The control of microbially induced corrosion by methyl eugenol – A dietary phytochemical with quorum sensing inhibitory potential

Abstract The development of biofilms by microorganisms is conventionally attributed to microbially induced corrosion on stainless steel surfaces and leads to severe consequences in industrial and environmental settings. Since bacterial biofilm formation is regulated by the signal mediated quorum sensing (QS) system, targeting biofilms through QS inhibitors will possibly control biologically induced corrosion on the metal surface. In this study, biofilm formation on 316L stainless steel (SS 316L) immersed in a natural pond water system was effectively inhibited in the presence of the QS inhibitor methyl eugenol, as evidenced through epifluorescence microscopy, confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) analyses. The exopolysaccharide (EPS) and protein extracted from the biofilm formed on the metal surface were found to be reduced by 64% and 60%, respectively, upon exposure to methyl eugenol. In addition, applied electrode potential (open circuit and cathodic) measurements indicated reduced oxygen reduction current at the metal surface that was exposed to methyl eugenol. This inhibitor also enhanced the polarization resistance (Rp) of the SS 316L as indicated by electrochemical impedance spectroscopic (EIS) study.