Microscopy and molecular techniques applied to study biofilms in drinking water closed loop

RASTELLI S.E, VIERA M.R AND ROSALES B.M.

Perth

Congreso; 18th International Corrosion Congress; 2011

International Corrosion Council

During water distribution operation, tubing material is submitted to permanent contact with aquatic microbial species. They colonize the network surface forming biofilms which frequently cause corrosion on metallic substrata. The present study approaches the analyses of laboratory biofilms formed on water pipe materials from several (SEM, ESEM, CLSM) microscopy techniques point of view and also from a microbial ecological analysis using DGGE for the study of the communities formed on each substrate. Microbial interactions with the different materials were described using an ample range of magnification. Three commercial metals (Fe, Zn, Cu) and polypropylene tubing used as substrata revealed very different behaviours. On Fe and Zn we/its/is observed hemispherical localized attack with corrosion products accumulated at the bottom, while the localized attack of the Cu reveals the alloy crystallography. PP samples did not reveal any biodegradation damage associated to the bacterial biofilm settlement. The results suggest a correlation amongst the different attack morphologies, the biofilm 3-D structures and the genetic profile of the established communities.