As a class I carcinogen, aflatoxin can cause serious damage to various tissues and organs through oxidative stress injuries. The liver, as the target organ of AFB1, is the most seriously damaged. Biological methods are commonly used to degrade AFB1. In our study, the aflatoxin B1-degrading strain ZJ20 was screened from AFB1-contaminated feed and soil, and the degradation of AFB1 by ZJ20 was investigated. The whole genome of strain ZJ20 was analyzed, revealing the genomic complexity of strain ZJ20. The 16S rRNA analysis of strain ZJ20 showed 100% identity to Bacillus subtilis IAM 12118. Through whole gene functional annotation, it was determined that ZJ20 has high antioxidant activity and enzymatic activity; more than 100 CAZymes and 11 gene clusters are involved in the production of secondary metabolites with antimicrobial properties. In addition, B. subtilis ZJ20 was predicted to contain a cluster of genes encoding AFB1-degrading enzymes, including chitinase, laccase, lactonase, and manganese oxidase. The comprehensive analysis of B. subtilis provides a theoretical basis for the subsequent development of the biological functions of ZJ20 and the combinatorial enzyme degradation of AFB1.
Ochratoxin A (OTA), a secondary metabolite produced by Penicillium and Aspergillus species, contaminates food and feed globally, posing serious threats to both livestock and human health. Among current detoxification strategies, probiotic-based degradation of OTA has emerged as a key research focus. This study aimed to isolate safe probiotic strains with high OTA-detoxifying efficacy to support their potential application in feed and food industries. A total of 57 bacterial strains were isolated from environmental samples, including soil, moldy feed, and animal feces. Among these, a novel strain identified as Bacillus amyloliquefaciens MM28 demonstrated strong OTA-degrading activity, removing 86.31% of OTA (0.4 µg/mL) within 48 h. Whole-genome analysis indicated that B. amyloliquefaciens MM28 harbors functional genes related to glucose metabolism, membrane transport, and properties associated with antibacterial, antioxidant, and immunomodulatory activities, suggesting multiple beneficial traits. In a 28-day chronic exposure study, mice were administered B. amyloliquefaciens MM28 via gavage (1 × 108 CFU/mL). Results showed that both female and male mice in the MM28 group exhibited higher body weight and improved growth performance compared to the PBS control group. Furthermore, intestinal morphology was enhanced in the MM28 group, as indicated by greater villus length and villus-length-to-crypt-depth ratio. The expression of proinflammatory cytokines was also reduced in the treated animals. Moreover, analysis of gut microbiota composition revealed that MM28 supplementation led to an increased abundance of Bacteroides and Desulfovibrio, alongside a reduction in Lachnospira and Oscillospira. In conclusion, this study demonstrates that Bacillus amyloliquefaciens MM28 is a safe and efficient strain capable of degrading OTA. These findings highlight its promising potential as a biological detoxifying agent in food and feed industries.