Biodegradation of aflatoxin B1 with cell-free extracts of Trametes versicolor and Bacillus subtilis

Abstract

Aflatoxin B₁ (AFB₁) is one of the most common contaminants of poultry feed and has been linked to adverse effects on animal health and productivity. In this study, the degradation of AFB₁ was studied with cell-free extracts (CFE) of Trametes versicolor and Bacillus subtilis using High-Performance Liquid chromatography (HPLC). CFE from B. subtilis and T. versicolor gave 60% and 34% of AFB₁ degradation respectively, while heat-inactivated extracts showed no degradation. By-products obtained at the end of AFB₁ degradation were analyzed by Liquid Chromatography with tandem mass spectrometry (LC-MS/MS). After 96 h of incubation, by-products with lower m/z values were obtained with CFE from B. subtilis as compared to that from T. versicolor, indicating a higher degradation efficiency of the former. Additionally, the detection of a by-product which could correspond to AFB1-8,9 dihydrodiol - a less toxic derivative of AFB₁ - after 72 and 96 h of incubation with CFE from B. subtilis, could indicate the simultaneous detoxification along with degradation of AFB₁ by B. subtilis CFE.

Keywords: Aflatoxin B(1); Cell-free extracts; Degradation products; Detoxification; Microbial degradation.