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Marizcurrena JJ, Herrera LM, Costábile A, Morales D, Villadóniga C, Eizmendi A, Davyt D, Castro-Sowinski S. Validating biochemical features at the genome level in the Antarctic bacterium Hymenobacter sp. strain UV11. FEMS Microbiol Lett 2020; 366:5545592. [PMID: 31397847 DOI: 10.1093/femsle/fnz177] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 08/08/2019] [Indexed: 12/13/2022] Open
Abstract
We present experimental data that complement and validate some biochemical features at the genome level in the UVC-resistant Antarctic bacterium Hymenobacter sp. UV11 strain. The genome was sequenced, assembled and annotated. It has 6 096 246 bp, a GC content of 60.6% and 5155 predicted genes. The secretome analysis, by combining in silico predictions with shotgun proteomics data, showed that UV11 strain produces extracellular proteases and carbohydrases with potential biotechnological uses. We observed the formation of outer membrane vesicles, mesosomes and carbon-storage compounds by using transmission electron microscopy. The in silico analysis of the genome revealed the presence of genes involved in the metabolism of glycogen-like molecules and starch. By HPLC-UV-Vis analysis and 1H-NMR spectra, we verified that strain UV11 produces xanthophyll-like carotenoids such as 2'-hydroxyflexixanthin, and the in silico analysis showed that this bacterium has genes involved in the biosynthesis of cathaxanthin, zeaxanthin and astaxanthin. We also found genes involved in the repair of UV-damaged DNA such as a photolyase, the nucleotide excision repair system and the production of ATP-dependent proteases that are important cellular components involved in the endurance to physiological stresses. This information will help us to better understand the ecological role played by Hymenobacter strains in the extreme Antarctic environment.
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Affiliation(s)
- Juan José Marizcurrena
- Biochemistry and Molecular Biology, Faculty of Sciences, Universidad de la República, Igua 4225, 11400 Montevideo, Uruguay
| | - Lorena M Herrera
- Biochemistry and Molecular Biology, Faculty of Sciences, Universidad de la República, Igua 4225, 11400 Montevideo, Uruguay
| | - Alicia Costábile
- Biochemistry and Molecular Biology, Faculty of Sciences, Universidad de la República, Igua 4225, 11400 Montevideo, Uruguay
| | - Danilo Morales
- Biochemistry and Molecular Biology, Faculty of Sciences, Universidad de la República, Igua 4225, 11400 Montevideo, Uruguay
| | - Carolina Villadóniga
- Hydrolytic Enzymes Laboratory, Faculty of Sciences, Universidad de la República, Igua 4225, 11400 Montevideo, Uruguay
| | - Agustina Eizmendi
- Organic Chemistry Department, Faculty of Chemistry, Universidad de la República, General Flores 2124, 11800 Montevideo, Uruguay
| | - Danilo Davyt
- Organic Chemistry Department, Faculty of Chemistry, Universidad de la República, General Flores 2124, 11800 Montevideo, Uruguay
| | - Susana Castro-Sowinski
- Biochemistry and Molecular Biology, Faculty of Sciences, Universidad de la República, Igua 4225, 11400 Montevideo, Uruguay.,Hydrolytic Enzymes Laboratory, Faculty of Sciences, Universidad de la República, Igua 4225, 11400 Montevideo, Uruguay
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Lopez-Santamarina A, Mondragon ADC, Lamas A, Miranda JM, Franco CM, Cepeda A. Animal-Origin Prebiotics Based on Chitin: An Alternative for the Future? A Critical Review. Foods 2020; 9:E782. [PMID: 32545663 PMCID: PMC7353569 DOI: 10.3390/foods9060782] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 06/03/2020] [Accepted: 06/10/2020] [Indexed: 02/07/2023] Open
Abstract
The human gut microbiota has been revealed in recent years as a factor that plays a decisive role in the maintenance of human health, as well as in the development of many non-communicable diseases. This microbiota can be modulated by various dietary factors, among which complex carbohydrates have a great influence. Although most complex carbohydrates included in the human diet come from vegetables, there are also options to include complex carbohydrates from non-vegetable sources, such as chitin and its derivatives. Chitin, and its derivatives such as chitosan can be obtained from non-vegetable sources, the best being insects, crustacean exoskeletons and fungi. The present review offers a broad perspective of the current knowledge surrounding the impacts of chitin and its derived polysaccharides on the human gut microbiota and the profound need for more in-depth investigations into this topic. Overall, the effects of whole insects or meal on the gut microbiota have contradictory results, possibly due to their high protein content. Better results are obtained for the case of chitin derivatives, regarding both metabolic effects and effects on the gut microbiota composition.
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Affiliation(s)
| | | | | | | | | | - Alberto Cepeda
- Laboratorio de Higiene Inspección y Control de Alimentos. Departamento de Química Analítica, Nutrición y Bromatología, Facultad de Veterinaria, Universidade de Santiago de Compostela, 27002 Lugo, Spain; (A.L.-S.); (A.d.C.M.); (A.L.); (J.M.M.); (C.M.F.)
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103
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Gong X, Li X, Bo A, Shi RY, Li QY, Lei LJ, Zhang L, Li MH. The interactions between gut microbiota and bioactive ingredients of traditional Chinese medicines: A review. Pharmacol Res 2020; 157:104824. [PMID: 32344049 DOI: 10.1016/j.phrs.2020.104824] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Revised: 03/09/2020] [Accepted: 04/06/2020] [Indexed: 02/06/2023]
Abstract
In recent years, the interaction between the bioactive ingredients of traditional Chinese medicine (TCM) and gut microbiota has been a focus of many studies. When TCM enters the digestive tract, some bioactive ingredients are not absorbed into the gut well thus leading to low bioavailability. Ingredients of TCM are metabolised, or biotransformed by gut microbiota, thereby producing new bioactive molecules, and promote medicine absorption into the circulation. At the same time, the ingredients of TCM effect the composition and structure of gut microbiota, thereby influencing the remote function of diseased organs / tissues through the systemic action of the gut microbiota. In this review, we summarise the gut microbiota-mediated metabolism of flavonoids, alkaloids, terpenoids, saponins, polysaccharides, phenylpropanoids, and organic acids, along with a discussion on the metabolites formed and the biotransformation pathways involving various enzymes. We also highlight the importance of bioactive ingredients of TCM in regulating gut microbiota.
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Affiliation(s)
- Xue Gong
- Baotou Medical College, Baotou, Inner Mongolia, China
| | - Xue Li
- Inner Mongolia Medical University, Hohhot, Inner Mongolia, China
| | - Agula Bo
- Baotou Medical College, Baotou, Inner Mongolia, China
| | - Ru-Yu Shi
- Baotou Medical College, Baotou, Inner Mongolia, China
| | - Qin-Yu Li
- Baotou Medical College, Baotou, Inner Mongolia, China
| | - Lu-Jing Lei
- Inner Mongolia Institute of Traditional Chinese Medicine, Hohhot, Inner Mongolia, China
| | - Lei Zhang
- Inner Mongolia Medical University, Hohhot, Inner Mongolia, China
| | - Min-Hui Li
- Baotou Medical College, Baotou, Inner Mongolia, China; Inner Mongolia Medical University, Hohhot, Inner Mongolia, China; Inner Mongolia Institute of Traditional Chinese Medicine, Hohhot, Inner Mongolia, China; Qiqihar Medical University, Qiqihar, Heilongjiang, China; Inner Mongolia Key Laboratory of Characteristic Geoherbs Resources and Utilization, Baotou Medical College, Baotou, Inner Mongolia, China.
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104
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Cultivable, Host-Specific Bacteroidetes Symbionts Exhibit Diverse Polysaccharolytic Strategies. Appl Environ Microbiol 2020; 86:AEM.00091-20. [PMID: 32060023 DOI: 10.1128/aem.00091-20] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 02/07/2020] [Indexed: 02/06/2023] Open
Abstract
Beneficial gut microbes can facilitate insect growth on diverse diets. The omnivorous American cockroach, Periplaneta americana (Insecta: Blattodea), thrives on a diet rich in plant polysaccharides and harbors a species-rich gut microbiota responsive to host diet. Bacteroidetes are among the most abundant taxa in P. americana and other cockroaches, based on cultivation-independent gut community profiling, and these potentially polysaccharolytic bacteria may contribute to host diet processing. Eleven Bacteroidetes isolates were cultivated from P. americana digestive tracts, and phylogenomic analyses suggest that they were new Bacteroides, Dysgonomonas, Paludibacter, and Parabacteroides species distinct from those previously isolated from other insects, humans, and environmental sources. In addition, complete genomes were generated for each isolate, and polysaccharide utilization loci (PULs) and several non-PUL-associated carbohydrate-active enzyme (CAZyme)-coding genes that putatively target starch, pectin, and/or cellulose were annotated in each of the isolate genomes. Type IX secretion system (T9SS)- and CAZyme-coding genes tagged with the corresponding T9SS recognition and export C-terminal domain were observed in some isolates, suggesting that these CAZymes were deployed via non-PUL outer membrane translocons. Additionally, single-substrate growth and enzymatic assays confirmed genomic predictions that a subset of the Bacteroides and Dysgonomonas isolates could degrade starch, pectin, and/or cellulose and grow in the presence of these substrates as a single sugar source. Plant polysaccharides enrich P. americana diets, and many of these gut isolates are well equipped to exploit host dietary inputs and potentially contribute to gut community and host nutrient accessibility.IMPORTANCE Gut microbes are increasingly being recognized as critical contributors to nutrient accessibility in animals. The globally distributed omnivorous American cockroach (Periplaneta americana) harbors many bacterial phyla (e.g., Bacteroidetes) that are abundant in vertebrates. P. americana thrives on a highly diverse plant-enriched diet, making this insect a rich potential source of uncharacterized polysaccharolytic bacteria. We have cultivated, completely sequenced, and functionally characterized several novel Bacteroidetes species that are endemic to the P. americana gut, and many of these isolates can degrade simple and complex polysaccharides. Cultivation and genomic characterization of these Bacteroidetes isolates further enable deeper insight into how these taxa participate in polysaccharide metabolism and, more broadly, how they affect animal health and development.
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105
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Lee YM, Baek K, Lee DH, Park Y, Shin SC, Jin YK. Antarcticibacterium arcticum sp. nov., a bacterium isolated from marine sediment of the Canadian Beaufort Sea. Int J Syst Evol Microbiol 2020; 70:2912-2917. [PMID: 32213252 DOI: 10.1099/ijsem.0.004122] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A Gram-stain-negative, aerobic, yellow-pigmented, flexirubin-negative, rod-shaped and non-motile bacterial strain, PAMC 28998T, was isolated from a surface sediment sample collected from the Canadian Beaufort Sea. Strain PAMC 28998T grew at 4-37 °C (optimum, 25 °C), at pH 7.0-9.0 (optimum, pH 7.5) and in the presence of 1.0-10.0 % (w/v) NaCl. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain PAMC 28998T belongs to the genus Antarcticibacterium showing the highest sequence similarity (96.8 %) with Antarcticibacterium flavum JB01H24T. The average nucleotide identity and genome-to-genome distance values between PAMC 28998T and the most closely related species (A. flavum JB01H24T) were 74.1 and 18.5 %, respectively, indicating that strain PAMC 28998T is clearly distinguished from A. flavum. The genomic DNA G+C content calculated from genome sequences was 39.8 %. The major fatty acids (>10 %) were iso-C15 : 0 (19.5 %), anteiso-C15 : 0 (18.0 %), iso-C16 : 0 (11.6 %) and summed feature 3 (C16:1 ω6c and/or C16:1 ω7c; 11.4 %). The major polar lipids were phosphatidylethanolamine, aminoglycolipid, two unidentified aminolipids, three unidentified phospholipids and four unidentified lipids. The major respiratory quinone was MK-6. Based on the phylogenetic, genomic and phenotypic data presented here, strain PAMC 28998T is considered to represent a novel species of the genus Antarcticibacterium, for which the name Antarcticibacterium arcticum sp. nov. is proposed with the strain PAMC 28998T (=KCCM 43316 T=JCM 33514T).
