Correlation between localized anodic areas and Oceanospirillum biofilms on copper

The marine bacterium Oceanospirillum produces copious amounts of exopolymer when grown on copper surfaces and binds Cu⁺² from the substratum. The organism and associated exopolymers result in local anodic regions that can be detected by scanning vibrating electrode microscopy. Oceanospirillum was grown in small laminar flow cells with two carbon sources on copper and 316 stainless steel as substrata. The chemical composition of the exopolymer varied with growth medium, but not with substratum. Exopolymers from cells grown in glutamic acid medium on both substrata contained glucose with no other sugar monomers or uronic acids. The quantity of exopolymer did vary with substratum and copper promoted greater polymer production that stainless steel.