Complex bilateral interactions determine the fate of microplastics and soil protists: implications from a soil amoeba

In this study, we investigated how nano- and micro-plastics interacted with a soil amoeba Dictyostelium discoideum. The results showed that environmental concentrations of nano- and micro-plastics could negatively affect the soil amoeba's fitness and development. D. discoideum ingested both nano- and micro-plastics through phagocytosis but packed and excreted them during slug migration, which may accelerate their biodegradation. Also, nano- and micro-plastic exposure disrupted the nutrient and energy metabolisms of D. discoideum and affected the expression of key genes (e.g., cf45-1, dcsA, aprA, dymB, gefB) related to morphogenesis and phagocytosis.