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Affiliation(s)
- Yung Mi Lee
- Division of Polar Life Sciences, Korea Polar Research Institute, 26 Songdomirae-ro, Yeonsu-gu, Incheon 21990, Republic of Korea
| | - Kiwoon Baek
- Bioresources Collection & Research Division, Nakdonggang National Institute of Biological Resources, 137 Donam 2-gil, Sangju 37242, Republic of Korea.,Department of Biological Sciences, Inha University, Inha-ro 100, Incheon 22212, Republic of Korea
| | - Dong-Hun Lee
- Hanyang University ERICA Campus, Hanyangdaehak-ro, Sangrok-gu, Ansan 15588, Republic of Korea
| | - Yerin Park
- Division of Polar Life Sciences, Korea Polar Research Institute, 26 Songdomirae-ro, Yeonsu-gu, Incheon 21990, Republic of Korea
| | - Seung Chul Shin
- Division of Polar Life Sciences, Korea Polar Research Institute, 26 Songdomirae-ro, Yeonsu-gu, Incheon 21990, Republic of Korea
| | - Young Keun Jin
- Division of Polar Earth-System Sciences, Korea Polar Research Institute, 26 Songdomirae-ro, Yeonsu-gu, Incheon 21990, Republic of Korea
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106
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Ancestry and adaptive radiation of Bacteroidetes as assessed by comparative genomics. Syst Appl Microbiol 2020; 43:126065. [DOI: 10.1016/j.syapm.2020.126065] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 12/20/2019] [Accepted: 01/16/2020] [Indexed: 11/19/2022]
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107
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Bendiks ZA, Knudsen KEB, Keenan MJ, Marco ML. Conserved and variable responses of the gut microbiome to resistant starch type 2. Nutr Res 2020; 77:12-28. [PMID: 32251948 DOI: 10.1016/j.nutres.2020.02.009] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 01/31/2020] [Accepted: 02/14/2020] [Indexed: 12/12/2022]
Abstract
Resistant starch type 2 (RS2), a dietary fiber comprised solely of glucose, has been extensively studied in clinical trials and animal models for its capacity to improve metabolic and systemic health. Because the health modulatory effects of RS2 and other dietary fibers are thought to occur through modification of the gut microbiome, those studies frequently include assessments of RS2-mediated changes to intestinal microbial composition and function. In this review, we identify the conserved responses of the gut microbiome among 13 human and 35 animal RS2 intervention studies. Consistent outcomes of RS2 interventions include reductions in bacterial α-diversity; increased production of lumenal short-chain fatty acids; and enrichment of Ruminococcus bromii, Bifidobacterium adolescentis, and other gut taxa. Different taxa are usually responsive in animal models, and many RS2-mediated changes to the gut microbiome vary within and between studies. The root causes for this variation are examined with regard to methodological and analytical differences, host genetics and age, species differences (eg, human, animal), health status, intervention dose and duration, and baseline microbial composition. The significant variation found for this single dietary compound highlights the challenges in targeting the gut microbiome to improve health with dietary interventions. This knowledge on RS2 also provides opportunities to improve the design of nutrition studies targeting the gut microbiome and to ultimately identify the precise mechanisms via which dietary fiber benefits human health.
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Affiliation(s)
- Zachary A Bendiks
- Department of Food Science & Technology, University of California-Davis, Davis, CA.
| | - Knud E B Knudsen
- Department of Animal Science, Aarhus University, 8830, Tjele, Denmark.
| | - Michael J Keenan
- School of Nutrition and Food Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA.
| | - Maria L Marco
- Department of Food Science & Technology, University of California-Davis, Davis, CA.
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108
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Resistant starch: impact on the gut microbiome and health. Curr Opin Biotechnol 2020; 61:66-71. [DOI: 10.1016/j.copbio.2019.10.008] [Citation(s) in RCA: 89] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 10/14/2019] [Accepted: 10/21/2019] [Indexed: 12/31/2022]
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109
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Cerqueira FM, Photenhauer AL, Pollet RM, Brown HA, Koropatkin NM. Starch Digestion by Gut Bacteria: Crowdsourcing for Carbs. Trends Microbiol 2020; 28:95-108. [DOI: 10.1016/j.tim.2019.09.004] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 08/29/2019] [Accepted: 09/09/2019] [Indexed: 12/12/2022]
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110
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Jones DR, Xing X, Tingley JP, Klassen L, King ML, Alexander TW, Abbott DW. Analysis of Active Site Architecture and Reaction Product Linkage Chemistry Reveals a Conserved Cleavage Substrate for an Endo-alpha-mannanase within Diverse Yeast Mannans. J Mol Biol 2020; 432:1083-1097. [PMID: 31945375 DOI: 10.1016/j.jmb.2019.12.048] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 12/16/2019] [Accepted: 12/17/2019] [Indexed: 01/06/2023]
Abstract
Yeast α-mannan (YM) is a densely branched N-linked glycan that decorates the surface of yeast cell walls. Owing to the high degree of branching, cleavage of the backbone of YM appears to rely on the coupled action of side-chain-cleaving enzymes. Upon examining the genome sequences of bovine-adapted Bacteroides thetaiotaomicron strains, isolated for their ability to degrade YM, we have identified a tandem pair of genes inserted into an orphan pathway predicted to be involved in YM metabolism. Here, we investigated the activity of one of these enzymes, a predicted endo-mannanase from glycoside hydrolase (GH) family 76 (BtGH76-MD40). Purified recombinant BtGH76-MD40 displayed activity on structurally distinct YMs from Saccharomyces cerevisiae and Schizosaccharomyces pombe. Linkage analysis of released oligosaccharide products from S. cerevisiae and S. pombe mannan determined BtGH76-MD40 targets a specific linkage that is conserved in structurally diverse YM substrates. In addition, using two differential derivatization methods, we have shown that there is an absolute requirement for undecorated d-mannopyranose in the -1 subsite. Determination of the BtGH76-MD40 X-ray crystal structure and structural superimposition and molecular docking of a branched alpha-mannopentatose substrate supported these findings. In contrast, BtGH76-MD40 can accommodate extended side chains in the +1 and -2 subsites, highlighting that a single alpha-1,6-mannosyl residue is a prerequisite for activity, and cleavage occurs at the reducing end of the undecorated monosaccharide. Collectively these results demonstrate how acquisition of new enzymes within extant pathways contributes to the functional abilities of saccharolytic bacteria persisting in complex digestive ecosystems.
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Affiliation(s)
- Darryl R Jones
- Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, Lethbridge, Alberta, T1J 4B1, Canada; Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, Alberta, T1K 3M4, Canada
| | - Xiaohui Xing
- Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, Lethbridge, Alberta, T1J 4B1, Canada; Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, Alberta, T1K 3M4, Canada
| | - Jeffrey P Tingley
- Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, Lethbridge, Alberta, T1J 4B1, Canada
| | - Leeann Klassen
- Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, Lethbridge, Alberta, T1J 4B1, Canada
| | - Marissa L King
- Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, Lethbridge, Alberta, T1J 4B1, Canada
| | - Trevor W Alexander
- Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, Lethbridge, Alberta, T1J 4B1, Canada
| | - D Wade Abbott
- Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, Lethbridge, Alberta, T1J 4B1, Canada; Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, Alberta, T1K 3M4, Canada.
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Abstract
Prebiotics are increasingly used as food supplements, especially in infant formulas, to modify the functioning and composition of the microbiota. However, little is currently known about the mechanisms of prebiotic recognition and transport by gut bacteria, while these steps are crucial in their metabolism. In this study, we established a new strategy to profile the specificity of oligosaccharide transporters, combining microbiomics, genetic locus and strain engineering, and state-of-the art metabolomics. We revisited the transporter classification database and proposed a new way to classify these membrane proteins based on their structural and mechanistic similarities. Based on these developments, we identified and characterized, at the molecular level, a fructooligosaccharide transporting phosphotransferase system, which constitutes a biomarker of diet and gut pathology. The deciphering of this prebiotic metabolization mechanism by a nonbeneficial bacterium highlights the controversial use of prebiotics, especially in the context of chronic gut diseases. Prebiotic oligosaccharides, such as fructooligosaccharides, are increasingly being used to modulate the composition and activity of the gut microbiota. However, carbohydrate utilization analyses and metagenomic studies recently revealed the ability of deleterious and uncultured human gut bacterial species to metabolize these functional foods. Moreover, because of the difficulties of functionally profiling transmembrane proteins, only a few prebiotic transporters have been biochemically characterized to date, while carbohydrate binding and transport are the first and thus crucial steps in their metabolization. Here, we describe the molecular mechanism of a phosphotransferase system, highlighted as a dietary and pathology biomarker in the human gut microbiome. This transporter is encoded by a metagenomic locus that is highly conserved in several human gut Firmicutes, including Dorea species. We developed a generic strategy to deeply analyze, in vitro and in cellulo, the specificity and functionality of recombinant transporters in Escherichia coli, combining carbohydrate utilization locus and host genome engineering and quantification of the binding, transport, and growth rates with analysis of phosphorylated carbohydrates by mass spectrometry. We demonstrated that the Dorea fructooligosaccharide transporter is specific for kestose, whether for binding, transport, or phosphorylation. This constitutes the biochemical proof of effective phosphorylation of glycosides with a degree of polymerization of more than 2, extending the known functional diversity of phosphotransferase systems. Based on these new findings, we revisited the classification of these carbohydrate transporters. IMPORTANCE Prebiotics are increasingly used as food supplements, especially in infant formulas, to modify the functioning and composition of the microbiota. However, little is currently known about the mechanisms of prebiotic recognition and transport by gut bacteria, while these steps are crucial in their metabolism. In this study, we established a new strategy to profile the specificity of oligosaccharide transporters, combining microbiomics, genetic locus and strain engineering, and state-of-the art metabolomics. We revisited the transporter classification database and proposed a new way to classify these membrane proteins based on their structural and mechanistic similarities. Based on these developments, we identified and characterized, at the molecular level, a fructooligosaccharide transporting phosphotransferase system, which constitutes a biomarker of diet and gut pathology. The deciphering of this prebiotic metabolization mechanism by a nonbeneficial bacterium highlights the controversial use of prebiotics, especially in the context of chronic gut diseases.
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112
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Larsbrink J, McKee LS. Bacteroidetes bacteria in the soil: Glycan acquisition, enzyme secretion, and gliding motility. ADVANCES IN APPLIED MICROBIOLOGY 2020; 110:63-98. [PMID: 32386606 DOI: 10.1016/bs.aambs.2019.11.001] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The secretion of extracellular enzymes by soil microbes is rate-limiting in the recycling of biomass. Fungi and bacteria compete and collaborate for nutrients in the soil, with wide ranging ecological impacts. Within soil microbiota, the Bacteroidetes tend to be a dominant phylum, just like in human and animal intestines. The Bacteroidetes thrive because of their ability to secrete diverse arrays of carbohydrate-active enzymes (CAZymes) that target the highly varied glycans in the soil. Bacteroidetes use an energy-saving system of genomic organization, whereby most of their CAZymes are grouped into Polysaccharide Utilization Loci (PULs). These loci enable high level production of specific CAZymes only when their substrate glycans are abundant in the local environment. This gives the Bacteroidetes a clear advantage over other species in the competitive soil environment, further enhanced by the phylum-specific Type IX Secretion System (T9SS). The T9SS is highly effective at secreting CAZymes and/or tethering them to the cell surface, and is tightly coupled to the ability to rapidly glide over solid surfaces, a connection that promotes an active hunt for nutrition. Although the soil Bacteroidetes are less well studied than human gut symbionts, research is uncovering important biochemical and physiological phenomena. In this review, we summarize the state of the art on research into the CAZymes secreted by soil Bacteroidetes in the contexts of microbial soil ecology and the discovery of novel CAZymes for use in industrial biotechnology. We hope that this review will stimulate further investigations into the somewhat neglected enzymology of non-gut Bacteroidetes.
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Affiliation(s)
- Johan Larsbrink
- Wallenberg Wood Science Center, Gothenburg and Stockholm, Sweden; Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Lauren Sara McKee
- Wallenberg Wood Science Center, Gothenburg and Stockholm, Sweden; Division of Glycoscience, Department of Chemistry, KTH Royal Institute of Technology, AlbaNova University Centre, Stockholm, Sweden.
