Biofilm formation of Escherichia coli under the redox-status modification

The ability of biofilm formation in Escherichia coli bearing mutants in the components of glutathione and thioredoxin redox systems, as well as in the regulator of the general stress response RpoS was studied at different growth temperatures. Statistically significant correlation between specific bacteria biofilm formation and expression of the antioxidant gene katG was revealed at 37°C. This indicates a possible contribution of the OxyR regulon activation in the formation of bacteria biofilms. Monitoring of the sodA gene expression in thiol redox system mutants at 37°C showed 1.15-1.8-fold increase in gshA, gor, trxA, gshAtrxA gortrxB mutants. A direct relationship between the biofilm formation and expression of the gene sodA under the same conditions was established. The presence of mutations in components of the thiol redox systems significantly changed the production of biofilms under temperature stresses, which is probably due to the interruptions in the redox regulation of intracellular signaling pathways. It was shown the RpoS participation in biofilm formation at the optimum growth temperature and RpoS-dependent nature of biofilm formation induction in 24°C and 44°C.