Monitoring the effects of biocide treatment of Pseudomonas fluorescens biofilms formed under different flow regimes

Abstract

The effectiveness of glutaraldehyde – a very common biocide – to control biofilms formed by Pseudomonas fluorescens on stainless steel slides, in laminar and turbulent flow, was investigated. Tests were performed using a concentration of the biocide of 200 mg L-1 and a range of exposure times. The cohesion of the biofilm before and after exposing the biofilm to different biocide concentrations was also studied. The GTA action on biofilm was assessed by means of activity tests and wet weight of the biofilms. The results showed that biofilms were not controlled after the treatment with biocide, in all the situations studied, and that the cohesion of the biofilms increased with biocide application.