Comparison between E. coli K-12 BW25113 wt and E. coli K-12 BW25113 yjgK deleted mutant on 8 h biofilm cell development

The role of six toxin-antitoxin (TA) systems on biofilm development was investigated (MazEF, RelBEF, ChpB, YefM-YoeB, DinJ-YafQ, and TomB-Hha). Although these TA systems were reported previously to not impact bacterial fitness, we found that biofilm formation is decreased by toxins and increased by anti-toxins, in part, through YjgK. Hence, one role of TA systems is to regulate biofilm formation. Strains: E. coli K-12 BW25113 wild-type and E. coli BW25113 yjgK deleted mutant Medium: LB Cells: biofilm cells on glass wool Time: 8 h Temperature: 37oC

本研究探究了6种毒素-抗毒素（toxin-antitoxin, TA）系统对细菌生物被膜（biofilm）发育的调控作用，所涉TA系统包括MazEF、RelBEF、ChpB、YefM-YoeB、DinJ-YafQ及TomB-Hha。尽管既往研究曾报道此类TA系统不会影响细菌适合度，但本研究发现：毒素可抑制生物被膜形成，抗毒素则能促进该过程，且这一效应部分通过YjgK蛋白介导。由此可见，毒素-抗毒素系统的功能之一是调控细菌生物被膜的形成。本实验相关参数如下：菌株为大肠杆菌K-12 BW25113野生型菌株与大肠杆菌BW25113 yjgK基因缺失突变株；培养基为LB培养基；培养样本为玻璃棉表面的生物被膜细胞；培养时长为8小时；培养温度为37℃。