A comparative review of microplastic remediation strategies: constraints of physical and chemical approaches and opportunities for synthetic biology

Microplastic pollution has emerged as a critical environmental challenge, yet existing remediation strategies remain limited in their ability to achieve more complete mineralization under environmentally relevant conditions. In this review, we examine different physical, chemical, and synthetic biology-based methods of microplastic remediation in terms of degradation efficiency, environmental safety, and applicability. The physical techniques can be used to obtain efficient particle removal, but they often lead to shifting contaminants from one environmental matrix to another rather than eliminating them. Chemical approaches enable partial polymer degradation, but they often require energy-intensive processes and generate secondary products. In contrast, synthetic biology-based strategies offer opportunities for a more selective, programmable, and even sustainable breakdown of polymers under less harsh conditions. More precisely, genetically engineered microbes and biological systems can increase the selectivity of such processes while minimizing the impact of traditional techniques on the environment. This review examines the possibilities as well as the constraints of using synthetic biology for microplastic remediation, along with its complementation by physical and chemical treatment strategies.