Efficient biodegradation and detoxification of 6:2 fluorotelomer sulfonic acid by Phanerochaete chrysosporium: Insights into enzymatic mechanisms and reduced ecotoxicity

Per- and polyfluoroalkyl substances (PFAS) are of significant concern due to their environmental persistence and biotoxicity. Among their substitutes, 6:2 fluorotelomer sulfonic acid (6:2 FTSA) is highly resistant to natural degradation due to its chemical stability, leading to continuous accumulation in the environment, thereby posing threats to ecosystems and health. This study aimed to investigate the biodegradation and detoxification capabilities of the white-rot fungus Phanerochaete chrysosporium (P. chrysosporium) on 6:2 FTSA and its molecular mechanisms. Mechanistic analyzes indicate that manganese peroxidase (MnP) and cytochrome P450 (CYP450)-associated oxidative processes are functionally involved in the transformation of 6:2 FTSA. MnP is associated with oxidative defluorination and C-F bond cleavage, while CYP450-associated processes contribute to desulfonation and hydroxylation, collectively enabling efficient breakdown of the 6:2 FTSA structure. P. chrysosporium was cultured and exposed to 6:2 FTSA, and its degradation efficiency and toxicity mitigation effects were systematically analyzed. The results revealed that P. chrysosporium degraded 6:2 FTSA at a rate of approximately 100 % (99.97 ± 0.21 %) within 7 days, producing short-chain perfluorocarboxylic acids via desulfonation, oxidation, and defluorination. Following enzymatic transformation, these metabolites significantly reduced oxidative stress, inflammatory responses, and behavioral abnormalities in zebrafish embryos, demonstrating their detoxification effects. Molecular mechanism analysis revealed that 6:2 FTSA induced reprogramming of the fungal redox balance, lipid metabolism, and energy metabolism pathways, with Mnp-associated oxidative processes closely linked to defluorination. This study demonstrates the strong potential of P. chrysosporium to remediate PFAS substitutes, thereby providing a theoretical foundation and experimental support for developing efficient and eco-friendly bioremediation technologies. © 2026 Elsevier B.V.