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21 results on '"Tauzin, Alexandra S."'

5. A discrete genetic locus confers xyloglucan metabolism in select human gut Bacteroidetes

Author

Larsbrink, Johan, Rogers, Theresa E., Hemsworth, Glyn R., McKee, Lauren S., Tauzin, Alexandra S., Spadiut, Oliver, Klinter, Stefan, Pudlo, Nicholas A., Urs, Karthik, Koropatkin, Nicole M., Creagh, A. Louise, Haynes, Charles A., Kelly, Amelia G., Cederholm, Stefan Nilsson, Davies, Gideon J., Martens, Eric C., and Brumer, Harry

Subjects
Metabolism -- Genetic aspects, Microbiota (Symbiotic organisms) -- Genetic aspects -- Physiological aspects, Xyloglucans -- Genetic aspects -- Physiological aspects, Quantitative trait loci -- Physiological aspects, Environmental issues, Science and technology, Zoology and wildlife conservation
Abstract

A well-balanced human diet includes a significant intake of non-starch polysaccharides, collectively termed 'dietary fibre', from the cell walls of diverse fruits and vegetables (1). Owing to the paucity of alimentary enzymes encoded by the human genome (2), our ability to derive energy from dietary fibre depends on the saccharification and fermentation of complex carbohydrates by the massive microbial community residing in our distal gut (3,4). The xyloglucans (XyGs) are a ubiquitous family of highly branched plant cell wall polysaccharides (5,6) whose mechanism(s) of degradation in the human gut and consequent importance in nutrition have been unclear (1,7,8). Here we demonstrate that a single, complex gene locus in Bacteroides ovatus confers XyG catabolism in this common colonic symbiont. Through targeted gene disruption, biochemical analysis of all predicted glycoside hydrolases and carbohydrate-binding proteins, and three-dimensional structural determination of the vanguard endo-xyloglucanase, we reveal the molecular mechanisms through which XyGs are hydrolysed to component monosaccharides for further metabolism. We also observe that orthologous XyG utilization loci (XyGULs) serve as genetic markers of XyG catabolism in Bacteroidetes, that XyGULs are restricted to a limited number of phylogenetically diverse strains, and that XyGULs are ubiquitous in surveyed human metagenomes. Our findings reveal that the metabolism of even highly abundant components of dietary fibre maybe mediated by niche species, which has immediate fundamental and practical implications for gut symbiont population ecology in the context of human diet, nutrition and health (9-12)., Despite our omnivory, a census of the glycoside hydrolases (GHs) encoded by the human genome indicates that our inherent ability to digest carbohydrates is restricted to starch and simple saccharides [...]

Published
2014

6. α-Galactosidase and Sucrose-Kinase Relationships in a Bi-functional AgaSK Enzyme Produced by the Human Gut Symbiont Ruminococcus gnavus E1

Author

Lafond, Mickael, primary, Tauzin, Alexandra S., additional, Bruel, Laetitia, additional, Laville, Elisabeth, additional, Lombard, Vincent, additional, Esque, Jérémy, additional, André, Isabelle, additional, Vidal, Nicolas, additional, Pompeo, Frédérique, additional, Quinson, Nathalie, additional, Perrier, Josette, additional, Fons, Michel, additional, Potocki-Veronese, Gabrielle, additional, and Giardina, Thierry, additional

Published
2020
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9. Investigating Host Microbiota Relationships Through Functional Metagenomics

Author

Laville, Elisabeth, primary, Perrier, Josette, additional, Bejar, Nada, additional, Maresca, Marc, additional, Esque, Jeremy, additional, Tauzin, Alexandra S., additional, Bouhajja, Emna, additional, Leclerc, Marion, additional, Drula, Elodie, additional, Henrissat, Bernard, additional, Berdah, Stephane, additional, Di Pasquale, Eric, additional, Robe, Patrick, additional, and Potocki-Veronese, Gabrielle, additional

Published
2019
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12. Highly Promiscuous Oxidases Discovered in the Bovine Rumen Microbiome

Author

Ufarté, Lisa, primary, Potocki-Veronese, Gabrielle, additional, Cecchini, Davide, additional, Tauzin, Alexandra S., additional, Rizzo, Angeline, additional, Morgavi, Diego P., additional, Cathala, Bernard, additional, Moreau, Céline, additional, Cleret, Megane, additional, Robe, Patrick, additional, Klopp, Christophe, additional, and Laville, Elisabeth, additional

Published
2018
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14. Functional characterization of a gene locus from an uncultured gut Bacteroides conferring xylo‐oligosaccharides utilization to Escherichia coli

Author

Tauzin, Alexandra S., primary, Laville, Elisabeth, additional, Xiao, Yao, additional, Nouaille, Sébastien, additional, Le Bourgeois, Pascal, additional, Heux, Stéphanie, additional, Portais, Jean‐Charles, additional, Monsan, Pierre, additional, Martens, Eric C., additional, Potocki‐Veronese, Gabrielle, additional, and Bordes, Florence, additional

Published
2016
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18. Functional characterization of a vacuolar invertase from Solanum lycopersicum: Post-translational regulation by N-glycosylation and a proteinaceous inhibitor

Author

Tauzin, Alexandra S., primary, Sulzenbacher, Gerlind, additional, Lafond, Mickael, additional, Desseaux, Véronique, additional, Reca, Ida Barbara, additional, Perrier, Josette, additional, Bellincampi, Daniela, additional, Fourquet, Patrick, additional, Lévêque, Christian, additional, and Giardina, Thierry, additional

Published
2014
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19. Additional file 1 of Investigating host-microbiome interactions by droplet based microfluidics

