Biocidal effect of cathodic protection on bacterial viability in biofilm attached to carbon steel

Abstract

Biofilm formed on carbon steel by various species of bacterial cells causes serious problems such as corrosion of steel, choking of flow in the pipe, deterioration of the heat-transfer efficiency, and so on. Cathodic protection is known to be a reliable method for protecting carbon steel from corrosion. However, the initial attachment of bacteria to the surface and the effects of cathodic protection on bacterial viability in the biofilm have not been clarified. In this study, cathodic protection was applied to an artificial biofilm containing Pseudomonas aeruginosa (PAO1), a biofilm constituent, on carbon steel. The aims of this study were to evaluate the inhibition effect of cathodic protection on biofilm formation and to reveal the inhibition mechanisms. The viability of PAO1 in artificial biofilm of 5 mm thickness on cathodically protected steel decreased to 1% of the initial cell concentration. Analysis of pH distribution in the artificial biofilm by pH microelectrode revealed that pH in proximity to carbon steel increased to approximately 11 after cathodic protection for 5 h. Moreover, 99% of region in the artificial biofilm was under the pH conditions of over nine. A simulation of pH profile was shown to correspond to experimental values. These results indicate cells in the artificial biofilm were killed or damaged by cathodic protection due to pH increase.

Grafting of antibacterial polymers on stainless steel via surface‐initiated atom transfer radical polymerization for inhibiting biocorrosion by Desulfovibrio desulfuricans

“…Alternatively, protective antifouling coatings, such as tributyltin (TBT)-based paints, are used extensively in seawater environments, despite concerns for their toxicity, to combat biofouling and biocorrosion of metallic materials (Jelic-Mrcelic et al, 2006;Yebra et al, 2004). Although cathodic protection has been reported to effectively inhibit biocorrosion of SS by aerobic bacteria (Guezennec, 1994;Miyanaga et al, 2007), it has been found to have no effect on the adhesion of anaerobic bacteria, and is thus unable to prevent the initiation of pitting corrosion by SRB (de Mele et al, 1995). In view of environmental, ecological, and economical impacts, more recent efforts are focused on developing environmentally benign antimicrobial coatings to prevent bacterial adhesion and biofilm formation (AlDarbi et al, 2002;Sreekumari et al, 2005;Telegdi et al, 2005), as the formation of biofilms is widely recognized as the key step in initiating biocorrosion.…”

Diffusion of bacteriophages through artificial biofilm models

“…However, biofilm formation is a big problem when controlling microorganisms in engineering systems. For example, the presence of biofilms on a metal surface as well as the metabolic activities of the biofilm can cause microbiologically influenced corrosion, which can clog the flow in pipes and lead to the deterioration of the heat‐transfer efficiency in oil recovery plants and industrial processes 2–4…”

“…Lytic phages from sewage were screened for their specificity for S. aureus , and two phage candidates were shown to control this pathogen in cows with mastitis 9. In addition to S. aureus , other pathogens, like Pseudomonas aeruginosa PAO1, are also being intensively researched as targets for phages 2, 10…”

Efficacy of Sterilization Methods and Their Influence on the Electrochemical Behavior of Plain Carbon Steel

“…14 It is important to mention that the methods listed in Table I correspond roughly to the same number of papers explicitly describing the sterilization procedures in the methodology section of the manuscript. Indeed, most of the papers reviewed do not describe sterilization procedures in enough detail to be reproduced by other laboratories.…”