Screening of lactic acid bacteria from Hotan black chicken and comprehensive evaluation of the potential probiotic Pediococcus pentosaceus HBC

Summary: To identify novel probiotics from indigenous avian sources, we isolated seven lactic acid bacterial (LAB) strains from the intestinal tracts of the Hotan black chicken, a native breed from Xinjiang, China. A preliminary safety screening based on hemolytic activity resulted in the exclusion of four isolates. The remaining three non-hemolytic strains were subsequently subjected to a systematic evaluation for key probiotic atributes, including tolerance to acid and bile salts, auto-aggregation, surface hydrophobicity, cell adhesion, and antimicrobial activity. Among these, Pediococcus pentosaceus HBC demonstrated the most promising probiotic profile and was selected for in-depth phenotypic and genomic characterization. Phenotypically, Pediococcus pentosaceus HBC exhibited exceptional resilience, with high survival rates under acidic (48% at pH 2.0) and bile salt (70% at 0.3%) conditions. It also displayed strong surface properties, including significant hydrophobicity (>49%), auto-aggregation capacity (>34%), and epithelial cell adhesion (>84%). Furthermore, the strain showed broad-spectrum antimicrobial activity against major poultry pathogens such as Salmonella and E. coli. Genomic analysis corroborated these findings, revealing a versatile genetic repertoire for carbohydrate metabolism, stress adaptation, and antimicrobial functions. Crucially, the analysis affirmed its safety profile by indicating a low risk of virulence and antibiotic resistance gene transfer. These comprehensive characteristics strongly support the potential of Pediococcus pentosaceus HBC as a safe and efficacious probiotic candidate for enhancing gut health and disease resistance in poultry production.