Biological Detoxification of Aflatoxin B₁ by <i>Enterococcus faecium</i> HB2-2

Abstract

Aflatoxin B1 (AFB1) contamination in food and feed is a global health and economic threat, necessitating the immediate development of effective strategies to mitigate its negative effects. This study focuses on the isolation and characterization of Enterococcus faecium HB2-2 (E. faecium HB2-2) as a potent AFB1-degrading microorganism, using morphological observation, biochemical profiling, and 16S rRNA sequence analysis. An incubation of E. faecium HB2-2 at 32 °C for 96 h in a pH 10 nutrient broth (NB) medium resulted in a remarkable degradation rate of 90.0% for AFB1. Furthermore, E. faecium HB2-2 demonstrated 82.9% AFB1 degradation rate in the peanut meal, reducing AFB1 levels from 105.1 to 17.9 μg/kg. The AFB1 degradation ability of E. faecium HB2-2 was found to be dependent on the fermentation supernatant. The products of AFB1 degradation by E. faecium HB2-2 were analyzed by liquid chromatography–mass spectrometry (LC-MS), and a possible degradation mechanism was proposed based on the identified degradation products. Additionally, cytotoxicity assays revealed a significant reduction in the toxicity of the degradation products compared to the parent AFB1. These findings highlight the potential of E. faecium HB2-2 as a safe and effective method for mitigating AFB1 contamination in food and feed.

Keywords

• aflatoxin B₁
• biological degradation
• <i>Enterococcus faecium</i>
• peanut meal