Advances in fungal-mediated plastic biodegradation: Mechanisms, challenges, and future directions

Plastic pollution represents one of the most critical environmental challenges of our time, requiring innovative and sustainable waste management strategies. Among emerging solutions, fungal-mediated plastic biodegradation has gained significant attention due to the ecological versatility and strong enzymatic potential of fungi. This review synthesizes recent advances in fungal degradation of conventional plastics, such as polyethylene (PE) and polyethylene terephthalate (PET), and biodegradable polymers, including polylactic acid (PLA) and polyhydroxyalkanoates (PHA)-based polymers. Methodological approaches used to assess biodegradation, encompassing chemical, physical, and biological metrics, are evaluated to identify current limitations and biases. Despite significant progress, major challenges remain, including slow degradation kinetics, variability in environmental performance, and scalability constraints. Addressing these limitations requires multidisciplinary strategies, integrating fungal genetics, enzyme engineering, materials science, and environmental biotechnology. A key step forward lies in the establishment of a standardized, evidence-based evaluation framework, or "ladder of evidence", to rank fungal taxa, enzymatic systems, and polymer types according to their true biodegradation potential. By identifying key knowledge gaps and highlighting future research priorities, this review underscores the potential of fungal-mediated biodegradation to contribute to effective plastic waste management and mitigate the global plastic crisis.