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Kmezik C, Bonzom C, Olsson L, Mazurkewich S, Larsbrink J. Multimodular fused acetyl-feruloyl esterases from soil and gut Bacteroidetes improve xylanase depolymerization of recalcitrant biomass. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:60. [PMID: 32266006 PMCID: PMC7110780 DOI: 10.1186/s13068-020-01698-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 03/16/2020] [Indexed: 05/04/2023]
Abstract
BACKGROUND Plant biomass is an abundant and renewable carbon source that is recalcitrant towards both chemical and biochemical degradation. Xylan is the second most abundant polysaccharide in biomass after cellulose, and it possesses a variety of carbohydrate substitutions and non-carbohydrate decorations which can impede enzymatic degradation by glycoside hydrolases. Carbohydrate esterases are able to cleave the ester-linked decorations and thereby improve the accessibility of the xylan backbone to glycoside hydrolases, thus improving the degradation process. Enzymes comprising multiple catalytic glycoside hydrolase domains on the same polypeptide have previously been shown to exhibit intramolecular synergism during degradation of biomass. Similarly, natively fused carbohydrate esterase domains are encoded by certain bacteria, but whether these enzymes can result in similar synergistic boosts in biomass degradation has not previously been evaluated. RESULTS Two carbohydrate esterases with similar architectures, each comprising two distinct physically linked catalytic domains from families 1 (CE1) and 6 (CE6), were selected from xylan-targeting polysaccharide utilization loci (PULs) encoded by the Bacteroidetes species Bacteroides ovatus and Flavobacterium johnsoniae. The full-length enzymes as well as the individual catalytic domains showed activity on a range of synthetic model substrates, corn cob biomass, and Japanese beechwood biomass, with predominant acetyl esterase activity for the N-terminal CE6 domains and feruloyl esterase activity for the C-terminal CE1 domains. Moreover, several of the enzyme constructs were able to substantially boost the performance of a commercially available xylanase on corn cob biomass (close to twofold) and Japanese beechwood biomass (up to 20-fold). Interestingly, a significant improvement in xylanase biomass degradation was observed following addition of the full-length multidomain enzyme from B. ovatus versus the addition of its two separated single domains, indicating an intramolecular synergy between the esterase domains. Despite high sequence similarities between the esterase domains from B. ovatus and F. johnsoniae, their addition to the xylanolytic reaction led to different degradation patterns. CONCLUSION We demonstrated that multidomain carbohydrate esterases, targeting the non-carbohydrate decorations on different xylan polysaccharides, can considerably facilitate glycoside hydrolase-mediated hydrolysis of xylan and xylan-rich biomass. Moreover, we demonstrated for the first time a synergistic effect between the two fused catalytic domains of a multidomain carbohydrate esterase.
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Affiliation(s)
- Cathleen Kmezik
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - Cyrielle Bonzom
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - Lisbeth Olsson
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden
- Wallenberg Wood Science Center, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - Scott Mazurkewich
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden
- Wallenberg Wood Science Center, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - Johan Larsbrink
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden
- Wallenberg Wood Science Center, Chalmers University of Technology, 412 96 Gothenburg, Sweden
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Tang KY, Wang ZW, Wan QH, Fang SG. Metagenomics Reveals Seasonal Functional Adaptation of the Gut Microbiome to Host Feeding and Fasting in the Chinese Alligator. Front Microbiol 2019; 10:2409. [PMID: 31708889 PMCID: PMC6824212 DOI: 10.3389/fmicb.2019.02409] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 10/07/2019] [Indexed: 12/20/2022] Open
Abstract
As a natural hibernator, the Chinese alligator (Alligator sinensis) is an ideal and intriguing model to investigate changes in microbial community structure and function caused by hibernation. In this study, we used 16S rRNA profiling and metagenomic analysis to compare the composition, diversity, and functional capacity in the gut microbiome of hibernating vs. active Chinese alligators. Our results show that gut microbial communities undergo seasonal restructuring in response to seasonal cycles of feeding and fasting in the Chinese alligator, but this animal harbors a core gut microbial community primarily dominated by Proteobacteria, Fusobacteria, Bacteroidetes, and Firmicutes across the gut regions. During hibernation, there is an increase in the abundance of bacterial taxa (e.g., the genus Bacteroides) that can degrade host mucin glycans, which allows adaptation to winter fasting. This is accompanied by the enrichment of mucin oligosaccharide-degrading enzyme and carbohydrate-active enzyme families. In contrast, during the active phase (feeding), active Chinese alligators exhibit a carnivore gut microbiome dominated by Fusobacteria, and there is an increase in the relative abundance of bacteria (e.g., Cetobacterium somerae) with known proteolytic and amino acids-fermentating functions that improve host protein-rich food digestion efficiency. In addition, seasonal variations in the expression of β-defensins play a protective role in intestinal immunity. These findings provide insights into the functional adaptations of host-gut microbe symbioses to seasonal dietary shifts to maintain gut homeostasis and health, especially in extreme physiological states.
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Affiliation(s)
- Ke-Yi Tang
- MOE Key Laboratory of Biosystems Homeostasis & Protection, State Conservation Centre for Gene Resources of Endangered Wildlife, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Zhen-Wei Wang
- Changxing Yinjiabian Chinese Alligator Nature Reserve, Changxing, China
| | - Qiu-Hong Wan
- MOE Key Laboratory of Biosystems Homeostasis & Protection, State Conservation Centre for Gene Resources of Endangered Wildlife, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Sheng-Guo Fang
- MOE Key Laboratory of Biosystems Homeostasis & Protection, State Conservation Centre for Gene Resources of Endangered Wildlife, College of Life Sciences, Zhejiang University, Hangzhou, China
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115
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Déjean G, Tauzin AS, Bennett SW, Creagh AL, Brumer H. Adaptation of Syntenic Xyloglucan Utilization Loci of Human Gut Bacteroidetes to Polysaccharide Side Chain Diversity. Appl Environ Microbiol 2019; 85:e01491-19. [PMID: 31420336 PMCID: PMC6805095 DOI: 10.1128/aem.01491-19] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 08/08/2019] [Indexed: 12/16/2022] Open
Abstract
Genome sequencing has revealed substantial variation in the predicted abilities of individual species within animal gut microbiota to metabolize the complex carbohydrates comprising dietary fiber. At the same time, a currently limited body of functional studies precludes a richer understanding of how dietary glycan structures affect the gut microbiota composition and community dynamics. Here, using biochemical and biophysical techniques, we identified and characterized differences among recombinant proteins from syntenic xyloglucan utilization loci (XyGUL) of three Bacteroides and one Dysgonomonas species from the human gut, which drive substrate specificity and access to distinct polysaccharide side chains. Enzymology of four syntenic glycoside hydrolase family 5 subfamily 4 (GH5_4) endo-xyloglucanases revealed surprising differences in xyloglucan (XyG) backbone cleavage specificity, including the ability of some homologs to hydrolyze congested branched positions. Further, differences in the complement of GH43 alpha-l-arabinofuranosidases and GH95 alpha-l-fucosidases among syntenic XyGUL confer distinct abilities to fully saccharify plant species-specific arabinogalactoxyloglucan and/or fucogalactoxyloglucan. Finally, characterization of highly sequence-divergent cell surface glycan-binding proteins (SGBPs) across syntenic XyGUL revealed a novel group of XyG oligosaccharide-specific SGBPs encoded within select BacteroidesIMPORTANCE The catabolism of complex carbohydrates that otherwise escape the endogenous digestive enzymes of humans and other animals drives the composition and function of the gut microbiota. Thus, detailed molecular characterization of dietary glycan utilization systems is essential both to understand the ecology of these complex communities and to manipulate their compositions, e.g., to benefit human health. Our research reveals new insight into how ubiquitous members of the human gut microbiota have evolved a set of microheterogeneous gene clusters to efficiently respond to the structural variations of plant xyloglucans. The data here will enable refined functional prediction of xyloglucan utilization among diverse environmental taxa in animal guts and beyond.
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Affiliation(s)
- Guillaume Déjean
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | - Alexandra S Tauzin
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | - Stuart W Bennett
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | - A Louise Creagh
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, British Columbia, Canada
| | - Harry Brumer
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
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116
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Comparative genomic analyses reveal diverse virulence factors and antimicrobial resistance mechanisms in clinical Elizabethkingia meningoseptica strains. PLoS One 2019; 14:e0222648. [PMID: 31600234 PMCID: PMC6786605 DOI: 10.1371/journal.pone.0222648] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 09/03/2019] [Indexed: 12/31/2022] Open
Abstract
Three human clinical isolates of bacteria (designated strains Em1, Em2 and Em3) had high average nucleotide identity (ANI) to Elizabethkingia meningoseptica. Their genome sizes (3.89, 4.04 and 4.04 Mb) were comparable to those of other Elizabethkingia species and strains, and exhibited open pan-genome characteristics, with two strains being nearly identical and the third divergent. These strains were susceptible only to trimethoprim/sulfamethoxazole and ciprofloxacin amongst 16 antibiotics in minimum inhibitory tests. The resistome exhibited a high diversity of resistance genes, including 5 different lactamase- and 18 efflux protein- encoding genes. Forty-four genes encoding virulence factors were conserved among the strains. Sialic acid transporters and curli synthesis genes were well conserved in E. meningoseptica but absent in E. anophelis and E. miricola. E. meningoseptica carried several genes contributing to biofilm formation. 58 glycoside hydrolases (GH) and 25 putative polysaccharide utilization loci (PULs) were found. The strains carried numerous genes encoding two-component system proteins (56), transcription factor proteins (187~191), and DNA-binding proteins (6~7). Several prophages and CRISPR/Cas elements were uniquely present in the genomes.
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117
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Cabral DJ, Penumutchu S, Reinhart EM, Zhang C, Korry BJ, Wurster JI, Nilson R, Guang A, Sano WH, Rowan-Nash AD, Li H, Belenky P. Microbial Metabolism Modulates Antibiotic Susceptibility within the Murine Gut Microbiome. Cell Metab 2019; 30:800-823.e7. [PMID: 31523007 PMCID: PMC6948150 DOI: 10.1016/j.cmet.2019.08.020] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 06/24/2019] [Accepted: 08/20/2019] [Indexed: 12/22/2022]
Abstract
Although antibiotics disturb the structure of the gut microbiota, factors that modulate these perturbations are poorly understood. Bacterial metabolism is an important regulator of susceptibility in vitro and likely plays a large role within the host. We applied a metagenomic and metatranscriptomic approach to link antibiotic-induced taxonomic and transcriptional responses within the murine microbiome. We found that antibiotics significantly alter the expression of key metabolic pathways at the whole-community and single-species levels. Notably, Bacteroides thetaiotaomicron, which blooms in response to amoxicillin, upregulated polysaccharide utilization. In vitro, we found that the sensitivity of this bacterium to amoxicillin was elevated by glucose and reduced by polysaccharides. Accordingly, we observed that dietary composition affected the abundance and expansion of B. thetaiotaomicron, as well as the extent of microbiome disruption with amoxicillin. Our work indicates that the metabolic environment of the microbiome plays a role in the response of this community to antibiotics.
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Affiliation(s)
- Damien J Cabral
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI 02906, USA
| | - Swathi Penumutchu
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI 02906, USA
| | - Elizabeth M Reinhart
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI 02906, USA
| | - Cheng Zhang
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN 55904, USA
| | - Benjamin J Korry
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI 02906, USA
| | - Jenna I Wurster
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI 02906, USA
| | - Rachael Nilson
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI 02906, USA
| | - August Guang
- Center for Computation & Visualization, Brown University, Brown University, Providence, RI 02906, USA; Center for Computational Biology of Human Disease, Brown University, Providence, RI 02906, USA
| | - William H Sano
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI 02906, USA
| | - Aislinn D Rowan-Nash
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI 02906, USA
| | - Hu Li
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN 55904, USA
| | - Peter Belenky
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI 02906, USA.
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118
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Janeček Š, Mareček F, MacGregor EA, Svensson B. Starch-binding domains as CBM families-history, occurrence, structure, function and evolution. Biotechnol Adv 2019; 37:107451. [PMID: 31536775 DOI: 10.1016/j.biotechadv.2019.107451] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 08/01/2019] [Accepted: 09/15/2019] [Indexed: 01/05/2023]
Abstract
The term "starch-binding domain" (SBD) has been applied to a domain within an amylolytic enzyme that gave the enzyme the ability to bind onto raw, i.e. thermally untreated, granular starch. An SBD is a special case of a carbohydrate-binding domain, which in general, is a structurally and functionally independent protein module exhibiting no enzymatic activity but possessing potential to target the catalytic domain to the carbohydrate substrate to accommodate it and process it at the active site. As so-called families, SBDs together with other carbohydrate-binding modules (CBMs) have become an integral part of the CAZy database (http://www.cazy.org/). The first two well-described SBDs, i.e. the C-terminal Aspergillus-type and the N-terminal Rhizopus-type have been assigned the families CBM20 and CBM21, respectively. Currently, among the 85 established CBM families in CAZy, fifteen can be considered as families having SBD functional characteristics: CBM20, 21, 25, 26, 34, 41, 45, 48, 53, 58, 68, 69, 74, 82 and 83. All known SBDs, with the exception of the extra long CBM74, were recognized as a module consisting of approximately 100 residues, adopting a β-sandwich fold and possessing at least one carbohydrate-binding site. The present review aims to deliver and describe: (i) the SBD identification in different amylolytic and related enzymes (e.g., CAZy GH families) as well as in other relevant enzymes and proteins (e.g., laforin, the β-subunit of AMPK, and others); (ii) information on the position in the polypeptide chain and the number of SBD copies and their CBM family affiliation (if appropriate); (iii) structure/function studies of SBDs with a special focus on solved tertiary structures, in particular, as complexes with α-glucan ligands; and (iv) the evolutionary relationships of SBDs in a tree common to all SBD CBM families (except for the extra long CBM74). Finally, some special cases and novel potential SBDs are also introduced.
