Biocorrosion induced by red-tide alga-bacterium symbiosis and the biofouling induced by dissolved iron for carbon steel in marine environment

The assemblages of unicellular microalgae and bacteria in phytoplankton communities can generally re-sult in biodeterioration of metals in marine environment. In this study, the self-promoted biofouling mechanism underneath red-tide alga Phaeodactylum tricornutum and its symbiotic bacterium Bacillus alti-tudinis was systematically revealed. The mutualistic interaction of the bacteria and algae quadrupled the corrosion rate in comparison to the individual effect of the bacterium or algal strain alone. Reversely, the corroded metal appeared to be an accelerator that can stimulate the activity of the P. tricornutum and aggravate the biological pollution based on the result of 62.3% up-regulation of the key photosynthesis genes. The corrosion-biofouling-accelerated corrosion-deteriorated biofouling formed a vicious cycle. (c) 2022 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Automated summary

This study reveals the mutualistic interaction between red-tide algae and its symbiotic bacteria can promote the corrosion rate of metals, leading to a cycle of corrosion-biofouling-accelerated corrosion-deteriorated biofouling.