Construction of a qseC-deleted mutant of Escherichia coli and evaluation of biofilm formation of the mutant / 中华微生物学和免疫学杂志

ABSTRACT

Objective To construct a qseC-deleted mutant strain of E.coli by Red recombination and to study the effect of qseC gene on biofilm formation in the mutants.Methods The chloramphenicolresistant gene flanked by homologues of target genes was amplified by PCR and electro-transformed into E.coli MC1000.When induced by L-arabinose,the plasmid pKD46 could express three recombinant proteins of λ-prophage,which led to the replacement of target gene(qseC) with chloramphenicol-resistant gene.Then the chloramphenicol-resistant gene was eliminated by FLP-promoted recombination events.The biofilm formation of wild-type and mutant strain was detected by crystal violet staining.Results The qseC-deleted mutant of E.coli was confirmed by various PCR and DNA sequencing.Gene qseC was completely deleted.There was no significant difference in growth ability between the qseC mutant strain and the wild-type strain MC1000.The biofilm formation of wild-type and mutant strain was quantified by crystal violet staining.The absorbance determined with a plate reader at 570 nm was 1.00±0.15 and 0.47±0.10 respectively.Conclusion The qseC-deleted mutant of E.coli was constructed successfully.And the qseC gene plays an important role in regulation of biofilm formation in E.coli.