Biodetoxification of both AFB1 and ZEN by Bacillus subtilis ZJ-2019-1 in gastrointestinal environment and in mice.

Abstract

Aflatoxin B1 (AFB1) and zearalenone (ZEN) are the most prevalent mycotoxins in production, posing a serious threat to human and animal health. Therefore, it is very urgent to find a safe and efficient method for the biodegradation of these mycotoxins. Our previous study demonstrated that Bacillus subtilis ZJ-2019-1 moderately degrades both mycotoxins in vitro and ZEN in female gilts. In this study, we assessed the effect of B. subtilis ZJ-2019-1 on AFB1 and ZEN degradation in naturally moldy corn gluten meal in a gastrointestinal environment while also evaluating the cytotoxicity of degradation products using the Cell Counting Kit-8 (CCK-8) assay. The efficacy of B. subtilis in degrading mycotoxins was further evaluated by orally administering 5 mg/kg AFB1 and 50 mg/kg ZEN to mice, followed by treatment with B. subtilis ZJ-2019-1 for 15 d. The results showed that B. subtilis ZJ-2019-1 moderately degraded both AFB1 and ZEN present in naturally moldy corn gluten meal in simulated small intestinal fluids, with degradation rates reaching 14.71% for AFB1 and 19.53% for ZEN respectively. Following degradation by B. subtilis ZJ-2019-1, the toxicity of resulting products from both AFB1 and ZEN decreased by 11.68-46.41% and 42.62-59.25%, respectively. Moreover, oral administration of B. subtilis ZJ-2019-1 exhibited remarkable detoxification effects on AFB1 and ZEN in mice, as evidenced by significant restoration of abnormal serum biochemical indices (including aspartate aminotransferase/alanine transaminase, alkaline phosphatase, total cholesterol, etc.) and alleviation of liver, intestine, and uterine damage caused by mycotoxins in mice. These findings indicate that B. subtilis ZJ-2019-1 possesses the ability to moderately degrade both AFB1 and ZEN, making it a promising candidate for biodegrading multi-mycotoxin contaminants in food and feed.