Adhesion and corrosion effects of biofilms on steel surface mediated by hydrophilic exopolysaccharide colanic acid

The corrosion mechanism involving bacterial biofilms has long been a focus of the research on microbiologically influenced corrosion. In this study, biofilms formed by Pseudoalteromonas marine and its mutant demonstrated the ability to inhibit uniform corrosion. However, the excessive secretion of colanic acid by the mutant Delta 01912 resulted in a significantly increased number of attached bacteria and the formation of unevenly hydrophilic biofilms, which aggravated localized pitting corrosion on the steel surface. This study provides evidence that unevenly hydrophilic biofilms can lead to local enrichment of chloride ions, thereby intensifying the pitting of metal materials.