Project description:Comparison of transcriptional profile of wild-type and bmoR mutant strains of Bacteroides fragilis grown under anaerobic conditions and after exposure to atmospheric oxygen for 1 hour.
Project description:Bacteroides thetaiotaomicron, one of the most eminent representative gut commensal Bacteroides species, is able to use the L-fucose in host-derived and dietary polysaccharides to modify its capsular polysaccharides and glycoproteins through a mammalian-like salvage metabolic pathway. This process is essential for the colonization of the bacteria and for symbiosis with the host. However, despite the importance of fucosylated proteins (FGPs) in Bacteroide thetaiotaomicron, their types, distribution, and functions remain unclear. In this project, the effects of different saccharide (glucose, corn starch, mucin, and fucoidan) nutrition conditions on FGP expressions and fucosylation are investigated using a chemical biological method based on metabolic labeling and bioorthogonal reaction. According to the results of label-free quantification, 559 FGPs (205 downregulated and 354 upregulated) are affected by the dietary conditions. Of these differentially expressed proteins, 65 proteins show extremely sensitive fucosylation levels. Specifically, the fucosylation of the chondroitin sulfate ABC enzyme, Sus proteins, and cationic efflux system proteins varies significantly upon the addition of mucin, corn starch, or fucoidan. Moreover, these polysaccharides can trigger an appreciable increase in the fucosylation level of the two-component system and ammonium transport proteins. These results highlight the efficiency of the combined metabolic glycan labeling and bio-orthogonal reaction in enriching the intestinal Bacteroide glycoproteins. Moreover, it emphasize the sensitivity of Bacteroides fucosylation to polysaccharide nutrition conditions, which allows for the regulation of bacterial growth.
Project description:Purpose: Examining the transcriptome of Bacteroides thetaiotaomicron VPI-5482 challenged with Bacteroides phage to assess surface molecule expression changes Methods: Bacteroides thetaiotaomicron was grown in BPRM in vitro or Germ-Free mice were monocolonized with Bacteroides thetaiotaomicron and gavaged with ARB25 phage. Fold change was calculated as live phage versus heat-killed phage treated samples with n=3 biological replicates. Once cells reached an optical density corresponding to mid-log phase growth (absorbance between 0.4-0.5), RNA was isolated and rRNA depleted. Samples were multiplexed for sequencing on the Illumina HiSeq platform at the University of Michigan Sequencing Core. Data was analyzed using Arraystar software (DNASTAR, Inc.) using DEseq2 normalization with default parameters. Genes with significant up- or down-regulation were determined by the following criteria: genes with an average fold-change >5-fold and with at least 2/3 biological replicates with a normalized expression level >1% of the overall average, and a p-value < 0.05 (t test with Benjamini-Hochberg correction) Results: Specific capsule expression was increased in wild-type B. thetaiotaomicron during phage infection in vitro and in vivo. Many corresponding in vivo genes were upregulated as well as other surface layer proteins.
Project description:These experiments were to investigate changes in gene expression associated with maize competition for light when grown at double normal population density or under 60% shaded conditions as opposed to when maize is grown under normal field conditions.
Project description:Genome expression study of Bacteroides fragilis strain 638R comparing an fur deletion mutant with the wild-type strain grown in minimal defined media with iron-replete, iron-limiting, heme-replete and heme-limiting conditions. The construction of the fur mutant analyzed in this study was described in Robertson KP, Smith CJ, Gough AM, Rocha ER. 2006. Characterization of Bacteroides fragilis hemolysins and regulation and synergistic interactions of HlyA and HlyB. Infect Immun. 74:2304-2316.