Screening, Identification, and Probiotic Properties of Bacillus Pumilus From Yak

The yak has a unique physiological structure suited to life in anoxic and cold environments at high altitudes. The aim of this study was to isolate Bacillus species with good probiotic properties from yak feces. A series of tests were performed on the isolated Bacillus: 16S rRNA identification, antibacterial activity, tolerance to gastroenteric fluid, hydrophobicity, auto-aggregation, antibiotic sensitivity, growth performance, antioxidants, and immune indexes. A safe and harmless Bacillus pumilus DX24 strain with good survival rate, hydrophobicity, auto-aggregation, and antibacterial activity was identified in the yak feces. Feeding mice with Bacillus pumilus DX24 increased their daily weight gain, jejunal villus length, villi/Crypt ratio, blood IgG levels, and jejunum sIgA levels. This study confirmed the probiotic effects of Bacillus pumilus isolated from yak feces and provides the theoretical basis for the clinical application and development of new feed additives.

Automated summary

The aim of this study was to isolate Bacillus species with good probiotic properties from yak feces. Various tests were conducted on the isolated Bacillus, which included identification, antibacterial activity, tolerance, hydrophobicity, auto-aggregation, sensitivity, growth performance, antioxidants, and immune indexes. A safe and harmless Bacillus pumilus strain with high survival rate, hydrophobicity, auto-aggregation, and antibacterial activity was identified. Feeding mice with this strain promoted weight gain, improved gut health, and enhanced immune response. This study confirms the probiotic effects of Bacillus pumilus isolated from yak feces and provides a theoretical basis for clinical application and development of new feed additives.