Microbially influenced corrosion and inhibition of nickel–zinc and nickel–copper coatings by Pseudomonas aeruginosa

• Bacteria attached to the nickel alloy coatings.
• Ecorr exhibited cathodic shift for Ni–Cu.
• Rct value of Ni–Zn increased.
• Crevices and pits was observed on the surface due to bacterium on Ni–Cu alloy.
• Bacteria protected Ni–Zn alloy by biofilm from corrosion.

The present study describes the effect of Pseudomonas aeruginosa on the corrosion rate of nickel–zinc and nickel–copper alloy coatings. The presence of bacteria was associated with decreases in Rct values, suggesting that P. aeruginosa promoted the corrosion of nickel–copper alloy coatings. However, Rct values of nickel–zinc coatings increased in response to bacterial inoculation, corresponding to a decrease in corrosion rate for nickel–zinc alloy coatings. Our results suggest that the activity of P. aeruginosa facilitated the corrosion of nickel–copper alloy, while serving a protective function for the nickel–zinc alloy.