Stainless steel immersed in seawater have an increased risk of localized corrosion due an increase of the Open Circuit Potential (OCP), also referred as ennoblement. That increase of potential occurs during the first days of exposure and correlates to the presence and development of microorganisms naturally found in the seawater. In a previous study about the effect of temperature on ennoblement and stainless steel microbial communities, we identified an electroactive bacteria based on 16S rRNA gene sequencing and proposed a new model to explain how microorganisms could be able to change the OCP of stainless steel. In order to investigate the role of electroactive bacteria, we used normal and applied potential conditions with a metagenomic and metatranscriptomic approach. We confirmed the presence of electroactive bacteria associated with the ennoblement and investigated the gene expression associated with the different conditions.