Abstract:This study aimed to isolate and characterize Bacillus subtilis strains with exceptional probiotic properties, thereby providing a theoretical foundation for the development and application of microbial ecological agents in goat dairy farming. The research team successfully isolated three Bacillus strains from fecal samples of healthy, high-yielding dairy goats in Shenmu City, Shaanxi Province, identifying them as Bacillus subtilis through both morphological and molecular biological techniques. Subsequently, the team evaluated the in vitro safety, efficacy, and feasibility of these strains using hemolysis assays, antibiotic susceptibility tests, antibacterial activity assessments, and simulated gastrointestinal tolerance experiments. (1) The results indicated that none of the strains exhibited hemolytic activity while demonstrating favorable drug sensitivity profiles. (2) they effectively inhibited common mastitis pathogens such as Staphylococcus aureus, Bacillus coagulans, and Escherichia coli. (3) these strains displayed robust acid resistance along with significant tolerance to gastric protease and trypsin. In conclusion, the three isolated Bacillus subtilis strains—L1-1, L3-1, and L3-2—exhibit promising in vitro probiotic characteristics that position them as potential candidates for microbial probiotics in goat dairy farming; this offers new opportunities for enhancing both health outcomes and economic benefits within this sector.
