Temporal succession of microfouling communities in microbiologically influenced corrosion of copper-nickel and titanium in seawater

Temporal succession of active and total microbial communities driving microbiologically influenced corrosion (MIC) on copper-nickel (CuNi) 90/10 and titanium (Ti) exposed to natural seawater over 16 weeks was investigated. Electrochemical analysis revealed increasing corrosion resistance of CuNi until 12 weeks, but showed corrosion signs at 16 weeks; Ti exhibited steadily increasing corrosion resistance. Raman spectroscopy confirmed unprotective cupric oxide (CuO) and hydroxide (Cu(OH)₂) presence on CuNi, while Ti maintained protective TiO₂. Pitting analysis identified pits on CuNi but none on Ti. Next-generation sequencing of complementary and genomic DNA identified Halomonas and Marinobacter as early colonizers on CuNi, and increasing species diversity over time. Ti exhibited decreasing diversity, with Aestuariibacter , Methylophaga , and predatory bacteria as early colonizers. Sulfate-reducing and acid-producing bacteria initially showed a declining trend on CuNi but increased from 12 weeks, indicating increased MIC susceptibility; they remained less/undetectable on Ti. Overall, findings highlight the role of early colonizers in driving MIC and distinct microbial succession.