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Affiliation(s)
- Štefan Janeček
- Laboratory of Protein Evolution, Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, SK-84551 Bratislava, Slovakia; Department of Biology, Faculty of Natural Sciences, University of SS. Cyril and Methodius, Nám. J. Herdu 2, SK-91701 Trnava, Slovakia.
| | - Filip Mareček
- Laboratory of Protein Evolution, Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, SK-84551 Bratislava, Slovakia; Department of Biology, Faculty of Natural Sciences, University of SS. Cyril and Methodius, Nám. J. Herdu 2, SK-91701 Trnava, Slovakia
| | - E Ann MacGregor
- 2 Nicklaus Green, Livingston EH54 8RX, West Lothian, United Kingdom
| | - Birte Svensson
- Enzyme and Protein Chemistry, Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, Building 224, DK-2800 Kgs. Lyngby, Denmark
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119
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Khan I, Ullah N, Zha L, Bai Y, Khan A, Zhao T, Che T, Zhang C. Alteration of Gut Microbiota in Inflammatory Bowel Disease (IBD): Cause or Consequence? IBD Treatment Targeting the Gut Microbiome. Pathogens 2019; 8:pathogens8030126. [PMID: 31412603 PMCID: PMC6789542 DOI: 10.3390/pathogens8030126] [Citation(s) in RCA: 397] [Impact Index Per Article: 79.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 08/03/2019] [Accepted: 08/05/2019] [Indexed: 02/06/2023] Open
Abstract
Inflammatory bowel disease (IBD) is a chronic complex inflammatory gut pathological condition, examples of which include Crohn’s disease (CD) and ulcerative colitis (UC), which is associated with significant morbidity. Although the etiology of IBD is unknown, gut microbiota alteration (dysbiosis) is considered a novel factor involved in the pathogenesis of IBD. The gut microbiota acts as a metabolic organ and contributes to human health by performing various physiological functions; deviation in the gut flora composition is involved in various disease pathologies, including IBD. This review aims to summarize the current knowledge of gut microbiota alteration in IBD and how this contributes to intestinal inflammation, as well as explore the potential role of gut microbiota-based treatment approaches for the prevention and treatment of IBD. The current literature has clearly demonstrated a perturbation of the gut microbiota in IBD patients and mice colitis models, but a clear causal link of cause and effect has not yet been presented. In addition, gut microbiota-based therapeutic approaches have also shown good evidence of their effects in the amelioration of colitis in animal models (mice) and IBD patients, which indicates that gut flora might be a new promising therapeutic target for the treatment of IBD. However, insufficient data and confusing results from previous studies have led to a failure to define a core microbiome associated with IBD and the hidden mechanism of pathogenesis, which suggests that well-designed randomized control trials and mouse models are required for further research. In addition, a better understanding of this ecosystem will also determine the role of prebiotics and probiotics as therapeutic agents in the management of IBD.
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Affiliation(s)
- Israr Khan
- School of Life Sciences, Lanzhou University, Lanzhou 730000, China
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, Lanzhou University, Lanzhou 730000, China
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, Lanzhou University, Lanzhou 730000, China
| | - Naeem Ullah
- School of Life Sciences, Lanzhou University, Lanzhou 730000, China
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, Lanzhou University, Lanzhou 730000, China
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, Lanzhou University, Lanzhou 730000, China
| | - Lajia Zha
- School of Life Sciences, Lanzhou University, Lanzhou 730000, China
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, Lanzhou University, Lanzhou 730000, China
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, Lanzhou University, Lanzhou 730000, China
| | - Yanrui Bai
- School of Life Sciences, Lanzhou University, Lanzhou 730000, China
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, Lanzhou University, Lanzhou 730000, China
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, Lanzhou University, Lanzhou 730000, China
| | - Ashiq Khan
- School of Life Sciences, Lanzhou University, Lanzhou 730000, China
- Probiotics and Biological Feed Research Center, Lanzhou University, Lanzhou 730000, China
| | - Tang Zhao
- School of Life Sciences, Lanzhou University, Lanzhou 730000, China
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, Lanzhou University, Lanzhou 730000, China
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, Lanzhou University, Lanzhou 730000, China
| | - Tuanjie Che
- Gansu Key Laboratory of Functional Genomics and Molecular Diagnosis, Lanzhou 730000, China
| | - Chunjiang Zhang
- School of Life Sciences, Lanzhou University, Lanzhou 730000, China.
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, Lanzhou University, Lanzhou 730000, China.
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, Lanzhou University, Lanzhou 730000, China.
- Gansu Key Laboratory of Functional Genomics and Molecular Diagnosis, Lanzhou 730000, China.
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120
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Santilli AD, Russell JT, Triplett EW, Whitehead KJ, Whitehead DC. Non-lethal growth inhibition by arresting the starch utilization system of clinically relevant human isolates of Bacteroides dorei. MEDCHEMCOMM 2019; 10:1875-1880. [PMID: 32280435 DOI: 10.1039/c9md00301k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 07/04/2019] [Indexed: 12/14/2022]
Abstract
We describe the inhibition of the starch utilization system (Sus) belonging to various strains of Bacteroides dorei in a non-lethal manner using the small molecule probe, acarbose. Concentrations of acarbose as low as 5 μM significantly impede the growth of B. dorei and increase the doubling time of cultures. The successful inhibition of this species of Bacteroides is relevant to several disease states including type I diabetes mellitus. This method continues to explore a new, potential route to intervene in illnesses associated with aberrant changes in the composition of the human gut microbiota through the strategic manipulation of its constituents.
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Affiliation(s)
- Anthony D Santilli
- Department of Chemistry , Clemson University , Clemson , SC 29631 , USA .
| | - Jordan T Russell
- Department of Microbiology and Cell Science , University of Florida , Gainesville , FL 32611 , USA
| | - Eric W Triplett
- Department of Microbiology and Cell Science , University of Florida , Gainesville , FL 32611 , USA
| | - Kristi J Whitehead
- Department of Biological Sciences , Clemson University , Clemson , SC 29631 , USA .
| | - Daniel C Whitehead
- Department of Chemistry , Clemson University , Clemson , SC 29631 , USA .
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121
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Characterization of a novel extracellular α-amylase from Ruminococcus bromii ATCC 27255 with neopullulanase-like activity. Int J Biol Macromol 2019; 130:605-614. [DOI: 10.1016/j.ijbiomac.2019.03.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2018] [Revised: 03/01/2019] [Accepted: 03/01/2019] [Indexed: 01/06/2023]
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122
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Hehemann JH, Reintjes G, Klassen L, Smith AD, Ndeh D, Arnosti C, Amann R, Abbott DW. Single cell fluorescence imaging of glycan uptake by intestinal bacteria. ISME JOURNAL 2019; 13:1883-1889. [PMID: 30936421 PMCID: PMC6776043 DOI: 10.1038/s41396-019-0406-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 12/03/2018] [Accepted: 02/27/2019] [Indexed: 01/15/2023]
Abstract
Microbes in the intestines of mammals degrade dietary glycans for energy and growth. The pathways required for polysaccharide utilization are functionally diverse; moreover, they are unequally dispersed between bacterial genomes. Hence, assigning metabolic phenotypes to genotypes remains a challenge in microbiome research. Here we demonstrate that glycan uptake in gut bacteria can be visualized with fluorescent glycan conjugates (FGCs) using epifluorescence microscopy. Yeast α-mannan and rhamnogalacturonan-II, two structurally distinct glycans from the cell walls of yeast and plants, respectively, were fluorescently labeled and fed to Bacteroides thetaiotaomicron VPI-5482. Wild-type cells rapidly consumed the FGCs and became fluorescent; whereas, strains that had deleted pathways for glycan degradation and transport were non-fluorescent. Uptake of FGCs, therefore, is direct evidence of genetic function and provides a direct method to assess specific glycan metabolism in intestinal bacteria at the single cell level.
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Affiliation(s)
- Jan-Hendrik Hehemann
- Max Planck-Institute for Marine Microbiology, 28359, Bremen, Germany. .,Center for Marine Environmental Sciences, University of Bremen (MARUM), 28359, Bremen, Germany.
| | - Greta Reintjes
- Max Planck-Institute for Marine Microbiology, 28359, Bremen, Germany
| | - Leeann Klassen
- Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, 5403-1st Avenue South, Lethbridge, AB, T1J 4B1, Canada
| | - Adam D Smith
- Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, 5403-1st Avenue South, Lethbridge, AB, T1J 4B1, Canada
| | - Didier Ndeh
- Institute for Cell and Molecular Biosciences, The Medical School Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Carol Arnosti
- Department of Marine Sciences, University of North Carolina, Chapel Hill, NC, USA
| | - Rudolf Amann
- Max Planck-Institute for Marine Microbiology, 28359, Bremen, Germany
| | - D Wade Abbott
- Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, 5403-1st Avenue South, Lethbridge, AB, T1J 4B1, Canada.
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123
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Foley MH, Déjean G, Hemsworth GR, Davies GJ, Brumer H, Koropatkin NM. A Cell-Surface GH9 Endo-Glucanase Coordinates with Surface Glycan-Binding Proteins to Mediate Xyloglucan Uptake in the Gut Symbiont Bacteroides ovatus. J Mol Biol 2019; 431:981-995. [PMID: 30668971 PMCID: PMC6478033 DOI: 10.1016/j.jmb.2019.01.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 12/14/2018] [Accepted: 01/04/2019] [Indexed: 01/07/2023]
Abstract
Dietary fiber is an important food source for members of the human gut microbiome. Members of the dominant Bacteroidetes phylum capture diverse polysaccharides via the action of multiple cell surface proteins encoded within polysaccharide utilization loci (PUL). The independent activities of PUL-encoded glycoside hydrolases (GHs) and surface glycan-binding proteins (SGBPs) for the harvest of various glycans have been studied in detail, but how these proteins work together to coordinate uptake is poorly understood. Here, we combine genetic and biochemical approaches to discern the interplay between the BoGH9 endoglucanase and the xyloglucan-binding proteins SGBP-A and SGBP-B from the Bacteroides ovatus xyloglucan utilization locus (XyGUL). The expression of BoGH9, a weakly active xyloglucanase in isolation, is required in a strain that expresses a non-binding version of SGBP-A (SGBP-A*). The crystal structure of the BoGH9 enzyme suggests the molecular basis for its robust activity on mixed-linkage β-glucan compared to xyloglucan. However, catalytically inactive site-directed mutants of BoGH9 fail to complement the deletion of the active BoGH9 in a SGBP-A* strain. We also find that SGBP-B is needed in an SGBP-A* background to support growth on xyloglucan, but that the non-binding SGBP-B* protein acts in a dominant negative manner to inhibit growth on xyloglucan. We postulate a model whereby the SGBP-A, SGBP-B, and BoGH9 work together at the cell surface, likely within a discrete complex, and that xyloglucan binding by SGBP-B and BoGH9 may facilitate the orientation of the xyloglucan for transfer across the outer membrane.
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Affiliation(s)
- Matthew H Foley
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Guillaume Déjean
- Michael Smith Laboratories, University of British Columbia, 2185 East Mall, Vancouver, BC V6T 1Z4, Canada
| | - Glyn R Hemsworth
- York Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York YO10 5DD, UK
| | - Gideon J Davies
- York Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York YO10 5DD, UK
| | - Harry Brumer
- Michael Smith Laboratories, University of British Columbia, 2185 East Mall, Vancouver, BC V6T 1Z4, Canada; Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada; Department of Biochemistry and Molecular Biology, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| | - Nicole M Koropatkin
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
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124
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Wang M, Xie Z, Li L, Chen Y, Li Y, Wang Y, Lu B, Zhang S, Ma F, Ma C, Lin L, Liao Q. Supplementation with compound polysaccharides contributes to the development and metabolic activity of young rat intestinal microbiota. Food Funct 2019; 10:2658-2675. [DOI: 10.1039/c8fo02565g] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Compound polysaccharides may be used as a functional food to modulate the composition and metabolism of gut microbiota, and to help maintain the health of the intestinal microecosystem.
