Protists as potential microbial tools for environmental microplastic remediation: a mini review.

Microplastics (MPs) are persistent pollutants that pose serious ecological and health hazards across terrestrial and aquatic ecosystems. Compared with physical and chemical degradation methods, the biological degradation of MPs is more pronounced and eco-friendlier. Although bacterial and fungal contributions to MP biodegradation have been extensively studied, the role of protists remains comparatively underexplored. Earlier laboratory studies have demonstrated that various protistan taxa can ingest latex microspheres through phagocytosis and influence their fate in an ecosystem. However, beyond ingestion and transfer, the potential of protists to transform and partially degrade MPs via enzymatic or oxidative processes has only recently attracted attention. Therefore, beyond existing summaries on protist-latex bead interactions, this review proposes a novel conceptual framework that not only positions protists as vectors that transfer MPs within food webs, but also as active agents in degradation processes and facilitators of microbial colonization. By introducing emerging evidence, we highlight protists as overlooked yet promising components of MP fate and outline future research directions to establish them as part of integrated microbial tools for environmental microplastic remediation.