Bacterial communities within steel corrosion tubercles in the Duluth-Superior Harbor. steel metagenome

Corrosion of steel structures in the Duluth-Superior Harbor (DSH) is a severe economic problem. This corrosion is characterized by deep pits covered by crusty, orange, blister-like structures called tubercles. Prior research demonstrated these tubercles contain both iron-oxidizing (IOB) and sulfate-reducing bacteria (SRB) but fine scale changes of bacterial community structure within these tubercles remain unknown. Experimental steel coupons were placed at four sites in the DSH in 2006 and 2012 and recovered in 2013 to measure chemical gradients and identify bacteria associated with young and old corrosion tubercles.