Use of biocides and surfactants to control biofilms: Role of the hydrodynamic conditions

Biofilms constitute a protected growth modality that allows the bacteria to survive in hostile environments. The most common practice to eliminate unwanted biofilms is the application of antimicrobial agents. However, current disinfection practices show often inefficacy in the control of biofilms.The main goals of this work were the development of effective strategies, based on the application of chemical agents, in order to control biofilms formed by Pseudomonas fluorescens, and the evaluation of the impact of the hydrodynamic conditions under which biofilms were formed, in the phenotypic characteristics of the biofilms, as well as, in their susceptibility to antimicrobial agents.The antimicrobial agents tested were two non- oxidizing aldehyde-based biocides (ortho- phthalaldehyde and glutaraldehyde), two oxidizing biocides (sodium hydroxide and sodium hypochlorite) and two surfactants (cetyltrimethyl ammonium bromide and sodium dodecyl sulfate). The antimicrobial agents were selected due to their emergent and practical application in several industrial areas.