Aflatoxin B1 Detoxification by Aspergillus oryzae from Meju, a Traditional Korean Fermented Soybean Starter

Kyu Ri Lee; Sun Min Yang; Sung Min Cho; Myunghee Kim; Sung-Yong Hong; Soo Hyun Chung

doi:10.4014/jmb.1607.07064

Aflatoxin B₁ Detoxification by Aspergillus oryzae from Meju, a Traditional Korean Fermented Soybean Starter

J Microbiol Biotechnol. 2017 Jan 28;27(1):57-66. doi: 10.4014/jmb.1607.07064.

Authors

Kyu Ri Lee¹, Sun Min Yang¹, Sung Min Cho¹, Myunghee Kim², Sung-Yong Hong¹, Soo Hyun Chung¹

Affiliations

¹ Department of Integrated Biomedical and Life Science, Korea University, Seoul 02841, Republic of Korea.
² Department of Food Science and Technology, Yeungnam University, Gyeongsan 38541, Republic of Korea.

PMID: 27817189
DOI: 10.4014/jmb.1607.07064

Abstract

Aflatoxins are classified as Group 1 (carcinogenic to humans) by the International Agency for Research on Cancer. In this study, a total of 134 fungal strains were isolated from 65 meju samples, and two fungal isolates were selected as potential aflatoxin B₁ (AFB₁)-biodetoxification fungi. These fungi were identified as Aspergillus oryzae MAO103 and A. oryzae MAO104 by sequencing the beta-tubulin gene. The two A. oryzae strains were able to degrade more than 90% of AFB₁ (initial concentration: 40 μg/l) in a culture broth in 14 days. The mutagenic effects of AFB₁ treated with A. oryzae MAO103 and MAO104 significantly decreased to 5.7% and 6.4%, respectively, in the frame-shift mutation of Ames tests using Salmonella typhimurium TA98. The base-substituting mutagenicity of AFB₁ was also decreased by the two fungi. Moreover, AFB₁ production by Aspergillus flavus was significantly decreased by the two A. oryzae strains on soybean-based agar plates. Our data suggest that the two AFB₁-detoxifying A. oryzae strains have potential application to control AFB₁ in foods and feeds.

Keywords: Aflatoxin B1; biodegradation; detoxification; soybean fermentation starter.