DOCSLIB.ORG

7 Structures of Bacterial Polysaccharides

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
7 Structures of Bacterial Polysaccharides Transworld Research Network 37/661 (2), Fort P.O., Trivandrum-695 023, Kerala, India Progress in the synthesis of complex carbohydrate chains of plant and microbial polysaccharides, 2009: 181-198 ISBN: 978-81-7895-424-0 Editor: Nikolay E. Nifantiev Structures of bacterial 7 polysaccharides Yuriy A. Knirel N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences Leninsky Prospekt 47, Moscow 119991, Russia Abstract This chapter is devoted to the composition and structure of various bacterial surface glycopolymers: lipopolysaccharides of Gram-negative bacteria, cell- wall anionic polysaccharides of Gram-positive bacteria, including teichoic and lipoteichoic acids, and mycobacterial lipoglycans. Extracellular polysaccharides, which build a protective capsule, participate in biofilm formation or are excreted as slime, are considered too. The occurrence of both monosaccharides and non-carbohydrate groups as components of the polysaccharide is surveyed. Various structural types of the polysaccharides are discussed, including homopolysaccharides and heteropolysaccharides built up of oligosaccharide or oligosaccharide-phosphate repeating units. Attention is paid to the mode of the attachment of various polysaccharides to the cell surface. Correspondence/Reprint request: Dr. Yuriy A. Knirel, N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospekt 47, Moscow 119991, Russia. E-mail: [email protected] 182 Yuriy A. Knirel 1. Introduction Glycopolymers are components of the cell envelope of various bacteria. In Gram- negative bacteria, the cell envelope consists of the inner (cytoplasmic) and outer membrane and a rigid peptidoglycan (murein) layer in between. The outer leaflet of the outer membrane consists mainly of lipopolysaccharide (LPS, endotoxin). Gram-positive bacteria lack the outer membrane and have a much thicker peptidoglycan layer. Their cell- wall polysaccharides are linked to peptidoglycan or anchored into the cytoplasmic membrane. Although mycobycteria stain slightly Gram-positive, they posses Gram- negative rather than Gram-positive cell envelope features, i.e. a thin peptidoglycan layer and a lipid bilayer outer membrane. Important lipoglycans protrude through the cell wall. Bacteria of yet another group, Archaea, have a differently composed rigid layer called pseudomurein. Bacterial cells may be surrounded by a polysaccharide capsule or a S-layer. The latter consists of proteins or glycoproteins that are self-aggregated to crystal-like planar structures by electrostatic or hydrophobic interactions to yield a porous envelope. As microorganisms spend a significant amount of energy on their synthesis, the polysaccharides should play an important role in bacterial life. Indeed, being located on the cell surface, they define the immunospecificity and are implicated in protection and virulence of microorganisms. The knowledge of structural details of bacterial surface polysaccharides helps a better understanding of the mechanisms of pathogenesis of infectious diseases and development of diagnostic agents and efficient vaccines. Recently, an impressive progress in elucidation of bacterial polysaccharide structures has been achieved, mainly due to elaboration of novel modern methods of structural analysis, first of all high-resolution NMR spectroscopy and mass spectrometry. In the last decades, the composition and structure of bacterial polysaccharides have been repeatedly surveyed [1-9], and the annually updated Bacterial Carbohydrate Structure Database is available via Internet at http://www.glyco.ac.ru/bcsdb. In the present Chapter, structural features of the major classes of bacterial polysaccharides, including LPSs of Gram-negative bacteria, teichoic and teichuronoic acids of Gram-positive bacteria, lipoglycans of mycobacteria, capsular and other extracellular polysaccharides as well as S-layer glycoproteins are discussed. 