Pseudoalteromonas spongiae - induced biomineralization on Q235B and 2507 steel for corrosion and biofouling resistance

The biomineralization process was initiated by bacteria recruiting mineral ions, the biomineral layers was formed spontaneously on metal surfaces, it influenced the service life of metal. We found that P. spongiae induced biomineralization layer formation on Q235B carbon steel and 2507 duplex stainless steel in bacterial suspension, and evaluated anti-corrosion and anti-fouling performance of mature biomineralization in simulated seawater. On Q235B, higher surface reactivity yielded a uniform, dark-gray, super hydrophilic biomineralization layer with minor iron oxides. It increased interfacial/charge-transfer resistance, suppressed corrosion, and reduced the attachment of Phaeodactylum tricornutum. On 2507, the native passive barrier limited nucleation, producing Ca–Mg carbonate deposits with exposed metal and faster charge transfer. Nonetheless, the hydrophilic protective layer still reduced biofouling in artificial seawater. Overall, P. spongiae–mediated biomineralization was substrate-dependent with dual anti-corrosion and anti-fouling capacity on carbon steel. On 2507, the heterogeneous biomineralization layer, while reducing biofouling, locally compromised the integrity of the passive film, resulting in pitting corrosion.