EXPOSURE TO AN ENVIRONMENTALLY RELEVANT MIXTURE OF PHARMACEUTICALS ALTERS ACTIVITY AND COMPOSITION OF STREAM BIOFILM COMMUNITIES
Pharmaceuticals and personal care products (PPCPs) are biologically active compounds that are pervasive in aquatic ecosystems globally. Multiple studies have demonstrated that PPCPs can affect benthic microbial communities, which are key components of stream ecosystems. Most prior studies have analyzed effects of single compounds, but in nature PPCPs are generally present in low concentrations and complex mixtures, creating the possibility for synergistic effects. To assess potential effects of PPCP mixtures, we added a cocktail of eight pharmaceuticals to laboratory-scale stream mesocosms at a concentration observed in an urban field site. After 21 days, biofilms from pre-colonized rocks in streams that received the pharmaceutical cocktail showed no difference in total biomass, but a decrease in community respiration compared to control streams. Furthermore, bacterial communities within biofilms in streams that received the pharmaceuticals were significantly different in taxonomic composition and had significantly higher taxonomic diversity relative to control streams, as indicated by high-throughput sequence analysis of 16S rRNA genes. Taken together, these data indicate that an environmentally relevant concentration of a mixture of pharmaceuticals can have significant effects on benthic microbial communities, which could have broader implications for stream ecosystem function.
Brianne Coffey (Primary Presenter/Author,Co-Presenter/Co-Author), Loyola University Chicago, firstname.lastname@example.org;
Stephanie Robson (Co-Presenter/Co-Author), Monash University, email@example.com;
John Kelly (Co-Presenter/Co-Author), Loyola University Chicago, Jkelly7@luc.edu;
Michael Grace (Co-Presenter/Co-Author), Monash University , firstname.lastname@example.org;
Emma Rosi (Co-Presenter/Co-Author), Cary Institute of Ecosystem Studies, email@example.com;