Microorganisms are able to intensely change the electrochemical conditions at the metal/solution interface by forming biofilms. These changes can result in acceleration of corrosion to corrosion inhibition. In this study microbiologically influenced corrosion inhibition (MICI) has been observed for Ni-Co alloy coatings when two bacteria inoculated to the medium. Experiments were performed in sterile medium and using Aeromonas salmonicida and Clavibacter michiganensis bacteria. After the inoculation of the bacteria, a decrease detected at the E-corr and I-corr values. Highest inhibition efficiency (eta(p) and eta(i)) values were detected for C. michiganensis, as it caused a slower corrosion reaction. (C) 2012 Elsevier Ltd. All rights reserved.