A comparative analysis of the chemical composition and biofilm formation on tire wear particles from six different tire types

Tire-wear particles (TWPs) are generated through the abrasion of motor-vehicle tires on roadways. These particles may be transported through the soil, water, and air. The surface of TWPs may also serve as an attachment site for pathogens and toxins, threatening the health of wildlife, domestic animals, and humans. Our research aims to investigate the chemical composition of various TWPs and their potential to serve as hosts for microbial biofilms - aggregations of bacterial cells adhered to the surface of these particles. TWPs from six different types/brands of tires were obtained from a tire test facility. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Fourier Transform Infrared Spectroscopy (FTIR) techniques were used to characterize the polymer types and elemental compositions of these particles. In addition, cell culture techniques in liquid growth media were used to assess biofilm formation utilizing a strain of Pseudomonas syringae (a known plant pathogen). Methods of bacterial cell quantification were developed to observe the relative amount of growth on TWPs. Associations between specific chemicals and bacterial growth on six tire particle types were explored. We observed that TWPs vary in their chemical composition, which also potentially affects their ability to serve as a substrate for bacterial cells to adhere and form biofilms. Overall, the findings of this study could pave the way for further research into the chemical composition and microbial biofilm potential of various types of microplastics across different environments worldwide. Also see: https://micro2024.sciencesconf.org/559150/document