Bacillus amyloliquefaciens strain:HAU3 Genome sequencing. Bacillus amyloliquefaciens strain:HAU3

Mycotoxin contamination, predominantly perpetuated by toxigenic fungi like Fusarium graminearum , presents a formidable threat to both human and animal health, posing significant challenges within the food and feed safety sectors. In our study, we successfully isolated a Bacillus amyloliquefaciens strain, HAU3, from wheat rhizosphere soil samples, which demonstrated a marked inhibition of F. graminearum growth. This strain's sterile supernatant, at a concentration of 20%, exhibited an impressive 98.46% inhibitory efficacy against F. graminearum. Additionally, antifungal spectrum tests substantiated the broad antifungal activity of B. amyloliquefaciens HAU3 against various pathogenic fungi. Further investigations into the mechanism of action, employing both scanning electron microscopy and transmission electron microscopy , revealed that B. amyloliquefaciens HAU3 specifically targets the fungal hyphae cell membrane. Staining techniques, including DCFH-DA and PI, indicated that this bacterial strain prompts an accumulation of reactive oxygen species, culminating in cell death within the hyphae of F. graminearum. Genomic exploration unveiled 13 gene clusters responsible for encoding secondary metabolites. The active antibacterial compounds were meticulously isolated and identified using preparative chromatography and two dimensional nuclear magnetic resonance, pinpointing fengycin as the primary active substance. Moreover, we delved into the potential application of B. amyloliquefaciens HAU3 as an additive in the microbial community management of F. graminearum infected whole crop wheat silage. Our findings suggest that the inclusion of B. amyloliquefaciens HAU3 not only curtails the proliferation of Coliform and Molds but also underscores its potential as a viable biological additive for mitigating mycotoxin contamination in feed. In summation, B. amyloliquefaciens HAU3 emerges as a promising biological agent, exerting its antibacterial effects primarily through cell membrane targeting via fengycin production, thus offering a novel approach to addressing the pervasive issue of mycotoxin contamination in the feed industry.