ompX contribute to biofilm formation, osmotic response and swimming motility in Citrobacter werkmanii

•ompX is a negative regulator for biofilm formation in C. werkmanii.•C. werkmanii swimming ability is inhibited by ompX.•ompX is involved in the resistance response to various bactericides.•Many gene expressions in C. werkmanii can be oscillated by ompX.•Both rbsR and tdcA regulate the expression of ompX, ompD, and ompW.