Zearalenone (ZEN) is an estrogen-like mycotoxin produced by Fusarium that seriously compromises the safety of animal and human health. In this study, our aim was to evaluate the protective effect of Bacillus velezensis A2 against biochemical and pathological changes induced by zearalenone in mice. Kunming mice (n = 40; 25 ± 2 g) were allotted to four treatment groups: a control group (basic feed); a ZEN group (basic feed with a ZEN dose of 60 mg/kg); an A2 strain fermented feed group (150 g of feed mixed with 150 mL of sterile distilled water and inoculated with 5 mL of phosphate buffer salt (PBS) resuspended A2 strain); and an A2 strain fermented ZEN-contaminated feed group. (A2 strain group 150 mL pure bacterial distilled water system mixed with 150 g ZEN-contaminated feed.) Our results showed that the Bacillus velezensis A2 strain can completely degrade the ZEN-contaminated feed within 5 days. (The concentration of ZEN in fermentation was 60 μg/mL.) After the mice fed for 28 days, compared with the control group, the activities of AST and ALT were increased, the activities of glutathione peroxidase (GSH-PX) and total superoxide dismutase (T-SOD) were decreased, and the amount of creatinine (CRE), blood urea nitrogen (BUN), uric acid (UA), and malondialdehyde (MDA) in the ZEN group were increased in the mice serum (p < 0.05; p < 0.01). However, compared with the ZEN group, these biochemical levels were reversed in the A2 strain fermented feed group and in the A2 strain fermented ZEN-contaminated feed group (p < 0.05; p < 0.01). Furthermore, histopathological analysis only showed pathological changes of the mice liver in the ZEN group. The results showed that Bacillus velezensis A2 as additive could effectively remove ZEN contamination in the feed and protect the mice against the toxic damage of ZEN. In conclusion, Bacillus velezensis A2 has great potential use as a microbial feed additive to detoxify the toxicity of zearalenone in production practice.
Keywords: Bacillus velezensis A2; feed detoxification; oxidative damage; serum enzyme; zearalenone (ZEN).