The plastisphere as an engine of environmental change: Impacts on biogeochemical cycling and pollutant fate

Plastic pollution is now a major microbiological and biogeochemical challenge. This review critically evaluates the plastisphere, the microbial biofilm colonizing plastic debris, and establishes its role as an engine of environmental change. We posit the central hypothesis that the plastisphere functions as a mobile hotspot of microbial activity that disrupts natural biogeochemical cycles and introduces novel pollutant dynamics. To evaluate this, we investigate three key questions: (1) how does the metabolic core of the plastisphere reconcile high in vitro enzymatic potential with limited in situ degradation efficacy? (2) what is the dual role of the plastisphere in pollutant fate, acting as both a transport vector and a bioreactor? (3) how are these functions intensified by global change drivers? Our synthesis concludes that the plastisphere collective metabolism short-circuits natural elemental cycles and introduces novel pollutant vectors. Addressing this multidimensional threat requires interdisciplinary research to inform both mitigation policies and the transition to a circular plastic economy.