Abstract

Pseudomonas aeruginosa is a commonly found nosocomial opportunistic pathogen that is characterized by its ability to form biofilm to protect itself from various external pressures. Biofilms are problematic in particular food industry sectors and in water distribution systems. In this study, we propose to explore the impact of UVC dose on biofilm production by P. aeruginosa strains. The biofilms densities were assessed by crystal violet assay. A relationship between UVC exposed dose and biofilm density was examined by establishment of new model linking between UVC dose and physiology bacteria response concerning biofilm production (UVC dose/ biofilm production).

Key words:  UVC dose, biofilm, P. aeruginosa, quorum sensing, RecA, model.

Abbreviation

Abbreviations: H_s, threshold UVC dose (mJ.cm^-2); H_t, UVC dose over than Hs dose (mJ.cm^-2); M_a, Active bacteria responsible for production and maturation of biofilm; M_b, The total biomass of the biofilm continues to grow for the control test (before exposure to UVC light; H_UV=0 mJ.cm^-2); M_d, Inactive bacteria no longer involved in the construction of biofilm; QS, quorum sensing; UV radiation,Ultraviolet radiation; μ, Biofilm growth rate.