2. Lipopolysaccharides of Gram-negative bacteria The LPS is the major constituent of the outer membrane of the cell envelope of Gram- negative bacteria. A complete LPS (S-form) has three domains, which differ in their chemical nature, genetics, biosynthesis and function. A polysaccharide portion of the LPS called O- specific polysaccharide (OPS, O-chain, O-antigen) is either a homopolymer or, more often, a regular heteropolymer built up of oligosaccharide (from di- to octa-saccaharide) repeating units (O-units). Based on the fine structure of the OPS, serologically distinct strains of bacterial species are classified into O-serotypes or O-serovars. The OPS is linked to a large oligosaccharide called core, which, in turn, is linked to the lipid moiety of the LPS, lipid A. The latter serves as an anchor that links by hydrophobic interactions the outer leaflet of the outer membrane composed mainly of the LPS to the inner phospholipid layer. Lipid A of endotoxic active LPSs is responsible for the biological activities of the LPS. Some pathogenic bacteria possess a truncated LPS that is either devoid of the O-chain (R-form) or has a single O-unit linked to the core (SR-form). Structures of bacterial polysaccharides 183 2.1. O-specific polysaccharides O-antigens of some bacteria are homopolysaccharides. They often consist of common monosaccharides (e.g. various glucans, galactans and mannans are known) but homopolymers of less common sugars and sugar derivatives, such as N-acyl derivatives of 4-amino-4,6-dideoxy-D-mannose and -L-mannose in Vibrio cholera, occur as well [8]. Legionella pneumophila serogroup 1 strains possess a homopolymer of α-(1→4)- interlinked residues of 5-acetamidino-7-acetamido-3,5,7,9-tetradeoxy-D-glycero-D- galacto-non-2-ulosonic (legionaminic) acid, either 8-O-acetylated or not, whereas in other L. pneumophila strains a similar homopolysaccharide of the corresponding D-glycero-D-talo isomer has been identified [10]. Heteropolysaccharides are more widespread and more diverse in composition than homopolysaccharides. They may include usual sugars, like hexoses, pentoses, 6-deoxyhexoses, N-acetylhexosamines and hexuronic acids, as well as less common 6- deoxyamino and 6-deoxydiamino sugars, aminouronic and diaminouronic acids as well as higher monosaccharides, including heptoses, 3-deoxy-D-manno-oct-2-ulosonic acid (Kdo) and 5,7-diamino-3,5,7,9-tetradeoxynon-2-ulosonic acids as well as branched monosaccharides [3]. N-Acetyl and O-acetyl groups are common and other non-sugar substituents often occur too, such as O-methyl groups, N-linked hydroxy and amino acids, carboxyl-linked amino components, including amino acids, lactic acid ethers, pyruvic acid acetals, alditol phosphates and ethanolamine phosphate [3] (examples 1-8 are shown in Figure 1). Figure 1. Examples of unusual monosaccharides and monosaccharide derivatives, components of bacterial polysaccharides. 1, amide of D-glucuronic acid with N-[(R)-1-carboxyethyl]-L-lysine; 2, 4- amino-4,6-dideoxy-D-glucose N-substituted with N-[(R)-3-hydroxybutanoyl]-L-alanyl; 3, (R)-acetal of pyruvic acid with D-galactose; 4, ether of (R)-lactic acid with L-rhamnose; 5, N-acetyl-D-glucosamine phosphorylated with phosphocholine; 6, non-2-ulosonic acid 5-N-acetyl-7-N-formylpseudaminic acid; 7, branched octose yersiniose A; 8, higher carbocyclic monosaccharide caryose. 