Genome of Bifidobacterium longum subsp. infantis YLGB-1496 provides insights into its carbohydrate utilization and genetic stability

Abstract

Abstract Background Bifidobacterium longum subsp. infantis YLGB-1496 is a probiotic strain isolated from human breast milk. The application of B. infantis YLGB-1496 is influenced by carbohydrate utilization and genetic stability. This study used genome sequencing to determine the carbohydrate utilization characteristics and genetic stability of YLGB-1496. Results The genome sequence of YLGB-1496 consists of 275,8242 bp base pairs, 2442 coding sequences, and a GC content of 59.87%. A comparison of carbohydrate transport and metabolism genes of B. infantis showed that YLGB-1496 was rich in GH13, 20, 25, and 109 gene families. Growth characteristic analysis, scanning electron microscopy, and SNP assays were performed in consecutive subcultures, and it was found that the growth characteristics and fermentation activity of the strain were highly stable. The surface and edges of the 1000th generation strains were progressively smoother and well-defined, with no perforations or breaks in the cell wall. There were 20 SNP loci at the 1000th generation, fulfilling the requirement of belonging to the same strain. The presence of genes associated with cell adhesion and the absence of resistance genes supported the probiotic characteristics of the strain. Conclusion This is the report on the whole genome sequence of B. infantis YLGB-1496 isolated from human breast milk of China. The data obtained in this study provide insights into broad-spectrum carbohydrate utilization, genomic stability, and probiotic properties of YLGB-1496, which provide theoretical support to promote the use of YLGB-1496 in infant foods.