Effect of quorum sensing on the ability of Desulfovibrio vulgaris to form biofilms and to biocorrode carbon steel in saline conditions

Abstract

Sulfate-reducing bacteria (SRB) are key contributors to microbe-induced corrosion (MIC), which can lead to serious economic and environmental impact. The presence of a biofilm significantly increases the MIC rate. Inhibition of the quorumsensing (QS) system is a promising alternative approach to prevent biofilm formation in various industrial settings, especially considering the significant ecological impact of conventional chemical-based mitigation strategies. In this study, the effect of the QS stimulation and inhibition on Desulfovibrio vulgaris is described in terms of anaerobic respiration, cell activity, biofilm formation, and biocorrosion of carbon steel. All these traits were repressed when bacteria were in contact with QS inhibitors but enhanced upon exposure to QS signal molecules compared to the control. The difference in the treatments was confirmed by transcriptomic analysis performed at different time points after treatment application. Genes related to lactate and pyruvate metabolism, sulfate reduction, electron transfer, and biofilm formation were downregulated upon QS inhibition. In contrast, QS stimulation led to an upregulation of the above-mentioned genes compared to the control. In summary, these results reveal the impact of QS on the activity of D. vulgaris, paving the way toward the prevention of corrosive SRB biofilm formation via QS inhibition.