Role of anaerobic electron acceptors in corrosion of Q235 carbon steel affected by Vreelandella titanicae IO

This study investigates the influence of different anaerobic electron acceptors on the corrosion of Q235 carbon steel affected by Vreelandella titanicae IO. It was found that corrosion was accelerated when nitrate was utilized as the electron acceptor by the bacterium, while inhibited with fumarate. Genomic and metabolomic analyses revealed that gallic acid (GA) was secreted when nitrate was the electron acceptor, but it was absent in the case of fumarate. GA injection promoted steel corrosion in V. titanicae IO cultures but had no effect in sterile media, confirming its role in extracellular electron transfer (EET). The findings suggest that the EET capability of V. titanicae IO was regulated by the type of electron acceptors, with GA mediating EET only in the presence of nitrate. This study provides new insights into the mechanisms of microbiologically influenced corrosion (MIC) and highlights the potential for controlling corrosion through the manipulation of microbial electron transfer pathways.