CotA laccase from Bacillus licheniformis ZOM-1 effectively degrades zearalenone, aflatoxin B1 and alternariol

In the present study, CotA laccase was cloned from Bacillus licheniformis ZOM-1 and expressed in Escherichia coli. In addition to the oxidative degradation of zearalenone (ZEN) and aflatoxin B1 (AFB1), CotA laccase also has the ability to degrade the Alternaria toxin alternariol (AOH). This is the first report of an Alternaria toxin-degrading enzyme. The optimal reaction temperature for CotA laccase is 80 °C, and the optimal reaction pH is approximately 9.0. By high-resolution mass spectrometry, we identified the oxidative degradation products. Additionally, toxicological analysis indicated that the degradation products had a significantly reduced effect on cell viability relative to the original toxins. In addition, we found that B. licheniformis ZOM-1 has the ability to degrade three mycotoxins, ZEN, AOH and alternariol monomethyl ether (AME). These findings provide possible application prospects for CotA laccase and B. licheniformis ZOM-1 as mycotoxin degradation products in food or feed.