The corrosion behavior of Ni-Cu alloy in Nutrient Broth medium (peptone from meat 5.0g. meat extract (N source) 3.0g. and sodium chloride 6.0 g in 1 L) and in the presence of Aeromonas eucrenophila, isolated from water treatment system, has been studied using electrochemical techniques. Results showed that the polarization curves exhibiting a cathodic shift of the corrosion potential confirmed the increase in the corrosion rates. According to EIS data lower Q(CPE) value for 5 h indicates surface inhomogeneity resulting from surface metal roughening, which is the likely cause of the enhanced dissolution of the metal also observed in SEM micrographs. In addition, the pH values of the medium did not change throughout the experiment; however, after immersion the pH value decreased to acidic value and caused corrosion. (C) 2011 Elsevier Ltd. All rights reserved.