Inhibition of Salmonella Typhimurium biofilm and polysaccharide production via eugenol-glucosyltransferase interactions

Abstract

This study hypothesizes that eugenol, due to its structural properties, can inhibit glucosyltransferase activity, thereby reducing polysaccharide synthesis in Salmonella Typhimurium biofilms. It was found that eugenol exhibited minimum inhibitory and bactericidal concentrations of 0.6 mg mL^-1 and 0.8 mg mL^-1, respectively, against planktonic S. Typhimurium growth. It also demonstrated minimum biofilm eradication and inhibition concentrations of 1.8 mg mL^-1 and 0.7 mg mL^-1, respectively. At 0.3 mg mL^-1, eugenol reduced biofilm formation and affected polysaccharide production. Moreover, eugenol reduced glucosyltransferase activity. Computational analysis indicated strong interactions between eugenol and the enzyme's active site residues with affinity energy -8.5 kcal mol^-1. Real-time PCR revealed a significant increase in bcsA gene expression in the presence of eugenol. These findings suggest that eugenol's ability to inhibit glucosyltransferase activity effectively reduces biofilm formation and polysaccharide content.

Keywords: Anti-biofilm compounds; bacterial polysaccharide production; extracellular polymeric substance; food safety; molecular analysis interaction.