Author

Tauzin, Alexandra S., Pereira, Mariana Rangel, Vliet, Liisa D. Van, Pierre-Yves Colin, Laville, Elisabeth, Esque, Jeremy, Laguerre, Sandrine, Henrissat, Bernard, Terrapon, Nicolas, Lombard, Vincent, Leclerc, Marion, Doré, Joël, Hollfelder, Florian, and Potocki-Veronese, Gabrielle

Subjects
3. Good health
Abstract

Additional file 1. Supplemental information including additional figures and tables. Fig. S1 Quantification of resorufin-β-GalNAc leakage between droplets at pH 8 and pH 9. Fig. S2 Activity of the different clones isolated at pH 9, quantified in liquid medium on resorufin-β-GalNAc. Fig. S3 SDS-PAGE analysis of cell extracts from clones 1 to 5 compared with control. Fig. S4 HPAEC-PAD analysis of human glycans hydrolyzed by the different clones and by the purified Uhgb_GH123 enzyme. Fig. S5 Abundance and prevalence in the human gut microbiome of European healthy and IBD affected individuals of the genes encoding the characterized GH123s. Fig. S6 Illustrations for the microfluidics-based screening. Table S1. Summary of the clonal redundancy identified by Sanger sequencing of the metagenomic DNA extremities. Table S2. Activity of the different clones on X-β-GalNAc and X-β-GlcNAc. Table S4. Repetition of droplet-based microfluidic screening. Table S5. Summary of the kinetic parameters of the characterized members of the GH123 family, including the Uhgb_GH123. Table S6. Estimated costs of screening 90 x 20,000 clones or 1.8 .106 experiments in microfluidic droplets compared to an automated robotic system.

20. Additional file 1 of Investigating host-microbiome interactions by droplet based microfluidics

Author

Tauzin, Alexandra S., Pereira, Mariana Rangel, Vliet, Liisa D. Van, Pierre-Yves Colin, Laville, Elisabeth, Esque, Jeremy, Laguerre, Sandrine, Henrissat, Bernard, Terrapon, Nicolas, Lombard, Vincent, Leclerc, Marion, Doré, Joël, Hollfelder, Florian, and Potocki-Veronese, Gabrielle

Subjects
3. Good health
Abstract

Additional file 1. Supplemental information including additional figures and tables. Fig. S1 Quantification of resorufin-β-GalNAc leakage between droplets at pH 8 and pH 9. Fig. S2 Activity of the different clones isolated at pH 9, quantified in liquid medium on resorufin-β-GalNAc. Fig. S3 SDS-PAGE analysis of cell extracts from clones 1 to 5 compared with control. Fig. S4 HPAEC-PAD analysis of human glycans hydrolyzed by the different clones and by the purified Uhgb_GH123 enzyme. Fig. S5 Abundance and prevalence in the human gut microbiome of European healthy and IBD affected individuals of the genes encoding the characterized GH123s. Fig. S6 Illustrations for the microfluidics-based screening. Table S1. Summary of the clonal redundancy identified by Sanger sequencing of the metagenomic DNA extremities. Table S2. Activity of the different clones on X-β-GalNAc and X-β-GlcNAc. Table S4. Repetition of droplet-based microfluidic screening. Table S5. Summary of the kinetic parameters of the characterized members of the GH123 family, including the Uhgb_GH123. Table S6. Estimated costs of screening 90 x 20,000 clones or 1.8 .106 experiments in microfluidic droplets compared to an automated robotic system.

21. Sucrose 6 F -phosphate phosphorylase: a novel insight in the human gut microbiome.

Author

Tauzin AS, Bruel L, Laville E, Nicoletti C, Navarro D, Henrissat B, Perrier J, Potocki-Veronese G, Giardina T, and Lafond M

Subjects
Animals, Humans, Intestines microbiology, Mice, Mice, Inbred C57BL, Substrate Specificity, Sucrose metabolism, Clostridiales enzymology, Gastrointestinal Microbiome, Glycoside Hydrolases chemistry, Glycoside Hydrolases classification, Glycoside Hydrolases genetics, Sucrose analogs & derivatives, Sugar Phosphates metabolism
Abstract

The human gut microbiome plays an essential role in maintaining human health including in degradation of dietary fibres and carbohydrates further used as nutrients by both the host and the gut bacteria. Previously, we identified a polysaccharide utilization loci (PUL) involved in sucrose and raffinose family oligosaccharide (RFO) metabolism from one of the most common Firmicutes present in individuals, Ruminococcus gnavus E1. One of the enzymes encoded by this PUL was annotated as a putative sucrose phosphate phosphorylase (RgSPP). In the present study, we have in-depth characterized the heterologously expressed RgSPP as sucrose 6 F -phosphate phosphorylase (SPP), expanding our knowledge of the glycoside hydrolase GH13_18 subfamily. Specifically, the enzymatic characterization showed a selective activity on sucrose 6 F -phosphate (S6 F P) acting both in phosphorolysis releasing alpha-d-glucose-1-phosphate (G1P) and alpha-d-fructose-6-phosphate (F6P), and in reverse phosphorolysis from G1P and F6P to S6 F P. Interestingly, such a SPP activity had never been observed in gut bacteria before. In addition, a phylogenetic and synteny analysis showed a clustering and a strictly conserved PUL organization specific to gut bacteria. However, a wide prevalence and abundance study with a human metagenomic library showed a correlation between SPP activity and the geographical origin of the individuals and, thus, most likely linked to diet. Rgspp gene overexpression has been observed in mice fed with a high-fat diet suggesting, as observed for humans, that intestine lipid and carbohydrate microbial metabolisms are intertwined. Finally, based on the genomic environment analysis, in vitro and in vivo studies, results provide new insights into the gut microbiota catabolism of sucrose, RFOs and S6 F P.

Published
2019
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