Mapping glycan binding profiles of the gut microbes using novel liquid glycan array

• Author / Creator

  Yadav, Pravina

• The role of glycan binding of gut microbes has been shown in colonization and interactions between microbiota and host. While glycan binding of selected pathogens has been explored in a targeted way, there has been limited research on glycan binding patterns of gut commensals. This has partially been limited by tools available to assess glycan binding. In this thesis a novel Liquid glycan array (LiGA), which comprises a library of glycosylated M13 phage particles with silent DNA barcodes in the phage genome, was used to test glycan binding profiles of gut bacteria. The potential role of glycan binding in host specificity of Limosilactobacillus reuteri was explored by comparing 16 L. reuteri strains consisting of 4 isolates from each of murine, porcine, poultry and human lineages. Many of the enriched glycans were shared amongst L. reuteri isolates, however, there was no evidence that isolates from the same host shared greater glycan binding similarity, thus glycan binding profile did not appear to be a key determinant of host specificity. However, some strains showed notable unique glycan enrichment. In particular a poultry isolate L. reuteri JCM1081 showed the drastically higher enrichment of Fucα1-2Galβ-Sp (Fold change (FC) = 88, FDR < 0.0001) and Galβ1-4Glcβ-P4 (FC = 46, FDR < 0.0001). The unique binding profile of this isolate conforms with observations of enhanced adhesive capacity to gut epithelial cells.
  Next, to understand the profiles of glycan binding of other bacterial species, we tested glycan binding of taxonomically diverse bacteria from three different phyla Firmicutes/Bacillota, Bacteroidetes/Bacteroidota, Proteobacteria/Pseudomonadota consisting of 9 different species L. reuteri, Escherichia coli, Bacteroides dorei, Bacteroides thetaiotamicron, Bacteroides fragilis, Bacteroides vulgatus, Limosilactobacillus mucosae, Citrobacter fruendii, and Clostridium ramosum. Results indicate that the taxonomic closeness leads to similar glycan binding of gut bacteria with few exceptions.
  We established that LiGA is an effective new tool for characterizing glycan binding of bacteria. Exploring glycan binding profiles of more commensal bacteria using this novel approach will provide new insights into intestinal microbial ecology and provide strategies to manipulate the microbial community through the provision of glycans.

• Subjects / Keywords

  • Glycan binding proteins
  • glycans
  • L. reuteri
  • Glycan array

• Graduation date

  Fall 2022

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-s63c-5x22

• License

  This thesis is made available by the University of Alberta Library with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.