title: Investigating electrochemical removal of bacterial biofilms from stainless steel substrates.
abstract: Electrochemical removal of biofilms deserves attention because of its ease of use and environmentally friendly nature. We investigated the influence of electrode potential and treatment time on the removal of a 10-day old Pseudomonas aeruginosa biofilm formed on stainless steel 316 L substrates. At electrode potentials more positive than -1.5 V vs. Ag/AgCl, lower removal rates were observed and only partial removal of the biofilm was achieved during a 1-min time interval. Electrostatic repulsion between the film and electrode surface is believed to drive biofilm detachment under these conditions. However, when the biofilm-coated substrates were treated at potentials negative of -1.5 V vs. Ag/AgCl, complete removal of a biofilm was achieved within seconds. Under these conditions, vigorous evolution of hydrogen gas is believed to be responsible for the film removal, mechanically detaching the bacteria and extracellular polymeric matrix from the substrate. Stainless steel substrates were also subjected to repeated cycles of biofilm formation and electrochemical removal. High removal efficiencies were maintained throughout this process suggesting the potential of the proposed technology for application on conductive surfaces in various industrial settings.
authors.affiliation: Department of Chemical Engineering, McGill University, Montreal, Quebec H3A 0C5, Canada.
authors.forename: Mahdi
authors.initials: M
authors.lastname: Dargahi
authors.affiliation: Department of Chemical Engineering, McGill University, Montreal, Quebec H3A 0C5, Canada.
authors.forename: Zeinab
authors.initials: Z
authors.lastname: Hosseinidoust
authors.affiliation: Department of Chemical Engineering, McGill University, Montreal, Quebec H3A 0C5, Canada. Electronic address: nathalie.tufenkji@mcgill.ca.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Tufenkji
authors.affiliation: Department of Chemical Engineering, McGill University, Montreal, Quebec H3A 0C5, Canada. Electronic address: sasha.omanovic@mcgill.ca.
authors.forename: Sasha
authors.initials: S
authors.lastname: Omanovic
mesh_terms: D001422:Bacterial Adhesion; D018441:Biofilms; D058266:Dielectric Spectroscopy; D004560:Electricity; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D007091:Image Processing, Computer-Assisted; D007700:Kinetics; D011550:Pseudomonas aeruginosa / Q000502:physiology / Q000648:ultrastructure; D013193:Stainless Steel / Q000032:analysis*
chemical_list: D013193:Stainless Steel
keywords: 316L stainless steel; Biofilm removal; Electrochemistry; Hydrogen evolution; Pseudomonas aeruginosa