BEN GHORBAL KLOULA SALMA1
WERHANI RIM 1
1Laboratoire de Traitement des Eaux Usées, Centre de Recherches et Technologies des Eaux Usées, Technopole Borj Cedria, BP 273-Soliman 8020.
Abstract – The biofilm formation and development might vary in presence of UVc radiations, since this biofilm could be considered as a form of adaptation and resistance of microbial organisms to stress exposure. The study of bacterial biofilm was investigated to determine the potential UVc effects on bacterial biofilm formation and development. Moreover, the protective role of superoxide dismutase (SOD) against UVc radiations has been studied in wild-type and mutant strain of Pseudomonas aeruginosa lacking cytosolic Mn-SOD (sodM), Fe-SOD (sodB), or both SODs (sodMB), forming biofilm. Pseudomonas aeruginosa PAO1 and its isogenic mutants sodM, sodB and sodMB were exposed to incremental UVc doses. To measure biofilm formation, samples of suspension were taken at indicated times during irradiation and used for both qualitative and quantitative biofilm tests.Our results showed that inactivation of sodM gene increase the sensitivity of P. aeruginosa toward stress induced by UVc radiations. Furthermore, our results showed an enhancement of biofilm production, after exposure to UVc radiations, in wild-type and sod B mutant which maintained significantly higher levels of biofilm production than sodM mutant strain. The overall results showed that Mn-SOD isoform has a protective role against a stress induced by UVc radiations in P. aeruginosa biofilm.