Abstract:Bacillus are well known antibiotic producers. In this study, dozens of Bacillus strains from different sources were screened. Among them, a strain with strong antifungal activity was found. With 16S rDNA test and Biolog assay, this strain was identified to be Bacillus amyloliquefaciens. The fermentation conditions were optimized in small conical flasks. After ammonium sulfate salting out, dialysis, freezing vacuum dehydration, the crude protein extracts were obtained. The thermal stability, pH stability, protease stability, ion stability and antifungal spectrum of this protein were studied further. Scanning electronic microscope was also used to explore the antifungal mechanism.