Microbial Degradation of Perfluorooctanoic Acid(PFOA) and Perfluorooctanesulfonic Acid(PFOS): Mechanisms, Advances, and Challenges

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are typical persistent organic pollutants (POPs) in the environment that are difficult to degrade due to the high C-F bonding energy in their molecular structure and their extremely stable chemical properties. The development of efficient and green removal technologies has become an important challenge in the field of environmental governance. Microbial degradation technology, with its advantages of low cost and environmental friendliness, is considered a promising means of remediation and has received widespread attention in recent years. This review systematically the microbial species that have been reported to degrade PFOA and PFOS, details their biodegradation pathways, including oxidation, reduction and co-metabolism, and analyses the key intermediates. The research progress on the key enzymesystems involved in PFOA/PFOS and their molecular mechanisms is highlighted. Finally, the paper discusses the major challenges currently facing the field and provides an outlook on future research directions, including the discovery of novel defluorinating microorganisms and enzymes, the construction of genetically engineered bacteria, and the development of microbial-physical-chemical technology cascade strategies. The aim of this paper is to provide a theoretical reference for an in-depth understanding of the biodegradation mechanism of PFOA and PFOS and the development of their bioremediation technologies.