Simultaneous degradation of aflatoxin B1 and zearalenone by Porin and Peroxiredoxin enzymes cloned from Acinetobacter nosocomialis Y1

Abstract

Mycotoxin contamination can cause severe health issues for both humans and animals. This study examined the potential of enzymes derived from Acinetobacter nosocomialis Y1 to simultaneously degrade aflatoxin B₁ (AFB₁) and zearalenone (ZEN), which could have significant implications in reducing mycotoxin contamination. Two enzymes, Porin and Peroxiredoxin, were identified with molecular weights of 27.8 and 20.8 kDa, respectively. Porin could completely degrade 2 µg/mL of AFB₁ and ZEN within 24 h at 80 °C and 60 °C, respectively. Peroxiredoxin could completely degrade 2 µg/mL of AFB₁ and reduce ZEN by 91.12% within 24 h. The addition of Na⁺, Cu²⁺, and K⁺ ions enhanced the degradation activities of both enzymes. LC-MS/MS analysis revealed that the molar masses of the degradation products of AFB₁ and ZEN were 286 g/mol and 322.06 g/mol, and the products were identified as AFD₁ and α or β-ZAL, respectively. Vibrio fischeri bioluminescence assays further confirmed that the cytotoxicity of the two degradation products was significantly lower than that of AFB₁ and ZEN. Based on these results, it can be inferred that the degradation product of ZEN is β-ZAL. These findings suggest that both enzymes have the potential to be utilized as detoxification enzymes in food and feed.

Keywords: Cytotoxicity; Degradation product; Mycotoxins; Porin and Peroxiredoxin; Simultaneous degradation.