Battling Biocorrosion in the Duluth-Superior Harbor

Problem: Aquatic bacteria cause up to $60 billion in damage to port infrastructure on a global scale. Locally, Duluth-Superior Harbor is home to some of Minnesota’s most critical shipping infrastructure, and it is not immune to bacterial degradation. This degradation occurs from bacterial biofilms that accumulate on underwater structures, corroding the steel and deteriorating the foundation of ports. Current coatings for steel contain high levels of copper-oxide, which is not friendly to aquatic ecosystems. Locally, Duluth-Superior Harbor is home to some of Minnesota’s most critical shipping infrastructure, and it is not immune to bacterial degradation.

Solution: Elias’s team identified a naturally occurring enzyme and engineered it to protect the harbor’s underwater steel infrastructure. The enzyme prevents formation of destructive biofilms by blocking communications between bacterial cells. Manufacturers can coat the submerged steel with a layer of the enzyme-infused paint, and early results indicate higher efficacy than the most widely used copper-oxide coatings.

Impact: The enzyme-coating could prevent the corrosion of 50,000 pounds of steel in Duluth’s ports each year, while withstanding harsh Minnesota winters. The technology has potential for commercial-scale installation at ports around the world with infrastructure affected by aquatic bacterial biofilms. The enzyme is also completely biodegradable, offering an environmentally conscious solution to an industry dominated by toxic, copper-oxide paints.