Mycotoxin cocontamination is a severe threat to health and economic security worldwide. The mycotoxins aflatoxin B₁ (AFB₁), zearalenone (ZEN), deoxynivalenol, T-2 toxin, fumonisin B₁, and ochratoxin A are of particular concern due to their substantial toxicity. Lac-W is a laccase with the unique property of degrading these six mycotoxins in the absence of redox mediators. Nevertheless, their degradation rates are low. This work aims to improve the ability of Lac-W to degrade these six mycotoxins and to elucidate its detoxification mechanism. Including redox mediators increased the Lac-W degradation efficiency drastically, and completely degraded AFB₁ and ZEN within one hour. Additionally, Lac-W-AS has good temperature, pH, and ions adaptability in ZEN degradation. Lac-W-AS reduced the ZEN toxicity because ZEN degradation products significantly restored the bioluminescence intensity of Vibrio fischeri. A Lac-W-AS-mediated oxidation product of ZEN was structurally characterized as 15-OH-ZEN by UHPLC-MS/MS. Linear sweep voltammetry showed that AS affected the potential of Lac-W and accelerated the oxidation of ZEN. Finally, the combination of mediators (acetosyringone and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonate)) improved the degradation rate of mycotoxins. This work highlights that the combination of Lac-W with mediators serves as a good candidate for degrading multi-mycotoxin contaminants in food and feedstuff.

Type B fumonisins (FBs), including fumonisin B₁ (FB₁), fumonisin B₂ (FB₂) and fumonisin B₃ (FB₃), 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 FB₁ (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 FB₁ was effectively degraded within 24 h (88.25 %), and FB₂ (93.16 %) and FB₃ (78.24 %) were degraded efficiently. The degradation products of FB₁, FB₂ and FB₃ failed to generate cell death of intestinal porcine epithelial cells. Additionally, two detoxification products (hydrolysed FB₁ (HFB₁) and tricarboxylic acid) of FB₁ 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 FB₁ was explained using molecular docking. This work highlights an eco-friendly bio-enzyme method that degrade FB₁, FB₂ and FB₃ simultaneously and efficiently using only one enzyme.