Microplastic pollution and microbial mitigation strategies: current knowledge, challenges, and future prospects

Abstract

Graphical abstract showing the journey of microplastics from their sources and environmental distribution to ecological impacts, plastisphere formation, microbial degradation using plastic-degrading enzymes, biotechnological enhancement, and sustainable environmental remediation. Microplastic (MP) pollution has gained increasing attention as a critical environmental concern owing to the persistent accumulation of plastic debris and its ubiquitous presence in ecological systems. The small size, high penetration potential, and potential toxicity of MPs pose high risks to ecological integrity and biological systems, including humans. The majority of scientific research has been focused on the distribution, utilization, fate, behaviour, and influence of MPs, whereas remediation studies remain underexplored. Therefore, this review provides an extensive critical synthesis of current knowledge on MP pollution and recent advances in microbes-mediated MP mitigation approaches. The primary focus is on the role of bacteria, fungi, microalgae, and their enzymes in MP degradation through plastisphere/biofilm formation, depolymerization, and metabolic assimilation pathways. Microbial degradation potential has been assessed for major polymer types, including polyethylene, polypropylene5, polystyrene, polyethylene terephthalate, polyvinyl chloride, and polyurethane. The MPs biodegradation section includes studies from 2021-2026, supplemented with previously curated literature addressing MP sources, fate, transport, and ecological impacts. The existing bottlenecks, including low degradation efficiencies, partial mineralization, and the lack of standardized protocols, are discussed. Through integration of ecological impacts, biodegradation mechanisms, and future technological developments, this review pinpoints critical knowledge gaps and proposes scalable and greener solutions formanaging MP pollution and advancing the circular plastic economy.