Probiotic and Microbial Enzymatic Mechanisms for PFAS Detoxification.

Per- and polyfluoroalkyl substances (PFAS) are highly persistent environmental contaminants that pose a significant threat to ecosystems and human health due to their exceptional chemical stability and resistance to degradation. Conventional remediation methods-such as activated carbon adsorption, ion exchange, and advanced oxidation-primarily transfer PFAS between phases rather than achieving complete mineralization, resulting in the generation of secondary waste. Microbial bioremediation has emerged as a promising, sustainable strategy. Several bacteria, fungi, and cyanobacteria can transform or defluorinate PFAS under environmentally relevant conditions, yielding less fluorinated intermediates. Enzymatic studies have identified oxygenases and reductive dehalogenases as key catalysts in the cleavage of C-F bonds. Moreover, recent evidence indicates that the gut microbiota can adsorb and sequester PFAS, facilitating fecal elimination and reducing systemic toxicity. Advances in synthetic biology now enable the engineering of microbial systems, including probiotic strains, with enhanced PFAS uptake and degradation capabilities. However, significant challenges remain; current microbial pathways primarily act through partial transformation rather than complete mineralization, often accumulating stable fluorinated intermediates. True mineralization is constrained by low enzymatic efficiency, narrow substrate specificity, and the difficulty of translating laboratory success to complex environmental matrices. This review critically synthesizes current progress in microbial and probiotic bioremediation of PFAS, emphasizing enzymatic mechanisms, microbial pathways, and integration with conventional treatment systems. By engaging with these limitations alongside promising advances, we provide a balanced assessment of the feasibility of microbial and engineered probiotic approaches, highlighting knowledge gaps and future directions for developing safe, scalable detoxification technologies.