High-efficiency detoxification of fumonisin B1, B2 and B3 by laccase Lac-W with ABTS

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Type B fumonisins (FBs), including fumonisin B 1 (FB 1 ), fumonisin B 2 (FB 2 ) and fumonisin B 3 (FB 3 ), are common mycotoxins in cereal and food products. FBs contamination causes substantial social impacts and economic losses. Effective control of FBs contamination is essential for human and animal health. Laccase Lac-W has the unique property of degrading a variety of mycotoxins in the absence of mediators. Nevertheless, the degradation rates are low. In this study, a laccase mediator system (LMS), Lac-W-2, 2′-azino-bis (3-ethylbenzothiazoline-6-sulfonate) (Lac-W-ABTS), was constructed by screening different mediators, which can improve the degradation rate of FB 1 (34.70 %) within 2 h. By optimizing the reaction conditions (static conditions, pH 7.0, 40 °C, 0.5 U/mL Lac-W, 5 mM ABTS), 1 μg/mL FB 1 was effectively degraded within 24 h (88.25 %), and FB 2 (93.16 %) and FB 3 (78.24 %) were degraded efficiently. The degradation products of FB 1 , FB 2 and FB 3 failed to generate cell death of intestinal porcine epithelial cells. Additionally, two detoxification products (hydrolysed FB 1 (HFB 1 ) and tricarboxylic acid) of FB 1 were identified by high resolution mass spectrometry. Finally, the mechanism by which ABTS acts as a more efficient electron acceptor and thus promotes Lac-W degradation of FB 1 was explained using molecular docking. This work highlights an eco-friendly bio-enzyme method that degrade FB 1 , FB 2 and FB 3 simultaneously and efficiently using only one enzyme. • The degradation rates of fumonisin B 1 , B 2 and B 3 by enzyme were significantly improved. • Degradation products of fumonisin B 1 , B 2 and B 3 were non-toxic to IPEC-J2 cells. • ABTS was a efficient electron acceptor that can promote Lac-W degradation of fumonisin B 1 .