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ABSTRACT:
PROVIDER: PRJNA133887 | ENA |
REPOSITORIES: ENA
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Project description:This SuperSeries is composed of the following subset Series: GSE25572: Depolymerization of plant cell wall glycans by symbiotic human gut bacteria (Bacteroides thetaiotaomicron) GSE25575: Depolymerization of plant cell wall glycans by symbiotic human gut bacteria (Bacteroides ovatus) Refer to individual Series
2011-05-01 | E-GEOD-25576 | biostudies-arrayexpress
Project description:Symbiotic bacteria inhabiting the distal human gut have evolved under intense pressure to utilize complex carbohydrates, predominantly plant cell wall glycans abundant in our diets. These substrates are recalcitrant to depolymerization by digestive enzymes encoded in the human genome, but are efficiently targeted by some of the ~103-104 bacterial species that inhabit this niche. These species augment our comparatively narrow carbohydrate digestive capacity by unlocking otherwise unusable sugars and fermenting them into host-absorbable forms, such as short-chain fatty acids. We used phenotype profiling, whole-genome transcriptional analysis and molecular genetic approaches to investigate complex glycan utilization by two fully sequenced and closely related human gut symbionts: Bacteroides thetaiotaomicron and Bacteroides ovatus. Together these species target all of the common glycosidic linkages found in the plant cell wall, as well as host polysaccharides, but each species exhibits a unique ‘glycan niche’: in vitro B. thetaiotaomicron targets plant cell wall pectins in addition to linkages contained in host N- and O-glycans; B. ovatus uniquely targets hemicellulosic polysaccharides along with several pectins, but is deficient in host glycan utilization. Bacteroides ovatus bacteria were grown either in vitro on defined complex glycan sources, or in vivo in the intestinal tract of gnotobiotic mice fed variable diets. Increased in vitro gene expression was used to indicate the genes required for metabolism of complex glycans and compared to in vivo transcriptional activity to determine expression in the mouse gut.
2011-05-01 | E-GEOD-25575 | biostudies-arrayexpress
Project description:Depolymerization of plant cell wall glycans by symbiotic human gut bacteria (Bacteroides thetaiotaomicron)
| PRJNA142409 | ENA
Project description:Depolymerization of plant cell wall glycans by symbiotic human gut bacteria (Bacteroides ovatus)
| PRJNA142411 | ENA
Project description:Symbiotic bacteria inhabiting the distal human gut have evolved under intense pressure to utilize complex carbohydrates, predominantly plant cell wall glycans abundant in our diets. These substrates are recalcitrant to depolymerization by digestive enzymes encoded in the human genome, but are efficiently targeted by some of the ~103-104 bacterial species that inhabit this niche. These species augment our comparatively narrow carbohydrate digestive capacity by unlocking otherwise unusable sugars and fermenting them into host-absorbable forms, such as short-chain fatty acids. We used phenotype profiling, whole-genome transcriptional analysis and molecular genetic approaches to investigate complex glycan utilization by two fully sequenced and closely related human gut symbionts: Bacteroides thetaiotaomicron and Bacteroides ovatus. Together these species target all of the common glycosidic linkages found in the plant cell wall, as well as host polysaccharides, but each species exhibits a unique ‘glycan niche’: in vitro B. thetaiotaomicron targets plant cell wall pectins in addition to linkages contained in host N- and O-glycans; B. ovatus uniquely targets hemicellulosic polysaccharides along with several pectins, but is deficient in host glycan utilization.