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Affiliation(s)
- Mengxia Wang
- School of Pharmaceutical Sciences
- Guangzhou University of Chinese Medicine
- Guangzhou
- P. R. China
| | - Zhiyong Xie
- School of Pharmaceutical Sciences (Shenzhen)
- Sun Yat-sen University
- Guangzhou
- P. R. China
- Guangdong Provincial Key Laboratory of New Drug Design and Evaluation
| | - Lin Li
- School of Pharmaceutical Sciences
- Guangzhou University of Chinese Medicine
- Guangzhou
- P. R. China
| | - Yongxiong Chen
- School of Pharmaceutical Sciences
- Guangzhou University of Chinese Medicine
- Guangzhou
- P. R. China
| | - Yuan Li
- School of Pharmaceutical Sciences
- Guangzhou University of Chinese Medicine
- Guangzhou
- P. R. China
| | | | - Biyu Lu
- School of Pharmaceutical Sciences
- Guangzhou University of Chinese Medicine
- Guangzhou
- P. R. China
| | - Shaobao Zhang
- School of Pharmaceutical Sciences (Shenzhen)
- Sun Yat-sen University
- Guangzhou
- P. R. China
| | - Fangli Ma
- Infinitus (China) Company Ltd
- Guangzhou
- China
| | | | - Lei Lin
- School of Pharmaceutical Sciences (Shenzhen)
- Sun Yat-sen University
- Guangzhou
- P. R. China
| | - Qiongfeng Liao
- School of Pharmaceutical Sciences
- Guangzhou University of Chinese Medicine
- Guangzhou
- P. R. China
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125
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Abstract
The Lpp lipoprotein of Escherichia coli is the first identified protein with a covalently linked lipid. It is chemically bound by its C-terminus to murein (peptidoglycan) and inserts by the lipid at the N-terminus into the outer membrane. As the most abundant protein in E. coli (106 molecules per cell) it plays an important role for the integrity of the cell envelope. Lpp represents the type protein of a large variety of lipoproteins found in Gram-negative and Gram-positive bacteria and in archaea that have in common the lipid structure for anchoring the proteins to membranes but otherwise strongly vary in sequence, structure, and function. Predicted lipoproteins in known prokaryotic genomes comprise 2.7% of all proteins. Lipoproteins are modified by a unique phospholipid pathway and transferred from the cytoplasmic membrane into the outer membrane by a special system. They are involved in protein incorporation into the outer membrane, protein secretion across the cytoplasmic membrane, periplasm and outer membrane, signal transduction, conjugation, cell wall metabolism, antibiotic resistance, biofilm formation, and adhesion to host tissues. They are only found in bacteria and function as signal molecules for the innate immune system of vertebrates, where they cause inflammation and elicit innate and adaptive immune response through Toll-like receptors. This review discusses various aspects of Lpp and other lipoproteins of Gram-negative and Gram-positive bacteria and archaea.
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Affiliation(s)
- Volkmar Braun
- Department of Protein Evolution, Max Planck Institute for Developmental Biology, Max Planck Ring 5, 72076, Tübingen, Germany.
| | - Klaus Hantke
- IMIT, University of Tuebingen, Auf der Morgenstelle 28, 72076, Tübingen, Germany
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126
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Ndeh D, Gilbert HJ. Biochemistry of complex glycan depolymerisation by the human gut microbiota. FEMS Microbiol Rev 2018; 42:146-164. [PMID: 29325042 DOI: 10.1093/femsre/fuy002] [Citation(s) in RCA: 157] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 01/06/2018] [Indexed: 12/21/2022] Open
Abstract
The human gut microbiota (HGM) makes an important contribution to health and disease. It is a complex microbial community of trillions of microbes with a majority of its members represented within two phyla, the Bacteroidetes and Firmicutes, although it also contains species of Actinobacteria and Proteobacteria. Reflecting its importance, the HGM is sometimes referred to as an 'organ' as it performs functions analogous to systemic tissues within the human host. The major nutrients available to the HGM are host and dietary complex carbohydrates. To utilise these nutrient sources, the HGM has developed elaborate, variable and sophisticated systems for the sensing, capture and utilisation of these glycans. Understanding nutrient acquisition by the HGM can thus provide mechanistic insights into the dynamics of this ecosystem, and how it impacts human health. Dietary nutrient sources include a wide variety of simple and complex plant and animal-derived glycans most of which are not degraded by enzymes in the digestive tract of the host. Here we review how various adaptive mechanisms that operate across the major phyla of the HGM contribute to glycan utilisation, focusing on the most complex carbohydrates presented to this ecosystem.
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Affiliation(s)
- Didier Ndeh
- Institute for Cell and Molecular Biosciences, The Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Harry J Gilbert
- Institute for Cell and Molecular Biosciences, The Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
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127
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Selfish, sharing and scavenging bacteria in the Atlantic Ocean: a biogeographical study of bacterial substrate utilisation. ISME JOURNAL 2018; 13:1119-1132. [PMID: 30531893 PMCID: PMC6474216 DOI: 10.1038/s41396-018-0326-3] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Revised: 11/06/2018] [Accepted: 11/23/2018] [Indexed: 12/12/2022]
Abstract
Identifying the roles played by individual heterotrophic bacteria in the degradation of high molecular weight (HMW) substrates is critical to understanding the constraints on carbon cycling in the ocean. At five sites in the Atlantic Ocean, we investigated the processing of organic matter by tracking changes in microbial community composition as HMW polysaccharides were enzymatically hydrolysed over time. During this investigation, we discovered that a considerable fraction of heterotrophic bacteria uses a newly-identified ‘selfish’ mode of substrate processing. We therefore additionally examined the balance of individual substrate utilisation mechanisms at different locations by linking individual microorganisms to distinct substrate utilisation mechanisms. Through FISH and uptake of fluorescently-labelled polysaccharides, ‘selfish’ organisms were identified as belonging to the Bacteroidetes, Planctomycetes and Gammaproteobacteria. ‘Sharing’ (extracellular enzyme producing) and ‘scavenging’ (non-enzyme producing) organisms predominantly belonged to the Alteromonadaceae and SAR11 clades, respectively. The extent to which individual mechanisms prevail depended on the initial population structure of the bacterial community at a given location and time, as well as the growth rate of specific bacteria. Furthermore, the same substrate was processed in different ways by different members of a pelagic microbial community, pointing to significant follow-on effects for carbon cycling.
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128
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Surface Exposure and Packing of Lipoproteins into Outer Membrane Vesicles Are Coupled Processes in Bacteroides. mSphere 2018; 3:3/6/e00559-18. [PMID: 30404931 PMCID: PMC6222051 DOI: 10.1128/msphere.00559-18] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Species from the Bacteroides genus are predominant members of the human gut microbiota. OMVs in Bacteroides have been shown to be important for the homeostasis of complex host-commensal relationships, mainly involving immune tolerance and protection from disease. OMVs carry many enzymatic activities involved in the cleavage of complex polysaccharides and have been proposed as public goods that can provide growth to other bacterial species by release of polysaccharide breakdown products into the gut lumen. This work shows that the presence of a negatively charged rich amino acid motif (LES) is required for efficient packing of the surface-exposed alpha-amylase SusG into OMVs. Our findings strongly suggest that surface exposure is coupled to packing of Bacteroides lipoproteins into OMVs. This is the first step in the generation of tailor-made probiotic interventions that can exploit LES-related sequences to generate Bacteroides strains displaying proteins of interest in OMVs. Outer membrane vesicles (OMVs) are spherical structures derived from the outer membranes (OMs) of Gram-negative bacteria. Bacteroides spp. are prominent components of the human gut microbiota, and OMVs produced by these species are proposed to play key roles in gut homeostasis. OMV biogenesis in Bacteroides is a poorly understood process. Here, we revisited the protein composition of Bacteroides thetaiotaomicron OMVs by mass spectrometry. We confirmed that OMVs produced by this organism contain large quantities of glycosidases and proteases, with most of them being lipoproteins. We found that most of these OMV-enriched lipoproteins are encoded by polysaccharide utilization loci (PULs), such as the sus operon. We examined the subcellular locations of the components of the Sus system and found a split localization; the alpha-amylase SusG is highly enriched in OMVs, while the oligosaccharide importer SusC remains mostly in the OM. We found that all OMV-enriched lipoproteins possess a lipoprotein export sequence (LES), and we show that this signal mediates translocation of SusG from the periplasmic face of the OM toward the extracellular milieu. Mutations in the LES motif caused defects in surface exposure and recruitment of SusG into OMVs. These experiments link, for the first time, surface exposure to recruitment of proteins into OMVs. We also show that surface-exposed SusG in OMVs is active and rescues the growth of bacterial cells incapable of growing on starch as the only carbon source. Our results support the role of OMVs as “public goods” that can be utilized by other organisms with different metabolic capabilities. IMPORTANCE Species from the Bacteroides genus are predominant members of the human gut microbiota. OMVs in Bacteroides have been shown to be important for the homeostasis of complex host-commensal relationships, mainly involving immune tolerance and protection from disease. OMVs carry many enzymatic activities involved in the cleavage of complex polysaccharides and have been proposed as public goods that can provide growth to other bacterial species by release of polysaccharide breakdown products into the gut lumen. This work shows that the presence of a negatively charged rich amino acid motif (LES) is required for efficient packing of the surface-exposed alpha-amylase SusG into OMVs. Our findings strongly suggest that surface exposure is coupled to packing of Bacteroides lipoproteins into OMVs. This is the first step in the generation of tailor-made probiotic interventions that can exploit LES-related sequences to generate Bacteroides strains displaying proteins of interest in OMVs.
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129
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Accetto T, Avguštin G. The diverse and extensive plant polysaccharide degradative apparatuses of the rumen and hindgut Prevotella species: A factor in their ubiquity? Syst Appl Microbiol 2018; 42:107-116. [PMID: 30853065 DOI: 10.1016/j.syapm.2018.10.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 10/02/2018] [Accepted: 10/03/2018] [Indexed: 10/28/2022]
Abstract
Although the Prevotella are commonly observed in high shares in the mammalian hindgut and rumen studies using NGS approach, the knowledge on their actual role, though postulated to lie in soluble fibre degradation, is scarce. Here we analyse in total 23, more than threefold of hitherto known rumen and hindgut Prevotella species and show that rumen/hindgut Prevotella generally possess extensive repertoires of polysaccharide utilization loci (PULs) and carbohydrate active enzymes targeting various plant polysaccharides. These PUL repertoires separate analysed Prevotella into generalists and specialists yet a finer diversity among generalists is evident too, both in range of substrates targeted and in PUL combinations targeting the same broad substrate classes. Upon evaluation of the shares of species analysed in this study in rumen metagenomes we found firstly, that they contributed significantly to total Prevotella abundance though much of rumen Prevotella diversity may still be unknown. Secondly, the hindgut Prevotella species originally isolated in pigs and humans occasionally dominated among the Prevotella with surprisingly high metagenome read shares and were consistently found in rumen metagenome samples from sites as apart as New Zealand and Scotland. This may indicate frequent passage between different hosts and relatively low barriers to their successful establishment in rumen versus the hindgut.
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Affiliation(s)
- Tomaž Accetto
- University of Ljubljana, Biotechnical faculty, Animal Science Department, Groblje 3, 1230 Domžale, Slovenia.
| | - Gorazd Avguštin
- University of Ljubljana, Biotechnical faculty, Animal Science Department, Groblje 3, 1230 Domžale, Slovenia
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130
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Chuzel L, Ganatra MB, Rapp E, Henrissat B, Taron CH. Functional metagenomics identifies an exosialidase with an inverting catalytic mechanism that defines a new glycoside hydrolase family (GH156). J Biol Chem 2018; 293:18138-18150. [PMID: 30249617 PMCID: PMC6254351 DOI: 10.1074/jbc.ra118.003302] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 09/11/2018] [Indexed: 12/24/2022] Open
Abstract
Exosialidases are glycoside hydrolases that remove a single terminal sialic acid residue from oligosaccharides. They are widely distributed in biology, having been found in prokaryotes, eukaryotes, and certain viruses. Most characterized prokaryotic sialidases are from organisms that are pathogenic or commensal with mammals. However, in this study, we used functional metagenomic screening to seek microbial sialidases encoded by environmental DNA isolated from an extreme ecological niche, a thermal spring. Using recombinant expression of potential exosialidase candidates and a fluorogenic sialidase substrate, we discovered an exosialidase having no homology to known sialidases. Phylogenetic analysis indicated that this protein is a member of a small family of bacterial proteins of previously unknown function. Proton NMR revealed that this enzyme functions via an inverting catalytic mechanism, a biochemical property that is distinct from those of known exosialidases. This unique inverting exosialidase defines a new CAZy glycoside hydrolase family we have designated GH156.
