ISMEJ: Effects of microplastics on Daphnia-associated microbiomes in-situ and in-vitro.

This research examines the impact of microplastics (MP) on Daphnia, a keystone species in freshwater ecosystems, focusing on both in situ pond sampling and an in vitro exposure experiment. In urban ponds, MP levels were notably higher in water and sediment than in natural ponds, affecting the composition and diversity of bacterioplankton and Daphnia microbiomes. Microbial communities in MP-polluted ponds showed an increase in PET degradation enzymes and antibiotic resistance genes, indicating a functional response to MP presence. In controlled experiments, network analysis identified specific taxa associated with MP within the Daphnia microbiome. The study highlights how MP pollution may influence host-associated freshwater microbiomes.