Plastic-Degrading Insects for Micro and Nanoplastic Recycling: How Far Are We?

Plastic degradation by insects, particularly Tenebrionidae, has garnered significant attention in the waste management community. The degradation process relies on the synergistic interaction between host-derived enzymes and gut microbiota. Despite promising findings, this review paper highlighted three critical challenges hindering their practical application: The environmental risks associated with byproduct formation, insufficient mechanistic understanding of insect-mediated plastic degradation and multifaceted challenges surrounding the upscaling of the process for realistic plastic waste management. First, while nanoplastics (NPs) are metabolized by insect glands and guts, microplastics (MPs) accumulate in frass, constituting residual management challenges. The metabolic fate of plastic additives, including enzymatic transformation, tissue distribution and multigenerational effects, also remains unclear. Additionally, the long-term ecotoxicological risks to insects are poorly understood; larvae fed on plastic-rich diets are unsuitable for food chains but could be repurposed for industrial applications. Second, mechanistic gaps remain regarding the roles of gut fungi, microbial interactions and the digestive system in the plastic degradation processes. The evolutionary adaptation of insects to degrade natural polymers, as seen in Tenebrio molitor, provides implications for filling these mechanistic gaps. Finally, recognizing that large-scale insect rearing for plastic waste management is not technologically ready, we suggest current and future research should prioritize screening key degradation microbes or enzymes to develop efficient ex vivo treatment systems. This review provides a foundation for future research and technological innovations in insect biodegradation for sustainable plastic waste management.