Biodegradation of Fluorinated β-Triketone Herbicide Tembotrione by a Bacterial–Fungal Consortium

The widespread use of agrochemicals and pesticides has led to persistent contamination of agricultural soils, threatening soil health, biodiversity, and food security. Tembotrione (TBT), a fluorinated β-triketone herbicide, poses environmental concerns due to its stability and persistence. This study investigates the microbial degradation of TBT by distinct bacterial and fungal systems, revealing taxon-specific catabolic pathways. Bacillus sp. MFK6, isolated from garden soil, exhibited the highest TBT-degrading capacity among the tested strains. GC-MS analysis identified six bacterial metabolites (M1–M6), indicating that Bacillus sp. MFK6 targets the cyclohexane-1,3-dione moiety of TBT. In contrast, the fungus Cunninghamella elegans preferentially cleaved the (trifluoroethoxymethyl)phenyl ring, producing unique metabolites (M7–M12), including the fluorinated by-product trifluoroacetic acid (M12), as confirmed by 19F NMR spectroscopy. Co-culturing Bacillus sp. MFK6 and C. elegans enhanced biotransformation, yielding two additional metabolites (M13, M14) indicative of synergistic or sequential metabolism. Inhibition assays using 1-aminobenzotriazole, a cytochrome P450 (CYP) inhibitor, significantly reduced bacterial metabolites M1, M2, and M5 and completely inhibited all other bacterial and fungal metabolites, indicating a central role for CYP enzymes in both systems. Two bifunctional cytochrome P450/NADPH–P450 reductases were identified in Bacillus sp. MFK6 showed conserved CYP102 family features and shared ∼60 % sequence identity, suggesting that they mediate oxidative cleavage of specific herbicide moieties, initiating the degradation pathways observed. The proposed degradation pathways integrate bacterial and fungal, revealing complementary enzymatic activities. These findings highlight the metabolic versatility and cooperative potential of microbial consortia for the transformation of fluorinated agrochemicals like TBT and support the development of nature-based bioremediation strategies.