184 Yuriy A. Knirel Often the OPSs of serologically distinct strains have quite different structures as, e.g., in Shigella dysenteriae [11], but in some bacteria they are related to various extents. For instance, the OPSs of Pseudomonas aeruginosa O1-O13 all have a 6-deoxy-D- hexosamine (N-acetyl-D-quinovosamine, N-acetyl-D-fucosamine or di-N-acylbacillosamine) as the first monosaccharide of the O-unit, whose transfer to a lipid carrier initiates the O- antigen biosynthesis. They are also enriched in amino and diamino hexuronic acids and diamino non-2-ulosonic acids [12], and some of them are closely related in structure. For instance, the OPSs of various subgroups in P. aeruginosa serogroup O6 have the same O-unit and differ only in the mode of connection of the O-units to each other [by α- (1→2)-, α-(1→3)- or β-(1→3)-linkage]: Other differences between P. aeruginosa OPSs are due to a replacement of one sugar isomer with another (e.g. D-QuiNAc with D-FucNAc in serogroup O4) or one N- acyl group with another [e.g. acetyl with (S)-3-hydroxybutanoyl at N-4 of QuiNAc4N in serogroup O3]. Some of the OPSs differ also in O-acetylation and uronic acid amidation, which are usually non-stoichiometric. Other non-stoichiometric modifications that mask the regularity of polymers are glycosylation (most often glucosylation), methylation and phosphorylation. The non-reducing terminus of the OPSs (mainly of homopolysaccharides) may be occupied by an O-methylated monosaccharide, which is usually one of the O-unit components. Examples are 3-O-methyl-D-rhamnose and 3-O-methyl-L-rhamnose (D- and L-acofriose) in the corresponding rhamnans or 3-O-methyl-D-mannose in D-mannans [6]. In V. cholerae O1, 2-O-methylation of the terminal D-Rha4N residue results in seroconversion from Inaba to Ogawa [13]. In some other cases, the OPSs are terminated with a monosaccharide that is different from the O-unit components. For instance, N-acyl derivatives of 2,3,4-triamino-2,3,4- trideoxy-D-galacturonamide occupies the non-reducing end of the OPS of Bordetella bronchiseptica and Bordetella parapertussis, which is a homopolymer of 2,3-diacetamido-2,3-dideoxy-D-galacturonamide [14]. The OPSs of Klebsiella pneumoniae O4 and O12 are terminated with a residue of Kdo, which is no component of the O-units [15]. In the OPS of the gastric bacterium Helicobacter pylori, which is built up of occasionally fucosylated N-acetyl-β-lactosamine repeating units, the terminal non- reducing O-unit often carries one or two α-L-fucose residues giving rise to Lewis x and Lewis y antigen determinants, respectively (Figure 2) [16]. It is suggested that such molecular mimicry has been acquired in the course of long co-evolution of the bacterium with humans. Similar or even identical OPSs are sometimes found in taxonomically distant bacteria, even in those belonging to different families. For instance, bacteria Francisella tularensis, Vibrio anguillarum, Sh. dysenteriae type 7 and P.
Load more

Recommended publications
  • B. Fragilis Is Mediated by Capsular
    bioRxiv preprint doi: https://doi.org/10.1101/2020.08.19.258442; this version posted August 21, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 1 Hemagglutination by B. fragilis is mediated by capsular 2 polysaccharides and is influenced by host ABO blood type. 3 Kathleen L. Arnolds a, Nancy Moreno-Huizar b, Maggie A. Stanislawski c, 4 Brent Palmer c, Catherine Lozupone c* 5 a Department of Microbiology, University of Colorado Anschutz Medical Campus, 6 Aurora, CO, USA [email protected] 7 b Department of Computer Science, University of Colorado Denver, Denver, CO, USA. 8 c Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, 9 CO, USA [email protected] 10 11 12 13 14 15 1 bioRxiv preprint doi: https://doi.org/10.1101/2020.08.19.258442; this version posted August 21, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 16 Hemagglutination by B. fragilis is mediated by capsular polysaccharides and is 17 influenced by host ABO blood type. 18 19 Bacterial hemagglutination of red blood cells (RBCs) is mediated by 20 interactions between bacterial cell components and RBC envelope glycans 21 that vary across individuals by ABO blood type.
