Mechanism and kinetics of degrading aflatoxin B1 by salt tolerant Candida versatilis CGMCC 3790

Four products were identified by liquid chromatography/time-of-flight mass spectrometry (LC/TOF-MS) for the degradation of aflatoxin B1 (AFB1) is by salt tolerant Candida versatilis CGMCC 3790 (C. versatilis CGMCC 3790), includingⅡ(C14H10O4), Ⅲ (C14H12O3), Ⅳ (C13H12O2), Ⅴ (C11H10O4), which were not toxic. Based on these products, it is speculated that AFB1 degradation has two pathways. The degradation ratio of active cell component (69.40%) and intracellular component (64.99%) was significantly higher than extracellular component (29.61%), suggesting that the AFB1 removal mainly resulted from biodegradation. The optimal degradation conditions of AFB1 (20 ng/mL) were: incubated at pH 5.0, 25 °C for 60 min in liquid medium system. The degradation ratio was ranged from 41.23%∼100% at 10.26∼130.44 ng/g in an actual system. This is the first report revealing that a salt tolerant yeast could effectively degrade AFB1. Therefore, Candida versatilis CGMCC 3790 might be an excellent candidate for bioremediation and detoxification for oriental fermentation condiment process.