G. Scarascia, R. Lehmann, L.L. Machuca, C. Morris, K.Y. Cheng, A. Kaksonen, P.-Y. Hong
Applied and Environmental Microbiology, (2019)
Sulfate reducing bacteria (SRB) are key contributors to microbial 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 quorum sensing (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 was 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, while they were enhanced upon exposure to QS signal molecules as compared to the control. The difference in the treatments was confirmed by transcriptomic analysis performed at different time points after treatments application. Genes related to lactate and pyruvate metabolism, sulfate reduction, electrons transfer and biofilm formation were downregulated upon QS inhibition. On the contrary, QS stimulation led to an upregulation of the above-mentioned genes compared with the control. In summary, these results reveal the impact of QS on the activity of D. vulgaris, paving the way towards the prevention of corrosive SRB biofilm formation via QS inhibition.