Diversity of Bacteria and Yeasts Present in an Automobile Treatment System.

The formation of biofilms in industrial environments poses a significant challenge because of their ability to degrade materials, contaminate products, and harbour pathogenic microorganisms. In the automotive industry, surface treatment systems (STS) used to prepare car bodies can provide a favourable environment for microbial development, driven by the presence of water, organic matter, and variable physicochemical conditions. In this context, the microbial diversity present in the different STS baths of an automotive plant, as well as in the process water, was analysed. Through culture-based methods and molecular analysis, 33 bacterial and 6 yeast species were identified. The results revealed a constant presence of bacteria at all sampling points, whereas yeasts were detected less frequently and in more localized areas (Industrial and Dechromatized Water, E2, Conversion stage, E4 and Passivation stage). This study underscores the importance to enhance cleaning and disinfection protocols in STS, as high bacterial counts persisted even after rinsing stages, in order to prevent economic losses, product degradation and health risks. Furthermore, it highlights the potential use of certain microorganisms in biotechnology and bioremediation applications.