Microplastics enhance the denitrification of glycogen-accumulating organisms by regulating electronic transport in carbon-nitrogen coupling.

Summary: Plastic pollution is universally considered harmful, but in the complex world of wastewater treatment, the story is surprisingly nuanced. Scientists investigated how "good bacteria" known as Glycogen-Accumulating Organisms (GAOs)—which are crucial for removing nitrogen from water—react to plastic particles. The study found that size changes everything. Extremely tiny "nanoplastics" (100 nm) acted as toxins, clogging the bacterial machinery and slowing down the cleaning process by roughly 8%. However, slightly larger "microplastics" (100 μm) had the opposite effect. They acted like a metabolic turbo-boost, helping the bacteria break down fuel (PHB) and transport energy more efficiently, ultimately improving the water-cleaning process by nearly 15%.