2011-05-01 | GSE25572 | GEO
Project description:Symbiotic bacteria inhabiting the distal human gut have evolved under intense pressure to utilize complex carbohydrates, predominantly plant cell wall glycans abundant in our diets. These substrates are recalcitrant to depolymerization by digestive enzymes encoded in the human genome, but are efficiently targeted by some of the ~103-104 bacterial species that inhabit this niche. These species augment our comparatively narrow carbohydrate digestive capacity by unlocking otherwise unusable sugars and fermenting them into host-absorbable forms, such as short-chain fatty acids. We used phenotype profiling, whole-genome transcriptional analysis and molecular genetic approaches to investigate complex glycan utilization by two fully sequenced and closely related human gut symbionts: Bacteroides thetaiotaomicron and Bacteroides ovatus. Together these species target all of the common glycosidic linkages found in the plant cell wall, as well as host polysaccharides, but each species exhibits a unique ‘glycan niche’: in vitro B. thetaiotaomicron targets plant cell wall pectins in addition to linkages contained in host N- and O-glycans; B. ovatus uniquely targets hemicellulosic polysaccharides along with several pectins, but is deficient in host glycan utilization.
2011-05-01 | GSE25575 | GEO
Project description:Symbiotic bacteria inhabiting the distal human gut have evolved under intense pressure to utilize complex carbohydrates, predominantly plant cell wall glycans abundant in our diets. These substrates are recalcitrant to depolymerization by digestive enzymes encoded in the human genome, but are efficiently targeted by some of the ~103-104 bacterial species that inhabit this niche. These species augment our comparatively narrow carbohydrate digestive capacity by unlocking otherwise unusable sugars and fermenting them into host-absorbable forms, such as short-chain fatty acids. We used phenotype profiling, whole-genome transcriptional analysis and molecular genetic approaches to investigate complex glycan utilization by two fully sequenced and closely related human gut symbionts: Bacteroides thetaiotaomicron and Bacteroides ovatus. Together these species target all of the common glycosidic linkages found in the plant cell wall, as well as host polysaccharides, but each species exhibits a unique ‘glycan niche’: in vitro B. thetaiotaomicron targets plant cell wall pectins in addition to linkages contained in host N- and O-glycans; B. ovatus uniquely targets hemicellulosic polysaccharides along with several pectins, but is deficient in host glycan utilization. Growth of Bacteroides thetaiotaomicron in vitro in minimal medium plus different purified complex glycans. Observation of increased gene expression was used to determine genes that are involved in metabolism of each glycan. Two biological replicates each.
2011-05-01 | E-GEOD-25572 | biostudies-arrayexpress
Project description:The large-scale application of genomic and metagenomic sequencing technologies has yielded a number of insights about the metabolic potential of symbiotic human gut microbes. Bacteria that colonize the mucosal layer that overlies the gut epithelium have access to highly-sulfated polysaccharides (i.e., mucin oligosaccharides and glycosaminoglycans), which they could potentially forage as nutrient sources. To be active, sulfatases must undergo a critical post-translational modification catalyzed in anaerobic bacteria by the AdoMet enzyme anSME (anaerobic Sulfatase-Maturating Enzyme). In the present study, we have tested the role of this pathway in the prominent gut symbiont Bacteroides thetaiotaomicron, which possesses more predicted sulfatases (28) than in the human genome and a single predicted anSME. In vitro studies revealed that deletion of its anSME (BT0238) results in loss of sulfatase activity and impaired ability to use sulfated polysaccharides as carbon sources. Co-colonization of germ-free animals with both isogenic strains, or invasion experiments involving the introduction of one then the other strain, established that anSME activity and the sulfatases that are activated via this pathway, are important fitness factors for B. thetaiotaomicron, especially when mice are fed a simple sugar diet that requires this saccharolytic bacterium to adaptively forage on host glycans as nutrients. Whole genome transcriptional profiling of wild-type and the anSME mutant in vivo revealed that loss of this enzyme alters expression of genes involved in mucin utilization and that this disrupted ability to access mucosal glycans likely underlies the observed dramatic colonization defect. Comparative genomic analysis reveals that 100% of 46 fully sequenced human gut Bacteroidetes contain homologs of BT0238 and genes encoding sulfatases, suggesting that this is an important and evolutionarily conserved feature. Three replicate samples from 4 different biological treatment groups: 1. Wild-type B. thetaiotaomicron from the cecum of gnotobiotic mice fed a simple-sugar diet; 2. chuR mutant B. thetaiotaomicron from the cecum of gnotobiotic mice fed a simple-sugar diet; 3. Wild-type B. thetaiotaomicron from the cecum of gnotobiotic mice fed a plant-rich diet; 4. chuR mutant B. thetaiotaomicron from the cecum of gnotobiotic mice fed a plant-rich diet.
