Project description:The global transcriptome of the Bifidobacterium animalis subsp. lactis Bl-04 was analyzed during exponential growth on 11 prebiotic carbohydrates and glucose to identify the specific gene cluster differentially upregulated in response to each carbohydrate.
Project description:Comparison of the growth of Bifidobacterium animalis subsp. lactis BB12 in MRS (without carbon source) with either 2% XOS (xylo-oligosaccharides) or 2% glucose using whole-genome transcriptome analysis.
Project description:The global transcriptome of the Bifidobacterium animalis subsp. lactis Bl-04 was analyzed during exponential growth on 11 prebiotic carbohydrates and glucose to identify the specific gene cluster differentially upregulated in response to each carbohydrate. Affymetrix hybridization experiments were performed to compare the differential transcriptional profiles of the B. lactis Bl-04 at the early-log (OD600nm 0.3-0.5) phase. 12 carbohydrates were tested with two technical replicates to each condition for a total of 24 hybridizations.
Project description:Stress survival tactics in bacteria utilize the up- and down-regulation of stress response genes. In bacteria that lack classical stress response genes for oxidative stress, other cellular systems can be used for cell survival. We used custom microarrays to study the regulation of genes in Bifidobacterium animalis ssp. lactis strains to oxidative stress to elucidate novel stress response mechanisms. Bifidobacterium cells were grown to late log phase then harvested and exposed to a sub-lethal level of hydrogen peroxide. Samples were taken at 5 and 20 mins for RNA extraction and hybridization on Affymetrix microarrays. Controls were prepared for each time point which recieved no hydrogen peroxide treatment.
Project description:This work aimed to investigate the ability of two human-derived bifidobacterial strains, i.e. Bifidobacterium breve UCC2003 and Bifidobacterium longum NCIMB 8809, to utilize various oligosaccharides (i.e., 4-galactosyl-kojibiose, lactulosucrose, lactosyl-oligofructosides, raffinosyl-oligofructosides and lactulose-derived galacto-oligosaccharides) synthesized by means of microbial glycoside hydrolases. With the exception of raffinosyl-oligofructosides, these biosynthetic oligosaccharides were shown to support growth of at least one of the two studied strains. Short-chain fatty acid (SCFA) analysis by HPLC corroborated the suitability of most of the studied novel oligosaccharides as growth substrates for the two bifidobacterial strains, showing that acetate is the main metabolic end product followed by lactic and formic acids. Transcriptomic and functional genomic approaches carried out for B. breve UCC2003 allowed the identification of key genes encoding glycoside hydrolases and protein transport systems involved in the metabolism of 4-galactosyl-kojibiose and lactulosucrose. In particular, the role of β-galactosidases in the hydrolysis of these particular trisaccharides was demonstrated, highlighting their importance in oligosaccharide metabolism by human bifidobacterial strains.
Project description:Stress survival tactics in bacteria utilize the up- and down-regulation of stress response genes. In bacteria that lack classical stress response genes for oxidative stress, other cellular systems can be used for cell survival. We used custom microarrays to study the regulation of genes in Bifidobacterium animalis ssp. lactis strains to oxidative stress to elucidate novel stress response mechanisms.
Project description:Bifidobacterium animalis ssp. lactis Bb12 (Bb12) is a probiotic bacteria with several reported benefits, including immunomodulatory capacity. This is due to the bacteria recognition by receptors such as TLR2, which in turn affects the miRNA transcriptome of immune system cells. We aimed to analyze miRNA expression in swine monocytes stimulated with Bb12, and their expression when TLR2 receptor is blocked. A microarray containing 407 porcine unique miRNA probes was employed to identify differences in the miRNA expression pattern in swine monocytes in response to Bb12. A total of 143 were differentially expressed miRNAs (p<0.05); out of which, 87 miRNAs are statistically significant but have lower signals (signal <500).