    [Show full text]
  • Uvic Thesis Template
    Insight into the Functionality of an Unusual Glycoside Hydrolase from Family 50 by Kaleigh Giles BSc, Brock University, 2011 A Thesis Submitted in Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCE in the Department of Biochemistry and Microbiology Kaleigh Giles, 2014 University of Victoria All rights reserved. This thesis may not be reproduced in whole or in part, by photocopy or other means, without the permission of the author. ii Supervisory Committee Insight into the Functionality of an Unusual Glycoside Hydrolase from Family 50 by Kaleigh Giles BSc, Brock University, 2011 Supervisory Committee Dr. Alisdair B. Boraston, Department of Biochemistry and Microbiology Supervisor Dr. Martin J. Boulanger (Department of Biochemistry and Microbiology) Departmental Member Dr. Fraser Hof (Department of Chemistry) Outside Member iii Abstract Supervisory Committee Dr. Alisdair B. Boraston, Department of Biochemistry and Microbiology Supervisor Dr. Martin J. Boulanger, Department of Biochemistry and Microbiology Departmental Member Dr. Fraser Hof, Department of Chemistry O utside Member Agarose and porphyran are related galactans that are only found within red marine algae. As such, marine microorganisms have adapted to using these polysaccharides as carbon sources through the acquisition of unique Carbohydrate Active enZymes (CAZymes). A recent metagenome study of the microbiomes from a Japanese human population identified putative CAZymes in several bacterial species, including Bacteroides plebeius that have significant amino acid sequence similarity with those from marine bacteria. Analysis of one potential CAZyme from B. plebeius (BpGH50) is described here. While displaying up to 30% sequence identity with β-agarases, BpGH50 has no detectable agarase activity. Its crystal structure reveals that the topology of the active site is much different than previously characterized agarases, while containing the same core catalytic machinery.
    [Show full text]
  • Bacteriophages Targeting Acinetobacter Baumannii Capsule
    bioRxiv preprint doi: https://doi.org/10.1101/2020.02.25.965590; this version posted February 26, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 1 Bacteriophages targeting Acinetobacter baumannii capsule 2 induce antimicrobial resensitization 3 4 Fernando Gordillo Altamirano1*, John H. Forsyth1, Ruzeen Patwa1, Xenia Kostoulias2, Michael Trim1, Dinesh 5 Subedi1, Stuart Archer3, Faye C. Morris2, Cody Oliveira1, Luisa Kielty1, Denis Korneev1, Moira K. O’Bryan1, 6 Trevor J. Lithgow2, Anton Y. Peleg2,4, Jeremy J. Barr1* 7 8 1 School of Biological Sciences, Monash University 9 2 Biomedicine Discovery Institute and Department of Microbiology, Monash University 10 3 Monash Bioinformatics Platform, Faculty of Medicine, Nursing and Health Sciences, Monash University 11 4 Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University 12 13 *Corresponding authors 14 Fernando Gordillo Altamirano [email protected] 15 Jeremy J. Barr [email protected] 16 School of Biological Sciences, Monash University 17 25 Rainforest Walk, 18 Clayton, 3800, VIC 19 Australia 20 21 Abstract 22 Carbapenem-resistant Acinetobacter baumannii is responsible for frequent, hard-to-treat and often fatal 23 healthcare-associated infections. Phage therapy, the use of viruses that infect and kill bacteria, is an approach 24 gaining significant clinical interest to combat antibiotic-resistant infections. However, a major limitation is that 25 bacteria can develop resistance against phages. Here, we isolated phages with activity against a panel of A.
