Abstract:

To construct flagellin gene (fliC) inactivation mutant of Escherichia coli (ΔfliC) and explore its biological characteristics under stresses after alteration of biofilm formation. A fliC gene-inactivated mutant strain (ΔfliC420s) was constructed using the Thermotargetron targeted gene inactivation system. The changes of growth rate, motility, biofilm formation ability, autolysis rate, pH sensitivity and antibiotic tolerance of ΔfliC420s and wild-type strain were measured. Compared with wild-type strain, ΔfliC420s mutant had no effect on growth rate, its motility in semi-solid medium was reduced, the biofilm formation ability was significantly reduced, the autolysis rate of bacteria was accelerated, the pH sensitivity was enhanced, Interestingly, the tolerance of ΔfliC420s mutant to D-cycloserine, erythromycin, norfloxacin was reduced. The fliC gene of E. coli plays an important role in the formation of bacterial biofilm and resistance to external stresses.

Key words: Escherichia coli, fliC gene, biofilm, gene inactivation, Thermotargetron