ABSTRACT
Microorganisms that are present in locations impacted by microbiologically influenced corrosion (MIC) exist as biofilms with several other species. It is well established that biocide dosage required for effective eradication of co–culture biofilms is higher than that required for planktonic cells and mono–species biofilms. In this study, the resistance of a two–species co–culture biofilm to biocide treatment was compared to single–culture biofilms using a microfluidic device bonded to carbon steel coated glass. Shewanella oneidensis and Vibrio natriegens were used as the representative bacteria as they are marine facultative anaerobes and reported to be present at several locations where MIC has been detected. The effect of biocides, glutaraldehyde and tetrakis–hydroxymethyl–phosphonium sulfate (THPS) on continuously grown short-term and long–term single–species biofilms and co–culture biofilms was investigated by comparing biofilm viability. The metal surfaces were also examined for indicators of corrosion. This study demonstrates the importance of investigating multi–species biofilms in determining the effective biocide.
