“…Microplastics (MPs), plastic particles smaller than 5 mm, are an emerging worldwide contaminant and ubiquitous in rivers, lakes, oceans, mountains, soils, and even in remote Arctic and Antarctic ice sheets (47). Microorganisms attach to and form biofilms on MPs, which then serve as dispersal vehicles to transport microbes to new locations where these communities affect endogenous microbiota and functions within ecosystems (47,78,90,103,136,163). MP biofilms formed in aquatic systems accelerated ammonia and nitrite oxidation as well as denitrification in indoor mesocosm experiments, effectively altering N and P cycling processes (29).…”