Project description:The main objective of the present proteomic study is to identify the metabolic response, in particular theglycan uptake and degradation machinery, conferring members of Roseburia growth on HMOs and/or onrelated O-glycans. Accordingly, the proteomes of R. hominis and R. inulinivorans bothgrown on humanmilk oligosaccharides (HMOs), were compared to glucose to reveal the molecular basis for growth onHMOs. Furthermore, we compare the proteomes of R. hominis and R. inulinivorans grownin co-culturewith A. muciniphilia either on mucin or on glucose to identify potential metabolic routes of mucin derivedO-glycan utilization in Roseburia.
Project description:β-Mannan is abundant in the human diet and in hemicellulose derived from softwood. Linear or galactose-substituted β-mannan-oligosaccharides (MOS/GMOSs) derived from β-mannan are considered emerging prebiotics that could stimulate health-associated gut microbiota. However, the underlying mechanisms are not yet resolved. Therefore, this study investigated the cross-feeding and metabolic interactions between Bifidobacterium adolescentis ATCC 15703, an acetate producer, and Roseburia hominis A2-183 DSMZ 16839, a butyrate producer, during utilization of MOS/GMOSs. Cocultivation studies suggest that both strains coexist due to differential MOS/GMOS utilization, along with the cross-feeding of acetate from B. adolescentis E194a to R. hominis A2-183. The data suggest that R. hominis A2-183 efficiently utilizes MOS/GMOS in mono- and cocultivation. Notably, we observed the transcriptional upregulation of certain genes within a dedicated MOS/GMOS utilization locus (RhMosUL), and an exo-oligomannosidase (RhMan113A) gene located distally in the R. hominis A2-183 genome. Significantly, biochemical analysis of β-1,4 mannan-oligosaccharide phosphorylase (RhMOP130A), α-galactosidase (RhGal36A), and exo-oligomannosidase (RhMan113A) suggested their potential synergistic role in the initial utilization of MOS/GMOSs. Thus, our results enhance the understanding of MOS/GMOS utilization by potential health-promoting human gut microbiota and highlight the role of cross-feeding and metabolic interactions between two secondary mannan degraders inhabiting the same ecological niche in the gut.
Project description:Here, we report analysis of both the bacterial and host transcriptome as affected by colonization of R. hominis in the mouse gut. Microbial genes required for colonization and adaptation in the murine gut, as well as host genes responding to colonization by this bacterial species, were uncovered.
