Project description:Bifidobacteria have been described as a key component of the human gut microbiota, and recently significant efforts have been made to investigate their genome contents and assess the genetic variability at inter- and intra-species level. In the current work we investigated genome diversity among representatives of bifidobacterial species, i.e., Bifidobacterium adolescentis. These analyses were performed with comparative genomic hybridization (CGH) experiments and they revealed the existence of a strictly conserved set of 685 gene families. Furthermore, CGH analyses showed that genetic regions of diversity included mobile elements and putative genomic life-style adaptation islands, such as loci that encode pili and capsular polysaccharides, and genes involved in carbohydrate metabolism. CGH analysis was performed with microarrays that were based on the genome sequences of B. adolescentis ATCC15703 (NC_008618) . A total of 39,249 probes of 35 bp in length were designed using OligoArray 2.1 software. Oligos were synthesized in triplicate on a 2 × 40-k CombiMatrix array (CombiMatrix, Mulkiteo, USA). Replicates were distributed on the chip at random, non-adjacent positions. A set of 74 negative control probes designed on phage and plant sequences was also included on the chip. Seventeen micrograms of purified genomic DNA was labeled with Cy5-ULS using the Kreatech ULS array CGH Labeling kit (Kreatech Diagnostics) according to the supplier’s instructions. Hybridization of labeled test DNA to these microarrays was performed according to CombiMatrix protocols.
Project description:In order to understand gene expression profile of Bifidobacterium adolescentis ATCC 15703, it was grown in minimal media upto late log phase in the presence of β-mannooligosaccharide from copra till OD A600 = 0.800
Project description:Bifidobacteria have been described as a key component of the human gut microbiota, and recently significant efforts have been made to investigate their genome contents and assess the genetic variability at inter- and intra-species level. In the current work we investigated genome diversity among representatives of bifidobacterial species, i.e., Bifidobacterium adolescentis. These analyses were performed with comparative genomic hybridization (CGH) experiments and they revealed the existence of a strictly conserved set of 685 gene families. Furthermore, CGH analyses showed that genetic regions of diversity included mobile elements and putative genomic life-style adaptation islands, such as loci that encode pili and capsular polysaccharides, and genes involved in carbohydrate metabolism. CGH analysis was performed with microarrays that were based on the genome sequences of B. adolescentis ATCC15703 (NC_008618) . A total of 39,249 probes of 35 bp in length were designed using OligoArray 2.1 software. Oligos were synthesized in triplicate on a 2 M-CM-^W 40-k CombiMatrix array (CombiMatrix, Mulkiteo, USA). Replicates were distributed on the chip at random, non-adjacent positions. A set of 74 negative control probes designed on phage and plant sequences was also included on the chip. Seventeen micrograms of purified genomic DNA was labeled with Cy5-ULS using the Kreatech ULS array CGH Labeling kit (Kreatech Diagnostics) according to the supplierM-bM-^@M-^Ys instructions. Hybridization of labeled test DNA to these microarrays was performed according to CombiMatrix protocols. We analysed seven strains belong to B. adolescentis species. Replicates were distributed on the chip at random, non-adjacent positions.
Project description:Bifidobacterium infantis is associated with the gut microbiota of breast-fed infants. B. infantis promotes intestinal barrier and immune function through several proposed mechanisms, including interactions between their surface polysaccharides, the host, and other gut microorganisms. Dairy foods and ingredients are some of the most conspicuous food-based niches for this species and may provide benefits for their delivery and efficacy in the gut. Milk phospholipid (MPL)-rich ingredients have been increasingly recognized for their versatile benefits to health, including interactions with the gut microbiota and intestinal cells. Therefore, our objective was to investigate the capacity for MPL to promote survival of B. infantis during simulated digestion and to modulate bacterial polysaccharide production. To achieve these aims, B. infantis was incubated with or without 0.5% MPL in de Man, Rogosa, and Sharpe (MRS) media at 37 °C under anaerobiosis. Survival across the oral, gastric, and intestinal phases using in vitro digestion was measured using plate count, along with adhesion to goblet-like intestinal cells. MPL increased B. infantis survival at the end of the intestinal phase by at least 7% and decreased adhesion to intestinal cells. The bacterial surface characteristics, which may contribute to these effects, were assessed by ζ-potential, changes in surface proteins using comparative proteomics, and production of bound polysaccharides. MPL decreased the surface charge of the bifidobacteria from –17 to –24 mV and increased a 50 kDa protein (3-fold) that appears to be involved in protection from stress. The production of bound polysaccharides was measured using FTIR, HPLC, and TEM imaging. These techniques all suggest an increase in bound polysaccharide production at least 1.7-fold in the presence of MPL. Our results show that MPL treatment is positively correlated with increased survival during simulated digestion, a stress resistance surface protein, and bound polysaccharide production of B. infantis, suggesting its use as a functional ingredient to enhance probiotic and postbiotic effects.