2011-01-01 | E-GEOD-25415 | biostudies-arrayexpress
Project description:The large-scale application of genomic and metagenomic sequencing technologies has yielded a number of insights about the metabolic potential of symbiotic human gut microbes. Bacteria that colonize the mucosal layer that overlies the gut epithelium have access to highly-sulfated polysaccharides (i.e., mucin oligosaccharides and glycosaminoglycans), which they could potentially forage as nutrient sources. To be active, sulfatases must undergo a critical post-translational modification catalyzed in anaerobic bacteria by the AdoMet enzyme anSME (anaerobic Sulfatase-Maturating Enzyme). In the present study, we have tested the role of this pathway in the prominent gut symbiont Bacteroides thetaiotaomicron, which possesses more predicted sulfatases (28) than in the human genome and a single predicted anSME. In vitro studies revealed that deletion of its anSME (BT0238) results in loss of sulfatase activity and impaired ability to use sulfated polysaccharides as carbon sources. Co-colonization of germ-free animals with both isogenic strains, or invasion experiments involving the introduction of one then the other strain, established that anSME activity and the sulfatases that are activated via this pathway, are important fitness factors for B. thetaiotaomicron, especially when mice are fed a simple sugar diet that requires this saccharolytic bacterium to adaptively forage on host glycans as nutrients. Whole genome transcriptional profiling of wild-type and the anSME mutant in vivo revealed that loss of this enzyme alters expression of genes involved in mucin utilization and that this disrupted ability to access mucosal glycans likely underlies the observed dramatic colonization defect. Comparative genomic analysis reveals that 100% of 46 fully sequenced human gut Bacteroidetes contain homologs of BT0238 and genes encoding sulfatases, suggesting that this is an important and evolutionarily conserved feature.
2011-01-01 | GSE25415 | GEO
Project description:Symbiotic interactions between humans and our communities of resident gut microbes (microbiota) play many roles in health and disease. Some gut bacteria utilize mucus as a nutrient source and can under certain conditions damage the protective barrier it forms, increasing disease susceptibility. We investigated how Ruminococcus torques—a known mucin-degrader that remains poorly studied despite its implication in inflammatory bowel diseases (IBDs)— degrades mucin glycoproteins or their component O-linked glycans to understand its effects on the availability of mucin-derived nutrients for other bacteria. We found that R. torques utilizes both mucin glycoproteins and released oligosaccharides from gastric and colonic mucins, degrading these substrates with a panoply of mostly constitutively expressed, secreted enzymes. Investigation of mucin oligosaccharide degradation by R. torques revealed strong fucosidase, sialidase and b1,4-galactosidase activities. There was a lack of detectable sulfatase and weak β1,3-galactosidase degradation, resulting in accumulation of glycans containing these structures on mucin polypeptides. While the Gram-negative symbiont, Bacteroides thetaiotaomicron grows poorly on mucin glycoproteins, we demonstrate a clear ability of R. torques to liberate products from mucins, making them accessible to B. thetaiotaomicron. This work underscores the diversity of mucin-degrading mechanisms in different bacterial species and the probability that some species are contingent on others for the ability to more fully access mucin-derived nutrients. The ability of R. torques to directly degrade a variety of mucin and mucin glycan structures and unlock released glycans for other species suggests that it is a keystone mucin degrader, which may contribute to its association with IBD.
2024-06-19 | GSE262875 | GEO