    [Show full text]
  • Glycoconjugates
    Background Information on Glycoconjugates Richard D. Cummings, Ph.D. Director, National Center for Functional Glycomics Professor Department of Surgery Beth Israel Deaconess Medical Center Harvard Medical School Boston, MA 02114 Tel: (617) 735-4643 e-mail: [email protected] For General Reference On-Line See: Essentials of Glycobiology (2nd Edition) Varki, Cummings, Esko, Freeze, Stanley, Bertozzi, Hart and Etzler) http://www.ncbi.nlm.nih.gov/books/NBK1908/ Mammalian Cells are Covered with Glycoconjugates GLYCOSAMINOGLYCANS/ GLYCOPROTEINS PROTEOGLYCANS GLYCOLIPIDS NUCLEAR/CYTOPLASMIC GLYCOPROTEINS 2 Mammalian Glycoconjugates are Recognized by a Wide Variety of Specific Proteins GLYCAN-BINDING PROTEIN (GBP) GBP ANTIBODY TOXIN GBP GBP VIRUS 7 ANTIBODY GBP MICROBE TOXIN 3 Glycosylation Pathways 4 Glycosylation Pathways 5 Glycoconjugates, Which are Molecules Containing Sugars (Monosaccharides) Linked Within Them, are the Major Constituents of Animal Cell Membranes (Glycocalyx) and Secreted Material: See Different Classes of Glycoconjugates Below in Red Boxes PROTEOGLYCANS GLYCOSAMINOGLYCANS GLYCOSAMINOGLYCANS GLYCOPROTEINS GPI-ANCHORED GLYCOPROTEINS GLYCOLIPIDS outside Cell Membrane cytoplasm Essentials of Glycobiology, 3rd Edition CYTOPLASMIC GLYCOPROTEINS Chapter 1, Figure 6 Glycans are as Ubiquitous as DNA/RNA and Appear to Represent Greater Molecular Diversity 7 Big Picture: Nucleotide Sugars Connection of • UDP-Glc, • UDP-Gal, • UDP-GlcNAc, Glycoconjugate • UDPGalNAc, • UDP-GlcA, Biosynthesis • UDP-Xyl, • GDP-Man, • GDP-Fuc, to Intermediary • CMP-Neu5Ac used for synthesizing Metabolism glycoconjugates, e.g, glycoproteins & glycolipids 8 Important Topics to Consider 1. The different types of monosaccharides found in animal cell glycoconjugates 2. The different types of glycoconjugates and their differences, e.g. glycoproteins, glycolipids 3. The nucleotide sugars, glycosyltransferases, glycosidases, transporters, endoplasmic reticulum, and Golgi in terms of their roles in glycoconjugate biosynthesis and turnover 4.
    [Show full text]
  • Collagen-Based Matrix Matrix Auf Der Basis Von Kollagen Matrice À Base De Collagène
    Europäisches Patentamt *EP000693523B1* (19) European Patent Office Office européen des brevets (11) EP 0 693 523 B1 (12) EUROPEAN PATENT SPECIFICATION (45) Date of publication and mention (51) Int Cl.7: C08H 1/06, A61L 27/00, of the grant of the patent: A61L 31/00 20.11.2002 Bulletin 2002/47 (21) Application number: 95111260.6 (22) Date of filing: 18.07.1995 (54) Collagen-based matrix Matrix auf der Basis von Kollagen Matrice à base de collagène (84) Designated Contracting States: • Noff, Matityahu AT BE CH DE DK ES FR GB GR IE IT LI LU MC NL Rehovot 76228 (IL) PT SE (74) Representative: Grünecker, Kinkeldey, (30) Priority: 19.07.1994 IL 11036794 Stockmair & Schwanhäusser Anwaltssozietät Maximilianstrasse 58 (43) Date of publication of application: 80538 München (DE) 24.01.1996 Bulletin 1996/04 (56) References cited: (73) Proprietor: COL-BAR R & D LTD. DE-A- 4 302 708 FR-A- 2 679 778 Ramat-Gan 52290 (IL) US-A- 4 971 954 (72) Inventors: Remarks: • Pitaru, Sandu The file contains technical information submitted Tel-Aviv 62300 (IL) after the application was filed and not included in this specification Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). EP 0 693 523 B1 Printed by Jouve, 75001 PARIS (FR) EP 0 693 523 B1 Description [0001] The present invention concerns a collagen-based matrix and devices comprising this matrix.