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Affiliation(s)
- Léa Chuzel
- From New England Biolabs, Ipswich, Massachusetts 01938,; the Max Planck Institute for Dynamics of Complex Technical Systems, 39106 Magdeburg, Germany
| | | | - Erdmann Rapp
- the Max Planck Institute for Dynamics of Complex Technical Systems, 39106 Magdeburg, Germany,; glyXera GmbH, 39120 Magdeburg, Germany
| | - Bernard Henrissat
- the Architecture et Fonction des Macromolécules Biologiques, CNRS, Aix-Marseille Université, F-13288 Marseille, France,; the Institut National de la Recherche Agronomique (INRA), Unité Sous Contrat (USC) 1408, Architecture et Fonction des Macromolécules Biologiques, 13288 Marseille, France, and; the Department of Biological Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia
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131
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Zhang T, Yang Y, Liang Y, Jiao X, Zhao C. Beneficial Effect of Intestinal Fermentation of Natural Polysaccharides. Nutrients 2018; 10:E1055. [PMID: 30096921 PMCID: PMC6116026 DOI: 10.3390/nu10081055] [Citation(s) in RCA: 99] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 07/27/2018] [Accepted: 08/07/2018] [Indexed: 12/11/2022] Open
Abstract
With the rapid development of modern society, many chronic diseases are increasing including diabetes, obesity, cardiovascular diseases, etc., which further cause an increased death rate worldwide. A high caloric diet with reduced natural polysaccharides, typically indigestible polysaccharides, is considered a health risk factor. With solid evidence accumulating that indigestible polysaccharides can effectively prevent and/or ameliorate symptoms of many chronic diseases, we give a narrative review of many natural polysaccharides extracted from various food resources which mainly contribute their health beneficial functions via intestinal fermentation.
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Affiliation(s)
- Tiehua Zhang
- College of Food Science and Engineering, Jilin University, Changchun 130062, Jilin, China.
| | - Yang Yang
- College of Food Science and Engineering, Jilin University, Changchun 130062, Jilin, China.
| | - Yuan Liang
- College of Food Science and Engineering, Jilin University, Changchun 130062, Jilin, China.
| | - Xu Jiao
- College of Food Science and Engineering, Jilin University, Changchun 130062, Jilin, China.
| | - Changhui Zhao
- College of Food Science and Engineering, Jilin University, Changchun 130062, Jilin, China.
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132
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TonB-dependent transport by the gut microbiota: novel aspects of an old problem. Curr Opin Struct Biol 2018; 51:35-43. [DOI: 10.1016/j.sbi.2018.03.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 03/01/2018] [Accepted: 03/03/2018] [Indexed: 12/20/2022]
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133
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Chi L, Bian X, Gao B, Tu P, Ru H, Lu K. The Effects of an Environmentally Relevant Level of Arsenic on the Gut Microbiome and Its Functional Metagenome. Toxicol Sci 2018; 160:193-204. [PMID: 28973555 DOI: 10.1093/toxsci/kfx174] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Multiple environmental factors induce dysbiosis in the gut microbiome and cause a variety of human diseases. Previously, we have first demonstrated that arsenic alters the composition of the gut microbiome. However, the functional impact of arsenic on the gut microbiome has not been adequately assessed, particularly at environmentally relevant concentrations. In this study, we used 16S rRNA sequencing and metagenomics sequencing to investigate how exposure to 100 ppb arsenic for 13 weeks alters the composition and functional capacity of the gut microbiome in mice. Arsenic exposure altered the alpha and beta diversities as well as the composition profile of the gut microbiota. Metagenomics data revealed that the abundances of genes involved in carbohydrate metabolism, especially pyruvate fermentation, short-chain fatty acid synthesis, and starch utilization, and were significantly changed. Moreover, lipopolysaccharide biosynthesis genes, multiple stress response genes, and DNA repair genes were significantly increased in the gut microbiome of arsenic-exposed mice. The genes involved in the production or processing of multiple vitamins, including folic acid and vitamins B6, B12, and K2, were also enriched in arsenic-treated mice. In, addition, genes involved in multidrug resistance and conjugative transposon proteins were highly increased after treatment with arsenic. In conclusion, we demonstrate that arsenic exposure, at an environmentally relevant dose, not only perturbed the communal composition of the gut microbiome but also profoundly altered a variety of important bacterial functional pathways.
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Affiliation(s)
- Liang Chi
- Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27519
| | - Xiaoming Bian
- Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27519
| | - Bei Gao
- Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27519.,Department of Molecular and Cellular Biology, NIH West Coast Metabolomics Center, University of California, Davis, Davis, California 95616
| | - Pengcheng Tu
- Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27519
| | - Hongyu Ru
- Department of Population Health and Pathobiology, North Carolina State University, Raleigh, North Carolina 27607
| | - Kun Lu
- Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27519
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134
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Tuson HH, Foley MH, Koropatkin NM, Biteen JS. The Starch Utilization System Assembles around Stationary Starch-Binding Proteins. Biophys J 2018; 115:242-250. [PMID: 29338841 PMCID: PMC6051301 DOI: 10.1016/j.bpj.2017.12.015] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 12/02/2017] [Accepted: 12/11/2017] [Indexed: 02/08/2023] Open
Abstract
Bacteroides thetaiotaomicron (Bt) is a prominent member of the human gut microbiota with an extensive capacity for glycan harvest. This bacterium expresses a five-protein complex in the outer membrane, called the starch utilization system (Sus), which binds, degrades, and imports starch into the cell. Sus is a model system for the many glycan-targeting polysaccharide utilization loci found in Bt and other members of the Bacteroidetes phylum. Our previous work has shown that SusG, a lipidated amylase in the outer membrane, explores the entire cell surface but diffuses more slowly as it interacts with starch. Here, we use a combination of single-molecule tracking, super-resolution imaging, reverse genetics, and proteomics to show that SusE and SusF, two proteins that bind starch, are immobile on the cell surface even when other members of the system are knocked out and under multiple different growth conditions. This observation suggests a new paradigm for protein complex formation: binding proteins form immobile complexes that transiently associate with a mobile enzyme partner.
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Affiliation(s)
- Hannah H Tuson
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan
| | - Matthew H Foley
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Nicole M Koropatkin
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan.
| | - Julie S Biteen
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan.
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135
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Santilli AD, Dawson EM, Whitehead KJ, Whitehead DC. Nonmicrobicidal Small Molecule Inhibition of Polysaccharide Metabolism in Human Gut Microbes: A Potential Therapeutic Avenue. ACS Chem Biol 2018; 13:1165-1172. [PMID: 29660284 DOI: 10.1021/acschembio.8b00309] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
A new approach for the nonmicrobicidal phenotypic manipulation of prominent gastrointestinal microbes is presented. Low micromolar concentrations of a chemical probe, acarbose, can selectively inhibit the Starch Utilization System and ablate the ability of Bacteroides thetaiotaomicron and B. fragilis strains to metabolize potato starch and pullulan. This strategy has potential therapeutic relevance for the selective modulation of the GI microbiota in a nonmicrobicidal manner.
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Affiliation(s)
- Anthony D. Santilli
- Department of Chemistry, Clemson University, Clemson, South Carolina 29634, United States
| | - Elizabeth M. Dawson
- Department of Chemistry, Clemson University, Clemson, South Carolina 29634, United States
| | - Kristi J. Whitehead
- Department of Biological Sciences, Clemson University, Clemson, South Carolina 29634, United States
| | - Daniel C. Whitehead
- Department of Chemistry, Clemson University, Clemson, South Carolina 29634, United States
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136
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Danso D, Schmeisser C, Chow J, Zimmermann W, Wei R, Leggewie C, Li X, Hazen T, Streit WR. New Insights into the Function and Global Distribution of Polyethylene Terephthalate (PET)-Degrading Bacteria and Enzymes in Marine and Terrestrial Metagenomes. Appl Environ Microbiol 2018; 84:e02773-17. [PMID: 29427431 PMCID: PMC5881046 DOI: 10.1128/aem.02773-17] [Citation(s) in RCA: 182] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 01/29/2018] [Indexed: 11/26/2022] Open
Abstract
Polyethylene terephthalate (PET) is one of the most important synthetic polymers used today. Unfortunately, the polymers accumulate in nature and to date no highly active enzymes are known that can degrade it at high velocity. Enzymes involved in PET degradation are mainly α- and β-hydrolases, like cutinases and related enzymes (EC 3.1.1). Currently, only a small number of such enzymes are well characterized. In this work, a search algorithm was developed that identified 504 possible PET hydrolase candidate genes from various databases. A further global search that comprised more than 16 Gb of sequence information within 108 marine and 25 terrestrial metagenomes obtained from the Integrated Microbial Genome (IMG) database detected 349 putative PET hydrolases. Heterologous expression of four such candidate enzymes verified the function of these enzymes and confirmed the usefulness of the developed search algorithm. In this way, two novel and thermostable enzymes with high potential for downstream application were partially characterized. Clustering of 504 novel enzyme candidates based on amino acid similarities indicated that PET hydrolases mainly occur in the phyla of Actinobacteria, Proteobacteria, and Bacteroidetes Within the Proteobacteria, the Betaproteobacteria, Deltaproteobacteria, and Gammaproteobacteria were the main hosts. Remarkably enough, in the marine environment, bacteria affiliated with the phylum Bacteroidetes appear to be the main hosts of PET hydrolase genes, rather than Actinobacteria or Proteobacteria, as observed for the terrestrial metagenomes. Our data further imply that PET hydrolases are truly rare enzymes. The highest occurrence of 1.5 hits/Mb was observed in sequences from a sample site containing crude oil.IMPORTANCE Polyethylene terephthalate (PET) accumulates in our environment without significant microbial conversion. Although a few PET hydrolases are already known, it is still unknown how frequently they appear and with which main bacterial phyla they are affiliated. In this study, deep sequence mining of protein databases and metagenomes demonstrated that PET hydrolases indeed occur at very low frequencies in the environment. Furthermore, it was possible to link them to phyla that were previously not known to harbor such enzymes. This work contributes novel knowledge on the phylogenetic relationships, the recent evolution, and the global distribution of PET hydrolases. Finally, we describe the biochemical traits of four novel PET hydrolases.
