Plasmid DNA supercoiling and survival in long-term cultures of Escherichia coli:: Role of NaCl
Plasmid DNA supercoiling and survival in long-term cultures of Escherichia coli:: Role of NaCl
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DOI：
10.1128/jb.185.17.5324-5327.2003
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发表时间：
2003-09-01
影响因子：
3.2
通讯作者：
Conter, A
中科院分区：
文献类型：
--
作者：
Conter, A
本文研究了大肠杆菌在富培养基中长期饥饿存活与报告质粒pBR 322超螺旋的关系。在通气连续振荡培养中，E.大肠杆菌在无NaCl的Luria-Bertani培养基中比在含NaCl的培养基中更早丧失形成菌落的能力，质粒pBR 322的负超螺旋在无NaCl的培养基中下降得更快。在第24小时添加NaCl可恢复活力和负超螺旋，与添加的NaCl浓度成比例。添加喹诺酮类促旋酶抑制剂奥曲肽，取消了按比例添加的氧氟沙星添加NaCl的救援。这一观察结果提出了一种可能性，即细胞有能力恢复质粒超螺旋，即使营养物质不可用，并可以在长期饥饿期间存活，其方式至少部分与DNA的拓扑状态和促旋酶活性有关。
The relationship between the survival of Escherichia coli during long-term starvation in rich medium and the supercoiling of a reporter plasmid (pBR322) has been studied. In aerated continuously shaken cultures, E. coli lost the ability to form colonies earlier in rich NaCl-free Luria-Bertani medium than in NaCl-containing medium, and the negative supercoiling of plasmid pBR322 declined more rapidly in the absence of NaCl. Addition of NaCl at the 24th hour restored both viability and negative supercoiling in proportion to the concentration of added NaCl. Addition of olloxacin, a quinolone inhibitor of gyrase, abolished rescue by added NaCl in proportion to the ofloxacin added. This observation raises the possibility that cells had the ability to recover plasmid supercoiling even if nutrients were not available and could survive during long-term starvation in a manner linked, at least in part, to the topological state of DNA and gyrase activity.