Marine Biofilms with Significant Corrosion Inhibition Performance by Secreting Extracellular Polymeric Substances

The development of environmentally friendly and sustainable corrosion protection technologies is a longstanding yet difficult problem, especially for the marine environment. The utilization of living biofilms isolated from local environments is an effective strategy for infrastructure protection. In this study, three aerobic marine bacteria, Tenacibaculum mesophilum D-6, Tenacibaculum litoreum W-4, and Bacillus sp. Y-6, with strong biofilm-forming abilities were isolated and evaluated for the corrosion protection of X80 carbon steel. The corrosion inhibitory effect of the bacteria was found to be closely related to their biofilm-forming abilities. This conclusion was corroborated by biofilm characterization, electrochemical tests, weight loss analysis, and corrosion product analysis. Moreover, secreted extracellular polymeric substances were identified to play significant roles in corrosion inhibition. Herein, we proposed a novel, eco-friendly, and cost-effective method for corrosion protection of carbon steels in the marine environment, providing guiding principles for identifying corrosion inhibitory bacteria from the local marine environment.