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Affiliation(s)
- Dominik Danso
- Department of Microbiology and Biotechnology, Biocenter Klein Flottbek, University of Hamburg, Hamburg, Germany
| | - Christel Schmeisser
- Department of Microbiology and Biotechnology, Biocenter Klein Flottbek, University of Hamburg, Hamburg, Germany
| | - Jennifer Chow
- Department of Microbiology and Biotechnology, Biocenter Klein Flottbek, University of Hamburg, Hamburg, Germany
| | - Wolfgang Zimmermann
- Institute of Biochemistry, Department of Microbiology and Bioprocess Technology, Leipzig University, Leipzig, Germany
| | - Ren Wei
- Institute of Biochemistry, Department of Microbiology and Bioprocess Technology, Leipzig University, Leipzig, Germany
| | | | | | - Terry Hazen
- The University of Tennessee, Knoxville, Tennessee, USA
| | - Wolfgang R Streit
- Department of Microbiology and Biotechnology, Biocenter Klein Flottbek, University of Hamburg, Hamburg, Germany
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137
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Luo J, Li Y, Xie J, Gao L, Liu L, Ou S, Chen L, Peng X. The primary biological network of Bifidobacterium in the gut. FEMS Microbiol Lett 2018; 365:4931718. [DOI: 10.1093/femsle/fny057] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 03/08/2018] [Indexed: 12/17/2022] Open
Affiliation(s)
- Jianming Luo
- Department of Food Science and Engineering, Jinan University, Guangzhou 510630, People's Republic of China
| | - Yuetong Li
- Department of Food Science and Engineering, Jinan University, Guangzhou 510630, People's Republic of China
| | - Jinli Xie
- Department of Food Science and Engineering, Jinan University, Guangzhou 510630, People's Republic of China
| | - Lijuan Gao
- Department of Food Science and Engineering, Jinan University, Guangzhou 510630, People's Republic of China
| | - Liu Liu
- Department of Food Science and Engineering, Jinan University, Guangzhou 510630, People's Republic of China
| | - Shiyi Ou
- Department of Food Science and Engineering, Jinan University, Guangzhou 510630, People's Republic of China
| | - Long Chen
- Department of Food Science and Engineering, Jinan University, Guangzhou 510630, People's Republic of China
| | - Xichun Peng
- Department of Food Science and Engineering, Jinan University, Guangzhou 510630, People's Republic of China
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138
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Abstract
In red algae, the most abundant principal cell wall polysaccharides are mixed galactan agars, of which agarose is a common component. While bioconversion of agarose is predominantly catalyzed by bacteria that live in the oceans, agarases have been discovered in microorganisms that inhabit diverse terrestrial ecosystems, including human intestines. Here we comprehensively define the structure-function relationship of the agarolytic pathway from the human intestinal bacterium Bacteroides uniformis (Bu) NP1. Using recombinant agarases from Bu NP1 to completely depolymerize agarose, we demonstrate that a non-agarolytic Bu strain can grow on GAL released from agarose. This relationship underscores that rare nutrient utilization by intestinal bacteria is facilitated by the acquisition of highly specific enzymes that unlock inaccessible carbohydrate resources contained within unusual polysaccharides. Intriguingly, the agarolytic pathway is differentially distributed throughout geographically distinct human microbiomes, reflecting a complex historical context for agarose consumption by human beings.
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139
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Zheng J, Cheng G, Li Q, Jiao S, Feng C, Zhao X, Yin H, Du Y, Liu H. Chitin Oligosaccharide Modulates Gut Microbiota and Attenuates High-Fat-Diet-Induced Metabolic Syndrome in Mice. Mar Drugs 2018; 16:md16020066. [PMID: 29463060 PMCID: PMC5852494 DOI: 10.3390/md16020066] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 02/10/2018] [Accepted: 02/17/2018] [Indexed: 02/07/2023] Open
Abstract
Gut microbiota has been proved to be an indispensable link between nutrient excess and metabolic syndrome, and chitin oligosaccharide (NACOS) has displayed therapeutic effects on multiple diseases such as cancer and gastritis. In this study, we aim to confirm whether NACOS can ameliorate high-fat diet (HFD)-induced metabolic syndrome by rebuilding the structure of the gut microbiota community. Male C57BL/6J mice fed with HFD were treated with NACOS (1 mg/mL) in drinking water for five months. The results indicate that NACOS improved glucose metabolic disorder in HFD-fed mice and suppressed mRNA expression of the protein regulators related to lipogenesis, gluconeogenesis, adipocyte differentiation, and inflammation in adipose tissues. Additionally, NACOS inhibited the destruction of the gut barrier in HFD-treated mice. Furthermore, 16S ribosome RNA sequencing of fecal samples demonstrates that NACOS promoted the growth of beneficial intestinal bacteria remarkably and decreased the abundance of inflammogenic taxa. In summary, NACOS partly rebuilt the microbial community and improved the metabolic syndrome of HFD-fed mice. These data confirm the preventive effects of NACOS on nutrient excess-related metabolic diseases.
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Affiliation(s)
- Junping Zheng
- Liaoning Provincial Key Laboratory of Carbohydrates, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
- University of Chinese Academy of Sciences, Beijing 100049, China.
- State Key Laboratory of Biochemical Engineering and Key Laboratory of Biopharmaceutical Production & Formulation Engineering, PLA, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
| | - Gong Cheng
- State Key Laboratory of Biochemical Engineering and Key Laboratory of Biopharmaceutical Production & Formulation Engineering, PLA, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
| | - Qiongyu Li
- State Key Laboratory of Biochemical Engineering and Key Laboratory of Biopharmaceutical Production & Formulation Engineering, PLA, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
| | - Siming Jiao
- State Key Laboratory of Biochemical Engineering and Key Laboratory of Biopharmaceutical Production & Formulation Engineering, PLA, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
| | - Cui Feng
- State Key Laboratory of Biochemical Engineering and Key Laboratory of Biopharmaceutical Production & Formulation Engineering, PLA, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
| | - Xiaoming Zhao
- Liaoning Provincial Key Laboratory of Carbohydrates, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
| | - Heng Yin
- Liaoning Provincial Key Laboratory of Carbohydrates, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
| | - Yuguang Du
- State Key Laboratory of Biochemical Engineering and Key Laboratory of Biopharmaceutical Production & Formulation Engineering, PLA, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
| | - Hongtao Liu
- State Key Laboratory of Biochemical Engineering and Key Laboratory of Biopharmaceutical Production & Formulation Engineering, PLA, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
- Zhengzhou Institute of Emerging Industrial Technology, Zhengzhou 450000, China.
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140
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Dietary pectic glycans are degraded by coordinated enzyme pathways in human colonic Bacteroides. Nat Microbiol 2017; 3:210-219. [PMID: 29255254 PMCID: PMC5784806 DOI: 10.1038/s41564-017-0079-1] [Citation(s) in RCA: 231] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 11/20/2017] [Indexed: 12/15/2022]
Abstract
The major nutrients available to human colonic
Bacteroides species are glycans exemplified by pectins, a
network of covalently linked plant cell wall polysaccharides containing
galacturonic acid (GalA). Metabolism of complex carbohydrates by the
Bacteroides genus is orchestrated by polysaccharide
utilisation loci or PULs. In Bacteroides thetaiotaomicron, a
human colonic bacterium, the PULs activated by the different pectin domains have
been identified, however, the mechanism by which these loci contribute to the
degradation of these GalA-containing polysaccharides is poorly understood. Here
we show that each PUL orchestrates the metabolism of specific pectin molecules,
recruiting enzymes from two previously unknown glycoside hydrolase (GH)
families. The apparatus that depolymerizes the backbone of rhamnogalacturonan-I
(RGI) is particularly complex. This system contains several GHs that trim the
remnants of other pectin domains attached to RGI, while nine enzymes contribute
to the degradation of the backbone comprising a rhamnose-GalA repeating unit.
The catalytic properties of the pectin degrading enzymes are optimized to
protect the glycan cues that activate the specific PULs ensuring a continuous
supply of inducing molecules throughout growth. The contribution of
Bacteroides spp. to the metabolism of the pectic network is
illustrated by cross-feeding between organisms.
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141
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Cockburn DW, Suh C, Medina KP, Duvall RM, Wawrzak Z, Henrissat B, Koropatkin NM. Novel carbohydrate binding modules in the surface anchored α-amylase of Eubacterium rectale provide a molecular rationale for the range of starches used by this organism in the human gut. Mol Microbiol 2017; 107:249-264. [PMID: 29139580 PMCID: PMC6939882 DOI: 10.1111/mmi.13881] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/11/2017] [Indexed: 12/30/2022]
Abstract
Gut bacteria recognize accessible glycan substrates within a complex environment. Carbohydrate binding modules (CBMs) of cell surface glycoside hydrolases often drive binding to the target substrate. Eubacterium rectale, an important butyrate-producing organism in the gut, consumes a limited range of substrates, including starch. Host consumption of resistant starch increases the abundance of E. rectale in the intestine, likely because it successfully captures the products of resistant starch degradation by other bacteria. Here, we demonstrate that the cell wall anchored starch-degrading α-amylase, Amy13K of E. rectale harbors five CBMs that all target starch with differing specificities. Intriguingly these CBMs efficiently bind to both regular and high amylose corn starch (a type of resistant starch), but have almost no affinity for potato starch (another type of resistant starch). Removal of these CBMs from Amy13K reduces the activity level of the enzyme toward corn starches by ∼40-fold, down to the level of activity toward potato starch, suggesting that the CBMs facilitate activity on corn starch and allow its utilization in vivo. The specificity of the Amy13K CBMs provides a molecular rationale for why E. rectale is able to only use certain starch types without the aid of other organisms.
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Affiliation(s)
- Darrell W Cockburn
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA.,Department of Food Science, Pennsylvania State University, University Park, PA 16802, USA
| | - Carolyn Suh
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Krizia Perez Medina
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Rebecca M Duvall
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Zdzislaw Wawrzak
- Life Sciences Collaborative Access Team (LS-CAT), Advanced Photon Source, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL, 60439, USA
| | - Bernard Henrissat
- Architecture et Fonction des Macromolécules Biologiques, CNRS, Aix-Marseille University, Marseille, F-13288, France.,Institut National de la Recherche Agronomique, USC1408 Architecture et Fonction des Macromolécules Biologiques, Marseille, F-13288, France.,Department of Biological Sciences, King Abdulaziz University, Jeddah, 21589, Saudi Arabia
| | - Nicole M Koropatkin
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
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142
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Navigating the Gut Buffet: Control of Polysaccharide Utilization in Bacteroides spp. Trends Microbiol 2017; 25:1005-1015. [DOI: 10.1016/j.tim.2017.06.009] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 06/09/2017] [Accepted: 06/20/2017] [Indexed: 12/26/2022]
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143
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Abstract
The human intestine harbors a dense microbial ecosystem (microbiota) that is different between individuals, dynamic over time, and critical for aspects of health and disease. Dietary polysaccharides directly shape the microbiota because of a gap in human digestive physiology, which is equipped to assimilate only proteins, lipids, simple sugars, and starch, leaving nonstarch polysaccharides as major nutrients reaching the microbiota. A mutualistic role of gut microbes is to digest dietary complex carbohydrates, liberating host-absorbable energy via fermentation products. Emerging data indicate that polysaccharides play extensive roles in host-gut microbiota symbiosis beyond dietary polysaccharide digestion, including microbial interactions with endogenous host glycans and the importance of microbial polysaccharides. In this review, we consider multiple mechanisms through which polysaccharides mediate aspects of host-microbe symbiosis in the gut, including some affecting health. As host and microbial metabolic pathways are intimately connected with diet, we highlight the potential to manipulate this system for health.
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Affiliation(s)
- Nathan T Porter
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan 48109;
| | - Eric C Martens
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan 48109;
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144
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Barouei J, Bendiks Z, Martinic A, Mishchuk D, Heeney D, Hsieh YH, Kieffer D, Zaragoza J, Martin R, Slupsky C, Marco ML. Microbiota, metabolome, and immune alterations in obese mice fed a high-fat diet containing type 2 resistant starch. Mol Nutr Food Res 2017; 61. [PMID: 28736992 DOI: 10.1002/mnfr.201700184] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 06/22/2017] [Accepted: 07/10/2017] [Indexed: 01/03/2023]
Abstract
SCOPE We examined the intestinal and systemic responses to incorporating a type 2 resistant starch (RS) into a high fat diet fed to obese mice. METHODS AND RESULTS Diet-induced obese, C57BL/6J male mice were fed an HF diet without or with 20% (by weight) high-amylose maize resistant starch (HF-RS) for 6 weeks. Serum adiponectin levels were higher with RS consumption, but there were no differences in weight gain and adiposity. With HF-RS, the expression levels of ileal TLR2 and Reg3g and cecal occludin, TLR2, TLR4, NOD1 and NOD2 were induced; whereas colonic concentrations of the inflammatory cytokine IL-17A declined. The intestinal, serum, liver, and urinary metabolomes were also altered. HF-RS resulted in lower amino acid concentrations, including lower serum branched chain amino acids, and increased quantities of urinary di/trimethylamine, 3-indoxylsulfate, and phenylacetylglycine. Corresponding to these changes were enrichments in Bacteroidetes (S24-7 family) and certain Firmicutes taxa (Lactobacillales and Erysipelotrichaceae) with the HF-RS diet. Parabacteroides and S24-7 positively associated with cecal maltose concentrations. These taxa and Erysipelotrichaceae, Allobaculum, and Bifidobacterium were directly correlated with uremic metabolites. CONCLUSION Consumption of RS modified the intestinal microbiota, stimulated intestinal immunity and endocrine-responses, and modified systemic metabolomes in obese mice consuming an otherwise obesogenic diet.
