CỦA BACILLUS SUBTILIS PHÂN LẬP TỪ PHÂN TRẺ EM

Abstract

Objective: This study aims to assess the safety and probiotic properties of Bacillus strains isolated from the feces of children. Research subjects and methods: Bacillus strains were isolated from stool samples of healthy children, initially identified through physical and chemical reactions. Subsequently, precise identification was conducted using automatic sequencing of the 16S rRNA gene. The selected bacteria underwent specialized probiotic assessments, and the safety of bacterial isolates was evaluated in vitro. Research results: Six strains were preliminarily identified as Bacillus M23, M26, M31, M36, M70 and M91. These strains were found to be non-hemolytic with a high spore-forming ability, demonstrating acid resistance, heat resistance, extracellular enzyme production, sensitivity to antibiotics, and resistance to pathogenic bacteria. Notably, Bacillus M70 exhibited outstanding characteristics. Automated 16S rDNA gene sequencing revealed that Bacillus M70 shares 100% similarity with B. subtilis HGUP 332 on Genbank. Safety testing on white mice demonstrated that B. subtilis M70 is safe. Conclusion: This study evaluated the properties of B. subtilis isolated from children's feces. The results suggest that the B. subtilis M70 strain may have the potential to be considered as a probiotic; however, further extensive in vitro/vivo studies are necessary.