Isolation and Experimental Study on Bacteriostasis of Bacillus haynesii

This experiment aims to isolate and inhibit three bacteria strains to provide candidate strains for the development and application of probiotics. Using bacterial morphological identification, 16S rDNA sequence alignment, and genetic evolution analysis, three strains were identified as Bacillus haynesii, named HP01, HD02, and HK03. Through biosurfactant activity tests, C-TAB tests, hemolysis tests, and antibacterial activity analyses, the results showed that all three strains of B. haynesii exhibited significant biosurfactant activity. Additionally, the solutions of the three strains demonstrated a pronounced antibacterial effect on Staphylococcus aureus. The resistance and safety of commonly used drugs were evaluated using the tablet diffusion method and a mouse feeding test. The results indicated that the three strains were not resistant to commonly used antibacterial drugs, and the oral bacterial solution was not pathogenic and had high safety in mice. The study concluded that all three B. haynesii strains met the basic conditions for use, with B. haynesii HP01 being the most promising candidate.