    [Show full text]
  • Intermediate Transfer Type Ink Jet Recording Method
    Europaisches Patentamt J European Patent Office © Publication number: 0 606 490 A1 Office europeen des brevets EUROPEAN PATENT APPLICATION published in accordance with Art. 158(3) EPC © Application number: 93914949.8 int. ci.5: B41J 2/01 @ Date of filing: 02.07.93 © International application number: PCT/JP93/00914 © International publication number: WO 94/01283 (20.01.94 94/03) © Priority: 02.07.92 JP 175384/92 Inventor: HOSONO, Yoshie 02.07.92 JP 175385/92 Seiko Epson Corporation, 02.07.92 JP 175386/92 3-5, Owa 3-chome 02.07.92 JP 175387/92 Suwa-shi, Nagano 392(JP) 16.10.92 JP 278938/92 Inventor: NAKAMURA, Hiroto 05.11.92 JP 296109/92 Seiko Epson Corporation, 05.11.92 JP 296110/92 3-5, Owa 3-chome 05.11.92 JP 296111/92 Suwa-shi, Nagano 392(JP) 06.01.93 JP 665/93 Inventor: KOIKE, Yoshiyuki Seiko Epson Corporation, © Date of publication of application: 3-5, Owa 3-chome 20.07.94 Bulletin 94/29 Suwa-shi, Nagano 392(JP) Inventor: MATSUZAKI, Makoto @ Designated Contracting States: Seiko Epson Corporation, CH DE FR GB IT LI NL SE 3-5, Owa 3-chome Suwa-shi, Nagano 392(JP) © Applicant: SEIKO EPSON CORPORATION Inventor: UEHARA, Fumie 4-1, Nishishinjuku 2-chome Seiko Shinjuku-ku Tokyo 163(JP) Epson Corporation, 3-5, Owa 3-chome © Inventor: FUJINO, Makoto Suwa-shi, Nagano 392(JP) Seiko Epson Corporation, Inventor: ISHIBASHI, Osamu 3-5, Owa 3-chome Seiko Epson Corporation, Suwa-shi, Nagano 392(JP) 3-5, Owa 3-chome Inventor: KUMAGAI, Toshio Suwa-shi, Nagano 392(JP) Seiko Epson Corporation, 3-5, Owa 3-chome Suwa-shi, Nagano 392(JP) © Representative: Lewin, John Harvey Inventor: TSUKAHARA, Michinari Elkington and Fife Seiko Epson Corporation, Prospect House CO 8 Pembroke Road o 3-5, Owa 3-chome CO Suwa-shi, Nagano 392(JP) Sevenoaks, Kent TN13 1XR (GB) &) INTERMEDIATE TRANSFER TYPE INK JET RECORDING METHOD.
    [Show full text]
  • An In-Vitro Investigation to Determine the Neuroinflammatory Response of CNS Cells to Oral Bacteria and Their Virulence Factors
    An in-vitro investigation to determine the neuroinflammatory response of CNS cells to oral bacteria and their virulence factors by Rahul Previn A thesis submitted in partial fulfilment for the requirements for the degree of MSc (by Research) at the University of Central Lancashire February 2013 i ACKNOWLEDGEMENTS I would like to thank the University of Central Lancashire, UK for the opportunity to undertake my postgraduate research degree. I wish to thank my Principle Investigator (PI) and Director of studies (D0S), Dean, Prof St John Crean for steering me into an interesting, and a hybrid dental-neurosciences project. His inspirational and expert guidance made the challenges of education seem more manageable. I would also like to thank Dr Peter Robinson, my Research Degrees Tutor (RDT), as without his expert help in getting through the various postgraduate degree hurdles would have been impossible. I would like to express my sincere gratitude to my supervisor, Dr Sim Singhrao for the daily guidance, advice, and patience throughout the practical work of the project. I would also like to thank Miss Sophie Poole, currently a PhD student, for ad-hoc assistance in the lab and for guidance in interpreting row data whenever she was nearby. I would like to acknowledge Prof. M. Curtis for the essential reagents I used to investigate my research question without which, my project would be incomplete. Above all, I would like to express my heartfelt gratitude to my family, especially my mother for her undying love, invaluable moral and financial support and encouragement to do well, during my time away from home.
