RAPID DETECTION OF BIOFILM ON CORRODED COPPER PIPES

Episcopic differential interference contrast (DIC) with UV fluorescenc e microscopy has been incorporated into a conventional light microscop e to view the surface topography of microorganisms, biofilms and opaqu e substrata surfaces without artefacts. This technique avoids the gene ration of artefacts produced through preparation for scanning electron microscopy (mainly dehydration) and has been used to investigate micr obially influenced corrosion (MIC) in copper and polypropylene pipes f rom a potable water installation. The copper and polypropylene materia l examined were obtained from a county hospital in Germany, as well as from test rigs installed in the hospital and in the laboratory where the corrosion process was simulated. Microorganisms such as diatoms an d bacteria, were rapidly and reliably detected on and in biofilms on p ipe surfaces. The observed biofilm possessed a structure that was neit her homogeneous nor confluent over the surface and which ressembled a heterogeneous mosaic of microcolonies.