Quorum sensing effect on Desulfovibrio vulgaris' ability to form biofilm and to biocorrode in saline conditions

Sulfate reducing bacteria (SRB) are key contributors to microbial induced corrosion (MIC), which has serious economic and environmental consequences. The presence of a biofilm structure significantly increases the impact of biocorrosion. In the last years, the inhibition of the quorum sensing (QS) system was proven as a promising alternative to tackle biofilm in different industrial settings, especially when common treatments result insufficient or detrimental. However, QS influence in SRB is mostly unknown and only fragmentary knowledge is available. In this work we described the effect of the QS stimulation and inhibition on Desulfovibrio vulgaris in terms of anaerobic respiration, cell activity, QS autoinducers production, biofilm formation and biocorrosion of carbon steel. All these traits were repressed when bacteria were in contact with QS inhibitors, while they were improved upon exposure to QS signal molecules. The difference in the two treatments was confirmed by transcriptomic analysis performed at different time points after treatment injection.