Deterioration of materials due to corrosion leads to major economic losses globally Part of corrosion is caused by the interaction with micro-organisms, termed biocorrosion Even though biocorrosion has been a field of study for decades, a general understanding of biocorrosion is lacking because of the numerous and entangled biophysicochemical mechanisms that can possibly intervene In the last decade major insights were gained into so-called electroactive microorganisms, enabling them to transfer electrons to and from electrodes and materials These insights have changed our perception on how microorganisms interact with materials such as steel, and as a result a revisit is needed of corrosion in view of electron transfer In this project we will use pure cultures and mixed populations and assess their role in biocorrosion from an electrochemical perspective We will operate long term systems in which we can effectively control the steel in terms of potential and current, rather than passively monitoring In these systems we can track the present microorganisms and monitor their evolution We will use the insights to develop new approaches that can minimize corrosion eg via biofilm based passivation or active anodic protection