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.