Inhibitory effect of vanillin on biofilm formation by multi-species wastewater culture

Abstract

This paper mainly investigates the inhibitory effect and mechanism of vanillin on mixed-culture biofilm formation, and discusses the feasibility of controlling membrane fouling with vanillin. The biofilms were cultured under static conditions and a microfluidic chamber, respectively. The results show that vanillin can effectively inhibit the microbial adhesion and biofilm formation; the inhibition rate increases with the vanillin concentration. After 12h treatment with 300mg/L vanillin, the inhibition rate of biofilm formation reached 85.34%. Besides, vanillin can mitigate bacterial adhesion by reducing the microbial secretion of exoprotein and exopolysaccharide, exhibit an inhibitory effect on the expression of N-acyl-l-homoserine lactones (AHLs), but had no effect on environmental deoxyribonucleic acid (eDNA). After being treated with 300mg/L vanillin, exoprotein, exopolysaccharide and AHLs decreased by 28.48%, 17.23% and 46.64%, respectively. Furthermore, there is a positive correlation between the AHLs and the content of extracellular polymeric substances (EPSs); the AHLs-mediated quorum sensing (QS) might be related to microbial adhesion through the regulation of EPS. Finally, vanillin has a great potential in membrane fouling control. The research findings provide a good reference for biofilm control in water purification and wastewater treatment systems.