Efficiency of an ortho-phthalaldehyde based biocide Against Pseudomonas fluorescens adhered to stainless steel surfaces

This work reports the study of the action of ortho-phthalaldehyde, OPA, to control Pseudomonas fluorescens adhered to stainless steel surfaces. The action of the biocide was assessed, in situ, microscopically using LIVE/DEAD® BacLight™ Bacterial Viability Kit, developed by Molecular Probes. The results show that When OPA concentration is lower than 0.1 % the number of dead cells on the surface are strongly dependent on biocide concentration. For lower biocide concentration, higher dead number of cells can be achieved by increasing the time of exposure to the biocide.Instituto de Biotecnologia e Química Fina, Project POCTI/1999/BIO/35683