因表达的影响

Effects of Electron Beam Irradiation on the Intracellular Components and Expression of Relative Genes in Listeria

为探讨电子束辐照对李斯特菌的致死机制,采用傅里叶红外光谱仪和实时荧光定量PCR技术研究其对李斯特菌胞内组分及相关基因表达量的影响。结果表明:电子束辐照后,李斯特菌细胞内组分特征吸收峰强度减弱,吸收频率发生偏移等,造成胞内细胞膜脂肪酸、蛋白质、核酸等物质结构和构象改变,且酰胺I带中α螺旋和β转角的含量明显减少,β折叠和无规则卷曲的含量明显增加,表明辐照后细胞内蛋白质结构向无序化发展。电子束辐照处理,诱导激活了recA基因和糖代谢相关基因,同时抑制了毒力因子的表达水平。以上结果表明,电子束辐照对李斯特菌细胞组分及相关基因表达影响显著,这些变化可能在李斯特菌的死亡中发挥重要作用。

In order to explore the inactivation mechanism of electron beam irradiation against Listeria,the effects of intracellular components and related gene expression on Listeria were studied by fourier transform infrared spectroscopy and real-time fluorescence quantitative PCR.The results showed that after the electron beam irradiation,the absorption peak intensity of the intracellular components of Listeria decreased,and the absorption frequency shifted,which resulted in the changes of the structure and conformation of intracellular membrane fatty acids,proteins,nucleic acids and other substances.And in the amide I band the content ofα-helix andβ-turn was significantly reduced,and the content ofβ-sheet and random coil were significantly increased,indicating that the intracellular protein structure became disorder after irradiation.In addition,electron beam irradiation treatment resulted in the elevations of recA gene and glucose metabolism related genes,while reductions in the level of virulence factors.The above results indicated that electron beam irradiation had significant effects on the intracellular components and the related genes expression of Listeria,and these changes may play an important role in the death of L.innocua caused by electron beam irradiation.