食品科学2017，Vol.38Issue(22)：48-53,6.DOI:10.7506/spkx1002-6630-201722008
单核细胞性李斯特菌基因dal的敲除及其生物学特性初步分析
Knockout of dal Gene and Its Effect on Listeria monocytogenes
摘要
Abstract
In this study,the actA and inlB double gene deletion mutant (EGDe △actA△inlB) of Listeria monocytogenes wild-type (WT) strain EGDe was used as the parent to delete the dal gene by homologous recombination technology,and the biological characteristics of the dal-deficient mutant such as growth capacity,virulence gene expression,cell invasion and biofilm formation were further studied.Growth curves showed that the concentration of the new mutant strain was significantly lower than that of EGDe △actA△inlB after 6 h of shaking culture at 37 ℃ (P ＜ 0.001),but there was no difference in the growth rates of the parental and the mutant strains when D-alanine was added to the medium.Quantitative real-time-PCR showed that the sigB gene expression level of the mutant strain was changed most significantly (P ＜ 0.01) and down-regulated by 90％ compared with EGDe △actA△inlB.The biofilm formation of the mutant strain increased compared with EGDe △actA△inlB,but this difference did not exist when D-alanine was added to the medium for the mutant.There was no significant difference in Caco-2 cells invasion ability compared with EGDe △actA△inlB.The results indicated that the dal gene played an important regulatory role in the growth and biofilm formation of bacteria and did not affect the ability of cell invasion.The construction of this deletion strain can provide a tool for further study of the function of the dal gene.关键词
单核细胞性李斯特菌/基因敲除/生长能力/细胞侵袭/生物被膜Key words
Listeria monocytogenes/gene knockout/growth capacity/biofilm/cell invasion分类
轻工纺织引用本文复制引用
曾海娟,刘武康,谢曼曼,丁承超,董庆利,刘箐..单核细胞性李斯特菌基因dal的敲除及其生物学特性初步分析[J].食品科学,2017,38(22):48-53,6.基金项目
国家自然科学基金面上项目(31371776) （31371776）
