ETD

• bifidobacteria

The human gut microbiota plays a key role in maintaining host health, with bifidobacteria representing some of its most important members.
B. breve, B. bifidum and B. catenulatum/pseudocatenulatum group are some of the most widespread species within this genus, present both in the infant and adult gut. In this thesis, isolates belonging to these species were analyzed using a combination of molecular and phenotypic approaches. REP-PCR fingerprinting analysis confirmed genetic variability among the isolates. MALDI-TOF MS method verified the species identity of all tested strains. Phase-contrast microscopy revealed typical bifidobacterial morphology and variability. Assessment of substrate utilization through ANAEROtest 23 and modified API 50 CHL test demonstrated a broad metabolic competence of the strains and confirmed notable differences in fermentation profiles depending on both host age and sample species.
Overall, the integrated genotypic and functional analyses provided a comprehensive overview of the genetic and metabolic diversity of the studied strains. The findings of this study expand the current knowledge of intraspecies variability of the selected Bifidobacterium species and highlight the importance of combining genotypic and phenotypic methods.