Efficient degradation and detoxification of quinolone antibiotics using the novel biocatalyst BpLac@IPM

A novel biocatalyst, Bp Lac@IPM, was constructed to enhance the remedi- ation of antibiotic wastewater. Compared with Bp Lac, Bp Lac@IPM showed better catalytic activity, stability, and reusability. Moreover, Bp Lac@IPM exhibited exceptional removal performance for quinolone antibiotics. Specifically, its ciprofloxacin removal efficiency reached 94.70%, which was 8.54% and 48.37% higher than that of Bp Lac and IPM, respectively. Furthermore, it effectively removed various quinolone antibiotics, including ciprofloxacin, norfloxacin, enrofloxacin, and moxifloxacin, with removal efficiencies ranging from 77.08% to 94.70%. Biotoxicity evaluation confirmed that Bp Lac@IPM treatment reduced the biotoxicity of ciprofloxacin. The biological toxicity of ciprofloxacin was 31% and 13% lower than that after IPM and Bp Lac treatment, respectively. Liquid chromatography-tandem mass spectrometry analysis identified the primary degradation pathways of ciprofloxacin as defluorination, decarboxylation, and cleavage of the piperazine ring. Further studies demonstrated a synergistic effect between adsorption and biocatalysis in Bp Lac@IPM, with a synergistic coefficient of 148.31% at 10 min. Mechanism analysis revealed that quinolone antibiotics were adsorbed onto Bp Lac@IPM via electrostatic attraction, hydrogen bonding, and hydrophilic interactions. Subsequently, the high concentration of quinolone antibiotics near Bp Lac@IPM promoted biocatalysis. This study provides a novel and efficient strategy for the removal and detoxification of quinolone antibiotics