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Affiliation(s)
- Javad Barouei
- Department of Food Science & Technology, University of California, Davis, CA, USA
| | - Zach Bendiks
- Department of Food Science & Technology, University of California, Davis, CA, USA
| | - Alice Martinic
- Department of Nutrition, University of California, Davis, CA, USA
| | - Darya Mishchuk
- Department of Food Science & Technology, University of California, Davis, CA, USA
| | - Dustin Heeney
- Department of Food Science & Technology, University of California, Davis, CA, USA
| | - Yu-Hsin Hsieh
- Department of Food Science & Technology, University of California, Davis, CA, USA
| | - Dorothy Kieffer
- Department of Nutrition, University of California, Davis, CA, USA
| | - Jose Zaragoza
- Department of Food Science & Technology, University of California, Davis, CA, USA
| | - Roy Martin
- Department of Nutrition, University of California, Davis, CA, USA.,Western Human Nutrition Research Center, USDA, Davis, CA, USA
| | - Carolyn Slupsky
- Department of Food Science & Technology, University of California, Davis, CA, USA.,Department of Nutrition, University of California, Davis, CA, USA
| | - Maria L Marco
- Department of Food Science & Technology, University of California, Davis, CA, USA
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145
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Rocha ER, Krykunivsky AS. Anaerobic utilization of Fe(III)-xenosiderophores among Bacteroides species and the distinct assimilation of Fe(III)-ferrichrome by Bacteroides fragilis within the genus. Microbiologyopen 2017; 6:e00479. [PMID: 28397401 PMCID: PMC5552952 DOI: 10.1002/mbo3.479] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 02/24/2017] [Accepted: 03/07/2017] [Indexed: 01/01/2023] Open
Abstract
In this study, we show that Bacteroides species utilize Fe(III)-xenosiderophores as the only source of exogenous iron to support growth under iron-limiting conditions in vitro anaerobically. Bacteroides fragilis was the only species able to utilize Fe(III)-ferrichrome while Bacteroides vulgatus ATCC 8482 and Bacteroides thetaiotaomicron VPI 5482 were able to utilize both Fe(III)-enterobactin and Fe(III)-salmochelin S4 as the only source of iron in a dose-dependent manner. We have investigated the way B. fragilis assimilates Fe(III)-ferrichrome as initial model to understand the utilization of xenosiderophores in anaerobes. B. fragilis contains two outer membrane TonB-dependent transporters (TBDTs), FchA1 and FchA2, which are homologues to Escherichia coli ferrichrome transporter FhuA. The disruption of fchA1 gene had only partial growth defect on Fe(III)-ferrichrome while the fchA2 mutant had no growth defect compared to the parent strain. The genetic complementation of fchA1 gene restored growth to parent strain levels indicating that it plays a role in Fe(III)-ferrichrome assimilation though we cannot rule out some functional overlap in transport systems as B. fragilis contains abundant TBDTs whose functions are yet not understood. However, the growth of B. fragilis on Fe(III)-ferrichrome was abolished in a feoAB mutant indicating that Fe(III)-ferrichrome transported into the periplasmic space was reduced in the periplasm releasing ferrous iron prior to transport through the FeoAB transport system. Moreover, the release of iron from the ferrichrome may be linked to the thiol redox system as the trxB deletion mutant was also unable to grow in the presence of Fe(III)-ferrichrome. The genetic complementation of feoAB and trxB mutants completely restored growth on Fe(III)-ferrichrome. Taken together, these findings show that Bacteroides species have developed mechanisms to utilize ferric iron bound to xenosiderophores under anaerobic growth conditions though the regulation and role in the biology of Bacteroides in the anaerobic intestinal environment remain to be understood.
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Affiliation(s)
- Edson R. Rocha
- Department of Microbiology and ImmunologyBrody School of MedicineEast Carolina UniversityGreenvilleNC
| | - Anna S. Krykunivsky
- Department of Microbiology and ImmunologyBrody School of MedicineEast Carolina UniversityGreenvilleNC
- Intern from the Undergraduate Research Internship Placement ProgramUniversity of the West of England (UWE)BristolUK
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146
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Svartström O, Alneberg J, Terrapon N, Lombard V, de Bruijn I, Malmsten J, Dalin AM, El Muller E, Shah P, Wilmes P, Henrissat B, Aspeborg H, Andersson AF. Ninety-nine de novo assembled genomes from the moose (Alces alces) rumen microbiome provide new insights into microbial plant biomass degradation. ISME JOURNAL 2017; 11:2538-2551. [PMID: 28731473 DOI: 10.1038/ismej.2017.108] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 05/05/2017] [Accepted: 05/30/2017] [Indexed: 12/25/2022]
Abstract
The moose (Alces alces) is a ruminant that harvests energy from fiber-rich lignocellulose material through carbohydrate-active enzymes (CAZymes) produced by its rumen microbes. We applied shotgun metagenomics to rumen contents from six moose to obtain insights into this microbiome. Following binning, 99 metagenome-assembled genomes (MAGs) belonging to 11 prokaryotic phyla were reconstructed and characterized based on phylogeny and CAZyme profile. The taxonomy of these MAGs reflected the overall composition of the metagenome, with dominance of the phyla Bacteroidetes and Firmicutes. Unlike in other ruminants, Spirochaetes constituted a significant proportion of the community and our analyses indicate that the corresponding strains are primarily pectin digesters. Pectin-degrading genes were also common in MAGs of Ruminococcus, Fibrobacteres and Bacteroidetes and were overall overrepresented in the moose microbiome compared with other ruminants. Phylogenomic analyses revealed several clades within the Bacteriodetes without previously characterized genomes. Several of these MAGs encoded a large numbers of dockerins, a module usually associated with cellulosomes. The Bacteroidetes dockerins were often linked to CAZymes and sometimes encoded inside polysaccharide utilization loci, which has never been reported before. The almost 100 CAZyme-annotated genomes reconstructed in this study provide an in-depth view of an efficient lignocellulose-degrading microbiome and prospects for developing enzyme technology for biorefineries.
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Affiliation(s)
- Olov Svartström
- School of Biotechnology, Division of Industrial Biotechnology, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Johannes Alneberg
- School of Biotechnology, Division of Gene Technology, KTH Royal Institute of Technology, Science for Life Laboratory, Stockholm, Sweden
| | - Nicolas Terrapon
- CNRS UMR 7257, Aix-Marseille University, 13288 Marseille, France.,INRA, USC 1408 AFMB, 13288 Marseille, France
| | - Vincent Lombard
- CNRS UMR 7257, Aix-Marseille University, 13288 Marseille, France.,INRA, USC 1408 AFMB, 13288 Marseille, France
| | - Ino de Bruijn
- School of Biotechnology, Division of Gene Technology, KTH Royal Institute of Technology, Science for Life Laboratory, Stockholm, Sweden
| | - Jonas Malmsten
- Department of Pathology and Wildlife Diseases, National Veterinary Institute, Uppsala, Sweden.,Division of Reproduction, Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Ann-Marie Dalin
- Division of Reproduction, Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Emilie El Muller
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Pranjul Shah
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Paul Wilmes
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Bernard Henrissat
- CNRS UMR 7257, Aix-Marseille University, 13288 Marseille, France.,INRA, USC 1408 AFMB, 13288 Marseille, France.,Department of Biological Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Henrik Aspeborg
- School of Biotechnology, Division of Industrial Biotechnology, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Anders F Andersson
- School of Biotechnology, Division of Gene Technology, KTH Royal Institute of Technology, Science for Life Laboratory, Stockholm, Sweden
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147
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Abstract
The complex carbohydrates of terrestrial and marine biomass represent a rich nutrient source for free-living and mutualistic microbes alike. The enzymatic saccharification of these diverse substrates is of critical importance for fueling a variety of complex microbial communities, including marine, soil, ruminant, and monogastric microbiota. Consequently, highly specific carbohydrate-active enzymes, recognition proteins, and transporters are enriched in the genomes of certain species and are of critical importance in competitive environments. In Bacteroidetes bacteria, these systems are organized as polysaccharide utilization loci (PULs), which are strictly regulated, colocalized gene clusters that encode enzyme and protein ensembles required for the saccharification of complex carbohydrates. This review provides historical perspectives and summarizes key findings in the study of these systems, highlighting a critical shift from sequence-based PUL discovery to systems-based analyses combining reverse genetics, biochemistry, enzymology, and structural biology to precisely illuminate the molecular mechanisms underpinning PUL function. The ecological implications of dynamic PUL deployment by key species in the human gastrointestinal tract are explored, as well as the wider distribution of these systems in other gut, terrestrial, and marine environments.
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148
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Thursby E, Juge N. Introduction to the human gut microbiota. Biochem J 2017; 474:1823-1836. [PMID: 28512250 PMCID: PMC5433529 DOI: 10.1042/bcj20160510] [Citation(s) in RCA: 1648] [Impact Index Per Article: 235.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 03/03/2017] [Accepted: 03/06/2017] [Indexed: 02/08/2023]
Abstract
The human gastrointestinal (GI) tract harbours a complex and dynamic population of microorganisms, the gut microbiota, which exert a marked influence on the host during homeostasis and disease. Multiple factors contribute to the establishment of the human gut microbiota during infancy. Diet is considered as one of the main drivers in shaping the gut microbiota across the life time. Intestinal bacteria play a crucial role in maintaining immune and metabolic homeostasis and protecting against pathogens. Altered gut bacterial composition (dysbiosis) has been associated with the pathogenesis of many inflammatory diseases and infections. The interpretation of these studies relies on a better understanding of inter-individual variations, heterogeneity of bacterial communities along and across the GI tract, functional redundancy and the need to distinguish cause from effect in states of dysbiosis. This review summarises our current understanding of the development and composition of the human GI microbiota, and its impact on gut integrity and host health, underlying the need for mechanistic studies focusing on host-microbe interactions.
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Affiliation(s)
- Elizabeth Thursby
- The Gut Health and Food Safety Programme, Institute of Food Research, Norwich Research Park, Norwich NR4 7UA, U.K
| | - Nathalie Juge
- The Gut Health and Food Safety Programme, Institute of Food Research, Norwich Research Park, Norwich NR4 7UA, U.K.
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149
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Janeček Š, Majzlová K, Svensson B, MacGregor EA. The starch-binding domain family CBM41-Anin silicoanalysis of evolutionary relationships. Proteins 2017; 85:1480-1492. [DOI: 10.1002/prot.25309] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 04/05/2017] [Accepted: 04/17/2017] [Indexed: 12/27/2022]
Affiliation(s)
- Štefan Janeček
- Institute of Molecular Biology, Slovak Academy of Sciences; Bratislava Slovakia
- Department of Biology; Faculty of Natural Sciences, University of SS. Cyril and Methodius; Trnava Slovakia
| | - Katarína Majzlová
- Institute of Molecular Biology, Slovak Academy of Sciences; Bratislava Slovakia
| | - Birte Svensson
- Department of Biotechnology and Biomedicine; Technical University of Denmark; Kgs. Lyngby Denmark
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150
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Xu J, Chen HB, Li SL. Understanding the Molecular Mechanisms of the Interplay Between Herbal Medicines and Gut Microbiota. Med Res Rev 2017; 37:1140-1185. [PMID: 28052344 DOI: 10.1002/med.21431] [Citation(s) in RCA: 217] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Revised: 10/21/2016] [Accepted: 11/16/2016] [Indexed: 02/06/2023]
Abstract
Herbal medicines (HMs) are much appreciated for their significant contribution to human survival and reproduction by remedial and prophylactic management of diseases. Defining the scientific basis of HMs will substantiate their value and promote their modernization. Ever-increasing evidence suggests that gut microbiota plays a crucial role in HM therapy by complicated interplay with HM components. This interplay includes such activities as: gut microbiota biotransforming HM chemicals into metabolites that harbor different bioavailability and bioactivity/toxicity from their precursors; HM chemicals improving the composition of gut microbiota, consequently ameliorating its dysfunction as well as associated pathological conditions; and gut microbiota mediating the interactions (synergistic and antagonistic) between the multiple chemicals in HMs. More advanced experimental designs are recommended for future study, such as overall chemical characterization of gut microbiota-metabolized HMs, direct microbial analysis of HM-targeted gut microbiota, and precise gut microbiota research model development. The outcomes of such research can further elucidate the interactions between HMs and gut microbiota, thereby opening a new window for defining the scientific basis of HMs and for guiding HM-based drug discovery.
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Affiliation(s)
- Jun Xu
- School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong
| | - Hu-Biao Chen
- School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong
| | - Song-Lin Li
- Department of Pharmaceutical Analysis, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, 210028, P.R. China.,Department of Metabolomics, Jiangsu Province Academy of Traditional Chinese Medicine and Jiangsu Branch of China Academy of Chinese Medical Sciences, Nanjing, 210028, P.R. China
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