Rapid biodegradation of aflatoxin B1 by metabolites of Fusarium sp. WCQ3361 with broad working temperature range and excellent thermostability.

Abstract

Contamination of food and feed by aflatoxin B1 (AFB1) poses serious economic and health problems worldwide, so the development of biological methods for effective AFB1 degradation is strongly required. Among three AFB1-degrading microorganisms isolated from moldy peanut, Fusarium sp. WCQ3361 could remove AFB1 extremely effectively, with a degradation ratio of 70.20% after 1 min and 95.38% after 24 h. Its degradation ratio was not much affected by temperature change (0-90 °C) and it also displayed excellent thermostability, maintaining 99.40% residual activity after boiling for 10 min. Since protease K could reduce the AFB1 degradation ratio by 55.15%, it is proposed that the effective component for AFB1 degradation is a protein. The AFB1 degradation ability of Fusarium sp. WCQ3361 was further verified by feed stock detoxification and the MTT test with HepG2 cells. In addition, no degradation products were detected by preliminary liquid chromatography/mass spectrometry, suggesting that AFB1 might be metabolized to products with different chemical characteristics from AFB1. Fusarium sp. WCQ3361 is the first reported AFB1 degradation fungus belonging to the genus Fusarium with broad working temperature range, excellent thermostability and high activity, which provides a potential highly useful solution for dealing with AFB1 contamination in the human diet and animal feed. © 2016 Society of Chemical Industry.