Characterization and mechanism of simultaneous degradation of aflatoxin B and zearalenone by an edible fungus of GC-Ac2.

Contamination with multiple mycotoxins is a major issue for global food safety and trade. This study focused on the degradation of aflatoxin B (AFB) and zearalenone (ZEN) by 8 types of edible fungi belonging to 6 species, inclulding , , , , and Among these fungi, strain GC-Ac2 was shown to be the most efficient in the degradation of AFB and ZEN. Under optimal degradation conditions (pH 6.0 and 37.4°C for 37.9 h), the degradation rate of both AFB and ZEN reached over 96%. Through the analysis of functional detoxification components, it was found that the removal of AFB and ZEN was primarily degraded by the culture supernatant of the fungus. The culture supernatant exhibited a maximum manganese peroxidase (MnP) activity of 2.37 U/mL. Interestingly, strain GC-Ac2 also showed the capability to degrade other mycotoxins in laboratory-scale mushroom substrates, including 15A-deoxynivalenol, fumonisin B, B, B, T-2 toxin, ochratoxin A, and sterigmatocystin. The mechanism of degradation of these mycotoxins was speculated to be catalyzed by a complex enzyme system, which include MnP and other ligninolytic enzymes. It is worth noting that can degrade multiple mycotoxins and produce MnP, which is a novel and significant discovery. These results suggest that this candidate strain and its enzyme system are expected to become valuable biomaterials for the simultaneous degradation of multiple mycotoxins.