Aflatoxin B1 Detoxification by Aspergillus oryzae from Meju, a Traditional Korean Fermented Soybean Starter
Kyu Ri Lee1, Sun Min Yang1, Sung Min Cho1
1Department of Integrated Biomedical and Life Science, Korea University, Seoul 02841, Republic of Korea.
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.
Insights
Two Aspergillus oryzae strains effectively biodetoxified aflatoxin B1 (AFB1), reducing its mutagenicity and production. These fungi show promise for controlling AFB1 contamination in food and feed.
Area of Science:
- Food Science
- Microbiology
- Toxicology
Background:
- Aflatoxins, particularly aflatoxin B1 (AFB1), are carcinogenic to humans (IARC Group 1).
- Contamination of food and feed with aflatoxins poses significant health risks.
- Effective methods for aflatoxin detoxification are crucial for food safety.
Purpose of the Study:
- To isolate and identify fungal strains capable of biodetoxifying aflatoxin B1 (AFB1).
- To evaluate the efficacy of selected strains in degrading AFB1 and reducing its mutagenicity.
- To assess the potential of these strains for controlling AFB1 contamination in food and feed.
Main Methods:
- Isolation and screening of 134 fungal strains from 65 meju samples.
- Identification of promising isolates (MAO103 and MAO104) using beta-tubulin gene sequencing.
- Quantification of AFB1 degradation and assessment of mutagenicity reduction using Ames tests and AFB1 production assays.
Main Results:
- Two Aspergillus oryzae strains, MAO103 and MAO104, were identified.
- These strains degraded over 90% of AFB1 (40 μg/l) within 14 days.
- Mutagenic effects of AFB1 were significantly reduced by MAO103 and MAO104, with frame-shift mutation decreasing to 5.7% and 6.4% respectively.
- AFB1 production by Aspergillus flavus was also inhibited by these Aspergillus oryzae strains.
Conclusions:
- Aspergillus oryzae strains MAO103 and MAO104 demonstrate significant potential for AFB1 biodetoxification.
- These findings suggest practical applications for controlling aflatoxin contamination in food and feed products.
- Further research can explore optimizing conditions for large-scale application of these detoxifying fungi.
More Related Videos
09:44RNAi-mediated Control of Aflatoxins in Peanut: Method to Analyze Mycotoxin Production and Transgene Expression in the Peanut/Aspergillus Pathosystem
Published on: December 21, 2015
10:01Quantification of Fungal Colonization, Sporogenesis, and Production of Mycotoxins Using Kernel Bioassays
Published on: April 23, 2012
