Identification and Antibacterial Activity Study of a Terrestrial Strain of Brevibacterium aureus 431

This study isolated and purified strain 431 from an animal probiotic product. Through staining and microscopic examination, colony morphology analysis, biochemical reaction tests, and 16S rDNA sequence alignment, the strain was identified and named Brevibacterium aureus 431. The study focused on the production of biosurfactants by strain 431, and antibacterial activity tests were conducted on the strain and its secondary metabolites. The results showed that strain 431 exhibited no resistance to 10 commonly used drugs, and its concentrated secondary metabolites were highly sensitive to the indicator bacterium Escherichia coli. Oral administration of strain 431 to BALB/c mice resulted in normal mental state, diet, and bowel movements, with no signs of illness or death, indicating that strain 431 is highly safe and non-pathogenic to mice. The study suggests that Brevibacterium aureus 431 has significant research value as a new source of actinomycetes and that its secondary metabolites have potential application value in the development of antibacterial drugs.