Insights into β-manno-oligosaccharide uptake and metabolism in Bifidobacterium adolescentis DSMZ 20083 from whole-genome microarray analysis

Abstract Aims To determine the ability of adult-associated B. adolescentis DSMZ 20083 to utilize dietary β-manno-oligosaccharides and understand the underlying molecular mechanism. Methods and Results In-vitro fermentation and TLC were used to determine the ability of B. adolescentis DSMZ 20083 to utilize β-manno-oligosaccharides from guar gum, locust bean gum, konjac and copra meal. Further, Whole-genome transcriptome analysis, q-RT-PCR and molecular docking were employed to reconstruct copra meal β-manno-oligosaccharides (CM-β-MOS) utilization pathway in B. adolescentis DSMZ 20083. B. adolescentis DSMZ 20083 grew appreciably (A 600nm up to 0.8) on all tested β-manno-oligosaccharides but maximally on CM-β-MOS. Transcriptome analysis revealed differential up-regulation of three distinct gene clusters encoding, ABC transporter cassette (ESBP’s and permeases), MFS transporter, GH1 β-glucosidase and, GH32 β-fructofuranosidases. ABC and MFS possibly transported majorly DP≥2 and DP≥3 CM-β-MOS, respectively. Sugar absorption and utilization pathways; ABC transport system, pyruvate metabolism, glycolysis/gluconeogenesis, pentose, and glucouronate inter-conversions were also up-regulated. Conclusions B. adolescentis DSMZ 20083 possibly utilizes ABC & MFS transporters to internalise and GH1 β-glucosidase, and GH32 β-fructofuranosidase to deconstruct CM-β-MOS. Significance and Impact of the Study First study reporting possible molecular determinants used by B. adolescentis DSMZ 20083 to utilize β-manno-oligosaccharides and thus, can prove resourceful in precision microbiome modulation.