Complete-genome sequence and in vitro probiotic characteristics analysis of Bifidobacterium pseudolongum YY-26

Aims The aim was to isolate a neotype bifidobacteria strain and evaluate its in vitro probiotic potential. Methods and Results Bifidobacterium pseudolongum YY-26 (CGMCC 24310) was isolated from faeces of mice treated with low-molecular-weight hydrolyzed guar gum (GMPS) and identified based on 16S rRNA sequence and genome sequence. Whole-genome sequencing obtained using PacBio's single-molecular and Illumina's paired-end sequencing technology. A genome of 2.1 Mb in length, with 1877 predicted protein-coding sequences was obtained. Carbohydrate-Activity enZyme analysis revealed that YY-26 encodes 66 enzymes related to carbohydrate metabolism. Whole genome sequence analysis revealed the typical probiotic characteristics of YY-26, including safety in genetic level and ability to produce beneficial metabolites and extracellular polysaccharides. Ability of extensive carbon source utilization and short-chain fatty acid production was observed with single YY-26 cultivation. Considerable acetic acids and lactic acids were determined in GMPS utilization. YY-26 showed tolerance to simulated gastrointestinal tract and displayed appreciable antioxidant activity of free radical scavenging. Conclusions B. pseudolongum YY-26 was identified with numerous probiotic-associated genes and its probiotic characteristics were verified in vitro. Significance and Impact of Study This study supplemented with limited publicly information regarding the genomes of B. pseudolongum strains and revealed the probiotic potential of YY-26.

Automated summary

This study identified a new strain of bifidobacteria, YY-26, and verified its potential as a probiotic through in vitro experiments, demonstrating its safety, ability to produce beneficial metabolites and extracellular polysaccharides, and antioxidant activity.