    [Show full text]
  • Bacterial Size, Shape and Arrangement & Cell Structure And
    Lecture 13, 14 and 15: bacterial size, shape and arrangement & Cell structure and components of bacteria and Functional anatomy and reproduction in bacteria Bacterial size, shape and arrangement Bacteria are prokaryotic, unicellular microorganisms, which lack chlorophyll pigments. The cell structure is simpler than that of other organisms as there is no nucleus or membrane bound organelles.Due to the presence of a rigid cell wall, bacteria maintain a definite shape, though they vary as shape, size and structure. When viewed under light microscope, most bacteria appear in variations of three major shapes: the rod (bacillus), the sphere (coccus) and the spiral type (vibrio). In fact, structure of bacteria has two aspects, arrangement and shape. So far as the arrangement is concerned, it may Paired (diplo), Grape-like clusters (staphylo) or Chains (strepto). In shape they may principally be Rods (bacilli), Spheres (cocci), and Spirals (spirillum). Size of Bacterial Cell The average diameter of spherical bacteria is 0.5- 2.0 µm. For rod-shaped or filamentous bacteria, length is 1-10 µm and diameter is 0.25-1 .0 µm. E. coli , a bacillus of about average size is 1.1 to 1.5 µm wide by 2.0 to 6.0 µm long. Spirochaetes occasionally reach 500 µm in length and the cyanobacterium Accepted wisdom is that bacteria are smaller than eukaryotes. But certain cyanobacteria are quite large; Oscillatoria cells are 7 micrometers diameter. The bacterium, Epulosiscium fishelsoni , can be seen with the naked eye (600 mm long by 80 mm in diameter). One group of bacteria, called the Mycoplasmas, have individuals with size much smaller than these dimensions.
    [Show full text]
  • Structures and Characteristics of Carbohydrates in Diets Fed to Pigs: a Review Diego M
    Navarro et al. Journal of Animal Science and Biotechnology (2019) 10:39 https://doi.org/10.1186/s40104-019-0345-6 REVIEW Open Access Structures and characteristics of carbohydrates in diets fed to pigs: a review Diego M. D. L. Navarro1, Jerubella J. Abelilla1 and Hans H. Stein1,2* Abstract The current paper reviews the content and variation of fiber fractions in feed ingredients commonly used in swine diets. Carbohydrates serve as the main source of energy in diets fed to pigs. Carbohydrates may be classified according to their degree of polymerization: monosaccharides, disaccharides, oligosaccharides, and polysaccharides. Digestible carbohydrates include sugars, digestible starch, and glycogen that may be digested by enzymes secreted in the gastrointestinal tract of the pig. Non-digestible carbohydrates, also known as fiber, may be fermented by microbial populations along the gastrointestinal tract to synthesize short-chain fatty acids that may be absorbed and metabolized by the pig. These non-digestible carbohydrates include two disaccharides, oligosaccharides, resistant starch, and non-starch polysaccharides. The concentration and structure of non-digestible carbohydrates in diets fed to pigs depend on the type of feed ingredients that are included in the mixed diet. Cellulose, arabinoxylans, and mixed linked β-(1,3) (1,4)-D-glucans are the main cell wall polysaccharides in cereal grains, but vary in proportion and structure depending on the grain and tissue within the grain. Cell walls of oilseeds, oilseed meals, and pulse crops contain cellulose, pectic polysaccharides, lignin, and xyloglucans. Pulse crops and legumes also contain significant quantities of galacto-oligosaccharides including raffinose, stachyose, and verbascose.
    [Show full text]
  • Bacterial Capsular Polysaccharides of Pathogens – a Toolbox for Vaccines and Therapeutics
    In: Glycome: The Hidden Code in Biology ISBN: 978-1-53619-377-0 Editor: Dipak K. Banerjee © 2021 Nova Science Publishers, Inc. Chapter 13 BACTERIAL CAPSULAR POLYSACCHARIDES OF PATHOGENS – A TOOLBOX FOR VACCINES AND THERAPEUTICS Vamsee Veeramachineni, PhD, Shonoi A. Ming, PhD, Justine Vionnet, PhD and Willie F. Vann*, PhD Laboratory of Bacterial Polysaccharides, Center for Biologics Evaluation and Research, FDA, Silver Spring, MD, US ABSTRACT The bacterial capsule is a hydrated polysaccharide structure that covers the outermost layer of the cell wall. It is an important virulence factor and acts as armor in shielding the bacteria from a variety of environmental pressures and host immune defenses. Considerable structural diversity exits not only between capsular polysaccharides of different bacterial species, but also within the same species. While most pathogenic bacteria are encapsulated, most encapsulated bacteria are not pathogenic. As a result, understanding the structural and immunological diversity of capsules together with cellular components and machinery involved in capsule biosynthesis is paramount in developing new therapeutics to fight deadly bacterial infections. This chapter presents an overview of the capsular polysaccharide of pathogenic bacteria. This overview includes the structural diversity of capsules among virulent bacteria, the organization of capsule genetic elements, the mechanisms of capsule biosynthesis and transport, along with current technologies employed in the preparation of glycoconjugate vaccines. Keywords: bacterial virulence, capsular polysaccharide, K-antigen, capsule diversity, gram- negative bacteria, gram-positive bacteria, capsular gene organization, capsular biosynthesis, ABC transporter pathway, wzy pathway, synthase pathway, capsule transport, glycoconjugate vaccines, vaccine preparation technologies * Corresponding Author’s Email: [email protected].
