苯乳酸与单增李斯特菌和大肠杆菌胞内外基因组的抑菌作用机制

吴汉东; 黄云坡; 金嫘; 查恩辉; 孙晶; 周铭懿

doi:10.13386/j.issn1002-0306.2017.23.022

苯乳酸与单增李斯特菌和大肠杆菌胞内外基因组的抑菌作用机制

The bacteriostatic mechanism of phenyllactic acid with Listeria monocytogenes and Escherichia coli genome DNA

摘要

摘要: 为研究苯乳酸与食源性致病菌基因组的相互作用机制,选取单增李斯特菌（Listeria monocytogenes 10403s）和大肠杆菌（E.coli 44752）采用凝胶电泳阻滞实验法和紫外-可见光谱法研究苯乳酸与胞内、胞外基因组DNA的作用机制。实验结果表明苯乳酸与单增李斯特菌和大肠杆菌的胞内DNA迁移率和条带亮度均未发生变化,无相互作用;苯乳酸对单增李斯特菌和大肠杆菌的胞外DNA发生结合作用。单增李斯特菌体外DNA在苯乳酸16³2 mmol/L浓度下,与苯乳酸发生结合作用,结合常数为9.16×10⁵M^-1;大肠杆菌体外DNA在苯乳酸2¹6 mmol/L的浓度下,与苯乳酸发生结合作用,结合常数为7.36×10⁵M^-1。两者的结合方式为静电结合和嵌插结合。

Abstract: The interaction between phenyllactic acid (PLA) and Foodborne pathogenic bacteria genome (Listeria monocytogenes10403s and E.coli 44752) in vivo/vitro was studied by agarose gel electrophoresis and UV spectra.The results showed that there was no apparent interaction between PLA and the intracellular DNA of Listeria monocytogenes 10403s and E.coli 44752.The absorption UV spectra demonstrated that PLA could interact with bacterial genomic DNA in vitro in the manner of intercalation and groove binding.The binding constant K of PLA (16³2 mmol/L) was 9.16×10⁵M^-1for Listeria monocytogenes 10403s and the binding constant of PLA (2¹6 mmol/L) K=7.36×10⁵M^-1for E.coli 44752.The combination of PLA with DNA in vitro demonstrated that was static interaction and intercalation.