    [Show full text]
  • Along the Path of Bacterial Nonulosonic Acids
    Faculty of Science and Technology Along the path of bacterial nonulosonic acids A study of the bio- and in vitro synthesis of sialic acid related compounds — Marie-Josée Haglund Halsør A dissertation for the degree of Philosophiae Doctor – June 2019 Along the path of nonulosonic acids A study of the bio- and in vitro synthesis of sialic acid related compounds Marie-Josée Haglund Halsør A dissertation for the degree of Philosophiae Doctor FACULTY OF SCIENCE AND TECHNOLOGY DEPARTMENT OF CHEMISTRY June 2019 "There is a single light of science and to brighten it anywhere is to brighten it everywhere." - Unsourced, credited to Isaac Asimov. Preface “Why?”, and later “How?”. Those two questions are what led me to research, without doubt. I’ve asked them (aloud or not) every day for as long as I can remember, about practically everything. The other thing is being amazed by Nature. The diversity of every aspect and how it all functions as one, somehow. My favorite as a child were the documentaries by “le Commandant Cousteau” (the sharks!), and my dream was to be an oceanographer. I pursued that dream up until my first year of university, when I discovered biochemistry. I had already grown a liking for chemistry, and it was the only discipline that answered the “biological whys and hows” without going into physics. Biochemistry studies and does, both trying to unravel Nature’s secrets and building its own means to do so. It also uses the knowledge to improve human living conditions, at least in theory. I was sold, and here I am.
    [Show full text]
  • University of Huddersfield Repository
    University of Huddersfield Repository Ngehnyuiy, Ngo Hansel Characterisation of Bacterial Polysaccharides Original Citation Ngehnyuiy, Ngo Hansel (2020) Characterisation of Bacterial Polysaccharides. Doctoral thesis, University of Huddersfield. This version is available at http://eprints.hud.ac.uk/id/eprint/35297/ The University Repository is a digital collection of the research output of the University, available on Open Access. Copyright and Moral Rights for the items on this site are retained by the individual author and/or other copyright owners. Users may access full items free of charge; copies of full text items generally can be reproduced, displayed or performed and given to third parties in any format or medium for personal research or study, educational or not-for-profit purposes without prior permission or charge, provided: • The authors, title and full bibliographic details is credited in any copy; • A hyperlink and/or URL is included for the original metadata page; and • The content is not changed in any way. For more information, including our policy and submission procedure, please contact the Repository Team at: [email protected]. http://eprints.hud.ac.uk/ CHARACTERISATION OF BACTERIAL POLYSACCHARIDES NGO HANSEL NGEHNYUIY, MSc A thesis submitted to the University of Huddersfield in partial fulfilment of the requirements for the degree of Doctor of Philosophy Department of Chemical and Biological Sciences School of Applied Sciences The University of Huddersfield March 2020 i ABSTRACT A number Gram-positive bacterial strains including Lactobacillus paracasei DG, Lactobacillus salivarius CCUG44481 and Bifidobacteria breve 7017 have been known to possess probiotic properties which has led to their increasing use in commercial probiotic products.
    [Show full text]